Patchwork [net-next,1/4] bridge: Add sysfs interface to control promisc mode

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Submitter Vlad Yasevich
Date March 13, 2013, 1:45 a.m.
Message ID <1363139126-13396-2-git-send-email-vyasevic@redhat.com>
Download mbox | patch
Permalink /patch/227138/
State Deferred
Delegated to: David Miller
Headers show

Comments

Vlad Yasevich - March 13, 2013, 1:45 a.m.
Add an sysfs interface to turn promiscusous mode on and off on
the bridge.  By default all interfaces in the bridge
are in promisc mode.  When promisc mode is turned off, it is
turned off on all bridge ports and the bridge turns on IFF_ALLMULTI
to handle multicast traffic.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
---
 net/bridge/br_device.c   |   41 +++++++++++++++++++++++++++++++++++++++++
 net/bridge/br_if.c       |   22 +++++++++++++++++-----
 net/bridge/br_private.h  |    2 ++
 net/bridge/br_sysfs_br.c |   17 +++++++++++++++++
 4 files changed, 77 insertions(+), 5 deletions(-)
stephen hemminger - March 13, 2013, 3:38 p.m.
On Tue, 12 Mar 2013 21:45:23 -0400
Vlad Yasevich <vyasevic@redhat.com> wrote:

> Add an sysfs interface to turn promiscusous mode on and off on
> the bridge.  By default all interfaces in the bridge
> are in promisc mode.  When promisc mode is turned off, it is
> turned off on all bridge ports and the bridge turns on IFF_ALLMULTI
> to handle multicast traffic.
> 
> Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
> ---
>  net/bridge/br_device.c   |   41 +++++++++++++++++++++++++++++++++++++++++
>  net/bridge/br_if.c       |   22 +++++++++++++++++-----
>  net/bridge/br_private.h  |    2 ++
>  net/bridge/br_sysfs_br.c |   17 +++++++++++++++++
>  4 files changed, 77 insertions(+), 5 deletions(-)
> 

All attribute changes must also be available through netlink, and changes
to attributes should cause a notification to applications listening for
netlink events on that bridge.
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Vlad Yasevich - March 13, 2013, 3:44 p.m.
On 03/13/2013 11:38 AM, Stephen Hemminger wrote:
> On Tue, 12 Mar 2013 21:45:23 -0400
> Vlad Yasevich <vyasevic@redhat.com> wrote:
>
>> Add an sysfs interface to turn promiscusous mode on and off on
>> the bridge.  By default all interfaces in the bridge
>> are in promisc mode.  When promisc mode is turned off, it is
>> turned off on all bridge ports and the bridge turns on IFF_ALLMULTI
>> to handle multicast traffic.
>>
>> Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
>> ---
>>   net/bridge/br_device.c   |   41 +++++++++++++++++++++++++++++++++++++++++
>>   net/bridge/br_if.c       |   22 +++++++++++++++++-----
>>   net/bridge/br_private.h  |    2 ++
>>   net/bridge/br_sysfs_br.c |   17 +++++++++++++++++
>>   4 files changed, 77 insertions(+), 5 deletions(-)
>>
>
> All attribute changes must also be available through netlink, and changes
> to attributes should cause a notification to applications listening for
> netlink events on that bridge.
>

There is currently no attribute for promisc vs non-promisc in the 
bridge.  Are you suggesting that this patch should add one?

-vlad
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Patch

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index d5f1d3f..37f611f 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -185,6 +185,46 @@  static int br_set_mac_address(struct net_device *dev, void *p)
 	return 0;
 }
 
+int br_set_promisc(struct net_bridge *br, unsigned long val)
+{
+	struct net_bridge_port *p;
+
+	if (!rtnl_trylock())
+		return restart_syscall();
+
+	spin_lock_bh(&br->lock);
+
+	if (val) {
+		if (br->promisc_enabled)
+			goto unlock;
+
+		br->promisc_enabled = 1;
+		/* For each port on the bridge, turn on promisc mode and
+		 * turn off ALLMULTI to handle multicast traffic.
+		 */
+		list_for_each_entry(p, &br->port_list, list) {
+			dev_set_promiscuity(p->dev, 1);
+			dev_set_allmulti(p->dev, -1);
+		}
+
+	} else {
+		if (!br->promisc_enabled)
+			goto unlock;
+
+		br->promisc_enabled = 0;
+		/* For each port on the bridge, turn off promisc mode */
+		list_for_each_entry(p, &br->port_list, list) {
+			dev_set_allmulti(p->dev, 1);
+			dev_set_promiscuity(p->dev, -1);
+		}
+	}
+unlock:
+	spin_unlock_bh(&br->lock);
+	rtnl_unlock();
+	return 0;
+}
+
+
 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 {
 	strlcpy(info->driver, "bridge", sizeof(info->driver));
@@ -371,6 +411,7 @@  void br_dev_setup(struct net_device *dev)
 	br->bridge_hello_time = br->hello_time = 2 * HZ;
 	br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 	br->ageing_time = 300 * HZ;
+	br->promisc_enabled = 1;
 
 	br_netfilter_rtable_init(br);
 	br_stp_timer_init(br);
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index ef1b914..02b4440 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -132,7 +132,10 @@  static void del_nbp(struct net_bridge_port *p)
 
 	sysfs_remove_link(br->ifobj, p->dev->name);
 
-	dev_set_promiscuity(dev, -1);
+	if (br->promisc_enabled)
+		dev_set_promiscuity(dev, -1);
+	else
+		dev_set_allmulti(dev, -1);
 
 	spin_lock_bh(&br->lock);
 	br_stp_disable_port(p);
@@ -350,9 +353,15 @@  int br_add_if(struct net_bridge *br, struct net_device *dev)
 
 	call_netdevice_notifiers(NETDEV_JOIN, dev);
 
-	err = dev_set_promiscuity(dev, 1);
-	if (err)
-		goto put_back;
+	if (br->promisc_enabled) {
+		err = dev_set_promiscuity(dev, 1);
+		if (err)
+			goto put_back;
+	} else {
+		err = dev_set_allmulti(dev, 1);
+		if (err)
+			goto put_back;
+	}
 
 	err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 				   SYSFS_BRIDGE_PORT_ATTR);
@@ -414,7 +423,10 @@  err2:
 	kobject_put(&p->kobj);
 	p = NULL; /* kobject_put frees */
 err1:
-	dev_set_promiscuity(dev, -1);
+	if (br->promisc_enabled)
+		dev_set_promiscuity(dev, -1);
+	else
+		dev_set_allmulti(dev, -1);
 put_back:
 	dev_put(dev);
 	kfree(p);
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 6d314c4..4a0fa29 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -277,6 +277,7 @@  struct net_bridge
 	struct timer_list		topology_change_timer;
 	struct timer_list		gc_timer;
 	struct kobject			*ifobj;
+	u8				promisc_enabled;
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
 	u8				vlan_enabled;
 	struct net_port_vlans __rcu	*vlan_info;
@@ -327,6 +328,7 @@  extern void br_dev_setup(struct net_device *dev);
 extern void br_dev_delete(struct net_device *dev, struct list_head *list);
 extern netdev_tx_t br_dev_xmit(struct sk_buff *skb,
 			       struct net_device *dev);
+extern int br_set_promisc(struct net_bridge *br, unsigned long val);
 #ifdef CONFIG_NET_POLL_CONTROLLER
 static inline struct netpoll_info *br_netpoll_info(struct net_bridge *br)
 {
diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 8baa9c0..5489219 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -710,6 +710,22 @@  static DEVICE_ATTR(vlan_filtering, S_IRUGO | S_IWUSR,
 		   show_vlan_filtering, store_vlan_filtering);
 #endif
 
+static ssize_t show_promisc(struct device *d,
+			    struct device_attribute *attr, char *buf)
+{
+	struct net_bridge *br = to_bridge(d);
+	return sprintf(buf, "%d\n", br->promisc_enabled);
+}
+
+static ssize_t store_promisc(struct device *d,
+			     struct device_attribute *attr,
+			     const char *buf, size_t len)
+{
+	return store_bridge_parm(d, buf, len, br_set_promisc);
+}
+static DEVICE_ATTR(promisc, S_IRUGO | S_IWUSR, show_promisc,
+		   store_promisc);
+
 static struct attribute *bridge_attrs[] = {
 	&dev_attr_forward_delay.attr,
 	&dev_attr_hello_time.attr,
@@ -753,6 +769,7 @@  static struct attribute *bridge_attrs[] = {
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
 	&dev_attr_vlan_filtering.attr,
 #endif
+	&dev_attr_promisc.attr,
 	NULL
 };