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, 12 insertions, 3 deletions

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 3adacdf3406f..974feccd28b1 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -26,7 +26,10 @@
 #define BR_PORT_BITS    10
 #define BR_MAX_PORTS    (1<<BR_PORT_BITS)
 
-#define BR_VERSION      "2.2"
+#define BR_VERSION      "2.3"
+
+/* Path to usermode spanning tree program */
+#define BR_STP_PROG     "/sbin/bridge-stp"
 
 typedef struct bridge_id bridge_id;
 typedef struct mac_addr mac_addr;
@@ -107,7 +110,13 @@ struct net_bridge
 
         u8                              group_addr[ETH_ALEN];
         u16                             root_port;
-        unsigned char                   stp_enabled;
+
+        enum {
+                BR_NO_STP,              /* no spanning tree */
+                BR_KERNEL_STP,          /* old STP in kernel */
+                BR_USER_STP,            /* new RSTP in userspace */
+        } stp_enabled;
+
         unsigned char                   topology_change;
         unsigned char                   topology_change_detected;
 
@@ -127,7 +136,6 @@ static inline int br_is_root_bridge(const struct net_bridge *br)
         return !memcmp(&br->bridge_id, &br->designated_root, 8);
 }
 
-
 /* br_device.c */
 extern void br_dev_setup(struct net_device *dev);
 extern int br_dev_xmit(struct sk_buff *skb, struct net_device *dev);
@@ -209,6 +217,7 @@ extern void br_become_designated_port(struct net_bridge_port *p);
 /* br_stp_if.c */
 extern void br_stp_enable_bridge(struct net_bridge *br);
 extern void br_stp_disable_bridge(struct net_bridge *br);
+extern void br_stp_set_enabled(struct net_bridge *br, unsigned long val);
 extern void br_stp_enable_port(struct net_bridge_port *p);
 extern void br_stp_disable_port(struct net_bridge_port *p);
 extern void br_stp_recalculate_bridge_id(struct net_bridge *br);