gonzui

    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: #include <sys/cdefs.h>
   49: #if defined(LIBC_SCCS) && !defined(lint)
   50: __RCSID("$NetBSD: getnameinfo.c,v 1.45 2006/10/15 16:14:46 christos Exp $");
   51: #endif /* LIBC_SCCS and not lint */
   52: 
   53: #ifdef T2EX
   54: #include <t2ex/errno.h>
   55: #include "port_before.h"
   56: #endif
   57: 
   58: #include "namespace.h"
   59: #include <sys/types.h>
   60: #include <sys/socket.h>
   61: #include <net/if.h>
   62: #include <net/if_dl.h>
   63: #include <net/if_ieee1394.h>
   64: #include <net/if_types.h>
   65: #include <netinet/in.h>
   66: #include <arpa/inet.h>
   67: #include <arpa/nameser.h>
   68: #include <assert.h>
   69: #include <limits.h>
   70: #include <netdb.h>
   71: #include <resolv.h>
   72: #include <stddef.h>
   73: #include <string.h>
   74: 
   75: #include "servent.h"
   76: 
   77: #ifdef __weak_alias
   78: __weak_alias(getnameinfo,_getnameinfo)
   79: #endif
   80: 
   81: static const struct afd {
   82:         int            a_af;
   83:         socklen_t      a_addrlen;
   84:         socklen_t      a_socklen;
   85:         int            a_off;
   86: } afdl [] = {
   87: #ifdef INET6
   88:         {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
   89:                 offsetof(struct sockaddr_in6, sin6_addr)},
   90: #endif
   91:         {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
   92:                 offsetof(struct sockaddr_in, sin_addr)},
   93:         {0, 0, 0, 0},
   94: };
   95: 
   96: struct sockinet {
   97:         u_char si_len;
   98:         u_char si_family;
   99:         u_short        si_port;
  100: };
  101: 
  102: static int getnameinfo_inet __P((const struct sockaddr *, socklen_t, char *,
  103:     socklen_t, char *, socklen_t, int));
  104: #ifdef INET6
  105: static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
  106:                                  socklen_t, int));
  107: static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t,
  108:                                  int));
  109: #endif
  110: static int getnameinfo_link __P((const struct sockaddr *, socklen_t, char *,
  111:     socklen_t, char *, socklen_t, int));
  112: static int hexname __P((const u_int8_t *, size_t, char *, socklen_t));
  113: 
  114: /*
  115:  * Top-level getnameinfo() code.  Look at the address family, and pick an
  116:  * appropriate function to call.
  117:  */
  118: int
  119: getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
  120:         const struct sockaddr *sa;
  121:         socklen_t salen;
  122:         char *host, *serv;
  123:         socklen_t hostlen, servlen;
  124:         int flags;
  125: {
  126: 
  127:         switch (sa->sa_family) {
  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:         default:
  136:                 return EAI_FAMILY;
  137:         }
  138: }
  139: 
  140: 
  141: /*
  142:  * getnameinfo_inet():
  143:  * Format an IPv4 or IPv6 sockaddr into a printable string.
  144:  */
  145: static int
  146: getnameinfo_inet(sa, salen, host, hostlen, serv, servlen, flags)
  147:         const struct sockaddr *sa;
  148:         socklen_t salen;
  149:         char *host;
  150:         socklen_t hostlen;
  151:         char *serv;
  152:         socklen_t servlen;
  153:         int flags;
  154: {
  155:         const struct afd *afd;
  156:         struct servent *sp;
  157:         struct hostent *hp;
  158:         u_short port;
  159:         int family, i;
  160:         const char *addr;
  161:         u_int32_t v4a;
  162: #ifndef T2EX
  163:         char numserv[512];
  164:         char numaddr[512];
  165: #else
  166:         char numserv[8];       /* Buffer to store a string which represents 
  167:                                    a 'short integer' value. */
  168: #if defined(INET6)
  169:         char numaddr[INET6_ADDRSTRLEN];
  170: #elif defined(INET)
  171:         char numaddr[INET_ADDRSTRLEN];
  172: #else
  173:         char numaddr[INET6_ADDRSTRLEN];
  174: #endif
  175: #endif
  176: 
  177:         /* sa is checked below */
  178:         /* host may be NULL */
  179:         /* serv may be NULL */
  180: 
  181:         if (sa == NULL)
  182:                 return EAI_FAIL;
  183: 
  184: #ifdef BSD4_4
  185:         if (sa->sa_len != salen)
  186:                 return EAI_FAIL;
  187: #endif
  188: 
  189:         family = sa->sa_family;
  190:         for (i = 0; afdl[i].a_af; i++)
  191:                 if (afdl[i].a_af == family) {
  192:                         afd = &afdl[i];
  193:                         goto found;
  194:                 }
  195:         return EAI_FAMILY;
  196: 
  197:  found:
  198:         if (salen != afd->a_socklen)
  199:                 return EAI_FAIL;
  200: 
  201:         /* network byte order */
  202:         port = ((const struct sockinet *)(const void *)sa)->si_port;
  203:         addr = (const char *)(const void *)sa + afd->a_off;
  204: 
  205:         if (serv == NULL || servlen == 0) {
  206:                 /*
  207:                  * do nothing in this case.
  208:                  * in case you are wondering if "&&" is more correct than
  209:                  * "||" here: rfc2553bis-03 says that serv == NULL OR
  210:                  * servlen == 0 means that the caller does not want the result.
  211:                  */
  212:         } else {
  213: #ifdef T2EX
  214:                 struct servent_data svd;
  215:                 struct servent sv;
  216:                 (void)memset(&svd, 0, sizeof(svd));
  217: #endif
  218: 
  219:                 if (flags & NI_NUMERICSERV)
  220:                         sp = NULL;
  221:                 else {
  222: #ifndef T2EX
  223:                         struct servent_data svd;
  224:                         struct servent sv;
  225: 
  226:                         (void)memset(&svd, 0, sizeof(svd));
  227: #endif
  228:                         sp = getservbyport_r(port,
  229:                                 (flags & NI_DGRAM) ? "udp" : "tcp", &sv, &svd);
  230: #ifndef T2EX
  231:                         endservent_r(&svd);
  232: #endif
  233:                 }
  234:                 if (sp) {
  235:                         if (strlen(sp->s_name) + 1 > servlen)
  236:                                 return EAI_MEMORY;
  237:                         strlcpy(serv, sp->s_name, servlen);
  238:                 } else {
  239:                         snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
  240:                         if (strlen(numserv) + 1 > servlen)
  241:                                 return EAI_MEMORY;
  242:                         strlcpy(serv, numserv, servlen);
  243:                 }
  244: 
  245: #ifdef T2EX
  246:                 endservent_r(&svd);
  247: #endif
  248:         }
  249: 
  250:         switch (sa->sa_family) {
  251:         case AF_INET:
  252:                 v4a = (u_int32_t)
  253:                     ntohl(((const struct sockaddr_in *)
  254:                     (const void *)sa)->sin_addr.s_addr);
  255:                 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
  256:                         flags |= NI_NUMERICHOST;
  257:                 v4a >>= IN_CLASSA_NSHIFT;
  258:                 if (v4a == 0)
  259:                         flags |= NI_NUMERICHOST;
  260:                 break;
  261: #ifdef INET6
  262:         case AF_INET6:
  263:             {
  264:                 const struct sockaddr_in6 *sin6;
  265:                 sin6 = (const struct sockaddr_in6 *)(const void *)sa;
  266:                 switch (sin6->sin6_addr.s6_addr[0]) {
  267:                 case 0x00:
  268:                         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
  269:                                 ;
  270:                         else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
  271:                                 ;
  272:                         else
  273:                                 flags |= NI_NUMERICHOST;
  274:                         break;
  275:                 default:
  276:                         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
  277:                                 flags |= NI_NUMERICHOST;
  278:                         }
  279:                         else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
  280:                                 flags |= NI_NUMERICHOST;
  281:                         break;
  282:                 }
  283:             }
  284:                 break;
  285: #endif
  286:         }
  287:         if (host == NULL || hostlen == 0) {
  288:                 /*
  289:                  * do nothing in this case.
  290:                  * in case you are wondering if "&&" is more correct than
  291:                  * "||" here: rfc2553bis-03 says that host == NULL or
  292:                  * hostlen == 0 means that the caller does not want the result.
  293:                  */
  294:         } else if (flags & NI_NUMERICHOST) {
  295:                 size_t numaddrlen;
  296: 
  297:                 /* NUMERICHOST and NAMEREQD conflicts with each other */
  298:                 if (flags & NI_NAMEREQD)
  299:                         return EAI_NONAME;
  300: 
  301:                 switch(afd->a_af) {
  302: #ifdef INET6
  303:                 case AF_INET6:
  304:                 {
  305:                         int error;
  306: 
  307:                         if ((error = ip6_parsenumeric(sa, addr, host,
  308:                                                       hostlen, flags)) != 0)
  309:                                 return(error);
  310:                         break;
  311:                 }
  312: #endif
  313:                 default:
  314:                         if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
  315:                             == NULL)
  316:                                 return EAI_SYSTEM;
  317:                         numaddrlen = strlen(numaddr);
  318:                         if (numaddrlen + 1 > hostlen) /* don't forget terminator */
  319:                                 return EAI_MEMORY;
  320:                         strlcpy(host, numaddr, hostlen);
  321:                         break;
  322:                 }
  323:         } else {
  324:                 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
  325: 
  326:                 if (hp) {
  327: #if 0
  328:                         /*
  329:                          * commented out, since "for local host" is not
  330:                          * implemented here - see RFC2553 p30
  331:                          */
  332:                         if (flags & NI_NOFQDN) {
  333:                                 char *p;
  334:                                 p = strchr(hp->h_name, '.');
  335:                                 if (p)
  336:                                         *p = '\0';
  337:                         }
  338: #endif
  339:                         if (strlen(hp->h_name) + 1 > hostlen) {
  340:                                 return EAI_MEMORY;
  341:                         }
  342:                         strlcpy(host, hp->h_name, hostlen);
  343:                 } else {
  344:                         if (flags & NI_NAMEREQD)
  345:                                 return EAI_NONAME;
  346:                         switch(afd->a_af) {
  347: #ifdef INET6
  348:                         case AF_INET6:
  349:                         {
  350:                                 int error;
  351: 
  352:                                 if ((error = ip6_parsenumeric(sa, addr, host,
  353:                                                               hostlen,
  354:                                                               flags)) != 0)
  355:                                         return(error);
  356:                                 break;
  357:                         }
  358: #endif
  359:                         default:
  360:                                 if (inet_ntop(afd->a_af, addr, host,
  361:                                     hostlen) == NULL)
  362:                                         return EAI_SYSTEM;
  363:                                 break;
  364:                         }
  365:                 }
  366:         }
  367:         return(0);
  368: }
  369: 
  370: #ifdef INET6
  371: static int
  372: ip6_parsenumeric(sa, addr, host, hostlen, flags)
  373:         const struct sockaddr *sa;
  374:         const char *addr;
  375:         char *host;
  376:         socklen_t hostlen;
  377:         int flags;
  378: {
  379:         size_t numaddrlen;
  380:         char numaddr[512];
  381: 
  382:         _DIAGASSERT(sa != NULL);
  383:         _DIAGASSERT(addr != NULL);
  384:         _DIAGASSERT(host != NULL);
  385: 
  386:         if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
  387:                 return EAI_SYSTEM;
  388: 
  389:         numaddrlen = strlen(numaddr);
  390:         if (numaddrlen + 1 > hostlen) /* don't forget terminator */
  391:                 return EAI_OVERFLOW;
  392:         strlcpy(host, numaddr, hostlen);
  393: 
  394:         if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) {
  395:                 char zonebuf[MAXHOSTNAMELEN];
  396:                 int zonelen;
  397: 
  398:                 zonelen = ip6_sa2str(
  399:                     (const struct sockaddr_in6 *)(const void *)sa,
  400:                     zonebuf, sizeof(zonebuf), flags);
  401:                 if (zonelen < 0)
  402:                         return EAI_OVERFLOW;
  403:                 if ((size_t) zonelen + 1 + numaddrlen + 1 > hostlen)
  404:                         return EAI_OVERFLOW;
  405:                 /* construct <numeric-addr><delim><zoneid> */
  406:                 memcpy(host + numaddrlen + 1, zonebuf,
  407:                     (size_t)zonelen);
  408:                 host[numaddrlen] = SCOPE_DELIMITER;
  409:                 host[numaddrlen + 1 + zonelen] = '\0';
  410:         }
  411: 
  412:         return 0;
  413: }
  414: 
  415: /* ARGSUSED */
  416: static int
  417: ip6_sa2str(sa6, buf, bufsiz, flags)
  418:         const struct sockaddr_in6 *sa6;
  419:         char *buf;
  420:         size_t bufsiz;
  421:         int flags;
  422: {
  423:         unsigned int ifindex;
  424:         const struct in6_addr *a6;
  425:         int n;
  426: 
  427:         _DIAGASSERT(sa6 != NULL);
  428:         _DIAGASSERT(buf != NULL);
  429: 
  430:         ifindex = (unsigned int)sa6->sin6_scope_id;
  431:         a6 = &sa6->sin6_addr;
  432: 
  433: #ifdef NI_NUMERICSCOPE
  434:         if ((flags & NI_NUMERICSCOPE) != 0) {
  435:                 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
  436:                 if (n < 0 || n >= bufsiz)
  437:                         return -1;
  438:                 else
  439:                         return n;
  440:         }
  441: #endif
  442: 
  443:         /* if_indextoname() does not take buffer size.  not a good api... */
  444:         if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
  445:             bufsiz >= IF_NAMESIZE) {
  446:                 char *p = if_indextoname(ifindex, buf);
  447:                 if (p) {
  448:                         return(strlen(p));
  449:                 }
  450:         }
  451: 
  452:         /* last resort */
  453:         n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
  454:         if (n < 0 || (size_t) n >= bufsiz)
  455:                 return -1;
  456:         else
  457:                 return n;
  458: }
  459: #endif /* INET6 */
  460: 
  461: 
  462: /*
  463:  * getnameinfo_link():
  464:  * Format a link-layer address into a printable format, paying attention to
  465:  * the interface type.
  466:  */
  467: /* ARGSUSED */
  468: static int
  469: getnameinfo_link(const struct sockaddr *sa, socklen_t salen,
  470:     char *host, socklen_t hostlen, char *serv, socklen_t servlen,
  471:     int flags)
  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:         switch (sdl->sdl_type) {
  491: #ifdef IFT_ECONET
  492:         case IFT_ECONET:
  493:                 if (sdl->sdl_alen < 2)
  494:                         return EAI_FAMILY;
  495:                 if (CLLADDR(sdl)[1] == 0)
  496:                         n = snprintf(host, hostlen, "%u", CLLADDR(sdl)[0]);
  497:                 else
  498:                         n = snprintf(host, hostlen, "%u.%u",
  499:                             CLLADDR(sdl)[1], CLLADDR(sdl)[0]);
  500:                 if (n < 0 || (socklen_t) n >= hostlen) {
  501:                         *host = '\0';
  502:                         return EAI_MEMORY;
  503:                 } else
  504:                         return 0;
  505: #endif
  506:         case IFT_IEEE1394:
  507:                 if (sdl->sdl_alen < sizeof(iha->iha_uid))
  508:                         return EAI_FAMILY;
  509:                 iha =
  510:                     (const struct ieee1394_hwaddr *)(const void *)CLLADDR(sdl);
  511:                 return hexname(iha->iha_uid, sizeof(iha->iha_uid),
  512:                     host, hostlen);
  513:         /*
  514:          * The following have zero-length addresses.
  515:          * IFT_ATM     (net/if_atmsubr.c)
  516:          * IFT_FAITH   (net/if_faith.c)
  517:          * IFT_GIF     (net/if_gif.c)
  518:          * IFT_LOOP    (net/if_loop.c)
  519:          * IFT_PPP     (net/if_ppp.c, net/if_spppsubr.c)
  520:          * IFT_SLIP    (net/if_sl.c, net/if_strip.c)
  521:          * IFT_STF     (net/if_stf.c)
  522:          * IFT_L2VLAN  (net/if_vlan.c)
  523:          * IFT_PROPVIRTUAL (net/if_bridge.h>
  524:          */
  525:         /*
  526:          * The following use IPv4 addresses as link-layer addresses:
  527:          * IFT_OTHER   (net/if_gre.c)
  528:          */
  529:         case IFT_ARCNET: /* default below is believed correct for all these. */
  530:         case IFT_ETHER:
  531:         case IFT_FDDI:
  532:         case IFT_HIPPI:
  533:         case IFT_ISO88025:
  534:         default:
  535:                 return hexname((const u_int8_t *)CLLADDR(sdl),
  536:                     (size_t)sdl->sdl_alen, host, hostlen);
  537:         }
  538: }
  539: 
  540: static int
  541: hexname(cp, len, host, hostlen)
  542:         const u_int8_t *cp;
  543:         char *host;
  544:         size_t len;
  545:         socklen_t hostlen;
  546: {
  547:         int n;
  548:         size_t i;
  549:         char *outp = host;
  550: 
  551:         *outp = '\0';
  552:         for (i = 0; i < len; i++) {
  553:                 n = snprintf(outp, hostlen, "%s%02x",
  554:                     i ? ":" : "", cp[i]);
  555:                 if (n < 0 || (socklen_t) n >= hostlen) {
  556:                         *host = '\0';
  557:                         return EAI_MEMORY;
  558:                 }
  559:                 outp += n;
  560:                 hostlen -= n;
  561:         }
  562:         return 0;
  563: }