netflow: Make thread safe.

In future patches upcall handler threads will need to update netflow.

Signed-off-by: Ethan Jackson <ethan@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

1 files changed, 66 insertions, 12 deletions

diff --git a/ofproto/netflow.c b/ofproto/netflow.c
index 4e8949324..c91ecf068 100644
--- a/ofproto/netflow.c
+++ b/ofproto/netflow.c
@@ -52,6 +52,8 @@ struct netflow {
     long long int reconfig_time;  /* When we reconfigured the timeouts. */
 
     struct hmap flows;            /* Contains 'netflow_flows'. */
+
+    atomic_int ref_cnt;
 };
 
 struct netflow_flow {
@@ -76,10 +78,15 @@ struct netflow_flow {
     long long int used;           /* Last-used time (0 if never used). */
 };
 
+static struct ovs_mutex mutex = OVS_MUTEX_INITIALIZER;
+
 static struct netflow_flow *netflow_flow_lookup(const struct netflow *,
-                                                const struct flow *);
+                                                const struct flow *)
+    OVS_REQUIRES(mutex);
 static uint32_t netflow_flow_hash(const struct flow *);
-static void netflow_expire__(struct netflow *, struct netflow_flow *);
+static void netflow_expire__(struct netflow *, struct netflow_flow *)
+    OVS_REQUIRES(mutex);
+static void netflow_run__(struct netflow *) OVS_REQUIRES(mutex);
 
 void
 netflow_mask_wc(struct flow *flow, struct flow_wildcards *wc)
@@ -98,6 +105,7 @@ netflow_mask_wc(struct flow *flow, struct flow_wildcards *wc)
 static void
 gen_netflow_rec(struct netflow *nf, struct netflow_flow *nf_flow,
                 uint32_t packet_count, uint32_t byte_count)
+    OVS_REQUIRES(mutex)
 {
     struct netflow_v5_header *nf_hdr;
     struct netflow_v5_record *nf_rec;
@@ -157,7 +165,7 @@ gen_netflow_rec(struct netflow *nf, struct netflow_flow *nf_flow,
 
     /* NetFlow messages are limited to 30 records. */
     if (ntohs(nf_hdr->count) >= 30) {
-        netflow_run(nf);
+        netflow_run__(nf);
     }
 }
 
@@ -165,6 +173,7 @@ void
 netflow_flow_update(struct netflow *nf, struct flow *flow,
                     ofp_port_t output_iface,
                     const struct dpif_flow_stats *stats)
+    OVS_EXCLUDED(mutex)
 {
     struct netflow_flow *nf_flow;
     long long int used;
@@ -174,6 +183,7 @@ netflow_flow_update(struct netflow *nf, struct flow *flow,
         return;
     }
 
+    ovs_mutex_lock(&mutex);
     nf_flow = netflow_flow_lookup(nf, flow);
     if (!nf_flow) {
         nf_flow = xzalloc(sizeof *nf_flow);
@@ -209,10 +219,13 @@ netflow_flow_update(struct netflow *nf, struct flow *flow,
             nf_flow->last_expired = time_msec();
         }
     }
+
+    ovs_mutex_unlock(&mutex);
 }
 
 static void
 netflow_expire__(struct netflow *nf, struct netflow_flow *nf_flow)
+    OVS_REQUIRES(mutex)
 {
     uint64_t pkts, bytes;
 
@@ -264,32 +277,38 @@ netflow_expire__(struct netflow *nf, struct netflow_flow *nf_flow)
 }
 
 void
-netflow_expire(struct netflow *nf, struct flow *flow)
+netflow_expire(struct netflow *nf, struct flow *flow) OVS_EXCLUDED(mutex)
 {
-    struct netflow_flow *nf_flow = netflow_flow_lookup(nf, flow);
+    struct netflow_flow *nf_flow;
 
+    ovs_mutex_lock(&mutex);
+    nf_flow = netflow_flow_lookup(nf, flow);
     if (nf_flow) {
         netflow_expire__(nf, nf_flow);
     }
+    ovs_mutex_unlock(&mutex);
 }
 
 void
-netflow_flow_clear(struct netflow *nf, struct flow *flow)
+netflow_flow_clear(struct netflow *nf, struct flow *flow) OVS_EXCLUDED(mutex)
 {
-    struct netflow_flow *nf_flow = netflow_flow_lookup(nf, flow);
+    struct netflow_flow *nf_flow;
 
+    ovs_mutex_lock(&mutex);
+    nf_flow = netflow_flow_lookup(nf, flow);
     if (nf_flow) {
         ovs_assert(!nf_flow->packet_count);
         ovs_assert(!nf_flow->byte_count);
         hmap_remove(&nf->flows, &nf_flow->hmap_node);
         free(nf_flow);
     }
+    ovs_mutex_unlock(&mutex);
 }
 
 /* Returns true if it's time to send out a round of NetFlow active timeouts,
  * false otherwise. */
-void
-netflow_run(struct netflow *nf)
+static void
+netflow_run__(struct netflow *nf) OVS_REQUIRES(mutex)
 {
     long long int now = time_msec();
     struct netflow_flow *nf_flow, *next;
@@ -321,23 +340,35 @@ netflow_run(struct netflow *nf)
 }
 
 void
-netflow_wait(struct netflow *nf)
+netflow_run(struct netflow *nf)
 {
+    ovs_mutex_lock(&mutex);
+    netflow_run__(nf);
+    ovs_mutex_unlock(&mutex);
+}
+
+void
+netflow_wait(struct netflow *nf) OVS_EXCLUDED(mutex)
+{
+    ovs_mutex_lock(&mutex);
     if (nf->active_timeout) {
         poll_timer_wait_until(nf->next_timeout);
     }
     if (nf->packet.size) {
         poll_immediate_wake();
     }
+    ovs_mutex_unlock(&mutex);
 }
 
 int
 netflow_set_options(struct netflow *nf,
                     const struct netflow_options *nf_options)
+    OVS_EXCLUDED(mutex)
 {
     int error = 0;
     long long int old_timeout;
 
+    ovs_mutex_lock(&mutex);
     nf->engine_type = nf_options->engine_type;
     nf->engine_id = nf_options->engine_id;
     nf->add_id_to_iface = nf_options->add_id_to_iface;
@@ -356,6 +387,7 @@ netflow_set_options(struct netflow *nf,
         nf->reconfig_time = time_msec();
         nf->next_timeout = time_msec();
     }
+    ovs_mutex_unlock(&mutex);
 
     return error;
 }
@@ -371,14 +403,35 @@ netflow_create(void)
     nf->add_id_to_iface = false;
     nf->netflow_cnt = 0;
     hmap_init(&nf->flows);
+    atomic_init(&nf->ref_cnt, 1);
     ofpbuf_init(&nf->packet, 1500);
     return nf;
 }
 
-void
-netflow_destroy(struct netflow *nf)
+struct netflow *
+netflow_ref(const struct netflow *nf_)
 {
+    struct netflow *nf = CONST_CAST(struct netflow *, nf_);
     if (nf) {
+        int orig;
+        atomic_add(&nf->ref_cnt, 1, &orig);
+        ovs_assert(orig > 0);
+    }
+    return nf;
+}
+
+void
+netflow_unref(struct netflow *nf)
+{
+    int orig;
+
+    if (!nf) {
+        return;
+    }
+
+    atomic_sub(&nf->ref_cnt, 1, &orig);
+    ovs_assert(orig > 0);
+    if (orig == 1) {
         ofpbuf_uninit(&nf->packet);
         collectors_destroy(nf->collectors);
         free(nf);
@@ -389,6 +442,7 @@ netflow_destroy(struct netflow *nf)
 
 static struct netflow_flow *
 netflow_flow_lookup(const struct netflow *nf, const struct flow *flow)
+    OVS_REQUIRES(mutex)
 {
     struct netflow_flow *nf_flow;