StdLib/BsdSocketLib/getnameinfo.c

   1 /*      $NetBSD: getnameinfo.c,v 1.45 2006/10/15 16:14:46 christos Exp $        */
   2 /*      $KAME: getnameinfo.c,v 1.45 2000/09/25 22:43:56 itojun Exp $    */
   3
   4 /*
   5  * Copyright (c) 2000 Ben Harris.
   6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Issues to be discussed:
  36  * - Thread safe-ness must be checked
  37  * - RFC2553 says that we should raise error on short buffer.  X/Open says
  38  *   we need to truncate the result.  We obey RFC2553 (and X/Open should be
  39  *   modified).  ipngwg rough consensus seems to follow RFC2553.
  40  * - What is "local" in NI_FQDN?
  41  * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
  42  * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if
  43  *   sin6_scope_id is filled - standardization status?
  44  *   XXX breaks backward compat for code that expects no scopeid.
  45  *   beware on merge.
  46  */
  47
  48 #define INET6   1
  49
  50 #include <sys/cdefs.h>
  51 #if defined(LIBC_SCCS) && !defined(lint)
  52 __RCSID("$NetBSD: getnameinfo.c,v 1.45 2006/10/15 16:14:46 christos Exp $");
  53 #endif /* LIBC_SCCS and not lint */
  54
  55 #include "namespace.h"
  56 #include <sys/types.h>
  57 #include <sys/socket.h>
  58 #include <net/if.h>
  59 #include <net/if_dl.h>
  60 //#include <net/if_ieee1394.h>
  61 //#include <net/if_types.h>
  62 #include <netinet/in.h>
  63 #include <arpa/inet.h>
  64 #include <arpa/nameser.h>
  65 #include <assert.h>
  66 #include <limits.h>
  67 #include <netdb.h>
  68 #include <resolv.h>
  69 #include <stddef.h>
  70 #include <string.h>
  71
  72 #include <net/servent.h>
  73
  74 #define CLLADDR(x)          ( LLADDR(x) )
  75 #define endservent_r(svd)   endservent()
  76 #define getservbyport_r(Port,pProto,pSv,pSvd)   getservbyport(Port,pProto)
  77
  78 #ifdef __weak_alias
  79 __weak_alias(getnameinfo,_getnameinfo)
  80 #endif
  81
  82 static
  83 int
  84 hexname(
  85   const u_int8_t * cp,
  86   size_t len,
  87   char * host,
  88   socklen_t hostlen
  89   );
  90
  91 static const struct afd {
  92         int             a_af;
  93         socklen_t       a_addrlen;
  94         socklen_t       a_socklen;
  95         int             a_off;
  96 } afdl [] = {
  97 #ifdef INET6
  98         {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
  99                 offsetof(struct sockaddr_in6, sin6_addr)},
 100 #endif
 101         {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
 102                 offsetof(struct sockaddr_in, sin_addr)},
 103         {0, 0, 0, 0},
 104 };
 105
 106 struct sockinet {
 107         u_char  si_len;
 108         u_char  si_family;
 109         u_short si_port;
 110 };
 111
 112 static int getnameinfo_inet __P((const struct sockaddr *, socklen_t, char *,
 113     socklen_t, char *, socklen_t, int));
 114 #ifdef INET6
 115 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
 116                                  socklen_t, int));
 117 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t,
 118                                  int));
 119 #endif
 120 static int getnameinfo_link __P((const struct sockaddr *, socklen_t, char *,
 121     socklen_t, char *, socklen_t, int));
 122 static int hexname __P((const u_int8_t *, size_t, char *, socklen_t));
 123
 124 /*
 125  * Top-level getnameinfo() code.  Look at the address family, and pick an
 126  * appropriate function to call.
 127  */
 128 int
 129 getnameinfo(
 130   const struct sockaddr * sa,
 131   socklen_t salen,
 132   char * host,
 133   socklen_t hostlen,
 134   char * serv,
 135   socklen_t servlen,
 136   int flags
 137   )
 138 {
 139
 140         switch (sa->sa_family) {
 141         case AF_INET:
 142         case AF_INET6:
 143                 return getnameinfo_inet(sa, salen, host, hostlen,
 144                     serv, servlen, flags);
 145         case AF_LINK:
 146                 return getnameinfo_link(sa, salen, host, hostlen,
 147                     serv, servlen, flags);
 148         default:
 149                 return EAI_FAMILY;
 150         }
 151 }
 152
 153
 154 /*
 155  * getnameinfo_inet():
 156  * Format an IPv4 or IPv6 sockaddr into a printable string.
 157  */
 158 static
 159 int
 160 getnameinfo_inet(
 161   const struct sockaddr * sa,
 162   socklen_t salen,
 163   char * host,
 164   socklen_t hostlen,
 165   char * serv,
 166   socklen_t servlen,
 167   int flags
 168   )
 169 {
 170         const struct afd *afd;
 171         struct servent *sp;
 172         struct hostent *hp;
 173         u_short port;
 174         int family, i;
 175         const char *addr;
 176         u_int32_t v4a;
 177         char numserv[512];
 178         char numaddr[512];
 179
 180         /* sa is checked below */
 181         /* host may be NULL */
 182         /* serv may be NULL */
 183
 184         if (sa == NULL)
 185                 return EAI_FAIL;
 186
 187 #ifdef BSD4_4
 188         if (sa->sa_len != salen)
 189                 return EAI_FAIL;
 190 #endif
 191
 192         family = sa->sa_family;
 193         for (i = 0; afdl[i].a_af; i++)
 194                 if (afdl[i].a_af == family) {
 195                         afd = &afdl[i];
 196                         goto found;
 197                 }
 198         return EAI_FAMILY;
 199
 200  found:
 201         if (salen != afd->a_socklen)
 202                 return EAI_FAIL;
 203
 204         /* network byte order */
 205         port = ((const struct sockinet *)(const void *)sa)->si_port;
 206         addr = (const char *)(const void *)sa + afd->a_off;
 207
 208         if (serv == NULL || servlen == 0) {
 209                 /*
 210                  * do nothing in this case.
 211                  * in case you are wondering if "&&" is more correct than
 212                  * "||" here: rfc2553bis-03 says that serv == NULL OR
 213                  * servlen == 0 means that the caller does not want the result.
 214                  */
 215         } else {
 216                 if (flags & NI_NUMERICSERV)
 217                         sp = NULL;
 218                 else {
 219                         struct servent_data svd;
 220 //                      struct servent sv;
 221
 222                         (void)memset(&svd, 0, sizeof(svd));
 223                         sp = getservbyport_r(port,
 224                                 (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd);
 225                         endservent_r(&svd);
 226                 }
 227                 if (sp) {
 228                         if (strlen(sp->s_name) + 1 > servlen)
 229                                 return EAI_MEMORY;
 230                         strlcpy(serv, sp->s_name, servlen);
 231                 } else {
 232                         snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
 233                         if (strlen(numserv) + 1 > servlen)
 234                                 return EAI_MEMORY;
 235                         strlcpy(serv, numserv, servlen);
 236                 }
 237         }
 238
 239         switch (sa->sa_family) {
 240         case AF_INET:
 241                 v4a = (u_int32_t)
 242                     ntohl(((const struct sockaddr_in *)
 243                     (const void *)sa)->sin_addr.s_addr);
 244                 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
 245                         flags |= NI_NUMERICHOST;
 246                 v4a >>= IN_CLASSA_NSHIFT;
 247                 if (v4a == 0)
 248                         flags |= NI_NUMERICHOST;
 249                 break;
 250 #ifdef INET6
 251         case AF_INET6:
 252             {
 253                 const struct sockaddr_in6 *sin6;
 254                 sin6 = (const struct sockaddr_in6 *)(const void *)sa;
 255                 switch (sin6->sin6_addr.s6_addr[0]) {
 256                 case 0x00:
 257                         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 258                                 ;
 259                         else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
 260                                 ;
 261                         else
 262                                 flags |= NI_NUMERICHOST;
 263                         break;
 264                 default:
 265                         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
 266                                 flags |= NI_NUMERICHOST;
 267                         }
 268                         else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 269                                 flags |= NI_NUMERICHOST;
 270                         break;
 271                 }
 272             }
 273                 break;
 274 #endif
 275         }
 276         if (host == NULL || hostlen == 0) {
 277                 /*
 278                  * do nothing in this case.
 279                  * in case you are wondering if "&&" is more correct than
 280                  * "||" here: rfc2553bis-03 says that host == NULL or
 281                  * hostlen == 0 means that the caller does not want the result.
 282                  */
 283         } else if (flags & NI_NUMERICHOST) {
 284                 size_t numaddrlen;
 285
 286                 /* NUMERICHOST and NAMEREQD conflicts with each other */
 287                 if (flags & NI_NAMEREQD)
 288                         return EAI_NONAME;
 289
 290                 switch(afd->a_af) {
 291 #ifdef INET6
 292                 case AF_INET6:
 293                 {
 294                         int error;
 295
 296                         if ((error = ip6_parsenumeric(sa, addr, host,
 297                                                       hostlen, flags)) != 0)
 298                                 return(error);
 299                         break;
 300                 }
 301 #endif
 302                 default:
 303                         if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
 304                             == NULL)
 305                                 return EAI_SYSTEM;
 306                         numaddrlen = strlen(numaddr);
 307                         if (numaddrlen + 1 > hostlen) /* don't forget terminator */
 308                                 return EAI_MEMORY;
 309                         strlcpy(host, numaddr, hostlen);
 310                         break;
 311                 }
 312         } else {
 313                 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
 314
 315                 if (hp) {
 316 #if 0
 317                         /*
 318                          * commented out, since "for local host" is not
 319                          * implemented here - see RFC2553 p30
 320                          */
 321                         if (flags & NI_NOFQDN) {
 322                                 char *p;
 323                                 p = strchr(hp->h_name, '.');
 324                                 if (p)
 325                                         *p = '\0';
 326                         }
 327 #endif
 328                         if (strlen(hp->h_name) + 1 > hostlen) {
 329                                 return EAI_MEMORY;
 330                         }
 331                         strlcpy(host, hp->h_name, hostlen);
 332                 } else {
 333                         if (flags & NI_NAMEREQD)
 334                                 return EAI_NONAME;
 335                         switch(afd->a_af) {
 336 #ifdef INET6
 337                         case AF_INET6:
 338                         {
 339                                 int error;
 340
 341                                 if ((error = ip6_parsenumeric(sa, addr, host,
 342                                                               hostlen,
 343                                                               flags)) != 0)
 344                                         return(error);
 345                                 break;
 346                         }
 347 #endif
 348                         default:
 349                                 if (inet_ntop(afd->a_af, addr, host,
 350                                     hostlen) == NULL)
 351                                         return EAI_SYSTEM;
 352                                 break;
 353                         }
 354                 }
 355         }
 356         return(0);
 357 }
 358
 359 #ifdef INET6
 360 static int
 361 ip6_parsenumeric(
 362   const struct sockaddr *sa,
 363   const char *addr,
 364   char *host,
 365   socklen_t hostlen,
 366   int flags
 367   )
 368 {
 369         size_t numaddrlen;
 370         char numaddr[512];
 371
 372         _DIAGASSERT(sa != NULL);
 373         _DIAGASSERT(addr != NULL);
 374         _DIAGASSERT(host != NULL);
 375
 376         if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
 377                 return EAI_SYSTEM;
 378
 379         numaddrlen = strlen(numaddr);
 380         if (numaddrlen + 1 > hostlen) /* don't forget terminator */
 381                 return EAI_OVERFLOW;
 382         strlcpy(host, numaddr, hostlen);
 383
 384         if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) {
 385                 char zonebuf[MAXHOSTNAMELEN];
 386                 int zonelen;
 387
 388                 zonelen = ip6_sa2str(
 389                     (const struct sockaddr_in6 *)(const void *)sa,
 390                     zonebuf, sizeof(zonebuf), flags);
 391                 if (zonelen < 0)
 392                         return EAI_OVERFLOW;
 393                 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen)
 394                         return EAI_OVERFLOW;
 395                 /* construct <numeric-addr><delim><zoneid> */
 396                 memcpy(host + numaddrlen + 1, zonebuf,
 397                     (size_t)zonelen);
 398                 host[numaddrlen] = SCOPE_DELIMITER;
 399                 host[numaddrlen + 1 + zonelen] = '\0';
 400         }
 401
 402         return 0;
 403 }
 404
 405 /* ARGSUSED */
 406 static int
 407 ip6_sa2str(
 408   const struct sockaddr_in6 *sa6,
 409   char *buf,
 410   size_t bufsiz,
 411   int flags
 412   )
 413 {
 414         unsigned int ifindex;
 415         const struct in6_addr *a6;
 416         int n;
 417
 418         _DIAGASSERT(sa6 != NULL);
 419         _DIAGASSERT(buf != NULL);
 420
 421         ifindex = (unsigned int)sa6->sin6_scope_id;
 422         a6 = &sa6->sin6_addr;
 423
 424 #ifdef NI_NUMERICSCOPE
 425         if ((flags & NI_NUMERICSCOPE) != 0) {
 426                 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
 427                 if ((n < 0) || ((size_t)n >= bufsiz))
 428                         return -1;
 429                 else
 430                         return n;
 431         }
 432 #endif
 433
 434 #if 0
 435         /* if_indextoname() does not take buffer size.  not a good api... */
 436         if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
 437             bufsiz >= IF_NAMESIZE) {
 438                 char *p = if_indextoname(ifindex, buf);
 439                 if (p) {
 440                         return(strlen(p));
 441                 }
 442         }
 443 #endif  //  0
 444
 445         /* last resort */
 446         n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
 447         if (n < 0 || (size_t) n >= bufsiz)
 448                 return -1;
 449         else
 450                 return n;
 451 }
 452 #endif /* INET6 */
 453
 454
 455 /*
 456  * getnameinfo_link():
 457  * Format a link-layer address into a printable format, paying attention to
 458  * the interface type.
 459  */
 460 /* ARGSUSED */
 461 static
 462 int
 463 getnameinfo_link (
 464   const struct sockaddr * sa,
 465   socklen_t salen,
 466   char * host,
 467   socklen_t hostlen,
 468   char * serv,
 469   socklen_t servlen,
 470   int flags
 471   )
 472 {
 473         const struct sockaddr_dl *sdl =
 474             (const struct sockaddr_dl *)(const void *)sa;
 475 //      const struct ieee1394_hwaddr *iha;
 476         int n;
 477
 478         if (serv != NULL && servlen > 0)
 479                 *serv = '\0';
 480
 481         if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) {
 482                 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index);
 483                 if (n < 0 || (socklen_t) n > hostlen) {
 484                         *host = '\0';
 485                         return EAI_MEMORY;
 486                 }
 487                 return 0;
 488         }
 489
 490 #if 0
 491         switch (sdl->sdl_type) {
 492 #ifdef IFT_ECONET
 493         case IFT_ECONET:
 494                 if (sdl->sdl_alen < 2)
 495                         return EAI_FAMILY;
 496                 if (CLLADDR(sdl)[1] == 0)
 497                         n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]);
 498                 else
 499                         n = snprintf(host, hostlen, "%u.%u",
 500                             CLLADDR(sdl)[1], CLLADDR(sdl)[0]);
 501                 if (n < 0 || (socklen_t) n >= hostlen) {
 502                         *host = '\0';
 503                         return EAI_MEMORY;
 504                 } else
 505                         return 0;
 506 #endif
 507         case IFT_IEEE1394:
 508                 if (sdl->sdl_alen < sizeof(iha->iha_uid))
 509                         return EAI_FAMILY;
 510                 iha =
 511                     (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl);
 512                 return hexname(iha->iha_uid, sizeof(iha->iha_uid),
 513                     host, hostlen);
 514         /*
 515          * The following have zero-length addresses.
 516          * IFT_ATM      (net/if_atmsubr.c)
 517          * IFT_FAITH    (net/if_faith.c)
 518          * IFT_GIF      (net/if_gif.c)
 519          * IFT_LOOP     (net/if_loop.c)
 520          * IFT_PPP      (net/if_ppp.c, net/if_spppsubr.c)
 521          * IFT_SLIP     (net/if_sl.c, net/if_strip.c)
 522          * IFT_STF      (net/if_stf.c)
 523          * IFT_L2VLAN   (net/if_vlan.c)
 524          * IFT_PROPVIRTUAL (net/if_bridge.h>
 525          */
 526         /*
 527          * The following use IPv4 addresses as link-layer addresses:
 528          * IFT_OTHER    (net/if_gre.c)
 529          */
 530         case IFT_ARCNET: /* default below is believed correct for all these. */
 531         case IFT_ETHER:
 532         case IFT_FDDI:
 533         case IFT_HIPPI:
 534         case IFT_ISO88025:
 535         default:
 536 #endif  //  0
 537                 return hexname((const u_int8_t *)CLLADDR(sdl),
 538                     (size_t)sdl->sdl_alen, host, hostlen);
 539 //      }
 540 }
 541
 542 static
 543 int
 544 hexname(
 545   const u_int8_t * cp,
 546   size_t len,
 547   char * host,
 548   socklen_t hostlen
 549   )
 550 {
 551         int n;
 552         size_t i;
 553         char *outp = host;
 554
 555         *outp = '\0';
 556         for (i = 0; i < len; i++) {
 557                 n = snprintf(outp, hostlen, "%s%02x",
 558                     i ? ":" : "", cp[i]);
 559                 if (n < 0 || (socklen_t) n >= hostlen) {
 560                         *host = '\0';
 561                         return EAI_MEMORY;
 562                 }
 563                 outp += n;
 564                 hostlen -= n;
 565         }
 566         return 0;
 567 }