part_efi: move uuid<->string conversion functions into lib/uuid.c

This commit introduces cleanup for uuid library.
Changes:
- move uuid<->string conversion functions into lib/uuid.c so they can be
  used by code outside part_efi.c.
- rename uuid_string() to uuid_bin_to_str() for consistency with existing
  uuid_str_to_bin()
- add an error return code to uuid_str_to_bin()
- update existing code to the new library functions.

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: trini@ti.com

disk/part_efi.c

@@ -63,26 +63,6 @@ static char *print_efiname(gpt_entry *pte)
 	return name;
 }
 
-static void uuid_string(unsigned char *uuid, char *str)
-{
-	static const u8 le[16] = {3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11,
-				  12, 13, 14, 15};
-	int i;
-
-	for (i = 0; i < 16; i++) {
-		sprintf(str, "%02x", uuid[le[i]]);
-		str += 2;
-		switch (i) {
-		case 3:
-		case 5:
-		case 7:
-		case 9:
-			*str++ = '-';
-			break;
-		}
-	}
-}
-
 static efi_guid_t system_guid = PARTITION_SYSTEM_GUID;
 
 static inline int is_bootable(gpt_entry *p)
@@ -103,6 +83,7 @@ void print_part_efi(block_dev_desc_t * dev_desc)
 	gpt_entry *gpt_pte = NULL;
 	int i = 0;
 	char uuid[37];
+	unsigned char *uuid_bin;
 
 	if (!dev_desc) {
 		printf("%s: Invalid Argument(s)\n", __func__);
@@ -132,9 +113,11 @@ void print_part_efi(block_dev_desc_t * dev_desc)
 			le64_to_cpu(gpt_pte[i].ending_lba),
 			print_efiname(&gpt_pte[i]));
 		printf("\tattrs:\t0x%016llx\n", gpt_pte[i].attributes.raw);
-		uuid_string(gpt_pte[i].partition_type_guid.b, uuid);
+		uuid_bin = (unsigned char *)gpt_pte[i].partition_type_guid.b;
+		uuid_bin_to_str(uuid_bin, uuid);
 		printf("\ttype:\t%s\n", uuid);
-		uuid_string(gpt_pte[i].unique_partition_guid.b, uuid);
+		uuid_bin = (unsigned char *)gpt_pte[i].unique_partition_guid.b;
+		uuid_bin_to_str(uuid_bin, uuid);
 		printf("\tuuid:\t%s\n", uuid);
 	}
 
@@ -182,7 +165,7 @@ int get_partition_info_efi(block_dev_desc_t * dev_desc, int part,
 	sprintf((char *)info->type, "U-Boot");
 	info->bootable = is_bootable(&gpt_pte[part - 1]);
 #ifdef CONFIG_PARTITION_UUIDS
-	uuid_string(gpt_pte[part - 1].unique_partition_guid.b, info->uuid);
+	uuid_bin_to_str(gpt_pte[part - 1].unique_partition_guid.b, info->uuid);
 #endif
 
 	debug("%s: start 0x" LBAF ", size 0x" LBAF ", name %s", __func__,
@@ -237,60 +220,6 @@ static int set_protective_mbr(block_dev_desc_t *dev_desc)
 	return 0;
 }
 
-/**
- * string_uuid(); Convert UUID stored as string to bytes
- *
- * @param uuid - UUID represented as string
- * @param dst - GUID buffer
- *
- * @return return 0 on successful conversion
- */
-static int string_uuid(char *uuid, u8 *dst)
-{
-	efi_guid_t guid;
-	u16 b, c, d;
-	u64 e;
-	u32 a;
-	u8 *p;
-	u8 i;
-
-	const u8 uuid_str_len = 36;
-
-	/* The UUID is written in text: */
-	/* 1        9    14   19   24 */
-	/* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx */
-
-	debug("%s: uuid: %s\n", __func__, uuid);
-
-	if (strlen(uuid) != uuid_str_len)
-		return -1;
-
-	for (i = 0; i < uuid_str_len; i++) {
-		if ((i == 8) || (i == 13) || (i == 18) || (i == 23)) {
-			if (uuid[i] != '-')
-				return -1;
-		} else {
-			if (!isxdigit(uuid[i]))
-				return -1;
-		}
-	}
-
-	a = (u32)simple_strtoul(uuid, NULL, 16);
-	b = (u16)simple_strtoul(uuid + 9, NULL, 16);
-	c = (u16)simple_strtoul(uuid + 14, NULL, 16);
-	d = (u16)simple_strtoul(uuid + 19, NULL, 16);
-	e = (u64)simple_strtoull(uuid + 24, NULL, 16);
-
-	p = (u8 *) &e;
-	guid = EFI_GUID(a, b, c, d >> 8, d & 0xFF,
-			*(p + 5), *(p + 4), *(p + 3),
-			*(p + 2), *(p + 1) , *p);
-
-	memcpy(dst, guid.b, sizeof(efi_guid_t));
-
-	return 0;
-}
-
 int write_gpt_table(block_dev_desc_t *dev_desc,
 		gpt_header *gpt_h, gpt_entry *gpt_e)
 {
@@ -358,6 +287,7 @@ int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
 	size_t efiname_len, dosname_len;
 #ifdef CONFIG_PARTITION_UUIDS
 	char *str_uuid;
+	unsigned char *bin_uuid;
 #endif
 
 	for (i = 0; i < parts; i++) {
@@ -391,7 +321,9 @@ int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e,
 
 #ifdef CONFIG_PARTITION_UUIDS
 		str_uuid = partitions[i].uuid;
-		if (string_uuid(str_uuid, gpt_e[i].unique_partition_guid.b)) {
+		bin_uuid = gpt_e[i].unique_partition_guid.b;
+
+		if (uuid_str_to_bin(str_uuid, bin_uuid)) {
 			printf("Partition no. %d: invalid guid: %s\n",
 				i, str_uuid);
 			return -1;
@@ -438,7 +370,7 @@ int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h,
 	gpt_h->header_crc32 = 0;
 	gpt_h->partition_entry_array_crc32 = 0;
 
-	if (string_uuid(str_guid, gpt_h->disk_guid.b))
+	if (uuid_str_to_bin(str_guid, gpt_h->disk_guid.b))
 		return -1;
 
 	return 0;

include/common.h

@@ -822,7 +822,8 @@ void	udelay        (unsigned long);
 void mdelay(unsigned long);
 
 /* lib/uuid.c */
-void uuid_str_to_bin(const char *uuid, unsigned char *out);
+void uuid_bin_to_str(unsigned char *uuid, char *str);
+int uuid_str_to_bin(char *uuid, unsigned char *out);
 int uuid_str_valid(const char *uuid);
 
 /* lib/vsprintf.c */

lib/Makefile

@@ -61,6 +61,7 @@ obj-y += string.o
 obj-y += time.o
 obj-$(CONFIG_TRACE) += trace.o
 obj-$(CONFIG_BOOTP_PXE) += uuid.o
+obj-$(CONFIG_PARTITION_UUIDS) += uuid.o
 obj-y += vsprintf.o
 obj-$(CONFIG_LIB_RAND) += rand.o
 

lib/uuid.c

@@ -5,18 +5,40 @@
  */
 
 #include <linux/ctype.h>
-#include "common.h"
+#include <errno.h>
+#include <common.h>
+
+#define UUID_STR_LEN		36
 
 /*
- * This is what a UUID string looks like.
+ * UUID - Universally Unique IDentifier - 128 bits unique number.
+ *        There are 5 versions and one variant of UUID defined by RFC4122
+ *        specification. Depends on version uuid number base on a time,
+ *        host name, MAC address or random data.
  *
- * x is a hexadecimal character. fields are separated by '-'s. When converting
+ * UUID binary format (16 bytes):
- * to a binary UUID, le means the field should be converted to little endian,
+ *
- * and be means it should be converted to big endian.
+ * 4B-2B-2B-2B-6B (big endian - network byte order)
+ *
+ * UUID string is 36 length of characters (36 bytes):
  *
  * 0        9    14   19   24
  * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
+ *    be     be   be   be       be
+ *
+ * where x is a hexadecimal character. Fields are separated by '-'s.
+ * When converting to a binary UUID, le means the field should be converted
+ * to little endian and be means it should be converted to big endian.
+ *
+ * UUID is also used as GUID (Globally Unique Identifier) with the same binary
+ * format but it differs in string format like below.
+ *
+ * GUID:
+ * 0        9    14   19   24
+ * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
  *    le     le   le   be       be
+ *
+ * GUID is used e.g. in GPT (GUID Partition Table) as a partiions unique id.
  */
 
 int uuid_str_valid(const char *uuid)
@@ -43,14 +65,17 @@ int uuid_str_valid(const char *uuid)
 	return 1;
 }
 
-void uuid_str_to_bin(const char *uuid, unsigned char *out)
+int uuid_str_to_bin(char *uuid, unsigned char *out)
 {
 	uint16_t tmp16;
 	uint32_t tmp32;
 	uint64_t tmp64;
 
 	if (!uuid || !out)
-		return;
+		return -EINVAL;
+
+	if (strlen(uuid) != UUID_STR_LEN)
+		return -EINVAL;
 
 	tmp32 = cpu_to_le32(simple_strtoul(uuid, NULL, 16));
 	memcpy(out, &tmp32, 4);
@@ -66,4 +91,26 @@ void uuid_str_to_bin(const char *uuid, unsigned char *out)
 
 	tmp64 = cpu_to_be64(simple_strtoull(uuid + 24, NULL, 16));
 	memcpy(out + 10, (char *)&tmp64 + 2, 6);
+
+	return 0;
+}
+
+void uuid_bin_to_str(unsigned char *uuid, char *str)
+{
+	static const u8 le[16] = {3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11,
+				  12, 13, 14, 15};
+	int i;
+
+	for (i = 0; i < 16; i++) {
+		sprintf(str, "%02x", uuid[le[i]]);
+		str += 2;
+		switch (i) {
+		case 3:
+		case 5:
+		case 7:
+		case 9:
+			*str++ = '-';
+			break;
+		}
+	}
 }