net/sched: Introduce act_tunnel_key

This action could be used before redirecting packets to a shared tunnel
device, or when redirecting packets arriving from a such a device.

The action will release the metadata created by the tunnel device
(decap), or set the metadata with the specified values for encap
operation.

For example, the following flower filter will forward all ICMP packets
destined to 11.11.11.2 through the shared vxlan device 'vxlan0'. Before
redirecting, a metadata for the vxlan tunnel is created using the
tunnel_key action and it's arguments:

$ tc filter add dev net0 protocol ip parent ffff: \
    flower \
      ip_proto 1 \
      dst_ip 11.11.11.2 \
    action tunnel_key set \
      src_ip 11.11.0.1 \
      dst_ip 11.11.0.2 \
      id 11 \
    action mirred egress redirect dev vxlan0

Signed-off-by: Amir Vadai <amir@vadai.me>
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tc_act/tc_tunnel_key.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2016, Amir Vadai <amir@vadai.me>
+ * Copyright (c) 2016, Mellanox Technologies. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __NET_TC_TUNNEL_KEY_H
+#define __NET_TC_TUNNEL_KEY_H
+
+#include <net/act_api.h>
+
+struct tcf_tunnel_key_params {
+	struct rcu_head		rcu;
+	int			tcft_action;
+	int			action;
+	struct metadata_dst     *tcft_enc_metadata;
+};
+
+struct tcf_tunnel_key {
+	struct tc_action	      common;
+	struct tcf_tunnel_key_params __rcu *params;
+};
+
+#define to_tunnel_key(a) ((struct tcf_tunnel_key *)a)
+
+#endif /* __NET_TC_TUNNEL_KEY_H */

include/uapi/linux/tc_act/tc_tunnel_key.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2016, Amir Vadai <amir@vadai.me>
+ * Copyright (c) 2016, Mellanox Technologies. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_TC_TUNNEL_KEY_H
+#define __LINUX_TC_TUNNEL_KEY_H
+
+#include <linux/pkt_cls.h>
+
+#define TCA_ACT_TUNNEL_KEY 17
+
+#define TCA_TUNNEL_KEY_ACT_SET	    1
+#define TCA_TUNNEL_KEY_ACT_RELEASE  2
+
+struct tc_tunnel_key {
+	tc_gen;
+	int t_action;
+};
+
+enum {
+	TCA_TUNNEL_KEY_UNSPEC,
+	TCA_TUNNEL_KEY_TM,
+	TCA_TUNNEL_KEY_PARMS,
+	TCA_TUNNEL_KEY_ENC_IPV4_SRC,	/* be32 */
+	TCA_TUNNEL_KEY_ENC_IPV4_DST,	/* be32 */
+	TCA_TUNNEL_KEY_ENC_IPV6_SRC,	/* struct in6_addr */
+	TCA_TUNNEL_KEY_ENC_IPV6_DST,	/* struct in6_addr */
+	TCA_TUNNEL_KEY_ENC_KEY_ID,	/* be64 */
+	TCA_TUNNEL_KEY_PAD,
+	__TCA_TUNNEL_KEY_MAX,
+};
+
+#define TCA_TUNNEL_KEY_MAX (__TCA_TUNNEL_KEY_MAX - 1)
+
+#endif

net/sched/Kconfig

@@ -761,6 +761,17 @@ config NET_ACT_IFE
 	  To compile this code as a module, choose M here: the
 	  module will be called act_ife.
 
+config NET_ACT_TUNNEL_KEY
+        tristate "IP tunnel metadata manipulation"
+        depends on NET_CLS_ACT
+        ---help---
+	  Say Y here to set/release ip tunnel metadata.
+
+	  If unsure, say N.
+
+	  To compile this code as a module, choose M here: the
+	  module will be called act_tunnel_key.
+
 config NET_IFE_SKBMARK
         tristate "Support to encoding decoding skb mark on IFE action"
         depends on NET_ACT_IFE

net/sched/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_NET_ACT_CONNMARK)	+= act_connmark.o
 obj-$(CONFIG_NET_ACT_IFE)	+= act_ife.o
 obj-$(CONFIG_NET_IFE_SKBMARK)	+= act_meta_mark.o
 obj-$(CONFIG_NET_IFE_SKBPRIO)	+= act_meta_skbprio.o
+obj-$(CONFIG_NET_ACT_TUNNEL_KEY)+= act_tunnel_key.o
 obj-$(CONFIG_NET_SCH_FIFO)	+= sch_fifo.o
 obj-$(CONFIG_NET_SCH_CBQ)	+= sch_cbq.o
 obj-$(CONFIG_NET_SCH_HTB)	+= sch_htb.o