ovs-tc: offload MPLS pop actions to TC datapath

TC now supports an action to pop the outer MPLS header from a packet. The next protocol after the header is required alongside this. Currently, OvS datapath rules also supply this information. Offload OvS MPLS pop actions to TC along with the next protocol. Signed-off-by: John Hurley <[email protected]> Reviewed-by: Simon Horman <[email protected]> Signed-off-by: Simon Horman <[email protected]>
yqnt418 · Aug 1, 2019 · 55412ea · 55412ea
1 parent abef795
commit 55412ea
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diff --git a/lib/netdev-offload-tc.c b/lib/netdev-offload-tc.c
@@ -645,6 +645,11 @@ parse_tc_flower_to_match(struct tc_flower *flower,
                                        | VLAN_CFI);
             }
             break;
+            case TC_ACT_MPLS_POP: {
+                nl_msg_put_be16(buf, OVS_ACTION_ATTR_POP_MPLS,
+                                action->mpls.proto);
+            }
+            break;
             case TC_ACT_PEDIT: {
                 parse_flower_rewrite_to_netlink_action(buf, flower);
             }
@@ -1328,6 +1333,10 @@ netdev_tc_flow_put(struct netdev *netdev, struct match *match,
         } else if (nl_attr_type(nla) == OVS_ACTION_ATTR_POP_VLAN) {
             action->type = TC_ACT_VLAN_POP;
             flower.action_count++;
+        } else if (nl_attr_type(nla) == OVS_ACTION_ATTR_POP_MPLS) {
+            action->mpls.proto = nl_attr_get_be16(nla);
+            action->type = TC_ACT_MPLS_POP;
+            flower.action_count++;
         } else if (nl_attr_type(nla) == OVS_ACTION_ATTR_SET) {
             const struct nlattr *set = nl_attr_get(nla);
             const size_t set_len = nl_attr_get_size(nla);

diff --git a/lib/tc.c b/lib/tc.c
@@ -25,6 +25,7 @@
 #include <linux/tc_act/tc_csum.h>
 #include <linux/tc_act/tc_gact.h>
 #include <linux/tc_act/tc_mirred.h>
+#include <linux/tc_act/tc_mpls.h>
 #include <linux/tc_act/tc_pedit.h>
 #include <linux/tc_act/tc_skbedit.h>
 #include <linux/tc_act/tc_tunnel_key.h>
@@ -1237,6 +1238,49 @@ nl_parse_act_vlan(struct nlattr *options, struct tc_flower *flower)
     return 0;
 }
 
+static const struct nl_policy mpls_policy[] = {
+    [TCA_MPLS_PARMS] = { .type = NL_A_UNSPEC,
+                         .min_len = sizeof(struct tc_mpls),
+                         .optional = false, },
+    [TCA_MPLS_PROTO] = { .type = NL_A_U16, .optional = true, },
+};
+
+static int
+nl_parse_act_mpls(struct nlattr *options, struct tc_flower *flower)
+{
+    struct nlattr *mpls_attrs[ARRAY_SIZE(mpls_policy)];
+    const struct nlattr *mpls_parms;
+    struct nlattr *mpls_proto;
+    struct tc_action *action;
+    const struct tc_mpls *m;
+
+    if (!nl_parse_nested(options, mpls_policy, mpls_attrs,
+                         ARRAY_SIZE(mpls_policy))) {
+        VLOG_ERR_RL(&error_rl, "failed to parse mpls action options");
+        return EPROTO;
+    }
+
+    action = &flower->actions[flower->action_count++];
+    mpls_parms = mpls_attrs[TCA_MPLS_PARMS];
+    m = nl_attr_get_unspec(mpls_parms, sizeof *m);
+
+    switch (m->m_action) {
+    case TCA_MPLS_ACT_POP:
+        mpls_proto = mpls_attrs[TCA_MPLS_PROTO];
+        if (mpls_proto) {
+            action->mpls.proto = nl_attr_get_be16(mpls_proto);
+        }
+        action->type = TC_ACT_MPLS_POP;
+        break;
+    default:
+        VLOG_ERR_RL(&error_rl, "unknown mpls action: %d, %d",
+                    m->action, m->m_action);
+        return EINVAL;
+    }
+
+    return 0;
+}
+
 static const struct nl_policy csum_policy[] = {
     [TCA_CSUM_PARMS] = { .type = NL_A_UNSPEC,
                          .min_len = sizeof(struct tc_csum),
@@ -1319,6 +1363,8 @@ nl_parse_single_action(struct nlattr *action, struct tc_flower *flower)
         err = nl_parse_act_mirred(act_options, flower);
     } else if (!strcmp(act_kind, "vlan")) {
         err = nl_parse_act_vlan(act_options, flower);
+    } else if (!strcmp(act_kind, "mpls")) {
+        err = nl_parse_act_mpls(act_options, flower);
     } else if (!strcmp(act_kind, "tunnel_key")) {
         err = nl_parse_act_tunnel_key(act_options, flower);
     } else if (!strcmp(act_kind, "pedit")) {
@@ -1648,6 +1694,23 @@ nl_msg_put_act_pop_vlan(struct ofpbuf *request)
     nl_msg_end_nested(request, offset);
 }
 
+static void
+nl_msg_put_act_pop_mpls(struct ofpbuf *request, ovs_be16 proto)
+{
+    size_t offset;
+
+    nl_msg_put_string(request, TCA_ACT_KIND, "mpls");
+    offset = nl_msg_start_nested(request, TCA_ACT_OPTIONS | NLA_F_NESTED);
+    {
+        struct tc_mpls parm = { .action = TC_ACT_PIPE,
+                                .m_action = TCA_MPLS_ACT_POP };
+
+        nl_msg_put_unspec(request, TCA_MPLS_PARMS, &parm, sizeof parm);
+        nl_msg_put_be16(request, TCA_MPLS_PROTO, proto);
+    }
+    nl_msg_end_nested(request, offset);
+}
+
 static void
 nl_msg_put_act_tunnel_key_release(struct ofpbuf *request)
 {
@@ -2025,6 +2088,12 @@ nl_msg_put_flower_acts(struct ofpbuf *request, struct tc_flower *flower)
                 nl_msg_end_nested(request, act_offset);
             }
             break;
+            case TC_ACT_MPLS_POP: {
+                act_offset = nl_msg_start_nested(request, act_index++);
+                nl_msg_put_act_pop_mpls(request, action->mpls.proto);
+                nl_msg_end_nested(request, act_offset);
+            }
+            break;
             case TC_ACT_OUTPUT: {
                 ingress = action->out.ingress;
                 ifindex = action->out.ifindex_out;

diff --git a/lib/tc.h b/lib/tc.h
@@ -153,6 +153,7 @@ enum tc_action_type {
     TC_ACT_PEDIT,
     TC_ACT_VLAN_POP,
     TC_ACT_VLAN_PUSH,
+    TC_ACT_MPLS_POP,
 };
 
 struct tc_action {
@@ -168,6 +169,10 @@ struct tc_action {
             uint8_t vlan_push_prio;
         } vlan;
 
+        struct {
+            ovs_be16 proto;
+        } mpls;
+
         struct {
             bool id_present;
             ovs_be64 id;