1 files changed, 61 insertions, 0 deletions
diff --git a/nss/ether_ntoh.c b/nss/ether_ntoh.c
new file mode 100644
index 0000000000..2f1eb4ec3d
--- /dev/null
+++ b/nss/ether_ntoh.c
@@ -0,0 +1,61 @@
+/* Copyright (C) 1996-2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <netinet/ether.h>
+#include <netinet/if_ether.h>
+#include <string.h>
+
+#include <nsswitch.h>
+
+
+/* Type of the lookup function we need here.  */
+typedef int (*lookup_function) (const struct ether_addr *, struct etherent *,
+				char *, size_t, int *);
+
+int
+ether_ntohost (char *hostname, const struct ether_addr *addr)
+{
+  nss_action_list nip;
+  union
+  {
+    lookup_function f;
+    void *ptr;
+  } fct;
+  int no_more;
+  enum nss_status status = NSS_STATUS_UNAVAIL;
+  struct etherent etherent;
+
+  no_more = __nss_ethers_lookup2 (&nip, "getntohost_r", NULL, &fct.ptr);
+
+  while (no_more == 0)
+    {
+      char buffer[1024];
+
+      status = (*fct.f) (addr, &etherent, buffer, sizeof buffer, &errno);
+
+      no_more = __nss_next2 (&nip, "getntohost_r", NULL, &fct.ptr, 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;
+}