//
// Copyright (C) 2012 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 "update_engine/common/utils.h"
#include <stdint.h>
#include <dirent.h>
#include <elf.h>
#include <endian.h>
#include <errno.h>
#include <ext2fs/ext2fs.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <algorithm>
#include <utility>
#include <vector>
#include <base/callback.h>
#include <base/files/file_path.h>
#include <base/files/file_util.h>
#include <base/files/scoped_file.h>
#include <base/format_macros.h>
#include <base/location.h>
#include <base/logging.h>
#include <base/posix/eintr_wrapper.h>
#include <base/rand_util.h>
#include <base/strings/string_number_conversions.h>
#include <base/strings/string_split.h>
#include <base/strings/string_util.h>
#include <base/strings/stringprintf.h>
#include <brillo/data_encoding.h>
#include <brillo/message_loops/message_loop.h>
#include "update_engine/common/clock_interface.h"
#include "update_engine/common/constants.h"
#include "update_engine/common/platform_constants.h"
#include "update_engine/common/prefs_interface.h"
#include "update_engine/common/subprocess.h"
#include "update_engine/payload_consumer/file_descriptor.h"
#include "update_engine/payload_consumer/file_writer.h"
#include "update_engine/payload_consumer/payload_constants.h"
using base::Time;
using base::TimeDelta;
using std::min;
using std::pair;
using std::string;
using std::vector;
namespace chromeos_update_engine {
namespace {
// The following constants control how UnmountFilesystem should retry if
// umount() fails with an errno EBUSY, i.e. retry 5 times over the course of
// one second.
const int kUnmountMaxNumOfRetries = 5;
const int kUnmountRetryIntervalInMicroseconds = 200 * 1000; // 200 ms
// Number of bytes to read from a file to attempt to detect its contents. Used
// in GetFileFormat.
const int kGetFileFormatMaxHeaderSize = 32;
// The path to the kernel's boot_id.
const char kBootIdPath[] = "/proc/sys/kernel/random/boot_id";
// A pointer to a null-terminated string containing the root directory where all
// the temporary files should be created. If null, the system default is used
// instead.
const char* root_temp_dir = nullptr;
// Return true if |disk_name| is an MTD or a UBI device. Note that this test is
// simply based on the name of the device.
bool IsMtdDeviceName(const string& disk_name) {
return base::StartsWith(disk_name, "/dev/ubi",
base::CompareCase::SENSITIVE) ||
base::StartsWith(disk_name, "/dev/mtd", base::CompareCase::SENSITIVE);
}
// Return the device name for the corresponding partition on a NAND device.
// WARNING: This function returns device names that are not mountable.
string MakeNandPartitionName(int partition_num) {
switch (partition_num) {
case 2:
case 4:
case 6: {
return base::StringPrintf("/dev/mtd%d", partition_num);
}
default: {
return base::StringPrintf("/dev/ubi%d_0", partition_num);
}
}
}
// Return the device name for the corresponding partition on a NAND device that
// may be mountable (but may not be writable).
string MakeNandPartitionNameForMount(int partition_num) {
switch (partition_num) {
case 2:
case 4:
case 6: {
return base::StringPrintf("/dev/mtd%d", partition_num);
}
case 3:
case 5:
case 7: {
return base::StringPrintf("/dev/ubiblock%d_0", partition_num);
}
default: {
return base::StringPrintf("/dev/ubi%d_0", partition_num);
}
}
}
// If |path| is absolute, or explicit relative to the current working directory,
// leaves it as is. Otherwise, uses the system's temp directory, as defined by
// base::GetTempDir() and prepends it to |path|. On success stores the full
// temporary path in |template_path| and returns true.
bool GetTempName(const string& path, base::FilePath* template_path) {
if (path[0] == '/' ||
base::StartsWith(path, "./", base::CompareCase::SENSITIVE) ||
base::StartsWith(path, "../", base::CompareCase::SENSITIVE)) {
*template_path = base::FilePath(path);
return true;
}
base::FilePath temp_dir;
if (root_temp_dir) {
temp_dir = base::FilePath(root_temp_dir);
} else {
#ifdef __ANDROID__
temp_dir = base::FilePath(constants::kNonVolatileDirectory).Append("tmp");
#else
TEST_AND_RETURN_FALSE(base::GetTempDir(&temp_dir));
#endif // __ANDROID__
}
if (!base::PathExists(temp_dir))
TEST_AND_RETURN_FALSE(base::CreateDirectory(temp_dir));
*template_path = temp_dir.Append(path);
return true;
}
} // namespace
namespace utils {
void SetRootTempDir(const char* new_root_temp_dir) {
root_temp_dir = new_root_temp_dir;
}
string ParseECVersion(string input_line) {
base::TrimWhitespaceASCII(input_line, base::TRIM_ALL, &input_line);
// At this point we want to convert the format key=value pair from mosys to
// a vector of key value pairs.
vector<pair<string, string>> kv_pairs;
if (base::SplitStringIntoKeyValuePairs(input_line, '=', ' ', &kv_pairs)) {
for (const pair<string, string>& kv_pair : kv_pairs) {
// Finally match against the fw_verion which may have quotes.
if (kv_pair.first == "fw_version") {
string output;
// Trim any quotes.
base::TrimString(kv_pair.second, "\"", &output);
return output;
}
}
}
LOG(ERROR) << "Unable to parse fwid from ec info.";
return "";
}
bool WriteFile(const char* path, const void* data, int data_len) {
DirectFileWriter writer;
TEST_AND_RETURN_FALSE_ERRNO(0 == writer.Open(path,
O_WRONLY | O_CREAT | O_TRUNC,
0600));
ScopedFileWriterCloser closer(&writer);
TEST_AND_RETURN_FALSE_ERRNO(writer.Write(data, data_len));
return true;
}
bool ReadAll(
int fd, void* buf, size_t count, size_t* out_bytes_read, bool* eof) {
char* c_buf = static_cast<char*>(buf);
size_t bytes_read = 0;
*eof = false;
while (bytes_read < count) {
ssize_t rc = HANDLE_EINTR(read(fd, c_buf + bytes_read, count - bytes_read));
if (rc < 0) {
// EAGAIN and EWOULDBLOCK are normal return values when there's no more
// input and we are in non-blocking mode.
if (errno != EWOULDBLOCK && errno != EAGAIN) {
PLOG(ERROR) << "Error reading fd " << fd;
*out_bytes_read = bytes_read;
return false;
}
break;
} else if (rc == 0) {
// A value of 0 means that we reached EOF and there is nothing else to
// read from this fd.
*eof = true;
break;
} else {
bytes_read += rc;
}
}
*out_bytes_read = bytes_read;
return true;
}
bool WriteAll(int fd, const void* buf, size_t count) {
const char* c_buf = static_cast<const char*>(buf);
ssize_t bytes_written = 0;
while (bytes_written < static_cast<ssize_t>(count)) {
ssize_t rc = write(fd, c_buf + bytes_written, count - bytes_written);
TEST_AND_RETURN_FALSE_ERRNO(rc >= 0);
bytes_written += rc;
}
return true;
}
bool PWriteAll(int fd, const void* buf, size_t count, off_t offset) {
const char* c_buf = static_cast<const char*>(buf);
size_t bytes_written = 0;
int num_attempts = 0;
while (bytes_written < count) {
num_attempts++;
ssize_t rc = pwrite(fd, c_buf + bytes_written, count - bytes_written,
offset + bytes_written);
// TODO(garnold) for debugging failure in chromium-os:31077; to be removed.
if (rc < 0) {
PLOG(ERROR) << "pwrite error; num_attempts=" << num_attempts
<< " bytes_written=" << bytes_written
<< " count=" << count << " offset=" << offset;
}
TEST_AND_RETURN_FALSE_ERRNO(rc >= 0);
bytes_written += rc;
}
return true;
}
bool WriteAll(FileDescriptorPtr fd, const void* buf, size_t count) {
const char* c_buf = static_cast<const char*>(buf);
ssize_t bytes_written = 0;
while (bytes_written < static_cast<ssize_t>(count)) {
ssize_t rc = fd->Write(c_buf + bytes_written, count - bytes_written);
TEST_AND_RETURN_FALSE_ERRNO(rc >= 0);
bytes_written += rc;
}
return true;
}
bool PWriteAll(FileDescriptorPtr fd,
const void* buf,
size_t count,
off_t offset) {
TEST_AND_RETURN_FALSE_ERRNO(fd->Seek(offset, SEEK_SET) !=
static_cast<off_t>(-1));
return WriteAll(fd, buf, count);
}
bool PReadAll(int fd, void* buf, size_t count, off_t offset,
ssize_t* out_bytes_read) {
char* c_buf = static_cast<char*>(buf);
ssize_t bytes_read = 0;
while (bytes_read < static_cast<ssize_t>(count)) {
ssize_t rc = pread(fd, c_buf + bytes_read, count - bytes_read,
offset + bytes_read);
TEST_AND_RETURN_FALSE_ERRNO(rc >= 0);
if (rc == 0) {
break;
}
bytes_read += rc;
}
*out_bytes_read = bytes_read;
return true;
}
bool PReadAll(FileDescriptorPtr fd, void* buf, size_t count, off_t offset,
ssize_t* out_bytes_read) {
TEST_AND_RETURN_FALSE_ERRNO(fd->Seek(offset, SEEK_SET) !=
static_cast<off_t>(-1));
char* c_buf = static_cast<char*>(buf);
ssize_t bytes_read = 0;
while (bytes_read < static_cast<ssize_t>(count)) {
ssize_t rc = fd->Read(c_buf + bytes_read, count - bytes_read);
TEST_AND_RETURN_FALSE_ERRNO(rc >= 0);
if (rc == 0) {
break;
}
bytes_read += rc;
}
*out_bytes_read = bytes_read;
return true;
}
// Append |nbytes| of content from |buf| to the vector pointed to by either
// |vec_p| or |str_p|.
static void AppendBytes(const uint8_t* buf, size_t nbytes,
brillo::Blob* vec_p) {
CHECK(buf);
CHECK(vec_p);
vec_p->insert(vec_p->end(), buf, buf + nbytes);
}
static void AppendBytes(const uint8_t* buf, size_t nbytes,
string* str_p) {
CHECK(buf);
CHECK(str_p);
str_p->append(buf, buf + nbytes);
}
// Reads from an open file |fp|, appending the read content to the container
// pointer to by |out_p|. Returns true upon successful reading all of the
// file's content, false otherwise. If |size| is not -1, reads up to |size|
// bytes.
template <class T>
static bool Read(FILE* fp, off_t size, T* out_p) {
CHECK(fp);
CHECK(size == -1 || size >= 0);
uint8_t buf[1024];
while (size == -1 || size > 0) {
off_t bytes_to_read = sizeof(buf);
if (size > 0 && bytes_to_read > size) {
bytes_to_read = size;
}
size_t nbytes = fread(buf, 1, bytes_to_read, fp);
if (!nbytes) {
break;
}
AppendBytes(buf, nbytes, out_p);
if (size != -1) {
CHECK(size >= static_cast<off_t>(nbytes));
size -= nbytes;
}
}
if (ferror(fp)) {
return false;
}
return size == 0 || feof(fp);
}
// Opens a file |path| for reading and appends its the contents to a container
// |out_p|. Starts reading the file from |offset|. If |offset| is beyond the end
// of the file, returns success. If |size| is not -1, reads up to |size| bytes.
template <class T>
static bool ReadFileChunkAndAppend(const string& path,
off_t offset,
off_t size,
T* out_p) {
CHECK_GE(offset, 0);
CHECK(size == -1 || size >= 0);
base::ScopedFILE fp(fopen(path.c_str(), "r"));
if (!fp.get())
return false;
if (offset) {
// Return success without appending any data if a chunk beyond the end of
// the file is requested.
if (offset >= FileSize(path)) {
return true;
}
TEST_AND_RETURN_FALSE_ERRNO(fseek(fp.get(), offset, SEEK_SET) == 0);
}
return Read(fp.get(), size, out_p);
}
// TODO(deymo): This is only used in unittest, but requires the private
// Read<string>() defined here. Expose Read<string>() or move to base/ version.
bool ReadPipe(const string& cmd, string* out_p) {
FILE* fp = popen(cmd.c_str(), "r");
if (!fp)
return false;
bool success = Read(fp, -1, out_p);
return (success && pclose(fp) >= 0);
}
bool ReadFile(const string& path, brillo::Blob* out_p) {
return ReadFileChunkAndAppend(path, 0, -1, out_p);
}
bool ReadFile(const string& path, string* out_p) {
return ReadFileChunkAndAppend(path, 0, -1, out_p);
}
bool ReadFileChunk(const string& path, off_t offset, off_t size,
brillo::Blob* out_p) {
return ReadFileChunkAndAppend(path, offset, size, out_p);
}
off_t BlockDevSize(int fd) {
uint64_t dev_size;
int rc = ioctl(fd, BLKGETSIZE64, &dev_size);
if (rc == -1) {
dev_size = -1;
PLOG(ERROR) << "Error running ioctl(BLKGETSIZE64) on " << fd;
}
return dev_size;
}
off_t FileSize(int fd) {
struct stat stbuf;
int rc = fstat(fd, &stbuf);
CHECK_EQ(rc, 0);
if (rc < 0) {
PLOG(ERROR) << "Error stat-ing " << fd;
return rc;
}
if (S_ISREG(stbuf.st_mode))
return stbuf.st_size;
if (S_ISBLK(stbuf.st_mode))
return BlockDevSize(fd);
LOG(ERROR) << "Couldn't determine the type of " << fd;
return -1;
}
off_t FileSize(const string& path) {
int fd = open(path.c_str(), O_RDONLY | O_CLOEXEC);
if (fd == -1) {
PLOG(ERROR) << "Error opening " << path;
return fd;
}
off_t size = FileSize(fd);
if (size == -1)
PLOG(ERROR) << "Error getting file size of " << path;
close(fd);
return size;
}
void HexDumpArray(const uint8_t* const arr, const size_t length) {
LOG(INFO) << "Logging array of length: " << length;
const unsigned int bytes_per_line = 16;
for (uint32_t i = 0; i < length; i += bytes_per_line) {
const unsigned int bytes_remaining = length - i;
const unsigned int bytes_per_this_line = min(bytes_per_line,
bytes_remaining);
char header[100];
int r = snprintf(header, sizeof(header), "0x%08x : ", i);
TEST_AND_RETURN(r == 13);
string line = header;
for (unsigned int j = 0; j < bytes_per_this_line; j++) {
char buf[20];
uint8_t c = arr[i + j];
r = snprintf(buf, sizeof(buf), "%02x ", static_cast<unsigned int>(c));
TEST_AND_RETURN(r == 3);
line += buf;
}
LOG(INFO) << line;
}
}
bool SplitPartitionName(const string& partition_name,
string* out_disk_name,
int* out_partition_num) {
if (!base::StartsWith(partition_name, "/dev/",
base::CompareCase::SENSITIVE)) {
LOG(ERROR) << "Invalid partition device name: " << partition_name;
return false;
}
size_t last_nondigit_pos = partition_name.find_last_not_of("0123456789");
if (last_nondigit_pos == string::npos ||
(last_nondigit_pos + 1) == partition_name.size()) {
LOG(ERROR) << "Unable to parse partition device name: " << partition_name;
return false;
}
size_t partition_name_len = string::npos;
if (partition_name[last_nondigit_pos] == '_') {
// NAND block devices have weird naming which could be something
// like "/dev/ubiblock2_0". We discard "_0" in such a case.
size_t prev_nondigit_pos =
partition_name.find_last_not_of("0123456789", last_nondigit_pos - 1);
if (prev_nondigit_pos == string::npos ||
(prev_nondigit_pos + 1) == last_nondigit_pos) {
LOG(ERROR) << "Unable to parse partition device name: " << partition_name;
return false;
}
partition_name_len = last_nondigit_pos - prev_nondigit_pos;
last_nondigit_pos = prev_nondigit_pos;
}
if (out_disk_name) {
// Special case for MMC devices which have the following naming scheme:
// mmcblk0p2
size_t disk_name_len = last_nondigit_pos;
if (partition_name[last_nondigit_pos] != 'p' ||
last_nondigit_pos == 0 ||
!isdigit(partition_name[last_nondigit_pos - 1])) {
disk_name_len++;
}
*out_disk_name = partition_name.substr(0, disk_name_len);
}
if (out_partition_num) {
string partition_str = partition_name.substr(last_nondigit_pos + 1,
partition_name_len);
*out_partition_num = atoi(partition_str.c_str());
}
return true;
}
string MakePartitionName(const string& disk_name, int partition_num) {
if (partition_num < 1) {
LOG(ERROR) << "Invalid partition number: " << partition_num;
return string();
}
if (!base::StartsWith(disk_name, "/dev/", base::CompareCase::SENSITIVE)) {
LOG(ERROR) << "Invalid disk name: " << disk_name;
return string();
}
if (IsMtdDeviceName(disk_name)) {
// Special case for UBI block devices.
// 1. ubiblock is not writable, we need to use plain "ubi".
// 2. There is a "_0" suffix.
return MakeNandPartitionName(partition_num);
}
string partition_name = disk_name;
if (isdigit(partition_name.back())) {
// Special case for devices with names ending with a digit.
// Add "p" to separate the disk name from partition number,
// e.g. "/dev/loop0p2"
partition_name += 'p';
}
partition_name += std::to_string(partition_num);
return partition_name;
}
string MakePartitionNameForMount(const string& part_name) {
if (IsMtdDeviceName(part_name)) {
int partition_num;
if (!SplitPartitionName(part_name, nullptr, &partition_num)) {
return "";
}
return MakeNandPartitionNameForMount(partition_num);
}
return part_name;
}
string ErrnoNumberAsString(int err) {
char buf[100];
buf[0] = '\0';
return strerror_r(err, buf, sizeof(buf));
}
bool FileExists(const char* path) {
struct stat stbuf;
return 0 == lstat(path, &stbuf);
}
bool IsSymlink(const char* path) {
struct stat stbuf;
return lstat(path, &stbuf) == 0 && S_ISLNK(stbuf.st_mode) != 0;
}
bool TryAttachingUbiVolume(int volume_num, int timeout) {
const string volume_path = base::StringPrintf("/dev/ubi%d_0", volume_num);
if (FileExists(volume_path.c_str())) {
return true;
}
int exit_code;
vector<string> cmd = {
"ubiattach",
"-m",
base::StringPrintf("%d", volume_num),
"-d",
base::StringPrintf("%d", volume_num)
};
TEST_AND_RETURN_FALSE(Subprocess::SynchronousExec(cmd, &exit_code, nullptr));
TEST_AND_RETURN_FALSE(exit_code == 0);
cmd = {
"ubiblock",
"--create",
volume_path
};
TEST_AND_RETURN_FALSE(Subprocess::SynchronousExec(cmd, &exit_code, nullptr));
TEST_AND_RETURN_FALSE(exit_code == 0);
while (timeout > 0 && !FileExists(volume_path.c_str())) {
sleep(1);
timeout--;
}
return FileExists(volume_path.c_str());
}
bool MakeTempFile(const string& base_filename_template,
string* filename,
int* fd) {
base::FilePath filename_template;
TEST_AND_RETURN_FALSE(
GetTempName(base_filename_template, &filename_template));
DCHECK(filename || fd);
vector<char> buf(filename_template.value().size() + 1);
memcpy(buf.data(), filename_template.value().data(),
filename_template.value().size());
buf[filename_template.value().size()] = '\0';
int mkstemp_fd = mkstemp(buf.data());
TEST_AND_RETURN_FALSE_ERRNO(mkstemp_fd >= 0);
if (filename) {
*filename = buf.data();
}
if (fd) {
*fd = mkstemp_fd;
} else {
close(mkstemp_fd);
}
return true;
}
bool MakeTempDirectory(const string& base_dirname_template,
string* dirname) {
base::FilePath dirname_template;
TEST_AND_RETURN_FALSE(GetTempName(base_dirname_template, &dirname_template));
DCHECK(dirname);
vector<char> buf(dirname_template.value().size() + 1);
memcpy(buf.data(), dirname_template.value().data(),
dirname_template.value().size());
buf[dirname_template.value().size()] = '\0';
char* return_code = mkdtemp(buf.data());
TEST_AND_RETURN_FALSE_ERRNO(return_code != nullptr);
*dirname = buf.data();
return true;
}
bool SetBlockDeviceReadOnly(const string& device, bool read_only) {
int fd = HANDLE_EINTR(open(device.c_str(), O_RDONLY | O_CLOEXEC));
if (fd < 0) {
PLOG(ERROR) << "Opening block device " << device;
return false;
}
ScopedFdCloser fd_closer(&fd);
// We take no action if not needed.
int read_only_flag;
int expected_flag = read_only ? 1 : 0;
int rc = ioctl(fd, BLKROGET, &read_only_flag);
// In case of failure reading the setting we will try to set it anyway.
if (rc == 0 && read_only_flag == expected_flag)
return true;
rc = ioctl(fd, BLKROSET, &expected_flag);
if (rc != 0) {
PLOG(ERROR) << "Marking block device " << device << " as read_only="
<< expected_flag;
return false;
}
return true;
}
bool MountFilesystem(const string& device,
const string& mountpoint,
unsigned long mountflags, // NOLINT(runtime/int)
const string& type,
const string& fs_mount_options) {
vector<const char*> fstypes;
if (type.empty()) {
fstypes = {"ext2", "ext3", "ext4", "squashfs"};
} else {
fstypes = {type.c_str()};
}
for (const char* fstype : fstypes) {
int rc = mount(device.c_str(), mountpoint.c_str(), fstype, mountflags,
fs_mount_options.c_str());
if (rc == 0)
return true;
PLOG(WARNING) << "Unable to mount destination device " << device
<< " on " << mountpoint << " as " << fstype;
}
if (!type.empty()) {
LOG(ERROR) << "Unable to mount " << device << " with any supported type";
}
return false;
}
bool UnmountFilesystem(const string& mountpoint) {
int num_retries = 1;
for (;; ++num_retries) {
if (umount(mountpoint.c_str()) == 0)
return true;
if (errno != EBUSY || num_retries >= kUnmountMaxNumOfRetries)
break;
usleep(kUnmountRetryIntervalInMicroseconds);
}
if (errno == EINVAL) {
LOG(INFO) << "Not a mountpoint: " << mountpoint;
return false;
}
PLOG(WARNING) << "Error unmounting " << mountpoint << " after " << num_retries
<< " attempts. Lazy unmounting instead, error was";
if (umount2(mountpoint.c_str(), MNT_DETACH) != 0) {
PLOG(ERROR) << "Lazy unmount failed";
return false;
}
return true;
}
bool GetFilesystemSize(const string& device,
int* out_block_count,
int* out_block_size) {
int fd = HANDLE_EINTR(open(device.c_str(), O_RDONLY));
TEST_AND_RETURN_FALSE_ERRNO(fd >= 0);
ScopedFdCloser fd_closer(&fd);
return GetFilesystemSizeFromFD(fd, out_block_count, out_block_size);
}
bool GetFilesystemSizeFromFD(int fd,
int* out_block_count,
int* out_block_size) {
TEST_AND_RETURN_FALSE(fd >= 0);
// Determine the filesystem size by directly reading the block count and
// block size information from the superblock. Supported FS are ext3 and
// squashfs.
// Read from the fd only once and detect in memory. The first 2 KiB is enough
// to read the ext2 superblock (located at offset 1024) and the squashfs
// superblock (located at offset 0).
const ssize_t kBufferSize = 2048;
uint8_t buffer[kBufferSize];
if (HANDLE_EINTR(pread(fd, buffer, kBufferSize, 0)) != kBufferSize) {
PLOG(ERROR) << "Unable to read the file system header:";
return false;
}
if (GetSquashfs4Size(buffer, kBufferSize, out_block_count, out_block_size))
return true;
if (GetExt3Size(buffer, kBufferSize, out_block_count, out_block_size))
return true;
LOG(ERROR) << "Unable to determine file system type.";
return false;
}
bool GetExt3Size(const uint8_t* buffer, size_t buffer_size,
int* out_block_count,
int* out_block_size) {
// See include/linux/ext2_fs.h for more details on the structure. We obtain
// ext2 constants from ext2fs/ext2fs.h header but we don't link with the
// library.
if (buffer_size < SUPERBLOCK_OFFSET + SUPERBLOCK_SIZE)
return false;
const uint8_t* superblock = buffer + SUPERBLOCK_OFFSET;
// ext3_fs.h: ext3_super_block.s_blocks_count
uint32_t block_count =
*reinterpret_cast<const uint32_t*>(superblock + 1 * sizeof(int32_t));
// ext3_fs.h: ext3_super_block.s_log_block_size
uint32_t log_block_size =
*reinterpret_cast<const uint32_t*>(superblock + 6 * sizeof(int32_t));
// ext3_fs.h: ext3_super_block.s_magic
uint16_t magic =
*reinterpret_cast<const uint16_t*>(superblock + 14 * sizeof(int32_t));
block_count = le32toh(block_count);
log_block_size = le32toh(log_block_size) + EXT2_MIN_BLOCK_LOG_SIZE;
magic = le16toh(magic);
// Sanity check the parameters.
TEST_AND_RETURN_FALSE(magic == EXT2_SUPER_MAGIC);
TEST_AND_RETURN_FALSE(log_block_size >= EXT2_MIN_BLOCK_LOG_SIZE &&
log_block_size <= EXT2_MAX_BLOCK_LOG_SIZE);
TEST_AND_RETURN_FALSE(block_count > 0);
if (out_block_count)
*out_block_count = block_count;
if (out_block_size)
*out_block_size = 1 << log_block_size;
return true;
}
bool GetSquashfs4Size(const uint8_t* buffer, size_t buffer_size,
int* out_block_count,
int* out_block_size) {
// See fs/squashfs/squashfs_fs.h for format details. We only support
// Squashfs 4.x little endian.
// sizeof(struct squashfs_super_block)
const size_t kSquashfsSuperBlockSize = 96;
if (buffer_size < kSquashfsSuperBlockSize)
return false;
// Check magic, squashfs_fs.h: SQUASHFS_MAGIC
if (memcmp(buffer, "hsqs", 4) != 0)
return false; // Only little endian is supported.
// squashfs_fs.h: struct squashfs_super_block.s_major
uint16_t s_major = *reinterpret_cast<const uint16_t*>(
buffer + 5 * sizeof(uint32_t) + 4 * sizeof(uint16_t));
if (s_major != 4) {
LOG(ERROR) << "Found unsupported squashfs major version " << s_major;
return false;
}
// squashfs_fs.h: struct squashfs_super_block.bytes_used
uint64_t bytes_used = *reinterpret_cast<const int64_t*>(
buffer + 5 * sizeof(uint32_t) + 6 * sizeof(uint16_t) + sizeof(uint64_t));
const int block_size = 4096;
// The squashfs' bytes_used doesn't need to be aligned with the block boundary
// so we round up to the nearest blocksize.
if (out_block_count)
*out_block_count = (bytes_used + block_size - 1) / block_size;
if (out_block_size)
*out_block_size = block_size;
return true;
}
bool IsExtFilesystem(const string& device) {
brillo::Blob header;
// The first 2 KiB is enough to read the ext2 superblock (located at offset
// 1024).
if (!ReadFileChunk(device, 0, 2048, &header))
return false;
return GetExt3Size(header.data(), header.size(), nullptr, nullptr);
}
bool IsSquashfsFilesystem(const string& device) {
brillo::Blob header;
// The first 96 is enough to read the squashfs superblock.
const ssize_t kSquashfsSuperBlockSize = 96;
if (!ReadFileChunk(device, 0, kSquashfsSuperBlockSize, &header))
return false;
return GetSquashfs4Size(header.data(), header.size(), nullptr, nullptr);
}
// Tries to parse the header of an ELF file to obtain a human-readable
// description of it on the |output| string.
static bool GetFileFormatELF(const uint8_t* buffer, size_t size,
string* output) {
// 0x00: EI_MAG - ELF magic header, 4 bytes.
if (size < SELFMAG || memcmp(buffer, ELFMAG, SELFMAG) != 0)
return false;
*output = "ELF";
// 0x04: EI_CLASS, 1 byte.
if (size < EI_CLASS + 1)
return true;
switch (buffer[EI_CLASS]) {
case ELFCLASS32:
*output += " 32-bit";
break;
case ELFCLASS64:
*output += " 64-bit";
break;
default:
*output += " ?-bit";
}
// 0x05: EI_DATA, endianness, 1 byte.
if (size < EI_DATA + 1)
return true;
uint8_t ei_data = buffer[EI_DATA];
switch (ei_data) {
case ELFDATA2LSB:
*output += " little-endian";
break;
case ELFDATA2MSB:
*output += " big-endian";
break;
default:
*output += " ?-endian";
// Don't parse anything after the 0x10 offset if endianness is unknown.
return true;
}
const Elf32_Ehdr* hdr = reinterpret_cast<const Elf32_Ehdr*>(buffer);
// 0x12: e_machine, 2 byte endianness based on ei_data. The position (0x12)
// and size is the same for both 32 and 64 bits.
if (size < offsetof(Elf32_Ehdr, e_machine) + sizeof(hdr->e_machine))
return true;
uint16_t e_machine;
// Fix endianess regardless of the host endianess.
if (ei_data == ELFDATA2LSB)
e_machine = le16toh(hdr->e_machine);
else
e_machine = be16toh(hdr->e_machine);
switch (e_machine) {
case EM_386:
*output += " x86";
break;
case EM_MIPS:
*output += " mips";
break;
case EM_ARM:
*output += " arm";
break;
case EM_X86_64:
*output += " x86-64";
break;
default:
*output += " unknown-arch";
}
return true;
}
string GetFileFormat(const string& path) {
brillo::Blob buffer;
if (!ReadFileChunkAndAppend(path, 0, kGetFileFormatMaxHeaderSize, &buffer))
return "File not found.";
string result;
if (GetFileFormatELF(buffer.data(), buffer.size(), &result))
return result;
return "data";
}
namespace {
// Do the actual trigger. We do it as a main-loop callback to (try to) get a
// consistent stack trace.
void TriggerCrashReporterUpload() {
pid_t pid = fork();
CHECK_GE(pid, 0) << "fork failed"; // fork() failed. Something is very wrong.
if (pid == 0) {
// We are the child. Crash.
abort(); // never returns
}
// We are the parent. Wait for child to terminate.
pid_t result = waitpid(pid, nullptr, 0);
LOG_IF(ERROR, result < 0) << "waitpid() failed";
}
} // namespace
void ScheduleCrashReporterUpload() {
brillo::MessageLoop::current()->PostTask(
FROM_HERE,
base::Bind(&TriggerCrashReporterUpload));
}
int FuzzInt(int value, unsigned int range) {
int min = value - range / 2;
int max = value + range - range / 2;
return base::RandInt(min, max);
}
string FormatSecs(unsigned secs) {
return FormatTimeDelta(TimeDelta::FromSeconds(secs));
}
string FormatTimeDelta(TimeDelta delta) {
string str;
// Handle negative durations by prefixing with a minus.
if (delta.ToInternalValue() < 0) {
delta *= -1;
str = "-";
}
// Canonicalize into days, hours, minutes, seconds and microseconds.
unsigned days = delta.InDays();
delta -= TimeDelta::FromDays(days);
unsigned hours = delta.InHours();
delta -= TimeDelta::FromHours(hours);
unsigned mins = delta.InMinutes();
delta -= TimeDelta::FromMinutes(mins);
unsigned secs = delta.InSeconds();
delta -= TimeDelta::FromSeconds(secs);
unsigned usecs = delta.InMicroseconds();
if (days)
base::StringAppendF(&str, "%ud", days);
if (days || hours)
base::StringAppendF(&str, "%uh", hours);
if (days || hours || mins)
base::StringAppendF(&str, "%um", mins);
base::StringAppendF(&str, "%u", secs);
if (usecs) {
int width = 6;
while ((usecs / 10) * 10 == usecs) {
usecs /= 10;
width--;
}
base::StringAppendF(&str, ".%0*u", width, usecs);
}
base::StringAppendF(&str, "s");
return str;
}
string ToString(const Time utc_time) {
Time::Exploded exp_time;
utc_time.UTCExplode(&exp_time);
return base::StringPrintf("%d/%d/%d %d:%02d:%02d GMT",
exp_time.month,
exp_time.day_of_month,
exp_time.year,
exp_time.hour,
exp_time.minute,
exp_time.second);
}
string ToString(bool b) {
return (b ? "true" : "false");
}
string ToString(DownloadSource source) {
switch (source) {
case kDownloadSourceHttpsServer: return "HttpsServer";
case kDownloadSourceHttpServer: return "HttpServer";
case kDownloadSourceHttpPeer: return "HttpPeer";
case kNumDownloadSources: return "Unknown";
// Don't add a default case to let the compiler warn about newly added
// download sources which should be added here.
}
return "Unknown";
}
string ToString(PayloadType payload_type) {
switch (payload_type) {
case kPayloadTypeDelta: return "Delta";
case kPayloadTypeFull: return "Full";
case kPayloadTypeForcedFull: return "ForcedFull";
case kNumPayloadTypes: return "Unknown";
// Don't add a default case to let the compiler warn about newly added
// payload types which should be added here.
}
return "Unknown";
}
ErrorCode GetBaseErrorCode(ErrorCode code) {
// Ignore the higher order bits in the code by applying the mask as
// we want the enumerations to be in the small contiguous range
// with values less than ErrorCode::kUmaReportedMax.
ErrorCode base_code = static_cast<ErrorCode>(
static_cast<int>(code) & ~static_cast<int>(ErrorCode::kSpecialFlags));
// Make additional adjustments required for UMA and error classification.
// TODO(jaysri): Move this logic to UeErrorCode.cc when we fix
// chromium-os:34369.
if (base_code >= ErrorCode::kOmahaRequestHTTPResponseBase) {
// Since we want to keep the enums to a small value, aggregate all HTTP
// errors into this one bucket for UMA and error classification purposes.
LOG(INFO) << "Converting error code " << base_code
<< " to ErrorCode::kOmahaErrorInHTTPResponse";
base_code = ErrorCode::kOmahaErrorInHTTPResponse;
}
return base_code;
}
Time TimeFromStructTimespec(struct timespec *ts) {
int64_t us = static_cast<int64_t>(ts->tv_sec) * Time::kMicrosecondsPerSecond +
static_cast<int64_t>(ts->tv_nsec) / Time::kNanosecondsPerMicrosecond;
return Time::UnixEpoch() + TimeDelta::FromMicroseconds(us);
}
string StringVectorToString(const vector<string> &vec_str) {
string str = "[";
for (vector<string>::const_iterator i = vec_str.begin();
i != vec_str.end(); ++i) {
if (i != vec_str.begin())
str += ", ";
str += '"';
str += *i;
str += '"';
}
str += "]";
return str;
}
string CalculateP2PFileId(const string& payload_hash, size_t payload_size) {
string encoded_hash = brillo::data_encoding::Base64Encode(payload_hash);
return base::StringPrintf("cros_update_size_%" PRIuS "_hash_%s",
payload_size,
encoded_hash.c_str());
}
bool DecodeAndStoreBase64String(const string& base64_encoded,
base::FilePath *out_path) {
brillo::Blob contents;
out_path->clear();
if (base64_encoded.size() == 0) {
LOG(ERROR) << "Can't decode empty string.";
return false;
}
if (!brillo::data_encoding::Base64Decode(base64_encoded, &contents) ||
contents.size() == 0) {
LOG(ERROR) << "Error decoding base64.";
return false;
}
FILE *file = base::CreateAndOpenTemporaryFile(out_path);
if (file == nullptr) {
LOG(ERROR) << "Error creating temporary file.";
return false;
}
if (fwrite(contents.data(), 1, contents.size(), file) != contents.size()) {
PLOG(ERROR) << "Error writing to temporary file.";
if (fclose(file) != 0)
PLOG(ERROR) << "Error closing temporary file.";
if (unlink(out_path->value().c_str()) != 0)
PLOG(ERROR) << "Error unlinking temporary file.";
out_path->clear();
return false;
}
if (fclose(file) != 0) {
PLOG(ERROR) << "Error closing temporary file.";
out_path->clear();
return false;
}
return true;
}
bool ConvertToOmahaInstallDate(Time time, int *out_num_days) {
time_t unix_time = time.ToTimeT();
// Output of: date +"%s" --date="Jan 1, 2007 0:00 PST".
const time_t kOmahaEpoch = 1167638400;
const int64_t kNumSecondsPerWeek = 7*24*3600;
const int64_t kNumDaysPerWeek = 7;
time_t omaha_time = unix_time - kOmahaEpoch;
if (omaha_time < 0)
return false;
// Note, as per the comment in utils.h we are deliberately not
// handling DST correctly.
int64_t num_weeks_since_omaha_epoch = omaha_time / kNumSecondsPerWeek;
*out_num_days = num_weeks_since_omaha_epoch * kNumDaysPerWeek;
return true;
}
bool GetMinorVersion(const brillo::KeyValueStore& store,
uint32_t* minor_version) {
string result;
if (store.GetString("PAYLOAD_MINOR_VERSION", &result)) {
if (!base::StringToUint(result, minor_version)) {
LOG(ERROR) << "StringToUint failed when parsing delta minor version.";
return false;
}
return true;
}
return false;
}
bool IsZlibCompatible(const string& fingerprint) {
if (fingerprint.size() != sizeof(kCompatibleZlibFingerprint[0]) - 1) {
LOG(ERROR) << "Invalid fingerprint: " << fingerprint;
return false;
}
for (auto& f : kCompatibleZlibFingerprint) {
if (base::CompareCaseInsensitiveASCII(fingerprint, f) == 0) {
return true;
}
}
return false;
}
bool ReadExtents(const string& path, const vector<Extent>& extents,
brillo::Blob* out_data, ssize_t out_data_size,
size_t block_size) {
brillo::Blob data(out_data_size);
ssize_t bytes_read = 0;
int fd = open(path.c_str(), O_RDONLY);
TEST_AND_RETURN_FALSE_ERRNO(fd >= 0);
ScopedFdCloser fd_closer(&fd);
for (const Extent& extent : extents) {
ssize_t bytes_read_this_iteration = 0;
ssize_t bytes = extent.num_blocks() * block_size;
TEST_AND_RETURN_FALSE(bytes_read + bytes <= out_data_size);
TEST_AND_RETURN_FALSE(utils::PReadAll(fd,
&data[bytes_read],
bytes,
extent.start_block() * block_size,
&bytes_read_this_iteration));
TEST_AND_RETURN_FALSE(bytes_read_this_iteration == bytes);
bytes_read += bytes_read_this_iteration;
}
TEST_AND_RETURN_FALSE(out_data_size == bytes_read);
*out_data = data;
return true;
}
bool GetBootId(string* boot_id) {
TEST_AND_RETURN_FALSE(
base::ReadFileToString(base::FilePath(kBootIdPath), boot_id));
base::TrimWhitespaceASCII(*boot_id, base::TRIM_TRAILING, boot_id);
return true;
}
} // namespace utils
} // namespace chromeos_update_engine