debugfs: create commands to edit extended attributes

Enhance debugfs to be able to display and modify extended attributes, and
create some simple tests for the extended attribute editing functions.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 297 insertions, 0 deletions

diff --git a/debugfs/xattrs.c b/debugfs/xattrs.c
new file mode 100644
index 000000000..0a2952143
--- /dev/null
+++ b/debugfs/xattrs.c
@@ -0,0 +1,297 @@
+/*
+ * xattrs.c --- Modify extended attributes via debugfs.
+ *
+ * Copyright (C) 2014 Oracle.  This file may be redistributed
+ * under the terms of the GNU Public License.
+ */
+
+#include "config.h"
+#include <stdio.h>
+#ifdef HAVE_GETOPT_H
+#include <getopt.h>
+#else
+extern int optind;
+extern char *optarg;
+#endif
+#include <ctype.h>
+
+#include "debugfs.h"
+
+/* Dump extended attributes */
+static void dump_xattr_string(FILE *out, const char *str, int len)
+{
+	int printable = 0;
+	int i;
+
+	/* check: is string "printable enough?" */
+	for (i = 0; i < len; i++)
+		if (isprint(str[i]))
+			printable++;
+
+	if (printable <= len*7/8)
+		printable = 0;
+
+	for (i = 0; i < len; i++)
+		if (printable)
+			fprintf(out, isprint(str[i]) ? "%c" : "\\%03o",
+				(unsigned char)str[i]);
+		else
+			fprintf(out, "%02x ", (unsigned char)str[i]);
+}
+
+static int dump_attr(char *name, char *value, size_t value_len, void *data)
+{
+	FILE *out = data;
+
+	fprintf(out, "  ");
+	dump_xattr_string(out, name, strlen(name));
+	fprintf(out, " = \"");
+	dump_xattr_string(out, value, value_len);
+	fprintf(out, "\" (%zu)\n", value_len);
+
+	return 0;
+}
+
+void dump_inode_attributes(FILE *out, ext2_ino_t ino)
+{
+	struct ext2_xattr_handle *h;
+	size_t sz;
+	errcode_t err;
+
+	err = ext2fs_xattrs_open(current_fs, ino, &h);
+	if (err)
+		return;
+
+	err = ext2fs_xattrs_read(h);
+	if (err)
+		goto out;
+
+	err = ext2fs_xattrs_count(h, &sz);
+	if (err || sz == 0)
+		goto out;
+
+	fprintf(out, "Extended attributes:\n");
+	err = ext2fs_xattrs_iterate(h, dump_attr, out);
+	if (err)
+		goto out;
+
+out:
+	err = ext2fs_xattrs_close(&h);
+}
+
+void do_list_xattr(int argc, char **argv)
+{
+	ext2_ino_t ino;
+
+	if (argc != 2) {
+		printf("%s: Usage: %s <file>\n", argv[0],
+		       argv[0]);
+		return;
+	}
+
+	if (check_fs_open(argv[0]))
+		return;
+
+	ino = string_to_inode(argv[1]);
+	if (!ino)
+		return;
+
+	dump_inode_attributes(stdout, ino);
+}
+
+void do_get_xattr(int argc, char **argv)
+{
+	ext2_ino_t ino;
+	struct ext2_xattr_handle *h;
+	FILE *fp = NULL;
+	char *buf = NULL;
+	size_t buflen;
+	int i;
+	errcode_t err;
+
+	reset_getopt();
+	while ((i = getopt(argc, argv, "f:")) != -1) {
+		switch (i) {
+		case 'f':
+			fp = fopen(optarg, "w");
+			if (fp == NULL) {
+				perror(optarg);
+				return;
+			}
+			break;
+		default:
+			printf("%s: Usage: %s <file> <attr> [-f outfile]\n",
+			       argv[0], argv[0]);
+			return;
+		}
+	}
+
+	if (optind != argc - 2) {
+		printf("%s: Usage: %s <file> <attr> [-f outfile]\n", argv[0],
+		       argv[0]);
+		return;
+	}
+
+	if (check_fs_open(argv[0]))
+		return;
+
+	ino = string_to_inode(argv[optind]);
+	if (!ino)
+		return;
+
+	err = ext2fs_xattrs_open(current_fs, ino, &h);
+	if (err)
+		return;
+
+	err = ext2fs_xattrs_read(h);
+	if (err)
+		goto out;
+
+	err = ext2fs_xattr_get(h, argv[optind + 1], (void **)&buf, &buflen);
+	if (err)
+		goto out;
+
+	if (fp) {
+		fwrite(buf, buflen, 1, fp);
+		fclose(fp);
+	} else {
+		dump_xattr_string(stdout, buf, buflen);
+		printf("\n");
+	}
+
+	if (buf)
+		ext2fs_free_mem(&buf);
+out:
+	ext2fs_xattrs_close(&h);
+	if (err)
+		com_err(argv[0], err, "while getting extended attribute");
+}
+
+void do_set_xattr(int argc, char **argv)
+{
+	ext2_ino_t ino;
+	struct ext2_xattr_handle *h;
+	FILE *fp = NULL;
+	char *buf = NULL;
+	size_t buflen;
+	int i;
+	errcode_t err;
+
+	reset_getopt();
+	while ((i = getopt(argc, argv, "f:")) != -1) {
+		switch (i) {
+		case 'f':
+			fp = fopen(optarg, "r");
+			if (fp == NULL) {
+				perror(optarg);
+				return;
+			}
+			break;
+		default:
+			printf("%s: Usage: %s <file> <attr> [-f infile | "
+			       "value]\n", argv[0], argv[0]);
+			return;
+		}
+	}
+
+	if (optind != argc - 2 && optind != argc - 3) {
+		printf("%s: Usage: %s <file> <attr> [-f infile | value>]\n",
+		       argv[0], argv[0]);
+		return;
+	}
+
+	if (check_fs_open(argv[0]))
+		return;
+	if (check_fs_read_write(argv[0]))
+		return;
+	if (check_fs_bitmaps(argv[0]))
+		return;
+
+	ino = string_to_inode(argv[optind]);
+	if (!ino)
+		return;
+
+	err = ext2fs_xattrs_open(current_fs, ino, &h);
+	if (err)
+		return;
+
+	err = ext2fs_xattrs_read(h);
+	if (err)
+		goto out;
+
+	if (fp) {
+		err = ext2fs_get_mem(current_fs->blocksize, &buf);
+		if (err)
+			goto out;
+		buflen = fread(buf, 1, current_fs->blocksize, fp);
+	} else {
+		buf = argv[optind + 2];
+		buflen = strlen(argv[optind + 2]);
+	}
+
+	err = ext2fs_xattr_set(h, argv[optind + 1], buf, buflen);
+	if (err)
+		goto out;
+
+	err = ext2fs_xattrs_write(h);
+	if (err)
+		goto out;
+
+out:
+	if (fp) {
+		fclose(fp);
+		ext2fs_free_mem(&buf);
+	}
+	ext2fs_xattrs_close(&h);
+	if (err)
+		com_err(argv[0], err, "while setting extended attribute");
+}
+
+void do_rm_xattr(int argc, char **argv)
+{
+	ext2_ino_t ino;
+	struct ext2_xattr_handle *h;
+	int i;
+	errcode_t err;
+
+	if (argc < 3) {
+		printf("%s: Usage: %s <file> <attrs>...\n", argv[0], argv[0]);
+		return;
+	}
+
+	if (check_fs_open(argv[0]))
+		return;
+	if (check_fs_read_write(argv[0]))
+		return;
+	if (check_fs_bitmaps(argv[0]))
+		return;
+
+	ino = string_to_inode(argv[1]);
+	if (!ino)
+		return;
+
+	err = ext2fs_xattrs_open(current_fs, ino, &h);
+	if (err)
+		return;
+
+	err = ext2fs_xattrs_read(h);
+	if (err)
+		goto out;
+
+	for (i = 2; i < argc; i++) {
+		size_t buflen;
+		char *buf;
+
+		err = ext2fs_xattr_remove(h, argv[i]);
+		if (err)
+			goto out;
+	}
+
+	err = ext2fs_xattrs_write(h);
+	if (err)
+		goto out;
+out:
+	ext2fs_xattrs_close(&h);
+	if (err)
+		com_err(argv[0], err, "while removing extended attribute");
+}