freebsd-dev/lib/libarchive/archive_read_support_compression_bzip2.c
Tim Kientzle b1ff9c25b8 MfP4: Big read filter refactoring.
This is an attempt to eliminate a lot of redundant
code from the read ("decompression") filters by
changing them to juggle arbitrary-sized blocks
and consolidate reblocking code at a single point
in archive_read.c.

Along the way, I've changed the internal read/consume
API used by the format handlers to a slightly
different style originally suggested by des@.  It
does seem to simplify a lot of common cases.

The most dramatic change is, of course, to
archive_read_support_compression_none(), which
has just evaporated into a no-op as the blocking
code this used to hold has all been moved up
a level.

There's at least one more big round of refactoring
yet to come before the individual filters are as
straightforward as I think they should be...
2008-12-06 06:45:15 +00:00

398 lines
10 KiB
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("$FreeBSD$");
#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 *out_block;
size_t out_block_size;
char valid; /* True = decompressor is initialized */
char eof; /* True = found end of compressed data. */
};
/* Bzip2 source */
static ssize_t bzip2_source_read(struct archive_read_source *, const void **);
static int bzip2_source_close(struct archive_read_source *);
#endif
/*
* Note that we can detect bzip2 archives even if we can't decompress
* them. (In fact, we like detecting them because we can give better
* error messages.) So the bid framework here gets compiled even
* if bzlib is unavailable.
*/
static int bzip2_reader_bid(struct archive_reader *, const void *, size_t);
static struct archive_read_source *bzip2_reader_init(struct archive_read *,
struct archive_reader *, struct archive_read_source *,
const void *, size_t);
static int bzip2_reader_free(struct archive_reader *);
int
archive_read_support_compression_bzip2(struct archive *_a)
{
struct archive_read *a = (struct archive_read *)_a;
struct archive_reader *reader = __archive_read_get_reader(a);
if (reader == NULL)
return (ARCHIVE_FATAL);
reader->data = NULL;
reader->bid = bzip2_reader_bid;
reader->init = bzip2_reader_init;
reader->free = bzip2_reader_free;
return (ARCHIVE_OK);
}
static int
bzip2_reader_free(struct archive_reader *self){
(void)self; /* UNUSED */
return (ARCHIVE_OK);
}
/*
* 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
bzip2_reader_bid(struct archive_reader *self, const void *buff, size_t len)
{
const unsigned char *buffer;
int bits_checked;
(void)self; /* UNUSED */
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 struct archive_read_source *
bzip2_reader_init(struct archive_read *a, struct archive_reader *reader,
struct archive_read_source *upstream, const void *buff, size_t n)
{
(void)a; /* UNUSED */
(void)reader; /* UNUSED */
(void)upstream; /* UNUSED */
(void)buff; /* UNUSED */
(void)n; /* UNUSED */
archive_set_error(&a->archive, -1,
"This version of libarchive was compiled without bzip2 support");
return (NULL);
}
#else
/*
* Setup the callbacks.
*/
static struct archive_read_source *
bzip2_reader_init(struct archive_read *a, struct archive_reader *reader,
struct archive_read_source *upstream, const void *buff, size_t n)
{
static const size_t out_block_size = 64 * 1024;
void *out_block;
struct archive_read_source *self;
struct private_data *state;
(void)reader; /* UNUSED */
a->archive.compression_code = ARCHIVE_COMPRESSION_BZIP2;
a->archive.compression_name = "bzip2";
self = calloc(sizeof(*self), 1);
state = (struct private_data *)calloc(sizeof(*state), 1);
out_block = (unsigned char *)malloc(out_block_size);
if (self == NULL || state == NULL || out_block == NULL) {
archive_set_error(&a->archive, ENOMEM,
"Can't allocate data for %s decompression",
a->archive.compression_name);
free(out_block);
free(state);
free(self);
return (NULL);
}
self->archive = a;
self->data = state;
state->out_block_size = out_block_size;
state->out_block = out_block;
self->upstream = upstream;
self->read = bzip2_source_read;
self->skip = NULL; /* not supported */
self->close = bzip2_source_close;
/*
* 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;
state->stream.next_out = state->out_block;
state->stream.avail_out = state->out_block_size;
return (self);
}
/*
* Return the next block of decompressed data.
*/
static ssize_t
bzip2_source_read(struct archive_read_source *self, const void **p)
{
struct private_data *state;
size_t read_avail, decompressed;
const void *read_buf;
int ret;
state = (struct private_data *)self->data;
read_avail = 0;
if (state->eof) {
*p = NULL;
return (0);
}
/* Empty our output buffer. */
state->stream.next_out = state->out_block;
state->stream.avail_out = state->out_block_size;
/* Try to fill the output buffer. */
for (;;) {
/* If the last upstream block is done, get another one. */
if (state->stream.avail_in == 0) {
ret = (self->upstream->read)(self->upstream,
&read_buf);
/* stream.next_in is really const, but bzlib
* doesn't declare it so. <sigh> */
state->stream.next_in
= (unsigned char *)(uintptr_t)read_buf;
if (ret < 0)
return (ARCHIVE_FATAL);
/* There is no more data, return whatever we have. */
if (ret == 0) {
state->eof = 1;
*p = state->out_block;
decompressed = state->stream.next_out
- state->out_block;
return (decompressed);
}
state->stream.avail_in = ret;
}
if (!state->valid) {
if (state->stream.next_in[0] != 'B') {
state->eof = 1;
*p = state->out_block;
decompressed = state->stream.next_out
- state->out_block;
return (decompressed);
}
/* Initialize compression library. */
ret = BZ2_bzDecompressInit(&(state->stream),
0 /* library verbosity */,
0 /* don't use low-mem algorithm */);
/* If init fails, try low-memory algorithm instead. */
if (ret == BZ_MEM_ERROR)
ret = BZ2_bzDecompressInit(&(state->stream),
0 /* library verbosity */,
1 /* do use low-mem algo */);
if (ret != BZ_OK) {
const char *detail = NULL;
int err = ARCHIVE_ERRNO_MISC;
switch (ret) {
case BZ_PARAM_ERROR:
detail = "invalid setup parameter";
break;
case BZ_MEM_ERROR:
err = ENOMEM;
detail = "out of memory";
break;
case BZ_CONFIG_ERROR:
detail = "mis-compiled library";
break;
}
archive_set_error(&self->archive->archive, err,
"Internal error initializing decompressor%s%s",
detail == NULL ? "" : ": ",
detail);
return (ARCHIVE_FATAL);
}
state->valid = 1;
}
/* Decompress as much as we can in one pass. */
ret = BZ2_bzDecompress(&(state->stream));
switch (ret) {
case BZ_STREAM_END: /* Found end of stream. */
switch (BZ2_bzDecompressEnd(&(state->stream))) {
case BZ_OK:
break;
default:
archive_set_error(&(self->archive->archive),
ARCHIVE_ERRNO_MISC,
"Failed to clean up decompressor");
return (ARCHIVE_FATAL);
}
state->valid = 0;
/* FALLTHROUGH */
case BZ_OK: /* Decompressor made some progress. */
/* If we filled our buffer, update stats and return. */
if (state->stream.avail_out == 0) {
*p = state->out_block;
decompressed = state->stream.next_out
- state->out_block;
return (decompressed);
}
break;
default: /* Return an error. */
archive_set_error(&self->archive->archive,
ARCHIVE_ERRNO_MISC, "bzip decompression failed");
return (ARCHIVE_FATAL);
}
}
}
/*
* Clean up the decompressor.
*/
static int
bzip2_source_close(struct archive_read_source *self)
{
struct private_data *state;
int ret = ARCHIVE_OK;
state = (struct private_data *)self->data;
if (state->valid) {
switch (BZ2_bzDecompressEnd(&state->stream)) {
case BZ_OK:
break;
default:
archive_set_error(&self->archive->archive,
ARCHIVE_ERRNO_MISC,
"Failed to clean up decompressor");
ret = ARCHIVE_FATAL;
}
}
free(state->out_block);
free(state);
free(self);
return (ARCHIVE_OK);
}
#endif /* HAVE_BZLIB_H */