1 /* Copyright (C) 2000-2022 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 <errno.h>
19 #include <stdlib.h>
20 #include <netdb.h>
21 #include "nsswitch.h"
22 
23 void *
__nss_getent(getent_r_function func,void ** resbuf,char ** buffer,size_t buflen,size_t * buffer_size,int * h_errnop)24 __nss_getent (getent_r_function func, void **resbuf, char **buffer,
25 	      size_t buflen, size_t *buffer_size, int *h_errnop)
26 {
27   void *result;
28 
29   if (*buffer == NULL)
30     {
31       *buffer_size = buflen;
32       *buffer = malloc (*buffer_size);
33     }
34 
35   while (*buffer != NULL
36 	 && func (resbuf, *buffer, *buffer_size, &result, h_errnop) == ERANGE
37 	 && (h_errnop == NULL || *h_errnop == NETDB_INTERNAL))
38     {
39       char *new_buf;
40       *buffer_size *= 2;
41       new_buf = realloc (*buffer, *buffer_size);
42       if (new_buf == NULL)
43 	{
44 	  /* We are out of memory.  Free the current buffer so that the
45 	     process gets a chance for a normal termination.  */
46 	  int save = errno;
47 	  free (*buffer);
48 	  __set_errno (save);
49 	}
50       *buffer = new_buf;
51     }
52 
53   if (*buffer == NULL)
54     result = NULL;
55 
56   return result;
57 }
58