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-rw-r--r--inet/ether_ntoh.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/inet/ether_ntoh.c b/inet/ether_ntoh.c
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+/* Copyright (C) 1996 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA. */
+
+#include <netinet/ether.h>
+#include <netinet/if_ether.h>
+
+#include "../nss/nsswitch.h"
+
+/* Because the `ethers' lookup does not fit so well in the scheme so
+ we define a dummy struct here which helps us to use the available
+ functions. */
+struct etherent
+{
+ const char *e_name;
+ struct ether_addr e_addr;
+};
+
+
+/* Type of the lookup function we need here. */
+typedef int (*lookup_function) (const struct ether_addr *, struct etherent *,
+ char *, int);
+
+
+int
+ether_ntohost (char *hostname, const struct ether_addr *addr)
+{
+ static service_user *startp = NULL;
+ static lookup_function start_fct;
+ service_user *nip;
+ lookup_function fct;
+ int no_more;
+ int result;
+ enum nss_status status = NSS_STATUS_UNAVAIL;
+ struct etherent etherent;
+
+ if (startp == NULL)
+ {
+ no_more = __nss_ethers_lookup (&nip, "getntohost_r", (void **) &fct);
+ if (no_more)
+ startp = (service_user *) -1;
+ else
+ {
+ startp = nip;
+ start_fct = fct;
+ }
+ }
+ else
+ {
+ fct = start_fct;
+ no_more = (nip = startp) == (service_user *) -1;
+ }
+
+ while (no_more == 0)
+ {
+ char buffer[1024];
+
+ status = (*fct) (addr, &etherent, buffer, sizeof buffer);
+
+ no_more = __nss_next (&nip, "getntohost_r", (void **) &fct, status, 0);
+ }
+
+ if (status == NSS_STATUS_SUCCESS)
+ /* XXX This is a potential cause of trouble because the size of
+ the HOSTNAME buffer is not known but the interface does not
+ provide this information. */
+ strcpy (hostname, etherent.e_name);
+
+ return status == NSS_STATUS_SUCCESS ? 0 : -1;
+}