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_if.c b/net/bridge/br_if.c
index f3a2e29..cf10b8f 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -203,7 +203,7 @@
memcpy(br->group_addr, br_group_address, ETH_ALEN);
br->feature_mask = dev->features;
- br->stp_enabled = 0;
+ br->stp_enabled = BR_NO_STP;
br->designated_root = br->bridge_id;
br->root_path_cost = 0;
br->root_port = 0;
diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c
index 147015f..eda0fbf 100644
--- a/net/bridge/br_ioctl.c
+++ b/net/bridge/br_ioctl.c
@@ -137,7 +137,8 @@
b.topology_change = br->topology_change;
b.topology_change_detected = br->topology_change_detected;
b.root_port = br->root_port;
- b.stp_enabled = br->stp_enabled;
+
+ b.stp_enabled = (br->stp_enabled != BR_NO_STP);
b.ageing_time = jiffies_to_clock_t(br->ageing_time);
b.hello_timer_value = br_timer_value(&br->hello_timer);
b.tcn_timer_value = br_timer_value(&br->tcn_timer);
@@ -251,7 +252,7 @@
if (!capable(CAP_NET_ADMIN))
return -EPERM;
- br->stp_enabled = args[1]?1:0;
+ br_stp_set_enabled(br, args[1]);
return 0;
case BRCTL_SET_BRIDGE_PRIORITY:
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index a14ac51..5e84ade 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -165,7 +165,7 @@
return -EINVAL;
/* if kernel STP is running, don't allow changes */
- if (p->br->stp_enabled)
+ if (p->br->stp_enabled == BR_KERNEL_STP)
return -EBUSY;
if (!netif_running(dev) ||
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 3adacdf..974fecc 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 @@
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 @@
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 @@
/* 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);
diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
index f9ff4d5..ebb0861 100644
--- a/net/bridge/br_stp.c
+++ b/net/bridge/br_stp.c
@@ -370,11 +370,11 @@
static void br_make_forwarding(struct net_bridge_port *p)
{
if (p->state == BR_STATE_BLOCKING) {
- if (p->br->stp_enabled) {
+ if (p->br->stp_enabled == BR_KERNEL_STP)
p->state = BR_STATE_LISTENING;
- } else {
+ else
p->state = BR_STATE_LEARNING;
- }
+
br_log_state(p);
mod_timer(&p->forward_delay_timer, jiffies + p->br->forward_delay); }
}
@@ -384,6 +384,10 @@
{
struct net_bridge_port *p;
+ /* Don't change port states if userspace is handling STP */
+ if (br->stp_enabled == BR_USER_STP)
+ return;
+
list_for_each_entry(p, &br->port_list, list) {
if (p->state != BR_STATE_DISABLED) {
if (p->port_no == br->root_port) {
diff --git a/net/bridge/br_stp_bpdu.c b/net/bridge/br_stp_bpdu.c
index b9fb0dc..60112bc 100644
--- a/net/bridge/br_stp_bpdu.c
+++ b/net/bridge/br_stp_bpdu.c
@@ -33,9 +33,6 @@
{
struct sk_buff *skb;
- if (!p->br->stp_enabled)
- return;
-
skb = dev_alloc_skb(length+LLC_RESERVE);
if (!skb)
return;
@@ -75,6 +72,9 @@
{
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 @@
{
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 @@
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)
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)
{
diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 6cc5cfe..7ec0b76 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -149,7 +149,9 @@
static void set_stp_state(struct net_bridge *br, unsigned long val)
{
- br->stp_enabled = val;
+ spin_unlock_bh(&br->lock);
+ br_stp_set_enabled(br, val);
+ spin_lock_bh(&br->lock);
}
static ssize_t store_stp_state(struct device *d,