Index: src/wp-includes/ms-functions.php
===================================================================
--- src/wp-includes/ms-functions.php	(revision 25472)
+++ src/wp-includes/ms-functions.php	(working copy)
@@ -2059,3 +2059,75 @@
 
 	return $site_results;
 }
+
+/**
+ * Retrieve a network meta field for a user from the sitemeta table
+ *
+ * @since 3.7.0
+ *
+ * @uses get_metadata()
+ *
+ * @param int $network_id Network ID. Corresponds to site_id in the sitemeta table.
+ * @param string $key Optional. The meta key to retrieve. By default, returns data for all keys.
+ * @param bool $single Whether to return a single value.
+ *
+ * @return array|string Array if $single is false. Value of the meta data field if $single is true.
+ */
+function get_network_meta( $network_id, $key = '', $single = false ) {
+	return get_metadata( 'site', $network_id, $key,  $single );
+}
+
+/** Add a metadata field to a network.
+ *
+ * $since 3.7.0
+ *
+ * @uses add_metadata()
+ *
+ * @param int $network_id Network ID. Corresponds to site_id in the sitemeta table.
+ * @param string $key Metadata name.
+ * @param mixed $value Metadata value. Must be serializable if non-scalar.
+ * @param bool $unique Optional. Default is false. Whether the same key should be added.
+ *
+ * @return bool|int Meta ID on success. False on failure.
+ */
+function add_network_meta( $network_id, $key, $value, $unique = false ) {
+	return add_metadata( 'site', $network_id, $key, $value, $unique );
+}
+
+/**
+ * Update network meta field based on network ID.
+ *
+ * Use the $prev_value parameter to differentiate between meta fields with the
+ * same key and network ID.
+ *
+ * @since 3.7.0
+ *
+ * @uses update_metadata()
+ *
+ * @param int $network_id Network ID. Corresponds to site_id in the sitemeta table.
+ * @param string $key Key of metadata to be updated.
+ * @param mixed $value Metadata value. Must be serializable if non-scalar.
+ * @param mixed $prev_value Optional. Previous value to check before removing.
+ *
+ * @return bool True on success. False on failure.
+ */
+function update_network_meta( $network_id, $key, $value, $prev_value = '' ) {
+	return update_metadata( 'site', $network_id, $key, $value, $prev_value );
+}
+
+/**
+ * Remove specified metadata from a network.
+ *
+ * @since 3.7.0
+ *
+ * @uses delete_metadata()
+ *
+ * @param int $network_id Network ID. Corresponds to site_id in the sitemeta table.
+ * @param string $key Key of metadata to be deleted.
+ * @param mixed $value Optional. Metadata value. Must be serializable if non-scalar.
+ *
+ * @return bool True on success. False on failure.
+ */
+function delete_network_meta( $network_id, $key, $value = '' ) {
+	return delete_metadata( 'site', $network_id, $key, $value );
+}