57b665990a
simple errx() function. Improve behavior when bzlib/zlib are missing by detecting and issuing an error message on attempts to read gzip/bzip2 compressed archives.
393 lines
10 KiB
C
393 lines
10 KiB
C
/*-
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* Copyright (c) 2003-2004 Tim Kientzle
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* 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
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* are met:
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* 1. 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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* in this position and unchanged.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "archive_platform.h"
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__FBSDID("$FreeBSD$");
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#include <errno.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#ifdef HAVE_BZLIB_H
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#include <bzlib.h>
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#endif
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#include "archive.h"
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#include "archive_private.h"
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#if HAVE_BZLIB_H
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struct private_data {
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bz_stream stream;
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unsigned char *uncompressed_buffer;
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size_t uncompressed_buffer_size;
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char *read_next;
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int64_t total_out;
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};
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static int finish(struct archive *);
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static ssize_t read_ahead(struct archive *, const void **, size_t);
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static ssize_t read_consume(struct archive *, size_t);
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static int drive_decompressor(struct archive *a, struct private_data *);
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#endif
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/* These two functions are defined even if we lack bzlib. See below. */
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static int bid(const void *, size_t);
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static int init(struct archive *, const void *, size_t);
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int
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archive_read_support_compression_bzip2(struct archive *a)
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{
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return (__archive_read_register_compression(a, bid, init));
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}
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/*
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* Test whether we can handle this data.
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*
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* This logic returns zero if any part of the signature fails. It
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* also tries to Do The Right Thing if a very short buffer prevents us
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* from verifying as much as we would like.
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*/
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static int
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bid(const void *buff, size_t len)
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{
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const unsigned char *buffer;
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int bits_checked;
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if (len < 1)
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return (0);
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buffer = buff;
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bits_checked = 0;
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if (buffer[0] != 'B') /* Verify first ID byte. */
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return (0);
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bits_checked += 8;
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if (len < 2)
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return (bits_checked);
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if (buffer[1] != 'Z') /* Verify second ID byte. */
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return (0);
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bits_checked += 8;
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if (len < 3)
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return (bits_checked);
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if (buffer[2] != 'h') /* Verify third ID byte. */
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return (0);
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bits_checked += 8;
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if (len < 4)
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return (bits_checked);
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if (buffer[3] < '1' || buffer[3] > '9')
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return (0);
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bits_checked += 5;
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/*
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* Research Question: Can we do any more to verify that this
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* really is BZip2 format?? For 99.9% of the time, the above
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* test is sufficient, but it would be nice to do a more
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* thorough check. It's especially troubling that the BZip2
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* signature begins with all ASCII characters; a tar archive
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* whose first filename begins with 'BZh3' would potentially
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* fool this logic. (It may also be possible to gaurd against
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* such anomalies in archive_read_support_compression_none.)
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*/
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return (bits_checked);
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}
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#ifndef HAVE_BZLIB_H
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/*
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* If we don't have bzlib on this system, we can't actually do the
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* decompression. We can, however, still detect bzip2-compressed
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* archives and emit a useful message.
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*/
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static int
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init(struct archive *a, const void *buff, size_t n)
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{
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(void)a; /* UNUSED */
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(void)buff; /* UNUSED */
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(void)n; /* UNUSED */
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archive_set_error(a, -1,
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"This version of libarchive was compiled without bzip2 support");
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return (ARCHIVE_FATAL);
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}
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#else
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/*
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* Setup the callbacks.
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*/
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static int
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init(struct archive *a, const void *buff, size_t n)
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{
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struct private_data *state;
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int ret;
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a->compression_code = ARCHIVE_COMPRESSION_BZIP2;
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a->compression_name = "bzip2";
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state = malloc(sizeof(*state));
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if (state == NULL) {
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archive_set_error(a, ENOMEM,
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"Can't allocate data for %s decompression",
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a->compression_name);
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return (ARCHIVE_FATAL);
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}
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memset(state, 0, sizeof(*state));
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state->uncompressed_buffer_size = 64 * 1024;
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state->uncompressed_buffer = malloc(state->uncompressed_buffer_size);
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state->stream.next_out = state->uncompressed_buffer;
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state->read_next = state->uncompressed_buffer;
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state->stream.avail_out = state->uncompressed_buffer_size;
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if (state->uncompressed_buffer == NULL) {
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archive_set_error(a, ENOMEM,
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"Can't allocate %s decompression buffers",
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a->compression_name);
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free(state);
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return (ARCHIVE_FATAL);
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}
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/*
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* A bug in bzlib.h: stream.next_in should be marked 'const'
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* but isn't (the library never alters data through the
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* next_in pointer, only reads it). The result: this ugly
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* cast to remove 'const'.
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*/
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state->stream.next_in = (void *)(uintptr_t)(const void *)buff;
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state->stream.avail_in = n;
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a->compression_read_ahead = read_ahead;
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a->compression_read_consume = read_consume;
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a->compression_finish = finish;
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/* Initialize compression library. */
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ret = BZ2_bzDecompressInit(&(state->stream),
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0 /* library verbosity */,
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0 /* don't use slow low-mem algorithm */);
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/* If init fails, try using low-memory algorithm instead. */
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if (ret == BZ_MEM_ERROR) {
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ret = BZ2_bzDecompressInit(&(state->stream),
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0 /* library verbosity */,
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1 /* do use slow low-mem algorithm */);
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}
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if (ret == BZ_OK) {
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a->compression_data = state;
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return (ARCHIVE_OK);
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}
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/* Library setup failed: Clean up. */
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archive_set_error(a, ARCHIVE_ERRNO_MISC,
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"Internal error initializing %s library", a->compression_name);
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free(state->uncompressed_buffer);
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free(state);
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/* Override the error message if we know what really went wrong. */
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switch (ret) {
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case BZ_PARAM_ERROR:
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archive_set_error(a, ARCHIVE_ERRNO_MISC,
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"Internal error initializing compression library: "
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"invalid setup parameter");
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break;
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case BZ_MEM_ERROR:
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archive_set_error(a, ARCHIVE_ERRNO_MISC,
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"Internal error initializing compression library: "
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"out of memory");
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break;
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case BZ_CONFIG_ERROR:
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archive_set_error(a, ARCHIVE_ERRNO_MISC,
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"Internal error initializing compression library: "
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"mis-compiled library");
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break;
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}
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return (ARCHIVE_FATAL);
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}
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/*
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* Return a block of data from the decompression buffer. Decompress more
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* as necessary.
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*/
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static ssize_t
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read_ahead(struct archive *a, const void **p, size_t min)
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{
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struct private_data *state;
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int read_avail, was_avail, ret;
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state = a->compression_data;
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was_avail = -1;
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if (!a->client_reader) {
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archive_set_error(a, ARCHIVE_ERRNO_PROGRAMMER,
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"No read callback is registered? "
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"This is probably an internal programming error.");
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return (ARCHIVE_FATAL);
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}
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read_avail = state->stream.next_out - state->read_next;
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if (read_avail + state->stream.avail_out < min) {
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memmove(state->uncompressed_buffer, state->read_next,
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read_avail);
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state->read_next = state->uncompressed_buffer;
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state->stream.next_out = state->read_next + read_avail;
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state->stream.avail_out
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= state->uncompressed_buffer_size - read_avail;
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}
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while (was_avail < read_avail && /* Made some progress. */
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read_avail < (int)min && /* Haven't satisfied min. */
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read_avail < (int)state->uncompressed_buffer_size) { /* !full */
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if ((ret = drive_decompressor(a, state)) != ARCHIVE_OK)
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return (ret);
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was_avail = read_avail;
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read_avail = state->stream.next_out - state->read_next;
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}
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*p = state->read_next;
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return (read_avail);
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}
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/*
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* Mark a previously-returned block of data as read.
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*/
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static ssize_t
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read_consume(struct archive *a, size_t n)
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{
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struct private_data *state;
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state = a->compression_data;
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a->file_position += n;
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state->read_next += n;
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if (state->read_next > state->stream.next_out)
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__archive_errx(1, "Request to consume too many "
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"bytes from bzip2 decompressor");
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return (n);
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}
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/*
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* Clean up the decompressor.
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*/
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static int
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finish(struct archive *a)
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{
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struct private_data *state;
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int ret;
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state = a->compression_data;
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ret = ARCHIVE_OK;
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switch (BZ2_bzDecompressEnd(&(state->stream))) {
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case BZ_OK:
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break;
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default:
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archive_set_error(a, ARCHIVE_ERRNO_MISC,
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"Failed to clean up %s compressor", a->compression_name);
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ret = ARCHIVE_FATAL;
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}
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free(state->uncompressed_buffer);
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free(state);
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a->compression_data = NULL;
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if (a->client_closer != NULL)
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(a->client_closer)(a, a->client_data);
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return (ret);
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}
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/*
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* Utility function to pull data through decompressor, reading input
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* blocks as necessary.
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*/
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static int
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drive_decompressor(struct archive *a, struct private_data *state)
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{
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ssize_t ret;
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int decompressed, total_decompressed;
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char *output;
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total_decompressed = 0;
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for (;;) {
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if (state->stream.avail_in == 0) {
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ret = (a->client_reader)(a, a->client_data,
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(const void **)&state->stream.next_in);
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if (ret < 0) {
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/*
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* TODO: Find a better way to handle
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* this read failure.
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*/
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goto fatal;
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}
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if (ret == 0 && total_decompressed == 0) {
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archive_set_error(a, EIO,
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"Premature end of %s compressed data",
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a->compression_name);
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return (ARCHIVE_FATAL);
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}
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a->raw_position += ret;
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state->stream.avail_in = ret;
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}
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{
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output = state->stream.next_out;
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/* Decompress some data. */
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ret = BZ2_bzDecompress(&(state->stream));
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decompressed = state->stream.next_out - output;
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/* Accumulate the total bytes of output. */
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state->total_out += decompressed;
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total_decompressed += decompressed;
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switch (ret) {
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case BZ_OK: /* Decompressor made some progress. */
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if (decompressed > 0)
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return (ARCHIVE_OK);
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break;
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case BZ_STREAM_END: /* Found end of stream. */
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return (ARCHIVE_OK);
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default:
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/* Any other return value is an error. */
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goto fatal;
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}
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}
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}
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return (ARCHIVE_OK);
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/* Return a fatal error. */
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fatal:
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archive_set_error(a, ARCHIVE_ERRNO_MISC, "%s decompression failed",
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a->compression_name);
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return (ARCHIVE_FATAL);
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}
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#endif /* HAVE_BZLIB_H */
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