vswitchd: Process special packets more aggressively.

Before this patch, special packets such as LACP and CFM messages
were only processed if they had NORMAL open flow actions.  With
this patch these messages are always processed unless originated in
ofproto_send_packet().

2 files changed, 27 insertions, 1 deletions

diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index e0f1b6632..39d345736 100644
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -125,6 +125,11 @@ struct action_xlate_ctx {
      * calling action_xlate_ctx_init(). */
     void (*resubmit_hook)(struct action_xlate_ctx *, const struct rule *);
 
+    /* If true, the speciality of 'flow' should be checked before executing
+     * its actions.  If special_cb returns false on 'flow' rendered
+     * uninstallable and no actions will be executed. */
+    bool check_special;
+
 /* xlate_actions() initializes and uses these members.  The client might want
  * to look at them after it returns. */
 
@@ -1446,6 +1451,8 @@ ofproto_send_packet(struct ofproto *p, const struct flow *flow,
     struct ofpbuf *odp_actions;
 
     action_xlate_ctx_init(&ctx, p, flow, packet);
+    /* Always xlate packets originated in this function. */
+    ctx.check_special = false;
     odp_actions = xlate_actions(&ctx, actions, n_actions);
 
     /* XXX Should we translate the dpif_execute() errno value into an OpenFlow
@@ -3110,6 +3117,7 @@ action_xlate_ctx_init(struct action_xlate_ctx *ctx,
     ctx->flow = *flow;
     ctx->packet = packet;
     ctx->resubmit_hook = NULL;
+    ctx->check_special = true;
 }
 
 static struct ofpbuf *
@@ -3124,7 +3132,16 @@ xlate_actions(struct action_xlate_ctx *ctx,
     ctx->nf_output_iface = NF_OUT_DROP;
     ctx->recurse = 0;
     ctx->last_pop_priority = -1;
-    do_xlate_actions(in, n_in, ctx);
+
+    if (!ctx->check_special
+        || (ctx->ofproto->ofhooks->special_cb
+            && ctx->ofproto->ofhooks->special_cb(&ctx->flow, ctx->packet,
+                                                 ctx->ofproto->aux))) {
+        do_xlate_actions(in, n_in, ctx);
+    } else {
+        ctx->may_set_up_flow = false;
+    }
+
     remove_pop_action(ctx);
 
     /* Check with in-band control to see if we're allowed to set up this
@@ -4370,6 +4387,12 @@ handle_miss_upcall(struct ofproto *p, struct dpif_upcall *upcall)
     /* Set header pointers in 'flow'. */
     flow_extract(upcall->packet, flow.tun_id, flow.in_port, &flow);
 
+    if (p->ofhooks->special_cb
+        && !p->ofhooks->special_cb(&flow, upcall->packet, p->aux)) {
+        ofpbuf_delete(upcall->packet);
+        return;
+    }
+
     /* Check with in-band control to see if this packet should be sent
      * to the local port regardless of the flow table. */
     if (in_band_msg_in_hook(p->in_band, &flow, upcall->packet)) {
@@ -5126,5 +5149,6 @@ default_normal_ofhook_cb(const struct flow *flow, const struct ofpbuf *packet,
 static const struct ofhooks default_ofhooks = {
     default_normal_ofhook_cb,
     NULL,
+    NULL,
     NULL
 };
diff --git a/ofproto/ofproto.h b/ofproto/ofproto.h
index 8e4e2a65d..7516068ff 100644
--- a/ofproto/ofproto.h
+++ b/ofproto/ofproto.h
@@ -149,6 +149,8 @@ struct ofhooks {
     bool (*normal_cb)(const struct flow *, const struct ofpbuf *packet,
                       struct ofpbuf *odp_actions, tag_type *,
                       uint16_t *nf_output_iface, void *aux);
+    bool (*special_cb)(const struct flow *flow, const struct ofpbuf *packet,
+                       void *aux);
     void (*account_flow_cb)(const struct flow *, tag_type tags,
                             const struct nlattr *odp_actions,
                             size_t actions_len,