1/* Handling of dynamic sring tokens.
2 Copyright (C) 1999-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include "trusted-dirs.h"
20
21#ifdef SHARED
22# define IS_RTLD(l) (l) == &GL(dl_rtld_map)
23#else
24# define IS_RTLD(l) 0
25#endif
26/* Guess from the number of DSTs the length of the result string. */
27#define DL_DST_REQUIRED(l, name, len, cnt) \
28 ({ \
29 size_t __len = (len); \
30 size_t __cnt = (cnt); \
31 \
32 if (__cnt > 0) \
33 { \
34 size_t dst_len; \
35 /* Now we make a guess how many extra characters on top of the \
36 length of S we need to represent the result. We know that \
37 we have CNT replacements. Each at most can use \
38 MAX (MAX (strlen (ORIGIN), strlen (_dl_platform)), \
39 strlen (DL_DST_LIB)) \
40 minus 4 (which is the length of "$LIB"). \
41 \
42 First get the origin string if it is not available yet. \
43 This can only happen for the map of the executable or, when \
44 auditing, in ld.so. */ \
45 if ((l)->l_origin == NULL) \
46 { \
47 assert ((l)->l_name[0] == '\0' || IS_RTLD (l)); \
48 (l)->l_origin = _dl_get_origin (); \
49 dst_len = ((l)->l_origin && (l)->l_origin != (char *) -1 \
50 ? strlen ((l)->l_origin) : 0); \
51 } \
52 else \
53 dst_len = (l)->l_origin == (char *) -1 \
54 ? 0 : strlen ((l)->l_origin); \
55 dst_len = MAX (MAX (dst_len, GLRO(dl_platformlen)), \
56 strlen (DL_DST_LIB)); \
57 if (dst_len > 4) \
58 __len += __cnt * (dst_len - 4); \
59 } \
60 \
61 __len; })
62