glibc/nss/nsswitch.c

140 lines
3.8 KiB
C

/* Copyright (C) 1996-2022 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 <ctype.h>
#include <dlfcn.h>
#include <errno.h>
#include <netdb.h>
#include <libc-lock.h>
#include <search.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include <aliases.h>
#include <grp.h>
#include <netinet/ether.h>
#include <pwd.h>
#include <shadow.h>
#include <unistd.h>
#if !defined DO_STATIC_NSS || defined SHARED
# include <gnu/lib-names.h>
#endif
#include "nsswitch.h"
#include "../nscd/nscd_proto.h"
#include <sysdep.h>
#include <config.h>
/* Declare external database variables. */
#define DEFINE_DATABASE(name) \
nss_action_list __nss_##name##_database attribute_hidden; \
weak_extern (__nss_##name##_database)
#include "databases.def"
#undef DEFINE_DATABASE
#ifdef USE_NSCD
/* Flags whether custom rules for database is set. */
bool __nss_database_custom[NSS_DBSIDX_max];
#endif
/*__libc_lock_define_initialized (static, lock)*/
/* -1 == not found
0 == function found
1 == finished */
int
__nss_lookup (nss_action_list *ni, const char *fct_name, const char *fct2_name,
void **fctp)
{
*fctp = __nss_lookup_function (*ni, fct_name);
if (*fctp == NULL && fct2_name != NULL)
*fctp = __nss_lookup_function (*ni, fct2_name);
while (*fctp == NULL
&& nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
&& (*ni)[1].module != NULL)
{
++(*ni);
*fctp = __nss_lookup_function (*ni, fct_name);
if (*fctp == NULL && fct2_name != NULL)
*fctp = __nss_lookup_function (*ni, fct2_name);
}
return *fctp != NULL ? 0 : (*ni)[1].module == NULL ? 1 : -1;
}
libc_hidden_def (__nss_lookup)
/* -1 == not found
0 == adjusted for next function
1 == finished */
int
__nss_next2 (nss_action_list *ni, const char *fct_name, const char *fct2_name,
void **fctp, int status, int all_values)
{
if (all_values)
{
if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
&& nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
&& nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
&& nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
return 1;
}
else
{
/* This is really only for debugging. */
if (__builtin_expect (NSS_STATUS_TRYAGAIN > status
|| status > NSS_STATUS_RETURN, 0))
__libc_fatal ("Illegal status in __nss_next.\n");
if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
return 1;
}
if ((*ni)[1].module == NULL)
return -1;
do
{
++(*ni);
*fctp = __nss_lookup_function (*ni, fct_name);
if (*fctp == NULL && fct2_name != NULL)
*fctp = __nss_lookup_function (*ni, fct2_name);
}
while (*fctp == NULL
&& nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
&& (*ni)[1].module != NULL);
return *fctp != NULL ? 0 : -1;
}
libc_hidden_def (__nss_next2)
void *
__nss_lookup_function (nss_action_list ni, const char *fct_name)
{
if (ni->module == NULL)
return NULL;
return __nss_module_get_function (ni->module, fct_name);
}
libc_hidden_def (__nss_lookup_function)