libblkid: f2fs: add checksum support

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

diff --git a/libblkid/src/superblocks/f2fs.c b/libblkid/src/superblocks/f2fs.c
index f271e80470945312eb1afe6b5c423cc86fae9a6f..33fcd7f46345b0c047a2f0dff9529c915590dced 100644 (file)
--- a/libblkid/src/superblocks/f2fs.c
+++ b/libblkid/src/superblocks/f2fs.c
@@ -9,6 +9,7 @@
 #include <string.h>
 
 #include "superblocks.h"
+#include "crc32.h"
 
 #define F2FS_MAGIC             "\x10\x20\xF5\xF2"
 #define F2FS_MAGIC_OFF         0
@@ -55,6 +56,29 @@ struct f2fs_super_block {                                    /* According to version 1.1 */
 #endif
 } __attribute__((packed));
 
+static int f2fs_validate_checksum(blkid_probe pr, size_t sb_off,
+               const struct f2fs_super_block *sb)
+{
+       uint32_t csum_off = le32_to_cpu(sb->checksum_offset);
+       if (!csum_off)
+               return 1;
+
+       unsigned char *csum_data = blkid_probe_get_buffer(pr,
+                       sb_off + csum_off, sizeof(uint32_t));
+       if (!csum_data)
+               return 0;
+
+       uint32_t expected = le32_to_cpu(*(uint32_t *) csum_data);
+
+       unsigned char *csummed = blkid_probe_get_buffer(pr, sb_off, csum_off);
+       if (!csummed)
+               return 0;
+
+       uint32_t csum = ul_crc32(be32_to_cpu(0x1020F5F2), csummed, csum_off);
+
+       return blkid_probe_verify_csum(pr, csum, expected);
+}
+
 static int probe_f2fs(blkid_probe pr, const struct blkid_idmag *mag)
 {
        struct f2fs_super_block *sb;
@@ -71,6 +95,9 @@ static int probe_f2fs(blkid_probe pr, const struct blkid_idmag *mag)
        if (vermaj == 1 && vermin == 0)
                return 0;
 
+       if (!f2fs_validate_checksum(pr, mag->kboff << 10, sb))
+               return 1;
+
        if (*((unsigned char *) sb->volume_name))
                blkid_probe_set_utf8label(pr, (unsigned char *) sb->volume_name,
                                                sizeof(sb->volume_name),