| /* |
| * Copyright (C) 2008 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/android_filesystem_config.h" |
| |
| #include <dirent.h> |
| #include <limits.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| /* |
| * Recursively walk the directory tree at <sysdir>/<subdir>, writing |
| * script commands to set permissions and create symlinks. |
| * Assume the contents already have the specified default permissions, |
| * so only output commands if they need to be changed from the defaults. |
| * |
| * Note that permissions are set by fs_config(), which uses a lookup table of |
| * Android permissions. They are not drawn from the build host filesystem. |
| */ |
| static void walk_files( |
| const char *sysdir, const char *subdir, |
| unsigned default_uid, unsigned default_gid, |
| unsigned default_dir_mode, unsigned default_file_mode) { |
| const char *sep = strcmp(subdir, "") ? "/" : ""; |
| |
| char fn[PATH_MAX]; |
| unsigned dir_uid = 0, dir_gid = 0, dir_mode = 0; |
| snprintf(fn, PATH_MAX, "system%s%s", sep, subdir); |
| fs_config(fn, 1, &dir_uid, &dir_gid, &dir_mode); |
| |
| snprintf(fn, PATH_MAX, "%s%s%s", sysdir, sep, subdir); |
| DIR *dir = opendir(fn); |
| if (dir == NULL) { |
| perror(fn); |
| exit(1); |
| } |
| |
| /* |
| * We can use "set_perm" and "set_perm_recursive" to set file permissions |
| * (owner, group, and file mode) for individual files and entire subtrees. |
| * We want to use set_perm_recursive efficiently to avoid setting the |
| * permissions of every single file in the system image individually. |
| * |
| * What we do is recursively set our entire subtree to the permissions |
| * used by the first file we encounter, and then use "set_perm" to adjust |
| * the permissions of subsequent files which don't match the first one. |
| * This is bad if the first file is an outlier, but it generally works. |
| * Subdirectories can do the same thing recursively if they're different. |
| */ |
| |
| int is_first = 1; |
| const struct dirent *e; |
| while ((e = readdir(dir))) { |
| // Skip over "." and ".." entries |
| if (!strcmp(e->d_name, ".") || !strcmp(e->d_name, "..")) continue; |
| |
| if (e->d_type == DT_LNK) { // Symlink |
| |
| // Symlinks don't really have permissions, so this is orthogonal. |
| snprintf(fn, PATH_MAX, "%s/%s%s%s", sysdir, subdir, sep, e->d_name); |
| int len = readlink(fn, fn, PATH_MAX - 1); |
| if (len <= 0) { |
| perror(fn); |
| exit(1); |
| } |
| fn[len] = '\0'; |
| printf("symlink %s SYSTEM:%s%s%s\n", fn, subdir, sep, e->d_name); |
| |
| } else if (e->d_type == DT_DIR) { // Subdirectory |
| |
| // Use the parent directory as the model for default permissions. |
| // We haven't seen a file, so just make up some file defaults. |
| if (is_first && ( |
| dir_mode != default_dir_mode || |
| dir_uid != default_uid || dir_gid != default_gid)) { |
| default_uid = dir_uid; |
| default_gid = dir_gid; |
| default_dir_mode = dir_mode; |
| default_file_mode = dir_mode & default_file_mode & 0666; |
| printf("set_perm_recursive %d %d 0%o 0%o SYSTEM:%s\n", |
| default_uid, default_gid, |
| default_dir_mode, default_file_mode, |
| subdir); |
| } |
| |
| is_first = 0; |
| |
| // Recursively handle the subdirectory. |
| // Note, the recursive call handles the directory's own permissions. |
| snprintf(fn, PATH_MAX, "%s%s%s", subdir, sep, e->d_name); |
| walk_files(sysdir, fn, |
| default_uid, default_gid, |
| default_dir_mode, default_file_mode); |
| |
| } else { // Ordinary file |
| |
| // Get the file's desired permissions. |
| unsigned file_uid = 0, file_gid = 0, file_mode = 0; |
| snprintf(fn, PATH_MAX, "system/%s%s%s", subdir, sep, e->d_name); |
| fs_config(fn, 0, &file_uid, &file_gid, &file_mode); |
| |
| // If this is the first file, its mode gets to become the default. |
| if (is_first && ( |
| dir_mode != default_dir_mode || |
| file_mode != default_file_mode || |
| dir_uid != default_uid || file_uid != default_uid || |
| dir_gid != default_gid || file_gid != default_gid)) { |
| default_uid = dir_uid; |
| default_gid = dir_gid; |
| default_dir_mode = dir_mode; |
| default_file_mode = file_mode; |
| printf("set_perm_recursive %d %d 0%o 0%o SYSTEM:%s\n", |
| default_uid, default_gid, |
| default_dir_mode, default_file_mode, |
| subdir); |
| } |
| |
| is_first = 0; |
| |
| // Otherwise, override this file if it doesn't match the defaults. |
| if (file_mode != default_file_mode || |
| file_uid != default_uid || file_gid != default_gid) { |
| printf("set_perm %d %d 0%o SYSTEM:%s%s%s\n", |
| file_uid, file_gid, file_mode, |
| subdir, sep, e->d_name); |
| } |
| |
| } |
| } |
| |
| // Set the directory's permissions directly, if they never got set. |
| if (dir_mode != default_dir_mode || |
| dir_uid != default_uid || dir_gid != default_gid) { |
| printf("set_perm %d %d 0%o SYSTEM:%s\n", |
| dir_uid, dir_gid, dir_mode, subdir); |
| } |
| |
| closedir(dir); |
| } |
| |
| /* |
| * Generate the update script (in "Amend", see commands/recovery/commands.c) |
| * for the complete-reinstall OTA update packages the build system makes. |
| * |
| * The generated script makes a variety of sanity checks about the device, |
| * erases and reinstalls system files, and sets file permissions appropriately. |
| */ |
| int main(int argc, char *argv[]) { |
| if (argc != 3) { |
| fprintf(stderr, "usage: %s systemdir android-info.txt >update-script\n", |
| argv[0]); |
| return 2; |
| } |
| |
| // ensure basic recovery script language compatibility |
| printf("assert compatible_with(\"0.2\") == \"true\"\n"); |
| |
| // if known, make sure the device name is correct |
| const char *device = getenv("TARGET_DEVICE"); |
| if (device != NULL) { |
| printf("assert getprop(\"ro.product.device\") == \"%s\" || " |
| "getprop(\"ro.build.product\") == \"%s\"\n", device, device); |
| } |
| |
| // scan android-info.txt to enforce compatibility with the target system |
| FILE *fp = fopen(argv[2], "r"); |
| if (fp == NULL) { |
| perror(argv[2]); |
| return 1; |
| } |
| |
| // The lines we're looking for look like: |
| // version-bootloader=x.yy.zzzz|x.yy.zzzz|... |
| // or: |
| // require version-bootloader=x.yy.zzzz|x.yy.zzzz|... |
| char line[256]; |
| while (fgets(line, sizeof(line), fp)) { |
| const char *name = strtok(line, "="), *value = strtok(NULL, "|\n"); |
| if (value != NULL && |
| (!strcmp(name, "version-bootloader") || |
| !strcmp(name, "require version-bootloader"))) { |
| printf("assert getprop(\"ro.bootloader\") == \"%s\"", value); |
| |
| while ((value = strtok(NULL, "|\n")) != NULL) { |
| printf(" || getprop(\"ro.bootloader\") == \"%s\"", value); |
| } |
| printf("\n"); |
| } |
| // We also used to check version-baseband, but we update radio.img |
| // ourselves, so there's no need. |
| } |
| |
| // erase the boot sector first, so if the update gets interrupted, |
| // the system will reboot into the recovery partition and start over. |
| printf("format BOOT:\n"); |
| |
| // write the radio image (actually just loads it into RAM for now) |
| printf("show_progress 0.1 0\n"); |
| printf("write_radio_image PACKAGE:radio.img\n"); |
| |
| // erase and reinstall the system image |
| printf("show_progress 0.5 0\n"); |
| printf("format SYSTEM:\n"); |
| printf("copy_dir PACKAGE:system SYSTEM:\n"); |
| |
| // walk the files in the system image, set their permissions, etc. |
| // use -1 for default values to force permissions to be set explicitly. |
| walk_files(argv[1], "", -1, -1, -1, -1); |
| |
| // as the last step, write the boot sector. |
| printf("show_progress 0.2 0\n"); |
| printf("write_raw_image PACKAGE:boot.img BOOT:\n"); |
| |
| // after the end of the script, the radio will be written to cache |
| // leave some space in the progress bar for this operation |
| printf("show_progress 0.2 10\n"); |
| return 0; |
| } |