contrib/bind-9.3/lib/bind/irs/getnameinfo.c

   1 /*
   2  * Issues to be discussed:
   3  * - Thread safe-ness must be checked
   4  */
   5
   6 #if ( defined(__linux__) || defined(__linux) || defined(LINUX) )
   7 #ifndef IF_NAMESIZE
   8 # ifdef IFNAMSIZ
   9 #  define IF_NAMESIZE  IFNAMSIZ
  10 # else
  11 #  define IF_NAMESIZE 16
  12 # endif
  13 #endif
  14 #endif
  15
  16 /*
  17  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  18  * All rights reserved.
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  * 1. Redistributions of source code must retain the above copyright
  24  *    notice, this list of conditions and the following disclaimer.
  25  * 2. Redistributions in binary form must reproduce the above copyright
  26  *    notice, this list of conditions and the following disclaimer in the
  27  *    documentation and/or other materials provided with the distribution.
  28  * 3. All advertising materials mentioning features or use of this software
  29  *    must display the following acknowledgement:
  30  *    This product includes software developed by WIDE Project and
  31  *    its contributors.
  32  * 4. Neither the name of the project nor the names of its contributors
  33  *    may be used to endorse or promote products derived from this software
  34  *    without specific prior written permission.
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  37  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  39  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  40  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  42  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  46  * SUCH DAMAGE.
  47  */
  48
  49 #include <port_before.h>
  50
  51 #include <sys/types.h>
  52 #include <sys/socket.h>
  53
  54 #include <netinet/in.h>
  55 #include <arpa/nameser.h>
  56 #include <arpa/inet.h>
  57 #include <net/if.h>
  58
  59 #include <netdb.h>
  60 #include <resolv.h>
  61 #include <string.h>
  62 #include <stddef.h>
  63
  64 #include <port_after.h>
  65
  66 /*
  67  * Note that a_off will be dynamically adjusted so that to be consistent
  68  * with the definition of sockaddr_in{,6}.
  69  * The value presented below is just a guess.
  70  */
  71 static struct afd {
  72         int a_af;
  73         int a_addrlen;
  74         size_t a_socklen;
  75         int a_off;
  76 } afdl [] = {
  77         /* first entry is linked last... */
  78         {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
  79          offsetof(struct sockaddr_in, sin_addr)},
  80         {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
  81          offsetof(struct sockaddr_in6, sin6_addr)},
  82         {0, 0, 0, 0},
  83 };
  84
  85 struct sockinet {
  86 #ifdef HAVE_SA_LEN
  87         u_char  si_len;
  88 #endif
  89         u_char  si_family;
  90         u_short si_port;
  91 };
  92
  93 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
  94                                  size_t, int));
  95 #ifdef HAVE_SIN6_SCOPE_ID
  96 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int));
  97 #endif
  98
  99 int
 100 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
 101         const struct sockaddr *sa;
 102         size_t salen;
 103         char *host;
 104         size_t hostlen;
 105         char *serv;
 106         size_t servlen;
 107         int flags;
 108 {
 109         struct afd *afd;
 110         struct servent *sp;
 111         struct hostent *hp;
 112         u_short port;
 113 #ifdef HAVE_SA_LEN
 114         size_t len;
 115 #endif
 116         int family, i;
 117         const char *addr;
 118         char *p;
 119         char numserv[512];
 120         char numaddr[512];
 121         const struct sockaddr_in6 *sin6;
 122
 123         if (sa == NULL)
 124                 return EAI_FAIL;
 125
 126 #ifdef HAVE_SA_LEN
 127         len = sa->sa_len;
 128         if (len != salen) return EAI_FAIL;
 129 #endif
 130
 131         family = sa->sa_family;
 132         for (i = 0; afdl[i].a_af; i++)
 133                 if (afdl[i].a_af == family) {
 134                         afd = &afdl[i];
 135                         goto found;
 136                 }
 137         return EAI_FAMILY;
 138
 139  found:
 140         if (salen != afd->a_socklen) return EAI_FAIL;
 141
 142         port = ((const struct sockinet *)sa)->si_port; /* network byte order */
 143         addr = (const char *)sa + afd->a_off;
 144
 145         if (serv == NULL || servlen == 0U) {
 146                 /*
 147                  * rfc2553bis says that serv == NULL or servlen == 0 means that
 148                  * the caller does not want the result.
 149                  */
 150         } else if (flags & NI_NUMERICSERV) {
 151                 sprintf(numserv, "%d", ntohs(port));
 152                 if (strlen(numserv) > servlen)
 153                         return EAI_MEMORY;
 154                 strcpy(serv, numserv);
 155         } else {
 156                 sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp");
 157                 if (sp) {
 158                         if (strlen(sp->s_name) + 1 > servlen)
 159                                 return EAI_MEMORY;
 160                         strcpy(serv, sp->s_name);
 161                 } else
 162                         return EAI_NONAME;
 163         }
 164
 165         switch (sa->sa_family) {
 166         case AF_INET:
 167                 if (ntohl(*(const u_int32_t *)addr) >> IN_CLASSA_NSHIFT == 0)
 168                         flags |= NI_NUMERICHOST;
 169                 break;
 170         case AF_INET6:
 171                 sin6 = (const struct sockaddr_in6 *)sa;
 172                 switch (sin6->sin6_addr.s6_addr[0]) {
 173                 case 0x00:
 174                         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 175                                 ;
 176                         else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
 177                                 ;
 178                         else
 179                                 flags |= NI_NUMERICHOST;
 180                         break;
 181                 default:
 182                         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
 183                                 flags |= NI_NUMERICHOST;
 184                         else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 185                                 flags |= NI_NUMERICHOST;
 186                         break;
 187                 }
 188                 break;
 189         }
 190         if (host == NULL || hostlen == 0U) {
 191                 /*
 192                  * rfc2553bis says that host == NULL or hostlen == 0 means that
 193                  * the caller does not want the result.
 194                  */
 195         } else if (flags & NI_NUMERICHOST) {
 196                 goto numeric;
 197         } else {
 198                 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
 199
 200                 if (hp) {
 201                         if (flags & NI_NOFQDN) {
 202                                 p = strchr(hp->h_name, '.');
 203                                 if (p) *p = '\0';
 204                         }
 205                         if (strlen(hp->h_name) + 1 > hostlen)
 206                                 return EAI_MEMORY;
 207                         strcpy(host, hp->h_name);
 208                 } else {
 209                         if (flags & NI_NAMEREQD)
 210                                 return EAI_NONAME;
 211                   numeric:
 212                         switch(afd->a_af) {
 213                         case AF_INET6:
 214                         {
 215                                 int error;
 216
 217                                 if ((error = ip6_parsenumeric(sa, addr, host,
 218                                                               hostlen,
 219                                                               flags)) != 0)
 220                                         return(error);
 221                                 break;
 222                         }
 223
 224                         default:
 225                                 if (inet_ntop(afd->a_af, addr, numaddr,
 226                                               sizeof(numaddr)) == NULL)
 227                                         return EAI_NONAME;
 228                                 if (strlen(numaddr) + 1 > hostlen)
 229                                         return EAI_MEMORY;
 230                                 strcpy(host, numaddr);
 231                         }
 232                 }
 233         }
 234         return(0);
 235 }
 236
 237 static int
 238 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host,
 239                  size_t hostlen, int flags)
 240 {
 241         size_t numaddrlen;
 242         char numaddr[512];
 243
 244 #ifndef HAVE_SIN6_SCOPE_ID
 245         UNUSED(sa);
 246         UNUSED(flags);
 247 #endif
 248
 249         if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr))
 250             == NULL)
 251                 return EAI_SYSTEM;
 252
 253         numaddrlen = strlen(numaddr);
 254         if (numaddrlen + 1 > hostlen) /* don't forget terminator */
 255                 return EAI_MEMORY;
 256         strcpy(host, numaddr);
 257
 258 #ifdef HAVE_SIN6_SCOPE_ID
 259         if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) {
 260                 char scopebuf[MAXHOSTNAMELEN]; /* XXX */
 261                 int scopelen;
 262
 263                 /* ip6_sa2str never fails */
 264                 scopelen = ip6_sa2str((const struct sockaddr_in6 *)sa,
 265                                       scopebuf, sizeof(scopebuf), flags);
 266
 267                 if (scopelen + 1 + numaddrlen + 1 > hostlen)
 268                         return EAI_MEMORY;
 269
 270                 /* construct <numeric-addr><delim><scopeid> */
 271                 memcpy(host + numaddrlen + 1, scopebuf,
 272                        scopelen);
 273                 host[numaddrlen] = SCOPE_DELIMITER;
 274                 host[numaddrlen + 1 + scopelen] = '\0';
 275         }
 276 #endif
 277
 278         return 0;
 279 }
 280
 281 #ifdef HAVE_SIN6_SCOPE_ID
 282 /* ARGSUSED */
 283 static int
 284 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf,
 285            size_t bufsiz, int flags)
 286 {
 287 #ifdef USE_IFNAMELINKID
 288         unsigned int ifindex = (unsigned int)sa6->sin6_scope_id;
 289         const struct in6_addr *a6 = &sa6->sin6_addr;
 290 #endif
 291         char tmp[64];
 292
 293 #ifdef NI_NUMERICSCOPE
 294         if (flags & NI_NUMERICSCOPE) {
 295                 sprintf(tmp, "%u", sa6->sin6_scope_id);
 296                 if (bufsiz != 0U) {
 297                         strncpy(buf, tmp, bufsiz - 1);
 298                         buf[bufsiz - 1] = '\0';
 299                 }
 300                 return(strlen(tmp));
 301         }
 302 #endif
 303
 304 #ifdef USE_IFNAMELINKID
 305         /*
 306          * For a link-local address, convert the index to an interface
 307          * name, assuming a one-to-one mapping between links and interfaces.
 308          * Note, however, that this assumption is stronger than the
 309          * specification of the scoped address architecture;  the
 310          * specficication says that more than one interfaces can belong to
 311          * a single link.
 312          */
 313
 314         /* if_indextoname() does not take buffer size.  not a good api... */
 315         if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
 316             bufsiz >= IF_NAMESIZE) {
 317                 char *p = if_indextoname(ifindex, buf);
 318                 if (p) {
 319                         return(strlen(p));
 320                 }
 321         }
 322 #endif
 323
 324         /* last resort */
 325         sprintf(tmp, "%u", sa6->sin6_scope_id);
 326         if (bufsiz != 0U) {
 327                 strncpy(buf, tmp, bufsiz - 1);
 328                 buf[bufsiz - 1] = '\0';
 329         }
 330         return(strlen(tmp));
 331 }
 332 #endif