/* * (C) 2000-2006 by the netfilter coreteam : * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* INT_MAX in ip_tables.h/ip6_tables.h */ #include #include #include #ifndef NO_SHARED_LIBS #include #endif #ifndef IPT_SO_GET_REVISION_MATCH /* Old kernel source. */ # define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2) # define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3) #endif #ifndef IP6T_SO_GET_REVISION_MATCH /* Old kernel source. */ # define IP6T_SO_GET_REVISION_MATCH 68 # define IP6T_SO_GET_REVISION_TARGET 69 #endif #include #define NPROTO 255 #ifndef PROC_SYS_MODPROBE #define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe" #endif void basic_exit_err(enum xtables_exittype status, const char *msg, ...) __attribute__((noreturn, format(printf,2,3))); struct xtables_globals *xt_params = NULL; void basic_exit_err(enum xtables_exittype status, const char *msg, ...) { va_list args; va_start(args, msg); fprintf(stderr, "%s v%s: ", xt_params->program_name, xt_params->program_version); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, "\n"); exit(status); } void xtables_free_opts(int reset_offset) { if (xt_params->opts != xt_params->orig_opts) { free(xt_params->opts); xt_params->opts = xt_params->orig_opts; if (reset_offset) xt_params->option_offset = 0; } } struct option *xtables_merge_options(struct option *oldopts, const struct option *newopts, unsigned int *option_offset) { unsigned int num_old, num_new, i; struct option *merge; if (newopts == NULL) return oldopts; for (num_old = 0; oldopts[num_old].name; num_old++) ; for (num_new = 0; newopts[num_new].name; num_new++) ; xt_params->option_offset += 256; *option_offset = xt_params->option_offset; merge = malloc(sizeof(struct option) * (num_new + num_old + 1)); if (merge == NULL) return NULL; memcpy(merge, oldopts, num_old * sizeof(struct option)); xtables_free_opts(0); /* Release any old options merged */ for (i = 0; i < num_new; i++) { merge[num_old + i] = newopts[i]; merge[num_old + i].val += *option_offset; } memset(merge + num_old + num_new, 0, sizeof(struct option)); return merge; } void xtables_set_revision(char *name, u_int8_t revision) { /* Old kernel sources don't have ".revision" field, * but we stole a byte from name. */ name[XT_FUNCTION_MAXNAMELEN - 2] = '\0'; name[XT_FUNCTION_MAXNAMELEN - 1] = revision; } /** * xtables_afinfo - protocol family dependent information * @kmod: kernel module basename (e.g. "ip_tables") * @libprefix: prefix of .so library name (e.g. "libipt_") * @family: nfproto family * @ipproto: used by setsockopt (e.g. IPPROTO_IP) * @so_rev_match: optname to check revision support of match * @so_rev_target: optname to check revision support of target */ struct xtables_afinfo { const char *kmod; const char *libprefix; uint8_t family; uint8_t ipproto; int so_rev_match; int so_rev_target; }; static const struct xtables_afinfo afinfo_ipv4 = { .kmod = "ip_tables", .libprefix = "libipt_", .family = NFPROTO_IPV4, .ipproto = IPPROTO_IP, .so_rev_match = IPT_SO_GET_REVISION_MATCH, .so_rev_target = IPT_SO_GET_REVISION_TARGET, }; static const struct xtables_afinfo afinfo_ipv6 = { .kmod = "ip6_tables", .libprefix = "libip6t_", .family = NFPROTO_IPV6, .ipproto = IPPROTO_IPV6, .so_rev_match = IP6T_SO_GET_REVISION_MATCH, .so_rev_target = IP6T_SO_GET_REVISION_TARGET, }; static const struct xtables_afinfo *afinfo; /* Search path for Xtables .so files */ static const char *xtables_libdir; /* the path to command to load kernel module */ const char *xtables_modprobe_program; /* Keeping track of external matches and targets: linked lists. */ struct xtables_match *xtables_matches; struct xtables_target *xtables_targets; void xtables_init(void) { xtables_libdir = getenv("XTABLES_LIBDIR"); if (xtables_libdir != NULL) return; xtables_libdir = getenv("IPTABLES_LIB_DIR"); if (xtables_libdir != NULL) { fprintf(stderr, "IPTABLES_LIB_DIR is deprecated, " "use XTABLES_LIBDIR.\n"); return; } /* * Well yes, IP6TABLES_LIB_DIR is of lower priority over * IPTABLES_LIB_DIR since this moved to libxtables; I think that is ok * for these env vars are deprecated anyhow, and in light of the * (shared) libxt_*.so files, makes less sense to have * IPTABLES_LIB_DIR != IP6TABLES_LIB_DIR. */ xtables_libdir = getenv("IP6TABLES_LIB_DIR"); if (xtables_libdir != NULL) { fprintf(stderr, "IP6TABLES_LIB_DIR is deprecated, " "use XTABLES_LIBDIR.\n"); return; } xtables_libdir = XTABLES_LIBDIR; } void xtables_set_nfproto(uint8_t nfproto) { switch (nfproto) { case NFPROTO_IPV4: afinfo = &afinfo_ipv4; break; case NFPROTO_IPV6: afinfo = &afinfo_ipv6; break; default: fprintf(stderr, "libxtables: unhandled NFPROTO in %s\n", __func__); } } /** * xtables_set_params - set the global parameters used by xtables * @xtp: input xtables_globals structure * * The app is expected to pass a valid xtables_globals data-filled * with proper values * @xtp cannot be NULL * * Returns -1 on failure to set and 0 on success */ int xtables_set_params(struct xtables_globals *xtp) { if (!xtp) { fprintf(stderr, "%s: Illegal global params\n",__func__); return -1; } xt_params = xtp; if (!xt_params->exit_err) xt_params->exit_err = basic_exit_err; return 0; } int xtables_init_all(struct xtables_globals *xtp, uint8_t nfproto) { xtables_init(); xtables_set_nfproto(nfproto); return xtables_set_params(xtp); } /** * xtables_*alloc - wrappers that exit on failure */ void *xtables_calloc(size_t count, size_t size) { void *p; if ((p = calloc(count, size)) == NULL) { perror("ip[6]tables: calloc failed"); exit(1); } return p; } void *xtables_malloc(size_t size) { void *p; if ((p = malloc(size)) == NULL) { perror("ip[6]tables: malloc failed"); exit(1); } return p; } void *xtables_realloc(void *ptr, size_t size) { void *p; if ((p = realloc(ptr, size)) == NULL) { perror("ip[6]tables: realloc failed"); exit(1); } return p; } static char *get_modprobe(void) { int procfile; char *ret; #define PROCFILE_BUFSIZ 1024 procfile = open(PROC_SYS_MODPROBE, O_RDONLY); if (procfile < 0) return NULL; ret = (char *) malloc(PROCFILE_BUFSIZ); if (ret) { memset(ret, 0, PROCFILE_BUFSIZ); switch (read(procfile, ret, PROCFILE_BUFSIZ)) { case -1: goto fail; case PROCFILE_BUFSIZ: goto fail; /* Partial read. Wierd */ } if (ret[strlen(ret)-1]=='\n') ret[strlen(ret)-1]=0; close(procfile); return ret; } fail: free(ret); close(procfile); return NULL; } int xtables_insmod(const char *modname, const char *modprobe, bool quiet) { char *buf = NULL; char *argv[4]; int status; /* If they don't explicitly set it, read out of kernel */ if (!modprobe) { buf = get_modprobe(); if (!buf) return -1; modprobe = buf; } /* * Need to flush the buffer, or the child may output it again * when switching the program thru execv. */ fflush(stdout); switch (vfork()) { case 0: argv[0] = (char *)modprobe; argv[1] = (char *)modname; if (quiet) { argv[2] = "-q"; argv[3] = NULL; } else { argv[2] = NULL; argv[3] = NULL; } execv(argv[0], argv); /* not usually reached */ exit(1); case -1: return -1; default: /* parent */ wait(&status); } free(buf); if (WIFEXITED(status) && WEXITSTATUS(status) == 0) return 0; return -1; } int xtables_load_ko(const char *modprobe, bool quiet) { static bool loaded = false; static int ret = -1; if (!loaded) { ret = xtables_insmod(afinfo->kmod, modprobe, quiet); loaded = (ret == 0); } return ret; } /** * xtables_strtou{i,l} - string to number conversion * @s: input string * @end: like strtoul's "end" pointer * @value: pointer for result * @min: minimum accepted value * @max: maximum accepted value * * If @end is NULL, we assume the caller wants a "strict strtoul", and hence * "15a" is rejected. * In either case, the value obtained is compared for min-max compliance. * Base is always 0, i.e. autodetect depending on @s. * * Returns true/false whether number was accepted. On failure, *value has * undefined contents. */ bool xtables_strtoul(const char *s, char **end, unsigned long *value, unsigned long min, unsigned long max) { unsigned long v; char *my_end; errno = 0; v = strtoul(s, &my_end, 0); if (my_end == s) return false; if (end != NULL) *end = my_end; if (errno != ERANGE && min <= v && (max == 0 || v <= max)) { if (value != NULL) *value = v; if (end == NULL) return *my_end == '\0'; return true; } return false; } bool xtables_strtoui(const char *s, char **end, unsigned int *value, unsigned int min, unsigned int max) { unsigned long v; bool ret; ret = xtables_strtoul(s, end, &v, min, max); if (value != NULL) *value = v; return ret; } int xtables_service_to_port(const char *name, const char *proto) { struct servent *service; if ((service = getservbyname(name, proto)) != NULL) return ntohs((unsigned short) service->s_port); return -1; } u_int16_t xtables_parse_port(const char *port, const char *proto) { unsigned int portnum; if (xtables_strtoui(port, NULL, &portnum, 0, UINT16_MAX) || (portnum = xtables_service_to_port(port, proto)) != (unsigned)-1) return portnum; xt_params->exit_err(PARAMETER_PROBLEM, "invalid port/service `%s' specified", port); } void xtables_parse_interface(const char *arg, char *vianame, unsigned char *mask) { unsigned int vialen = strlen(arg); unsigned int i; memset(mask, 0, IFNAMSIZ); memset(vianame, 0, IFNAMSIZ); if (vialen + 1 > IFNAMSIZ) xt_params->exit_err(PARAMETER_PROBLEM, "interface name `%s' must be shorter than IFNAMSIZ" " (%i)", arg, IFNAMSIZ-1); strcpy(vianame, arg); if (vialen == 0) memset(mask, 0, IFNAMSIZ); else if (vianame[vialen - 1] == '+') { memset(mask, 0xFF, vialen - 1); memset(mask + vialen - 1, 0, IFNAMSIZ - vialen + 1); /* Don't remove `+' here! -HW */ } else { /* Include nul-terminator in match */ memset(mask, 0xFF, vialen + 1); memset(mask + vialen + 1, 0, IFNAMSIZ - vialen - 1); for (i = 0; vianame[i]; i++) { if (vianame[i] == '/' || vianame[i] == ' ') { fprintf(stderr, "Warning: weird character in interface" " `%s' ('/' and ' ' are not allowed by the kernel).\n", vianame); break; } } } } #ifndef NO_SHARED_LIBS static void *load_extension(const char *search_path, const char *prefix, const char *name, bool is_target) { const char *dir = search_path, *next; void *ptr = NULL; struct stat sb; char path[256]; do { next = strchr(dir, ':'); if (next == NULL) next = dir + strlen(dir); snprintf(path, sizeof(path), "%.*s/libxt_%s.so", (unsigned int)(next - dir), dir, name); if (dlopen(path, RTLD_NOW) != NULL) { /* Found library. If it didn't register itself, maybe they specified target as match. */ if (is_target) ptr = xtables_find_target(name, XTF_DONT_LOAD); else ptr = xtables_find_match(name, XTF_DONT_LOAD, NULL); } else if (stat(path, &sb) == 0) { fprintf(stderr, "%s: %s\n", path, dlerror()); } if (ptr != NULL) return ptr; snprintf(path, sizeof(path), "%.*s/%s%s.so", (unsigned int)(next - dir), dir, prefix, name); if (dlopen(path, RTLD_NOW) != NULL) { if (is_target) ptr = xtables_find_target(name, XTF_DONT_LOAD); else ptr = xtables_find_match(name, XTF_DONT_LOAD, NULL); } else if (stat(path, &sb) == 0) { fprintf(stderr, "%s: %s\n", path, dlerror()); } if (ptr != NULL) return ptr; dir = next + 1; } while (*next != '\0'); return NULL; } #endif struct xtables_match * xtables_find_match(const char *name, enum xtables_tryload tryload, struct xtables_rule_match **matches) { struct xtables_match *ptr; const char *icmp6 = "icmp6"; if (strlen(name) > XT_FUNCTION_MAXNAMELEN - 1) xtables_error(PARAMETER_PROBLEM, "Invalid match name \"%s\" (%u chars max)", name, XT_FUNCTION_MAXNAMELEN - 1); /* This is ugly as hell. Nonetheless, there is no way of changing * this without hurting backwards compatibility */ if ( (strcmp(name,"icmpv6") == 0) || (strcmp(name,"ipv6-icmp") == 0) || (strcmp(name,"icmp6") == 0) ) name = icmp6; for (ptr = xtables_matches; ptr; ptr = ptr->next) { if (strcmp(name, ptr->name) == 0) { struct xtables_match *clone; /* First match of this type: */ if (ptr->m == NULL) break; /* Second and subsequent clones */ clone = xtables_malloc(sizeof(struct xtables_match)); memcpy(clone, ptr, sizeof(struct xtables_match)); clone->mflags = 0; /* This is a clone: */ clone->next = clone; ptr = clone; break; } } #ifndef NO_SHARED_LIBS if (!ptr && tryload != XTF_DONT_LOAD && tryload != XTF_DURING_LOAD) { ptr = load_extension(xtables_libdir, afinfo->libprefix, name, false); if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) xt_params->exit_err(PARAMETER_PROBLEM, "Couldn't load match `%s':%s\n", name, dlerror()); } #else if (ptr && !ptr->loaded) { if (tryload != XTF_DONT_LOAD) ptr->loaded = 1; else ptr = NULL; } if(!ptr && (tryload == XTF_LOAD_MUST_SUCCEED)) { xt_params->exit_err(PARAMETER_PROBLEM, "Couldn't find match `%s'\n", name); } #endif if (ptr && matches) { struct xtables_rule_match **i; struct xtables_rule_match *newentry; newentry = xtables_malloc(sizeof(struct xtables_rule_match)); for (i = matches; *i; i = &(*i)->next) { if (strcmp(name, (*i)->match->name) == 0) (*i)->completed = true; } newentry->match = ptr; newentry->completed = false; newentry->next = NULL; *i = newentry; } return ptr; } struct xtables_target * xtables_find_target(const char *name, enum xtables_tryload tryload) { struct xtables_target *ptr; /* Standard target? */ if (strcmp(name, "") == 0 || strcmp(name, XTC_LABEL_ACCEPT) == 0 || strcmp(name, XTC_LABEL_DROP) == 0 || strcmp(name, XTC_LABEL_QUEUE) == 0 || strcmp(name, XTC_LABEL_RETURN) == 0) name = "standard"; for (ptr = xtables_targets; ptr; ptr = ptr->next) { if (strcmp(name, ptr->name) == 0) break; } #ifndef NO_SHARED_LIBS if (!ptr && tryload != XTF_DONT_LOAD && tryload != XTF_DURING_LOAD) { ptr = load_extension(xtables_libdir, afinfo->libprefix, name, true); if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) xt_params->exit_err(PARAMETER_PROBLEM, "Couldn't load target `%s':%s\n", name, dlerror()); } #else if (ptr && !ptr->loaded) { if (tryload != XTF_DONT_LOAD) ptr->loaded = 1; else ptr = NULL; } if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) { xt_params->exit_err(PARAMETER_PROBLEM, "Couldn't find target `%s'\n", name); } #endif if (ptr) ptr->used = 1; return ptr; } static int compatible_revision(const char *name, u_int8_t revision, int opt) { struct xt_get_revision rev; socklen_t s = sizeof(rev); int max_rev, sockfd; sockfd = socket(afinfo->family, SOCK_RAW, IPPROTO_RAW); if (sockfd < 0) { if (errno == EPERM) { /* revision 0 is always supported. */ if (revision != 0) fprintf(stderr, "Could not determine whether " "revision %u is supported, " "assuming it is.\n", revision); return 1; } fprintf(stderr, "Could not open socket to kernel: %s\n", strerror(errno)); exit(1); } xtables_load_ko(xtables_modprobe_program, true); strcpy(rev.name, name); rev.revision = revision; max_rev = getsockopt(sockfd, afinfo->ipproto, opt, &rev, &s); if (max_rev < 0) { /* Definitely don't support this? */ if (errno == ENOENT || errno == EPROTONOSUPPORT) { close(sockfd); return 0; } else if (errno == ENOPROTOOPT) { close(sockfd); /* Assume only revision 0 support (old kernel) */ return (revision == 0); } else { fprintf(stderr, "getsockopt failed strangely: %s\n", strerror(errno)); exit(1); } } close(sockfd); return 1; } static int compatible_match_revision(const char *name, u_int8_t revision) { return compatible_revision(name, revision, afinfo->so_rev_match); } static int compatible_target_revision(const char *name, u_int8_t revision) { return compatible_revision(name, revision, afinfo->so_rev_target); } void xtables_register_match(struct xtables_match *me) { struct xtables_match **i, *old; if (me->version == NULL) { fprintf(stderr, "%s: match %s<%u> is missing a version\n", xt_params->program_name, me->name, me->revision); exit(1); } if (strcmp(me->version, XTABLES_VERSION) != 0) { fprintf(stderr, "%s: match \"%s\" has version \"%s\", " "but \"%s\" is required.\n", xt_params->program_name, me->name, me->version, XTABLES_VERSION); exit(1); } /* Revision field stole a char from name. */ if (strlen(me->name) >= XT_FUNCTION_MAXNAMELEN-1) { fprintf(stderr, "%s: target `%s' has invalid name\n", xt_params->program_name, me->name); exit(1); } if (me->family >= NPROTO) { fprintf(stderr, "%s: BUG: match %s has invalid protocol family\n", xt_params->program_name, me->name); exit(1); } /* ignore not interested match */ if (me->family != afinfo->family && me->family != AF_UNSPEC) return; old = xtables_find_match(me->name, XTF_DURING_LOAD, NULL); if (old) { if (old->revision == me->revision && old->family == me->family) { fprintf(stderr, "%s: match `%s' already registered.\n", xt_params->program_name, me->name); exit(1); } /* Now we have two (or more) options, check compatibility. */ if (compatible_match_revision(old->name, old->revision) && old->revision > me->revision) return; /* See if new match can be used. */ if (!compatible_match_revision(me->name, me->revision)) return; /* Prefer !AF_UNSPEC over AF_UNSPEC for same revision. */ if (old->revision == me->revision && me->family == AF_UNSPEC) return; /* Delete old one. */ for (i = &xtables_matches; *i!=old; i = &(*i)->next); *i = old->next; } if (me->size != XT_ALIGN(me->size)) { fprintf(stderr, "%s: match `%s' has invalid size %u.\n", xt_params->program_name, me->name, (unsigned int)me->size); exit(1); } /* Append to list. */ for (i = &xtables_matches; *i; i = &(*i)->next); me->next = NULL; *i = me; me->m = NULL; me->mflags = 0; } void xtables_register_matches(struct xtables_match *match, unsigned int n) { do { xtables_register_match(&match[--n]); } while (n > 0); } void xtables_register_target(struct xtables_target *me) { struct xtables_target *old; if (me->version == NULL) { fprintf(stderr, "%s: target %s<%u> is missing a version\n", xt_params->program_name, me->name, me->revision); exit(1); } if (strcmp(me->version, XTABLES_VERSION) != 0) { fprintf(stderr, "%s: target \"%s\" has version \"%s\", " "but \"%s\" is required.\n", xt_params->program_name, me->name, me->version, XTABLES_VERSION); exit(1); } /* Revision field stole a char from name. */ if (strlen(me->name) >= XT_FUNCTION_MAXNAMELEN-1) { fprintf(stderr, "%s: target `%s' has invalid name\n", xt_params->program_name, me->name); exit(1); } if (me->family >= NPROTO) { fprintf(stderr, "%s: BUG: target %s has invalid protocol family\n", xt_params->program_name, me->name); exit(1); } /* ignore not interested target */ if (me->family != afinfo->family && me->family != AF_UNSPEC) return; old = xtables_find_target(me->name, XTF_DURING_LOAD); if (old) { struct xtables_target **i; if (old->revision == me->revision && old->family == me->family) { fprintf(stderr, "%s: target `%s' already registered.\n", xt_params->program_name, me->name); exit(1); } /* Now we have two (or more) options, check compatibility. */ if (compatible_target_revision(old->name, old->revision) && old->revision > me->revision) return; /* See if new target can be used. */ if (!compatible_target_revision(me->name, me->revision)) return; /* Prefer !AF_UNSPEC over AF_UNSPEC for same revision. */ if (old->revision == me->revision && me->family == AF_UNSPEC) return; /* Delete old one. */ for (i = &xtables_targets; *i!=old; i = &(*i)->next); *i = old->next; } if (me->size != XT_ALIGN(me->size)) { fprintf(stderr, "%s: target `%s' has invalid size %u.\n", xt_params->program_name, me->name, (unsigned int)me->size); exit(1); } /* Prepend to list. */ me->next = xtables_targets; xtables_targets = me; me->t = NULL; me->tflags = 0; } void xtables_register_targets(struct xtables_target *target, unsigned int n) { do { xtables_register_target(&target[--n]); } while (n > 0); } /** * xtables_param_act - act on condition * @status: a constant from enum xtables_exittype * * %XTF_ONLY_ONCE: print error message that option may only be used once. * @p1: module name (e.g. "mark") * @p2(...): option in conflict (e.g. "--mark") * @p3(...): condition to match on (see extensions/ for examples) * * %XTF_NO_INVERT: option does not support inversion * @p1: module name * @p2: option in conflict * @p3: condition to match on * * %XTF_BAD_VALUE: bad value for option * @p1: module name * @p2: option with which the problem occured (e.g. "--mark") * @p3: string the user passed in (e.g. "99999999999999") * * %XTF_ONE_ACTION: two mutually exclusive actions have been specified * @p1: module name * * Displays an error message and exits the program. */ void xtables_param_act(unsigned int status, const char *p1, ...) { const char *p2, *p3; va_list args; bool b; va_start(args, p1); switch (status) { case XTF_ONLY_ONCE: p2 = va_arg(args, const char *); b = va_arg(args, unsigned int); if (!b) return; xt_params->exit_err(PARAMETER_PROBLEM, "%s: \"%s\" option may only be specified once", p1, p2); break; case XTF_NO_INVERT: p2 = va_arg(args, const char *); b = va_arg(args, unsigned int); if (!b) return; xt_params->exit_err(PARAMETER_PROBLEM, "%s: \"%s\" option cannot be inverted", p1, p2); break; case XTF_BAD_VALUE: p2 = va_arg(args, const char *); p3 = va_arg(args, const char *); xt_params->exit_err(PARAMETER_PROBLEM, "%s: Bad value for \"%s\" option: \"%s\"", p1, p2, p3); break; case XTF_ONE_ACTION: b = va_arg(args, unsigned int); if (!b) return; xt_params->exit_err(PARAMETER_PROBLEM, "%s: At most one action is possible", p1); break; default: xt_params->exit_err(status, p1, args); break; } va_end(args); } const char *xtables_ipaddr_to_numeric(const struct in_addr *addrp) { static char buf[20]; const unsigned char *bytep = (const void *)&addrp->s_addr; sprintf(buf, "%u.%u.%u.%u", bytep[0], bytep[1], bytep[2], bytep[3]); return buf; } static const char *ipaddr_to_host(const struct in_addr *addr) { struct hostent *host; host = gethostbyaddr(addr, sizeof(struct in_addr), AF_INET); if (host == NULL) return NULL; return host->h_name; } static const char *ipaddr_to_network(const struct in_addr *addr) { struct netent *net; if ((net = getnetbyaddr(ntohl(addr->s_addr), AF_INET)) != NULL) return net->n_name; return NULL; } const char *xtables_ipaddr_to_anyname(const struct in_addr *addr) { const char *name; if ((name = ipaddr_to_host(addr)) != NULL || (name = ipaddr_to_network(addr)) != NULL) return name; return xtables_ipaddr_to_numeric(addr); } const char *xtables_ipmask_to_numeric(const struct in_addr *mask) { static char buf[20]; uint32_t maskaddr, bits; int i; maskaddr = ntohl(mask->s_addr); if (maskaddr == 0xFFFFFFFFL) /* we don't want to see "/32" */ return ""; i = 32; bits = 0xFFFFFFFEL; while (--i >= 0 && maskaddr != bits) bits <<= 1; if (i >= 0) sprintf(buf, "/%d", i); else /* mask was not a decent combination of 1's and 0's */ sprintf(buf, "/%s", xtables_ipaddr_to_numeric(mask)); return buf; } static struct in_addr *__numeric_to_ipaddr(const char *dotted, bool is_mask) { static struct in_addr addr; unsigned char *addrp; unsigned int onebyte; char buf[20], *p, *q; int i; /* copy dotted string, because we need to modify it */ strncpy(buf, dotted, sizeof(buf) - 1); buf[sizeof(buf) - 1] = '\0'; addrp = (void *)&addr.s_addr; p = buf; for (i = 0; i < 3; ++i) { if ((q = strchr(p, '.')) == NULL) { if (is_mask) return NULL; /* autocomplete, this is a network address */ if (!xtables_strtoui(p, NULL, &onebyte, 0, UINT8_MAX)) return NULL; addrp[i] = onebyte; while (i < 3) addrp[++i] = 0; return &addr; } *q = '\0'; if (!xtables_strtoui(p, NULL, &onebyte, 0, UINT8_MAX)) return NULL; addrp[i] = onebyte; p = q + 1; } /* we have checked 3 bytes, now we check the last one */ if (!xtables_strtoui(p, NULL, &onebyte, 0, UINT8_MAX)) return NULL; addrp[3] = onebyte; return &addr; } struct in_addr *xtables_numeric_to_ipaddr(const char *dotted) { return __numeric_to_ipaddr(dotted, false); } struct in_addr *xtables_numeric_to_ipmask(const char *dotted) { return __numeric_to_ipaddr(dotted, true); } static struct in_addr *network_to_ipaddr(const char *name) { static struct in_addr addr; struct netent *net; if ((net = getnetbyname(name)) != NULL) { if (net->n_addrtype != AF_INET) return NULL; addr.s_addr = htonl(net->n_net); return &addr; } return NULL; } static struct in_addr *host_to_ipaddr(const char *name, unsigned int *naddr) { struct hostent *host; struct in_addr *addr; unsigned int i; *naddr = 0; if ((host = gethostbyname(name)) != NULL) { if (host->h_addrtype != AF_INET || host->h_length != sizeof(struct in_addr)) return NULL; while (host->h_addr_list[*naddr] != NULL) ++*naddr; addr = xtables_calloc(*naddr, sizeof(struct in_addr) * *naddr); for (i = 0; i < *naddr; i++) memcpy(&addr[i], host->h_addr_list[i], sizeof(struct in_addr)); return addr; } return NULL; } static struct in_addr * ipparse_hostnetwork(const char *name, unsigned int *naddrs) { struct in_addr *addrptmp, *addrp; if ((addrptmp = xtables_numeric_to_ipaddr(name)) != NULL || (addrptmp = network_to_ipaddr(name)) != NULL) { addrp = xtables_malloc(sizeof(struct in_addr)); memcpy(addrp, addrptmp, sizeof(*addrp)); *naddrs = 1; return addrp; } if ((addrptmp = host_to_ipaddr(name, naddrs)) != NULL) return addrptmp; xt_params->exit_err(PARAMETER_PROBLEM, "host/network `%s' not found", name); } static struct in_addr *parse_ipmask(const char *mask) { static struct in_addr maskaddr; struct in_addr *addrp; unsigned int bits; if (mask == NULL) { /* no mask at all defaults to 32 bits */ maskaddr.s_addr = 0xFFFFFFFF; return &maskaddr; } if ((addrp = xtables_numeric_to_ipmask(mask)) != NULL) /* dotted_to_addr already returns a network byte order addr */ return addrp; if (!xtables_strtoui(mask, NULL, &bits, 0, 32)) xt_params->exit_err(PARAMETER_PROBLEM, "invalid mask `%s' specified", mask); if (bits != 0) { maskaddr.s_addr = htonl(0xFFFFFFFF << (32 - bits)); return &maskaddr; } maskaddr.s_addr = 0U; return &maskaddr; } void xtables_ipparse_multiple(const char *name, struct in_addr **addrpp, struct in_addr **maskpp, unsigned int *naddrs) { struct in_addr *addrp; char buf[256], *p; unsigned int len, i, j, n, count = 1; const char *loop = name; while ((loop = strchr(loop, ',')) != NULL) { ++count; ++loop; /* skip ',' */ } *addrpp = xtables_malloc(sizeof(struct in_addr) * count); *maskpp = xtables_malloc(sizeof(struct in_addr) * count); loop = name; for (i = 0; i < count; ++i) { if (loop == NULL) break; if (*loop == ',') ++loop; if (*loop == '\0') break; p = strchr(loop, ','); if (p != NULL) len = p - loop; else len = strlen(loop); if (len == 0 || sizeof(buf) - 1 < len) break; strncpy(buf, loop, len); buf[len] = '\0'; loop += len; if ((p = strrchr(buf, '/')) != NULL) { *p = '\0'; addrp = parse_ipmask(p + 1); } else { addrp = parse_ipmask(NULL); } memcpy(*maskpp + i, addrp, sizeof(*addrp)); /* if a null mask is given, the name is ignored, like in "any/0" */ if ((*maskpp + i)->s_addr == 0) /* * A bit pointless to process multiple addresses * in this case... */ strcpy(buf, "0.0.0.0"); addrp = ipparse_hostnetwork(buf, &n); if (n > 1) { count += n - 1; *addrpp = xtables_realloc(*addrpp, sizeof(struct in_addr) * count); *maskpp = xtables_realloc(*maskpp, sizeof(struct in_addr) * count); for (j = 0; j < n; ++j) /* for each new addr */ memcpy(*addrpp + i + j, addrp + j, sizeof(*addrp)); for (j = 1; j < n; ++j) /* for each new mask */ memcpy(*maskpp + i + j, *maskpp + i, sizeof(*addrp)); i += n - 1; } else { memcpy(*addrpp + i, addrp, sizeof(*addrp)); } /* free what ipparse_hostnetwork had allocated: */ free(addrp); } *naddrs = count; for (i = 0; i < n; ++i) (*addrpp+i)->s_addr &= (*maskpp+i)->s_addr; } /** * xtables_ipparse_any - transform arbitrary name to in_addr * * Possible inputs (pseudo regex): * m{^($hostname|$networkname|$ipaddr)(/$mask)?} * "1.2.3.4/5", "1.2.3.4", "hostname", "networkname" */ void xtables_ipparse_any(const char *name, struct in_addr **addrpp, struct in_addr *maskp, unsigned int *naddrs) { unsigned int i, j, k, n; struct in_addr *addrp; char buf[256], *p; strncpy(buf, name, sizeof(buf) - 1); buf[sizeof(buf) - 1] = '\0'; if ((p = strrchr(buf, '/')) != NULL) { *p = '\0'; addrp = parse_ipmask(p + 1); } else { addrp = parse_ipmask(NULL); } memcpy(maskp, addrp, sizeof(*maskp)); /* if a null mask is given, the name is ignored, like in "any/0" */ if (maskp->s_addr == 0U) strcpy(buf, "0.0.0.0"); addrp = *addrpp = ipparse_hostnetwork(buf, naddrs); n = *naddrs; for (i = 0, j = 0; i < n; ++i) { addrp[j++].s_addr &= maskp->s_addr; for (k = 0; k < j - 1; ++k) if (addrp[k].s_addr == addrp[j-1].s_addr) { --*naddrs; --j; break; } } } const char *xtables_ip6addr_to_numeric(const struct in6_addr *addrp) { /* 0000:0000:0000:0000:0000:000.000.000.000 * 0000:0000:0000:0000:0000:0000:0000:0000 */ static char buf[50+1]; return inet_ntop(AF_INET6, addrp, buf, sizeof(buf)); } static const char *ip6addr_to_host(const struct in6_addr *addr) { static char hostname[NI_MAXHOST]; struct sockaddr_in6 saddr; int err; memset(&saddr, 0, sizeof(struct sockaddr_in6)); memcpy(&saddr.sin6_addr, addr, sizeof(*addr)); saddr.sin6_family = AF_INET6; err = getnameinfo((const void *)&saddr, sizeof(struct sockaddr_in6), hostname, sizeof(hostname) - 1, NULL, 0, 0); if (err != 0) { #ifdef DEBUG fprintf(stderr,"IP2Name: %s\n",gai_strerror(err)); #endif return NULL; } #ifdef DEBUG fprintf (stderr, "\naddr2host: %s\n", hostname); #endif return hostname; } const char *xtables_ip6addr_to_anyname(const struct in6_addr *addr) { const char *name; if ((name = ip6addr_to_host(addr)) != NULL) return name; return xtables_ip6addr_to_numeric(addr); } static int ip6addr_prefix_length(const struct in6_addr *k) { unsigned int bits = 0; uint32_t a, b, c, d; a = ntohl(k->s6_addr32[0]); b = ntohl(k->s6_addr32[1]); c = ntohl(k->s6_addr32[2]); d = ntohl(k->s6_addr32[3]); while (a & 0x80000000U) { ++bits; a <<= 1; a |= (b >> 31) & 1; b <<= 1; b |= (c >> 31) & 1; c <<= 1; c |= (d >> 31) & 1; d <<= 1; } if (a != 0 || b != 0 || c != 0 || d != 0) return -1; return bits; } const char *xtables_ip6mask_to_numeric(const struct in6_addr *addrp) { static char buf[50+2]; int l = ip6addr_prefix_length(addrp); if (l == -1) { strcpy(buf, "/"); strcat(buf, xtables_ip6addr_to_numeric(addrp)); return buf; } sprintf(buf, "/%d", l); return buf; } struct in6_addr *xtables_numeric_to_ip6addr(const char *num) { static struct in6_addr ap; int err; if ((err = inet_pton(AF_INET6, num, &ap)) == 1) return ≈ #ifdef DEBUG fprintf(stderr, "\nnumeric2addr: %d\n", err); #endif return NULL; } static struct in6_addr * host_to_ip6addr(const char *name, unsigned int *naddr) { static struct in6_addr *addr; struct addrinfo hints; struct addrinfo *res; int err; memset(&hints, 0, sizeof(hints)); hints.ai_flags = AI_CANONNAME; hints.ai_family = AF_INET6; hints.ai_socktype = SOCK_RAW; hints.ai_protocol = IPPROTO_IPV6; hints.ai_next = NULL; *naddr = 0; if ((err = getaddrinfo(name, NULL, &hints, &res)) != 0) { #ifdef DEBUG fprintf(stderr,"Name2IP: %s\n",gai_strerror(err)); #endif return NULL; } else { if (res->ai_family != AF_INET6 || res->ai_addrlen != sizeof(struct sockaddr_in6)) return NULL; #ifdef DEBUG fprintf(stderr, "resolved: len=%d %s ", res->ai_addrlen, ip6addr_to_numeric(&((struct sockaddr_in6 *)res->ai_addr)->sin6_addr)); #endif /* Get the first element of the address-chain */ addr = xtables_malloc(sizeof(struct in6_addr)); memcpy(addr, &((const struct sockaddr_in6 *)res->ai_addr)->sin6_addr, sizeof(struct in6_addr)); freeaddrinfo(res); *naddr = 1; return addr; } return NULL; } static struct in6_addr *network_to_ip6addr(const char *name) { /* abort();*/ /* TODO: not implemented yet, but the exception breaks the * name resolvation */ return NULL; } static struct in6_addr * ip6parse_hostnetwork(const char *name, unsigned int *naddrs) { struct in6_addr *addrp, *addrptmp; if ((addrptmp = xtables_numeric_to_ip6addr(name)) != NULL || (addrptmp = network_to_ip6addr(name)) != NULL) { addrp = xtables_malloc(sizeof(struct in6_addr)); memcpy(addrp, addrptmp, sizeof(*addrp)); *naddrs = 1; return addrp; } if ((addrp = host_to_ip6addr(name, naddrs)) != NULL) return addrp; xt_params->exit_err(PARAMETER_PROBLEM, "host/network `%s' not found", name); } static struct in6_addr *parse_ip6mask(char *mask) { static struct in6_addr maskaddr; struct in6_addr *addrp; unsigned int bits; if (mask == NULL) { /* no mask at all defaults to 128 bits */ memset(&maskaddr, 0xff, sizeof maskaddr); return &maskaddr; } if ((addrp = xtables_numeric_to_ip6addr(mask)) != NULL) return addrp; if (!xtables_strtoui(mask, NULL, &bits, 0, 128)) xt_params->exit_err(PARAMETER_PROBLEM, "invalid mask `%s' specified", mask); if (bits != 0) { char *p = (void *)&maskaddr; memset(p, 0xff, bits / 8); memset(p + (bits / 8) + 1, 0, (128 - bits) / 8); p[bits/8] = 0xff << (8 - (bits & 7)); return &maskaddr; } memset(&maskaddr, 0, sizeof(maskaddr)); return &maskaddr; } void xtables_ip6parse_multiple(const char *name, struct in6_addr **addrpp, struct in6_addr **maskpp, unsigned int *naddrs) { static const struct in6_addr zero_addr; struct in6_addr *addrp; char buf[256], *p; unsigned int len, i, j, n, count = 1; const char *loop = name; while ((loop = strchr(loop, ',')) != NULL) { ++count; ++loop; /* skip ',' */ } *addrpp = xtables_malloc(sizeof(struct in6_addr) * count); *maskpp = xtables_malloc(sizeof(struct in6_addr) * count); loop = name; for (i = 0; i < count /*NB: count can grow*/; ++i) { if (loop == NULL) break; if (*loop == ',') ++loop; if (*loop == '\0') break; p = strchr(loop, ','); if (p != NULL) len = p - loop; else len = strlen(loop); if (len == 0 || sizeof(buf) - 1 < len) break; strncpy(buf, loop, len); buf[len] = '\0'; loop += len; if ((p = strrchr(buf, '/')) != NULL) { *p = '\0'; addrp = parse_ip6mask(p + 1); } else { addrp = parse_ip6mask(NULL); } memcpy(*maskpp + i, addrp, sizeof(*addrp)); /* if a null mask is given, the name is ignored, like in "any/0" */ if (memcmp(*maskpp + i, &zero_addr, sizeof(zero_addr)) == 0) strcpy(buf, "::"); addrp = ip6parse_hostnetwork(buf, &n); /* ip6parse_hostnetwork only ever returns one IP address (it exits if the resolution fails). Therefore, n will always be 1 here. Leaving the code below in anyway in case ip6parse_hostnetwork is improved some day to behave like ipparse_hostnetwork: */ if (n > 1) { count += n - 1; *addrpp = xtables_realloc(*addrpp, sizeof(struct in6_addr) * count); *maskpp = xtables_realloc(*maskpp, sizeof(struct in6_addr) * count); for (j = 0; j < n; ++j) /* for each new addr */ memcpy(*addrpp + i + j, addrp + j, sizeof(*addrp)); for (j = 1; j < n; ++j) /* for each new mask */ memcpy(*maskpp + i + j, *maskpp + i, sizeof(*addrp)); i += n - 1; } else { memcpy(*addrpp + i, addrp, sizeof(*addrp)); } /* free what ip6parse_hostnetwork had allocated: */ free(addrp); } *naddrs = count; for (i = 0; i < n; ++i) for (j = 0; j < 4; ++j) (*addrpp+i)->s6_addr32[j] &= (*maskpp+i)->s6_addr32[j]; } void xtables_ip6parse_any(const char *name, struct in6_addr **addrpp, struct in6_addr *maskp, unsigned int *naddrs) { static const struct in6_addr zero_addr; struct in6_addr *addrp; unsigned int i, j, k, n; char buf[256], *p; strncpy(buf, name, sizeof(buf) - 1); buf[sizeof(buf)-1] = '\0'; if ((p = strrchr(buf, '/')) != NULL) { *p = '\0'; addrp = parse_ip6mask(p + 1); } else { addrp = parse_ip6mask(NULL); } memcpy(maskp, addrp, sizeof(*maskp)); /* if a null mask is given, the name is ignored, like in "any/0" */ if (memcmp(maskp, &zero_addr, sizeof(zero_addr)) == 0) strcpy(buf, "::"); addrp = *addrpp = ip6parse_hostnetwork(buf, naddrs); n = *naddrs; for (i = 0, j = 0; i < n; ++i) { for (k = 0; k < 4; ++k) addrp[j].s6_addr32[k] &= maskp->s6_addr32[k]; ++j; for (k = 0; k < j - 1; ++k) if (IN6_ARE_ADDR_EQUAL(&addrp[k], &addrp[j - 1])) { --*naddrs; --j; break; } } } void xtables_save_string(const char *value) { static const char no_quote_chars[] = "_-0123456789" "abcdefghijklmnopqrstuvwxyz" "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; static const char escape_chars[] = "\"\\'"; size_t length; const char *p; length = strcspn(value, no_quote_chars); if (length > 0 && value[length] == 0) { /* no quoting required */ fputs(value, stdout); putchar(' '); } else { /* there is at least one dangerous character in the value, which we have to quote. Write double quotes around the value and escape special characters with a backslash */ putchar('"'); for (p = strpbrk(value, escape_chars); p != NULL; p = strpbrk(value, escape_chars)) { if (p > value) fwrite(value, 1, p - value, stdout); putchar('\\'); putchar(*p); value = p + 1; } /* print the rest and finish the double quoted string */ fputs(value, stdout); printf("\" "); } } /** * Check for option-intrapositional negation. * Do not use in new code. */ int xtables_check_inverse(const char option[], int *invert, int *my_optind, int argc, char **argv) { if (option == NULL || strcmp(option, "!") != 0) return false; fprintf(stderr, "Using intrapositioned negation " "(`--option ! this`) is deprecated in favor of " "extrapositioned (`! --option this`).\n"); if (*invert) xt_params->exit_err(PARAMETER_PROBLEM, "Multiple `!' flags not allowed"); *invert = true; if (my_optind != NULL) { optarg = argv[*my_optind]; ++*my_optind; if (argc && *my_optind > argc) xt_params->exit_err(PARAMETER_PROBLEM, "no argument following `!'"); } return true; } const struct xtables_pprot xtables_chain_protos[] = { {"tcp", IPPROTO_TCP}, {"sctp", IPPROTO_SCTP}, {"udp", IPPROTO_UDP}, {"udplite", IPPROTO_UDPLITE}, {"icmp", IPPROTO_ICMP}, {"icmpv6", IPPROTO_ICMPV6}, {"ipv6-icmp", IPPROTO_ICMPV6}, {"esp", IPPROTO_ESP}, {"ah", IPPROTO_AH}, {"ipv6-mh", IPPROTO_MH}, {"mh", IPPROTO_MH}, {"all", 0}, {NULL}, }; u_int16_t xtables_parse_protocol(const char *s) { unsigned int proto; if (!xtables_strtoui(s, NULL, &proto, 0, UINT8_MAX)) { struct protoent *pent; /* first deal with the special case of 'all' to prevent * people from being able to redefine 'all' in nsswitch * and/or provoke expensive [not working] ldap/nis/... * lookups */ if (!strcmp(s, "all")) return 0; if ((pent = getprotobyname(s))) proto = pent->p_proto; else { unsigned int i; for (i = 0; i < ARRAY_SIZE(xtables_chain_protos); ++i) { if (xtables_chain_protos[i].name == NULL) continue; if (strcmp(s, xtables_chain_protos[i].name) == 0) { proto = xtables_chain_protos[i].num; break; } } if (i == ARRAY_SIZE(xtables_chain_protos)) xt_params->exit_err(PARAMETER_PROBLEM, "unknown protocol `%s' specified", s); } } return proto; }