| /* |
| * Copyright (C) 2007 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. |
| */ |
| |
| // |
| // Misc zip/gzip utility functions. |
| // |
| |
| #define LOG_TAG "ziputil" |
| |
| #include "utils/ZipUtils.h" |
| #include "utils/ZipFileRO.h" |
| #include "utils/Log.h" |
| |
| #include <stdlib.h> |
| #include <string.h> |
| #include <assert.h> |
| |
| #include <zlib.h> |
| |
| using namespace android; |
| |
| /* |
| * Utility function that expands zip/gzip "deflate" compressed data |
| * into a buffer. |
| * |
| * "fd" is an open file positioned at the start of the "deflate" data |
| * "buf" must hold at least "uncompressedLen" bytes. |
| */ |
| /*static*/ bool ZipUtils::inflateToBuffer(int fd, void* buf, |
| long uncompressedLen, long compressedLen) |
| { |
| bool result = false; |
| const unsigned long kReadBufSize = 32768; |
| unsigned char* readBuf = NULL; |
| z_stream zstream; |
| int zerr; |
| unsigned long compRemaining; |
| |
| assert(uncompressedLen >= 0); |
| assert(compressedLen >= 0); |
| |
| readBuf = new unsigned char[kReadBufSize]; |
| if (readBuf == NULL) |
| goto bail; |
| compRemaining = compressedLen; |
| |
| /* |
| * Initialize the zlib stream. |
| */ |
| 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 = (Bytef*) buf; |
| zstream.avail_out = uncompressedLen; |
| 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 = inflateInit2(&zstream, -MAX_WBITS); |
| if (zerr != Z_OK) { |
| if (zerr == Z_VERSION_ERROR) { |
| LOGE("Installed zlib is not compatible with linked version (%s)\n", |
| ZLIB_VERSION); |
| } else { |
| LOGE("Call to inflateInit2 failed (zerr=%d)\n", zerr); |
| } |
| goto bail; |
| } |
| |
| /* |
| * Loop while we have data. |
| */ |
| do { |
| unsigned long getSize; |
| |
| /* read as much as we can */ |
| if (zstream.avail_in == 0) { |
| getSize = (compRemaining > kReadBufSize) ? |
| kReadBufSize : compRemaining; |
| LOGV("+++ reading %ld bytes (%ld left)\n", |
| getSize, compRemaining); |
| |
| int cc = read(fd, readBuf, getSize); |
| if (cc != (int) getSize) { |
| LOGD("inflate read failed (%d vs %ld)\n", |
| cc, getSize); |
| goto z_bail; |
| } |
| |
| compRemaining -= getSize; |
| |
| zstream.next_in = readBuf; |
| zstream.avail_in = getSize; |
| } |
| |
| /* uncompress the data */ |
| zerr = inflate(&zstream, Z_NO_FLUSH); |
| if (zerr != Z_OK && zerr != Z_STREAM_END) { |
| LOGD("zlib inflate call failed (zerr=%d)\n", zerr); |
| goto z_bail; |
| } |
| |
| /* output buffer holds all, so no need to write the output */ |
| } while (zerr == Z_OK); |
| |
| assert(zerr == Z_STREAM_END); /* other errors should've been caught */ |
| |
| if ((long) zstream.total_out != uncompressedLen) { |
| LOGW("Size mismatch on inflated file (%ld vs %ld)\n", |
| zstream.total_out, uncompressedLen); |
| goto z_bail; |
| } |
| |
| // success! |
| result = true; |
| |
| z_bail: |
| inflateEnd(&zstream); /* free up any allocated structures */ |
| |
| bail: |
| delete[] readBuf; |
| return result; |
| } |
| |
| /* |
| * Utility function that expands zip/gzip "deflate" compressed data |
| * into a buffer. |
| * |
| * (This is a clone of the previous function, but it takes a FILE* instead |
| * of an fd. We could pass fileno(fd) to the above, but we can run into |
| * trouble when "fp" has a different notion of what fd's file position is.) |
| * |
| * "fp" is an open file positioned at the start of the "deflate" data |
| * "buf" must hold at least "uncompressedLen" bytes. |
| */ |
| /*static*/ bool ZipUtils::inflateToBuffer(FILE* fp, void* buf, |
| long uncompressedLen, long compressedLen) |
| { |
| bool result = false; |
| const unsigned long kReadBufSize = 32768; |
| unsigned char* readBuf = NULL; |
| z_stream zstream; |
| int zerr; |
| unsigned long compRemaining; |
| |
| assert(uncompressedLen >= 0); |
| assert(compressedLen >= 0); |
| |
| readBuf = new unsigned char[kReadBufSize]; |
| if (readBuf == NULL) |
| goto bail; |
| compRemaining = compressedLen; |
| |
| /* |
| * Initialize the zlib stream. |
| */ |
| 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 = (Bytef*) buf; |
| zstream.avail_out = uncompressedLen; |
| 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 = inflateInit2(&zstream, -MAX_WBITS); |
| if (zerr != Z_OK) { |
| if (zerr == Z_VERSION_ERROR) { |
| LOGE("Installed zlib is not compatible with linked version (%s)\n", |
| ZLIB_VERSION); |
| } else { |
| LOGE("Call to inflateInit2 failed (zerr=%d)\n", zerr); |
| } |
| goto bail; |
| } |
| |
| /* |
| * Loop while we have data. |
| */ |
| do { |
| unsigned long getSize; |
| |
| /* read as much as we can */ |
| if (zstream.avail_in == 0) { |
| getSize = (compRemaining > kReadBufSize) ? |
| kReadBufSize : compRemaining; |
| LOGV("+++ reading %ld bytes (%ld left)\n", |
| getSize, compRemaining); |
| |
| int cc = fread(readBuf, getSize, 1, fp); |
| if (cc != (int) getSize) { |
| LOGD("inflate read failed (%d vs %ld)\n", |
| cc, getSize); |
| goto z_bail; |
| } |
| |
| compRemaining -= getSize; |
| |
| zstream.next_in = readBuf; |
| zstream.avail_in = getSize; |
| } |
| |
| /* uncompress the data */ |
| zerr = inflate(&zstream, Z_NO_FLUSH); |
| if (zerr != Z_OK && zerr != Z_STREAM_END) { |
| LOGD("zlib inflate call failed (zerr=%d)\n", zerr); |
| goto z_bail; |
| } |
| |
| /* output buffer holds all, so no need to write the output */ |
| } while (zerr == Z_OK); |
| |
| assert(zerr == Z_STREAM_END); /* other errors should've been caught */ |
| |
| if ((long) zstream.total_out != uncompressedLen) { |
| LOGW("Size mismatch on inflated file (%ld vs %ld)\n", |
| zstream.total_out, uncompressedLen); |
| goto z_bail; |
| } |
| |
| // success! |
| result = true; |
| |
| z_bail: |
| inflateEnd(&zstream); /* free up any allocated structures */ |
| |
| bail: |
| delete[] readBuf; |
| return result; |
| } |
| |
| /* |
| * Look at the contents of a gzip archive. We want to know where the |
| * data starts, and how long it will be after it is uncompressed. |
| * |
| * We expect to find the CRC and length as the last 8 bytes on the file. |
| * This is a pretty reasonable thing to expect for locally-compressed |
| * files, but there's a small chance that some extra padding got thrown |
| * on (the man page talks about compressed data written to tape). We |
| * don't currently deal with that here. If "gzip -l" whines, we're going |
| * to fail too. |
| * |
| * On exit, "fp" is pointing at the start of the compressed data. |
| */ |
| /*static*/ bool ZipUtils::examineGzip(FILE* fp, int* pCompressionMethod, |
| long* pUncompressedLen, long* pCompressedLen, unsigned long* pCRC32) |
| { |
| enum { // flags |
| FTEXT = 0x01, |
| FHCRC = 0x02, |
| FEXTRA = 0x04, |
| FNAME = 0x08, |
| FCOMMENT = 0x10, |
| }; |
| int ic; |
| int method, flags; |
| int i; |
| |
| ic = getc(fp); |
| if (ic != 0x1f || getc(fp) != 0x8b) |
| return false; // not gzip |
| method = getc(fp); |
| flags = getc(fp); |
| |
| /* quick sanity checks */ |
| if (method == EOF || flags == EOF) |
| return false; |
| if (method != ZipFileRO::kCompressDeflated) |
| return false; |
| |
| /* skip over 4 bytes of mod time, 1 byte XFL, 1 byte OS */ |
| for (i = 0; i < 6; i++) |
| (void) getc(fp); |
| /* consume "extra" field, if present */ |
| if ((flags & FEXTRA) != 0) { |
| int len; |
| |
| len = getc(fp); |
| len |= getc(fp) << 8; |
| while (len-- && getc(fp) != EOF) |
| ; |
| } |
| /* consume filename, if present */ |
| if ((flags & FNAME) != 0) { |
| do { |
| ic = getc(fp); |
| } while (ic != 0 && ic != EOF); |
| } |
| /* consume comment, if present */ |
| if ((flags & FCOMMENT) != 0) { |
| do { |
| ic = getc(fp); |
| } while (ic != 0 && ic != EOF); |
| } |
| /* consume 16-bit header CRC, if present */ |
| if ((flags & FHCRC) != 0) { |
| (void) getc(fp); |
| (void) getc(fp); |
| } |
| |
| if (feof(fp) || ferror(fp)) |
| return false; |
| |
| /* seek to the end; CRC and length are in the last 8 bytes */ |
| long curPosn = ftell(fp); |
| unsigned char buf[8]; |
| fseek(fp, -8, SEEK_END); |
| *pCompressedLen = ftell(fp) - curPosn; |
| |
| if (fread(buf, 1, 8, fp) != 8) |
| return false; |
| /* seek back to start of compressed data */ |
| fseek(fp, curPosn, SEEK_SET); |
| |
| *pCompressionMethod = method; |
| *pCRC32 = ZipFileRO::get4LE(&buf[0]); |
| *pUncompressedLen = ZipFileRO::get4LE(&buf[4]); |
| |
| return true; |
| } |
| |