[PATCH v3 1/5] erofs-utils: introduce dump.erofs

[Guo Xuenan <guoxuenan@huawei.com>]

From: Wang Qi <mpiglet@outlook.com>

Add dump-tool for erofs to facilitate users directly
analyzing the erofs image file.

Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Signed-off-by: Wang Qi <mpiglet@outlook.com>
---
 Makefile.am        |  2 +-
 configure.ac       |  1 +
 dump/Makefile.am   |  8 +++++
 dump/main.c        | 81 ++++++++++++++++++++++++++++++++++++++++++++++
 include/erofs/io.h |  3 ++
 lib/config.c       |  3 ++
 lib/namei.c        |  5 ++-
 7 files changed, 99 insertions(+), 4 deletions(-)
 create mode 100644 dump/Makefile.am
 create mode 100644 dump/main.c

diff --git a/Makefile.am b/Makefile.am
index b804aa9..fedf7b5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3,7 +3,7 @@
 
 ACLOCAL_AMFLAGS = -I m4
 
-SUBDIRS = man lib mkfs
+SUBDIRS = man lib mkfs dump
 if ENABLE_FUSE
 SUBDIRS += fuse
 endif
diff --git a/configure.ac b/configure.ac
index f626064..81c493a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -280,6 +280,7 @@ AC_CONFIG_FILES([Makefile
 		 man/Makefile
 		 lib/Makefile
 		 mkfs/Makefile
+		 dump/Makefile
 		 fuse/Makefile])
 AC_OUTPUT
 
diff --git a/dump/Makefile.am b/dump/Makefile.am
new file mode 100644
index 0000000..3d8a32c
--- /dev/null
+++ b/dump/Makefile.am
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Makefile.am
+
+AUTOMAKE_OPTIONS = foreign
+bin_PROGRAMS     = dump.erofs
+dump_erofs_SOURCES = main.c
+dump_erofs_CFLAGS = -Wall -Werror -I$(top_srcdir)/include
+dump_erofs_LDADD = $(top_builddir)/lib/liberofs.la
\ No newline at end of file
diff --git a/dump/main.c b/dump/main.c
new file mode 100644
index 0000000..af8db4b
--- /dev/null
+++ b/dump/main.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021-2022 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Wang Qi <mpiglet@outlook.com>
+ *            Guo Xuenan <guoxuenan@huawei.com>
+ */
+
+#include <stdlib.h>
+#include <getopt.h>
+#include <sys/sysmacros.h>
+#include <time.h>
+#include "erofs/print.h"
+#include "erofs/io.h"
+
+static struct option long_options[] = {
+	{"help", no_argument, 0, 1},
+	{0, 0, 0, 0},
+};
+
+static void usage(void)
+{
+	fputs("usage: [options] IMAGE\n\n"
+		"Dump erofs layout from IMAGE, and [options] are:\n"
+		"-V      print the version number of dump.erofs and exit.\n"
+		"--help  display this help and exit.\n",
+		stderr);
+}
+static void dumpfs_print_version(void)
+{
+	fprintf(stderr, "dump.erofs %s\n", cfg.c_version);
+}
+
+static int dumpfs_parse_options_cfg(int argc, char **argv)
+{
+	int opt;
+
+	while ((opt = getopt_long(argc, argv, "V",
+					long_options, NULL)) != -1) {
+		switch (opt) {
+		case 'V':
+			dumpfs_print_version();
+			exit(0);
+		case 1:
+			usage();
+			exit(0);
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (optind >= argc)
+		return -EINVAL;
+
+	cfg.c_img_path = strdup(argv[optind++]);
+	if (!cfg.c_img_path)
+		return -ENOMEM;
+
+	if (optind < argc) {
+		erofs_err("unexpected argument: %s\n", argv[optind]);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int err = 0;
+
+	erofs_init_configure();
+	err = dumpfs_parse_options_cfg(argc, argv);
+	if (err) {
+		if (err == -EINVAL)
+			usage();
+		goto exit;
+	}
+
+exit:
+	erofs_exit_configure();
+	return err;
+}
diff --git a/include/erofs/io.h b/include/erofs/io.h
index 5574245..00e5de8 100644
--- a/include/erofs/io.h
+++ b/include/erofs/io.h
@@ -10,6 +10,7 @@
 #define __EROFS_IO_H
 
 #include <unistd.h>
+#include <sys/types.h>
 #include "internal.h"
 
 #ifndef O_BINARY
@@ -25,6 +26,8 @@ int dev_fillzero(u64 offset, size_t len, bool padding);
 int dev_fsync(void);
 int dev_resize(erofs_blk_t nblocks);
 u64 dev_length(void);
+dev_t erofs_new_decode_dev(u32 dev);
+int erofs_read_inode_from_disk(struct erofs_inode *vi);
 
 static inline int blk_write(const void *buf, erofs_blk_t blkaddr,
 			    u32 nblocks)
diff --git a/lib/config.c b/lib/config.c
index 99fcf49..405fae6 100644
--- a/lib/config.c
+++ b/lib/config.c
@@ -7,6 +7,7 @@
  * Created by Li Guifu <bluce.liguifu@huawei.com>
  */
 #include <string.h>
+#include <stdlib.h>
 #include "erofs/print.h"
 #include "erofs/internal.h"
 
@@ -45,6 +46,8 @@ void erofs_exit_configure(void)
 	if (cfg.sehnd)
 		selabel_close(cfg.sehnd);
 #endif
+	if (cfg.c_img_path)
+		free(cfg.c_img_path);
 }
 
 static unsigned int fullpath_prefix;	/* root directory prefix length */
diff --git a/lib/namei.c b/lib/namei.c
index 4e06ba4..b45e9d8 100644
--- a/lib/namei.c
+++ b/lib/namei.c
@@ -5,7 +5,6 @@
  * Created by Li Guifu <blucerlee@gmail.com>
  */
 #include <linux/kdev_t.h>
-#include <sys/types.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <errno.h>
@@ -15,7 +14,7 @@
 #include "erofs/print.h"
 #include "erofs/io.h"
 
-static dev_t erofs_new_decode_dev(u32 dev)
+dev_t erofs_new_decode_dev(u32 dev)
 {
 	const unsigned int major = (dev & 0xfff00) >> 8;
 	const unsigned int minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
@@ -23,7 +22,7 @@ static dev_t erofs_new_decode_dev(u32 dev)
 	return makedev(major, minor);
 }
 
-static int erofs_read_inode_from_disk(struct erofs_inode *vi)
+int erofs_read_inode_from_disk(struct erofs_inode *vi)
 {
 	int ret, ifmt;
 	char buf[sizeof(struct erofs_inode_extended)];
-- 
2.25.4