From: Ben Pfaff <blp@nicira.com>
Date: Wed, 11 Mar 2009 18:13:01 +0000 (-0700)
Subject: datapath: Refuse module load if an active bridge exists.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fb8dc8eff38ae583fa692111bd5b515e9e627f1d;p=openvswitch

datapath: Refuse module load if an active bridge exists.

Loading when an active bridge exists will cause an OOPS as soon as any
packet is received on a bridged interface, because the datapath will
attempt to interpret the bridge's "struct net_bridge_port" as a datapath
"struct net_bridge_port", which is completely wrong.
---

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 6aee55fa..851af969 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -1522,9 +1522,23 @@ static int __init dp_init(void)
 
 	/* Hook into callback used by the bridge to intercept packets.
 	 * Parasites we are. */
-	if (br_handle_frame_hook)
+	rtnl_lock();
+	if (br_handle_frame_hook) {
+		struct net_device *dev;
+		for_each_netdev (&init_net, dev) {
+			if (!dev->br_port)
+				continue;
+
+			rtnl_unlock();
+			printk("openflow: must delete bridges "
+			       "before loading\n");
+			err = -EBUSY;
+			goto error_unreg_notifier;
+		}
 		printk("openflow: hijacking bridge hook\n");
+	}
 	br_handle_frame_hook = dp_frame_hook;
+	rtnl_unlock();
 
 	return 0;
 
diff --git a/datapath/linux-2.6/compat-2.6/include/linux/netdevice.h b/datapath/linux-2.6/compat-2.6/include/linux/netdevice.h
index 015c6efd..042e30d7 100644
--- a/datapath/linux-2.6/compat-2.6/include/linux/netdevice.h
+++ b/datapath/linux-2.6/compat-2.6/include/linux/netdevice.h
@@ -17,4 +17,13 @@ struct net *dev_net(const struct net_device *dev)
 }
 #endif /* linux kernel < 2.6.26 */
 
+#ifndef for_each_netdev
+/* Linux before 2.6.22 didn't have for_each_netdev at all. */
+#define for_each_netdev(net, d) for (d = dev_base; d; d = d->next)
+#elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
+/* Linux 2.6.24 added a network namespace pointer to the macro. */
+#undef for_each_netdev
+#define for_each_netdev(net,d) list_for_each_entry(d, &dev_base_head, dev_list)
+#endif
+
 #endif