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zip_archive.cc
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zip_archive.cc
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/*
* 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.
*/
/*
* Read-only access to Zip archives, with minimal heap allocation.
*/
#define LOG_TAG "ziparchive"
#include "ziparchive/zip_archive.h"
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <memory>
#include <vector>
#if defined(__APPLE__)
#define lseek64 lseek
#endif
#if defined(__BIONIC__)
#include <android/fdsan.h>
#endif
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/macros.h> // TEMP_FAILURE_RETRY may or may not be in unistd
#include <android-base/mapped_file.h>
#include <android-base/memory.h>
#include <android-base/strings.h>
#include <android-base/utf8.h>
#include <log/log.h>
#include "zlib.h"
#include "entry_name_utils-inl.h"
#include "zip_archive_common.h"
#include "zip_archive_private.h"
using android::base::get_unaligned;
// Used to turn on crc checks - verify that the content CRC matches the values
// specified in the local file header and the central directory.
static const bool kCrcChecksEnabled = false;
// The maximum number of bytes to scan backwards for the EOCD start.
static const uint32_t kMaxEOCDSearch = kMaxCommentLen + sizeof(EocdRecord);
/*
* A Read-only Zip archive.
*
* We want "open" and "find entry by name" to be fast operations, and
* we want to use as little memory as possible. We memory-map the zip
* central directory, and load a hash table with pointers to the filenames
* (which aren't null-terminated). The other fields are at a fixed offset
* from the filename, so we don't need to extract those (but we do need
* to byte-read and endian-swap them every time we want them).
*
* It's possible that somebody has handed us a massive (~1GB) zip archive,
* so we can't expect to mmap the entire file.
*
* To speed comparisons when doing a lookup by name, we could make the mapping
* "private" (copy-on-write) and null-terminate the filenames after verifying
* the record structure. However, this requires a private mapping of
* every page that the Central Directory touches. Easier to tuck a copy
* of the string length into the hash table entry.
*/
/*
* Round up to the next highest power of 2.
*
* Found on http://graphics.stanford.edu/~seander/bithacks.html.
*/
static uint32_t RoundUpPower2(uint32_t val) {
val--;
val |= val >> 1;
val |= val >> 2;
val |= val >> 4;
val |= val >> 8;
val |= val >> 16;
val++;
return val;
}
static uint32_t ComputeHash(std::string_view name) {
return static_cast<uint32_t>(std::hash<std::string_view>{}(name));
}
/*
* Convert a ZipEntry to a hash table index, verifying that it's in a
* valid range.
*/
static int64_t EntryToIndex(const ZipStringOffset* hash_table, const uint32_t hash_table_size,
std::string_view name, const uint8_t* start) {
const uint32_t hash = ComputeHash(name);
// NOTE: (hash_table_size - 1) is guaranteed to be non-negative.
uint32_t ent = hash & (hash_table_size - 1);
while (hash_table[ent].name_offset != 0) {
if (hash_table[ent].ToStringView(start) == name) {
return ent;
}
ent = (ent + 1) & (hash_table_size - 1);
}
ALOGV("Zip: Unable to find entry %.*s", static_cast<int>(name.size()), name.data());
return kEntryNotFound;
}
/*
* Add a new entry to the hash table.
*/
static int32_t AddToHash(ZipStringOffset* hash_table, const uint32_t hash_table_size,
std::string_view name, const uint8_t* start) {
const uint64_t hash = ComputeHash(name);
uint32_t ent = hash & (hash_table_size - 1);
/*
* We over-allocated the table, so we're guaranteed to find an empty slot.
* Further, we guarantee that the hashtable size is not 0.
*/
while (hash_table[ent].name_offset != 0) {
if (hash_table[ent].ToStringView(start) == name) {
// We've found a duplicate entry. We don't accept duplicates.
ALOGW("Zip: Found duplicate entry %.*s", static_cast<int>(name.size()), name.data());
return kDuplicateEntry;
}
ent = (ent + 1) & (hash_table_size - 1);
}
// `name` has already been validated before entry.
const char* start_char = reinterpret_cast<const char*>(start);
hash_table[ent].name_offset = static_cast<uint32_t>(name.data() - start_char);
hash_table[ent].name_length = static_cast<uint16_t>(name.size());
return 0;
}
#if defined(__BIONIC__)
uint64_t GetOwnerTag(const ZipArchive* archive) {
return android_fdsan_create_owner_tag(ANDROID_FDSAN_OWNER_TYPE_ZIPARCHIVE,
reinterpret_cast<uint64_t>(archive));
}
#endif
ZipArchive::ZipArchive(const int fd, bool assume_ownership)
: mapped_zip(fd),
close_file(assume_ownership),
directory_offset(0),
central_directory(),
directory_map(),
num_entries(0),
hash_table_size(0),
hash_table(nullptr) {
#if defined(__BIONIC__)
if (assume_ownership) {
android_fdsan_exchange_owner_tag(fd, 0, GetOwnerTag(this));
}
#endif
}
ZipArchive::ZipArchive(const void* address, size_t length)
: mapped_zip(address, length),
close_file(false),
directory_offset(0),
central_directory(),
directory_map(),
num_entries(0),
hash_table_size(0),
hash_table(nullptr) {}
ZipArchive::~ZipArchive() {
if (close_file && mapped_zip.GetFileDescriptor() >= 0) {
#if defined(__BIONIC__)
android_fdsan_close_with_tag(mapped_zip.GetFileDescriptor(), GetOwnerTag(this));
#else
close(mapped_zip.GetFileDescriptor());
#endif
}
free(hash_table);
}
static int32_t MapCentralDirectory0(const char* debug_file_name, ZipArchive* archive,
off64_t file_length, uint32_t read_amount,
uint8_t* scan_buffer) {
const off64_t search_start = file_length - read_amount;
if (!archive->mapped_zip.ReadAtOffset(scan_buffer, read_amount, search_start)) {
ALOGE("Zip: read %" PRId64 " from offset %" PRId64 " failed", static_cast<int64_t>(read_amount),
static_cast<int64_t>(search_start));
return kIoError;
}
/*
* Scan backward for the EOCD magic. In an archive without a trailing
* comment, we'll find it on the first try. (We may want to consider
* doing an initial minimal read; if we don't find it, retry with a
* second read as above.)
*/
CHECK_LE(read_amount, std::numeric_limits<int32_t>::max());
int32_t i = read_amount - sizeof(EocdRecord);
for (; i >= 0; i--) {
if (scan_buffer[i] == 0x50) {
uint32_t* sig_addr = reinterpret_cast<uint32_t*>(&scan_buffer[i]);
if (get_unaligned<uint32_t>(sig_addr) == EocdRecord::kSignature) {
ALOGV("+++ Found EOCD at buf+%d", i);
break;
}
}
}
if (i < 0) {
ALOGD("Zip: EOCD not found, %s is not zip", debug_file_name);
return kInvalidFile;
}
const off64_t eocd_offset = search_start + i;
const EocdRecord* eocd = reinterpret_cast<const EocdRecord*>(scan_buffer + i);
/*
* Verify that there's no trailing space at the end of the central directory
* and its comment.
*/
const off64_t calculated_length = eocd_offset + sizeof(EocdRecord) + eocd->comment_length;
if (calculated_length != file_length) {
ALOGW("Zip: %" PRId64 " extraneous bytes at the end of the central directory",
static_cast<int64_t>(file_length - calculated_length));
return kInvalidFile;
}
/*
* Grab the CD offset and size, and the number of entries in the
* archive and verify that they look reasonable.
*/
if (static_cast<off64_t>(eocd->cd_start_offset) + eocd->cd_size > eocd_offset) {
ALOGW("Zip: bad offsets (dir %" PRIu32 ", size %" PRIu32 ", eocd %" PRId64 ")",
eocd->cd_start_offset, eocd->cd_size, static_cast<int64_t>(eocd_offset));
return kInvalidOffset;
}
if (eocd->num_records == 0) {
#if defined(__ANDROID__)
ALOGW("Zip: empty archive?");
#endif
return kEmptyArchive;
}
ALOGV("+++ num_entries=%" PRIu32 " dir_size=%" PRIu32 " dir_offset=%" PRIu32, eocd->num_records,
eocd->cd_size, eocd->cd_start_offset);
/*
* It all looks good. Create a mapping for the CD, and set the fields
* in archive.
*/
if (!archive->InitializeCentralDirectory(static_cast<off64_t>(eocd->cd_start_offset),
static_cast<size_t>(eocd->cd_size))) {
ALOGE("Zip: failed to intialize central directory.\n");
return kMmapFailed;
}
archive->num_entries = eocd->num_records;
archive->directory_offset = eocd->cd_start_offset;
return 0;
}
/*
* Find the zip Central Directory and memory-map it.
*
* On success, returns 0 after populating fields from the EOCD area:
* directory_offset
* directory_ptr
* num_entries
*/
static int32_t MapCentralDirectory(const char* debug_file_name, ZipArchive* archive) {
// Test file length. We use lseek64 to make sure the file
// is small enough to be a zip file (Its size must be less than
// 0xffffffff bytes).
off64_t file_length = archive->mapped_zip.GetFileLength();
if (file_length == -1) {
return kInvalidFile;
}
if (file_length > static_cast<off64_t>(0xffffffff)) {
ALOGV("Zip: zip file too long %" PRId64, static_cast<int64_t>(file_length));
return kInvalidFile;
}
if (file_length < static_cast<off64_t>(sizeof(EocdRecord))) {
ALOGV("Zip: length %" PRId64 " is too small to be zip", static_cast<int64_t>(file_length));
return kInvalidFile;
}
/*
* Perform the traditional EOCD snipe hunt.
*
* We're searching for the End of Central Directory magic number,
* which appears at the start of the EOCD block. It's followed by
* 18 bytes of EOCD stuff and up to 64KB of archive comment. We
* need to read the last part of the file into a buffer, dig through
* it to find the magic number, parse some values out, and use those
* to determine the extent of the CD.
*
* We start by pulling in the last part of the file.
*/
uint32_t read_amount = kMaxEOCDSearch;
if (file_length < read_amount) {
read_amount = static_cast<uint32_t>(file_length);
}
std::vector<uint8_t> scan_buffer(read_amount);
int32_t result =
MapCentralDirectory0(debug_file_name, archive, file_length, read_amount, scan_buffer.data());
return result;
}
/*
* Parses the Zip archive's Central Directory. Allocates and populates the
* hash table.
*
* Returns 0 on success.
*/
static int32_t ParseZipArchive(ZipArchive* archive) {
const uint8_t* const cd_ptr = archive->central_directory.GetBasePtr();
const size_t cd_length = archive->central_directory.GetMapLength();
const uint16_t num_entries = archive->num_entries;
/*
* Create hash table. We have a minimum 75% load factor, possibly as
* low as 50% after we round off to a power of 2. There must be at
* least one unused entry to avoid an infinite loop during creation.
*/
archive->hash_table_size = RoundUpPower2(1 + (num_entries * 4) / 3);
archive->hash_table =
reinterpret_cast<ZipStringOffset*>(calloc(archive->hash_table_size, sizeof(ZipStringOffset)));
if (archive->hash_table == nullptr) {
ALOGW("Zip: unable to allocate the %u-entry hash_table, entry size: %zu",
archive->hash_table_size, sizeof(ZipStringOffset));
return -1;
}
/*
* Walk through the central directory, adding entries to the hash
* table and verifying values.
*/
const uint8_t* const cd_end = cd_ptr + cd_length;
const uint8_t* ptr = cd_ptr;
for (uint16_t i = 0; i < num_entries; i++) {
if (ptr > cd_end - sizeof(CentralDirectoryRecord)) {
ALOGW("Zip: ran off the end (at %" PRIu16 ")", i);
#if defined(__ANDROID__)
android_errorWriteLog(0x534e4554, "36392138");
#endif
return -1;
}
const CentralDirectoryRecord* cdr = reinterpret_cast<const CentralDirectoryRecord*>(ptr);
if (cdr->record_signature != CentralDirectoryRecord::kSignature) {
ALOGW("Zip: missed a central dir sig (at %" PRIu16 ")", i);
return -1;
}
const off64_t local_header_offset = cdr->local_file_header_offset;
if (local_header_offset >= archive->directory_offset) {
ALOGW("Zip: bad LFH offset %" PRId64 " at entry %" PRIu16,
static_cast<int64_t>(local_header_offset), i);
return -1;
}
const uint16_t file_name_length = cdr->file_name_length;
const uint16_t extra_length = cdr->extra_field_length;
const uint16_t comment_length = cdr->comment_length;
const uint8_t* file_name = ptr + sizeof(CentralDirectoryRecord);
if (file_name + file_name_length > cd_end) {
ALOGW("Zip: file name for entry %" PRIu16
" exceeds the central directory range, file_name_length: %" PRIu16 ", cd_length: %zu",
i, file_name_length, cd_length);
return -1;
}
// Check that file name is valid UTF-8 and doesn't contain NUL (U+0000) characters.
if (!IsValidEntryName(file_name, file_name_length)) {
ALOGW("Zip: invalid file name at entry %" PRIu16, i);
return -1;
}
// Add the CDE filename to the hash table.
std::string_view entry_name{reinterpret_cast<const char*>(file_name), file_name_length};
const int add_result = AddToHash(archive->hash_table, archive->hash_table_size, entry_name,
archive->central_directory.GetBasePtr());
if (add_result != 0) {
ALOGW("Zip: Error adding entry to hash table %d", add_result);
return add_result;
}
ptr += sizeof(CentralDirectoryRecord) + file_name_length + extra_length + comment_length;
if ((ptr - cd_ptr) > static_cast<int64_t>(cd_length)) {
ALOGW("Zip: bad CD advance (%tu vs %zu) at entry %" PRIu16, ptr - cd_ptr, cd_length, i);
return -1;
}
}
uint32_t lfh_start_bytes;
if (!archive->mapped_zip.ReadAtOffset(reinterpret_cast<uint8_t*>(&lfh_start_bytes),
sizeof(uint32_t), 0)) {
ALOGW("Zip: Unable to read header for entry at offset == 0.");
return -1;
}
if (lfh_start_bytes != LocalFileHeader::kSignature) {
ALOGW("Zip: Entry at offset zero has invalid LFH signature %" PRIx32, lfh_start_bytes);
#if defined(__ANDROID__)
android_errorWriteLog(0x534e4554, "64211847");
#endif
return -1;
}
ALOGV("+++ zip good scan %" PRIu16 " entries", num_entries);
return 0;
}
static int32_t OpenArchiveInternal(ZipArchive* archive, const char* debug_file_name) {
int32_t result = -1;
if ((result = MapCentralDirectory(debug_file_name, archive)) != 0) {
return result;
}
if ((result = ParseZipArchive(archive))) {
return result;
}
return 0;
}
int32_t OpenArchiveFd(int fd, const char* debug_file_name, ZipArchiveHandle* handle,
bool assume_ownership) {
ZipArchive* archive = new ZipArchive(fd, assume_ownership);
*handle = archive;
return OpenArchiveInternal(archive, debug_file_name);
}
int32_t OpenArchive(const char* fileName, ZipArchiveHandle* handle) {
const int fd = ::android::base::utf8::open(fileName, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
ZipArchive* archive = new ZipArchive(fd, true);
*handle = archive;
if (fd < 0) {
ALOGW("Unable to open '%s': %s", fileName, strerror(errno));
return kIoError;
}
return OpenArchiveInternal(archive, fileName);
}
int32_t OpenArchiveFromMemory(const void* address, size_t length, const char* debug_file_name,
ZipArchiveHandle* handle) {
ZipArchive* archive = new ZipArchive(address, length);
*handle = archive;
return OpenArchiveInternal(archive, debug_file_name);
}
ZipArchiveInfo GetArchiveInfo(ZipArchiveHandle archive) {
ZipArchiveInfo result;
result.archive_size = archive->mapped_zip.GetFileLength();
result.entry_count = archive->num_entries;
return result;
}
/*
* Close a ZipArchive, closing the file and freeing the contents.
*/
void CloseArchive(ZipArchiveHandle archive) {
ALOGV("Closing archive %p", archive);
delete archive;
}
static int32_t ValidateDataDescriptor(MappedZipFile& mapped_zip, ZipEntry* entry) {
uint8_t ddBuf[sizeof(DataDescriptor) + sizeof(DataDescriptor::kOptSignature)];
off64_t offset = entry->offset;
if (entry->method != kCompressStored) {
offset += entry->compressed_length;
} else {
offset += entry->uncompressed_length;
}
if (!mapped_zip.ReadAtOffset(ddBuf, sizeof(ddBuf), offset)) {
return kIoError;
}
const uint32_t ddSignature = *(reinterpret_cast<const uint32_t*>(ddBuf));
const uint16_t ddOffset = (ddSignature == DataDescriptor::kOptSignature) ? 4 : 0;
const DataDescriptor* descriptor = reinterpret_cast<const DataDescriptor*>(ddBuf + ddOffset);
// Validate that the values in the data descriptor match those in the central
// directory.
if (entry->compressed_length != descriptor->compressed_size ||
entry->uncompressed_length != descriptor->uncompressed_size ||
entry->crc32 != descriptor->crc32) {
ALOGW("Zip: size/crc32 mismatch. expected {%" PRIu32 ", %" PRIu32 ", %" PRIx32
"}, was {%" PRIu32 ", %" PRIu32 ", %" PRIx32 "}",
entry->compressed_length, entry->uncompressed_length, entry->crc32,
descriptor->compressed_size, descriptor->uncompressed_size, descriptor->crc32);
return kInconsistentInformation;
}
return 0;
}
static int32_t FindEntry(const ZipArchive* archive, const int32_t ent, ZipEntry* data) {
const uint16_t nameLen = archive->hash_table[ent].name_length;
// Recover the start of the central directory entry from the filename
// pointer. The filename is the first entry past the fixed-size data,
// so we can just subtract back from that.
const uint8_t* base_ptr = archive->central_directory.GetBasePtr();
const uint8_t* ptr = base_ptr + archive->hash_table[ent].name_offset;
ptr -= sizeof(CentralDirectoryRecord);
// This is the base of our mmapped region, we have to sanity check that
// the name that's in the hash table is a pointer to a location within
// this mapped region.
if (ptr < base_ptr || ptr > base_ptr + archive->central_directory.GetMapLength()) {
ALOGW("Zip: Invalid entry pointer");
return kInvalidOffset;
}
const CentralDirectoryRecord* cdr = reinterpret_cast<const CentralDirectoryRecord*>(ptr);
// The offset of the start of the central directory in the zipfile.
// We keep this lying around so that we can sanity check all our lengths
// and our per-file structures.
const off64_t cd_offset = archive->directory_offset;
// Fill out the compression method, modification time, crc32
// and other interesting attributes from the central directory. These
// will later be compared against values from the local file header.
data->method = cdr->compression_method;
data->mod_time = cdr->last_mod_date << 16 | cdr->last_mod_time;
data->crc32 = cdr->crc32;
data->compressed_length = cdr->compressed_size;
data->uncompressed_length = cdr->uncompressed_size;
// Figure out the local header offset from the central directory. The
// actual file data will begin after the local header and the name /
// extra comments.
const off64_t local_header_offset = cdr->local_file_header_offset;
if (local_header_offset + static_cast<off64_t>(sizeof(LocalFileHeader)) >= cd_offset) {
ALOGW("Zip: bad local hdr offset in zip");
return kInvalidOffset;
}
uint8_t lfh_buf[sizeof(LocalFileHeader)];
if (!archive->mapped_zip.ReadAtOffset(lfh_buf, sizeof(lfh_buf), local_header_offset)) {
ALOGW("Zip: failed reading lfh name from offset %" PRId64,
static_cast<int64_t>(local_header_offset));
return kIoError;
}
const LocalFileHeader* lfh = reinterpret_cast<const LocalFileHeader*>(lfh_buf);
if (lfh->lfh_signature != LocalFileHeader::kSignature) {
ALOGW("Zip: didn't find signature at start of lfh, offset=%" PRId64,
static_cast<int64_t>(local_header_offset));
return kInvalidOffset;
}
// Paranoia: Match the values specified in the local file header
// to those specified in the central directory.
// Warn if central directory and local file header don't agree on the use
// of a trailing Data Descriptor. The reference implementation is inconsistent
// and appears to use the LFH value during extraction (unzip) but the CD value
// while displayng information about archives (zipinfo). The spec remains
// silent on this inconsistency as well.
//
// For now, always use the version from the LFH but make sure that the values
// specified in the central directory match those in the data descriptor.
//
// NOTE: It's also worth noting that unzip *does* warn about inconsistencies in
// bit 11 (EFS: The language encoding flag, marking that filename and comment are
// encoded using UTF-8). This implementation does not check for the presence of
// that flag and always enforces that entry names are valid UTF-8.
if ((lfh->gpb_flags & kGPBDDFlagMask) != (cdr->gpb_flags & kGPBDDFlagMask)) {
ALOGW("Zip: gpb flag mismatch at bit 3. expected {%04" PRIx16 "}, was {%04" PRIx16 "}",
cdr->gpb_flags, lfh->gpb_flags);
}
// If there is no trailing data descriptor, verify that the central directory and local file
// header agree on the crc, compressed, and uncompressed sizes of the entry.
if ((lfh->gpb_flags & kGPBDDFlagMask) == 0) {
data->has_data_descriptor = 0;
if (data->compressed_length != lfh->compressed_size ||
data->uncompressed_length != lfh->uncompressed_size || data->crc32 != lfh->crc32) {
ALOGW("Zip: size/crc32 mismatch. expected {%" PRIu32 ", %" PRIu32 ", %" PRIx32
"}, was {%" PRIu32 ", %" PRIu32 ", %" PRIx32 "}",
data->compressed_length, data->uncompressed_length, data->crc32, lfh->compressed_size,
lfh->uncompressed_size, lfh->crc32);
return kInconsistentInformation;
}
} else {
data->has_data_descriptor = 1;
}
// 4.4.2.1: the upper byte of `version_made_by` gives the source OS. Unix is 3.
data->version_made_by = cdr->version_made_by;
data->external_file_attributes = cdr->external_file_attributes;
if ((data->version_made_by >> 8) == 3) {
data->unix_mode = (cdr->external_file_attributes >> 16) & 0xffff;
} else {
data->unix_mode = 0777;
}
// 4.4.4: general purpose bit flags.
data->gpbf = lfh->gpb_flags;
// 4.4.14: the lowest bit of the internal file attributes field indicates text.
// Currently only needed to implement zipinfo.
data->is_text = (cdr->internal_file_attributes & 1);
// Check that the local file header name matches the declared
// name in the central directory.
if (lfh->file_name_length != nameLen) {
ALOGW("Zip: lfh name length did not match central directory");
return kInconsistentInformation;
}
const off64_t name_offset = local_header_offset + sizeof(LocalFileHeader);
if (name_offset + lfh->file_name_length > cd_offset) {
ALOGW("Zip: lfh name has invalid declared length");
return kInvalidOffset;
}
std::vector<uint8_t> name_buf(nameLen);
if (!archive->mapped_zip.ReadAtOffset(name_buf.data(), nameLen, name_offset)) {
ALOGW("Zip: failed reading lfh name from offset %" PRId64, static_cast<int64_t>(name_offset));
return kIoError;
}
const std::string_view entry_name =
archive->hash_table[ent].ToStringView(archive->central_directory.GetBasePtr());
if (memcmp(entry_name.data(), name_buf.data(), nameLen) != 0) {
ALOGW("Zip: lfh name did not match central directory");
return kInconsistentInformation;
}
const off64_t data_offset = local_header_offset + sizeof(LocalFileHeader) +
lfh->file_name_length + lfh->extra_field_length;
if (data_offset > cd_offset) {
ALOGW("Zip: bad data offset %" PRId64 " in zip", static_cast<int64_t>(data_offset));
return kInvalidOffset;
}
if (static_cast<off64_t>(data_offset + data->compressed_length) > cd_offset) {
ALOGW("Zip: bad compressed length in zip (%" PRId64 " + %" PRIu32 " > %" PRId64 ")",
static_cast<int64_t>(data_offset), data->compressed_length,
static_cast<int64_t>(cd_offset));
return kInvalidOffset;
}
if (data->method == kCompressStored &&
static_cast<off64_t>(data_offset + data->uncompressed_length) > cd_offset) {
ALOGW("Zip: bad uncompressed length in zip (%" PRId64 " + %" PRIu32 " > %" PRId64 ")",
static_cast<int64_t>(data_offset), data->uncompressed_length,
static_cast<int64_t>(cd_offset));
return kInvalidOffset;
}
data->offset = data_offset;
return 0;
}
struct IterationHandle {
ZipArchive* archive;
std::string prefix;
std::string suffix;
uint32_t position = 0;
IterationHandle(ZipArchive* archive, std::string_view in_prefix, std::string_view in_suffix)
: archive(archive), prefix(in_prefix), suffix(in_suffix) {}
};
int32_t StartIteration(ZipArchiveHandle archive, void** cookie_ptr,
const std::string_view optional_prefix,
const std::string_view optional_suffix) {
if (archive == NULL || archive->hash_table == NULL) {
ALOGW("Zip: Invalid ZipArchiveHandle");
return kInvalidHandle;
}
if (optional_prefix.size() > static_cast<size_t>(UINT16_MAX) ||
optional_suffix.size() > static_cast<size_t>(UINT16_MAX)) {
ALOGW("Zip: prefix/suffix too long");
return kInvalidEntryName;
}
*cookie_ptr = new IterationHandle(archive, optional_prefix, optional_suffix);
return 0;
}
void EndIteration(void* cookie) {
delete reinterpret_cast<IterationHandle*>(cookie);
}
int32_t FindEntry(const ZipArchiveHandle archive, const std::string_view entryName,
ZipEntry* data) {
if (entryName.empty() || entryName.size() > static_cast<size_t>(UINT16_MAX)) {
ALOGW("Zip: Invalid filename of length %zu", entryName.size());
return kInvalidEntryName;
}
const int64_t ent = EntryToIndex(archive->hash_table, archive->hash_table_size, entryName,
archive->central_directory.GetBasePtr());
if (ent < 0) {
ALOGV("Zip: Could not find entry %.*s", static_cast<int>(entryName.size()), entryName.data());
return static_cast<int32_t>(ent); // kEntryNotFound is safe to truncate.
}
// We know there are at most hash_table_size entries, safe to truncate.
return FindEntry(archive, static_cast<uint32_t>(ent), data);
}
int32_t Next(void* cookie, ZipEntry* data, std::string* name) {
std::string_view sv;
int32_t result = Next(cookie, data, &sv);
if (result == 0 && name) {
*name = std::string(sv);
}
return result;
}
int32_t Next(void* cookie, ZipEntry* data, std::string_view* name) {
IterationHandle* handle = reinterpret_cast<IterationHandle*>(cookie);
if (handle == NULL) {
ALOGW("Zip: Null ZipArchiveHandle");
return kInvalidHandle;
}
ZipArchive* archive = handle->archive;
if (archive == NULL || archive->hash_table == NULL) {
ALOGW("Zip: Invalid ZipArchiveHandle");
return kInvalidHandle;
}
const uint32_t currentOffset = handle->position;
const uint32_t hash_table_length = archive->hash_table_size;
const ZipStringOffset* hash_table = archive->hash_table;
for (uint32_t i = currentOffset; i < hash_table_length; ++i) {
const std::string_view entry_name =
hash_table[i].ToStringView(archive->central_directory.GetBasePtr());
if (hash_table[i].name_offset != 0 && (android::base::StartsWith(entry_name, handle->prefix) &&
android::base::EndsWith(entry_name, handle->suffix))) {
handle->position = (i + 1);
const int error = FindEntry(archive, i, data);
if (!error && name) {
*name = entry_name;
}
return error;
}
}
handle->position = 0;
return kIterationEnd;
}
// A Writer that writes data to a fixed size memory region.
// The size of the memory region must be equal to the total size of
// the data appended to it.
class MemoryWriter : public zip_archive::Writer {
public:
MemoryWriter(uint8_t* buf, size_t size) : Writer(), buf_(buf), size_(size), bytes_written_(0) {}
virtual bool Append(uint8_t* buf, size_t buf_size) override {
if (bytes_written_ + buf_size > size_) {
ALOGW("Zip: Unexpected size %zu (declared) vs %zu (actual)", size_,
bytes_written_ + buf_size);
return false;
}
memcpy(buf_ + bytes_written_, buf, buf_size);
bytes_written_ += buf_size;
return true;
}
private:
uint8_t* const buf_;
const size_t size_;
size_t bytes_written_;
};
// A Writer that appends data to a file |fd| at its current position.
// The file will be truncated to the end of the written data.
class FileWriter : public zip_archive::Writer {
public:
// Creates a FileWriter for |fd| and prepare to write |entry| to it,
// guaranteeing that the file descriptor is valid and that there's enough
// space on the volume to write out the entry completely and that the file
// is truncated to the correct length (no truncation if |fd| references a
// block device).
//
// Returns a valid FileWriter on success, |nullptr| if an error occurred.
static FileWriter Create(int fd, const ZipEntry* entry) {
const uint32_t declared_length = entry->uncompressed_length;
const off64_t current_offset = lseek64(fd, 0, SEEK_CUR);
if (current_offset == -1) {
ALOGW("Zip: unable to seek to current location on fd %d: %s", fd, strerror(errno));
return FileWriter{};
}
#if defined(__linux__)
if (declared_length > 0) {
// Make sure we have enough space on the volume to extract the compressed
// entry. Note that the call to ftruncate below will change the file size but
// will not allocate space on disk and this call to fallocate will not
// change the file size.
// Note: fallocate is only supported by the following filesystems -
// btrfs, ext4, ocfs2, and xfs. Therefore fallocate might fail with
// EOPNOTSUPP error when issued in other filesystems.
// Hence, check for the return error code before concluding that the
// disk does not have enough space.
long result = TEMP_FAILURE_RETRY(fallocate(fd, 0, current_offset, declared_length));
if (result == -1 && errno == ENOSPC) {
ALOGW("Zip: unable to allocate %" PRId64 " bytes at offset %" PRId64 ": %s",
static_cast<int64_t>(declared_length), static_cast<int64_t>(current_offset),
strerror(errno));
return FileWriter{};
}
}
#endif // __linux__
struct stat sb;
if (fstat(fd, &sb) == -1) {
ALOGW("Zip: unable to fstat file: %s", strerror(errno));
return FileWriter{};
}
// Block device doesn't support ftruncate(2).
if (!S_ISBLK(sb.st_mode)) {
long result = TEMP_FAILURE_RETRY(ftruncate(fd, declared_length + current_offset));
if (result == -1) {
ALOGW("Zip: unable to truncate file to %" PRId64 ": %s",
static_cast<int64_t>(declared_length + current_offset), strerror(errno));
return FileWriter{};
}
}
return FileWriter(fd, declared_length);
}
FileWriter(FileWriter&& other) noexcept
: fd_(other.fd_),
declared_length_(other.declared_length_),
total_bytes_written_(other.total_bytes_written_) {
other.fd_ = -1;
}
bool IsValid() const { return fd_ != -1; }
virtual bool Append(uint8_t* buf, size_t buf_size) override {
if (total_bytes_written_ + buf_size > declared_length_) {
ALOGW("Zip: Unexpected size %zu (declared) vs %zu (actual)", declared_length_,
total_bytes_written_ + buf_size);
return false;
}
const bool result = android::base::WriteFully(fd_, buf, buf_size);
if (result) {
total_bytes_written_ += buf_size;
} else {
ALOGW("Zip: unable to write %zu bytes to file; %s", buf_size, strerror(errno));
}
return result;
}
private:
explicit FileWriter(const int fd = -1, const size_t declared_length = 0)
: Writer(), fd_(fd), declared_length_(declared_length), total_bytes_written_(0) {}
int fd_;
const size_t declared_length_;
size_t total_bytes_written_;
};
class EntryReader : public zip_archive::Reader {
public:
EntryReader(const MappedZipFile& zip_file, const ZipEntry* entry)
: Reader(), zip_file_(zip_file), entry_(entry) {}
virtual bool ReadAtOffset(uint8_t* buf, size_t len, uint32_t offset) const {
return zip_file_.ReadAtOffset(buf, len, entry_->offset + offset);
}
virtual ~EntryReader() {}
private:
const MappedZipFile& zip_file_;
const ZipEntry* entry_;
};
// This method is using libz macros with old-style-casts
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wold-style-cast"
static inline int zlib_inflateInit2(z_stream* stream, int window_bits) {
return inflateInit2(stream, window_bits);
}
#pragma GCC diagnostic pop
namespace zip_archive {
// Moved out of line to avoid -Wweak-vtables.
Reader::~Reader() {}
Writer::~Writer() {}
int32_t Inflate(const Reader& reader, const uint32_t compressed_length,
const uint32_t uncompressed_length, Writer* writer, uint64_t* crc_out) {
const size_t kBufSize = 32768;
std::vector<uint8_t> read_buf(kBufSize);
std::vector<uint8_t> write_buf(kBufSize);
z_stream zstream;
int zerr;
/*
* Initialize the zlib stream struct.
*/
memset(&zstream, 0, sizeof(zstream));
zstream.zalloc = Z_NULL;
zstream.zfree = Z_NULL;
zstream.opaque = Z_NULL;
zstream.next_in = NULL;
zstream.avail_in = 0;
zstream.next_out = &write_buf[0];
zstream.avail_out = kBufSize;
zstream.data_type = Z_UNKNOWN;
/*
* Use the undocumented "negative window bits" feature to tell zlib
* that there's no zlib header waiting for it.
*/
zerr = zlib_inflateInit2(&zstream, -MAX_WBITS);
if (zerr != Z_OK) {
if (zerr == Z_VERSION_ERROR) {
ALOGE("Installed zlib is not compatible with linked version (%s)", ZLIB_VERSION);
} else {
ALOGW("Call to inflateInit2 failed (zerr=%d)", zerr);
}
return kZlibError;
}
auto zstream_deleter = [](z_stream* stream) {
inflateEnd(stream); /* free up any allocated structures */
};
std::unique_ptr<z_stream, decltype(zstream_deleter)> zstream_guard(&zstream, zstream_deleter);
const bool compute_crc = (crc_out != nullptr);
uLong crc = 0;
uint32_t remaining_bytes = compressed_length;
do {
/* read as much as we can */
if (zstream.avail_in == 0) {
const uint32_t read_size = (remaining_bytes > kBufSize) ? kBufSize : remaining_bytes;
const uint32_t offset = (compressed_length - remaining_bytes);
// Make sure to read at offset to ensure concurrent access to the fd.
if (!reader.ReadAtOffset(read_buf.data(), read_size, offset)) {
ALOGW("Zip: inflate read failed, getSize = %u: %s", read_size, strerror(errno));
return kIoError;
}
remaining_bytes -= read_size;
zstream.next_in = &read_buf[0];
zstream.avail_in = read_size;
}
/* uncompress the data */
zerr = inflate(&zstream, Z_NO_FLUSH);
if (zerr != Z_OK && zerr != Z_STREAM_END) {
ALOGW("Zip: inflate zerr=%d (nIn=%p aIn=%u nOut=%p aOut=%u)", zerr, zstream.next_in,
zstream.avail_in, zstream.next_out, zstream.avail_out);
return kZlibError;
}