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