release/src/router/busybox/libbb/inet_common.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * stolen from net-tools-1.59 and stripped down for busybox by
   4  *                      Erik Andersen <andersen@codepoet.org>
   5  *
   6  * Heavily modified by Manuel Novoa III       Mar 12, 2001
   7  *
   8  * Licensed under GPLv2, see file LICENSE in this source tree.
   9  */
  10
  11 #include "libbb.h"
  12 #include "inet_common.h"
  13
  14 int FAST_FUNC INET_resolve(const char *name, struct sockaddr_in *s_in, int hostfirst)
  15 {
  16         struct hostent *hp;
  17 #if ENABLE_FEATURE_ETC_NETWORKS
  18         struct netent *np;
  19 #endif
  20
  21         /* Grmpf. -FvK */
  22         s_in->sin_family = AF_INET;
  23         s_in->sin_port = 0;
  24
  25         /* Default is special, meaning 0.0.0.0. */
  26         if (strcmp(name, "default") == 0) {
  27                 s_in->sin_addr.s_addr = INADDR_ANY;
  28                 return 1;
  29         }
  30         /* Look to see if it's a dotted quad. */
  31         if (inet_aton(name, &s_in->sin_addr)) {
  32                 return 0;
  33         }
  34         /* If we expect this to be a hostname, try hostname database first */
  35 #ifdef DEBUG
  36         if (hostfirst) {
  37                 bb_error_msg("gethostbyname(%s)", name);
  38         }
  39 #endif
  40         if (hostfirst) {
  41                 hp = gethostbyname(name);
  42                 if (hp != NULL) {
  43                         memcpy(&s_in->sin_addr, hp->h_addr_list[0],
  44                                 sizeof(struct in_addr));
  45                         return 0;
  46                 }
  47         }
  48 #if ENABLE_FEATURE_ETC_NETWORKS
  49         /* Try the NETWORKS database to see if this is a known network. */
  50 #ifdef DEBUG
  51         bb_error_msg("getnetbyname(%s)", name);
  52 #endif
  53         np = getnetbyname(name);
  54         if (np != NULL) {
  55                 s_in->sin_addr.s_addr = htonl(np->n_net);
  56                 return 1;
  57         }
  58 #endif
  59         if (hostfirst) {
  60                 /* Don't try again */
  61                 return -1;
  62         }
  63 #ifdef DEBUG
  64         res_init();
  65         _res.options |= RES_DEBUG;
  66         bb_error_msg("gethostbyname(%s)", name);
  67 #endif
  68         hp = gethostbyname(name);
  69         if (hp == NULL) {
  70                 return -1;
  71         }
  72         memcpy(&s_in->sin_addr, hp->h_addr_list[0], sizeof(struct in_addr));
  73         return 0;
  74 }
  75
  76
  77 /* numeric: & 0x8000: default instead of *,
  78  *          & 0x4000: host instead of net,
  79  *          & 0x0fff: don't resolve
  80  */
  81 char* FAST_FUNC INET_rresolve(struct sockaddr_in *s_in, int numeric, uint32_t netmask)
  82 {
  83         /* addr-to-name cache */
  84         struct addr {
  85                 struct addr *next;
  86                 struct sockaddr_in addr;
  87                 int host;
  88                 char name[1];
  89         };
  90         static struct addr *cache = NULL;
  91
  92         struct addr *pn;
  93         char *name;
  94         uint32_t ad, host_ad;
  95         int host = 0;
  96
  97         if (s_in->sin_family != AF_INET) {
  98 #ifdef DEBUG
  99                 bb_error_msg("rresolve: unsupported address family %d!",
 100                                   s_in->sin_family);
 101 #endif
 102                 errno = EAFNOSUPPORT;
 103                 return NULL;
 104         }
 105         ad = s_in->sin_addr.s_addr;
 106 #ifdef DEBUG
 107         bb_error_msg("rresolve: %08x, mask %08x, num %08x", (unsigned)ad, netmask, numeric);
 108 #endif
 109         if (ad == INADDR_ANY) {
 110                 if ((numeric & 0x0FFF) == 0) {
 111                         if (numeric & 0x8000)
 112                                 return xstrdup("default");
 113                         return xstrdup("*");
 114                 }
 115         }
 116         if (numeric & 0x0FFF)
 117                 return xstrdup(inet_ntoa(s_in->sin_addr));
 118
 119         if ((ad & (~netmask)) != 0 || (numeric & 0x4000))
 120                 host = 1;
 121         pn = cache;
 122         while (pn) {
 123                 if (pn->addr.sin_addr.s_addr == ad && pn->host == host) {
 124 #ifdef DEBUG
 125                         bb_error_msg("rresolve: found %s %08x in cache",
 126                                           (host ? "host" : "net"), (unsigned)ad);
 127 #endif
 128                         return xstrdup(pn->name);
 129                 }
 130                 pn = pn->next;
 131         }
 132
 133         host_ad = ntohl(ad);
 134         name = NULL;
 135         if (host) {
 136                 struct hostent *ent;
 137 #ifdef DEBUG
 138                 bb_error_msg("gethostbyaddr (%08x)", (unsigned)ad);
 139 #endif
 140                 ent = gethostbyaddr((char *) &ad, 4, AF_INET);
 141                 if (ent)
 142                         name = xstrdup(ent->h_name);
 143         } else if (ENABLE_FEATURE_ETC_NETWORKS) {
 144                 struct netent *np;
 145 #ifdef DEBUG
 146                 bb_error_msg("getnetbyaddr (%08x)", (unsigned)host_ad);
 147 #endif
 148                 np = getnetbyaddr(host_ad, AF_INET);
 149                 if (np)
 150                         name = xstrdup(np->n_name);
 151         }
 152         if (!name)
 153                 name = xstrdup(inet_ntoa(s_in->sin_addr));
 154         pn = xmalloc(sizeof(*pn) + strlen(name)); /* no '+ 1', it's already accounted for */
 155         pn->next = cache;
 156         pn->addr = *s_in;
 157         pn->host = host;
 158         strcpy(pn->name, name);
 159         cache = pn;
 160         return name;
 161 }
 162
 163 #if ENABLE_FEATURE_IPV6
 164
 165 int FAST_FUNC INET6_resolve(const char *name, struct sockaddr_in6 *sin6)
 166 {
 167         struct addrinfo req, *ai = NULL;
 168         int s;
 169
 170         memset(&req, 0, sizeof(req));
 171         req.ai_family = AF_INET6;
 172         s = getaddrinfo(name, NULL, &req, &ai);
 173         if (s != 0) {
 174                 bb_error_msg("getaddrinfo: %s: %d", name, s);
 175                 return -1;
 176         }
 177         memcpy(sin6, ai->ai_addr, sizeof(*sin6));
 178         if (ai)
 179                 freeaddrinfo(ai);
 180         return 0;
 181 }
 182
 183 #ifndef IN6_IS_ADDR_UNSPECIFIED
 184 # define IN6_IS_ADDR_UNSPECIFIED(a) \
 185         (((uint32_t *) (a))[0] == 0 && ((uint32_t *) (a))[1] == 0 && \
 186          ((uint32_t *) (a))[2] == 0 && ((uint32_t *) (a))[3] == 0)
 187 #endif
 188
 189
 190 char* FAST_FUNC INET6_rresolve(struct sockaddr_in6 *sin6, int numeric)
 191 {
 192         char name[128];
 193         int s;
 194
 195         if (sin6->sin6_family != AF_INET6) {
 196 #ifdef DEBUG
 197                 bb_error_msg("rresolve: unsupported address family %d!",
 198                                   sin6->sin6_family);
 199 #endif
 200                 errno = EAFNOSUPPORT;
 201                 return NULL;
 202         }
 203         if (numeric & 0x7FFF) {
 204                 inet_ntop(AF_INET6, &sin6->sin6_addr, name, sizeof(name));
 205                 return xstrdup(name);
 206         }
 207         if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
 208                 if (numeric & 0x8000)
 209                         return xstrdup("default");
 210                 return xstrdup("*");
 211         }
 212
 213         s = getnameinfo((struct sockaddr *) sin6, sizeof(*sin6),
 214                                 name, sizeof(name),
 215                                 /*serv,servlen:*/ NULL, 0,
 216                                 0);
 217         if (s != 0) {
 218                 bb_error_msg("getnameinfo failed");
 219                 return NULL;
 220         }
 221         return xstrdup(name);
 222 }
 223
 224 #endif  /* CONFIG_FEATURE_IPV6 */