[block] Allow SAN boot device to be identified by UUID

Add a "--uuid" option which may be used to specify a boot device UUID,
to be matched against the GPT partition GUID.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/parseopt.c

@@ -129,20 +129,21 @@ int parse_timeout ( char *text, unsigned long *value ) {
  * Parse UUID
  *
  * @v text		Text
- * @ret value		UUID value
+ * @ret uuid		UUID value
  * @ret rc		Return status code
  */
-int parse_uuid ( char *text, union uuid *value ) {
+int parse_uuid ( char *text, struct uuid_option *uuid ) {
 	int rc;
 
 	/* Sanity check */
 	assert ( text != NULL );
 
 	/* Parse UUID */
-	if ( ( rc = uuid_aton ( text, value ) ) != 0 ) {
+	if ( ( rc = uuid_aton ( text, &uuid->buf ) ) != 0 ) {
 		printf ( "\"%s\": invalid UUID\n", text );
 		return rc;
 	}
+	uuid->value = &uuid->buf;
 
 	return 0;
 }

src/hci/commands/sanboot_cmd.c

@@ -49,12 +49,14 @@ struct sanboot_options {
 	int keep;
 	/** Filename */
 	char *filename;
+	/** UUID */
+	struct uuid_option uuid;
 };
 
 /** "sanboot" option list */
 static union {
-	/* "sanboot" takes all four options */
+	/* "sanboot" takes all options */
-	struct option_descriptor sanboot[4];
+	struct option_descriptor sanboot[5];
 	/* "sanhook" takes only --drive and --no-describe */
 	struct option_descriptor sanhook[2];
 	/* "sanunhook" takes only --drive */
@@ -69,10 +71,11 @@ static union {
 			      struct sanboot_options, keep, parse_flag ),
 		OPTION_DESC ( "filename", 'f', required_argument,
 			      struct sanboot_options, filename, parse_string ),
+		OPTION_DESC ( "uuid", 'u', required_argument,
+			      struct sanboot_options, uuid, parse_uuid ),
 	},
 };
 
-
 /** "sanhook" command descriptor */
 static struct command_descriptor sanhook_cmd =
 	COMMAND_DESC ( struct sanboot_options, opts.sanhook, 1, MAX_ARGUMENTS,
@@ -127,6 +130,7 @@ static int sanboot_core_exec ( int argc, char **argv,
 
 	/* Construct configuration parameters */
 	config.filename = opts.filename;
+	config.uuid = opts.uuid.value;
 
 	/* Construct flags */
 	flags = default_flags;

src/include/ipxe/parseopt.h

@@ -126,10 +126,18 @@ struct named_setting {
 	struct setting setting;
 };
 
+/** A UUID command-line option */
+struct uuid_option {
+	/** UUID */
+	union uuid *value;
+	/** Storage buffer */
+	union uuid buf;
+};
+
 extern int parse_string ( char *text, char **value );
 extern int parse_integer ( char *text, unsigned int *value );
 extern int parse_timeout ( char *text, unsigned long *value );
-extern int parse_uuid ( char *text, union uuid *value );
+extern int parse_uuid ( char *text, struct uuid_option *uuid );
 extern int parse_netdev ( char *text, struct net_device **netdev );
 extern int
 parse_netdev_configurator ( char *text,

src/include/ipxe/sanboot.h

@@ -19,6 +19,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/process.h>
 #include <ipxe/blockdev.h>
 #include <ipxe/acpi.h>
+#include <ipxe/uuid.h>
 #include <config/sanboot.h>
 
 /**
@@ -109,6 +110,8 @@ enum san_device_flags {
 struct san_boot_config {
 	/** Boot filename (or NULL to use default) */
 	const char *filename;
+	/** UUID (or NULL to ignore UUID) */
+	union uuid *uuid;
 };
 
 /**

src/interface/efi/efi_block.c

@@ -597,6 +597,7 @@ static int efi_block_match ( unsigned int drive, EFI_HANDLE handle,
 		EFI_DEVICE_PATH_PROTOCOL *path;
 		void *interface;
 	} u;
+	union uuid guid;
 	EFI_STATUS efirc;
 	int rc;
 
@@ -623,6 +624,21 @@ static int efi_block_match ( unsigned int drive, EFI_HANDLE handle,
 	DBGC ( drive, "EFIBLK %#02x contains filesystem %s\n",
 	       drive, efi_devpath_text ( u.path ) );
 
+	/* Check if filesystem matches GUID, if applicable */
+	if ( config->uuid ) {
+		if ( ( rc = efi_path_guid ( u.path, &guid ) ) != 0 ) {
+			DBGC ( drive, "EFIBLK %#02x could not determine GUID: "
+			       "%s\n", drive, strerror ( rc ) );
+			goto err_no_guid;
+		}
+		if ( memcmp ( config->uuid, &guid, sizeof ( guid ) ) != 0 ) {
+			DBGC ( drive, "EFIBLK %#02x has wrong GUID %s\n",
+			       drive, uuid_ntoa ( &guid ) );
+			rc = -ENOENT;
+			goto err_wrong_guid;
+		}
+	}
+
 	/* Check if filesystem contains boot filename */
 	if ( ( rc = efi_block_filename ( drive, handle,
 					 config->filename ) ) != 0 ) {
@@ -633,6 +649,8 @@ static int efi_block_match ( unsigned int drive, EFI_HANDLE handle,
 	rc = 0;
 
  err_filename:
+ err_wrong_guid:
+ err_no_guid:
  err_not_child:
 	bs->CloseProtocol ( handle, protocol, efi_image_handle, handle );
  err_open: