/* $OpenBSD: parse.c,v 1.34 2000/04/05 05:35:28 kjell 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. */ #include #if !defined(__SVR4) && !defined(__svr4__) #include #else #include #endif #include #include #include #include #include #include #include #include #if __FreeBSD_version >= 300000 # include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ipf.h" #include "facpri.h" #if !defined(lint) static const char sccsid[] = "@(#)parse.c 1.44 6/5/96 (C) 1993-1996 Darren Reed"; static const char rcsid[] = "@(#)$IPFilter: parse.c,v 2.1.2.12 2000/03/08 11:43:55 darrenr Exp $"; #endif extern struct ipopt_names ionames[], secclass[]; extern int opts; int portnum __P((char *, u_short *, int)); u_char tcp_flags __P((char *, u_char *, int)); int addicmp __P((char ***, struct frentry *, int)); int extras __P((char ***, struct frentry *, int)); char ***seg; u_long *sa, *msk; u_short *pp, *tp; u_char *cp; int hostmask __P((char ***, u_32_t *, u_32_t *, u_short *, u_char *, u_short *, int)); int ports __P((char ***, u_short *, u_char *, u_short *, int)); int icmpcode __P((char *)), addkeep __P((char ***, struct frentry *, int)); int to_interface __P((frdest_t *, char *, int)); void print_toif __P((char *, frdest_t *)); void optprint __P((u_short *, u_long, u_long)); int countbits __P((u_32_t)); char *portname __P((int, int)); int ratoi __P((char *, int *, int, int)); int loglevel __P((char **, u_short *, int)); void printlog __P((frentry_t *)); #if defined(__OpenBSD__) extern int if_addr __P((char *, struct in_addr *)); #endif char *proto = NULL; char flagset[] = "FSRPAU"; u_char flags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH, TH_ACK, TH_URG }; static char thishost[MAXHOSTNAMELEN]; void initparse() { gethostname(thishost, sizeof(thishost)); } /* parse() * * parse a line read from the input filter rule file */ struct frentry *parse(line, linenum) char *line; int linenum; { static struct frentry fil; struct protoent *p = NULL; char *cps[31], **cpp, *endptr; u_char ch; int i, cnt = 1, j; while (*line && isspace(*line)) line++; if (!*line) return NULL; bzero((char *)&fil, sizeof(fil)); fil.fr_mip.fi_v = 0xf; fil.fr_ip.fi_v = 4; fil.fr_loglevel = 0xffff; /* * break line up into max of 20 segments */ if (opts & OPT_DEBUG) fprintf(stderr, "parse [%s]\n", line); for (i = 0, *cps = strtok(line, " \b\t\r\n"); cps[i] && i < 30; cnt++) cps[++i] = strtok(NULL, " \b\t\r\n"); cps[i] = NULL; if (cnt < 3) { fprintf(stderr, "%d: not enough segments in line\n", linenum); return NULL; } cpp = cps; if (**cpp == '@') fil.fr_hits = (U_QUAD_T)atoi(*cpp++ + 1) + 1; if (!strcasecmp("block", *cpp)) { fil.fr_flags |= FR_BLOCK; if (!strncasecmp(*(cpp+1), "return-icmp-as-dest", 19) && (i = 19)) fil.fr_flags |= FR_FAKEICMP; else if (!strncasecmp(*(cpp+1), "return-icmp", 11) && (i = 11)) fil.fr_flags |= FR_RETICMP; if (fil.fr_flags & FR_RETICMP) { cpp++; if (strlen(*cpp) == i) { if (*(cpp + 1) && **(cpp +1) == '(') { cpp++; i = 0; } else i = -1; } /* * The ICMP code is not required to follow in ()'s */ if ((i >= 0) && (*(*cpp + i) == '(')) { i++; j = icmpcode(*cpp + i); if (j == -1) { fprintf(stderr, "%d: unrecognised icmp code %s\n", linenum, *cpp + 20); return NULL; } fil.fr_icode = j; } } else if (!strncasecmp(*(cpp+1), "return-rst", 10)) { fil.fr_flags |= FR_RETRST; cpp++; } } else if (!strcasecmp("count", *cpp)) { fil.fr_flags |= FR_ACCOUNT; } else if (!strcasecmp("pass", *cpp)) { fil.fr_flags |= FR_PASS; } else if (!strcasecmp("auth", *cpp)) { fil.fr_flags |= FR_AUTH; } else if (!strcasecmp("preauth", *cpp)) { fil.fr_flags |= FR_PREAUTH; } else if (!strcasecmp("skip", *cpp)) { cpp++; if (ratoi(*cpp, &i, 0, USHRT_MAX)) fil.fr_skip = i; else { fprintf(stderr, "%d: integer must follow skip\n", linenum); return NULL; } } else if (!strcasecmp("log", *cpp)) { fil.fr_flags |= FR_LOG; if (!strcasecmp(*(cpp+1), "body")) { fil.fr_flags |= FR_LOGBODY; cpp++; } if (!strcasecmp(*(cpp+1), "first")) { fil.fr_flags |= FR_LOGFIRST; cpp++; } if (*cpp && !strcasecmp(*(cpp+1), "or-block")) { fil.fr_flags |= FR_LOGORBLOCK; cpp++; } if (!strcasecmp(*(cpp+1), "level")) { cpp++; if (loglevel(cpp, &fil.fr_loglevel, linenum) == -1) return NULL; cpp++; } } else { /* * Doesn't start with one of the action words */ fprintf(stderr, "%d: unknown keyword (%s)\n", linenum, *cpp); return NULL; } if (!*++cpp) { fprintf(stderr, "%d: missing 'in'/'out' keyword\n", linenum); return NULL; } if (!strcasecmp("in", *cpp)) fil.fr_flags |= FR_INQUE; else if (!strcasecmp("out", *cpp)) { fil.fr_flags |= FR_OUTQUE; if (fil.fr_flags & FR_RETICMP) { fprintf(stderr, "%d: Can only use return-icmp with 'in'\n", linenum); return NULL; } else if (fil.fr_flags & FR_RETRST) { fprintf(stderr, "%d: Can only use return-rst with 'in'\n", linenum); return NULL; } } if (!*++cpp) { fprintf(stderr, "%d: missing source specification\n", linenum); return NULL; } if (!strcasecmp("log", *cpp)) { if (!*++cpp) { fprintf(stderr, "%d: missing source specification\n", linenum); return NULL; } if (fil.fr_flags & FR_PASS) fil.fr_flags |= FR_LOGP; else if (fil.fr_flags & FR_BLOCK) fil.fr_flags |= FR_LOGB; if (*cpp && !strcasecmp(*cpp, "body")) { fil.fr_flags |= FR_LOGBODY; cpp++; } if (*cpp && !strcasecmp(*cpp, "first")) { fil.fr_flags |= FR_LOGFIRST; cpp++; } if (*cpp && !strcasecmp(*cpp, "or-block")) { if (!(fil.fr_flags & FR_PASS)) { fprintf(stderr, "%d: or-block must be used with pass\n", linenum); return NULL; } fil.fr_flags |= FR_LOGORBLOCK; cpp++; } if (*cpp && !strcasecmp(*cpp, "level")) { int fac, pri; char *s; fac = 0; pri = 0; if (!*++cpp) { fprintf(stderr, "%d: %s\n", linenum, "missing identifier after level"); return NULL; } s = index(*cpp, '.'); if (s) { *s++ = '\0'; fac = fac_findname(*cpp); if (fac == -1) { fprintf(stderr, "%d: %s %s\n", linenum, "Unknown facility", *cpp); return NULL; } pri = pri_findname(s); if (pri == -1) { fprintf(stderr, "%d: %s %s\n", linenum, "Unknown priority", s); return NULL; } } else { pri = pri_findname(*cpp); if (pri == -1) { fprintf(stderr, "%d: %s %s\n", linenum, "Unknown priority", *cpp); return NULL; } } fil.fr_loglevel = fac|pri; cpp++; } if (*cpp && !strcasecmp(*cpp, "level")) { if (loglevel(cpp, &fil.fr_loglevel, linenum) == -1) return NULL; cpp++; cpp++; } } if (*cpp && !strcasecmp("quick", *cpp)) { cpp++; fil.fr_flags |= FR_QUICK; } *fil.fr_ifname = '\0'; if (*cpp && !strcasecmp(*cpp, "on")) { if (!*++cpp) { fprintf(stderr, "%d: interface name missing\n", linenum); return NULL; } (void)strncpy(fil.fr_ifname, *cpp, IFNAMSIZ-1); fil.fr_ifname[IFNAMSIZ-1] = '\0'; cpp++; if (!*cpp) { if ((fil.fr_flags & FR_RETMASK) == FR_RETRST) { fprintf(stderr, "%d: %s can only be used with TCP\n", linenum, "return-rst"); return NULL; } return &fil; } if (*cpp) { if (!strcasecmp(*cpp, "dup-to") && *(cpp + 1)) { cpp++; if (to_interface(&fil.fr_dif, *cpp, linenum)) return NULL; cpp++; } if (*cpp && !strcasecmp(*cpp, "to") && *(cpp + 1)) { cpp++; if (to_interface(&fil.fr_tif, *cpp, linenum)) return NULL; cpp++; } else if (*cpp && !strcasecmp(*cpp, "fastroute")) { if (!(fil.fr_flags & FR_INQUE)) { fprintf(stderr, "can only use %s with 'in'\n", "fastroute"); return NULL; } fil.fr_flags |= FR_FASTROUTE; cpp++; } } } if (*cpp && !strcasecmp(*cpp, "tos")) { if (!*++cpp) { fprintf(stderr, "%d: tos missing value\n", linenum); return NULL; } fil.fr_tos = strtol(*cpp, NULL, 0); fil.fr_mip.fi_tos = 0xff; cpp++; } if (*cpp && !strcasecmp(*cpp, "ttl")) { if (!*++cpp) { fprintf(stderr, "%d: ttl missing hopcount value\n", linenum); return NULL; } if (ratoi(*cpp, &i, 0, 255)) fil.fr_ttl = i; else { fprintf(stderr, "%d: invalid ttl (%s)\n", linenum, *cpp); return NULL; } fil.fr_mip.fi_ttl = 0xff; cpp++; } /* * check for "proto " only decode udp/tcp/icmp as protoname */ proto = NULL; if (*cpp && !strcasecmp(*cpp, "proto")) { if (!*++cpp) { fprintf(stderr, "%d: protocol name missing\n", linenum); return NULL; } proto = *cpp++; if (!strcasecmp(proto, "tcp/udp")) { fil.fr_ip.fi_fl |= FI_TCPUDP; fil.fr_mip.fi_fl |= FI_TCPUDP; } else { if (!(p = getprotobyname(proto)) && !isdigit(*proto)) { fprintf(stderr, "%d: unknown protocol (%s)\n", linenum, proto); return NULL; } if (p) fil.fr_proto = p->p_proto; else if (isdigit(*proto)) { i = (int)strtol(proto, &endptr, 0); if (*endptr != '\0' || i < 0 || i > 255) { fprintf(stderr, "%d: unknown protocol (%s)\n", linenum, proto); return NULL; } fil.fr_proto = i; } fil.fr_mip.fi_p = 0xff; } } if ((fil.fr_proto != IPPROTO_TCP) && ((fil.fr_flags & FR_RETMASK) == FR_RETRST)) { fprintf(stderr, "%d: %s can only be used with TCP\n", linenum, "return-rst"); return NULL; } /* * get the from host and bit mask to use against packets */ if (!*cpp) { fprintf(stderr, "%d: missing source specification\n", linenum); return NULL; } if (!strcasecmp(*cpp, "all")) { cpp++; if (!*cpp) return &fil; } else { if (strcasecmp(*cpp, "from")) { fprintf(stderr, "%d: unexpected keyword (%s) - from\n", linenum, *cpp); return NULL; } if (!*++cpp) { fprintf(stderr, "%d: missing host after from\n", linenum); return NULL; } ch = 0; if (**cpp == '!') { fil.fr_flags |= FR_NOTSRCIP; (*cpp)++; } if (hostmask(&cpp, (u_32_t *)&fil.fr_src, (u_32_t *)&fil.fr_smsk, &fil.fr_sport, &ch, &fil.fr_stop, linenum)) { return NULL; } fil.fr_scmp = ch; if (!*cpp) { fprintf(stderr, "%d: missing to fields\n", linenum); return NULL; } /* * do the same for the to field (destination host) */ if (strcasecmp(*cpp, "to")) { fprintf(stderr, "%d: unexpected keyword (%s) - to\n", linenum, *cpp); return NULL; } if (!*++cpp) { fprintf(stderr, "%d: missing host after to\n", linenum); return NULL; } ch = 0; if (**cpp == '!') { fil.fr_flags |= FR_NOTDSTIP; (*cpp)++; } if (hostmask(&cpp, (u_32_t *)&fil.fr_dst, (u_32_t *)&fil.fr_dmsk, &fil.fr_dport, &ch, &fil.fr_dtop, linenum)) { return NULL; } fil.fr_dcmp = ch; } /* * check some sanity, make sure we don't have icmp checks with tcp * or udp or visa versa. */ if (fil.fr_proto && (fil.fr_dcmp || fil.fr_scmp) && fil.fr_proto != IPPROTO_TCP && fil.fr_proto != IPPROTO_UDP) { fprintf(stderr, "%d: port operation on non tcp/udp\n", linenum); return NULL; } if (fil.fr_icmp && fil.fr_proto != IPPROTO_ICMP) { fprintf(stderr, "%d: icmp comparisons on wrong protocol\n", linenum); return NULL; } if (!*cpp) return &fil; if (*cpp && !strcasecmp(*cpp, "flags")) { if (!*++cpp) { fprintf(stderr, "%d: no flags present\n", linenum); return NULL; } fil.fr_tcpf = tcp_flags(*cpp, &fil.fr_tcpfm, linenum); cpp++; } /* * extras... */ if (*cpp && (!strcasecmp(*cpp, "with") || !strcasecmp(*cpp, "and"))) if (extras(&cpp, &fil, linenum)) return NULL; /* * icmp types for use with the icmp protocol */ if (*cpp && !strcasecmp(*cpp, "icmp-type")) { if (fil.fr_proto != IPPROTO_ICMP) { fprintf(stderr, "%d: icmp with wrong protocol (%d)\n", linenum, fil.fr_proto); return NULL; } if (addicmp(&cpp, &fil, linenum)) return NULL; fil.fr_icmp = htons(fil.fr_icmp); fil.fr_icmpm = htons(fil.fr_icmpm); } /* * Keep something... */ while (*cpp && !strcasecmp(*cpp, "keep")) if (addkeep(&cpp, &fil, linenum)) return NULL; /* * head of a new group ? */ if (*cpp && !strcasecmp(*cpp, "head")) { if (!*++cpp) { fprintf(stderr, "%d: head without group #\n", linenum); return NULL; } if (ratoi(*cpp, &i, 0, USHRT_MAX)) fil.fr_grhead = i; else { fprintf(stderr, "%d: invalid group (%s)\n", linenum, *cpp); return NULL; } cpp++; } /* * head of a new group ? */ if (*cpp && !strcasecmp(*cpp, "group")) { if (!*++cpp) { fprintf(stderr, "%d: group without group #\n", linenum); return NULL; } if (ratoi(*cpp, &i, 0, USHRT_MAX)) fil.fr_group = i; else { fprintf(stderr, "%d: invalid group (%s)\n", linenum, *cpp); return NULL; } cpp++; } /* * leftovers...yuck */ if (*cpp && **cpp) { fprintf(stderr, "%d: unknown words at end: [", linenum); for (; *cpp; cpp++) fprintf(stderr, "%s ", *cpp); fprintf(stderr, "]\n"); return NULL; } /* * lazy users... */ if ((fil.fr_tcpf || fil.fr_tcpfm) && fil.fr_proto != IPPROTO_TCP) { fprintf(stderr, "%d: TCP protocol not specified\n", linenum); return NULL; } if (!(fil.fr_ip.fi_fl & FI_TCPUDP) && (fil.fr_proto != IPPROTO_TCP) && (fil.fr_proto != IPPROTO_UDP) && (fil.fr_dcmp || fil.fr_scmp)) { if (!fil.fr_proto) { fil.fr_ip.fi_fl |= FI_TCPUDP; fil.fr_mip.fi_fl |= FI_TCPUDP; } else { fprintf(stderr, "%d: port comparisons for non-TCP/UDP\n", linenum); return NULL; } } /* if ((fil.fr_flags & FR_KEEPFRAG) && (!(fil.fr_ip.fi_fl & FI_FRAG) || !(fil.fr_ip.fi_fl & FI_FRAG))) { fprintf(stderr, "%d: must use 'with frags' with 'keep frags'\n", linenum); return NULL; } */ return &fil; } int loglevel(cpp, facpri, linenum) char **cpp; u_short *facpri; int linenum; { int fac, pri; char *s; fac = 0; pri = 0; if (!*++cpp) { fprintf(stderr, "%d: %s\n", linenum, "missing identifier after level"); return -1; } s = index(*cpp, '.'); if (s) { *s++ = '\0'; fac = fac_findname(*cpp); if (fac == -1) { fprintf(stderr, "%d: %s %s\n", linenum, "Unknown facility", *cpp); return -1; } pri = pri_findname(s); if (pri == -1) { fprintf(stderr, "%d: %s %s\n", linenum, "Unknown priority", s); return -1; } } else { pri = pri_findname(*cpp); if (pri == -1) { fprintf(stderr, "%d: %s %s\n", linenum, "Unknown priority", *cpp); return -1; } } *facpri = fac|pri; return 0; } int to_interface(fdp, to, linenum) frdest_t *fdp; char *to; int linenum; { int r = 0; char *s; s = index(to, ':'); fdp->fd_ifp = NULL; if (s) { *s++ = '\0'; fdp->fd_ip.s_addr = hostnum(s, &r, linenum); if (r == -1) return -1; } (void) strncpy(fdp->fd_ifname, to, sizeof(fdp->fd_ifname) - 1); fdp->fd_ifname[sizeof(fdp->fd_ifname) - 1] = '\0'; return 0; } void print_toif(tag, fdp) char *tag; frdest_t *fdp; { printf("%s %s%s", tag, fdp->fd_ifname, (fdp->fd_ifp || (long)fdp->fd_ifp == -1) ? "" : "(!)"); if (fdp->fd_ip.s_addr) printf(":%s", inet_ntoa(fdp->fd_ip)); putchar(' '); } /* * returns -1 if neither "hostmask/num" or "hostmask mask addr" are * found in the line segments, there is an error processing this information, * or there is an error processing ports information. */ int hostmask(seg, sa, msk, pp, cp, tp, linenum) char ***seg; u_32_t *sa, *msk; u_short *pp, *tp; u_char *cp; int linenum; { char *s, *endptr; int bits = -1, resolved; struct in_addr maskaddr; /* * is it possibly hostname/num ? */ if ((s = index(**seg, '/')) || (s = index(**seg, ':'))) { *s++ = '\0'; if (index(s, '.') || index(s, 'x')) { /* possibly of the form xxx.xxx.xxx.xxx * or 0xYYYYYYYY */ if (inet_aton(s, &maskaddr) == 0) { fprintf(stderr, "%d: bad mask (%s)\n", linenum, s); return -1; } *msk = maskaddr.s_addr; } else { /* * set x most significant bits */ bits = (int)strtol(s, &endptr, 0); if (*endptr != '\0' || bits > 32 || bits < 0) { fprintf(stderr, "%d: bad mask (/%s)\n", linenum, s); return -1; } if (bits == 0) *msk = 0; else *msk = htonl(0xffffffff << (32 - bits)); } *sa = hostnum(**seg, &resolved, linenum) & *msk; if (resolved == -1) { fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg); return -1; } (*seg)++; return ports(seg, pp, cp, tp, linenum); } /* * look for extra segments if "mask" found in right spot */ if (*(*seg+1) && *(*seg+2) && !strcasecmp(*(*seg+1), "mask")) { *sa = hostnum(**seg, &resolved, linenum); if (resolved == -1) { fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg); return -1; } (*seg)++; (*seg)++; if (inet_aton(**seg, &maskaddr) == 0) { fprintf(stderr, "%d: bad mask (%s)\n", linenum, **seg); return -1; } *msk = maskaddr.s_addr; (*seg)++; *sa &= *msk; return ports(seg, pp, cp, tp, linenum); } if (**seg) { *sa = hostnum(**seg, &resolved, linenum); if (resolved == -1) { fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg); return -1; } (*seg)++; *msk = (*sa ? inet_addr("255.255.255.255") : 0L); *sa &= *msk; return ports(seg, pp, cp, tp, linenum); } fprintf(stderr, "%d: bad host (%s)\n", linenum, **seg); return -1; } /* * returns an ip address as a long var as a result of either a DNS lookup or * straight inet_addr() call */ u_32_t hostnum(host, resolved, linenum) char *host; int *resolved; int linenum; { struct hostent *hp; struct netent *np; struct in_addr ip; #if defined(__OpenBSD__) struct in_addr addr; #endif *resolved = 0; if (!strcasecmp("any", host)) return 0; if (isdigit(*host) && inet_aton(host, &ip)) return ip.s_addr; if (!strcasecmp("", host)) host = thishost; #if defined(__OpenBSD__) /* attempt a map from interface name to address */ if (if_addr(host, &addr)) return (u_32_t)addr.s_addr; #endif if (!(hp = gethostbyname(host))) { if (!(np = getnetbyname(host))) { *resolved = -1; fprintf(stderr, "%d: can't resolve hostname: %s\n", linenum, host); return 0; } return htonl(np->n_net); } return *(u_32_t *)hp->h_addr; } /* * check for possible presence of the port fields in the line */ int ports(seg, pp, cp, tp, linenum) char ***seg; u_short *pp, *tp; u_char *cp; int linenum; { int comp = -1; if (!*seg || !**seg || !***seg) return 0; if (!strcasecmp(**seg, "port") && *(*seg + 1) && *(*seg + 2)) { (*seg)++; if (isdigit(***seg) && *(*seg + 2)) { if (portnum(**seg, pp, linenum) == 0) return -1; (*seg)++; if (!strcmp(**seg, "<>")) comp = FR_OUTRANGE; else if (!strcmp(**seg, "><")) comp = FR_INRANGE; else { fprintf(stderr, "%d: unknown range operator (%s)\n", linenum, **seg); return -1; } (*seg)++; if (**seg == NULL) { fprintf(stderr, "%d: missing 2nd port value\n", linenum); return -1; } if (portnum(**seg, tp, linenum) == 0) return -1; } else if (!strcmp(**seg, "=") || !strcasecmp(**seg, "eq")) comp = FR_EQUAL; else if (!strcmp(**seg, "!=") || !strcasecmp(**seg, "ne")) comp = FR_NEQUAL; else if (!strcmp(**seg, "<") || !strcasecmp(**seg, "lt")) comp = FR_LESST; else if (!strcmp(**seg, ">") || !strcasecmp(**seg, "gt")) comp = FR_GREATERT; else if (!strcmp(**seg, "<=") || !strcasecmp(**seg, "le")) comp = FR_LESSTE; else if (!strcmp(**seg, ">=") || !strcasecmp(**seg, "ge")) comp = FR_GREATERTE; else { fprintf(stderr, "%d: unknown comparator (%s)\n", linenum, **seg); return -1; } if (comp != FR_OUTRANGE && comp != FR_INRANGE) { (*seg)++; if (portnum(**seg, pp, linenum) == 0) return -1; } *cp = comp; (*seg)++; } return 0; } /* * find the port number given by the name, either from getservbyname() or * straight atoi(). Return 1 on success, 0 on failure */ int portnum(name, port, linenum) char *name; u_short *port; int linenum; { struct servent *sp, *sp2; u_short p1 = 0; int i; if (isdigit(*name)) { if (ratoi(name, &i, 0, USHRT_MAX)) { *port = (u_short)i; return 1; } fprintf(stderr, "%d: unknown port \"%s\"\n", linenum, name); return 0; } if (proto != NULL && strcasecmp(proto, "tcp/udp") != 0) { sp = getservbyname(name, proto); if (sp) { *port = ntohs(sp->s_port); return 1; } fprintf(stderr, "%d: unknown service \"%s\".\n", linenum, name); return 0; } sp = getservbyname(name, "tcp"); if (sp) p1 = sp->s_port; sp2 = getservbyname(name, "udp"); if (!sp || !sp2) { fprintf(stderr, "%d: unknown tcp/udp service \"%s\".\n", linenum, name); return 0; } if (p1 != sp2->s_port) { fprintf(stderr, "%d: %s %d/tcp is a different port to ", linenum, name, p1); fprintf(stderr, "%d: %s %d/udp\n", linenum, name, sp->s_port); return 0; } *port = ntohs(p1); return 1; } u_char tcp_flags(flgs, mask, linenum) char *flgs; u_char *mask; int linenum; { u_char tcpf = 0, tcpfm = 0, *fp = &tcpf; char *s, *t; for (s = flgs; *s; s++) { if (*s == '/' && fp == &tcpf) { fp = &tcpfm; continue; } if (!(t = index(flagset, *s))) { fprintf(stderr, "%d: unknown flag (%c)\n", linenum, *s); return 0; } *fp |= flags[t - flagset]; } if (!tcpfm) tcpfm = 0xff; *mask = tcpfm; return tcpf; } /* * deal with extra bits on end of the line */ int extras(cp, fr, linenum) char ***cp; struct frentry *fr; int linenum; { u_short secmsk; u_long opts; int notopt; char oflags; opts = 0; secmsk = 0; notopt = 0; (*cp)++; if (!**cp) return -1; while (**cp && (!strncasecmp(**cp, "ipopt", 5) || !strncasecmp(**cp, "not", 3) || !strncasecmp(**cp, "opt", 4) || !strncasecmp(**cp, "frag", 3) || !strncasecmp(**cp, "no", 2) || !strncasecmp(**cp, "short", 5))) { if (***cp == 'n' || ***cp == 'N') { notopt = 1; (*cp)++; continue; } else if (***cp == 'i' || ***cp == 'I') { if (!notopt) fr->fr_ip.fi_fl |= FI_OPTIONS; fr->fr_mip.fi_fl |= FI_OPTIONS; goto nextopt; } else if (***cp == 'f' || ***cp == 'F') { if (!notopt) fr->fr_ip.fi_fl |= FI_FRAG; fr->fr_mip.fi_fl |= FI_FRAG; goto nextopt; } else if (***cp == 'o' || ***cp == 'O') { if (!*(*cp + 1)) { fprintf(stderr, "%d: opt missing arguements\n", linenum); return -1; } (*cp)++; if (!(opts = optname(cp, &secmsk, linenum))) return -1; oflags = FI_OPTIONS; } else if (***cp == 's' || ***cp == 'S') { if (fr->fr_tcpf) { fprintf(stderr, "%d: short cannot be used with TCP flags\n", linenum); return -1; } if (!notopt) fr->fr_ip.fi_fl |= FI_SHORT; fr->fr_mip.fi_fl |= FI_SHORT; goto nextopt; } else return -1; if (!notopt || !opts) fr->fr_mip.fi_fl |= oflags; if (notopt) { if (!secmsk) { fr->fr_mip.fi_optmsk |= opts; } else { fr->fr_mip.fi_optmsk |= (opts & ~0x0100); } } else { fr->fr_mip.fi_optmsk |= opts; } fr->fr_mip.fi_secmsk |= secmsk; if (notopt) { fr->fr_ip.fi_fl &= (~oflags & 0xf); fr->fr_ip.fi_optmsk &= ~opts; fr->fr_ip.fi_secmsk &= ~secmsk; } else { fr->fr_ip.fi_fl |= oflags; fr->fr_ip.fi_optmsk |= opts; fr->fr_ip.fi_secmsk |= secmsk; } nextopt: notopt = 0; opts = 0; oflags = 0; secmsk = 0; (*cp)++; } return 0; } u_32_t optname(cp, sp, linenum) char ***cp; u_short *sp; int linenum; { struct ipopt_names *io, *so; u_long msk = 0; u_short smsk = 0; char *s; int sec = 0; for (s = strtok(**cp, ","); s; s = strtok(NULL, ",")) { for (io = ionames; io->on_name; io++) if (!strcasecmp(s, io->on_name)) { msk |= io->on_bit; break; } if (!io->on_name) { fprintf(stderr, "%d: unknown IP option name %s\n", linenum, s); return 0; } if (!strcasecmp(s, "sec-class")) sec = 1; } if (sec && !*(*cp + 1)) { fprintf(stderr, "%d: missing security level after sec-class\n", linenum); return 0; } if (sec) { (*cp)++; for (s = strtok(**cp, ","); s; s = strtok(NULL, ",")) { for (so = secclass; so->on_name; so++) if (!strcasecmp(s, so->on_name)) { smsk |= so->on_bit; break; } if (!so->on_name) { fprintf(stderr, "%d: no such security level: %s\n", linenum, s); return 0; } } if (smsk) *sp = smsk; } return msk; } #ifdef __STDC__ void optprint(u_short *sec, u_long optmsk, u_long optbits) #else void optprint(sec, optmsk, optbits) u_short *sec; u_long optmsk, optbits; #endif { u_short secmsk = sec[0], secbits = sec[1]; struct ipopt_names *io, *so; char *s; int secflag = 0; s = " opt "; for (io = ionames; io->on_name; io++) if ((io->on_bit & optmsk) && ((io->on_bit & optmsk) == (io->on_bit & optbits))) { if ((io->on_value != IPOPT_SECURITY) || (!secmsk && !secbits)) { printf("%s%s", s, io->on_name); if (io->on_value == IPOPT_SECURITY) io++; s = ","; } else secflag = 1; } if (secmsk & secbits) { printf("%ssec-class", s); s = " "; for (so = secclass; so->on_name; so++) if ((secmsk & so->on_bit) && ((so->on_bit & secmsk) == (so->on_bit & secbits))) { printf("%s%s", s, so->on_name); s = ","; } } if ((optmsk && (optmsk != optbits)) || (secmsk && (secmsk != secbits))) { s = " "; printf(" not opt"); if (optmsk != optbits) { for (io = ionames; io->on_name; io++) if ((io->on_bit & optmsk) && ((io->on_bit & optmsk) != (io->on_bit & optbits))) { if ((io->on_value != IPOPT_SECURITY) || (!secmsk && !secbits)) { printf("%s%s", s, io->on_name); s = ","; if (io->on_value == IPOPT_SECURITY) io++; } else io++; } } if (secmsk != secbits) { printf("%ssec-class", s); s = " "; for (so = secclass; so->on_name; so++) if ((so->on_bit & secmsk) && ((so->on_bit & secmsk) != (so->on_bit & secbits))) { printf("%s%s", s, so->on_name); s = ","; } } } } char *icmptypes[] = { "echorep", (char *)NULL, (char *)NULL, "unreach", "squench", "redir", (char *)NULL, (char *)NULL, "echo", "routerad", "routersol", "timex", "paramprob", "timest", "timestrep", "inforeq", "inforep", "maskreq", "maskrep", "END" }; /* * set the icmp field to the correct type if "icmp" word is found */ int addicmp(cp, fp, linenum) char ***cp; struct frentry *fp; int linenum; { char **t; int i; (*cp)++; if (!**cp) return -1; if (!fp->fr_proto) /* to catch lusers */ fp->fr_proto = IPPROTO_ICMP; if (isdigit(***cp)) { if (!ratoi(**cp, &i, 0, 255)) { fprintf(stderr, "%d: Invalid icmp-type (%s) specified\n", linenum, **cp); return -1; } } else { for (t = icmptypes, i = 0; ; t++, i++) { if (!*t) continue; if (!strcasecmp("END", *t)) { i = -1; break; } if (!strcasecmp(*t, **cp)) break; } if (i == -1) { fprintf(stderr, "%d: Invalid icmp-type (%s) specified\n", linenum, **cp); return -1; } } fp->fr_icmp = (u_short)(i << 8); fp->fr_icmpm = (u_short)0xff00; (*cp)++; if (!**cp) return 0; if (**cp && strcasecmp("code", **cp)) return 0; (*cp)++; if (isdigit(***cp)) { if (!ratoi(**cp, &i, 0, 255)) { fprintf(stderr, "%d: Invalid icmp code (%s) specified\n", linenum, **cp); return -1; } fp->fr_icmp |= (u_short)i; fp->fr_icmpm = (u_short)0xffff; (*cp)++; return 0; } fprintf(stderr, "%d: Invalid icmp code (%s) specified\n", linenum, **cp); return -1; } #define MAX_ICMPCODE 15 char *icmpcodes[] = { "net-unr", "host-unr", "proto-unr", "port-unr", "needfrag", "srcfail", "net-unk", "host-unk", "isolate", "net-prohib", "host-prohib", "net-tos", "host-tos", "filter-prohib", "host-preced", "preced-cutoff", NULL }; /* * Return the number for the associated ICMP unreachable code. */ int icmpcode(str) char *str; { char *s; int i, len; if (!(s = strrchr(str, ')'))) return -1; *s = '\0'; if (isdigit(*str)) { if (!ratoi(str, &i, 0, 255)) return -1; else return i; } len = strlen(str); for (i = 0; icmpcodes[i]; i++) if (!strncasecmp(str, icmpcodes[i], MIN(len, strlen(icmpcodes[i])) )) return i; return -1; } /* * set the icmp field to the correct type if "icmp" word is found */ int addkeep(cp, fp, linenum) char ***cp; struct frentry *fp; int linenum; { if (fp->fr_proto != IPPROTO_TCP && fp->fr_proto != IPPROTO_UDP && fp->fr_proto != IPPROTO_ICMP && !(fp->fr_ip.fi_fl & FI_TCPUDP)) { fprintf(stderr, "%d: Can only use keep with UDP/ICMP/TCP\n", linenum); return -1; } (*cp)++; if (!**cp) { fprintf(stderr, "%d: Missing state/frag after keep\n", linenum); return -1; } if (**cp && strcasecmp(**cp, "state") && strcasecmp(**cp, "frags")) { fprintf(stderr, "%d: Unrecognised state keyword \"%s\"\n", linenum, **cp); return -1; } if (***cp == 's' || ***cp == 'S') fp->fr_flags |= FR_KEEPSTATE; else if (***cp == 'f' || ***cp == 'F') fp->fr_flags |= FR_KEEPFRAG; (*cp)++; return 0; } /* * count consecutive 1's in bit mask. If the mask generated by counting * consecutive 1's is different to that passed, return -1, else return # * of bits. */ int countbits(ip) u_32_t ip; { u_32_t ipn; int cnt = 0, i, j; ip = ipn = ntohl(ip); for (i = 32; i; i--, ipn *= 2) if (ipn & 0x80000000) cnt++; else break; ipn = 0; for (i = 32, j = cnt; i; i--, j--) { ipn *= 2; if (j > 0) ipn++; } if (ipn == ip) return cnt; return -1; } char *portname(pr, port) int pr, port; { static char buf[32]; struct protoent *p = NULL; struct servent *sv = NULL, *sv1 = NULL; if (pr == -1) { if ((sv = getservbyport(htons(port), "tcp"))) { strncpy(buf, sv->s_name, sizeof(buf)-1); buf[sizeof(buf)-1] = '\0'; sv1 = getservbyport(htons(port), "udp"); sv = strncasecmp(buf, sv->s_name, strlen(buf)) ? NULL : sv1; } if (sv) return buf; } else if (pr && (p = getprotobynumber(pr))) { if ((sv = getservbyport(htons(port), p->p_name))) { strncpy(buf, sv->s_name, sizeof(buf)-1); buf[sizeof(buf)-1] = '\0'; return buf; } } (void) sprintf(buf, "%d", port); return buf; } /* * print the filter structure in a useful way */ void printfr(fp) struct frentry *fp; { static char *pcmp1[] = { "*", "=", "!=", "<", ">", "<=", ">=", "<>", "><"}; struct protoent *p; int ones = 0, pr; char *s; u_char *t; u_short sec[2]; if (fp->fr_flags & FR_PASS) printf("pass"); else if (fp->fr_flags & FR_BLOCK) { printf("block"); if (fp->fr_flags & FR_RETICMP) { if ((fp->fr_flags & FR_RETMASK) == FR_FAKEICMP) printf(" return-icmp-as-dest"); else if ((fp->fr_flags & FR_RETMASK) == FR_RETICMP) printf(" return-icmp"); if (fp->fr_icode) { if (fp->fr_icode <= MAX_ICMPCODE) printf("(%s)", icmpcodes[(int)fp->fr_icode]); else printf("(%d)", fp->fr_icode); } } else if ((fp->fr_flags & FR_RETMASK) == FR_RETRST) printf(" return-rst"); } else if ((fp->fr_flags & FR_LOGMASK) == FR_LOG) { printlog(fp); } else if (fp->fr_flags & FR_ACCOUNT) printf("count"); else if (fp->fr_flags & FR_AUTH) printf("auth"); else if (fp->fr_flags & FR_PREAUTH) printf("preauth"); else if (fp->fr_skip) printf("skip %hu", fp->fr_skip); if (fp->fr_flags & FR_OUTQUE) printf(" out "); else printf(" in "); if (((fp->fr_flags & FR_LOGB) == FR_LOGB) || ((fp->fr_flags & FR_LOGP) == FR_LOGP)) { printlog(fp); putchar(' '); } if (fp->fr_flags & FR_QUICK) printf("quick "); if (*fp->fr_ifname) { printf("on %s%s ", fp->fr_ifname, (fp->fr_ifa || (long)fp->fr_ifa == -1) ? "" : "(!)"); if (*fp->fr_dif.fd_ifname) print_toif("dup-to", &fp->fr_dif); if (*fp->fr_tif.fd_ifname) print_toif("to", &fp->fr_tif); if (fp->fr_flags & FR_FASTROUTE) printf("fastroute "); } if (fp->fr_mip.fi_tos) printf("tos %#x ", fp->fr_tos); if (fp->fr_mip.fi_ttl) printf("ttl %d ", fp->fr_ttl); if (fp->fr_ip.fi_fl & FI_TCPUDP) { printf("proto tcp/udp "); pr = -1; } else if ((pr = fp->fr_mip.fi_p)) { if ((p = getprotobynumber(fp->fr_proto))) printf("proto %s ", p->p_name); else printf("proto %d ", fp->fr_proto); } printf("from %s", fp->fr_flags & FR_NOTSRCIP ? "!" : ""); if (!fp->fr_src.s_addr && !fp->fr_smsk.s_addr) printf("any "); else { printf("%s", inet_ntoa(fp->fr_src)); if ((ones = countbits(fp->fr_smsk.s_addr)) == -1) printf("/%s ", inet_ntoa(fp->fr_smsk)); else printf("/%d ", ones); } if (fp->fr_scmp) { if (fp->fr_scmp == FR_INRANGE || fp->fr_scmp == FR_OUTRANGE) printf("port %d %s %d ", fp->fr_sport, pcmp1[fp->fr_scmp], fp->fr_stop); else printf("port %s %s ", pcmp1[fp->fr_scmp], portname(pr, fp->fr_sport)); } printf("to %s", fp->fr_flags & FR_NOTDSTIP ? "!" : ""); if (!fp->fr_dst.s_addr && !fp->fr_dmsk.s_addr) printf("any"); else { printf("%s", inet_ntoa(fp->fr_dst)); if ((ones = countbits(fp->fr_dmsk.s_addr)) == -1) printf("/%s", inet_ntoa(fp->fr_dmsk)); else printf("/%d", ones); } if (fp->fr_dcmp) { if (fp->fr_dcmp == FR_INRANGE || fp->fr_dcmp == FR_OUTRANGE) printf(" port %d %s %d", fp->fr_dport, pcmp1[fp->fr_dcmp], fp->fr_dtop); else printf(" port %s %s", pcmp1[fp->fr_dcmp], portname(pr, fp->fr_dport)); } if ((fp->fr_ip.fi_fl & ~FI_TCPUDP) || (fp->fr_mip.fi_fl & ~FI_TCPUDP) || fp->fr_ip.fi_optmsk || fp->fr_mip.fi_optmsk || fp->fr_ip.fi_secmsk || fp->fr_mip.fi_secmsk) { printf(" with"); if (fp->fr_ip.fi_optmsk || fp->fr_mip.fi_optmsk || fp->fr_ip.fi_secmsk || fp->fr_mip.fi_secmsk) { sec[0] = fp->fr_mip.fi_secmsk; sec[1] = fp->fr_ip.fi_secmsk; optprint(sec, fp->fr_mip.fi_optmsk, fp->fr_ip.fi_optmsk); } else if (fp->fr_mip.fi_fl & FI_OPTIONS) { if (!(fp->fr_ip.fi_fl & FI_OPTIONS)) printf(" not"); printf(" ipopt"); } if (fp->fr_mip.fi_fl & FI_SHORT) { if (!(fp->fr_ip.fi_fl & FI_SHORT)) printf(" not"); printf(" short"); } if (fp->fr_mip.fi_fl & FI_FRAG) { if (!(fp->fr_ip.fi_fl & FI_FRAG)) printf(" not"); printf(" frag"); } } if (fp->fr_proto == IPPROTO_ICMP && fp->fr_icmpm) { int type = fp->fr_icmp, code; type = ntohs(fp->fr_icmp); code = type & 0xff; type /= 256; if (type < (sizeof(icmptypes) / sizeof(char *) - 1) && icmptypes[type]) printf(" icmp-type %s", icmptypes[type]); else printf(" icmp-type %d", type); if (code) printf(" code %d", code); } if (fp->fr_proto == IPPROTO_TCP && (fp->fr_tcpf || fp->fr_tcpfm)) { printf(" flags "); for (s = flagset, t = flags; *s; s++, t++) if (fp->fr_tcpf & *t) (void)putchar(*s); if (fp->fr_tcpfm) { (void)putchar('/'); for (s = flagset, t = flags; *s; s++, t++) if (fp->fr_tcpfm & *t) (void)putchar(*s); } } if (fp->fr_flags & FR_KEEPSTATE) printf(" keep state"); if (fp->fr_flags & FR_KEEPFRAG) printf(" keep frags"); if (fp->fr_grhead) printf(" head %d", fp->fr_grhead); if (fp->fr_group) printf(" group %d", fp->fr_group); (void)putchar('\n'); } void binprint(fp) struct frentry *fp; { int i = sizeof(*fp), j = 0; u_char *s; for (s = (u_char *)fp; i; i--, s++) { j++; printf("%02x ", *s); if (j == 16) { printf("\n"); j = 0; } } putchar('\n'); (void)fflush(stdout); } void printlog(fp) frentry_t *fp; { char *s, *u; printf("log"); if (fp->fr_flags & FR_LOGBODY) printf(" body"); if (fp->fr_flags & FR_LOGFIRST) printf(" first"); if (fp->fr_flags & FR_LOGORBLOCK) printf(" or-block"); if (fp->fr_loglevel != 0xffff) { printf(" level "); if (fp->fr_loglevel & LOG_FACMASK) { s = fac_toname(fp->fr_loglevel); if (s == NULL) s = "!!!"; } else s = ""; u = pri_toname(fp->fr_loglevel); if (u == NULL) u = "!!!"; if (*s) printf("%s.%s", s, u); else printf("%s", u); } } int ratoi(ps, pi, min, max) char *ps; int *pi, min, max; { int i; char *pe; i = (int)strtol(ps, &pe, 0); if (*pe != '\0' || i < min || i > max) return 0; *pi = i; return 1; }