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>
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index a285897..1c1806d 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -123,6 +123,62 @@
br_become_root_bridge(br);
}
+static void br_stp_start(struct net_bridge *br)
+{
+ int r;
+ char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
+ char *envp[] = { NULL };
+
+ r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
+ if (r == 0) {
+ br->stp_enabled = BR_USER_STP;
+ printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
+ } else {
+ br->stp_enabled = BR_KERNEL_STP;
+ printk(KERN_INFO "%s: starting userspace STP failed, "
+ "staring kernel STP\n", br->dev->name);
+
+ /* To start timers on any ports left in blocking */
+ spin_lock_bh(&br->lock);
+ br_port_state_selection(br);
+ spin_unlock_bh(&br->lock);
+ }
+}
+
+static void br_stp_stop(struct net_bridge *br)
+{
+ int r;
+ char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
+ char *envp[] = { NULL };
+
+ if (br->stp_enabled == BR_USER_STP) {
+ r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
+ printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
+ br->dev->name, r);
+
+
+ /* To start timers on any ports left in blocking */
+ spin_lock_bh(&br->lock);
+ br_port_state_selection(br);
+ spin_unlock_bh(&br->lock);
+ }
+
+ br->stp_enabled = BR_NO_STP;
+}
+
+void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
+{
+ ASSERT_RTNL();
+
+ if (val) {
+ if (br->stp_enabled == BR_NO_STP)
+ br_stp_start(br);
+ } else {
+ if (br->stp_enabled != BR_NO_STP)
+ br_stp_stop(br);
+ }
+}
+
/* called under bridge lock */
void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
{