Merge commit 'origin/trunk@12184' into fedora
[iptables.git] / trunk / xtables.c
diff --git a/trunk/xtables.c b/trunk/xtables.c
new file mode 100644 (file)
index 0000000..a97bdaa
--- /dev/null
@@ -0,0 +1,1227 @@
+/*
+ * (C) 2000-2006 by the netfilter coreteam <coreteam@netfilter.org>:
+ *
+ *     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 <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <arpa/inet.h>
+
+#include <xtables.h>
+
+#ifndef NO_SHARED_LIBS
+#include <dlfcn.h>
+#endif
+
+#define NPROTO 255
+
+#ifndef PROC_SYS_MODPROBE
+#define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe"
+#endif
+
+char *lib_dir;
+
+/* the path to command to load kernel module */
+const char *modprobe_program = NULL;
+
+/* Keeping track of external matches and targets: linked lists.  */
+struct xtables_match *xtables_matches;
+struct xtables_target *xtables_targets;
+
+void *fw_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 *fw_malloc(size_t size)
+{
+       void *p;
+
+       if ((p = malloc(size)) == NULL) {
+               perror("ip[6]tables: malloc 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, int 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;
+       }
+
+       switch (fork()) {
+       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 load_xtables_ko(const char *modprobe, int quiet)
+{
+       static int loaded = 0;
+       static int ret = -1;
+
+       if (!loaded) {
+               ret = xtables_insmod(afinfo.kmod, modprobe, quiet);
+               loaded = (ret == 0);
+       }
+
+       return ret;
+}
+
+int string_to_number_ll(const char *s, unsigned long long min,
+                       unsigned long long max, unsigned long long *ret)
+{
+       unsigned long long number;
+       char *end;
+
+       /* Handle hex, octal, etc. */
+       errno = 0;
+       number = strtoull(s, &end, 0);
+       if (*end == '\0' && end != s) {
+               /* we parsed a number, let's see if we want this */
+               if (errno != ERANGE && min <= number && (!max || number <= max)) {
+                       *ret = number;
+                       return 0;
+               }
+       }
+       return -1;
+}
+
+int string_to_number_l(const char *s, unsigned long min, unsigned long max,
+                      unsigned long *ret)
+{
+       int result;
+       unsigned long long number;
+
+       result = string_to_number_ll(s, min, max, &number);
+       *ret = (unsigned long)number;
+
+       return result;
+}
+
+int string_to_number(const char *s, unsigned int min, unsigned int max,
+               unsigned int *ret)
+{
+       int result;
+       unsigned long number;
+
+       result = string_to_number_l(s, min, max, &number);
+       *ret = (unsigned int)number;
+
+       return result;
+}
+
+/*
+ * strtonum{,l} - string to number conversion
+ *
+ * If @end is NULL, we assume the caller does not want
+ * a case like "15a", so reject it.
+ */
+bool strtonuml(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 strtonum(const char *s, char **end, unsigned int *value,
+                  unsigned int min, unsigned int max)
+{
+       unsigned long v;
+       bool ret;
+
+       ret = strtonuml(s, end, &v, min, max);
+       if (value != NULL)
+               *value = v;
+       return ret;
+}
+
+int 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 parse_port(const char *port, const char *proto)
+{
+       unsigned int portnum;
+
+       if ((string_to_number(port, 0, 65535, &portnum)) != -1 ||
+           (portnum = service_to_port(port, proto)) != (unsigned)-1)
+               return (u_int16_t)portnum;
+
+       exit_error(PARAMETER_PROBLEM,
+                  "invalid port/service `%s' specified", port);
+}
+
+void parse_interface(const char *arg, char *vianame, unsigned char *mask)
+{
+       int vialen = strlen(arg);
+       unsigned int i;
+
+       memset(mask, 0, IFNAMSIZ);
+       memset(vianame, 0, IFNAMSIZ);
+
+       if (vialen + 1 > IFNAMSIZ)
+               exit_error(PARAMETER_PROBLEM,
+                          "interface name `%s' must be shorter than IFNAMSIZ"
+                          " (%i)", arg, IFNAMSIZ-1);
+
+       strcpy(vianame, arg);
+       if ((vialen == 0) || (vialen == 1 && vianame[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] == '!' ||
+                           vianame[i] == '*') {
+                               fprintf(stderr,
+                                       "Warning: weird character in interface"
+                                       " `%s' (No aliases, :, ! or *).\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 = find_target(name, DONT_LOAD);
+                       else
+                               ptr = find_match(name, 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 = find_target(name, DONT_LOAD);
+                       else
+                               ptr = find_match(name, 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 *find_match(const char *name, enum xt_tryload tryload,
+                                struct xtables_rule_match **matches)
+{
+       struct xtables_match *ptr;
+       const char *icmp6 = "icmp6";
+
+       /* 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 = fw_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 != DONT_LOAD && tryload != DURING_LOAD) {
+               ptr = load_extension(lib_dir, afinfo.libprefix, name, false);
+
+               if (ptr == NULL && tryload == LOAD_MUST_SUCCEED)
+                       exit_error(PARAMETER_PROBLEM,
+                                  "Couldn't load match `%s':%s\n",
+                                  name, dlerror());
+       }
+#else
+       if (ptr && !ptr->loaded) {
+               if (tryload != DONT_LOAD)
+                       ptr->loaded = 1;
+               else
+                       ptr = NULL;
+       }
+       if(!ptr && (tryload == LOAD_MUST_SUCCEED)) {
+               exit_error(PARAMETER_PROBLEM,
+                          "Couldn't find match `%s'\n", name);
+       }
+#endif
+
+       if (ptr && matches) {
+               struct xtables_rule_match **i;
+               struct xtables_rule_match *newentry;
+
+               newentry = fw_malloc(sizeof(struct xtables_rule_match));
+
+               for (i = matches; *i; i = &(*i)->next) {
+                       if (strcmp(name, (*i)->match->name) == 0)
+                               (*i)->completed = 1;
+               }
+               newentry->match = ptr;
+               newentry->completed = 0;
+               newentry->next = NULL;
+               *i = newentry;
+       }
+
+       return ptr;
+}
+
+
+struct xtables_target *find_target(const char *name, enum xt_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 != DONT_LOAD && tryload != DURING_LOAD) {
+               ptr = load_extension(lib_dir, afinfo.libprefix, name, true);
+
+               if (ptr == NULL && tryload == LOAD_MUST_SUCCEED)
+                       exit_error(PARAMETER_PROBLEM,
+                                  "Couldn't load target `%s':%s\n",
+                                  name, dlerror());
+       }
+#else
+       if (ptr && !ptr->loaded) {
+               if (tryload != DONT_LOAD)
+                       ptr->loaded = 1;
+               else
+                       ptr = NULL;
+       }
+       if(!ptr && (tryload == LOAD_MUST_SUCCEED)) {
+               exit_error(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);
+       }
+
+       load_xtables_ko(modprobe_program, 1);
+
+       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 (strcmp(me->version, program_version) != 0) {
+               fprintf(stderr, "%s: match `%s' v%s (I'm v%s).\n",
+                       program_name, me->name, me->version, program_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",
+                       program_name, me->name);
+               exit(1);
+       }
+
+       if (me->family >= NPROTO) {
+               fprintf(stderr,
+                       "%s: BUG: match %s has invalid protocol family\n",
+                       program_name, me->name);
+               exit(1);
+       }
+
+       /* ignore not interested match */
+       if (me->family != afinfo.family && me->family != AF_UNSPEC)
+               return;
+
+       old = find_match(me->name, DURING_LOAD, NULL);
+       if (old) {
+               if (old->revision == me->revision &&
+                   old->family == me->family) {
+                       fprintf(stderr,
+                               "%s: match `%s' already registered.\n",
+                               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",
+                       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_target(struct xtables_target *me)
+{
+       struct xtables_target *old;
+
+       if (strcmp(me->version, program_version) != 0) {
+               fprintf(stderr, "%s: target `%s' v%s (I'm v%s).\n",
+                       program_name, me->name, me->version, program_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",
+                       program_name, me->name);
+               exit(1);
+       }
+
+       if (me->family >= NPROTO) {
+               fprintf(stderr,
+                       "%s: BUG: target %s has invalid protocol family\n",
+                       program_name, me->name);
+               exit(1);
+       }
+
+       /* ignore not interested target */
+       if (me->family != afinfo.family && me->family != AF_UNSPEC)
+               return;
+
+       old = find_target(me->name, 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",
+                               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",
+                       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 param_act(unsigned int status, const char *p1, ...)
+{
+       const char *p2, *p3;
+       va_list args;
+       bool b;
+
+       va_start(args, p1);
+
+       switch (status) {
+       case P_ONLY_ONCE:
+               p2 = va_arg(args, const char *);
+               b  = va_arg(args, unsigned int);
+               if (!b)
+                       return;
+               exit_error(PARAMETER_PROBLEM,
+                          "%s: \"%s\" option may only be specified once",
+                          p1, p2);
+               break;
+       case P_NO_INVERT:
+               p2 = va_arg(args, const char *);
+               b  = va_arg(args, unsigned int);
+               if (!b)
+                       return;
+               exit_error(PARAMETER_PROBLEM,
+                          "%s: \"%s\" option cannot be inverted", p1, p2);
+               break;
+       case P_BAD_VALUE:
+               p2 = va_arg(args, const char *);
+               p3 = va_arg(args, const char *);
+               exit_error(PARAMETER_PROBLEM,
+                          "%s: Bad value for \"%s\" option: \"%s\"",
+                          p1, p2, p3);
+               break;
+       case P_ONE_ACTION:
+               b = va_arg(args, unsigned int);
+               if (!b)
+                       return;
+               exit_error(PARAMETER_PROBLEM,
+                          "%s: At most one action is possible", p1);
+               break;
+       default:
+               exit_error(status, p1, args);
+               break;
+       }
+
+       va_end(args);
+}
+
+const char *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 *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 ipaddr_to_numeric(addr);
+}
+
+const char *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", 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 (!strtonum(p, NULL, &onebyte, 0, 255))
+                               return NULL;
+
+                       addrp[i] = onebyte;
+                       while (i < 3)
+                               addrp[++i] = 0;
+
+                       return &addr;
+               }
+
+               *q = '\0';
+               if (!strtonum(p, NULL, &onebyte, 0, 255))
+                       return NULL;
+
+               addrp[i] = onebyte;
+               p = q + 1;
+       }
+
+       /* we have checked 3 bytes, now we check the last one */
+       if (!strtonum(p, NULL, &onebyte, 0, 255))
+               return NULL;
+
+       addrp[3] = onebyte;
+       return &addr;
+}
+
+struct in_addr *numeric_to_ipaddr(const char *dotted)
+{
+       return __numeric_to_ipaddr(dotted, false);
+}
+
+struct in_addr *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 = fw_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 = numeric_to_ipaddr(name)) != NULL ||
+           (addrptmp = network_to_ipaddr(name)) != NULL) {
+               addrp = fw_malloc(sizeof(struct in_addr));
+               memcpy(addrp, addrptmp, sizeof(*addrp));
+               *naddrs = 1;
+               return addrp;
+       }
+       if ((addrptmp = host_to_ipaddr(name, naddrs)) != NULL)
+               return addrptmp;
+
+       exit_error(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 = numeric_to_ipmask(mask)) != NULL)
+               /* dotted_to_addr already returns a network byte order addr */
+               return addrp;
+       if (string_to_number(mask, 0, 32, &bits) == -1)
+               exit_error(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 ipparse_hostnetworkmask(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 *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 *ip6addr_to_anyname(const struct in6_addr *addr)
+{
+       const char *name;
+
+       if ((name = ip6addr_to_host(addr)) != NULL)
+               return name;
+
+       return 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 *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, ip6addr_to_numeric(addrp));
+               return buf;
+       }
+       sprintf(buf, "/%d", l);
+       return buf;
+}
+
+struct in6_addr *numeric_to_ip6addr(const char *num)
+{
+       static struct in6_addr ap;
+       int err;
+
+       if ((err = inet_pton(AF_INET6, num, &ap)) == 1)
+               return &ap;
+#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 = fw_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 = numeric_to_ip6addr(name)) != NULL ||
+           (addrptmp = network_to_ip6addr(name)) != NULL) {
+               addrp = fw_malloc(sizeof(struct in6_addr));
+               memcpy(addrp, addrptmp, sizeof(*addrp));
+               *naddrs = 1;
+               return addrp;
+       }
+       if ((addrp = host_to_ip6addr(name, naddrs)) != NULL)
+               return addrp;
+
+       exit_error(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 = numeric_to_ip6addr(mask)) != NULL)
+               return addrp;
+       if (string_to_number(mask, 0, 128, &bits) == -1)
+               exit_error(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 ip6parse_hostnetworkmask(const char *name, struct in6_addr **addrpp,
+                              struct in6_addr *maskp, unsigned int *naddrs)
+{
+       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, &in6addr_any, sizeof(in6addr_any)) == 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 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("\" ");
+       }
+}