glibc/inet/ether_hton.c
Florian Weimer c88ffc239e NSS: Replace exported NSS lookup functions with stubs [BZ #21962]
Commit 384ca55174 from 2007 added this to
nss/XXX-lookup.c:

+#ifndef NO_COMPAT
+int
+internal_function attribute_compat_text_section
+DB_COMPAT_FCT (service_user **ni, const char *fct_name, void **fctp)
+{
+  return DB_LOOKUP_FCT (ni, fct_name, NULL, fctp);
+}
+#endif

That is, it adds a pseudo-compat function with an internal_function
attribute.  The function it was supposed to replace did not have the
attribute:

 extern int DB_LOOKUP_FCT (service_user **ni, const char *fct_name,
-			  void **fctp) internal_function;
+			  const char *fct2_name, void **fctp)
+  internal_function;

This changed the calling convention on i386 for the following
functions in the public ABI:

  __nss_passwd_lookup
  __nss_group_lookup
  __nss_hosts_lookup

This commit replaces the functions with always-failing stubs,
with true compat symbols.  Due to a happy accident, the calling
convention of the stub is identical for the internal_function
and non-internal_function case on i386.

In addition, this commit auto-generates the __nss_*_lookup2
function declarations as part of <nsswitch.h>.
2017-08-14 18:13:42 +02:00

77 lines
2.1 KiB
C

/* Copyright (C) 1996-2017 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 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
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <netinet/ether.h>
#include <netinet/if_ether.h>
#include <string.h>
#include "../nss/nsswitch.h"
/* Type of the lookup function we need here. */
typedef int (*lookup_function) (const char *, struct etherent *, char *, int,
int *);
int
ether_hostton (const char *hostname, struct ether_addr *addr)
{
static service_user *startp;
static lookup_function start_fct;
service_user *nip;
union
{
lookup_function f;
void *ptr;
} fct;
int no_more;
enum nss_status status = NSS_STATUS_UNAVAIL;
struct etherent etherent;
if (startp == NULL)
{
no_more = __nss_ethers_lookup2 (&nip, "gethostton_r", NULL, &fct.ptr);
if (no_more)
startp = (service_user *) -1;
else
{
startp = nip;
start_fct = fct.f;
}
}
else
{
fct.f = start_fct;
no_more = (nip = startp) == (service_user *) -1;
}
while (no_more == 0)
{
char buffer[1024];
status = (*fct.f) (hostname, &etherent, buffer, sizeof buffer, &errno);
no_more = __nss_next2 (&nip, "gethostton_r", NULL, &fct.ptr, status, 0);
}
if (status == NSS_STATUS_SUCCESS)
memcpy (addr, etherent.e_addr.ether_addr_octet,
sizeof (struct ether_addr));
return status == NSS_STATUS_SUCCESS ? 0 : -1;
}