/* $NetBSD: natparse.c,v 1.1.1.1 1999/12/11 22:23:59 veego 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 #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 "netinet/ip_compat.h" #include "netinet/ip_fil.h" #include "netinet/ip_proxy.h" #include "netinet/ip_nat.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[] = "@(#)Id: natparse.c,v 1.2.2.1 1999/11/20 22:50:30 darrenr Exp"; #endif #if SOLARIS #define bzero(a,b) memset(a,0,b) #endif extern int countbits __P((u_32_t)); extern u_32_t hostnum __P((char *, int *, int)); ipnat_t *natparse __P((char *, int)); void printnat __P((ipnat_t *, int, void *)); void natparsefile __P((int, char *, int)); u_32_t n_hostmask __P((char *)); u_short n_portnum __P((char *, char *, int)); void nat_setgroupmap __P((struct ipnat *)); #define OPT_REM 1 #define OPT_NODO 2 #define OPT_STAT 4 #define OPT_LIST 8 #define OPT_VERBOSE 16 #define OPT_FLUSH 32 #define OPT_CLEAR 64 void printnat(np, verbose, ptr) ipnat_t *np; int verbose; 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; } if (np->in_redir == NAT_REDIRECT) { printf("%s ", np->in_ifname); if (np->in_src[0].s_addr || np->in_src[1].s_addr) { printf("from %s",inet_ntoa(np->in_src[0])); bits = countbits(np->in_src[1].s_addr); if (bits != -1) printf("/%d ", bits); else printf("/%s ", inet_ntoa(np->in_src[1])); } 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)); printf("-> %s", inet_ntoa(np->in_in[0])); 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"); printf("\n"); if (verbose) printf("\t%p %lu %x %u %p %d\n", np->in_ifp, np->in_space, np->in_flags, np->in_pnext, np, np->in_use); } else { np->in_nextip.s_addr = htonl(np->in_nextip.s_addr); printf("%s %s/", np->in_ifname, 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_RANGE) { 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 (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 (verbose) 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 (verbose) { 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; { struct protoent *pr; static ipnat_t ipn; char *s, *t; char *shost, *snetm, *dhost, *proto, *srchost, *srcnetm; char *dnetm = NULL, *dport = NULL, *tport = NULL; int resolved; srchost = NULL; srcnetm = NULL; bzero((char *)&ipn, sizeof(ipn)); if ((s = strchr(line, '\n'))) *s = '\0'; if ((s = strchr(line, '#'))) *s = '\0'; if (!*line) return NULL; if (!(s = strtok(line, " \t"))) return NULL; if (!strcasecmp(s, "map")) ipn.in_redir = NAT_MAP; else if (!strcasecmp(s, "map-block")) ipn.in_redir = NAT_MAPBLK; else if (!strcasecmp(s, "rdr")) ipn.in_redir = NAT_REDIRECT; else if (!strcasecmp(s, "bimap")) ipn.in_redir = NAT_BIMAP; else { fprintf(stderr, "%d: unknown mapping: \"%s\"\n", linenum, s); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (interface)\n", linenum); return NULL; } strncpy(ipn.in_ifname, s, sizeof(ipn.in_ifname) - 1); ipn.in_ifname[sizeof(ipn.in_ifname) - 1] = '\0'; if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (%s)\n", linenum, ipn.in_redir ? "from source | destination" : "source"); return NULL; } if ((ipn.in_redir == NAT_REDIRECT) && !strcasecmp(s, "from")) { if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (source address)\n", linenum); return NULL; } srchost = s; srcnetm = strrchr(srchost, '/'); if (srcnetm == NULL) { if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (source netmask)\n", linenum); return NULL; } if (strcasecmp(s, "netmask")) { fprintf(stderr, "%d: missing fields (netmask)\n", linenum); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (source netmask)\n", linenum); return NULL; } srcnetm = s; } if (*srcnetm == '/') *srcnetm++ = '\0'; /* re read the next word -- destination */ if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (destination)\n", linenum); return NULL; } } shost = s; if (ipn.in_redir == NAT_REDIRECT) { if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (destination port)\n", linenum); return NULL; } if (strcasecmp(s, "port")) { fprintf(stderr, "%d: missing fields (port)\n", linenum); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (destination port)\n", linenum); return NULL; } dport = s; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (->)\n", linenum); return NULL; } if (!strcmp(s, "->")) { snetm = strrchr(shost, '/'); if (!snetm) { fprintf(stderr, "%d: missing fields (%s netmask)\n", linenum, ipn.in_redir ? "destination" : "source"); return NULL; } } else { if (strcasecmp(s, "netmask")) { fprintf(stderr, "%d: missing fields (netmask)\n", linenum); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (%s netmask)\n", linenum, ipn.in_redir ? "destination" : "source"); return NULL; } snetm = s; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (%s)\n", linenum, ipn.in_redir ? "destination":"target"); return NULL; } if (ipn.in_redir == NAT_MAP) { if (!strcasecmp(s, "range")) { ipn.in_flags |= IPN_RANGE; if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (%s)\n", linenum, ipn.in_redir ? "destination":"target"); return NULL; } } } dhost = s; if (ipn.in_redir & (NAT_MAP|NAT_MAPBLK)) { if (ipn.in_flags & IPN_RANGE) { dnetm = strrchr(dhost, '-'); if (dnetm == NULL) { if (!(s = strtok(NULL, " \t"))) dnetm = NULL; else { if (strcmp(s, "-")) s = NULL; else if ((s = strtok(NULL, " \t"))) { dnetm = s; } } } else *dnetm++ = '\0'; if (dnetm == NULL || *dnetm == '\0') { fprintf(stderr, "%d: desination range not specified\n", linenum); return NULL; } } else { dnetm = strrchr(dhost, '/'); if (dnetm == NULL) { if (!(s = strtok(NULL, " \t"))) dnetm = NULL; else if (!strcasecmp(s, "netmask")) if ((s = strtok(NULL, " \t")) != NULL) dnetm = s; } if (dnetm == NULL) { fprintf(stderr, "%d: missing fields (dest netmask)\n", linenum); return NULL; } if (*dnetm == '/') *dnetm++ = '\0'; } s = strtok(NULL, " \t"); } if (ipn.in_redir & NAT_MAPBLK) { if (s && strcasecmp(s, "ports")) { fprintf(stderr, "%d: expected \"ports\" - got \"%s\"\n", linenum, s); return NULL; } if (s != NULL) { if ((s = strtok(NULL, " \t")) == NULL) return NULL; ipn.in_pmin = atoi(s); s = strtok(NULL, " \t"); } else ipn.in_pmin = 0; } else if ((ipn.in_redir & NAT_BIMAP) == NAT_REDIRECT) { if (strrchr(dhost, '/') != 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 (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (destination port)\n", linenum); return NULL; } if (strcasecmp(s, "port")) { fprintf(stderr, "%d: missing fields (port)\n", linenum); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing fields (destination port)\n", linenum); return NULL; } tport = s; } if (dnetm && *dnetm == '/') *dnetm++ = '\0'; if (snetm && *snetm == '/') *snetm++ = '\0'; if (ipn.in_redir & (NAT_MAP|NAT_MAPBLK)) { ipn.in_inip = hostnum(shost, &resolved, linenum); if (resolved == -1) return NULL; ipn.in_inmsk = n_hostmask(snetm); ipn.in_outip = hostnum(dhost, &resolved, linenum); if (resolved == -1) return NULL; if (ipn.in_flags & IPN_RANGE) { ipn.in_outmsk = hostnum(dnetm, &resolved, linenum); if (resolved == -1) return NULL; } else ipn.in_outmsk = n_hostmask(dnetm); if (srchost) { ipn.in_srcip = hostnum(srchost, &resolved, linenum); if (resolved == -1) return NULL; } if (srcnetm) ipn.in_srcmsk = n_hostmask(srcnetm); } else { if (srchost) { ipn.in_srcip = hostnum(srchost, &resolved, linenum); if (resolved == -1) return NULL; } if (srcnetm) ipn.in_srcmsk = n_hostmask(srcnetm); ipn.in_inip = hostnum(dhost, &resolved, linenum); if (resolved == -1) return NULL; ipn.in_inmsk = n_hostmask("255.255.255.255"); ipn.in_outip = hostnum(shost, &resolved, linenum); if (resolved == -1) return NULL; ipn.in_outmsk = n_hostmask(snetm); if (!(s = strtok(NULL, " \t"))) { ipn.in_flags = IPN_TCP; /* XXX- TCP only by default */ proto = "tcp"; } else { if (!strcasecmp(s, "tcp")) ipn.in_flags = IPN_TCP; else if (!strcasecmp(s, "udp")) ipn.in_flags = IPN_UDP; else if (!strcasecmp(s, "tcp/udp")) ipn.in_flags = IPN_TCPUDP; else if (!strcasecmp(s, "tcpudp")) ipn.in_flags = IPN_TCPUDP; else if (!strcasecmp(s, "ip")) ipn.in_flags = IPN_ANY; else { ipn.in_flags = IPN_ANY; if ((pr = getprotobyname(s))) ipn.in_p = pr->p_proto; else ipn.in_p = atoi(s); } proto = s; if ((s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: extra junk at the end of rdr: %s\n", linenum, s); return NULL; } } ipn.in_pmin = n_portnum(dport, proto, linenum); ipn.in_pmax = ipn.in_pmin; ipn.in_pnext = n_portnum(tport, proto, linenum); s = NULL; } ipn.in_inip &= ipn.in_inmsk; if ((ipn.in_flags & IPN_RANGE) == 0) ipn.in_outip &= ipn.in_outmsk; ipn.in_srcip &= ipn.in_srcmsk; if ((ipn.in_redir & NAT_MAPBLK) != 0) nat_setgroupmap(&ipn); if (!s) return &ipn; if (ipn.in_redir == NAT_BIMAP) { fprintf(stderr, "%d: extra words at the end of bimap line: %s\n", linenum, s); return NULL; } if (!strcasecmp(s, "proxy")) { if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing parameter for \"proxy\"\n", linenum); return NULL; } dport = NULL; if (!strcasecmp(s, "port")) { if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: missing parameter for \"port\"\n", linenum); return NULL; } dport = s; if (!(s = strtok(NULL, " \t"))) { 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(s, '/'))) { *proto++ = '\0'; if ((pr = getprotobyname(proto))) ipn.in_p = pr->p_proto; else ipn.in_p = atoi(proto); if (dport) ipn.in_dport = n_portnum(dport, proto, linenum); } else { ipn.in_p = 0; if (dport) ipn.in_dport = n_portnum(dport, NULL, linenum); } (void) strncpy(ipn.in_plabel, s, sizeof(ipn.in_plabel)); if ((s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: too many parameters for \"proxy\"\n", linenum); return NULL; } return &ipn; } if (strcasecmp(s, "portmap")) { fprintf(stderr, "%d: expected \"portmap\" - got \"%s\"\n", linenum, s); return NULL; } if (!(s = strtok(NULL, " \t"))) return NULL; if (!strcasecmp(s, "tcp")) ipn.in_flags = IPN_TCP; else if (!strcasecmp(s, "udp")) ipn.in_flags = IPN_UDP; else if (!strcasecmp(s, "tcpudp")) ipn.in_flags = IPN_TCPUDP; else if (!strcasecmp(s, "tcp/udp")) ipn.in_flags = IPN_TCPUDP; else { fprintf(stderr, "%d: expected protocol name - got \"%s\"\n", linenum, s); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "%d: no port range found\n", linenum); return NULL; } if (!strcasecmp(s, "auto")) { ipn.in_flags |= IPN_AUTOPORTMAP; ipn.in_pmin = htons(1024); ipn.in_pmax = htons(65535); nat_setgroupmap(&ipn); return &ipn; } proto = s; if (!(t = strchr(s, ':'))) { fprintf(stderr, "%d: no port range in \"%s\"\n", linenum, s); return NULL; } *t++ = '\0'; ipn.in_pmin = n_portnum(s, proto, linenum); ipn.in_pmax = n_portnum(t, proto, linenum); 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 & OPT_VERBOSE, NULL); if (!(opts & OPT_NODO)) { if (!(opts & OPT_REM)) { if (ioctl(fd, SIOCADNAT, np) == -1) perror("ioctl(SIOCADNAT)"); } else if (ioctl(fd, SIOCRMNAT, np) == -1) perror("ioctl(SIOCRMNAT)"); } } } if (fp != stdin) fclose(fp); } u_32_t n_hostmask(msk) char *msk; { int bits = -1; u_32_t mask; if (!isdigit(*msk)) return (u_32_t)-1; if (strchr(msk, '.')) return inet_addr(msk); if (strchr(msk, 'x')) return (u_32_t)strtol(msk, NULL, 0); /* * set x most significant bits */ for (mask = 0, bits = atoi(msk); bits; bits--) { mask /= 2; mask |= ntohl(inet_addr("128.0.0.0")); } mask = htonl(mask); return mask; } u_short n_portnum(name, proto, linenum) char *name, *proto; int linenum; { struct servent *sp, *sp2; u_short p1 = 0; if (isdigit(*name)) return htons((u_short)atoi(name)); if (!proto) proto = "tcp/udp"; if (strcasecmp(proto, "tcp/udp")) { sp = getservbyname(name, proto); if (sp) return sp->s_port; 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; } return p1; }