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.
26 #include <libubox/utils.h>
30 struct avl_tree libraries;
31 static LIST_HEAD(library_paths);
33 void alloc_library_path(const char *path)
39 struct library_path *p;
42 p = calloc_a(sizeof(*p),
43 &_path, strlen(path) + 1);
47 p->path = strcpy(_path, path);
49 list_add_tail(&p->list, &library_paths);
50 DEBUG("adding ld.so path %s\n", path);
53 static void alloc_library(const char *path, const char *name)
58 l = calloc_a(sizeof(*l),
59 &_path, strlen(path) + 1,
60 &_name, strlen(name) + 1);
64 l->avl.key = l->name = strcpy(_name, name);
65 l->path = strcpy(_path, path);
67 avl_insert(&libraries, &l->avl);
68 DEBUG("adding library %s/%s\n", path, name);
71 static int elf_open(char **dir, const char *file)
73 struct library_path *p;
79 list_for_each_entry(p, &library_paths, list) {
81 snprintf(path, sizeof(path), "%s/%s", p->path, file);
83 strncpy(path, file, sizeof(path));
84 fd = open(path, O_RDONLY);
92 fd = open(file, O_RDONLY);
97 const char* find_lib(const char *file)
100 static char path[256];
103 l = avl_find_element(&libraries, file, l, avl);
108 if (strstr(p, "local"))
111 snprintf(path, sizeof(path), "%s/%s", p, file);
116 static int elf64_find_section(const char *map, unsigned int type, unsigned int *offset, unsigned int *size, unsigned int *vaddr)
122 e = (Elf64_Ehdr *) map;
123 ph = (Elf64_Phdr *) (map + e->e_phoff);
125 for (i = 0; i < e->e_phnum; i++) {
126 if (ph[i].p_type == type) {
127 *offset = ph[i].p_offset;
129 *size = ph[i].p_filesz;
131 *vaddr = ph[i].p_vaddr;
139 static int elf32_find_section(const char *map, unsigned int type, unsigned int *offset, unsigned int *size, unsigned int *vaddr)
145 e = (Elf32_Ehdr *) map;
146 ph = (Elf32_Phdr *) (map + e->e_phoff);
148 for (i = 0; i < e->e_phnum; i++) {
149 if (ph[i].p_type == type) {
150 *offset = ph[i].p_offset;
152 *size = ph[i].p_filesz;
154 *vaddr = ph[i].p_vaddr;
162 static int elf_find_section(const char *map, unsigned int type, unsigned int *offset, unsigned int *size, unsigned int *vaddr)
164 int clazz = map[EI_CLASS];
166 if (clazz == ELFCLASS32)
167 return elf32_find_section(map, type, offset, size, vaddr);
168 else if (clazz == ELFCLASS64)
169 return elf64_find_section(map, type, offset, size, vaddr);
171 ERROR("unknown elf format %d\n", clazz);
176 static int elf32_scan_dynamic(const char *map, int dyn_offset, int dyn_size, int load_offset)
178 Elf32_Dyn *dynamic = (Elf32_Dyn *) (map + dyn_offset);
179 const char *strtab = NULL;
181 while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) {
182 Elf32_Dyn *curr = dynamic;
185 if (curr->d_tag != DT_STRTAB)
188 strtab = map + (curr->d_un.d_val - load_offset);
195 dynamic = (Elf32_Dyn *) (map + dyn_offset);
196 while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) {
197 Elf32_Dyn *curr = dynamic;
200 if (curr->d_tag != DT_NEEDED)
203 if (elf_load_deps(&strtab[curr->d_un.d_val]))
210 static int elf64_scan_dynamic(const char *map, int dyn_offset, int dyn_size, int load_offset)
212 Elf64_Dyn *dynamic = (Elf64_Dyn *) (map + dyn_offset);
213 const char *strtab = NULL;
215 while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) {
216 Elf64_Dyn *curr = dynamic;
219 if (curr->d_tag != DT_STRTAB)
222 strtab = map + (curr->d_un.d_val - load_offset);
229 dynamic = (Elf64_Dyn *) (map + dyn_offset);
230 while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) {
231 Elf64_Dyn *curr = dynamic;
234 if (curr->d_tag != DT_NEEDED)
237 if (elf_load_deps(&strtab[curr->d_un.d_val]))
244 int elf_load_deps(const char *library)
246 unsigned int dyn_offset, dyn_size;
247 unsigned int load_offset, load_vaddr;
249 char *map = NULL, *dir = NULL;
250 int clazz, fd, ret = -1;
252 if (avl_find(&libraries, library))
255 fd = elf_open(&dir, library);
258 ERROR("failed to open %s\n", library);
262 if (fstat(fd, &s) == -1) {
263 ERROR("failed to stat %s\n", library);
268 map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
269 if (map == MAP_FAILED) {
270 ERROR("failed to mmap %s\n", library);
275 if (elf_find_section(map, PT_LOAD, &load_offset, NULL, &load_vaddr)) {
276 ERROR("failed to load the .load section from %s\n", library);
281 if (elf_find_section(map, PT_DYNAMIC, &dyn_offset, &dyn_size, NULL)) {
282 ERROR("failed to load the .dynamic section from %s\n", library);
288 alloc_library(dir, library);
290 char *elf1 = strdup(library);
291 char *elf2 = strdup(library);
293 alloc_library(dirname(elf1), basename(elf2));
297 clazz = map[EI_CLASS];
299 if (clazz == ELFCLASS32)
300 ret = elf32_scan_dynamic(map, dyn_offset, dyn_size, load_vaddr - load_offset);
301 else if (clazz == ELFCLASS64)
302 ret = elf64_scan_dynamic(map, dyn_offset, dyn_size, load_vaddr - load_offset);
306 munmap(map, s.st_size);
312 void load_ldso_conf(const char *conf)
314 FILE* fp = fopen(conf, "r");
318 DEBUG("failed to open %s\n", conf);
325 if (!fgets(line, 256, fp))
332 if (line[len - 1] == '\n')
333 line[len - 1] = '\0';
334 if (!strncmp(line, "include ", 8)) {
335 char *sep = strstr(line, " ");
343 if (glob(sep, GLOB_NOESCAPE | GLOB_MARK, NULL, &gl)) {
344 ERROR("glob failed on %s\n", sep);
347 for (i = 0; i < gl.gl_pathc; i++)
348 load_ldso_conf(gl.gl_pathv[i]);
351 alloc_library_path(line);