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 <[email protected]>
Co-authored-by: Feng Yang <[email protected]>
Signed-off-by: Yi Yang <[email protected]>
Co-authored-by: Yi Yang <[email protected]>
Signed-off-by: William Tu <[email protected]>
Acked-by: Ben Pfaff <[email protected]>

Documentation/faq/configuration.rst

@@ -225,6 +225,19 @@ Q: Does Open vSwitch support IPv6 GRE?
                 options:remote_ip=fc00:100::1 \
                 options:packet_type=legacy_l2
 
+Q: Does Open vSwitch support GTP-U?
+
+    A: Yes. Starting with version 2.13, the Open vSwitch userspace
+    datapath supports GTP-U (GPRS Tunnelling Protocol User Plane
+    (GTPv1-U)). TEID is set by using tunnel key field.
+
+    ::
+
+        $ ovs-vsctl add-br br0
+        $ ovs-vsctl add-port br0 gtpu0 -- \
+                set int gtpu0 type=gtpu options:key=<teid> \
+                options:remote_ip=172.31.1.1
+
 Q: How do I connect two bridges?
 
     A: First, why do you want to do this?  Two connected bridges are not much

Documentation/faq/releases.rst

@@ -131,6 +131,7 @@ Q: Are all features available with all datapaths?
     Tunnel - Geneve-IPv6            4.4            2.6          2.6      NO
     Tunnel - ERSPAN                 4.18           2.10         2.10     NO
     Tunnel - ERSPAN-IPv6            4.18           2.10         2.10     NO
+    Tunnel - GTP-U                  NO             NO           2.13     NO
     QoS - Policing                  YES            1.1          2.6      NO
     QoS - Shaping                   YES            1.1          NO       NO
     sFlow                           YES            1.0          1.0      NO

NEWS

@@ -57,6 +57,9 @@ v2.13.0 - 14 Feb 2020
    - 'ovs-appctl dpctl/dump-flows' can now show offloaded=partial for
      partially offloaded flows, dp:dpdk for fully offloaded by dpdk, and
      type filter supports new filters: "dpdk" and "partially-offloaded".
+   - GTP-U Tunnel Protocol
+     * Add two new fields: tun_gtpu_flags, tun_gtpu_msgtype.
+     * Only support for userspace datapath.
 
 v2.12.0 - 03 Sep 2019
 ---------------------

datapath/linux/compat/include/linux/openvswitch.h

@@ -245,6 +245,7 @@ enum ovs_vport_type {
 	OVS_VPORT_TYPE_ERSPAN = 107, /* ERSPAN tunnel. */
 	OVS_VPORT_TYPE_IP6ERSPAN = 108, /* ERSPAN tunnel. */
 	OVS_VPORT_TYPE_IP6GRE = 109,
+	OVS_VPORT_TYPE_GTPU = 110,
 	__OVS_VPORT_TYPE_MAX
 };
 
@@ -404,6 +405,7 @@ enum ovs_tunnel_key_attr {
 	OVS_TUNNEL_KEY_ATTR_IPV6_DST,		/* struct in6_addr dst IPv6 address. */
 	OVS_TUNNEL_KEY_ATTR_PAD,
 	OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS,	/* struct erspan_metadata */
+	OVS_TUNNEL_KEY_ATTR_GTPU_OPTS,		/* struct gtpu_metadata */
 	__OVS_TUNNEL_KEY_ATTR_MAX
 };
 

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.

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);

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>".
      *

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;
 };
 

lib/dpif-netlink-rtnl.c

@@ -111,6 +111,8 @@ vport_type_to_kind(enum ovs_vport_type type,
         } else {
             return NULL;
         }
+    case OVS_VPORT_TYPE_GTPU:
+        return NULL;
     case OVS_VPORT_TYPE_NETDEV:
     case OVS_VPORT_TYPE_INTERNAL:
     case OVS_VPORT_TYPE_LISP:
@@ -277,6 +279,7 @@ dpif_netlink_rtnl_verify(const struct netdev_tunnel_config *tnl_cfg,
     case OVS_VPORT_TYPE_INTERNAL:
     case OVS_VPORT_TYPE_LISP:
     case OVS_VPORT_TYPE_STT:
+    case OVS_VPORT_TYPE_GTPU:
     case OVS_VPORT_TYPE_UNSPEC:
     case __OVS_VPORT_TYPE_MAX:
     default:
@@ -358,6 +361,7 @@ dpif_netlink_rtnl_create(const struct netdev_tunnel_config *tnl_cfg,
     case OVS_VPORT_TYPE_INTERNAL:
     case OVS_VPORT_TYPE_LISP:
     case OVS_VPORT_TYPE_STT:
+    case OVS_VPORT_TYPE_GTPU:
     case OVS_VPORT_TYPE_UNSPEC:
     case __OVS_VPORT_TYPE_MAX:
     default:
@@ -471,6 +475,7 @@ dpif_netlink_rtnl_port_destroy(const char *name, const char *type)
     case OVS_VPORT_TYPE_INTERNAL:
     case OVS_VPORT_TYPE_LISP:
     case OVS_VPORT_TYPE_STT:
+    case OVS_VPORT_TYPE_GTPU:
     case OVS_VPORT_TYPE_UNSPEC:
     case __OVS_VPORT_TYPE_MAX:
     default:

lib/dpif-netlink.c

@@ -745,6 +745,9 @@ get_vport_type(const struct dpif_netlink_vport *vport)
     case OVS_VPORT_TYPE_IP6GRE:
         return "ip6gre";
 
+    case OVS_VPORT_TYPE_GTPU:
+        return "gtpu";
+
     case OVS_VPORT_TYPE_UNSPEC:
     case __OVS_VPORT_TYPE_MAX:
         break;
@@ -778,6 +781,8 @@ netdev_to_ovs_vport_type(const char *type)
         return OVS_VPORT_TYPE_IP6GRE;
     } else if (!strcmp(type, "gre")) {
         return OVS_VPORT_TYPE_GRE;
+    } else if (!strcmp(type, "gtpu")) {
+        return OVS_VPORT_TYPE_GTPU;
     } else {
         return OVS_VPORT_TYPE_UNSPEC;
     }

lib/flow.c

@@ -129,7 +129,7 @@ struct mf_ctx {
  * away.  Some GCC versions gave warnings on ALWAYS_INLINE, so these are
  * defined as macros. */
 
-#if (FLOW_WC_SEQ != 41)
+#if (FLOW_WC_SEQ != 42)
 #define MINIFLOW_ASSERT(X) ovs_assert(X)
 BUILD_MESSAGE("FLOW_WC_SEQ changed: miniflow_extract() will have runtime "
                "assertions enabled. Consider updating FLOW_WC_SEQ after "
@@ -731,7 +731,7 @@ void
 miniflow_extract(struct dp_packet *packet, struct miniflow *dst)
 {
     /* Add code to this function (or its callees) to extract new fields. */
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
 
     const struct pkt_metadata *md = &packet->md;
     const void *data = dp_packet_data(packet);
@@ -1187,7 +1187,7 @@ flow_get_metadata(const struct flow *flow, struct match *flow_metadata)
 {
     int i;
 
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
 
     match_init_catchall(flow_metadata);
     if (flow->tunnel.tun_id != htonll(0)) {
@@ -1227,6 +1227,12 @@ flow_get_metadata(const struct flow *flow, struct match *flow_metadata)
     if (flow->tunnel.erspan_hwid) {
         match_set_tun_erspan_hwid(flow_metadata, flow->tunnel.erspan_hwid);
     }
+    if (flow->tunnel.gtpu_flags) {
+        match_set_tun_gtpu_flags(flow_metadata, flow->tunnel.gtpu_flags);
+    }
+    if (flow->tunnel.gtpu_msgtype) {
+        match_set_tun_gtpu_msgtype(flow_metadata, flow->tunnel.gtpu_msgtype);
+    }
     tun_metadata_get_fmd(&flow->tunnel, flow_metadata);
     if (flow->metadata != htonll(0)) {
         match_set_metadata(flow_metadata, flow->metadata);
@@ -1767,7 +1773,7 @@ flow_wildcards_init_for_packet(struct flow_wildcards *wc,
     memset(&wc->masks, 0x0, sizeof wc->masks);
 
     /* Update this function whenever struct flow changes. */
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
 
     if (flow_tnl_dst_is_set(&flow->tunnel)) {
         if (flow->tunnel.flags & FLOW_TNL_F_KEY) {
@@ -1788,6 +1794,8 @@ flow_wildcards_init_for_packet(struct flow_wildcards *wc,
         WC_MASK_FIELD(wc, tunnel.erspan_idx);
         WC_MASK_FIELD(wc, tunnel.erspan_dir);
         WC_MASK_FIELD(wc, tunnel.erspan_hwid);
+        WC_MASK_FIELD(wc, tunnel.gtpu_flags);
+        WC_MASK_FIELD(wc, tunnel.gtpu_msgtype);
 
         if (!(flow->tunnel.flags & FLOW_TNL_F_UDPIF)) {
             if (flow->tunnel.metadata.present.map) {
@@ -1918,7 +1926,7 @@ void
 flow_wc_map(const struct flow *flow, struct flowmap *map)
 {
     /* Update this function whenever struct flow changes. */
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
 
     flowmap_init(map);
 
@@ -2021,7 +2029,7 @@ void
 flow_wildcards_clear_non_packet_fields(struct flow_wildcards *wc)
 {
     /* Update this function whenever struct flow changes. */
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
 
     memset(&wc->masks.metadata, 0, sizeof wc->masks.metadata);
     memset(&wc->masks.regs, 0, sizeof wc->masks.regs);
@@ -2165,7 +2173,7 @@ flow_wildcards_set_xxreg_mask(struct flow_wildcards *wc, int idx,
 uint32_t
 miniflow_hash_5tuple(const struct miniflow *flow, uint32_t basis)
 {
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
     uint32_t hash = basis;
 
     if (flow) {
@@ -2212,7 +2220,7 @@ ASSERT_SEQUENTIAL(ipv6_src, ipv6_dst);
 uint32_t
 flow_hash_5tuple(const struct flow *flow, uint32_t basis)
 {
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
     uint32_t hash = basis;
 
     if (flow) {
@@ -2890,7 +2898,7 @@ flow_push_mpls(struct flow *flow, int n, ovs_be16 mpls_eth_type,
 
         if (clear_flow_L3) {
             /* Clear all L3 and L4 fields and dp_hash. */
-            BUILD_ASSERT(FLOW_WC_SEQ == 41);
+            BUILD_ASSERT(FLOW_WC_SEQ == 42);
             memset((char *) flow + FLOW_SEGMENT_2_ENDS_AT, 0,
                    sizeof(struct flow) - FLOW_SEGMENT_2_ENDS_AT);
             flow->dp_hash = 0;
@@ -3188,7 +3196,7 @@ flow_compose(struct dp_packet *p, const struct flow *flow,
     /* Add code to this function (or its callees) for emitting new fields or
      * protocols.  (This isn't essential, so it can be skipped for initial
      * testing.) */
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
 
     uint32_t pseudo_hdr_csum;
     size_t l4_len;

lib/flow.h

@@ -964,7 +964,7 @@ static inline void
 pkt_metadata_from_flow(struct pkt_metadata *md, const struct flow *flow)
 {
     /* Update this function whenever struct flow changes. */
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
 
     md->recirc_id = flow->recirc_id;
     md->dp_hash = flow->dp_hash;

lib/match.c

@@ -374,6 +374,34 @@ match_set_tun_erspan_hwid(struct match *match, uint8_t hwid)
     match_set_tun_erspan_hwid_masked(match, hwid, UINT8_MAX);
 }
 
+void
+match_set_tun_gtpu_flags_masked(struct match *match, uint8_t flags,
+                                uint8_t mask)
+{
+    match->wc.masks.tunnel.gtpu_flags = flags;
+    match->flow.tunnel.gtpu_flags = flags & mask;
+}
+
+void
+match_set_tun_gtpu_flags(struct match *match, uint8_t flags)
+{
+    match_set_tun_gtpu_flags_masked(match, flags, UINT8_MAX);
+}
+
+void
+match_set_tun_gtpu_msgtype_masked(struct match *match, uint8_t msgtype,
+                                  uint8_t mask)
+{
+    match->wc.masks.tunnel.gtpu_msgtype = msgtype;
+    match->flow.tunnel.gtpu_msgtype = msgtype & mask;
+}
+
+void
+match_set_tun_gtpu_msgtype(struct match *match, uint8_t msgtype)
+{
+    match_set_tun_gtpu_msgtype_masked(match, msgtype, UINT8_MAX);
+}
+
 void
 match_set_in_port(struct match *match, ofp_port_t ofp_port)
 {
@@ -1325,6 +1353,12 @@ format_flow_tunnel(struct ds *s, const struct match *match)
     if (wc->masks.tunnel.erspan_hwid && tnl->erspan_ver == 2) {
         ds_put_format(s, "tun_erspan_hwid=%#"PRIx8",", tnl->erspan_hwid);
     }
+    if (wc->masks.tunnel.gtpu_flags) {
+        ds_put_format(s, "gtpu_flags=%#"PRIx8",", tnl->gtpu_flags);
+    }
+    if (wc->masks.tunnel.gtpu_msgtype) {
+        ds_put_format(s, "gtpu_msgtype=%"PRIu8",", tnl->gtpu_msgtype);
+    }
     if (wc->masks.tunnel.flags & FLOW_TNL_F_MASK) {
         format_flags_masked(s, "tun_flags", flow_tun_flag_to_string,
                             tnl->flags & FLOW_TNL_F_MASK,
@@ -1396,7 +1430,7 @@ match_format(const struct match *match,
     bool is_megaflow = false;
     int i;
 
-    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 42);
 
     if (priority != OFP_DEFAULT_PRIORITY) {
         ds_put_format(s, "%spriority=%s%d,",