1  /* Copyright (C) 1996-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <ctype.h>
      19  #include <dlfcn.h>
      20  #include <errno.h>
      21  #include <netdb.h>
      22  #include <libc-lock.h>
      23  #include <search.h>
      24  #include <stdio.h>
      25  #include <stdio_ext.h>
      26  #include <stdlib.h>
      27  #include <string.h>
      28  
      29  #include <aliases.h>
      30  #include <grp.h>
      31  #include <netinet/ether.h>
      32  #include <pwd.h>
      33  #include <shadow.h>
      34  #include <unistd.h>
      35  
      36  #if !defined DO_STATIC_NSS || defined SHARED
      37  # include <gnu/lib-names.h>
      38  #endif
      39  
      40  #include "nsswitch.h"
      41  #include "../nscd/nscd_proto.h"
      42  #include <sysdep.h>
      43  #include <config.h>
      44  
      45  /* Declare external database variables.  */
      46  #define DEFINE_DATABASE(name)						      \
      47    nss_action_list __nss_##name##_database attribute_hidden;		      \
      48    weak_extern (__nss_##name##_database)
      49  #include "databases.def"
      50  #undef DEFINE_DATABASE
      51  
      52  
      53  #ifdef USE_NSCD
      54  /* Flags whether custom rules for database is set.  */
      55  bool __nss_database_custom[NSS_DBSIDX_max];
      56  #endif
      57  
      58  /*__libc_lock_define_initialized (static, lock)*/
      59  
      60  /* -1 == not found
      61      0 == function found
      62      1 == finished */
      63  int
      64  __nss_lookup (nss_action_list *ni, const char *fct_name, const char *fct2_name,
      65  	      void **fctp)
      66  {
      67    *fctp = __nss_lookup_function (*ni, fct_name);
      68    if (*fctp == NULL && fct2_name != NULL)
      69      *fctp = __nss_lookup_function (*ni, fct2_name);
      70  
      71    while (*fctp == NULL
      72  	 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
      73  	 && (*ni)[1].module != NULL)
      74      {
      75        ++(*ni);
      76  
      77        *fctp = __nss_lookup_function (*ni, fct_name);
      78        if (*fctp == NULL && fct2_name != NULL)
      79  	*fctp = __nss_lookup_function (*ni, fct2_name);
      80      }
      81  
      82    return *fctp != NULL ? 0 : (*ni)[1].module == NULL ? 1 : -1;
      83  }
      84  libc_hidden_def (__nss_lookup)
      85  
      86  
      87  /* -1 == not found
      88      0 == adjusted for next function
      89      1 == finished */
      90  int
      91  __nss_next2 (nss_action_list *ni, const char *fct_name, const char *fct2_name,
      92  	     void **fctp, int status, int all_values)
      93  {
      94    if (all_values)
      95      {
      96        if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
      97  	  && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
      98  	  && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
      99  	  && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
     100  	return 1;
     101      }
     102    else
     103      {
     104        /* This is really only for debugging.  */
     105        if (__builtin_expect (NSS_STATUS_TRYAGAIN > status
     106  			    || status > NSS_STATUS_RETURN, 0))
     107  	 __libc_fatal ("Illegal status in __nss_next.\n");
     108  
     109         if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
     110  	 return 1;
     111      }
     112  
     113    if ((*ni)[1].module == NULL)
     114      return -1;
     115  
     116    do
     117      {
     118        ++(*ni);
     119  
     120        *fctp = __nss_lookup_function (*ni, fct_name);
     121        if (*fctp == NULL && fct2_name != NULL)
     122  	*fctp = __nss_lookup_function (*ni, fct2_name);
     123      }
     124    while (*fctp == NULL
     125  	 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
     126  	 && (*ni)[1].module != NULL);
     127  
     128    return *fctp != NULL ? 0 : -1;
     129  }
     130  libc_hidden_def (__nss_next2)
     131  
     132  void *
     133  __nss_lookup_function (nss_action_list ni, const char *fct_name)
     134  {
     135    if (ni->module == NULL)
     136      return NULL;
     137    return __nss_module_get_function (ni->module, fct_name);
     138  }
     139  libc_hidden_def (__nss_lookup_function)