sunrpc/rpc_gethostbyname.c

   1 /* IPv4-only variant of gethostbyname.
   2    Copyright (C) 2016-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If
  17    not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <netdb.h>
  21 #include <rpc/rpc.h>
  22 #include <scratch_buffer.h>
  23 #include <string.h>
  24
  25 int
  26 __libc_rpc_gethostbyname (const char *host, struct sockaddr_in *addr)
  27 {
  28   struct hostent hostbuf;
  29   struct hostent *hp = NULL;
  30   int herr;
  31   struct scratch_buffer tmpbuf;
  32   scratch_buffer_init (&tmpbuf);
  33
  34   while (__gethostbyname2_r (host, AF_INET,
  35                              &hostbuf, tmpbuf.data, tmpbuf.length, &hp,
  36                              &herr) != 0
  37          || hp == NULL)
  38     if (herr != NETDB_INTERNAL || errno != ERANGE)
  39       {
  40         struct rpc_createerr *ce = &get_rpc_createerr ();
  41         ce->cf_stat = RPC_UNKNOWNHOST;
  42         scratch_buffer_free (&tmpbuf);
  43         return -1;
  44       }
  45     else
  46       {
  47         if (!scratch_buffer_grow (&tmpbuf))
  48           {
  49             /* If memory allocation failed, allocating the RPC error
  50                structure might could as well, so this could lead to a
  51                crash.  */
  52             struct rpc_createerr *ce = &get_rpc_createerr ();
  53             ce->cf_stat = RPC_SYSTEMERROR;
  54             ce->cf_error.re_errno = ENOMEM;
  55             return -1;
  56           }
  57       }
  58
  59   if (hp->h_addrtype != AF_INET || hp->h_length != sizeof (addr->sin_addr))
  60     {
  61       struct rpc_createerr *ce = &get_rpc_createerr ();
  62       ce->cf_stat = RPC_SYSTEMERROR;
  63       ce->cf_error.re_errno = EAFNOSUPPORT;
  64       scratch_buffer_free (&tmpbuf);
  65       return -1;
  66     }
  67
  68   addr->sin_family = AF_INET;
  69   addr->sin_port = htons (0);
  70   memcpy (&addr->sin_addr, hp->h_addr, sizeof (addr->sin_addr));
  71   scratch_buffer_free (&tmpbuf);
  72   return 0;
  73 }