src/kits/network/netresolv/irs/getnameinfo.c

   1 /*      $NetBSD: getnameinfo.c,v 1.53 2012/09/26 23:13:00 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. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *    This product includes software developed by WIDE Project and
  20  *    its contributors.
  21  * 4. Neither the name of the project nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  */
  37
  38 /*
  39  * Issues to be discussed:
  40  * - Thread safe-ness must be checked
  41  * - RFC2553 says that we should raise error on short buffer.  X/Open says
  42  *   we need to truncate the result.  We obey RFC2553 (and X/Open should be
  43  *   modified).  ipngwg rough consensus seems to follow RFC2553.
  44  * - What is "local" in NI_FQDN?
  45  * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
  46  * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if
  47  *   sin6_scope_id is filled - standardization status?
  48  *   XXX breaks backward compat for code that expects no scopeid.
  49  *   beware on merge.
  50  */
  51
  52 #include <sys/cdefs.h>
  53 #if defined(LIBC_SCCS) && !defined(lint)
  54 __RCSID("$NetBSD: getnameinfo.c,v 1.53 2012/09/26 23:13:00 christos Exp $");
  55 #endif /* LIBC_SCCS and not lint */
  56
  57 #include <sys/types.h>
  58 #include <sys/socket.h>
  59 #include <sys/un.h>
  60 #include <net/if.h>
  61 #include <net/if_dl.h>
  62 #include <net/if_types.h>
  63 #include <netinet/in.h>
  64 #include <arpa/inet.h>
  65 #include <arpa/nameser.h>
  66 #include <assert.h>
  67 #include <limits.h>
  68 #include <netdb.h>
  69 #include <resolv.h>
  70 #include <stddef.h>
  71 #include <string.h>
  72
  73 #include "nsswitch.h"
  74 #include "servent.h"
  75
  76 static const struct afd {
  77         int             a_af;
  78         socklen_t       a_addrlen;
  79         socklen_t       a_socklen;
  80         int             a_off;
  81 } afdl [] = {
  82 #ifdef INET6
  83         {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
  84                 offsetof(struct sockaddr_in6, sin6_addr)},
  85 #endif
  86         {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
  87                 offsetof(struct sockaddr_in, sin_addr)},
  88         {0, 0, 0, 0},
  89 };
  90
  91 struct sockinet {
  92         u_char  si_len;
  93         u_char  si_family;
  94         u_short si_port;
  95 };
  96
  97 static int getnameinfo_inet(const struct sockaddr *, socklen_t, char *,
  98     socklen_t, char *, socklen_t, int);
  99 #ifdef INET6
 100 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *,
 101                                  socklen_t, int);
 102 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int);
 103 #endif
 104 static int getnameinfo_atalk(const struct sockaddr *, socklen_t, char *,
 105     socklen_t, char *, socklen_t, int);
 106 static int getnameinfo_local(const struct sockaddr *, socklen_t, char *,
 107     socklen_t, char *, socklen_t, int);
 108
 109 static int getnameinfo_link(const struct sockaddr *, socklen_t, char *,
 110     socklen_t, char *, socklen_t, int);
 111 static int hexname(const uint8_t *, size_t, char *, socklen_t);
 112
 113 /*
 114 +  * Top-level getnameinfo() code.  Look at the address family, and pick an
 115 +  * appropriate function to call.
 116 +  */
 117 int
 118 getnameinfo(const struct sockaddr *sa, socklen_t salen,
 119         char *host, socklen_t hostlen,
 120         char *serv, socklen_t servlen,
 121         int flags)
 122 {
 123
 124         switch (sa->sa_family) {
 125         case AF_APPLETALK:
 126                 return getnameinfo_atalk(sa, salen, host, hostlen,
 127                     serv, servlen, flags);
 128         case AF_INET:
 129         case AF_INET6:
 130                 return getnameinfo_inet(sa, salen, host, hostlen,
 131                     serv, servlen, flags);
 132         case AF_LINK:
 133                 return getnameinfo_link(sa, salen, host, hostlen,
 134                     serv, servlen, flags);
 135         case AF_LOCAL:
 136                 return getnameinfo_local(sa, salen, host, hostlen,
 137                     serv, servlen, flags);
 138         default:
 139                 return EAI_FAMILY;
 140         }
 141 }
 142
 143 /*
 144  * getnameinfo_atalk():
 145  * Format an AppleTalk address into a printable format.
 146  */
 147 /* ARGSUSED */
 148 static int
 149 getnameinfo_atalk(const struct sockaddr *sa, socklen_t salen,
 150     char *host, socklen_t hostlen, char *serv, socklen_t servlen,
 151     int flags)
 152 {
 153 #if 0
 154         char numserv[8];
 155         int n, m=0;
 156
 157         const struct sockaddr_at *sat =
 158             (const struct sockaddr_at *)(const void *)sa;
 159
 160         if (serv != NULL && servlen > 0) {
 161                 snprintf(numserv, sizeof(numserv), "%u", sat->sat_port);
 162                 if (strlen(numserv) + 1 > servlen)
 163                         return EAI_MEMORY;
 164                 strlcpy(serv, numserv, servlen);
 165         }
 166
 167         n = snprintf(host, hostlen, "%u.%u",
 168             ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node);
 169
 170         if (n < 0 || (socklen_t)(m+n) >= hostlen)
 171                 goto errout;
 172
 173         m += n;
 174
 175         if (sat->sat_range.r_netrange.nr_phase) {
 176                 n = snprintf(host+m, hostlen-m, " phase %u",
 177                         sat->sat_range.r_netrange.nr_phase);
 178
 179                 if (n < 0 || (socklen_t)(m+n) >= hostlen)
 180                         goto errout;
 181
 182                 m += n;
 183         }
 184         if (sat->sat_range.r_netrange.nr_firstnet) {
 185                 n = snprintf(host+m, hostlen-m, " range %u - %u",
 186                         ntohs(sat->sat_range.r_netrange.nr_firstnet),
 187                         ntohs(sat->sat_range.r_netrange.nr_lastnet ));
 188
 189                 if (n < 0 || (socklen_t)(m+n) >= hostlen)
 190                         goto errout;
 191
 192                 m += n;
 193         }
 194
 195         return 0;
 196
 197 errout:
 198         if (host && hostlen>0)
 199                 host[m] = '\0'; /* XXX ??? */
 200
 201 #endif
 202         return EAI_MEMORY;
 203 }
 204
 205 /*
 206  * getnameinfo_local():
 207  * Format an local address into a printable format.
 208  */
 209 /* ARGSUSED */
 210 static int
 211 getnameinfo_local(const struct sockaddr *sa, socklen_t salen,
 212     char *host, socklen_t hostlen, char *serv, socklen_t servlen,
 213     int flags)
 214 {
 215         const struct sockaddr_un *sun =
 216             (const struct sockaddr_un *)(const void *)sa;
 217
 218         if (serv != NULL && servlen > 0)
 219                 serv[0] = '\0';
 220
 221         if (host && hostlen > 0)
 222                 strlcpy(host, sun->sun_path,
 223                     MIN(sizeof(sun->sun_path) + 1, hostlen));
 224
 225         return 0;
 226 }
 227
 228 /*
 229  * getnameinfo_inet():
 230  * Format an IPv4 or IPv6 sockaddr into a printable string.
 231  */
 232 static int
 233 getnameinfo_inet(const struct sockaddr *sa, socklen_t salen,
 234         char *host, socklen_t hostlen,
 235         char *serv, socklen_t servlen,
 236         int flags)
 237 {
 238         const struct afd *afd;
 239         struct servent *sp;
 240         struct hostent *hp;
 241         u_short port;
 242         int family, i;
 243         const char *addr;
 244         uint32_t v4a;
 245         char numserv[512];
 246         char numaddr[512];
 247
 248         /* sa is checked below */
 249         /* host may be NULL */
 250         /* serv may be NULL */
 251
 252         if (sa == NULL)
 253                 return EAI_FAIL;
 254
 255
 256         family = sa->sa_family;
 257         for (i = 0; afdl[i].a_af; i++)
 258                 if (afdl[i].a_af == family) {
 259                         afd = &afdl[i];
 260                         goto found;
 261                 }
 262         return EAI_FAMILY;
 263
 264  found:
 265         if (salen != afd->a_socklen)
 266                 return EAI_FAIL;
 267
 268         /* network byte order */
 269         port = ((const struct sockinet *)(const void *)sa)->si_port;
 270         addr = (const char *)(const void *)sa + afd->a_off;
 271
 272         if (serv == NULL || servlen == 0) {
 273                 /*
 274                  * do nothing in this case.
 275                  * in case you are wondering if "&&" is more correct than
 276                  * "||" here: rfc2553bis-03 says that serv == NULL OR
 277                  * servlen == 0 means that the caller does not want the result.
 278                 */
 279         } else {
 280                 struct servent_data svd;
 281                 struct servent sv;
 282
 283                 if (flags & NI_NUMERICSERV)
 284                         sp = NULL;
 285                 else {
 286                         (void)memset(&svd, 0, sizeof(svd));
 287                         sp = getservbyport_r(port,
 288                                 (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd);
 289                 }
 290                 if (sp) {
 291                         if (strlen(sp->s_name) + 1 > servlen) {
 292                                 endservent_r(&svd);
 293                                 return EAI_MEMORY;
 294                         }
 295                         strlcpy(serv, sp->s_name, servlen);
 296                         endservent_r(&svd);
 297                 } else {
 298                         snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
 299                         if (strlen(numserv) + 1 > servlen)
 300                                 return EAI_MEMORY;
 301                         strlcpy(serv, numserv, servlen);
 302                 }
 303         }
 304
 305         switch (sa->sa_family) {
 306         case AF_INET:
 307                 v4a = (uint32_t)
 308                     ntohl(((const struct sockaddr_in *)
 309                     (const void *)sa)->sin_addr.s_addr);
 310                 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
 311                         flags |= NI_NUMERICHOST;
 312                 v4a >>= IN_CLASSA_NSHIFT;
 313                 if (v4a == 0)
 314                         flags |= NI_NUMERICHOST;
 315                 break;
 316 #ifdef INET6
 317         case AF_INET6:
 318             {
 319                 const struct sockaddr_in6 *sin6;
 320                 sin6 = (const struct sockaddr_in6 *)(const void *)sa;
 321                 switch (sin6->sin6_addr.s6_addr[0]) {
 322                 case 0x00:
 323                         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 324                                 ;
 325                         else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
 326                                 ;
 327                         else
 328                                 flags |= NI_NUMERICHOST;
 329                         break;
 330                 default:
 331                         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
 332                                 flags |= NI_NUMERICHOST;
 333                         }
 334                         else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 335                                 flags |= NI_NUMERICHOST;
 336                         break;
 337                 }
 338             }
 339                 break;
 340 #endif
 341         }
 342         if (host == NULL || hostlen == 0) {
 343                 /*
 344                  * do nothing in this case.
 345                  * in case you are wondering if "&&" is more correct than
 346                  * "||" here: rfc2553bis-03 says that host == NULL or
 347                  * hostlen == 0 means that the caller does not want the result.
 348                  */
 349         } else if (flags & NI_NUMERICHOST) {
 350                 size_t numaddrlen;
 351
 352                 /* NUMERICHOST and NAMEREQD conflicts with each other */
 353                 if (flags & NI_NAMEREQD)
 354                         return EAI_NONAME;
 355
 356                 switch(afd->a_af) {
 357 #ifdef INET6
 358                 case AF_INET6:
 359                 {
 360                         int error;
 361
 362                         if ((error = ip6_parsenumeric(sa, addr, host,
 363                                                       hostlen, flags)) != 0)
 364                                 return(error);
 365                         break;
 366                 }
 367 #endif
 368                 default:
 369                         if (inet_ntop(afd->a_af, addr, numaddr,
 370                             (socklen_t)sizeof(numaddr)) == NULL)
 371                                 return EAI_SYSTEM;
 372                         numaddrlen = strlen(numaddr);
 373                         if (numaddrlen + 1 > hostlen) /* don't forget terminator */
 374                                 return EAI_MEMORY;
 375                         strlcpy(host, numaddr, hostlen);
 376                         break;
 377                 }
 378         } else {
 379                 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
 380
 381                 if (hp) {
 382 #if 0
 383                         /*
 384                          * commented out, since "for local host" is not
 385                          * implemented here - see RFC2553 p30
 386                          */
 387                         if (flags & NI_NOFQDN) {
 388                                 char *p;
 389                                 p = strchr(hp->h_name, '.');
 390                                 if (p)
 391                                         *p = '\0';
 392                         }
 393 #endif
 394                         if (strlen(hp->h_name) + 1 > hostlen) {
 395                                 return EAI_MEMORY;
 396                         }
 397                         strlcpy(host, hp->h_name, hostlen);
 398                 } else {
 399                         if (flags & NI_NAMEREQD)
 400                                 return EAI_NONAME;
 401                         switch(afd->a_af) {
 402 #ifdef INET6
 403                         case AF_INET6:
 404                         {
 405                                 int error;
 406
 407                                 if ((error = ip6_parsenumeric(sa, addr, host,
 408                                                               hostlen,
 409                                                               flags)) != 0)
 410                                         return(error);
 411                                 break;
 412                         }
 413 #endif
 414                         default:
 415                                 if (inet_ntop(afd->a_af, addr, host,
 416                                     hostlen) == NULL)
 417                                         return EAI_SYSTEM;
 418                                 break;
 419                         }
 420                 }
 421         }
 422         return(0);
 423 }
 424
 425 #ifdef INET6
 426 static int
 427 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host,
 428         socklen_t hostlen, int flags)
 429 {
 430         size_t numaddrlen;
 431         char numaddr[512];
 432
 433         assert(sa != NULL);
 434         assert(addr != NULL);
 435         assert(host != NULL);
 436
 437         if (inet_ntop(AF_INET6, addr, numaddr, (socklen_t)sizeof(numaddr))
 438             == NULL)
 439                 return EAI_SYSTEM;
 440
 441         numaddrlen = strlen(numaddr);
 442         if (numaddrlen + 1 > hostlen) /* don't forget terminator */
 443                 return EAI_OVERFLOW;
 444         strlcpy(host, numaddr, hostlen);
 445
 446         if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) {
 447                 char zonebuf[MAXHOSTNAMELEN];
 448                 int zonelen;
 449
 450                 zonelen = ip6_sa2str(
 451                     (const struct sockaddr_in6 *)(const void *)sa,
 452                     zonebuf, sizeof(zonebuf), flags);
 453                 if (zonelen < 0)
 454                         return EAI_OVERFLOW;
 455                 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen)
 456                         return EAI_OVERFLOW;
 457                 /* construct <numeric-addr><delim><zoneid> */
 458                 memcpy(host + numaddrlen + 1, zonebuf,
 459                     (size_t)zonelen);
 460                 host[numaddrlen] = SCOPE_DELIMITER;
 461                 host[numaddrlen + 1 + zonelen] = '\0';
 462         }
 463
 464         return 0;
 465 }
 466
 467 /* ARGSUSED */
 468 static int
 469 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags)
 470 {
 471         unsigned int ifindex;
 472         const struct in6_addr *a6;
 473         int n;
 474
 475         assert(sa6 != NULL);
 476         assert(buf != NULL);
 477
 478         ifindex = (unsigned int)sa6->sin6_scope_id;
 479         a6 = &sa6->sin6_addr;
 480
 481 #ifdef NI_NUMERICSCOPE
 482         if ((flags & NI_NUMERICSCOPE) != 0) {
 483                 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
 484                 if (n < 0 || (size_t)n >= bufsiz)
 485                         return -1;
 486                 else
 487                         return n;
 488         }
 489 #endif
 490
 491         /* if_indextoname() does not take buffer size.  not a good api... */
 492         if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
 493             bufsiz >= IF_NAMESIZE) {
 494                 char *p = if_indextoname(ifindex, buf);
 495                 if (p) {
 496                         return (int)strlen(p);
 497                 }
 498         }
 499
 500         /* last resort */
 501         n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
 502         if (n < 0 || (size_t) n >= bufsiz)
 503                 return -1;
 504         else
 505                 return n;
 506 }
 507 #endif /* INET6 */
 508
 509
 510 /*
 511  * getnameinfo_link():
 512  * Format a link-layer address into a printable format, paying attention to
 513  * the interface type.
 514  */
 515 /* ARGSUSED */
 516 static int
 517 getnameinfo_link(const struct sockaddr *sa, socklen_t salen,
 518     char *host, socklen_t hostlen, char *serv, socklen_t servlen,
 519     int flags)
 520 {
 521         const struct sockaddr_dl *sdl =
 522             (const struct sockaddr_dl *)(const void *)sa;
 523         int n;
 524
 525         if (serv != NULL && servlen > 0)
 526                 *serv = '\0';
 527
 528         if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) {
 529                 n = snprintf(host, hostlen, "link#%u", sdl->sdl_index);
 530                 if (n < 0 || (socklen_t) n > hostlen) {
 531                         *host = '\0';
 532                         return EAI_MEMORY;
 533                 }
 534                 return 0;
 535         }
 536
 537         switch (sdl->sdl_type) {
 538 #ifdef IFT_ECONET
 539         case IFT_ECONET:
 540                 if (sdl->sdl_alen < 2)
 541                         return EAI_FAMILY;
 542                 if (LLADDR(sdl)[1] == 0)
 543                         n = snprintf(host, hostlen, "%u", LLADDR(sdl)[0]);
 544                 else
 545                         n = snprintf(host, hostlen, "%u.%u",
 546                             LLADDR(sdl)[1], LLADDR(sdl)[0]);
 547                 if (n < 0 || (socklen_t) n >= hostlen) {
 548                         *host = '\0';
 549                         return EAI_MEMORY;
 550                 } else
 551                         return 0;
 552 #endif
 553 #ifdef IFT_IEEE1394
 554         case IFT_IEEE1394:
 555         {
 556                 const struct ieee1394_hwaddr *iha;
 557                 if (sdl->sdl_alen < sizeof(iha->iha_uid))
 558                         return EAI_FAMILY;
 559                 iha =
 560                     (const struct ieee1394_hwaddr *)(const void *)LLADDR(sdl);
 561                 return hexname(iha->iha_uid, sizeof(iha->iha_uid),
 562                     host, hostlen);
 563         }
 564 #endif
 565         /*
 566          * The following have zero-length addresses.
 567          * IFT_ATM      (net/if_atmsubr.c)
 568          * IFT_FAITH    (net/if_faith.c)
 569          * IFT_GIF      (net/if_gif.c)
 570          * IFT_LOOP     (net/if_loop.c)
 571          * IFT_PPP      (net/if_ppp.c, net/if_spppsubr.c)
 572          * IFT_SLIP     (net/if_sl.c, net/if_strip.c)
 573          * IFT_STF      (net/if_stf.c)
 574          * IFT_L2VLAN   (net/if_vlan.c)
 575          * IFT_PROPVIRTUAL (net/if_bridge.h>
 576          */
 577         /*
 578          * The following use IPv4 addresses as link-layer addresses:
 579          * IFT_OTHER    (net/if_gre.c)
 580          */
 581 #ifdef IFT_ARCNET
 582         case IFT_ARCNET: /* default below is believed correct for all these. */
 583 #endif
 584         case IFT_ETHER:
 585 #ifdef IFT_FDDI
 586         case IFT_FDDI:
 587 #endif
 588 #ifdef IFT_HIPPI
 589         case IFT_HIPPI:
 590 #endif
 591 #ifdef IFT_ISO88025
 592         case IFT_ISO88025:
 593 #endif
 594         default:
 595                 return hexname((const uint8_t *)LLADDR(sdl),
 596                     (size_t)sdl->sdl_alen, host, hostlen);
 597         }
 598 }
 599
 600 static int
 601 hexname(const uint8_t *cp, size_t len, char *host, socklen_t hostlen)
 602 {
 603         int n;
 604         size_t i;
 605         char *outp = host;
 606
 607         *outp = '\0';
 608         for (i = 0; i < len; i++) {
 609                 n = snprintf(outp, hostlen, "%s%02x",
 610                     i ? ":" : "", cp[i]);
 611                 if (n < 0 || (socklen_t) n >= hostlen) {
 612                         *host = '\0';
 613                         return EAI_MEMORY;
 614                 }
 615                 outp += n;
 616                 hostlen -= n;
 617         }
 618         return 0;
 619 }