NetBSD-5.0.2/dist/libarchive/libarchive/archive_read_support_compression_bzip2.c
/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "archive_platform.h"
__FBSDID("$FreeBSD: src/lib/libarchive/archive_read_support_compression_bzip2.c,v 1.17 2008/02/19 05:44:59 kientzle Exp $");
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_BZLIB_H
#include <bzlib.h>
#endif
#include "archive.h"
#include "archive_private.h"
#include "archive_read_private.h"
#if HAVE_BZLIB_H
struct private_data {
bz_stream stream;
char *uncompressed_buffer;
size_t uncompressed_buffer_size;
char *read_next;
int64_t total_out;
char eof; /* True = found end of compressed data. */
};
static int finish(struct archive_read *);
static ssize_t read_ahead(struct archive_read *, const void **, size_t);
static ssize_t read_consume(struct archive_read *, size_t);
static int drive_decompressor(struct archive_read *a, struct private_data *);
#endif
/* These two functions are defined even if we lack the library. See below. */
static int bid(const void *, size_t);
static int init(struct archive_read *, const void *, size_t);
int
archive_read_support_compression_bzip2(struct archive *_a)
{
struct archive_read *a = (struct archive_read *)_a;
if (__archive_read_register_compression(a, bid, init) != NULL)
return (ARCHIVE_OK);
return (ARCHIVE_FATAL);
}
/*
* Test whether we can handle this data.
*
* This logic returns zero if any part of the signature fails. It
* also tries to Do The Right Thing if a very short buffer prevents us
* from verifying as much as we would like.
*/
static int
bid(const void *buff, size_t len)
{
const unsigned char *buffer;
int bits_checked;
if (len < 1)
return (0);
buffer = (const unsigned char *)buff;
bits_checked = 0;
if (buffer[0] != 'B') /* Verify first ID byte. */
return (0);
bits_checked += 8;
if (len < 2)
return (bits_checked);
if (buffer[1] != 'Z') /* Verify second ID byte. */
return (0);
bits_checked += 8;
if (len < 3)
return (bits_checked);
if (buffer[2] != 'h') /* Verify third ID byte. */
return (0);
bits_checked += 8;
if (len < 4)
return (bits_checked);
if (buffer[3] < '1' || buffer[3] > '9')
return (0);
bits_checked += 5;
if (len < 5)
return (bits_checked);
/* After BZh[1-9], there must be either a data block
* which begins with 0x314159265359 or an end-of-data
* marker of 0x177245385090. */
if (buffer[4] == 0x31) {
/* Verify the data block signature. */
size_t s = len;
if (s > 10) s = 10;
if (memcmp(buffer + 4, "\x31\x41\x59\x26\x53\x59", s - 4) != 0)
return (0);
bits_checked += 8 * (s - 4);
} else if (buffer[4] == 0x17) {
/* Verify the end-of-data marker. */
size_t s = len;
if (s > 10) s = 10;
if (memcmp(buffer + 4, "\x17\x72\x45\x38\x50\x90", s - 4) != 0)
return (0);
bits_checked += 8 * (s - 4);
} else
return (0);
return (bits_checked);
}
#ifndef HAVE_BZLIB_H
/*
* If we don't have the library on this system, we can't actually do the
* decompression. We can, however, still detect compressed archives
* and emit a useful message.
*/
static int
init(struct archive_read *a, const void *buff, size_t n)
{
(void)a; /* UNUSED */
(void)buff; /* UNUSED */
(void)n; /* UNUSED */
archive_set_error(&a->archive, -1,
"This version of libarchive was compiled without bzip2 support");
return (ARCHIVE_FATAL);
}
#else
/*
* Setup the callbacks.
*/
static int
init(struct archive_read *a, const void *buff, size_t n)
{
struct private_data *state;
int ret;
a->archive.compression_code = ARCHIVE_COMPRESSION_BZIP2;
a->archive.compression_name = "bzip2";
state = (struct private_data *)malloc(sizeof(*state));
if (state == NULL) {
archive_set_error(&a->archive, ENOMEM,
"Can't allocate data for %s decompression",
a->archive.compression_name);
return (ARCHIVE_FATAL);
}
memset(state, 0, sizeof(*state));
state->uncompressed_buffer_size = 64 * 1024;
state->uncompressed_buffer = (char *)malloc(state->uncompressed_buffer_size);
state->stream.next_out = state->uncompressed_buffer;
state->read_next = state->uncompressed_buffer;
state->stream.avail_out = state->uncompressed_buffer_size;
if (state->uncompressed_buffer == NULL) {
archive_set_error(&a->archive, ENOMEM,
"Can't allocate %s decompression buffers",
a->archive.compression_name);
free(state);
return (ARCHIVE_FATAL);
}
/*
* A bug in bzlib.h: stream.next_in should be marked 'const'
* but isn't (the library never alters data through the
* next_in pointer, only reads it). The result: this ugly
* cast to remove 'const'.
*/
state->stream.next_in = (char *)(uintptr_t)(const void *)buff;
state->stream.avail_in = n;
a->decompressor->read_ahead = read_ahead;
a->decompressor->consume = read_consume;
a->decompressor->skip = NULL; /* not supported */
a->decompressor->finish = finish;
/* Initialize compression library. */
ret = BZ2_bzDecompressInit(&(state->stream),
0 /* library verbosity */,
0 /* don't use slow low-mem algorithm */);
/* If init fails, try using low-memory algorithm instead. */
if (ret == BZ_MEM_ERROR) {
ret = BZ2_bzDecompressInit(&(state->stream),
0 /* library verbosity */,
1 /* do use slow low-mem algorithm */);
}
if (ret == BZ_OK) {
a->decompressor->data = state;
return (ARCHIVE_OK);
}
/* Library setup failed: Clean up. */
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"Internal error initializing %s library",
a->archive.compression_name);
free(state->uncompressed_buffer);
free(state);
/* Override the error message if we know what really went wrong. */
switch (ret) {
case BZ_PARAM_ERROR:
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"Internal error initializing compression library: "
"invalid setup parameter");
break;
case BZ_MEM_ERROR:
archive_set_error(&a->archive, ENOMEM,
"Internal error initializing compression library: "
"out of memory");
break;
case BZ_CONFIG_ERROR:
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"Internal error initializing compression library: "
"mis-compiled library");
break;
}
return (ARCHIVE_FATAL);
}
/*
* Return a block of data from the decompression buffer. Decompress more
* as necessary.
*/
static ssize_t
read_ahead(struct archive_read *a, const void **p, size_t min)
{
struct private_data *state;
size_t read_avail, was_avail;
int ret;
state = (struct private_data *)a->decompressor->data;
if (!a->client_reader) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"No read callback is registered? "
"This is probably an internal programming error.");
return (ARCHIVE_FATAL);
}
read_avail = state->stream.next_out - state->read_next;
if (read_avail + state->stream.avail_out < min) {
memmove(state->uncompressed_buffer, state->read_next,
read_avail);
state->read_next = state->uncompressed_buffer;
state->stream.next_out = state->read_next + read_avail;
state->stream.avail_out
= state->uncompressed_buffer_size - read_avail;
}
while (read_avail < min && /* Haven't satisfied min. */
read_avail < state->uncompressed_buffer_size) { /* !full */
was_avail = read_avail;
if ((ret = drive_decompressor(a, state)) < ARCHIVE_OK)
return (ret);
if (ret == ARCHIVE_EOF)
break; /* Break on EOF even if we haven't met min. */
read_avail = state->stream.next_out - state->read_next;
if (was_avail == read_avail) /* No progress? */
break;
}
*p = state->read_next;
return (read_avail);
}
/*
* Mark a previously-returned block of data as read.
*/
static ssize_t
read_consume(struct archive_read *a, size_t n)
{
struct private_data *state;
state = (struct private_data *)a->decompressor->data;
a->archive.file_position += n;
state->read_next += n;
if (state->read_next > state->stream.next_out)
__archive_errx(1, "Request to consume too many "
"bytes from bzip2 decompressor");
return (n);
}
/*
* Clean up the decompressor.
*/
static int
finish(struct archive_read *a)
{
struct private_data *state;
int ret;
state = (struct private_data *)a->decompressor->data;
ret = ARCHIVE_OK;
switch (BZ2_bzDecompressEnd(&(state->stream))) {
case BZ_OK:
break;
default:
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"Failed to clean up %s compressor",
a->archive.compression_name);
ret = ARCHIVE_FATAL;
}
free(state->uncompressed_buffer);
free(state);
a->decompressor->data = NULL;
return (ret);
}
/*
* Utility function to pull data through decompressor, reading input
* blocks as necessary.
*/
static int
drive_decompressor(struct archive_read *a, struct private_data *state)
{
ssize_t ret;
int decompressed, total_decompressed;
char *output;
const void *read_buf;
if (state->eof)
return (ARCHIVE_EOF);
total_decompressed = 0;
for (;;) {
if (state->stream.avail_in == 0) {
read_buf = state->stream.next_in;
ret = (a->client_reader)(&a->archive, a->client_data,
&read_buf);
state->stream.next_in = (void *)(uintptr_t)read_buf;
if (ret < 0) {
/*
* TODO: Find a better way to handle
* this read failure.
*/
goto fatal;
}
if (ret == 0 && total_decompressed == 0) {
archive_set_error(&a->archive, EIO,
"Premature end of %s compressed data",
a->archive.compression_name);
return (ARCHIVE_FATAL);
}
a->archive.raw_position += ret;
state->stream.avail_in = ret;
}
{
output = state->stream.next_out;
/* Decompress some data. */
ret = BZ2_bzDecompress(&(state->stream));
decompressed = state->stream.next_out - output;
/* Accumulate the total bytes of output. */
state->total_out += decompressed;
total_decompressed += decompressed;
switch (ret) {
case BZ_OK: /* Decompressor made some progress. */
if (decompressed > 0)
return (ARCHIVE_OK);
break;
case BZ_STREAM_END: /* Found end of stream. */
state->eof = 1;
return (ARCHIVE_OK);
default:
/* Any other return value is an error. */
goto fatal;
}
}
}
return (ARCHIVE_OK);
/* Return a fatal error. */
fatal:
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"%s decompression failed", a->archive.compression_name);
return (ARCHIVE_FATAL);
}
#endif /* HAVE_BZLIB_H */