Add parse_uuid() that creates a binary representation of an UUID from

a string representation.

2 files changed, 48 insertions, 0 deletions

diff --git a/sys/kern/kern_uuid.c b/sys/kern/kern_uuid.c
index 6205bfb4ee1d..e3549b4d397e 100644
--- a/sys/kern/kern_uuid.c
+++ b/sys/kern/kern_uuid.c
@@ -313,3 +313,49 @@ be_uuid_dec(void const *buf, struct uuid *uuid)
 	for (i = 0; i < _UUID_NODE_LEN; i++)
 		uuid->node[i] = p[10 + i];
 }
+
+int
+parse_uuid(const char *str, struct uuid *uuid)
+{
+	u_int c[11];
+	int n;
+
+	/* An empty string represents a nil UUID. */
+	if (*str == '\0') {
+		bzero(uuid, sizeof(*uuid));
+		return (0);
+	}
+
+	/* The UUID string representation has a fixed length. */
+	if (strlen(str) != 36)
+		return (EINVAL);
+
+	/*
+	 * We only work with "new" UUIDs. New UUIDs have the form:
+	 *      01234567-89ab-cdef-0123-456789abcdef
+	 * The so called "old" UUIDs, which we don't support, have the form:
+	 *      0123456789ab.cd.ef.01.23.45.67.89.ab
+	 */
+	if (str[8] != '-')
+		return (EINVAL);
+
+	n = sscanf(str, "%8x-%4x-%4x-%2x%2x-%2x%2x%2x%2x%2x%2x", c + 0, c + 1,
+	    c + 2, c + 3, c + 4, c + 5, c + 6, c + 7, c + 8, c + 9, c + 10);
+	/* Make sure we have all conversions. */
+	if (n != 11)
+		return (EINVAL);
+
+	/* Successful scan. Build the UUID. */
+	uuid->time_low = c[0];
+	uuid->time_mid = c[1];
+	uuid->time_hi_and_version = c[2];
+	uuid->clock_seq_hi_and_reserved = c[3];
+	uuid->clock_seq_low = c[4];
+	for (n = 0; n < 6; n++)
+		uuid->node[n] = c[n + 5];
+
+	/* Check semantics... */
+	return (((c[3] & 0x80) != 0x00 &&		/* variant 0? */
+	    (c[3] & 0xc0) != 0x80 &&			/* variant 1? */
+	    (c[3] & 0xe0) != 0xc0) ? EINVAL : 0);	/* variant 2? */
+}
diff --git a/sys/sys/uuid.h b/sys/sys/uuid.h
index 41f02b5db587..0f40bb20e31b 100644
--- a/sys/sys/uuid.h
+++ b/sys/sys/uuid.h
@@ -61,6 +61,8 @@ struct uuid *kern_uuidgen(struct uuid *, size_t);
 int snprintf_uuid(char *, size_t, struct uuid *);
 int printf_uuid(struct uuid *);
 int sbuf_printf_uuid(struct sbuf *, struct uuid *);
+int parse_uuid(const char *, struct uuid *);
+
 void be_uuid_dec(void const *buf, struct uuid *uuid);
 void be_uuid_enc(void *buf, struct uuid const *uuid);
 void le_uuid_dec(void const *buf, struct uuid *uuid);