/*-

 * 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 defined(HAVE_BZLIB_H) && defined(BZ_CONFIG_ERROR)

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 filter */

static ssize_t	bzip2_filter_read(struct archive_read_filter *, const void **);

static int	bzip2_filter_close(struct archive_read_filter *);

#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_read_filter_bidder *, struct archive_read_filter *);

static int	bzip2_reader_init(struct archive_read_filter *);

static int	bzip2_reader_free(struct archive_read_filter_bidder *);

#if ARCHIVE_VERSION_NUMBER < 4000000

/* Deprecated; remove in libarchive 4.0 */

int

archive_read_support_compression_bzip2(struct archive *a)

{

	return archive_read_support_filter_bzip2(a);

}

#endif

int

archive_read_support_filter_bzip2(struct archive *_a)

{

	struct archive_read *a = (struct archive_read *)_a;

	struct archive_read_filter_bidder *reader;

	archive_check_magic(_a, ARCHIVE_READ_MAGIC,

	    ARCHIVE_STATE_NEW, "archive_read_support_filter_bzip2");

	if (__archive_read_get_bidder(a, &reader) != ARCHIVE_OK)

		return (ARCHIVE_FATAL);

	reader->data = NULL;

	reader->name = "bzip2";

	reader->bid = bzip2_reader_bid;

	reader->init = bzip2_reader_init;

	reader->options = NULL;

	reader->free = bzip2_reader_free;

#if defined(HAVE_BZLIB_H) && defined(BZ_CONFIG_ERROR)

	return (ARCHIVE_OK);

#else

	archive_set_error(_a, ARCHIVE_ERRNO_MISC,

	    "Using external bzip2 program");

	return (ARCHIVE_WARN);

#endif

}

static int

bzip2_reader_free(struct archive_read_filter_bidder *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_read_filter_bidder *self, struct archive_read_filter *filter)

{

	const unsigned char *buffer;

	ssize_t avail;

	int bits_checked;

	(void)self; /* UNUSED */

	/* Minimal bzip2 archive is 14 bytes. */

	buffer = __archive_read_filter_ahead(filter, 14, &avail);

	if (buffer == NULL)

		return (0);

	/* First three bytes must be "BZh" */

	bits_checked = 0;

	if (memcmp(buffer, "BZh", 3) != 0)

		return (0);

	bits_checked += 24;

	/* Next follows a compression flag which must be an ASCII digit. */

	if (buffer[3] < '1' || buffer[3] > '9')

		return (0);

	bits_checked += 5;

	/* After BZh[1-9], there must be either a data block

	 * which begins with 0x314159265359 or an end-of-data

	 * marker of 0x177245385090. */

	if (memcmp(buffer + 4, "\x31\x41\x59\x26\x53\x59", 6) == 0)

		bits_checked += 48;

	else if (memcmp(buffer + 4, "\x17\x72\x45\x38\x50\x90", 6) == 0)

		bits_checked += 48;

	else

		return (0);

	return (bits_checked);

}

#if !defined(HAVE_BZLIB_H) || !defined(BZ_CONFIG_ERROR)

/*

 * 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

bzip2_reader_init(struct archive_read_filter *self)

{

	int r;

	r = __archive_read_program(self, "bzip2 -d");

	/* Note: We set the format here even if __archive_read_program()

	 * above fails.  We do, after all, know what the format is

	 * even if we weren't able to read it. */

	self->code = ARCHIVE_FILTER_BZIP2;

	self->name = "bzip2";

	return (r);

}

#else

/*

 * Setup the callbacks.

 */

static int

bzip2_reader_init(struct archive_read_filter *self)

{

	static const size_t out_block_size = 64 * 1024;

	void *out_block;

	struct private_data *state;

	self->code = ARCHIVE_FILTER_BZIP2;

	self->name = "bzip2";

	state = (struct private_data *)calloc(sizeof(*state), 1);

	out_block = (unsigned char *)malloc(out_block_size);

	if (state == NULL || out_block == NULL) {

		archive_set_error(&self->archive->archive, ENOMEM,

		    "Can't allocate data for bzip2 decompression");

		free(out_block);

		free(state);

		return (ARCHIVE_FATAL);

	}

	self->data = state;

	state->out_block_size = out_block_size;

	state->out_block = out_block;

	self->read = bzip2_filter_read;

	self->skip = NULL; /* not supported */

	self->close = bzip2_filter_close;

	return (ARCHIVE_OK);

}

/*

 * Return the next block of decompressed data.

 */

static ssize_t

bzip2_filter_read(struct archive_read_filter *self, const void **p)

{

	struct private_data *state;

	size_t decompressed;

	const char *read_buf;

	ssize_t ret;

	state = (struct private_data *)self->data;

	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 (!state->valid) {

			if (bzip2_reader_bid(self->bidder, self->upstream) == 0) {

				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;

		}

		/* stream.next_in is really const, but bzlib

		 * doesn't declare it so. <sigh> */

		read_buf =

		    __archive_read_filter_ahead(self->upstream, 1, &ret;;

		if (read_buf == NULL) {

			archive_set_error(&self->archive->archive,

			    ARCHIVE_ERRNO_MISC,

			    "truncated bzip2 input");

			return (ARCHIVE_FATAL);

		}

		state->stream.next_in = (char *)(uintptr_t)read_buf;

		state->stream.avail_in = ret;

		/* 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);

		}

		/* Decompress as much as we can in one pass. */

		ret = BZ2_bzDecompress(&(state->stream));

		__archive_read_filter_consume(self->upstream,

		    state->stream.next_in - read_buf);

		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_filter_close(struct archive_read_filter *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;

		}

		state->valid = 0;

	}

	free(state->out_block);

	free(state);

	return (ret);

}

#endif /* HAVE_BZLIB_H && BZ_CONFIG_ERROR */