Maintain per-network channel information.

network.c

@@ -181,6 +181,28 @@ check_network_ipv4(struct network *net)
     return 0;
 }
 
+int
+check_network_channel(struct network *net)
+{
+    int channel = NET_CONF(net, channel);
+
+    if(channel == NET_CHANNEL_UNKNOWN) {
+        if((net->flags & NET_WIRED)) {
+            channel = NET_CHANNEL_NONINTERFERING;
+        } else {
+            channel = kernel_interface_channel(net->ifname, net->ifindex);
+            if(channel <= 0)
+                channel = NET_CHANNEL_INTERFERING;
+        }
+    }
+
+    if(net->channel != channel) {
+        net->channel = channel;
+        return 1;
+    }
+    return 0;
+}
+
 int
 network_up(struct network *net, int up)
 {
@@ -363,6 +385,7 @@ network_up(struct network *net, int up)
         net->numll = 0;
     }
 
+    check_network_channel(net);
     update_network_metric(net);
     rc = check_network_ipv4(net);
     if(up && rc > 0)
@@ -411,6 +434,7 @@ check_networks(void)
             network_up(net, rc > 0);
         }
 
+        check_network_channel(net);
         rc = check_network_ipv4(net);
         if(rc > 0) {
             send_request(net, NULL, 0);

network.h

@@ -35,6 +35,7 @@ struct network_conf {
     char wired;
     char split_horizon;
     char lq;
+    int channel;
     struct network_conf *next;
 };
 
@@ -47,12 +48,17 @@ struct network_conf {
 #define NET_SPLIT_HORIZON (1 << 2)
 #define NET_LQ (1 << 3)
 
+#define NET_CHANNEL_UNKNOWN 0
+#define NET_CHANNEL_INTERFERING -2
+#define NET_CHANNEL_NONINTERFERING -3
+
 struct network {
     struct network *next;
     struct network_conf *conf;
     unsigned int ifindex;
     unsigned short flags;
     unsigned short cost;
+    int channel;
     struct timeval hello_timeout;
     struct timeval update_timeout;
     struct timeval flush_timeout;