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[glibc.git] / nss / getXXent.c
blob497c0dee2217e235f377037219bc17fcd493f960
1 /* Copyright (C) 1996, 1997, 1999 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
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 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If not,
16 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 Boston, MA 02111-1307, USA. */
19 #include <errno.h>
20 #include <bits/libc-lock.h>
21 #include <stdlib.h>
23 #include "nsswitch.h"
25 /*******************************************************************\
26 |* Here we assume several symbols to be defined: *|
27 |* *|
28 |* LOOKUP_TYPE - the return type of the function *|
29 |* *|
30 |* GETFUNC_NAME - name of the non-reentrant getXXXent function *|
31 |* *|
32 |* BUFLEN - size of static buffer *|
33 |* *|
34 |* Optionally the following vars can be defined: *|
35 |* *|
36 |* NEED_H_ERRNO - an extra parameter will be passed to point to *|
37 |* the global `h_errno' variable. *|
38 |* *|
39 \*******************************************************************/
41 /* To make the real sources a bit prettier. */
42 #define REENTRANT_GETNAME APPEND_R (GETFUNC_NAME)
43 #define APPEND_R(name) APPEND_R1 (name)
44 #define APPEND_R1(name) name##_r
45 #define INTERNAL(name) INTERNAL1 (name)
46 #define INTERNAL1(name) __##name
48 /* Sometimes we need to store error codes in the `h_errno' variable. */
49 #ifdef NEED_H_ERRNO
50 # define H_ERRNO_PARM , int *h_errnop
51 # define H_ERRNO_VAR , &h_errno
52 #else
53 # define H_ERRNO_PARM
54 # define H_ERRNO_VAR
55 #endif
57 /* Prototype of the reentrant version. */
58 extern int INTERNAL (REENTRANT_GETNAME) (LOOKUP_TYPE *resbuf, char *buffer,
59 size_t buflen, LOOKUP_TYPE **result
60 H_ERRNO_PARM);
62 /* We need to protect the dynamic buffer handling. */
63 __libc_lock_define_initialized (static, lock);
65 /* This points to the static buffer used. */
66 static char *buffer;
69 LOOKUP_TYPE *
70 GETFUNC_NAME (void)
72 static size_t buffer_size;
73 static LOOKUP_TYPE resbuf;
74 LOOKUP_TYPE *result;
75 int save;
77 /* Get lock. */
78 __libc_lock_lock (lock);
80 if (buffer == NULL)
82 buffer_size = BUFLEN;
83 buffer = malloc (buffer_size);
86 while (buffer != NULL
87 && INTERNAL (REENTRANT_GETNAME) (&resbuf, buffer, buffer_size, &result
88 H_ERRNO_VAR) == ERANGE
89 #ifdef NEED_H_ERRNO
90 && h_errno == NETDB_INTERNAL
91 #endif
94 char *new_buf;
95 buffer_size += BUFLEN;
96 new_buf = realloc (buffer, buffer_size);
97 if (new_buf == NULL)
99 /* We are out of memory. Free the current buffer so that the
100 process gets a chance for a normal termination. */
101 save = errno;
102 free (buffer);
103 __set_errno (save);
105 buffer = new_buf;
108 if (buffer == NULL)
109 result = NULL;
111 /* Release lock. Preserve error value. */
112 save = errno;
113 __libc_lock_unlock (lock);
114 __set_errno (save);
116 return result;
120 /* Free all resources if necessary. */
121 static void __attribute__ ((unused))
122 free_mem (void)
124 if (buffer != NULL)
125 free (buffer);
128 text_set_element (__libc_subfreeres, free_mem);