From 381f455cac0905b023dde79625b06c27b6165dd0 Mon Sep 17 00:00:00 2001 From: Tao Bao Date: Tue, 5 May 2015 18:36:45 -0700 Subject: uncrypt: Switch to C++ Also apply some trivial changes like int -> bool and clean-ups. Change-Id: Ic55fc8b82d7e91b321f69d10175be23d5c04eb92 --- uncrypt/Android.mk | 2 +- uncrypt/uncrypt.c | 467 ---------------------------------------------------- uncrypt/uncrypt.cpp | 465 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 466 insertions(+), 468 deletions(-) delete mode 100644 uncrypt/uncrypt.c create mode 100644 uncrypt/uncrypt.cpp (limited to 'uncrypt') diff --git a/uncrypt/Android.mk b/uncrypt/Android.mk index 878d2757e..d832d9724 100644 --- a/uncrypt/Android.mk +++ b/uncrypt/Android.mk @@ -16,7 +16,7 @@ LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) -LOCAL_SRC_FILES := uncrypt.c +LOCAL_SRC_FILES := uncrypt.cpp LOCAL_MODULE := uncrypt diff --git a/uncrypt/uncrypt.c b/uncrypt/uncrypt.c deleted file mode 100644 index 42ae649cc..000000000 --- a/uncrypt/uncrypt.c +++ /dev/null @@ -1,467 +0,0 @@ -/* - * Copyright (C) 2014 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. - */ - -// This program takes a file on an ext4 filesystem and produces a list -// of the blocks that file occupies, which enables the file contents -// to be read directly from the block device without mounting the -// filesystem. -// -// If the filesystem is using an encrypted block device, it will also -// read the file and rewrite it to the same blocks of the underlying -// (unencrypted) block device, so the file contents can be read -// without the need for the decryption key. -// -// The output of this program is a "block map" which looks like this: -// -// /dev/block/platform/msm_sdcc.1/by-name/userdata # block device -// 49652 4096 # file size in bytes, block size -// 3 # count of block ranges -// 1000 1008 # block range 0 -// 2100 2102 # ... block range 1 -// 30 33 # ... block range 2 -// -// Each block range represents a half-open interval; the line "30 33" -// reprents the blocks [30, 31, 32]. -// -// Recovery can take this block map file and retrieve the underlying -// file data to use as an update package. - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#define LOG_TAG "uncrypt" -#include -#include -#include - -#define WINDOW_SIZE 5 -#define RECOVERY_COMMAND_FILE "/cache/recovery/command" -#define RECOVERY_COMMAND_FILE_TMP "/cache/recovery/command.tmp" -#define CACHE_BLOCK_MAP "/cache/recovery/block.map" - -static struct fstab* fstab = NULL; - -static int write_at_offset(unsigned char* buffer, size_t size, - int wfd, off64_t offset) -{ - if (TEMP_FAILURE_RETRY(lseek64(wfd, offset, SEEK_SET)) == -1) { - ALOGE("error seeking to offset %lld: %s\n", offset, strerror(errno)); - return -1; - } - size_t written = 0; - while (written < size) { - ssize_t wrote = TEMP_FAILURE_RETRY(write(wfd, buffer + written, size - written)); - if (wrote == -1) { - ALOGE("error writing offset %lld: %s\n", (offset + written), strerror(errno)); - return -1; - } - written += wrote; - } - return 0; -} - -void add_block_to_ranges(int** ranges, int* range_alloc, int* range_used, int new_block) -{ - // If the current block start is < 0, set the start to the new - // block. (This only happens for the very first block of the very - // first range.) - if ((*ranges)[*range_used*2-2] < 0) { - (*ranges)[*range_used*2-2] = new_block; - (*ranges)[*range_used*2-1] = new_block; - } - - if (new_block == (*ranges)[*range_used*2-1]) { - // If the new block comes immediately after the current range, - // all we have to do is extend the current range. - ++(*ranges)[*range_used*2-1]; - } else { - // We need to start a new range. - - // If there isn't enough room in the array, we need to expand it. - if (*range_used >= *range_alloc) { - *range_alloc *= 2; - *ranges = realloc(*ranges, *range_alloc * 2 * sizeof(int)); - } - - ++*range_used; - (*ranges)[*range_used*2-2] = new_block; - (*ranges)[*range_used*2-1] = new_block+1; - } -} - -static struct fstab* read_fstab() -{ - fstab = NULL; - - // The fstab path is always "/fstab.${ro.hardware}". - char fstab_path[PATH_MAX+1] = "/fstab."; - if (!property_get("ro.hardware", fstab_path+strlen(fstab_path), "")) { - ALOGE("failed to get ro.hardware\n"); - return NULL; - } - - fstab = fs_mgr_read_fstab(fstab_path); - if (!fstab) { - ALOGE("failed to read %s\n", fstab_path); - return NULL; - } - - return fstab; -} - -const char* find_block_device(const char* path, int* encryptable, int* encrypted) -{ - // Look for a volume whose mount point is the prefix of path and - // return its block device. Set encrypted if it's currently - // encrypted. - int i; - for (i = 0; i < fstab->num_entries; ++i) { - struct fstab_rec* v = &fstab->recs[i]; - if (!v->mount_point) continue; - int len = strlen(v->mount_point); - if (strncmp(path, v->mount_point, len) == 0 && - (path[len] == '/' || path[len] == 0)) { - *encrypted = 0; - *encryptable = 0; - if (fs_mgr_is_encryptable(v)) { - *encryptable = 1; - char buffer[PROPERTY_VALUE_MAX+1]; - if (property_get("ro.crypto.state", buffer, "") && - strcmp(buffer, "encrypted") == 0) { - *encrypted = 1; - } - } - return v->blk_device; - } - } - - return NULL; -} - -// Parse the command file RECOVERY_COMMAND_FILE to find the update package -// name. If it's on the /data partition, replace the package name with the -// block map file name and store it temporarily in RECOVERY_COMMAND_FILE_TMP. -// It will be renamed to RECOVERY_COMMAND_FILE if uncrypt finishes -// successfully. -static char* find_update_package() -{ - FILE* f = fopen(RECOVERY_COMMAND_FILE, "r"); - if (f == NULL) { - return NULL; - } - int fd = open(RECOVERY_COMMAND_FILE_TMP, O_WRONLY | O_CREAT | O_SYNC, S_IRUSR | S_IWUSR); - if (fd < 0) { - ALOGE("failed to open %s\n", RECOVERY_COMMAND_FILE_TMP); - return NULL; - } - FILE* fo = fdopen(fd, "w"); - char* fn = NULL; - char* line = NULL; - size_t len = 0; - while (getline(&line, &len, f) != -1) { - if (strncmp(line, "--update_package=", strlen("--update_package=")) == 0) { - fn = strdup(line + strlen("--update_package=")); - // Replace the package name with block map file if it's on /data partition. - if (strncmp(fn, "/data/", strlen("/data/")) == 0) { - fputs("--update_package=@" CACHE_BLOCK_MAP "\n", fo); - continue; - } - } - fputs(line, fo); - } - free(line); - fclose(f); - if (fsync(fd) == -1) { - ALOGE("failed to fsync \"%s\": %s\n", RECOVERY_COMMAND_FILE_TMP, strerror(errno)); - fclose(fo); - return NULL; - } - fclose(fo); - - if (fn) { - char* newline = strchr(fn, '\n'); - if (newline) *newline = 0; - } - return fn; -} - -int produce_block_map(const char* path, const char* map_file, const char* blk_dev, - int encrypted) -{ - struct stat sb; - int ret; - - int mapfd = open(map_file, O_WRONLY | O_CREAT | O_SYNC, S_IRUSR | S_IWUSR); - if (mapfd < 0) { - ALOGE("failed to open %s\n", map_file); - return -1; - } - FILE* mapf = fdopen(mapfd, "w"); - - ret = stat(path, &sb); - if (ret != 0) { - ALOGE("failed to stat %s\n", path); - return -1; - } - - ALOGI(" block size: %ld bytes\n", (long)sb.st_blksize); - - int blocks = ((sb.st_size-1) / sb.st_blksize) + 1; - ALOGI(" file size: %lld bytes, %d blocks\n", (long long)sb.st_size, blocks); - - int* ranges; - int range_alloc = 1; - int range_used = 1; - ranges = malloc(range_alloc * 2 * sizeof(int)); - ranges[0] = -1; - ranges[1] = -1; - - fprintf(mapf, "%s\n%lld %lu\n", blk_dev, (long long)sb.st_size, (unsigned long)sb.st_blksize); - - unsigned char* buffers[WINDOW_SIZE]; - int i; - if (encrypted) { - for (i = 0; i < WINDOW_SIZE; ++i) { - buffers[i] = malloc(sb.st_blksize); - } - } - int head_block = 0; - int head = 0, tail = 0; - size_t pos = 0; - - int fd = open(path, O_RDONLY); - if (fd < 0) { - ALOGE("failed to open fd for reading: %s\n", strerror(errno)); - return -1; - } - - int wfd = -1; - if (encrypted) { - wfd = open(blk_dev, O_WRONLY | O_SYNC); - if (wfd < 0) { - ALOGE("failed to open fd for writing: %s\n", strerror(errno)); - return -1; - } - } - - while (pos < sb.st_size) { - if ((tail+1) % WINDOW_SIZE == head) { - // write out head buffer - int block = head_block; - ret = ioctl(fd, FIBMAP, &block); - if (ret != 0) { - ALOGE("failed to find block %d\n", head_block); - return -1; - } - add_block_to_ranges(&ranges, &range_alloc, &range_used, block); - if (encrypted) { - if (write_at_offset(buffers[head], sb.st_blksize, wfd, (off64_t)sb.st_blksize * block) != 0) { - return -1; - } - } - head = (head + 1) % WINDOW_SIZE; - ++head_block; - } - - // read next block to tail - if (encrypted) { - size_t so_far = 0; - while (so_far < sb.st_blksize && pos < sb.st_size) { - ssize_t this_read = - TEMP_FAILURE_RETRY(read(fd, buffers[tail] + so_far, sb.st_blksize - so_far)); - if (this_read == -1) { - ALOGE("failed to read: %s\n", strerror(errno)); - return -1; - } - so_far += this_read; - pos += this_read; - } - } else { - // If we're not encrypting; we don't need to actually read - // anything, just skip pos forward as if we'd read a - // block. - pos += sb.st_blksize; - } - tail = (tail+1) % WINDOW_SIZE; - } - - while (head != tail) { - // write out head buffer - int block = head_block; - ret = ioctl(fd, FIBMAP, &block); - if (ret != 0) { - ALOGE("failed to find block %d\n", head_block); - return -1; - } - add_block_to_ranges(&ranges, &range_alloc, &range_used, block); - if (encrypted) { - if (write_at_offset(buffers[head], sb.st_blksize, wfd, (off64_t)sb.st_blksize * block) != 0) { - return -1; - } - } - head = (head + 1) % WINDOW_SIZE; - ++head_block; - } - - fprintf(mapf, "%d\n", range_used); - for (i = 0; i < range_used; ++i) { - fprintf(mapf, "%d %d\n", ranges[i*2], ranges[i*2+1]); - } - - if (fsync(mapfd) == -1) { - ALOGE("failed to fsync \"%s\": %s\n", map_file, strerror(errno)); - return -1; - } - fclose(mapf); - close(fd); - if (encrypted) { - if (fsync(wfd) == -1) { - ALOGE("failed to fsync \"%s\": %s\n", blk_dev, strerror(errno)); - return -1; - } - close(wfd); - } - - return 0; -} - -void wipe_misc() { - ALOGI("removing old commands from misc"); - int i; - for (i = 0; i < fstab->num_entries; ++i) { - struct fstab_rec* v = &fstab->recs[i]; - if (!v->mount_point) continue; - if (strcmp(v->mount_point, "/misc") == 0) { - int fd = open(v->blk_device, O_WRONLY | O_SYNC); - uint8_t zeroes[1088]; // sizeof(bootloader_message) from recovery - memset(zeroes, 0, sizeof(zeroes)); - - size_t written = 0; - size_t size = sizeof(zeroes); - while (written < size) { - ssize_t w = TEMP_FAILURE_RETRY(write(fd, zeroes, size-written)); - if (w == -1) { - ALOGE("zero write failed: %s\n", strerror(errno)); - return; - } else { - written += w; - } - } - if (fsync(fd) == -1) { - ALOGE("failed to fsync \"%s\": %s\n", v->blk_device, strerror(errno)); - close(fd); - return; - } - close(fd); - } - } -} - -void reboot_to_recovery() { - ALOGI("rebooting to recovery"); - property_set("sys.powerctl", "reboot,recovery"); - sleep(10); - ALOGE("reboot didn't succeed?"); -} - -int main(int argc, char** argv) -{ - const char* input_path; - const char* map_file; - int do_reboot = 1; - - if (argc != 1 && argc != 3) { - fprintf(stderr, "usage: %s [ ]\n", argv[0]); - return 2; - } - - if (argc == 3) { - // when command-line args are given this binary is being used - // for debugging; don't reboot to recovery at the end. - input_path = argv[1]; - map_file = argv[2]; - do_reboot = 0; - } else { - input_path = find_update_package(); - if (input_path == NULL) { - // if we're rebooting to recovery without a package (say, - // to wipe data), then we don't need to do anything before - // going to recovery. - ALOGI("no recovery command file or no update package arg"); - reboot_to_recovery(); - return 1; - } - map_file = CACHE_BLOCK_MAP; - } - - ALOGI("update package is %s", input_path); - - // Turn the name of the file we're supposed to convert into an - // absolute path, so we can find what filesystem it's on. - char path[PATH_MAX+1]; - if (realpath(input_path, path) == NULL) { - ALOGE("failed to convert %s to absolute path: %s", input_path, strerror(errno)); - return 1; - } - - int encryptable; - int encrypted; - if (read_fstab() == NULL) { - return 1; - } - const char* blk_dev = find_block_device(path, &encryptable, &encrypted); - if (blk_dev == NULL) { - ALOGE("failed to find block device for %s", path); - return 1; - } - - // If the filesystem it's on isn't encrypted, we only produce the - // block map, we don't rewrite the file contents (it would be - // pointless to do so). - ALOGI("encryptable: %s\n", encryptable ? "yes" : "no"); - ALOGI(" encrypted: %s\n", encrypted ? "yes" : "no"); - - // Recovery supports installing packages from 3 paths: /cache, - // /data, and /sdcard. (On a particular device, other locations - // may work, but those are three we actually expect.) - // - // On /data we want to convert the file to a block map so that we - // can read the package without mounting the partition. On /cache - // and /sdcard we leave the file alone. - if (strncmp(path, "/data/", 6) != 0) { - // path does not start with "/data/"; leave it alone. - unlink(RECOVERY_COMMAND_FILE_TMP); - wipe_misc(); - } else { - ALOGI("writing block map %s", map_file); - if (produce_block_map(path, map_file, blk_dev, encrypted) != 0) { - return 1; - } - wipe_misc(); - rename(RECOVERY_COMMAND_FILE_TMP, RECOVERY_COMMAND_FILE); - } - - if (do_reboot) reboot_to_recovery(); - return 0; -} diff --git a/uncrypt/uncrypt.cpp b/uncrypt/uncrypt.cpp new file mode 100644 index 000000000..11766f14c --- /dev/null +++ b/uncrypt/uncrypt.cpp @@ -0,0 +1,465 @@ +/* + * Copyright (C) 2014 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. + */ + +// This program takes a file on an ext4 filesystem and produces a list +// of the blocks that file occupies, which enables the file contents +// to be read directly from the block device without mounting the +// filesystem. +// +// If the filesystem is using an encrypted block device, it will also +// read the file and rewrite it to the same blocks of the underlying +// (unencrypted) block device, so the file contents can be read +// without the need for the decryption key. +// +// The output of this program is a "block map" which looks like this: +// +// /dev/block/platform/msm_sdcc.1/by-name/userdata # block device +// 49652 4096 # file size in bytes, block size +// 3 # count of block ranges +// 1000 1008 # block range 0 +// 2100 2102 # ... block range 1 +// 30 33 # ... block range 2 +// +// Each block range represents a half-open interval; the line "30 33" +// reprents the blocks [30, 31, 32]. +// +// Recovery can take this block map file and retrieve the underlying +// file data to use as an update package. + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define LOG_TAG "uncrypt" +#include +#include +#include + +#define WINDOW_SIZE 5 +#define RECOVERY_COMMAND_FILE "/cache/recovery/command" +#define RECOVERY_COMMAND_FILE_TMP "/cache/recovery/command.tmp" +#define CACHE_BLOCK_MAP "/cache/recovery/block.map" + +static struct fstab* fstab = NULL; + +static int write_at_offset(unsigned char* buffer, size_t size, int wfd, off64_t offset) { + if (TEMP_FAILURE_RETRY(lseek64(wfd, offset, SEEK_SET)) == -1) { + ALOGE("error seeking to offset %lld: %s\n", offset, strerror(errno)); + return -1; + } + size_t written = 0; + while (written < size) { + ssize_t wrote = TEMP_FAILURE_RETRY(write(wfd, buffer + written, size - written)); + if (wrote == -1) { + ALOGE("error writing offset %lld: %s\n", (offset + written), strerror(errno)); + return -1; + } + written += wrote; + } + return 0; +} + +static void add_block_to_ranges(int** ranges, int* range_alloc, int* range_used, int new_block) { + // If the current block start is < 0, set the start to the new + // block. (This only happens for the very first block of the very + // first range.) + if ((*ranges)[*range_used*2-2] < 0) { + (*ranges)[*range_used*2-2] = new_block; + (*ranges)[*range_used*2-1] = new_block; + } + + if (new_block == (*ranges)[*range_used*2-1]) { + // If the new block comes immediately after the current range, + // all we have to do is extend the current range. + ++(*ranges)[*range_used*2-1]; + } else { + // We need to start a new range. + + // If there isn't enough room in the array, we need to expand it. + if (*range_used >= *range_alloc) { + *range_alloc *= 2; + *ranges = reinterpret_cast(realloc(*ranges, *range_alloc * 2 * sizeof(int))); + } + + ++*range_used; + (*ranges)[*range_used*2-2] = new_block; + (*ranges)[*range_used*2-1] = new_block+1; + } +} + +static struct fstab* read_fstab() { + fstab = NULL; + + // The fstab path is always "/fstab.${ro.hardware}". + char fstab_path[PATH_MAX+1] = "/fstab."; + if (!property_get("ro.hardware", fstab_path+strlen(fstab_path), "")) { + ALOGE("failed to get ro.hardware\n"); + return NULL; + } + + fstab = fs_mgr_read_fstab(fstab_path); + if (!fstab) { + ALOGE("failed to read %s\n", fstab_path); + return NULL; + } + + return fstab; +} + +static const char* find_block_device(const char* path, bool* encryptable, bool* encrypted) { + // Look for a volume whose mount point is the prefix of path and + // return its block device. Set encrypted if it's currently + // encrypted. + for (int i = 0; i < fstab->num_entries; ++i) { + struct fstab_rec* v = &fstab->recs[i]; + if (!v->mount_point) { + continue; + } + int len = strlen(v->mount_point); + if (strncmp(path, v->mount_point, len) == 0 && + (path[len] == '/' || path[len] == 0)) { + *encrypted = false; + *encryptable = false; + if (fs_mgr_is_encryptable(v)) { + *encryptable = true; + char buffer[PROPERTY_VALUE_MAX+1]; + if (property_get("ro.crypto.state", buffer, "") && + strcmp(buffer, "encrypted") == 0) { + *encrypted = true; + } + } + return v->blk_device; + } + } + + return NULL; +} + +// Parse the command file RECOVERY_COMMAND_FILE to find the update package +// name. If it's on the /data partition, replace the package name with the +// block map file name and store it temporarily in RECOVERY_COMMAND_FILE_TMP. +// It will be renamed to RECOVERY_COMMAND_FILE if uncrypt finishes +// successfully. +static char* find_update_package() +{ + FILE* f = fopen(RECOVERY_COMMAND_FILE, "r"); + if (f == NULL) { + return NULL; + } + int fd = open(RECOVERY_COMMAND_FILE_TMP, O_WRONLY | O_CREAT | O_SYNC, S_IRUSR | S_IWUSR); + if (fd < 0) { + ALOGE("failed to open %s\n", RECOVERY_COMMAND_FILE_TMP); + return NULL; + } + FILE* fo = fdopen(fd, "w"); + char* fn = NULL; + char* line = NULL; + size_t len = 0; + while (getline(&line, &len, f) != -1) { + if (strncmp(line, "--update_package=", strlen("--update_package=")) == 0) { + fn = strdup(line + strlen("--update_package=")); + // Replace the package name with block map file if it's on /data partition. + if (strncmp(fn, "/data/", strlen("/data/")) == 0) { + fputs("--update_package=@" CACHE_BLOCK_MAP "\n", fo); + continue; + } + } + fputs(line, fo); + } + free(line); + fclose(f); + if (fsync(fd) == -1) { + ALOGE("failed to fsync \"%s\": %s\n", RECOVERY_COMMAND_FILE_TMP, strerror(errno)); + fclose(fo); + return NULL; + } + fclose(fo); + + if (fn) { + char* newline = strchr(fn, '\n'); + if (newline) { + *newline = 0; + } + } + return fn; +} + +static int produce_block_map(const char* path, const char* map_file, const char* blk_dev, + bool encrypted) { + + int mapfd = open(map_file, O_WRONLY | O_CREAT | O_SYNC, S_IRUSR | S_IWUSR); + if (mapfd < 0) { + ALOGE("failed to open %s\n", map_file); + return -1; + } + FILE* mapf = fdopen(mapfd, "w"); + + struct stat sb; + int ret = stat(path, &sb); + if (ret != 0) { + ALOGE("failed to stat %s\n", path); + return -1; + } + + ALOGI(" block size: %ld bytes\n", (long)sb.st_blksize); + + int blocks = ((sb.st_size-1) / sb.st_blksize) + 1; + ALOGI(" file size: %lld bytes, %d blocks\n", (long long)sb.st_size, blocks); + + int range_alloc = 1; + int range_used = 1; + int* ranges = reinterpret_cast(malloc(range_alloc * 2 * sizeof(int))); + ranges[0] = -1; + ranges[1] = -1; + + fprintf(mapf, "%s\n%lld %lu\n", blk_dev, (long long)sb.st_size, (unsigned long)sb.st_blksize); + + unsigned char* buffers[WINDOW_SIZE]; + if (encrypted) { + for (size_t i = 0; i < WINDOW_SIZE; ++i) { + buffers[i] = reinterpret_cast(malloc(sb.st_blksize)); + } + } + int head_block = 0; + int head = 0, tail = 0; + size_t pos = 0; + + int fd = open(path, O_RDONLY); + if (fd < 0) { + ALOGE("failed to open fd for reading: %s\n", strerror(errno)); + return -1; + } + + int wfd = -1; + if (encrypted) { + wfd = open(blk_dev, O_WRONLY | O_SYNC); + if (wfd < 0) { + ALOGE("failed to open fd for writing: %s\n", strerror(errno)); + return -1; + } + } + + while (pos < sb.st_size) { + if ((tail+1) % WINDOW_SIZE == head) { + // write out head buffer + int block = head_block; + ret = ioctl(fd, FIBMAP, &block); + if (ret != 0) { + ALOGE("failed to find block %d\n", head_block); + return -1; + } + add_block_to_ranges(&ranges, &range_alloc, &range_used, block); + if (encrypted) { + if (write_at_offset(buffers[head], sb.st_blksize, wfd, + (off64_t)sb.st_blksize * block) != 0) { + return -1; + } + } + head = (head + 1) % WINDOW_SIZE; + ++head_block; + } + + // read next block to tail + if (encrypted) { + size_t so_far = 0; + while (so_far < sb.st_blksize && pos < sb.st_size) { + ssize_t this_read = + TEMP_FAILURE_RETRY(read(fd, buffers[tail] + so_far, sb.st_blksize - so_far)); + if (this_read == -1) { + ALOGE("failed to read: %s\n", strerror(errno)); + return -1; + } + so_far += this_read; + pos += this_read; + } + } else { + // If we're not encrypting; we don't need to actually read + // anything, just skip pos forward as if we'd read a + // block. + pos += sb.st_blksize; + } + tail = (tail+1) % WINDOW_SIZE; + } + + while (head != tail) { + // write out head buffer + int block = head_block; + ret = ioctl(fd, FIBMAP, &block); + if (ret != 0) { + ALOGE("failed to find block %d\n", head_block); + return -1; + } + add_block_to_ranges(&ranges, &range_alloc, &range_used, block); + if (encrypted) { + if (write_at_offset(buffers[head], sb.st_blksize, wfd, + (off64_t)sb.st_blksize * block) != 0) { + return -1; + } + } + head = (head + 1) % WINDOW_SIZE; + ++head_block; + } + + fprintf(mapf, "%d\n", range_used); + for (int i = 0; i < range_used; ++i) { + fprintf(mapf, "%d %d\n", ranges[i*2], ranges[i*2+1]); + } + + if (fsync(mapfd) == -1) { + ALOGE("failed to fsync \"%s\": %s\n", map_file, strerror(errno)); + return -1; + } + fclose(mapf); + close(fd); + if (encrypted) { + if (fsync(wfd) == -1) { + ALOGE("failed to fsync \"%s\": %s\n", blk_dev, strerror(errno)); + return -1; + } + close(wfd); + } + + return 0; +} + +static void wipe_misc() { + ALOGI("removing old commands from misc"); + for (int i = 0; i < fstab->num_entries; ++i) { + struct fstab_rec* v = &fstab->recs[i]; + if (!v->mount_point) continue; + if (strcmp(v->mount_point, "/misc") == 0) { + int fd = open(v->blk_device, O_WRONLY | O_SYNC); + uint8_t zeroes[1088]; // sizeof(bootloader_message) from recovery + memset(zeroes, 0, sizeof(zeroes)); + + size_t written = 0; + size_t size = sizeof(zeroes); + while (written < size) { + ssize_t w = TEMP_FAILURE_RETRY(write(fd, zeroes, size-written)); + if (w == -1) { + ALOGE("zero write failed: %s\n", strerror(errno)); + return; + } else { + written += w; + } + } + if (fsync(fd) == -1) { + ALOGE("failed to fsync \"%s\": %s\n", v->blk_device, strerror(errno)); + close(fd); + return; + } + close(fd); + } + } +} + +static void reboot_to_recovery() { + ALOGI("rebooting to recovery"); + property_set("sys.powerctl", "reboot,recovery"); + sleep(10); + ALOGE("reboot didn't succeed?"); +} + +int main(int argc, char** argv) +{ + const char* input_path; + const char* map_file; + bool do_reboot = true; + + if (argc != 1 && argc != 3) { + fprintf(stderr, "usage: %s [ ]\n", argv[0]); + return 2; + } + + if (argc == 3) { + // when command-line args are given this binary is being used + // for debugging; don't reboot to recovery at the end. + input_path = argv[1]; + map_file = argv[2]; + do_reboot = false; + } else { + input_path = find_update_package(); + if (input_path == NULL) { + // if we're rebooting to recovery without a package (say, + // to wipe data), then we don't need to do anything before + // going to recovery. + ALOGI("no recovery command file or no update package arg"); + reboot_to_recovery(); + return 1; + } + map_file = CACHE_BLOCK_MAP; + } + + ALOGI("update package is %s", input_path); + + // Turn the name of the file we're supposed to convert into an + // absolute path, so we can find what filesystem it's on. + char path[PATH_MAX+1]; + if (realpath(input_path, path) == NULL) { + ALOGE("failed to convert %s to absolute path: %s", input_path, strerror(errno)); + return 1; + } + + if (read_fstab() == NULL) { + return 1; + } + + bool encryptable; + bool encrypted; + const char* blk_dev = find_block_device(path, &encryptable, &encrypted); + if (blk_dev == NULL) { + ALOGE("failed to find block device for %s", path); + return 1; + } + + // If the filesystem it's on isn't encrypted, we only produce the + // block map, we don't rewrite the file contents (it would be + // pointless to do so). + ALOGI("encryptable: %s\n", encryptable ? "yes" : "no"); + ALOGI(" encrypted: %s\n", encrypted ? "yes" : "no"); + + // Recovery supports installing packages from 3 paths: /cache, + // /data, and /sdcard. (On a particular device, other locations + // may work, but those are three we actually expect.) + // + // On /data we want to convert the file to a block map so that we + // can read the package without mounting the partition. On /cache + // and /sdcard we leave the file alone. + if (strncmp(path, "/data/", 6) != 0) { + // path does not start with "/data/"; leave it alone. + unlink(RECOVERY_COMMAND_FILE_TMP); + wipe_misc(); + } else { + ALOGI("writing block map %s", map_file); + if (produce_block_map(path, map_file, blk_dev, encrypted) != 0) { + return 1; + } + wipe_misc(); + rename(RECOVERY_COMMAND_FILE_TMP, RECOVERY_COMMAND_FILE); + } + + if (do_reboot) { + reboot_to_recovery(); + } + return 0; +} -- cgit v1.2.3