1 /* Copyright (C) 1996-2022 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #include <errno.h>
19 #include <netinet/ether.h>
20 #include <netinet/if_ether.h>
21 #include <string.h>
22 
23 #include "../nss/nsswitch.h"
24 
25 /* Type of the lookup function we need here.  */
26 typedef int (*lookup_function) (const char *, struct etherent *, char *, int,
27 				int *);
28 
29 int
ether_hostton(const char * hostname,struct ether_addr * addr)30 ether_hostton (const char *hostname, struct ether_addr *addr)
31 {
32   nss_action_list nip;
33   union
34   {
35     lookup_function f;
36     void *ptr;
37   } fct;
38   int no_more;
39   enum nss_status status = NSS_STATUS_UNAVAIL;
40   struct etherent etherent;
41 
42   no_more = __nss_ethers_lookup2 (&nip, "gethostton_r", NULL, &fct.ptr);
43 
44   while (no_more == 0)
45     {
46       char buffer[1024];
47 
48       status = (*fct.f) (hostname, &etherent, buffer, sizeof buffer, &errno);
49 
50       no_more = __nss_next2 (&nip, "gethostton_r", NULL, &fct.ptr, status, 0);
51     }
52 
53   if (status == NSS_STATUS_SUCCESS)
54     memcpy (addr, etherent.e_addr.ether_addr_octet,
55 	    sizeof (struct ether_addr));
56 
57   return status == NSS_STATUS_SUCCESS ? 0 : -1;
58 }
59