2 * Copyright (c) 2007 - 2008, Nicolas François
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the copyright holders or contributors may not be used to
14 * endorse or promote products derived from this software without
15 * specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
20 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 * According to the Linux-PAM documentation:
33 * 4.1. Care about standard library calls
35 * In general, writers of authorization-granting applications should
36 * assume that each module is likely to call any or all 'libc' functions.
37 * For 'libc' functions that return pointers to static/dynamically
38 * allocated structures (ie. the library allocates the memory and the
39 * user is not expected to 'free()' it) any module call to this function
40 * is likely to corrupt a pointer previously obtained by the application.
41 * The application programmer should either re-call such a 'libc'
42 * function after a call to the Linux-PAM library, or copy the structure
43 * contents to some safe area of memory before passing control to the
46 * Two important function classes that fall into this category are
47 * getpwnam(3) and syslog(3).
49 * This file provide wrapper to the getpwnam or getpwnam_r functions.
56 #include "prototypes.h"
58 #define XFUNCTION_NAME XPREFIX (FUNCTION_NAME)
59 #define XPREFIX(name) XPREFIX1 (name)
60 #define XPREFIX1(name) x##name
61 #define REENTRANT_NAME APPEND_R (FUNCTION_NAME)
62 #define APPEND_R(name) APPEND_R1 (name)
63 #define APPEND_R1(name) name##_r
64 #define STRINGIZE(name) STRINGIZE1 (name)
65 #define STRINGIZE1(name) #name
67 LOOKUP_TYPE *XFUNCTION_NAME (ARG_TYPE ARG_NAME)
70 LOOKUP_TYPE *result=NULL;
72 /* we have to start with something */
73 size_t length = 0x100;
75 result = malloc(sizeof(LOOKUP_TYPE));
77 fprintf (stderr, _("%s: out of memory\n"),
78 "x" STRINGIZE(FUNCTION_NAME));
84 LOOKUP_TYPE *resbuf = NULL;
85 buffer = (char *)realloc (buffer, length);
87 fprintf (stderr, _("%s: out of memory\n"),
88 "x" STRINGIZE(FUNCTION_NAME));
92 status = REENTRANT_NAME(ARG_NAME, result, buffer,
94 if ((0 ==status) && (resbuf == result)) {
95 /* Build a result structure that can be freed by
96 * the shadow *_free functions. */
97 LOOKUP_TYPE *ret_result = DUP_FUNCTION(result);
103 if (ERANGE != errno) {
110 } while (length < MAX_LENGTH);
116 #else /* !HAVE_FUNCTION_R */
118 /* No reentrant function.
119 * Duplicate the structure to avoid other call to overwrite it.
121 * We should also restore the initial structure. But that would be
124 LOOKUP_TYPE *result = FUNCTION_NAME(ARG_NAME);
127 result = DUP_FUNCTION(result);
128 if (NULL == result) {
129 fprintf (stderr, _("%s: out of memory\n"),
130 "x" STRINGIZE(FUNCTION_NAME));