lib/getaddrinfo.c

   1 /* Get address information (partial implementation).
   2    Copyright (C) 1997, 2001-2002, 2004-2018 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 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 General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Don't use __attribute__ __nonnull__ in this compilation unit.  Otherwise gcc
  19    optimizes away the sa == NULL test below.  */
  20 #define _GL_ARG_NONNULL(params)
  21
  22 #include <config.h>
  23
  24 #include <netdb.h>
  25
  26 #if HAVE_NETINET_IN_H
  27 # include <netinet/in.h>
  28 #endif
  29
  30 /* Get inet_ntop.  */
  31 #include <arpa/inet.h>
  32
  33 /* Get calloc. */
  34 #include <stdlib.h>
  35
  36 /* Get memcpy, strdup. */
  37 #include <string.h>
  38
  39 /* Get snprintf. */
  40 #include <stdio.h>
  41
  42 #include <stdbool.h>
  43
  44 #include "gettext.h"
  45 #define _(String) gettext (String)
  46 #define N_(String) String
  47
  48 /* BeOS has AF_INET, but not PF_INET.  */
  49 #ifndef PF_INET
  50 # define PF_INET AF_INET
  51 #endif
  52 /* BeOS also lacks PF_UNSPEC.  */
  53 #ifndef PF_UNSPEC
  54 # define PF_UNSPEC 0
  55 #endif
  56
  57 #if defined _WIN32 && !defined __CYGWIN__
  58 # define WINDOWS_NATIVE
  59 #endif
  60
  61 /* gl_sockets_startup */
  62 #include "sockets.h"
  63
  64 #ifdef WINDOWS_NATIVE
  65
  66 /* Avoid warnings from gcc -Wcast-function-type.  */
  67 # define GetProcAddress \
  68    (void *) GetProcAddress
  69
  70 typedef int (WSAAPI *getaddrinfo_func) (const char*, const char*,
  71                                         const struct addrinfo*,
  72                                         struct addrinfo**);
  73 typedef void (WSAAPI *freeaddrinfo_func) (struct addrinfo*);
  74 typedef int (WSAAPI *getnameinfo_func) (const struct sockaddr*,
  75                                         socklen_t, char*, DWORD,
  76                                         char*, DWORD, int);
  77
  78 static getaddrinfo_func getaddrinfo_ptr = NULL;
  79 static freeaddrinfo_func freeaddrinfo_ptr = NULL;
  80 static getnameinfo_func getnameinfo_ptr = NULL;
  81
  82 static int
  83 use_win32_p (void)
  84 {
  85   static int done = 0;
  86   HMODULE h;
  87
  88   if (done)
  89     return getaddrinfo_ptr ? 1 : 0;
  90
  91   done = 1;
  92
  93   h = GetModuleHandle ("ws2_32.dll");
  94
  95   if (h)
  96     {
  97       getaddrinfo_ptr = (getaddrinfo_func) GetProcAddress (h, "getaddrinfo");
  98       freeaddrinfo_ptr = (freeaddrinfo_func) GetProcAddress (h, "freeaddrinfo");
  99       getnameinfo_ptr = (getnameinfo_func) GetProcAddress (h, "getnameinfo");
 100     }
 101
 102   /* If either is missing, something is odd. */
 103   if (!getaddrinfo_ptr || !freeaddrinfo_ptr || !getnameinfo_ptr)
 104     {
 105       getaddrinfo_ptr = NULL;
 106       freeaddrinfo_ptr = NULL;
 107       getnameinfo_ptr = NULL;
 108       return 0;
 109     }
 110
 111   gl_sockets_startup (SOCKETS_1_1);
 112
 113   return 1;
 114 }
 115 #endif
 116
 117 static bool
 118 validate_family (int family)
 119 {
 120   /* FIXME: Support more families. */
 121 #if HAVE_IPV4
 122      if (family == PF_INET)
 123        return true;
 124 #endif
 125 #if HAVE_IPV6
 126      if (family == PF_INET6)
 127        return true;
 128 #endif
 129      if (family == PF_UNSPEC)
 130        return true;
 131      return false;
 132 }
 133
 134 /* Translate name of a service location and/or a service name to set of
 135    socket addresses. */
 136 int
 137 getaddrinfo (const char *restrict nodename,
 138              const char *restrict servname,
 139              const struct addrinfo *restrict hints,
 140              struct addrinfo **restrict res)
 141 {
 142   struct addrinfo *tmp;
 143   int port = 0;
 144   struct hostent *he;
 145   void *storage;
 146   size_t size;
 147 #if HAVE_IPV6
 148   struct v6_pair {
 149     struct addrinfo addrinfo;
 150     struct sockaddr_in6 sockaddr_in6;
 151   };
 152 #endif
 153 #if HAVE_IPV4
 154   struct v4_pair {
 155     struct addrinfo addrinfo;
 156     struct sockaddr_in sockaddr_in;
 157   };
 158 #endif
 159
 160 #ifdef WINDOWS_NATIVE
 161   if (use_win32_p ())
 162     return getaddrinfo_ptr (nodename, servname, hints, res);
 163 #endif
 164
 165   if (hints && (hints->ai_flags & ~(AI_CANONNAME|AI_PASSIVE)))
 166     /* FIXME: Support more flags. */
 167     return EAI_BADFLAGS;
 168
 169   if (hints && !validate_family (hints->ai_family))
 170     return EAI_FAMILY;
 171
 172   if (hints &&
 173       hints->ai_socktype != SOCK_STREAM && hints->ai_socktype != SOCK_DGRAM)
 174     /* FIXME: Support other socktype. */
 175     return EAI_SOCKTYPE; /* FIXME: Better return code? */
 176
 177   if (!nodename)
 178     {
 179       if (!(hints->ai_flags & AI_PASSIVE))
 180         return EAI_NONAME;
 181
 182 #ifdef HAVE_IPV6
 183       nodename = (hints->ai_family == AF_INET6) ? "::" : "0.0.0.0";
 184 #else
 185       nodename = "0.0.0.0";
 186 #endif
 187     }
 188
 189   if (servname)
 190     {
 191       struct servent *se = NULL;
 192       const char *proto =
 193         (hints && hints->ai_socktype == SOCK_DGRAM) ? "udp" : "tcp";
 194
 195       if (hints == NULL || !(hints->ai_flags & AI_NUMERICSERV))
 196         /* FIXME: Use getservbyname_r if available. */
 197         se = getservbyname (servname, proto);
 198
 199       if (!se)
 200         {
 201           char *c;
 202           if (!(*servname >= '0' && *servname <= '9'))
 203             return EAI_NONAME;
 204           port = strtoul (servname, &c, 10);
 205           if (*c || port > 0xffff)
 206             return EAI_NONAME;
 207           port = htons (port);
 208         }
 209       else
 210         port = se->s_port;
 211     }
 212
 213   /* FIXME: Use gethostbyname_r if available. */
 214   he = gethostbyname (nodename);
 215   if (!he || he->h_addr_list[0] == NULL)
 216     return EAI_NONAME;
 217
 218   switch (he->h_addrtype)
 219     {
 220 #if HAVE_IPV6
 221     case PF_INET6:
 222       size = sizeof (struct v6_pair);
 223       break;
 224 #endif
 225
 226 #if HAVE_IPV4
 227     case PF_INET:
 228       size = sizeof (struct v4_pair);
 229       break;
 230 #endif
 231
 232     default:
 233       return EAI_NODATA;
 234     }
 235
 236   storage = calloc (1, size);
 237   if (!storage)
 238     return EAI_MEMORY;
 239
 240   switch (he->h_addrtype)
 241     {
 242 #if HAVE_IPV6
 243     case PF_INET6:
 244       {
 245         struct v6_pair *p = storage;
 246         struct sockaddr_in6 *sinp = &p->sockaddr_in6;
 247         tmp = &p->addrinfo;
 248
 249         if (port)
 250           sinp->sin6_port = port;
 251
 252         if (he->h_length != sizeof (sinp->sin6_addr))
 253           {
 254             free (storage);
 255             return EAI_SYSTEM; /* FIXME: Better return code?  Set errno? */
 256           }
 257
 258         memcpy (&sinp->sin6_addr, he->h_addr_list[0], sizeof sinp->sin6_addr);
 259
 260         tmp->ai_addr = (struct sockaddr *) sinp;
 261         tmp->ai_addrlen = sizeof *sinp;
 262       }
 263       break;
 264 #endif
 265
 266 #if HAVE_IPV4
 267     case PF_INET:
 268       {
 269         struct v4_pair *p = storage;
 270         struct sockaddr_in *sinp = &p->sockaddr_in;
 271         tmp = &p->addrinfo;
 272
 273         if (port)
 274           sinp->sin_port = port;
 275
 276         if (he->h_length != sizeof (sinp->sin_addr))
 277           {
 278             free (storage);
 279             return EAI_SYSTEM; /* FIXME: Better return code?  Set errno? */
 280           }
 281
 282         memcpy (&sinp->sin_addr, he->h_addr_list[0], sizeof sinp->sin_addr);
 283
 284         tmp->ai_addr = (struct sockaddr *) sinp;
 285         tmp->ai_addrlen = sizeof *sinp;
 286       }
 287       break;
 288 #endif
 289
 290     default:
 291       free (storage);
 292       return EAI_NODATA;
 293     }
 294
 295   if (hints && hints->ai_flags & AI_CANONNAME)
 296     {
 297       const char *cn;
 298       if (he->h_name)
 299         cn = he->h_name;
 300       else
 301         cn = nodename;
 302
 303       tmp->ai_canonname = strdup (cn);
 304       if (!tmp->ai_canonname)
 305         {
 306           free (storage);
 307           return EAI_MEMORY;
 308         }
 309     }
 310
 311   tmp->ai_protocol = (hints) ? hints->ai_protocol : 0;
 312   tmp->ai_socktype = (hints) ? hints->ai_socktype : 0;
 313   tmp->ai_addr->sa_family = he->h_addrtype;
 314   tmp->ai_family = he->h_addrtype;
 315
 316 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
 317   switch (he->h_addrtype)
 318     {
 319 #if HAVE_IPV4
 320     case AF_INET:
 321       tmp->ai_addr->sa_len = sizeof (struct sockaddr_in);
 322       break;
 323 #endif
 324 #if HAVE_IPV6
 325     case AF_INET6:
 326       tmp->ai_addr->sa_len = sizeof (struct sockaddr_in6);
 327       break;
 328 #endif
 329     }
 330 #endif
 331
 332   /* FIXME: If more than one address, create linked list of addrinfo's. */
 333
 334   *res = tmp;
 335
 336   return 0;
 337 }
 338
 339 /* Free 'addrinfo' structure AI including associated storage.  */
 340 void
 341 freeaddrinfo (struct addrinfo *ai)
 342 {
 343 #ifdef WINDOWS_NATIVE
 344   if (use_win32_p ())
 345     {
 346       freeaddrinfo_ptr (ai);
 347       return;
 348     }
 349 #endif
 350
 351   while (ai)
 352     {
 353       struct addrinfo *cur;
 354
 355       cur = ai;
 356       ai = ai->ai_next;
 357
 358       free (cur->ai_canonname);
 359       free (cur);
 360     }
 361 }
 362
 363 int
 364 getnameinfo (const struct sockaddr *restrict sa, socklen_t salen,
 365              char *restrict node, socklen_t nodelen,
 366              char *restrict service, socklen_t servicelen,
 367              int flags)
 368 {
 369 #ifdef WINDOWS_NATIVE
 370   if (use_win32_p ())
 371     return getnameinfo_ptr (sa, salen, node, nodelen,
 372                             service, servicelen, flags);
 373 #endif
 374
 375   /* FIXME: Support other flags. */
 376   if ((node && nodelen > 0 && !(flags & NI_NUMERICHOST)) ||
 377       (service && servicelen > 0 && !(flags & NI_NUMERICHOST)) ||
 378       (flags & ~(NI_NUMERICHOST|NI_NUMERICSERV)))
 379     return EAI_BADFLAGS;
 380
 381   if (sa == NULL || salen < sizeof (sa->sa_family))
 382     return EAI_FAMILY;
 383
 384   switch (sa->sa_family)
 385     {
 386 #if HAVE_IPV4
 387     case AF_INET:
 388       if (salen < sizeof (struct sockaddr_in))
 389         return EAI_FAMILY;
 390       break;
 391 #endif
 392 #if HAVE_IPV6
 393     case AF_INET6:
 394       if (salen < sizeof (struct sockaddr_in6))
 395         return EAI_FAMILY;
 396       break;
 397 #endif
 398     default:
 399       return EAI_FAMILY;
 400     }
 401
 402   if (node && nodelen > 0 && flags & NI_NUMERICHOST)
 403     {
 404       switch (sa->sa_family)
 405         {
 406 #if HAVE_IPV4
 407         case AF_INET:
 408           if (!inet_ntop (AF_INET,
 409                           &(((const struct sockaddr_in *) sa)->sin_addr),
 410                           node, nodelen))
 411             return EAI_SYSTEM;
 412           break;
 413 #endif
 414
 415 #if HAVE_IPV6
 416         case AF_INET6:
 417           if (!inet_ntop (AF_INET6,
 418                           &(((const struct sockaddr_in6 *) sa)->sin6_addr),
 419                           node, nodelen))
 420             return EAI_SYSTEM;
 421           break;
 422 #endif
 423
 424         default:
 425           return EAI_FAMILY;
 426         }
 427     }
 428
 429   if (service && servicelen > 0 && flags & NI_NUMERICSERV)
 430     switch (sa->sa_family)
 431       {
 432 #if HAVE_IPV4
 433       case AF_INET:
 434 #endif
 435 #if HAVE_IPV6
 436       case AF_INET6:
 437 #endif
 438         {
 439           unsigned short int port
 440             = ntohs (((const struct sockaddr_in *) sa)->sin_port);
 441           if (servicelen <= snprintf (service, servicelen, "%u", port))
 442             return EAI_OVERFLOW;
 443         }
 444         break;
 445       }
 446
 447   return 0;
 448 }