summaryrefslogtreecommitdiffstats
path: root/libs/androidfw/ZipUtils.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'libs/androidfw/ZipUtils.cpp')
-rw-r--r--libs/androidfw/ZipUtils.cpp343
1 files changed, 343 insertions, 0 deletions
diff --git a/libs/androidfw/ZipUtils.cpp b/libs/androidfw/ZipUtils.cpp
new file mode 100644
index 0000000..db3479d
--- /dev/null
+++ b/libs/androidfw/ZipUtils.cpp
@@ -0,0 +1,343 @@
+/*
+ * 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 <androidfw/ZipUtils.h>
+#include <androidfw/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) {
+ ALOGE("Installed zlib is not compatible with linked version (%s)\n",
+ ZLIB_VERSION);
+ } else {
+ ALOGE("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) {
+ ALOGE("Installed zlib is not compatible with linked version (%s)\n",
+ ZLIB_VERSION);
+ } else {
+ ALOGE("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;
+}
generated by cgit v1.1 at 2024-07-12 07:58:58 +0000