Re: [PATCH net] bridge: mdb: fix delmdb state in the notification

2015-07-29 Thread David Miller
From: Nikolay Aleksandrov ra...@blackwall.org
Date: Tue, 28 Jul 2015 13:10:44 +0200

 From: Nikolay Aleksandrov niko...@cumulusnetworks.com
 
 Since mdb states were introduced when deleting an entry the state was
 left as it was set in the delete request from the user which leads to
 the following output when doing a monitor (for example):
 $ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
 (monitor) dev br0 port eth3 grp 239.0.0.1 permanent
 $ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
 (monitor) dev br0 port eth3 grp 239.0.0.1 temp
 ^^^
 Note the temp state in the delete notification which is wrong since
 the entry was permanent, the state in a delete is always reported as
 temp regardless of the real state of the entry.
 
 After this patch:
 $ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
 (monitor) dev br0 port eth3 grp 239.0.0.1 permanent
 $ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
 (monitor) dev br0 port eth3 grp 239.0.0.1 permanent
 
 There's one important note to make here that the state is actually not
 matched when doing a delete, so one can delete a permanent entry by
 stating temp in the end of the command, I've chosen this fix in order
 not to break user-space tools which rely on this (incorrect) behaviour.
 
 So to give an example after this patch and using the wrong state:
 $ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
 (monitor) dev br0 port eth3 grp 239.0.0.1 permanent
 $ bridge mdb del dev br0 port eth3 grp 239.0.0.1 temp
 (monitor) dev br0 port eth3 grp 239.0.0.1 permanent
 
 Note the state of the entry that got deleted is correct in the
 notification.
 
 Signed-off-by: Nikolay Aleksandrov niko...@cumulusnetworks.com
 Fixes: ccb1c31a7a87 (bridge: add flags to distinguish permanent mdb entires)

Applied and queued up for -stable, thanks.
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Re: [PATCH net] bridge: mdb: fix delmdb state in the notification

2015-07-28 Thread Cong Wang
On Tue, Jul 28, 2015 at 4:10 AM, Nikolay Aleksandrov
ra...@blackwall.org wrote:
 From: Nikolay Aleksandrov niko...@cumulusnetworks.com

 Since mdb states were introduced when deleting an entry the state was
 left as it was set in the delete request from the user which leads to
 the following output when doing a monitor (for example):
 $ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
 (monitor) dev br0 port eth3 grp 239.0.0.1 permanent
 $ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
 (monitor) dev br0 port eth3 grp 239.0.0.1 temp
 ^^^
 Note the temp state in the delete notification which is wrong since
 the entry was permanent, the state in a delete is always reported as
 temp regardless of the real state of the entry.


Hmm?

I think it is iproute2 who forgets to set entry-state when deleting it?

} else if (strcmp(*argv, permanent) == 0) {
if (cmd == RTM_NEWMDB)
entry.state |= MDB_PERMANENT;

Kernel simply returns what you pass to it.

Please fix iproute2.
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Re: [PATCH net] bridge: mdb: fix delmdb state in the notification

2015-07-28 Thread Nikolay Aleksandrov
On 07/29/2015 12:38 AM, Cong Wang wrote:
 On Tue, Jul 28, 2015 at 4:10 AM, Nikolay Aleksandrov
 ra...@blackwall.org wrote:
 From: Nikolay Aleksandrov niko...@cumulusnetworks.com

 Since mdb states were introduced when deleting an entry the state was
 left as it was set in the delete request from the user which leads to
 the following output when doing a monitor (for example):
 $ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
 (monitor) dev br0 port eth3 grp 239.0.0.1 permanent
 $ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
 (monitor) dev br0 port eth3 grp 239.0.0.1 temp
 ^^^
 Note the temp state in the delete notification which is wrong since
 the entry was permanent, the state in a delete is always reported as
 temp regardless of the real state of the entry.

 
 Hmm?
 
 I think it is iproute2 who forgets to set entry-state when deleting it?
 
 } else if (strcmp(*argv, permanent) == 0) {
 if (cmd == RTM_NEWMDB)
 entry.state |= MDB_PERMANENT;
 
 Kernel simply returns what you pass to it.
 
 Please fix iproute2.
 

Hi Cong,
Please read the full commit log, I've explained that the state is not honored 
in the kernel
so it doesn't matter if iproute2 sets the correct state that you give on the 
command
line, that is if I give it temp and the entry is permanent - it will still get
deleted and the notification will have the wrong state as temp because I've 
set
it, while this way it'll at least return the correct state of the entry being 
deleted.
Again I'm saying that I chose this solution over a check for the entry state 
because
it may break some user-space tools that rely on the behaviour that the state is
not checked in the kernel.

Cheers,
 Nik
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[PATCH net] bridge: mdb: fix delmdb state in the notification

2015-07-28 Thread Nikolay Aleksandrov
From: Nikolay Aleksandrov niko...@cumulusnetworks.com

Since mdb states were introduced when deleting an entry the state was
left as it was set in the delete request from the user which leads to
the following output when doing a monitor (for example):
$ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent
$ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 temp
^^^
Note the temp state in the delete notification which is wrong since
the entry was permanent, the state in a delete is always reported as
temp regardless of the real state of the entry.

After this patch:
$ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent
$ bridge mdb del dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent

There's one important note to make here that the state is actually not
matched when doing a delete, so one can delete a permanent entry by
stating temp in the end of the command, I've chosen this fix in order
not to break user-space tools which rely on this (incorrect) behaviour.

So to give an example after this patch and using the wrong state:
$ bridge mdb add dev br0 port eth3 grp 239.0.0.1 permanent
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent
$ bridge mdb del dev br0 port eth3 grp 239.0.0.1 temp
(monitor) dev br0 port eth3 grp 239.0.0.1 permanent

Note the state of the entry that got deleted is correct in the
notification.

Signed-off-by: Nikolay Aleksandrov niko...@cumulusnetworks.com
Fixes: ccb1c31a7a87 (bridge: add flags to distinguish permanent mdb entires)
---
I propose to fix the state matching in net-next but we may risk breaking
some user-space tools which rely on this behaviour.

 net/bridge/br_mdb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index 1198a3dbad95..c94321955db7 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -445,6 +445,7 @@ static int __br_mdb_del(struct net_bridge *br, struct 
br_mdb_entry *entry)
if (p-port-state == BR_STATE_DISABLED)
goto unlock;
 
+   entry-state = p-state;
rcu_assign_pointer(*pp, p-next);
hlist_del_init(p-mglist);
del_timer(p-timer);
-- 
2.4.3

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