efi_loader: allow concatenation with contained end node

Allow appending a device-path to a device-path that contains an end node
as separator. We need this feature for creating boot options specifying
kernel, initrd, and dtb.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

cmd/eficonfig.c

@@ -530,7 +530,7 @@ struct efi_device_path *eficonfig_create_device_path(struct efi_device_path *dp_
 	dp = efi_dp_shorten(dp_volume);
 	if (!dp)
 		dp = dp_volume;
-	dp = efi_dp_concat(dp, &fp->dp, false);
+	dp = efi_dp_concat(dp, &fp->dp, 0);
 	free(buf);
 
 	return dp;
@@ -1484,7 +1484,7 @@ static efi_status_t eficonfig_edit_boot_option(u16 *varname, struct eficonfig_bo
 			goto out;
 		}
 		initrd_dp = efi_dp_concat((const struct efi_device_path *)&id_dp,
-					  dp, false);
+					  dp, 0);
 		efi_free_pool(dp);
 	}
 
@@ -1495,7 +1495,7 @@ static efi_status_t eficonfig_edit_boot_option(u16 *varname, struct eficonfig_bo
 	}
 	final_dp_size = efi_dp_size(dp) + sizeof(END);
 	if (initrd_dp) {
-		final_dp = efi_dp_concat(dp, initrd_dp, true);
+		final_dp = efi_dp_concat(dp, initrd_dp, 1);
 		final_dp_size += efi_dp_size(initrd_dp) + sizeof(END);
 	} else {
 		final_dp = efi_dp_dup(dp);

cmd/efidebug.c

@@ -696,7 +696,7 @@ struct efi_device_path *create_initrd_dp(const char *dev, const char *part,
 		short_fp = tmp_fp;
 
 	initrd_dp = efi_dp_concat((const struct efi_device_path *)&id_dp,
-				  short_fp, false);
+				  short_fp, 0);
 
 out:
 	efi_free_pool(tmp_dp);
@@ -916,7 +916,7 @@ static int do_efi_boot_add(struct cmd_tbl *cmdtp, int flag,
 		goto out;
 	}
 
-	final_fp = efi_dp_concat(file_path, initrd_dp, true);
+	final_fp = efi_dp_concat(file_path, initrd_dp, 1);
 	if (!final_fp) {
 		printf("Cannot create final device path\n");
 		r = CMD_RET_FAILURE;

include/efi_loader.h

@@ -946,7 +946,7 @@ struct efi_device_path *efi_dp_from_lo(struct efi_load_option *lo,
 				       const efi_guid_t *guid);
 struct efi_device_path *efi_dp_concat(const struct efi_device_path *dp1,
 				      const struct efi_device_path *dp2,
-				      bool split_end_node);
+				      size_t split_end_node);
 struct efi_device_path *search_gpt_dp_node(struct efi_device_path *device_path);
 efi_status_t efi_deserialize_load_option(struct efi_load_option *lo, u8 *data,
 					 efi_uintn_t *size);

lib/efi_loader/efi_bootbin.c

@@ -150,7 +150,7 @@ efi_status_t efi_run_image(void *source_buffer, efi_uintn_t source_size)
 		msg_path = file_path;
 	} else {
 		file_path = efi_dp_concat(bootefi_device_path,
-					  bootefi_image_path, false);
+					  bootefi_image_path, 0);
 		msg_path = bootefi_image_path;
 		log_debug("Loaded from disk\n");
 	}

lib/efi_loader/efi_bootmgr.c

@@ -130,7 +130,7 @@ static efi_status_t try_load_from_file_path(efi_handle_t *fs_handles,
 		if (!dp)
 			continue;
 
-		dp = efi_dp_concat(dp, fp, false);
+		dp = efi_dp_concat(dp, fp, 0);
 		if (!dp)
 			continue;
 

lib/efi_loader/efi_boottime.c

@@ -1816,7 +1816,7 @@ efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
 	if (device_path) {
 		info->device_handle = efi_dp_find_obj(device_path, NULL, NULL);
 
-		dp = efi_dp_concat(device_path, file_path, false);
+		dp = efi_dp_concat(device_path, file_path, 0);
 		if (!dp) {
 			ret = EFI_OUT_OF_RESOURCES;
 			goto failure;

lib/efi_loader/efi_device_path.c

@@ -276,10 +276,11 @@ struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
  *
  * @dp1:	    First device path
  * @dp2:	    Second device path
- * @split_end_node: If true the two device paths will be concatenated and
+ * @split_end_node:
- *                  separated by an end node (DEVICE_PATH_SUB_TYPE_END).
+ * * 0 to concatenate
- *		    If false the second device path will be concatenated to the
+ * * 1 to concatenate with end node added as separator
- *		    first one as-is.
+ * * size of dp1 excluding last end node to concatenate with end node as
+ *   separator in case dp1 contains an end node
  *
  * Return:
  * concatenated device path or NULL. Caller must free the returned value
@@ -287,7 +288,7 @@ struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
 struct
 efi_device_path *efi_dp_concat(const struct efi_device_path *dp1,
 			       const struct efi_device_path *dp2,
-			       bool split_end_node)
+			       size_t split_end_node)
 {
 	struct efi_device_path *ret;
 	size_t end_size;
@@ -301,10 +302,15 @@ efi_device_path *efi_dp_concat(const struct efi_device_path *dp1,
 		ret = efi_dp_dup(dp1);
 	} else {
 		/* both dp1 and dp2 are non-null */
-		unsigned sz1 = efi_dp_size(dp1);
+		size_t sz1;
-		unsigned sz2 = efi_dp_size(dp2);
+		size_t sz2 = efi_dp_size(dp2);
 		void *p;
 
+		if (split_end_node < sizeof(struct efi_device_path))
+			sz1 = efi_dp_size(dp1);
+		else
+			sz1 = split_end_node;
+
 		if (split_end_node)
 			end_size = 2 * sizeof(END);
 		else

lib/efi_loader/efi_device_path_utilities.c

@@ -76,7 +76,7 @@ static struct efi_device_path * EFIAPI append_device_path(
 	const struct efi_device_path *src2)
 {
 	EFI_ENTRY("%pD, %pD", src1, src2);
-	return EFI_EXIT(efi_dp_concat(src1, src2, false));
+	return EFI_EXIT(efi_dp_concat(src1, src2, 0));
 }
 
 /*