hub: Check that hubs are configured correctly

Checks can be performed to make sure that hubs have at least one NIC and
one host device, warning the user if this is not the case.
Configurations which do not meet this rule tend to be broken but just
emit a warning.  This patch preserves compatibility with the checks
performed by net core on vlans.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

2 files changed, 46 insertions, 0 deletions

diff --git a/net/hub.c b/net/hub.c
index 9806a592f0..5cdd8c9152 100644
--- a/net/hub.c
+++ b/net/hub.c
@@ -244,3 +244,48 @@ int net_init_hubport(const NetClientOptions *opts, const char *name,
     net_hub_add_port(hubport->hubid, name);
     return 0;
 }
+
+/**
+ * Warn if hub configurations are likely wrong
+ */
+void net_hub_check_clients(void)
+{
+    NetHub *hub;
+    NetHubPort *port;
+    VLANClientState *peer;
+
+    QLIST_FOREACH(hub, &hubs, next) {
+        int has_nic = 0, has_host_dev = 0;
+
+        QLIST_FOREACH(port, &hub->ports, next) {
+            peer = port->nc.peer;
+            if (!peer) {
+                fprintf(stderr, "Warning: hub port %s has no peer\n",
+                        port->nc.name);
+                continue;
+            }
+
+            switch (peer->info->type) {
+            case NET_CLIENT_OPTIONS_KIND_NIC:
+                has_nic = 1;
+                break;
+            case NET_CLIENT_OPTIONS_KIND_USER:
+            case NET_CLIENT_OPTIONS_KIND_TAP:
+            case NET_CLIENT_OPTIONS_KIND_SOCKET:
+            case NET_CLIENT_OPTIONS_KIND_VDE:
+                has_host_dev = 1;
+                break;
+            default:
+                break;
+            }
+        }
+        if (has_host_dev && !has_nic) {
+            fprintf(stderr, "Warning: vlan %d with no nics\n", hub->id);
+        }
+        if (has_nic && !has_host_dev) {
+            fprintf(stderr,
+                    "Warning: vlan %d is not connected to host network\n",
+                    hub->id);
+        }
+    }
+}
diff --git a/net/hub.h b/net/hub.h
index 677085069b..9973da3bb9 100644
--- a/net/hub.h
+++ b/net/hub.h
@@ -23,5 +23,6 @@ VLANClientState *net_hub_add_port(int hub_id, const char *name);
 VLANClientState *net_hub_find_client_by_name(int hub_id, const char *name);
 void net_hub_info(Monitor *mon);
 int net_hub_id_for_client(VLANClientState *nc, int *id);
+void net_hub_check_clients(void);
 
 #endif /* NET_HUB_H */