Add a Netlink utility function to add a RTA header and reserve space for data

[strongswan.git] / src / libhydra / plugins / kernel_netlink / kernel_netlink_shared.h

diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h
index f5721df..8be935b 100644 (file)
--- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h
+++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_shared.h
@@ -76,4 +76,15 @@ netlink_socket_t *netlink_socket_create(int protocol);
 void netlink_add_attribute(struct nlmsghdr *hdr, int rta_type, chunk_t data,
                                                   size_t buflen);
 
+/**
+ * Reserve space in a netlink message for given size and type, returning buffer.
+ *
+ * @param hdr                  netlink message
+ * @param buflen               size of full netlink buffer
+ * @param type                 RTA type
+ * @param len                  length of RTA data
+ * @return                             buffer to len bytes of attribute data, NULL on error
+ */
+void* netlink_reserve(struct nlmsghdr *hdr, int buflen, int type, int len);
+
 #endif /* KERNEL_NETLINK_SHARED_H_ */