| /* |
| * Copyright (C) 1993-2003 by Darren Reed. |
| * |
| * See the IPFILTER.LICENCE file for details on licencing. |
| * |
| * Copyright 2008 Sun Microsystems. |
| */ |
| #if defined(KERNEL) || defined(_KERNEL) |
| # undef KERNEL |
| # undef _KERNEL |
| # define KERNEL 1 |
| # define _KERNEL 1 |
| #endif |
| #include <sys/errno.h> |
| #include <sys/types.h> |
| #include <sys/param.h> |
| #include <sys/time.h> |
| #include <sys/file.h> |
| #ifdef __hpux |
| # include <sys/timeout.h> |
| #endif |
| #if !defined(_KERNEL) |
| # include <stdio.h> |
| # include <string.h> |
| # include <stdlib.h> |
| # define _KERNEL |
| # ifdef __OpenBSD__ |
| struct file; |
| # endif |
| # include <sys/uio.h> |
| # undef _KERNEL |
| #endif |
| #if defined(_KERNEL) && (__FreeBSD_version >= 220000) |
| # include <sys/filio.h> |
| # include <sys/fcntl.h> |
| #else |
| # include <sys/ioctl.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__) |
| # if defined(_KERNEL) && !defined(__sgi) && !defined(AIX) |
| # include <sys/kernel.h> |
| # endif |
| #else |
| # include <sys/byteorder.h> |
| # ifdef _KERNEL |
| # include <sys/dditypes.h> |
| # endif |
| # include <sys/stream.h> |
| # include <sys/kmem.h> |
| #endif |
| #include <net/if.h> |
| #ifdef sun |
| # include <net/af.h> |
| #endif |
| #include <net/route.h> |
| #include <netinet/in.h> |
| #include <netinet/in_systm.h> |
| #include <netinet/ip.h> |
| #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_auth.h" |
| #include "netinet/ip_proxy.h" |
| #include "netinet/ip_sync.h" |
| #if (__FreeBSD_version >= 300000) |
| # include <sys/malloc.h> |
| # if defined(_KERNEL) |
| # ifndef IPFILTER_LKM |
| # include <sys/libkern.h> |
| # include <sys/systm.h> |
| # endif |
| extern struct callout_handle ipf_slowtimer_ch; |
| # endif |
| #endif |
| #if defined(__NetBSD__) && (__NetBSD_Version__ >= 104230000) |
| # include <sys/callout.h> |
| extern struct callout ipf_slowtimer_ch; |
| #endif |
| #if defined(__OpenBSD__) |
| # include <sys/timeout.h> |
| extern struct timeout ipf_slowtimer_ch; |
| #endif |
| /* END OF INCLUDES */ |
| |
| #if !defined(lint) |
| static const char sccsid[] = "@(#)ip_frag.c 1.11 3/24/96 (C) 1993-2000 Darren Reed"; |
| static const char rcsid[] = "@(#)$Id$"; |
| #endif |
| |
| |
| ipfr_t *ipfr_list = NULL; |
| ipfr_t **ipfr_tail = &ipfr_list; |
| |
| ipfr_t *ipfr_natlist = NULL; |
| ipfr_t **ipfr_nattail = &ipfr_natlist; |
| |
| ipfr_t *ipfr_ipidlist = NULL; |
| ipfr_t **ipfr_ipidtail = &ipfr_ipidlist; |
| |
| static ipfr_t **ipfr_heads; |
| static ipfr_t **ipfr_nattab; |
| static ipfr_t **ipfr_ipidtab; |
| |
| static ipfrstat_t ipfr_stats; |
| static frentry_t ipfr_block; |
| static int ipfr_inuse = 0; |
| int ipfr_size = IPFT_SIZE; |
| |
| int ipf_ipfrttl = 120; /* 60 seconds */ |
| int ipf_frag_lock = 0; |
| int ipf_frag_inited = 0; |
| u_32_t ipf_ticks = 0; |
| |
| |
| #ifdef USE_MUTEXES |
| static ipfr_t *ipfr_frag_new __P((fr_info_t *, u_32_t, ipfr_t **, |
| ipfrwlock_t *)); |
| static ipfr_t *ipf_frag_lookup __P((fr_info_t *, ipfr_t **, ipfrwlock_t *)); |
| #else |
| static ipfr_t *ipfr_frag_new __P((fr_info_t *, u_32_t, ipfr_t **)); |
| static ipfr_t *ipf_frag_lookup __P((fr_info_t *, ipfr_t **)); |
| #endif |
| static void ipf_frag_delete __P((ipfr_t *, ipfr_t ***)); |
| static void ipf_frag_free __P((ipfr_t *)); |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_init */ |
| /* Returns: int - 0 == success, -1 == error */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Initialise the hash tables for the fragment cache lookups. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_frag_init() |
| { |
| KMALLOCS(ipfr_heads, ipfr_t **, ipfr_size * sizeof(ipfr_t *)); |
| if (ipfr_heads == NULL) |
| return -1; |
| bzero((char *)ipfr_heads, ipfr_size * sizeof(ipfr_t *)); |
| |
| KMALLOCS(ipfr_nattab, ipfr_t **, ipfr_size * sizeof(ipfr_t *)); |
| if (ipfr_nattab == NULL) |
| return -1; |
| bzero((char *)ipfr_nattab, ipfr_size * sizeof(ipfr_t *)); |
| |
| KMALLOCS(ipfr_ipidtab, ipfr_t **, ipfr_size * sizeof(ipfr_t *)); |
| if (ipfr_ipidtab == NULL) |
| return -1; |
| bzero((char *)ipfr_ipidtab, ipfr_size * sizeof(ipfr_t *)); |
| |
| RWLOCK_INIT(&ipf_frag, "ipf fragment rwlock"); |
| |
| bzero((char *)&ipfr_block, sizeof(ipfr_block)); |
| ipfr_block.fr_flags = FR_BLOCK|FR_QUICK; |
| ipfr_block.fr_ref = 1; |
| |
| ipf_frag_inited = 1; |
| |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_unload */ |
| /* Returns: Nil */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Free all memory allocated whilst running and from initialisation. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_frag_unload() |
| { |
| if (ipf_frag_inited == 1) { |
| ipf_frag_clear(); |
| |
| RW_DESTROY(&ipf_frag); |
| ipf_frag_inited = 0; |
| } |
| |
| if (ipfr_heads != NULL) |
| KFREES(ipfr_heads, ipfr_size * sizeof(ipfr_t *)); |
| ipfr_heads = NULL; |
| |
| if (ipfr_nattab != NULL) |
| KFREES(ipfr_nattab, ipfr_size * sizeof(ipfr_t *)); |
| ipfr_nattab = NULL; |
| |
| if (ipfr_ipidtab != NULL) |
| KFREES(ipfr_ipidtab, ipfr_size * sizeof(ipfr_t *)); |
| ipfr_ipidtab = NULL; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_stats */ |
| /* Returns: ipfrstat_t* - pointer to struct with current frag stats */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Updates ipfr_stats with current information and returns a pointer to it */ |
| /* ------------------------------------------------------------------------ */ |
| ipfrstat_t * |
| ipf_frag_stats() |
| { |
| ipfr_stats.ifs_table = ipfr_heads; |
| ipfr_stats.ifs_nattab = ipfr_nattab; |
| ipfr_stats.ifs_inuse = ipfr_inuse; |
| return &ipfr_stats; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipfr_frag_new */ |
| /* Returns: ipfr_t * - pointer to fragment cache state info or NULL */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* table(I) - pointer to frag table to add to */ |
| /* lock(I) - pointer to lock to get a write hold of */ |
| /* */ |
| /* Add a new entry to the fragment cache, registering it as having come */ |
| /* through this box, with the result of the filter operation. */ |
| /* */ |
| /* If this function succeeds, it returns with a write lock held on "lock". */ |
| /* If it fails, no lock is held on return. */ |
| /* ------------------------------------------------------------------------ */ |
| static ipfr_t * |
| ipfr_frag_new(fin, pass, table |
| #ifdef USE_MUTEXES |
| , lock |
| #endif |
| ) |
| fr_info_t *fin; |
| u_32_t pass; |
| ipfr_t *table[]; |
| #ifdef USE_MUTEXES |
| ipfrwlock_t *lock; |
| #endif |
| { |
| ipfr_t *fra, frag, *fran; |
| u_int idx, off; |
| frentry_t *fr; |
| |
| if (ipfr_inuse >= ipfr_size) { |
| ATOMIC_INCL(ipfr_stats.ifs_maximum); |
| return NULL; |
| } |
| |
| if ((fin->fin_flx & (FI_FRAG|FI_BAD)) != FI_FRAG) { |
| ATOMIC_INCL(ipfr_stats.ifs_newbad); |
| return NULL; |
| } |
| |
| if (pass & FR_FRSTRICT) { |
| if (fin->fin_off != 0) { |
| ATOMIC_INCL(ipfr_stats.ifs_newrestrictnot0); |
| return NULL; |
| } |
| } |
| |
| frag.ipfr_p = fin->fin_p; |
| idx = fin->fin_p; |
| frag.ipfr_id = fin->fin_id; |
| idx += fin->fin_id; |
| frag.ipfr_source = fin->fin_fi.fi_src; |
| idx += frag.ipfr_src.s_addr; |
| frag.ipfr_dest = fin->fin_fi.fi_dst; |
| idx += frag.ipfr_dst.s_addr; |
| frag.ipfr_ifp = fin->fin_ifp; |
| idx *= 127; |
| idx %= ipfr_size; |
| |
| frag.ipfr_optmsk = fin->fin_fi.fi_optmsk & IPF_OPTCOPY; |
| frag.ipfr_secmsk = fin->fin_fi.fi_secmsk; |
| frag.ipfr_auth = fin->fin_fi.fi_auth; |
| |
| off = fin->fin_off >> 3; |
| #ifdef USE_INET6 |
| if ((off == 0) && (fin->fin_v == 6)) { |
| char *ptr; |
| int end; |
| |
| ptr = (char *)fin->fin_fraghdr + sizeof(struct ip6_frag); |
| end = fin->fin_plen - (ptr - (char *)fin->fin_ip); |
| frag.ipfr_firstend = end >> 3; |
| } else |
| #endif |
| frag.ipfr_firstend = 0; |
| |
| /* |
| * allocate some memory, if possible, if not, just record that we |
| * failed to do so. |
| */ |
| KMALLOC(fran, ipfr_t *); |
| if (fran == NULL) { |
| ipfr_stats.ifs_nomem++; |
| return NULL; |
| } |
| |
| WRITE_ENTER(lock); |
| |
| /* |
| * first, make sure it isn't already there... |
| */ |
| for (fra = table[idx]; (fra != NULL); fra = fra->ipfr_hnext) |
| if (!bcmp((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp, |
| IPFR_CMPSZ)) { |
| RWLOCK_EXIT(lock); |
| ATOMIC_INCL(ipfr_stats.ifs_exists); |
| KFREE(fra); |
| return NULL; |
| } |
| |
| fra = fran; |
| fran = NULL; |
| fr = fin->fin_fr; |
| fra->ipfr_rule = fr; |
| if (fr != NULL) { |
| MUTEX_ENTER(&fr->fr_lock); |
| fr->fr_ref++; |
| MUTEX_EXIT(&fr->fr_lock); |
| } |
| |
| /* |
| * Insert the fragment into the fragment table, copy the struct used |
| * in the search using bcopy rather than reassign each field. |
| * Set the ttl to the default. |
| */ |
| if ((fra->ipfr_hnext = table[idx]) != NULL) |
| table[idx]->ipfr_hprev = &fra->ipfr_hnext; |
| fra->ipfr_hprev = table + idx; |
| fra->ipfr_data = NULL; |
| table[idx] = fra; |
| bcopy((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp, IPFR_CMPSZ); |
| fra->ipfr_ttl = ipf_ticks + ipf_ipfrttl; |
| fra->ipfr_firstend = frag.ipfr_firstend; |
| |
| /* |
| * Compute the offset of the expected start of the next packet. |
| */ |
| if (off == 0) |
| fra->ipfr_seen0 = 1; |
| fra->ipfr_off = off + (fin->fin_dlen >> 3); |
| fra->ipfr_pass = pass; |
| fra->ipfr_ref = 1; |
| ipfr_stats.ifs_new++; |
| ipfr_inuse++; |
| return fra; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_new */ |
| /* Returns: int - 0 == success, -1 == error */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* */ |
| /* Add a new entry to the fragment cache table based on the current packet */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_frag_new(fin, pass) |
| u_32_t pass; |
| fr_info_t *fin; |
| { |
| ipfr_t *fra; |
| |
| if (ipf_frag_lock != 0) |
| return -1; |
| |
| #ifdef USE_MUTEXES |
| fra = ipfr_frag_new(fin, pass, ipfr_heads, &ipf_frag); |
| #else |
| fra = ipfr_frag_new(fin, pass, ipfr_heads); |
| #endif |
| if (fra != NULL) { |
| *ipfr_tail = fra; |
| fra->ipfr_prev = ipfr_tail; |
| ipfr_tail = &fra->ipfr_next; |
| if (ipfr_list == NULL) |
| ipfr_list = fra; |
| fra->ipfr_next = NULL; |
| RWLOCK_EXIT(&ipf_frag); |
| } |
| return fra ? 0 : -1; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_natnew */ |
| /* Returns: int - 0 == success, -1 == error */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* nat(I) - pointer to NAT structure */ |
| /* */ |
| /* Create a new NAT fragment cache entry based on the current packet and */ |
| /* the NAT structure for this "session". */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_frag_natnew(fin, pass, nat) |
| fr_info_t *fin; |
| u_32_t pass; |
| nat_t *nat; |
| { |
| ipfr_t *fra; |
| |
| if ((fin->fin_v != 4) || (ipf_frag_lock != 0)) |
| return 0; |
| |
| #ifdef USE_MUTEXES |
| fra = ipfr_frag_new(fin, pass, ipfr_nattab, &ipf_natfrag); |
| #else |
| fra = ipfr_frag_new(fin, pass, ipfr_nattab); |
| #endif |
| if (fra != NULL) { |
| fra->ipfr_data = nat; |
| nat->nat_data = fra; |
| *ipfr_nattail = fra; |
| fra->ipfr_prev = ipfr_nattail; |
| ipfr_nattail = &fra->ipfr_next; |
| fra->ipfr_next = NULL; |
| RWLOCK_EXIT(&ipf_natfrag); |
| } |
| return fra ? 0 : -1; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_ipidnew */ |
| /* Returns: int - 0 == success, -1 == error */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* ipid(I) - new IP ID for this fragmented packet */ |
| /* */ |
| /* Create a new fragment cache entry for this packet and store, as a data */ |
| /* pointer, the new IP ID value. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_frag_ipidnew(fin, ipid) |
| fr_info_t *fin; |
| u_32_t ipid; |
| { |
| ipfr_t *fra; |
| |
| if (ipf_frag_lock) |
| return 0; |
| |
| #ifdef USE_MUTEXES |
| fra = ipfr_frag_new(fin, 0, ipfr_ipidtab, &ipf_ipidfrag); |
| #else |
| fra = ipfr_frag_new(fin, 0, ipfr_ipidtab); |
| #endif |
| if (fra != NULL) { |
| fra->ipfr_data = (void *)ipid; |
| *ipfr_ipidtail = fra; |
| fra->ipfr_prev = ipfr_ipidtail; |
| ipfr_ipidtail = &fra->ipfr_next; |
| fra->ipfr_next = NULL; |
| RWLOCK_EXIT(&ipf_ipidfrag); |
| } |
| return fra ? 0 : -1; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_lookup */ |
| /* Returns: ipfr_t * - pointer to ipfr_t structure if there's a */ |
| /* matching entry in the frag table, else NULL */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* table(I) - pointer to fragment cache table to search */ |
| /* */ |
| /* Check the fragment cache to see if there is already a record of this */ |
| /* packet with its filter result known. */ |
| /* */ |
| /* If this function succeeds, it returns with a write lock held on "lock". */ |
| /* If it fails, no lock is held on return. */ |
| /* ------------------------------------------------------------------------ */ |
| static ipfr_t * |
| ipf_frag_lookup(fin, table |
| #ifdef USE_MUTEXES |
| , lock |
| #endif |
| ) |
| fr_info_t *fin; |
| ipfr_t *table[]; |
| #ifdef USE_MUTEXES |
| ipfrwlock_t *lock; |
| #endif |
| { |
| ipfr_t *f, frag; |
| u_int idx; |
| |
| /* |
| * We don't want to let short packets match because they could be |
| * compromising the security of other rules that want to match on |
| * layer 4 fields (and can't because they have been fragmented off.) |
| * Why do this check here? The counter acts as an indicator of this |
| * kind of attack, whereas if it was elsewhere, it wouldn't know if |
| * other matching packets had been seen. |
| */ |
| if (fin->fin_flx & FI_SHORT) { |
| ATOMIC_INCL(ipfr_stats.ifs_short); |
| return NULL; |
| } |
| |
| if ((fin->fin_flx & FI_BAD) != 0) { |
| ATOMIC_INCL(ipfr_stats.ifs_bad); |
| return NULL; |
| } |
| |
| /* |
| * For fragments, we record protocol, packet id, TOS and both IP#'s |
| * (these should all be the same for all fragments of a packet). |
| * |
| * build up a hash value to index the table with. |
| */ |
| frag.ipfr_p = fin->fin_p; |
| idx = fin->fin_p; |
| frag.ipfr_id = fin->fin_id; |
| idx += fin->fin_id; |
| frag.ipfr_source = fin->fin_fi.fi_src; |
| idx += frag.ipfr_src.s_addr; |
| frag.ipfr_dest = fin->fin_fi.fi_dst; |
| idx += frag.ipfr_dst.s_addr; |
| frag.ipfr_ifp = fin->fin_ifp; |
| idx *= 127; |
| idx %= ipfr_size; |
| |
| frag.ipfr_optmsk = fin->fin_fi.fi_optmsk & IPF_OPTCOPY; |
| frag.ipfr_secmsk = fin->fin_fi.fi_secmsk; |
| frag.ipfr_auth = fin->fin_fi.fi_auth; |
| |
| READ_ENTER(lock); |
| |
| /* |
| * check the table, careful to only compare the right amount of data |
| */ |
| for (f = table[idx]; f; f = f->ipfr_hnext) { |
| if (!bcmp((char *)&frag.ipfr_ifp, (char *)&f->ipfr_ifp, |
| IPFR_CMPSZ)) { |
| u_short off; |
| |
| /* |
| * XXX - We really need to be guarding against the |
| * retransmission of (src,dst,id,offset-range) here |
| * because a fragmented packet is never resent with |
| * the same IP ID# (or shouldn't). |
| */ |
| off = fin->fin_off >> 3; |
| if (f->ipfr_seen0) { |
| if (off == 0) { |
| ATOMIC_INCL(ipfr_stats.ifs_retrans0); |
| continue; |
| } |
| |
| /* |
| * Case 3. See comment for frpr_fragment6. |
| */ |
| if ((f->ipfr_firstend != 0) && |
| (off < f->ipfr_firstend)) { |
| ATOMIC_INCL(ipfr_stats.ifs_overlap); |
| fin->fin_flx |= FI_BAD; |
| break; |
| } |
| } else if (off == 0) |
| f->ipfr_seen0 = 1; |
| |
| if (f != table[idx]) { |
| ipfr_t **fp; |
| |
| /* |
| * Move fragment info. to the top of the list |
| * to speed up searches. First, delink... |
| */ |
| fp = f->ipfr_hprev; |
| (*fp) = f->ipfr_hnext; |
| if (f->ipfr_hnext != NULL) |
| f->ipfr_hnext->ipfr_hprev = fp; |
| /* |
| * Then put back at the top of the chain. |
| */ |
| f->ipfr_hnext = table[idx]; |
| table[idx]->ipfr_hprev = &f->ipfr_hnext; |
| f->ipfr_hprev = table + idx; |
| table[idx] = f; |
| } |
| |
| /* |
| * If we've follwed the fragments, and this is the |
| * last (in order), shrink expiration time. |
| */ |
| if (off == f->ipfr_off) { |
| f->ipfr_off = (fin->fin_dlen >> 3) + off; |
| |
| /* |
| * Well, we could shrink the expiration time |
| * but only if every fragment has been seen |
| * in order upto this, the last. ipfr_badorder |
| * is used here to count those out of order |
| * and if it equals 0 when we get to the last |
| * fragment then we can assume all of the |
| * fragments have been seen and in order. |
| */ |
| if (!ntohs(fin->fin_ip->ip_off & IP_MF) && |
| (f->ipfr_badorder == 0)) |
| f->ipfr_ttl = ipf_ticks + 1; |
| |
| } else { |
| f->ipfr_badorder++; |
| ATOMIC_INCL(ipfr_stats.ifs_unordered); |
| if (f->ipfr_pass & FR_FRSTRICT) { |
| ATOMIC_INCL(ipfr_stats.ifs_strict); |
| continue; |
| } |
| } |
| ATOMIC_INCL(ipfr_stats.ifs_hits); |
| return f; |
| } |
| } |
| |
| RWLOCK_EXIT(lock); |
| ATOMIC_INCL(ipfr_stats.ifs_miss); |
| return NULL; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_natknown */ |
| /* Returns: nat_t* - pointer to 'parent' NAT structure if frag table */ |
| /* match found, else NULL */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* */ |
| /* Functional interface for NAT lookups of the NAT fragment cache */ |
| /* ------------------------------------------------------------------------ */ |
| nat_t * |
| ipf_frag_natknown(fin) |
| fr_info_t *fin; |
| { |
| nat_t *nat; |
| ipfr_t *ipf; |
| |
| if ((ipf_frag_lock) || !ipfr_natlist) |
| return NULL; |
| #ifdef USE_MUTEXES |
| ipf = ipf_frag_lookup(fin, ipfr_nattab, &ipf_natfrag); |
| #else |
| ipf = ipf_frag_lookup(fin, ipfr_nattab); |
| #endif |
| if (ipf != NULL) { |
| nat = ipf->ipfr_data; |
| /* |
| * This is the last fragment for this packet. |
| */ |
| if ((ipf->ipfr_ttl == ipf_ticks + 1) && (nat != NULL)) { |
| nat->nat_data = NULL; |
| ipf->ipfr_data = NULL; |
| } |
| RWLOCK_EXIT(&ipf_natfrag); |
| } else |
| nat = NULL; |
| return nat; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_ipidknown */ |
| /* Returns: u_32_t - IPv4 ID for this packet if match found, else */ |
| /* return 0xfffffff to indicate no match. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* */ |
| /* Functional interface for IP ID lookups of the IP ID fragment cache */ |
| /* ------------------------------------------------------------------------ */ |
| u_32_t |
| ipf_frag_ipidknown(fin) |
| fr_info_t *fin; |
| { |
| ipfr_t *ipf; |
| u_32_t id; |
| |
| if ((fin->fin_v != 4) || (ipf_frag_lock) || !ipfr_ipidlist) |
| return 0xffffffff; |
| |
| #ifdef USE_MUTEXES |
| ipf = ipf_frag_lookup(fin, ipfr_ipidtab, &ipf_ipidfrag); |
| #else |
| ipf = ipf_frag_lookup(fin, ipfr_ipidtab); |
| #endif |
| if (ipf != NULL) { |
| id = (u_32_t)ipf->ipfr_data; |
| RWLOCK_EXIT(&ipf_ipidfrag); |
| } else |
| id = 0xffffffff; |
| return id; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_known */ |
| /* Returns: frentry_t* - pointer to filter rule if a match is found in */ |
| /* the frag cache table, else NULL. */ |
| /* Parameters: fin(I) - pointer to packet information */ |
| /* passp(O) - pointer to where to store rule flags resturned */ |
| /* */ |
| /* Functional interface for normal lookups of the fragment cache. If a */ |
| /* match is found, return the rule pointer and flags from the rule, except */ |
| /* that if FR_LOGFIRST is set, reset FR_LOG. */ |
| /* ------------------------------------------------------------------------ */ |
| frentry_t * |
| ipf_frag_known(fin, passp) |
| fr_info_t *fin; |
| u_32_t *passp; |
| { |
| frentry_t *fr = NULL; |
| ipfr_t *fra; |
| u_32_t pass; |
| |
| if ((ipf_frag_lock) || (ipfr_list == NULL)) |
| return NULL; |
| |
| #ifdef USE_MUTEXES |
| fra = ipf_frag_lookup(fin, ipfr_heads, &ipf_frag); |
| #else |
| fra = ipf_frag_lookup(fin, ipfr_heads); |
| #endif |
| if (fra != NULL) { |
| if (fin->fin_flx & FI_BAD) { |
| fr = &ipfr_block; |
| fin->fin_reason = 10; |
| } else { |
| fr = fra->ipfr_rule; |
| } |
| fin->fin_fr = fr; |
| if (fr != NULL) { |
| pass = fr->fr_flags; |
| if ((pass & FR_KEEPSTATE) != 0) { |
| fin->fin_flx |= FI_STATE; |
| } |
| if ((pass & FR_LOGFIRST) != 0) |
| pass &= ~(FR_LOGFIRST|FR_LOG); |
| *passp = pass; |
| } |
| RWLOCK_EXIT(&ipf_frag); |
| } |
| return fr; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_forget */ |
| /* Returns: Nil */ |
| /* Parameters: ptr(I) - pointer to data structure */ |
| /* */ |
| /* Search through all of the fragment cache entries and wherever a pointer */ |
| /* is found to match ptr, reset it to NULL. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_frag_forget(ptr) |
| void *ptr; |
| { |
| ipfr_t *fr; |
| |
| WRITE_ENTER(&ipf_frag); |
| for (fr = ipfr_list; fr; fr = fr->ipfr_next) |
| if (fr->ipfr_data == ptr) |
| fr->ipfr_data = NULL; |
| RWLOCK_EXIT(&ipf_frag); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_natforget */ |
| /* Returns: Nil */ |
| /* Parameters: ptr(I) - pointer to data structure */ |
| /* */ |
| /* Search through all of the fragment cache entries for NAT and wherever a */ |
| /* pointer is found to match ptr, reset it to NULL. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_frag_natforget(ptr) |
| void *ptr; |
| { |
| ipfr_t *fr; |
| |
| WRITE_ENTER(&ipf_natfrag); |
| for (fr = ipfr_natlist; fr; fr = fr->ipfr_next) |
| if (fr->ipfr_data == ptr) |
| fr->ipfr_data = NULL; |
| RWLOCK_EXIT(&ipf_natfrag); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_delete */ |
| /* Returns: Nil */ |
| /* Parameters: fra(I) - pointer to fragment structure to delete */ |
| /* tail(IO) - pointer to the pointer to the tail of the frag */ |
| /* list */ |
| /* */ |
| /* Remove a fragment cache table entry from the table & list. Also free */ |
| /* the filter rule it is associated with it if it is no longer used as a */ |
| /* result of decreasing the reference count. */ |
| /* ------------------------------------------------------------------------ */ |
| static void |
| ipf_frag_delete(fra, tail) |
| ipfr_t *fra, ***tail; |
| { |
| |
| if (fra->ipfr_next) |
| fra->ipfr_next->ipfr_prev = fra->ipfr_prev; |
| *fra->ipfr_prev = fra->ipfr_next; |
| if (*tail == &fra->ipfr_next) |
| *tail = fra->ipfr_prev; |
| |
| if (fra->ipfr_hnext) |
| fra->ipfr_hnext->ipfr_hprev = fra->ipfr_hprev; |
| *fra->ipfr_hprev = fra->ipfr_hnext; |
| |
| if (fra->ipfr_rule != NULL) { |
| (void) ipf_derefrule(&fra->ipfr_rule); |
| } |
| |
| if (fra->ipfr_ref <= 0) |
| ipf_frag_free(fra); |
| } |
| |
| |
| static void |
| ipf_frag_free(fra) |
| ipfr_t *fra; |
| { |
| KFREE(fra); |
| ipfr_stats.ifs_expire++; |
| ipfr_inuse--; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_clear */ |
| /* Returns: Nil */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Free memory in use by fragment state information kept. Do the normal */ |
| /* fragment state stuff first and then the NAT-fragment table. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_frag_clear() |
| { |
| ipfr_t *fra; |
| nat_t *nat; |
| |
| WRITE_ENTER(&ipf_frag); |
| while ((fra = ipfr_list) != NULL) { |
| fra->ipfr_ref--; |
| ipf_frag_delete(fra, &ipfr_tail); |
| } |
| ipfr_tail = &ipfr_list; |
| RWLOCK_EXIT(&ipf_frag); |
| |
| WRITE_ENTER(&ipf_nat); |
| WRITE_ENTER(&ipf_natfrag); |
| while ((fra = ipfr_natlist) != NULL) { |
| nat = fra->ipfr_data; |
| if (nat != NULL) { |
| if (nat->nat_data == fra) |
| nat->nat_data = NULL; |
| } |
| fra->ipfr_ref--; |
| ipf_frag_delete(fra, &ipfr_nattail); |
| } |
| ipfr_nattail = &ipfr_natlist; |
| RWLOCK_EXIT(&ipf_natfrag); |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_expire */ |
| /* Returns: Nil */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Expire entries in the fragment cache table that have been there too long */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_frag_expire() |
| { |
| ipfr_t **fp, *fra; |
| nat_t *nat; |
| SPL_INT(s); |
| |
| if (ipf_frag_lock) |
| return; |
| |
| SPL_NET(s); |
| WRITE_ENTER(&ipf_frag); |
| /* |
| * Go through the entire table, looking for entries to expire, |
| * which is indicated by the ttl being less than or equal to ipf_ticks. |
| */ |
| for (fp = &ipfr_list; ((fra = *fp) != NULL); ) { |
| if (fra->ipfr_ttl > ipf_ticks) |
| break; |
| fra->ipfr_ref--; |
| ipf_frag_delete(fra, &ipfr_tail); |
| } |
| RWLOCK_EXIT(&ipf_frag); |
| |
| WRITE_ENTER(&ipf_ipidfrag); |
| for (fp = &ipfr_ipidlist; ((fra = *fp) != NULL); ) { |
| if (fra->ipfr_ttl > ipf_ticks) |
| break; |
| fra->ipfr_ref--; |
| ipf_frag_delete(fra, &ipfr_ipidtail); |
| } |
| RWLOCK_EXIT(&ipf_ipidfrag); |
| |
| /* |
| * Same again for the NAT table, except that if the structure also |
| * still points to a NAT structure, and the NAT structure points back |
| * at the one to be free'd, NULL the reference from the NAT struct. |
| * NOTE: We need to grab both mutex's early, and in this order so as |
| * to prevent a deadlock if both try to expire at the same time. |
| * The extra if() statement here is because it locks out all NAT |
| * operations - no need to do that if there are no entries in this |
| * list, right? |
| */ |
| if (ipfr_natlist != NULL) { |
| WRITE_ENTER(&ipf_nat); |
| WRITE_ENTER(&ipf_natfrag); |
| for (fp = &ipfr_natlist; ((fra = *fp) != NULL); ) { |
| if (fra->ipfr_ttl > ipf_ticks) |
| break; |
| nat = fra->ipfr_data; |
| if (nat != NULL) { |
| if (nat->nat_data == fra) |
| nat->nat_data = NULL; |
| } |
| fra->ipfr_ref--; |
| ipf_frag_delete(fra, &ipfr_nattail); |
| } |
| RWLOCK_EXIT(&ipf_natfrag); |
| RWLOCK_EXIT(&ipf_nat); |
| } |
| SPL_X(s); |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_slowtimer */ |
| /* Returns: Nil */ |
| /* Parameters: Nil */ |
| /* */ |
| /* Slowly expire held state for fragments. Timeouts are set * in */ |
| /* expectation of this being called twice per second. */ |
| /* ------------------------------------------------------------------------ */ |
| #if !defined(_KERNEL) || (!SOLARIS && !defined(__hpux) && !defined(__sgi) && \ |
| !defined(__osf__)) |
| # if defined(_KERNEL) && ((BSD >= 199103) || defined(__sgi)) |
| void |
| ipf_slowtimer __P((void *ptr)) |
| # else |
| int |
| ipf_slowtimer() |
| # endif |
| { |
| READ_ENTER(&ipf_global); |
| |
| ipf_expiretokens(); |
| ipf_frag_expire(); |
| ipf_state_timeout(); |
| ipf_nat_expire(); |
| ipf_auth_expire(); |
| #ifdef IPFILTER_SYNC |
| ipf_sync_expire(); |
| #endif |
| ipf_ticks++; |
| if (ipf_running <= 0) |
| goto done; |
| # ifdef _KERNEL |
| # if defined(__NetBSD__) && (__NetBSD_Version__ >= 104240000) |
| callout_reset(&ipf_slowtimer_ch, hz / 2, ipf_slowtimer, NULL); |
| # else |
| # if defined(__OpenBSD__) |
| timeout_add(&ipf_slowtimer_ch, hz/2); |
| # else |
| # if (__FreeBSD_version >= 300000) |
| ipf_slowtimer_ch = timeout(ipf_slowtimer, NULL, hz/2); |
| # else |
| # ifdef linux |
| ; |
| # else |
| timeout(ipf_slowtimer, NULL, hz/2); |
| # endif |
| # endif /* FreeBSD */ |
| # endif /* OpenBSD */ |
| # endif /* NetBSD */ |
| # endif |
| done: |
| RWLOCK_EXIT(&ipf_global); |
| # if (BSD < 199103) || !defined(_KERNEL) |
| return 0; |
| # endif |
| } |
| #endif /* !SOLARIS && !defined(__hpux) && !defined(__sgi) */ |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_next */ |
| /* Returns: int - 0 == success, else error */ |
| /* Parameters: token(I) - pointer to token information for this caller */ |
| /* itp(I) - pointer to generic iterator from caller */ |
| /* top(I) - top of the fragment list */ |
| /* tail(I) - tail of the fragment list */ |
| /* lock(I) - fragment cache lock */ |
| /* */ |
| /* This function is used to interate through the list of entries in the */ |
| /* fragment cache. It increases the reference count on the one currently */ |
| /* being returned so that the caller can come back and resume from it later.*/ |
| /* */ |
| /* This function is used for both the NAT fragment cache as well as the ipf */ |
| /* fragment cache - hence the reason for passing in top, tail and lock. */ |
| /* ------------------------------------------------------------------------ */ |
| int |
| ipf_frag_next(token, itp, top, tail |
| #ifdef USE_MUTEXES |
| , lock |
| #endif |
| ) |
| ipftoken_t *token; |
| ipfgeniter_t *itp; |
| ipfr_t **top, ***tail; |
| #ifdef USE_MUTEXES |
| ipfrwlock_t *lock; |
| #endif |
| { |
| ipfr_t *frag, *next, zero; |
| int error = 0; |
| |
| READ_ENTER(lock); |
| |
| /* |
| * Retrieve "previous" entry from token and find the next entry. |
| */ |
| frag = token->ipt_data; |
| if (frag == NULL) |
| next = *top; |
| else |
| next = frag->ipfr_next; |
| |
| /* |
| * If we found an entry, add reference to it and update token. |
| * Otherwise, zero out data to be returned and NULL out token. |
| */ |
| if (next != NULL) { |
| ATOMIC_INC(next->ipfr_ref); |
| token->ipt_data = next; |
| } else { |
| bzero(&zero, sizeof(zero)); |
| next = &zero; |
| token->ipt_data = NULL; |
| } |
| |
| /* |
| * Now that we have ref, it's save to give up lock. |
| */ |
| RWLOCK_EXIT(lock); |
| |
| /* |
| * Copy out data and clean up references and token as needed. |
| */ |
| error = COPYOUT(next, itp->igi_data, sizeof(*next)); |
| if (error != 0) { |
| ipf_interror = 20002; |
| error = EFAULT; |
| } |
| if (token->ipt_data == NULL) { |
| ipf_freetoken(token); |
| } else { |
| if (frag != NULL) |
| #ifdef USE_MUTEXES |
| ipf_frag_deref(&frag, lock); |
| #else |
| ipf_frag_deref(&frag); |
| #endif |
| if (next->ipfr_next == NULL) |
| ipf_freetoken(token); |
| } |
| return error; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| /* Function: ipf_frag_deref */ |
| /* Returns: Nil */ |
| /* Parameters: frp(IO) - pointer to fragment structure to deference */ |
| /* lock(I) - lock associated with the fragment */ |
| /* */ |
| /* This function dereferences a fragment structure (ipfr_t). The pointer */ |
| /* passed in will always be reset back to NULL, even if the structure is */ |
| /* not freed, to enforce the notion that the caller is no longer entitled */ |
| /* to use the pointer it is dropping the reference to. */ |
| /* ------------------------------------------------------------------------ */ |
| void |
| ipf_frag_deref(frp |
| #ifdef USE_MUTEXES |
| , lock |
| #endif |
| ) |
| ipfr_t **frp; |
| #ifdef USE_MUTEXES |
| ipfrwlock_t *lock; |
| #endif |
| { |
| ipfr_t *fra; |
| |
| fra = *frp; |
| *frp = NULL; |
| |
| WRITE_ENTER(lock); |
| fra->ipfr_ref--; |
| if (fra->ipfr_ref <= 0) |
| ipf_frag_free(fra); |
| RWLOCK_EXIT(lock); |
| } |