[PATCH net-next] bridge: mdb: add vlan support for user entries

[PATCH net-next] bridge: mdb: add vlan support for user entries

[Nikolay Aleksandrov]

Until now all user mdb entries were added in vlan 0, this patch adds
support to allow the user to specify the vlan for the entry.
About the uapi change a hole in struct br_mdb_entry is used so the size
and offsets are kept the same (verified with pahole and tested with older
iproute2).

Example:
$ bridge mdb
dev br0 port eth1 grp 239.0.0.1 permanent vlan 2000
dev br0 port eth1 grp 239.0.0.1 permanent vlan 200
dev br0 port eth1 grp 239.0.0.1 permanent

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
---
note: an iproute2 patch will follow if this one is accepted

 include/uapi/linux/if_bridge.h | 1 +
 net/bridge/br_mdb.c            | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index eaaea6208b42..3635b7797508 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -182,6 +182,7 @@ struct br_mdb_entry {
 #define MDB_TEMPORARY 0
 #define MDB_PERMANENT 1
 	__u8 state;
+	__u16 vid;
 	struct {
 		union {
 			__be32	ip4;
diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index 1fb7d076f15c..a8d0e93d43f2 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -85,6 +85,7 @@ static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
 					memset(&e, 0, sizeof(e));
 					e.ifindex = port->dev->ifindex;
 					e.state = p->state;
+					e.vid = p->addr.vid;
 					if (p->addr.proto == htons(ETH_P_IP))
 						e.addr.u.ip4 = p->addr.u.ip4;
 #if IS_ENABLED(CONFIG_IPV6)
@@ -242,6 +243,7 @@ void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
 	entry.addr.u.ip6 = group->u.ip6;
 #endif
 	entry.state = state;
+	entry.vid = group->vid;
 	__br_mdb_notify(dev, &entry, type);
 }
 
@@ -264,6 +266,8 @@ static bool is_valid_mdb_entry(struct br_mdb_entry *entry)
 		return false;
 	if (entry->state != MDB_PERMANENT && entry->state != MDB_TEMPORARY)
 		return false;
+	if (entry->vid >= VLAN_VID_MASK)
+		return false;
 
 	return true;
 }
@@ -372,6 +376,7 @@ static int __br_mdb_add(struct net *net, struct net_bridge *br,
 	if (!p || p->br != br || p->state == BR_STATE_DISABLED)
 		return -EINVAL;
 
+	ip.vid = entry->vid;
 	ip.proto = entry->addr.proto;
 	if (ip.proto == htons(ETH_P_IP))
 		ip.u.ip4 = entry->addr.u.ip4;
@@ -418,6 +423,7 @@ static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
 	if (!netif_running(br->dev) || br->multicast_disabled)
 		return -EINVAL;
 
+	ip.vid = entry->vid;
 	ip.proto = entry->addr.proto;
 	if (ip.proto == htons(ETH_P_IP)) {
 		if (timer_pending(&br->ip4_other_query.timer))
-- 
1.9.1

Re: [PATCH net-next] bridge: mdb: add vlan support for user entries

[David Miller]

From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Fri, 10 Jul 2015 08:02:08 -0700

> Until now all user mdb entries were added in vlan 0, this patch adds
> support to allow the user to specify the vlan for the entry.
> About the uapi change a hole in struct br_mdb_entry is used so the size
> and offsets are kept the same (verified with pahole and tested with older
> iproute2).
> 
> Example:
> $ bridge mdb
> dev br0 port eth1 grp 239.0.0.1 permanent vlan 2000
> dev br0 port eth1 grp 239.0.0.1 permanent vlan 200
> dev br0 port eth1 grp 239.0.0.1 permanent
> 
> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>

This looks ok, applied thanks Nikolay.

Re: [PATCH net-next] bridge: mdb: add vlan support for user entries

[Stephen Hemminger]

On Fri, 10 Jul 2015 08:02:08 -0700
Nikolay Aleksandrov <nikolay@cumulusnetworks.com> wrote:

> diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
> index eaaea6208b42..3635b7797508 100644
> --- a/include/uapi/linux/if_bridge.h
> +++ b/include/uapi/linux/if_bridge.h
> @@ -182,6 +182,7 @@ struct br_mdb_entry {
>  #define MDB_TEMPORARY 0
>  #define MDB_PERMANENT 1
>  	__u8 state;
> +	__u16 vid;
>  	struct {
>  		union {
>  			__be32	ip4;

You added a new field into an unused hole in a data
structure shared as part of API with user space.

This seems like it might break when newer iproute
is run on older kernels. The vid would always be 0
on show and ignored when adding entries.

Re: [PATCH net-next] bridge: mdb: add vlan support for user entries

[Nikolay Aleksandrov]

On 07/21/2015 12:28 AM, Stephen Hemminger wrote:
> On Fri, 10 Jul 2015 08:02:08 -0700
> Nikolay Aleksandrov <nikolay@cumulusnetworks.com> wrote:
> 
>> diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
>> index eaaea6208b42..3635b7797508 100644
>> --- a/include/uapi/linux/if_bridge.h
>> +++ b/include/uapi/linux/if_bridge.h
>> @@ -182,6 +182,7 @@ struct br_mdb_entry {
>>  #define MDB_TEMPORARY 0
>>  #define MDB_PERMANENT 1
>>  	__u8 state;
>> +	__u16 vid;
>>  	struct {
>>  		union {
>>  			__be32	ip4;
> 
> You added a new field into an unused hole in a data
> structure shared as part of API with user space.
> 
> This seems like it might break when newer iproute
> is run on older kernels. The vid would always be 0
> on show and ignored when adding entries.
> 

I thought it'd be fine because the vid was 0 anyway and 
when it's 0 it's not shown i.e. no vid so the show command
will have the same output. And when set - it'll be ignored
which is again as the behaviour before when it couldn't be
specified.

Here's the new iproute2 on an older kernel:
# ./bridge/bridge mdb add dev virbr0 port vnet1 grp 239.0.0.1 permanent vid 200
# ./bridge/bridge mdb
dev virbr0 port vnet1 grp 239.0.0.1 permanent