/* * 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: ip_fil_bsdos.c,v 2.45.2.8 2004/06/22 20:57:47 darrenr Exp $"; #endif #if defined(KERNEL) || defined(_KERNEL) # undef KERNEL # undef _KERNEL # define KERNEL 1 # define _KERNEL 1 #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "netinet/ip_compat.h" #ifdef USE_INET6 # include #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" #include extern int ip_optcopy __P((struct ip *, struct ip *)); #ifdef IPFILTER_M_IPFILTER MALLOC_DEFINE(M_IPFILTER, "IP Filter", "IP Filter packet filter data structures"); #endif extern struct protosw inetsw[]; static int (*fr_savep) __P((ip_t *, int, void *, int, struct mbuf **)); static int fr_send_ip __P((ip_t *, fr_info_t *, mb_t *, mb_t **)); #ifdef KMUTEX_T extern ipfmutex_t ipf_rw; extern ipfrwlock_t ipf_mutex; #endif #if (_BSDI_VERSION >= 199510) # include # include struct cfdriver iplcd = { NULL, "ipl", NULL, NULL, DV_DULL, 0 }; struct devsw iplsw = { &iplcd, iplopen, iplclose, iplread, nowrite, iplioctl, noselect, nommap, nostrat, nodump, nopsize, 0, nostop }; #endif /* _BSDI_VERSION >= 199510 */ #if (_BSDI_VERSION >= 199701) # include #endif /* _BSDI_VERSION >= 199701 */ #if defined(IPFILTER_LKM) int iplidentify(s) char *s; { if (strcmp(s, "ipl") == 0) return 1; return 0; } #endif /* IPFILTER_LKM */ int iplattach() { char *defpass; int s; SPL_NET(s); if ((fr_running > 0) || (fr_checkp == fr_check)) { printf("IP Filter: already initialized\n"); SPL_X(s); return EBUSY; } if (fr_initialise() < 0) { SPL_X(s); return EIO; } bzero((char *)frcache, sizeof(frcache)); fr_savep = fr_checkp; fr_checkp = fr_check; fr_running = 1; if (fr_control_forwarding & 1) ip_forwarding = 1; SPL_X(s); if (FR_ISPASS(fr_pass)) defpass = "pass"; else if (FR_ISBLOCK(fr_pass)) defpass = "block"; else defpass = "no-match -> block"; printf("%s initialized. Default = %s all, Logging = %s%s\n", ipfilter_version, defpass, #ifdef IPFILTER_LOG "enabled", #else "disabled", #endif #ifdef IPFILTER_COMPILED " (COMPILED)" #else "" #endif ); timeout(fr_slowtimer, NULL, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT); return 0; } /* * Disable the filter by removing the hooks from the IP input/output * stream. */ int ipldetach() { int s; if (fr_refcnt) return EBUSY; SPL_NET(s); untimeout(fr_slowtimer, NULL); if (fr_control_forwarding & 2) ip_forwarding = 0; fr_deinitialise(); fr_checkp = fr_savep; (void) frflush(IPL_LOGIPF, 0, FR_INQUE|FR_OUTQUE|FR_INACTIVE); (void) frflush(IPL_LOGIPF, 0, FR_INQUE|FR_OUTQUE); fr_running = -1; SPL_X(s); printf("%s unloaded\n", ipfilter_version); return 0; } /* * Filter ioctl interface. */ int iplioctl(dev, cmd, data, mode #if (_BSDI_VERSION >= 199510) , p) struct proc *p; #else ) #endif dev_t dev; ioctlcmd_t cmd; caddr_t data; int mode; { int s; int error = 0, unit = 0, tmp; friostat_t fio; if ((securelevel >= 2) && (mode & FWRITE)) return EPERM; 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 && cmd != SIOCGETFF) return EIO; } SPL_NET(s); error = fr_ioctlswitch(unit, data, cmd, mode); if (error != -1) { SPL_X(s); return error; } error = 0; 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, 4, tmp); error = COPYOUT(&tmp, data, sizeof(tmp)); } } break; #ifdef USE_INET6 case SIOCIPFL6 : if (!(mode & FWRITE)) error = EPERM; else { error = COPYIN(data, &tmp, sizeof(tmp)); if (!error) { tmp = frflush(unit, 6, tmp); error = COPYOUT(&tmp, data, sizeof(tmp)); } } break; #endif 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 (_BSDI_VERSION >= 199510) , devtype, p) int devtype; struct proc *p; #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 (_BSDI_VERSION >= 199510) , devtype, p) int devtype; struct proc *p; #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. */ int iplread(dev, uio, ioflag) dev_t dev; register struct uio *uio; int ioflag; { #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 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 #ifdef MGETHDR MGETHDR(m, M_DONTWAIT, MT_HEADER); #else MGET(m, M_DONTWAIT, MT_HEADER); #endif if (m == NULL) return -1; if (sizeof(*tcp2) + hlen > MHLEN) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { FREE_MB_T(m); return -1; } } m->m_len = sizeof(*tcp2) + hlen; m->m_data += max_linkhdr; m->m_pkthdr.len = m->m_len; m->m_pkthdr.rcvif = (struct ifnet *)0; ip = mtod(m, struct ip *); #ifdef USE_INET6 ip6 = (ip6_t *)ip; #endif 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; tcp2->th_ack = 0; } else { tcp2->th_seq = 0; 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_X2_A(tcp2, 0); TCP_OFF_A(tcp2, sizeof(*tcp2) >> 2); tcp2->th_win = tcp->th_win; tcp2->th_sum = 0; tcp2->th_urp = 0; #ifdef USE_INET6 if (fin->fin_v == 6) { ip6->ip6_flow = 0; ip6->ip6_plen = htons(sizeof(struct tcphdr)); ip6->ip6_nxt = IPPROTO_TCP; ip6->ip6_hlim = 0 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 *); oip = fin->fin_ip; IP_V_A(ip, fin->fin_v); switch (fin->fin_v) { case 4 : IP_HL_A(ip, sizeof(*oip) >> 2); ip->ip_tos = oip->ip_tos; ip->ip_id = fin->fin_ip->ip_id; ip->ip_off = ip_mtudisc ? IP_DF : 0; ip->ip_ttl = ip_defttl; ip->ip_sum = 0; break; #ifdef USE_INET6 case 6 : { ip6_t *ip6 = (ip6_t *)ip; ip6->ip6_vfc = 0x60; 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 #ifdef MGETHDR MGETHDR(m, M_DONTWAIT, MT_HEADER); #else MGET(m, M_DONTWAIT, MT_HEADER); #endif if (m == NULL) return -1; avail = MHLEN; 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 (dst == 0) { if (fr_ifpaddr(4, FRI_NORMAL, ifp, &dst, 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]; if (hlen + sizeof(*icmp) + max_linkhdr + fin->fin_plen > avail) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { FREE_MB_T(m); return -1; } avail = MCLBYTES; } xtra = MIN(fin->fin_plen, 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; 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; if (avail < 0) { FREE_MB_T(m); return -1; } m->m_len = iclen; ip = mtod(m, ip_t *); icmp = (struct icmp *)((char *)ip + hlen); ip2 = (ip_t *)&icmp->icmp_ip; 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; 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 { 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) void iplinit __P((void)); void iplinit() { if (iplattach() != 0) printf("IP Filter failed to attach\n"); ip_init(); } # endif /* ! IPFILTER_LKM */ int fr_fastroute(m0, mpp, fin, fdp) mb_t *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) { FREE_MB_T(m); m = m0; *mpp = m; } else { error = ENOBUFS; FREE_MB_T(m); *mpp = NULL; fr_frouteok[1]++; } } #endif hlen = fin->fin_hlen; ip = mtod(m0, struct ip *); #ifdef USE_INET6 if (fin->fin_v == 6) { /* * currently "to " and "to :ip#" are not supported * for IPv6 */ return ip6_output(m0, NULL, NULL, 0, NULL, NULL); } #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 " 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. */ if (fin->fin_out == 0) { fin->fin_out = 1; sifp = fin->fin_ifp; fin->fin_ifp = ifp; if ((fin->fin_fr = ipacct[1][fr_active]) && (fr_scanlist(fin, FR_NOMATCH) & FR_ACCOUNT)) { ATOMIC_INCL(frstats[1].fr_acct); } fin->fin_fr = NULL; if (!fr || !(fr->fr_flags & FR_RETMASK)) { u_32_t pass; (void) fr_checkstate(fin, &pass); } switch (fr_checknatout(fin, &pass)) { case 0 : break; case 1 : ip->ip_sum = 0; break; case -1 : error = -1; goto done; break; } fin->fin_ifp = sifp; fin->fin_out = 0; } else ip->ip_sum = 0; /* * If small enough for interface, can just send directly. */ if (ip->ip_len <= ifp->if_mtu) { # if !(_BSDI_VERSION >= 199510)) ip->ip_id = htons(ip->ip_id); # endif 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) { m = m0; error = ENOBUFS; goto bad; } m->m_data += max_linkhdr; mhip = mtod(m, struct ip *); bcopy((char *)fin->fin_ip, (char *)mhip, sizeof(*ip)); if (hlen > sizeof (struct ip)) { mhlen = ip_optcopy(fin->fin_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 FREE_MB_T(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; } FREE_MB_T(m); goto done; } int fr_verifysrc(fin) fr_info_t *fin; { struct sockaddr_in *dst; struct route iproute; struct in_addr ipa; 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_in *sin *mask; struct ifaddr *ifa; struct in_addr in; struct ifnet *ifp; if ((ifptr == NULL) || (ifptr == (void *)-1)) return -1; ifp = ifptr; if (v == 4) inp->s_addr = 0; #ifdef USE_INET6 else if (v == 6) bzero((char *)inp, sizeof(struct in6_addr)); #endif ifa = ifp->if_addrlist; sin = (struct sockaddr_in *)ifa->ifa_addr; while (sin && ifa) { 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 ifa = ifa->ifa_next; if (ifa != NULL) sin = (struct sockaddr_in *)ifa->ifa_addr; } if (ifa == NULL || sin == NULL) return -1; mask = ifa->ifa_netmask; if (atype == FRI_BROADCAST) sin = ifa->ifa_broadaddr; else if (atype == FRI_PEERADDR) sin = ifa->ifa_dstaddr; #ifdef USE_INET6 if (v == 6) { return fr_ifpfillv6addr(atype, (struct sockaddr_in6 *)sin, (struct sockaddr_in6 *)mask, inp, inpmask); } #endif return fr_ifpfillv4addr(atype, sin, mask, inp, inpmask); } u_32_t fr_newisn(fin) fr_info_t *fin; { static iss_seq_off = 0; u_char hash[16]; u_32_t newiss; 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; 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; { static u_short ipid = 0; u_short id; MUTEX_ENTER(&ipf_rw); id = ipid++; MUTEX_EXIT(&ipf_rw); return id; } INLINE void fr_checkv4sum(fin) fr_info_t *fin; { #ifdef IPFILTER_CKSUM if (fr_checkl4sum(fin) == -1) fin->fin_flx |= FI_BAD; #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 */ size_t mbufchainlen(m0) struct mbuf *m0; { size_t len; if ((m0->m_flags & M_PKTHDR) != 0) { len = m0->m_pkthdr.len; } else { struct mbuf *m; for (m = m0, len = 0; m != NULL; m = m->m_next) len += m->m_len; } return len; }