From: Thomas Weißschuh <thomas@t-8ch.de>
Date: Sun, 11 Sep 2022 15:05:09 +0000 (+0200)
Subject: libblkid: linux_raid: add checksum support
X-Git-Tag: v2.39-rc1~517^2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c68a29cabfd49052f1ec7fd50e99a03a5252ed01;p=thirdparty%2Futil-linux.git

libblkid: linux_raid: add checksum support

Signed-off-by: Thomas Weißschuh <thomas@t-8ch.de>
---

diff --git a/libblkid/src/superblocks/linux_raid.c b/libblkid/src/superblocks/linux_raid.c
index 4388e56508..360cd4eb34 100644
--- a/libblkid/src/superblocks/linux_raid.c
+++ b/libblkid/src/superblocks/linux_raid.c
@@ -182,6 +182,32 @@ static int probe_raid0(blkid_probe pr, uint64_t off)
 	return 0;
 }
 
+static int raid1_verify_csum(blkid_probe pr, off_t off,
+		const struct mdp1_super_block *mdp1)
+{
+	size_t csummed_size = sizeof(struct mdp1_super_block)
+		+ le32_to_cpu(mdp1->max_dev) * sizeof(mdp1->dev_roles[0]);
+	unsigned char *csummed = blkid_probe_get_buffer(pr, off, csummed_size);
+	if (!csummed)
+		return 1;
+
+	memset(csummed + offsetof(struct mdp1_super_block, sb_csum), 0,
+			sizeof(mdp1->sb_csum));
+
+	uint64_t csum = 0;
+
+	while (csummed_size >= 4) {
+		csum += le32_to_cpu(*(uint32_t *) csummed);
+		csummed_size -= 4;
+		csummed += 4;
+	}
+	if (csummed_size == 2)
+		csum += le16_to_cpu(*(uint16_t *) csummed);
+
+	csum = (csum >> 32) + (uint32_t) csum;
+	return blkid_probe_verify_csum(pr, csum, le32_to_cpu(mdp1->sb_csum));
+}
+
 static int probe_raid1(blkid_probe pr, off_t off)
 {
 	struct mdp1_super_block *mdp1;
@@ -198,6 +224,8 @@ static int probe_raid1(blkid_probe pr, off_t off)
 		return 1;
 	if (le64_to_cpu(mdp1->super_offset) != (uint64_t) off >> 9)
 		return 1;
+	if (!raid1_verify_csum(pr, off, mdp1))
+		return 1;
 	if (blkid_probe_set_uuid(pr, (unsigned char *) mdp1->set_uuid) != 0)
 		return 1;
 	if (blkid_probe_set_uuid_as(pr,