Add LZO compressor implementation

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

8 files changed, 114 insertions, 1 deletions

diff --git a/README b/README
index 98f6353..a953acf 100644
--- a/README
+++ b/README
@@ -83,5 +83,5 @@ At the moment, the following things are still missing:
  - hard links
  - NFS export tables
  - compressor options
- - compressors other than XZ and GZIP (i.e. lzo, lz4, zstd, *maybe* lzma1?)
+ - compressors other than XZ and GZIP (i.e. lz4, zstd, *maybe* lzma1?)
  - support for extracting SquashFS < 4.0
diff --git a/configure.ac b/configure.ac
index 4cb29bd..422a113 100644
--- a/configure.ac
+++ b/configure.ac
@@ -61,13 +61,25 @@ AC_ARG_WITH([xz],
 	esac],
 	[AM_CONDITIONAL([WITH_XZ], [true])])
 
+AC_ARG_WITH([lzo],
+	[AS_HELP_STRING([--without-lzo],
+			[Build without lzo compression support])],
+	[case "${withval}" in
+	yes) AM_CONDITIONAL([WITH_LZO], [true]) ;;
+	no)  AM_CONDITIONAL([WITH_LZO], [false]) ;;
+	*) AC_MSG_ERROR([bad value ${withval} for --without-lzo]) ;;
+	esac],
+	[AM_CONDITIONAL([WITH_LZO], [true])])
+
 ##### search for dependencies #####
 
 need_zlib="no"
 need_xz="no"
+need_lzo="no"
 
 AM_COND_IF([WITH_GZIP], [need_zlib="yes"])
 AM_COND_IF([WITH_XZ], [need_xz="yes"])
+AM_COND_IF([WITH_LZO], [need_lzo="yes"])
 
 if test "x$need_zlib" = "xyes"; then
 	PKG_CHECK_MODULES(ZLIB, [zlib], [], [AC_MSG_ERROR([cannot find zlib])])
@@ -78,6 +90,16 @@ if test "x$need_xz" = "xyes"; then
 			      [AC_MSG_ERROR([cannot find xz sdk])])
 fi
 
+if test "x$need_lzo" = "xyes"; then
+	AC_ARG_VAR([LZO_CFLAGS], [C compiler flags for lzo])
+	AC_ARG_VAR([LZO_LIBS], [linker flags for lzo])
+	AC_CHECK_LIB([lzo2], [lzo1x_1_15_compress], [LZO_LIBS="-llzo2"],
+		[AC_CHECK_LIB([lzo],[lzo1x_1_15_compress],[LZO_LIBS="-llzo"],
+			[AC_MSG_ERROR([cannot find lzo library])]
+		)]
+	)
+fi
+
 ##### generate output #####
 
 AC_CONFIG_HEADERS([config.h])
diff --git a/lib/Makemodule.am b/lib/Makemodule.am
index d174c99..aacec34 100644
--- a/lib/Makemodule.am
+++ b/lib/Makemodule.am
@@ -35,4 +35,11 @@ libcompress_a_CFLAGS += $(XZ_CFLAGS)
 libcompress_a_CPPFLAGS += -DWITH_XZ
 endif
 
+if WITH_LZO
+libcompress_a_SOURCES += lib/comp/lzo.c
+
+libcompress_a_CFLAGS += $(LZO_CFLAGS)
+libcompress_a_CPPFLAGS += -DWITH_LZO
+endif
+
 noinst_LIBRARIES += libfstree.a libcompress.a libutil.a libsquashfs.a
diff --git a/lib/comp/compressor.c b/lib/comp/compressor.c
index 1ede111..42ebd8b 100644
--- a/lib/comp/compressor.c
+++ b/lib/comp/compressor.c
@@ -12,6 +12,9 @@ static compressor_fun_t compressors[SQFS_COMP_MAX + 1] = {
 #ifdef WITH_XZ
 	[SQFS_COMP_XZ] = create_xz_compressor,
 #endif
+#ifdef WITH_LZO
+	[SQFS_COMP_LZO] = create_lzo_compressor,
+#endif
 };
 
 bool compressor_exists(E_SQFS_COMPRESSOR id)
diff --git a/lib/comp/internal.h b/lib/comp/internal.h
index d1cf1f2..3b24af0 100644
--- a/lib/comp/internal.h
+++ b/lib/comp/internal.h
@@ -8,4 +8,6 @@ compressor_t *create_xz_compressor(bool compress, size_t block_size);
 
 compressor_t *create_gzip_compressor(bool compress, size_t block_size);
 
+compressor_t *create_lzo_compressor(bool compress, size_t block_size);
+
 #endif /* INTERNAL_H */
diff --git a/lib/comp/lzo.c b/lib/comp/lzo.c
new file mode 100644
index 0000000..30b14cb
--- /dev/null
+++ b/lib/comp/lzo.c
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <lzo/lzo1x.h>
+
+#include "internal.h"
+
+typedef struct {
+	compressor_t base;
+
+	uint8_t buffer[LZO1X_999_MEM_COMPRESS];
+} lzo_compressor_t;
+
+static ssize_t lzo_comp_block(compressor_t *base, const uint8_t *in,
+			      size_t size, uint8_t *out, size_t outsize)
+{
+	lzo_compressor_t *lzo = (lzo_compressor_t *)base;
+	lzo_uint len = outsize;
+
+	if (lzo1x_999_compress(in, size, out, &len, lzo->buffer) != LZO_E_OK) {
+		fputs("lzo1x_999 failed. According to its "
+		      "manual, this shouldn't happen!\n", stderr);
+		return -1;
+	}
+
+	if (len < size)
+		return len;
+
+	return 0;
+}
+
+static ssize_t lzo_uncomp_block(compressor_t *base, const uint8_t *in,
+				size_t size, uint8_t *out, size_t outsize)
+{
+	lzo_compressor_t *lzo = (lzo_compressor_t *)base;
+	lzo_uint len = outsize;
+	int ret;
+
+	ret = lzo1x_decompress_safe(in, size, out, &len, lzo->buffer);
+
+	if (ret != LZO_E_OK) {
+		fputs("lzo decompress: input data is corrupted\n", stderr);
+		return -1;
+	}
+
+	return len;
+}
+
+static void lzo_destroy(compressor_t *base)
+{
+	free(base);
+}
+
+compressor_t *create_lzo_compressor(bool compress, size_t block_size)
+{
+	lzo_compressor_t *lzo = calloc(1, sizeof(*lzo));
+	compressor_t *base = (compressor_t *)lzo;
+	(void)block_size;
+
+	if (lzo == NULL) {
+		perror("creating lzo compressor");
+		return NULL;
+	}
+
+	base->destroy = lzo_destroy;
+	base->do_block = compress ? lzo_comp_block : lzo_uncomp_block;
+	return base;
+}
diff --git a/mkfs/Makemodule.am b/mkfs/Makemodule.am
index 5af5ad5..35e937c 100644
--- a/mkfs/Makemodule.am
+++ b/mkfs/Makemodule.am
@@ -10,4 +10,8 @@ if WITH_GZIP
 gensquashfs_LDADD += $(ZLIB_LIBS)
 endif
 
+if WITH_LZO
+gensquashfs_LDADD += $(LZO_LIBS)
+endif
+
 bin_PROGRAMS += gensquashfs
diff --git a/unpack/Makemodule.am b/unpack/Makemodule.am
index d47cb5e..c3e61aa 100644
--- a/unpack/Makemodule.am
+++ b/unpack/Makemodule.am
@@ -12,4 +12,8 @@ if WITH_GZIP
 rdsquashfs_LDADD += $(ZLIB_LIBS)
 endif
 
+if WITH_LZO
+rdsquashfs_LDADD += $(LZO_LIBS)
+endif
+
 bin_PROGRAMS += rdsquashfs