/* $NetBSD: ipnat.c,v 1.18 1998/05/29 20:52:04 veego Exp $ */ /* * Copyright (C) 1993-1997 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. * * Added redirect stuff and a variety of bug fixes. (mcn@EnGarde.com) * * Broken still: * Displaying the nat with redirect entries is way confusing * * Example redirection line: * rdr le1 0.0.0.0/0 port 79 -> 199.165.219.129 port 9901 * * Will redirect all incoming packets on le1 to any machine, port 79 to * host 199.165.219.129, port 9901 */ #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 #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" #include "kmem.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: ipnat.c,v 2.0.2.21.2.6 1998/05/23 19:07:02 darrenr Exp "; #endif #if SOLARIS #define bzero(a,b) memset(a,0,b) #endif extern char *optarg; ipnat_t *parse __P((char *)); u_32_t hostnum __P((char *, int *)); u_32_t hostmask __P((char *)); u_short portnum __P((char *, char *)); void dostats __P((int, int)), flushtable __P((int, int)); void printnat __P((ipnat_t *, int, void *)); void parsefile __P((int, char *, int)); void usage __P((char *)); int countbits __P((u_32_t)); char *getnattype __P((ipnat_t *)); int main __P((int, char*[])); #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 usage(name) char *name; { fprintf(stderr, "%s: [-CFlnrsv] [-f filename]\n", name); exit(1); } int main(argc, argv) int argc; char *argv[]; { char *file = NULL; int fd = -1, opts = 1, c; while ((c = getopt(argc, argv, "CFf:lnrsv")) != -1) switch (c) { case 'C' : opts |= OPT_CLEAR; break; case 'f' : file = optarg; break; case 'F' : opts |= OPT_FLUSH; break; case 'l' : opts |= OPT_LIST; break; case 'n' : opts |= OPT_NODO; break; case 'r' : opts &= ~OPT_REM; break; case 's' : opts |= OPT_STAT; break; case 'v' : opts |= OPT_VERBOSE; break; default : usage(argv[0]); } if (!(opts & OPT_NODO) && ((fd = open(IPL_NAT, O_RDWR)) == -1) && ((fd = open(IPL_NAT, O_RDONLY)) == -1)) { (void) fprintf(stderr, "%s: open: %s\n", IPL_NAT, STRERROR(errno)); exit(-1); } if (opts & (OPT_FLUSH|OPT_CLEAR)) flushtable(fd, opts); if (file) parsefile(fd, file, opts); if (opts & (OPT_LIST|OPT_STAT)) dostats(fd, opts); 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; } void printnat(np, verbose, ptr) ipnat_t *np; int verbose; void *ptr; { int bits; struct protoent *pr; switch (np->in_redir) { case NAT_REDIRECT : printf("rdr "); break; case NAT_MAP : printf("map "); 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 %s", np->in_ifname, 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 %u %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(" -> %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) { printf(" proxy port"); if (np->in_dport) printf(" %hu", ntohs(np->in_dport)); printf(" %.*s/", (int)sizeof(np->in_plabel), np->in_plabel); if ((pr = getprotobynumber(np->in_p))) fputs(pr->p_name, stdout); else printf("%d", np->in_p); } else if (np->in_pmin || np->in_pmax) { printf(" portmap"); 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("\t%p %u %s %d %x\n", np->in_ifp, np->in_space, inet_ntoa(np->in_nextip), np->in_pnext, np->in_flags); } } /* * Get a nat filter type given its kernel address. */ char *getnattype(ipnat) ipnat_t *ipnat; { char *which; ipnat_t ipnatbuff; if (ipnat && kmemcpy((char *)&ipnatbuff, (long)ipnat, sizeof(ipnatbuff))) return "???"; switch (ipnatbuff.in_redir) { case NAT_MAP : which = "MAP"; break; case NAT_REDIRECT : which = "RDR"; break; case NAT_BIMAP : which = "BIMAP"; break; default : which = "unknown"; break; } return which; } void dostats(fd, opts) int fd, opts; { natstat_t ns; ipnat_t ipn; nat_t **nt[2], *np, nat; int i = 0; bzero((char *)&ns, sizeof(ns)); if (!(opts & OPT_NODO) && ioctl(fd, SIOCGNATS, &ns) == -1) { perror("ioctl(SIOCGNATS)"); return; } if (opts & OPT_STAT) { printf("mapped\tin\t%lu\tout\t%lu\n", ns.ns_mapped[0], ns.ns_mapped[1]); printf("added\t%lu\texpired\t%lu\n", ns.ns_added, ns.ns_expire); printf("inuse\t%lu\nrules\t%lu\n", ns.ns_inuse, ns.ns_rules); if (opts & OPT_VERBOSE) printf("table %p list %p\n", ns.ns_table, ns.ns_list); } if (opts & OPT_LIST) { printf("List of active MAP/Redirect filters:\n"); while (ns.ns_list) { if (kmemcpy((char *)&ipn, (long)ns.ns_list, sizeof(ipn))) { perror("kmemcpy"); break; } printnat(&ipn, opts & OPT_VERBOSE, (void *)ns.ns_list); ns.ns_list = ipn.in_next; } nt[0] = (nat_t **)malloc(sizeof(*nt) * NAT_SIZE); if (kmemcpy((char *)nt[0], (long)ns.ns_table[0], sizeof(**nt) * NAT_SIZE)) { perror("kmemcpy"); return; } printf("\nList of active sessions:\n"); for (i = 0; i < NAT_SIZE; i++) for (np = nt[0][i]; np; np = nat.nat_hnext[0]) { if (kmemcpy((char *)&nat, (long)np, sizeof(nat))) break; printf("%s %-15s %-5hu <- ->", getnattype(nat.nat_ptr), inet_ntoa(nat.nat_inip), ntohs(nat.nat_inport)); printf(" %-15s %-5hu", inet_ntoa(nat.nat_outip), ntohs(nat.nat_outport)); printf(" [%s %hu]", inet_ntoa(nat.nat_oip), ntohs(nat.nat_oport)); printf(" %ld %hu %d", nat.nat_age, nat.nat_use, nat.nat_sumd); #if SOLARIS printf(" %lx", nat.nat_ipsumd); #endif putchar('\n'); } free(nt[0]); } } u_short portnum(name, proto) char *name, *proto; { 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; (void) fprintf(stderr, "unknown service \"%s\".\n", name); return 0; } sp = getservbyname(name, "tcp"); if (sp) p1 = sp->s_port; sp2 = getservbyname(name, "udp"); if (!sp || !sp2) { (void) fprintf(stderr, "unknown tcp/udp service \"%s\".\n", name); return 0; } if (p1 != sp2->s_port) { (void) fprintf(stderr, "%s %d/tcp is a different port to ", name, p1); (void) fprintf(stderr, "%s %d/udp\n", name, sp->s_port); return 0; } return p1; } u_32_t 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; } /* * 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) char *host; int *resolved; { struct hostent *hp; struct netent *np; *resolved = 0; if (!strcasecmp("any", host)) return 0L; if (isdigit(*host)) return inet_addr(host); if (!(hp = gethostbyname(host))) { if (!(np = getnetbyname(host))) { *resolved = -1; fprintf(stderr, "can't resolve hostname: %s\n", host); return 0; } return htonl(np->n_net); } return *(u_32_t *)hp->h_addr; } ipnat_t *parse(line) char *line; { struct protoent *pr; static ipnat_t ipn; char *s, *t; char *shost, *snetm, *dhost, *proto; char *dnetm = NULL, *dport = NULL, *tport = NULL; int resolved; 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, "rdr")) ipn.in_redir = NAT_REDIRECT; else if (!strcasecmp(s, "bimap")) ipn.in_redir = NAT_BIMAP; else { (void)fprintf(stderr, "expected map/rdr/bimap, got \"%s\"\n", s); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing fields (interface)\n"); 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, "missing fields (%s)\n", ipn.in_redir ? "destination": "source"); return NULL; } shost = s; if (ipn.in_redir == NAT_REDIRECT) { if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing fields (destination port)\n"); return NULL; } if (strcasecmp(s, "port")) { fprintf(stderr, "missing fields (port)\n"); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing fields (destination port)\n"); return NULL; } dport = s; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing fields (->)\n"); return NULL; } if (!strcmp(s, "->")) { snetm = strrchr(shost, '/'); if (!snetm) { fprintf(stderr, "missing fields (%s netmask)\n", ipn.in_redir ? "destination":"source"); return NULL; } } else { if (strcasecmp(s, "netmask")) { fprintf(stderr, "missing fields (netmask)\n"); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing fields (%s netmask)\n", ipn.in_redir ? "destination":"source"); return NULL; } snetm = s; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing fields (%s)\n", ipn.in_redir ? "destination":"target"); return NULL; } dhost = s; if (ipn.in_redir & NAT_MAP) { if (!(s = strtok(NULL, " \t"))) { dnetm = strrchr(dhost, '/'); if (!dnetm) { fprintf(stderr, "missing fields (dest netmask)\n"); return NULL; } } if (!s || !strcasecmp(s, "portmap") || !strcasecmp(s, "proxy")) { dnetm = strrchr(dhost, '/'); if (!dnetm) { fprintf(stderr, "missing fields (dest netmask)\n"); return NULL; } } else { if (strcasecmp(s, "netmask")) { fprintf(stderr, "missing fields (dest netmask)\n"); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing fields (dest netmask)\n"); return NULL; } dnetm = s; } if (*dnetm == '/') *dnetm++ = '\0'; } else { /* If it's a in_redir, expect target port */ if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing fields (destination port)\n"); return NULL; } if (strcasecmp(s, "port")) { fprintf(stderr, "missing fields (port)\n"); return NULL; } if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing fields (destination port)\n"); return NULL; } tport = s; } if (*snetm == '/') *snetm++ = '\0'; if (ipn.in_redir & NAT_MAP) { ipn.in_inip = hostnum(shost, &resolved); if (resolved == -1) return NULL; ipn.in_inmsk = hostmask(snetm); ipn.in_outip = hostnum(dhost, &resolved); if (resolved == -1) return NULL; ipn.in_outmsk = hostmask(dnetm); } else { ipn.in_inip = hostnum(dhost, &resolved); /* Inside is target */ if (resolved == -1) return NULL; ipn.in_inmsk = hostmask("255.255.255.255"); ipn.in_outip = hostnum(shost, &resolved); if (resolved == -1) return NULL; ipn.in_outmsk = 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 { fprintf(stderr, "expected protocol - got \"%s\"\n", s); return NULL; } proto = s; if ((s = strtok(NULL, " \t"))) { fprintf(stderr, "extra junk at the end of rdr: %s\n", s); return NULL; } } ipn.in_pmin = portnum(dport, proto); /* dest port */ ipn.in_pmax = ipn.in_pmin; /* NECESSARY of removing nats */ ipn.in_pnext = portnum(tport, proto); /* target port */ s = NULL; /* That's all she wrote! */ } ipn.in_inip &= ipn.in_inmsk; ipn.in_outip &= ipn.in_outmsk; if (!s) return &ipn; if (ipn.in_redir == NAT_BIMAP) { fprintf(stderr, "extra words at the end of bimap line: %s\n", s); return NULL; } if (!strcasecmp(s, "proxy")) { if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing parameter for \"proxy\"\n"); return NULL; } dport = NULL; if (!strcasecmp(s, "port")) { if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing parameter for \"port\"\n"); return NULL; } dport = s; if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "missing parameter for \"proxy\"\n"); 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 = portnum(dport, proto); } else { ipn.in_p = 0; if (dport) ipn.in_dport = portnum(dport, NULL); } (void) strncpy(ipn.in_plabel, s, sizeof(ipn.in_plabel)); if ((s = strtok(NULL, " \t"))) { fprintf(stderr, "too many parameters for \"proxy\"\n"); return NULL; } return &ipn; } if (strcasecmp(s, "portmap")) { fprintf(stderr, "expected \"portmap\" - got \"%s\"\n", 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, "expected protocol name - got \"%s\"\n", s); return NULL; } proto = s; if (!(s = strtok(NULL, " \t"))) { fprintf(stderr, "no port range found\n"); return NULL; } if (!(t = strchr(s, ':'))) { fprintf(stderr, "no port range in \"%s\"\n", s); return NULL; } *t++ = '\0'; ipn.in_pmin = portnum(s, proto); ipn.in_pmax = portnum(t, proto); return &ipn; } void parsefile(fd, file, opts) int fd; char *file; int opts; { char line[512], *s; ipnat_t *np; FILE *fp; int linenum = 1; if (strcmp(file, "-")) { if (!(fp = fopen(file, "r"))) { (void) fprintf(stderr, "%s: open: %s\n", file, STRERROR(errno)); exit(1); } } else fp = stdin; while (fgets(line, sizeof(line) - 1, fp)) { line[sizeof(line) - 1] = '\0'; if ((s = strchr(line, '\n'))) *s = '\0'; if (!(np = parse(line))) { if (*line) fprintf(stderr, "%d: syntax error in \"%s\"\n", linenum, line); } else if (!(opts & OPT_NODO)) { if ((opts & OPT_VERBOSE) && np) printnat(np, opts & OPT_VERBOSE, NULL); if (opts & OPT_REM) { if (ioctl(fd, SIOCADNAT, np) == -1) perror("ioctl(SIOCADNAT)"); } else if (ioctl(fd, SIOCRMNAT, np) == -1) perror("ioctl(SIOCRMNAT)"); } linenum++; } if (fp != stdin) fclose(fp); } void flushtable(fd, opts) int fd, opts; { int n = 0; if (opts & OPT_FLUSH) { n = 0; if (!(opts & OPT_NODO) && ioctl(fd, SIOCFLNAT, &n) == -1) perror("ioctl(SIOCFLNAT)"); else printf("%d entries flushed from NAT table\n", n); } if (opts & OPT_CLEAR) { n = 0; if (!(opts & OPT_NODO) && ioctl(fd, SIOCCNATL, &n) == -1) perror("ioctl(SIOCCNATL)"); else printf("%d entries flushed from NAT list\n", n); } }