Patch from Aurelien Jacobs to add unlzma. (A new decompression type,

see www.7-zip.org)

12 files changed, 691 insertions, 5 deletions

diff --git a/archival/Config.in b/archival/Config.in
index db358db..e7d5deb 100644
--- a/archival/Config.in
+++ b/archival/Config.in
@@ -157,6 +157,14 @@ config CONFIG_FEATURE_TAR_BZIP2
 	  If you enable this option you'll be able to extract
 	  archives compressed with bzip2.
 
+config CONFIG_FEATURE_TAR_LZMA
+	bool "  Enable -a option to handle .tar.lzma files"
+	default n
+	depends on CONFIG_TAR
+	help
+	  If you enable this option you'll be able to extract
+	  archives compressed with lzma.
+
 config CONFIG_FEATURE_TAR_FROM
 	bool "  Enable -X (exclude from) and -T (include from) options)"
 	default n
@@ -212,6 +220,29 @@ config CONFIG_UNCOMPRESS
 	  uncompress is used to decompress archives created by compress.
 	  Not much used anymore, replaced by gzip/gunzip.
 
+config CONFIG_UNLZMA
+	bool "unlzma"
+	default n
+	help
+	  unlzma is a compression utility using the Lempel-Ziv-Markov chain
+	  compression algorithm, and range coding.  Compression
+	  is generally considerably better than that achieved by the bzip2
+	  compressors.
+	
+	  The BusyBox unlzma applet is limited to de-compression only.
+	  On an x86 system, this applet adds about 4K.
+	
+	  Unless you have a specific application which requires unlzma, you
+	  should probably say N here.
+
+config CONFIG_FEATURE_LZMA_FAST
+	bool "  Optimze unlzma for speed"
+	default n
+	depends on CONFIG_UNLZMA
+	help
+	  This option reduce decompression time by about 33% at the cost of
+	  a 2K bigger binary.
+
 config CONFIG_UNZIP
 	bool "unzip"
 	default n
@@ -255,4 +286,15 @@ config CONFIG_FEATURE_DEB_TAR_BZ2
 	  You only want this if you are creating your own custom debian packages that
 	  use an internal control.tar.bz2 or data.tar.bz2.
 
+config CONFIG_FEATURE_DEB_TAR_LZMA
+	bool "  lzma debian packages"
+	default n
+	depends on CONFIG_DPKG || CONFIG_DPKG_DEB
+	help
+	  This allows dpkg and dpkg-deb to extract deb's that are compressed
+          internally with lzma instead of gzip.
+	
+	  You only want this if you are creating your own custom debian
+          packages that use an internal control.tar.lzma or data.tar.lzma.
+
 endmenu
diff --git a/archival/Makefile.in b/archival/Makefile.in
index 735b659..b4fcabf 100644
--- a/archival/Makefile.in
+++ b/archival/Makefile.in
@@ -14,6 +14,7 @@ ARCHIVAL-y:=
 ARCHIVAL-$(CONFIG_APT_GET)	+=
 ARCHIVAL-$(CONFIG_AR)		+= ar.o
 ARCHIVAL-$(CONFIG_BUNZIP2)	+= bunzip2.o
+ARCHIVAL-$(CONFIG_UNLZMA)	+= unlzma.o
 ARCHIVAL-$(CONFIG_CPIO)		+= cpio.o
 ARCHIVAL-$(CONFIG_DPKG)		+= dpkg.o
 ARCHIVAL-$(CONFIG_DPKG_DEB)	+= dpkg_deb.o
diff --git a/archival/libunarchive/Makefile.in b/archival/libunarchive/Makefile.in
index 99eb638..2b49398 100644
--- a/archival/libunarchive/Makefile.in
+++ b/archival/libunarchive/Makefile.in
@@ -51,17 +51,20 @@ DPKG_FILES:= \
 
 LIBUNARCHIVE-$(CONFIG_AR) += get_header_ar.o unpack_ar_archive.o
 LIBUNARCHIVE-$(CONFIG_BUNZIP2) += decompress_bunzip2.o
+LIBUNARCHIVE-$(CONFIG_UNLZMA) += decompress_unlzma.o
 LIBUNARCHIVE-$(CONFIG_CPIO) += get_header_cpio.o
 LIBUNARCHIVE-$(CONFIG_DPKG) += $(DPKG_FILES)
 LIBUNARCHIVE-$(CONFIG_DPKG_DEB) += $(DPKG_FILES)
 LIBUNARCHIVE-$(CONFIG_FEATURE_DEB_TAR_GZ) += $(GUNZIP_FILES) get_header_tar_gz.o
 LIBUNARCHIVE-$(CONFIG_FEATURE_DEB_TAR_BZ2) += decompress_bunzip2.o get_header_tar_bz2.o
+LIBUNARCHIVE-$(CONFIG_FEATURE_DEB_TAR_LZMA) += decompress_unlzma.o get_header_tar_lzma.o
 LIBUNARCHIVE-$(CONFIG_GUNZIP) += $(GUNZIP_FILES)
 LIBUNARCHIVE-$(CONFIG_FEATURE_GUNZIP_UNCOMPRESS) += decompress_uncompress.o
 LIBUNARCHIVE-$(CONFIG_RPM2CPIO) += $(GUNZIP_FILES) get_header_cpio.o
 LIBUNARCHIVE-$(CONFIG_RPM) += $(GUNZIP_FILES) get_header_cpio.o
 LIBUNARCHIVE-$(CONFIG_TAR) += get_header_tar.o
 LIBUNARCHIVE-$(CONFIG_FEATURE_TAR_BZIP2) += decompress_bunzip2.o get_header_tar_bz2.o
+LIBUNARCHIVE-$(CONFIG_FEATURE_TAR_LZMA) += decompress_unlzma.o get_header_tar_lzma.o
 LIBUNARCHIVE-$(CONFIG_FEATURE_TAR_GZIP) += $(GUNZIP_FILES) get_header_tar_gz.o
 LIBUNARCHIVE-$(CONFIG_FEATURE_TAR_COMPRESS) += decompress_uncompress.o
 LIBUNARCHIVE-$(CONFIG_UNCOMPRESS) += decompress_uncompress.o
diff --git a/archival/libunarchive/decompress_unlzma.c b/archival/libunarchive/decompress_unlzma.c
new file mode 100644
index 0000000..977cb48
--- /dev/null
+++ b/archival/libunarchive/decompress_unlzma.c
@@ -0,0 +1,347 @@
+/*
+ * Small lzma deflate implementation.
+ * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
+ *
+ * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
+ * Copyright (C) 1999-2005  Igor Pavlov
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <stdint.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <byteswap.h>
+
+#include "libbb.h"
+
+#include "rangecoder.h"
+
+
+typedef struct {
+	uint8_t pos;
+	uint32_t dict_size;
+	uint64_t dst_size;
+} __attribute__ ((packed)) lzma_header_t;
+
+
+#define LZMA_BASE_SIZE 1846
+#define LZMA_LIT_SIZE 768
+
+#define LZMA_NUM_POS_BITS_MAX 4
+
+#define LZMA_LEN_NUM_LOW_BITS 3
+#define LZMA_LEN_NUM_MID_BITS 3
+#define LZMA_LEN_NUM_HIGH_BITS 8
+
+#define LZMA_LEN_CHOICE 0
+#define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
+#define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
+#define LZMA_LEN_MID (LZMA_LEN_LOW \
+                      + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
+#define LZMA_LEN_HIGH (LZMA_LEN_MID \
+                       +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
+#define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
+
+#define LZMA_NUM_STATES 12
+#define LZMA_NUM_LIT_STATES 7
+
+#define LZMA_START_POS_MODEL_INDEX 4
+#define LZMA_END_POS_MODEL_INDEX 14
+#define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
+
+#define LZMA_NUM_POS_SLOT_BITS 6
+#define LZMA_NUM_LEN_TO_POS_STATES 4
+
+#define LZMA_NUM_ALIGN_BITS 4
+
+#define LZMA_MATCH_MIN_LEN 2
+
+#define LZMA_IS_MATCH 0
+#define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES <<LZMA_NUM_POS_BITS_MAX))
+#define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
+#define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
+#define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
+#define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
+#define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
+                       + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
+#define LZMA_SPEC_POS (LZMA_POS_SLOT \
+                       +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
+#define LZMA_ALIGN (LZMA_SPEC_POS \
+                    + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
+#define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
+#define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
+#define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
+
+
+int unlzma(int src_fd, int dst_fd)
+{
+	lzma_header_t header;
+	int lc, pb, lp;
+	uint32_t pos_state_mask;
+	uint32_t literal_pos_mask;
+	uint32_t pos;
+	uint16_t *p;
+	uint16_t *prob;
+	uint16_t *prob_lit;
+	int num_bits;
+	int num_probs;
+	rc_t rc;
+	int i, mi;
+	uint8_t *buffer;
+	uint8_t previous_byte = 0;
+	size_t buffer_pos = 0, global_pos = 0;
+	int len = 0;
+	int state = 0;
+	uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
+
+	if (read(src_fd, &header, sizeof(header)) != sizeof(header))
+		bb_error_msg_and_die("can't read header");
+
+	if (header.pos >= (9 * 5 * 5))
+		bb_error_msg_and_die("bad header");
+	mi = header.pos / 9;
+	lc = header.pos % 9;
+	pb = mi / 5;
+	lp = mi % 5;
+	pos_state_mask = (1 << pb) - 1;
+	literal_pos_mask = (1 << lp) - 1;
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+	header.dict_size = bswap_32(header.dict_size);
+	header.dst_size = bswap_64(header.dst_size);
+#endif							/* __BYTE_ORDER */
+
+	if (header.dict_size == 0)
+		header.dict_size = 1;
+
+	buffer = xmalloc(MIN(header.dst_size, header.dict_size));
+
+	num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
+	p = xmalloc(num_probs * sizeof(*p));
+	num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
+	for (i = 0; i < num_probs; i++)
+		p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
+
+	rc_init(&rc, src_fd, 0x10000);
+
+	while (global_pos + buffer_pos < header.dst_size) {
+		int pos_state = (buffer_pos + global_pos) & pos_state_mask;
+
+		prob =
+			p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
+		if (rc_is_bit_0(&rc, prob)) {
+			mi = 1;
+			rc_update_bit_0(&rc, prob);
+			prob = (p + LZMA_LITERAL + (LZMA_LIT_SIZE
+					* ((((buffer_pos + global_pos) & literal_pos_mask) << lc)
+					+ (previous_byte >> (8 - lc)))));
+
+			if (state >= LZMA_NUM_LIT_STATES) {
+				int match_byte;
+
+				pos = buffer_pos - rep0;
+				while (pos >= header.dict_size)
+					pos += header.dict_size;
+				match_byte = buffer[pos];
+				do {
+					int bit;
+
+					match_byte <<= 1;
+					bit = match_byte & 0x100;
+					prob_lit = prob + 0x100 + bit + mi;
+					if (rc_get_bit(&rc, prob_lit, &mi)) {
+						if (!bit)
+							break;
+					} else {
+						if (bit)
+							break;
+					}
+				} while (mi < 0x100);
+			}
+			while (mi < 0x100) {
+				prob_lit = prob + mi;
+				rc_get_bit(&rc, prob_lit, &mi);
+			}
+			previous_byte = (uint8_t) mi;
+
+			buffer[buffer_pos++] = previous_byte;
+			if (buffer_pos == header.dict_size) {
+				buffer_pos = 0;
+				global_pos += header.dict_size;
+				write(dst_fd, buffer, header.dict_size);
+			}
+			if (state < 4)
+				state = 0;
+			else if (state < 10)
+				state -= 3;
+			else
+				state -= 6;
+		} else {
+			int offset;
+			uint16_t *prob_len;
+
+			rc_update_bit_1(&rc, prob);
+			prob = p + LZMA_IS_REP + state;
+			if (rc_is_bit_0(&rc, prob)) {
+				rc_update_bit_0(&rc, prob);
+				rep3 = rep2;
+				rep2 = rep1;
+				rep1 = rep0;
+				state = state < LZMA_NUM_LIT_STATES ? 0 : 3;
+				prob = p + LZMA_LEN_CODER;
+			} else {
+				rc_update_bit_1(&rc, prob);
+				prob = p + LZMA_IS_REP_G0 + state;
+				if (rc_is_bit_0(&rc, prob)) {
+					rc_update_bit_0(&rc, prob);
+					prob = (p + LZMA_IS_REP_0_LONG
+							+ (state << LZMA_NUM_POS_BITS_MAX) + pos_state);
+					if (rc_is_bit_0(&rc, prob)) {
+						rc_update_bit_0(&rc, prob);
+
+						state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
+						pos = buffer_pos - rep0;
+						while (pos >= header.dict_size)
+							pos += header.dict_size;
+						previous_byte = buffer[pos];
+						buffer[buffer_pos++] = previous_byte;
+						if (buffer_pos == header.dict_size) {
+							buffer_pos = 0;
+							global_pos += header.dict_size;
+							write(dst_fd, buffer, header.dict_size);
+						}
+						continue;
+					} else {
+						rc_update_bit_1(&rc, prob);
+					}
+				} else {
+					uint32_t distance;
+
+					rc_update_bit_1(&rc, prob);
+					prob = p + LZMA_IS_REP_G1 + state;
+					if (rc_is_bit_0(&rc, prob)) {
+						rc_update_bit_0(&rc, prob);
+						distance = rep1;
+					} else {
+						rc_update_bit_1(&rc, prob);
+						prob = p + LZMA_IS_REP_G2 + state;
+						if (rc_is_bit_0(&rc, prob)) {
+							rc_update_bit_0(&rc, prob);
+							distance = rep2;
+						} else {
+							rc_update_bit_1(&rc, prob);
+							distance = rep3;
+							rep3 = rep2;
+						}
+						rep2 = rep1;
+					}
+					rep1 = rep0;
+					rep0 = distance;
+				}
+				state = state < LZMA_NUM_LIT_STATES ? 8 : 11;
+				prob = p + LZMA_REP_LEN_CODER;
+			}
+
+			prob_len = prob + LZMA_LEN_CHOICE;
+			if (rc_is_bit_0(&rc, prob_len)) {
+				rc_update_bit_0(&rc, prob_len);
+				prob_len = (prob + LZMA_LEN_LOW
+							+ (pos_state << LZMA_LEN_NUM_LOW_BITS));
+				offset = 0;
+				num_bits = LZMA_LEN_NUM_LOW_BITS;
+			} else {
+				rc_update_bit_1(&rc, prob_len);
+				prob_len = prob + LZMA_LEN_CHOICE_2;
+				if (rc_is_bit_0(&rc, prob_len)) {
+					rc_update_bit_0(&rc, prob_len);
+					prob_len = (prob + LZMA_LEN_MID
+								+ (pos_state << LZMA_LEN_NUM_MID_BITS));
+					offset = 1 << LZMA_LEN_NUM_LOW_BITS;
+					num_bits = LZMA_LEN_NUM_MID_BITS;
+				} else {
+					rc_update_bit_1(&rc, prob_len);
+					prob_len = prob + LZMA_LEN_HIGH;
+					offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
+							  + (1 << LZMA_LEN_NUM_MID_BITS));
+					num_bits = LZMA_LEN_NUM_HIGH_BITS;
+				}
+			}
+			rc_bit_tree_decode(&rc, prob_len, num_bits, &len);
+			len += offset;
+
+			if (state < 4) {
+				int pos_slot;
+
+				state += LZMA_NUM_LIT_STATES;
+				prob =
+					p + LZMA_POS_SLOT +
+					((len <
+					  LZMA_NUM_LEN_TO_POS_STATES ? len :
+					  LZMA_NUM_LEN_TO_POS_STATES - 1)
+					 << LZMA_NUM_POS_SLOT_BITS);
+				rc_bit_tree_decode(&rc, prob, LZMA_NUM_POS_SLOT_BITS,
+								   &pos_slot);
+				if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
+					num_bits = (pos_slot >> 1) - 1;
+					rep0 = 2 | (pos_slot & 1);
+					if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
+						rep0 <<= num_bits;
+						prob = p + LZMA_SPEC_POS + rep0 - pos_slot - 1;
+					} else {
+						num_bits -= LZMA_NUM_ALIGN_BITS;
+						while (num_bits--)
+							rep0 = (rep0 << 1) | rc_direct_bit(&rc);
+						prob = p + LZMA_ALIGN;
+						rep0 <<= LZMA_NUM_ALIGN_BITS;
+						num_bits = LZMA_NUM_ALIGN_BITS;
+					}
+					i = 1;
+					mi = 1;
+					while (num_bits--) {
+						if (rc_get_bit(&rc, prob + mi, &mi))
+							rep0 |= i;
+						i <<= 1;
+					}
+				} else
+					rep0 = pos_slot;
+				if (++rep0 == 0)
+					break;
+			}
+
+			len += LZMA_MATCH_MIN_LEN;
+
+			do {
+				pos = buffer_pos - rep0;
+				while (pos >= header.dict_size)
+					pos += header.dict_size;
+				previous_byte = buffer[pos];
+				buffer[buffer_pos++] = previous_byte;
+				if (buffer_pos == header.dict_size) {
+					buffer_pos = 0;
+					global_pos += header.dict_size;
+					write(dst_fd, buffer, header.dict_size);
+				}
+				len--;
+			} while (len != 0 && buffer_pos < header.dst_size);
+		}
+	}
+
+	write(dst_fd, buffer, buffer_pos);
+	rc_free(&rc);
+	return 0;
+}
+
+/* vi:set ts=4: */
diff --git a/archival/libunarchive/filter_accept_list_reassign.c b/archival/libunarchive/filter_accept_list_reassign.c
index d043654..a09f564 100644
--- a/archival/libunarchive/filter_accept_list_reassign.c
+++ b/archival/libunarchive/filter_accept_list_reassign.c
@@ -50,6 +50,10 @@ extern char filter_accept_list_reassign(archive_handle_t *archive_handle)
 			return(EXIT_SUCCESS);
 		}
 #endif
+		if (ENABLE_FEATURE_DEB_TAR_LZMA && !strcmp(name_ptr, ".lzma")) {
+			archive_handle->action_data_subarchive = get_header_tar_lzma;
+			return(EXIT_SUCCESS);
+		}
 	}
 	return(EXIT_FAILURE);
 }
diff --git a/archival/libunarchive/get_header_tar_lzma.c b/archival/libunarchive/get_header_tar_lzma.c
new file mode 100644
index 0000000..63dc8bc
--- /dev/null
+++ b/archival/libunarchive/get_header_tar_lzma.c
@@ -0,0 +1,23 @@
+/*
+ * Small lzma deflate implementation.
+ * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
+ *
+ * Licensed under GPL v2, see file LICENSE in this tarball for details.
+ */
+
+#include "unarchive.h"
+
+char get_header_tar_lzma(archive_handle_t * archive_handle)
+{
+	/* Can't lseek over pipes */
+	archive_handle->seek = seek_by_char;
+
+	archive_handle->src_fd = open_transformer(archive_handle->src_fd, unlzma);
+	archive_handle->offset = 0;
+	while (get_header_tar(archive_handle) == EXIT_SUCCESS);
+
+	/* Can only do one file at a time */
+	return EXIT_FAILURE;
+}
+
+/* vi:set ts=4: */
diff --git a/archival/libunarchive/rangecoder.h b/archival/libunarchive/rangecoder.h
new file mode 100644
index 0000000..bb41591
--- /dev/null
+++ b/archival/libunarchive/rangecoder.h
@@ -0,0 +1,158 @@
+/*
+ * Small range coder implementation for lzma.
+ * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
+ *
+ * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
+ * Copyright (c) 1999-2005  Igor Pavlov
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <stdint.h>
+
+#include "libbb.h"
+
+#ifndef always_inline
+#  if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ >0)
+#    define always_inline __attribute__((always_inline)) inline
+#  else
+#    define always_inline inline
+#  endif
+#endif
+
+#ifdef CONFIG_FEATURE_LZMA_FAST
+#  define speed_inline always_inline
+#else
+#  define speed_inline
+#endif
+
+
+typedef struct {
+	int fd;
+	uint8_t *ptr;
+	uint8_t *buffer;
+	uint8_t *buffer_end;
+	int buffer_size;
+	uint32_t code;
+	uint32_t range;
+	uint32_t bound;
+} rc_t;
+
+
+#define RC_TOP_BITS 24
+#define RC_MOVE_BITS 5
+#define RC_MODEL_TOTAL_BITS 11
+
+
+static speed_inline void rc_read(rc_t * rc)
+{
+	rc->buffer_size = read(rc->fd, rc->buffer, rc->buffer_size);
+	if (rc->buffer_size <= 0)
+		bb_error_msg_and_die("unexpected EOF");
+	rc->ptr = rc->buffer;
+	rc->buffer_end = rc->buffer + rc->buffer_size;
+}
+
+static always_inline void rc_init(rc_t * rc, int fd, int buffer_size)
+{
+	int i;
+
+	rc->fd = fd;
+	rc->buffer = malloc(buffer_size);
+	rc->buffer_size = buffer_size;
+	rc->buffer_end = rc->buffer + rc->buffer_size;
+	rc->ptr = rc->buffer_end;
+
+	rc->code = 0;
+	rc->range = 0xFFFFFFFF;
+	for (i = 0; i < 5; i++) {
+		if (rc->ptr >= rc->buffer_end)
+			rc_read(rc);
+		rc->code = (rc->code << 8) | *rc->ptr++;
+	}
+}
+
+static always_inline void rc_free(rc_t * rc)
+{
+	if (ENABLE_FEATURE_CLEAN_UP)
+		free(rc->buffer);
+}
+
+static always_inline void rc_normalize(rc_t * rc)
+{
+	if (rc->range < (1 << RC_TOP_BITS)) {
+		if (rc->ptr >= rc->buffer_end)
+			rc_read(rc);
+		rc->range <<= 8;
+		rc->code = (rc->code << 8) | *rc->ptr++;
+	}
+}
+
+static speed_inline int rc_is_bit_0(rc_t * rc, uint16_t * p)
+{
+	rc_normalize(rc);
+	rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
+	return rc->code < rc->bound;
+}
+
+static speed_inline void rc_update_bit_0(rc_t * rc, uint16_t * p)
+{
+	rc->range = rc->bound;
+	*p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
+}
+
+static speed_inline void rc_update_bit_1(rc_t * rc, uint16_t * p)
+{
+	rc->range -= rc->bound;
+	rc->code -= rc->bound;
+	*p -= *p >> RC_MOVE_BITS;
+}
+
+static speed_inline int rc_get_bit(rc_t * rc, uint16_t * p, int *symbol)
+{
+	if (rc_is_bit_0(rc, p)) {
+		rc_update_bit_0(rc, p);
+		*symbol *= 2;
+		return 0;
+	} else {
+		rc_update_bit_1(rc, p);
+		*symbol = *symbol * 2 + 1;
+		return 1;
+	}
+}
+
+static always_inline int rc_direct_bit(rc_t * rc)
+{
+	rc_normalize(rc);
+	rc->range >>= 1;
+	if (rc->code >= rc->range) {
+		rc->code -= rc->range;
+		return 1;
+	}
+	return 0;
+}
+
+static speed_inline void
+rc_bit_tree_decode(rc_t * rc, uint16_t * p, int num_levels, int *symbol)
+{
+	int i = num_levels;
+
+	*symbol = 1;
+	while (i--)
+		rc_get_bit(rc, p + *symbol, symbol);
+	*symbol -= 1 << num_levels;
+}
+
+/* vi:set ts=4: */
diff --git a/archival/tar.c b/archival/tar.c
index d5fa954..a4b13b5 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -615,14 +615,23 @@ static char get_header_tar_Z(archive_handle_t *archive_handle)
 # define TAR_OPT_AFTER_BZIP2              TAR_OPT_AFTER_CREATE
 #endif
 
-#define TAR_OPT_INCLUDE_FROM              (1 << (TAR_OPT_AFTER_BZIP2))
-#define TAR_OPT_EXCLUDE_FROM              (1 << (TAR_OPT_AFTER_BZIP2 + 1))
+#define TAR_OPT_LZMA                      (1 << (TAR_OPT_AFTER_BZIP2))
+#ifdef CONFIG_FEATURE_TAR_LZMA
+# define TAR_OPT_STR_LZMA                 "a"
+# define TAR_OPT_AFTER_LZMA               TAR_OPT_AFTER_BZIP2 + 1
+#else
+# define TAR_OPT_STR_LZMA                 ""
+# define TAR_OPT_AFTER_LZMA               TAR_OPT_AFTER_BZIP2
+#endif
+
+#define TAR_OPT_INCLUDE_FROM              (1 << (TAR_OPT_AFTER_LZMA))
+#define TAR_OPT_EXCLUDE_FROM              (1 << (TAR_OPT_AFTER_LZMA + 1))
 #ifdef CONFIG_FEATURE_TAR_FROM
 # define TAR_OPT_STR_FROM                 "T:X:"
-# define TAR_OPT_AFTER_FROM               TAR_OPT_AFTER_BZIP2 + 2
+# define TAR_OPT_AFTER_FROM               TAR_OPT_AFTER_LZMA + 2
 #else
 # define TAR_OPT_STR_FROM                 ""
-# define TAR_OPT_AFTER_FROM               TAR_OPT_AFTER_BZIP2
+# define TAR_OPT_AFTER_FROM               TAR_OPT_AFTER_LZMA
 #endif
 
 #define TAR_OPT_GZIP                      (1 << (TAR_OPT_AFTER_FROM))
@@ -651,6 +660,7 @@ static char get_header_tar_Z(archive_handle_t *archive_handle)
 static const char tar_options[]="txC:f:Opvk" \
 	TAR_OPT_STR_CREATE \
 	TAR_OPT_STR_BZIP2 \
+	TAR_OPT_STR_LZMA \
 	TAR_OPT_STR_FROM \
 	TAR_OPT_STR_GZIP \
 	TAR_OPT_STR_COMPRESS \
@@ -675,6 +685,9 @@ static const struct option tar_long_options[] = {
 # ifdef CONFIG_FEATURE_TAR_BZIP2
 	{ "bzip2",				0,	NULL,	'j' },
 # endif
+# ifdef CONFIG_FEATURE_TAR_LZMA
+	{ "lzma",				0,	NULL,	'a' },
+# endif
 # ifdef CONFIG_FEATURE_TAR_FROM
 	{ "files-from",			1,	NULL,	'T' },
 	{ "exclude-from",		1,	NULL,	'X' },
@@ -757,6 +770,9 @@ int tar_main(int argc, char **argv)
 	if (ENABLE_FEATURE_TAR_BZIP2 && (opt & TAR_OPT_BZIP2))
 		get_header_ptr = get_header_tar_bz2;
 
+	if (ENABLE_FEATURE_TAR_LZMA && (opt & TAR_OPT_LZMA))
+		get_header_ptr = get_header_tar_lzma;
+
 	if (ENABLE_FEATURE_TAR_COMPRESS && (opt & TAR_OPT_UNCOMPRESS))
 		get_header_ptr = get_header_tar_Z;
 
diff --git a/archival/unlzma.c b/archival/unlzma.c
new file mode 100644
index 0000000..dc85cb2
--- /dev/null
+++ b/archival/unlzma.c
@@ -0,0 +1,65 @@
+/*
+ * Small lzma deflate implementation.
+ * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
+ *
+ * Based on bunzip.c from busybox
+ *
+ * Licensed under GPL v2, see file LICENSE in this tarball for details.
+ */
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "busybox.h"
+#include "unarchive.h"
+
+#define UNLZMA_OPT_STDOUT	1
+
+int unlzma_main(int argc, char **argv)
+{
+	char *filename;
+	unsigned long opt;
+	int status, src_fd, dst_fd;
+
+	opt = bb_getopt_ulflags(argc, argv, "c");
+
+	/* Set input filename and number */
+	filename = argv[optind];
+	if ((filename) && (filename[0] != '-') && (filename[1] != '\0')) {
+		/* Open input file */
+		src_fd = bb_xopen(filename, O_RDONLY);
+	} else {
+		src_fd = STDIN_FILENO;
+		filename = 0;
+	}
+
+	/* if called as lzmacat force the stdout flag */
+	if ((opt & UNLZMA_OPT_STDOUT) || bb_applet_name[4] == 'c')
+		filename = 0;
+
+	if (filename) {
+		char *extension = filename + strlen(filename) - 5;
+
+		if (strcmp(extension, ".lzma") != 0) {
+			bb_error_msg_and_die("Invalid extension");
+		}
+		*extension = 0;
+		dst_fd = bb_xopen(filename, O_WRONLY | O_CREAT);
+	} else
+		dst_fd = STDOUT_FILENO;
+	status = unlzma(src_fd, dst_fd);
+	if (filename) {
+		if (!status)
+			filename[strlen(filename)] = '.';
+		if (unlink(filename) < 0) {
+			bb_error_msg_and_die("Couldn't remove %s", filename);
+		}
+	}
+
+	return status;
+}
+
+/* vi:set ts=4: */
diff --git a/include/applets.h b/include/applets.h
index 47376c6..c6f54e1 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -408,6 +408,9 @@
 #ifdef CONFIG_LSMOD
 	APPLET(lsmod, lsmod_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
 #endif
+#ifdef CONFIG_UNLZMA
+	APPLET(lzmacat, unlzma_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
+#endif
 #ifdef CONFIG_MAKEDEVS
 	APPLET(makedevs, makedevs_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
 #endif
@@ -712,6 +715,9 @@
 #ifdef CONFIG_UNIX2DOS
 	APPLET(unix2dos, dos2unix_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
 #endif
+#ifdef CONFIG_UNLZMA
+	APPLET(unlzma, unlzma_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
+#endif
 #ifdef CONFIG_UNZIP
 	APPLET(unzip, unzip_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
 #endif
diff --git a/include/unarchive.h b/include/unarchive.h
index 72a803f..2075ca2 100644
--- a/include/unarchive.h
+++ b/include/unarchive.h
@@ -87,6 +87,7 @@ extern char get_header_ar(archive_handle_t *archive_handle);
 extern char get_header_cpio(archive_handle_t *archive_handle);
 extern char get_header_tar(archive_handle_t *archive_handle);
 extern char get_header_tar_bz2(archive_handle_t *archive_handle);
+extern char get_header_tar_lzma(archive_handle_t *archive_handle);
 extern char get_header_tar_gz(archive_handle_t *archive_handle);
 
 extern void seek_by_jump(const archive_handle_t *archive_handle, const unsigned int amount);
@@ -103,6 +104,7 @@ extern void inflate_init(unsigned int bufsize);
 extern void inflate_cleanup(void);
 extern int inflate_unzip(int in, int out);
 extern int inflate_gunzip(int in, int out);
+extern int unlzma(int src_fd, int dst_fd);
 
 extern int open_transformer(int src_fd, int (*transformer)(int src_fd, int dst_fd));
 
diff --git a/include/usage.h b/include/usage.h
index e6287c8..8982f8d 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -102,6 +102,19 @@
 #define bzcat_full_usage \
 	"Uncompress to stdout."
 
+#define unlzma_trivial_usage \
+	"[OPTION]... [FILE]"
+#define unlzma_full_usage \
+	"Uncompress FILE (or standard input if FILE is '-' or omitted).\n\n" \
+	"Options:\n" \
+	"\t-c\tWrite output to standard output\n" \
+	"\t-f\tForce"
+
+#define lzmacat_trivial_usage \
+	"FILE"
+#define lzmacat_full_usage \
+	"Uncompress to stdout."
+
 #define cal_trivial_usage \
 	"[-jy] [[month] year]"
 #define cal_full_usage \
@@ -2964,6 +2977,11 @@
 #else
 #  define USAGE_TAR_BZIP2(a)
 #endif
+#ifdef CONFIG_FEATURE_TAR_LZMA
+#  define USAGE_TAR_LZMA(a) a
+#else
+#  define USAGE_TAR_LZMA(a)
+#endif
 #ifdef CONFIG_FEATURE_TAR_COMPRESS
 #  define USAGE_TAR_COMPRESS(a) a
 #else
@@ -2971,7 +2989,7 @@
 #endif
 
 #define tar_trivial_usage \
-	"-[" USAGE_TAR_CREATE("c") USAGE_TAR_GZIP("z") USAGE_TAR_BZIP2("j") USAGE_TAR_COMPRESS("Z") "xtvO] " \
+	"-[" USAGE_TAR_CREATE("c") USAGE_TAR_GZIP("z") USAGE_TAR_BZIP2("j") USAGE_TAR_LZMA("a") USAGE_TAR_COMPRESS("Z") "xtvO] " \
 	USAGE_TAR_EXCLUDE("[-X FILE]") \
 	"[-f TARFILE] [-C DIR] [FILE(s)] ..."
 #define tar_full_usage \
@@ -2983,6 +3001,7 @@
 	"\nArchive format selection:\n" \
 	USAGE_TAR_GZIP("\tz\t\tFilter the archive through gzip\n") \
 	USAGE_TAR_BZIP2("\tj\t\tFilter the archive through bzip2\n") \
+	USAGE_TAR_LZMA("\ta\t\tFilter the archive through lzma\n") \
 	USAGE_TAR_COMPRESS("\tZ\t\tFilter the archive through compress\n") \
 	"\nFile selection:\n" \
 	"\tf\t\tname of TARFILE or \"-\" for stdin\n" \