154 lines
4.3 KiB
C
154 lines
4.3 KiB
C
/* Copyright (c) 2015, The Linux Foundation. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials provided
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* with the distribution.
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* * Neither the name of The Linux Foundation, Inc. nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
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* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#define NO_GZIP
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#include "zutil.h"
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#ifdef DYNAMIC_CRC_TABLE
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#include "crc32.h"
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#endif
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#include "zconf.h"
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#include "zlib.h"
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#include "inftrees.h"
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#include "inflate.h"
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#include "inffast.h"
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#include "decompress.h"
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#include <sys/types.h> /* for size_t */
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#include <string.h>
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#include <debug.h>
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#include <malloc.h>
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#define GZIP_HEADER_LEN 10
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#define GZIP_FILENAME_LIMIT 256
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static void zlib_free(voidpf qpaque, void *addr)
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{
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return free(addr);
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}
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static void *zlib_alloc(voidpf qpaque, uInt items, size_t size)
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{
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return malloc(items * size);
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}
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/* decompress gzip file "in_buf", return 0 if decompressed successful,
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* return -1 if decompressed failed.
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* in_buf - input gzip file
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* in_len - input the length file
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* out_buf - output the decompressed data
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* out_buf_len - the available length of out_buf
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* pos - position of the end of gzip file
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* out_len - the length of decompressed data
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*/
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int decompress(unsigned char *in_buf, unsigned int in_len,
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unsigned char *out_buf,
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unsigned int out_buf_len,
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unsigned int *pos,
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unsigned int *out_len) {
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struct z_stream_s *stream;
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int rc = -1;
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int i;
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if (in_len < GZIP_HEADER_LEN) {
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dprintf(INFO, "the input data is not a gzip package.\n");
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return rc;
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}
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if (out_buf_len < in_len) {
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dprintf(INFO, "the avaiable length of out_buf is not enough.\n");
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return rc;
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}
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stream = malloc(sizeof(*stream));
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if (stream == NULL) {
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dprintf(INFO, "allocating z_stream failed.\n");
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return rc;
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}
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stream->zalloc = zlib_alloc;
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stream->zfree = zlib_free;
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stream->next_out = out_buf;
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stream->avail_out = out_buf_len;
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/* skip over gzip header */
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stream->next_in = in_buf + GZIP_HEADER_LEN;
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stream->avail_in = out_buf_len - GZIP_HEADER_LEN;
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/* skip over asciz filename */
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if (in_buf[3] & 0x8) {
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for (i = 0; i < GZIP_FILENAME_LIMIT && *stream->next_in++; i++) {
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if (stream->avail_in == 0) {
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dprintf(INFO, "header error\n");
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goto gunzip_end;
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}
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--stream->avail_in;
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}
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}
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rc = inflateInit2(stream, -MAX_WBITS);
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if (rc != Z_OK) {
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dprintf(INFO, "inflateInit2 failed!\n");
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goto gunzip_end;
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}
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rc = inflate(stream, 0);
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/* Z_STREAM_END is "we unpacked it all" */
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if (rc == Z_STREAM_END) {
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rc = 0;
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} else if (rc != Z_OK) {
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dprintf(INFO, "uncompression error \n");
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rc = -1;
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}
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inflateEnd(stream);
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if (pos)
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/* alculation the length of the compressed package */
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*pos = stream->next_in - in_buf + 8;
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if (out_len)
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*out_len = stream->total_out;
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gunzip_end:
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free(stream);
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return rc; /* returns 0 if decompressed successful */
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}
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/* check if the input "buf" file was a gzip package.
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* Return true if the input "buf" is a gzip package.
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*/
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int is_gzip_package(unsigned char *buf, unsigned int len)
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{
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if (len < 10 || !buf || buf[0] != 0x1f ||
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buf[1] != 0x8b || buf[2] != 0x08)
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{
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return false;
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}
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return true;
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}
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