bridge: add support for user mode STP

This patchset based on work by Aji_Srinivas@emc.com provides allows
spanning tree to be controled from userspace.  Like hotplug, it
uses call_usermodehelper when spanning tree is enabled so there
is no visible API change. If call to start usermode STP fails
it falls back to existing kernel STP.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>

1 files changed, 13 insertions, 6 deletions

diff --git a/net/bridge/br_stp_bpdu.c b/net/bridge/br_stp_bpdu.c
index b9fb0dc4ab12..60112bce6698 100644
--- a/net/bridge/br_stp_bpdu.c
+++ b/net/bridge/br_stp_bpdu.c
@@ -33,9 +33,6 @@ static void br_send_bpdu(struct net_bridge_port *p,
 {
         struct sk_buff *skb;
 
-        if (!p->br->stp_enabled)
-                return;
-
         skb = dev_alloc_skb(length+LLC_RESERVE);
         if (!skb)
                 return;
@@ -75,6 +72,9 @@ void br_send_config_bpdu(struct net_bridge_port *p, struct br_config_bpdu *bpdu)
 {
         unsigned char buf[35];
 
+        if (p->br->stp_enabled != BR_KERNEL_STP)
+                return;
+
         buf[0] = 0;
         buf[1] = 0;
         buf[2] = 0;
@@ -117,6 +117,9 @@ void br_send_tcn_bpdu(struct net_bridge_port *p)
 {
         unsigned char buf[4];
 
+        if (p->br->stp_enabled != BR_KERNEL_STP)
+                return;
+
         buf[0] = 0;
         buf[1] = 0;
         buf[2] = 0;
@@ -157,9 +160,13 @@ int br_stp_rcv(struct sk_buff *skb, struct net_device *dev,
         br = p->br;
         spin_lock(&br->lock);
 
-        if (p->state == BR_STATE_DISABLED
-            || !br->stp_enabled
-            || !(br->dev->flags & IFF_UP))
+        if (br->stp_enabled != BR_KERNEL_STP)
+                goto out;
+
+        if (!(br->dev->flags & IFF_UP))
+                goto out;
+
+        if (p->state == BR_STATE_DISABLED)
                 goto out;
 
         if (compare_ether_addr(dest, br->group_addr) != 0)