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