libblkid: Add hyphens to UUID string representation in Stratis superblock parsing

[kzak@redhat.com: - small code cleanup]

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libblkid/src/superblocks/stratis.c b/libblkid/src/superblocks/stratis.c
index 7a889b2d4c8fcafe4483ebb572058e854f38af37..fe4a452774b6aba2d6f4e2ed76777c8b79008bb5 100644 (file)
--- a/libblkid/src/superblocks/stratis.c
+++ b/libblkid/src/superblocks/stratis.c
@@ -19,13 +19,18 @@
 #include "superblocks.h"
 #include "crc32c.h"
 
+/* Macro to avoid error in struct declaration. */
+#define STRATIS_UUID_LEN 32
+/* Contains 4 hyphens and trailing null byte. */
+const int STRATIS_UUID_STR_LEN = 37;
+
 struct stratis_sb {
        uint32_t crc32;
        uint8_t magic[16];
        uint64_t sectors;
        uint8_t reserved[4];
-       uint8_t pool_uuid[32];
-       uint8_t dev_uuid[32];
+       uint8_t pool_uuid[STRATIS_UUID_LEN];
+       uint8_t dev_uuid[STRATIS_UUID_LEN];
        uint64_t mda_size;
        uint64_t reserved_size;
        uint64_t flags;
@@ -57,11 +62,29 @@ static int stratis_valid_sb(uint8_t *p)
        return crc == le32_to_cpu(stratis->crc32);
 }
 
+/*
+ * Format UUID string representation to include hyphens given that Stratis stores
+ * UUIDs without hyphens in the superblock to keep the UUID length a power of 2.
+ */
+static void stratis_format_uuid(const unsigned char *src_uuid,
+                               unsigned char *dst_uuid)
+{
+       int i;
+
+       for (i = 0; i < STRATIS_UUID_LEN; i++) {
+               *dst_uuid++ = *src_uuid++;
+               if (i == 7 || i == 11 || i == 15 || i == 19)
+                       *dst_uuid ++ = '-';
+       }
+       *dst_uuid = '\0';
+}
+
 static int probe_stratis(blkid_probe pr,
                const struct blkid_idmag *mag __attribute__((__unused__)))
 {
        const struct stratis_sb *stratis = NULL;
        uint8_t *buf = blkid_probe_get_buffer(pr, 0, SB_AREA_SIZE);
+       unsigned char uuid[STRATIS_UUID_STR_LEN];
 
        if (!buf)
                return errno ? -errno : 1;
@@ -76,17 +99,16 @@ static int probe_stratis(blkid_probe pr,
                                (buf + SECOND_COPY_OFFSET);
        }
 
-       blkid_probe_strncpy_uuid(pr, stratis->dev_uuid,
-                                       sizeof(stratis->dev_uuid));
-       blkid_probe_set_value(pr, "POOL_UUID",
-                               stratis->pool_uuid,
-                               sizeof(stratis->pool_uuid));
+       stratis_format_uuid(stratis->dev_uuid, uuid);
+       blkid_probe_strncpy_uuid(pr, uuid, sizeof(uuid));
+
+       stratis_format_uuid(stratis->pool_uuid, uuid);
+       blkid_probe_set_value(pr, "POOL_UUID", uuid, sizeof(uuid));
 
        blkid_probe_sprintf_value(pr, "BLOCKDEV_SECTORS", "%" PRIu64,
                                le64_to_cpu(stratis->sectors));
        blkid_probe_sprintf_value(pr, "BLOCKDEV_INITTIME", "%" PRIu64,
                                le64_to_cpu(stratis->initialization_time));
-
        return 0;
 }