diff options
Diffstat (limited to 'jail/elf.c')
-rw-r--r-- | jail/elf.c | 355 |
1 files changed, 0 insertions, 355 deletions
diff --git a/jail/elf.c b/jail/elf.c deleted file mode 100644 index cbb3051..0000000 --- a/jail/elf.c +++ /dev/null @@ -1,355 +0,0 @@ -/* - * Copyright (C) 2015 John Crispin <blogic@openwrt.org> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU Lesser General Public License version 2.1 - * as published by the Free Software Foundation - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - */ - -#define _GNU_SOURCE -#include <sys/mman.h> - -#include <stdlib.h> -#include <unistd.h> -#include <stdio.h> -#include <string.h> -#include <sys/stat.h> -#include <fcntl.h> -#include <libgen.h> -#include <glob.h> -#include <elf.h> - -#include <libubox/utils.h> - -#include "elf.h" - -struct avl_tree libraries; -static LIST_HEAD(library_paths); - -void alloc_library_path(const char *path) -{ - struct library_path *p; - char *_path; - - p = calloc_a(sizeof(*p), - &_path, strlen(path) + 1); - if (!p) - return; - - p->path = strcpy(_path, path); - - list_add_tail(&p->list, &library_paths); - DEBUG("adding ld.so path %s\n", path); -} - -static void alloc_library(const char *path, const char *name) -{ - struct library *l; - char *_name, *_path; - - l = calloc_a(sizeof(*l), - &_path, strlen(path) + 1, - &_name, strlen(name) + 1); - if (!l) - return; - - l->avl.key = l->name = strcpy(_name, name); - l->path = strcpy(_path, path); - - avl_insert(&libraries, &l->avl); - DEBUG("adding library %s/%s\n", path, name); -} - -static int elf_open(char **dir, char *file) -{ - struct library_path *p; - char path[256]; - int fd = -1; - - *dir = NULL; - - list_for_each_entry(p, &library_paths, list) { - if (strlen(p->path)) - snprintf(path, sizeof(path), "%s/%s", p->path, file); - else - strncpy(path, file, sizeof(path)); - fd = open(path, O_RDONLY); - if (fd >= 0) { - *dir = p->path; - break; - } - } - - if (fd == -1) - fd = open(file, O_RDONLY); - - return fd; -} - -char* find_lib(char *file) -{ - struct library *l; - static char path[256]; - const char *p; - - l = avl_find_element(&libraries, file, l, avl); - if (!l) - return NULL; - - p = l->path; - if (strstr(p, "local")) - p = "/lib"; - - snprintf(path, sizeof(path), "%s/%s", p, file); - - return path; -} - -static int elf64_find_section(char *map, unsigned int type, unsigned int *offset, unsigned int *size, unsigned int *vaddr) -{ - Elf64_Ehdr *e; - Elf64_Phdr *ph; - int i; - - e = (Elf64_Ehdr *) map; - ph = (Elf64_Phdr *) (map + e->e_phoff); - - for (i = 0; i < e->e_phnum; i++) { - if (ph[i].p_type == type) { - *offset = ph[i].p_offset; - if (size) - *size = ph[i].p_filesz; - if (vaddr) - *vaddr = ph[i].p_vaddr; - return 0; - } - } - - return -1; -} - -static int elf32_find_section(char *map, unsigned int type, unsigned int *offset, unsigned int *size, unsigned int *vaddr) -{ - Elf32_Ehdr *e; - Elf32_Phdr *ph; - int i; - - e = (Elf32_Ehdr *) map; - ph = (Elf32_Phdr *) (map + e->e_phoff); - - for (i = 0; i < e->e_phnum; i++) { - if (ph[i].p_type == type) { - *offset = ph[i].p_offset; - if (size) - *size = ph[i].p_filesz; - if (vaddr) - *vaddr = ph[i].p_vaddr; - return 0; - } - } - - return -1; -} - -static int elf_find_section(char *map, unsigned int type, unsigned int *offset, unsigned int *size, unsigned int *vaddr) -{ - int clazz = map[EI_CLASS]; - - if (clazz == ELFCLASS32) - return elf32_find_section(map, type, offset, size, vaddr); - else if (clazz == ELFCLASS64) - return elf64_find_section(map, type, offset, size, vaddr); - - ERROR("unknown elf format %d\n", clazz); - - return -1; -} - -static int elf32_scan_dynamic(char *map, int dyn_offset, int dyn_size, int load_offset) -{ - Elf32_Dyn *dynamic = (Elf32_Dyn *) (map + dyn_offset); - char *strtab = NULL; - - while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) { - Elf32_Dyn *curr = dynamic; - - dynamic++; - if (curr->d_tag != DT_STRTAB) - continue; - - strtab = map + (curr->d_un.d_val - load_offset); - break; - } - - if (!strtab) - return -1; - - dynamic = (Elf32_Dyn *) (map + dyn_offset); - while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) { - Elf32_Dyn *curr = dynamic; - - dynamic++; - if (curr->d_tag != DT_NEEDED) - continue; - - if (elf_load_deps(&strtab[curr->d_un.d_val])) - return -1; - } - - return 0; -} - -static int elf64_scan_dynamic(char *map, int dyn_offset, int dyn_size, int load_offset) -{ - Elf64_Dyn *dynamic = (Elf64_Dyn *) (map + dyn_offset); - char *strtab = NULL; - - while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) { - Elf64_Dyn *curr = dynamic; - - dynamic++; - if (curr->d_tag != DT_STRTAB) - continue; - - strtab = map + (curr->d_un.d_val - load_offset); - break; - } - - if (!strtab) - return -1; - - dynamic = (Elf64_Dyn *) (map + dyn_offset); - while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) { - Elf64_Dyn *curr = dynamic; - - dynamic++; - if (curr->d_tag != DT_NEEDED) - continue; - - if (elf_load_deps(&strtab[curr->d_un.d_val])) - return -1; - } - - return 0; -} - -int elf_load_deps(char *library) -{ - unsigned int dyn_offset, dyn_size; - unsigned int load_offset, load_vaddr; - struct stat s; - char *map = NULL, *dir = NULL; - int clazz, fd, ret = -1; - - if (avl_find(&libraries, library)) - return 0; - - fd = elf_open(&dir, library); - - if (fd < 0) { - ERROR("failed to open %s\n", library); - return -1; - } - - if (fstat(fd, &s) == -1) { - ERROR("failed to stat %s\n", library); - ret = -1; - goto err_out; - } - - map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0); - if (map == MAP_FAILED) { - ERROR("failed to mmap %s\n", library); - ret = -1; - goto err_out; - } - - if (elf_find_section(map, PT_LOAD, &load_offset, NULL, &load_vaddr)) { - ERROR("failed to load the .load section from %s\n", library); - ret = -1; - goto err_out; - } - - if (elf_find_section(map, PT_DYNAMIC, &dyn_offset, &dyn_size, NULL)) { - ERROR("failed to load the .dynamic section from %s\n", library); - ret = -1; - goto err_out; - } - - if (dir) { - alloc_library(dir, library); - } else { - char *elf = strdup(library); - - alloc_library(dirname(elf), basename(library)); - free(elf); - } - clazz = map[EI_CLASS]; - - if (clazz == ELFCLASS32) - ret = elf32_scan_dynamic(map, dyn_offset, dyn_size, load_vaddr - load_offset); - else if (clazz == ELFCLASS64) - ret = elf64_scan_dynamic(map, dyn_offset, dyn_size, load_vaddr - load_offset); - -err_out: - if (map) - munmap(map, s.st_size); - close(fd); - - return ret; -} - -void load_ldso_conf(const char *conf) -{ - FILE* fp = fopen(conf, "r"); - char line[256]; - - if (!fp) { - DEBUG("failed to open %s\n", conf); - return; - } - - while (!feof(fp)) { - int len; - - if (!fgets(line, 256, fp)) - break; - len = strlen(line); - if (len < 2) - continue; - if (*line == '#') - continue; - if (line[len - 1] == '\n') - line[len - 1] = '\0'; - if (!strncmp(line, "include ", 8)) { - char *sep = strstr(line, " "); - glob_t gl; - int i; - - if (!sep) - continue;; - while (*sep == ' ') - sep++; - if (glob(sep, GLOB_NOESCAPE | GLOB_MARK, NULL, &gl)) { - ERROR("glob failed on %s\n", sep); - continue; - } - for (i = 0; i < gl.gl_pathc; i++) - load_ldso_conf(gl.gl_pathv[i]); - globfree(&gl); - } else { - struct stat s; - - if (stat(line, &s)) - continue; - alloc_library_path(line); - } - } - - fclose(fp); -} |