/* $OpenBSD: fil.c,v 1.14 1999/02/05 05:58:49 deraadt Exp $ */ /* * Copyright (C) 1993-1998 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[] = "@(#)$Id: fil.c,v 1.14 1999/02/05 05:58:49 deraadt Exp $"; #endif #include #include #include #include #include #include #if (defined(_KERNEL) || defined(KERNEL)) && !defined(linux) # include #else # include # include # include #endif #include #if !defined(__SVR4) && !defined(__svr4__) # ifndef linux # include # endif #else # include # if SOLARIS2 < 5 # include # endif # include #endif #ifndef linux # include # include #endif #include #ifdef sun # include #endif #include #include #include #include #ifndef linux # include #endif #include #include #include #if defined(__OpenBSD__) # include #else # include #endif #include #include #include #include #include #include #include #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 KRWLOCK_T ipf_mutex, ipf_auth; extern kmutex_t ipf_rw; # 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 */ 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 */ 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; 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); 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 & IP_OFFMASK) << 3; if (ip->ip_off & 0x3fff) fi->fi_fl |= FI_FRAG; switch (ip->ip_p) { case IPPROTO_ICMP : { int minicmpsz = sizeof(struct icmp); icmphdr_t *icmp; icmp = (icmphdr_t *)tcp; if (!off && (icmp->icmp_type == ICMP_ECHOREPLY || icmp->icmp_type == ICMP_ECHO)) 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_tcpfm && 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 & IP_OFFMASK; 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)) { ATOMIC_INC(frstats[fin->fin_out].fr_skip); } ATOMIC_INC(frstats[fin->fin_out].fr_pkl); } #endif /* IPFILTER_LOG */ FR_DEBUG(("pass %#x\n", pass)); ATOMIC_INC(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/ports 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; if ((ip->ip_off & IP_OFFMASK) == 0) switch(ip->ip_p) { case IPPROTO_TCP: plen = sizeof(tcphdr_t); break; case IPPROTO_UDP: plen = sizeof(udphdr_t); break; /* 96 - enough for complete ICMP error IP header */ case IPPROTO_ICMP: plen = 76 + sizeof(struct icmp); break; } up = MIN(hlen + plen, ip->ip_len); if (up > m->m_len) { # ifdef __sgi /* Under IRIX, avoid m_pullup as it makes ping panic */ if ((up > sizeof(hbuf)) || (m_length(m) < up)) { ATOMIC_INC(frstats[out].fr_pull[1]); return -1; } m_copydata(m, 0, up, hbuf); ATOMIC_INC(frstats[out].fr_pull[0]); ip = (ip_t *)hbuf; # else /* __ sgi */ # ifndef linux if ((*mp = m_pullup(m, up)) == 0) { ATOMIC_INC(frstats[out].fr_pull[1]); return -1; } else { ATOMIC_INC(frstats[out].fr_pull[0]); m = *mp; ip = mtod(m, ip_t *); } # endif /* !linux */ # endif /* __sgi */ } else up = 0; } else up = 0; # endif /* !defined(__SVR4) && !defined(__svr4__) */ # if SOLARIS mb_t *m = qif->qf_m; fin->fin_qfm = m; # endif #endif /* _KERNEL */ fr_makefrip(hlen, ip, fin); fin->fin_ifp = ifp; fin->fin_out = out; fin->fin_mp = mp; READ_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)) { ATOMIC_INC(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); ATOMIC_INC(frstats[out].fr_chit); if ((fr = fin->fin_fr)) { ATOMIC_INC(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) { ATOMIC_INC(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) { READ_ENTER(&ipf_auth); if ((fin->fin_fr = ipauth) && (pass = FR_SCANLIST(0, ip, fin, m))) { ATOMIC_INC(fr_authstats.fas_hits); } else { ATOMIC_INC(fr_authstats.fas_miss); } RWLOCK_EXIT(&ipf_auth); } if (pass & FR_KEEPFRAG) { if (fin->fin_fi.fi_fl & FI_FRAG) { if (ipfr_newfrag(ip, fin, pass) == -1) { ATOMIC_INC(frstats[out].fr_bnfr); } else { ATOMIC_INC(frstats[out].fr_nfr); } } else { ATOMIC_INC(frstats[out].fr_cfr); } } if (pass & FR_KEEPSTATE) { if (fr_addstate(ip, fin, pass) == -1) { ATOMIC_INC(frstats[out].fr_bads); } else { ATOMIC_INC(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)) { ATOMIC_INC(frstats[1].fr_acct); } fin->fin_fr = NULL; changed = ip_natout(ip, hlen, fin); } fin->fin_fr = fr; RWLOCK_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; ATOMIC_INC(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; ATOMIC_INC(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; ATOMIC_INC(frstats[out].fr_bpkl); logit: if (!IPLLOG(pass, ip, fin, m)) { ATOMIC_INC(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) { ATOMIC_INC(frstats[out].fr_pass); } else if (pass & FR_BLOCK) { ATOMIC_INC(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 ATOMIC_INC(frstats[0].fr_ret); } else if ((pass & FR_RETRST) && !(fin->fin_fi.fi_fl & FI_SHORT)) { if (SEND_RESET(ip, qif, ifp) == 0) { ATOMIC_INC(frstats[1].fr_ret); } } #else if (pass & FR_RETICMP) { verbose("- ICMP unreachable sent\n"); ATOMIC_INC(frstats[0].fr_ret); } else if ((pass & FR_RETRST) && !(fin->fin_fi.fi_fl & FI_SHORT)) { verbose("- TCP RST sent\n"); ATOMIC_INC(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; { u_short *sp, slen, ts; u_int sum, sum2; int hlen; /* * Add up IP Header portion */ hlen = ip->ip_hl << 2; slen = ip->ip_len - hlen; sum = htons(ip->ip_p); sum += htons(slen); sp = (u_short *)&ip->ip_src; sum += *sp++; /* ip_src */ sum += *sp++; sum += *sp++; /* ip_dst */ sum += *sp++; ts = tcp->th_sum; tcp->th_sum = 0; #ifdef KERNEL # if SOLARIS sum2 = ip_cksum(m, hlen, sum); sum2 = (sum2 & 0xffff) + (sum2 >> 16); sum2 = ~sum2 & 0xffff; # else /* SOLARIS */ # if defined(BSD) || defined(sun) # if BSD >= 199306 m->m_data += hlen; # else m->m_off += hlen; # endif m->m_len -= hlen; sum2 = in_cksum(m, slen); m->m_len += hlen; # if BSD >= 199306 m->m_data -= hlen; # else m->m_off -= hlen; # endif /* * Both sum and sum2 are partial sums, so combine them together. */ sum = (sum & 0xffff) + (sum >> 16); sum = ~sum & 0xffff; sum2 += sum; sum2 = (sum2 & 0xffff) + (sum2 >> 16); # else /* defined(BSD) || defined(sun) */ { union { u_char c[2]; u_short s; } bytes; u_32_t sum; u_short *sp, slen; # if defined(__sgi) int add; # endif /* * Add up IP Header portion */ sp = (u_short *)&ip->ip_src; len -= (ip->ip_hl << 2); sum = ntohs(IPPROTO_TCP); sum += htons((u_short)len); sum += *sp++; /* ip_src */ sum += *sp++; sum += *sp++; /* ip_dst */ sum += *sp++; if (sp != (u_short *)tcp) sp = (u_short *)tcp; sum += *sp++; /* sport */ sum += *sp++; /* dport */ sum += *sp++; /* seq */ sum += *sp++; sum += *sp++; /* ack */ sum += *sp++; sum += *sp++; /* off */ sum += *sp; /* win */ sp += 2; /* Skip over checksum */ sum += *sp++; /* urp */ # 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; if (!hlen) { if (!m) break; sp = mtod(m, u_short *); } PANIC((!m),("fr_tcpsum(1): not enough data")); } } } # endif if (!(len -= sizeof(*tcp))) goto nodata; while (len > 1) { if (((caddr_t)sp - mtod(m, caddr_t)) >= m->m_len) { m = m->m_next; PANIC((!m),("fr_tcpsum(2): not enough data")); sp = mtod(m, u_short *); } if (((caddr_t)(sp + 1) - mtod(m, caddr_t)) > m->m_len) { bytes.c[0] = *(u_char *)sp; m = m->m_next; PANIC((!m),("fr_tcpsum(3): not enough data")); sp = mtod(m, u_short *); bytes.c[1] = *(u_char *)sp; sum += bytes.s; sp = (u_short *)((u_char *)sp + 1); } if ((u_long)sp & 1) { bcopy((char *)sp++, (char *)&bytes.s, sizeof(bytes.s)); sum += bytes.s; } else sum += *sp++; len -= 2; } if (len) sum += ntohs(*(u_char *)sp << 8); nodata: while (sum > 0xffff) sum = (sum & 0xffff) + (sum >> 16); sum2 = (u_short)(~sum & 0xffff); } # endif /* defined(BSD) || defined(sun) */ # endif /* SOLARIS */ #else /* KERNEL */ sum2 = 0; #endif /* KERNEL */ tcp->th_sum = ts; return sum2; } #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 * $Id: fil.c,v 1.14 1999/02/05 05:58:49 deraadt Exp $ */ /* * 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; WRITE_ENTER(&ipf_mutex); 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]); } } RWLOCK_EXIT(&ipf_mutex); *result = flushed; }