| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <8d8ec8cd-5aa6-3d42-ae47-442c5194d289@yandex-team.ru>
Date: Fri, 3 Nov 2017 01:39:11 +0300
From: Vadim Fedorenko <vfedorenko@...dex-team.ru>
To: Eric Dumazet <eric.dumazet@...il.com>
Cc: Linux Kernel Network Developers <netdev@...r.kernel.org>,
Paweł Staszewski <pstaszewski@...are.pl>
Subject: Re: [PATCH net] add support of IFF_XMIT_DST_RELEASE bit in vlan
On 02.11.2017 19:25, Eric Dumazet wrote:
> On Thu, 2017-11-02 at 17:47 +0300, Vadim Fedorenko wrote:
>> On Thu, 2017-11-02 at 07:33 -7000, Eric Dumazet wrote:
>>> On Thu, 2017-11-02 at 15:49 +0300, Vadim Fedorenko wrote:
>>>> Some time ago Eric Dumazet suggested a "hack the IFF_XMIT_DST_RELEASE
>>>> flag on the vlan netdev". But the last comment was "does not support
>>>> properly bonding/team.(If the real_dev->privflags IFF_XMIT_DST_RELEASE
>>>> bit changes, we want to update all the vlans at the same time )"
>>>>
>>>> I've extended that patch to support changes of IFF_XMIT_DST_RELEASE in
>>>> bonding/team.
>>>> Both bonding and team call netdev_change_features() after recalculation
>>>> of features including priv_flags IFF_XMIT_DST_RELEASE bit. So the only
>>>> thing needed to support is to recheck this bit in
>>>> vlan_transfer_features().
>>>>
>>>> Suggested-by: Eric Dumazet <eric.dumazet@...il.com>
>>>> Signed-off-by: Vadim Fedorenko <vfedorenko@...dex-team.ru>
>>>> ---
>>>> net/8021q/vlan.c | 3 +++
>>>> net/8021q/vlan_netlink.c | 1 +
>>>> 2 files changed, 4 insertions(+)
>>>>
>>>> diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
>>>> index 9649579..510986c 100644
>>>> --- a/net/8021q/vlan.c
>>>> +++ b/net/8021q/vlan.c
>>>> @@ -328,6 +328,9 @@ static void vlan_transfer_features(struct net_device *dev,
>>>> vlandev->fcoe_ddp_xid = dev->fcoe_ddp_xid;
>>>> #endif
>>>>
>>>> + vlandev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
>>>> + vlandev->priv_flags |= (vlan->real_dev->priv_flags & IFF_XMIT_DST_RELEASE);
>>>> +
>>>> netdev_update_features(vlandev);
>>>> }
>>>>
>>>> diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c
>>>> index 5e831de..9472de8 100644
>>>> --- a/net/8021q/vlan_netlink.c
>>>> +++ b/net/8021q/vlan_netlink.c
>>>> @@ -143,6 +143,7 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev,
>>>> vlan->vlan_proto = proto;
>>>> vlan->vlan_id = nla_get_u16(data[IFLA_VLAN_ID]);
>>>> vlan->real_dev = real_dev;
>>>> + dev->priv_flags |= (real_dev->priv_flags & IFF_XMIT_DST_RELEASE);
>>>> vlan->flags = VLAN_FLAG_REORDER_HDR;
>>>>
>>>> err = vlan_check_real_dev(real_dev, vlan->vlan_proto, vlan->vlan_id);
>>>
>>> What happens if a bonding is composed of two slaves, with different
>>> IFF_XMIT_DST_RELEASE settings ?
>>
>> According to bond_compute_features() IFF_XMIT_DST_RELEASE flag is cleared from priv_flags
>> in such case, so it is cleared in vlan_transfer_features() and vlan device works as before
>> the patch.
>> The same code exists in team netdev.
>
> I repeat the question.
>
> What happens if a bonding is composed of two slaves A & B,
> A has IFF_XMIT_DST_RELEASE set
> B has IFF_XMIT_DST_RELEASE cleared.
>
> 1) A is added , then B is added.
> 2) B is added to the bond, then A is added.
> 3) Before, and after your patches.
>
> Thanks.
>
>
Do you mean what happens with vlan device with real_dev is bonding ?
With patches:
1) A is added
bond_enslave()
bond_compute_features()
-> bond_dev IFF_XMIT_DST_RELEASE is not changed (set)
netdev_change_features()
vlan_device_event(event=NETDEV_FEAT_CHANGE)
vlan_transfer_features()
-> vlan_dev IFF_XMIT_DST_RELEASE is not changed (still set)
Then B is added
bond_enslave()
bond_compute_features()
-> bond_dev IFF_XMIT_DST_RELEASE is changed (cleared)
netdev_change_features()
vlan_device_event(event=NETDEV_FEAT_CHANGE)
vlan_transfer_features()
-> vlan_dev IFF_XMIT_DST_RELEASE is changed (cleared)
2) B is added
bond_enslave()
bond_compute_features()
-> bond_dev IFF_XMIT_DST_RELEASE is changed (cleared)
netdev_change_features()
vlan_device_event(event=NETDEV_FEAT_CHANGE)
vlan_transfer_features()
-> vlan_dev IFF_XMIT_DST_RELEASE is changed (cleared)
Then A is added
bond_enslave()
bond_compute_features()
-> bond_dev IFF_XMIT_DST_RELEASE is not changed (cleared)
netdev_change_features()
vlan_device_event(event=NETDEV_FEAT_CHANGE)
vlan_transfer_features()
-> vlan_dev IFF_XMIT_DST_RELEASE is not changed (cleared).
Without patches:
1) A is added
bond_enslave()
bond_compute_features()
-> bond_dev IFF_XMIT_DST_RELEASE is not changed (set)
netdev_change_features()
vlan_device_event(event=NETDEV_FEAT_CHANGE)
vlan_transfer_features()
-> vlan_dev IFF_XMIT_DST_RELEASE is not changed (cleared)
Then B is added
bond_enslave()
bond_compute_features()
-> bond_dev IFF_XMIT_DST_RELEASE is changed (cleared)
netdev_change_features()
vlan_device_event(event=NETDEV_FEAT_CHANGE)
vlan_transfer_features()
-> vlan_dev IFF_XMIT_DST_RELEASE is not changed(cleared)
2) B is added
bond_enslave()
bond_compute_features()
-> bond_dev IFF_XMIT_DST_RELEASE is changed (cleared)
netdev_change_features()
vlan_device_event(event=NETDEV_FEAT_CHANGE)
vlan_transfer_features()
-> vlan_dev IFF_XMIT_DST_RELEASE is not changed(cleared)
Then A is added
bond_enslave()
bond_compute_features()
-> bond_dev IFF_XMIT_DST_RELEASE is not changed (cleared)
netdev_change_features()
vlan_device_event(event=NETDEV_FEAT_CHANGE)
vlan_transfer_features()
-> vlan_dev IFF_XMIT_DST_RELEASE is not changed (cleared).
Do you mean that the problem is in the first case in the gap between
netdev_change_features() and vlan_device_event() when bond_dev
IFF_XMIT_DST_RELEASE is cleared and vlan_dev IFF_XMIT_DST_RELEASE is
still set?
Powered by blists - more mailing lists