From 348663a34b4b442ea51ed0f87fc82bdd2f33dda0 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@nicira.com>
Date: Tue, 17 Mar 2009 16:10:40 -0700
Subject: [PATCH] secchan: Support priorities over UINT16_MAX for internal use.

The plan is for in-band control to use these higher priorities for flows
that are to be hidden from, and take precedence over, flows set up by the
controller.
---
 secchan/ofproto.c | 36 ++++++++++++++++++++++++++++--------
 secchan/ofproto.h |  6 +++---
 2 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/secchan/ofproto.c b/secchan/ofproto.c
index 1eec332d..6a932e94 100644
--- a/secchan/ofproto.c
+++ b/secchan/ofproto.c
@@ -138,6 +138,25 @@ struct rule {
     union odp_action *odp_actions;
 };
 
+static inline bool
+rule_is_hidden(const struct rule *rule)
+{
+    /* Subrules are merely an implementation detail, so hide them from the
+     * controller. */
+    if (rule->super != NULL) {
+        return true;
+    }
+
+    /* Rules with priority higher than UINT16_MAX are set up by secchan itself
+     * (e.g. by in-band control) and are intentionally hidden from the
+     * controller. */
+    if (rule->cr.priority > UINT16_MAX) {
+        return true;
+    }
+
+    return false;
+}
+
 static struct rule *rule_create(struct rule *super, const union ofp_action *,
                                 size_t n_actions, uint16_t idle_timeout,
                                 uint16_t hard_timeout);
@@ -392,7 +411,7 @@ ofproto_set_in_band(struct ofproto *p, bool in_band)
 {
     if (in_band != (p->in_band != NULL)) {
         if (in_band) {
-            return in_band_create(&p->dpif, p->switch_status,
+            return in_band_create(p, &p->dpif, p->switch_status,
                                   p->controller->rconn, &p->in_band);
         } else {
             ofproto_set_discovery(p, false, NULL, true);
@@ -910,7 +929,7 @@ ofproto_send_packet(struct ofproto *p, const flow_t *flow,
 
 void
 ofproto_add_flow(struct ofproto *p,
-                 const flow_t *flow, uint32_t wildcards, uint16_t priority,
+                 const flow_t *flow, uint32_t wildcards, unsigned int priority,
                  const union ofp_action *actions, size_t n_actions,
                  const struct ofpbuf *packet, int idle_timeout)
 {
@@ -942,7 +961,7 @@ ofproto_add_flow(struct ofproto *p,
 
 void
 ofproto_delete_flow(struct ofproto *ofproto, const flow_t *flow,
-                    uint32_t wildcards, uint16_t priority)
+                    uint32_t wildcards, unsigned int priority)
 {
     struct rule *rule;
 
@@ -2103,7 +2122,7 @@ flow_stats_cb(struct cls_rule *rule_, void *cbdata_)
     uint64_t packet_count, byte_count;
     size_t act_len, len;
 
-    if (rule->super || !rule_has_out_port(rule, cbdata->out_port)) {
+    if (rule_is_hidden(rule) || !rule_has_out_port(rule, cbdata->out_port)) {
         return;
     }
 
@@ -2177,7 +2196,7 @@ aggregate_stats_cb(struct cls_rule *rule_, void *cbdata_)
     struct aggregate_stats_cbdata *cbdata = cbdata_;
     uint64_t packet_count, byte_count;
 
-    if (rule->super || !rule_has_out_port(rule, cbdata->out_port)) {
+    if (rule_is_hidden(rule) || !rule_has_out_port(rule, cbdata->out_port)) {
         return;
     }
 
@@ -2385,8 +2404,7 @@ static int
 modify_flow(struct ofproto *p, const struct ofp_flow_mod *ofm,
             size_t n_actions, uint16_t command, struct rule *rule)
 {
-    if (rule->super) {
-        /* Subrules are invisible to the controller. */
+    if (rule_is_hidden(rule)) {
         return 0;
     }
 
@@ -2742,7 +2760,9 @@ handle_odp_msg(struct ofproto *p, struct ofpbuf *packet)
 
         subrule = rule_create(rule, NULL, 0,
                               rule->idle_timeout, rule->hard_timeout);
-        cls_rule_from_flow(&subrule->cr, &flow, 0, 0);
+        cls_rule_from_flow(&subrule->cr, &flow, 0,
+                           (rule->cr.priority <= UINT16_MAX ? UINT16_MAX
+                            : rule->cr.priority));
 
         old_sr = rule_from_cls_rule(classifier_insert(&p->cls, &subrule->cr));
         if (old_sr) {
diff --git a/secchan/ofproto.h b/secchan/ofproto.h
index 584bd1bc..e4d19ab6 100644
--- a/secchan/ofproto.h
+++ b/secchan/ofproto.h
@@ -101,12 +101,12 @@ void ofproto_get_snoops(const struct ofproto *, struct svec *);
 int ofproto_send_packet(struct ofproto *, const flow_t *,
                         const union ofp_action *, size_t n_actions,
                         const struct ofpbuf *);
-void ofproto_add_flow(struct ofproto *,
-                      const flow_t *, uint32_t wildcards, uint16_t priority,
+void ofproto_add_flow(struct ofproto *, const flow_t *, uint32_t wildcards,
+                      unsigned int priority,
                       const union ofp_action *, size_t n_actions,
                       const struct ofpbuf *, int idle_timeout);
 void ofproto_delete_flow(struct ofproto *, const flow_t *, uint32_t wildcards,
-                         uint16_t priority);
+                         unsigned int priority);
 void ofproto_flush_flows(struct ofproto *);
 
 /* Hooks for vswitchd. */
-- 
2.30.2