blob: 51155741737443b02d028e0a7ec2defe7e08ae21 [file] [log] [blame] [raw]
/*
* Copyright (C) 1993-2003 by Darren Reed.
*
* See the IPFILTER.LICENCE file for details on licencing.
*/
#if !defined(lint)
static const char sccsid[] = "@(#)ip_fil.c 2.41 6/5/96 (C) 1993-2000 Darren Reed";
static const char rcsid[] = "@(#)$Id$";
#endif
#if defined(KERNEL) || defined(_KERNEL)
# undef KERNEL
# undef _KERNEL
# define KERNEL 1
# define _KERNEL 1
#endif
#if defined(__FreeBSD_version) && (__FreeBSD_version >= 400000) && \
!defined(KLD_MODULE) && !defined(IPFILTER_LKM)
# include "opt_inet6.h"
#endif
#if defined(__FreeBSD_version) && (__FreeBSD_version >= 440000) && \
!defined(KLD_MODULE) && !defined(IPFILTER_LKM)
# include "opt_random_ip_id.h"
#endif
#include <sys/param.h>
#if defined(__FreeBSD__) && !defined(__FreeBSD_version)
# if defined(IPFILTER_LKM)
# ifndef __FreeBSD_cc_version
# include <osreldate.h>
# else
# if __FreeBSD_cc_version < 430000
# include <osreldate.h>
# endif
# endif
# endif
#endif
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/file.h>
#if __FreeBSD_version >= 220000
# include <sys/fcntl.h>
# include <sys/filio.h>
#else
# include <sys/ioctl.h>
#endif
#include <sys/time.h>
#include <sys/systm.h>
#if (__FreeBSD_version >= 300000)
# include <sys/dirent.h>
#else
# include <sys/dir.h>
#endif
#if !defined(__hpux)
# include <sys/mbuf.h>
#endif
#include <sys/protosw.h>
#include <sys/socket.h>
#include <net/if.h>
#if __FreeBSD_version >= 300000
# include <net/if_var.h>
# if !defined(IPFILTER_LKM)
# include "opt_ipfilter.h"
# endif
#endif
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#if defined(__osf__)
# include <netinet/tcp_timer.h>
#endif
#include <netinet/udp.h>
#include <netinet/tcpip.h>
#include <netinet/ip_icmp.h>
#ifndef _KERNEL
# include "netinet/ipf.h"
#endif
#include "netinet/ip_compat.h"
#ifdef USE_INET6
# include <netinet/icmp6.h>
#endif
#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"
#include "netinet/ip_auth.h"
#ifdef IPFILTER_SYNC
#include "netinet/ip_sync.h"
#endif
#ifdef IPFILTER_SCAN
#include "netinet/ip_scan.h"
#endif
#include "netinet/ip_pool.h"
#if defined(__FreeBSD_version) && (__FreeBSD_version >= 300000)
# include <sys/malloc.h>
#endif
#include <sys/kernel.h>
#ifdef CSUM_DATA_VALID
#include <machine/in_cksum.h>
#endif
extern int ip_optcopy __P((struct ip *, struct ip *));
#if (__FreeBSD_version > 460000)
extern int path_mtu_discovery;
#endif
# ifdef IPFILTER_M_IPFILTER
MALLOC_DEFINE(M_IPFILTER, "IP Filter", "IP Filter packet filter data structures");
# endif
#if !defined(__osf__)
extern struct protosw inetsw[];
#endif
static int (*fr_savep) __P((ip_t *, int, void *, int, struct mbuf **));
static int fr_send_ip __P((fr_info_t *, mb_t *, mb_t **));
# ifdef USE_MUTEXES
ipfmutex_t ipl_mutex, ipf_authmx, ipf_rw, ipf_stinsert;
ipfmutex_t ipf_nat_new, ipf_natio, ipf_timeoutlock;
ipfrwlock_t ipf_mutex, ipf_global, ipf_ipidfrag;
ipfrwlock_t ipf_frag, ipf_state, ipf_nat, ipf_natfrag, ipf_auth;
# endif
int ipf_locks_done = 0;
#if (__FreeBSD_version >= 300000)
struct callout_handle fr_slowtimer_ch;
#endif
#if (__FreeBSD_version >= 500011)
# include <sys/conf.h>
# if defined(NETBSD_PF)
# include <net/pfil.h>
/*
* We provide the fr_checkp name just to minimize changes later.
*/
int (*fr_checkp) __P((ip_t *ip, int hlen, void *ifp, int out, mb_t **mp));
# endif /* NETBSD_PF */
#endif /* __FreeBSD_version >= 500011 */
#if defined(IPFILTER_LKM)
int iplidentify(s)
char *s;
{
if (strcmp(s, "ipl") == 0)
return 1;
return 0;
}
#endif /* IPFILTER_LKM */
int iplattach()
{
#ifdef USE_SPL
int s;
#endif
#if defined(NETBSD_PF) && (__FreeBSD_version >= 500011)
int error = 0;
#endif
SPL_NET(s);
if (fr_running > 0) {
SPL_X(s);
return EBUSY;
}
MUTEX_INIT(&ipf_rw, "ipf rw mutex");
RWLOCK_INIT(&ipf_global, "ipf filter load/unload mutex");
MUTEX_INIT(&ipf_timeoutlock, "ipf timeout queue mutex");
RWLOCK_INIT(&ipf_mutex, "ipf filter rwlock");
RWLOCK_INIT(&ipf_ipidfrag, "ipf IP NAT-Frag rwlock");
ipf_locks_done = 1;
if (fr_initialise() == -1) {
SPL_X(s);
return EIO;
}
#ifdef NETBSD_PF
error = pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IP]].pr_pfh);
if (error) {
# ifdef USE_INET6
goto pfil_error;
# else
fr_deinitialise();
SPL_X(s);
return error;
# endif
}
# ifdef USE_INET6
error = pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IPV6]].pr_pfh);
if (error) {
pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IP]].pr_pfh);
pfil_error:
fr_deinitialise();
SPL_X(s);
return error;
}
# endif
#endif
if (fr_checkp != fr_check) {
fr_savep = fr_check;
fr_checkp = fr_check;
}
bzero((char *)frcache, sizeof(frcache));
fr_savep = fr_checkp;
fr_checkp = fr_check;
fr_running = 1;
if (fr_control_forwarding & 1)
ipforwarding = 1;
SPL_X(s);
#if (__FreeBSD_version >= 300000)
fr_slowtimer_ch = timeout(fr_slowtimer, NULL,
(hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT);
#else
timeout(fr_slowtimer, NULL, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT);
#endif
return 0;
}
/*
* Disable the filter by removing the hooks from the IP input/output
* stream.
*/
int ipldetach()
{
#ifdef USE_SPL
int s;
#endif
#if defined(NETBSD_PF) && (__FreeBSD_version >= 500011)
int error = 0;
#endif
if (fr_refcnt)
return EBUSY;
if (fr_control_forwarding & 2)
ipforwarding = 0;
SPL_NET(s);
#if (__FreeBSD_version >= 300000)
if (fr_slowtimer_ch.callout != NULL)
untimeout(fr_slowtimer, NULL, fr_slowtimer_ch);
bzero(&fr_slowtimer_ch, sizeof(fr_slowtimer_ch));
#else
untimeout(fr_slowtimer, NULL);
#endif /* FreeBSD */
#ifndef NETBSD_PF
if (fr_savep != NULL)
fr_checkp = fr_savep;
fr_savep = NULL;
#endif
#ifdef NETBSD_PF
# if (__FreeBSD_version >= 500011)
error = pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IP]].pr_pfh);
if (error) {
SPL_X(s);
return error;
}
# else
pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT);
# endif
# ifdef USE_INET6
error = pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT,
&inetsw[ip_protox[IPPROTO_IPV6]].pr_pfh);
if (error) {
SPL_X(s);
return error;
}
# endif
#endif
fr_deinitialise();
fr_running = -2;
(void) frflush(IPL_LOGIPF, FR_INQUE|FR_OUTQUE|FR_INACTIVE);
(void) frflush(IPL_LOGIPF, FR_INQUE|FR_OUTQUE);
if (ipf_locks_done == 1) {
MUTEX_DESTROY(&ipf_timeoutlock);
MUTEX_DESTROY(&ipf_rw);
RW_DESTROY(&ipf_mutex);
RW_DESTROY(&ipf_ipidfrag);
RW_DESTROY(&ipf_global);
ipf_locks_done = 0;
}
SPL_X(s);
return 0;
}
/*
* Filter ioctl interface.
*/
int iplioctl(dev, cmd, data, mode
# if defined(_KERNEL) && ((BSD >= 199506) || (__FreeBSD_version >= 220000))
, p)
# if (__FreeBSD_version >= 500024)
struct thread *p;
# else
struct proc *p;
# endif /* __FreeBSD_version >= 500024 */
# else
)
# endif
dev_t dev;
ioctlcmd_t cmd;
caddr_t data;
int mode;
{
#ifdef USE_SPL
int s;
#endif
int error = 0, unit = 0, tmp;
friostat_t fio;
#if (BSD >= 199306) && defined(_KERNEL)
if ((securelevel >= 2) && (mode & FWRITE))
return EPERM;
#endif
unit = GET_MINOR(dev);
if ((IPL_LOGMAX < unit) || (unit < 0))
return ENXIO;
if (fr_running <= 0) {
if (unit != IPL_LOGIPF)
return EIO;
if (cmd != SIOCIPFGETNEXT && cmd != SIOCIPFGET &&
cmd != SIOCIPFSET && cmd != SIOCFRENB && cmd != SIOCGETFS)
return EIO;
}
SPL_NET(s);
error = fr_ioctlswitch(unit, data, cmd, mode);
if (error != -1) {
SPL_X(s);
return error;
}
error = 0;
switch (unit)
{
case IPL_LOGIPF :
break;
case IPL_LOGNAT :
if (fr_running > 0)
error = fr_nat_ioctl(data, cmd, mode);
else
error = EIO;
SPL_X(s);
return error;
case IPL_LOGSTATE :
if (fr_running > 0)
error = fr_state_ioctl(data, cmd, mode);
else
error = EIO;
SPL_X(s);
return error;
case IPL_LOGAUTH :
if (fr_running > 0) {
if ((cmd == SIOCADAFR) || (cmd == SIOCRMAFR)) {
if (!(mode & FWRITE)) {
error = EPERM;
} else {
error = frrequest(unit, cmd, data,
fr_active, 1);
}
} else {
error = fr_auth_ioctl(data, mode, cmd);
}
} else
error = EIO;
SPL_X(s);
return error;
case IPL_LOGSYNC :
#ifdef IPFILTER_SYNC
if (fr_running > 0)
error = fr_sync_ioctl(data, cmd, mode);
else
#endif
error = EIO;
SPL_X(s);
return error;
case IPL_LOGSCAN :
#ifdef IPFILTER_SCAN
if (fr_running > 0)
error = fr_scan_ioctl(data, cmd, mode);
else
#endif
error = EIO;
SPL_X(s);
return error;
case IPL_LOGLOOKUP :
#ifdef IPFILTER_LOOKUP
if (fr_running > 0)
error = ip_lookup_ioctl(data, cmd, mode);
else
#endif
error = EIO;
SPL_X(s);
return error;
default :
SPL_X(s);
return EIO;
}
switch (cmd)
{
case FIONREAD :
#ifdef IPFILTER_LOG
error = COPYOUT(&iplused[IPL_LOGIPF], (caddr_t)data,
sizeof(iplused[IPL_LOGIPF]));
#endif
break;
case SIOCFRENB :
if (!(mode & FWRITE))
error = EPERM;
else {
error = COPYIN(data, &tmp, sizeof(tmp));
if (error)
break;
if (tmp) {
if (fr_running > 0)
error = 0;
else
error = iplattach();
if (error == 0)
fr_running = 1;
else
(void) ipldetach();
} else {
error = ipldetach();
if (error == 0)
fr_running = -1;
}
}
break;
case SIOCIPFSET :
if (!(mode & FWRITE)) {
error = EPERM;
break;
}
case SIOCIPFGETNEXT :
case SIOCIPFGET :
error = fr_ipftune(cmd, data);
break;
case SIOCSETFF :
if (!(mode & FWRITE))
error = EPERM;
else
error = COPYIN(data, &fr_flags, sizeof(fr_flags));
break;
case SIOCGETFF :
error = COPYOUT(&fr_flags, data, sizeof(fr_flags));
break;
case SIOCFUNCL :
error = fr_resolvefunc(data);
break;
case SIOCINAFR :
case SIOCRMAFR :
case SIOCADAFR :
case SIOCZRLST :
if (!(mode & FWRITE))
error = EPERM;
else
error = frrequest(unit, cmd, data, fr_active, 1);
break;
case SIOCINIFR :
case SIOCRMIFR :
case SIOCADIFR :
if (!(mode & FWRITE))
error = EPERM;
else
error = frrequest(unit, cmd, data, 1 - fr_active, 1);
break;
case SIOCSWAPA :
if (!(mode & FWRITE))
error = EPERM;
else {
bzero((char *)frcache, sizeof(frcache[0]) * 2);
*(u_int *)data = fr_active;
fr_active = 1 - fr_active;
}
break;
case SIOCGETFS :
fr_getstat(&fio);
error = fr_outobj(data, &fio, IPFOBJ_IPFSTAT);
break;
case SIOCFRZST :
if (!(mode & FWRITE))
error = EPERM;
else
error = fr_zerostats(data);
break;
case SIOCIPFFL :
if (!(mode & FWRITE))
error = EPERM;
else {
error = COPYIN(data, &tmp, sizeof(tmp));
if (!error) {
tmp = frflush(unit, tmp);
error = COPYOUT(&tmp, data, sizeof(tmp));
}
}
break;
case SIOCSTLCK :
error = COPYIN(data, &tmp, sizeof(tmp));
if (error == 0) {
fr_state_lock = tmp;
fr_nat_lock = tmp;
fr_frag_lock = tmp;
fr_auth_lock = tmp;
} else
error = EFAULT;
break;
#ifdef IPFILTER_LOG
case SIOCIPFFB :
if (!(mode & FWRITE))
error = EPERM;
else
*(int *)data = ipflog_clear(unit);
break;
#endif /* IPFILTER_LOG */
case SIOCGFRST :
error = fr_outobj(data, fr_fragstats(), IPFOBJ_FRAGSTAT);
break;
case SIOCFRSYN :
if (!(mode & FWRITE))
error = EPERM;
else {
frsync();
}
break;
default :
error = EINVAL;
break;
}
SPL_X(s);
return error;
}
void fr_forgetifp(ifp)
void *ifp;
{
register frentry_t *f;
WRITE_ENTER(&ipf_mutex);
for (f = ipacct[0][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipacct[1][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipfilter[0][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipfilter[1][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
#ifdef USE_INET6
for (f = ipacct6[0][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipacct6[1][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipfilter6[0][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
for (f = ipfilter6[1][fr_active]; (f != NULL); f = f->fr_next)
if (f->fr_ifa == ifp)
f->fr_ifa = (void *)-1;
#endif
RWLOCK_EXIT(&ipf_mutex);
fr_natsync(ifp);
}
/*
* routines below for saving IP headers to buffer
*/
int iplopen(dev, flags
#if ((BSD >= 199506) || (__FreeBSD_version >= 220000)) && defined(_KERNEL)
, devtype, p)
int devtype;
# if (__FreeBSD_version >= 500024)
struct thread *p;
# else
struct proc *p;
# endif /* __FreeBSD_version >= 500024 */
#else
)
#endif
dev_t dev;
int flags;
{
u_int min = GET_MINOR(dev);
if (IPL_LOGMAX < min)
min = ENXIO;
else
min = 0;
return min;
}
int iplclose(dev, flags
#if ((BSD >= 199506) || (__FreeBSD_version >= 220000)) && defined(_KERNEL)
, devtype, p)
int devtype;
# if (__FreeBSD_version >= 500024)
struct thread *p;
# else
struct proc *p;
# endif /* __FreeBSD_version >= 500024 */
#else
)
#endif
dev_t dev;
int flags;
{
u_int min = GET_MINOR(dev);
if (IPL_LOGMAX < min)
min = ENXIO;
else
min = 0;
return min;
}
/*
* iplread/ipllog
* both of these must operate with at least splnet() lest they be
* called during packet processing and cause an inconsistancy to appear in
* the filter lists.
*/
#if (BSD >= 199306)
int iplread(dev, uio, ioflag)
int ioflag;
#else
int iplread(dev, uio)
#endif
dev_t dev;
register struct uio *uio;
{
#ifdef IPFILTER_LOG
return ipflog_read(GET_MINOR(dev), uio);
#else
return ENXIO;
#endif
}
/*
* fr_send_reset - this could conceivably be a call to tcp_respond(), but that
* requires a large amount of setting up and isn't any more efficient.
*/
int fr_send_reset(fin)
fr_info_t *fin;
{
struct tcphdr *tcp, *tcp2;
int tlen = 0, hlen;
struct mbuf *m;
#ifdef USE_INET6
ip6_t *ip6;
#endif
ip_t *ip;
tcp = fin->fin_dp;
if (tcp->th_flags & TH_RST)
return -1; /* feedback loop */
#ifndef IPFILTER_CKSUM
if (fr_checkl4sum(fin) == -1)
return -1;
#endif
#if (BSD < 199103)
m = m_get(M_DONTWAIT, MT_HEADER);
#else
m = m_gethdr(M_DONTWAIT, MT_HEADER);
#endif
if (m == NULL)
return ENOBUFS;
if (m == NULL)
return -1;
tlen = fin->fin_dlen - (TCP_OFF(tcp) << 2) +
((tcp->th_flags & TH_SYN) ? 1 : 0) +
((tcp->th_flags & TH_FIN) ? 1 : 0);
#ifdef USE_INET6
hlen = (fin->fin_v == 6) ? sizeof(ip6_t) : sizeof(ip_t);
#else
hlen = sizeof(ip_t);
#endif
m->m_len = sizeof(*tcp2) + hlen;
#if (BSD >= 199103)
m->m_data += max_linkhdr;
m->m_pkthdr.len = m->m_len;
m->m_pkthdr.rcvif = (struct ifnet *)0;
#endif
ip = mtod(m, struct ip *);
#ifdef USE_INET6
ip6 = (ip6_t *)ip;
#endif
bzero((char *)ip, sizeof(*tcp2) + hlen);
tcp2 = (struct tcphdr *)((char *)ip + hlen);
tcp2->th_sport = tcp->th_dport;
tcp2->th_dport = tcp->th_sport;
if (tcp->th_flags & TH_ACK) {
tcp2->th_seq = tcp->th_ack;
tcp2->th_flags = TH_RST;
} else {
tcp2->th_ack = ntohl(tcp->th_seq);
tcp2->th_ack += tlen;
tcp2->th_ack = htonl(tcp2->th_ack);
tcp2->th_flags = TH_RST|TH_ACK;
}
TCP_OFF_A(tcp2, sizeof(*tcp2) >> 2);
#ifdef USE_INET6
if (fin->fin_v == 6) {
ip6->ip6_plen = htons(sizeof(struct tcphdr));
ip6->ip6_nxt = IPPROTO_TCP;
ip6->ip6_src = fin->fin_dst6;
ip6->ip6_dst = fin->fin_src6;
tcp2->th_sum = in6_cksum(m, IPPROTO_TCP,
sizeof(*ip6), sizeof(*tcp2));
return fr_send_ip(fin, m, &m);
}
#endif
ip->ip_p = IPPROTO_TCP;
ip->ip_len = htons(sizeof(struct tcphdr));
ip->ip_src.s_addr = fin->fin_daddr;
ip->ip_dst.s_addr = fin->fin_saddr;
tcp2->th_sum = in_cksum(m, hlen + sizeof(*tcp2));
ip->ip_len = hlen + sizeof(*tcp2);
return fr_send_ip(fin, m, &m);
}
static int fr_send_ip(fin, m, mpp)
fr_info_t *fin;
mb_t *m, **mpp;
{
ip_t *ip, *oip;
ip = mtod(m, ip_t *);
IP_V_A(ip, fin->fin_v);
switch (fin->fin_v)
{
case 4 :
oip = fin->fin_ip;
IP_HL_A(ip, sizeof(*oip) >> 2);
ip->ip_tos = oip->ip_tos;
ip->ip_id = fin->fin_ip->ip_id;
#if (__FreeBSD_version > 460000)
ip->ip_off = path_mtu_discovery ? IP_DF : 0;
#else
ip->ip_off = 0;
#endif
ip->ip_ttl = ip_defttl;
ip->ip_sum = 0;
break;
#ifdef USE_INET6
case 6 :
{
ip6_t *ip6 = (ip6_t *)ip;
ip6->ip6_hlim = IPDEFTTL;
}
#endif
default :
return EINVAL;
}
#ifdef IPSEC
m->m_pkthdr.rcvif = NULL;
#endif
return fr_fastroute(m, mpp, fin, NULL);
}
int fr_send_icmp_err(type, fin, dst)
int type;
fr_info_t *fin;
int dst;
{
int err, hlen = 0, xtra = 0, iclen, ohlen = 0, avail, code;
struct in_addr dst4;
struct icmp *icmp;
struct mbuf *m;
void *ifp;
#ifdef USE_INET6
ip6_t *ip6, *ip62;
struct in6_addr dst6;
#endif
ip_t *ip, *ip2;
if ((type < 0) || (type > ICMP_MAXTYPE))
return -1;
code = fin->fin_icode;
#ifdef USE_INET6
if ((code < 0) || (code > sizeof(icmptoicmp6unreach)/sizeof(int)))
return -1;
#endif
#ifndef IPFILTER_CKSUM
if (fr_checkl4sum(fin) == -1)
return -1;
#endif
avail = 0;
m = NULL;
ifp = fin->fin_ifp;
if (fin->fin_v == 4) {
if ((fin->fin_p == IPPROTO_ICMP) &&
!(fin->fin_flx & FI_SHORT))
switch (ntohs(fin->fin_data[0]) >> 8)
{
case ICMP_ECHO :
case ICMP_TSTAMP :
case ICMP_IREQ :
case ICMP_MASKREQ :
break;
default :
return 0;
}
#if (BSD < 199103)
avail = MLEN;
m = m_get(M_DONTWAIT, MT_HEADER);
#else
avail = MHLEN;
m = m_gethdr(M_DONTWAIT, MT_HEADER);
#endif
if (m == NULL)
return ENOBUFS;
if (dst == 0) {
if (fr_ifpaddr(4, FRI_NORMAL, ifp,
&dst4, NULL) == -1) {
FREE_MB_T(m);
return -1;
}
} else
dst4.s_addr = fin->fin_daddr;
hlen = sizeof(ip_t);
if (fin->fin_hlen < fin->fin_plen)
xtra = MIN(fin->fin_dlen, 8);
else
xtra = 0;
}
#ifdef USE_INET6
else if (fin->fin_v == 6) {
hlen = sizeof(ip6_t);
ohlen = sizeof(ip6_t);
type = icmptoicmp6types[type];
if (type == ICMP6_DST_UNREACH)
code = icmptoicmp6unreach[code];
MGETHDR(m, M_DONTWAIT, MT_HEADER);
if (m == NULL)
return ENOBUFS;
MCLGET(m, M_DONTWAIT);
if (m == NULL)
return ENOBUFS;
avail = (m->m_flags & M_EXT) ? MCLBYTES : MHLEN;
xtra = MIN(fin->fin_plen + sizeof(ip6_t),
avail - hlen - sizeof(*icmp) - max_linkhdr);
if (dst == 0) {
if (fr_ifpaddr(6, FRI_NORMAL, ifp,
(struct in_addr *)&dst6, NULL) == -1) {
FREE_MB_T(m);
return -1;
}
} else
dst6 = fin->fin_dst6;
}
#endif
iclen = hlen + sizeof(*icmp) + xtra;
# if (BSD >= 199103)
avail -= (max_linkhdr + iclen);
m->m_data += max_linkhdr;
m->m_pkthdr.rcvif = (struct ifnet *)0;
if (xtra > avail)
xtra = avail;
iclen += xtra;
m->m_pkthdr.len = iclen;
#else
avail -= (m->m_off + iclen);
if (xtra > avail)
xtra = avail;
iclen += xtra;
#endif
if (avail < 0) {
m_freem(m);
return ENOBUFS;
}
m->m_len = iclen;
ip = mtod(m, ip_t *);
icmp = (struct icmp *)((char *)ip + hlen);
ip2 = (ip_t *)&icmp->icmp_ip;
bzero((char *)ip, iclen);
icmp->icmp_type = type;
icmp->icmp_code = fin->fin_icode;
icmp->icmp_cksum = 0;
#ifdef icmp_nextmtu
if (type == ICMP_UNREACH &&
fin->fin_icode == ICMP_UNREACH_NEEDFRAG && ifp)
icmp->icmp_nextmtu = htons(((struct ifnet *)ifp)->if_mtu);
#endif
bcopy((char *)fin->fin_ip, (char *)ip2, ohlen);
#ifdef USE_INET6
ip6 = (ip6_t *)ip;
if (fin->fin_v == 6) {
ip62 = (ip6_t *)ip2;
ip62->ip6_plen = htons(ip62->ip6_plen);
ip6->ip6_flow = 0;
ip6->ip6_plen = htons(iclen - hlen);
ip6->ip6_nxt = IPPROTO_ICMPV6;
ip6->ip6_hlim = 0;
ip6->ip6_src = dst6;
ip6->ip6_dst = fin->fin_src6;
if (xtra > 0)
bcopy((char *)fin->fin_ip + ohlen,
(char *)&icmp->icmp_ip + ohlen, xtra);
icmp->icmp_cksum = in6_cksum(m, IPPROTO_ICMPV6,
sizeof(*ip6), iclen - hlen);
} else
#endif
{
ip2->ip_len = htons(ip2->ip_len);
ip->ip_p = IPPROTO_ICMP;
ip->ip_src.s_addr = dst4.s_addr;
ip->ip_dst.s_addr = fin->fin_saddr;
if (xtra > 0)
bcopy((char *)fin->fin_ip + ohlen,
(char *)&icmp->icmp_ip + ohlen, xtra);
icmp->icmp_cksum = ipf_cksum((u_short *)icmp,
sizeof(*icmp) + 8);
ip->ip_len = iclen;
ip->ip_p = IPPROTO_ICMP;
}
err = fr_send_ip(fin, m, &m);
return err;
}
#if !defined(IPFILTER_LKM) && (__FreeBSD_version < 300000)
# if (BSD < 199306)
int iplinit __P((void));
int
# else
void iplinit __P((void));
void
# endif
iplinit()
{
if (iplattach() != 0)
printf("IP Filter failed to attach\n");
ip_init();
}
#endif /* __FreeBSD_version < 300000 */
int fr_fastroute(m0, mpp, fin, fdp)
struct mbuf *m0, **mpp;
fr_info_t *fin;
frdest_t *fdp;
{
register struct ip *ip, *mhip;
register struct mbuf *m = m0;
register struct route *ro;
int len, off, error = 0, hlen, code;
struct ifnet *ifp, *sifp;
struct sockaddr_in *dst;
struct route iproute;
u_short ip_off;
frentry_t *fr;
#ifdef M_WRITABLE
/*
* HOT FIX/KLUDGE:
*
* If the mbuf we're about to send is not writable (because of
* a cluster reference, for example) we'll need to make a copy
* of it since this routine modifies the contents.
*
* If you have non-crappy network hardware that can transmit data
* from the mbuf, rather than making a copy, this is gonna be a
* problem.
*/
if (M_WRITABLE(m) == 0) {
if ((m0 = m_dup(m, M_DONTWAIT)) != 0) {
m_freem(m);
m = m0;
} else {
error = ENOBUFS;
m_freem(m);
fr_frouteok[1]++;
}
}
#endif
hlen = fin->fin_hlen;
ip = mtod(m0, struct ip *);
#ifdef USE_INET6
if (fin->fin_v == 6) {
/*
* currently "to <if>" and "to <if>:ip#" are not supported
* for IPv6
*/
#if (__FreeBSD_version >= 490000)
return ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL);
#else
return ip6_output(m0, NULL, NULL, 0, NULL, NULL);
#endif
}
#endif
/*
* Route packet.
*/
ro = &iproute;
bzero((caddr_t)ro, sizeof (*ro));
dst = (struct sockaddr_in *)&ro->ro_dst;
dst->sin_family = AF_INET;
fr = fin->fin_fr;
if (fdp)
ifp = fdp->fd_ifp;
else {
ifp = fin->fin_ifp;
dst->sin_addr = ip->ip_dst;
}
/*
* In case we're here due to "to <if>" being used with "keep state",
* check that we're going in the correct direction.
*/
if ((fr != NULL) && (fin->fin_rev != 0)) {
if ((ifp != NULL) && (fdp == &fr->fr_tif))
return -1;
dst->sin_addr = ip->ip_dst;
} else if (fdp) {
if (fdp->fd_ip.s_addr) {
dst->sin_addr = fdp->fd_ip;
ip->ip_dst = fdp->fd_ip;
} else
dst->sin_addr = ip->ip_dst;
}
dst->sin_len = sizeof(*dst);
rtalloc(ro);
if (!ifp) {
if (!fr || !(fr->fr_flags & FR_FASTROUTE)) {
error = -2;
goto bad;
}
if (ro->ro_rt == 0 || (ifp = ro->ro_rt->rt_ifp) == 0) {
if (in_localaddr(ip->ip_dst))
error = EHOSTUNREACH;
else
error = ENETUNREACH;
goto bad;
}
if (ro->ro_rt->rt_flags & RTF_GATEWAY)
dst = (struct sockaddr_in *)&ro->ro_rt->rt_gateway;
}
if (ro->ro_rt)
ro->ro_rt->rt_use++;
/*
* For input packets which are being "fastrouted", they won't
* go back through output filtering and miss their chance to get
* NAT'd and counted.
*/
fin->fin_ifp = ifp;
if (fin->fin_out == 0) {
u_32_t pass;
fin->fin_out = 1;
(void) fr_acctpkt(fin, &pass);
fin->fin_fr = NULL;
if (!fr || !(fr->fr_flags & FR_RETMASK)) {
(void) fr_checkstate(fin, &pass);
}
(void) fr_checknatout(fin, &pass);
} else
ip->ip_sum = 0;
/*
* If small enough for interface, can just send directly.
*/
if (ip->ip_len <= ifp->if_mtu) {
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
if (!ip->ip_sum)
ip->ip_sum = in_cksum(m, hlen);
error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst,
ro->ro_rt);
goto done;
}
/*
* Too large for interface; fragment if possible.
* Must be able to put at least 8 bytes per fragment.
*/
ip_off = ip->ip_off;
if (ip_off & IP_DF) {
error = EMSGSIZE;
goto bad;
}
len = (ifp->if_mtu - hlen) &~ 7;
if (len < 8) {
error = EMSGSIZE;
goto bad;
}
{
int mhlen, firstlen = len;
struct mbuf **mnext = &m->m_act;
/*
* Loop through length of segment after first fragment,
* make new header and copy data of each part and link onto chain.
*/
m0 = m;
mhlen = sizeof (struct ip);
for (off = hlen + len; off < ip->ip_len; off += len) {
#ifdef MGETHDR
MGETHDR(m, M_DONTWAIT, MT_HEADER);
#else
MGET(m, M_DONTWAIT, MT_HEADER);
#endif
if (m == 0) {
error = ENOBUFS;
goto bad;
}
m->m_data += max_linkhdr;
mhip = mtod(m, struct ip *);
bcopy((char *)ip, (char *)mhip, sizeof(*ip));
if (hlen > sizeof (struct ip)) {
mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
IP_HL_A(mhip, mhlen >> 2);
}
m->m_len = mhlen;
mhip->ip_off = ((off - hlen) >> 3) + ip_off;
if (off + len >= ip->ip_len)
len = ip->ip_len - off;
else
mhip->ip_off |= IP_MF;
mhip->ip_len = htons((u_short)(len + mhlen));
m->m_next = m_copy(m0, off, len);
if (m->m_next == 0) {
error = ENOBUFS; /* ??? */
goto sendorfree;
}
m->m_pkthdr.len = mhlen + len;
m->m_pkthdr.rcvif = NULL;
mhip->ip_off = htons((u_short)mhip->ip_off);
mhip->ip_sum = 0;
mhip->ip_sum = in_cksum(m, mhlen);
*mnext = m;
mnext = &m->m_act;
}
/*
* Update first fragment by trimming what's been copied out
* and updating header, then send each fragment (in order).
*/
m_adj(m0, hlen + firstlen - ip->ip_len);
ip->ip_len = htons((u_short)(hlen + firstlen));
ip->ip_off = htons((u_short)IP_MF);
ip->ip_sum = 0;
ip->ip_sum = in_cksum(m0, hlen);
sendorfree:
for (m = m0; m; m = m0) {
m0 = m->m_act;
m->m_act = 0;
if (error == 0)
error = (*ifp->if_output)(ifp, m,
(struct sockaddr *)dst, ro->ro_rt);
else
m_freem(m);
}
}
done:
if (!error)
fr_frouteok[0]++;
else
fr_frouteok[1]++;
if (ro->ro_rt) {
RTFREE(ro->ro_rt);
}
*mpp = NULL;
return 0;
bad:
if (error == EMSGSIZE) {
sifp = fin->fin_ifp;
code = fin->fin_icode;
fin->fin_icode = ICMP_UNREACH_NEEDFRAG;
fin->fin_ifp = ifp;
(void) fr_send_icmp_err(ICMP_UNREACH, fin, 1);
fin->fin_ifp = sifp;
fin->fin_icode = code;
}
m_freem(m);
goto done;
}
int fr_verifysrc(fin)
fr_info_t *fin;
{
struct sockaddr_in *dst;
struct route iproute;
bzero((char *)&iproute, sizeof(iproute));
dst = (struct sockaddr_in *)&iproute.ro_dst;
dst->sin_len = sizeof(*dst);
dst->sin_family = AF_INET;
dst->sin_addr = fin->fin_src;
rtalloc(&iproute);
if (iproute.ro_rt == NULL)
return 0;
return (fin->fin_ifp == iproute.ro_rt->rt_ifp);
}
/*
* return the first IP Address associated with an interface
*/
int fr_ifpaddr(v, atype, ifptr, inp, inpmask)
int v, atype;
void *ifptr;
struct in_addr *inp, *inpmask;
{
#ifdef USE_INET6
struct in6_addr *inp6 = NULL;
#endif
struct sockaddr *sock, *mask;
struct sockaddr_in *sin;
struct ifaddr *ifa;
struct ifnet *ifp;
sin = NULL;
ifp = ifptr;
if (v == 4)
inp->s_addr = 0;
#ifdef USE_INET6
else if (v == 6)
bzero((char *)inp, sizeof(struct in6_addr));
#endif
#if (__FreeBSD_version >= 300000)
ifa = TAILQ_FIRST(&ifp->if_addrhead);
#else
ifa = ifp->if_addrlist;
#endif /* __FreeBSD_version >= 300000 */
sock = ifa->ifa_addr;
while (sock != NULL && ifa != NULL) {
sin = (struct sockaddr_in *)sock;
if ((v == 4) && (sin->sin_family == AF_INET))
break;
#ifdef USE_INET6
if ((v == 6) && (sin->sin_family == AF_INET6)) {
inp6 = &((struct sockaddr_in6 *)sin)->sin6_addr;
if (!IN6_IS_ADDR_LINKLOCAL(inp6) &&
!IN6_IS_ADDR_LOOPBACK(inp6))
break;
}
#endif
#if (__FreeBSD_version >= 300000)
ifa = TAILQ_NEXT(ifa, ifa_link);
#else
ifa = ifa->ifa_next;
#endif /* __FreeBSD_version >= 300000 */
if (ifa != NULL)
sock = ifa->ifa_addr;
}
if (ifa == NULL || sin == NULL)
return -1;
mask = ifa->ifa_netmask;
if (atype == FRI_BROADCAST)
sock = ifa->ifa_broadaddr;
else if (atype == FRI_PEERADDR)
sock = ifa->ifa_dstaddr;
#ifdef USE_INET6
if (v == 6) {
return fr_ifpfillv6addr(atype, (struct sockaddr_in6 *)sock,
(struct sockaddr_in6 *)mask,
inp, inpmask);
}
#endif
return fr_ifpfillv4addr(atype, (struct sockaddr_in *)sock,
(struct sockaddr_in *)mask, inp, inpmask);
}
u_32_t fr_newisn(fin)
fr_info_t *fin;
{
u_32_t newiss;
#if (__FreeBSD_version >= 400000)
newiss = arc4random();
#else
static iss_seq_off = 0;
u_char hash[16];
MD5_CTX ctx;
/*
* Compute the base value of the ISS. It is a hash
* of (saddr, sport, daddr, dport, secret).
*/
MD5Init(&ctx);
MD5Update(&ctx, (u_char *) &fin->fin_fi.fi_src,
sizeof(fin->fin_fi.fi_src));
MD5Update(&ctx, (u_char *) &fin->fin_fi.fi_dst,
sizeof(fin->fin_fi.fi_dst));
MD5Update(&ctx, (u_char *) &fin->fin_dat, sizeof(fin->fin_dat));
MD5Update(&ctx, ipf_iss_secret, sizeof(ipf_iss_secret));
MD5Final(hash, &ctx);
memcpy(&newiss, hash, sizeof(newiss));
/*
* Now increment our "timer", and add it in to
* the computed value.
*
* XXX Use `addin'?
* XXX TCP_ISSINCR too large to use?
*/
iss_seq_off += 0x00010000;
newiss += iss_seq_off;
#endif
return newiss;
}
/* ------------------------------------------------------------------------ */
/* Function: fr_nextipid */
/* Returns: int - 0 == success, -1 == error (packet should be droppped) */
/* Parameters: fin(I) - pointer to packet information */
/* */
/* Returns the next IPv4 ID to use for this packet. */
/* ------------------------------------------------------------------------ */
INLINE u_short fr_nextipid(fin)
fr_info_t *fin;
{
#ifndef RANDOM_IP_ID
static u_short ipid = 0;
u_short id;
MUTEX_ENTER(&ipf_rw);
id = ipid++;
MUTEX_EXIT(&ipf_rw);
#else
u_short id;
id = ip_randomid();
#endif
return id;
}
INLINE void fr_checkv4sum(fin)
fr_info_t *fin;
{
#ifdef CSUM_DATA_VALID
int manual = 0;
u_short sum;
ip_t *ip;
mb_t *m;
m = fin->fin_m;
if (m == NULL) {
manual = 1;
goto skipauto;
}
ip = fin->fin_ip;
if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
sum = m->m_pkthdr.csum_data;
else
sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
htonl(m->m_pkthdr.csum_data +
fin->fin_ip->ip_len + fin->fin_p));
sum ^= 0xffff;
if (sum != 0)
fin->fin_flx |= FI_BAD;
} else
manual = 1;
skipauto:
# ifdef IPFILTER_CKSUM
if (manual != 0)
if (fr_checkl4sum(fin) == -1)
fin->fin_flx |= FI_BAD;
# else
;
# endif
#else
# ifdef IPFILTER_CKSUM
if (fr_checkl4sum(fin) == -1)
fin->fin_flx |= FI_BAD;
# endif
#endif
}
#ifdef USE_INET6
INLINE void fr_checkv6sum(fin)
fr_info_t *fin;
{
# ifdef IPFILTER_CKSUM
if (fr_checkl4sum(fin) == -1)
fin->fin_flx |= FI_BAD;
# endif
}
#endif /* USE_INET6 */