ipv6: sr: define core operations for seg6local lightweight tunnel

This patch implements a new type of lightweight tunnel named seg6local.
A seg6local lwt is defined by a type of action and a set of parameters.
The action represents the operation to perform on the packets matching the
lwt's route, and is not necessarily an encapsulation. The set of parameters
are arguments for the processing function.

Each action is defined in a struct seg6_action_desc within
seg6_action_table[]. This structure contains the action, mandatory
attributes, the processing function, and a static headroom size required by
the action. The mandatory attributes are encoded as a bitmask field. The
static headroom is set to a non-zero value when the processing function
always add a constant number of bytes to the skb (e.g. the header size for
encapsulations).

To facilitate rtnetlink-related operations such as parsing, fill_encap,
and cmp_encap, each type of action parameter is associated to three
function pointers, in seg6_action_params[].

All actions defined in seg6_local.h are detailed in [1].

[1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 68 insertions, 0 deletions

diff --git a/include/uapi/linux/seg6_local.h b/include/uapi/linux/seg6_local.h
new file mode 100644
index 000000000000..ef2d8c3e76c1
--- /dev/null
+++ b/include/uapi/linux/seg6_local.h
@@ -0,0 +1,68 @@
+/*
+ *  SR-IPv6 implementation
+ *
+ *  Author:
+ *  David Lebrun <david.lebrun@uclouvain.be>
+ *
+ *
+ *  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 _UAPI_LINUX_SEG6_LOCAL_H
+#define _UAPI_LINUX_SEG6_LOCAL_H
+
+#include <linux/seg6.h>
+
+enum {
+	SEG6_LOCAL_UNSPEC,
+	SEG6_LOCAL_ACTION,
+	SEG6_LOCAL_SRH,
+	SEG6_LOCAL_TABLE,
+	SEG6_LOCAL_NH4,
+	SEG6_LOCAL_NH6,
+	SEG6_LOCAL_IIF,
+	SEG6_LOCAL_OIF,
+	__SEG6_LOCAL_MAX,
+};
+#define SEG6_LOCAL_MAX (__SEG6_LOCAL_MAX - 1)
+
+enum {
+	SEG6_LOCAL_ACTION_UNSPEC	= 0,
+	/* node segment */
+	SEG6_LOCAL_ACTION_END		= 1,
+	/* adjacency segment (IPv6 cross-connect) */
+	SEG6_LOCAL_ACTION_END_X		= 2,
+	/* lookup of next seg NH in table */
+	SEG6_LOCAL_ACTION_END_T		= 3,
+	/* decap and L2 cross-connect */
+	SEG6_LOCAL_ACTION_END_DX2	= 4,
+	/* decap and IPv6 cross-connect */
+	SEG6_LOCAL_ACTION_END_DX6	= 5,
+	/* decap and IPv4 cross-connect */
+	SEG6_LOCAL_ACTION_END_DX4	= 6,
+	/* decap and lookup of DA in v6 table */
+	SEG6_LOCAL_ACTION_END_DT6	= 7,
+	/* decap and lookup of DA in v4 table */
+	SEG6_LOCAL_ACTION_END_DT4	= 8,
+	/* binding segment with insertion */
+	SEG6_LOCAL_ACTION_END_B6	= 9,
+	/* binding segment with encapsulation */
+	SEG6_LOCAL_ACTION_END_B6_ENCAP	= 10,
+	/* binding segment with MPLS encap */
+	SEG6_LOCAL_ACTION_END_BM	= 11,
+	/* lookup last seg in table */
+	SEG6_LOCAL_ACTION_END_S		= 12,
+	/* forward to SR-unaware VNF with static proxy */
+	SEG6_LOCAL_ACTION_END_AS	= 13,
+	/* forward to SR-unaware VNF with masquerading */
+	SEG6_LOCAL_ACTION_END_AM	= 14,
+
+	__SEG6_LOCAL_ACTION_MAX,
+};
+
+#define SEG6_LOCAL_ACTION_MAX (__SEG6_LOCAL_ACTION_MAX - 1)
+
+#endif