contrib/tcpdump-3.8.3/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[] _U_ =
  46      "@(#) $Header: /tcpdump/master/tcpdump/missing/getnameinfo.c,v 1.9.2.2 2003/11/16 08:52:00 guy 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 #ifdef NEED_ADDRINFO_H
  62 #include "addrinfo.h"
  63 #endif
  64
  65 #define SUCCESS 0
  66 #define ANY 0
  67 #define YES 1
  68 #define NO  0
  69
  70 static struct afd {
  71         int a_af;
  72         int a_addrlen;
  73         int a_socklen;
  74         int a_off;
  75 } afdl [] = {
  76 #ifdef INET6
  77         {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
  78                 offsetof(struct sockaddr_in6, sin6_addr)},
  79 #endif
  80         {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
  81                 offsetof(struct sockaddr_in, sin_addr)},
  82         {0, 0, 0},
  83 };
  84
  85 struct sockinet {
  86         u_char  si_len;
  87         u_char  si_family;
  88         u_short si_port;
  89 };
  90
  91 #define ENI_NOSOCKET    0
  92 #define ENI_NOSERVNAME  1
  93 #define ENI_NOHOSTNAME  2
  94 #define ENI_MEMORY      3
  95 #define ENI_SYSTEM      4
  96 #define ENI_FAMILY      5
  97 #define ENI_SALEN       6
  98
  99 int
 100 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
 101         const struct sockaddr *sa;
 102         size_t salen;
 103         char *host;
 104         size_t hostlen;
 105         char *serv;
 106         size_t servlen;
 107         int flags;
 108 {
 109         struct afd *afd;
 110         struct servent *sp;
 111         struct hostent *hp;
 112         u_short port;
 113         int family, i;
 114         char *addr, *p;
 115         u_int32_t v4a;
 116         int h_error;
 117         char numserv[512];
 118         char numaddr[512];
 119
 120         if (sa == NULL)
 121                 return ENI_NOSOCKET;
 122
 123 #ifdef HAVE_SA_LEN      /*XXX*/
 124         if (sa->sa_len != salen)
 125                 return ENI_SALEN;
 126 #endif
 127
 128         family = sa->sa_family;
 129         for (i = 0; afdl[i].a_af; i++)
 130                 if (afdl[i].a_af == family) {
 131                         afd = &afdl[i];
 132                         goto found;
 133                 }
 134         return ENI_FAMILY;
 135
 136  found:
 137         if (salen != afd->a_socklen)
 138                 return ENI_SALEN;
 139
 140         port = ((struct sockinet *)sa)->si_port; /* network byte order */
 141         addr = (char *)sa + afd->a_off;
 142
 143         if (serv == NULL || servlen == 0) {
 144                 /*
 145                  * do nothing in this case.
 146                  * in case you are wondering if "&&" is more correct than
 147                  * "||" here: RFC2553 says that serv == NULL OR servlen == 0
 148                  * means that the caller does not want the result.
 149                  */
 150         } else {
 151                 if (flags & NI_NUMERICSERV)
 152                         sp = NULL;
 153                 else {
 154                         sp = getservbyport(port,
 155                                 (flags & NI_DGRAM) ? "udp" : "tcp");
 156                 }
 157                 if (sp) {
 158                         if (strlen(sp->s_name) + 1 > servlen)
 159                                 return ENI_MEMORY;
 160                         strcpy(serv, sp->s_name);
 161                 } else {
 162                         snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
 163                         if (strlen(numserv) + 1 > servlen)
 164                                 return ENI_MEMORY;
 165                         strcpy(serv, numserv);
 166                 }
 167         }
 168
 169         switch (sa->sa_family) {
 170         case AF_INET:
 171                 v4a = (u_int32_t)
 172                         ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr);
 173                 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
 174                         flags |= NI_NUMERICHOST;
 175                 v4a >>= IN_CLASSA_NSHIFT;
 176                 if (v4a == 0)
 177                         flags |= NI_NUMERICHOST;
 178                 break;
 179 #ifdef INET6
 180         case AF_INET6:
 181             {
 182                 struct sockaddr_in6 *sin6;
 183                 sin6 = (struct sockaddr_in6 *)sa;
 184                 switch (sin6->sin6_addr.s6_addr[0]) {
 185                 case 0x00:
 186                         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 187                                 ;
 188                         else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
 189                                 ;
 190                         else
 191                                 flags |= NI_NUMERICHOST;
 192                         break;
 193                 default:
 194                         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
 195                                 flags |= NI_NUMERICHOST;
 196                         }
 197                         else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 198                                 flags |= NI_NUMERICHOST;
 199                         break;
 200                 }
 201             }
 202                 break;
 203 #endif
 204         }
 205         if (host == NULL || hostlen == 0) {
 206                 /*
 207                  * do nothing in this case.
 208                  * in case you are wondering if "&&" is more correct than
 209                  * "||" here: RFC2553 says that host == NULL OR hostlen == 0
 210                  * means that the caller does not want the result.
 211                  */
 212         } else if (flags & NI_NUMERICHOST) {
 213                 /* NUMERICHOST and NAMEREQD conflicts with each other */
 214                 if (flags & NI_NAMEREQD)
 215                         return ENI_NOHOSTNAME;
 216                 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
 217                     == NULL)
 218                         return ENI_SYSTEM;
 219                 if (strlen(numaddr) + 1 > hostlen)
 220                         return ENI_MEMORY;
 221                 strcpy(host, numaddr);
 222 #if defined(INET6) && defined(NI_WITHSCOPEID)
 223                 if (afd->a_af == AF_INET6 &&
 224                     (IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr) ||
 225                      IN6_IS_ADDR_MULTICAST((struct in6_addr *)addr)) &&
 226                     ((struct sockaddr_in6 *)sa)->sin6_scope_id) {
 227 #ifndef ALWAYS_WITHSCOPE
 228                         if (flags & NI_WITHSCOPEID)
 229 #endif /* !ALWAYS_WITHSCOPE */
 230                         {
 231                                 char *ep = strchr(host, '\0');
 232                                 unsigned int ifindex =
 233                                         ((struct sockaddr_in6 *)sa)->sin6_scope_id;
 234
 235                                 *ep = SCOPE_DELIMITER;
 236                                 if ((if_indextoname(ifindex, ep + 1)) == NULL)
 237                                         /* XXX what should we do? */
 238                                         strncpy(ep + 1, "???", 3);
 239                         }
 240                 }
 241 #endif /* INET6 */
 242         } else {
 243 #ifdef USE_GETIPNODEBY
 244                 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
 245 #else
 246                 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
 247 #ifdef HAVE_H_ERRNO
 248                 h_error = h_errno;
 249 #else
 250                 h_error = EINVAL;
 251 #endif
 252 #endif
 253
 254                 if (hp) {
 255                         if (flags & NI_NOFQDN) {
 256                                 p = strchr(hp->h_name, '.');
 257                                 if (p) *p = '\0';
 258                         }
 259                         if (strlen(hp->h_name) + 1 > hostlen) {
 260 #ifdef USE_GETIPNODEBY
 261                                 freehostent(hp);
 262 #endif
 263                                 return ENI_MEMORY;
 264                         }
 265                         strcpy(host, hp->h_name);
 266 #ifdef USE_GETIPNODEBY
 267                         freehostent(hp);
 268 #endif
 269                 } else {
 270                         if (flags & NI_NAMEREQD)
 271                                 return ENI_NOHOSTNAME;
 272                         if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
 273                             == NULL)
 274                                 return ENI_NOHOSTNAME;
 275                         if (strlen(numaddr) + 1 > hostlen)
 276                                 return ENI_MEMORY;
 277                         strcpy(host, numaddr);
 278                 }
 279         }
 280         return SUCCESS;
 281 }