learning-switch: Introduce struct for configuration.

This should make extensions easier.

lib/learning-switch.c

@@ -69,35 +69,23 @@ static packet_handler_func process_switch_features;
 static packet_handler_func process_packet_in;
 static packet_handler_func process_echo_request;
 
-/* Creates and returns a new learning switch.
- *
- * If 'learn_macs' is true, the new switch will learn the ports on which MAC
- * addresses appear.  Otherwise, the new switch will flood all packets.
- *
- * If 'max_idle' is nonnegative, the new switch will set up flows that expire
- * after the given number of seconds (or never expire, if 'max_idle' is
- * OFP_FLOW_PERMANENT).  Otherwise, the new switch will process every packet.
- *
- * The caller may provide an ofpbuf 'default_flows' that consists of a chain of
- * one or more OpenFlow messages to send to the switch at time of connection.
- * Presumably these will be OFPT_FLOW_MOD requests to set up the flow table.
+/* Creates and returns a new learning switch whose configuration is given by
+ * 'cfg'.
  *
  * 'rconn' is used to send out an OpenFlow features request. */
 struct lswitch *
-lswitch_create(struct rconn *rconn, bool learn_macs,
-               bool exact_flows, int max_idle, bool action_normal,
-               const struct ofpbuf *default_flows)
+lswitch_create(struct rconn *rconn, const struct lswitch_config *cfg)
 {
     const struct ofpbuf *b;
     struct lswitch *sw;
 
     sw = xzalloc(sizeof *sw);
-    sw->max_idle = max_idle;
+    sw->max_idle = cfg->max_idle;
     sw->datapath_id = 0;
     sw->last_features_request = time_now() - 1;
-    sw->ml = learn_macs ? mac_learning_create() : NULL;
-    sw->action_normal = action_normal;
-    if (exact_flows) {
+    sw->ml = cfg->mode == LSW_LEARN ? mac_learning_create() : NULL;
+    sw->action_normal = cfg->mode == LSW_NORMAL;
+    if (cfg->exact_flows) {
         /* Exact match. */
         sw->wildcards = 0;
     } else {
@@ -107,11 +95,11 @@ lswitch_create(struct rconn *rconn, bool learn_macs,
         sw->wildcards = (OFPFW_DL_TYPE | OFPFW_NW_SRC_MASK | OFPFW_NW_DST_MASK
                          | OFPFW_NW_PROTO | OFPFW_TP_SRC | OFPFW_TP_DST);
     }
-    sw->queue = UINT32_MAX;
+    sw->queue = cfg->queue_id;
     sw->queued = rconn_packet_counter_create();
     send_features_request(sw, rconn);
 
-    for (b = default_flows; b; b = b->next) {
+    for (b = cfg->default_flows; b; b = b->next) {
         queue_tx(sw, rconn, ofpbuf_clone(b));
     }
 
@@ -129,15 +117,6 @@ lswitch_destroy(struct lswitch *sw)
     }
 }
 
-/* Sets 'queue' as the OpenFlow queue used by packets and flows set up by 'sw'.
- * Specify UINT32_MAX to avoid specifying a particular queue, which is also the
- * default if this function is never called for 'sw'.  */
-void
-lswitch_set_queue(struct lswitch *sw, uint32_t queue)
-{
-    sw->queue = queue;
-}
-
 /* Takes care of necessary 'sw' activity, except for receiving packets (which
  * the caller must do). */
 void

lib/learning-switch.h

@@ -24,10 +24,34 @@
 struct ofpbuf;
 struct rconn;
 
-struct lswitch *lswitch_create(struct rconn *, bool learn_macs,
-                               bool exact_flows, int max_idle,
-                               bool action_normal,
-                               const struct ofpbuf *default_flows);
+enum lswitch_mode {
+    LSW_NORMAL,                 /* Always use OFPP_NORMAL. */
+    LSW_FLOOD,                  /* Always use OFPP_FLOOD. */
+    LSW_LEARN                   /* Learn MACs at controller. */
+};
+
+struct lswitch_config {
+    enum lswitch_mode mode;
+
+    /* Set up only exact-match flows? */
+    bool exact_flows;
+
+    /* <0: Process every packet at the controller.
+     * >=0: Expire flows after they are unused for 'max_idle' seconds.
+     * OFP_FLOW_PERMANENT: Set up permanent flows. */
+    int max_idle;
+
+    /* Optionally, a chain of one or more OpenFlow messages to send to the
+     * switch at time of connection.  Presumably these will be OFPT_FLOW_MOD
+     * requests to set up the flow table. */
+    const struct ofpbuf *default_flows;
+
+    /* The OpenFlow queue used by packets and flows set up by 'sw'.  Use
+     * UINT32_MAX to avoid specifying a particular queue. */
+    uint32_t queue_id;
+};
+
+struct lswitch *lswitch_create(struct rconn *, const struct lswitch_config *);
 void lswitch_set_queue(struct lswitch *sw, uint32_t queue);
 void lswitch_run(struct lswitch *);
 void lswitch_wait(struct lswitch *);

utilities/ovs-controller.c

@@ -215,13 +215,18 @@ main(int argc, char *argv[])
 static void
 new_switch(struct switch_ *sw, struct vconn *vconn)
 {
+    struct lswitch_config cfg;
+
     sw->rconn = rconn_create(60, 0);
     rconn_connect_unreliably(sw->rconn, vconn, NULL);
-    sw->lswitch = lswitch_create(sw->rconn, learn_macs, exact_flows,
-                                 set_up_flows ? max_idle : -1,
-                                 action_normal, default_flows.head);
 
-    lswitch_set_queue(sw->lswitch, queue_id);
+    cfg.mode = (action_normal ? LSW_NORMAL
+                : learn_macs ? LSW_LEARN
+                : LSW_FLOOD);
+    cfg.max_idle = set_up_flows ? max_idle : -1;
+    cfg.default_flows = default_flows.head;
+    cfg.queue_id = queue_id;
+    sw->lswitch = lswitch_create(sw->rconn, &cfg);
 }
 
 static int