net: sched: add mpls manipulation actions to TC

Currently, TC offers the ability to match on the MPLS fields of a packet
through the use of the flow_dissector_key_mpls struct. However, as yet, TC
actions do not allow the modification or manipulation of such fields.

Add a new module that registers TC action ops to allow manipulation of
MPLS. This includes the ability to push and pop headers as well as modify
the contents of new or existing headers. A further action to decrement the
TTL field of an MPLS header is also provided with a new helper added to
support this.

Examples of the usage of the new action with flower rules to push and pop
MPLS labels are:

tc filter add dev eth0 protocol ip parent ffff: flower \
    action mpls push protocol mpls_uc label 123  \
    action mirred egress redirect dev eth1

tc filter add dev eth0 protocol mpls_uc parent ffff: flower \
    action mpls pop protocol ipv4  \
    action mirred egress redirect dev eth1

Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 0 deletions

diff --git a/include/uapi/linux/tc_act/tc_mpls.h b/include/uapi/linux/tc_act/tc_mpls.h
new file mode 100644
index 000000000000..9360e95273c7
--- /dev/null
+++ b/include/uapi/linux/tc_act/tc_mpls.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* Copyright (C) 2019 Netronome Systems, Inc. */
+
+#ifndef __LINUX_TC_MPLS_H
+#define __LINUX_TC_MPLS_H
+
+#include <linux/pkt_cls.h>
+
+#define TCA_MPLS_ACT_POP	1
+#define TCA_MPLS_ACT_PUSH	2
+#define TCA_MPLS_ACT_MODIFY	3
+#define TCA_MPLS_ACT_DEC_TTL	4
+
+struct tc_mpls {
+	tc_gen;		/* generic TC action fields. */
+	int m_action;	/* action of type TCA_MPLS_ACT_*. */
+};
+
+enum {
+	TCA_MPLS_UNSPEC,
+	TCA_MPLS_TM,	/* struct tcf_t; time values associated with action. */
+	TCA_MPLS_PARMS,	/* struct tc_mpls; action type and general TC fields. */
+	TCA_MPLS_PAD,
+	TCA_MPLS_PROTO,	/* be16; eth_type of pushed or next (for pop) header. */
+	TCA_MPLS_LABEL,	/* u32; MPLS label. Lower 20 bits are used. */
+	TCA_MPLS_TC,	/* u8; MPLS TC field. Lower 3 bits are used. */
+	TCA_MPLS_TTL,	/* u8; MPLS TTL field. Must not be 0. */
+	TCA_MPLS_BOS,	/* u8; MPLS BOS field. Either 1 or 0. */
+	__TCA_MPLS_MAX,
+};
+#define TCA_MPLS_MAX (__TCA_MPLS_MAX - 1)
+
+#endif