From edad96ffe90db633c073f962c4e309f2894f9c92 Mon Sep 17 00:00:00 2001
From: Daniel Mack <zonque@gmail.com>
Date: Fri, 15 Aug 2014 19:20:51 +0200
Subject: [PATCH] metadata: add kdbus_meta_offset_of()

kdbus_meta_offset_of() will iterate over the given metadata and return
the offset of the item of type @type, if it exists.
---
 metadata.c | 24 ++++++++++++++++++++++++
 metadata.h |  1 +
 2 files changed, 25 insertions(+)

diff --git a/metadata.c b/metadata.c
index ff1d203..c8b86c3 100644
--- a/metadata.c
+++ b/metadata.c
@@ -57,6 +57,30 @@ int kdbus_meta_new(struct kdbus_meta **meta)
 	return 0;
 }
 
+/**
+ * kdbus_meta_offset_of() - return the offset of a meta data element
+ * @meta:		Metadata object
+ * @type:		The metadata type to look for (KDBUS_ITEM_*)
+ * @off:		Return pointer for the offset, if any
+ *
+ * This function will iterate over the given metadata and return the
+ * offset of the item of type @type, if it exists.
+ *
+ * Return: 0 on success, -ENOENT if the item was not found.
+ */
+int kdbus_meta_offset_of(struct kdbus_meta *meta, u64 type, off_t *off)
+{
+	const struct kdbus_item *item;
+
+	KDBUS_ITEMS_FOREACH(item, meta->data, meta->size)
+		if (item->type == type) {
+			*off = (u8 *) item - (u8 *) meta->data;
+			return 0;
+		}
+
+	return -ENOENT;
+}
+
 /**
  * kdbus_meta_free() - release metadata
  * @meta:		Metadata object
diff --git a/metadata.h b/metadata.h
index 77b7303..82344b3 100644
--- a/metadata.h
+++ b/metadata.h
@@ -41,5 +41,6 @@ int kdbus_meta_append(struct kdbus_meta *meta,
 		      struct kdbus_conn *conn,
 		      u64 seq,
 		      u64 which);
+int kdbus_meta_offset_of(struct kdbus_meta *meta, u64 type, off_t *off);
 void kdbus_meta_free(struct kdbus_meta *meta);
 #endif
-- 
2.34.1