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platform_system_core/libziparchive/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 <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <memory>
#include <vector>
#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/memory.h>
#include <log/log.h>
#include <utils/Compat.h>
#include <utils/FileMap.h>
#include "ziparchive/zip_archive.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;
// This is for windows. If we don't open a file in binary mode, weird
// things will happen.
#ifndef O_BINARY
#define O_BINARY 0
#endif
// The maximum number of bytes to scan backwards for the EOCD start.
static const uint32_t kMaxEOCDSearch = kMaxCommentLen + sizeof(EocdRecord);
static const char* kErrorMessages[] = {
"Unknown return code.",
"Iteration ended",
"Zlib error",
"Invalid file",
"Invalid handle",
"Duplicate entries in archive",
"Empty archive",
"Entry not found",
"Invalid offset",
"Inconsistent information",
"Invalid entry name",
"I/O Error",
"File mapping failed"
};
static const int32_t kErrorMessageUpperBound = 0;
static const int32_t kIterationEnd = -1;
// We encountered a Zlib error when inflating a stream from this file.
// Usually indicates file corruption.
static const int32_t kZlibError = -2;
// The input file cannot be processed as a zip archive. Usually because
// it's too small, too large or does not have a valid signature.
static const int32_t kInvalidFile = -3;
// An invalid iteration / ziparchive handle was passed in as an input
// argument.
static const int32_t kInvalidHandle = -4;
// The zip archive contained two (or possibly more) entries with the same
// name.
static const int32_t kDuplicateEntry = -5;
// The zip archive contains no entries.
static const int32_t kEmptyArchive = -6;
// The specified entry was not found in the archive.
static const int32_t kEntryNotFound = -7;
// The zip archive contained an invalid local file header pointer.
static const int32_t kInvalidOffset = -8;
// The zip archive contained inconsistent entry information. This could
// be because the central directory & local file header did not agree, or
// if the actual uncompressed length or crc32 do not match their declared
// values.
static const int32_t kInconsistentInformation = -9;
// An invalid entry name was encountered.
static const int32_t kInvalidEntryName = -10;
// An I/O related system call (read, lseek, ftruncate, map) failed.
static const int32_t kIoError = -11;
// We were not able to mmap the central directory or entry contents.
static const int32_t kMmapFailed = -12;
static const int32_t kErrorMessageLowerBound = -13;
/*
* 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(const ZipString& name) {
uint32_t hash = 0;
uint16_t len = name.name_length;
const uint8_t* str = name.name;
while (len--) {
hash = hash * 31 + *str++;
}
return hash;
}
/*
* Convert a ZipEntry to a hash table index, verifying that it's in a
* valid range.
*/
static int64_t EntryToIndex(const ZipString* hash_table,
const uint32_t hash_table_size,
const ZipString& name) {
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 != NULL) {
if (hash_table[ent] == name) {
return ent;
}
ent = (ent + 1) & (hash_table_size - 1);
}
ALOGV("Zip: Unable to find entry %.*s", name.name_length, name.name);
return kEntryNotFound;
}
/*
* Add a new entry to the hash table.
*/
static int32_t AddToHash(ZipString *hash_table, const uint64_t hash_table_size,
const ZipString& name) {
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 != NULL) {
if (hash_table[ent] == name) {
// We've found a duplicate entry. We don't accept it
ALOGW("Zip: Found duplicate entry %.*s", name.name_length, name.name);
return kDuplicateEntry;
}
ent = (ent + 1) & (hash_table_size - 1);
}
hash_table[ent].name = name.name;
hash_table[ent].name_length = name.name_length;
return 0;
}
static int32_t MapCentralDirectory0(const char* debug_file_name, ZipArchive* archive,
off64_t file_length, off64_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.)
*/
int 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));
#if defined(__ANDROID__)
if (eocd->cd_start_offset + eocd->cd_size <= eocd_offset) {
android_errorWriteLog(0x534e4554, "31251826");
}
#endif
return kInvalidOffset;
}
if (eocd->num_records == 0) {
ALOGW("Zip: empty archive?");
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(debug_file_name,
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.
*/
off64_t read_amount = kMaxEOCDSearch;
if (file_length < read_amount) {
read_amount = 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<ZipString*>(calloc(archive->hash_table_size,
sizeof(ZipString)));
/*
* 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++) {
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;
}
if (ptr + sizeof(CentralDirectoryRecord) > cd_end) {
ALOGW("Zip: ran off the end (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);
/* check that file name is valid UTF-8 and doesn't contain NUL (U+0000) characters */
if (!IsValidEntryName(file_name, file_name_length)) {
return -1;
}
/* add the CDE filename to the hash table */
ZipString entry_name;
entry_name.name = file_name;
entry_name.name_length = file_name_length;
const int add_result = AddToHash(archive->hash_table,
archive->hash_table_size, entry_name);
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;
}
}
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 = open(fileName, O_RDONLY | O_BINARY, 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(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);
}
/*
* Close a ZipArchive, closing the file and freeing the contents.
*/
void CloseArchive(ZipArchiveHandle handle) {
ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle);
ALOGV("Closing archive %p", archive);
delete archive;
}
static int32_t UpdateEntryFromDataDescriptor(MappedZipFile& mapped_zip,
ZipEntry *entry) {
uint8_t ddBuf[sizeof(DataDescriptor) + sizeof(DataDescriptor::kOptSignature)];
if (!mapped_zip.ReadData(ddBuf, sizeof(ddBuf))) {
return kIoError;
}
const uint32_t ddSignature = *(reinterpret_cast<const uint32_t*>(ddBuf));
const uint16_t offset = (ddSignature == DataDescriptor::kOptSignature) ? 4 : 0;
const DataDescriptor* descriptor = reinterpret_cast<const DataDescriptor*>(ddBuf + offset);
entry->crc32 = descriptor->crc32;
entry->compressed_length = descriptor->compressed_size;
entry->uncompressed_length = descriptor->uncompressed_size;
return 0;
}
static int32_t FindEntry(const ZipArchive* archive, const int 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* ptr = archive->hash_table[ent].name;
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.
const uint8_t* base_ptr = archive->central_directory.GetBasePtr();
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.
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;
}
// Check that the local file header name matches the declared
// name in the central directory.
if (lfh->file_name_length == nameLen) {
const off64_t name_offset = local_header_offset + sizeof(LocalFileHeader);
if (name_offset + lfh->file_name_length > cd_offset) {
ALOGW("Zip: 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;
}
if (memcmp(archive->hash_table[ent].name, name_buf.data(), nameLen)) {
return kInconsistentInformation;
}
} else {
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 {
uint32_t position;
// We're not using vector here because this code is used in the Windows SDK
// where the STL is not available.
ZipString prefix;
ZipString suffix;
ZipArchive* archive;
IterationHandle(const ZipString* in_prefix,
const ZipString* in_suffix) {
if (in_prefix) {
uint8_t* name_copy = new uint8_t[in_prefix->name_length];
memcpy(name_copy, in_prefix->name, in_prefix->name_length);
prefix.name = name_copy;
prefix.name_length = in_prefix->name_length;
} else {
prefix.name = NULL;
prefix.name_length = 0;
}
if (in_suffix) {
uint8_t* name_copy = new uint8_t[in_suffix->name_length];
memcpy(name_copy, in_suffix->name, in_suffix->name_length);
suffix.name = name_copy;
suffix.name_length = in_suffix->name_length;
} else {
suffix.name = NULL;
suffix.name_length = 0;
}
}
~IterationHandle() {
delete[] prefix.name;
delete[] suffix.name;
}
};
int32_t StartIteration(ZipArchiveHandle handle, void** cookie_ptr,
const ZipString* optional_prefix,
const ZipString* optional_suffix) {
ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle);
if (archive == NULL || archive->hash_table == NULL) {
ALOGW("Zip: Invalid ZipArchiveHandle");
return kInvalidHandle;
}
IterationHandle* cookie = new IterationHandle(optional_prefix, optional_suffix);
cookie->position = 0;
cookie->archive = archive;
*cookie_ptr = cookie ;
return 0;
}
void EndIteration(void* cookie) {
delete reinterpret_cast<IterationHandle*>(cookie);
}
int32_t FindEntry(const ZipArchiveHandle handle, const ZipString& entryName,
ZipEntry* data) {
const ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle);
if (entryName.name_length == 0) {
ALOGW("Zip: Invalid filename %.*s", entryName.name_length, entryName.name);
return kInvalidEntryName;
}
const int64_t ent = EntryToIndex(archive->hash_table,
archive->hash_table_size, entryName);
if (ent < 0) {
ALOGV("Zip: Could not find entry %.*s", entryName.name_length, entryName.name);
return ent;
}
return FindEntry(archive, ent, data);
}
int32_t Next(void* cookie, ZipEntry* data, ZipString* name) {
IterationHandle* handle = reinterpret_cast<IterationHandle*>(cookie);
if (handle == NULL) {
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 ZipString* hash_table = archive->hash_table;
for (uint32_t i = currentOffset; i < hash_table_length; ++i) {
if (hash_table[i].name != NULL &&
(handle->prefix.name_length == 0 ||
hash_table[i].StartsWith(handle->prefix)) &&
(handle->suffix.name_length == 0 ||
hash_table[i].EndsWith(handle->suffix))) {
handle->position = (i + 1);
const int error = FindEntry(archive, i, data);
if (!error) {
name->name = hash_table[i].name;
name->name_length = hash_table[i].name_length;
}
return error;
}
}
handle->position = 0;
return kIterationEnd;
}
class Writer {
public:
virtual bool Append(uint8_t* buf, size_t buf_size) = 0;
virtual ~Writer() {}
protected:
Writer() = default;
private:
DISALLOW_COPY_AND_ASSIGN(Writer);
};
// 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 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 " ZD " (declared) vs " ZD " (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 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 std::unique_ptr<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 nullptr;
}
int result = 0;
#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.
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 std::unique_ptr<FileWriter>(nullptr);
}
}
#endif // __linux__
struct stat sb;
if (fstat(fd, &sb) == -1) {
ALOGW("Zip: unable to fstat file: %s", strerror(errno));
return std::unique_ptr<FileWriter>(nullptr);
}
// Block device doesn't support ftruncate(2).
if (!S_ISBLK(sb.st_mode)) {
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 std::unique_ptr<FileWriter>(nullptr);
}
}
return std::unique_ptr<FileWriter>(new FileWriter(fd, declared_length));
}
virtual bool Append(uint8_t* buf, size_t buf_size) override {
if (total_bytes_written_ + buf_size > declared_length_) {
ALOGW("Zip: Unexpected size " ZD " (declared) vs " ZD " (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 " ZD " bytes to file; %s", buf_size, strerror(errno));
}
return result;
}
private:
FileWriter(const int fd, const size_t declared_length) :
Writer(),
fd_(fd),
declared_length_(declared_length),
total_bytes_written_(0) {
}
const int fd_;
const size_t declared_length_;
size_t total_bytes_written_;
};
// 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
static int32_t InflateEntryToWriter(MappedZipFile& mapped_zip, const ZipEntry* entry,
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 uint32_t uncompressed_length = entry->uncompressed_length;
uint32_t compressed_length = entry->compressed_length;
do {
/* read as much as we can */
if (zstream.avail_in == 0) {
const size_t getSize = (compressed_length > kBufSize) ? kBufSize : compressed_length;
if (!mapped_zip.ReadData(read_buf.data(), getSize)) {
ALOGW("Zip: inflate read failed, getSize = %zu: %s", getSize, strerror(errno));
return kIoError;
}
compressed_length -= getSize;
zstream.next_in = &read_buf[0];
zstream.avail_in = getSize;
}
/* 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;
}
/* write when we're full or when we're done */
if (zstream.avail_out == 0 ||
(zerr == Z_STREAM_END && zstream.avail_out != kBufSize)) {
const size_t write_size = zstream.next_out - &write_buf[0];
if (!writer->Append(&write_buf[0], write_size)) {
// The file might have declared a bogus length.
return kInconsistentInformation;
}
zstream.next_out = &write_buf[0];
zstream.avail_out = kBufSize;
}
} while (zerr == Z_OK);
assert(zerr == Z_STREAM_END); /* other errors should've been caught */
// stream.adler holds the crc32 value for such streams.
*crc_out = zstream.adler;
if (zstream.total_out != uncompressed_length || compressed_length != 0) {
ALOGW("Zip: size mismatch on inflated file (%lu vs %" PRIu32 ")",
zstream.total_out, uncompressed_length);
return kInconsistentInformation;
}
return 0;
}
static int32_t CopyEntryToWriter(MappedZipFile& mapped_zip, const ZipEntry* entry, Writer* writer,
uint64_t *crc_out) {
static const uint32_t kBufSize = 32768;
std::vector<uint8_t> buf(kBufSize);
const uint32_t length = entry->uncompressed_length;
uint32_t count = 0;
uint64_t crc = 0;
while (count < length) {
uint32_t remaining = length - count;
// Safe conversion because kBufSize is narrow enough for a 32 bit signed
// value.
const size_t block_size = (remaining > kBufSize) ? kBufSize : remaining;
if (!mapped_zip.ReadData(buf.data(), block_size)) {
ALOGW("CopyFileToFile: copy read failed, block_size = %zu: %s", block_size, strerror(errno));
return kIoError;
}
if (!writer->Append(&buf[0], block_size)) {
return kIoError;
}
crc = crc32(crc, &buf[0], block_size);
count += block_size;
}
*crc_out = crc;
return 0;
}
int32_t ExtractToWriter(ZipArchiveHandle handle,
ZipEntry* entry, Writer* writer) {
ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle);
const uint16_t method = entry->method;
off64_t data_offset = entry->offset;
if (!archive->mapped_zip.SeekToOffset(data_offset)) {
ALOGW("Zip: lseek to data at %" PRId64 " failed", static_cast<int64_t>(data_offset));
return kIoError;
}
// this should default to kUnknownCompressionMethod.
int32_t return_value = -1;
uint64_t crc = 0;
if (method == kCompressStored) {
return_value = CopyEntryToWriter(archive->mapped_zip, entry, writer, &crc);
} else if (method == kCompressDeflated) {
return_value = InflateEntryToWriter(archive->mapped_zip, entry, writer, &crc);
}
if (!return_value && entry->has_data_descriptor) {
return_value = UpdateEntryFromDataDescriptor(archive->mapped_zip, entry);
if (return_value) {
return return_value;
}
}
// TODO: Fix this check by passing the right flags to inflate2 so that
// it calculates the CRC for us.
if (entry->crc32 != crc && false) {
ALOGW("Zip: crc mismatch: expected %" PRIu32 ", was %" PRIu64, entry->crc32, crc);
return kInconsistentInformation;
}
return return_value;
}
int32_t ExtractToMemory(ZipArchiveHandle handle, ZipEntry* entry,
uint8_t* begin, uint32_t size) {
std::unique_ptr<Writer> writer(new MemoryWriter(begin, size));
return ExtractToWriter(handle, entry, writer.get());
}
int32_t ExtractEntryToFile(ZipArchiveHandle handle,
ZipEntry* entry, int fd) {
std::unique_ptr<Writer> writer(FileWriter::Create(fd, entry));
if (writer.get() == nullptr) {
return kIoError;
}
return ExtractToWriter(handle, entry, writer.get());
}
const char* ErrorCodeString(int32_t error_code) {
if (error_code > kErrorMessageLowerBound && error_code < kErrorMessageUpperBound) {
return kErrorMessages[error_code * -1];
}
return kErrorMessages[0];
}
int GetFileDescriptor(const ZipArchiveHandle handle) {
return reinterpret_cast<ZipArchive*>(handle)->mapped_zip.GetFileDescriptor();
}
ZipString::ZipString(const char* entry_name)
: name(reinterpret_cast<const uint8_t*>(entry_name)) {
size_t len = strlen(entry_name);
CHECK_LE(len, static_cast<size_t>(UINT16_MAX));
name_length = static_cast<uint16_t>(len);
}
#if !defined(_WIN32)
class ProcessWriter : public Writer {
public:
ProcessWriter(ProcessZipEntryFunction func, void* cookie) : Writer(),
proc_function_(func),
cookie_(cookie) {
}
virtual bool Append(uint8_t* buf, size_t buf_size) override {
return proc_function_(buf, buf_size, cookie_);
}
private:
ProcessZipEntryFunction proc_function_;
void* cookie_;
};
int32_t ProcessZipEntryContents(ZipArchiveHandle handle, ZipEntry* entry,
ProcessZipEntryFunction func, void* cookie) {
ProcessWriter writer(func, cookie);
return ExtractToWriter(handle, entry, &writer);
}
#endif //!defined(_WIN32)
int MappedZipFile::GetFileDescriptor() const {
if (!has_fd_) {
ALOGW("Zip: MappedZipFile doesn't have a file descriptor.");
return -1;
}
return fd_;
}
void* MappedZipFile::GetBasePtr() const {
if (has_fd_) {
ALOGW("Zip: MappedZipFile doesn't have a base pointer.");
return nullptr;
}
return base_ptr_;
}
off64_t MappedZipFile::GetFileLength() const {
if (has_fd_) {
off64_t result = lseek64(fd_, 0, SEEK_END);
if (result == -1) {
ALOGE("Zip: lseek on fd %d failed: %s", fd_, strerror(errno));
}
return result;
} else {
if (base_ptr_ == nullptr) {
ALOGE("Zip: invalid file map\n");
return -1;
}
return static_cast<off64_t>(data_length_);
}
}
bool MappedZipFile::SeekToOffset(off64_t offset) {
if (has_fd_) {
if (lseek64(fd_, offset, SEEK_SET) != offset) {
ALOGE("Zip: lseek to %" PRId64 " failed: %s\n", offset, strerror(errno));
return false;
}
return true;
} else {
if (offset < 0 || offset > static_cast<off64_t>(data_length_)) {
ALOGE("Zip: invalid offset: %" PRId64 ", data length: %" PRId64 "\n" , offset,
data_length_);
return false;
}
read_pos_ = offset;
return true;
}
}
bool MappedZipFile::ReadData(uint8_t* buffer, size_t read_amount) {
if (has_fd_) {
if(!android::base::ReadFully(fd_, buffer, read_amount)) {
ALOGE("Zip: read from %d failed\n", fd_);
return false;
}
} else {
memcpy(buffer, static_cast<uint8_t*>(base_ptr_) + read_pos_, read_amount);
read_pos_ += read_amount;
}
return true;
}
// Attempts to read |len| bytes into |buf| at offset |off|.
bool MappedZipFile::ReadAtOffset(uint8_t* buf, size_t len, off64_t off) {
#if !defined(_WIN32)
if (has_fd_) {
if (static_cast<size_t>(TEMP_FAILURE_RETRY(pread64(fd_, buf, len, off))) != len) {
ALOGE("Zip: failed to read at offset %" PRId64 "\n", off);
return false;
}
return true;
}
#endif
if (!SeekToOffset(off)) {
return false;
}
return ReadData(buf, len);
}
void CentralDirectory::Initialize(void* map_base_ptr, off64_t cd_start_offset, size_t cd_size) {
base_ptr_ = static_cast<uint8_t*>(map_base_ptr) + cd_start_offset;
length_ = cd_size;
}
bool ZipArchive::InitializeCentralDirectory(const char* debug_file_name, off64_t cd_start_offset,
size_t cd_size) {
if (mapped_zip.HasFd()) {
if (!directory_map->create(debug_file_name, mapped_zip.GetFileDescriptor(),
cd_start_offset, cd_size, true /* read only */)) {
return false;
}
CHECK_EQ(directory_map->getDataLength(), cd_size);
central_directory.Initialize(directory_map->getDataPtr(), 0/*offset*/, cd_size);
} else {
if (mapped_zip.GetBasePtr() == nullptr) {
ALOGE("Zip: Failed to map central directory, bad mapped_zip base pointer\n");
return false;
}
if (static_cast<off64_t>(cd_start_offset) + static_cast<off64_t>(cd_size) >
mapped_zip.GetFileLength()) {
ALOGE("Zip: Failed to map central directory, offset exceeds mapped memory region ("
"start_offset %" PRId64 ", cd_size %zu, mapped_region_size %" PRId64 ")",
static_cast<int64_t>(cd_start_offset), cd_size, mapped_zip.GetFileLength());
return false;
}
central_directory.Initialize(mapped_zip.GetBasePtr(), cd_start_offset, cd_size);
}
return true;
}
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