/* $OpenBSD: natparse.c,v 1.11 2001/02/18 23:20:42 millert Exp $ */ /* * Copyright (C) 1993-2000 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 #include #include #include #include #if !defined(__SVR4) && !defined(__svr4__) #include #else #include #endif #include #include #include #include #include #include #include #if defined(sun) && (defined(__svr4__) || defined(__SVR4)) # include # include #endif #include #include #include #include #include #if __FreeBSD_version >= 300000 # include #endif #include #include #include #include #include #include #include #include #include #include "ipf.h" #if defined(sun) && !SOLARIS2 # define STRERROR(x) sys_errlist[x] extern char *sys_errlist[]; #else # define STRERROR(x) strerror(x) #endif #if !defined(lint) static const char sccsid[] ="@(#)ipnat.c 1.9 6/5/96 (C) 1993 Darren Reed"; static const char rcsid[] = "@(#)$IPFilter: natparse.c,v 1.17.2.6 2000/07/08 02:14:40 darrenr Exp $"; #endif #if SOLARIS #define bzero(a,b) memset(a,0,b) #endif extern int countbits __P((u_32_t)); extern char *proto; ipnat_t *natparse __P((char *, int)); void printnat __P((ipnat_t *, int, void *)); void natparsefile __P((int, char *, int)); void nat_setgroupmap __P((struct ipnat *)); void printnat(np, opts, ptr) ipnat_t *np; int opts; void *ptr; { struct protoent *pr; struct servent *sv; int bits; switch (np->in_redir) { case NAT_REDIRECT : printf("rdr"); break; case NAT_MAP : printf("map"); break; case NAT_MAPBLK : printf("map-block"); break; case NAT_BIMAP : printf("bimap"); break; default : fprintf(stderr, "unknown value for in_redir: %#x\n", np->in_redir); break; } printf(" %s ", np->in_ifname); if (np->in_flags & IPN_FILTER) { if (np->in_flags & IPN_NOTSRC) printf("! "); printf("from "); if (np->in_redir == NAT_REDIRECT) { printhostmask(4, (u_32_t *)&np->in_srcip, (u_32_t *)&np->in_srcmsk); if (np->in_scmp) printportcmp(np->in_p, &np->in_tuc.ftu_src); } else { printhostmask(4, (u_32_t *)&np->in_inip, (u_32_t *)&np->in_inmsk); if (np->in_dcmp) printportcmp(np->in_p, &np->in_tuc.ftu_dst); } if (np->in_flags & IPN_NOTDST) printf(" !"); printf(" to "); if (np->in_redir == NAT_REDIRECT) { printhostmask(4, (u_32_t *)&np->in_outip, (u_32_t *)&np->in_outmsk); if (np->in_dcmp) printportcmp(np->in_p, &np->in_tuc.ftu_dst); } else { printhostmask(4, (u_32_t *)&np->in_srcip, (u_32_t *)&np->in_srcmsk); if (np->in_scmp) printportcmp(np->in_p, &np->in_tuc.ftu_src); } } if (np->in_redir == NAT_REDIRECT) { if (!(np->in_flags & IPN_FILTER)) { printf("%s", inet_ntoa(np->in_out[0])); bits = countbits(np->in_out[1].s_addr); if (bits != -1) printf("/%d ", bits); else printf("/%s ", inet_ntoa(np->in_out[1])); if (np->in_pmin) printf("port %d", ntohs(np->in_pmin)); if (np->in_pmax != np->in_pmin) printf("- %d", ntohs(np->in_pmax)); } printf(" -> %s", inet_ntoa(np->in_in[0])); if (np->in_flags & IPN_SPLIT) printf(",%s", inet_ntoa(np->in_in[1])); if (np->in_pnext) printf(" port %d", ntohs(np->in_pnext)); if ((np->in_flags & IPN_TCPUDP) == IPN_TCPUDP) printf(" tcp/udp"); else if ((np->in_flags & IPN_TCP) == IPN_TCP) printf(" tcp"); else if ((np->in_flags & IPN_UDP) == IPN_UDP) printf(" udp"); if (np->in_flags & IPN_ROUNDR) printf(" round-robin"); printf("\n"); if (opts & OPT_DEBUG) printf("\t%p %lu %#x %u %p %d\n", np->in_ifp, np->in_space, np->in_flags, np->in_pmax, np, np->in_use); } else { np->in_nextip.s_addr = htonl(np->in_nextip.s_addr); if (!(np->in_flags & IPN_FILTER)) { printf("%s/", inet_ntoa(np->in_in[0])); bits = countbits(np->in_in[1].s_addr); if (bits != -1) printf("%d ", bits); else printf("%s", inet_ntoa(np->in_in[1])); } printf(" -> "); if (np->in_flags & IPN_IPRANGE) { printf("range %s-", inet_ntoa(np->in_out[0])); printf("%s", inet_ntoa(np->in_out[1])); } else { printf("%s/", inet_ntoa(np->in_out[0])); bits = countbits(np->in_out[1].s_addr); if (bits != -1) printf("%d ", bits); else printf("%s", inet_ntoa(np->in_out[1])); } if (*np->in_plabel) { pr = getprotobynumber(np->in_p); printf(" proxy port"); if (np->in_dport != 0) { if (pr != NULL) sv = getservbyport(np->in_dport, pr->p_name); else sv = getservbyport(np->in_dport, NULL); if (sv != NULL) printf(" %s", sv->s_name); else printf(" %hu", ntohs(np->in_dport)); } printf(" %.*s/", (int)sizeof(np->in_plabel), np->in_plabel); if (pr != NULL) fputs(pr->p_name, stdout); else printf("%d", np->in_p); } else if (np->in_redir == NAT_MAPBLK) { printf(" ports %d", np->in_pmin); if (opts & OPT_VERBOSE) printf("\n\tip modulous %d", np->in_pmax); } else if (np->in_pmin || np->in_pmax) { printf(" portmap"); if (np->in_flags & IPN_AUTOPORTMAP) { printf(" auto"); if (opts & OPT_DEBUG) printf(" [%d:%d %d %d]", ntohs(np->in_pmin), ntohs(np->in_pmax), np->in_ippip, np->in_ppip); } else { if ((np->in_flags & IPN_TCPUDP) == IPN_TCPUDP) printf(" tcp/udp"); else if (np->in_flags & IPN_TCP) printf(" tcp"); else if (np->in_flags & IPN_UDP) printf(" udp"); printf(" %d:%d", ntohs(np->in_pmin), ntohs(np->in_pmax)); } } printf("\n"); if (opts & OPT_DEBUG) { printf("\tifp %p space %lu nextip %s pnext %d", np->in_ifp, np->in_space, inet_ntoa(np->in_nextip), np->in_pnext); printf(" flags %x use %u\n", np->in_flags, np->in_use); } } } void nat_setgroupmap(n) ipnat_t *n; { if (n->in_outmsk == n->in_inmsk) n->in_ippip = 1; else if (n->in_flags & IPN_AUTOPORTMAP) { n->in_ippip = ~ntohl(n->in_inmsk); if (n->in_outmsk != 0xffffffff) n->in_ippip /= (~ntohl(n->in_outmsk) + 1); n->in_ippip++; if (n->in_ippip == 0) n->in_ippip = 1; n->in_ppip = USABLE_PORTS / n->in_ippip; } else { n->in_space = USABLE_PORTS * ~ntohl(n->in_outmsk); n->in_nip = 0; if (!(n->in_ppip = n->in_pmin)) n->in_ppip = 1; n->in_ippip = USABLE_PORTS / n->in_ppip; } } ipnat_t *natparse(line, linenum) char *line; int linenum; { static ipnat_t ipn; struct protoent *pr; char *dnetm = NULL, *dport = NULL; char *s, *t, *cps[31], **cpp; int i, cnt; if ((s = strchr(line, '\n'))) *s = '\0'; if ((s = strchr(line, '#'))) *s = '\0'; while (*line && isspace(*line)) line++; if (!*line) return NULL; bzero((char *)&ipn, sizeof(ipn)); cnt = 0; 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 (!strcasecmp(*cpp, "map")) ipn.in_redir = NAT_MAP; else if (!strcasecmp(*cpp, "map-block")) ipn.in_redir = NAT_MAPBLK; else if (!strcasecmp(*cpp, "rdr")) ipn.in_redir = NAT_REDIRECT; else if (!strcasecmp(*cpp, "bimap")) ipn.in_redir = NAT_BIMAP; else { fprintf(stderr, "%d: unknown mapping: \"%s\"\n", linenum, *cpp); return NULL; } cpp++; strncpy(ipn.in_ifname, *cpp, sizeof(ipn.in_ifname) - 1); ipn.in_ifname[sizeof(ipn.in_ifname) - 1] = '\0'; cpp++; if (!strcasecmp(*cpp, "from") || (**cpp == '!')) { if (!strcmp(*cpp, "!")) { cpp++; if (strcasecmp(*cpp, "from")) { fprintf(stderr, "Missing from after !\n"); return NULL; } ipn.in_flags |= IPN_NOTSRC; } else if (**cpp == '!') { if (strcasecmp(*cpp + 1, "from")) { fprintf(stderr, "Missing from after !\n"); return NULL; } ipn.in_flags |= IPN_NOTSRC; } if ((ipn.in_flags & IPN_NOTSRC) && (ipn.in_redir & (NAT_MAP|NAT_MAPBLK))) { fprintf(stderr, "Cannot use '! from' with map\n"); return NULL; } ipn.in_flags |= IPN_FILTER; cpp++; if (ipn.in_redir == NAT_REDIRECT) { if (hostmask(&cpp, (u_32_t *)&ipn.in_srcip, (u_32_t *)&ipn.in_srcmsk, &ipn.in_sport, &ipn.in_scmp, &ipn.in_stop, linenum)) { return NULL; } } else { if (hostmask(&cpp, (u_32_t *)&ipn.in_inip, (u_32_t *)&ipn.in_inmsk, &ipn.in_sport, &ipn.in_scmp, &ipn.in_stop, linenum)) { return NULL; } } if (!strcmp(*cpp, "!")) { cpp++; ipn.in_flags |= IPN_NOTDST; } else if (**cpp == '!') { (*cpp)++; ipn.in_flags |= IPN_NOTDST; } if (strcasecmp(*cpp, "to")) { fprintf(stderr, "%d: unexpected keyword (%s) - to\n", linenum, *cpp); return NULL; } if ((ipn.in_flags & IPN_NOTDST) && (ipn.in_redir & (NAT_REDIRECT))) { fprintf(stderr, "Cannot use '! to' with rdr\n"); return NULL; } if (!*++cpp) { fprintf(stderr, "%d: missing host after to\n", linenum); return NULL; } if (ipn.in_redir == NAT_REDIRECT) { if (hostmask(&cpp, (u_32_t *)&ipn.in_outip, (u_32_t *)&ipn.in_outmsk, &ipn.in_dport, &ipn.in_dcmp, &ipn.in_dtop, linenum)) { return NULL; } ipn.in_pmin = htons(ipn.in_dport); } else { if (hostmask(&cpp, (u_32_t *)&ipn.in_srcip, (u_32_t *)&ipn.in_srcmsk, &ipn.in_dport, &ipn.in_dcmp, &ipn.in_dtop, linenum)) { return NULL; } } } else { s = *cpp; if (!s) return NULL; t = strchr(s, '/'); if (!t) return NULL; *t++ = '\0'; if (ipn.in_redir == NAT_REDIRECT) { if (hostnum((u_32_t *)&ipn.in_outip, s, linenum) == -1) return NULL; if (genmask(t, (u_32_t *)&ipn.in_outmsk) == -1) { return NULL; } } else { if (hostnum((u_32_t *)&ipn.in_inip, s, linenum) == -1) return NULL; if (genmask(t, (u_32_t *)&ipn.in_inmsk) == -1) { return NULL; } } cpp++; if (!*cpp) return NULL; } if ((ipn.in_redir == NAT_REDIRECT) && !(ipn.in_flags & IPN_FILTER)) { if (strcasecmp(*cpp, "port")) { fprintf(stderr, "%d: missing fields - 1st port\n", linenum); return NULL; } /* The default protocol for "redir" is TCP */ ipn.in_flags |= IPN_TCP; proto = "tcp"; cpp++; if (!*cpp) { fprintf(stderr, "%d: missing fields (destination port)\n", linenum); return NULL; } if (isdigit(**cpp) && (s = strchr(*cpp, '-'))) *s++ = '\0'; else s = NULL; if (!portnum(*cpp, &ipn.in_pmin, linenum)) return NULL; ipn.in_pmin = htons(ipn.in_pmin); cpp++; if (!strcmp(*cpp, "-")) { cpp++; s = *cpp++; } if (s) { if (!portnum(s, &ipn.in_pmax, linenum)) return NULL; ipn.in_pmax = htons(ipn.in_pmax); } else ipn.in_pmax = ipn.in_pmin; } if (!*cpp) { fprintf(stderr, "%d: missing fields (->)\n", linenum); return NULL; } if (strcmp(*cpp, "->")) { fprintf(stderr, "%d: missing ->\n", linenum); return NULL; } cpp++; if (!*cpp) { fprintf(stderr, "%d: missing fields (%s)\n", linenum, ipn.in_redir ? "destination" : "target"); return NULL; } if (ipn.in_redir == NAT_MAP) { if (!strcasecmp(*cpp, "range")) { cpp++; ipn.in_flags |= IPN_IPRANGE; if (!*cpp) { fprintf(stderr, "%d: missing fields (%s)\n", linenum, ipn.in_redir ? "destination":"target"); return NULL; } } } if (ipn.in_flags & IPN_IPRANGE) { dnetm = strrchr(*cpp, '-'); if (dnetm == NULL) { cpp++; if (*cpp && !strcmp(*cpp, "-") && *(cpp + 1)) dnetm = *(cpp + 1); } else *dnetm++ = '\0'; if (dnetm == NULL || *dnetm == '\0') { fprintf(stderr, "%d: desination range not specified\n", linenum); return NULL; } } else if (ipn.in_redir != NAT_REDIRECT) { dnetm = strrchr(*cpp, '/'); if (dnetm == NULL) { cpp++; if (*cpp && !strcasecmp(*cpp, "netmask")) dnetm = *++cpp; } if (dnetm == NULL) { fprintf(stderr, "%d: missing fields (dest netmask)\n", linenum); return NULL; } if (*dnetm == '/') *dnetm++ = '\0'; } if (ipn.in_redir == NAT_REDIRECT) { dnetm = strchr(*cpp, ','); if (dnetm != NULL) { ipn.in_flags |= IPN_SPLIT; *dnetm++ = '\0'; } if (hostnum((u_32_t *)&ipn.in_inip, *cpp, linenum) == -1) return NULL; } else { if (hostnum((u_32_t *)&ipn.in_outip, *cpp, linenum) == -1) return NULL; } cpp++; if (ipn.in_redir & NAT_MAPBLK) { if (*cpp && strcasecmp(*cpp, "ports")) { fprintf(stderr, "%d: expected \"ports\" - got \"%s\"\n", linenum, *cpp); return NULL; } cpp++; if (*cpp) { ipn.in_pmin = atoi(*cpp); cpp++; } else ipn.in_pmin = 0; } else if ((ipn.in_redir & NAT_BIMAP) == NAT_REDIRECT) { if (strrchr(*cpp, '/') != NULL) { fprintf(stderr, "%d: No netmask supported in %s\n", linenum, "destination host for redirect"); return NULL; } /* If it's a in_redir, expect target port */ if (strcasecmp(*cpp, "port")) { fprintf(stderr, "%d: missing fields - 2nd port (%s)\n", linenum, *cpp); return NULL; } cpp++; if (!*cpp) { fprintf(stderr, "%d: missing fields (destination port)\n", linenum); return NULL; } if (!portnum(*cpp, &ipn.in_pnext, linenum)) return NULL; ipn.in_pnext = htons(ipn.in_pnext); cpp++; } if (dnetm && *dnetm == '/') *dnetm++ = '\0'; if (ipn.in_redir & (NAT_MAP|NAT_MAPBLK)) { if (ipn.in_flags & IPN_IPRANGE) { if (hostnum((u_32_t *)&ipn.in_outmsk, dnetm, linenum) == -1) return NULL; } else if (genmask(dnetm, (u_32_t *)&ipn.in_outmsk)) return NULL; } else { if (ipn.in_flags & IPN_SPLIT) { if (hostnum((u_32_t *)&ipn.in_inmsk, dnetm, linenum) == -1) return NULL; } else if (genmask("255.255.255.255", (u_32_t *)&ipn.in_inmsk)) return NULL; if (*cpp) { ipn.in_flags &= ~IPN_TCP; /* override default */ if (!strcasecmp(*cpp, "tcp")) ipn.in_flags |= IPN_TCP; else if (!strcasecmp(*cpp, "udp")) ipn.in_flags |= IPN_UDP; else if (!strcasecmp(*cpp, "tcp/udp")) ipn.in_flags |= IPN_TCPUDP; else if (!strcasecmp(*cpp, "tcpudp")) ipn.in_flags |= IPN_TCPUDP; else if (!strcasecmp(*cpp, "ip")) ipn.in_flags |= IPN_ANY; else { ipn.in_flags |= IPN_ANY; if ((pr = getprotobyname(*cpp))) ipn.in_p = pr->p_proto; else ipn.in_p = atoi(*cpp); } proto = *cpp; cpp++; if (*cpp && !strcasecmp(*cpp, "round-robin")) { cpp++; ipn.in_flags |= IPN_ROUNDR; } if (*cpp) { fprintf(stderr, "%d: extra junk at the end of rdr: %s\n", linenum, *cpp); return NULL; } } } if (!(ipn.in_flags & IPN_SPLIT)) ipn.in_inip &= ipn.in_inmsk; if ((ipn.in_flags & IPN_IPRANGE) == 0) ipn.in_outip &= ipn.in_outmsk; ipn.in_srcip &= ipn.in_srcmsk; if ((ipn.in_redir & NAT_MAPBLK) != 0) nat_setgroupmap(&ipn); if (!*cpp) return &ipn; if (ipn.in_redir == NAT_BIMAP) { fprintf(stderr, "%d: extra words at the end of bimap line: %s\n", linenum, *cpp); return NULL; } if (!strcasecmp(*cpp, "proxy")) { cpp++; if (!*cpp) { fprintf(stderr, "%d: missing parameter for \"proxy\"\n", linenum); return NULL; } dport = NULL; if (!strcasecmp(*cpp, "port")) { cpp++; if (!*cpp) { fprintf(stderr, "%d: missing parameter for \"port\"\n", linenum); return NULL; } dport = *cpp; cpp++; if (!*cpp) { fprintf(stderr, "%d: missing parameter for \"proxy\"\n", linenum); return NULL; } } else { fprintf(stderr, "%d: missing keyword \"port\"\n", linenum); return NULL; } if ((proto = index(*cpp, '/'))) { *proto++ = '\0'; if ((pr = getprotobyname(proto))) ipn.in_p = pr->p_proto; else ipn.in_p = atoi(proto); } else ipn.in_p = 0; if (dport && !portnum(dport, &ipn.in_dport, linenum)) return NULL; ipn.in_dport = htons(ipn.in_dport); (void) strncpy(ipn.in_plabel, *cpp, sizeof(ipn.in_plabel)); cpp++; if (*cpp) { fprintf(stderr, "%d: too many parameters for \"proxy\"\n", linenum); return NULL; } return &ipn; } if (strcasecmp(*cpp, "portmap")) { fprintf(stderr, "%d: expected \"portmap\" - got \"%s\"\n", linenum, *cpp); return NULL; } cpp++; if (!*cpp) { fprintf(stderr, "%d: missing expression following portmap\n", linenum); return NULL; } if (!strcasecmp(*cpp, "tcp")) ipn.in_flags |= IPN_TCP; else if (!strcasecmp(*cpp, "udp")) ipn.in_flags |= IPN_UDP; else if (!strcasecmp(*cpp, "tcpudp")) ipn.in_flags |= IPN_TCPUDP; else if (!strcasecmp(*cpp, "tcp/udp")) ipn.in_flags |= IPN_TCPUDP; else { fprintf(stderr, "%d: expected protocol name - got \"%s\"\n", linenum, *cpp); return NULL; } proto = *cpp; cpp++; if (!*cpp) { fprintf(stderr, "%d: no port range found\n", linenum); return NULL; } if (!strcasecmp(*cpp, "auto")) { ipn.in_flags |= IPN_AUTOPORTMAP; ipn.in_pmin = htons(1024); ipn.in_pmax = htons(65535); nat_setgroupmap(&ipn); return &ipn; } if (!(t = strchr(*cpp, ':'))) { fprintf(stderr, "%d: no port range in \"%s\"\n", linenum, *cpp); return NULL; } *t++ = '\0'; if (!portnum(*cpp, &ipn.in_pmin, linenum) || !portnum(t, &ipn.in_pmax, linenum)) return NULL; ipn.in_pmin = htons(ipn.in_pmin); ipn.in_pmax = htons(ipn.in_pmax); return &ipn; } void natparsefile(fd, file, opts) int fd; char *file; int opts; { char line[512], *s; ipnat_t *np; FILE *fp; int linenum = 0; if (strcmp(file, "-")) { if (!(fp = fopen(file, "r"))) { fprintf(stderr, "%s: open: %s\n", file, STRERROR(errno)); exit(1); } } else fp = stdin; while (fgets(line, sizeof(line) - 1, fp)) { linenum++; line[sizeof(line) - 1] = '\0'; if ((s = strchr(line, '\n'))) *s = '\0'; if (!(np = natparse(line, linenum))) { if (*line) fprintf(stderr, "%d: syntax error in \"%s\"\n", linenum, line); } else { if ((opts & OPT_VERBOSE) && np) printnat(np, opts, NULL); if (!(opts & OPT_NODO)) { if (!(opts & OPT_REMOVE)) { if (ioctl(fd, SIOCADNAT, &np) == -1) { fprintf(stderr, "%d:", linenum); perror("ioctl(SIOCADNAT)"); } } else if (ioctl(fd, SIOCRMNAT, &np) == -1) { fprintf(stderr, "%d:", linenum); perror("ioctl(SIOCRMNAT)"); } } } } if (fp != stdin) fclose(fp); }