diff options
Diffstat (limited to '')
| -rw-r--r-- | uncrypt/uncrypt.cpp | 260 |
1 files changed, 181 insertions, 79 deletions
diff --git a/uncrypt/uncrypt.cpp b/uncrypt/uncrypt.cpp index 2a32108a3..e783b9e7a 100644 --- a/uncrypt/uncrypt.cpp +++ b/uncrypt/uncrypt.cpp @@ -39,6 +39,53 @@ // Recovery can take this block map file and retrieve the underlying // file data to use as an update package. +/** + * In addition to the uncrypt work, uncrypt also takes care of setting and + * clearing the bootloader control block (BCB) at /misc partition. + * + * uncrypt is triggered as init services on demand. It uses socket to + * communicate with its caller (i.e. system_server). The socket is managed by + * init (i.e. created prior to the service starts, and destroyed when uncrypt + * exits). + * + * Below is the uncrypt protocol. + * + * a. caller b. init c. uncrypt + * --------------- ------------ -------------- + * a1. ctl.start: + * setup-bcb / + * clear-bcb / + * uncrypt + * + * b2. create socket at + * /dev/socket/uncrypt + * + * c3. listen and accept + * + * a4. send a 4-byte int + * (message length) + * c5. receive message length + * a6. send message + * c7. receive message + * c8. <do the work; may send + * the progress> + * a9. <may handle progress> + * c10. <upon finishing> + * send "100" or "-1" + * + * a11. receive status code + * a12. send a 4-byte int to + * ack the receive of the + * final status code + * c13. receive and exit + * + * b14. destroy the socket + * + * Note that a12 and c13 are necessary to ensure a11 happens before the socket + * gets destroyed in b14. + */ + +#include <arpa/inet.h> #include <errno.h> #include <fcntl.h> #include <inttypes.h> @@ -49,6 +96,7 @@ #include <stdlib.h> #include <string.h> #include <sys/mman.h> +#include <sys/socket.h> #include <sys/stat.h> #include <sys/types.h> #include <unistd.h> @@ -63,6 +111,7 @@ #include <android-base/strings.h> #include <cutils/android_reboot.h> #include <cutils/properties.h> +#include <cutils/sockets.h> #include <fs_mgr.h> #define LOG_TAG "uncrypt" @@ -73,12 +122,21 @@ #define WINDOW_SIZE 5 +// uncrypt provides three services: SETUP_BCB, CLEAR_BCB and UNCRYPT. +// +// SETUP_BCB and CLEAR_BCB services use socket communication and do not rely +// on /cache partitions. They will handle requests to reboot into recovery +// (for applying updates for non-A/B devices, or factory resets for all +// devices). +// +// UNCRYPT service still needs files on /cache partition (UNCRYPT_PATH_FILE +// and CACHE_BLOCK_MAP). It will be working (and needed) only for non-A/B +// devices, on which /cache partitions always exist. static const std::string CACHE_BLOCK_MAP = "/cache/recovery/block.map"; -static const std::string COMMAND_FILE = "/cache/recovery/command"; -static const std::string STATUS_FILE = "/cache/recovery/uncrypt_status"; static const std::string UNCRYPT_PATH_FILE = "/cache/recovery/uncrypt_file"; +static const std::string UNCRYPT_SOCKET = "uncrypt"; -static struct fstab* fstab = NULL; +static struct fstab* fstab = nullptr; 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) { @@ -152,6 +210,11 @@ static const char* find_block_device(const char* path, bool* encryptable, bool* return NULL; } +static bool write_status_to_socket(int status, int socket) { + int status_out = htonl(status); + return android::base::WriteFully(socket, &status_out, sizeof(int)); +} + // Parse uncrypt_file to find the update package name. static bool find_uncrypt_package(const std::string& uncrypt_path_file, std::string* package_name) { CHECK(package_name != nullptr); @@ -167,7 +230,7 @@ static bool find_uncrypt_package(const std::string& uncrypt_path_file, std::stri } static int produce_block_map(const char* path, const char* map_file, const char* blk_dev, - bool encrypted, int status_fd) { + bool encrypted, int socket) { std::string err; if (!android::base::RemoveFileIfExists(map_file, &err)) { ALOGE("failed to remove the existing map file %s: %s", map_file, err.c_str()); @@ -180,9 +243,9 @@ static int produce_block_map(const char* path, const char* map_file, const char* return -1; } - // Make sure we can write to the status_file. - if (!android::base::WriteStringToFd("0\n", status_fd)) { - ALOGE("failed to update \"%s\"\n", STATUS_FILE.c_str()); + // Make sure we can write to the socket. + if (!write_status_to_socket(0, socket)) { + ALOGE("failed to write to socket %d\n", socket); return -1; } @@ -234,8 +297,8 @@ static int produce_block_map(const char* path, const char* map_file, const char* // Update the status file, progress must be between [0, 99]. int progress = static_cast<int>(100 * (double(pos) / double(sb.st_size))); if (progress > last_progress) { - last_progress = progress; - android::base::WriteStringToFd(std::to_string(progress) + "\n", status_fd); + last_progress = progress; + write_status_to_socket(progress, socket); } if ((tail+1) % WINDOW_SIZE == head) { @@ -352,15 +415,12 @@ static int produce_block_map(const char* path, const char* map_file, const char* } static std::string get_misc_blk_device() { - struct fstab* fstab = read_fstab(); if (fstab == nullptr) { return ""; } - for (int i = 0; i < fstab->num_entries; ++i) { - fstab_rec* v = &fstab->recs[i]; - if (v->mount_point != nullptr && strcmp(v->mount_point, "/misc") == 0) { - return v->blk_device; - } + struct fstab_rec* rec = fs_mgr_get_entry_for_mount_point(fstab, "/misc"); + if (rec != nullptr) { + return rec->blk_device; } return ""; } @@ -406,8 +466,7 @@ static int write_bootloader_message(const bootloader_message* in) { return 0; } -static int uncrypt(const char* input_path, const char* map_file, int status_fd) { - +static int uncrypt(const char* input_path, const char* map_file, const int socket) { ALOGI("update package is \"%s\"", input_path); // Turn the name of the file we're supposed to convert into an @@ -418,10 +477,6 @@ static int uncrypt(const char* input_path, const char* map_file, int status_fd) return 1; } - if (read_fstab() == NULL) { - return 1; - } - bool encryptable; bool encrypted; const char* blk_dev = find_block_device(path, &encryptable, &encrypted); @@ -445,7 +500,7 @@ static int uncrypt(const char* input_path, const char* map_file, int status_fd) // and /sdcard we leave the file alone. if (strncmp(path, "/data/", 6) == 0) { ALOGI("writing block map %s", map_file); - if (produce_block_map(path, map_file, blk_dev, encrypted, status_fd) != 0) { + if (produce_block_map(path, map_file, blk_dev, encrypted, socket) != 0) { return 1; } } @@ -453,71 +508,66 @@ static int uncrypt(const char* input_path, const char* map_file, int status_fd) return 0; } -static int uncrypt_wrapper(const char* input_path, const char* map_file, - const std::string& status_file) { - // The pipe has been created by the system server. - unique_fd status_fd(open(status_file.c_str(), O_WRONLY | O_CREAT | O_SYNC, S_IRUSR | S_IWUSR)); - if (!status_fd) { - ALOGE("failed to open pipe \"%s\": %s", status_file.c_str(), strerror(errno)); - return 1; - } - +static bool uncrypt_wrapper(const char* input_path, const char* map_file, const int socket) { std::string package; if (input_path == nullptr) { if (!find_uncrypt_package(UNCRYPT_PATH_FILE, &package)) { - android::base::WriteStringToFd("-1\n", status_fd.get()); - return 1; + write_status_to_socket(-1, socket); + return false; } input_path = package.c_str(); } CHECK(map_file != nullptr); - int status = uncrypt(input_path, map_file, status_fd.get()); + int status = uncrypt(input_path, map_file, socket); if (status != 0) { - android::base::WriteStringToFd("-1\n", status_fd.get()); - return 1; + write_status_to_socket(-1, socket); + return false; } - android::base::WriteStringToFd("100\n", status_fd.get()); - return 0; + write_status_to_socket(100, socket); + return true; } -static int clear_bcb(const std::string& status_file) { - unique_fd status_fd(open(status_file.c_str(), O_WRONLY | O_CREAT | O_SYNC, S_IRUSR | S_IWUSR)); - if (!status_fd) { - ALOGE("failed to open pipe \"%s\": %s", status_file.c_str(), strerror(errno)); - return 1; - } +static bool clear_bcb(const int socket) { bootloader_message boot = {}; if (write_bootloader_message(&boot) != 0) { - android::base::WriteStringToFd("-1\n", status_fd.get()); - return 1; + write_status_to_socket(-1, socket); + return false; } - android::base::WriteStringToFd("100\n", status_fd.get()); - return 0; + write_status_to_socket(100, socket); + return true; } -static int setup_bcb(const std::string& command_file, const std::string& status_file) { - unique_fd status_fd(open(status_file.c_str(), O_WRONLY | O_CREAT | O_SYNC, S_IRUSR | S_IWUSR)); - if (!status_fd) { - ALOGE("failed to open pipe \"%s\": %s", status_file.c_str(), strerror(errno)); - return 1; +static bool setup_bcb(const int socket) { + // c5. receive message length + int length; + if (!android::base::ReadFully(socket, &length, 4)) { + ALOGE("failed to read the length: %s", strerror(errno)); + return false; } + length = ntohl(length); + + // c7. receive message std::string content; - if (!android::base::ReadFileToString(command_file, &content)) { - ALOGE("failed to read \"%s\": %s", command_file.c_str(), strerror(errno)); - android::base::WriteStringToFd("-1\n", status_fd.get()); - return 1; + content.resize(length); + if (!android::base::ReadFully(socket, &content[0], length)) { + ALOGE("failed to read the length: %s", strerror(errno)); + return false; } + ALOGI(" received command: [%s] (%zu)", content.c_str(), content.size()); + + // c8. setup the bcb command bootloader_message boot = {}; strlcpy(boot.command, "boot-recovery", sizeof(boot.command)); strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery)); strlcat(boot.recovery, content.c_str(), sizeof(boot.recovery)); if (write_bootloader_message(&boot) != 0) { ALOGE("failed to set bootloader message"); - android::base::WriteStringToFd("-1\n", status_fd.get()); - return 1; + write_status_to_socket(-1, socket); + return false; } - android::base::WriteStringToFd("100\n", status_fd.get()); - return 0; + // c10. send "100" status + write_status_to_socket(100, socket); + return true; } static int read_bcb() { @@ -540,23 +590,75 @@ static void usage(const char* exename) { } int main(int argc, char** argv) { - if (argc == 2) { - if (strcmp(argv[1], "--clear-bcb") == 0) { - return clear_bcb(STATUS_FILE); - } else if (strcmp(argv[1], "--setup-bcb") == 0) { - return setup_bcb(COMMAND_FILE, STATUS_FILE); - } else if (strcmp(argv[1], "--read-bcb") == 0) { - return read_bcb(); - } - } else if (argc == 1 || argc == 3) { - const char* input_path = nullptr; - const char* map_file = CACHE_BLOCK_MAP.c_str(); - if (argc == 3) { - input_path = argv[1]; - map_file = argv[2]; - } - return uncrypt_wrapper(input_path, map_file, STATUS_FILE); + enum { UNCRYPT, SETUP_BCB, CLEAR_BCB } action; + const char* input_path = nullptr; + const char* map_file = CACHE_BLOCK_MAP.c_str(); + + if (argc == 2 && strcmp(argv[1], "--clear-bcb") == 0) { + action = CLEAR_BCB; + } else if (argc == 2 && strcmp(argv[1], "--setup-bcb") == 0) { + action = SETUP_BCB; + } else if (argc ==2 && strcmp(argv[1], "--read-bcb") == 0) { + return read_bcb(); + } else if (argc == 1) { + action = UNCRYPT; + } else if (argc == 3) { + input_path = argv[1]; + map_file = argv[2]; + action = UNCRYPT; + } else { + usage(argv[0]); + return 2; + } + + if ((fstab = read_fstab()) == nullptr) { + return 1; + } + + // c3. The socket is created by init when starting the service. uncrypt + // will use the socket to communicate with its caller. + unique_fd service_socket(android_get_control_socket(UNCRYPT_SOCKET.c_str())); + if (!service_socket) { + ALOGE("failed to open socket \"%s\": %s", UNCRYPT_SOCKET.c_str(), strerror(errno)); + return 1; + } + fcntl(service_socket.get(), F_SETFD, FD_CLOEXEC); + + if (listen(service_socket.get(), 1) == -1) { + ALOGE("failed to listen on socket %d: %s", service_socket.get(), strerror(errno)); + return 1; + } + + unique_fd socket_fd(accept4(service_socket.get(), nullptr, nullptr, SOCK_CLOEXEC)); + if (!socket_fd) { + ALOGE("failed to accept on socket %d: %s", service_socket.get(), strerror(errno)); + return 1; + } + + bool success = false; + switch (action) { + case UNCRYPT: + success = uncrypt_wrapper(input_path, map_file, socket_fd.get()); + break; + case SETUP_BCB: + success = setup_bcb(socket_fd.get()); + break; + case CLEAR_BCB: + success = clear_bcb(socket_fd.get()); + break; + default: // Should never happen. + ALOGE("Invalid uncrypt action code: %d", action); + return 1; + } + + // c13. Read a 4-byte code from the client before uncrypt exits. This is to + // ensure the client to receive the last status code before the socket gets + // destroyed. + int code; + if (android::base::ReadFully(socket_fd.get(), &code, 4)) { + ALOGI(" received %d, exiting now", code); + } else { + ALOGE("failed to read the code: %s", strerror(errno)); } - usage(argv[0]); - return 2; + return success ? 0 : 1; } |