userspace: Add GTP-U support.

GTP, GPRS Tunneling Protocol, is a group of IP-based communications
protocols used to carry general packet radio service (GPRS) within
GSM, UMTS and LTE networks.  GTP protocol has two parts: Signalling
(GTP-Control, GTP-C) and User data (GTP-User, GTP-U). GTP-C is used
for setting up GTP-U protocol, which is an IP-in-UDP tunneling
protocol. Usually GTP is used in connecting between base station for
radio, Serving Gateway (S-GW), and PDN Gateway (P-GW).

This patch implements GTP-U protocol for userspace datapath,
supporting only required header fields and G-PDU message type.
See spec in:
https://tools.ietf.org/html/draft-hmm-dmm-5g-uplane-analysis-00

Tested-at: https://travis-ci.org/github/williamtu/ovs-travis/builds/666518784
Signed-off-by: Feng Yang <yangfengee04@gmail.com>
Co-authored-by: Feng Yang <yangfengee04@gmail.com>
Signed-off-by: Yi Yang <yangyi01@inspur.com>
Co-authored-by: Yi Yang <yangyi01@inspur.com>
Signed-off-by: William Tu <u9012063@gmail.com>
Acked-by: Ben Pfaff <blp@ovn.org>

4 files changed, 39 insertions, 3 deletions

diff --git a/include/openvswitch/flow.h b/include/openvswitch/flow.h
index 57b6c925c..3054015d9 100644
--- a/include/openvswitch/flow.h
+++ b/include/openvswitch/flow.h
@@ -27,7 +27,7 @@ extern "C" {
 /* This sequence number should be incremented whenever anything involving flows
  * or the wildcarding of flows changes.  This will cause build assertion
  * failures in places which likely need to be updated. */
-#define FLOW_WC_SEQ 41
+#define FLOW_WC_SEQ 42
 
 /* Number of Open vSwitch extension 32-bit registers. */
 #define FLOW_N_REGS 16
@@ -168,7 +168,7 @@ BUILD_ASSERT_DECL(sizeof(struct ovs_key_nsh) % sizeof(uint64_t) == 0);
 /* Remember to update FLOW_WC_SEQ when changing 'struct flow'. */
 BUILD_ASSERT_DECL(offsetof(struct flow, igmp_group_ip4) + sizeof(uint32_t)
                   == sizeof(struct flow_tnl) + sizeof(struct ovs_key_nsh) + 300
-                  && FLOW_WC_SEQ == 41);
+                  && FLOW_WC_SEQ == 42);
 
 /* Incremental points at which flow classification may be performed in
  * segments.
diff --git a/include/openvswitch/match.h b/include/openvswitch/match.h
index eeabd5f47..8af3b74ed 100644
--- a/include/openvswitch/match.h
+++ b/include/openvswitch/match.h
@@ -121,6 +121,12 @@ void match_set_tun_erspan_dir_masked(struct match *match, uint8_t dir,
 void match_set_tun_erspan_hwid(struct match *match, uint8_t hwid);
 void match_set_tun_erspan_hwid_masked(struct match *match, uint8_t hwid,
                                       uint8_t mask);
+void match_set_tun_gtpu_flags(struct match *match, uint8_t flags);
+void match_set_tun_gtpu_flags_masked(struct match *match, uint8_t flags,
+                                     uint8_t mask);
+void match_set_tun_gtpu_msgtype(struct match *match, uint8_t msgtype);
+void match_set_tun_gtpu_msgtype_masked(struct match *match, uint8_t msgtype,
+                                       uint8_t mask);
 void match_set_in_port(struct match *, ofp_port_t ofp_port);
 void match_set_pkt_mark(struct match *, uint32_t pkt_mark);
 void match_set_pkt_mark_masked(struct match *, uint32_t pkt_mark, uint32_t mask);
diff --git a/include/openvswitch/meta-flow.h b/include/openvswitch/meta-flow.h
index 1f81d830e..d529a9f0d 100644
--- a/include/openvswitch/meta-flow.h
+++ b/include/openvswitch/meta-flow.h
@@ -506,6 +506,34 @@ enum OVS_PACKED_ENUM mf_field_id {
      */
     MFF_TUN_ERSPAN_HWID,
 
+    /* "tun_gtpu_flags".
+     *
+     * GTP-U tunnel flags.
+     *
+     * Type: u8.
+     * Maskable: bitwise.
+     * Formatting: hexadecimal.
+     * Prerequisites: none.
+     * Access: read-only.
+     * NXM: none.
+     * OXM: NXOXM_ET_GTPU_FLAGS(15) since v2.13.
+     */
+    MFF_TUN_GTPU_FLAGS,
+
+    /* "tun_gtpu_msgtype".
+     *
+     * GTP-U tunnel message type.
+     *
+     * Type: u8.
+     * Maskable: bitwise.
+     * Formatting: decimal.
+     * Prerequisites: none.
+     * Access: read-only.
+     * NXM: none.
+     * OXM: NXOXM_ET_GTPU_MSGTYPE(16) since v2.13.
+     */
+    MFF_TUN_GTPU_MSGTYPE,
+
 #if TUN_METADATA_NUM_OPTS == 64
     /* "tun_metadata<N>".
      *
diff --git a/include/openvswitch/packets.h b/include/openvswitch/packets.h
index 925844eda..a65cb0d04 100644
--- a/include/openvswitch/packets.h
+++ b/include/openvswitch/packets.h
@@ -43,7 +43,9 @@ struct flow_tnl {
     uint32_t erspan_idx;
     uint8_t erspan_dir;
     uint8_t erspan_hwid;
-    uint8_t pad1[6];     /* Pad to 64 bits. */
+    uint8_t gtpu_flags;
+    uint8_t gtpu_msgtype;
+    uint8_t pad1[4];     /* Pad to 64 bits. */
     struct tun_metadata metadata;
 };