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freebsd/sys/netinet/fil.c
Peter Wemm c3aac50f28 $Id$ -> $FreeBSD$
1999-08-28 01:08:13 +00:00

1330 lines
31 KiB
C
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/*
* Copyright (C) 1993-1997 by Darren Reed.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and due credit is given
* to the original author and the contributors.
*/
#if !defined(lint)
static const char sccsid[] = "@(#)fil.c 1.36 6/5/96 (C) 1993-1996 Darren Reed";
static const char rcsid[] = "@(#)$FreeBSD$";
#endif
#include "opt_ipfilter.h"
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/file.h>
#if !defined(__FreeBSD__)
# include <sys/ioctl.h>
#endif
#if (defined(_KERNEL) || defined(KERNEL)) && !defined(linux)
# include <sys/systm.h>
#else
# include <stdio.h>
# include <string.h>
# include <stdlib.h>
#endif
#include <sys/uio.h>
#if !defined(__SVR4) && !defined(__svr4__)
# ifndef linux
# include <sys/mbuf.h>
# endif
#else
# include <sys/byteorder.h>
# include <sys/dditypes.h>
# include <sys/stream.h>
#endif
#if defined(__FreeBSD__)
# include <sys/malloc.h>
#endif
#ifndef linux
# include <sys/protosw.h>
# include <sys/socket.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>
#ifndef 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_proxy.h"
#include "netinet/ip_nat.h"
#include "netinet/ip_frag.h"
#include "netinet/ip_state.h"
#include "netinet/ip_auth.h"
#ifndef MIN
#define MIN(a,b) (((a)<(b))?(a):(b))
#endif
#ifndef _KERNEL
# include "ipf.h"
# include "ipt.h"
extern int opts;
# define FR_IFVERBOSE(ex,second,verb_pr) if (ex) { verbose verb_pr; \
second; }
# define FR_IFDEBUG(ex,second,verb_pr) if (ex) { debug verb_pr; \
second; }
# define FR_VERBOSE(verb_pr) verbose verb_pr
# define FR_DEBUG(verb_pr) debug verb_pr
# define SEND_RESET(ip, qif, if, m) send_reset(ip, if)
# define IPLLOG(a, c, d, e) ipllog()
# define FR_NEWAUTH(m, fi, ip, qif) fr_newauth((mb_t *)m, fi, ip)
# if SOLARIS
# define ICMP_ERROR(b, ip, t, c, if, src) icmp_error(ip)
# else
# define ICMP_ERROR(b, ip, t, c, if, src) icmp_error(b, ip, if)
# endif
#else /* #ifndef _KERNEL */
# define FR_IFVERBOSE(ex,second,verb_pr) ;
# define FR_IFDEBUG(ex,second,verb_pr) ;
# define FR_VERBOSE(verb_pr)
# define FR_DEBUG(verb_pr)
# define IPLLOG(a, c, d, e) ipflog(a, c, d, e)
# if SOLARIS || defined(__sgi)
extern kmutex_t ipf_mutex, ipf_auth;
# endif
# if SOLARIS
# define FR_NEWAUTH(m, fi, ip, qif) fr_newauth((mb_t *)m, fi, \
ip, qif)
# define SEND_RESET(ip, qif, if) send_reset(ip, qif)
# define ICMP_ERROR(b, ip, t, c, if, src) \
icmp_error(ip, t, c, if, src)
# else /* SOLARIS */
# define FR_NEWAUTH(m, fi, ip, qif) fr_newauth((mb_t *)m, fi, ip)
# ifdef linux
# define SEND_RESET(ip, qif, if) send_reset((tcpiphdr_t *)ip,\
ifp)
# else
# define SEND_RESET(ip, qif, if) send_reset((tcpiphdr_t *)ip)
# endif
# ifdef __sgi
# define ICMP_ERROR(b, ip, t, c, if, src) \
icmp_error(b, t, c, if, src, if)
# else
# if BSD < 199103
# ifdef linux
# define ICMP_ERROR(b, ip, t, c, if, src) icmp_send(b,t,c,0,if)
# else
# define ICMP_ERROR(b, ip, t, c, if, src) \
icmp_error(mtod(b, ip_t *), t, c, if, src)
# endif /* linux */
# else
# define ICMP_ERROR(b, ip, t, c, if, src) \
icmp_error(b, t, c, (src).s_addr, if)
# endif /* BSD < 199103 */
# endif /* __sgi */
# endif /* SOLARIS || __sgi */
#endif /* _KERNEL */
struct filterstats frstats[2] = {{0,0,0,0,0},{0,0,0,0,0}};
struct frentry *ipfilter[2][2] = { { NULL, NULL }, { NULL, NULL } },
*ipacct[2][2] = { { NULL, NULL }, { NULL, NULL } };
struct frgroup *ipfgroups[3][2];
int fr_flags = IPF_LOGGING, fr_active = 0;
#if defined(IPFILTER_DEFAULT_BLOCK)
int fr_pass = FR_NOMATCH|FR_BLOCK;
#else
int fr_pass = (IPF_DEFAULT_PASS|FR_NOMATCH);
#endif
fr_info_t frcache[2];
static void fr_makefrip __P((int, ip_t *, fr_info_t *));
static int fr_tcpudpchk __P((frentry_t *, fr_info_t *));
static int frflushlist __P((int, int, int *, frentry_t *, frentry_t **));
/*
* bit values for identifying presence of individual IP options
*/
static struct optlist ipopts[20] = {
{ IPOPT_NOP, 0x000001 },
{ IPOPT_RR, 0x000002 },
{ IPOPT_ZSU, 0x000004 },
{ IPOPT_MTUP, 0x000008 },
{ IPOPT_MTUR, 0x000010 },
{ IPOPT_ENCODE, 0x000020 },
{ IPOPT_TS, 0x000040 },
{ IPOPT_TR, 0x000080 },
{ IPOPT_SECURITY, 0x000100 },
{ IPOPT_LSRR, 0x000200 },
{ IPOPT_E_SEC, 0x000400 },
{ IPOPT_CIPSO, 0x000800 },
{ IPOPT_SATID, 0x001000 },
{ IPOPT_SSRR, 0x002000 },
{ IPOPT_ADDEXT, 0x004000 },
{ IPOPT_VISA, 0x008000 },
{ IPOPT_IMITD, 0x010000 },
{ IPOPT_EIP, 0x020000 },
{ IPOPT_FINN, 0x040000 },
{ 0, 0x000000 }
};
/*
* bit values for identifying presence of individual IP security options
*/
static struct optlist secopt[8] = {
{ IPSO_CLASS_RES4, 0x01 },
{ IPSO_CLASS_TOPS, 0x02 },
{ IPSO_CLASS_SECR, 0x04 },
{ IPSO_CLASS_RES3, 0x08 },
{ IPSO_CLASS_CONF, 0x10 },
{ IPSO_CLASS_UNCL, 0x20 },
{ IPSO_CLASS_RES2, 0x40 },
{ IPSO_CLASS_RES1, 0x80 }
};
/*
* compact the IP header into a structure which contains just the info.
* which is useful for comparing IP headers with.
*/
static void fr_makefrip(hlen, ip, fin)
int hlen;
ip_t *ip;
fr_info_t *fin;
{
struct optlist *op;
tcphdr_t *tcp;
icmphdr_t *icmp;
fr_ip_t *fi = &fin->fin_fi;
u_short optmsk = 0, secmsk = 0, auth = 0;
int i, mv, ol, off;
u_char *s, opt;
fin->fin_fr = NULL;
fin->fin_tcpf = 0;
fin->fin_data[0] = 0;
fin->fin_data[1] = 0;
fin->fin_rule = -1;
fin->fin_group = -1;
fin->fin_id = ip->ip_id;
#ifdef _KERNEL
fin->fin_icode = ipl_unreach;
#endif
fi->fi_v = ip->ip_v;
fi->fi_tos = ip->ip_tos;
fin->fin_hlen = hlen;
fin->fin_dlen = ip->ip_len - hlen;
tcp = (tcphdr_t *)((char *)ip + hlen);
icmp = (icmphdr_t *)tcp;
fin->fin_dp = (void *)tcp;
(*(((u_short *)fi) + 1)) = (*(((u_short *)ip) + 4));
(*(((u_32_t *)fi) + 1)) = (*(((u_32_t *)ip) + 3));
(*(((u_32_t *)fi) + 2)) = (*(((u_32_t *)ip) + 4));
fi->fi_fl = (hlen > sizeof(ip_t)) ? FI_OPTIONS : 0;
off = (ip->ip_off & 0x1fff) << 3;
if (ip->ip_off & 0x3fff)
fi->fi_fl |= FI_FRAG;
switch (ip->ip_p)
{
case IPPROTO_ICMP :
{
int minicmpsz = sizeof(struct icmp);
if (!off && ip->ip_len > ICMP_MINLEN + hlen &&
(icmp->icmp_type == ICMP_ECHOREPLY ||
icmp->icmp_type == ICMP_UNREACH))
minicmpsz = ICMP_MINLEN;
if ((!(ip->ip_len >= hlen + minicmpsz) && !off) ||
(off && off < sizeof(struct icmp)))
fi->fi_fl |= FI_SHORT;
if (fin->fin_dlen > 1)
fin->fin_data[0] = *(u_short *)tcp;
break;
}
case IPPROTO_TCP :
fi->fi_fl |= FI_TCPUDP;
if ((!IPMINLEN(ip, tcphdr) && !off) ||
(off && off < sizeof(struct tcphdr)))
fi->fi_fl |= FI_SHORT;
if (!(fi->fi_fl & FI_SHORT) && !off)
fin->fin_tcpf = tcp->th_flags;
goto getports;
case IPPROTO_UDP :
fi->fi_fl |= FI_TCPUDP;
if ((!IPMINLEN(ip, udphdr) && !off) ||
(off && off < sizeof(struct udphdr)))
fi->fi_fl |= FI_SHORT;
getports:
if (!off && (fin->fin_dlen > 3)) {
fin->fin_data[0] = ntohs(tcp->th_sport);
fin->fin_data[1] = ntohs(tcp->th_dport);
}
break;
default :
break;
}
for (s = (u_char *)(ip + 1), hlen -= sizeof(*ip); hlen; ) {
if (!(opt = *s))
break;
ol = (opt == IPOPT_NOP) ? 1 : (int)*(s+1);
if (opt > 1 && (ol < 2 || ol > hlen))
break;
for (i = 9, mv = 4; mv >= 0; ) {
op = ipopts + i;
if (opt == (u_char)op->ol_val) {
optmsk |= op->ol_bit;
if (opt == IPOPT_SECURITY) {
struct optlist *sp;
u_char sec;
int j, m;
sec = *(s + 2); /* classification */
for (j = 3, m = 2; m >= 0; ) {
sp = secopt + j;
if (sec == sp->ol_val) {
secmsk |= sp->ol_bit;
auth = *(s + 3);
auth *= 256;
auth += *(s + 4);
break;
}
if (sec < sp->ol_val)
j -= m--;
else
j += m--;
}
}
break;
}
if (opt < op->ol_val)
i -= mv--;
else
i += mv--;
}
hlen -= ol;
s += ol;
}
if (auth && !(auth & 0x0100))
auth &= 0xff00;
fi->fi_optmsk = optmsk;
fi->fi_secmsk = secmsk;
fi->fi_auth = auth;
}
/*
* check an IP packet for TCP/UDP characteristics such as ports and flags.
*/
static int fr_tcpudpchk(fr, fin)
frentry_t *fr;
fr_info_t *fin;
{
register u_short po, tup;
register char i;
register int err = 1;
/*
* Both ports should *always* be in the first fragment.
* So far, I cannot find any cases where they can not be.
*
* compare destination ports
*/
if ((i = (int)fr->fr_dcmp)) {
po = fr->fr_dport;
tup = fin->fin_data[1];
/*
* Do opposite test to that required and
* continue if that succeeds.
*/
if (!--i && tup != po) /* EQUAL */
err = 0;
else if (!--i && tup == po) /* NOTEQUAL */
err = 0;
else if (!--i && tup >= po) /* LESSTHAN */
err = 0;
else if (!--i && tup <= po) /* GREATERTHAN */
err = 0;
else if (!--i && tup > po) /* LT or EQ */
err = 0;
else if (!--i && tup < po) /* GT or EQ */
err = 0;
else if (!--i && /* Out of range */
(tup >= po && tup <= fr->fr_dtop))
err = 0;
else if (!--i && /* In range */
(tup <= po || tup >= fr->fr_dtop))
err = 0;
}
/*
* compare source ports
*/
if (err && (i = (int)fr->fr_scmp)) {
po = fr->fr_sport;
tup = fin->fin_data[0];
if (!--i && tup != po)
err = 0;
else if (!--i && tup == po)
err = 0;
else if (!--i && tup >= po)
err = 0;
else if (!--i && tup <= po)
err = 0;
else if (!--i && tup > po)
err = 0;
else if (!--i && tup < po)
err = 0;
else if (!--i && /* Out of range */
(tup >= po && tup <= fr->fr_stop))
err = 0;
else if (!--i && /* In range */
(tup <= po || tup >= fr->fr_stop))
err = 0;
}
/*
* If we don't have all the TCP/UDP header, then how can we
* expect to do any sort of match on it ? If we were looking for
* TCP flags, then NO match. If not, then match (which should
* satisfy the "short" class too).
*/
if (err && (fin->fin_fi.fi_p == IPPROTO_TCP)) {
if (fin->fin_fi.fi_fl & FI_SHORT)
return !(fr->fr_tcpf | fr->fr_tcpfm);
/*
* Match the flags ? If not, abort this match.
*/
if (fr->fr_tcpf &&
fr->fr_tcpf != (fin->fin_tcpf & fr->fr_tcpfm)) {
FR_DEBUG(("f. %#x & %#x != %#x\n", fin->fin_tcpf,
fr->fr_tcpfm, fr->fr_tcpf));
err = 0;
}
}
return err;
}
/*
* Check the input/output list of rules for a match and result.
* Could be per interface, but this gets real nasty when you don't have
* kernel sauce.
*/
int fr_scanlist(pass, ip, fin, m)
int pass;
ip_t *ip;
register fr_info_t *fin;
void *m;
{
register struct frentry *fr;
register fr_ip_t *fi = &fin->fin_fi;
int rulen, portcmp = 0, off, skip = 0;
fr = fin->fin_fr;
fin->fin_fr = NULL;
fin->fin_rule = 0;
fin->fin_group = 0;
off = ip->ip_off & 0x1fff;
pass |= (fi->fi_fl << 24);
if ((fi->fi_fl & FI_TCPUDP) && (fin->fin_dlen > 3) && !off)
portcmp = 1;
for (rulen = 0; fr; fr = fr->fr_next, rulen++) {
if (skip) {
skip--;
continue;
}
/*
* In all checks below, a null (zero) value in the
* filter struture is taken to mean a wildcard.
*
* check that we are working for the right interface
*/
#ifdef _KERNEL
if (fr->fr_ifa && fr->fr_ifa != fin->fin_ifp)
continue;
#else
if (opts & (OPT_VERBOSE|OPT_DEBUG))
printf("\n");
FR_VERBOSE(("%c", (pass & FR_PASS) ? 'p' :
(pass & FR_AUTH) ? 'a' : 'b'));
if (fr->fr_ifa && fr->fr_ifa != fin->fin_ifp)
continue;
FR_VERBOSE((":i"));
#endif
{
register u_32_t *ld, *lm, *lip;
register int i;
lip = (u_32_t *)fi;
lm = (u_32_t *)&fr->fr_mip;
ld = (u_32_t *)&fr->fr_ip;
i = ((lip[0] & lm[0]) != ld[0]);
FR_IFDEBUG(i,continue,("0. %#08x & %#08x != %#08x\n",
lip[0], lm[0], ld[0]));
i |= ((lip[1] & lm[1]) != ld[1]) << 21;
FR_IFDEBUG(i,continue,("1. %#08x & %#08x != %#08x\n",
lip[1], lm[1], ld[1]));
i |= ((lip[2] & lm[2]) != ld[2]) << 22;
FR_IFDEBUG(i,continue,("2. %#08x & %#08x != %#08x\n",
lip[2], lm[2], ld[2]));
i |= ((lip[3] & lm[3]) != ld[3]);
FR_IFDEBUG(i,continue,("3. %#08x & %#08x != %#08x\n",
lip[3], lm[3], ld[3]));
i |= ((lip[4] & lm[4]) != ld[4]);
FR_IFDEBUG(i,continue,("4. %#08x & %#08x != %#08x\n",
lip[4], lm[4], ld[4]));
i ^= (fi->fi_fl & (FR_NOTSRCIP|FR_NOTDSTIP));
if (i)
continue;
}
/*
* If a fragment, then only the first has what we're looking
* for here...
*/
if (!portcmp && (fr->fr_dcmp || fr->fr_scmp || fr->fr_tcpf ||
fr->fr_tcpfm))
continue;
if (fi->fi_fl & FI_TCPUDP) {
if (!fr_tcpudpchk(fr, fin))
continue;
} else if (fr->fr_icmpm || fr->fr_icmp) {
if ((fi->fi_p != IPPROTO_ICMP) || off ||
(fin->fin_dlen < 2))
continue;
if ((fin->fin_data[0] & fr->fr_icmpm) != fr->fr_icmp) {
FR_DEBUG(("i. %#x & %#x != %#x\n",
fin->fin_data[0], fr->fr_icmpm,
fr->fr_icmp));
continue;
}
}
FR_VERBOSE(("*"));
/*
* Just log this packet...
*/
if (!(skip = fr->fr_skip))
pass = fr->fr_flags;
if ((pass & FR_CALLNOW) && fr->fr_func)
pass = (*fr->fr_func)(pass, ip, fin);
#ifdef IPFILTER_LOG
if ((pass & FR_LOGMASK) == FR_LOG) {
if (!IPLLOG(fr->fr_flags, ip, fin, m))
frstats[fin->fin_out].fr_skip++;
frstats[fin->fin_out].fr_pkl++;
}
#endif /* IPFILTER_LOG */
FR_DEBUG(("pass %#x\n", pass));
fr->fr_hits++;
if (pass & FR_ACCOUNT)
fr->fr_bytes += (U_QUAD_T)ip->ip_len;
else
fin->fin_icode = fr->fr_icode;
fin->fin_rule = rulen;
fin->fin_group = fr->fr_group;
fin->fin_fr = fr;
if (fr->fr_grp) {
fin->fin_fr = fr->fr_grp;
pass = fr_scanlist(pass, ip, fin, m);
if (fin->fin_fr == NULL) {
fin->fin_rule = rulen;
fin->fin_group = fr->fr_group;
fin->fin_fr = fr;
}
}
if (pass & FR_QUICK)
break;
}
return pass;
}
/*
* frcheck - filter check
* check using source and destination addresses/pors in a packet whether
* or not to pass it on or not.
*/
int fr_check(ip, hlen, ifp, out
#if defined(_KERNEL) && SOLARIS
, qif, mp)
qif_t *qif;
#else
, mp)
#endif
mb_t **mp;
ip_t *ip;
int hlen;
void *ifp;
int out;
{
/*
* The above really sucks, but short of writing a diff
*/
fr_info_t frinfo, *fc;
register fr_info_t *fin = &frinfo;
frentry_t *fr = NULL;
int pass, changed, apass, error = EHOSTUNREACH;
#if !SOLARIS || !defined(_KERNEL)
register mb_t *m = *mp;
#endif
#ifdef _KERNEL
mb_t *mc = NULL;
# if !defined(__SVR4) && !defined(__svr4__)
# ifdef __sgi
char hbuf[(0xf << 2) + sizeof(struct icmp) + sizeof(ip_t) + 8];
# endif
int up;
#ifdef M_CANFASTFWD
/*
* XXX For now, IP Filter and fast-forwarding of cached flows
* XXX are mutually exclusive. Eventually, IP Filter should
* XXX get a "can-fast-forward" filter rule.
*/
m->m_flags &= ~M_CANFASTFWD;
#endif /* M_CANFASTFWD */
if ((ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP ||
ip->ip_p == IPPROTO_ICMP)) {
int plen = 0;
switch(ip->ip_p)
{
case IPPROTO_TCP:
plen = sizeof(tcphdr_t);
break;
case IPPROTO_UDP:
plen = sizeof(udphdr_t);
break;
case IPPROTO_ICMP:
/* 96 - enough for complete ICMP error IP header */
plen = sizeof(struct icmp) + sizeof(ip_t) + 8;
break;
}
up = MIN(hlen + plen, ip->ip_len);
if (up > m->m_len) {
#ifdef __sgi /* Under IRIX, avoid m_pullup as it makes ping <hostname> panic */
if ((up > sizeof(hbuf)) || (m_length(m) < up)) {
frstats[out].fr_pull[1]++;
return -1;
}
m_copydata(m, 0, up, hbuf);
frstats[out].fr_pull[0]++;
ip = (ip_t *)hbuf;
#else
# ifndef linux
if ((*mp = m_pullup(m, up)) == 0) {
frstats[out].fr_pull[1]++;
return -1;
} else {
frstats[out].fr_pull[0]++;
m = *mp;
ip = mtod(m, ip_t *);
}
# endif
#endif
} else
up = 0;
} else
up = 0;
# endif
# if SOLARIS
mb_t *m = qif->qf_m;
# endif
#endif
fr_makefrip(hlen, ip, fin);
fin->fin_ifp = ifp;
fin->fin_out = out;
fin->fin_mp = mp;
MUTEX_ENTER(&ipf_mutex);
/*
* Check auth now. This, combined with the check below to see if apass
* is 0 is to ensure that we don't count the packet twice, which can
* otherwise occur when we reprocess it. As it is, we only count it
* after it has no auth. table matchup. This also stops NAT from
* occuring until after the packet has been auth'd.
*/
apass = fr_checkauth(ip, fin);
if (!out) {
changed = ip_natin(ip, hlen, fin);
if (!apass && (fin->fin_fr = ipacct[0][fr_active]) &&
(FR_SCANLIST(FR_NOMATCH, ip, fin, m) & FR_ACCOUNT))
frstats[0].fr_acct++;
}
if (apass || (!(pass = ipfr_knownfrag(ip, fin)) &&
!(pass = fr_checkstate(ip, fin)))) {
/*
* If a packet is found in the auth table, then skip checking
* the access lists for permission but we do need to consider
* the result as if it were from the ACL's.
*/
if (!apass) {
fc = frcache + out;
if (!bcmp((char *)fin, (char *)fc, FI_CSIZE)) {
/*
* copy cached data so we can unlock the mutex
* earlier.
*/
bcopy((char *)fc, (char *)fin, FI_COPYSIZE);
frstats[out].fr_chit++;
if ((fr = fin->fin_fr)) {
fr->fr_hits++;
pass = fr->fr_flags;
} else
pass = fr_pass;
} else {
pass = fr_pass;
if ((fin->fin_fr = ipfilter[out][fr_active]))
pass = FR_SCANLIST(fr_pass, ip, fin, m);
bcopy((char *)fin, (char *)fc, FI_COPYSIZE);
if (pass & FR_NOMATCH)
frstats[out].fr_nom++;
}
fr = fin->fin_fr;
} else
pass = apass;
/*
* If we fail to add a packet to the authorization queue,
* then we drop the packet later. However, if it was added
* then pretend we've dropped it already.
*/
if ((pass & FR_AUTH))
if (FR_NEWAUTH(m, fin, ip, qif) != 0)
#ifdef _KERNEL
m = *mp = NULL;
#else
;
#endif
if (pass & FR_PREAUTH) {
MUTEX_ENTER(&ipf_auth);
if ((fin->fin_fr = ipauth) &&
(pass = FR_SCANLIST(0, ip, fin, m)))
fr_authstats.fas_hits++;
else
fr_authstats.fas_miss++;
MUTEX_EXIT(&ipf_auth);
}
if (pass & FR_KEEPFRAG) {
if (fin->fin_fi.fi_fl & FI_FRAG) {
if (ipfr_newfrag(ip, fin, pass) == -1)
frstats[out].fr_bnfr++;
else
frstats[out].fr_nfr++;
} else
frstats[out].fr_cfr++;
}
if (pass & FR_KEEPSTATE) {
if (fr_addstate(ip, fin, pass) == -1)
frstats[out].fr_bads++;
else
frstats[out].fr_ads++;
}
}
if (fr && fr->fr_func && !(pass & FR_CALLNOW))
pass = (*fr->fr_func)(pass, ip, fin);
/*
* Only count/translate packets which will be passed on, out the
* interface.
*/
if (out && (pass & FR_PASS)) {
if ((fin->fin_fr = ipacct[1][fr_active]) &&
(FR_SCANLIST(FR_NOMATCH, ip, fin, m) & FR_ACCOUNT))
frstats[1].fr_acct++;
fin->fin_fr = NULL;
changed = ip_natout(ip, hlen, fin);
}
fin->fin_fr = fr;
MUTEX_EXIT(&ipf_mutex);
#ifdef IPFILTER_LOG
if ((fr_flags & FF_LOGGING) || (pass & FR_LOGMASK)) {
if ((fr_flags & FF_LOGNOMATCH) && (pass & FR_NOMATCH)) {
pass |= FF_LOGNOMATCH;
frstats[out].fr_npkl++;
goto logit;
} else if (((pass & FR_LOGMASK) == FR_LOGP) ||
((pass & FR_PASS) && (fr_flags & FF_LOGPASS))) {
if ((pass & FR_LOGMASK) != FR_LOGP)
pass |= FF_LOGPASS;
frstats[out].fr_ppkl++;
goto logit;
} else if (((pass & FR_LOGMASK) == FR_LOGB) ||
((pass & FR_BLOCK) && (fr_flags & FF_LOGBLOCK))) {
if ((pass & FR_LOGMASK) != FR_LOGB)
pass |= FF_LOGBLOCK;
frstats[out].fr_bpkl++;
logit:
if (!IPLLOG(pass, ip, fin, m)) {
frstats[out].fr_skip++;
if ((pass & (FR_PASS|FR_LOGORBLOCK)) ==
(FR_PASS|FR_LOGORBLOCK))
pass ^= FR_PASS|FR_BLOCK;
}
}
}
#endif /* IPFILTER_LOG */
#ifdef _KERNEL
/*
* Only allow FR_DUP to work if a rule matched - it makes no sense to
* set FR_DUP as a "default" as there are no instructions about where
* to send the packet.
*/
if (fr && (pass & FR_DUP))
# if SOLARIS
mc = dupmsg(m);
# else
# ifndef linux
mc = m_copy(m, 0, M_COPYALL);
# else
;
# endif
# endif
#endif
if (pass & FR_PASS)
frstats[out].fr_pass++;
else if (pass & FR_BLOCK) {
frstats[out].fr_block++;
/*
* Should we return an ICMP packet to indicate error
* status passing through the packet filter ?
* WARNING: ICMP error packets AND TCP RST packets should
* ONLY be sent in repsonse to incoming packets. Sending them
* in response to outbound packets can result in a panic on
* some operating systems.
*/
if (!out) {
#ifdef _KERNEL
if (pass & FR_RETICMP) {
# if SOLARIS
ICMP_ERROR(q, ip, ICMP_UNREACH, fin->fin_icode,
qif, ip->ip_src);
# else
ICMP_ERROR(m, ip, ICMP_UNREACH, fin->fin_icode,
ifp, ip->ip_src);
m = *mp = NULL; /* freed by icmp_error() */
# endif
frstats[0].fr_ret++;
} else if ((pass & FR_RETRST) &&
!(fin->fin_fi.fi_fl & FI_SHORT)) {
if (SEND_RESET(ip, qif, ifp) == 0)
frstats[1].fr_ret++;
}
#else
if (pass & FR_RETICMP) {
verbose("- ICMP unreachable sent\n");
frstats[0].fr_ret++;
} else if ((pass & FR_RETRST) &&
!(fin->fin_fi.fi_fl & FI_SHORT)) {
verbose("- TCP RST sent\n");
frstats[1].fr_ret++;
}
#endif
} else {
if (pass & FR_RETRST)
error = ECONNRESET;
}
}
/*
* If we didn't drop off the bottom of the list of rules (and thus
* the 'current' rule fr is not NULL), then we may have some extra
* instructions about what to do with a packet.
* Once we're finished return to our caller, freeing the packet if
* we are dropping it (* BSD ONLY *).
*/
#if defined(_KERNEL)
# if !SOLARIS
# if !defined(linux)
if (fr) {
frdest_t *fdp = &fr->fr_tif;
if ((pass & FR_FASTROUTE) ||
(fdp->fd_ifp && fdp->fd_ifp != (struct ifnet *)-1)) {
ipfr_fastroute(m, fin, fdp);
m = *mp = NULL;
}
if (mc)
ipfr_fastroute(mc, fin, &fr->fr_dif);
}
if (!(pass & FR_PASS) && m)
m_freem(m);
# ifdef __sgi
else if (changed && up && m)
m_copyback(m, 0, up, hbuf);
# endif
# endif /* !linux */
return (pass & FR_PASS) ? 0 : error;
# else /* !SOLARIS */
if (fr) {
frdest_t *fdp = &fr->fr_tif;
if ((pass & FR_FASTROUTE) ||
(fdp->fd_ifp && fdp->fd_ifp != (struct ifnet *)-1)) {
ipfr_fastroute(qif, ip, m, mp, fin, fdp);
m = *mp = NULL;
}
if (mc)
ipfr_fastroute(qif, ip, mc, mp, fin, &fr->fr_dif);
}
return (pass & FR_PASS) ? changed : error;
# endif /* !SOLARIS */
#else /* _KERNEL */
if (pass & FR_NOMATCH)
return 1;
if (pass & FR_PASS)
return 0;
if (pass & FR_AUTH)
return -2;
return -1;
#endif /* _KERNEL */
}
/*
* ipf_cksum
* addr should be 16bit aligned and len is in bytes.
* length is in bytes
*/
u_short ipf_cksum(addr, len)
register u_short *addr;
register int len;
{
register u_32_t sum = 0;
for (sum = 0; len > 1; len -= 2)
sum += *addr++;
/* mop up an odd byte, if necessary */
if (len == 1)
sum += *(u_char *)addr;
/*
* add back carry outs from top 16 bits to low 16 bits
*/
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
sum += (sum >> 16); /* add carry */
return (u_short)(~sum);
}
/*
* NB: This function assumes we've pullup'd enough for all of the IP header
* and the TCP header. We also assume that data blocks aren't allocated in
* odd sizes.
*/
u_short fr_tcpsum(m, ip, tcp, len)
mb_t *m;
ip_t *ip;
tcphdr_t *tcp;
int len;
{
union {
u_char c[2];
u_short s;
} bytes;
u_32_t sum;
u_short *sp;
# if SOLARIS || defined(__sgi)
int add, hlen;
# endif
# if SOLARIS
/* skip any leading M_PROTOs */
while(m && (MTYPE(m) != M_DATA))
m = m->b_cont;
PANIC((!m),("fr_tcpsum: no M_DATA"));
# endif
/*
* Add up IP Header portion
*/
bytes.c[0] = 0;
bytes.c[1] = IPPROTO_TCP;
len -= (ip->ip_hl << 2);
sum = bytes.s;
sum += htons((u_short)len);
sp = (u_short *)&ip->ip_src;
sum += *sp++;
sum += *sp++;
sum += *sp++;
sum += *sp++;
if (sp != (u_short *)tcp)
sp = (u_short *)tcp;
sum += *sp++;
sum += *sp++;
sum += *sp++;
sum += *sp++;
sum += *sp++;
sum += *sp++;
sum += *sp++;
sum += *sp;
sp += 2; /* Skip over checksum */
sum += *sp++;
#if SOLARIS
/*
* In case we had to copy the IP & TCP header out of mblks,
* skip over the mblk bits which are the header
*/
if ((caddr_t)ip != (caddr_t)m->b_rptr) {
hlen = (caddr_t)sp - (caddr_t)ip;
while (hlen) {
add = MIN(hlen, m->b_wptr - m->b_rptr);
sp = (u_short *)((caddr_t)m->b_rptr + add);
hlen -= add;
if ((caddr_t)sp >= (caddr_t)m->b_wptr) {
m = m->b_cont;
PANIC((!m),("fr_tcpsum: not enough data"));
if (!hlen)
sp = (u_short *)m->b_rptr;
}
}
}
#endif
#ifdef __sgi
/*
* In case we had to copy the IP & TCP header out of mbufs,
* skip over the mbuf bits which are the header
*/
if ((caddr_t)ip != mtod(m, caddr_t)) {
hlen = (caddr_t)sp - (caddr_t)ip;
while (hlen) {
add = MIN(hlen, m->m_len);
sp = (u_short *)(mtod(m, caddr_t) + add);
hlen -= add;
if (add >= m->m_len) {
m = m->m_next;
PANIC((!m),("fr_tcpsum: not enough data"));
if (!hlen)
sp = mtod(m, u_short *);
}
}
}
#endif
if (!(len -= sizeof(*tcp)))
goto nodata;
while (len > 0) {
#if SOLARIS
while ((caddr_t)sp >= (caddr_t)m->b_wptr) {
m = m->b_cont;
PANIC((!m),("fr_tcpsum: not enough data"));
sp = (u_short *)m->b_rptr;
}
#else
while (((caddr_t)sp - mtod(m, caddr_t)) >= m->m_len)
{
m = m->m_next;
PANIC((!m),("fr_tcpsum: not enough data"));
sp = mtod(m, u_short *);
}
#endif /* SOLARIS */
if (len < 2)
break;
if((u_32_t)sp & 1) {
bcopy((char *)sp++, (char *)&bytes.s, sizeof(bytes.s));
sum += bytes.s;
} else
sum += *sp++;
len -= 2;
}
if (len) {
bytes.c[1] = 0;
bytes.c[0] = *(u_char *)sp;
sum += bytes.s;
}
nodata:
sum = (sum >> 16) + (sum & 0xffff);
sum += (sum >> 16);
sum = (u_short)((~sum) & 0xffff);
return sum;
}
#if defined(_KERNEL) && ( ((BSD < 199306) && !SOLARIS) || defined(__sgi) )
/*
* Copyright (c) 1982, 1986, 1988, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94
* $FreeBSD$
*/
/*
* Copy data from an mbuf chain starting "off" bytes from the beginning,
* continuing for "len" bytes, into the indicated buffer.
*/
void
m_copydata(m, off, len, cp)
register mb_t *m;
register int off;
register int len;
caddr_t cp;
{
register unsigned count;
if (off < 0 || len < 0)
panic("m_copydata");
while (off > 0) {
if (m == 0)
panic("m_copydata");
if (off < m->m_len)
break;
off -= m->m_len;
m = m->m_next;
}
while (len > 0) {
if (m == 0)
panic("m_copydata");
count = MIN(m->m_len - off, len);
bcopy(mtod(m, caddr_t) + off, cp, count);
len -= count;
cp += count;
off = 0;
m = m->m_next;
}
}
# ifndef linux
/*
* Copy data from a buffer back into the indicated mbuf chain,
* starting "off" bytes from the beginning, extending the mbuf
* chain if necessary.
*/
void
m_copyback(m0, off, len, cp)
struct mbuf *m0;
register int off;
register int len;
caddr_t cp;
{
register int mlen;
register struct mbuf *m = m0, *n;
int totlen = 0;
if (m0 == 0)
return;
while (off > (mlen = m->m_len)) {
off -= mlen;
totlen += mlen;
if (m->m_next == 0) {
n = m_getclr(M_DONTWAIT, m->m_type);
if (n == 0)
goto out;
n->m_len = min(MLEN, len + off);
m->m_next = n;
}
m = m->m_next;
}
while (len > 0) {
mlen = min (m->m_len - off, len);
bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen);
cp += mlen;
len -= mlen;
mlen += off;
off = 0;
totlen += mlen;
if (len == 0)
break;
if (m->m_next == 0) {
n = m_get(M_DONTWAIT, m->m_type);
if (n == 0)
break;
n->m_len = min(MLEN, len);
m->m_next = n;
}
m = m->m_next;
}
out:
#if 0
if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
m->m_pkthdr.len = totlen;
#endif
return;
}
# endif /* linux */
#endif /* (_KERNEL) && ( ((BSD < 199306) && !SOLARIS) || __sgi) */
frgroup_t *fr_findgroup(num, flags, which, set, fgpp)
u_short num;
u_32_t flags;
int which, set;
frgroup_t ***fgpp;
{
frgroup_t *fg, **fgp;
if (which == IPL_LOGAUTH)
fgp = &ipfgroups[2][set];
else if (flags & FR_ACCOUNT)
fgp = &ipfgroups[1][set];
else if (flags & (FR_OUTQUE|FR_INQUE))
fgp = &ipfgroups[0][set];
else
return NULL;
while ((fg = *fgp))
if (fg->fg_num == num)
break;
else
fgp = &fg->fg_next;
if (fgpp)
*fgpp = fgp;
return fg;
}
frgroup_t *fr_addgroup(num, fp, which, set)
u_short num;
frentry_t *fp;
int which, set;
{
frgroup_t *fg, **fgp;
if ((fg = fr_findgroup(num, fp->fr_flags, which, set, &fgp)))
return fg;
KMALLOC(fg, frgroup_t *, sizeof(*fg));
if (fg) {
fg->fg_num = num;
fg->fg_next = *fgp;
fg->fg_head = fp;
fg->fg_start = &fp->fr_grp;
*fgp = fg;
}
return fg;
}
void fr_delgroup(num, flags, which, set)
u_short num;
u_32_t flags;
int which, set;
{
frgroup_t *fg, **fgp;
if (!(fg = fr_findgroup(num, flags, which, set, &fgp)))
return;
*fgp = fg->fg_next;
KFREE(fg);
}
/*
* recursively flush rules from the list, descending groups as they are
* encountered. if a rule is the head of a group and it has lost all its
* group members, then also delete the group reference.
*/
static int frflushlist(set, unit, nfreedp, list, listp)
int set, unit, *nfreedp;
frentry_t *list, **listp;
{
register frentry_t *fp = list, *fpn;
register int freed = 0;
while (fp) {
fpn = fp->fr_next;
if (fp->fr_grp) {
fp->fr_ref -= frflushlist(set, unit, nfreedp,
fp->fr_grp, &fp->fr_grp);
}
if (fp->fr_ref == 1) {
if (fp->fr_grhead)
fr_delgroup(fp->fr_grhead, fp->fr_flags, unit,
set);
KFREE(fp);
*listp = fpn;
freed++;
}
fp = fpn;
}
*nfreedp += freed;
return freed;
}
void frflush(unit, result)
int unit;
int *result;
{
int flags = *result, flushed = 0, set = fr_active;
bzero((char *)frcache, sizeof(frcache[0]) * 2);
if (flags & FR_INACTIVE)
set = 1 - set;
if (unit == IPL_LOGIPF) {
if (flags & FR_OUTQUE) {
(void) frflushlist(set, unit, &flushed,
ipfilter[1][set],
&ipfilter[1][set]);
(void) frflushlist(set, unit, &flushed,
ipacct[1][set], &ipacct[1][set]);
}
if (flags & FR_INQUE) {
(void) frflushlist(set, unit, &flushed,
ipfilter[0][set],
&ipfilter[0][set]);
(void) frflushlist(set, unit, &flushed,
ipacct[0][set], &ipacct[0][set]);
}
}
*result = flushed;
}
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