dpkg: update supported compression methods

Based on a patch by Ron Yorston <rmy@tigress.co.uk>

function                                             old     new   delta
get_header_tar_xz                                      -      60     +60
filter_accept_list_reassign                          128     188     +60
unpack_package                                       585     621     +36
init_archive_deb_control                              52      76     +24
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 3/0 up/down: 180/0)             Total: 180 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

6 files changed, 50 insertions, 0 deletions

diff --git a/archival/dpkg.c b/archival/dpkg.c
index 2893cfc2d..151f0ca43 100644
--- a/archival/dpkg.c
+++ b/archival/dpkg.c
@@ -1472,12 +1472,16 @@ static void init_archive_deb_control(archive_handle_t *ar_handle)
 	tar_handle->src_fd = ar_handle->src_fd;
 
 	/* We don't care about data.tar.* or debian-binary, just control.tar.* */
+	llist_add_to(&(ar_handle->accept), (char*)"control.tar");
 #if ENABLE_FEATURE_SEAMLESS_GZ
 	llist_add_to(&(ar_handle->accept), (char*)"control.tar.gz");
 #endif
 #if ENABLE_FEATURE_SEAMLESS_BZ2
 	llist_add_to(&(ar_handle->accept), (char*)"control.tar.bz2");
 #endif
+#if ENABLE_FEATURE_SEAMLESS_XZ
+	llist_add_to(&(ar_handle->accept), (char*)"control.tar.xz");
+#endif
 
 	/* Assign the tar handle as a subarchive of the ar handle */
 	ar_handle->dpkg__sub_archive = tar_handle;
@@ -1492,12 +1496,19 @@ static void init_archive_deb_data(archive_handle_t *ar_handle)
 	tar_handle->src_fd = ar_handle->src_fd;
 
 	/* We don't care about control.tar.* or debian-binary, just data.tar.* */
+	llist_add_to(&(ar_handle->accept), (char*)"data.tar");
 #if ENABLE_FEATURE_SEAMLESS_GZ
 	llist_add_to(&(ar_handle->accept), (char*)"data.tar.gz");
 #endif
 #if ENABLE_FEATURE_SEAMLESS_BZ2
 	llist_add_to(&(ar_handle->accept), (char*)"data.tar.bz2");
 #endif
+#if ENABLE_FEATURE_SEAMLESS_LZMA
+	llist_add_to(&(ar_handle->accept), (char*)"data.tar.lzma");
+#endif
+#if ENABLE_FEATURE_SEAMLESS_XZ
+	llist_add_to(&(ar_handle->accept), (char*)"data.tar.xz");
+#endif
 
 	/* Assign the tar handle as a subarchive of the ar handle */
 	ar_handle->dpkg__sub_archive = tar_handle;
diff --git a/archival/dpkg_deb.c b/archival/dpkg_deb.c
index 13f9db991..0285273fe 100644
--- a/archival/dpkg_deb.c
+++ b/archival/dpkg_deb.c
@@ -70,6 +70,8 @@ int dpkg_deb_main(int argc, char **argv)
 	ar_archive->dpkg__sub_archive = tar_archive;
 	ar_archive->filter = filter_accept_list_reassign;
 
+	llist_add_to(&ar_archive->accept, (char*)"data.tar");
+	llist_add_to(&control_tar_llist, (char*)"control.tar");
 #if ENABLE_FEATURE_SEAMLESS_GZ
 	llist_add_to(&ar_archive->accept, (char*)"data.tar.gz");
 	llist_add_to(&control_tar_llist, (char*)"control.tar.gz");
@@ -82,6 +84,10 @@ int dpkg_deb_main(int argc, char **argv)
 	llist_add_to(&ar_archive->accept, (char*)"data.tar.lzma");
 	llist_add_to(&control_tar_llist, (char*)"control.tar.lzma");
 #endif
+#if ENABLE_FEATURE_SEAMLESS_XZ
+	llist_add_to(&ar_archive->accept, (char*)"data.tar.xz");
+	llist_add_to(&control_tar_llist, (char*)"control.tar.xz");
+#endif
 
 	opt_complementary = "c--efXx:e--cfXx:f--ceXx:X--cefx:x--cefX";
 	opt = getopt32(argv, "cefXx");
diff --git a/archival/libarchive/Kbuild.src b/archival/libarchive/Kbuild.src
index 968fdf8ab..7e89e9e89 100644
--- a/archival/libarchive/Kbuild.src
+++ b/archival/libarchive/Kbuild.src
@@ -35,6 +35,7 @@ DPKG_FILES:= \
 	get_header_tar_gz.o \
 	get_header_tar_bz2.o \
 	get_header_tar_lzma.o \
+	get_header_tar_xz.o \
 
 INSERT
 
diff --git a/archival/libarchive/filter_accept_list_reassign.c b/archival/libarchive/filter_accept_list_reassign.c
index 3d19abe44..b9acfbc05 100644
--- a/archival/libarchive/filter_accept_list_reassign.c
+++ b/archival/libarchive/filter_accept_list_reassign.c
@@ -28,6 +28,10 @@ char FAST_FUNC filter_accept_list_reassign(archive_handle_t *archive_handle)
 		name_ptr++;
 
 		/* Modify the subarchive handler based on the extension */
+		if (strcmp(name_ptr, "tar") == 0) {
+			archive_handle->dpkg__action_data_subarchive = get_header_tar;
+			return EXIT_SUCCESS;
+		}
 		if (ENABLE_FEATURE_SEAMLESS_GZ
 		 && strcmp(name_ptr, "gz") == 0
 		) {
@@ -46,6 +50,12 @@ char FAST_FUNC filter_accept_list_reassign(archive_handle_t *archive_handle)
 			archive_handle->dpkg__action_data_subarchive = get_header_tar_lzma;
 			return EXIT_SUCCESS;
 		}
+		if (ENABLE_FEATURE_SEAMLESS_XZ
+		 && strcmp(name_ptr, "xz") == 0
+		) {
+			archive_handle->dpkg__action_data_subarchive = get_header_tar_xz;
+			return EXIT_SUCCESS;
+		}
 	}
 	return EXIT_FAILURE;
 }
diff --git a/archival/libarchive/get_header_tar_xz.c b/archival/libarchive/get_header_tar_xz.c
new file mode 100644
index 000000000..7bf3b3b56
--- /dev/null
+++ b/archival/libarchive/get_header_tar_xz.c
@@ -0,0 +1,21 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+#include "libbb.h"
+#include "bb_archive.h"
+
+char FAST_FUNC get_header_tar_xz(archive_handle_t *archive_handle)
+{
+	/* Can't lseek over pipes */
+	archive_handle->seek = seek_by_read;
+
+	fork_transformer_with_sig(archive_handle->src_fd, unpack_xz_stream, "unxz");
+	archive_handle->offset = 0;
+	while (get_header_tar(archive_handle) == EXIT_SUCCESS)
+		continue;
+
+	/* Can only do one file at a time */
+	return EXIT_FAILURE;
+}
diff --git a/include/bb_archive.h b/include/bb_archive.h
index a6b166fe3..5d9e24c17 100644
--- a/include/bb_archive.h
+++ b/include/bb_archive.h
@@ -184,6 +184,7 @@ char get_header_tar(archive_handle_t *archive_handle) FAST_FUNC;
 char get_header_tar_gz(archive_handle_t *archive_handle) FAST_FUNC;
 char get_header_tar_bz2(archive_handle_t *archive_handle) FAST_FUNC;
 char get_header_tar_lzma(archive_handle_t *archive_handle) FAST_FUNC;
+char get_header_tar_xz(archive_handle_t *archive_handle) FAST_FUNC;
 
 void seek_by_jump(int fd, off_t amount) FAST_FUNC;
 void seek_by_read(int fd, off_t amount) FAST_FUNC;