resolv/ns_samename.c

   1 /* Check if two domain names are equal after trailing dot normalization.
   2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (c) 1995,1999 by Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  10  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  11  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  12  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  13  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  14  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  15  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  16  * SOFTWARE.
  17  */
  18
  19 #include <arpa/nameser.h>
  20 #include <string.h>
  21
  22 /* Determines whether domain name A is the same as domain name B.
  23    Returns -1 on error, 0 if names differ, 1 if names are the
  24    same.  */
  25 int
  26 __libc_ns_samename (const char *a, const char *b)
  27 {
  28   char ta[NS_MAXDNAME], tb[NS_MAXDNAME];
  29
  30   if (__libc_ns_makecanon (a, ta, sizeof ta) < 0 ||
  31       __libc_ns_makecanon (b, tb, sizeof tb) < 0)
  32     return -1;
  33   if (__strcasecmp (ta, tb) == 0)
  34     return 1;
  35   else
  36     return 0;
  37 }
  38 libc_hidden_def (__libc_ns_samename)