lib/roken/getipnodebyname.c

   1 /*
   2  * Copyright (c) 1999 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <config.h>
  35
  36 #include "roken.h"
  37
  38 #ifndef HAVE_H_ERRNO
  39 static int h_errno = NO_RECOVERY;
  40 #endif
  41
  42 /*
  43  * lookup `name' (address family `af') in DNS and return a pointer
  44  * to a malloced struct hostent or NULL.
  45  */
  46
  47 struct hostent * ROKEN_LIB_FUNCTION
  48 getipnodebyname (const char *name, int af, int flags, int *error_num)
  49 {
  50     struct hostent *tmp;
  51
  52 #ifdef HAVE_GETHOSTBYNAME2
  53     tmp = gethostbyname2 (name, af);
  54 #else
  55     if (af != AF_INET) {
  56         *error_num = NO_ADDRESS;
  57         return NULL;
  58     }
  59     tmp = gethostbyname (name);
  60 #endif
  61     if (tmp == NULL) {
  62         switch (h_errno) {
  63         case HOST_NOT_FOUND :
  64         case TRY_AGAIN :
  65         case NO_RECOVERY :
  66             *error_num = h_errno;
  67             break;
  68         case NO_DATA :
  69             *error_num = NO_ADDRESS;
  70             break;
  71         default :
  72             *error_num = NO_RECOVERY;
  73             break;
  74         }
  75         return NULL;
  76     }
  77     tmp = copyhostent (tmp);
  78     if (tmp == NULL) {
  79         *error_num = TRY_AGAIN;
  80         return NULL;
  81     }
  82     return tmp;
  83 }