| /* |
| * Copyright (C) 1995-2003 by Darren Reed. |
| * |
| * See the IPFILTER.LICENCE file for details on licencing. |
| */ |
| #if defined(KERNEL) || defined(_KERNEL) |
| # undef KERNEL |
| # undef ipf_nat_KERNEL |
| # define KERNEL 1 |
| # define ipf_nat_KERNEL 1 |
| #endif |
| #include <sys/errno.h> |
| #include <sys/types.h> |
| #include <sys/param.h> |
| #include <sys/time.h> |
| #include <sys/file.h> |
| #if defined(_KERNEL) && defined(__NetBSD_Version__) && \ |
| (__NetBSD_Version__ >= 399002000) |
| # include <sys/kauth.h> |
| #endif |
| #if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \ |
| defined(_KERNEL) |
| #if defined(__NetBSD_Version__) && (__NetBSD_Version__ < 399001400) |
| # include "opt_ipfilter_log.h" |
| # else |
| # include "opt_ipfilter.h" |
| # endif |
| #endif |
| #if !defined(_KERNEL) |
| # include <stdio.h> |
| # include <string.h> |
| # include <stdlib.h> |
| # define ipf_nat_KERNEL |
| # ifdef ipf_nat__OpenBSD__ |
| struct file; |
| # endif |
| # include <sys/uio.h> |
| # undef ipf_nat_KERNEL |
| #endif |
| #if defined(_KERNEL) && (__FreeBSD_version >= 220000) |
| # include <sys/filio.h> |
| # include <sys/fcntl.h> |
| #else |
| # include <sys/ioctl.h> |
| #endif |
| #if !defined(AIX) |
| # include <sys/fcntl.h> |
| #endif |
| #if !defined(linux) |
| # include <sys/protosw.h> |
| #endif |
| #include <sys/socket.h> |
| #if defined(_KERNEL) |
| # include <sys/systm.h> |
| # if !defined(__SVR4) && !defined(__svr4__) |
| # include <sys/mbuf.h> |
| # endif |
| #endif |
| #if defined(__SVR4) || defined(__svr4__) |
| # include <sys/filio.h> |
| # include <sys/byteorder.h> |
| # ifdef ipf_nat_KERNEL |
| # include <sys/dditypes.h> |
| # endif |
| # include <sys/stream.h> |
| # include <sys/kmem.h> |
| #endif |
| #if ipf_nat__FreeBSD_version >= 300000 |
| # include <sys/queue.h> |
| #endif |
| #include <net/if.h> |
| #if ipf_nat__FreeBSD_version >= 300000 |
| # include <net/if_var.h> |
| # if defined(_KERNEL) && !defined(IPFILTER_LKM) |
| # include "opt_ipfilter.h" |
| # endif |
| #endif |
| #ifdef sun |
| # include <net/af.h> |
| #endif |
| #include <net/route.h> |
| #include <netinet/in.h> |
| #include <netinet/in_systm.h> |
| #include <netinet/ip.h> |
| |
| #ifdef RFC1825 |
| # include <vpn/md5.h> |
| # include <vpn/ipsec.h> |
| extern struct ifnet vpnif; |
| #endif |
| |
| #if !defined(linux) |
| # include <netinet/ip_var.h> |
| #endif |
| #include <netinet/tcp.h> |
| #include <netinet/udp.h> |
| #include <netinet/ip_icmp.h> |
| #include "netinet/ip_compat.h" |
| #include <netinet/tcpip.h> |
| #include "netinet/ip_fil.h" |
| #include "netinet/ip_nat.h" |
| #include "netinet/ip_frag.h" |
| #include "netinet/ip_state.h" |
| #include "netinet/ip_proxy.h" |
| #ifdef IPFILTER_SYNC |
| #include "netinet/ip_sync.h" |
| #endif |
| #if (__FreeBSD_version >= 300000) |
| # include <sys/malloc.h> |
| #endif |
| #include "md5.h" |
| /* END OF INCLUDES */ |
| |
| #undef SOCKADDR_IN |
| #define SOCKADDR_IN struct sockaddr_in |
| |
| #if !defined(lint) |
| static const char sccsid[] = "@(#)ip_nat.c 1.11 6/5/96 (C) 1995 Darren Reed"; |
| static const char rcsid[] = "@(#)$Id$"; |
| #endif |
| |
| |
| /* ======================================================================== */ |
| /* How the NAT is organised and works. */ |
| /* */ |
| /* Inside (interface y) NAT Outside (interface x) */ |
| /* -------------------- -+- ------------------------------------- */ |
| /* Packet going | out, processsed by ipf_nat_checkout() for x */ |
| /* ------------> | ------------> */ |
| /* src=10.1.1.1 | src=192.1.1.1 */ |
| /* | */ |
| /* | in, processed by ipf_nat_checkin() for x */ |
| /* <------------ | <------------ */ |
| /* dst=10.1.1.1 | dst=192.1.1.1 */ |
| /* -------------------- -+- ------------------------------------- */ |
| /* ipf_nat_checkout() - changes ip_src and if required, sport */ |
| /* - creates a new mapping, if required. */ |
| /* ipf_nat_checkin() - changes ip_dst and if required, dport */ |
| /* */ |
| /* In the NAT table, internal source is recorded as "in" and externally */ |
| /* seen as "out". */ |
| /* ======================================================================== */ |
| |
| |
| nat_t **ipf_nat_table[2] = { NULL, NULL }, |
| *ipf_nat_instances = NULL; |
| ipnat_t *ipf_nat_list = NULL; |
| u_int ipf_nat_table_max = NAT_TABLE_MAX; |
| u_int ipf_nat_table_sz = NAT_TABLE_SZ; |
| u_int ipf_nat_maprules_sz = NAT_SIZE; |
| u_int ipf_nat_rdrrules_sz = RDR_SIZE; |
| u_int ipf_nat_hostmap_sz = HOSTMAP_SIZE; |
| u_int ipf_nat_maxbucket = 0, |
| ipf_nat_maxbucket_reset = 1; |
| u_32_t ipf_nat_map_masks = 0; |
| u_32_t ipf_nat_rdr_masks = 0; |
| u_int ipf_nat_last_force_flush = 0; |
| ipnat_t **ipf_nat_map_rules = NULL; |
| ipnat_t **ipf_nat_rdr_rules = NULL; |
| hostmap_t **ipf_hm_maptable = NULL; |
| hostmap_t *ipf_hm_maplist = NULL; |
| ipftq_t ipf_nat_tqb[IPF_TCP_NSTATES]; |
| ipftq_t ipf_nat_udptq; |
| ipftq_t ipf_nat_icmptq; |
| ipftq_t ipf_nat_iptq; |
| ipftq_t ipf_nat_pending; |
| ipftq_t *ipf_nat_utqe = NULL; |
| frentry_t ipfnatblock; |
| int ipf_nat_doflush = 0; |
| #ifdef IPFILTER_LOG |
| int ipf_nat_logging = 1; |
| #else |
| int ipf_nat_logging = 0; |
| #endif |
| |
| u_int ipf_nat_defage = DEF_NAT_AGE, |
| ipf_nat_defipage = 120, /* 60 seconds */ |
| ipf_nat_deficmpage = 6; /* 3 seconds */ |
| natstat_t ipf_nat_stats; |
| int ipf_nat_lock = 0; |
| int ipf_nat_inited = 0; |
| int ipf_nat_table_wm_high = 99; |
| int ipf_nat_table_wm_low = 90; |
| |
| #if SOLARIS |
| extern int pfil_delayed_copy; |
| #endif |
| |
| static nat_t *ipf_nat_clone __P((fr_info_t *, nat_t *)); |
| static int ipf_nat_flush_entry __P((void *)); |
| static int ipf_nat_getent __P((caddr_t)); |
| static int ipf_nat_getsz __P((caddr_t)); |
| static int ipf_nat_putent __P((caddr_t, int)); |
| static void ipf_nat_addencap __P((ipnat_t *)); |
| static void ipf_nat_addnat __P((struct ipnat *)); |
| static void ipf_nat_addrdr __P((struct ipnat *)); |
| static int ipf_nat_builddivertmp __P((ipnat_t *)); |
| static int ipf_nat_clearlist __P((void)); |
| static int ipf_nat_decap __P((fr_info_t *, nat_t *)); |
| static void ipf_nat_delete __P((struct nat *, int)); |
| static void ipf_nat_delnat __P((struct ipnat *)); |
| static void ipf_nat_delrdr __P((struct ipnat *)); |
| static void ipf_nat_delrule __P((struct ipnat *)); |
| static int ipf_nat_encapok __P((fr_info_t *, nat_t *)); |
| static int ipf_nat_extraflush __P((int)); |
| static int ipf_nat_finalise __P((fr_info_t *, nat_t *, natinfo_t *, |
| nat_t **, int)); |
| static int ipf_nat_flushtable __P((void)); |
| static int ipf_nat_getnext __P((ipftoken_t *, ipfgeniter_t *)); |
| static int ipf_nat_gettable __P((char *)); |
| static hostmap_t *ipf_nat_hostmap __P((ipnat_t *, struct in_addr, |
| struct in_addr, struct in_addr, |
| u_32_t)); |
| static int ipf_nat_icmpquerytype4 __P((int)); |
| static int ipf_nat_iterator __P((ipftoken_t *, ipfgeniter_t *)); |
| static int ipf_nat_match_v4 __P((fr_info_t *, ipnat_t *)); |
| static int ipf_nat_matcharray __P((nat_t *, int *)); |
| static int ipf_nat_matchencap __P((fr_info_t *, ipnat_t *)); |
| static int ipf_nat_matchflush __P((caddr_t)); |
| static void ipf_nat_mssclamp __P((tcphdr_t *, u_32_t, fr_info_t *, |
| u_short *)); |
| static nat_t *ipf_nat_clone __P((fr_info_t *, nat_t *)); |
| static int ipf_nat_newmap __P((fr_info_t *, nat_t *, natinfo_t *)); |
| static int ipf_nat_newdivert __P((fr_info_t *, nat_t *, natinfo_t *)); |
| static int ipf_nat_newrdr __P((fr_info_t *, nat_t *, natinfo_t *)); |
| static int ipf_nat_newrewrite __P((fr_info_t *, nat_t *, natinfo_t *)); |
| static int ipf_nat_nextaddr __P((fr_info_t *, nat_addr_t *, u_32_t *, |
| u_32_t *)); |
| static int ipf_nat_nextaddrinit __P((nat_addr_t *, int, void *)); |
| static nat_t *ipf_nat_rebuildencapicmp __P((fr_info_t *, nat_t *)); |
| static int ipf_nat_resolverule __P((ipnat_t *)); |
| static int ipf_nat_siocaddnat __P((ipnat_t *, ipnat_t **, int)); |
| static void ipf_nat_siocdelnat __P((ipnat_t *, ipnat_t **, int)); |
| static void ipf_nat_tabmove __P((nat_t *)); |
| static int ipf_nat_wildok __P((nat_t *, int, int, int, int)); |
| |
| |
| #define NATFSUM(n,f) ((n)->nat_v == 4 ? (n)->f.in4.s_addr : (n)->f.i6[0] + \ |
| (n)->f.i6[1] + (n)->f.i6[2] + (n)->f.i6[3]) |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_init */ |
| /* Returns: int - 0 == success, -1 == failure */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Initialise all of the NAT locks, tables and other structures. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_nat_init() |
| { |
| int i; |
| |
| KMALLOCS(ipf_nat_table[0], nat_t **, \ |
| sizeof(nat_t *) * ipf_nat_table_sz); |
| |
| if (ipf_nat_table[0] != NULL) { |
| bzero((char *)ipf_nat_table[0], |
| ipf_nat_table_sz * sizeof(nat_t *)); |
| } else { |
| return -1; |
| } |
| |
| KMALLOCS(ipf_nat_table[1], nat_t **, \ |
| sizeof(nat_t *) * ipf_nat_table_sz); |
| |
| if (ipf_nat_table[1] != NULL) { |
| bzero((char *)ipf_nat_table[1], |
| ipf_nat_table_sz * sizeof(nat_t *)); |
| } else { |
| return -2; |
| } |
| |
| KMALLOCS(ipf_nat_map_rules, ipnat_t **, \ |
| sizeof(ipnat_t *) * ipf_nat_maprules_sz); |
| |
| if (ipf_nat_map_rules != NULL) { |
| bzero((char *)ipf_nat_map_rules, |
| ipf_nat_maprules_sz * sizeof(ipnat_t *)); |
| } else { |
| return -3; |
| } |
| |
| KMALLOCS(ipf_nat_rdr_rules, ipnat_t **, \ |
| sizeof(ipnat_t *) * ipf_nat_rdrrules_sz); |
| |
| if (ipf_nat_rdr_rules != NULL) { |
| bzero((char *)ipf_nat_rdr_rules, |
| ipf_nat_rdrrules_sz * sizeof(ipnat_t *)); |
| } else { |
| return -4; |
| } |
| |
| KMALLOCS(ipf_hm_maptable, hostmap_t **, \ |
| sizeof(hostmap_t *) * ipf_nat_hostmap_sz); |
| |
| if (ipf_hm_maptable != NULL) { |
| bzero((char *)ipf_hm_maptable, |
| sizeof(hostmap_t *) * ipf_nat_hostmap_sz); |
| } else { |
| return -5; |
| } |
| ipf_hm_maplist = NULL; |
| |
| KMALLOCS(ipf_nat_stats.ns_side[0].ns_bucketlen, u_int *, |
| ipf_nat_table_sz * sizeof(u_int)); |
| |
| if (ipf_nat_stats.ns_side[0].ns_bucketlen == NULL) { |
| return -6; |
| } |
| bzero((char *)ipf_nat_stats.ns_side[0].ns_bucketlen, |
| ipf_nat_table_sz * sizeof(u_int)); |
| |
| KMALLOCS(ipf_nat_stats.ns_side[1].ns_bucketlen, u_int *, |
| ipf_nat_table_sz * sizeof(u_int)); |
| |
| if (ipf_nat_stats.ns_side[1].ns_bucketlen == NULL) { |
| return -7; |
| } |
| |
| bzero((char *)ipf_nat_stats.ns_side[1].ns_bucketlen, |
| ipf_nat_table_sz * sizeof(u_int)); |
| |
| if (ipf_nat_maxbucket == 0) { |
| for (i = ipf_nat_table_sz; i > 0; i >>= 1) |
| ipf_nat_maxbucket++; |
| ipf_nat_maxbucket *= 2; |
| } |
| |
| ipf_sttab_init(ipf_nat_tqb); |
| /* |
| * Increase this because we may have "keep state" following this too |
| * and packet storms can occur if this is removed too quickly. |
| */ |
| ipf_nat_tqb[IPF_TCPS_CLOSED].ifq_ttl = ipf_tcplastack; |
| ipf_nat_tqb[IPF_TCP_NSTATES - 1].ifq_next = &ipf_nat_udptq; |
| |
| IPFTQ_INIT(&ipf_nat_udptq, ipf_nat_defage, "nat ipftq udp tab"); |
| ipf_nat_udptq.ifq_next = &ipf_nat_icmptq; |
| |
| IPFTQ_INIT(&ipf_nat_icmptq, ipf_nat_deficmpage, "nat icmp ipftq tab"); |
| ipf_nat_icmptq.ifq_next = &ipf_nat_iptq; |
| |
| IPFTQ_INIT(&ipf_nat_iptq, ipf_nat_defipage, "nat ip ipftq tab"); |
| ipf_nat_iptq.ifq_next = &ipf_nat_pending; |
| |
| IPFTQ_INIT(&ipf_nat_pending, 1, "nat pending ipftq tab"); |
| ipf_nat_pending.ifq_next = NULL; |
| |
| for (i = 0; i < IPF_TCP_NSTATES; i++) { |
| if (ipf_nat_tqb[i].ifq_ttl < ipf_nat_deficmpage) |
| ipf_nat_tqb[i].ifq_ttl = ipf_nat_deficmpage; |
| #ifdef LARGE_NAT |
| else if (ipf_nat_tqb[i].ifq_ttl > ipf_nat_defage) |
| ipf_nat_tqb[i].ifq_ttl = ipf_nat_defage; |
| #endif |
| } |
| |
| /* |
| * Increase this because we may have "keep state" following |
| * this too and packet storms can occur if this is removed |
| * too quickly. |
| */ |
| ipf_nat_tqb[IPF_TCPS_CLOSED].ifq_ttl = ipf_nat_tqb[IPF_TCPS_LAST_ACK].ifq_ttl; |
| |
| RWLOCK_INIT(&ipf_nat, "ipf IP NAT rwlock"); |
| RWLOCK_INIT(&ipf_natfrag, "ipf IP NAT-Frag rwlock"); |
| MUTEX_INIT(&ipf_nat_new, "ipf nat new mutex"); |
| MUTEX_INIT(&ipf_natio, "ipf nat io mutex"); |
| |
| bzero((char *)&ipfnatblock, sizeof(ipfnatblock)); |
| ipfnatblock.fr_flags = FR_BLOCK|FR_QUICK; |
| ipfnatblock.fr_ref = 1; |
| |
| ipf_nat_inited = 1; |
| |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_addrdr */ |
| /* Returns: Nil */ |
| /* Parameters: n(I) - pointer to NAT rule to add */ |
| /* */ |
| /* Adds a redirect rule to the hash table of redirect rules and the list of */ |
| /* loaded NAT rules. Updates the bitmask indicating which netmasks are in */ |
| /* use by redirect rules. */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_addrdr(n) |
| ipnat_t *n; |
| { |
| ipnat_t **np; |
| u_32_t j; |
| u_int hv; |
| int k; |
| |
| if (n->in_odstatype == FRI_NORMAL) { |
| k = count4bits(n->in_odstmsk); |
| if ((k >= 0) && (k != 32)) |
| ipf_nat_rdr_masks |= 1 << k; |
| j = (n->in_odstaddr & n->in_odstmsk); |
| hv = NAT_HASH_FN(j, 0, ipf_nat_rdrrules_sz); |
| } else { |
| ipf_nat_rdr_masks |= 1; |
| j = 0; |
| hv = 0; |
| } |
| np = ipf_nat_rdr_rules + hv; |
| while (*np != NULL) |
| np = &(*np)->in_rnext; |
| n->in_rnext = NULL; |
| n->in_prnext = np; |
| n->in_hv[0] = hv; |
| *np = n; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_addnat */ |
| /* Returns: Nil */ |
| /* Parameters: n(I) - pointer to NAT rule to add */ |
| /* */ |
| /* Adds a NAT map rule to the hash table of rules and the list of loaded */ |
| /* NAT rules. Updates the bitmask indicating which netmasks are in use by */ |
| /* redirect rules. */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_addnat(n) |
| ipnat_t *n; |
| { |
| ipnat_t **np; |
| u_32_t j; |
| u_int hv; |
| int k; |
| |
| if (n->in_osrcatype == FRI_NORMAL) { |
| k = count4bits(n->in_osrcmsk); |
| if ((k >= 0) && (k != 32)) |
| ipf_nat_map_masks |= 1 << k; |
| j = (n->in_osrcaddr & n->in_osrcmsk); |
| hv = NAT_HASH_FN(j, 0, ipf_nat_maprules_sz); |
| } else { |
| ipf_nat_map_masks |= 1; |
| j = 0; |
| hv = 0; |
| } |
| np = ipf_nat_map_rules + hv; |
| while (*np != NULL) |
| np = &(*np)->in_mnext; |
| n->in_mnext = NULL; |
| n->in_pmnext = np; |
| n->in_hv[1] = hv; |
| *np = n; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_addencap */ |
| /* Returns: Nil */ |
| /* Parameters: n(I) - pointer to NAT rule to add */ |
| /* */ |
| /* Here we add in a pointer in the NAT rules hash table to match reply */ |
| /* packets that are encapsulated. For encap rules that are "out", what we */ |
| /* will want to match upon will be the source address in the encap rule as */ |
| /* this is what will become the destination in packets coming back to us. */ |
| /* For encaps pointing in, it is still the same because it is still the */ |
| /* reply packet we want to match. */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_addencap(n) |
| ipnat_t *n; |
| { |
| ipnat_t **np; |
| u_32_t j; |
| u_int hv; |
| int k; |
| |
| k = -1; |
| |
| /* |
| * It is the new source address we're after... |
| */ |
| if (n->in_nsrcatype == FRI_NORMAL) { |
| k = count4bits(n->in_nsrcmsk); |
| j = (n->in_nsrcaddr & n->in_nsrcmsk); |
| hv = NAT_HASH_FN(j, 0, ipf_nat_maprules_sz); |
| } else { |
| j = 0; |
| hv = 0; |
| } |
| |
| /* |
| * And place the rules table entry in the reverse spot, so for out |
| * we use the rdr-links and for rdr, we use the map-links/ |
| */ |
| if (n->in_redir & NAT_MAP) { |
| if ((k >= 0) && (k != 32)) |
| ipf_nat_rdr_masks |= 1 << k; |
| else |
| ipf_nat_rdr_masks |= 1; |
| np = ipf_nat_rdr_rules + hv; |
| while (*np != NULL) |
| np = &(*np)->in_rnext; |
| n->in_rnext = NULL; |
| n->in_prnext = np; |
| n->in_hv[0] = hv; |
| *np = n; |
| } else if (n->in_redir & NAT_REDIRECT) { |
| if ((k >= 0) && (k != 32)) |
| ipf_nat_map_masks |= 1 << k; |
| else |
| ipf_nat_map_masks |= 1; |
| np = ipf_nat_map_rules + hv; |
| while (*np != NULL) |
| np = &(*np)->in_mnext; |
| n->in_mnext = NULL; |
| n->in_pmnext = np; |
| n->in_hv[1] = hv; |
| *np = n; |
| } |
| |
| /* TRACE(n, hv, k) */ |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_delrdr */ |
| /* Returns: Nil */ |
| /* Parameters: n(I) - pointer to NAT rule to delete */ |
| /* */ |
| /* Removes a redirect rule from the hash table of redirect rules. */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_delrdr(n) |
| ipnat_t *n; |
| { |
| if (n->in_rnext) |
| n->in_rnext->in_prnext = n->in_prnext; |
| *n->in_prnext = n->in_rnext; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_delnat */ |
| /* Returns: Nil */ |
| /* Parameters: n(I) - pointer to NAT rule to delete */ |
| /* */ |
| /* Removes a NAT map rule from the hash table of NAT map rules. */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_delnat(n) |
| ipnat_t *n; |
| { |
| if (n->in_mnext != NULL) |
| n->in_mnext->in_pmnext = n->in_pmnext; |
| *n->in_pmnext = n->in_mnext; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_hostmap */ |
| /* Returns: struct hostmap* - NULL if no hostmap could be created, */ |
| /* else a pointer to the hostmapping to use */ |
| /* Parameters: np(I) - pointer to NAT rule */ |
| /* real(I) - real IP address */ |
| /* map(I) - mapped IP address */ |
| /* port(I) - destination port number */ |
| /* Write Locks: ipf_nat */ |
| /* */ |
| /* Check if an ip address has already been allocated for a given mapping */ |
| /* that is not doing port based translation. If is not yet allocated, then */ |
| /* create a new entry if a non-NULL NAT rule pointer has been supplied. */ |
| /* ------------------------------------------------------------------------ */ |
| static struct hostmap * |
| ipf_nat_hostmap(np, src, dst, map, port) |
| ipnat_t *np; |
| struct in_addr src; |
| struct in_addr dst; |
| struct in_addr map; |
| u_32_t port; |
| { |
| hostmap_t *hm; |
| u_int hv; |
| |
| hv = (src.s_addr ^ dst.s_addr); |
| hv += src.s_addr; |
| hv += dst.s_addr; |
| hv %= HOSTMAP_SIZE; |
| for (hm = ipf_hm_maptable[hv]; hm; hm = hm->hm_next) |
| if ((hm->hm_osrcip.s_addr == src.s_addr) && |
| (hm->hm_odstip.s_addr == dst.s_addr) && |
| ((np == NULL) || (np == hm->hm_ipnat)) && |
| ((port == 0) || (port == hm->hm_port))) { |
| ipf_nat_stats.ns_hm_addref++; |
| hm->hm_ref++; |
| return hm; |
| } |
| |
| if (np == NULL) { |
| ipf_nat_stats.ns_hm_nullnp++; |
| return NULL; |
| } |
| |
| KMALLOC(hm, hostmap_t *); |
| if (hm) { |
| hm->hm_next = ipf_hm_maplist; |
| hm->hm_pnext = &ipf_hm_maplist; |
| if (ipf_hm_maplist != NULL) |
| ipf_hm_maplist->hm_pnext = &hm->hm_next; |
| ipf_hm_maplist = hm; |
| hm->hm_hnext = ipf_hm_maptable[hv]; |
| hm->hm_phnext = ipf_hm_maptable + hv; |
| if (ipf_hm_maptable[hv] != NULL) |
| ipf_hm_maptable[hv]->hm_phnext = &hm->hm_hnext; |
| ipf_hm_maptable[hv] = hm; |
| hm->hm_ipnat = np; |
| hm->hm_osrcip = src; |
| hm->hm_odstip = dst; |
| hm->hm_nsrcip = map; |
| hm->hm_ndstip.s_addr = 0; |
| hm->hm_ref = 1; |
| hm->hm_port = port; |
| hm->hm_hv = hv; |
| ipf_nat_stats.ns_hm_new++; |
| } else { |
| ipf_nat_stats.ns_hm_newfail++; |
| } |
| return hm; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_hostmapdel */ |
| /* Returns: Nil */ |
| /* Parameters: hmp(I) - pointer to hostmap structure pointer */ |
| /* Write Locks: ipf_nat */ |
| /* */ |
| /* Decrement the references to this hostmap structure by one. If this */ |
| /* reaches zero then remove it and free it. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_hostmapdel(hmp) |
| struct hostmap **hmp; |
| { |
| struct hostmap *hm; |
| |
| hm = *hmp; |
| *hmp = NULL; |
| |
| hm->hm_ref--; |
| if (hm->hm_ref == 0) { |
| if (hm->hm_hnext) |
| hm->hm_hnext->hm_phnext = hm->hm_phnext; |
| *hm->hm_phnext = hm->hm_hnext; |
| if (hm->hm_next) |
| hm->hm_next->hm_pnext = hm->hm_pnext; |
| *hm->hm_pnext = hm->hm_next; |
| KFREE(hm); |
| } |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_fix_outcksum */ |
| /* Returns: Nil */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* sp(I) - location of 16bit checksum to update */ |
| /* n((I) - amount to adjust checksum by */ |
| /* */ |
| /* Adjusts the 16bit checksum by "n" for packets going out. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_fix_outcksum(fin, sp, n) |
| fr_info_t *fin; |
| u_short *sp; |
| u_32_t n; |
| { |
| u_short sumshort; |
| u_32_t sum1; |
| |
| if (n == 0) |
| return; |
| |
| if (n & NAT_HW_CKSUM) { |
| n &= 0xffff; |
| n += fin->fin_dlen; |
| n = (n & 0xffff) + (n >> 16); |
| *sp = n & 0xffff; |
| return; |
| } |
| sum1 = (~ntohs(*sp)) & 0xffff; |
| sum1 += (n); |
| sum1 = (sum1 >> 16) + (sum1 & 0xffff); |
| /* Again */ |
| sum1 = (sum1 >> 16) + (sum1 & 0xffff); |
| sumshort = ~(u_short)sum1; |
| *(sp) = htons(sumshort); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_fix_incksum */ |
| /* Returns: Nil */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* sp(I) - location of 16bit checksum to update */ |
| /* n((I) - amount to adjust checksum by */ |
| /* */ |
| /* Adjusts the 16bit checksum by "n" for packets going in. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_fix_incksum(fin, sp, n) |
| fr_info_t *fin; |
| u_short *sp; |
| u_32_t n; |
| { |
| u_short sumshort; |
| u_32_t sum1; |
| |
| if (n == 0) |
| return; |
| |
| if (n & NAT_HW_CKSUM) { |
| n &= 0xffff; |
| n += fin->fin_dlen; |
| n = (n & 0xffff) + (n >> 16); |
| *sp = n & 0xffff; |
| return; |
| } |
| sum1 = (~ntohs(*sp)) & 0xffff; |
| sum1 += ~(n) & 0xffff; |
| sum1 = (sum1 >> 16) + (sum1 & 0xffff); |
| /* Again */ |
| sum1 = (sum1 >> 16) + (sum1 & 0xffff); |
| sumshort = ~(u_short)sum1; |
| *(sp) = htons(sumshort); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_fix_datacksum */ |
| /* Returns: Nil */ |
| /* Parameters: sp(I) - location of 16bit checksum to update */ |
| /* n((I) - amount to adjust checksum by */ |
| /* */ |
| /* Fix_datacksum is used *only* for the adjustments of checksums in the */ |
| /* data section of an IP packet. */ |
| /* */ |
| /* The only situation in which you need to do this is when NAT'ing an */ |
| /* ICMP error message. Such a message, contains in its body the IP header */ |
| /* of the original IP packet, that causes the error. */ |
| /* */ |
| /* You can't use fix_incksum or fix_outcksum in that case, because for the */ |
| /* kernel the data section of the ICMP error is just data, and no special */ |
| /* processing like hardware cksum or ntohs processing have been done by the */ |
| /* kernel on the data section. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_fix_datacksum(sp, n) |
| u_short *sp; |
| u_32_t n; |
| { |
| u_short sumshort; |
| u_32_t sum1; |
| |
| if (n == 0) |
| return; |
| |
| sum1 = (~ntohs(*sp)) & 0xffff; |
| sum1 += (n); |
| sum1 = (sum1 >> 16) + (sum1 & 0xffff); |
| /* Again */ |
| sum1 = (sum1 >> 16) + (sum1 & 0xffff); |
| sumshort = ~(u_short)sum1; |
| *(sp) = htons(sumshort); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_ioctl */ |
| /* Returns: int - 0 == success, != 0 == failure */ |
| /* Parameters: data(I) - pointer to ioctl data */ |
| /* cmd(I) - ioctl command integer */ |
| /* mode(I) - file mode bits used with open */ |
| /* */ |
| /* Processes an ioctl call made to operate on the IP Filter NAT device. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_nat_ioctl(data, cmd, mode, uid, ctx) |
| ioctlcmd_t cmd; |
| caddr_t data; |
| int mode, uid; |
| void *ctx; |
| { |
| ipnat_t *nat, *nt, *n = NULL, **np = NULL; |
| int error = 0, ret, arg, getlock; |
| ipnat_t natd; |
| SPL_INT(s); |
| |
| #if (BSD >= 199306) && defined(_KERNEL) |
| # if defined(__NetBSD_Version__) && (__NetBSD_Version__ >= 399002000) |
| if ((mode & FWRITE) && |
| kauth_authorize_network(curlwp->l_cred, KAUTH_NETWORK_FIREWALL, |
| KAUTH_REQ_NETWORK_FIREWALL_FW, |
| NULL, NULL, NULL)) |
| # else |
| if ((securelevel >= 2) && (mode & FWRITE)) |
| # endif |
| { |
| ipf_interror = 60001; |
| return EPERM; |
| } |
| #endif |
| |
| #if defined(__osf__) && defined(_KERNEL) |
| getlock = 0; |
| #else |
| getlock = (mode & NAT_LOCKHELD) ? 0 : 1; |
| #endif |
| |
| nat = NULL; /* XXX gcc -Wuninitialized */ |
| if (cmd == (ioctlcmd_t)SIOCADNAT) { |
| KMALLOC(nt, ipnat_t *); |
| } else { |
| nt = NULL; |
| } |
| |
| if ((cmd == (ioctlcmd_t)SIOCADNAT) || (cmd == (ioctlcmd_t)SIOCRMNAT)) { |
| if (mode & NAT_SYSSPACE) { |
| bcopy(data, (char *)&natd, sizeof(natd)); |
| error = 0; |
| } else { |
| error = ipf_inobj(data, &natd, IPFOBJ_IPNAT); |
| } |
| } |
| |
| if (error != 0) |
| goto done; |
| |
| /* |
| * For add/delete, look to see if the NAT entry is already present |
| */ |
| if ((cmd == (ioctlcmd_t)SIOCADNAT) || (cmd == (ioctlcmd_t)SIOCRMNAT)) { |
| nat = &natd; |
| nat->in_flags &= IPN_USERFLAGS; |
| if ((nat->in_redir & NAT_MAPBLK) == 0) { |
| if (nat->in_osrcatype == FRI_NORMAL || |
| nat->in_osrcatype == FRI_NONE) |
| nat->in_osrcaddr &= nat->in_osrcmsk; |
| if (nat->in_odstatype == FRI_NORMAL || |
| nat->in_odstatype == FRI_NONE) |
| nat->in_odstaddr &= nat->in_odstmsk; |
| if ((nat->in_flags & (IPN_SPLIT|IPN_SIPRANGE)) == 0) { |
| if (nat->in_nsrcatype == FRI_NORMAL) |
| nat->in_nsrcaddr &= nat->in_nsrcmsk; |
| if (nat->in_ndstatype == FRI_NORMAL) |
| nat->in_ndstaddr &= nat->in_ndstmsk; |
| } |
| } |
| MUTEX_ENTER(&ipf_natio); |
| for (np = &ipf_nat_list; ((n = *np) != NULL); np = &n->in_next) |
| if (!bcmp((char *)&nat->in_v, (char *)&n->in_v, |
| IPN_CMPSIZ)) |
| break; |
| } |
| |
| switch (cmd) |
| { |
| #ifdef IPFILTER_LOG |
| case SIOCIPFFB : |
| { |
| int tmp; |
| |
| if (!(mode & FWRITE)) { |
| ipf_interror = 60002; |
| error = EPERM; |
| } else { |
| tmp = ipf_log_clear(IPL_LOGNAT); |
| error = BCOPYOUT(&tmp, data, sizeof(tmp)); |
| if (error != 0) { |
| ipf_interror = 60057; |
| error = EFAULT; |
| } |
| } |
| break; |
| } |
| |
| case SIOCSETLG : |
| if (!(mode & FWRITE)) { |
| ipf_interror = 60003; |
| error = EPERM; |
| } else { |
| error = BCOPYIN(data, &ipf_nat_logging, |
| sizeof(ipf_nat_logging)); |
| if (error != 0) |
| error = EFAULT; |
| } |
| break; |
| |
| case SIOCGETLG : |
| error = BCOPYOUT(&ipf_nat_logging, data, |
| sizeof(ipf_nat_logging)); |
| if (error != 0) { |
| ipf_interror = 60004; |
| error = EFAULT; |
| } |
| break; |
| |
| case FIONREAD : |
| arg = iplused[IPL_LOGNAT]; |
| error = BCOPYOUT(&arg, data, sizeof(arg)); |
| if (error != 0) { |
| ipf_interror = 60005; |
| error = EFAULT; |
| } |
| break; |
| #endif |
| case SIOCADNAT : |
| if (!(mode & FWRITE)) { |
| ipf_interror = 60006; |
| error = EPERM; |
| } else if (n != NULL) { |
| ipf_interror = 60007; |
| error = EEXIST; |
| } else if (nt == NULL) { |
| ipf_interror = 60008; |
| error = ENOMEM; |
| } |
| if (error != 0) { |
| MUTEX_EXIT(&ipf_natio); |
| break; |
| } |
| bcopy((char *)nat, (char *)nt, sizeof(*n)); |
| error = ipf_nat_siocaddnat(nt, np, getlock); |
| MUTEX_EXIT(&ipf_natio); |
| if (error == 0) |
| nt = NULL; |
| break; |
| |
| case SIOCRMNAT : |
| if (!(mode & FWRITE)) { |
| ipf_interror = 60009; |
| error = EPERM; |
| n = NULL; |
| } else if (n == NULL) { |
| ipf_interror = 60010; |
| error = ESRCH; |
| } |
| |
| if (error != 0) { |
| MUTEX_EXIT(&ipf_natio); |
| break; |
| } |
| ipf_nat_siocdelnat(n, np, getlock); |
| |
| MUTEX_EXIT(&ipf_natio); |
| n = NULL; |
| break; |
| |
| case SIOCGNATS : |
| ipf_nat_stats.ns_side[0].ns_table = ipf_nat_table[0]; |
| ipf_nat_stats.ns_side[1].ns_table = ipf_nat_table[1]; |
| ipf_nat_stats.ns_list = ipf_nat_list; |
| ipf_nat_stats.ns_maptable = ipf_hm_maptable; |
| ipf_nat_stats.ns_maplist = ipf_hm_maplist; |
| ipf_nat_stats.ns_nattab_sz = ipf_nat_table_sz; |
| ipf_nat_stats.ns_nattab_max = ipf_nat_table_max; |
| ipf_nat_stats.ns_rultab_sz = ipf_nat_maprules_sz; |
| ipf_nat_stats.ns_rdrtab_sz = ipf_nat_rdrrules_sz; |
| ipf_nat_stats.ns_hostmap_sz = ipf_nat_hostmap_sz; |
| ipf_nat_stats.ns_instances = ipf_nat_instances; |
| ipf_nat_stats.ns_apslist = ap_sess_list; |
| ipf_nat_stats.ns_ticks = ipf_ticks; |
| error = ipf_outobj(data, &ipf_nat_stats, IPFOBJ_NATSTAT); |
| break; |
| |
| case SIOCGNATL : |
| { |
| natlookup_t nl; |
| |
| if (getlock) { |
| READ_ENTER(&ipf_nat); |
| } |
| error = ipf_inobj(data, &nl, IPFOBJ_NATLOOKUP); |
| if (error == 0) { |
| if (ipf_nat_lookupredir(&nl) != NULL) { |
| error = ipf_outobj(data, &nl, IPFOBJ_NATLOOKUP); |
| } else { |
| ipf_interror = 60011; |
| error = ESRCH; |
| } |
| } |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| break; |
| } |
| |
| case SIOCIPFFL : /* old SIOCFLNAT & SIOCCNATL */ |
| if (!(mode & FWRITE)) { |
| ipf_interror = 60012; |
| error = EPERM; |
| break; |
| } |
| if (getlock) { |
| WRITE_ENTER(&ipf_nat); |
| } |
| |
| error = BCOPYIN(data, &arg, sizeof(arg)); |
| if (error != 0) { |
| ipf_interror = 60013; |
| error = EFAULT; |
| } else { |
| if (arg == 0) |
| ret = ipf_nat_flushtable(); |
| else if (arg == 1) |
| ret = ipf_nat_clearlist(); |
| else |
| ret = ipf_nat_extraflush(arg); |
| appr_flush(arg); |
| } |
| |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| if (error == 0) { |
| error = BCOPYOUT(&ret, data, sizeof(ret)); |
| } |
| break; |
| |
| case SIOCMATCHFLUSH : |
| if (!(mode & FWRITE)) { |
| ipf_interror = 60014; |
| error = EPERM; |
| break; |
| } |
| if (getlock) { |
| WRITE_ENTER(&ipf_nat); |
| } |
| |
| error = ipf_nat_matchflush(data); |
| |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| break; |
| |
| case SIOCPROXY : |
| error = appr_ioctl(data, cmd, mode, ctx); |
| break; |
| |
| case SIOCSTLCK : |
| if (!(mode & FWRITE)) { |
| ipf_interror = 60015; |
| error = EPERM; |
| } else { |
| error = ipf_lock(data, &ipf_nat_lock); |
| } |
| break; |
| |
| case SIOCSTPUT : |
| if ((mode & FWRITE) != 0) { |
| error = ipf_nat_putent(data, getlock); |
| } else { |
| ipf_interror = 60016; |
| error = EACCES; |
| } |
| break; |
| |
| case SIOCSTGSZ : |
| if (ipf_nat_lock) { |
| if (getlock) { |
| READ_ENTER(&ipf_nat); |
| } |
| error = ipf_nat_getsz(data); |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| } else { |
| ipf_interror = 60017; |
| error = EACCES; |
| } |
| break; |
| |
| case SIOCSTGET : |
| if (ipf_nat_lock) { |
| if (getlock) { |
| READ_ENTER(&ipf_nat); |
| } |
| error = ipf_nat_getent(data); |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| } else { |
| ipf_interror = 60018; |
| error = EACCES; |
| } |
| break; |
| |
| case SIOCGENITER : |
| { |
| ipfgeniter_t iter; |
| ipftoken_t *token; |
| |
| error = ipf_inobj(data, &iter, IPFOBJ_GENITER); |
| if (error != 0) |
| break; |
| |
| SPL_SCHED(s); |
| token = ipf_findtoken(iter.igi_type, uid, ctx); |
| if (token != NULL) { |
| error = ipf_nat_iterator(token, &iter); |
| } |
| RWLOCK_EXIT(&ipf_tokens); |
| SPL_X(s); |
| break; |
| } |
| |
| case SIOCIPFDELTOK : |
| error = BCOPYIN(data, &arg, sizeof(arg)); |
| if (error == 0) { |
| SPL_SCHED(s); |
| error = ipf_deltoken(arg, uid, ctx); |
| SPL_X(s); |
| } else { |
| ipf_interror = 60019; |
| error = EFAULT; |
| } |
| break; |
| |
| case SIOCGTQTAB : |
| error = ipf_outobj(data, ipf_nat_tqb, IPFOBJ_STATETQTAB); |
| break; |
| |
| case SIOCGTABL : |
| error = ipf_nat_gettable(data); |
| break; |
| |
| default : |
| ipf_interror = 60020; |
| error = EINVAL; |
| break; |
| } |
| done: |
| if (nt != NULL) |
| KFREE(nt); |
| return error; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_siocaddnat */ |
| /* Returns: int - 0 == success, != 0 == failure */ |
| /* Parameters: n(I) - pointer to new NAT rule */ |
| /* np(I) - pointer to where to insert new NAT rule */ |
| /* getlock(I) - flag indicating if lock on is held */ |
| /* Mutex Locks: ipf_natio */ |
| /* */ |
| /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ |
| /* from information passed to the kernel, then add it to the appropriate */ |
| /* NAT rule table(s). */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_siocaddnat(n, np, getlock) |
| ipnat_t *n, **np; |
| int getlock; |
| { |
| int error = 0; |
| int idx; |
| |
| /* |
| * This combination of flags is incompatible because in_flags will |
| * be checked for packets coming back in too. |
| */ |
| if ((n->in_flags & IPN_TCPUDP) && (n->in_redir & NAT_ENCAP)) { |
| ipf_interror = 60021; |
| return EINVAL; |
| } |
| |
| if (ipf_nat_resolverule(n) != 0) { |
| ipf_interror = 60022; |
| return ENOENT; |
| } |
| |
| if ((n->in_age[0] == 0) && (n->in_age[1] != 0)) { |
| ipf_interror = 60023; |
| return EINVAL; |
| } |
| |
| n->in_use = 0; |
| |
| if ((n->in_flags & IPN_SIPRANGE) != 0) |
| n->in_nsrcatype = FRI_RANGE; |
| |
| if ((n->in_flags & IPN_DIPRANGE) != 0) |
| n->in_ndstatype = FRI_RANGE; |
| |
| if ((n->in_flags & IPN_SPLIT) != 0) |
| n->in_ndstatype = FRI_SPLIT; |
| |
| if (n->in_redir == NAT_BIMAP) { |
| n->in_ndstaddr = n->in_osrcaddr; |
| n->in_ndstmsk = n->in_osrcmsk; |
| n->in_odstaddr = n->in_nsrcaddr; |
| n->in_odstmsk = n->in_nsrcmsk; |
| |
| } |
| |
| if ((n->in_redir & (NAT_MAP|NAT_REWRITE|NAT_DIVERTUDP)) != 0) |
| n->in_spnext = n->in_spmin; |
| |
| if ((n->in_redir & (NAT_REWRITE|NAT_DIVERTUDP)) != 0) { |
| n->in_dpnext = n->in_dpmin; |
| } else if (n->in_redir == NAT_REDIRECT) { |
| n->in_dpnext = n->in_dpmin; |
| } |
| |
| n->in_stepnext = 0; |
| |
| if (n->in_redir & NAT_REDIRECT) |
| idx = 1; |
| else |
| idx = 0; |
| /* |
| * Initialise all of the address fields. |
| */ |
| error = ipf_nat_nextaddrinit(&n->in_osrc, 1, n->in_ifps[idx]); |
| if (error != 0) |
| return error; |
| |
| error = ipf_nat_nextaddrinit(&n->in_odst, 1, n->in_ifps[idx]); |
| if (error != 0) |
| return error; |
| |
| error = ipf_nat_nextaddrinit(&n->in_nsrc, 1, n->in_ifps[idx]); |
| if (error != 0) |
| return error; |
| |
| error = ipf_nat_nextaddrinit(&n->in_ndst, 1, n->in_ifps[idx]); |
| if (error != 0) |
| return error; |
| |
| if (getlock) { |
| WRITE_ENTER(&ipf_nat); |
| } |
| n->in_next = NULL; |
| *np = n; |
| |
| if (n->in_age[0] != 0) |
| n->in_tqehead[0] = ipf_addtimeoutqueue(&ipf_nat_utqe, |
| n->in_age[0]); |
| |
| if (n->in_age[1] != 0) |
| n->in_tqehead[1] = ipf_addtimeoutqueue(&ipf_nat_utqe, |
| n->in_age[1]); |
| |
| if (n->in_redir & NAT_REDIRECT) { |
| n->in_flags &= ~IPN_NOTDST; |
| ipf_nat_addrdr(n); |
| if (n->in_redir & NAT_ENCAP) |
| ipf_nat_addencap(n); |
| } |
| |
| if (n->in_redir & (NAT_MAP|NAT_MAPBLK)) { |
| n->in_flags &= ~IPN_NOTSRC; |
| ipf_nat_addnat(n); |
| if (n->in_redir & NAT_ENCAP) |
| ipf_nat_addencap(n); |
| } |
| |
| if (n->in_redir & (NAT_ENCAP|NAT_DIVERTUDP)) |
| ipf_nat_builddivertmp(n); |
| |
| MUTEX_INIT(&n->in_lock, "ipnat rule lock"); |
| |
| n = NULL; |
| ATOMIC_INC(ipf_nat_stats.ns_rules); |
| #if SOLARIS |
| pfil_delayed_copy = 0; |
| #endif |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); /* WRITE */ |
| } |
| |
| return error; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_resolvrule */ |
| /* Returns: Nil */ |
| /* Parameters: n(I) - pointer to NAT rule */ |
| /* */ |
| /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ |
| /* from information passed to the kernel, then add it to the appropriate */ |
| /* NAT rule table(s). */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_resolverule(n) |
| ipnat_t *n; |
| { |
| n->in_ifnames[0][LIFNAMSIZ - 1] = '\0'; |
| n->in_ifps[0] = ipf_resolvenic(n->in_ifnames[0], n->in_v); |
| |
| n->in_ifnames[1][LIFNAMSIZ - 1] = '\0'; |
| if (n->in_ifnames[1][0] == '\0') { |
| (void) strncpy(n->in_ifnames[1], n->in_ifnames[0], LIFNAMSIZ); |
| n->in_ifps[1] = n->in_ifps[0]; |
| } else { |
| n->in_ifps[1] = ipf_resolvenic(n->in_ifnames[1], n->in_v); |
| } |
| |
| if (n->in_plabel[0] != '\0') { |
| if (n->in_redir & NAT_REDIRECT) |
| n->in_apr = appr_lookup(n->in_pr[0], n->in_plabel); |
| else |
| n->in_apr = appr_lookup(n->in_pr[1], n->in_plabel); |
| if (n->in_apr == NULL) |
| return -1; |
| } |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_siocdelnat */ |
| /* Returns: int - 0 == success, != 0 == failure */ |
| /* Parameters: n(I) - pointer to new NAT rule */ |
| /* np(I) - pointer to where to insert new NAT rule */ |
| /* getlock(I) - flag indicating if lock on is held */ |
| /* Mutex Locks: ipf_natio */ |
| /* */ |
| /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ |
| /* from information passed to the kernel, then add it to the appropriate */ |
| /* NAT rule table(s). */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_siocdelnat(n, np, getlock) |
| ipnat_t *n, **np; |
| int getlock; |
| { |
| if (getlock) { |
| WRITE_ENTER(&ipf_nat); |
| } |
| if (n->in_redir & NAT_REDIRECT) |
| ipf_nat_delrdr(n); |
| if (n->in_redir & (NAT_MAPBLK|NAT_MAP)) |
| ipf_nat_delnat(n); |
| if (ipf_nat_list == NULL) { |
| ipf_nat_map_masks = 0; |
| ipf_nat_rdr_masks = 0; |
| } |
| |
| if (n->in_tqehead[0] != NULL) { |
| if (ipf_deletetimeoutqueue(n->in_tqehead[0]) == 0) { |
| ipf_freetimeoutqueue(n->in_tqehead[1]); |
| } |
| } |
| |
| if (n->in_tqehead[1] != NULL) { |
| if (ipf_deletetimeoutqueue(n->in_tqehead[1]) == 0) { |
| ipf_freetimeoutqueue(n->in_tqehead[1]); |
| } |
| } |
| |
| *np = n->in_next; |
| |
| if (n->in_use == 0) { |
| if (n->in_apr) |
| appr_free(n->in_apr); |
| KFREE(n); |
| ATOMIC_DEC(ipf_nat_stats.ns_rules); |
| #if SOLARIS |
| if (ipf_nat_stats.ns_rules == 0) |
| pfil_delayed_copy = 1; |
| #endif |
| } else { |
| n->in_flags |= IPN_DELETE; |
| n->in_next = NULL; |
| } |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); /* READ/WRITE */ |
| } |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_getsz */ |
| /* Returns: int - 0 == success, != 0 is the error value. */ |
| /* Parameters: data(I) - pointer to natget structure with kernel pointer */ |
| /* get the size of. */ |
| /* */ |
| /* Handle SIOCSTGSZ. */ |
| /* Return the size of the nat list entry to be copied back to user space. */ |
| /* The size of the entry is stored in the ng_sz field and the enture natget */ |
| /* structure is copied back to the user. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_getsz(data) |
| caddr_t data; |
| { |
| ap_session_t *aps; |
| nat_t *nat, *n; |
| natget_t ng; |
| int error; |
| |
| error = BCOPYIN(data, &ng, sizeof(ng)); |
| if (error != 0) { |
| ipf_interror = 60024; |
| return EFAULT; |
| } |
| |
| nat = ng.ng_ptr; |
| if (!nat) { |
| nat = ipf_nat_instances; |
| ng.ng_sz = 0; |
| /* |
| * Empty list so the size returned is 0. Simple. |
| */ |
| if (nat == NULL) { |
| error = BCOPYOUT(&ng, data, sizeof(ng)); |
| if (error != 0) { |
| ipf_interror = 60025; |
| return EFAULT; |
| } |
| return 0; |
| } |
| } else { |
| /* |
| * Make sure the pointer we're copying from exists in the |
| * current list of entries. Security precaution to prevent |
| * copying of random kernel data. |
| */ |
| for (n = ipf_nat_instances; n; n = n->nat_next) |
| if (n == nat) |
| break; |
| if (n == NULL) { |
| ipf_interror = 60026; |
| return ESRCH; |
| } |
| } |
| |
| /* |
| * Incluse any space required for proxy data structures. |
| */ |
| ng.ng_sz = sizeof(nat_save_t); |
| aps = nat->nat_aps; |
| if (aps != NULL) { |
| ng.ng_sz += sizeof(ap_session_t) - 4; |
| if (aps->aps_data != 0) |
| ng.ng_sz += aps->aps_psiz; |
| } |
| |
| error = BCOPYOUT(&ng, data, sizeof(ng)); |
| if (error != 0) { |
| ipf_interror = 60027; |
| return EFAULT; |
| } |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_getent */ |
| /* Returns: int - 0 == success, != 0 is the error value. */ |
| /* Parameters: data(I) - pointer to natget structure with kernel pointer */ |
| /* to NAT structure to copy out. */ |
| /* */ |
| /* Handle SIOCSTGET. */ |
| /* Copies out NAT entry to user space. Any additional data held for a */ |
| /* proxy is also copied, as to is the NAT rule which was responsible for it */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_getent(data) |
| caddr_t data; |
| { |
| int error, outsize; |
| ap_session_t *aps; |
| nat_save_t *ipn, ipns; |
| nat_t *n, *nat; |
| |
| error = ipf_inobj(data, &ipns, IPFOBJ_NATSAVE); |
| if (error != 0) |
| return error; |
| |
| if ((ipns.ipn_dsize < sizeof(ipns)) || (ipns.ipn_dsize > 81920)) { |
| ipf_interror = 60028; |
| return EINVAL; |
| } |
| |
| KMALLOCS(ipn, nat_save_t *, ipns.ipn_dsize); |
| if (ipn == NULL) { |
| ipf_interror = 60029; |
| return ENOMEM; |
| } |
| |
| ipn->ipn_dsize = ipns.ipn_dsize; |
| nat = ipns.ipn_next; |
| if (nat == NULL) { |
| nat = ipf_nat_instances; |
| if (nat == NULL) { |
| if (ipf_nat_instances == NULL) { |
| ipf_interror = 60030; |
| error = ENOENT; |
| } |
| goto finished; |
| } |
| } else { |
| /* |
| * Make sure the pointer we're copying from exists in the |
| * current list of entries. Security precaution to prevent |
| * copying of random kernel data. |
| */ |
| for (n = ipf_nat_instances; n; n = n->nat_next) |
| if (n == nat) |
| break; |
| if (n == NULL) { |
| ipf_interror = 60031; |
| error = ESRCH; |
| goto finished; |
| } |
| } |
| ipn->ipn_next = nat->nat_next; |
| |
| /* |
| * Copy the NAT structure. |
| */ |
| bcopy((char *)nat, &ipn->ipn_nat, sizeof(*nat)); |
| |
| /* |
| * If we have a pointer to the NAT rule it belongs to, save that too. |
| */ |
| if (nat->nat_ptr != NULL) |
| bcopy((char *)nat->nat_ptr, (char *)&ipn->ipn_ipnat, |
| sizeof(ipn->ipn_ipnat)); |
| |
| /* |
| * If we also know the NAT entry has an associated filter rule, |
| * save that too. |
| */ |
| if (nat->nat_fr != NULL) |
| bcopy((char *)nat->nat_fr, (char *)&ipn->ipn_fr, |
| sizeof(ipn->ipn_fr)); |
| |
| /* |
| * Last but not least, if there is an application proxy session set |
| * up for this NAT entry, then copy that out too, including any |
| * private data saved along side it by the proxy. |
| */ |
| aps = nat->nat_aps; |
| outsize = ipn->ipn_dsize - sizeof(*ipn) + sizeof(ipn->ipn_data); |
| if (aps != NULL) { |
| char *s; |
| |
| if (outsize < sizeof(*aps)) { |
| ipf_interror = 60032; |
| error = ENOBUFS; |
| goto finished; |
| } |
| |
| s = ipn->ipn_data; |
| bcopy((char *)aps, s, sizeof(*aps)); |
| s += sizeof(*aps); |
| outsize -= sizeof(*aps); |
| if ((aps->aps_data != NULL) && (outsize >= aps->aps_psiz)) |
| bcopy(aps->aps_data, s, aps->aps_psiz); |
| else { |
| ipf_interror = 60033; |
| error = ENOBUFS; |
| } |
| } |
| if (error == 0) { |
| error = ipf_outobjsz(data, ipn, IPFOBJ_NATSAVE, ipns.ipn_dsize); |
| } |
| |
| finished: |
| if (ipn != NULL) { |
| KFREES(ipn, ipns.ipn_dsize); |
| } |
| return error; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_putent */ |
| /* Returns: int - 0 == success, != 0 is the error value. */ |
| /* Parameters: data(I) - pointer to natget structure with NAT */ |
| /* structure information to load into the kernel */ |
| /* getlock(I) - flag indicating whether or not a write lock */ |
| /* on is already held. */ |
| /* */ |
| /* Handle SIOCSTPUT. */ |
| /* Loads a NAT table entry from user space, including a NAT rule, proxy and */ |
| /* firewall rule data structures, if pointers to them indicate so. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_putent(data, getlock) |
| caddr_t data; |
| int getlock; |
| { |
| nat_save_t ipn, *ipnn; |
| ap_session_t *aps; |
| nat_t *n, *nat; |
| frentry_t *fr; |
| fr_info_t fin; |
| ipnat_t *in; |
| int error; |
| |
| error = ipf_inobj(data, &ipn, IPFOBJ_NATSAVE); |
| if (error != 0) |
| return error; |
| |
| /* |
| * Initialise early because of code at junkput label. |
| */ |
| in = NULL; |
| aps = NULL; |
| nat = NULL; |
| ipnn = NULL; |
| fr = NULL; |
| |
| /* |
| * New entry, copy in the rest of the NAT entry if it's size is more |
| * than just the nat_t structure. |
| */ |
| if (ipn.ipn_dsize > sizeof(ipn)) { |
| if (ipn.ipn_dsize > 81920) { |
| ipf_interror = 60034; |
| error = ENOMEM; |
| goto junkput; |
| } |
| |
| KMALLOCS(ipnn, nat_save_t *, ipn.ipn_dsize); |
| if (ipnn == NULL) { |
| ipf_interror = 60035; |
| return ENOMEM; |
| } |
| |
| error = ipf_inobjsz(data, ipnn, IPFOBJ_NATSAVE, ipn.ipn_dsize); |
| if (error != 0) { |
| goto junkput; |
| } |
| } else |
| ipnn = &ipn; |
| |
| KMALLOC(nat, nat_t *); |
| if (nat == NULL) { |
| ipf_interror = 60037; |
| error = ENOMEM; |
| goto junkput; |
| } |
| |
| bcopy((char *)&ipnn->ipn_nat, (char *)nat, sizeof(*nat)); |
| /* |
| * Initialize all these so that ipf_nat_delete() doesn't cause a crash. |
| */ |
| bzero((char *)nat, offsetof(struct nat, nat_tqe)); |
| nat->nat_tqe.tqe_pnext = NULL; |
| nat->nat_tqe.tqe_next = NULL; |
| nat->nat_tqe.tqe_ifq = NULL; |
| nat->nat_tqe.tqe_parent = nat; |
| |
| /* |
| * Restore the rule associated with this nat session |
| */ |
| in = ipnn->ipn_nat.nat_ptr; |
| if (in != NULL) { |
| KMALLOC(in, ipnat_t *); |
| nat->nat_ptr = in; |
| if (in == NULL) { |
| ipf_interror = 60038; |
| error = ENOMEM; |
| goto junkput; |
| } |
| bzero((char *)in, offsetof(struct ipnat, in_space)); |
| bcopy((char *)&ipnn->ipn_ipnat, (char *)in, sizeof(*in)); |
| in->in_use = 1; |
| in->in_flags |= IPN_DELETE; |
| |
| ATOMIC_INC(ipf_nat_stats.ns_rules); |
| |
| if (ipf_nat_resolverule(in) != 0) { |
| ipf_interror = 60039; |
| error = ESRCH; |
| goto junkput; |
| } |
| } |
| |
| /* |
| * Check that the NAT entry doesn't already exist in the kernel. |
| * |
| * For NAT_OUTBOUND, we're lookup for a duplicate MAP entry. To do |
| * this, we check to see if the inbound combination of addresses and |
| * ports is already known. Similar logic is applied for NAT_INBOUND. |
| * |
| */ |
| bzero((char *)&fin, sizeof(fin)); |
| fin.fin_p = nat->nat_pr[0]; |
| fin.fin_ifp = nat->nat_ifps[0]; |
| fin.fin_data[0] = ntohs(nat->nat_ndport); |
| fin.fin_data[1] = ntohs(nat->nat_nsport); |
| |
| if (nat->nat_dir == NAT_OUTBOUND) { |
| if (getlock) { |
| READ_ENTER(&ipf_nat); |
| } |
| n = ipf_nat_inlookup(&fin, nat->nat_flags, fin.fin_p, |
| nat->nat_ndstip, nat->nat_nsrcip); |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| if (n != NULL) { |
| ipf_interror = 60040; |
| error = EEXIST; |
| goto junkput; |
| } |
| } else if (nat->nat_dir == NAT_INBOUND) { |
| if (getlock) { |
| READ_ENTER(&ipf_nat); |
| } |
| n = ipf_nat_outlookup(&fin, nat->nat_flags, fin.fin_p, |
| nat->nat_ndstip, nat->nat_nsrcip); |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| if (n != NULL) { |
| ipf_interror = 60041; |
| error = EEXIST; |
| goto junkput; |
| } |
| } else { |
| ipf_interror = 60042; |
| error = EINVAL; |
| goto junkput; |
| } |
| |
| /* |
| * Restore ap_session_t structure. Include the private data allocated |
| * if it was there. |
| */ |
| aps = nat->nat_aps; |
| if (aps != NULL) { |
| KMALLOC(aps, ap_session_t *); |
| nat->nat_aps = aps; |
| if (aps == NULL) { |
| ipf_interror = 60043; |
| error = ENOMEM; |
| goto junkput; |
| } |
| bcopy(ipnn->ipn_data, (char *)aps, sizeof(*aps)); |
| if (in != NULL) |
| aps->aps_apr = in->in_apr; |
| else |
| aps->aps_apr = NULL; |
| if (aps->aps_psiz != 0) { |
| if (aps->aps_psiz > 81920) { |
| ipf_interror = 60044; |
| error = ENOMEM; |
| goto junkput; |
| } |
| KMALLOCS(aps->aps_data, void *, aps->aps_psiz); |
| if (aps->aps_data == NULL) { |
| ipf_interror = 60045; |
| error = ENOMEM; |
| goto junkput; |
| } |
| bcopy(ipnn->ipn_data + sizeof(*aps), aps->aps_data, |
| aps->aps_psiz); |
| } else { |
| aps->aps_psiz = 0; |
| aps->aps_data = NULL; |
| } |
| } |
| |
| /* |
| * If there was a filtering rule associated with this entry then |
| * build up a new one. |
| */ |
| fr = nat->nat_fr; |
| if (fr != NULL) { |
| if ((nat->nat_flags & SI_NEWFR) != 0) { |
| KMALLOC(fr, frentry_t *); |
| nat->nat_fr = fr; |
| if (fr == NULL) { |
| ipf_interror = 60046; |
| error = ENOMEM; |
| goto junkput; |
| } |
| ipnn->ipn_nat.nat_fr = fr; |
| fr->fr_ref = 1; |
| (void) ipf_outobj(data, ipnn, IPFOBJ_NATSAVE); |
| bcopy((char *)&ipnn->ipn_fr, (char *)fr, sizeof(*fr)); |
| |
| fr->fr_ref = 1; |
| fr->fr_dsize = 0; |
| fr->fr_data = NULL; |
| fr->fr_type = FR_T_NONE; |
| |
| MUTEX_NUKE(&fr->fr_lock); |
| MUTEX_INIT(&fr->fr_lock, "nat-filter rule lock"); |
| } else { |
| if (getlock) { |
| READ_ENTER(&ipf_nat); |
| } |
| for (n = ipf_nat_instances; n; n = n->nat_next) |
| if (n->nat_fr == fr) |
| break; |
| |
| if (n != NULL) { |
| MUTEX_ENTER(&fr->fr_lock); |
| fr->fr_ref++; |
| MUTEX_EXIT(&fr->fr_lock); |
| } |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| |
| if (n == NULL) { |
| ipf_interror = 60047; |
| error = ESRCH; |
| goto junkput; |
| } |
| } |
| } |
| |
| if (ipnn != &ipn) { |
| KFREES(ipnn, ipn.ipn_dsize); |
| ipnn = NULL; |
| } |
| |
| if (getlock) { |
| WRITE_ENTER(&ipf_nat); |
| } |
| error = ipf_nat_insert(nat, nat->nat_rev); |
| if ((error == 0) && (aps != NULL)) { |
| aps->aps_next = ap_sess_list; |
| ap_sess_list = aps; |
| } |
| if (getlock) { |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| |
| if (error == 0) |
| return 0; |
| |
| ipf_interror = 60048; |
| error = ENOMEM; |
| |
| junkput: |
| if (fr != NULL) { |
| (void) ipf_derefrule(&fr); |
| } |
| |
| if ((ipnn != NULL) && (ipnn != &ipn)) { |
| KFREES(ipnn, ipn.ipn_dsize); |
| } |
| if (nat != NULL) { |
| if (aps != NULL) { |
| if (aps->aps_data != NULL) { |
| KFREES(aps->aps_data, aps->aps_psiz); |
| } |
| KFREE(aps); |
| } |
| if (in != NULL) { |
| if (in->in_apr) |
| appr_free(in->in_apr); |
| KFREE(in); |
| } |
| KFREE(nat); |
| } |
| return error; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_delete */ |
| /* Returns: Nil */ |
| /* Parameters: natd(I) - pointer to NAT structure to delete */ |
| /* logtype(I) - type of LOG record to create before deleting */ |
| /* Write Lock: ipf_nat */ |
| /* */ |
| /* Delete a nat entry from the various lists and table. If NAT logging is */ |
| /* enabled then generate a NAT log record for this event. */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_delete(nat, logtype) |
| struct nat *nat; |
| int logtype; |
| { |
| int madeorphan = 0, bkt; |
| struct ipnat *ipn; |
| |
| if (logtype != 0 && ipf_nat_logging != 0) |
| ipf_nat_log(nat, logtype); |
| |
| /* |
| * Take it as a general indication that all the pointers are set if |
| * nat_pnext is set. |
| */ |
| if (nat->nat_pnext != NULL) { |
| bkt = nat->nat_hv[0]; |
| ipf_nat_stats.ns_side[0].ns_bucketlen[bkt]--; |
| if (ipf_nat_stats.ns_side[0].ns_bucketlen[bkt] == 0) { |
| ipf_nat_stats.ns_side[0].ns_inuse--; |
| } |
| bkt = nat->nat_hv[1]; |
| ipf_nat_stats.ns_side[1].ns_bucketlen[bkt]--; |
| if (ipf_nat_stats.ns_side[1].ns_bucketlen[bkt] == 0) { |
| ipf_nat_stats.ns_side[1].ns_inuse--; |
| } |
| |
| *nat->nat_pnext = nat->nat_next; |
| if (nat->nat_next != NULL) { |
| nat->nat_next->nat_pnext = nat->nat_pnext; |
| nat->nat_next = NULL; |
| } |
| nat->nat_pnext = NULL; |
| |
| *nat->nat_phnext[0] = nat->nat_hnext[0]; |
| if (nat->nat_hnext[0] != NULL) { |
| nat->nat_hnext[0]->nat_phnext[0] = nat->nat_phnext[0]; |
| nat->nat_hnext[0] = NULL; |
| } |
| nat->nat_phnext[0] = NULL; |
| |
| *nat->nat_phnext[1] = nat->nat_hnext[1]; |
| if (nat->nat_hnext[1] != NULL) { |
| nat->nat_hnext[1]->nat_phnext[1] = nat->nat_phnext[1]; |
| nat->nat_hnext[1] = NULL; |
| } |
| nat->nat_phnext[1] = NULL; |
| |
| if ((nat->nat_flags & SI_WILDP) != 0) { |
| ATOMIC_DEC(ipf_nat_stats.ns_wilds); |
| } |
| madeorphan = 1; |
| } |
| |
| if (nat->nat_me != NULL) { |
| *nat->nat_me = NULL; |
| nat->nat_me = NULL; |
| } |
| |
| if (nat->nat_tqe.tqe_ifq != NULL) |
| ipf_deletequeueentry(&nat->nat_tqe); |
| |
| if (logtype == NL_EXPIRE) |
| ipf_nat_stats.ns_expire++; |
| |
| MUTEX_ENTER(&nat->nat_lock); |
| if (nat->nat_ref > 1) { |
| nat->nat_ref--; |
| MUTEX_EXIT(&nat->nat_lock); |
| if (madeorphan == 1) |
| ipf_nat_stats.ns_orphans++; |
| return; |
| } |
| MUTEX_EXIT(&nat->nat_lock); |
| |
| nat->nat_ref = 0; |
| |
| if (madeorphan == 0) |
| ipf_nat_stats.ns_orphans--; |
| |
| /* |
| * At this point, nat_ref can be either 0 or -1 |
| */ |
| |
| #ifdef IPFILTER_SYNC |
| if (nat->nat_sync) |
| ipf_sync_del(nat->nat_sync); |
| #endif |
| |
| if (nat->nat_fr != NULL) { |
| (void) ipf_derefrule(&nat->nat_fr); |
| } |
| |
| if (nat->nat_hm != NULL) { |
| ipf_nat_hostmapdel(&nat->nat_hm); |
| } |
| |
| /* |
| * If there is an active reference from the nat entry to its parent |
| * rule, decrement the rule's reference count and free it too if no |
| * longer being used. |
| */ |
| ipn = nat->nat_ptr; |
| nat->nat_ptr = NULL; |
| |
| if (ipn != NULL) { |
| ipf_nat_rulederef(&ipn); |
| } |
| |
| MUTEX_DESTROY(&nat->nat_lock); |
| |
| aps_free(nat->nat_aps); |
| ipf_nat_stats.ns_active--; |
| |
| /* |
| * If there's a fragment table entry too for this nat entry, then |
| * dereference that as well. This is after nat_lock is released |
| * because of Tru64. |
| */ |
| ipf_frag_natforget((void *)nat); |
| |
| KFREE(nat); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_flushtable */ |
| /* Returns: int - number of NAT rules deleted */ |
| /* Parameters: Nil */ |
| /* Write Lock: ipf_nat */ |
| /* */ |
| /* Deletes all currently active NAT sessions. In deleting each NAT entry a */ |
| /* log record should be emitted in ipf_nat_delete() if NAT logging is */ |
| /* enabled. */ |
| /* ------------------------------------------------------------------------ */ |
| /* |
| * nat_flushtable - clear the NAT table of all mapping entries. |
| */ |
| static int |
| ipf_nat_flushtable() |
| { |
| nat_t *nat; |
| int j = 0; |
| |
| /* |
| * ALL NAT mappings deleted, so lets just make the deletions |
| * quicker. |
| */ |
| if (ipf_nat_table[0] != NULL) |
| bzero((char *)ipf_nat_table[0], |
| sizeof(ipf_nat_table[0]) * ipf_nat_table_sz); |
| if (ipf_nat_table[1] != NULL) |
| bzero((char *)ipf_nat_table[1], |
| sizeof(ipf_nat_table[1]) * ipf_nat_table_sz); |
| |
| while ((nat = ipf_nat_instances) != NULL) { |
| ipf_nat_delete(nat, NL_FLUSH); |
| j++; |
| } |
| |
| ipf_nat_stats.ns_active = 0; |
| return j; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_clearlist */ |
| /* Returns: int - number of NAT/RDR rules deleted */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Delete all rules in the current list of rules. There is nothing elegant */ |
| /* about this cleanup: simply free all entries on the list of rules and */ |
| /* clear out the tables used for hashed NAT rule lookups. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_clearlist() |
| { |
| ipnat_t *n, **np = &ipf_nat_list; |
| int i = 0; |
| |
| if (ipf_nat_map_rules != NULL) { |
| bzero((char *)ipf_nat_map_rules, |
| sizeof(*ipf_nat_map_rules) * ipf_nat_maprules_sz); |
| } |
| if (ipf_nat_rdr_rules != NULL) { |
| bzero((char *)ipf_nat_rdr_rules, |
| sizeof(*ipf_nat_rdr_rules) * ipf_nat_rdrrules_sz); |
| } |
| |
| while ((n = *np) != NULL) { |
| *np = n->in_next; |
| ipf_nat_delrule(n); |
| i++; |
| } |
| #if SOLARIS |
| pfil_delayed_copy = 1; |
| #endif |
| ipf_nat_map_masks = 0; |
| ipf_nat_rdr_masks = 0; |
| return i; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_delrule */ |
| /* Returns: Nil */ |
| /* Parameters: np(I) - pointer to NAT rule to delete */ |
| /* */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_delrule(np) |
| ipnat_t *np; |
| { |
| if (np->in_use == 0) { |
| if (np->in_apr != NULL) |
| appr_free(np->in_apr); |
| |
| if (np->in_divmp != NULL) { |
| FREE_MB_T(np->in_divmp); |
| } |
| |
| KFREE(np); |
| ipf_nat_stats.ns_rules--; |
| } else { |
| np->in_flags |= IPN_DELETE; |
| np->in_next = NULL; |
| } |
| |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_newmap */ |
| /* Returns: int - -1 == error, 0 == success */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to NAT entry */ |
| /* ni(I) - pointer to structure with misc. information needed */ |
| /* to create new NAT entry. */ |
| /* */ |
| /* Given an empty NAT structure, populate it with new information about a */ |
| /* new NAT session, as defined by the matching NAT rule. */ |
| /* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/ |
| /* to the new IP address for the translation. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_newmap(fin, nat, ni) |
| fr_info_t *fin; |
| nat_t *nat; |
| natinfo_t *ni; |
| { |
| u_short st_port, dport, sport, port, sp, dp; |
| struct in_addr in, inb; |
| hostmap_t *hm; |
| u_32_t flags; |
| u_32_t st_ip; |
| ipnat_t *np; |
| nat_t *natl; |
| int l; |
| |
| /* |
| * If it's an outbound packet which doesn't match any existing |
| * record, then create a new port |
| */ |
| l = 0; |
| hm = NULL; |
| np = ni->nai_np; |
| st_ip = np->in_snip; |
| st_port = np->in_spnext; |
| flags = ni->nai_flags; |
| |
| if (flags & IPN_ICMPQUERY) { |
| sport = fin->fin_data[1]; |
| dport = 0; |
| } else { |
| sport = htons(fin->fin_data[0]); |
| dport = htons(fin->fin_data[1]); |
| } |
| |
| /* |
| * Do a loop until we either run out of entries to try or we find |
| * a NAT mapping that isn't currently being used. This is done |
| * because the change to the source is not (usually) being fixed. |
| */ |
| do { |
| port = 0; |
| in.s_addr = htonl(np->in_snip); |
| if (l == 0) { |
| /* |
| * Check to see if there is an existing NAT |
| * setup for this IP address pair. |
| */ |
| hm = ipf_nat_hostmap(np, fin->fin_src, fin->fin_dst, |
| in, 0); |
| if (hm != NULL) |
| in.s_addr = hm->hm_nsrcip.s_addr; |
| } else if ((l == 1) && (hm != NULL)) { |
| ipf_nat_hostmapdel(&hm); |
| } |
| in.s_addr = ntohl(in.s_addr); |
| |
| nat->nat_hm = hm; |
| |
| if ((np->in_nsrcmsk == 0xffffffff) && (np->in_spnext == 0)) { |
| if (l > 0) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1]. |
| ns_exhausted); |
| return -1; |
| } |
| } |
| |
| if (np->in_redir == NAT_BIMAP && |
| np->in_osrcmsk == np->in_nsrcmsk) { |
| /* |
| * map the address block in a 1:1 fashion |
| */ |
| in.s_addr = np->in_nsrcaddr; |
| in.s_addr |= fin->fin_saddr & ~np->in_osrcmsk; |
| in.s_addr = ntohl(in.s_addr); |
| |
| } else if (np->in_redir & NAT_MAPBLK) { |
| if ((l >= np->in_ppip) || ((l > 0) && |
| !(flags & IPN_TCPUDP))) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1]. |
| ns_exhausted); |
| return -1; |
| } |
| /* |
| * map-block - Calculate destination address. |
| */ |
| in.s_addr = ntohl(fin->fin_saddr); |
| in.s_addr &= ntohl(~np->in_osrcmsk); |
| inb.s_addr = in.s_addr; |
| in.s_addr /= np->in_ippip; |
| in.s_addr &= ntohl(~np->in_nsrcmsk); |
| in.s_addr += ntohl(np->in_nsrcaddr); |
| /* |
| * Calculate destination port. |
| */ |
| if ((flags & IPN_TCPUDP) && |
| (np->in_ppip != 0)) { |
| port = ntohs(sport) + l; |
| port %= np->in_ppip; |
| port += np->in_ppip * |
| (inb.s_addr % np->in_ippip); |
| port += MAPBLK_MINPORT; |
| port = htons(port); |
| } |
| |
| } else if ((np->in_nsrcaddr == 0) && |
| (np->in_nsrcmsk == 0xffffffff)) { |
| i6addr_t in6; |
| |
| /* |
| * 0/32 - use the interface's IP address. |
| */ |
| if ((l > 0) || |
| ipf_ifpaddr(fin->fin_v, FRI_NORMAL, fin->fin_ifp, |
| &in6, NULL) == -1) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1]. |
| ns_new_ifpaddr); |
| return -1; |
| } |
| if (fin->fin_v == 4) |
| in.s_addr = ntohl(in6.in4.s_addr); |
| |
| } else if ((np->in_nsrcaddr == 0) && (np->in_nsrcmsk == 0)) { |
| /* |
| * 0/0 - use the original source address/port. |
| */ |
| if (l > 0) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1]. |
| ns_exhausted); |
| return -1; |
| } |
| in.s_addr = ntohl(fin->fin_saddr); |
| |
| } else if ((np->in_nsrcmsk != 0xffffffff) && |
| (np->in_spnext == 0) && ((l > 0) || (hm == NULL))) |
| np->in_snip++; |
| |
| natl = NULL; |
| |
| if ((flags & IPN_TCPUDP) && |
| ((np->in_redir & NAT_MAPBLK) == 0) && |
| (np->in_flags & IPN_AUTOPORTMAP)) { |
| /* |
| * "ports auto" (without map-block) |
| */ |
| if ((l > 0) && (l % np->in_ppip == 0)) { |
| if ((l > np->in_ppip) && |
| np->in_nsrcmsk != 0xffffffff) |
| np->in_snip++; |
| } |
| if (np->in_ppip != 0) { |
| port = ntohs(sport); |
| port += (l % np->in_ppip); |
| port %= np->in_ppip; |
| port += np->in_ppip * |
| (ntohl(fin->fin_saddr) % |
| np->in_ippip); |
| port += MAPBLK_MINPORT; |
| port = htons(port); |
| } |
| |
| } else if (((np->in_redir & NAT_MAPBLK) == 0) && |
| (flags & IPN_TCPUDPICMP) && (np->in_spnext != 0)) { |
| /* |
| * Standard port translation. Select next port. |
| */ |
| port = htons(np->in_spnext++); |
| |
| if (np->in_spnext > np->in_spmax) { |
| np->in_spnext = np->in_spmin; |
| if (np->in_nsrcmsk != 0xffffffff) |
| np->in_snip++; |
| } |
| } |
| |
| if (np->in_flags & IPN_SIPRANGE) { |
| if (np->in_snip > ntohl(np->in_nsrcmsk)) |
| np->in_snip = ntohl(np->in_nsrcaddr); |
| } else { |
| if ((np->in_nsrcmsk != 0xffffffff) && |
| ((np->in_snip + 1) & ntohl(np->in_nsrcmsk)) > |
| ntohl(np->in_nsrcaddr)) |
| np->in_snip = ntohl(np->in_nsrcaddr) + 1; |
| } |
| |
| if ((port == 0) && (flags & (IPN_TCPUDPICMP|IPN_ICMPQUERY))) |
| port = sport; |
| |
| /* |
| * Here we do a lookup of the connection as seen from |
| * the outside. If an IP# pair already exists, try |
| * again. So if you have A->B becomes C->B, you can |
| * also have D->E become C->E but not D->B causing |
| * another C->B. Also take protocol and ports into |
| * account when determining whether a pre-existing |
| * NAT setup will cause an external conflict where |
| * this is appropriate. |
| */ |
| inb.s_addr = htonl(in.s_addr); |
| sp = fin->fin_data[0]; |
| dp = fin->fin_data[1]; |
| fin->fin_data[0] = fin->fin_data[1]; |
| fin->fin_data[1] = ntohs(port); |
| natl = ipf_nat_inlookup(fin, flags & ~(SI_WILDP|NAT_SEARCH), |
| (u_int)fin->fin_p, fin->fin_dst, inb); |
| fin->fin_data[0] = sp; |
| fin->fin_data[1] = dp; |
| |
| /* |
| * Has the search wrapped around and come back to the |
| * start ? |
| */ |
| if ((natl != NULL) && |
| (np->in_spnext != 0) && (st_port == np->in_spnext) && |
| (np->in_snip != 0) && (st_ip == np->in_snip)) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_wrap); |
| return -1; |
| } |
| l++; |
| } while (natl != NULL); |
| |
| /* Setup the NAT table */ |
| nat->nat_osrcip = fin->fin_src; |
| nat->nat_nsrcaddr = htonl(in.s_addr); |
| nat->nat_odstip = fin->fin_dst; |
| nat->nat_ndstip = fin->fin_dst; |
| if (nat->nat_hm == NULL) |
| nat->nat_hm = ipf_nat_hostmap(np, fin->fin_src, fin->fin_dst, |
| nat->nat_nsrcip, 0); |
| |
| if (flags & IPN_TCPUDP) { |
| nat->nat_osport = sport; |
| nat->nat_nsport = port; /* sport */ |
| nat->nat_odport = dport; |
| nat->nat_ndport = dport; |
| ((tcphdr_t *)fin->fin_dp)->th_sport = port; |
| } else if (flags & IPN_ICMPQUERY) { |
| nat->nat_oicmpid = fin->fin_data[1]; |
| ((icmphdr_t *)fin->fin_dp)->icmp_id = port; |
| nat->nat_nicmpid = port; |
| } |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_newrdr */ |
| /* Returns: int - -1 == error, 0 == success (no move), 1 == success and */ |
| /* allow rule to be moved if IPN_ROUNDR is set. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to NAT entry */ |
| /* ni(I) - pointer to structure with misc. information needed */ |
| /* to create new NAT entry. */ |
| /* */ |
| /* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/ |
| /* to the new IP address for the translation. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_newrdr(fin, nat, ni) |
| fr_info_t *fin; |
| nat_t *nat; |
| natinfo_t *ni; |
| { |
| u_short nport, dport, sport; |
| struct in_addr in, inb; |
| u_short sp, dp; |
| hostmap_t *hm; |
| u_32_t flags; |
| ipnat_t *np; |
| nat_t *natl; |
| int move; |
| |
| move = 1; |
| hm = NULL; |
| in.s_addr = 0; |
| np = ni->nai_np; |
| flags = ni->nai_flags; |
| |
| if (flags & IPN_ICMPQUERY) { |
| dport = fin->fin_data[1]; |
| sport = 0; |
| } else { |
| sport = htons(fin->fin_data[0]); |
| dport = htons(fin->fin_data[1]); |
| } |
| |
| /* TRACE sport, dport */ |
| |
| |
| /* |
| * If the matching rule has IPN_STICKY set, then we want to have the |
| * same rule kick in as before. Why would this happen? If you have |
| * a collection of rdr rules with "round-robin sticky", the current |
| * packet might match a different one to the previous connection but |
| * we want the same destination to be used. |
| */ |
| if (((np->in_flags & (IPN_ROUNDR|IPN_SPLIT)) != 0) && |
| ((np->in_flags & IPN_STICKY) != 0)) { |
| hm = ipf_nat_hostmap(NULL, fin->fin_src, fin->fin_dst, in, |
| (u_32_t)dport); |
| if (hm != NULL) { |
| in.s_addr = ntohl(hm->hm_ndstip.s_addr); |
| np = hm->hm_ipnat; |
| ni->nai_np = np; |
| move = 0; |
| } |
| } |
| |
| /* |
| * Otherwise, it's an inbound packet. Most likely, we don't |
| * want to rewrite source ports and source addresses. Instead, |
| * we want to rewrite to a fixed internal address and fixed |
| * internal port. |
| */ |
| if (np->in_flags & IPN_SPLIT) { |
| in.s_addr = np->in_dnip; |
| |
| if ((np->in_flags & (IPN_ROUNDR|IPN_STICKY)) == IPN_STICKY) { |
| hm = ipf_nat_hostmap(NULL, fin->fin_src, fin->fin_dst, |
| in, (u_32_t)dport); |
| if (hm != NULL) { |
| in.s_addr = hm->hm_ndstip.s_addr; |
| move = 0; |
| } |
| } |
| |
| if (hm == NULL || hm->hm_ref == 1) { |
| if (np->in_ndstaddr == htonl(in.s_addr)) { |
| np->in_dnip = ntohl(np->in_ndstmsk); |
| move = 0; |
| } else { |
| np->in_dnip = ntohl(np->in_ndstaddr); |
| } |
| } |
| |
| } else if ((np->in_ndstaddr == 0) && (np->in_ndstmsk == 0xffffffff)) { |
| i6addr_t in6; |
| |
| /* |
| * 0/32 - use the interface's IP address. |
| */ |
| if (ipf_ifpaddr(fin->fin_v, FRI_NORMAL, fin->fin_ifp, |
| &in6, NULL) == -1) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_new_ifpaddr); |
| return -1; |
| } |
| if (fin->fin_v == 4) |
| in.s_addr = ntohl(in6.in4.s_addr); |
| |
| } else if ((np->in_ndstaddr == 0) && (np->in_ndstmsk== 0)) { |
| /* |
| * 0/0 - use the original destination address/port. |
| */ |
| in.s_addr = ntohl(fin->fin_daddr); |
| |
| } else if (np->in_redir == NAT_BIMAP && |
| np->in_ndstmsk == np->in_odstmsk) { |
| /* |
| * map the address block in a 1:1 fashion |
| */ |
| in.s_addr = np->in_ndstaddr; |
| in.s_addr |= fin->fin_daddr & ~np->in_ndstmsk; |
| in.s_addr = ntohl(in.s_addr); |
| } else { |
| in.s_addr = ntohl(np->in_ndstaddr); |
| } |
| |
| if ((np->in_dpnext == 0) || ((flags & NAT_NOTRULEPORT) != 0)) |
| nport = dport; |
| else { |
| /* |
| * Whilst not optimized for the case where |
| * pmin == pmax, the gain is not significant. |
| */ |
| if (((np->in_flags & IPN_FIXEDDPORT) == 0) && |
| (np->in_odport != np->in_dtop)) { |
| nport = ntohs(dport) - np->in_odport + np->in_dpmax; |
| nport = htons(nport); |
| } else { |
| nport = htons(np->in_dpnext); |
| np->in_dpnext++; |
| if (np->in_dpnext > np->in_dpmax) |
| np->in_dpnext = np->in_dpmin; |
| } |
| } |
| |
| /* |
| * When the redirect-to address is set to 0.0.0.0, just |
| * assume a blank `forwarding' of the packet. We don't |
| * setup any translation for this either. |
| */ |
| if (in.s_addr == 0) { |
| if (nport == dport) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_xlate_null); |
| return -1; |
| } |
| in.s_addr = ntohl(fin->fin_daddr); |
| } |
| |
| /* |
| * Check to see if this redirect mapping already exists and if |
| * it does, return "failure" (allowing it to be created will just |
| * cause one or both of these "connections" to stop working.) |
| */ |
| inb.s_addr = htonl(in.s_addr); |
| sp = fin->fin_data[0]; |
| dp = fin->fin_data[1]; |
| fin->fin_data[1] = fin->fin_data[0]; |
| fin->fin_data[0] = ntohs(nport); |
| natl = ipf_nat_outlookup(fin, flags & ~(SI_WILDP|NAT_SEARCH), |
| (u_int)fin->fin_p, inb, fin->fin_src); |
| fin->fin_data[0] = sp; |
| fin->fin_data[1] = dp; |
| if (natl != NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_xlate_exists); |
| return -1; |
| } |
| |
| nat->nat_ndstaddr = htonl(in.s_addr); |
| nat->nat_odstip = fin->fin_dst; |
| nat->nat_nsrcip = fin->fin_src; |
| nat->nat_osrcip = fin->fin_src; |
| if ((nat->nat_hm == NULL) && ((np->in_flags & IPN_STICKY) != 0)) |
| nat->nat_hm = ipf_nat_hostmap(np, fin->fin_src, fin->fin_dst, |
| in, (u_32_t)dport); |
| |
| if (flags & IPN_TCPUDP) { |
| nat->nat_odport = dport; |
| nat->nat_ndport = nport; |
| nat->nat_osport = sport; |
| nat->nat_nsport = sport; |
| ((tcphdr_t *)fin->fin_dp)->th_dport = nport; |
| } else if (flags & IPN_ICMPQUERY) { |
| nat->nat_oicmpid = fin->fin_data[1]; |
| ((icmphdr_t *)fin->fin_dp)->icmp_id = nport; |
| nat->nat_nicmpid = nport; |
| } |
| |
| return move; |
| } |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_add */ |
| /* Returns: nat_t* - NULL == failure to create new NAT structure, */ |
| /* else pointer to new NAT structure */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* np(I) - pointer to NAT rule */ |
| /* natsave(I) - pointer to where to store NAT struct pointer */ |
| /* flags(I) - flags describing the current packet */ |
| /* direction(I) - direction of packet (in/out) */ |
| /* Write Lock: ipf_nat */ |
| /* */ |
| /* Attempts to create a new NAT entry. Does not actually change the packet */ |
| /* in any way. */ |
| /* */ |
| /* This fucntion is in three main parts: (1) deal with creating a new NAT */ |
| /* structure for a "MAP" rule (outgoing NAT translation); (2) deal with */ |
| /* creating a new NAT structure for a "RDR" rule (incoming NAT translation) */ |
| /* and (3) building that structure and putting it into the NAT table(s). */ |
| /* */ |
| /* NOTE: natsave should NOT be used top point back to an ipstate_t struct */ |
| /* as it can result in memory being corrupted. */ |
| /* ------------------------------------------------------------------------ */ |
| nat_t * |
| ipf_nat_add(fin, np, natsave, flags, direction) |
| fr_info_t *fin; |
| ipnat_t *np; |
| nat_t **natsave; |
| u_int flags; |
| int direction; |
| { |
| hostmap_t *hm = NULL; |
| nat_t *nat, *natl; |
| u_int nflags; |
| natinfo_t ni; |
| int move; |
| #if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) && defined(ICK_M_CTL_MAGIC) |
| qpktinfo_t *qpi = fin->fin_qpi; |
| #endif |
| |
| if ((ipf_nat_stats.ns_active * 100 / ipf_nat_table_max) > |
| ipf_nat_table_wm_high) { |
| ipf_nat_doflush = 1; |
| } |
| |
| if (ipf_nat_stats.ns_active >= ipf_nat_table_max) { |
| ipf_nat_stats.ns_side[fin->fin_out].ns_table_max++; |
| return NULL; |
| } |
| |
| move = 1; |
| nflags = np->in_flags & flags; |
| nflags &= NAT_FROMRULE; |
| |
| ni.nai_np = np; |
| ni.nai_nflags = nflags; |
| ni.nai_flags = flags; |
| ni.nai_dport = 0; |
| ni.nai_sport = 0; |
| |
| /* Give me a new nat */ |
| KMALLOC(nat, nat_t *); |
| if (nat == NULL) { |
| ipf_nat_stats.ns_side[fin->fin_out].ns_memfail++; |
| /* |
| * Try to automatically tune the max # of entries in the |
| * table allowed to be less than what will cause kmem_alloc() |
| * to fail and try to eliminate panics due to out of memory |
| * conditions arising. |
| */ |
| if ((ipf_nat_table_max > ipf_nat_table_sz) && |
| (ipf_nat_stats.ns_active > 100)) { |
| ipf_nat_table_max = ipf_nat_stats.ns_active - 100; |
| printf("table_max reduced to %d\n", |
| ipf_nat_table_max); |
| } |
| return NULL; |
| } |
| |
| if (flags & IPN_ICMPQUERY) { |
| /* |
| * In the ICMP query NAT code, we translate the ICMP id fields |
| * to make them unique. This is indepedent of the ICMP type |
| * (e.g. in the unlikely event that a host sends an echo and |
| * an tstamp request with the same id, both packets will have |
| * their ip address/id field changed in the same way). |
| */ |
| /* The icmp_id field is used by the sender to identify the |
| * process making the icmp request. (the receiver justs |
| * copies it back in its response). So, it closely matches |
| * the concept of source port. We overlay sport, so we can |
| * maximally reuse the existing code. |
| */ |
| ni.nai_sport = fin->fin_data[1]; |
| ni.nai_dport = 0; |
| } |
| |
| bzero((char *)nat, sizeof(*nat)); |
| nat->nat_flags = flags; |
| nat->nat_redir = np->in_redir; |
| nat->nat_dir = direction; |
| nat->nat_pr[0] = fin->fin_p; |
| nat->nat_pr[1] = fin->fin_p; |
| |
| if ((flags & NAT_SLAVE) == 0) { |
| MUTEX_ENTER(&ipf_nat_new); |
| } |
| |
| /* |
| * Search the current table for a match and create a new mapping |
| * if there is none found. |
| */ |
| if (np->in_redir & (NAT_ENCAP|NAT_DIVERTUDP)) { |
| move = ipf_nat_newdivert(fin, nat, &ni); |
| |
| } else if (np->in_redir & NAT_REWRITE) { |
| move = ipf_nat_newrewrite(fin, nat, &ni); |
| |
| } else if (direction == NAT_OUTBOUND) { |
| /* |
| * We can now arrange to call this for the same connection |
| * because ipf_nat_new doesn't protect the code path into |
| * this function. |
| */ |
| natl = ipf_nat_outlookup(fin, nflags, (u_int)fin->fin_p, |
| fin->fin_src, fin->fin_dst); |
| if (natl != NULL) { |
| KFREE(nat); |
| nat = natl; |
| goto done; |
| } |
| |
| move = ipf_nat_newmap(fin, nat, &ni); |
| } else { |
| /* |
| * NAT_INBOUND is used for redirects rules |
| */ |
| natl = ipf_nat_inlookup(fin, nflags, (u_int)fin->fin_p, |
| fin->fin_src, fin->fin_dst); |
| if (natl != NULL) { |
| KFREE(nat); |
| nat = natl; |
| goto done; |
| } |
| |
| move = ipf_nat_newrdr(fin, nat, &ni); |
| } |
| if (move == -1) |
| goto badnat; |
| |
| np = ni.nai_np; |
| |
| if ((move == 1) && (np->in_flags & IPN_ROUNDR)) { |
| if ((np->in_redir & (NAT_REDIRECT|NAT_MAP)) == NAT_REDIRECT) { |
| ipf_nat_delrdr(np); |
| ipf_nat_addrdr(np); |
| } else if ((np->in_redir & (NAT_REDIRECT|NAT_MAP)) == NAT_MAP) { |
| ipf_nat_delnat(np); |
| ipf_nat_addnat(np); |
| } |
| } |
| |
| if (ipf_nat_finalise(fin, nat, &ni, natsave, direction) == -1) { |
| goto badnat; |
| } |
| |
| if (flags & SI_WILDP) |
| ipf_nat_stats.ns_wilds++; |
| goto done; |
| badnat: |
| ipf_nat_stats.ns_side[fin->fin_out].ns_badnatnew++; |
| if ((hm = nat->nat_hm) != NULL) |
| ipf_nat_hostmapdel(&hm); |
| KFREE(nat); |
| nat = NULL; |
| done: |
| if ((flags & NAT_SLAVE) == 0) { |
| MUTEX_EXIT(&ipf_nat_new); |
| } |
| return nat; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_finalise */ |
| /* Returns: int - 0 == sucess, -1 == failure */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to NAT entry */ |
| /* ni(I) - pointer to structure with misc. information needed */ |
| /* to create new NAT entry. */ |
| /* Write Lock: */ |
| /* */ |
| /* This is the tail end of constructing a new NAT entry and is the same */ |
| /* for both IPv4 and IPv6. */ |
| /* ------------------------------------------------------------------------ */ |
| /*ARGSUSED*/ |
| static int |
| ipf_nat_finalise(fin, nat, ni, natsave, direction) |
| fr_info_t *fin; |
| nat_t *nat; |
| natinfo_t *ni; |
| nat_t **natsave; |
| int direction; |
| { |
| u_32_t sum1, sum2, sumd; |
| frentry_t *fr; |
| ipnat_t *np; |
| u_32_t flags; |
| |
| np = ni->nai_np; |
| flags = ni->nai_flags; |
| |
| switch (fin->fin_p) |
| { |
| case IPPROTO_ICMP : |
| sum1 = LONG_SUM(ntohs(nat->nat_osport)); |
| sum2 = LONG_SUM(ntohs(nat->nat_nsport)); |
| CALC_SUMD(sum1, sum2, sumd); |
| nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16); |
| |
| break; |
| |
| default : |
| sum1 = LONG_SUM(ntohl(nat->nat_osrcaddr) + \ |
| ntohs(nat->nat_osport)); |
| sum2 = LONG_SUM(ntohl(nat->nat_nsrcaddr) + \ |
| ntohs(nat->nat_nsport)); |
| CALC_SUMD(sum1, sum2, sumd); |
| nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16); |
| |
| sum1 = LONG_SUM(ntohl(nat->nat_odstaddr) + \ |
| ntohs(nat->nat_odport)); |
| sum2 = LONG_SUM(ntohl(nat->nat_ndstaddr) + \ |
| ntohs(nat->nat_ndport)); |
| CALC_SUMD(sum1, sum2, sumd); |
| nat->nat_sumd[0] += (sumd & 0xffff) + (sumd >> 16); |
| break; |
| } |
| |
| #if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) && defined(ICK_M_CTL_MAGIC) |
| if ((flags & IPN_TCP) && dohwcksum && |
| (((ill_t *)qpi->qpi_ill)->ill_ick.ick_magic == ICK_M_CTL_MAGIC)) { |
| if (direction == NAT_OUTBOUND) |
| ni.nai_sum1 = LONG_SUM(in.s_addr); |
| else |
| ni.nai_sum1 = LONG_SUM(ntohl(fin->fin_saddr)); |
| ni.nai_sum1 += LONG_SUM(ntohl(fin->fin_daddr)); |
| ni.nai_sum1 += 30; |
| ni.nai_sum1 = (ni.nai_sum1 & 0xffff) + (ni.nai_sum1 >> 16); |
| nat->nat_sumd[1] = NAT_HW_CKSUM|(ni.nai_sum1 & 0xffff); |
| } else |
| #endif |
| nat->nat_sumd[1] = nat->nat_sumd[0]; |
| |
| sum1 = LONG_SUM(ntohl(nat->nat_osrcaddr)); |
| sum2 = LONG_SUM(ntohl(nat->nat_nsrcaddr)); |
| CALC_SUMD(sum1, sum2, sumd); |
| nat->nat_ipsumd = (sumd & 0xffff) + (sumd >> 16); |
| |
| sum1 = LONG_SUM(ntohl(nat->nat_odstaddr)); |
| sum2 = LONG_SUM(ntohl(nat->nat_ndstaddr)); |
| CALC_SUMD(sum1, sum2, sumd); |
| nat->nat_ipsumd += (sumd & 0xffff) + (sumd >> 16); |
| |
| if (np->in_ifps[0] != NULL) { |
| COPYIFNAME(np->in_ifps[0], nat->nat_ifnames[0]); |
| } |
| if (np->in_ifps[1] != NULL) { |
| COPYIFNAME(np->in_ifps[1], nat->nat_ifnames[1]); |
| } |
| #ifdef IPFILTER_SYNC |
| if ((nat->nat_flags & SI_CLONE) == 0) |
| nat->nat_sync = ipf_sync_new(SMC_NAT, fin, nat); |
| #endif |
| |
| nat->nat_me = natsave; |
| nat->nat_ifps[0] = np->in_ifps[0]; |
| |
| if ((nat->nat_ifps[0] != NULL) && (nat->nat_ifps[0] != (void *)-1)) { |
| nat->nat_mtu[0] = GETIFMTU(nat->nat_ifps[0]); |
| } |
| |
| nat->nat_ifps[1] = np->in_ifps[1]; |
| if ((nat->nat_ifps[1] != NULL) && (nat->nat_ifps[1] != (void *)-1)) { |
| nat->nat_mtu[1] = GETIFMTU(nat->nat_ifps[1]); |
| } |
| |
| nat->nat_ptr = np; |
| nat->nat_mssclamp = np->in_mssclamp; |
| nat->nat_v = fin->fin_v; |
| |
| if ((np->in_apr != NULL) && ((ni->nai_flags & NAT_SLAVE) == 0)) |
| if (appr_new(fin, nat) == -1) |
| return -1; |
| |
| if (ipf_nat_insert(nat, fin->fin_rev) == 0) { |
| if (ipf_nat_logging) |
| ipf_nat_log(nat, NL_NEW); |
| np->in_use++; |
| fr = fin->fin_fr; |
| nat->nat_fr = fr; |
| if (fr != NULL) { |
| MUTEX_ENTER(&fr->fr_lock); |
| fr->fr_ref++; |
| MUTEX_EXIT(&fr->fr_lock); |
| } |
| return 0; |
| } |
| |
| ATOMIC_INCL(ipf_nat_stats.ns_side[fin->fin_out].ns_unfinalised); |
| /* |
| * nat_insert failed, so cleanup time... |
| */ |
| return -1; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_insert */ |
| /* Returns: int - 0 == sucess, -1 == failure */ |
| /* Parameters: nat(I) - pointer to NAT structure */ |
| /* rev(I) - flag indicating forward/reverse direction of packet */ |
| /* Write Lock: ipf_nat */ |
| /* */ |
| /* Insert a NAT entry into the hash tables for searching and add it to the */ |
| /* list of active NAT entries. Adjust global counters when complete. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_nat_insert(nat, rev) |
| nat_t *nat; |
| int rev; |
| { |
| u_int hv1, hv2; |
| nat_t **natp; |
| |
| /* |
| * Try and return an error as early as possible, so calculate the hash |
| * entry numbers first and then proceed. |
| */ |
| if ((nat->nat_flags & (SI_W_SPORT|SI_W_DPORT)) == 0) { |
| hv1 = NAT_HASH_FN(nat->nat_osrcaddr, nat->nat_osport, |
| 0xffffffff); |
| hv1 = NAT_HASH_FN(nat->nat_odstaddr, hv1 + nat->nat_odport, |
| ipf_nat_table_sz); |
| |
| /* |
| * TRACE nat_osrcaddr, nat_osport, nat_odstaddr, |
| * nat_odport, hv1 |
| */ |
| |
| hv2 = NAT_HASH_FN(nat->nat_nsrcaddr, nat->nat_nsport, |
| 0xffffffff); |
| hv2 = NAT_HASH_FN(nat->nat_ndstaddr, hv2 + nat->nat_ndport, |
| ipf_nat_table_sz); |
| /* |
| * TRACE nat_nsrcaddr, nat_nsport, nat_ndstaddr, |
| * nat_ndport, hv1 |
| */ |
| } else { |
| hv1 = NAT_HASH_FN(nat->nat_osrcaddr, 0, 0xffffffff); |
| hv1 = NAT_HASH_FN(nat->nat_odstaddr, hv1, ipf_nat_table_sz); |
| /* TRACE nat_osrcaddr, nat_odstaddr, hv1 */ |
| |
| hv2 = NAT_HASH_FN(nat->nat_nsrcaddr, 0, 0xffffffff); |
| hv2 = NAT_HASH_FN(nat->nat_ndstaddr, hv2, ipf_nat_table_sz); |
| /* TRACE nat_nsrcaddr, nat_ndstaddr, hv2 */ |
| } |
| |
| if (ipf_nat_stats.ns_side[0].ns_bucketlen[hv1] >= ipf_nat_maxbucket) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_bucket_max); |
| return -1; |
| } |
| |
| if (ipf_nat_stats.ns_side[1].ns_bucketlen[hv2] >= ipf_nat_maxbucket) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_bucket_max); |
| return -1; |
| } |
| |
| if (nat->nat_dir == NAT_INBOUND || nat->nat_dir == NAT_ENCAPIN || |
| nat->nat_dir == NAT_DIVERTIN) { |
| u_int swap; |
| |
| swap = hv2; |
| hv2 = hv1; |
| hv1 = swap; |
| } |
| nat->nat_hv[0] = hv1; |
| nat->nat_hv[1] = hv2; |
| |
| MUTEX_INIT(&nat->nat_lock, "nat entry lock"); |
| |
| nat->nat_rev = rev; |
| nat->nat_ref = 1; |
| nat->nat_bytes[0] = 0; |
| nat->nat_pkts[0] = 0; |
| nat->nat_bytes[1] = 0; |
| nat->nat_pkts[1] = 0; |
| |
| nat->nat_ifnames[0][LIFNAMSIZ - 1] = '\0'; |
| nat->nat_ifps[0] = ipf_resolvenic(nat->nat_ifnames[0], nat->nat_v); |
| |
| if (nat->nat_ifnames[1][0] != '\0') { |
| nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0'; |
| nat->nat_ifps[1] = ipf_resolvenic(nat->nat_ifnames[1], |
| nat->nat_v); |
| } else { |
| ipnat_t *in = nat->nat_ptr; |
| |
| if (in->in_ifnames[1][1] != '\0' && |
| in->in_ifnames[1][0] != '-' && |
| in->in_ifnames[1][0] != '*') { |
| (void) strncpy(nat->nat_ifnames[1], |
| nat->nat_ifnames[0], LIFNAMSIZ); |
| nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0'; |
| nat->nat_ifps[1] = nat->nat_ifps[0]; |
| } |
| } |
| if ((nat->nat_ifps[0] != NULL) && (nat->nat_ifps[0] != (void *)-1)) { |
| nat->nat_mtu[0] = GETIFMTU(nat->nat_ifps[0]); |
| } |
| if ((nat->nat_ifps[1] != NULL) && (nat->nat_ifps[1] != (void *)-1)) { |
| nat->nat_mtu[1] = GETIFMTU(nat->nat_ifps[1]); |
| } |
| |
| nat->nat_next = ipf_nat_instances; |
| nat->nat_pnext = &ipf_nat_instances; |
| if (ipf_nat_instances) |
| ipf_nat_instances->nat_pnext = &nat->nat_next; |
| ipf_nat_instances = nat; |
| |
| natp = &ipf_nat_table[0][hv1]; |
| if (*natp) |
| (*natp)->nat_phnext[0] = &nat->nat_hnext[0]; |
| else |
| ipf_nat_stats.ns_side[0].ns_inuse++; |
| nat->nat_phnext[0] = natp; |
| nat->nat_hnext[0] = *natp; |
| *natp = nat; |
| ipf_nat_stats.ns_side[0].ns_bucketlen[hv1]++; |
| |
| natp = &ipf_nat_table[1][hv2]; |
| if (*natp) |
| (*natp)->nat_phnext[1] = &nat->nat_hnext[1]; |
| else |
| ipf_nat_stats.ns_side[1].ns_inuse++; |
| nat->nat_phnext[1] = natp; |
| nat->nat_hnext[1] = *natp; |
| *natp = nat; |
| ipf_nat_stats.ns_side[1].ns_bucketlen[hv2]++; |
| |
| ipf_nat_setqueue(nat, rev); |
| |
| ipf_nat_stats.ns_added++; |
| ipf_nat_stats.ns_active++; |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_icmperrorlookup */ |
| /* Returns: nat_t* - point to matching NAT structure */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* dir(I) - direction of packet (in/out) */ |
| /* */ |
| /* Check if the ICMP error message is related to an existing TCP, UDP or */ |
| /* ICMP query nat entry. It is assumed that the packet is already of the */ |
| /* the required length. */ |
| /* ------------------------------------------------------------------------ */ |
| nat_t * |
| ipf_nat_icmperrorlookup(fin, dir) |
| fr_info_t *fin; |
| int dir; |
| { |
| int flags = 0, type, minlen; |
| icmphdr_t *icmp, *orgicmp; |
| nat_stat_side_t *nside; |
| tcphdr_t *tcp = NULL; |
| u_short data[2]; |
| nat_t *nat; |
| ip_t *oip; |
| u_int p; |
| |
| icmp = fin->fin_dp; |
| type = icmp->icmp_type; |
| nside = &ipf_nat_stats.ns_side[fin->fin_out]; |
| /* |
| * Does it at least have the return (basic) IP header ? |
| * Only a basic IP header (no options) should be with an ICMP error |
| * header. Also, if it's not an error type, then return. |
| */ |
| if ((fin->fin_hlen != sizeof(ip_t)) || !(fin->fin_flx & FI_ICMPERR)) { |
| ATOMIC_INCL(nside->ns_icmp_basic); |
| return NULL; |
| } |
| |
| /* |
| * Check packet size |
| */ |
| oip = (ip_t *)((char *)fin->fin_dp + 8); |
| minlen = IP_HL(oip) << 2; |
| if ((minlen < sizeof(ip_t)) || |
| (fin->fin_plen < ICMPERR_IPICMPHLEN + minlen)) { |
| ATOMIC_INCL(nside->ns_icmp_size); |
| return NULL; |
| } |
| |
| /* |
| * Is the buffer big enough for all of it ? It's the size of the IP |
| * header claimed in the encapsulated part which is of concern. It |
| * may be too big to be in this buffer but not so big that it's |
| * outside the ICMP packet, leading to TCP deref's causing problems. |
| * This is possible because we don't know how big oip_hl is when we |
| * do the pullup early in ipf_check() and thus can't gaurantee it is |
| * all here now. |
| */ |
| #ifdef ipf_nat_KERNEL |
| { |
| mb_t *m; |
| |
| m = fin->fin_m; |
| # if defined(MENTAT) |
| if ((char *)oip + fin->fin_dlen - ICMPERR_ICMPHLEN > |
| (char *)m->b_wptr) { |
| ATOMIC_INCL(nside->ns_icmp_mbuf); |
| return NULL; |
| } |
| # else |
| if ((char *)oip + fin->fin_dlen - ICMPERR_ICMPHLEN > |
| (char *)fin->fin_ip + M_LEN(m)) { |
| ATOMIC_INCL(nside->ns_icmp_mbuf); |
| return NULL; |
| } |
| # endif |
| } |
| #endif |
| |
| if (fin->fin_daddr != oip->ip_src.s_addr) { |
| ATOMIC_INCL(nside->ns_icmp_address); |
| return NULL; |
| } |
| |
| p = oip->ip_p; |
| if (p == IPPROTO_TCP) |
| flags = IPN_TCP; |
| else if (p == IPPROTO_UDP) |
| flags = IPN_UDP; |
| else if (p == IPPROTO_ICMP) { |
| orgicmp = (icmphdr_t *)((char *)oip + (IP_HL(oip) << 2)); |
| |
| /* see if this is related to an ICMP query */ |
| if (ipf_nat_icmpquerytype4(orgicmp->icmp_type)) { |
| data[0] = fin->fin_data[0]; |
| data[1] = fin->fin_data[1]; |
| fin->fin_data[0] = 0; |
| fin->fin_data[1] = orgicmp->icmp_id; |
| |
| flags = IPN_ICMPERR|IPN_ICMPQUERY; |
| /* |
| * NOTE : dir refers to the direction of the original |
| * ip packet. By definition the icmp error |
| * message flows in the opposite direction. |
| */ |
| if (dir == NAT_INBOUND) |
| nat = ipf_nat_inlookup(fin, flags, p, |
| oip->ip_dst, |
| oip->ip_src); |
| else |
| nat = ipf_nat_outlookup(fin, flags, p, |
| oip->ip_dst, |
| oip->ip_src); |
| fin->fin_data[0] = data[0]; |
| fin->fin_data[1] = data[1]; |
| return nat; |
| } |
| } |
| |
| if (flags & IPN_TCPUDP) { |
| minlen += 8; /* + 64bits of data to get ports */ |
| /* TRACE (fin,minlen) */ |
| if (fin->fin_plen < ICMPERR_IPICMPHLEN + minlen) { |
| ATOMIC_INCL(nside->ns_icmp_short); |
| return NULL; |
| } |
| |
| data[0] = fin->fin_data[0]; |
| data[1] = fin->fin_data[1]; |
| tcp = (tcphdr_t *)((char *)oip + (IP_HL(oip) << 2)); |
| fin->fin_data[0] = ntohs(tcp->th_dport); |
| fin->fin_data[1] = ntohs(tcp->th_sport); |
| |
| if (dir == NAT_INBOUND) { |
| nat = ipf_nat_inlookup(fin, flags, p, oip->ip_dst, |
| oip->ip_src); |
| } else { |
| nat = ipf_nat_outlookup(fin, flags, p, oip->ip_dst, |
| oip->ip_src); |
| } |
| fin->fin_data[0] = data[0]; |
| fin->fin_data[1] = data[1]; |
| return nat; |
| } |
| if (dir == NAT_INBOUND) |
| nat = ipf_nat_inlookup(fin, 0, p, oip->ip_dst, oip->ip_src); |
| else |
| nat = ipf_nat_outlookup(fin, 0, p, oip->ip_dst, oip->ip_src); |
| |
| return nat; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_icmperror */ |
| /* Returns: nat_t* - point to matching NAT structure */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nflags(I) - NAT flags for this packet */ |
| /* dir(I) - direction of packet (in/out) */ |
| /* */ |
| /* Fix up an ICMP packet which is an error message for an existing NAT */ |
| /* session. This will correct both packet header data and checksums. */ |
| /* */ |
| /* This should *ONLY* be used for incoming ICMP error packets to make sure */ |
| /* a NAT'd ICMP packet gets correctly recognised. */ |
| /* ------------------------------------------------------------------------ */ |
| nat_t * |
| ipf_nat_icmperror(fin, nflags, dir) |
| fr_info_t *fin; |
| u_int *nflags; |
| int dir; |
| { |
| u_32_t sum1, sum2, sumd, sumd2; |
| struct in_addr a1, a2, a3, a4; |
| int flags, dlen, odst; |
| icmphdr_t *icmp; |
| u_short *csump; |
| tcphdr_t *tcp; |
| nat_t *nat; |
| ip_t *oip; |
| void *dp; |
| |
| if ((fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[fin->fin_out].ns_icmp_short); |
| return NULL; |
| } |
| |
| /* |
| * ipf_nat_icmperrorlookup() will return NULL for `defective' packets. |
| */ |
| if ((fin->fin_v != 4) || !(nat = ipf_nat_icmperrorlookup(fin, dir))) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[fin->fin_out]. |
| ns_icmp_notfound); |
| return NULL; |
| } |
| |
| if (nat->nat_dir == NAT_ENCAPIN || nat->nat_dir == NAT_ENCAPOUT) { |
| /* |
| * For ICMP replies to encapsulated packets, we need to |
| * rebuild the ICMP reply completely to match the original |
| * packet... |
| */ |
| if (ipf_nat_rebuildencapicmp(fin, nat) == 0) |
| return nat; |
| ATOMIC_INCL(ipf_nat_stats.ns_side[fin->fin_out]. |
| ns_icmp_rebuild); |
| return NULL; |
| } |
| |
| tcp = NULL; |
| csump = NULL; |
| flags = 0; |
| sumd2 = 0; |
| *nflags = IPN_ICMPERR; |
| icmp = fin->fin_dp; |
| oip = (ip_t *)&icmp->icmp_ip; |
| dp = (((char *)oip) + (IP_HL(oip) << 2)); |
| if (oip->ip_p == IPPROTO_TCP) { |
| tcp = (tcphdr_t *)dp; |
| csump = (u_short *)&tcp->th_sum; |
| flags = IPN_TCP; |
| } else if (oip->ip_p == IPPROTO_UDP) { |
| udphdr_t *udp; |
| |
| udp = (udphdr_t *)dp; |
| tcp = (tcphdr_t *)dp; |
| csump = (u_short *)&udp->uh_sum; |
| flags = IPN_UDP; |
| } else if (oip->ip_p == IPPROTO_ICMP) |
| flags = IPN_ICMPQUERY; |
| dlen = fin->fin_plen - ((char *)dp - (char *)fin->fin_ip); |
| |
| /* |
| * Need to adjust ICMP header to include the real IP#'s and |
| * port #'s. Only apply a checksum change relative to the |
| * IP address change as it will be modified again in ipf_nat_checkout |
| * for both address and port. Two checksum changes are |
| * necessary for the two header address changes. Be careful |
| * to only modify the checksum once for the port # and twice |
| * for the IP#. |
| */ |
| |
| /* |
| * Step 1 |
| * Fix the IP addresses in the offending IP packet. You also need |
| * to adjust the IP header checksum of that offending IP packet. |
| * |
| * Normally, you would expect that the ICMP checksum of the |
| * ICMP error message needs to be adjusted as well for the |
| * IP address change in oip. |
| * However, this is a NOP, because the ICMP checksum is |
| * calculated over the complete ICMP packet, which includes the |
| * changed oip IP addresses and oip->ip_sum. However, these |
| * two changes cancel each other out (if the delta for |
| * the IP address is x, then the delta for ip_sum is minus x), |
| * so no change in the icmp_cksum is necessary. |
| * |
| * Inbound ICMP |
| * ------------ |
| * MAP rule, SRC=a,DST=b -> SRC=c,DST=b |
| * - response to outgoing packet (a,b)=>(c,b) (OIP_SRC=c,OIP_DST=b) |
| * - OIP_SRC(c)=nat_newsrcip, OIP_DST(b)=nat_newdstip |
| *=> OIP_SRC(c)=nat_oldsrcip, OIP_DST(b)=nat_olddstip |
| * |
| * RDR rule, SRC=a,DST=b -> SRC=a,DST=c |
| * - response to outgoing packet (c,a)=>(b,a) (OIP_SRC=b,OIP_DST=a) |
| * - OIP_SRC(b)=nat_olddstip, OIP_DST(a)=nat_oldsrcip |
| *=> OIP_SRC(b)=nat_newdstip, OIP_DST(a)=nat_newsrcip |
| * |
| * REWRITE out rule, SRC=a,DST=b -> SRC=c,DST=d |
| * - response to outgoing packet (a,b)=>(c,d) (OIP_SRC=c,OIP_DST=d) |
| * - OIP_SRC(c)=nat_newsrcip, OIP_DST(d)=nat_newdstip |
| *=> OIP_SRC(c)=nat_oldsrcip, OIP_DST(d)=nat_olddstip |
| * |
| * REWRITE in rule, SRC=a,DST=b -> SRC=c,DST=d |
| * - response to outgoing packet (d,c)=>(b,a) (OIP_SRC=b,OIP_DST=a) |
| * - OIP_SRC(b)=nat_olddstip, OIP_DST(a)=nat_oldsrcip |
| *=> OIP_SRC(b)=nat_newdstip, OIP_DST(a)=nat_newsrcip |
| * |
| * Outbound ICMP |
| * ------------- |
| * MAP rule, SRC=a,DST=b -> SRC=c,DST=b |
| * - response to incoming packet (b,c)=>(b,a) (OIP_SRC=b,OIP_DST=a) |
| * - OIP_SRC(b)=nat_olddstip, OIP_DST(a)=nat_oldsrcip |
| *=> OIP_SRC(b)=nat_newdstip, OIP_DST(a)=nat_newsrcip |
| * |
| * RDR rule, SRC=a,DST=b -> SRC=a,DST=c |
| * - response to incoming packet (a,b)=>(a,c) (OIP_SRC=a,OIP_DST=c) |
| * - OIP_SRC(a)=nat_newsrcip, OIP_DST(c)=nat_newdstip |
| *=> OIP_SRC(a)=nat_oldsrcip, OIP_DST(c)=nat_olddstip |
| * |
| * REWRITE out rule, SRC=a,DST=b -> SRC=c,DST=d |
| * - response to incoming packet (d,c)=>(b,a) (OIP_SRC=c,OIP_DST=d) |
| * - OIP_SRC(c)=nat_olddstip, OIP_DST(d)=nat_oldsrcip |
| *=> OIP_SRC(b)=nat_newdstip, OIP_DST(a)=nat_newsrcip |
| * |
| * REWRITE in rule, SRC=a,DST=b -> SRC=c,DST=d |
| * - response to incoming packet (a,b)=>(c,d) (OIP_SRC=b,OIP_DST=a) |
| * - OIP_SRC(b)=nat_newsrcip, OIP_DST(a)=nat_newdstip |
| *=> OIP_SRC(a)=nat_oldsrcip, OIP_DST(c)=nat_olddstip |
| */ |
| |
| if (((fin->fin_out == 0) && ((nat->nat_redir & NAT_MAP) != 0)) || |
| ((fin->fin_out == 1) && ((nat->nat_redir & NAT_REDIRECT) != 0))) { |
| a1.s_addr = ntohl(nat->nat_osrcaddr); |
| a4.s_addr = ntohl(oip->ip_src.s_addr); |
| a3.s_addr = ntohl(nat->nat_odstaddr); |
| a2.s_addr = ntohl(oip->ip_dst.s_addr); |
| oip->ip_src.s_addr = htonl(a1.s_addr); |
| oip->ip_dst.s_addr = htonl(a3.s_addr); |
| odst = 1; |
| } else { |
| a1.s_addr = ntohl(nat->nat_ndstaddr); |
| a2.s_addr = ntohl(oip->ip_dst.s_addr); |
| a3.s_addr = ntohl(nat->nat_nsrcaddr); |
| a4.s_addr = ntohl(oip->ip_src.s_addr); |
| oip->ip_dst.s_addr = htonl(a3.s_addr); |
| oip->ip_src.s_addr = htonl(a1.s_addr); |
| odst = 0; |
| } |
| sumd = 0; |
| if ((a3.s_addr != a2.s_addr) || (a1.s_addr != a4.s_addr)) { |
| if (a3.s_addr > a2.s_addr) |
| sumd = a2.s_addr - a3.s_addr - 1; |
| else |
| sumd = a2.s_addr - a3.s_addr; |
| if (a1.s_addr > a4.s_addr) |
| sumd += a4.s_addr - a1.s_addr - 1; |
| else |
| sumd += a4.s_addr - a1.s_addr; |
| sumd = ~sumd; |
| |
| ipf_fix_datacksum(&oip->ip_sum, sumd); |
| } |
| |
| sumd2 = sumd; |
| sum1 = 0; |
| sum2 = 0; |
| |
| /* |
| * Fix UDP pseudo header checksum to compensate for the |
| * IP address change. |
| */ |
| if (((flags & IPN_TCPUDP) != 0) && (dlen >= 4)) { |
| u_32_t sum3, sum4; |
| /* |
| * Step 2 : |
| * For offending TCP/UDP IP packets, translate the ports as |
| * well, based on the NAT specification. Of course such |
| * a change may be reflected in the ICMP checksum as well. |
| * |
| * Since the port fields are part of the TCP/UDP checksum |
| * of the offending IP packet, you need to adjust that checksum |
| * as well... except that the change in the port numbers should |
| * be offset by the checksum change. However, the TCP/UDP |
| * checksum will also need to change if there has been an |
| * IP address change. |
| */ |
| if (odst == 1) { |
| sum1 = ntohs(nat->nat_osport); |
| sum4 = ntohs(tcp->th_sport); |
| sum3 = ntohs(nat->nat_odport); |
| sum2 = ntohs(tcp->th_dport); |
| |
| tcp->th_sport = htons(sum1); |
| tcp->th_dport = htons(sum3); |
| } else { |
| sum1 = ntohs(nat->nat_ndport); |
| sum2 = ntohs(tcp->th_dport); |
| sum3 = ntohs(nat->nat_nsport); |
| sum4 = ntohs(tcp->th_sport); |
| |
| tcp->th_dport = htons(sum3); |
| tcp->th_sport = htons(sum1); |
| } |
| sumd += sum1 - sum4; |
| sumd += sum3 - sum2; |
| |
| if (sumd != 0 || sumd2 != 0) { |
| /* |
| * At this point, sumd is the delta to apply to the |
| * TCP/UDP header, given the changes in both the IP |
| * address and the ports and sumd2 is the delta to |
| * apply to the ICMP header, given the IP address |
| * change delta that may need to be applied to the |
| * TCP/UDP checksum instead. |
| * |
| * If we will both the IP and TCP/UDP checksums |
| * then the ICMP checksum changes by the address |
| * delta applied to the TCP/UDP checksum. If we |
| * do not change the TCP/UDP checksum them we |
| * apply the delta in ports to the ICMP checksum. |
| */ |
| if (oip->ip_p == IPPROTO_UDP) { |
| if ((dlen >= 8) && (*csump != 0)) { |
| ipf_fix_datacksum(csump, sumd); |
| } else { |
| sumd2 = sum4 - sum1; |
| if (sum1 > sum4) |
| sumd2--; |
| sumd2 += sum2 - sum3; |
| if (sum3 > sum2) |
| sumd2--; |
| } |
| } else if (oip->ip_p == IPPROTO_TCP) { |
| if (dlen >= 18) { |
| ipf_fix_datacksum(csump, sumd); |
| } else { |
| sumd2 = sum4 - sum1; |
| if (sum1 > sum4) |
| sumd2--; |
| sumd2 += sum2 - sum3; |
| if (sum3 > sum2) |
| sumd2--; |
| } |
| } |
| if (sumd2 != 0) { |
| sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16); |
| sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16); |
| sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16); |
| ipf_fix_incksum(fin, &icmp->icmp_cksum, sumd2); |
| } |
| } |
| } else if (((flags & IPN_ICMPQUERY) != 0) && (dlen >= 8)) { |
| icmphdr_t *orgicmp; |
| |
| /* |
| * XXX - what if this is bogus hl and we go off the end ? |
| * In this case, ipf_nat_icmperrorlookup() will have |
| * returned NULL. |
| */ |
| orgicmp = (icmphdr_t *)dp; |
| |
| if (odst == 1) { |
| if (orgicmp->icmp_id != nat->nat_osport) { |
| |
| /* |
| * Fix ICMP checksum (of the offening ICMP |
| * query packet) to compensate the change |
| * in the ICMP id of the offending ICMP |
| * packet. |
| * |
| * Since you modify orgicmp->icmp_id with |
| * a delta (say x) and you compensate that |
| * in origicmp->icmp_cksum with a delta |
| * minus x, you don't have to adjust the |
| * overall icmp->icmp_cksum |
| */ |
| sum1 = ntohs(orgicmp->icmp_id); |
| sum2 = ntohs(nat->nat_osport); |
| CALC_SUMD(sum1, sum2, sumd); |
| orgicmp->icmp_id = nat->nat_oicmpid; |
| ipf_fix_datacksum(&orgicmp->icmp_cksum, sumd); |
| } |
| } /* nat_dir == NAT_INBOUND is impossible for icmp queries */ |
| } |
| return nat; |
| } |
| |
| |
| /* |
| * MAP-IN MAP-OUT RDR-IN RDR-OUT |
| * osrc X == src == src X |
| * odst X == dst == dst X |
| * nsrc == dst X X == dst |
| * ndst == src X X == src |
| * MAP = NAT_OUTBOUND, RDR = NAT_INBOUND |
| */ |
| /* |
| * NB: these lookups don't lock access to the list, it assumed that it has |
| * already been done! |
| */ |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_inlookup */ |
| /* Returns: nat_t* - NULL == no match, */ |
| /* else pointer to matching NAT entry */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* flags(I) - NAT flags for this packet */ |
| /* p(I) - protocol for this packet */ |
| /* src(I) - source IP address */ |
| /* mapdst(I) - destination IP address */ |
| /* */ |
| /* Lookup a nat entry based on the mapped destination ip address/port and */ |
| /* real source address/port. We use this lookup when receiving a packet, */ |
| /* we're looking for a table entry, based on the destination address. */ |
| /* */ |
| /* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */ |
| /* */ |
| /* NOTE: IT IS ASSUMED THAT IS ONLY HELD WITH A READ LOCK WHEN */ |
| /* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */ |
| /* */ |
| /* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */ |
| /* the packet is of said protocol */ |
| /* ------------------------------------------------------------------------ */ |
| nat_t * |
| ipf_nat_inlookup(fin, flags, p, src, mapdst) |
| fr_info_t *fin; |
| u_int flags, p; |
| struct in_addr src , mapdst; |
| { |
| u_short sport, dport; |
| grehdr_t *gre; |
| ipnat_t *ipn; |
| u_int sflags; |
| nat_t *nat; |
| int nflags; |
| u_32_t dst; |
| void *ifp; |
| u_int hv; |
| |
| ifp = fin->fin_ifp; |
| sport = 0; |
| dport = 0; |
| gre = NULL; |
| dst = mapdst.s_addr; |
| sflags = flags & NAT_TCPUDPICMP; |
| |
| switch (p) |
| { |
| case IPPROTO_TCP : |
| case IPPROTO_UDP : |
| sport = htons(fin->fin_data[0]); |
| dport = htons(fin->fin_data[1]); |
| break; |
| case IPPROTO_ICMP : |
| if (flags & IPN_ICMPERR) |
| sport = fin->fin_data[1]; |
| else |
| dport = fin->fin_data[1]; |
| break; |
| default : |
| break; |
| } |
| |
| |
| if ((flags & SI_WILDP) != 0) |
| goto find_in_wild_ports; |
| |
| hv = NAT_HASH_FN(dst, dport, 0xffffffff); |
| hv = NAT_HASH_FN(src.s_addr, hv + sport, ipf_nat_table_sz); |
| nat = ipf_nat_table[1][hv]; |
| /* TRACE dst, dport, src, sport, hv, nat */ |
| |
| for (; nat; nat = nat->nat_hnext[1]) { |
| if (nat->nat_ifps[0] != NULL) { |
| if ((ifp != NULL) && (ifp != nat->nat_ifps[0])) |
| continue; |
| } |
| |
| if ((p != 0) && (nat->nat_pr[0] != p)) |
| continue; |
| |
| switch (nat->nat_dir) |
| { |
| case NAT_INBOUND : |
| if (nat->nat_osrcaddr != src.s_addr || |
| nat->nat_odstaddr != dst) |
| continue; |
| if ((nat->nat_flags & IPN_TCPUDP) != 0) { |
| if (nat->nat_osport != sport) |
| continue; |
| if (nat->nat_odport != dport) |
| continue; |
| |
| } else if (p == IPPROTO_ICMP) { |
| if (nat->nat_osport != dport) { |
| continue; |
| } |
| } |
| break; |
| case NAT_OUTBOUND : |
| if (nat->nat_ndstaddr != src.s_addr || |
| nat->nat_nsrcaddr != dst) |
| continue; |
| if ((nat->nat_flags & IPN_TCPUDP) != 0) { |
| if (nat->nat_ndport != sport) |
| continue; |
| if (nat->nat_nsport != dport) |
| continue; |
| |
| } else if (p == IPPROTO_ICMP) { |
| if (nat->nat_osport != dport) { |
| continue; |
| } |
| } |
| break; |
| } |
| |
| |
| if ((nat->nat_flags & IPN_TCPUDP) != 0) { |
| ipn = nat->nat_ptr; |
| if ((ipn != NULL) && (nat->nat_aps != NULL)) |
| if (appr_match(fin, nat) != 0) |
| continue; |
| } |
| if (ifp != NULL) { |
| nat->nat_ifps[0] = ifp; |
| nat->nat_mtu[0] = GETIFMTU(ifp); |
| } |
| return nat; |
| } |
| |
| /* |
| * So if we didn't find it but there are wildcard members in the hash |
| * table, go back and look for them. We do this search and update here |
| * because it is modifying the NAT table and we want to do this only |
| * for the first packet that matches. The exception, of course, is |
| * for "dummy" (FI_IGNORE) lookups. |
| */ |
| find_in_wild_ports: |
| if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_lookup_miss); |
| return NULL; |
| } |
| if (ipf_nat_stats.ns_wilds == 0) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_lookup_nowild); |
| return NULL; |
| } |
| |
| RWLOCK_EXIT(&ipf_nat); |
| |
| hv = NAT_HASH_FN(dst, 0, 0xffffffff); |
| hv = NAT_HASH_FN(src.s_addr, hv, ipf_nat_table_sz); |
| WRITE_ENTER(&ipf_nat); |
| |
| nat = ipf_nat_table[1][hv]; |
| /* TRACE dst, src, hv, nat */ |
| for (; nat; nat = nat->nat_hnext[1]) { |
| if (nat->nat_ifps[0] != NULL) { |
| if ((ifp != NULL) && (ifp != nat->nat_ifps[0])) |
| continue; |
| } |
| |
| if (nat->nat_pr[0] != fin->fin_p) |
| continue; |
| |
| switch (nat->nat_dir) |
| { |
| case NAT_INBOUND : |
| if (nat->nat_osrcaddr != src.s_addr || |
| nat->nat_odstaddr != dst) |
| continue; |
| break; |
| case NAT_OUTBOUND : |
| if (nat->nat_ndstaddr != src.s_addr || |
| nat->nat_nsrcaddr != dst) |
| continue; |
| break; |
| } |
| |
| nflags = nat->nat_flags; |
| if (!(nflags & (NAT_TCPUDP|SI_WILDP))) |
| continue; |
| |
| if (ipf_nat_wildok(nat, (int)sport, (int)dport, nflags, |
| NAT_INBOUND) == 1) { |
| if ((fin->fin_flx & FI_IGNORE) != 0) |
| break; |
| if ((nflags & SI_CLONE) != 0) { |
| nat = ipf_nat_clone(fin, nat); |
| if (nat == NULL) |
| break; |
| } else { |
| MUTEX_ENTER(&ipf_nat_new); |
| ipf_nat_stats.ns_wilds--; |
| MUTEX_EXIT(&ipf_nat_new); |
| } |
| |
| if (nat->nat_dir == NAT_INBOUND) { |
| if (nat->nat_osport == 0) { |
| nat->nat_osport = sport; |
| nat->nat_nsport = sport; |
| } |
| if (nat->nat_odport == 0) { |
| nat->nat_odport = dport; |
| nat->nat_ndport = dport; |
| } |
| } else { |
| if (nat->nat_osport == 0) { |
| nat->nat_osport = dport; |
| nat->nat_nsport = dport; |
| } |
| if (nat->nat_odport == 0) { |
| nat->nat_odport = sport; |
| nat->nat_ndport = sport; |
| } |
| } |
| if (ifp != NULL) { |
| nat->nat_ifps[0] = ifp; |
| nat->nat_mtu[0] = GETIFMTU(ifp); |
| } |
| nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT); |
| ipf_nat_tabmove(nat); |
| break; |
| } |
| } |
| |
| MUTEX_DOWNGRADE(&ipf_nat); |
| |
| if (nat == NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_lookup_miss); |
| } |
| return nat; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_tabmove */ |
| /* Returns: Nil */ |
| /* Parameters: nat(I) - pointer to NAT structure */ |
| /* Write Lock: */ |
| /* */ |
| /* This function is only called for TCP/UDP NAT table entries where the */ |
| /* original was placed in the table without hashing on the ports and we now */ |
| /* want to include hashing on port numbers. */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_tabmove(nat) |
| nat_t *nat; |
| { |
| nat_t **natp; |
| u_int hv0, hv1; |
| |
| if (nat->nat_flags & SI_CLONE) |
| return; |
| |
| /* |
| * Remove the NAT entry from the old location |
| */ |
| if (nat->nat_hnext[0]) |
| nat->nat_hnext[0]->nat_phnext[0] = nat->nat_phnext[0]; |
| *nat->nat_phnext[0] = nat->nat_hnext[0]; |
| ipf_nat_stats.ns_side[0].ns_bucketlen[nat->nat_hv[0]]--; |
| |
| if (nat->nat_hnext[1]) |
| nat->nat_hnext[1]->nat_phnext[1] = nat->nat_phnext[1]; |
| *nat->nat_phnext[1] = nat->nat_hnext[1]; |
| ipf_nat_stats.ns_side[1].ns_bucketlen[nat->nat_hv[1]]--; |
| |
| /* |
| * Add into the NAT table in the new position |
| */ |
| hv0 = NAT_HASH_FN(nat->nat_osrcaddr, nat->nat_osport, 0xffffffff); |
| hv0 = NAT_HASH_FN(nat->nat_odstaddr, hv0 + nat->nat_odport, |
| ipf_nat_table_sz); |
| hv1 = NAT_HASH_FN(nat->nat_nsrcaddr, nat->nat_nsport, 0xffffffff); |
| hv1 = NAT_HASH_FN(nat->nat_ndstaddr, hv1 + nat->nat_ndport, |
| ipf_nat_table_sz); |
| |
| if (nat->nat_dir == NAT_INBOUND || nat->nat_dir == NAT_ENCAPIN || |
| nat->nat_dir == NAT_DIVERTIN) { |
| u_int swap; |
| |
| swap = hv0; |
| hv0 = hv1; |
| hv1 = swap; |
| } |
| |
| /* TRACE nat_osrcaddr, nat_osport, nat_odstaddr, nat_odport, hv0 */ |
| /* TRACE nat_nsrcaddr, nat_nsport, nat_ndstaddr, nat_ndport, hv1 */ |
| |
| nat->nat_hv[0] = hv0; |
| natp = &ipf_nat_table[0][hv0]; |
| if (*natp) |
| (*natp)->nat_phnext[0] = &nat->nat_hnext[0]; |
| nat->nat_phnext[0] = natp; |
| nat->nat_hnext[0] = *natp; |
| *natp = nat; |
| ipf_nat_stats.ns_side[0].ns_bucketlen[hv0]++; |
| |
| nat->nat_hv[1] = hv1; |
| natp = &ipf_nat_table[1][hv1]; |
| if (*natp) |
| (*natp)->nat_phnext[1] = &nat->nat_hnext[1]; |
| nat->nat_phnext[1] = natp; |
| nat->nat_hnext[1] = *natp; |
| *natp = nat; |
| ipf_nat_stats.ns_side[1].ns_bucketlen[hv1]++; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_outlookup */ |
| /* Returns: nat_t* - NULL == no match, */ |
| /* else pointer to matching NAT entry */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* flags(I) - NAT flags for this packet */ |
| /* p(I) - protocol for this packet */ |
| /* src(I) - source IP address */ |
| /* dst(I) - destination IP address */ |
| /* rw(I) - 1 == write lock on held, 0 == read lock. */ |
| /* */ |
| /* Lookup a nat entry based on the source 'real' ip address/port and */ |
| /* destination address/port. We use this lookup when sending a packet out, */ |
| /* we're looking for a table entry, based on the source address. */ |
| /* */ |
| /* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */ |
| /* */ |
| /* NOTE: IT IS ASSUMED THAT IS ONLY HELD WITH A READ LOCK WHEN */ |
| /* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */ |
| /* */ |
| /* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */ |
| /* the packet is of said protocol */ |
| /* ------------------------------------------------------------------------ */ |
| nat_t * |
| ipf_nat_outlookup(fin, flags, p, src, dst) |
| fr_info_t *fin; |
| u_int flags, p; |
| struct in_addr src , dst; |
| { |
| u_short sport, dport; |
| u_int sflags; |
| ipnat_t *ipn; |
| nat_t *nat; |
| void *ifp; |
| u_int hv; |
| |
| ifp = fin->fin_ifp; |
| sflags = flags & IPN_TCPUDPICMP; |
| sport = 0; |
| dport = 0; |
| |
| switch (p) |
| { |
| case IPPROTO_TCP : |
| case IPPROTO_UDP : |
| sport = htons(fin->fin_data[0]); |
| dport = htons(fin->fin_data[1]); |
| break; |
| case IPPROTO_ICMP : |
| if (flags & IPN_ICMPERR) |
| sport = fin->fin_data[1]; |
| else |
| dport = fin->fin_data[1]; |
| break; |
| default : |
| break; |
| } |
| |
| if ((flags & SI_WILDP) != 0) |
| goto find_out_wild_ports; |
| |
| hv = NAT_HASH_FN(src.s_addr, sport, 0xffffffff); |
| hv = NAT_HASH_FN(dst.s_addr, hv + dport, ipf_nat_table_sz); |
| nat = ipf_nat_table[0][hv]; |
| |
| /* TRACE src, sport, dst, dport, hv, nat */ |
| |
| for (; nat; nat = nat->nat_hnext[0]) { |
| if (nat->nat_ifps[1] != NULL) { |
| if ((ifp != NULL) && (ifp != nat->nat_ifps[1])) |
| continue; |
| } |
| |
| if ((p != 0) && (nat->nat_pr[1] != p)) |
| continue; |
| |
| switch (nat->nat_dir) |
| { |
| case NAT_INBOUND : |
| if (nat->nat_ndstaddr != src.s_addr || |
| nat->nat_nsrcaddr != dst.s_addr) |
| continue; |
| |
| if ((nat->nat_flags & IPN_TCPUDP) != 0) { |
| if (nat->nat_ndport != sport) |
| continue; |
| if (nat->nat_nsport != dport) |
| continue; |
| |
| } else if (p == IPPROTO_ICMP) { |
| if (nat->nat_osport != dport) { |
| continue; |
| } |
| } |
| break; |
| case NAT_OUTBOUND : |
| if (nat->nat_osrcaddr != src.s_addr || |
| nat->nat_odstaddr != dst.s_addr) |
| continue; |
| |
| if ((nat->nat_flags & IPN_TCPUDP) != 0) { |
| if (nat->nat_odport != dport) |
| continue; |
| if (nat->nat_osport != sport) |
| continue; |
| |
| } else if (p == IPPROTO_ICMP) { |
| if (nat->nat_osport != dport) { |
| continue; |
| } |
| } |
| break; |
| } |
| |
| ipn = nat->nat_ptr; |
| if ((ipn != NULL) && (nat->nat_aps != NULL)) |
| if (appr_match(fin, nat) != 0) |
| continue; |
| |
| if (ifp != NULL) { |
| nat->nat_ifps[1] = ifp; |
| nat->nat_mtu[1] = GETIFMTU(ifp); |
| } |
| return nat; |
| } |
| |
| /* |
| * So if we didn't find it but there are wildcard members in the hash |
| * table, go back and look for them. We do this search and update here |
| * because it is modifying the NAT table and we want to do this only |
| * for the first packet that matches. The exception, of course, is |
| * for "dummy" (FI_IGNORE) lookups. |
| */ |
| find_out_wild_ports: |
| if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_lookup_miss); |
| return NULL; |
| } |
| if (ipf_nat_stats.ns_wilds == 0) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_lookup_nowild); |
| return NULL; |
| } |
| |
| RWLOCK_EXIT(&ipf_nat); |
| |
| hv = NAT_HASH_FN(src.s_addr, 0, 0xffffffff); |
| hv = NAT_HASH_FN(dst.s_addr, hv, ipf_nat_table_sz); |
| |
| WRITE_ENTER(&ipf_nat); |
| |
| nat = ipf_nat_table[0][hv]; |
| for (; nat; nat = nat->nat_hnext[0]) { |
| if (nat->nat_ifps[1] != NULL) { |
| if ((ifp != NULL) && (ifp != nat->nat_ifps[1])) |
| continue; |
| } |
| |
| if (nat->nat_pr[1] != fin->fin_p) |
| continue; |
| |
| switch (nat->nat_dir) |
| { |
| case NAT_INBOUND : |
| if (nat->nat_ndstaddr != src.s_addr || |
| nat->nat_nsrcaddr != dst.s_addr) |
| continue; |
| break; |
| case NAT_OUTBOUND : |
| if (nat->nat_osrcaddr != src.s_addr || |
| nat->nat_odstaddr != dst.s_addr) |
| continue; |
| break; |
| } |
| |
| if (!(nat->nat_flags & (NAT_TCPUDP|SI_WILDP))) |
| continue; |
| |
| if (ipf_nat_wildok(nat, (int)sport, (int)dport, nat->nat_flags, |
| NAT_OUTBOUND) == 1) { |
| if ((fin->fin_flx & FI_IGNORE) != 0) |
| break; |
| if ((nat->nat_flags & SI_CLONE) != 0) { |
| nat = ipf_nat_clone(fin, nat); |
| if (nat == NULL) |
| break; |
| } else { |
| MUTEX_ENTER(&ipf_nat_new); |
| ipf_nat_stats.ns_wilds--; |
| MUTEX_EXIT(&ipf_nat_new); |
| } |
| |
| if (nat->nat_dir == NAT_OUTBOUND) { |
| if (nat->nat_osport == 0) { |
| nat->nat_osport = sport; |
| nat->nat_nsport = sport; |
| } |
| if (nat->nat_odport == 0) { |
| nat->nat_odport = dport; |
| nat->nat_ndport = dport; |
| } |
| } else { |
| if (nat->nat_osport == 0) { |
| nat->nat_osport = dport; |
| nat->nat_nsport = dport; |
| } |
| if (nat->nat_odport == 0) { |
| nat->nat_odport = sport; |
| nat->nat_ndport = sport; |
| } |
| } |
| if (ifp != NULL) { |
| nat->nat_ifps[1] = ifp; |
| nat->nat_mtu[1] = GETIFMTU(ifp); |
| } |
| nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT); |
| ipf_nat_tabmove(nat); |
| break; |
| } |
| } |
| |
| MUTEX_DOWNGRADE(&ipf_nat); |
| |
| if (nat == NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_lookup_miss); |
| } |
| return nat; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_lookupredir */ |
| /* Returns: nat_t* - NULL == no match, */ |
| /* else pointer to matching NAT entry */ |
| /* Parameters: np(I) - pointer to description of packet to find NAT table */ |
| /* entry for. */ |
| /* */ |
| /* Lookup the NAT tables to search for a matching redirect */ |
| /* The contents of natlookup_t should imitate those found in a packet that */ |
| /* would be translated - ie a packet coming in for RDR or going out for MAP.*/ |
| /* We can do the lookup in one of two ways, imitating an inbound or */ |
| /* outbound packet. By default we assume outbound, unless IPN_IN is set. */ |
| /* For IN, the fields are set as follows: */ |
| /* nl_real* = source information */ |
| /* nl_out* = destination information (translated) */ |
| /* For an out packet, the fields are set like this: */ |
| /* nl_in* = source information (untranslated) */ |
| /* nl_out* = destination information (translated) */ |
| /* ------------------------------------------------------------------------ */ |
| nat_t * |
| ipf_nat_lookupredir(np) |
| natlookup_t *np; |
| { |
| fr_info_t fi; |
| nat_t *nat; |
| |
| bzero((char *)&fi, sizeof(fi)); |
| if (np->nl_flags & IPN_IN) { |
| fi.fin_data[0] = ntohs(np->nl_realport); |
| fi.fin_data[1] = ntohs(np->nl_outport); |
| } else { |
| fi.fin_data[0] = ntohs(np->nl_inport); |
| fi.fin_data[1] = ntohs(np->nl_outport); |
| } |
| if (np->nl_flags & IPN_TCP) |
| fi.fin_p = IPPROTO_TCP; |
| else if (np->nl_flags & IPN_UDP) |
| fi.fin_p = IPPROTO_UDP; |
| else if (np->nl_flags & (IPN_ICMPERR|IPN_ICMPQUERY)) |
| fi.fin_p = IPPROTO_ICMP; |
| |
| /* |
| * We can do two sorts of lookups: |
| * - IPN_IN: we have the `real' and `out' address, look for `in'. |
| * - default: we have the `in' and `out' address, look for `real'. |
| */ |
| if (np->nl_flags & IPN_IN) { |
| if ((nat = ipf_nat_inlookup(&fi, np->nl_flags, fi.fin_p, |
| np->nl_realip, np->nl_outip))) { |
| np->nl_inip = nat->nat_odstip; |
| np->nl_inport = nat->nat_odport; |
| } |
| } else { |
| /* |
| * If nl_inip is non null, this is a lookup based on the real |
| * ip address. Else, we use the fake. |
| */ |
| if ((nat = ipf_nat_outlookup(&fi, np->nl_flags, fi.fin_p, |
| np->nl_inip, np->nl_outip))) { |
| |
| if ((np->nl_flags & IPN_FINDFORWARD) != 0) { |
| fr_info_t fin; |
| bzero((char *)&fin, sizeof(fin)); |
| fin.fin_p = nat->nat_pr[0]; |
| fin.fin_data[0] = ntohs(nat->nat_ndport); |
| fin.fin_data[1] = ntohs(nat->nat_nsport); |
| if (ipf_nat_inlookup(&fin, np->nl_flags, |
| fin.fin_p, nat->nat_ndstip, |
| nat->nat_nsrcip) != NULL) { |
| np->nl_flags &= ~IPN_FINDFORWARD; |
| } |
| } |
| |
| np->nl_realip = nat->nat_ndstip; |
| np->nl_realport = nat->nat_ndport; |
| } |
| } |
| |
| return nat; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_match_v4 */ |
| /* Returns: int - 0 == no match, 1 == match */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* np(I) - pointer to NAT rule */ |
| /* */ |
| /* Pull the matching of a packet against a NAT rule out of that complex */ |
| /* loop inside ipf_nat_checkin() and lay it out properly in its own function. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_match_v4(fin, np) |
| fr_info_t *fin; |
| ipnat_t *np; |
| { |
| frtuc_t *ft; |
| int match; |
| |
| if ((fin->fin_p == IPPROTO_ENCAP) && (np->in_redir & NAT_ENCAP)) |
| return ipf_nat_matchencap(fin, np); |
| |
| match = 0; |
| switch (np->in_osrcatype) |
| { |
| case FRI_NORMAL : |
| match = ((fin->fin_saddr & np->in_osrcmsk) != np->in_osrcaddr); |
| break; |
| #ifdef IPFILTER_LOOKUP |
| case FRI_LOOKUP : |
| match = (*np->in_osrcfunc)(np->in_osrcptr, np->in_v, |
| &fin->fin_saddr); |
| break; |
| #endif |
| } |
| match ^= ((np->in_flags & IPN_NOTSRC) != 0); |
| if (match) |
| return 0; |
| |
| match = 0; |
| switch (np->in_odstatype) |
| { |
| case FRI_NORMAL : |
| match = ((fin->fin_daddr & np->in_odstmsk) != np->in_odstaddr); |
| break; |
| #ifdef IPFILTER_LOOKUP |
| case FRI_LOOKUP : |
| match = (*np->in_odstfunc)(np->in_odstptr, fin->fin_v, |
| &fin->fin_daddr); |
| break; |
| #endif |
| } |
| |
| match ^= ((np->in_flags & IPN_NOTDST) != 0); |
| if (match) |
| return 0; |
| |
| ft = &np->in_tuc; |
| if (!(fin->fin_flx & FI_TCPUDP) || |
| (fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) { |
| if (ft->ftu_scmp || ft->ftu_dcmp) |
| return 0; |
| return 1; |
| } |
| |
| return ipf_tcpudpchk(&fin->fin_fi, ft); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_update */ |
| /* Returns: Nil */ |
| /* Parameters: nat(I) - pointer to NAT structure */ |
| /* np(I) - pointer to NAT rule */ |
| /* */ |
| /* Updates the lifetime of a NAT table entry for non-TCP packets. Must be */ |
| /* called with fin_rev updated - i.e. after calling ipf_nat_proto(). */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_update(fin, nat, np) |
| fr_info_t *fin; |
| nat_t *nat; |
| ipnat_t *np; |
| { |
| ipftq_t *ifq, *ifq2; |
| ipftqent_t *tqe; |
| |
| MUTEX_ENTER(&nat->nat_lock); |
| tqe = &nat->nat_tqe; |
| ifq = tqe->tqe_ifq; |
| |
| /* |
| * We allow over-riding of NAT timeouts from NAT rules, even for |
| * TCP, however, if it is TCP and there is no rule timeout set, |
| * then do not update the timeout here. |
| */ |
| if (np != NULL) |
| ifq2 = np->in_tqehead[fin->fin_rev]; |
| else |
| ifq2 = NULL; |
| |
| if (nat->nat_pr[0] == IPPROTO_TCP && ifq2 == NULL) { |
| (void) ipf_tcp_age(&nat->nat_tqe, fin, ipf_nat_tqb, 0, 2); |
| } else { |
| if (ifq2 == NULL) { |
| if (nat->nat_pr[0] == IPPROTO_UDP) |
| ifq2 = &ipf_nat_udptq; |
| else if (nat->nat_pr[0] == IPPROTO_ICMP) |
| ifq2 = &ipf_nat_icmptq; |
| else |
| ifq2 = &ipf_nat_iptq; |
| } |
| |
| ipf_movequeue(tqe, ifq, ifq2); |
| } |
| MUTEX_EXIT(&nat->nat_lock); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_ipfout */ |
| /* Returns: frentry_t* - NULL (packet may have been translated, let it */ |
| /* pass), &ipfnatblock - block/drop the packet. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* passp(I) - point to filtering result flags */ |
| /* */ |
| /* This is purely and simply a wrapper around ipf_nat_checkout for the sole */ |
| /* reason of being able to activate NAT from an ipf rule using "call-now". */ |
| /* ------------------------------------------------------------------------ */ |
| frentry_t * |
| ipf_nat_ipfout(fin, passp) |
| fr_info_t *fin; |
| u_32_t *passp; |
| { |
| frentry_t *fr = fin->fin_fr; |
| |
| switch (ipf_nat_checkout(fin, passp)) |
| { |
| case -1 : |
| fin->fin_reason = 13; |
| fr = &ipfnatblock; |
| MUTEX_ENTER(&fr->fr_lock); |
| fr->fr_ref++; |
| MUTEX_EXIT(&fr->fr_lock); |
| return fr; |
| |
| case 0 : |
| break; |
| |
| case 1 : |
| /* |
| * Returing NULL causes this rule to be "ignored" but |
| * it has actually had an influence on the packet so we |
| * increment counters for it. |
| */ |
| MUTEX_ENTER(&fr->fr_lock); |
| fr->fr_bytes += (U_QUAD_T)fin->fin_plen; |
| fr->fr_hits++; |
| MUTEX_EXIT(&fr->fr_lock); |
| break; |
| } |
| |
| return NULL; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_checkout */ |
| /* Returns: int - -1 == packet failed NAT checks so block it, */ |
| /* 0 == no packet translation occurred, */ |
| /* 1 == packet was successfully translated. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* passp(I) - pointer to filtering result flags */ |
| /* */ |
| /* Check to see if an outcoming packet should be changed. ICMP packets are */ |
| /* first checked to see if they match an existing entry (if an error), */ |
| /* otherwise a search of the current NAT table is made. If neither results */ |
| /* in a match then a search for a matching NAT rule is made. Create a new */ |
| /* NAT entry if a we matched a NAT rule. Lastly, actually change the */ |
| /* packet header(s) as required. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_nat_checkout(fin, passp) |
| fr_info_t *fin; |
| u_32_t *passp; |
| { |
| struct ifnet *ifp, *sifp; |
| icmphdr_t *icmp = NULL; |
| tcphdr_t *tcp = NULL; |
| int rval, natfailed; |
| ipnat_t *np = NULL; |
| u_int nflags = 0; |
| u_32_t ipa, iph; |
| int natadd = 1; |
| frentry_t *fr; |
| nat_t *nat; |
| |
| if (ipf_nat_stats.ns_rules == 0 || ipf_nat_lock != 0) |
| return 0; |
| |
| natfailed = 0; |
| fr = fin->fin_fr; |
| sifp = fin->fin_ifp; |
| if (fr != NULL) { |
| ifp = fr->fr_tifs[fin->fin_rev].fd_ifp; |
| if ((ifp != NULL) && (ifp != (void *)-1)) |
| fin->fin_ifp = ifp; |
| } |
| ifp = fin->fin_ifp; |
| |
| if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { |
| switch (fin->fin_p) |
| { |
| case IPPROTO_TCP : |
| nflags = IPN_TCP; |
| break; |
| case IPPROTO_UDP : |
| nflags = IPN_UDP; |
| break; |
| case IPPROTO_ICMP : |
| icmp = fin->fin_dp; |
| |
| /* |
| * This is an incoming packet, so the destination is |
| * the icmp_id and the source port equals 0 |
| */ |
| if ((fin->fin_flx & FI_ICMPQUERY) != 0) |
| nflags = IPN_ICMPQUERY; |
| break; |
| default : |
| break; |
| } |
| |
| if ((nflags & IPN_TCPUDP)) |
| tcp = fin->fin_dp; |
| } |
| |
| ipa = fin->fin_saddr; |
| |
| READ_ENTER(&ipf_nat); |
| |
| if ((fin->fin_p == IPPROTO_ICMP) && !(nflags & IPN_ICMPQUERY) && |
| (nat = ipf_nat_icmperror(fin, &nflags, NAT_OUTBOUND))) |
| /*EMPTY*/; |
| else if ((fin->fin_flx & FI_FRAG) && (nat = ipf_frag_natknown(fin))) |
| natadd = 0; |
| else if ((nat = ipf_nat_outlookup(fin, nflags|NAT_SEARCH, |
| (u_int)fin->fin_p, fin->fin_src, |
| fin->fin_dst))) { |
| nflags = nat->nat_flags; |
| } else { |
| u_32_t hv, msk, nmsk; |
| |
| /* |
| * If there is no current entry in the nat table for this IP#, |
| * create one for it (if there is a matching rule). |
| */ |
| RWLOCK_EXIT(&ipf_nat); |
| msk = 0xffffffff; |
| nmsk = ipf_nat_map_masks; |
| WRITE_ENTER(&ipf_nat); |
| maskloop: |
| iph = ipa & htonl(msk); |
| hv = NAT_HASH_FN(iph, 0, ipf_nat_maprules_sz); |
| for (np = ipf_nat_map_rules[hv]; np; np = np->in_mnext) |
| { |
| if ((np->in_ifps[1] && (np->in_ifps[1] != ifp))) |
| continue; |
| if (np->in_v != fin->fin_v) |
| continue; |
| if (np->in_pr[1] && (np->in_pr[1] != fin->fin_p)) |
| continue; |
| if ((np->in_flags & IPN_RF) && |
| !(np->in_flags & nflags)) |
| continue; |
| if (np->in_flags & IPN_FILTER) { |
| switch (ipf_nat_match_v4(fin, np)) |
| { |
| case 0 : |
| continue; |
| case -1 : |
| rval = -1; |
| goto outmatchfail; |
| case 1 : |
| default : |
| break; |
| } |
| } else if ((ipa & np->in_osrcaddr) != np->in_osrcaddr) |
| continue; |
| |
| if ((fr != NULL) && |
| !ipf_matchtag(&np->in_tag, &fr->fr_nattag)) |
| continue; |
| |
| if (*np->in_plabel != '\0') { |
| if (((np->in_flags & IPN_FILTER) == 0) && |
| (np->in_odport != fin->fin_data[1])) |
| continue; |
| if (appr_ok(fin, tcp, np) == 0) |
| continue; |
| } |
| |
| if (np->in_flags & IPN_NO) { |
| np->in_hits++; |
| break; |
| } |
| |
| if ((nat = ipf_nat_add(fin, np, NULL, nflags, |
| NAT_OUTBOUND))) { |
| np->in_hits++; |
| break; |
| } else |
| natfailed = -1; |
| } |
| if ((np == NULL) && (nmsk != 0)) { |
| while (nmsk) { |
| msk <<= 1; |
| if (nmsk & 0x80000000) |
| break; |
| nmsk <<= 1; |
| } |
| if (nmsk != 0) { |
| nmsk <<= 1; |
| goto maskloop; |
| } |
| } |
| MUTEX_DOWNGRADE(&ipf_nat); |
| } |
| |
| if (nat != NULL) { |
| rval = ipf_nat_out(fin, nat, natadd, nflags); |
| if (rval == 1) { |
| MUTEX_ENTER(&nat->nat_lock); |
| nat->nat_ref++; |
| MUTEX_EXIT(&nat->nat_lock); |
| nat->nat_touched = ipf_ticks; |
| fin->fin_nat = nat; |
| } |
| } else |
| rval = natfailed; |
| outmatchfail: |
| RWLOCK_EXIT(&ipf_nat); |
| |
| switch (rval) |
| { |
| case -1 : |
| if (passp != NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_drop); |
| *passp = FR_BLOCK; |
| fin->fin_reason = 11; |
| } |
| fin->fin_flx |= FI_BADNAT; |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_badnat); |
| break; |
| case 0 : |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_ignored); |
| break; |
| case 1 : |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_translated); |
| break; |
| } |
| fin->fin_ifp = sifp; |
| return rval; |
| } |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_out */ |
| /* Returns: int - -1 == packet failed NAT checks so block it, */ |
| /* 1 == packet was successfully translated. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to NAT structure */ |
| /* natadd(I) - flag indicating if it is safe to add frag cache */ |
| /* nflags(I) - NAT flags set for this packet */ |
| /* */ |
| /* Translate a packet coming "out" on an interface. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_nat_out(fin, nat, natadd, nflags) |
| fr_info_t *fin; |
| nat_t *nat; |
| int natadd; |
| u_32_t nflags; |
| { |
| icmphdr_t *icmp; |
| u_short *csump; |
| tcphdr_t *tcp; |
| ipnat_t *np; |
| int skip; |
| int i; |
| |
| tcp = NULL; |
| icmp = NULL; |
| csump = NULL; |
| np = nat->nat_ptr; |
| |
| if ((natadd != 0) && (fin->fin_flx & FI_FRAG) && (np != NULL)) |
| (void) ipf_frag_natnew(fin, 0, nat); |
| |
| MUTEX_ENTER(&nat->nat_lock); |
| nat->nat_bytes[1] += fin->fin_plen; |
| nat->nat_pkts[1]++; |
| MUTEX_EXIT(&nat->nat_lock); |
| |
| /* |
| * Fix up checksums, not by recalculating them, but |
| * simply computing adjustments. |
| * This is only done for STREAMS based IP implementations where the |
| * checksum has already been calculated by IP. In all other cases, |
| * IPFilter is called before the checksum needs calculating so there |
| * is no call to modify whatever is in the header now. |
| */ |
| if (fin->fin_v == 4) { |
| if (nflags == IPN_ICMPERR) { |
| u_32_t s1, s2, sumd, msumd; |
| |
| s1 = LONG_SUM(ntohl(fin->fin_saddr)); |
| if (nat->nat_dir == NAT_OUTBOUND) { |
| s2 = LONG_SUM(ntohl(nat->nat_nsrcaddr)); |
| } else { |
| s2 = LONG_SUM(ntohl(nat->nat_odstaddr)); |
| } |
| CALC_SUMD(s1, s2, sumd); |
| msumd = sumd; |
| |
| s1 = LONG_SUM(ntohl(fin->fin_daddr)); |
| if (nat->nat_dir == NAT_OUTBOUND) { |
| s2 = LONG_SUM(ntohl(nat->nat_ndstaddr)); |
| } else { |
| s2 = LONG_SUM(ntohl(nat->nat_osrcaddr)); |
| } |
| CALC_SUMD(s1, s2, sumd); |
| msumd += sumd; |
| |
| ipf_fix_outcksum(fin, &fin->fin_ip->ip_sum, msumd); |
| } |
| #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ |
| defined(linux) || defined(BRIDGE_IPF) |
| else { |
| /* |
| * Strictly speaking, this isn't necessary on BSD |
| * kernels because they do checksum calculation after |
| * this code has run BUT if ipfilter is being used |
| * to do NAT as a bridge, that code doesn't exist. |
| */ |
| switch (nat->nat_dir) |
| { |
| case NAT_OUTBOUND : |
| ipf_fix_outcksum(fin, &fin->fin_ip->ip_sum, |
| nat->nat_ipsumd); |
| break; |
| |
| case NAT_INBOUND : |
| ipf_fix_incksum(fin, &fin->fin_ip->ip_sum, |
| nat->nat_ipsumd); |
| break; |
| |
| default : |
| break; |
| } |
| } |
| #endif |
| } |
| |
| /* |
| * Address assignment is after the checksum modification because |
| * we are using the address in the packet for determining the |
| * correct checksum offset (the ICMP error could be coming from |
| * anyone...) |
| */ |
| switch (nat->nat_dir) |
| { |
| case NAT_OUTBOUND : |
| fin->fin_ip->ip_src = nat->nat_nsrcip; |
| fin->fin_saddr = nat->nat_nsrcaddr; |
| fin->fin_ip->ip_dst = nat->nat_ndstip; |
| fin->fin_daddr = nat->nat_ndstaddr; |
| break; |
| |
| case NAT_INBOUND : |
| fin->fin_ip->ip_src = nat->nat_odstip; |
| fin->fin_saddr = nat->nat_ndstaddr; |
| fin->fin_ip->ip_dst = nat->nat_osrcip; |
| fin->fin_daddr = nat->nat_nsrcaddr; |
| break; |
| |
| case NAT_ENCAPIN : |
| fin->fin_flx |= FI_ENCAP; |
| case NAT_DIVERTIN : |
| { |
| mb_t *m; |
| |
| skip = ipf_nat_decap(fin, nat); |
| if (skip <= 0) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_decap_fail); |
| return -1; |
| } |
| |
| m = fin->fin_m; |
| |
| #if defined(MENTAT) && defined(_KERNEL) |
| m->b_rptr += skip; |
| #else |
| m->m_data += skip; |
| m->m_len -= skip; |
| |
| # ifdef M_PKTHDR |
| if (m->m_flags & M_PKTHDR) |
| m->m_pkthdr.len -= skip; |
| # endif |
| #endif |
| |
| ipf_nat_update(fin, nat, np); |
| nflags &= ~IPN_TCPUDPICMP; |
| fin->fin_flx |= FI_NATED; |
| if (np != NULL && np->in_tag.ipt_num[0] != 0) |
| fin->fin_nattag = &np->in_tag; |
| return 1; |
| /* NOTREACHED */ |
| } |
| |
| case NAT_ENCAPOUT : |
| { |
| u_32_t s1, s2, sumd; |
| ip_t *ip; |
| mb_t *m; |
| |
| if (ipf_nat_encapok(fin, nat) == -1) |
| return -1; |
| |
| m = M_DUPLICATE(np->in_divmp); |
| if (m == NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_encap_dup); |
| return -1; |
| } |
| |
| ip = MTOD(m, ip_t *); |
| /* TRACE (fin,ip) */ |
| ip->ip_off = (fin->fin_ip->ip_off & htons(IP_DF)); |
| ip->ip_id = htons(ipf_nextipid(fin)); |
| ip->ip_len = htons(fin->fin_plen + 20); |
| s1 = 0; |
| /* |
| * We subtract 20 here because ip_len has already been set |
| * to this value when the template checksum is created. |
| */ |
| s2 = ntohs(ip->ip_id) + ntohs(ip->ip_len) - 20; |
| s2 += ntohs(ip->ip_off) & IP_DF; |
| /* TRACE (s1,s2,ip) */ |
| CALC_SUMD(s1, s2, sumd); |
| /* TRACE (sumd) */ |
| |
| #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ |
| defined(linux) || defined(BRIDGE_IPF) |
| ipf_fix_outcksum(fin, &ip->ip_sum, sumd); |
| #endif |
| /* TRACE (ip) */ |
| |
| PREP_MB_T(fin, m); |
| |
| fin->fin_ip = ip; |
| fin->fin_plen += 20; /* UDP + new IPv4 hdr */ |
| fin->fin_dlen += 20; /* UDP + old IPv4 hdr */ |
| fin->fin_flx |= FI_ENCAP; |
| |
| nflags &= ~IPN_TCPUDPICMP; |
| |
| break; |
| } |
| case NAT_DIVERTOUT : |
| { |
| u_32_t s1, s2, sumd; |
| udphdr_t *uh; |
| ip_t *ip; |
| mb_t *m; |
| |
| m = M_DUPLICATE(np->in_divmp); |
| if (m == NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_divert_dup); |
| return -1; |
| } |
| |
| ip = MTOD(m, ip_t *); |
| ip->ip_id = htons(ipf_nextipid(fin)); |
| |
| s1 = ip->ip_len; |
| ip->ip_len = ntohs(ip->ip_len); |
| ip->ip_len += fin->fin_plen; |
| ip->ip_len = htons(ip->ip_len); |
| |
| uh = (udphdr_t *)(ip + 1); |
| uh->uh_ulen += fin->fin_plen; |
| uh->uh_ulen = htons(uh->uh_ulen); |
| |
| s2 = ntohs(ip->ip_id) + ntohs(ip->ip_len); |
| CALC_SUMD(s1, s2, sumd); |
| |
| #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ |
| defined(linux) || defined(BRIDGE_IPF) |
| ipf_fix_incksum(fin, &ip->ip_sum, sumd); |
| #endif |
| |
| PREP_MB_T(fin, m); |
| |
| fin->fin_ip = ip; |
| fin->fin_plen += 28; /* UDP + new IPv4 hdr */ |
| fin->fin_dlen += 28; /* UDP + old IPv4 hdr */ |
| |
| nflags &= ~IPN_TCPUDPICMP; |
| |
| break; |
| } |
| |
| default : |
| break; |
| } |
| |
| if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { |
| if ((nat->nat_nsport != 0) && (nflags & IPN_TCPUDP)) { |
| tcp = fin->fin_dp; |
| |
| switch (nat->nat_dir) |
| { |
| case NAT_OUTBOUND : |
| tcp->th_sport = nat->nat_nsport; |
| fin->fin_data[0] = ntohs(nat->nat_nsport); |
| tcp->th_dport = nat->nat_ndport; |
| fin->fin_data[0] = ntohs(nat->nat_ndport); |
| break; |
| |
| case NAT_INBOUND : |
| tcp->th_sport = nat->nat_odport; |
| fin->fin_data[0] = ntohs(nat->nat_odport); |
| tcp->th_dport = nat->nat_osport; |
| fin->fin_data[0] = ntohs(nat->nat_osport); |
| break; |
| } |
| } |
| |
| if ((nat->nat_nsport != 0) && (nflags & IPN_ICMPQUERY)) { |
| icmp = fin->fin_dp; |
| icmp->icmp_id = nat->nat_nicmpid; |
| } |
| |
| csump = ipf_nat_proto(fin, nat, nflags); |
| } |
| |
| ipf_nat_update(fin, nat, np); |
| |
| /* |
| * The above comments do not hold for layer 4 (or higher) checksums... |
| */ |
| if (csump != NULL) { |
| if (nat->nat_dir == NAT_OUTBOUND) |
| ipf_fix_outcksum(fin, csump, nat->nat_sumd[1]); |
| else |
| ipf_fix_incksum(fin, csump, nat->nat_sumd[1]); |
| } |
| #ifdef IPFILTER_SYNC |
| ipf_sync_update(SMC_NAT, fin, nat->nat_sync); |
| #endif |
| /* ------------------------------------------------------------- */ |
| /* A few quick notes: */ |
| /* Following are test conditions prior to calling the */ |
| /* appr_check routine. */ |
| /* */ |
| /* A NULL tcp indicates a non TCP/UDP packet. When dealing */ |
| /* with a redirect rule, we attempt to match the packet's */ |
| /* source port against in_dport, otherwise we'd compare the */ |
| /* packet's destination. */ |
| /* ------------------------------------------------------------- */ |
| if ((np != NULL) && (np->in_apr != NULL)) { |
| i = appr_check(fin, nat); |
| if (i == 0) |
| i = 1; |
| else if (i == -1) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[1].ns_appr_fail); |
| } |
| } else { |
| i = 1; |
| } |
| fin->fin_flx |= FI_NATED; |
| return i; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_ipfin */ |
| /* Returns: frentry_t* - NULL (packet may have been translated, let it */ |
| /* pass), &ipfnatblock - block/drop the packet. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* passp(I) - point to filtering result flags */ |
| /* */ |
| /* This is purely and simply a wrapper around ipf_nat_checkin for the sole */ |
| /* reason of being able to activate NAT from an ipf rule using "call-now". */ |
| /* ------------------------------------------------------------------------ */ |
| frentry_t * |
| ipf_nat_ipfin(fin, passp) |
| fr_info_t *fin; |
| u_32_t *passp; |
| { |
| frentry_t *fr = fin->fin_fr; |
| |
| switch (ipf_nat_checkin(fin, passp)) |
| { |
| case -1 : |
| fin->fin_reason = 13; |
| fr = &ipfnatblock; |
| MUTEX_ENTER(&fr->fr_lock); |
| fr->fr_ref++; |
| MUTEX_EXIT(&fr->fr_lock); |
| return fr; |
| |
| case 0 : |
| return NULL; |
| |
| case 1 : |
| /* |
| * Returing NULL causes this rule to be "ignored" but |
| * it has actually had an influence on the packet so we |
| * increment counters for it. |
| */ |
| MUTEX_ENTER(&fr->fr_lock); |
| fr->fr_bytes += (U_QUAD_T)fin->fin_plen; |
| fr->fr_hits++; |
| MUTEX_EXIT(&fr->fr_lock); |
| return NULL; |
| } |
| |
| return NULL; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_checkin */ |
| /* Returns: int - -1 == packet failed NAT checks so block it, */ |
| /* 0 == no packet translation occurred, */ |
| /* 1 == packet was successfully translated. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* passp(I) - pointer to filtering result flags */ |
| /* */ |
| /* Check to see if an incoming packet should be changed. ICMP packets are */ |
| /* first checked to see if they match an existing entry (if an error), */ |
| /* otherwise a search of the current NAT table is made. If neither results */ |
| /* in a match then a search for a matching NAT rule is made. Create a new */ |
| /* NAT entry if a we matched a NAT rule. Lastly, actually change the */ |
| /* packet header(s) as required. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_nat_checkin(fin, passp) |
| fr_info_t *fin; |
| u_32_t *passp; |
| { |
| u_int nflags, natadd; |
| int rval, natfailed; |
| struct ifnet *ifp; |
| struct in_addr in; |
| icmphdr_t *icmp; |
| tcphdr_t *tcp; |
| u_short dport; |
| ipnat_t *np; |
| nat_t *nat; |
| u_32_t iph; |
| |
| if (ipf_nat_stats.ns_rules == 0 || ipf_nat_lock != 0) |
| return 0; |
| |
| tcp = NULL; |
| icmp = NULL; |
| dport = 0; |
| natadd = 1; |
| nflags = 0; |
| natfailed = 0; |
| ifp = fin->fin_ifp; |
| |
| if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { |
| switch (fin->fin_p) |
| { |
| case IPPROTO_TCP : |
| nflags = IPN_TCP; |
| break; |
| case IPPROTO_UDP : |
| nflags = IPN_UDP; |
| break; |
| case IPPROTO_ICMP : |
| icmp = fin->fin_dp; |
| |
| /* |
| * This is an incoming packet, so the destination is |
| * the icmp_id and the source port equals 0 |
| */ |
| if ((fin->fin_flx & FI_ICMPQUERY) != 0) { |
| nflags = IPN_ICMPQUERY; |
| dport = icmp->icmp_id; |
| } break; |
| default : |
| break; |
| } |
| |
| if ((nflags & IPN_TCPUDP)) { |
| tcp = fin->fin_dp; |
| dport = fin->fin_data[1]; |
| } |
| } |
| |
| in = fin->fin_dst; |
| |
| READ_ENTER(&ipf_nat); |
| |
| if ((fin->fin_p == IPPROTO_ICMP) && !(nflags & IPN_ICMPQUERY) && |
| (nat = ipf_nat_icmperror(fin, &nflags, NAT_INBOUND))) |
| /*EMPTY*/; |
| else if ((fin->fin_flx & FI_FRAG) && (nat = ipf_frag_natknown(fin))) |
| natadd = 0; |
| else if ((nat = ipf_nat_inlookup(fin, nflags|NAT_SEARCH, |
| (u_int)fin->fin_p, |
| fin->fin_src, in))) { |
| nflags = nat->nat_flags; |
| } else { |
| u_32_t hv, msk, rmsk; |
| |
| RWLOCK_EXIT(&ipf_nat); |
| rmsk = ipf_nat_rdr_masks; |
| msk = 0xffffffff; |
| WRITE_ENTER(&ipf_nat); |
| /* |
| * If there is no current entry in the nat table for this IP#, |
| * create one for it (if there is a matching rule). |
| */ |
| maskloop: |
| iph = in.s_addr & htonl(msk); |
| hv = NAT_HASH_FN(iph, 0, ipf_nat_rdrrules_sz); |
| /* TRACE (iph,msk,rmsk,hv,ipf_nat_rdrrules_sz) */ |
| for (np = ipf_nat_rdr_rules[hv]; np; np = np->in_rnext) { |
| if (np->in_ifps[0] && (np->in_ifps[0] != ifp)) |
| continue; |
| if (np->in_v != fin->fin_v) |
| continue; |
| if (np->in_pr[0] && (np->in_pr[0] != fin->fin_p)) |
| continue; |
| if ((np->in_flags & IPN_RF) && !(np->in_flags & nflags)) |
| continue; |
| if (np->in_flags & IPN_FILTER) { |
| switch (ipf_nat_match_v4(fin, np)) |
| { |
| case 0 : |
| continue; |
| case -1 : |
| rval = -1; |
| goto inmatchfail; |
| case 1 : |
| default : |
| break; |
| } |
| } else { |
| if ((in.s_addr & np->in_odstmsk) != |
| np->in_odstaddr) |
| continue; |
| if (np->in_odport && |
| ((np->in_dtop < dport) || |
| (dport < np->in_odport))) |
| continue; |
| } |
| |
| if (*np->in_plabel != '\0') { |
| if (!appr_ok(fin, tcp, np)) { |
| continue; |
| } |
| } |
| |
| if (np->in_flags & IPN_NO) { |
| np->in_hits++; |
| break; |
| } |
| |
| nat = ipf_nat_add(fin, np, NULL, nflags, NAT_INBOUND); |
| if (nat != NULL) { |
| np->in_hits++; |
| break; |
| } else |
| natfailed = -1; |
| } |
| |
| if ((np == NULL) && (rmsk != 0)) { |
| while (rmsk) { |
| msk <<= 1; |
| if (rmsk & 0x80000000) |
| break; |
| rmsk <<= 1; |
| } |
| if (rmsk != 0) { |
| rmsk <<= 1; |
| goto maskloop; |
| } |
| } |
| MUTEX_DOWNGRADE(&ipf_nat); |
| } |
| if (nat != NULL) { |
| rval = ipf_nat_in(fin, nat, natadd, nflags); |
| if (rval == 1) { |
| MUTEX_ENTER(&nat->nat_lock); |
| nat->nat_ref++; |
| MUTEX_EXIT(&nat->nat_lock); |
| nat->nat_touched = ipf_ticks; |
| fin->fin_nat = nat; |
| } |
| } else |
| rval = natfailed; |
| inmatchfail: |
| RWLOCK_EXIT(&ipf_nat); |
| |
| switch (rval) |
| { |
| case -1 : |
| if (passp != NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_drop); |
| *passp = FR_BLOCK; |
| fin->fin_reason = 12; |
| } |
| fin->fin_flx |= FI_BADNAT; |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_badnat); |
| break; |
| case 0 : |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_ignored); |
| break; |
| case 1 : |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_translated); |
| break; |
| } |
| return rval; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_in */ |
| /* Returns: int - -1 == packet failed NAT checks so block it, */ |
| /* 1 == packet was successfully translated. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to NAT structure */ |
| /* natadd(I) - flag indicating if it is safe to add frag cache */ |
| /* nflags(I) - NAT flags set for this packet */ |
| /* Locks Held: (READ) */ |
| /* */ |
| /* Translate a packet coming "in" on an interface. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_nat_in(fin, nat, natadd, nflags) |
| fr_info_t *fin; |
| nat_t *nat; |
| int natadd; |
| u_32_t nflags; |
| { |
| u_32_t sumd, ipsumd, sum1, sum2; |
| icmphdr_t *icmp; |
| u_short *csump; |
| tcphdr_t *tcp; |
| ipnat_t *np; |
| int skip; |
| int i; |
| |
| tcp = NULL; |
| csump = NULL; |
| np = nat->nat_ptr; |
| fin->fin_fr = nat->nat_fr; |
| |
| if (np != NULL) { |
| if ((natadd != 0) && (fin->fin_flx & FI_FRAG)) |
| (void) ipf_frag_natnew(fin, 0, nat); |
| |
| /* ------------------------------------------------------------- */ |
| /* A few quick notes: */ |
| /* Following are test conditions prior to calling the */ |
| /* appr_check routine. */ |
| /* */ |
| /* A NULL tcp indicates a non TCP/UDP packet. When dealing */ |
| /* with a map rule, we attempt to match the packet's */ |
| /* source port against in_dport, otherwise we'd compare the */ |
| /* packet's destination. */ |
| /* ------------------------------------------------------------- */ |
| if (np->in_apr != NULL) { |
| i = appr_check(fin, nat); |
| if (i == -1) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0]. |
| ns_appr_fail); |
| return -1; |
| } |
| } |
| } |
| |
| #ifdef IPFILTER_SYNC |
| ipf_sync_update(SMC_NAT, fin, nat->nat_sync); |
| #endif |
| |
| MUTEX_ENTER(&nat->nat_lock); |
| nat->nat_bytes[0] += fin->fin_plen; |
| nat->nat_pkts[0]++; |
| MUTEX_EXIT(&nat->nat_lock); |
| |
| ipsumd = nat->nat_ipsumd; |
| /* |
| * Fix up checksums, not by recalculating them, but |
| * simply computing adjustments. |
| * Why only do this for some platforms on inbound packets ? |
| * Because for those that it is done, IP processing is yet to happen |
| * and so the IPv4 header checksum has not yet been evaluated. |
| * Perhaps it should always be done for the benefit of things like |
| * fast forwarding (so that it doesn't need to be recomputed) but with |
| * header checksum offloading, perhaps it is a moot point. |
| */ |
| |
| switch (nat->nat_dir) |
| { |
| case NAT_INBOUND : |
| if ((fin->fin_flx & FI_ICMPERR) == 0) { |
| fin->fin_ip->ip_src = nat->nat_nsrcip; |
| fin->fin_saddr = nat->nat_nsrcaddr; |
| } else { |
| sum1 = nat->nat_osrcaddr; |
| sum2 = nat->nat_nsrcaddr; |
| CALC_SUMD(sum1, sum2, sumd); |
| ipsumd -= sumd; |
| } |
| fin->fin_ip->ip_dst = nat->nat_ndstip; |
| fin->fin_daddr = nat->nat_ndstaddr; |
| #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ |
| defined(__osf__) || defined(linux) |
| ipf_fix_outcksum(fin, &fin->fin_ip->ip_sum, ipsumd); |
| #endif |
| break; |
| |
| case NAT_OUTBOUND : |
| if ((fin->fin_flx & FI_ICMPERR) == 0) { |
| fin->fin_ip->ip_src = nat->nat_odstip; |
| fin->fin_saddr = nat->nat_odstaddr; |
| } else { |
| sum1 = nat->nat_odstaddr; |
| sum2 = nat->nat_ndstaddr; |
| CALC_SUMD(sum1, sum2, sumd); |
| ipsumd -= sumd; |
| } |
| fin->fin_ip->ip_dst = nat->nat_osrcip; |
| fin->fin_daddr = nat->nat_osrcaddr; |
| #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ |
| defined(__osf__) || defined(linux) |
| ipf_fix_incksum(fin, &fin->fin_ip->ip_sum, ipsumd); |
| #endif |
| break; |
| |
| case NAT_ENCAPIN : |
| { |
| ip_t *ip; |
| mb_t *m; |
| |
| /* |
| * XXX |
| * This is not necessarily true. What we need to know here |
| * is the MTU of the interface out which the packets will go |
| * and this won't be nat_ifps[1] because that is where we |
| * send packets after stripping off stuff - what's needed |
| * here is the MTU of the interface for the route to the |
| * destination of the outer header. |
| */ |
| if (ipf_nat_encapok(fin, nat) == -1) |
| return -1; |
| |
| m = M_DUPLICATE(np->in_divmp); |
| if (m == NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_encap_dup); |
| return -1; |
| } |
| |
| ip = MTOD(m, ip_t *); |
| ip->ip_id = htons(ipf_nextipid(fin)); |
| sum1 = ntohs(ip->ip_len); |
| ip->ip_len = htons(fin->fin_plen + 20); |
| sum2 = ntohs(ip->ip_id) + ntohs(ip->ip_len); |
| CALC_SUMD(sum1, sum2, sumd); |
| |
| #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ |
| defined(__osf__) || defined(linux) |
| ipf_fix_outcksum(fin, &ip->ip_sum, sumd); |
| #endif |
| |
| PREP_MB_T(fin, m); |
| |
| fin->fin_ip = ip; |
| fin->fin_plen += 20; /* UDP + new IPv4 hdr */ |
| fin->fin_dlen += 20; /* UDP + old IPv4 hdr */ |
| fin->fin_flx |= FI_ENCAP; |
| |
| nflags &= ~IPN_TCPUDPICMP; |
| |
| break; |
| } |
| |
| case NAT_DIVERTIN : |
| { |
| udphdr_t *uh; |
| ip_t *ip; |
| mb_t *m; |
| |
| m = M_DUPLICATE(np->in_divmp); |
| if (m == NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_divert_dup); |
| return -1; |
| } |
| |
| ip = MTOD(m, ip_t *); |
| ip->ip_id = htons(ipf_nextipid(fin)); |
| sum1 = ntohs(ip->ip_len); |
| ip->ip_len = ntohs(ip->ip_len); |
| ip->ip_len += fin->fin_plen; |
| ip->ip_len = htons(ip->ip_len); |
| |
| uh = (udphdr_t *)(ip + 1); |
| uh->uh_ulen += fin->fin_plen; |
| uh->uh_ulen = htons(uh->uh_ulen); |
| |
| sum2 = ntohs(ip->ip_id) + ntohs(ip->ip_len); |
| sum2 += ntohs(ip->ip_off) & IP_DF; |
| CALC_SUMD(sum1, sum2, sumd); |
| |
| #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ |
| defined(__osf__) || defined(linux) |
| ipf_fix_outcksum(fin, &ip->ip_sum, sumd); |
| #endif |
| PREP_MB_T(fin, m); |
| |
| fin->fin_ip = ip; |
| fin->fin_plen += 28; /* UDP + new IPv4 hdr */ |
| fin->fin_dlen += 28; /* UDP + old IPv4 hdr */ |
| |
| nflags &= ~IPN_TCPUDPICMP; |
| |
| break; |
| } |
| |
| case NAT_ENCAPOUT : |
| fin->fin_flx |= FI_ENCAP; |
| case NAT_DIVERTOUT : |
| { |
| mb_t *m; |
| |
| skip = ipf_nat_decap(fin, nat); |
| if (skip <= 0) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[0].ns_decap_fail); |
| return -1; |
| } |
| |
| m = fin->fin_m; |
| |
| #if defined(MENTAT) && defined(_KERNEL) |
| m->b_rptr += skip; |
| #else |
| m->m_data += skip; |
| m->m_len -= skip; |
| |
| # ifdef M_PKTHDR |
| if (m->m_flags & M_PKTHDR) |
| m->m_pkthdr.len -= skip; |
| # endif |
| #endif |
| |
| ipf_nat_update(fin, nat, np); |
| nflags &= ~IPN_TCPUDPICMP; |
| fin->fin_flx |= FI_NATED; |
| if (np != NULL && np->in_tag.ipt_num[0] != 0) |
| fin->fin_nattag = &np->in_tag; |
| return 1; |
| /* NOTREACHED */ |
| } |
| } |
| if (nflags & IPN_TCPUDP) |
| tcp = fin->fin_dp; |
| |
| if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { |
| if ((nat->nat_odport != 0) && (nflags & IPN_TCPUDP)) { |
| switch (nat->nat_dir) |
| { |
| case NAT_INBOUND : |
| tcp->th_sport = nat->nat_nsport; |
| fin->fin_data[0] = ntohs(nat->nat_nsport); |
| tcp->th_dport = nat->nat_ndport; |
| fin->fin_data[1] = ntohs(nat->nat_ndport); |
| break; |
| |
| case NAT_OUTBOUND : |
| tcp->th_sport = nat->nat_odport; |
| fin->fin_data[0] = ntohs(nat->nat_odport); |
| tcp->th_dport = nat->nat_osport; |
| fin->fin_data[1] = ntohs(nat->nat_osport); |
| break; |
| } |
| } |
| |
| |
| if ((nat->nat_odport != 0) && (nflags & IPN_ICMPQUERY)) { |
| icmp = fin->fin_dp; |
| |
| icmp->icmp_id = nat->nat_nicmpid; |
| } |
| |
| csump = ipf_nat_proto(fin, nat, nflags); |
| } |
| |
| ipf_nat_update(fin, nat, np); |
| |
| /* |
| * The above comments do not hold for layer 4 (or higher) checksums... |
| */ |
| if (csump != NULL) { |
| if (nat->nat_dir == NAT_OUTBOUND) |
| ipf_fix_incksum(fin, csump, nat->nat_sumd[0]); |
| else |
| ipf_fix_outcksum(fin, csump, nat->nat_sumd[0]); |
| } |
| fin->fin_flx |= FI_NATED; |
| if (np != NULL && np->in_tag.ipt_num[0] != 0) |
| fin->fin_nattag = &np->in_tag; |
| return 1; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_proto */ |
| /* Returns: u_short* - pointer to transport header checksum to update, */ |
| /* NULL if the transport protocol is not recognised */ |
| /* as needing a checksum update. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to NAT structure */ |
| /* nflags(I) - NAT flags set for this packet */ |
| /* */ |
| /* Return the pointer to the checksum field for each protocol so understood.*/ |
| /* If support for making other changes to a protocol header is required, */ |
| /* that is not strictly 'address' translation, such as clamping the MSS in */ |
| /* TCP down to a specific value, then do it from here. */ |
| /* ------------------------------------------------------------------------ */ |
| u_short * |
| ipf_nat_proto(fin, nat, nflags) |
| fr_info_t *fin; |
| nat_t *nat; |
| u_int nflags; |
| { |
| icmphdr_t *icmp; |
| u_short *csump; |
| tcphdr_t *tcp; |
| udphdr_t *udp; |
| |
| csump = NULL; |
| if (fin->fin_out == 0) { |
| fin->fin_rev = (nat->nat_dir & NAT_OUTBOUND); |
| } else { |
| fin->fin_rev = ((nat->nat_dir & NAT_OUTBOUND) == 0); |
| } |
| |
| switch (fin->fin_p) |
| { |
| case IPPROTO_TCP : |
| tcp = fin->fin_dp; |
| |
| if ((nflags & IPN_TCP) != 0) |
| csump = &tcp->th_sum; |
| |
| /* |
| * Do a MSS CLAMPING on a SYN packet, |
| * only deal IPv4 for now. |
| */ |
| if ((nat->nat_mssclamp != 0) && (tcp->th_flags & TH_SYN) != 0) |
| ipf_nat_mssclamp(tcp, nat->nat_mssclamp, fin, csump); |
| |
| break; |
| |
| case IPPROTO_UDP : |
| udp = fin->fin_dp; |
| |
| if ((nflags & IPN_UDP) != 0) { |
| if (udp->uh_sum != 0) |
| csump = &udp->uh_sum; |
| } |
| break; |
| |
| case IPPROTO_ICMP : |
| icmp = fin->fin_dp; |
| |
| if ((nflags & IPN_ICMPQUERY) != 0) { |
| if (icmp->icmp_cksum != 0) |
| csump = &icmp->icmp_cksum; |
| } |
| break; |
| } |
| return csump; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_unload */ |
| /* Returns: Nil */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Free all memory used by NAT structures allocated at runtime. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_unload() |
| { |
| ipftq_t *ifq, *ifqnext; |
| |
| (void) ipf_nat_clearlist(); |
| (void) ipf_nat_flushtable(); |
| |
| /* |
| * Proxy timeout queues are not cleaned here because although they |
| * exist on the NAT list, appr_unload is called after unload |
| * and the proxies actually are responsible for them being created. |
| * Should the proxy timeouts have their own list? There's no real |
| * justification as this is the only complication. |
| */ |
| for (ifq = ipf_nat_utqe; ifq != NULL; ifq = ifqnext) { |
| ifqnext = ifq->ifq_next; |
| if (((ifq->ifq_flags & IFQF_PROXY) == 0) && |
| (ipf_deletetimeoutqueue(ifq) == 0)) |
| ipf_freetimeoutqueue(ifq); |
| } |
| |
| if (ipf_nat_table[0] != NULL) { |
| KFREES(ipf_nat_table[0], sizeof(nat_t *) * ipf_nat_table_sz); |
| ipf_nat_table[0] = NULL; |
| } |
| if (ipf_nat_table[1] != NULL) { |
| KFREES(ipf_nat_table[1], sizeof(nat_t *) * ipf_nat_table_sz); |
| ipf_nat_table[1] = NULL; |
| } |
| if (ipf_nat_map_rules != NULL) { |
| KFREES(ipf_nat_map_rules, |
| sizeof(ipnat_t *) * ipf_nat_maprules_sz); |
| ipf_nat_map_rules = NULL; |
| } |
| if (ipf_nat_rdr_rules != NULL) { |
| KFREES(ipf_nat_rdr_rules, |
| sizeof(ipnat_t *) * ipf_nat_rdrrules_sz); |
| ipf_nat_rdr_rules = NULL; |
| } |
| if (ipf_hm_maptable != NULL) { |
| KFREES(ipf_hm_maptable, |
| sizeof(hostmap_t *) * ipf_nat_hostmap_sz); |
| ipf_hm_maptable = NULL; |
| } |
| if (ipf_nat_stats.ns_side[0].ns_bucketlen != NULL) { |
| KFREES(ipf_nat_stats.ns_side[0].ns_bucketlen, |
| sizeof(u_int *) * ipf_nat_table_sz); |
| ipf_nat_stats.ns_side[0].ns_bucketlen = NULL; |
| } |
| if (ipf_nat_stats.ns_side[1].ns_bucketlen != NULL) { |
| KFREES(ipf_nat_stats.ns_side[1].ns_bucketlen, |
| sizeof(u_int *) * ipf_nat_table_sz); |
| ipf_nat_stats.ns_side[1].ns_bucketlen = NULL; |
| } |
| |
| if (ipf_nat_maxbucket_reset == 1) |
| ipf_nat_maxbucket = 0; |
| |
| if (ipf_nat_inited == 1) { |
| ipf_nat_inited = 0; |
| ipf_sttab_destroy(ipf_nat_tqb); |
| |
| RW_DESTROY(&ipf_natfrag); |
| RW_DESTROY(&ipf_nat); |
| |
| MUTEX_DESTROY(&ipf_nat_new); |
| MUTEX_DESTROY(&ipf_natio); |
| |
| MUTEX_DESTROY(&ipf_nat_udptq.ifq_lock); |
| MUTEX_DESTROY(&ipf_nat_icmptq.ifq_lock); |
| MUTEX_DESTROY(&ipf_nat_iptq.ifq_lock); |
| } |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_expire */ |
| /* Returns: Nil */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Check all of the timeout queues for entries at the top which need to be */ |
| /* expired. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_expire() |
| { |
| ipftq_t *ifq, *ifqnext; |
| ipftqent_t *tqe, *tqn; |
| int i; |
| SPL_INT(s); |
| |
| SPL_NET(s); |
| WRITE_ENTER(&ipf_nat); |
| for (ifq = ipf_nat_tqb, i = 0; ifq != NULL; ifq = ifq->ifq_next) { |
| for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); i++) { |
| if (tqe->tqe_die > ipf_ticks) |
| break; |
| tqn = tqe->tqe_next; |
| ipf_nat_delete(tqe->tqe_parent, NL_EXPIRE); |
| } |
| } |
| |
| for (ifq = ipf_nat_utqe; ifq != NULL; ifq = ifqnext) { |
| ifqnext = ifq->ifq_next; |
| |
| for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); i++) { |
| if (tqe->tqe_die > ipf_ticks) |
| break; |
| tqn = tqe->tqe_next; |
| ipf_nat_delete(tqe->tqe_parent, NL_EXPIRE); |
| } |
| } |
| |
| for (ifq = ipf_nat_utqe; ifq != NULL; ifq = ifqnext) { |
| ifqnext = ifq->ifq_next; |
| |
| if (((ifq->ifq_flags & IFQF_DELETE) != 0) && |
| (ifq->ifq_ref == 0)) { |
| ipf_freetimeoutqueue(ifq); |
| } |
| } |
| |
| if (ipf_nat_doflush != 0) { |
| ipf_nat_extraflush(2); |
| ipf_nat_doflush = 0; |
| } |
| |
| RWLOCK_EXIT(&ipf_nat); |
| SPL_X(s); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_sync */ |
| /* Returns: Nil */ |
| /* Parameters: ifp(I) - pointer to network interface */ |
| /* */ |
| /* Walk through all of the currently active NAT sessions, looking for those */ |
| /* which need to have their translated address updated. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_sync(ifp) |
| void *ifp; |
| { |
| u_32_t sum1, sum2, sumd; |
| i6addr_t in; |
| ipnat_t *n; |
| nat_t *nat; |
| void *ifp2; |
| int idx; |
| SPL_INT(s); |
| |
| if (ipf_running <= 0) |
| return; |
| |
| /* |
| * Change IP addresses for NAT sessions for any protocol except TCP |
| * since it will break the TCP connection anyway. The only rules |
| * which will get changed are those which are "map ... -> 0/32", |
| * where the rule specifies the address is taken from the interface. |
| */ |
| SPL_NET(s); |
| WRITE_ENTER(&ipf_nat); |
| |
| if (ipf_running <= 0) { |
| RWLOCK_EXIT(&ipf_nat); |
| return; |
| } |
| |
| for (nat = ipf_nat_instances; nat; nat = nat->nat_next) { |
| if ((nat->nat_flags & IPN_TCP) != 0) |
| continue; |
| |
| n = nat->nat_ptr; |
| if (n != NULL) { |
| if (n->in_redir & NAT_MAP) { |
| if ((n->in_nsrcaddr != 0) || |
| (n->in_nsrcmsk != 0xffffffff)) |
| continue; |
| } else if (n->in_redir & NAT_REDIRECT) { |
| if ((n->in_ndstaddr != 0) || |
| (n->in_ndstmsk != 0xffffffff)) |
| continue; |
| } |
| } |
| |
| if (((ifp == NULL) || (ifp == nat->nat_ifps[0]) || |
| (ifp == nat->nat_ifps[1]))) { |
| nat->nat_ifps[0] = GETIFP(nat->nat_ifnames[0], |
| nat->nat_v); |
| if ((nat->nat_ifps[0] != NULL) && |
| (nat->nat_ifps[0] != (void *)-1)) { |
| nat->nat_mtu[0] = GETIFMTU(nat->nat_ifps[0]); |
| } |
| if (nat->nat_ifnames[1][0] != '\0') { |
| nat->nat_ifps[1] = GETIFP(nat->nat_ifnames[1], |
| nat->nat_v); |
| } else { |
| nat->nat_ifps[1] = nat->nat_ifps[0]; |
| } |
| if ((nat->nat_ifps[1] != NULL) && |
| (nat->nat_ifps[1] != (void *)-1)) { |
| nat->nat_mtu[1] = GETIFMTU(nat->nat_ifps[1]); |
| } |
| ifp2 = nat->nat_ifps[0]; |
| if (ifp2 == NULL) |
| continue; |
| |
| /* |
| * Change the map-to address to be the same as the |
| * new one. |
| */ |
| sum1 = NATFSUM(nat, nat_nsrc6); |
| if (ipf_ifpaddr(nat->nat_v, FRI_NORMAL, ifp2, |
| &in, NULL) != -1) { |
| if (nat->nat_v == 4) |
| nat->nat_nsrcip = in.in4; |
| } |
| sum2 = NATFSUM(nat, nat_nsrc6); |
| |
| if (sum1 == sum2) |
| continue; |
| /* |
| * Readjust the checksum adjustment to take into |
| * account the new IP#. |
| */ |
| CALC_SUMD(sum1, sum2, sumd); |
| /* XXX - dont change for TCP when solaris does |
| * hardware checksumming. |
| */ |
| sumd += nat->nat_sumd[0]; |
| nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16); |
| nat->nat_sumd[1] = nat->nat_sumd[0]; |
| } |
| } |
| |
| for (n = ipf_nat_list; (n != NULL); n = n->in_next) { |
| if ((ifp == NULL) || (n->in_ifps[0] == ifp)) |
| n->in_ifps[0] = ipf_resolvenic(n->in_ifnames[0], |
| n->in_v); |
| if ((ifp == NULL) || (n->in_ifps[1] == ifp)) |
| n->in_ifps[1] = ipf_resolvenic(n->in_ifnames[1], |
| n->in_v); |
| |
| if (n->in_redir & NAT_REDIRECT) |
| idx = 1; |
| else |
| idx = 0; |
| |
| if (((ifp == NULL) || (n->in_ifps[idx] == ifp)) && |
| (n->in_ifps[idx] != NULL && |
| n->in_ifps[idx] != (void *)-1)) { |
| |
| ipf_nat_nextaddrinit(&n->in_osrc, 0, n->in_ifps[idx]); |
| ipf_nat_nextaddrinit(&n->in_odst, 0, n->in_ifps[idx]); |
| ipf_nat_nextaddrinit(&n->in_nsrc, 0, n->in_ifps[idx]); |
| ipf_nat_nextaddrinit(&n->in_ndst, 0, n->in_ifps[idx]); |
| } |
| } |
| RWLOCK_EXIT(&ipf_nat); |
| SPL_X(s); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_icmpquerytype4 */ |
| /* Returns: int - 1 == success, 0 == failure */ |
| /* Parameters: icmptype(I) - ICMP type number */ |
| /* */ |
| /* Tests to see if the ICMP type number passed is a query/response type or */ |
| /* not. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_icmpquerytype4(icmptype) |
| int icmptype; |
| { |
| |
| /* |
| * For the ICMP query NAT code, it is essential that both the query |
| * and the reply match on the NAT rule. Because the NAT structure |
| * does not keep track of the icmptype, and a single NAT structure |
| * is used for all icmp types with the same src, dest and id, we |
| * simply define the replies as queries as well. The funny thing is, |
| * altough it seems silly to call a reply a query, this is exactly |
| * as it is defined in the IPv4 specification |
| */ |
| |
| switch (icmptype) |
| { |
| |
| case ICMP_ECHOREPLY: |
| case ICMP_ECHO: |
| /* route aedvertisement/solliciation is currently unsupported: */ |
| /* it would require rewriting the ICMP data section */ |
| case ICMP_TSTAMP: |
| case ICMP_TSTAMPREPLY: |
| case ICMP_IREQ: |
| case ICMP_IREQREPLY: |
| case ICMP_MASKREQ: |
| case ICMP_MASKREPLY: |
| return 1; |
| default: |
| return 0; |
| } |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_log */ |
| /* Returns: Nil */ |
| /* Parameters: nat(I) - pointer to NAT structure */ |
| /* action(I) - action related to NAT structure being performed */ |
| /* */ |
| /* Creates a NAT log entry. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_log(nat, action) |
| struct nat *nat; |
| u_int action; |
| { |
| #ifdef IPFILTER_LOG |
| # ifndef LARGE_NAT |
| struct ipnat *np; |
| int rulen; |
| # endif |
| struct natlog natl; |
| void *items[1]; |
| size_t sizes[1]; |
| int types[1]; |
| |
| bcopy((char *)&nat->nat_osrc6, (char *)&natl.nl_osrcip, |
| sizeof(natl.nl_osrcip)); |
| bcopy((char *)&nat->nat_nsrc6, (char *)&natl.nl_nsrcip, |
| sizeof(natl.nl_nsrcip)); |
| bcopy((char *)&nat->nat_odst6, (char *)&natl.nl_odstip, |
| sizeof(natl.nl_odstip)); |
| bcopy((char *)&nat->nat_ndst6, (char *)&natl.nl_ndstip, |
| sizeof(natl.nl_ndstip)); |
| |
| natl.nl_bytes[0] = nat->nat_bytes[0]; |
| natl.nl_bytes[1] = nat->nat_bytes[1]; |
| natl.nl_pkts[0] = nat->nat_pkts[0]; |
| natl.nl_pkts[1] = nat->nat_pkts[1]; |
| natl.nl_odstport = nat->nat_odport; |
| natl.nl_osrcport = nat->nat_osport; |
| natl.nl_nsrcport = nat->nat_nsport; |
| natl.nl_ndstport = nat->nat_ndport; |
| natl.nl_p = nat->nat_pr[0]; |
| natl.nl_v = nat->nat_v; |
| natl.nl_type = nat->nat_redir; |
| natl.nl_action = action; |
| natl.nl_rule = -1; |
| |
| bcopy(nat->nat_ifnames[0], natl.nl_ifnames[0], |
| sizeof(nat->nat_ifnames[0])); |
| bcopy(nat->nat_ifnames[1], natl.nl_ifnames[1], |
| sizeof(nat->nat_ifnames[1])); |
| |
| # ifndef LARGE_NAT |
| if (nat->nat_ptr != NULL) { |
| for (rulen = 0, np = ipf_nat_list; np != NULL; |
| np = np->in_next, rulen++) |
| if (np == nat->nat_ptr) { |
| natl.nl_rule = rulen; |
| break; |
| } |
| } |
| # endif |
| items[0] = &natl; |
| sizes[0] = sizeof(natl); |
| types[0] = 0; |
| |
| if (ipf_log_items(IPL_LOGNAT, NULL, items, sizes, types, 1) == 0) |
| ipf_nat_stats.ns_side[0].ns_log++; |
| else |
| ipf_nat_stats.ns_side[1].ns_log++; |
| #endif |
| } |
| |
| |
| #if defined(__OpenBSD__) |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_ifdetach */ |
| /* Returns: Nil */ |
| /* Parameters: ifp(I) - pointer to network interface */ |
| /* */ |
| /* Compatibility interface for OpenBSD to trigger the correct updating of */ |
| /* interface references within IPFilter. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_ifdetach(ifp) |
| void *ifp; |
| { |
| ipf_sync(ifp); |
| return; |
| } |
| #endif |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_rulederef */ |
| /* Returns: Nil */ |
| /* Parameters: isp(I) - pointer to pointer to NAT rule */ |
| /* Write Locks: ipf_nat */ |
| /* */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_rulederef(inp) |
| ipnat_t **inp; |
| { |
| ipnat_t *in; |
| |
| in = *inp; |
| *inp = NULL; |
| in->in_space++; |
| in->in_use--; |
| if (in->in_use == 0 && (in->in_flags & IPN_DELETE)) { |
| if (in->in_apr) |
| appr_free(in->in_apr); |
| ipf_nat_stats.ns_rules--; |
| KFREE(in); |
| #if SOLARIS |
| if (ipf_nat_stats.ns_rules) |
| pfil_delayed_copy = 1; |
| #endif |
| } |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_deref */ |
| /* Returns: Nil */ |
| /* Parameters: isp(I) - pointer to pointer to NAT table entry */ |
| /* */ |
| /* Decrement the reference counter for this NAT table entry and free it if */ |
| /* there are no more things using it. */ |
| /* */ |
| /* IF nat_ref == 1 when this function is called, then we have an orphan nat */ |
| /* structure *because* it only gets called on paths _after_ nat_ref has been*/ |
| /* incremented. If nat_ref == 1 then we shouldn't decrement it here */ |
| /* because nat_delete() will do that and send nat_ref to -1. */ |
| /* */ |
| /* Holding the lock on nat_lock is required to serialise nat_delete() being */ |
| /* called from a NAT flush ioctl with a deref happening because of a packet.*/ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_deref(natp) |
| nat_t **natp; |
| { |
| nat_t *nat; |
| |
| nat = *natp; |
| *natp = NULL; |
| |
| MUTEX_ENTER(&nat->nat_lock); |
| if (nat->nat_ref > 1) { |
| nat->nat_ref--; |
| MUTEX_EXIT(&nat->nat_lock); |
| return; |
| } |
| MUTEX_EXIT(&nat->nat_lock); |
| |
| WRITE_ENTER(&ipf_nat); |
| ipf_nat_delete(nat, NL_EXPIRE); |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_clone */ |
| /* Returns: ipstate_t* - NULL == cloning failed, */ |
| /* else pointer to new state structure */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* is(I) - pointer to master state structure */ |
| /* Write Lock: ipf_nat */ |
| /* */ |
| /* Create a "duplcate" state table entry from the master. */ |
| /* ------------------------------------------------------------------------ */ |
| static nat_t * |
| ipf_nat_clone(fin, nat) |
| fr_info_t *fin; |
| nat_t *nat; |
| { |
| frentry_t *fr; |
| nat_t *clone; |
| ipnat_t *np; |
| |
| KMALLOC(clone, nat_t *); |
| if (clone == NULL) { |
| ipf_nat_stats.ns_side[fin->fin_out].ns_clone_nomem++; |
| return NULL; |
| } |
| bcopy((char *)nat, (char *)clone, sizeof(*clone)); |
| |
| MUTEX_NUKE(&clone->nat_lock); |
| |
| clone->nat_aps = NULL; |
| /* |
| * Initialize all these so that ipf_nat_delete() doesn't cause a crash. |
| */ |
| clone->nat_tqe.tqe_pnext = NULL; |
| clone->nat_tqe.tqe_next = NULL; |
| clone->nat_tqe.tqe_ifq = NULL; |
| clone->nat_tqe.tqe_parent = clone; |
| |
| clone->nat_flags &= ~SI_CLONE; |
| clone->nat_flags |= SI_CLONED; |
| |
| if (clone->nat_hm) |
| clone->nat_hm->hm_ref++; |
| |
| if (ipf_nat_insert(clone, fin->fin_rev) == -1) { |
| KFREE(clone); |
| ipf_nat_stats.ns_side[fin->fin_out].ns_insert_fail++; |
| return NULL; |
| } |
| np = clone->nat_ptr; |
| if (np != NULL) { |
| if (ipf_nat_logging) |
| ipf_nat_log(clone, NL_CLONE); |
| np->in_use++; |
| } |
| fr = clone->nat_fr; |
| if (fr != NULL) { |
| MUTEX_ENTER(&fr->fr_lock); |
| fr->fr_ref++; |
| MUTEX_EXIT(&fr->fr_lock); |
| } |
| |
| |
| /* |
| * Because the clone is created outside the normal loop of things and |
| * TCP has special needs in terms of state, initialise the timeout |
| * state of the new NAT from here. |
| */ |
| if (clone->nat_pr[0] == IPPROTO_TCP) { |
| (void) ipf_tcp_age(&clone->nat_tqe, fin, ipf_nat_tqb, |
| clone->nat_flags, 2); |
| } |
| #ifdef IPFILTER_SYNC |
| clone->nat_sync = ipf_sync_new(SMC_NAT, fin, clone); |
| #endif |
| if (ipf_nat_logging) |
| ipf_nat_log(clone, NL_CLONE); |
| return clone; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_wildok */ |
| /* Returns: int - 1 == packet's ports match wildcards */ |
| /* 0 == packet's ports don't match wildcards */ |
| /* Parameters: nat(I) - NAT entry */ |
| /* sport(I) - source port */ |
| /* dport(I) - destination port */ |
| /* flags(I) - wildcard flags */ |
| /* dir(I) - packet direction */ |
| /* */ |
| /* Use NAT entry and packet direction to determine which combination of */ |
| /* wildcard flags should be used. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_wildok(nat, sport, dport, flags, dir) |
| nat_t *nat; |
| int sport, dport, flags, dir; |
| { |
| /* |
| * When called by dir is set to |
| * nat_inlookup NAT_INBOUND (0) |
| * nat_outlookup NAT_OUTBOUND (1) |
| * |
| * We simply combine the packet's direction in dir with the original |
| * "intended" direction of that NAT entry in nat->nat_dir to decide |
| * which combination of wildcard flags to allow. |
| */ |
| switch ((dir << 1) | nat->nat_dir) |
| { |
| case 3: /* outbound packet / outbound entry */ |
| if (((nat->nat_osport == sport) || |
| (flags & SI_W_SPORT)) && |
| ((nat->nat_odport == dport) || |
| (flags & SI_W_DPORT))) |
| return 1; |
| break; |
| case 2: /* outbound packet / inbound entry */ |
| if (((nat->nat_osport == dport) || |
| (flags & SI_W_SPORT)) && |
| ((nat->nat_odport == sport) || |
| (flags & SI_W_DPORT))) |
| return 1; |
| break; |
| case 1: /* inbound packet / outbound entry */ |
| if (((nat->nat_osport == dport) || |
| (flags & SI_W_SPORT)) && |
| ((nat->nat_odport == sport) || |
| (flags & SI_W_DPORT))) |
| return 1; |
| break; |
| case 0: /* inbound packet / inbound entry */ |
| if (((nat->nat_osport == sport) || |
| (flags & SI_W_SPORT)) && |
| ((nat->nat_odport == dport) || |
| (flags & SI_W_DPORT))) |
| return 1; |
| break; |
| default: |
| break; |
| } |
| |
| return(0); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_mssclamp */ |
| /* Returns: Nil */ |
| /* Parameters: tcp(I) - pointer to TCP header */ |
| /* maxmss(I) - value to clamp the TCP MSS to */ |
| /* fin(I) - pointer to packet information */ |
| /* csump(I) - pointer to TCP checksum */ |
| /* */ |
| /* Check for MSS option and clamp it if necessary. If found and changed, */ |
| /* then the TCP header checksum will be updated to reflect the change in */ |
| /* the MSS. */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_nat_mssclamp(tcp, maxmss, fin, csump) |
| tcphdr_t *tcp; |
| u_32_t maxmss; |
| fr_info_t *fin; |
| u_short *csump; |
| { |
| u_char *cp, *ep, opt; |
| int hlen, advance; |
| u_32_t mss, sumd; |
| |
| hlen = TCP_OFF(tcp) << 2; |
| if (hlen > sizeof(*tcp)) { |
| cp = (u_char *)tcp + sizeof(*tcp); |
| ep = (u_char *)tcp + hlen; |
| |
| while (cp < ep) { |
| opt = cp[0]; |
| if (opt == TCPOPT_EOL) |
| break; |
| else if (opt == TCPOPT_NOP) { |
| cp++; |
| continue; |
| } |
| |
| if (cp + 1 >= ep) |
| break; |
| advance = cp[1]; |
| if ((cp + advance > ep) || (advance <= 0)) |
| break; |
| switch (opt) |
| { |
| case TCPOPT_MAXSEG: |
| if (advance != 4) |
| break; |
| mss = cp[2] * 256 + cp[3]; |
| if (mss > maxmss) { |
| cp[2] = maxmss / 256; |
| cp[3] = maxmss & 0xff; |
| CALC_SUMD(mss, maxmss, sumd); |
| ipf_fix_outcksum(fin, csump, sumd); |
| } |
| break; |
| default: |
| /* ignore unknown options */ |
| break; |
| } |
| |
| cp += advance; |
| } |
| } |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_setqueue */ |
| /* Returns: Nil */ |
| /* Parameters: nat(I)- pointer to NAT structure */ |
| /* rev(I) - forward(0) or reverse(1) direction */ |
| /* Locks: ipf_nat (read or write) */ |
| /* */ |
| /* Put the NAT entry on its default queue entry, using rev as a helped in */ |
| /* determining which queue it should be placed on. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_setqueue(nat, rev) |
| nat_t *nat; |
| int rev; |
| { |
| ipftq_t *oifq, *nifq; |
| |
| if (nat->nat_ptr != NULL) |
| nifq = nat->nat_ptr->in_tqehead[rev]; |
| else |
| nifq = NULL; |
| |
| if (nifq == NULL) { |
| switch (nat->nat_pr[0]) |
| { |
| case IPPROTO_UDP : |
| nifq = &ipf_nat_udptq; |
| break; |
| case IPPROTO_ICMP : |
| nifq = &ipf_nat_icmptq; |
| break; |
| case IPPROTO_TCP : |
| nifq = ipf_nat_tqb + nat->nat_tqe.tqe_state[rev]; |
| break; |
| default : |
| nifq = &ipf_nat_iptq; |
| break; |
| } |
| } |
| |
| oifq = nat->nat_tqe.tqe_ifq; |
| /* |
| * If it's currently on a timeout queue, move it from one queue to |
| * another, else put it on the end of the newly determined queue. |
| */ |
| if (oifq != NULL) |
| ipf_movequeue(&nat->nat_tqe, oifq, nifq); |
| else |
| ipf_queueappend(&nat->nat_tqe, nifq, nat); |
| return; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_getnext */ |
| /* Returns: int - 0 == ok, else error */ |
| /* Parameters: t(I) - pointer to ipftoken structure */ |
| /* itp(I) - pointer to ipfgeniter_t structure */ |
| /* */ |
| /* Fetch the next nat/ipnat structure pointer from the linked list and */ |
| /* copy it out to the storage space pointed to by itp_data. The next item */ |
| /* in the list to look at is put back in the ipftoken struture. */ |
| /* If we call ipf_freetoken, the accompanying pointer is set to NULL because*/ |
| /* ipf_freetoken will call a deref function for us and we dont want to call */ |
| /* that twice (second time would be in the second switch statement below. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_getnext(t, itp) |
| ipftoken_t *t; |
| ipfgeniter_t *itp; |
| { |
| hostmap_t *hm, *nexthm = NULL, zerohm; |
| ipnat_t *ipn, *nextipnat = NULL, zeroipn; |
| nat_t *nat, *nextnat = NULL, zeronat; |
| int error = 0, count; |
| ipftoken_t *freet; |
| char *dst; |
| |
| freet = NULL; |
| count = itp->igi_nitems; |
| if (count < 1) |
| return ENOSPC; |
| |
| READ_ENTER(&ipf_nat); |
| |
| switch (itp->igi_type) |
| { |
| case IPFGENITER_HOSTMAP : |
| hm = t->ipt_data; |
| if (hm == NULL) { |
| nexthm = ipf_hm_maplist; |
| } else { |
| nexthm = hm->hm_next; |
| } |
| break; |
| |
| case IPFGENITER_IPNAT : |
| ipn = t->ipt_data; |
| if (ipn == NULL) { |
| nextipnat = ipf_nat_list; |
| } else { |
| nextipnat = ipn->in_next; |
| } |
| break; |
| |
| case IPFGENITER_NAT : |
| nat = t->ipt_data; |
| if (nat == NULL) { |
| nextnat = ipf_nat_instances; |
| } else { |
| nextnat = nat->nat_next; |
| } |
| break; |
| default : |
| RWLOCK_EXIT(&ipf_nat); |
| ipf_interror = 60055; |
| return EINVAL; |
| } |
| |
| dst = itp->igi_data; |
| for (;;) { |
| switch (itp->igi_type) |
| { |
| case IPFGENITER_HOSTMAP : |
| if (nexthm != NULL) { |
| if (nexthm->hm_next == NULL) { |
| freet = t; |
| count = 1; |
| } |
| if (count == 1) { |
| ATOMIC_INC32(nexthm->hm_ref); |
| } |
| } else { |
| bzero(&zerohm, sizeof(zerohm)); |
| nexthm = &zerohm; |
| count = 1; |
| } |
| break; |
| |
| case IPFGENITER_IPNAT : |
| if (nextipnat != NULL) { |
| if (nextipnat->in_next == NULL) { |
| freet = t; |
| count = 1; |
| } |
| if (count == 1) { |
| MUTEX_ENTER(&nextipnat->in_lock); |
| nextipnat->in_use++; |
| MUTEX_EXIT(&nextipnat->in_lock); |
| } |
| } else { |
| bzero(&zeroipn, sizeof(zeroipn)); |
| nextipnat = &zeroipn; |
| count = 1; |
| } |
| break; |
| |
| case IPFGENITER_NAT : |
| if (nextnat != NULL) { |
| if (nextnat->nat_next == NULL) { |
| count = 1; |
| freet = t; |
| } |
| if (count == 1) { |
| MUTEX_ENTER(&nextnat->nat_lock); |
| nextnat->nat_ref++; |
| MUTEX_EXIT(&nextnat->nat_lock); |
| } |
| } else { |
| bzero(&zeronat, sizeof(zeronat)); |
| nextnat = &zeronat; |
| count = 1; |
| } |
| break; |
| default : |
| break; |
| } |
| RWLOCK_EXIT(&ipf_nat); |
| |
| if (freet != NULL) { |
| ipf_freetoken(freet); |
| } |
| |
| switch (itp->igi_type) |
| { |
| case IPFGENITER_HOSTMAP : |
| error = COPYOUT(nexthm, dst, sizeof(*nexthm)); |
| if (error != 0) { |
| ipf_interror = 60049; |
| error = EFAULT; |
| } else { |
| dst += sizeof(*nexthm); |
| } |
| if (freet == NULL) { |
| t->ipt_data = nexthm; |
| hm = nexthm; |
| nexthm = hm->hm_next; |
| } |
| break; |
| |
| case IPFGENITER_IPNAT : |
| error = COPYOUT(nextipnat, dst, sizeof(*nextipnat)); |
| if (error != 0) { |
| ipf_interror = 60050; |
| error = EFAULT; |
| } else { |
| dst += sizeof(*nextipnat); |
| } |
| if (freet == NULL) { |
| t->ipt_data = nextipnat; |
| ipn = nextipnat; |
| nextipnat = ipn->in_next; |
| } |
| break; |
| |
| case IPFGENITER_NAT : |
| error = COPYOUT(nextnat, dst, sizeof(*nextnat)); |
| if (error != 0) { |
| ipf_interror = 60051; |
| error = EFAULT; |
| } else { |
| dst += sizeof(*nextnat); |
| } |
| if (freet == NULL) { |
| t->ipt_data = nextnat; |
| nat = nextnat; |
| nextnat = nat->nat_next; |
| } |
| break; |
| } |
| |
| if ((count == 1) || (error != 0)) |
| break; |
| |
| READ_ENTER(&ipf_nat); |
| } |
| |
| return error; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_extraflush */ |
| /* Returns: int - 0 == success, -1 == failure */ |
| /* Parameters: which(I) - how to flush the active NAT table */ |
| /* Write Locks: ipf_nat */ |
| /* */ |
| /* Flush nat tables. Three actions currently defined: */ |
| /* which == 0 : flush all nat table entries */ |
| /* which == 1 : flush TCP connections which have started to close but are */ |
| /* stuck for some reason. */ |
| /* which == 2 : flush TCP connections which have been idle for a long time, */ |
| /* starting at > 4 days idle and working back in successive half-*/ |
| /* days to at most 12 hours old. If this fails to free enough */ |
| /* slots then work backwards in half hour slots to 30 minutes. */ |
| /* If that too fails, then work backwards in 30 second intervals */ |
| /* for the last 30 minutes to at worst 30 seconds idle. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_extraflush(which) |
| int which; |
| { |
| ipftq_t *ifq, *ifqnext; |
| nat_t *nat, **natp; |
| ipftqent_t *tqn; |
| int removed; |
| SPL_INT(s); |
| |
| removed = 0; |
| |
| SPL_NET(s); |
| switch (which) |
| { |
| case 0 : |
| ipf_nat_stats.ns_flush_all++; |
| /* |
| * Style 0 flush removes everything... |
| */ |
| for (natp = &ipf_nat_instances; ((nat = *natp) != NULL); ) { |
| ipf_nat_delete(nat, NL_FLUSH); |
| removed++; |
| } |
| break; |
| |
| case 1 : |
| ipf_nat_stats.ns_flush_closing++; |
| /* |
| * Since we're only interested in things that are closing, |
| * we can start with the appropriate timeout queue. |
| */ |
| for (ifq = ipf_nat_tqb + IPF_TCPS_CLOSE_WAIT; ifq != NULL; |
| ifq = ifq->ifq_next) { |
| |
| for (tqn = ifq->ifq_head; tqn != NULL; ) { |
| nat = tqn->tqe_parent; |
| tqn = tqn->tqe_next; |
| if (nat->nat_pr[0] != IPPROTO_TCP || |
| nat->nat_pr[1] != IPPROTO_TCP) |
| break; |
| ipf_nat_delete(nat, NL_EXPIRE); |
| removed++; |
| } |
| } |
| |
| /* |
| * Also need to look through the user defined queues. |
| */ |
| for (ifq = ipf_nat_utqe; ifq != NULL; ifq = ifqnext) { |
| ifqnext = ifq->ifq_next; |
| for (tqn = ifq->ifq_head; tqn != NULL; ) { |
| nat = tqn->tqe_parent; |
| tqn = tqn->tqe_next; |
| if (nat->nat_pr[0] != IPPROTO_TCP || |
| nat->nat_pr[1] != IPPROTO_TCP) |
| continue; |
| |
| if ((nat->nat_tcpstate[0] > |
| IPF_TCPS_ESTABLISHED) && |
| (nat->nat_tcpstate[1] > |
| IPF_TCPS_ESTABLISHED)) { |
| ipf_nat_delete(nat, NL_EXPIRE); |
| removed++; |
| } |
| } |
| } |
| break; |
| |
| /* |
| * Args 5-11 correspond to flushing those particular states |
| * for TCP connections. |
| */ |
| case IPF_TCPS_CLOSE_WAIT : |
| case IPF_TCPS_FIN_WAIT_1 : |
| case IPF_TCPS_CLOSING : |
| case IPF_TCPS_LAST_ACK : |
| case IPF_TCPS_FIN_WAIT_2 : |
| case IPF_TCPS_TIME_WAIT : |
| case IPF_TCPS_CLOSED : |
| ipf_nat_stats.ns_flush_state++; |
| tqn = ipf_nat_tqb[which].ifq_head; |
| while (tqn != NULL) { |
| nat = tqn->tqe_parent; |
| tqn = tqn->tqe_next; |
| ipf_nat_delete(nat, NL_FLUSH); |
| removed++; |
| } |
| break; |
| |
| default : |
| if (which < 30) |
| break; |
| |
| ipf_nat_stats.ns_flush_timeout++; |
| /* |
| * Take a large arbitrary number to mean the number of seconds |
| * for which which consider to be the maximum value we'll allow |
| * the expiration to be. |
| */ |
| which = IPF_TTLVAL(which); |
| for (natp = &ipf_nat_instances; ((nat = *natp) != NULL); ) { |
| if (ipf_ticks - nat->nat_touched > which) { |
| ipf_nat_delete(nat, NL_FLUSH); |
| removed++; |
| } else |
| natp = &nat->nat_next; |
| } |
| break; |
| } |
| |
| if (which != 2) { |
| SPL_X(s); |
| return removed; |
| } |
| |
| ipf_nat_stats.ns_flush_queue++; |
| |
| /* |
| * Asked to remove inactive entries because the table is full, try |
| * again, 3 times, if first attempt failed with a different criteria |
| * each time. The order tried in must be in decreasing age. |
| * Another alternative is to implement random drop and drop N entries |
| * at random until N have been freed up. |
| */ |
| if (ipf_ticks - ipf_nat_last_force_flush > IPF_TTLVAL(5)) { |
| ipf_nat_last_force_flush = ipf_ticks; |
| |
| removed = ipf_queueflush(ipf_nat_flush_entry, ipf_nat_tqb, |
| ipf_nat_utqe, &ipf_nat_stats.ns_active, |
| ipf_nat_table_sz, |
| ipf_nat_table_wm_low); |
| } |
| |
| SPL_X(s); |
| return removed; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_flush_entry */ |
| /* Returns: 0 - always succeeds */ |
| /* Parameters: entry(I) - pointer to NAT entry */ |
| /* Write Locks: ipf_nat */ |
| /* */ |
| /* This function is a stepping stone between ipf_queueflush() and */ |
| /* nat_dlete(). It is used so we can provide a uniform interface via the */ |
| /* ipf_queueflush() function. Since the nat_delete() function returns void */ |
| /* we translate that to mean it always succeeds in deleting something. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_flush_entry(entry) |
| void *entry; |
| { |
| ipf_nat_delete(entry, NL_FLUSH); |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_iterator */ |
| /* Returns: int - 0 == ok, else error */ |
| /* Parameters: token(I) - pointer to ipftoken structure */ |
| /* itp(I) - pointer to ipfgeniter_t structure */ |
| /* */ |
| /* This function acts as a handler for the SIOCGENITER ioctls that use a */ |
| /* generic structure to iterate through a list. There are three different */ |
| /* linked lists of NAT related information to go through: NAT rules, active */ |
| /* NAT mappings and the NAT fragment cache. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_iterator(token, itp) |
| ipftoken_t *token; |
| ipfgeniter_t *itp; |
| { |
| int error; |
| |
| if (itp->igi_data == NULL) { |
| ipf_interror = 60052; |
| return EFAULT; |
| } |
| |
| token->ipt_subtype = itp->igi_type; |
| |
| switch (itp->igi_type) |
| { |
| case IPFGENITER_HOSTMAP : |
| case IPFGENITER_IPNAT : |
| case IPFGENITER_NAT : |
| error = ipf_nat_getnext(token, itp); |
| break; |
| |
| case IPFGENITER_NATFRAG : |
| #ifdef USE_MUTEXES |
| error = ipf_frag_next(token, itp, &ipfr_natlist, |
| &ipfr_nattail, &ipf_natfrag); |
| #else |
| error = ipf_frag_next(token, itp, &ipfr_natlist, &ipfr_nattail); |
| #endif |
| break; |
| default : |
| ipf_interror = 60053; |
| error = EINVAL; |
| break; |
| } |
| |
| return error; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_setpending */ |
| /* Returns: Nil */ |
| /* Parameters: nat(I) - pointer to NAT structure */ |
| /* Locks: ipf_nat (read or write) */ |
| /* */ |
| /* Put the NAT entry on to the pending queue - this queue has a very short */ |
| /* lifetime where items are put that can't be deleted straight away because */ |
| /* of locking issues but we want to delete them ASAP, anyway. In calling */ |
| /* this function, it is assumed that the owner (if there is one, as shown */ |
| /* by nat_me) is no longer interested in it. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_nat_setpending(nat) |
| nat_t *nat; |
| { |
| ipftq_t *oifq; |
| |
| oifq = nat->nat_tqe.tqe_ifq; |
| if (oifq != NULL) |
| ipf_movequeue(&nat->nat_tqe, oifq, &ipf_nat_pending); |
| else |
| ipf_queueappend(&nat->nat_tqe, &ipf_nat_pending, nat); |
| |
| if (nat->nat_me != NULL) { |
| *nat->nat_me = NULL; |
| nat->nat_me = NULL; |
| } |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_newrewrite */ |
| /* Returns: int - -1 == error, 0 == success (no move), 1 == success and */ |
| /* allow rule to be moved if IPN_ROUNDR is set. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to NAT entry */ |
| /* ni(I) - pointer to structure with misc. information needed */ |
| /* to create new NAT entry. */ |
| /* Write Lock: ipf_nat */ |
| /* */ |
| /* This function is responsible for setting up an active NAT session where */ |
| /* we are changing both the source and destination parameters at the same */ |
| /* time. The loop in here works differently to elsewhere - each iteration */ |
| /* is responsible for changing a single parameter that can be incremented. */ |
| /* So one pass may increase the source IP#, next source port, next dest. IP#*/ |
| /* and the last destination port for a total of 4 iterations to try each. */ |
| /* This is done to try and exhaustively use the translation space available.*/ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_newrewrite(fin, nat, nai) |
| fr_info_t *fin; |
| nat_t *nat; |
| natinfo_t *nai; |
| { |
| int src_search = 1; |
| int dst_search = 1; |
| fr_info_t frnat; |
| u_32_t flags; |
| u_short swap; |
| ipnat_t *np; |
| nat_t *natl; |
| int l = 0; |
| int changed; |
| |
| natl = NULL; |
| changed = -1; |
| np = nai->nai_np; |
| flags = nai->nai_flags; |
| bcopy((char *)fin, (char *)&frnat, sizeof(*fin)); |
| frnat.fin_state = NULL; |
| |
| nat->nat_hm = NULL; |
| |
| do { |
| changed = -1; |
| /* TRACE (l, src_search, dst_search, np) */ |
| |
| if ((src_search == 0) && (np->in_spnext == 0) && |
| (dst_search == 0) && (np->in_dpnext == 0)) { |
| if (l > 0) |
| return -1; |
| } |
| |
| /* |
| * Find a new source address |
| */ |
| if (ipf_nat_nextaddr(fin, &np->in_nsrc, &frnat.fin_saddr, |
| &frnat.fin_saddr) == -1) { |
| return -1; |
| } |
| |
| if ((np->in_nsrcaddr == 0) && (np->in_nsrcmsk == 0xffffffff)) { |
| src_search = 0; |
| if (np->in_stepnext == 0) |
| np->in_stepnext = 1; |
| |
| } else if ((np->in_nsrcaddr == 0) && (np->in_nsrcmsk == 0)) { |
| src_search = 0; |
| if (np->in_stepnext == 0) |
| np->in_stepnext = 1; |
| |
| } else if (np->in_nsrcmsk == 0xffffffff) { |
| src_search = 0; |
| if (np->in_stepnext == 0) |
| np->in_stepnext = 1; |
| |
| } else if (np->in_nsrcmsk != 0xffffffff) { |
| if (np->in_stepnext == 0 && changed == -1) { |
| np->in_snip++; |
| np->in_stepnext++; |
| changed = 0; |
| } |
| } |
| |
| if ((flags & IPN_TCPUDPICMP) != 0) { |
| if (np->in_spnext != 0) |
| frnat.fin_data[0] = np->in_spnext; |
| |
| /* |
| * Standard port translation. Select next port. |
| */ |
| if ((flags & IPN_FIXEDSPORT) != 0) { |
| np->in_stepnext = 2; |
| } else if ((np->in_stepnext == 1) && |
| (changed == -1) && (natl != NULL)) { |
| np->in_spnext++; |
| np->in_stepnext++; |
| changed = 1; |
| if (np->in_spnext > np->in_spmax) |
| np->in_spnext = np->in_spmin; |
| } |
| } else { |
| np->in_stepnext = 2; |
| } |
| np->in_stepnext &= 0x3; |
| |
| /* |
| * Find a new destination address |
| */ |
| /* TRACE (fin, np, l, frnat) */ |
| |
| if (ipf_nat_nextaddr(fin, &np->in_ndst, &frnat.fin_daddr, |
| &frnat.fin_daddr) == -1) |
| return -1; |
| |
| if ((np->in_ndstaddr == 0) && (np->in_ndstmsk == 0xffffffff)) { |
| dst_search = 0; |
| if (np->in_stepnext == 2) |
| np->in_stepnext = 3; |
| |
| } else if ((np->in_ndstaddr == 0) && (np->in_ndstmsk == 0)) { |
| dst_search = 0; |
| if (np->in_stepnext == 2) |
| np->in_stepnext = 3; |
| |
| } else if (np->in_ndstmsk == 0xffffffff) { |
| dst_search = 0; |
| if (np->in_stepnext == 2) |
| np->in_stepnext = 3; |
| |
| } else if (np->in_ndstmsk != 0xffffffff) { |
| if ((np->in_stepnext == 2) && (changed == -1) && |
| (natl != NULL)) { |
| changed = 2; |
| np->in_stepnext++; |
| np->in_dnip++; |
| } |
| } |
| |
| if ((flags & IPN_TCPUDPICMP) != 0) { |
| if (np->in_dpnext != 0) |
| frnat.fin_data[1] = np->in_dpnext; |
| |
| /* |
| * Standard port translation. Select next port. |
| */ |
| if ((flags & IPN_FIXEDDPORT) != 0) { |
| np->in_stepnext = 0; |
| } else if (np->in_stepnext == 3 && changed == -1) { |
| np->in_dpnext++; |
| np->in_stepnext++; |
| changed = 3; |
| if (np->in_dpnext > np->in_dpmax) |
| np->in_dpnext = np->in_dpmin; |
| } |
| } else { |
| if (np->in_stepnext == 3) |
| np->in_stepnext = 0; |
| } |
| |
| /* TRACE (frnat) */ |
| |
| /* |
| * Here we do a lookup of the connection as seen from |
| * the outside. If an IP# pair already exists, try |
| * again. So if you have A->B becomes C->B, you can |
| * also have D->E become C->E but not D->B causing |
| * another C->B. Also take protocol and ports into |
| * account when determining whether a pre-existing |
| * NAT setup will cause an external conflict where |
| * this is appropriate. |
| * |
| * fin_data[] is swapped around because we are doing a |
| * lookup of the packet is if it were moving in the opposite |
| * direction of the one we are working with now. |
| */ |
| if (flags & IPN_TCPUDP) { |
| swap = frnat.fin_data[0]; |
| frnat.fin_data[0] = frnat.fin_data[1]; |
| frnat.fin_data[1] = swap; |
| } |
| if (fin->fin_out == 1) { |
| natl = ipf_nat_inlookup(&frnat, |
| flags & ~(SI_WILDP|NAT_SEARCH), |
| (u_int)frnat.fin_p, frnat.fin_dst, |
| frnat.fin_src); |
| |
| } else { |
| natl = ipf_nat_outlookup(&frnat, |
| flags & ~(SI_WILDP|NAT_SEARCH), |
| (u_int)frnat.fin_p, frnat.fin_dst, |
| frnat.fin_src); |
| } |
| if (flags & IPN_TCPUDP) { |
| swap = frnat.fin_data[0]; |
| frnat.fin_data[0] = frnat.fin_data[1]; |
| frnat.fin_data[1] = swap; |
| } |
| |
| /* TRACE natl, in_stepnext, l */ |
| |
| if ((natl != NULL) && (l > 8)) /* XXX 8 is arbitrary */ |
| return -1; |
| |
| np->in_stepnext &= 0x3; |
| |
| l++; |
| changed = -1; |
| } while (natl != NULL); |
| nat->nat_osrcip = fin->fin_src; |
| nat->nat_odstip = fin->fin_dst; |
| nat->nat_nsrcip = frnat.fin_src; |
| nat->nat_ndstip = frnat.fin_dst; |
| |
| if ((flags & IPN_TCPUDPICMP) != 0) { |
| nat->nat_osport = htons(fin->fin_data[0]); |
| nat->nat_odport = htons(fin->fin_data[1]); |
| nat->nat_nsport = htons(frnat.fin_data[0]); |
| nat->nat_ndport = htons(frnat.fin_data[1]); |
| } |
| |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_newdivert */ |
| /* Returns: int - -1 == error, 0 == success */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to NAT entry */ |
| /* ni(I) - pointer to structure with misc. information needed */ |
| /* to create new NAT entry. */ |
| /* Write Lock: ipf_nat */ |
| /* */ |
| /* Create a new NAT encap/divert session as defined by the NAT rule. This */ |
| /* is somewhat different to other NAT session creation routines because we */ |
| /* do not iterate through either port numbers or IP addresses, searching */ |
| /* for a unique mapping, however, a complimentary duplicate check is made. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_newdivert(fin, nat, nai) |
| fr_info_t *fin; |
| nat_t *nat; |
| natinfo_t *nai; |
| { |
| fr_info_t frnat; |
| ipnat_t *np; |
| nat_t *natl; |
| int p; |
| |
| np = nai->nai_np; |
| bcopy((char *)fin, (char *)&frnat, sizeof(*fin)); |
| |
| nat->nat_pr[0] = 0; |
| nat->nat_osrcaddr = fin->fin_saddr; |
| nat->nat_odstaddr = fin->fin_daddr; |
| nat->nat_osport = htons(fin->fin_data[0]); |
| nat->nat_odport = htons(fin->fin_data[1]); |
| frnat.fin_saddr = htonl(np->in_snip); |
| frnat.fin_daddr = htonl(np->in_dnip); |
| |
| if (np->in_redir & NAT_DIVERTUDP) { |
| frnat.fin_data[0] = np->in_spnext; |
| frnat.fin_data[1] = np->in_dpnext; |
| frnat.fin_flx |= FI_TCPUDP; |
| p = IPPROTO_UDP; |
| } else { |
| frnat.fin_flx &= ~FI_TCPUDP; |
| p = IPPROTO_ENCAP; |
| } |
| |
| if (fin->fin_out == 1) { |
| natl = ipf_nat_inlookup(&frnat, 0, p, |
| frnat.fin_dst, frnat.fin_src); |
| |
| } else { |
| natl = ipf_nat_outlookup(&frnat, 0, p, |
| frnat.fin_dst, frnat.fin_src); |
| } |
| |
| if (natl != NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[fin->fin_out]. |
| ns_divert_exist); |
| return -1; |
| } |
| |
| nat->nat_nsrcaddr = frnat.fin_saddr; |
| nat->nat_ndstaddr = frnat.fin_daddr; |
| if (np->in_redir & NAT_DIVERTUDP) { |
| nat->nat_nsport = htons(frnat.fin_data[0]); |
| nat->nat_ndport = htons(frnat.fin_data[1]); |
| } |
| nat->nat_pr[fin->fin_out] = fin->fin_p; |
| nat->nat_pr[1 - fin->fin_out] = p; |
| |
| if (np->in_redir & NAT_ENCAP) { |
| if (np->in_redir & NAT_REDIRECT) |
| nat->nat_dir = NAT_ENCAPIN; |
| else |
| nat->nat_dir = NAT_ENCAPOUT; |
| } else { |
| if (np->in_redir & NAT_REDIRECT) |
| nat->nat_dir = NAT_DIVERTIN; |
| else |
| nat->nat_dir = NAT_DIVERTOUT; |
| } |
| |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_builddivertmp */ |
| /* Returns: int - -1 == error, 0 == success */ |
| /* Parameters: np(I) - pointer to a NAT rule */ |
| /* */ |
| /* For encap/divert rules, a skeleton packet representing what will be */ |
| /* prepended to the real packet is created. Even though we don't have the */ |
| /* full packet here, a checksum is calculated that we update later when we */ |
| /* fill in the final details. At present a 0 checksum for UDP is being set */ |
| /* here because it is expected that divert will be used for localhost. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_builddivertmp(np) |
| ipnat_t *np; |
| { |
| udphdr_t *uh; |
| size_t len; |
| ip_t *ip; |
| |
| if ((np->in_redir & NAT_DIVERTUDP) != 0) |
| len = sizeof(ip_t) + sizeof(udphdr_t); |
| else |
| len = sizeof(ip_t); |
| |
| ALLOC_MB_T(np->in_divmp, len); |
| if (np->in_divmp == NULL) { |
| ATOMIC_INCL(ipf_nat_stats.ns_divert_build); |
| return -1; |
| } |
| |
| /* |
| * First, the header to get the packet diverted to the new destination |
| */ |
| ip = MTOD(np->in_divmp, ip_t *); |
| IP_V_A(ip, 4); |
| IP_HL_A(ip, 5); |
| ip->ip_tos = 0; |
| if ((np->in_redir & NAT_DIVERTUDP) != 0) |
| ip->ip_p = IPPROTO_UDP; |
| else |
| ip->ip_p = IPPROTO_ENCAP; |
| ip->ip_ttl = 255; |
| ip->ip_off = 0; |
| ip->ip_sum = 0; |
| ip->ip_len = htons(len); |
| ip->ip_id = 0; |
| ip->ip_src.s_addr = htonl(np->in_snip); |
| ip->ip_dst.s_addr = htonl(np->in_dnip); |
| ip->ip_sum = ipf_cksum((u_short *)ip, sizeof(*ip)); |
| |
| if (np->in_redir & NAT_DIVERTUDP) { |
| uh = (udphdr_t *)(ip + 1); |
| uh->uh_sum = 0; |
| uh->uh_ulen = 8; |
| uh->uh_sport = htons(np->in_spnext); |
| uh->uh_dport = htons(np->in_dpnext); |
| } |
| |
| return 0; |
| } |
| |
| |
| #define MINDECAP (sizeof(ip_t) + sizeof(udphdr_t) + sizeof(ip_t)) |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_decap */ |
| /* Returns: int - -1 == error, 0 == success */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to current NAT session */ |
| /* */ |
| /* This function is responsible for undoing a packet's encapsulation in the */ |
| /* reverse of an encap/divert rule. After removing the outer encapsulation */ |
| /* it is necessary to call ipf_makefrip() again so that the contents of 'fin'*/ |
| /* match the "new" packet as it may still be used by IPFilter elsewhere. */ |
| /* We use "dir" here as the basis for some of the expectations about the */ |
| /* outer header. If we return an error, the goal is to leave the original */ |
| /* packet information undisturbed - this falls short at the end where we'd */ |
| /* need to back a backup copy of "fin" - expensive. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_decap(fin, nat) |
| fr_info_t *fin; |
| nat_t *nat; |
| { |
| char *hdr; |
| int hlen; |
| int skip; |
| mb_t *m; |
| |
| if ((fin->fin_flx & FI_ICMPERR) != 0) { |
| /* |
| * ICMP packets don't get decapsulated, instead what we need |
| * to do is change the ICMP reply from including (in the data |
| * portion for errors) the encapsulated packet that we sent |
| * out to something that resembles the original packet prior |
| * to encapsulation. This isn't done here - all we're doing |
| * here is changing the outer address to ensure that it gets |
| * targetted back to the correct system. |
| */ |
| |
| if (nat->nat_dir & NAT_OUTBOUND) { |
| u_32_t sum1, sum2, sumd; |
| |
| sum1 = ntohl(fin->fin_daddr); |
| sum2 = ntohl(nat->nat_osrcaddr); |
| CALC_SUMD(sum1, sum2, sumd); |
| fin->fin_ip->ip_dst = nat->nat_osrcip; |
| fin->fin_daddr = nat->nat_osrcaddr; |
| #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ |
| defined(__osf__) || defined(linux) |
| ipf_fix_outcksum(fin, &fin->fin_ip->ip_sum, sumd); |
| #endif |
| } |
| return 0; |
| } |
| |
| m = fin->fin_m; |
| skip = fin->fin_hlen; |
| |
| switch (nat->nat_dir) |
| { |
| case NAT_DIVERTIN : |
| case NAT_DIVERTOUT : |
| if (fin->fin_plen < MINDECAP) |
| return -1; |
| skip += sizeof(udphdr_t); |
| break; |
| |
| case NAT_ENCAPIN : |
| case NAT_ENCAPOUT : |
| if (fin->fin_plen < (skip + sizeof(ip_t))) |
| return -1; |
| break; |
| default : |
| return -1; |
| /* NOTREACHED */ |
| } |
| |
| /* |
| * The aim here is to keep the original packet details in "fin" for |
| * as long as possible so that returning with an error is for the |
| * original packet and there is little undoing work to do. |
| */ |
| if (M_LEN(m) < skip + sizeof(ip_t)) { |
| if (ipf_pr_pullup(fin, skip + sizeof(ip_t)) == -1) |
| return -1; |
| } |
| |
| hdr = MTOD(fin->fin_m, char *); |
| fin->fin_ip = (ip_t *)(hdr + skip); |
| hlen = IP_HL(fin->fin_ip) << 2; |
| |
| if (ipf_pr_pullup(fin, skip + hlen) == -1) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[fin->fin_out]. |
| ns_decap_pullup); |
| return -1; |
| } |
| |
| fin->fin_hlen = hlen; |
| fin->fin_dlen -= skip; |
| fin->fin_plen -= skip; |
| fin->fin_ipoff += skip; |
| |
| if (ipf_makefrip(hlen, (ip_t *)hdr, fin) == -1) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[fin->fin_out].ns_decap_bad); |
| return -1; |
| } |
| |
| return skip; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_matchencap */ |
| /* Returns: int - -1 == packet error, 1 == success, 0 = no match */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* np(I) - pointer to a NAT rule */ |
| /* */ |
| /* To properly compare a packet travelling in the reverse direction to an */ |
| /* encap rule, it needs to be pseudo-decapsulated so we can check if a */ |
| /* reply to it would be encapsulated. In doing this, we have to be careful */ |
| /* so as not to actually do any decapsulation nor affect any of the current */ |
| /* stored parameters in "fin" so that we can continue processing it else- */ |
| /* where if it doesn't match. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_matchencap(fin, np) |
| fr_info_t *fin; |
| ipnat_t *np; |
| { |
| int hlen, match, skip; |
| u_short *ports; |
| frtuc_t *ft; |
| fr_ip_t fi; |
| char *hdr; |
| ip_t *ip; |
| mb_t *m; |
| |
| /* |
| * This function is only for matching packets that are appearing from |
| * the reverse direction against "encap" rules. |
| */ |
| if (fin->fin_out == 1) { |
| if ((np->in_redir & NAT_REDIRECT) == 0) |
| return 0; |
| } else { |
| if ((np->in_redir & NAT_MAP) == 0) |
| return 0; |
| } |
| if (np->in_pr[fin->fin_out] != fin->fin_p) |
| return 0; |
| |
| /* |
| * The aim here is to keep the original packet details in "fin" for |
| * as long as possible so that returning with an error is for the |
| * original packet and there is little undoing work to do. |
| */ |
| m = fin->fin_m; |
| skip = fin->fin_hlen; |
| if (M_LEN(m) < skip + sizeof(ip_t)) { |
| if (ipf_pr_pullup(fin, sizeof(ip_t)) == -1) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[fin->fin_out]. |
| ns_encap_pullup); |
| return -1; |
| } |
| } |
| |
| hdr = MTOD(fin->fin_m, char *); |
| ip = (ip_t *)(hdr + skip); |
| hlen = IP_HL(ip) << 2; |
| |
| if (ipf_pr_pullup(fin, hlen) == -1) { |
| ATOMIC_INCL(ipf_nat_stats.ns_side[fin->fin_out]. |
| ns_encap_pullup); |
| return -1; |
| } |
| |
| match = 1; |
| |
| /* |
| * Now we should have the entire innder header, so match up the |
| * address fields - easy enough. Reverse matching of source and |
| * destination because this is purportedly a "reply" to an encap rule. |
| */ |
| switch (np->in_osrcatype) |
| { |
| case FRI_NORMAL : |
| match = ((ip->ip_dst.s_addr & np->in_osrcmsk) |
| != np->in_osrcaddr); |
| break; |
| #ifdef IPFILTER_LOOKUP |
| case FRI_LOOKUP : |
| match = (*np->in_nsrcfunc)(np->in_osrcptr, np->in_v, |
| &ip->ip_dst.s_addr); |
| break; |
| #endif |
| } |
| if (match) |
| return 0; |
| |
| switch (np->in_odstatype) |
| { |
| case FRI_NORMAL : |
| match = ((ip->ip_src.s_addr & np->in_odstmsk) |
| != np->in_odstaddr); |
| break; |
| #ifdef IPFILTER_LOOKUP |
| case FRI_LOOKUP : |
| match = (*np->in_nsrcfunc)(np->in_odstptr, np->in_v, |
| &ip->ip_src.s_addr); |
| break; |
| #endif |
| } |
| if (match) |
| return 0; |
| |
| ft = &np->in_tuc; |
| |
| switch (ip->ip_p) |
| { |
| case IPPROTO_TCP : |
| case IPPROTO_UDP : |
| /* |
| * Only need to fetch port numbers for NAT |
| */ |
| if (ipf_pr_pullup(fin, hlen + 4) == -1) { |
| ipf_nat_stats.ns_side[fin->fin_out].ns_encap_pullup++; |
| return -1; |
| } |
| |
| ports = (u_short *)((char *)ip + hlen); |
| |
| fi.fi_tcpf = 0; |
| /* |
| * And again, because we're simulating a reply, put the port |
| * numbers in the revese place to where they are now. |
| */ |
| fi.fi_ports[0] = ntohs(ports[1]); |
| fi.fi_ports[1] = ntohs(ports[0]); |
| return ipf_tcpudpchk(&fi, ft); |
| |
| /* NOTREACHED */ |
| |
| default : |
| if (ft->ftu_scmp || ft->ftu_dcmp) |
| return 0; |
| break; |
| } |
| |
| return 1; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_nextaddr */ |
| /* Returns: int - -1 == bad input (no new address), */ |
| /* 0 == success and dst has new address */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* na(I) - how to generate new address */ |
| /* old(I) - original address being replaced */ |
| /* dst(O) - where to put the new address */ |
| /* Write Lock: ipf_nat */ |
| /* */ |
| /* This function uses the contents of the "na" structure, in combination */ |
| /* with "old" to produce a new address to store in "dst". Not all of the */ |
| /* possible uses of "na" will result in a new address. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_nextaddr(fin, na, old, dst) |
| fr_info_t *fin; |
| nat_addr_t *na; |
| u_32_t *old, *dst; |
| { |
| u_32_t min, max, new; |
| i6addr_t newip; |
| int range; |
| |
| new = 0; |
| min = na->na_addr[0].in4.s_addr; |
| |
| switch (na->na_atype) |
| { |
| case FRI_RANGE : |
| max = na->na_addr[1].in4.s_addr; |
| break; |
| |
| case FRI_NETMASKED : |
| case FRI_DYNAMIC : |
| case FRI_NORMAL : |
| /* |
| * Compute the maximum address by adding the inverse of the |
| * netmask to the minimum address. |
| */ |
| max = ~na->na_addr[1].in4.s_addr; |
| max |= min; |
| break; |
| |
| case FRI_BROADCAST : |
| case FRI_PEERADDR : |
| case FRI_NETWORK : |
| case FRI_LOOKUP : |
| default : |
| return -1; |
| } |
| |
| switch (na->na_function) |
| { |
| case NA_RANDOM : |
| range = ntohl(max) - ntohl(min); |
| new = ipf_random(range); |
| new += ntohl(min); |
| new = htonl(new); |
| break; |
| |
| case NA_NORMAL : |
| /* |
| * 0/0 as the new address means leave it alone. |
| */ |
| if (na->na_addr[0].in4.s_addr == 0 && |
| na->na_addr[1].in4.s_addr == 0) { |
| new = *old; |
| |
| /* |
| * 0/32 means get the interface's address |
| */ |
| } else if (na->na_addr[0].in4.s_addr == 0 && |
| na->na_addr[1].in4.s_addr == 0xffffffff) { |
| if (ipf_ifpaddr(fin->fin_v, na->na_atype, |
| fin->fin_ifp, &newip, NULL) == -1) { |
| ipf_nat_stats.ns_side[fin->fin_out]. |
| ns_ifpaddrfail++; |
| return -1; |
| } |
| new = newip.in4.s_addr; |
| } else { |
| new = htonl(na->na_nextip); |
| } |
| break; |
| |
| case NA_HASHMD5 : |
| { |
| u_char hash[16]; |
| MD5_CTX ctx; |
| |
| range = ntohl(max) - ntohl(min); |
| MD5Init(&ctx); |
| MD5Update(&ctx, (u_char *)dst, 4); |
| MD5Final(hash, &ctx); |
| new = 0; |
| if (range > 0xffffff) |
| new = hash[0]; |
| new <<= 8; |
| if (range > 0xffff) |
| new |= hash[1]; |
| new <<= 8; |
| if (range > 0xff) |
| new |= hash[2]; |
| new <<= 8; |
| new |= hash[3]; |
| new %= range; |
| new += ntohl(min); |
| new = htonl(new); |
| break; |
| } |
| default : |
| ipf_nat_stats.ns_side[fin->fin_out].ns_badnextaddr++; |
| return -1; |
| } |
| |
| *dst = new; |
| |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_nextaddrinit */ |
| /* Returns: int - 0 == success, else error number */ |
| /* Parameters: na(I) - NAT address information for generating new addr*/ |
| /* initial(I) - flag indicating if it is the first call for */ |
| /* this "na" structure. */ |
| /* ifp(I) - network interface to derive address */ |
| /* information from. */ |
| /* */ |
| /* This function is expected to be called in two scenarious: when a new NAT */ |
| /* rule is loaded into the kernel and when the list of NAT rules is sync'd */ |
| /* up with the valid network interfaces (possibly due to them changing.) */ |
| /* To distinguish between these, the "initial" parameter is used. If it is */ |
| /* 1 then this indicates the rule has just been reloaded and 0 for when we */ |
| /* are updating information. This difference is important because in */ |
| /* instances where we are not updating address information associated with */ |
| /* a network interface, we don't want to disturb what the "next" address to */ |
| /* come out of ipf_nat_nextaddr() will be. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_nextaddrinit(na, initial, ifp) |
| nat_addr_t *na; |
| int initial; |
| void *ifp; |
| { |
| switch (na->na_atype) |
| { |
| #ifdef IPFILTER_LOOKUP |
| case FRI_LOOKUP : |
| if (na->na_ptr == NULL) { |
| na->na_ptr = ipf_resolvelookup(IPL_LOGNAT, |
| na->na_type, |
| na->na_num, |
| &na->na_func); |
| } |
| if (na->na_ptr == NULL) { |
| ipf_interror = 60056; |
| return ESRCH; |
| } |
| break; |
| #endif |
| case FRI_DYNAMIC : |
| case FRI_BROADCAST : |
| case FRI_NETWORK : |
| case FRI_NETMASKED : |
| case FRI_PEERADDR : |
| if (ifp != NULL) |
| (void )ipf_ifpaddr(4, na->na_atype, ifp, |
| &na->na_addr[0], &na->na_addr[1]); |
| break; |
| |
| case FRI_SPLIT : |
| case FRI_RANGE : |
| if (initial) |
| na->na_nextip = ntohl(na->na_addr[0].in4.s_addr); |
| break; |
| |
| case FRI_NONE : |
| na->na_addr[0].in4.s_addr &= na->na_addr[1].in4.s_addr; |
| return 0; |
| |
| case FRI_NORMAL : |
| na->na_addr[0].in4.s_addr &= na->na_addr[1].in4.s_addr; |
| break; |
| |
| default : |
| ipf_interror = 60054; |
| return EINVAL; |
| } |
| |
| if (initial && (na->na_atype == FRI_NORMAL)) { |
| if (na->na_addr[0].in4.s_addr == 0) { |
| if ((na->na_addr[1].in4.s_addr == 0xffffffff) || |
| (na->na_addr[1].in4.s_addr == 0)) { |
| return 0; |
| } |
| } |
| |
| if (na->na_addr[1].in4.s_addr == 0xffffffff) { |
| na->na_nextip = ntohl(na->na_addr[0].in4.s_addr); |
| } else { |
| na->na_nextip = ntohl(na->na_addr[0].in4.s_addr) + 1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: nat_encapok */ |
| /* Returns: int - -1 == MTU not big enough, 0 == ok to send packet */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to current NAT session */ |
| /* */ |
| /* The purpose of this function is to determine whether or not a packet can */ |
| /* be sent out of a network interface after it has been encapsulated, before*/ |
| /* the actual encapsulation happens. If it cannot - because the "Don't */ |
| /* fragment" bit has been set - then generate an ICMP error message back to */ |
| /* the origin of the packet, informing it that the packet is too big and */ |
| /* what the actual MTU out for the connection is. */ |
| /* */ |
| /* At present the only question this would leave for strange behaviour is */ |
| /* with local connections that will go out an encapsulation as sending of */ |
| /* ICMP messages to local destinations isn't considered robust. */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_encapok(fin, nat) |
| fr_info_t *fin; |
| nat_t *nat; |
| { |
| void *sifp; |
| ipnat_t *n; |
| int extra; |
| int mtu; |
| |
| if (!(fin->fin_ip->ip_off & htons(IP_DF))) |
| return 0; |
| |
| n = nat->nat_ptr; |
| |
| if (n->in_redir & NAT_ENCAP) { |
| extra = sizeof(ip_t); |
| |
| } else { |
| return 0; |
| } |
| |
| mtu = GETIFMTU(nat->nat_ifps[1]); |
| |
| if (fin->fin_plen + extra < mtu) |
| return 0; |
| |
| sifp = fin->fin_ifp; |
| fin->fin_ifp = NULL; |
| fin->fin_icode = ICMP_UNREACH_NEEDFRAG; |
| fin->fin_mtu = mtu - extra; |
| |
| (void) ipf_send_icmp_err(ICMP_UNREACH, fin, 1); |
| |
| fin->fin_mtu = 0; |
| |
| return -1; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_rebuildencapicmp */ |
| /* Returns: int - -1 == error, 0 == success */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to current NAT session */ |
| /* */ |
| /* For ICMP replies received in response to packets we've encapsulated on */ |
| /* the way out, we need to replace all of the addressing fields found in */ |
| /* the data section of the ICMP header. The ICMP packet is going to */ |
| /* contain the the IP packet we sent out (IPENCAP) plus at least 64 bits of */ |
| /* the original IP packet - not something that will be of use to the origin */ |
| /* of the offending packet. */ |
| /* ------------------------------------------------------------------------ */ |
| static nat_t * |
| ipf_nat_rebuildencapicmp(fin, nat) |
| fr_info_t *fin; |
| nat_t *nat; |
| { |
| icmphdr_t *icmp; |
| udphdr_t *udp; |
| ip_t *oip; |
| int p; |
| |
| icmp = fin->fin_dp; |
| oip = (ip_t *)&icmp->icmp_ip; |
| |
| if (fin->fin_out == 0) { |
| if (nat->nat_dir == NAT_ENCAPIN) { |
| oip->ip_src = nat->nat_odstip; |
| oip->ip_dst = nat->nat_osrcip; |
| } else { |
| oip->ip_src = nat->nat_osrcip; |
| oip->ip_dst = nat->nat_odstip; |
| } |
| } else { |
| if (nat->nat_dir == NAT_ENCAPIN) { |
| oip->ip_src = nat->nat_osrcip; |
| oip->ip_dst = nat->nat_odstip; |
| } else { |
| oip->ip_src = nat->nat_odstip; |
| oip->ip_dst = nat->nat_osrcip; |
| } |
| } |
| |
| udp = (udphdr_t *)(oip + 1); |
| |
| /* |
| * We use nat_p here because the original UDP header is quite likely |
| * to have been lost - the error packet returned contains the outer |
| * encapsulation header plus 64 bits of the inner IP header, no room |
| * for a UDP or TCP header unless extra data is returned. |
| * |
| * XXX - If the entire original packet has been included (possible) |
| * then we should be just stripping off the outer encapsulation. |
| * This is a "todo" for the near future. |
| */ |
| p = nat->nat_pr[1 - fin->fin_out]; |
| |
| switch (p) |
| { |
| case IPPROTO_UDP : |
| udp->uh_sum = 0; |
| break; |
| case IPPROTO_TCP : |
| /* |
| * NAT doesn't track the sequence number so we can't pretend |
| * to know what value this field should carry. |
| */ |
| ((tcphdr_t *)udp)->th_seq = 0; |
| break; |
| default : |
| break; |
| } |
| |
| if (p == IPPROTO_TCP || p == IPPROTO_UDP) { |
| if (fin->fin_out == 0) { |
| if (nat->nat_dir == NAT_ENCAPIN) { |
| udp->uh_sport = nat->nat_odport; |
| udp->uh_dport = nat->nat_osport; |
| } else { |
| udp->uh_sport = nat->nat_osport; |
| udp->uh_dport = nat->nat_odport; |
| } |
| } else { |
| if (nat->nat_dir == NAT_ENCAPIN) { |
| udp->uh_sport = nat->nat_osport; |
| udp->uh_dport = nat->nat_odport; |
| } else { |
| udp->uh_sport = nat->nat_odport; |
| udp->uh_dport = nat->nat_osport; |
| } |
| } |
| } |
| |
| /* TRACE (fin,oip,udp,icmp) */ |
| oip->ip_p = nat->nat_pr[1 - fin->fin_out]; |
| oip->ip_sum = 0; |
| oip->ip_sum = ipf_cksum((u_short *)oip, sizeof(*oip)); |
| |
| /* |
| * Reduce the next MTU setting by the size of the encap header |
| */ |
| if (icmp->icmp_type == ICMP_UNREACH && |
| icmp->icmp_code == ICMP_UNREACH_NEEDFRAG) { |
| icmp->icmp_nextmtu = ntohs(icmp->icmp_nextmtu); |
| icmp->icmp_nextmtu -= 20; |
| icmp->icmp_nextmtu = htons(icmp->icmp_nextmtu); |
| } |
| |
| icmp->icmp_cksum = 0; |
| icmp->icmp_cksum = ipf_cksum((u_short *)icmp, fin->fin_dlen); |
| |
| /* TRACE (fin,oip,udp,icmp) */ |
| |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_matchflush */ |
| /* Returns: int - -1 == error, 0 == success */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to current NAT session */ |
| /* */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_matchflush(data) |
| caddr_t data; |
| { |
| int *array, flushed, error; |
| nat_t *nat, *natnext; |
| ipfobj_t obj; |
| |
| error = ipf_matcharray_load(data, &obj, &array); |
| if (error != 0) |
| return error; |
| |
| flushed = 0; |
| |
| for (nat = ipf_nat_instances; nat != NULL; nat = natnext) { |
| natnext = nat->nat_next; |
| if (ipf_nat_matcharray(nat, array) == 0) { |
| ipf_nat_delete(nat, NL_FLUSH); |
| flushed++; |
| } |
| } |
| |
| obj.ipfo_retval = flushed; |
| error = BCOPYOUT(&obj, data, sizeof(obj)); |
| |
| KFREES(array, array[0] * sizeof(*array)); |
| |
| return error; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_matcharray */ |
| /* Returns: int - -1 == error, 0 == success */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to current NAT session */ |
| /* */ |
| /* ------------------------------------------------------------------------ */ |
| static int |
| ipf_nat_matcharray(nat, array) |
| nat_t *nat; |
| int *array; |
| { |
| int i, n, *x, e, p; |
| |
| e = 0; |
| n = array[0]; |
| x = array + 1; |
| |
| for (; n > 0; x += 3 + x[2]) { |
| if (x[0] == IPF_EXP_END) |
| break; |
| e = 0; |
| |
| n -= x[2] + 3; |
| if (n < 0) |
| break; |
| |
| p = x[0] >> 16; |
| if (p != 0 && p != nat->nat_pr[1]) |
| break; |
| |
| switch (x[0]) |
| { |
| case IPF_EXP_IP_PR : |
| for (i = 0; !e && i < x[2]; i++) { |
| e |= (nat->nat_pr[1] == x[i + 3]); |
| } |
| break; |
| |
| case IPF_EXP_IP_SRCADDR : |
| for (i = 0; !e && i < x[2]; i++) { |
| e |= ((nat->nat_nsrcaddr & x[i + 4]) == |
| x[i + 3]); |
| } |
| break; |
| |
| case IPF_EXP_IP_DSTADDR : |
| for (i = 0; !e && i < x[2]; i++) { |
| e |= ((nat->nat_ndstaddr & x[i + 4]) == |
| x[i + 3]); |
| } |
| break; |
| |
| case IPF_EXP_IP_ADDR : |
| for (i = 0; !e && i < x[2]; i++) { |
| e |= ((nat->nat_nsrcaddr & x[i + 4]) == |
| x[i + 3]) || |
| ((nat->nat_ndstaddr & x[i + 4]) == |
| x[i + 3]); |
| } |
| break; |
| |
| case IPF_EXP_UDP_PORT : |
| case IPF_EXP_TCP_PORT : |
| for (i = 0; !e && i < x[2]; i++) { |
| e |= (nat->nat_nsport == x[i + 3]) || |
| (nat->nat_ndport == x[i + 3]); |
| } |
| break; |
| |
| case IPF_EXP_UDP_SPORT : |
| case IPF_EXP_TCP_SPORT : |
| for (i = 0; !e && i < x[2]; i++) { |
| e |= (nat->nat_nsport == x[i + 3]); |
| } |
| break; |
| |
| case IPF_EXP_UDP_DPORT : |
| case IPF_EXP_TCP_DPORT : |
| for (i = 0; !e && i < x[2]; i++) { |
| e |= (nat->nat_ndport == x[i + 3]); |
| } |
| break; |
| |
| case IPF_EXP_TCP_STATE : |
| for (i = 0; !e && i < x[2]; i++) { |
| e |= (nat->nat_tcpstate[0] == x[i + 3]) || |
| (nat->nat_tcpstate[1] == x[i + 3]); |
| } |
| break; |
| |
| case IPF_EXP_IDLE_GT : |
| e |= (ipf_ticks - nat->nat_touched > x[3]); |
| break; |
| } |
| e ^= x[1]; |
| |
| if (!e) |
| break; |
| } |
| |
| return e; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_nat_gettable */ |
| /* Returns: int - 0 = success, else error */ |
| /* Parameters: data(I) - pointer to ioctl data */ |
| /* */ |
| /* This function handles ioctl requests for tables of nat information. */ |
| /* At present the only table it deals with is the hash bucket statistics. */ |
| /* ------------------------------------------------------------------------ */ |
| static int ipf_nat_gettable(data) |
| char *data; |
| { |
| ipftable_t table; |
| int error; |
| |
| error = ipf_inobj(data, &table, IPFOBJ_GTABLE); |
| if (error != 0) |
| return error; |
| |
| switch (table.ita_type) |
| { |
| case IPFTABLE_BUCKETS_NATIN : |
| error = COPYOUT(ipf_nat_stats.ns_side[0].ns_bucketlen, |
| table.ita_table, |
| ipf_nat_table_sz * sizeof(u_long)); |
| break; |
| |
| case IPFTABLE_BUCKETS_NATOUT : |
| error = COPYOUT(ipf_nat_stats.ns_side[1].ns_bucketlen, |
| table.ita_table, |
| ipf_nat_table_sz * sizeof(u_long)); |
| break; |
| |
| default : |
| ipf_interror = 60058; |
| return EINVAL; |
| } |
| |
| if (error != 0) { |
| ipf_interror = 60059; |
| error = EFAULT; |
| } |
| return error; |
| } |