1 /* IPv4-only variant of gethostbyname.
2    Copyright (C) 2016-2022 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
__libc_rpc_gethostbyname(const char * host,struct sockaddr_in * addr)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 }
74