| /* | 
 |  * 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; | 
 |             ALOGV("+++ reading %ld bytes (%ld left)\n", | 
 |                 getSize, compRemaining); | 
 |  | 
 |             int cc = read(fd, readBuf, getSize); | 
 |             if (cc != (int) getSize) { | 
 |                 ALOGD("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) { | 
 |             ALOGD("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) { | 
 |         ALOGW("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; | 
 |             ALOGV("+++ reading %ld bytes (%ld left)\n", | 
 |                 getSize, compRemaining); | 
 |  | 
 |             int cc = fread(readBuf, 1, getSize, fp); | 
 |             if (cc != (int) getSize) { | 
 |                 ALOGD("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) { | 
 |             ALOGD("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) { | 
 |         ALOGW("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; | 
 | } |