Update.
[glibc.git] / inet / ether_ntoh.c
blob6937201c038c90ef4dbfea46f8b3c70ce9b93a3f
1 /* Copyright (C) 1996, 1997, 1999 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
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 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
20 #include <netinet/ether.h>
21 #include <netinet/if_ether.h>
22 #include <string.h>
24 #include <nss/nsswitch.h>
26 /* Because the `ethers' lookup does not fit so well in the scheme so
27 we define a dummy struct here which helps us to use the available
28 functions. */
29 struct etherent
31 const char *e_name;
32 struct ether_addr e_addr;
36 /* Type of the lookup function we need here. */
37 typedef int (*lookup_function) (const struct ether_addr *, struct etherent *,
38 char *, int);
40 /* The lookup function for the first entry of this service. */
41 extern int __nss_ethers_lookup (service_user **nip, const char *name,
42 void **fctp);
45 int
46 ether_ntohost (char *hostname, const struct ether_addr *addr)
48 static service_user *startp;
49 static lookup_function start_fct;
50 service_user *nip;
51 lookup_function fct;
52 int no_more;
53 enum nss_status status = NSS_STATUS_UNAVAIL;
54 struct etherent etherent;
56 if (startp == NULL)
58 no_more = __nss_ethers_lookup (&nip, "getntohost_r", (void **) &fct);
59 if (no_more)
60 startp = (service_user *) -1;
61 else
63 startp = nip;
64 start_fct = fct;
67 else
69 fct = start_fct;
70 no_more = (nip = startp) == (service_user *) -1;
73 while (no_more == 0)
75 char buffer[1024];
77 status = (*fct) (addr, &etherent, buffer, sizeof buffer);
79 no_more = __nss_next (&nip, "getntohost_r", (void **) &fct, status, 0);
82 if (status == NSS_STATUS_SUCCESS)
83 /* XXX This is a potential cause of trouble because the size of
84 the HOSTNAME buffer is not known but the interface does not
85 provide this information. */
86 strcpy (hostname, etherent.e_name);
88 return status == NSS_STATUS_SUCCESS ? 0 : -1;