Message ID | 20170901092225.31597-1-idosch@mellanox.com |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
Series | [net] bridge: switchdev: Clear forward mark when transmitting packet | expand |
On 01/09/17 12:22, Ido Schimmel wrote: > Commit 6bc506b4fb06 ("bridge: switchdev: Add forward mark support for > stacked devices") added the 'offload_fwd_mark' bit to the skb in order > to allow drivers to indicate to the bridge driver that they already > forwarded the packet in L2. > > In case the bit is set, before transmitting the packet from each port, > the port's mark is compared with the mark stored in the skb's control > block. If both marks are equal, we know the packet arrived from a switch > device that already forwarded the packet and it's not re-transmitted. > > However, if the packet is transmitted from the bridge device itself > (e.g., br0), we should clear the 'offload_fwd_mark' bit as the mark > stored in the skb's control block isn't valid. > > This scenario can happen in rare cases where a packet was trapped during > L3 forwarding and forwarded by the kernel to a bridge device. > > Fixes: 6bc506b4fb06 ("bridge: switchdev: Add forward mark support for stacked devices") > Signed-off-by: Ido Schimmel <idosch@mellanox.com> > Reported-by: Yotam Gigi <yotamg@mellanox.com> > Tested-by: Yotam Gigi <yotamg@mellanox.com> > Reviewed-by: Jiri Pirko <jiri@mellanox.com> > --- > net/bridge/br_device.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c > index 861ae2a165f4..5a7be3bddfa9 100644 > --- a/net/bridge/br_device.c > +++ b/net/bridge/br_device.c > @@ -53,6 +53,9 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) > brstats->tx_bytes += skb->len; > u64_stats_update_end(&brstats->syncp); > > +#ifdef CONFIG_NET_SWITCHDEV > + skb->offload_fwd_mark = 0; > +#endif > BR_INPUT_SKB_CB(skb)->brdev = dev; > > skb_reset_mac_header(skb); > Good catch, just one minor nit since there is already an ifdef switchdev/else in br_private.h, why not make this a helper and avoid the ifdef/endif in here ? Currently there is no ifdef switchdev anywhere else. Thanks, Nik
Fri, Sep 01, 2017 at 01:45:15PM CEST, nikolay@cumulusnetworks.com wrote: >On 01/09/17 12:22, Ido Schimmel wrote: >> Commit 6bc506b4fb06 ("bridge: switchdev: Add forward mark support for >> stacked devices") added the 'offload_fwd_mark' bit to the skb in order >> to allow drivers to indicate to the bridge driver that they already >> forwarded the packet in L2. >> >> In case the bit is set, before transmitting the packet from each port, >> the port's mark is compared with the mark stored in the skb's control >> block. If both marks are equal, we know the packet arrived from a switch >> device that already forwarded the packet and it's not re-transmitted. >> >> However, if the packet is transmitted from the bridge device itself >> (e.g., br0), we should clear the 'offload_fwd_mark' bit as the mark >> stored in the skb's control block isn't valid. >> >> This scenario can happen in rare cases where a packet was trapped during >> L3 forwarding and forwarded by the kernel to a bridge device. >> >> Fixes: 6bc506b4fb06 ("bridge: switchdev: Add forward mark support for stacked devices") >> Signed-off-by: Ido Schimmel <idosch@mellanox.com> >> Reported-by: Yotam Gigi <yotamg@mellanox.com> >> Tested-by: Yotam Gigi <yotamg@mellanox.com> >> Reviewed-by: Jiri Pirko <jiri@mellanox.com> >> --- >> net/bridge/br_device.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c >> index 861ae2a165f4..5a7be3bddfa9 100644 >> --- a/net/bridge/br_device.c >> +++ b/net/bridge/br_device.c >> @@ -53,6 +53,9 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) >> brstats->tx_bytes += skb->len; >> u64_stats_update_end(&brstats->syncp); >> >> +#ifdef CONFIG_NET_SWITCHDEV >> + skb->offload_fwd_mark = 0; >> +#endif >> BR_INPUT_SKB_CB(skb)->brdev = dev; >> >> skb_reset_mac_header(skb); >> > >Good catch, just one minor nit since there is already an ifdef >switchdev/else in br_private.h, why not make this a helper and avoid the >ifdef/endif in here ? Currently there is no ifdef switchdev anywhere else. I think it would be better to convert this to a helper in -net-next and take the patch as it is for -net
On 01/09/17 15:01, Jiri Pirko wrote: > Fri, Sep 01, 2017 at 01:45:15PM CEST, nikolay@cumulusnetworks.com wrote: >> On 01/09/17 12:22, Ido Schimmel wrote: >>> Commit 6bc506b4fb06 ("bridge: switchdev: Add forward mark support for >>> stacked devices") added the 'offload_fwd_mark' bit to the skb in order >>> to allow drivers to indicate to the bridge driver that they already >>> forwarded the packet in L2. >>> >>> In case the bit is set, before transmitting the packet from each port, >>> the port's mark is compared with the mark stored in the skb's control >>> block. If both marks are equal, we know the packet arrived from a switch >>> device that already forwarded the packet and it's not re-transmitted. >>> >>> However, if the packet is transmitted from the bridge device itself >>> (e.g., br0), we should clear the 'offload_fwd_mark' bit as the mark >>> stored in the skb's control block isn't valid. >>> >>> This scenario can happen in rare cases where a packet was trapped during >>> L3 forwarding and forwarded by the kernel to a bridge device. >>> >>> Fixes: 6bc506b4fb06 ("bridge: switchdev: Add forward mark support for stacked devices") >>> Signed-off-by: Ido Schimmel <idosch@mellanox.com> >>> Reported-by: Yotam Gigi <yotamg@mellanox.com> >>> Tested-by: Yotam Gigi <yotamg@mellanox.com> >>> Reviewed-by: Jiri Pirko <jiri@mellanox.com> >>> --- >>> net/bridge/br_device.c | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c >>> index 861ae2a165f4..5a7be3bddfa9 100644 >>> --- a/net/bridge/br_device.c >>> +++ b/net/bridge/br_device.c >>> @@ -53,6 +53,9 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) >>> brstats->tx_bytes += skb->len; >>> u64_stats_update_end(&brstats->syncp); >>> >>> +#ifdef CONFIG_NET_SWITCHDEV >>> + skb->offload_fwd_mark = 0; >>> +#endif >>> BR_INPUT_SKB_CB(skb)->brdev = dev; >>> >>> skb_reset_mac_header(skb); >>> >> >> Good catch, just one minor nit since there is already an ifdef >> switchdev/else in br_private.h, why not make this a helper and avoid the >> ifdef/endif in here ? Currently there is no ifdef switchdev anywhere else. > > I think it would be better to convert this to a helper in -net-next and > take the patch as it is for -net > Either way is fine I guess, it's just more work for something as simple. :-) Whichever way you choose, Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
From: Ido Schimmel <idosch@mellanox.com> Date: Fri, 1 Sep 2017 12:22:25 +0300 > Commit 6bc506b4fb06 ("bridge: switchdev: Add forward mark support for > stacked devices") added the 'offload_fwd_mark' bit to the skb in order > to allow drivers to indicate to the bridge driver that they already > forwarded the packet in L2. > > In case the bit is set, before transmitting the packet from each port, > the port's mark is compared with the mark stored in the skb's control > block. If both marks are equal, we know the packet arrived from a switch > device that already forwarded the packet and it's not re-transmitted. > > However, if the packet is transmitted from the bridge device itself > (e.g., br0), we should clear the 'offload_fwd_mark' bit as the mark > stored in the skb's control block isn't valid. > > This scenario can happen in rare cases where a packet was trapped during > L3 forwarding and forwarded by the kernel to a bridge device. > > Fixes: 6bc506b4fb06 ("bridge: switchdev: Add forward mark support for stacked devices") > Signed-off-by: Ido Schimmel <idosch@mellanox.com> > Reported-by: Yotam Gigi <yotamg@mellanox.com> > Tested-by: Yotam Gigi <yotamg@mellanox.com> > Reviewed-by: Jiri Pirko <jiri@mellanox.com> Applied and queued up for -stable, thanks.
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index 861ae2a165f4..5a7be3bddfa9 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -53,6 +53,9 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) brstats->tx_bytes += skb->len; u64_stats_update_end(&brstats->syncp); +#ifdef CONFIG_NET_SWITCHDEV + skb->offload_fwd_mark = 0; +#endif BR_INPUT_SKB_CB(skb)->brdev = dev; skb_reset_mac_header(skb);