release/src/router/dnsmasq/src/domain.c

   1 /* dnsmasq is Copyright (c) 2000-2013 Simon Kelley
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; version 2 dated June, 1991, or
   6    (at your option) version 3 dated 29 June, 2007.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12
  13    You should have received a copy of the GNU General Public License
  14    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15 */
  16
  17 #include "dnsmasq.h"
  18
  19
  20 static struct cond_domain *search_domain(struct in_addr addr, struct cond_domain *c);
  21 #ifdef HAVE_IPV6
  22 static struct cond_domain *search_domain6(struct in6_addr *addr, struct cond_domain *c);
  23 #endif
  24
  25
  26 int is_name_synthetic(int flags, char *name, struct all_addr *addr)
  27 {
  28   char *p;
  29   struct cond_domain *c = NULL;
  30   int prot = AF_INET;
  31
  32 #ifdef HAVE_IPV6
  33   if (flags & F_IPV6)
  34     prot = AF_INET6;
  35 #endif
  36
  37   for (c = daemon->synth_domains; c; c = c->next)
  38     {
  39       int found = 0;
  40       char *tail, *pref;
  41
  42       for (tail = name, pref = c->prefix; *tail != 0 && pref && *pref != 0; tail++, pref++)
  43         {
  44           unsigned int c1 = (unsigned char) *pref;
  45           unsigned int c2 = (unsigned char) *tail;
  46
  47           if (c1 >= 'A' && c1 <= 'Z')
  48             c1 += 'a' - 'A';
  49           if (c2 >= 'A' && c2 <= 'Z')
  50             c2 += 'a' - 'A';
  51
  52           if (c1 != c2)
  53             break;
  54         }
  55
  56       if (pref && *pref != 0)
  57         continue; /* prefix match fail */
  58
  59       /* NB, must not alter name if we return zero */
  60       for (p = tail; *p; p++)
  61         {
  62           char c = *p;
  63
  64           if ((c >='0' && c <= '9') || c == '-')
  65             continue;
  66
  67 #ifdef HAVE_IPV6
  68           if (prot == AF_INET6 && ((c >='A' && c <= 'F') || (c >='a' && c <= 'f')))
  69             continue;
  70 #endif
  71
  72           break;
  73         }
  74
  75       if (*p != '.')
  76         continue;
  77
  78       *p = 0;
  79
  80       /* swap . or : for - */
  81       for (p = tail; *p; p++)
  82         if (*p == '-')
  83           {
  84             if (prot == AF_INET)
  85               *p = '.';
  86 #ifdef HAVE_IPV6
  87             else
  88               *p = ':';
  89 #endif
  90           }
  91
  92       if (hostname_isequal(c->domain, p+1) && inet_pton(prot, tail, addr))
  93         {
  94           if (prot == AF_INET)
  95             {
  96               if (!c->is6 &&
  97                   ntohl(addr->addr.addr4.s_addr) >= ntohl(c->start.s_addr) &&
  98                   ntohl(addr->addr.addr4.s_addr) <= ntohl(c->end.s_addr))
  99                 found = 1;
 100             }
 101 #ifdef HAVE_IPV6
 102           else
 103             {
 104               u64 addrpart = addr6part(&addr->addr.addr6);
 105
 106               if (c->is6 &&
 107                   is_same_net6(&addr->addr.addr6, &c->start6, 64) &&
 108                   addrpart >= addr6part(&c->start6) &&
 109                   addrpart <= addr6part(&c->end6))
 110                 found = 1;
 111             }
 112 #endif
 113         }
 114
 115       /* restore name */
 116       for (p = tail; *p; p++)
 117         if (*p == '.' || *p == ':')
 118           *p = '-';
 119
 120       *p = '.';
 121
 122       if (found)
 123         return 1;
 124     }
 125
 126   return 0;
 127 }
 128
 129
 130 int is_rev_synth(int flag, struct all_addr *addr, char *name)
 131 {
 132    struct cond_domain *c;
 133
 134    if (flag & F_IPV4 && (c = search_domain(addr->addr.addr4, daemon->synth_domains)))
 135      {
 136        char *p;
 137
 138        *name = 0;
 139        if (c->prefix)
 140          strncpy(name, c->prefix, MAXDNAME - ADDRSTRLEN);
 141
 142        inet_ntop(AF_INET, &addr->addr.addr4, name + strlen(name), ADDRSTRLEN);
 143        for (p = name; *p; p++)
 144          if (*p == '.')
 145            *p = '-';
 146
 147        strncat(name, ".", MAXDNAME);
 148        strncat(name, c->domain, MAXDNAME);
 149
 150        return 1;
 151      }
 152
 153 #ifdef HAVE_IPV6
 154    if (flag & F_IPV6 && (c = search_domain6(&addr->addr.addr6, daemon->synth_domains)))
 155      {
 156        char *p;
 157
 158        *name = 0;
 159        if (c->prefix)
 160          strncpy(name, c->prefix, MAXDNAME - ADDRSTRLEN);
 161
 162        inet_ntop(AF_INET6, &addr->addr.addr6, name + strlen(name), ADDRSTRLEN);
 163
 164        /* IPv6 presentation address can start with ":", but valid domain names
 165           cannot start with "-" so prepend a zero in that case. */
 166        if (!c->prefix && *name == ':')
 167          {
 168            *name = '0';
 169            inet_ntop(AF_INET6, &addr->addr.addr6, name+1, ADDRSTRLEN);
 170          }
 171
 172        for (p = name; *p; p++)
 173          if (*p == ':')
 174            *p = '-';
 175
 176        strncat(name, ".", MAXDNAME);
 177        strncat(name, c->domain, MAXDNAME);
 178
 179        return 1;
 180      }
 181 #endif
 182
 183    return 0;
 184 }
 185
 186
 187 static struct cond_domain *search_domain(struct in_addr addr, struct cond_domain *c)
 188 {
 189   for (; c; c = c->next)
 190     if (!c->is6 &&
 191         ntohl(addr.s_addr) >= ntohl(c->start.s_addr) &&
 192         ntohl(addr.s_addr) <= ntohl(c->end.s_addr))
 193       return c;
 194
 195   return NULL;
 196 }
 197
 198 char *get_domain(struct in_addr addr)
 199 {
 200   struct cond_domain *c;
 201
 202   if ((c = search_domain(addr, daemon->cond_domain)))
 203     return c->domain;
 204
 205   return daemon->domain_suffix;
 206 }
 207
 208 #ifdef HAVE_IPV6
 209 static struct cond_domain *search_domain6(struct in6_addr *addr, struct cond_domain *c)
 210 {
 211   u64 addrpart = addr6part(addr);
 212
 213   for (; c; c = c->next)
 214     if (c->is6 &&
 215         is_same_net6(addr, &c->start6, 64) &&
 216         addrpart >= addr6part(&c->start6) &&
 217         addrpart <= addr6part(&c->end6))
 218       return c;
 219
 220   return NULL;
 221 }
 222
 223 char *get_domain6(struct in6_addr *addr)
 224 {
 225   struct cond_domain *c;
 226
 227   if ((c = search_domain6(addr, daemon->cond_domain)))
 228     return c->domain;
 229
 230   return daemon->domain_suffix;
 231 }
 232 #endif