lib/getaddrinfo.c

   1 /* Get address information (partial implementation).
   2    Copyright (C) 1997, 2001-2002, 2004-2010 Free Software Foundation, Inc.
   3    Contributed by Simon Josefsson <simon@josefsson.org>.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 #include <config.h>
  20
  21 /* Don't use __attribute__ __nonnull__ in this compilation unit.  Otherwise gcc
  22    optimizes away the sa == NULL test below.  */
  23 #define _GL_ARG_NONNULL(params)
  24
  25 #include <netdb.h>
  26
  27 #if HAVE_NETINET_IN_H
  28 # include <netinet/in.h>
  29 #endif
  30
  31 /* Get inet_ntop.  */
  32 #include <arpa/inet.h>
  33
  34 /* Get calloc. */
  35 #include <stdlib.h>
  36
  37 /* Get memcpy, strdup. */
  38 #include <string.h>
  39
  40 /* Get snprintf. */
  41 #include <stdio.h>
  42
  43 #include <stdbool.h>
  44
  45 #include "gettext.h"
  46 #define _(String) gettext (String)
  47 #define N_(String) String
  48
  49 /* BeOS has AF_INET, but not PF_INET.  */
  50 #ifndef PF_INET
  51 # define PF_INET AF_INET
  52 #endif
  53 /* BeOS also lacks PF_UNSPEC.  */
  54 #ifndef PF_UNSPEC
  55 # define PF_UNSPEC 0
  56 #endif
  57
  58 #if defined _WIN32 || defined __WIN32__
  59 # define WIN32_NATIVE
  60 #endif
  61
  62 #ifdef WIN32_NATIVE
  63 typedef int (WSAAPI *getaddrinfo_func) (const char*, const char*,
  64                                         const struct addrinfo*,
  65                                         struct addrinfo**);
  66 typedef void (WSAAPI *freeaddrinfo_func) (struct addrinfo*);
  67 typedef int (WSAAPI *getnameinfo_func) (const struct sockaddr*,
  68                                         socklen_t, char*, DWORD,
  69                                         char*, DWORD, int);
  70
  71 static getaddrinfo_func getaddrinfo_ptr = NULL;
  72 static freeaddrinfo_func freeaddrinfo_ptr = NULL;
  73 static getnameinfo_func getnameinfo_ptr = NULL;
  74
  75 static int
  76 use_win32_p (void)
  77 {
  78   static int done = 0;
  79   HMODULE h;
  80
  81   if (done)
  82     return getaddrinfo_ptr ? 1 : 0;
  83
  84   done = 1;
  85
  86   h = GetModuleHandle ("ws2_32.dll");
  87
  88   if (h)
  89     {
  90       getaddrinfo_ptr = (getaddrinfo_func) GetProcAddress (h, "getaddrinfo");
  91       freeaddrinfo_ptr = (freeaddrinfo_func) GetProcAddress (h, "freeaddrinfo");
  92       getnameinfo_ptr = (getnameinfo_func) GetProcAddress (h, "getnameinfo");
  93     }
  94
  95   /* If either is missing, something is odd. */
  96   if (!getaddrinfo_ptr || !freeaddrinfo_ptr || !getnameinfo_ptr)
  97     {
  98       getaddrinfo_ptr = NULL;
  99       freeaddrinfo_ptr = NULL;
 100       getnameinfo_ptr = NULL;
 101       return 0;
 102     }
 103
 104   return 1;
 105 }
 106 #endif
 107
 108 static inline bool
 109 validate_family (int family)
 110 {
 111   /* FIXME: Support more families. */
 112 #if HAVE_IPV4
 113      if (family == PF_INET)
 114        return true;
 115 #endif
 116 #if HAVE_IPV6
 117      if (family == PF_INET6)
 118        return true;
 119 #endif
 120      if (family == PF_UNSPEC)
 121        return true;
 122      return false;
 123 }
 124
 125 /* Translate name of a service location and/or a service name to set of
 126    socket addresses. */
 127 int
 128 getaddrinfo (const char *restrict nodename,
 129              const char *restrict servname,
 130              const struct addrinfo *restrict hints,
 131              struct addrinfo **restrict res)
 132 {
 133   struct addrinfo *tmp;
 134   int port = 0;
 135   struct hostent *he;
 136   void *storage;
 137   size_t size;
 138 #if HAVE_IPV6
 139   struct v6_pair {
 140     struct addrinfo addrinfo;
 141     struct sockaddr_in6 sockaddr_in6;
 142   };
 143 #endif
 144 #if HAVE_IPV4
 145   struct v4_pair {
 146     struct addrinfo addrinfo;
 147     struct sockaddr_in sockaddr_in;
 148   };
 149 #endif
 150
 151 #ifdef WIN32_NATIVE
 152   if (use_win32_p ())
 153     return getaddrinfo_ptr (nodename, servname, hints, res);
 154 #endif
 155
 156   if (hints && (hints->ai_flags & ~(AI_CANONNAME|AI_PASSIVE)))
 157     /* FIXME: Support more flags. */
 158     return EAI_BADFLAGS;
 159
 160   if (hints && !validate_family (hints->ai_family))
 161     return EAI_FAMILY;
 162
 163   if (hints &&
 164       hints->ai_socktype != SOCK_STREAM && hints->ai_socktype != SOCK_DGRAM)
 165     /* FIXME: Support other socktype. */
 166     return EAI_SOCKTYPE; /* FIXME: Better return code? */
 167
 168   if (!nodename)
 169     {
 170       if (!(hints->ai_flags & AI_PASSIVE))
 171         return EAI_NONAME;
 172
 173 #ifdef HAVE_IPV6
 174       nodename = (hints->ai_family == AF_INET6) ? "::" : "0.0.0.0";
 175 #else
 176       nodename = "0.0.0.0";
 177 #endif
 178     }
 179
 180   if (servname)
 181     {
 182       struct servent *se = NULL;
 183       const char *proto =
 184         (hints && hints->ai_socktype == SOCK_DGRAM) ? "udp" : "tcp";
 185
 186       if (hints == NULL || !(hints->ai_flags & AI_NUMERICSERV))
 187         /* FIXME: Use getservbyname_r if available. */
 188         se = getservbyname (servname, proto);
 189
 190       if (!se)
 191         {
 192           char *c;
 193           if (!(*servname >= '0' && *servname <= '9'))
 194             return EAI_NONAME;
 195           port = strtoul (servname, &c, 10);
 196           if (*c || port > 0xffff)
 197             return EAI_NONAME;
 198           port = htons (port);
 199         }
 200       else
 201         port = se->s_port;
 202     }
 203
 204   /* FIXME: Use gethostbyname_r if available. */
 205   he = gethostbyname (nodename);
 206   if (!he || he->h_addr_list[0] == NULL)
 207     return EAI_NONAME;
 208
 209   switch (he->h_addrtype)
 210     {
 211 #if HAVE_IPV6
 212     case PF_INET6:
 213       size = sizeof (struct v6_pair);
 214       break;
 215 #endif
 216
 217 #if HAVE_IPV4
 218     case PF_INET:
 219       size = sizeof (struct v4_pair);
 220       break;
 221 #endif
 222
 223     default:
 224       return EAI_NODATA;
 225     }
 226
 227   storage = calloc (1, size);
 228   if (!storage)
 229     return EAI_MEMORY;
 230
 231   switch (he->h_addrtype)
 232     {
 233 #if HAVE_IPV6
 234     case PF_INET6:
 235       {
 236         struct v6_pair *p = storage;
 237         struct sockaddr_in6 *sinp = &p->sockaddr_in6;
 238         tmp = &p->addrinfo;
 239
 240         if (port)
 241           sinp->sin6_port = port;
 242
 243         if (he->h_length != sizeof (sinp->sin6_addr))
 244           {
 245             free (storage);
 246             return EAI_SYSTEM; /* FIXME: Better return code?  Set errno? */
 247           }
 248
 249         memcpy (&sinp->sin6_addr, he->h_addr_list[0], sizeof sinp->sin6_addr);
 250
 251         tmp->ai_addr = (struct sockaddr *) sinp;
 252         tmp->ai_addrlen = sizeof *sinp;
 253       }
 254       break;
 255 #endif
 256
 257 #if HAVE_IPV4
 258     case PF_INET:
 259       {
 260         struct v4_pair *p = storage;
 261         struct sockaddr_in *sinp = &p->sockaddr_in;
 262         tmp = &p->addrinfo;
 263
 264         if (port)
 265           sinp->sin_port = port;
 266
 267         if (he->h_length != sizeof (sinp->sin_addr))
 268           {
 269             free (storage);
 270             return EAI_SYSTEM; /* FIXME: Better return code?  Set errno? */
 271           }
 272
 273         memcpy (&sinp->sin_addr, he->h_addr_list[0], sizeof sinp->sin_addr);
 274
 275         tmp->ai_addr = (struct sockaddr *) sinp;
 276         tmp->ai_addrlen = sizeof *sinp;
 277       }
 278       break;
 279 #endif
 280
 281     default:
 282       free (storage);
 283       return EAI_NODATA;
 284     }
 285
 286   if (hints && hints->ai_flags & AI_CANONNAME)
 287     {
 288       const char *cn;
 289       if (he->h_name)
 290         cn = he->h_name;
 291       else
 292         cn = nodename;
 293
 294       tmp->ai_canonname = strdup (cn);
 295       if (!tmp->ai_canonname)
 296         {
 297           free (storage);
 298           return EAI_MEMORY;
 299         }
 300     }
 301
 302   tmp->ai_protocol = (hints) ? hints->ai_protocol : 0;
 303   tmp->ai_socktype = (hints) ? hints->ai_socktype : 0;
 304   tmp->ai_addr->sa_family = he->h_addrtype;
 305   tmp->ai_family = he->h_addrtype;
 306
 307 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
 308   switch (he->h_addrtype)
 309     {
 310 #if HAVE_IPV4
 311     case AF_INET:
 312       tmp->ai_addr->sa_len = sizeof (struct sockaddr_in);
 313       break;
 314 #endif
 315 #if HAVE_IPV6
 316     case AF_INET6:
 317       tmp->ai_addr->sa_len = sizeof (struct sockaddr_in6);
 318       break;
 319 #endif
 320     }
 321 #endif
 322
 323   /* FIXME: If more than one address, create linked list of addrinfo's. */
 324
 325   *res = tmp;
 326
 327   return 0;
 328 }
 329
 330 /* Free `addrinfo' structure AI including associated storage.  */
 331 void
 332 freeaddrinfo (struct addrinfo *ai)
 333 {
 334 #ifdef WIN32_NATIVE
 335   if (use_win32_p ())
 336     {
 337       freeaddrinfo_ptr (ai);
 338       return;
 339     }
 340 #endif
 341
 342   while (ai)
 343     {
 344       struct addrinfo *cur;
 345
 346       cur = ai;
 347       ai = ai->ai_next;
 348
 349       free (cur->ai_canonname);
 350       free (cur);
 351     }
 352 }
 353
 354 int
 355 getnameinfo (const struct sockaddr *restrict sa, socklen_t salen,
 356              char *restrict node, socklen_t nodelen,
 357              char *restrict service, socklen_t servicelen,
 358              int flags)
 359 {
 360 #ifdef WIN32_NATIVE
 361   if (use_win32_p ())
 362     return getnameinfo_ptr (sa, salen, node, nodelen,
 363                             service, servicelen, flags);
 364 #endif
 365
 366   /* FIXME: Support other flags. */
 367   if ((node && nodelen > 0 && !(flags & NI_NUMERICHOST)) ||
 368       (service && servicelen > 0 && !(flags & NI_NUMERICHOST)) ||
 369       (flags & ~(NI_NUMERICHOST|NI_NUMERICSERV)))
 370     return EAI_BADFLAGS;
 371
 372   if (sa == NULL || salen < sizeof (sa->sa_family))
 373     return EAI_FAMILY;
 374
 375   switch (sa->sa_family)
 376     {
 377 #if HAVE_IPV4
 378     case AF_INET:
 379       if (salen < sizeof (struct sockaddr_in))
 380         return EAI_FAMILY;
 381       break;
 382 #endif
 383 #if HAVE_IPV6
 384     case AF_INET6:
 385       if (salen < sizeof (struct sockaddr_in6))
 386         return EAI_FAMILY;
 387       break;
 388 #endif
 389     default:
 390       return EAI_FAMILY;
 391     }
 392
 393   if (node && nodelen > 0 && flags & NI_NUMERICHOST)
 394     {
 395       switch (sa->sa_family)
 396         {
 397 #if HAVE_IPV4
 398         case AF_INET:
 399           if (!inet_ntop (AF_INET,
 400                           &(((const struct sockaddr_in *) sa)->sin_addr),
 401                           node, nodelen))
 402             return EAI_SYSTEM;
 403           break;
 404 #endif
 405
 406 #if HAVE_IPV6
 407         case AF_INET6:
 408           if (!inet_ntop (AF_INET6,
 409                           &(((const struct sockaddr_in6 *) sa)->sin6_addr),
 410                           node, nodelen))
 411             return EAI_SYSTEM;
 412           break;
 413 #endif
 414
 415         default:
 416           return EAI_FAMILY;
 417         }
 418     }
 419
 420   if (service && servicelen > 0 && flags & NI_NUMERICSERV)
 421     switch (sa->sa_family)
 422       {
 423 #if HAVE_IPV4
 424       case AF_INET:
 425 #endif
 426 #if HAVE_IPV6
 427       case AF_INET6:
 428 #endif
 429         {
 430           unsigned short int port
 431             = ntohs (((const struct sockaddr_in *) sa)->sin_port);
 432           if (servicelen <= snprintf (service, servicelen, "%u", port))
 433             return EAI_OVERFLOW;
 434         }
 435         break;
 436       }
 437
 438   return 0;
 439 }