| /* |
| * Copyright (C) 2007 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <private/fs_config.h> |
| |
| // This file is used to define the properties of the filesystem |
| // images generated by build tools (mkbootfs and mkyaffs2image) and |
| // by the device side of adb. |
| |
| #define LOG_TAG "fs_config" |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| |
| #include <log/log.h> |
| #include <private/android_filesystem_config.h> |
| #include <utils/Compat.h> |
| |
| #ifndef O_BINARY |
| #define O_BINARY 0 |
| #endif |
| |
| // My kingdom for <endian.h> |
| static inline uint16_t get2LE(const uint8_t* src) { |
| return src[0] | (src[1] << 8); |
| } |
| |
| static inline uint64_t get8LE(const uint8_t* src) { |
| uint32_t low, high; |
| |
| low = src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24); |
| high = src[4] | (src[5] << 8) | (src[6] << 16) | (src[7] << 24); |
| return ((uint64_t)high << 32) | (uint64_t)low; |
| } |
| |
| #define ALIGN(x, alignment) (((x) + ((alignment)-1)) & ~((alignment)-1)) |
| |
| // Rules for directories. |
| // These rules are applied based on "first match", so they |
| // should start with the most specific path and work their |
| // way up to the root. |
| |
| static const struct fs_path_config android_dirs[] = { |
| // clang-format off |
| { 00770, AID_SYSTEM, AID_CACHE, 0, "cache" }, |
| { 00555, AID_ROOT, AID_ROOT, 0, "config" }, |
| { 00771, AID_SYSTEM, AID_SYSTEM, 0, "data/app" }, |
| { 00771, AID_SYSTEM, AID_SYSTEM, 0, "data/app-private" }, |
| { 00771, AID_SYSTEM, AID_SYSTEM, 0, "data/app-ephemeral" }, |
| { 00771, AID_ROOT, AID_ROOT, 0, "data/dalvik-cache" }, |
| { 00771, AID_SYSTEM, AID_SYSTEM, 0, "data/data" }, |
| { 00771, AID_SHELL, AID_SHELL, 0, "data/local/tmp" }, |
| { 00771, AID_SHELL, AID_SHELL, 0, "data/local" }, |
| { 00770, AID_DHCP, AID_DHCP, 0, "data/misc/dhcp" }, |
| { 00771, AID_SHARED_RELRO, AID_SHARED_RELRO, 0, "data/misc/shared_relro" }, |
| { 01771, AID_SYSTEM, AID_MISC, 0, "data/misc" }, |
| { 00775, AID_MEDIA_RW, AID_MEDIA_RW, 0, "data/media/Music" }, |
| { 00775, AID_MEDIA_RW, AID_MEDIA_RW, 0, "data/media" }, |
| { 00750, AID_ROOT, AID_SHELL, 0, "data/nativetest" }, |
| { 00750, AID_ROOT, AID_SHELL, 0, "data/nativetest64" }, |
| { 00775, AID_ROOT, AID_ROOT, 0, "data/preloads" }, |
| { 00771, AID_SYSTEM, AID_SYSTEM, 0, "data" }, |
| { 00755, AID_ROOT, AID_SYSTEM, 0, "mnt" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "product/bin" }, |
| { 00750, AID_ROOT, AID_SHELL, 0, "sbin" }, |
| { 00777, AID_ROOT, AID_ROOT, 0, "sdcard" }, |
| { 00751, AID_ROOT, AID_SDCARD_R, 0, "storage" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "system/bin" }, |
| { 00755, AID_ROOT, AID_ROOT, 0, "system/etc/ppp" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "system/vendor" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "system/xbin" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "vendor" }, |
| { 00755, AID_ROOT, AID_ROOT, 0, 0 }, |
| // clang-format on |
| }; |
| #ifndef __ANDROID_VNDK__ |
| auto __for_testing_only__android_dirs = android_dirs; |
| #endif |
| |
| // Rules for files. |
| // These rules are applied based on "first match", so they |
| // should start with the most specific path and work their |
| // way up to the root. Prefixes ending in * denotes wildcard |
| // and will allow partial matches. |
| static const char sys_conf_dir[] = "/system/etc/fs_config_dirs"; |
| static const char sys_conf_file[] = "/system/etc/fs_config_files"; |
| // No restrictions are placed on the vendor and oem file-system config files, |
| // although the developer is advised to restrict the scope to the /vendor or |
| // oem/ file-system since the intent is to provide support for customized |
| // portions of a separate vendor.img or oem.img. Has to remain open so that |
| // customization can also land on /system/vendor, /system/oem or /system/odm. |
| // We expect build-time checking or filtering when constructing the associated |
| // fs_config_* files (see build/tools/fs_config/fs_config_generate.c) |
| static const char ven_conf_dir[] = "/vendor/etc/fs_config_dirs"; |
| static const char ven_conf_file[] = "/vendor/etc/fs_config_files"; |
| static const char oem_conf_dir[] = "/oem/etc/fs_config_dirs"; |
| static const char oem_conf_file[] = "/oem/etc/fs_config_files"; |
| static const char odm_conf_dir[] = "/odm/etc/fs_config_dirs"; |
| static const char odm_conf_file[] = "/odm/etc/fs_config_files"; |
| static const char* conf[][2] = { |
| {sys_conf_file, sys_conf_dir}, |
| {ven_conf_file, ven_conf_dir}, |
| {oem_conf_file, oem_conf_dir}, |
| {odm_conf_file, odm_conf_dir}, |
| }; |
| |
| // Do not use android_files to grant Linux capabilities. Use ambient capabilities in their |
| // associated init.rc file instead. See https://source.android.com/devices/tech/config/ambient. |
| |
| // Do not place any new vendor/, data/vendor/, etc entries in android_files. |
| // Vendor entries should be done via a vendor or device specific config.fs. |
| // See https://source.android.com/devices/tech/config/filesystem#using-file-system-capabilities |
| static const struct fs_path_config android_files[] = { |
| // clang-format off |
| { 00644, AID_SYSTEM, AID_SYSTEM, 0, "data/app/*" }, |
| { 00644, AID_SYSTEM, AID_SYSTEM, 0, "data/app-ephemeral/*" }, |
| { 00644, AID_SYSTEM, AID_SYSTEM, 0, "data/app-private/*" }, |
| { 00644, AID_APP, AID_APP, 0, "data/data/*" }, |
| { 00644, AID_MEDIA_RW, AID_MEDIA_RW, 0, "data/media/*" }, |
| { 00640, AID_ROOT, AID_SHELL, 0, "data/nativetest/tests.txt" }, |
| { 00640, AID_ROOT, AID_SHELL, 0, "data/nativetest64/tests.txt" }, |
| { 00750, AID_ROOT, AID_SHELL, 0, "data/nativetest/*" }, |
| { 00750, AID_ROOT, AID_SHELL, 0, "data/nativetest64/*" }, |
| { 00600, AID_ROOT, AID_ROOT, 0, "default.prop" }, // legacy |
| { 00600, AID_ROOT, AID_ROOT, 0, "system/etc/prop.default" }, |
| { 00600, AID_ROOT, AID_ROOT, 0, "odm/build.prop" }, |
| { 00600, AID_ROOT, AID_ROOT, 0, "odm/default.prop" }, |
| { 00444, AID_ROOT, AID_ROOT, 0, odm_conf_dir + 1 }, |
| { 00444, AID_ROOT, AID_ROOT, 0, odm_conf_file + 1 }, |
| { 00444, AID_ROOT, AID_ROOT, 0, oem_conf_dir + 1 }, |
| { 00444, AID_ROOT, AID_ROOT, 0, oem_conf_file + 1 }, |
| { 00600, AID_ROOT, AID_ROOT, 0, "product/build.prop" }, |
| { 00600, AID_ROOT, AID_ROOT, 0, "product-services/build.prop" }, |
| { 00750, AID_ROOT, AID_SHELL, 0, "sbin/fs_mgr" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "system/bin/crash_dump32" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "system/bin/crash_dump64" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "system/bin/debuggerd" }, |
| { 00750, AID_ROOT, AID_ROOT, 0, "system/bin/install-recovery.sh" }, |
| { 00550, AID_LOGD, AID_LOGD, 0, "system/bin/logd" }, |
| { 00700, AID_ROOT, AID_ROOT, 0, "system/bin/secilc" }, |
| { 00750, AID_ROOT, AID_ROOT, 0, "system/bin/uncrypt" }, |
| { 00600, AID_ROOT, AID_ROOT, 0, "system/build.prop" }, |
| { 00444, AID_ROOT, AID_ROOT, 0, sys_conf_dir + 1 }, |
| { 00444, AID_ROOT, AID_ROOT, 0, sys_conf_file + 1 }, |
| { 00440, AID_ROOT, AID_SHELL, 0, "system/etc/init.goldfish.rc" }, |
| { 00550, AID_ROOT, AID_SHELL, 0, "system/etc/init.goldfish.sh" }, |
| { 00550, AID_ROOT, AID_SHELL, 0, "system/etc/init.ril" }, |
| { 00555, AID_ROOT, AID_ROOT, 0, "system/etc/ppp/*" }, |
| { 00555, AID_ROOT, AID_ROOT, 0, "system/etc/rc.*" }, |
| { 00440, AID_ROOT, AID_ROOT, 0, "system/etc/recovery.img" }, |
| { 00600, AID_ROOT, AID_ROOT, 0, "vendor/build.prop" }, |
| { 00600, AID_ROOT, AID_ROOT, 0, "vendor/default.prop" }, |
| { 00444, AID_ROOT, AID_ROOT, 0, ven_conf_dir + 1 }, |
| { 00444, AID_ROOT, AID_ROOT, 0, ven_conf_file + 1 }, |
| |
| // the following two files are INTENTIONALLY set-uid, but they |
| // are NOT included on user builds. |
| { 06755, AID_ROOT, AID_ROOT, 0, "system/xbin/procmem" }, |
| { 04750, AID_ROOT, AID_SHELL, 0, "system/xbin/su" }, |
| |
| // the following files have enhanced capabilities and ARE included |
| // in user builds. |
| { 00700, AID_SYSTEM, AID_SHELL, CAP_MASK_LONG(CAP_BLOCK_SUSPEND), |
| "system/bin/inputflinger" }, |
| { 00750, AID_ROOT, AID_SHELL, CAP_MASK_LONG(CAP_SETUID) | |
| CAP_MASK_LONG(CAP_SETGID), |
| "system/bin/run-as" }, |
| |
| // Support FIFO scheduling mode in SurfaceFlinger. |
| { 00755, AID_SYSTEM, AID_GRAPHICS, CAP_MASK_LONG(CAP_SYS_NICE), |
| "system/bin/surfaceflinger" }, |
| // generic defaults |
| { 00755, AID_ROOT, AID_ROOT, 0, "bin/*" }, |
| { 00640, AID_ROOT, AID_SHELL, 0, "fstab.*" }, |
| { 00750, AID_ROOT, AID_SHELL, 0, "init*" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "product/bin/*" }, |
| { 00750, AID_ROOT, AID_SHELL, 0, "sbin/*" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "system/bin/*" }, |
| { 00755, AID_ROOT, AID_ROOT, 0, "system/lib/valgrind/*" }, |
| { 00755, AID_ROOT, AID_ROOT, 0, "system/lib64/valgrind/*" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "system/xbin/*" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "vendor/bin/*" }, |
| { 00755, AID_ROOT, AID_SHELL, 0, "vendor/xbin/*" }, |
| { 00644, AID_ROOT, AID_ROOT, 0, 0 }, |
| // clang-format on |
| }; |
| #ifndef __ANDROID_VNDK__ |
| auto __for_testing_only__android_files = android_files; |
| #endif |
| |
| static size_t strip(const char* path, size_t len, const char suffix[]) { |
| if (len < strlen(suffix)) return len; |
| if (strncmp(path + len - strlen(suffix), suffix, strlen(suffix))) return len; |
| return len - strlen(suffix); |
| } |
| |
| static int fs_config_open(int dir, int which, const char* target_out_path) { |
| int fd = -1; |
| |
| if (target_out_path && *target_out_path) { |
| // target_out_path is the path to the directory holding content of |
| // system partition but as we cannot guarantee it ends with '/system' |
| // or with or without a trailing slash, need to strip them carefully. |
| char* name = NULL; |
| size_t len = strlen(target_out_path); |
| len = strip(target_out_path, len, "/"); |
| len = strip(target_out_path, len, "/system"); |
| if (asprintf(&name, "%.*s%s", (int)len, target_out_path, conf[which][dir]) != -1) { |
| fd = TEMP_FAILURE_RETRY(open(name, O_RDONLY | O_BINARY)); |
| free(name); |
| } |
| } |
| if (fd < 0) { |
| fd = TEMP_FAILURE_RETRY(open(conf[which][dir], O_RDONLY | O_BINARY)); |
| } |
| return fd; |
| } |
| |
| // if path is "odm/<stuff>", "oem/<stuff>", "product/<stuff>" or |
| // "vendor/<stuff>" |
| static bool is_partition(const char* path, size_t len) { |
| static const char* partitions[] = {"odm/", "oem/", "product/", "vendor/"}; |
| for (size_t i = 0; i < (sizeof(partitions) / sizeof(partitions[0])); ++i) { |
| size_t plen = strlen(partitions[i]); |
| if (len <= plen) continue; |
| if (!strncmp(path, partitions[i], plen)) return true; |
| } |
| return false; |
| } |
| |
| static inline bool prefix_cmp(bool partial, const char* prefix, size_t len, const char* path, |
| size_t plen) { |
| return ((partial && plen >= len) || (plen == len)) && !strncmp(prefix, path, len); |
| } |
| |
| // alias prefixes of "<partition>/<stuff>" to "system/<partition>/<stuff>" or |
| // "system/<partition>/<stuff>" to "<partition>/<stuff>" |
| static bool fs_config_cmp(bool partial, const char* prefix, size_t len, const char* path, |
| size_t plen) { |
| // If name ends in * then allow partial matches. |
| if (!partial && prefix[len - 1] == '*') { |
| len--; |
| partial = true; |
| } |
| |
| if (prefix_cmp(partial, prefix, len, path, plen)) return true; |
| |
| static const char system[] = "system/"; |
| if (!strncmp(path, system, strlen(system))) { |
| path += strlen(system); |
| plen -= strlen(system); |
| } else if (len <= strlen(system)) { |
| return false; |
| } else if (strncmp(prefix, system, strlen(system))) { |
| return false; |
| } else { |
| prefix += strlen(system); |
| len -= strlen(system); |
| } |
| return is_partition(prefix, len) && prefix_cmp(partial, prefix, len, path, plen); |
| } |
| #ifndef __ANDROID_VNDK__ |
| auto __for_testing_only__fs_config_cmp = fs_config_cmp; |
| #endif |
| |
| void fs_config(const char* path, int dir, const char* target_out_path, unsigned* uid, unsigned* gid, |
| unsigned* mode, uint64_t* capabilities) { |
| const struct fs_path_config* pc; |
| size_t which, plen; |
| |
| if (path[0] == '/') { |
| path++; |
| } |
| |
| plen = strlen(path); |
| |
| for (which = 0; which < (sizeof(conf) / sizeof(conf[0])); ++which) { |
| struct fs_path_config_from_file header; |
| |
| int fd = fs_config_open(dir, which, target_out_path); |
| if (fd < 0) continue; |
| |
| while (TEMP_FAILURE_RETRY(read(fd, &header, sizeof(header))) == sizeof(header)) { |
| char* prefix; |
| uint16_t host_len = get2LE((const uint8_t*)&header.len); |
| ssize_t len, remainder = host_len - sizeof(header); |
| if (remainder <= 0) { |
| ALOGE("%s len is corrupted", conf[which][dir]); |
| break; |
| } |
| prefix = static_cast<char*>(calloc(1, remainder)); |
| if (!prefix) { |
| ALOGE("%s out of memory", conf[which][dir]); |
| break; |
| } |
| if (TEMP_FAILURE_RETRY(read(fd, prefix, remainder)) != remainder) { |
| free(prefix); |
| ALOGE("%s prefix is truncated", conf[which][dir]); |
| break; |
| } |
| len = strnlen(prefix, remainder); |
| if (len >= remainder) { // missing a terminating null |
| free(prefix); |
| ALOGE("%s is corrupted", conf[which][dir]); |
| break; |
| } |
| if (fs_config_cmp(dir, prefix, len, path, plen)) { |
| free(prefix); |
| close(fd); |
| *uid = get2LE((const uint8_t*)&(header.uid)); |
| *gid = get2LE((const uint8_t*)&(header.gid)); |
| *mode = (*mode & (~07777)) | get2LE((const uint8_t*)&(header.mode)); |
| *capabilities = get8LE((const uint8_t*)&(header.capabilities)); |
| return; |
| } |
| free(prefix); |
| } |
| close(fd); |
| } |
| |
| for (pc = dir ? android_dirs : android_files; pc->prefix; pc++) { |
| if (fs_config_cmp(dir, pc->prefix, strlen(pc->prefix), path, plen)) { |
| break; |
| } |
| } |
| *uid = pc->uid; |
| *gid = pc->gid; |
| *mode = (*mode & (~07777)) | pc->mode; |
| *capabilities = pc->capabilities; |
| } |
| |
| ssize_t fs_config_generate(char* buffer, size_t length, const struct fs_path_config* pc) { |
| struct fs_path_config_from_file* p = (struct fs_path_config_from_file*)buffer; |
| size_t len = ALIGN(sizeof(*p) + strlen(pc->prefix) + 1, sizeof(uint64_t)); |
| |
| if ((length < len) || (len > UINT16_MAX)) { |
| return -ENOSPC; |
| } |
| memset(p, 0, len); |
| uint16_t host_len = len; |
| p->len = get2LE((const uint8_t*)&host_len); |
| p->mode = get2LE((const uint8_t*)&(pc->mode)); |
| p->uid = get2LE((const uint8_t*)&(pc->uid)); |
| p->gid = get2LE((const uint8_t*)&(pc->gid)); |
| p->capabilities = get8LE((const uint8_t*)&(pc->capabilities)); |
| strcpy(p->prefix, pc->prefix); |
| return len; |
| } |
