Add support for multiple OpenFlow controllers on a single bridge.

With this commit, Open vSwitch permits a bridge to have any number of
OpenFlow controllers.  When multiple controllers are configured, Open
vSwitch connects to all of them simultaneously.  Details of configuration
are in the vswitch schema documentation.

OpenFlow 1.0 does not specify how multiple controllers coordinate in
interacting with a single switch, so more than one controller should be
specified only if the controllers are themselves designed to coordinate
with each other.

An upcoming commit will provide a simple means for coordination between
multiple controllers.

Feature #2495.

1 files changed, 113 insertions, 91 deletions

diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index b9e39c9c7..cf0212205 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -158,11 +158,6 @@ struct bridge {
     bool sent_config_request;   /* Successfully sent config request? */
     uint8_t default_ea[ETH_ADDR_LEN]; /* Default MAC. */
 
-    /* Support for remote controllers. */
-    char *controller;           /* NULL if there is no remote controller;
-                                 * "discover" to do controller discovery;
-                                 * otherwise a vconn name. */
-
     /* OpenFlow switch processing. */
     struct ofproto *ofproto;    /* OpenFlow switch. */
 
@@ -208,9 +203,9 @@ static void bridge_destroy(struct bridge *);
 static struct bridge *bridge_lookup(const char *name);
 static unixctl_cb_func bridge_unixctl_dump_flows;
 static int bridge_run_one(struct bridge *);
-static const struct ovsrec_controller *bridge_get_controller(
-                      const struct ovsrec_open_vswitch *ovs_cfg,
-                      const struct bridge *br);
+static size_t bridge_get_controllers(const struct ovsrec_open_vswitch *ovs_cfg,
+                                     const struct bridge *br,
+                                     struct ovsrec_controller ***controllersp);
 static void bridge_reconfigure_one(const struct ovsrec_open_vswitch *,
                                    struct bridge *);
 static void bridge_reconfigure_controller(const struct ovsrec_open_vswitch *,
@@ -745,8 +740,10 @@ bridge_reconfigure(const struct ovsrec_open_vswitch *ovs_cfg)
         /* Set sFlow configuration on this bridge. */
         if (br->cfg->sflow) {
             const struct ovsrec_sflow *sflow_cfg = br->cfg->sflow;
-            const struct ovsrec_controller *ctrl;
+            struct ovsrec_controller **controllers;
             struct ofproto_sflow_options oso;
+            size_t n_controllers;
+            size_t i;
 
             memset(&oso, 0, sizeof oso);
 
@@ -771,8 +768,14 @@ bridge_reconfigure(const struct ovsrec_open_vswitch *ovs_cfg)
             oso.sub_id = sflow_bridge_number++;
             oso.agent_device = sflow_cfg->agent;
 
-            ctrl = bridge_get_controller(ovs_cfg, br);
-            oso.control_ip = ctrl ? ctrl->local_ip : NULL;
+            oso.control_ip = NULL;
+            n_controllers = bridge_get_controllers(ovs_cfg, br, &controllers);
+            for (i = 0; i < n_controllers; i++) {
+                if (controllers[i]->local_ip) {
+                    oso.control_ip = controllers[i]->local_ip;
+                    break;
+                }
+            }
             ofproto_set_sflow(br->ofproto, &oso);
 
             svec_destroy(&oso.targets);
@@ -1052,7 +1055,7 @@ bridge_wait(void)
 
     LIST_FOR_EACH (br, struct bridge, node, &all_bridges) {
         ofproto_wait(br->ofproto);
-        if (br->controller) {
+        if (ofproto_has_controller(br->ofproto)) {
             continue;
         }
 
@@ -1182,7 +1185,6 @@ bridge_destroy(struct bridge *br)
         }
         dpif_close(br->dpif);
         ofproto_destroy(br->ofproto);
-        free(br->controller);
         mac_learning_destroy(br->ml);
         port_array_destroy(&br->ifaces);
         free(br->ports);
@@ -1258,21 +1260,31 @@ bridge_run_one(struct bridge *br)
     return error;
 }
 
-static const struct ovsrec_controller *
-bridge_get_controller(const struct ovsrec_open_vswitch *ovs_cfg,
-                      const struct bridge *br)
+static size_t
+bridge_get_controllers(const struct ovsrec_open_vswitch *ovs_cfg,
+                       const struct bridge *br,
+                       struct ovsrec_controller ***controllersp)
 {
-    const struct ovsrec_controller *controller;
+    struct ovsrec_controller **controllers;
+    size_t n_controllers;
 
-    controller = (br->cfg->controller ? br->cfg->controller
-                  : ovs_cfg->controller ? ovs_cfg->controller
-                  : NULL);
+    if (br->cfg->n_controller) {
+        controllers = br->cfg->controller;
+        n_controllers = br->cfg->n_controller;
+    } else {
+        controllers = ovs_cfg->controller;
+        n_controllers = ovs_cfg->n_controller;
+    }
 
-    if (controller && !strcmp(controller->target, "none")) {
-        return NULL;
+    if (n_controllers == 1 && !strcmp(controllers[0]->target, "none")) {
+        controllers = NULL;
+        n_controllers = 0;
     }
 
-    return controller;
+    if (controllersp) {
+        *controllersp = controllers;
+    }
+    return n_controllers;
 }
 
 static bool
@@ -1391,7 +1403,7 @@ bridge_reconfigure_one(const struct ovsrec_open_vswitch *ovs_cfg,
      * user didn't specify one.
      *
      * XXX perhaps we should synthesize a port ourselves in this case. */
-    if (bridge_get_controller(ovs_cfg, br)) {
+    if (bridge_get_controllers(ovs_cfg, br, NULL)) {
         char local_name[IF_NAMESIZE];
         int error;
 
@@ -1506,79 +1518,21 @@ static void
 bridge_reconfigure_controller(const struct ovsrec_open_vswitch *ovs_cfg,
                               struct bridge *br)
 {
-    const struct ovsrec_controller *c;
+    struct ovsrec_controller **controllers;
+    size_t n_controllers;
 
-    c = bridge_get_controller(ovs_cfg, br);
-    if ((br->controller != NULL) != (c != NULL)) {
+    n_controllers = bridge_get_controllers(ovs_cfg, br, &controllers);
+    if (ofproto_has_controller(br->ofproto) != (n_controllers != 0)) {
         ofproto_flush_flows(br->ofproto);
     }
-    free(br->controller);
-    br->controller = c ? xstrdup(c->target) : NULL;
-
-    if (c) {
-        struct ofproto_controller oc;
-
-        if (strcmp(c->target, "discover")) {
-            struct iface *local_iface;
-            struct in_addr ip;
-
-            local_iface = bridge_get_local_iface(br);
-            if (local_iface && c->local_ip && inet_aton(c->local_ip, &ip)) {
-                struct netdev *netdev = local_iface->netdev;
-                struct in_addr mask, gateway;
-
-                if (!c->local_netmask || !inet_aton(c->local_netmask, &mask)) {
-                    mask.s_addr = 0;
-                }
-                if (!c->local_gateway
-                    || !inet_aton(c->local_gateway, &gateway)) {
-                    gateway.s_addr = 0;
-                }
-
-                netdev_turn_flags_on(netdev, NETDEV_UP, true);
-                if (!mask.s_addr) {
-                    mask.s_addr = guess_netmask(ip.s_addr);
-                }
-                if (!netdev_set_in4(netdev, ip, mask)) {
-                    VLOG_INFO("bridge %s: configured IP address "IP_FMT", "
-                              "netmask "IP_FMT,
-                              br->name, IP_ARGS(&ip.s_addr),
-                              IP_ARGS(&mask.s_addr));
-                }
-
-                if (gateway.s_addr) {
-                    if (!netdev_add_router(netdev, gateway)) {
-                        VLOG_INFO("bridge %s: configured gateway "IP_FMT,
-                                  br->name, IP_ARGS(&gateway.s_addr));
-                    }
-                }
-            }
-        }
 
-        oc.target = c->target;
-        oc.max_backoff = c->max_backoff ? *c->max_backoff / 1000 : 8;
-        oc.probe_interval = (c->inactivity_probe
-                             ? *c->inactivity_probe / 1000 : 5);
-        oc.fail = (!c->fail_mode
-                   || !strcmp(c->fail_mode, "standalone")
-                   || !strcmp(c->fail_mode, "open")
-                   ? OFPROTO_FAIL_STANDALONE
-                   : OFPROTO_FAIL_SECURE);
-        oc.band = (!c->connection_mode
-                   || !strcmp(c->connection_mode, "in-band")
-                   ? OFPROTO_IN_BAND
-                   : OFPROTO_OUT_OF_BAND);
-        oc.accept_re = c->discover_accept_regex;
-        oc.update_resolv_conf = c->discover_update_resolv_conf;
-        oc.rate_limit = (c->controller_rate_limit
-                         ? *c->controller_rate_limit : 0);
-        oc.burst_limit = (c->controller_burst_limit
-                          ? *c->controller_burst_limit : 0);
-        ofproto_set_controller(br->ofproto, &oc);
-    } else {
+    if (!n_controllers) {
         union ofp_action action;
         flow_t flow;
 
+        /* Clear out controllers. */
+        ofproto_set_controllers(br->ofproto, NULL, 0);
+
         /* Set up a flow that matches every packet and directs them to
          * OFPP_NORMAL (which goes to us). */
         memset(&action, 0, sizeof action);
@@ -1587,8 +1541,76 @@ bridge_reconfigure_controller(const struct ovsrec_open_vswitch *ovs_cfg,
         action.output.port = htons(OFPP_NORMAL);
         memset(&flow, 0, sizeof flow);
         ofproto_add_flow(br->ofproto, &flow, OVSFW_ALL, 0, &action, 1, 0);
+    } else {
+        struct ofproto_controller *ocs;
+        size_t i;
+
+        ocs = xmalloc(n_controllers * sizeof *ocs);
+        for (i = 0; i < n_controllers; i++) {
+            struct ovsrec_controller *c = controllers[i];
+            struct ofproto_controller *oc = &ocs[i];
+
+            if (strcmp(c->target, "discover")) {
+                struct iface *local_iface;
+                struct in_addr ip;
+
+                local_iface = bridge_get_local_iface(br);
+                if (local_iface && c->local_ip
+                    && inet_aton(c->local_ip, &ip)) {
+                    struct netdev *netdev = local_iface->netdev;
+                    struct in_addr mask, gateway;
+
+                    if (!c->local_netmask
+                        || !inet_aton(c->local_netmask, &mask)) {
+                        mask.s_addr = 0;
+                    }
+                    if (!c->local_gateway
+                        || !inet_aton(c->local_gateway, &gateway)) {
+                        gateway.s_addr = 0;
+                    }
+
+                    netdev_turn_flags_on(netdev, NETDEV_UP, true);
+                    if (!mask.s_addr) {
+                        mask.s_addr = guess_netmask(ip.s_addr);
+                    }
+                    if (!netdev_set_in4(netdev, ip, mask)) {
+                        VLOG_INFO("bridge %s: configured IP address "IP_FMT", "
+                                  "netmask "IP_FMT,
+                                  br->name, IP_ARGS(&ip.s_addr),
+                                  IP_ARGS(&mask.s_addr));
+                    }
+
+                    if (gateway.s_addr) {
+                        if (!netdev_add_router(netdev, gateway)) {
+                            VLOG_INFO("bridge %s: configured gateway "IP_FMT,
+                                      br->name, IP_ARGS(&gateway.s_addr));
+                        }
+                    }
+                }
+            }
 
-        ofproto_set_controller(br->ofproto, NULL);
+            oc->target = c->target;
+            oc->max_backoff = c->max_backoff ? *c->max_backoff / 1000 : 8;
+            oc->probe_interval = (c->inactivity_probe
+                                 ? *c->inactivity_probe / 1000 : 5);
+            oc->fail = (!c->fail_mode
+                       || !strcmp(c->fail_mode, "standalone")
+                       || !strcmp(c->fail_mode, "open")
+                       ? OFPROTO_FAIL_STANDALONE
+                       : OFPROTO_FAIL_SECURE);
+            oc->band = (!c->connection_mode
+                       || !strcmp(c->connection_mode, "in-band")
+                       ? OFPROTO_IN_BAND
+                       : OFPROTO_OUT_OF_BAND);
+            oc->accept_re = c->discover_accept_regex;
+            oc->update_resolv_conf = c->discover_update_resolv_conf;
+            oc->rate_limit = (c->controller_rate_limit
+                             ? *c->controller_rate_limit : 0);
+            oc->burst_limit = (c->controller_burst_limit
+                              ? *c->controller_burst_limit : 0);
+        }
+        ofproto_set_controllers(br->ofproto, ocs, n_controllers);
+        free(ocs);
     }
 }