diff options
Diffstat (limited to 'bootloader_message/bootloader_message.cpp')
| -rw-r--r-- | bootloader_message/bootloader_message.cpp | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/bootloader_message/bootloader_message.cpp b/bootloader_message/bootloader_message.cpp new file mode 100644 index 000000000..eb99bdb42 --- /dev/null +++ b/bootloader_message/bootloader_message.cpp @@ -0,0 +1,332 @@ +/* + * Copyright (C) 2016 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 <bootloader_message/bootloader_message.h> + +#include <errno.h> +#include <fcntl.h> +#include <string.h> +#include <stdlib.h> +#include <sys/stat.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/system_properties.h> + +#include <string> +#include <vector> + +/* +#include <android-base/file.h> +#include <android-base/stringprintf.h> +#include <android-base/unique_fd.h> +*/ +#ifndef EXCLUDE_FS_MGR +#include <fs_mgr.h> +#endif + +static std::string misc_blkdev; + +void set_misc_device(const char* type, const char* name) { + misc_blkdev = name; +} + +#ifndef EXCLUDE_FS_MGR +static struct fstab* read_fstab(std::string* err) { + // The fstab path is always "/fstab.${ro.hardware}". + std::string fstab_path = "/fstab."; + char value[PROP_VALUE_MAX]; + if (__system_property_get("ro.hardware", value) == 0) { + *err = "failed to get ro.hardware"; + return nullptr; + } + fstab_path += value; + struct fstab* fstab = fs_mgr_read_fstab(fstab_path.c_str()); + if (fstab == nullptr) { + *err = "failed to read " + fstab_path; + } + return fstab; +} +#endif + +static std::string get_misc_blk_device(std::string* err) { +#ifdef EXCLUDE_FS_MGR + return misc_blkdev; +#else + struct fstab* fstab = read_fstab(err); + if (fstab == nullptr) { + return ""; + } + fstab_rec* record = fs_mgr_get_entry_for_mount_point(fstab, "/misc"); + if (record == nullptr) { + *err = "failed to find /misc partition"; + return ""; + } + return record->blk_device; +#endif +} + + +// In recovery mode, recovery can get started and try to access the misc +// device before the kernel has actually created it. +static bool wait_for_device(const std::string& blk_device, std::string* err) { + int tries = 0; + int ret; + err->clear(); + do { + ++tries; + struct stat buf; + ret = stat(blk_device.c_str(), &buf); + if (ret == -1) { + char buffer[2048]; + sprintf(buffer, "failed to stat %s try %d: %s\n", + blk_device.c_str(), tries, strerror(errno)); + *err += buffer; + /* + *err += android::base::StringPrintf("failed to stat %s try %d: %s\n", + blk_device.c_str(), tries, strerror(errno)); + */ + sleep(1); + } + } while (ret && tries < 10); + + if (ret) { + *err += "failed to stat " + blk_device + "\n"; + /* + *err += android::base::StringPrintf("failed to stat %s\n", blk_device.c_str()); + */ + } + return ret == 0; +} + +static bool read_misc_partition(void* p, size_t size, size_t offset, std::string* err) { + std::string misc_blk_device = get_misc_blk_device(err); + if (misc_blk_device.empty()) { + return false; + } + if (!wait_for_device(misc_blk_device, err)) { + return false; + } + int fd(open(misc_blk_device.c_str(), O_RDONLY)); + if (fd < 0) { + *err = "failed to open " + misc_blk_device + ": "; + *err += strerror(errno); + /* + *err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(), + strerror(errno)); + */ + return false; + } + if (lseek(fd, static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) { + *err = "failed to lseek " + misc_blk_device + ": "; + *err += strerror(errno); + close(fd); + /* + *err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(), + strerror(errno)); + */ + return false; + } + if (read(fd, p, size) != size) { + *err = "failed to read " + misc_blk_device + ": "; + *err += strerror(errno); + close(fd); + /* + *err = android::base::StringPrintf("failed to read %s: %s", misc_blk_device.c_str(), + strerror(errno)); + */ + return false; + } + close(fd); + return true; +} + +static bool write_misc_partition(const void* p, size_t size, size_t offset, std::string* err) { + std::string misc_blk_device = get_misc_blk_device(err); + if (misc_blk_device.empty()) { + *err = "no misc device set"; + return false; + } + int fd = (open(misc_blk_device.c_str(), O_WRONLY | O_SYNC)); + if (fd == -1) { + *err = "failed to open " + misc_blk_device + ": "; + *err += strerror(errno); + /* + *err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(), + strerror(errno)); + */ + return false; + } + if (lseek(fd, static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) { + *err = "failed to lseek " + misc_blk_device + ": "; + *err += strerror(errno); + close(fd); + /* + *err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(), + strerror(errno)); + */ + return false; + } + if (write(fd, p, size) != size) { + *err = "failed to write " + misc_blk_device + ": "; + *err += strerror(errno); + close(fd); + /* + *err = android::base::StringPrintf("failed to write %s: %s", misc_blk_device.c_str(), + strerror(errno)); + */ + return false; + } + + // TODO: O_SYNC and fsync duplicates each other? + if (fsync(fd) == -1) { + *err = "failed to fsync " + misc_blk_device + ": "; + *err += strerror(errno); + close(fd); + /* + *err = android::base::StringPrintf("failed to fsync %s: %s", misc_blk_device.c_str(), + strerror(errno)); + */ + return false; + } + close(fd); + return true; +} + +bool read_bootloader_message(bootloader_message* boot, std::string* err) { + return read_misc_partition(boot, sizeof(*boot), BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err); +} + +bool write_bootloader_message(const bootloader_message& boot, std::string* err) { + return write_misc_partition(&boot, sizeof(boot), BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err); +} + +bool clear_bootloader_message(std::string* err) { + bootloader_message boot = {}; + return write_bootloader_message(boot, err); +} + +bool write_bootloader_message(const std::vector<std::string>& options, std::string* err) { + bootloader_message boot = {}; + strlcpy(boot.command, "boot-recovery", sizeof(boot.command)); + strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery)); + for (const auto& s : options) { + strlcat(boot.recovery, s.c_str(), sizeof(boot.recovery)); + if (s.substr(s.size() - 1) != "\n") { + strlcat(boot.recovery, "\n", sizeof(boot.recovery)); + } + } + return write_bootloader_message(boot, err); +} + +bool read_wipe_package(std::string* package_data, size_t size, std::string* err) { + package_data->resize(size); + return read_misc_partition(&(*package_data)[0], size, WIPE_PACKAGE_OFFSET_IN_MISC, err); +} + +bool write_wipe_package(const std::string& package_data, std::string* err) { + return write_misc_partition(package_data.data(), package_data.size(), + WIPE_PACKAGE_OFFSET_IN_MISC, err); +} + +extern "C" bool write_bootloader_message(const char* options) { + std::string err; + bootloader_message boot = {}; + memcpy(&boot, options, sizeof(boot)); + return write_bootloader_message(boot, &err); +} + +static const char *COMMAND_FILE = "/cache/recovery/command"; +static const int MAX_ARG_LENGTH = 4096; +static const int MAX_ARGS = 100; + +// command line args come from, in decreasing precedence: +// - the actual command line +// - the bootloader control block (one per line, after "recovery") +// - the contents of COMMAND_FILE (one per line) +void +get_args(int *argc, char ***argv) { + bootloader_message boot = {}; + std::string err; + if (!read_bootloader_message(&boot, &err)) { + printf("%s\n", err.c_str()); + // If fails, leave a zeroed bootloader_message. + memset(&boot, 0, sizeof(boot)); + } + //stage = strndup(boot.stage, sizeof(boot.stage)); + + if (boot.command[0] != 0 && boot.command[0] != 255) { + printf("Boot command: %.*s\n", (int)sizeof(boot.command), boot.command); + } + + if (boot.status[0] != 0 && boot.status[0] != 255) { + printf("Boot status: %.*s\n", (int)sizeof(boot.status), boot.status); + } + + // --- if arguments weren't supplied, look in the bootloader control block + if (*argc <= 1) { + boot.recovery[sizeof(boot.recovery) - 1] = '\0'; // Ensure termination + const char *arg = strtok(boot.recovery, "\n"); + if (arg != NULL && !strcmp(arg, "recovery")) { + *argv = (char **) malloc(sizeof(char *) * MAX_ARGS); + (*argv)[0] = strdup(arg); + for (*argc = 1; *argc < MAX_ARGS; ++*argc) { + if ((arg = strtok(NULL, "\n")) == NULL) break; + (*argv)[*argc] = strdup(arg); + } + printf("Got arguments from boot message\n"); + } else if (boot.recovery[0] != 0 && boot.recovery[0] != 255) { + printf("Bad boot message\n\"%.20s\"\n", boot.recovery); + } + } + + // --- if that doesn't work, try the command file (if we have /cache). + if (*argc <= 1/* && has_cache*/) { + FILE *fp = fopen(COMMAND_FILE, "r"); + if (fp != NULL) { + char *token; + char *argv0 = (*argv)[0]; + *argv = (char **) malloc(sizeof(char *) * MAX_ARGS); + (*argv)[0] = argv0; // use the same program name + + char buf[MAX_ARG_LENGTH]; + for (*argc = 1; *argc < MAX_ARGS; ++*argc) { + if (!fgets(buf, sizeof(buf), fp)) break; + token = strtok(buf, "\r\n"); + if (token != NULL) { + (*argv)[*argc] = strdup(token); // Strip newline. + } else { + --*argc; + } + } + + fclose(fp); + printf("Got arguments from %s\n", COMMAND_FILE); + } + } + + // --> write the arguments we have back into the bootloader control block + // always boot into recovery after this (until finish_recovery() is called) + strlcpy(boot.command, "boot-recovery", sizeof(boot.command)); + strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery)); + int i; + for (i = 1; i < *argc; ++i) { + strlcat(boot.recovery, (*argv)[i], sizeof(boot.recovery)); + strlcat(boot.recovery, "\n", sizeof(boot.recovery)); + } + if (!write_bootloader_message(boot, &err)) { + printf("%s\n", err.c_str()); + } +} |