efi_loader: refactor efi_open_protocol

efi_open_protocol was implemented to call a protocol specific open
function to retrieve the protocol interface.

The UEFI specification does not know of such a function.

It is not possible to implement InstallProtocolInterface with the
current design.

With the patch the protocol interface itself is stored in the list
of installed protocols of an efi_object instead of an open function.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
[agraf: fix efi gop support]
Signed-off-by: Alexander Graf <agraf@suse.de>

cmd/bootefi.c

@@ -54,14 +54,6 @@ static struct efi_device_path_file_path bootefi_device_path[] = {
 	}
 };
 
-static efi_status_t EFIAPI bootefi_open_dp(void *handle, efi_guid_t *protocol,
-			void **protocol_interface, void *agent_handle,
-			void *controller_handle, uint32_t attributes)
-{
-	*protocol_interface = bootefi_device_path;
-	return EFI_SUCCESS;
-}
-
 /* The EFI loaded_image interface for the image executed via "bootefi" */
 static struct efi_loaded_image loaded_image_info = {
 	.device_handle = bootefi_device_path,
@@ -78,7 +70,7 @@ static struct efi_object loaded_image_info_obj = {
 			 * return handle which points to loaded_image_info
 			 */
 			.guid = &efi_guid_loaded_image,
-			.open = &efi_return_handle,
+			.protocol_interface = &loaded_image_info,
 		},
 		{
 			/*
@@ -86,7 +78,7 @@ static struct efi_object loaded_image_info_obj = {
 			 * bootefi_device_path
 			 */
 			.guid = &efi_guid_device_path,
-			.open = &bootefi_open_dp,
+			.protocol_interface = bootefi_device_path,
 		},
 	},
 };
@@ -99,7 +91,7 @@ static struct efi_object bootefi_device_obj = {
 			/* When asking for the device path interface, return
 			 * bootefi_device_path */
 			.guid = &efi_guid_device_path,
-			.open = &bootefi_open_dp,
+			.protocol_interface = bootefi_device_path
 		}
 	},
 };

include/efi_loader.h

@@ -49,15 +49,10 @@ struct efi_class_map {
 /*
  * When the UEFI payload wants to open a protocol on an object to get its
  * interface (usually a struct with callback functions), this struct maps the
- * protocol GUID to the respective protocol handler open function for that
- * object protocol combination.
- */
+ * protocol GUID to the respective protocol interface */
 struct efi_handler {
 	const efi_guid_t *guid;
-	efi_status_t (EFIAPI *open)(void *handle,
-			efi_guid_t *protocol, void **protocol_interface,
-			void *agent_handle, void *controller_handle,
-			uint32_t attributes);
+	void *protocol_interface;
 };
 
 /*
@@ -91,14 +86,6 @@ void efi_smbios_register(void);
 /* Called by networking code to memorize the dhcp ack package */
 void efi_net_set_dhcp_ack(void *pkt, int len);
 
-/*
- * Stub implementation for a protocol opener that just returns the handle as
- * interface
- */
-efi_status_t EFIAPI efi_return_handle(void *handle,
-		efi_guid_t *protocol, void **protocol_interface,
-		void *agent_handle, void *controller_handle,
-		uint32_t attributes);
 /* Called from places to check whether a timer expired */
 void efi_timer_check(void);
 /* PE loader implementation */

lib/efi_loader/efi_boottime.c

@@ -442,7 +442,6 @@ static efi_status_t EFIAPI efi_load_image(bool boot_policy,
 		.protocols = {
 			{
 				.guid = &efi_guid_loaded_image,
-				.open = &efi_return_handle,
 			},
 		},
 	};
@@ -452,6 +451,7 @@ static efi_status_t EFIAPI efi_load_image(bool boot_policy,
 	EFI_ENTRY("%d, %p, %p, %p, %ld, %p", boot_policy, parent_image,
 		  file_path, source_buffer, source_size, image_handle);
 	info = malloc(sizeof(*info));
+	loaded_image_info_obj.protocols[0].protocol_interface = info;
 	obj = malloc(sizeof(loaded_image_info_obj));
 	memset(info, 0, sizeof(*info));
 	memcpy(obj, &loaded_image_info_obj, sizeof(loaded_image_info_obj));
@@ -723,6 +723,13 @@ static efi_status_t EFIAPI efi_open_protocol(
 	EFI_ENTRY("%p, %p, %p, %p, %p, 0x%x", handle, protocol,
 		  protocol_interface, agent_handle, controller_handle,
 		  attributes);
+
+	if (!protocol_interface && attributes !=
+	    EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
+		r = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+
 	list_for_each(lhandle, &efi_obj_list) {
 		struct efi_object *efiobj;
 		efiobj = list_entry(lhandle, struct efi_object, link);
@@ -736,9 +743,12 @@ static efi_status_t EFIAPI efi_open_protocol(
 			if (!hprotocol)
 				break;
 			if (!guidcmp(hprotocol, protocol)) {
-				r = handler->open(handle, protocol,
-				    protocol_interface, agent_handle,
-				    controller_handle, attributes);
+				if (attributes !=
+				    EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
+					*protocol_interface =
+						handler->protocol_interface;
+				}
+				r = EFI_SUCCESS;
 				goto out;
 			}
 		}

lib/efi_loader/efi_disk.c

@@ -35,29 +35,6 @@ struct efi_disk_obj {
 	const struct blk_desc *desc;
 };
 
-static efi_status_t EFIAPI efi_disk_open_block(void *handle,
-			efi_guid_t *protocol, void **protocol_interface,
-			void *agent_handle, void *controller_handle,
-			uint32_t attributes)
-{
-	struct efi_disk_obj *diskobj = handle;
-
-	*protocol_interface = &diskobj->ops;
-
-	return EFI_SUCCESS;
-}
-
-static efi_status_t EFIAPI efi_disk_open_dp(void *handle, efi_guid_t *protocol,
-			void **protocol_interface, void *agent_handle,
-			void *controller_handle, uint32_t attributes)
-{
-	struct efi_disk_obj *diskobj = handle;
-
-	*protocol_interface = diskobj->dp;
-
-	return EFI_SUCCESS;
-}
-
 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
 			char extended_verification)
 {
@@ -210,10 +187,11 @@ static void efi_disk_add_dev(const char *name,
 	diskobj = calloc(1, objlen);
 
 	/* Fill in object data */
+	dp = (void *)&diskobj[1];
 	diskobj->parent.protocols[0].guid = &efi_block_io_guid;
-	diskobj->parent.protocols[0].open = efi_disk_open_block;
+	diskobj->parent.protocols[0].protocol_interface = &diskobj->ops;
 	diskobj->parent.protocols[1].guid = &efi_guid_device_path;
-	diskobj->parent.protocols[1].open = efi_disk_open_dp;
+	diskobj->parent.protocols[1].protocol_interface = dp;
 	diskobj->parent.handle = diskobj;
 	diskobj->ops = block_io_disk_template;
 	diskobj->ifname = if_typename;
@@ -230,7 +208,6 @@ static void efi_disk_add_dev(const char *name,
 	diskobj->ops.media = &diskobj->media;
 
 	/* Fill in device path */
-	dp = (void*)&diskobj[1];
 	diskobj->dp = dp;
 	dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 	dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;

lib/efi_loader/efi_gop.c

@@ -172,7 +172,7 @@ int efi_gop_register(void)
 
 	/* Fill in object data */
 	gopobj->parent.protocols[0].guid = &efi_gop_guid;
-	gopobj->parent.protocols[0].open = efi_return_handle;
+	gopobj->parent.protocols[0].protocol_interface = &gopobj->ops;
 	gopobj->parent.handle = &gopobj->ops;
 	gopobj->ops.query_mode = gop_query_mode;
 	gopobj->ops.set_mode = gop_set_mode;

lib/efi_loader/efi_image_loader.c

@@ -18,14 +18,6 @@ DECLARE_GLOBAL_DATA_PTR;
 const efi_guid_t efi_guid_device_path = DEVICE_PATH_GUID;
 const efi_guid_t efi_guid_loaded_image = LOADED_IMAGE_GUID;
 
-efi_status_t EFIAPI efi_return_handle(void *handle, efi_guid_t *protocol,
-			void **protocol_interface, void *agent_handle,
-			void *controller_handle, uint32_t attributes)
-{
-	*protocol_interface = handle;
-	return EFI_SUCCESS;
-}
-
 static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel,
 			unsigned long rel_size, void *efi_reloc)
 {

lib/efi_loader/efi_net.c

@@ -199,30 +199,6 @@ static efi_status_t EFIAPI efi_net_receive(struct efi_simple_network *this,
 	return EFI_EXIT(EFI_SUCCESS);
 }
 
-static efi_status_t EFIAPI efi_net_open_dp(void *handle, efi_guid_t *protocol,
-			void **protocol_interface, void *agent_handle,
-			void *controller_handle, uint32_t attributes)
-{
-	struct efi_simple_network *net = handle;
-	struct efi_net_obj *netobj = container_of(net, struct efi_net_obj, net);
-
-	*protocol_interface = &netobj->dp_mac;
-
-	return EFI_SUCCESS;
-}
-
-static efi_status_t EFIAPI efi_net_open_pxe(void *handle, efi_guid_t *protocol,
-			void **protocol_interface, void *agent_handle,
-			void *controller_handle, uint32_t attributes)
-{
-	struct efi_simple_network *net = handle;
-	struct efi_net_obj *netobj = container_of(net, struct efi_net_obj, net);
-
-	*protocol_interface = &netobj->pxe;
-
-	return EFI_SUCCESS;
-}
-
 void efi_net_set_dhcp_ack(void *pkt, int len)
 {
 	int maxsize = sizeof(*dhcp_ack);
@@ -258,11 +234,11 @@ int efi_net_register(void **handle)
 
 	/* Fill in object data */
 	netobj->parent.protocols[0].guid = &efi_net_guid;
-	netobj->parent.protocols[0].open = efi_return_handle;
+	netobj->parent.protocols[0].protocol_interface = &netobj->net;
 	netobj->parent.protocols[1].guid = &efi_guid_device_path;
-	netobj->parent.protocols[1].open = efi_net_open_dp;
+	netobj->parent.protocols[1].protocol_interface = &netobj->dp_mac;
 	netobj->parent.protocols[2].guid = &efi_pxe_guid;
-	netobj->parent.protocols[2].open = efi_net_open_pxe;
+	netobj->parent.protocols[2].protocol_interface = &netobj->pxe;
 	netobj->parent.handle = &netobj->net;
 	netobj->net.start = efi_net_start;
 	netobj->net.stop = efi_net_stop;