2 * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU Lesser General Public License version 2.1
6 * as published by the Free Software Foundation
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
21 #include <linux/limits.h>
23 #include <libubox/utils.h>
29 struct avl_tree libraries
;
30 static LIST_HEAD(library_paths
);
32 static void alloc_library_path(const char *path
)
38 struct library_path
*p
;
41 p
= calloc_a(sizeof(*p
),
42 &_path
, strlen(path
) + 1);
46 p
->path
= strcpy(_path
, path
);
48 list_add_tail(&p
->list
, &library_paths
);
49 DEBUG("adding ld.so path %s\n", path
);
54 * name = soname/avl key
56 void alloc_library(const char *path
, const char *name
)
61 l
= calloc_a(sizeof(*l
),
62 &_path
, strlen(path
) + 1,
63 &_name
, strlen(name
) + 1);
67 l
->avl
.key
= l
->name
= strcpy(_name
, name
);
68 l
->path
= strcpy(_path
, path
);
70 avl_insert(&libraries
, &l
->avl
);
71 DEBUG("adding library %s (%s)\n", path
, name
);
74 int lib_open(char **fullpath
, const char *file
)
76 struct library_path
*p
;
82 list_for_each_entry(p
, &library_paths
, list
) {
83 snprintf(path
, sizeof(path
), "%s/%s", p
->path
, file
);
84 fd
= open(path
, O_RDONLY
|O_CLOEXEC
);
86 *fullpath
= strdup(path
);
94 const char* find_lib(const char *file
)
98 l
= avl_find_element(&libraries
, file
, l
, avl
);
105 static int elf64_find_section(const char *map
, unsigned int type
, unsigned long *offset
, unsigned long *size
, unsigned long *vaddr
)
111 e
= (Elf64_Ehdr
*) map
;
112 ph
= (Elf64_Phdr
*) (map
+ e
->e_phoff
);
114 for (i
= 0; i
< e
->e_phnum
; i
++) {
115 if (ph
[i
].p_type
== type
) {
116 *offset
= ph
[i
].p_offset
;
118 *size
= ph
[i
].p_filesz
;
120 *vaddr
= ph
[i
].p_vaddr
;
128 static int elf32_find_section(const char *map
, unsigned int type
, unsigned long *offset
, unsigned long *size
, unsigned long *vaddr
)
134 e
= (Elf32_Ehdr
*) map
;
135 ph
= (Elf32_Phdr
*) (map
+ e
->e_phoff
);
137 for (i
= 0; i
< e
->e_phnum
; i
++) {
138 if (ph
[i
].p_type
== type
) {
139 *offset
= ph
[i
].p_offset
;
141 *size
= ph
[i
].p_filesz
;
143 *vaddr
= ph
[i
].p_vaddr
;
151 static int elf_find_section(const char *map
, unsigned int type
, unsigned long *offset
, unsigned long *size
, unsigned long *vaddr
)
153 int clazz
= map
[EI_CLASS
];
155 if (clazz
== ELFCLASS32
)
156 return elf32_find_section(map
, type
, offset
, size
, vaddr
);
157 else if (clazz
== ELFCLASS64
)
158 return elf64_find_section(map
, type
, offset
, size
, vaddr
);
160 ERROR("unknown elf format %d\n", clazz
);
165 static int elf32_scan_dynamic(const char *map
, unsigned long dyn_offset
, unsigned long dyn_size
, long load_offset
)
167 Elf32_Dyn
*dynamic
= (Elf32_Dyn
*) (map
+ dyn_offset
);
168 const char *strtab
= NULL
;
170 while ((void *) dynamic
< (void *) (map
+ dyn_offset
+ dyn_size
)) {
171 Elf32_Dyn
*curr
= dynamic
;
174 if (curr
->d_tag
!= DT_STRTAB
)
177 strtab
= map
+ (curr
->d_un
.d_ptr
- load_offset
);
184 dynamic
= (Elf32_Dyn
*) (map
+ dyn_offset
);
185 while ((void *) dynamic
< (void *) (map
+ dyn_offset
+ dyn_size
)) {
186 Elf32_Dyn
*curr
= dynamic
;
189 if (curr
->d_tag
!= DT_NEEDED
)
192 if (add_path_and_deps(&strtab
[curr
->d_un
.d_val
], 1, -1, 1))
199 static int elf64_scan_dynamic(const char *map
, unsigned long dyn_offset
, unsigned long dyn_size
, long load_offset
)
201 Elf64_Dyn
*dynamic
= (Elf64_Dyn
*) (map
+ dyn_offset
);
202 const char *strtab
= NULL
;
204 while ((void *) dynamic
< (void *) (map
+ dyn_offset
+ dyn_size
)) {
205 Elf64_Dyn
*curr
= dynamic
;
208 if (curr
->d_tag
!= DT_STRTAB
)
211 strtab
= map
+ (curr
->d_un
.d_ptr
- load_offset
);
218 dynamic
= (Elf64_Dyn
*) (map
+ dyn_offset
);
219 while ((void *) dynamic
< (void *) (map
+ dyn_offset
+ dyn_size
)) {
220 Elf64_Dyn
*curr
= dynamic
;
223 if (curr
->d_tag
!= DT_NEEDED
)
226 if (add_path_and_deps(&strtab
[curr
->d_un
.d_val
], 1, -1, 1))
233 int elf_load_deps(const char *path
, const char *map
)
235 unsigned long dyn_offset
, dyn_size
;
236 unsigned long load_offset
, load_vaddr
;
237 unsigned long interp_offset
;
239 if (elf_find_section(map
, PT_INTERP
, &interp_offset
, NULL
, NULL
) == 0) {
240 add_path_and_deps(map
+interp_offset
, 1, -1, 0);
243 if (elf_find_section(map
, PT_LOAD
, &load_offset
, NULL
, &load_vaddr
)) {
244 DEBUG("failed to load the .load section from %s\n", path
);
248 if (elf_find_section(map
, PT_DYNAMIC
, &dyn_offset
, &dyn_size
, NULL
)) {
249 DEBUG("failed to load the .dynamic section from %s\n", path
);
253 int clazz
= map
[EI_CLASS
];
255 if (clazz
== ELFCLASS32
)
256 return elf32_scan_dynamic(map
, dyn_offset
, dyn_size
, load_vaddr
- load_offset
);
257 else if (clazz
== ELFCLASS64
)
258 return elf64_scan_dynamic(map
, dyn_offset
, dyn_size
, load_vaddr
- load_offset
);
260 ERROR("unknown elf format %d\n", clazz
);
264 static void load_ldso_conf(const char *conf
)
266 FILE* fp
= fopen(conf
, "r");
270 DEBUG("failed to open %s\n", conf
);
277 if (!fgets(line
, sizeof(line
), fp
))
284 if (line
[len
- 1] == '\n')
285 line
[len
- 1] = '\0';
286 if (!strncmp(line
, "include ", 8)) {
287 char *sep
= strstr(line
, " ");
295 if (glob(sep
, GLOB_NOESCAPE
| GLOB_MARK
, NULL
, &gl
)) {
296 ERROR("glob failed on %s\n", sep
);
299 for (i
= 0; i
< gl
.gl_pathc
; i
++)
300 load_ldso_conf(gl
.gl_pathv
[i
]);
303 alloc_library_path(line
);
310 void init_library_search(void)
312 avl_init(&libraries
, avl_strcmp
, false, NULL
);
313 alloc_library_path("/lib");
314 alloc_library_path("/lib64");
315 alloc_library_path("/usr/lib");
316 load_ldso_conf("/etc/ld.so.conf");
319 void free_library_search(void)
321 struct library_path
*p
, *ptmp
;
322 struct library
*l
, *tmp
;
324 list_for_each_entry_safe(p
, ptmp
, &library_paths
, list
)
327 avl_remove_all_elements(&libraries
, l
, avl
, tmp
)