Currently the bridge does not impl. split horizon which will easily
cause loops when 2 or more VLANs are added from the same physical interface.
Impl. split horizon and add /sys/class/net/br0/bridge/split_horizon
to turn it off.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund at transmode.se>
---
Leaving for 1 week vacation next week, but feel free to
comment and/or test.
Jocke
net/bridge/br_forward.c | 12 +++++++++++-
net/bridge/br_if.c | 2 +-
net/bridge/br_private.h | 1 +
net/bridge/br_sysfs_br.c | 26 ++++++++++++++++++++++++++
4 files changed, 39 insertions(+), 2 deletions(-)
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index d2c27c8..cfa1f7e 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -22,7 +22,17 @@
static inline int should_deliver(const struct net_bridge_port *p,
const struct sk_buff *skb)
{
- return (skb->dev != p->dev && p->state ==
BR_STATE_FORWARDING);
+ struct net_device *indev = skb->dev;
+ struct net_device *todev = p->dev;
+
+ if (p->br->flags & BR_SPLIT_HORIZON) {
+ if (indev->priv_flags & IFF_802_1Q_VLAN)
+ indev = vlan_dev_real_dev(indev);
+ if (todev->priv_flags & IFF_802_1Q_VLAN)
+ todev = vlan_dev_real_dev(todev);
+ }
+
+ return (indev != todev && p->state == BR_STATE_FORWARDING);
}
static inline unsigned packet_length(const struct sk_buff *skb)
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 727c5c5..f23e338 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -203,7 +203,7 @@ static struct net_device *new_bridge_dev(struct net *net,
const char *name)
br->topology_change = 0;
br->topology_change_detected = 0;
br->ageing_time = 300 * HZ;
-
+ br->flags = BR_SPLIT_HORIZON;
br_netfilter_rtable_init(br);
INIT_LIST_HEAD(&br->age_list);
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index b6c3b71..2c99877 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -98,6 +98,7 @@ struct net_bridge
#endif
unsigned long flags;
#define BR_SET_MAC_ADDR 0x00000001
+#define BR_SPLIT_HORIZON 0x00000002
/* STP */
bridge_id designated_root;
diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 603d892..d0eebc1 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -344,6 +344,31 @@ static ssize_t store_flush(struct device *d,
}
static DEVICE_ATTR(flush, S_IWUSR, NULL, store_flush);
+static ssize_t show_split_horizon(struct device *d,
+ struct device_attribute *attr, char *buf)
+{
+ struct net_bridge *br = to_bridge(d);
+ int val = !!(br->flags & BR_SPLIT_HORIZON);
+
+ return sprintf(buf, "%d\n", val);
+}
+static int set_split_horizon(struct net_bridge *br, unsigned long val)
+{
+ if (val)
+ br->flags |= BR_SPLIT_HORIZON;
+ else
+ br->flags &= ~BR_SPLIT_HORIZON;
+ return 0;
+}
+
+static ssize_t store_split_horizon(struct device *d,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ return store_bridge_parm(d, buf, len, set_split_horizon);
+}
+static DEVICE_ATTR(split_horizon, S_IRUGO | S_IWUSR, show_split_horizon,
store_split_horizon);
+
static struct attribute *bridge_attrs[] = {
&dev_attr_forward_delay.attr,
&dev_attr_hello_time.attr,
@@ -363,6 +388,7 @@ static struct attribute *bridge_attrs[] = {
&dev_attr_gc_timer.attr,
&dev_attr_group_addr.attr,
&dev_attr_flush.attr,
+ &dev_attr_split_horizon.attr,
NULL
};
--
1.6.2.3
Joakim Tjernlund <Joakim.Tjernlund at transmode.se> writes:> Currently the bridge does not impl. split horizon which will easily > cause loops when 2 or more VLANs are added from the same physical interface.Why would they cause loops? If your topology isn't loop free, run spanning tree in the VLAN's. Yet another thing most hardware switches can't do, incidentally. /Benny
richardvoigt at gmail.com
2009-Jun-13 04:39 UTC
[Bridge] [PATCH] [bridge] Add split horizon
On Fri, Jun 12, 2009 at 4:26 PM, Joakim Tjernlund<Joakim.Tjernlund at transmode.se> wrote:> Currently the bridge does not impl. split horizon which will easily > cause loops when 2 or more VLANs are added from the same physical interface.I call shenanigans. Got multiple VLANs from the same physical interface added to a bridge and no loops, almost no trouble of any sort. A second bridge on the same router has loops, uses spanning tree to shut one VLAN down selectively (to automatically bypass a traffic shaper appliance with a history of failure) and the only trouble is that the PDUs sent by spanning tree cause klog warnings when they come back to the other VLAN of the same physical interface. And I don't think split horizon means what you think it does.