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  */
  36
  37 #ifdef HAVE_CONFIG_H
  38 #include "config.h"
  39 #endif
  40
  41 #ifndef lint
  42 static const char rcsid[] =
  43      "@(#) $Header: /tcpdump/master/tcpdump/missing/getnameinfo.c,v 1.4 2000-01-09 21:35:44 fenner Exp $";
  44 #endif
  45
  46 #include <sys/types.h>
  47 #include <sys/socket.h>
  48 #include <net/if.h>
  49 #include <netinet/in.h>
  50 #include <arpa/inet.h>
  51 #include <arpa/nameser.h>
  52 #include <netdb.h>
  53 #include <resolv.h>
  54 #include <string.h>
  55 #include <stddef.h>
  56 #include <errno.h>
  57
  58 #ifndef HAVE_PORTABLE_PROTOTYPE
  59 #include "cdecl_ext.h"
  60 #endif
  61
  62 #include "addrinfo.h"
  63
  64 #define SUCCESS 0
  65 #define ANY 0
  66 #define YES 1
  67 #define NO  0
  68
  69 static struct afd {
  70         int a_af;
  71         int a_addrlen;
  72         int a_socklen;
  73         int a_off;
  74 } afdl [] = {
  75 #ifdef INET6
  76         {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
  77                 offsetof(struct sockaddr_in6, sin6_addr)},
  78 #endif
  79         {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
  80                 offsetof(struct sockaddr_in, sin_addr)},
  81         {0, 0, 0},
  82 };
  83
  84 struct sockinet {
  85         u_char  si_len;
  86         u_char  si_family;
  87         u_short si_port;
  88 };
  89
  90 #define ENI_NOSOCKET    0
  91 #define ENI_NOSERVNAME  1
  92 #define ENI_NOHOSTNAME  2
  93 #define ENI_MEMORY      3
  94 #define ENI_SYSTEM      4
  95 #define ENI_FAMILY      5
  96 #define ENI_SALEN       6
  97
  98 int
  99 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
 100         const struct sockaddr *sa;
 101         size_t salen;
 102         char *host;
 103         size_t hostlen;
 104         char *serv;
 105         size_t servlen;
 106         int flags;
 107 {
 108         struct afd *afd;
 109         struct servent *sp;
 110         struct hostent *hp;
 111         u_short port;
 112         int family, i;
 113         char *addr, *p;
 114         u_long v4a;
 115         int h_error;
 116         char numserv[512];
 117         char numaddr[512];
 118
 119         if (sa == NULL)
 120                 return ENI_NOSOCKET;
 121
 122 #ifdef HAVE_SA_LEN      /*XXX*/
 123         if (sa->sa_len != salen)
 124                 return ENI_SALEN;
 125 #endif
 126
 127         family = sa->sa_family;
 128         for (i = 0; afdl[i].a_af; i++)
 129                 if (afdl[i].a_af == family) {
 130                         afd = &afdl[i];
 131                         goto found;
 132                 }
 133         return ENI_FAMILY;
 134
 135  found:
 136         if (salen != afd->a_socklen)
 137                 return ENI_SALEN;
 138
 139         port = ((struct sockinet *)sa)->si_port; /* network byte order */
 140         addr = (char *)sa + afd->a_off;
 141
 142         if (serv == NULL || servlen == 0) {
 143                 /* what we should do? */
 144         } else {
 145                 if (flags & NI_NUMERICSERV)
 146                         sp = NULL;
 147                 else {
 148                         sp = getservbyport(port,
 149                                 (flags & NI_DGRAM) ? "udp" : "tcp");
 150                 }
 151                 if (sp) {
 152                         if (strlen(sp->s_name) > servlen)
 153                                 return ENI_MEMORY;
 154                         strcpy(serv, sp->s_name);
 155                 } else {
 156                         sprintf(numserv, "%d", ntohs(port));
 157                         if (strlen(numserv) > servlen)
 158                                 return ENI_MEMORY;
 159                         strcpy(serv, numserv);
 160                 }
 161         }
 162
 163         switch (sa->sa_family) {
 164         case AF_INET:
 165                 v4a = ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr);
 166                 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
 167                         flags |= NI_NUMERICHOST;
 168                 v4a >>= IN_CLASSA_NSHIFT;
 169                 if (v4a == 0 || v4a == IN_LOOPBACKNET)
 170                         flags |= NI_NUMERICHOST;
 171                 break;
 172 #ifdef INET6
 173         case AF_INET6:
 174             {
 175                 struct sockaddr_in6 *sin6;
 176                 sin6 = (struct sockaddr_in6 *)sa;
 177                 switch (sin6->sin6_addr.s6_addr[0]) {
 178                 case 0x00:
 179                         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 180                                 ;
 181                         else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
 182                                 ;
 183                         else
 184                                 flags |= NI_NUMERICHOST;
 185                         break;
 186                 default:
 187                         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
 188                                 flags |= NI_NUMERICHOST;
 189                         }
 190                         else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 191                                 flags |= NI_NUMERICHOST;
 192                         break;
 193                 }
 194             }
 195                 break;
 196 #endif
 197         }
 198         if (host == NULL || hostlen == 0) {
 199                 /* what should we do? */
 200         } else if (flags & NI_NUMERICHOST) {
 201                 /* NUMERICHOST and NAMEREQD conflicts with each other */
 202                 if (flags & NI_NAMEREQD)
 203                         return ENI_NOHOSTNAME;
 204                 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
 205                     == NULL)
 206                         return ENI_SYSTEM;
 207                 if (strlen(numaddr) > hostlen)
 208                         return ENI_MEMORY;
 209                 strcpy(host, numaddr);
 210 #ifdef INET6
 211                 if (afd->a_af == AF_INET6 &&
 212                     (IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr) ||
 213                      IN6_IS_ADDR_MULTICAST((struct in6_addr *)addr)) &&
 214                     ((struct sockaddr_in6 *)sa)->sin6_scope_id) {
 215 #ifndef ALWAYS_WITHSCOPE
 216                         if (flags & NI_WITHSCOPEID)
 217 #endif /* !ALWAYS_WITHSCOPE */
 218                         {
 219                                 char *ep = strchr(host, '\0');
 220                                 unsigned int ifindex =
 221                                         ((struct sockaddr_in6 *)sa)->sin6_scope_id;
 222
 223                                 *ep = SCOPE_DELIMITER;
 224                                 if ((if_indextoname(ifindex, ep + 1)) == NULL)
 225                                         /* XXX what should we do? */
 226                                         strncpy(ep + 1, "???", 3);
 227                         }
 228                 }
 229 #endif /* INET6 */
 230         } else {
 231 #ifdef USE_GETIPNODEBY
 232                 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
 233 #else
 234                 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
 235 #ifdef HAVE_H_ERRNO
 236                 h_error = h_errno;
 237 #else
 238                 h_error = EINVAL;
 239 #endif
 240 #endif
 241
 242                 if (hp) {
 243                         if (flags & NI_NOFQDN) {
 244                                 p = strchr(hp->h_name, '.');
 245                                 if (p) *p = '\0';
 246                         }
 247                         if (strlen(hp->h_name) > hostlen) {
 248 #ifdef USE_GETIPNODEBY
 249                                 freehostent(hp);
 250 #endif
 251                                 return ENI_MEMORY;
 252                         }
 253                         strcpy(host, hp->h_name);
 254 #ifdef USE_GETIPNODEBY
 255                         freehostent(hp);
 256 #endif
 257                 } else {
 258                         if (flags & NI_NAMEREQD)
 259                                 return ENI_NOHOSTNAME;
 260                         if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
 261                             == NULL)
 262                                 return ENI_NOHOSTNAME;
 263                         if (strlen(numaddr) > hostlen)
 264                                 return ENI_MEMORY;
 265                         strcpy(host, numaddr);
 266                 }
 267         }
 268         return SUCCESS;
 269 }