about summary refs log tree commit diff
path: root/nss/getXXbyYY.c
blob: ee6f640002bfe9b91cc95755ae8ef880b769ce90 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/* Copyright (C) 1996,1997,1998,1999,2000,2001 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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <assert.h>
#include <errno.h>
#include <bits/libc-lock.h>
#include <stdlib.h>
#include <resolv.h>

#include "nsswitch.h"

/*******************************************************************\
|* Here we assume several symbols to be defined:		   *|
|*								   *|
|* LOOKUP_TYPE   - the return type of the function		   *|
|*								   *|
|* FUNCTION_NAME - name of the non-reentrant function		   *|
|*								   *|
|* DATABASE_NAME - name of the database the function accesses	   *|
|*		   (e.g., host, services, ...)			   *|
|*								   *|
|* ADD_PARAMS    - additional parameter, can vary in number	   *|
|*								   *|
|* ADD_VARIABLES - names of additional parameter		   *|
|*								   *|
|* BUFLEN	 - length of buffer allocated for the non	   *|
|*		   reentrant version				   *|
|*								   *|
|* Optionally the following vars can be defined:		   *|
|*								   *|
|* NEED_H_ERRNO  - an extra parameter will be passed to point to   *|
|*		   the global `h_errno' variable.		   *|
|*								   *|
\*******************************************************************/

/* To make the real sources a bit prettier.  */
#define REENTRANT_NAME APPEND_R (FUNCTION_NAME)
#define APPEND_R(name) APPEND_R1 (name)
#define APPEND_R1(name) name##_r
#define INTERNAL(name) INTERNAL1 (name)
#define INTERNAL1(name) __##name

/* Sometimes we need to store error codes in the `h_errno' variable.  */
#ifdef NEED_H_ERRNO
# define H_ERRNO_PARM , int *h_errnop
# define H_ERRNO_VAR , &h_errno_tmp
# define H_ERRNO_VAR_P &h_errno_tmp
#else
# define H_ERRNO_PARM
# define H_ERRNO_VAR
# define H_ERRNO_VAR_P NULL
#endif

#ifndef HAVE_TYPE
# define TYPE_VAR_P NULL
# define FLAGS_VAR 0
#endif

#ifdef HAVE_AF
# define AF_VAR_P &af
#else
# define AF_VAR_P NULL
#endif

/* Prototype for reentrant version we use here.  */
extern int INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf,
				      char *buffer, size_t buflen,
				      LOOKUP_TYPE **result H_ERRNO_PARM);

/* We need to protect the dynamic buffer handling.  */
__libc_lock_define_initialized (static, lock);

/* This points to the static buffer used.  */
static char *buffer;


LOOKUP_TYPE *
FUNCTION_NAME (ADD_PARAMS)
{
  static size_t buffer_size;
  static LOOKUP_TYPE resbuf;
  LOOKUP_TYPE *result;
  int save;
#ifdef NEED_H_ERRNO
  int h_errno_tmp = 0;
#endif

  /* Get lock.  */
  __libc_lock_lock (lock);

  if (buffer == NULL)
    {
      buffer_size = BUFLEN;
      buffer = malloc (buffer_size);
    }

#ifdef HANDLE_DIGITS_DOTS
  if (buffer != NULL)
    {
      if (__nss_hostname_digits_dots (name, &resbuf, &buffer,
				      &buffer_size,
				      0, &result, NULL, TYPE_VAR_P,
				      FLAGS_VAR, AF_VAR_P,
				      H_ERRNO_VAR_P))
	goto done;
    }
#endif

  while (buffer != NULL
	 && (INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, &resbuf, buffer,
					buffer_size, &result H_ERRNO_VAR)
	     == ERANGE)
#ifdef NEED_H_ERRNO
	 && h_errno_tmp == NETDB_INTERNAL
#endif
	 )
    {
      char *new_buf;
      buffer_size += BUFLEN;
      new_buf = realloc (buffer, buffer_size);
      if (new_buf == NULL)
	{
	  /* We are out of memory.  Free the current buffer so that the
	     process gets a chance for a normal termination.  */
	  save = errno;
	  free (buffer);
	  __set_errno (save);
	}
      buffer = new_buf;
    }

  if (buffer == NULL)
    result = NULL;

#ifdef HANDLE_DIGITS_DOTS
done:
#endif
  /* Release lock.  Preserve error value.  */
  save = errno;
  __libc_lock_unlock (lock);
  __set_errno (save);

#ifdef NEED_H_ERRNO
  if (h_errno_tmp != 0)
    __set_h_errno (h_errno_tmp);
#endif

  return result;
}


/* Free all resources if necessary.  */
static void __attribute__ ((unused))
free_mem (void)
{
  free (buffer);
}

text_set_element (__libc_subfreeres, free_mem);