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From: "Darrick J. Wong" <djwong@us.ibm.com>
To: Andreas Dilger <adilger.kernel@dilger.ca>,
	Theodore Tso <tytso@mit.edu>,
	"Darrick J. Wong" <djwong@us.ibm.com>
Cc: Sunil Mushran <sunil.mushran@oracle.com>,
	Amir Goldstein <amir73il@gmail.com>,
	Andi Kleen <andi@firstfloor.org>, Mingming Cao <cmm@us.ibm.com>,
	Joel Becker <jlbec@evilplan.org>,
	linux-ext4@vger.kernel.org, Coly Li <colyli@gmail.com>
Subject: [PATCH 24/37] libext2fs: Add dx_root/dx_node checksum calculation and verification helpers
Date: Wed, 31 Aug 2011 17:37:44 -0700	[thread overview]
Message-ID: <20110901003744.1176.39972.stgit@elm3c44.beaverton.ibm.com> (raw)
In-Reply-To: <20110901003509.1176.51159.stgit@elm3c44.beaverton.ibm.com>

Verify and calculate checksums of htree internal node blocks.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
 lib/ext2fs/csum.c    |  107 ++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/ext2fs/dirhash.c |   41 +++++++++++++++++++
 lib/ext2fs/ext2fs.h  |    8 ++++
 3 files changed, 156 insertions(+), 0 deletions(-)


diff --git a/lib/ext2fs/csum.c b/lib/ext2fs/csum.c
index fdca971..4963524 100644
--- a/lib/ext2fs/csum.c
+++ b/lib/ext2fs/csum.c
@@ -29,6 +29,113 @@
 #define STATIC static
 #endif
 
+__u32 ext2fs_dx_csum(ext2_filsys fs, ext2_ino_t inum,
+		     struct ext2_dir_entry *dirent)
+{
+	char *buf = (char *)dirent;
+	struct ext2_dx_countlimit *c;
+	int size, count_offset, limit, count;
+	__u32 crc = 0;
+
+	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 0;
+
+	c = ext2fs_get_dx_countlimit(fs, dirent, &count_offset);
+	if (!c)
+		return 0;
+	limit = ext2fs_le16_to_cpu(c->limit);
+	count = ext2fs_le16_to_cpu(c->count);
+	if (count_offset + (limit * sizeof(struct ext2_dx_entry)) >
+	    fs->blocksize - sizeof(struct ext2_dx_tail))
+		return 0;
+
+	size = count_offset + (count * sizeof(struct ext2_dx_entry));
+
+	/*
+	 * The dx_root/dx_entry structures are always accessed via
+	 * le*_to_cpu helpers and don't need swapping here.  However, the
+	 * dirent container fields need to be swapped.
+	 */
+#ifdef WORDS_BIGENDIAN
+	errcode_t retval;
+
+	retval = ext2fs_get_mem(fs->blocksize, &buf);
+	if (retval)
+		return 0;
+	memcpy(buf, dirent, fs->blocksize);
+	retval = ext2fs_dirent_swab_out(fs, buf, 0);
+	if (retval) {
+		crc = 0;
+		goto out;
+	}
+#endif
+
+	inum = ext2fs_cpu_to_le32(inum);
+	crc = crc32c_le(~0, fs->super->s_uuid, sizeof(fs->super->s_uuid));
+	crc = crc32c_le(crc, (char *)&inum, sizeof(inum));
+	crc = crc32c_le(crc, buf, size);
+
+#ifdef WORDS_BIGENDIAN
+out:
+	ext2fs_free_mem(&buf);
+#endif
+
+	return crc;
+}
+
+int ext2fs_dx_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+			  struct ext2_dir_entry *dirent)
+{
+	struct ext2_dx_countlimit *c;
+	struct ext2_dx_tail *t;
+	int count_offset, limit, count;
+
+	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	c = ext2fs_get_dx_countlimit(fs, dirent, &count_offset);
+	if (!c)
+		return 1;
+	limit = ext2fs_le16_to_cpu(c->limit);
+	count = ext2fs_le16_to_cpu(c->count);
+	if (count_offset + (limit * sizeof(struct ext2_dx_entry)) >
+	    fs->blocksize - sizeof(struct ext2_dx_tail))
+		return 0;
+	/* htree structs are accessed in LE order */
+	t = (struct ext2_dx_tail *)(((struct ext2_dx_entry *)c) + limit);
+	if (ext2fs_le32_to_cpu(t->checksum) != ext2fs_dx_csum(fs, inum, dirent))
+		return 0;
+
+	return 1;
+}
+
+void ext2fs_dx_csum_set(ext2_filsys fs, ext2_ino_t inum,
+			struct ext2_dir_entry *dirent)
+{
+	struct ext2_dx_countlimit *c;
+	struct ext2_dx_tail *t;
+	int count_offset, limit, count;
+
+	if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	c = ext2fs_get_dx_countlimit(fs, dirent, &count_offset);
+	if (!c)
+		return;
+	limit = ext2fs_le16_to_cpu(c->limit);
+	count = ext2fs_le16_to_cpu(c->count);
+	if (count_offset + (limit * sizeof(struct ext2_dx_entry)) >
+	    fs->blocksize - sizeof(struct ext2_dx_tail))
+		return;
+	t = (struct ext2_dx_tail *)(((struct ext2_dx_entry *)c) + limit);
+
+	/* htree structs are accessed in LE order */
+	t->checksum = ext2fs_cpu_to_le32(ext2fs_dx_csum(fs, inum, dirent));
+}
+
 #define EXT3_EXTENT_TAIL_OFFSET(hdr)	(sizeof(struct ext3_extent_header) + \
 	(sizeof(struct ext3_extent) * ext2fs_le16_to_cpu((hdr)->eh_max)))
 
diff --git a/lib/ext2fs/dirhash.c b/lib/ext2fs/dirhash.c
index a069706..76ac274 100644
--- a/lib/ext2fs/dirhash.c
+++ b/lib/ext2fs/dirhash.c
@@ -255,3 +255,44 @@ errcode_t ext2fs_dirhash(int version, const char *name, int len,
 		*ret_minor_hash = minor_hash;
 	return 0;
 }
+
+struct ext2_dx_countlimit *ext2fs_get_dx_countlimit(ext2_filsys fs,
+		struct ext2_dir_entry *dirent, int *offset)
+{
+	struct ext2_dir_entry *dp;
+	struct ext2_dx_root_info *root;
+	struct ext2_dx_countlimit *c;
+	int count_offset, max_sane_entries;
+	unsigned int rec_len;
+	errcode_t retval;
+
+	retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
+	if (retval)
+		return NULL;
+
+	if (rec_len == fs->blocksize && dirent->name_len == 0)
+		count_offset = 8;
+	else if (rec_len == 12) {
+		dp = (struct ext2_dir_entry *)(((void *)dirent) + rec_len);
+		retval = ext2fs_get_rec_len(fs, dp, &rec_len);
+		if (retval || rec_len != fs->blocksize - 12)
+			return NULL;
+		root = (struct ext2_dx_root_info *)(((void *)dp + 12));
+		if (root->reserved_zero ||
+		    root->info_length != sizeof(struct ext2_dx_root_info))
+			return NULL;
+		count_offset = 32;
+	} else
+		return NULL;
+
+	c = (struct ext2_dx_countlimit *)(((void *)dirent) + count_offset);
+	max_sane_entries = (fs->blocksize - count_offset) /
+			   sizeof(struct ext2_dx_entry);
+	if (ext2fs_le16_to_cpu(c->limit) > max_sane_entries ||
+	    ext2fs_le16_to_cpu(c->count) > max_sane_entries)
+		return NULL;
+
+	if (offset)
+		*offset = count_offset;
+	return c;
+}
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 1e3e9f1..7110f72 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -894,6 +894,12 @@ extern __u32 crc32c_be(__u32 crc, unsigned char const *p, size_t len);
 extern __u32 crc32c_le(__u32 crc, unsigned char const *p, size_t len);
 
 /* csum.c */
+extern __u32 ext2fs_dx_csum(ext2_filsys fs, ext2_ino_t inum,
+			    struct ext2_dir_entry *dirent);
+extern int ext2fs_dx_csum_verify(ext2_filsys fs, ext2_ino_t inum,
+				 struct ext2_dir_entry *dirent);
+extern void ext2fs_dx_csum_set(ext2_filsys fs, ext2_ino_t inum,
+			       struct ext2_dir_entry *dirent);
 extern __u32 ext2fs_extent_block_csum(ext2_filsys fs, ext2_ino_t inum,
 				      struct ext3_extent_header *eh);
 extern int ext2fs_extent_block_csum_verify(ext2_filsys fs,
@@ -983,6 +989,8 @@ extern errcode_t ext2fs_write_dir_block3(ext2_filsys fs, blk64_t block,
 					 void *buf, int flags);
 
 /* dirhash.c */
+extern struct ext2_dx_countlimit *ext2fs_get_dx_countlimit(ext2_filsys fs,
+				struct ext2_dir_entry *dirent, int *offset);
 extern errcode_t ext2fs_dirhash(int version, const char *name, int len,
 				const __u32 *seed,
 				ext2_dirhash_t *ret_hash,


  parent reply	other threads:[~2011-09-01  0:37 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-01  0:35 [PATCH v1 00/37] e2fsprogs: Add metadata checksumming Darrick J. Wong
2011-09-01  0:35 ` [PATCH 01/37] e2fsprogs: Read and write full-sized inodes Darrick J. Wong
2011-09-03 18:05   ` Andreas Dilger
2011-09-04 14:04     ` Ted Ts'o
2011-09-04 17:40       ` Andreas Dilger
2011-09-14 16:39   ` Ted Ts'o
2011-09-15 20:25     ` Darrick J. Wong
2011-09-15 21:35       ` Andreas Dilger
2011-09-16  1:04         ` Darrick J. Wong
2011-09-18  1:52           ` Ted Ts'o
2011-09-01  0:35 ` [PATCH 02/37] libext2fs: Add metadata checksum flag Darrick J. Wong
2011-09-04  1:47   ` Andreas Dilger
2011-09-01  0:35 ` [PATCH 03/37] debugfs: Optionally ignore bad checksums Darrick J. Wong
2011-09-01  0:35 ` [PATCH 04/37] libext2fs: Add crc32c implementation for metadata checksumming Darrick J. Wong
2011-09-16  3:32   ` Ted Ts'o
2011-09-01  0:35 ` [PATCH 05/37] libext2fs: Implement a crc32c self-test Darrick J. Wong
2011-09-01  0:35 ` [PATCH 06/37] libext2fs: Add inode checksum support Darrick J. Wong
2011-09-04 17:59   ` Andreas Dilger
2011-09-05 18:59     ` Darrick J. Wong
2011-09-01  0:35 ` [PATCH 07/37] debugfs: Dump inode checksum when appropriate Darrick J. Wong
2011-09-01  0:36 ` [PATCH 08/37] tune2fs: Add inode checksum support Darrick J. Wong
2011-09-01  0:36 ` [PATCH 09/37] e2fsck: Verify and correct inode checksums Darrick J. Wong
2011-09-04 18:17   ` Andreas Dilger
2011-09-05 19:05     ` Darrick J. Wong
2011-09-01  0:36 ` [PATCH 10/37] mke2fs: Allow metadata checksums to be turned on at mkfs time Darrick J. Wong
2011-09-04 18:28   ` Andreas Dilger
2011-09-05 19:20     ` Darrick J. Wong
2011-09-06  1:54       ` Andreas Dilger
2011-09-06 17:13         ` Darrick J. Wong
2011-09-01  0:36 ` [PATCH 11/37] libext2fs: Create the inode bitmap checksum Darrick J. Wong
2011-09-14 17:02   ` Ted Ts'o
2011-09-14 19:31     ` Darrick J. Wong
2011-09-14 20:00       ` Andreas Dilger
2011-09-14 19:59     ` Andreas Dilger
2011-09-14 22:14       ` Ted Ts'o
2011-09-01  0:36 ` [PATCH 12/37] tune2fs: Rewrite inode bitmap checksums Darrick J. Wong
2011-09-01  0:36 ` [PATCH 13/37] dumpe2fs: Display inode bitmap checksum Darrick J. Wong
2011-09-04 18:30   ` Andreas Dilger
2011-09-05 19:20     ` Darrick J. Wong
2011-09-01  0:36 ` [PATCH 14/37] e2fsck: Verify " Darrick J. Wong
2011-09-01  0:36 ` [PATCH 15/37] libext2fs: Create the block " Darrick J. Wong
2011-09-01  0:36 ` [PATCH 16/37] dumpe2fs: Display " Darrick J. Wong
2011-09-01  0:37 ` [PATCH 17/37] e2fsck: Verify " Darrick J. Wong
2011-09-01  0:37 ` [PATCH 18/37] e2fsck: Don't verify bitmap checksums Darrick J. Wong
2011-09-01  0:37 ` [PATCH 19/37] tune2fs: Rewrite block " Darrick J. Wong
2011-09-01  0:37 ` [PATCH 20/37] libext2fs: Verify and calculate extent tree block checksums Darrick J. Wong
2011-09-01  0:37 ` [PATCH 21/37] tune2fs: Enable extent tree checksums Darrick J. Wong
2011-09-01  0:37 ` [PATCH 22/37] libext2fs: Introduce dx_tail and dir_entry_tail Darrick J. Wong
2011-09-01  0:37 ` [PATCH 23/37] debugfs: Print htree internal node checksums Darrick J. Wong
2011-09-01  0:37 ` Darrick J. Wong [this message]
2011-09-01  0:37 ` [PATCH 25/37] e2fsck: Verify htree root/node checksums Darrick J. Wong
2011-09-01  0:37 ` [PATCH 26/37] libext2fs: Introduce dir_entry_tail to provide checksums for directory leaf nodes Darrick J. Wong
2011-09-01  0:38 ` [PATCH 27/37] e2fsck: Check directory leaf block checksums Darrick J. Wong
2011-09-01  0:38 ` [PATCH 28/37] tune2fs: Rebuild and checksum directories when toggling metadata_csum or changing UUID Darrick J. Wong
2011-09-01  0:38 ` [PATCH 29/37] libext2fs: Verify and calculate extended attribute block checksums Darrick J. Wong
2011-09-01  0:38 ` [PATCH 30/37] e2fsck: Check " Darrick J. Wong
2011-09-01  0:38 ` [PATCH 32/37] libext2fs: Extend inode checksum to cover the EA block Darrick J. Wong
2011-09-14 16:48   ` Ted Ts'o
2011-09-01  0:38 ` [PATCH 33/37] tune2fs: Rewrite extended attribute block checksums Darrick J. Wong
2011-09-01  0:38 ` [PATCH 34/37] libext2fs: Calculate and verify superblock checksums Darrick J. Wong
2011-09-01  0:38 ` [PATCH 35/37] e2fsck: Handle superblock checksum errors gracefully Darrick J. Wong
2011-09-01  0:39 ` [PATCH 36/37] e2p: Print superblock checksum in list_super Darrick J. Wong
2011-09-01  0:39 ` [PATCH 37/37] e2fsck: Support CRC32c checksum in journal commit blocks Darrick J. Wong

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