The Tcpdump Group git mirrors - tcpdump/blob - missing/getnameinfo.c

   1 /*
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * Issues to be discussed:
  32  * - Thread safe-ness must be checked
  33  * - Return values.  There seems to be no standard for return value (RFC2553)
  34  *   but INRIA implementation returns EAI_xxx defined for getaddrinfo().
  35  * - RFC2553 says that we should raise error on short buffer.  X/Open says
  36  *   we need to truncate the result.  We obey RFC2553 (and X/Open should be
  37  *   modified).
  38  */
  39
  40 #ifdef HAVE_CONFIG_H
  41 #include <config.h>
  42 #endif
  43
  44 #ifndef lint
  45 static const char rcsid[] =
  46      "@(#) $Header: /tcpdump/master/tcpdump/missing/getnameinfo.c,v 1.5 2000-01-19 04:42:21 itojun Exp $";
  47 #endif
  48
  49 #include <sys/types.h>
  50 #include <sys/socket.h>
  51 #include <net/if.h>
  52 #include <netinet/in.h>
  53 #include <arpa/inet.h>
  54 #include <arpa/nameser.h>
  55 #include <netdb.h>
  56 #include <resolv.h>
  57 #include <string.h>
  58 #include <stddef.h>
  59 #include <errno.h>
  60
  61 #ifndef HAVE_PORTABLE_PROTOTYPE
  62 #include "cdecl_ext.h"
  63 #endif
  64
  65 #ifndef HAVE_ADDRINFO
  66 #include "addrinfo.h"
  67 #endif
  68
  69 #define SUCCESS 0
  70 #define ANY 0
  71 #define YES 1
  72 #define NO  0
  73
  74 static struct afd {
  75         int a_af;
  76         int a_addrlen;
  77         int a_socklen;
  78         int a_off;
  79 } afdl [] = {
  80 #ifdef INET6
  81         {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
  82                 offsetof(struct sockaddr_in6, sin6_addr)},
  83 #endif
  84         {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
  85                 offsetof(struct sockaddr_in, sin_addr)},
  86         {0, 0, 0},
  87 };
  88
  89 struct sockinet {
  90         u_char  si_len;
  91         u_char  si_family;
  92         u_short si_port;
  93 };
  94
  95 #define ENI_NOSOCKET    0
  96 #define ENI_NOSERVNAME  1
  97 #define ENI_NOHOSTNAME  2
  98 #define ENI_MEMORY      3
  99 #define ENI_SYSTEM      4
 100 #define ENI_FAMILY      5
 101 #define ENI_SALEN       6
 102
 103 int
 104 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
 105         const struct sockaddr *sa;
 106         size_t salen;
 107         char *host;
 108         size_t hostlen;
 109         char *serv;
 110         size_t servlen;
 111         int flags;
 112 {
 113         struct afd *afd;
 114         struct servent *sp;
 115         struct hostent *hp;
 116         u_short port;
 117         int family, i;
 118         char *addr, *p;
 119         u_int32_t v4a;
 120         int h_error;
 121         char numserv[512];
 122         char numaddr[512];
 123
 124         if (sa == NULL)
 125                 return ENI_NOSOCKET;
 126
 127 #ifdef HAVE_SA_LEN      /*XXX*/
 128         if (sa->sa_len != salen)
 129                 return ENI_SALEN;
 130 #endif
 131
 132         family = sa->sa_family;
 133         for (i = 0; afdl[i].a_af; i++)
 134                 if (afdl[i].a_af == family) {
 135                         afd = &afdl[i];
 136                         goto found;
 137                 }
 138         return ENI_FAMILY;
 139
 140  found:
 141         if (salen != afd->a_socklen)
 142                 return ENI_SALEN;
 143
 144         port = ((struct sockinet *)sa)->si_port; /* network byte order */
 145         addr = (char *)sa + afd->a_off;
 146
 147         if (serv == NULL || servlen == 0) {
 148                 /*
 149                  * do nothing in this case.
 150                  * in case you are wondering if "&&" is more correct than
 151                  * "||" here: RFC2553 says that serv == NULL OR servlen == 0
 152                  * means that the caller does not want the result.
 153                  */
 154         } else {
 155                 if (flags & NI_NUMERICSERV)
 156                         sp = NULL;
 157                 else {
 158                         sp = getservbyport(port,
 159                                 (flags & NI_DGRAM) ? "udp" : "tcp");
 160                 }
 161                 if (sp) {
 162                         if (strlen(sp->s_name) > servlen)
 163                                 return ENI_MEMORY;
 164                         strcpy(serv, sp->s_name);
 165                 } else {
 166                         snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
 167                         if (strlen(numserv) > servlen)
 168                                 return ENI_MEMORY;
 169                         strcpy(serv, numserv);
 170                 }
 171         }
 172
 173         switch (sa->sa_family) {
 174         case AF_INET:
 175                 v4a = (u_int32_t)
 176                         ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr);
 177                 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
 178                         flags |= NI_NUMERICHOST;
 179                 v4a >>= IN_CLASSA_NSHIFT;
 180                 if (v4a == 0)
 181                         flags |= NI_NUMERICHOST;
 182                 break;
 183 #ifdef INET6
 184         case AF_INET6:
 185             {
 186                 struct sockaddr_in6 *sin6;
 187                 sin6 = (struct sockaddr_in6 *)sa;
 188                 switch (sin6->sin6_addr.s6_addr[0]) {
 189                 case 0x00:
 190                         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 191                                 ;
 192                         else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
 193                                 ;
 194                         else
 195                                 flags |= NI_NUMERICHOST;
 196                         break;
 197                 default:
 198                         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
 199                                 flags |= NI_NUMERICHOST;
 200                         }
 201                         else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 202                                 flags |= NI_NUMERICHOST;
 203                         break;
 204                 }
 205             }
 206                 break;
 207 #endif
 208         }
 209         if (host == NULL || hostlen == 0) {
 210                 /*
 211                  * do nothing in this case.
 212                  * in case you are wondering if "&&" is more correct than
 213                  * "||" here: RFC2553 says that host == NULL OR hostlen == 0
 214                  * means that the caller does not want the result.
 215                  */
 216         } else if (flags & NI_NUMERICHOST) {
 217                 /* NUMERICHOST and NAMEREQD conflicts with each other */
 218                 if (flags & NI_NAMEREQD)
 219                         return ENI_NOHOSTNAME;
 220                 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
 221                     == NULL)
 222                         return ENI_SYSTEM;
 223                 if (strlen(numaddr) > hostlen)
 224                         return ENI_MEMORY;
 225                 strcpy(host, numaddr);
 226 #if defined(INET6) && defined(NI_WITHSCOPEID)
 227                 if (afd->a_af == AF_INET6 &&
 228                     (IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr) ||
 229                      IN6_IS_ADDR_MULTICAST((struct in6_addr *)addr)) &&
 230                     ((struct sockaddr_in6 *)sa)->sin6_scope_id) {
 231 #ifndef ALWAYS_WITHSCOPE
 232                         if (flags & NI_WITHSCOPEID)
 233 #endif /* !ALWAYS_WITHSCOPE */
 234                         {
 235                                 char *ep = strchr(host, '\0');
 236                                 unsigned int ifindex =
 237                                         ((struct sockaddr_in6 *)sa)->sin6_scope_id;
 238
 239                                 *ep = SCOPE_DELIMITER;
 240                                 if ((if_indextoname(ifindex, ep + 1)) == NULL)
 241                                         /* XXX what should we do? */
 242                                         strncpy(ep + 1, "???", 3);
 243                         }
 244                 }
 245 #endif /* INET6 */
 246         } else {
 247 #ifdef USE_GETIPNODEBY
 248                 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
 249 #else
 250                 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
 251 #ifdef HAVE_H_ERRNO
 252                 h_error = h_errno;
 253 #else
 254                 h_error = EINVAL;
 255 #endif
 256 #endif
 257
 258                 if (hp) {
 259                         if (flags & NI_NOFQDN) {
 260                                 p = strchr(hp->h_name, '.');
 261                                 if (p) *p = '\0';
 262                         }
 263                         if (strlen(hp->h_name) > hostlen) {
 264 #ifdef USE_GETIPNODEBY
 265                                 freehostent(hp);
 266 #endif
 267                                 return ENI_MEMORY;
 268                         }
 269                         strcpy(host, hp->h_name);
 270 #ifdef USE_GETIPNODEBY
 271                         freehostent(hp);
 272 #endif
 273                 } else {
 274                         if (flags & NI_NAMEREQD)
 275                                 return ENI_NOHOSTNAME;
 276                         if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
 277                             == NULL)
 278                                 return ENI_NOHOSTNAME;
 279                         if (strlen(numaddr) > hostlen)
 280                                 return ENI_MEMORY;
 281                         strcpy(host, numaddr);
 282                 }
 283         }
 284         return SUCCESS;
 285 }