Messages in this thread | | | Date | Tue, 8 Mar 2022 11:36:53 +0200 | From | Vladimir Oltean <> | Subject | Re: [PATCH net-next] net: dsa: tag_dsa: Fix tx from VLAN uppers on non-filtering bridges |
| |
On Mon, Mar 07, 2022 at 12:05:48PM +0100, Tobias Waldekranz wrote: > In this situation (VLAN filtering disabled on br0): > > br0.10 > / > br0 > / \ > swp0 swp1 > > When a frame is transmitted from the VLAN upper, the bridge will send > it down to one of the switch ports with forward offloading > enabled. This will cause tag_dsa to generate a FORWARD tag. Before > this change, that tag would have it's VID set to 10, even though VID > 10 is not loaded in the VTU. > > Before the blamed commit, the frame would trigger a VTU miss and be > forwarded according to the PVT configuration. Now that all fabric > ports are in 802.1Q secure mode, the frame is dropped instead. > > Therefore, restrict the condition under which we rewrite an 802.1Q tag > to a DSA tag. On standalone port's, reuse is always safe since we will > always generate FROM_CPU tags in that case. For bridged ports though, > we must ensure that VLAN filtering is enabled, which in turn > guarantees that the VID in question is loaded into the VTU. > > Fixes: d352b20f4174 ("net: dsa: mv88e6xxx: Improve multichip isolation of standalone ports") > Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> > --- > net/dsa/tag_dsa.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c > index c8b4bbd46191..e4b6e3f2a3db 100644 > --- a/net/dsa/tag_dsa.c > +++ b/net/dsa/tag_dsa.c > @@ -127,6 +127,7 @@ static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev, > u8 extra) > { > struct dsa_port *dp = dsa_slave_to_port(dev); > + struct net_device *br_dev; > u8 tag_dev, tag_port; > enum dsa_cmd cmd; > u8 *dsa_header; > @@ -149,7 +150,16 @@ static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev, > tag_port = dp->index; > } > > - if (skb->protocol == htons(ETH_P_8021Q)) { > + br_dev = dsa_port_bridge_dev_get(dp); > + > + /* If frame is already 802.1Q tagged, we can convert it to a DSA > + * tag (avoiding a memmove), but only if the port is standalone > + * (in which case we always send FROM_CPU) or if the port's > + * bridge has VLAN filtering enabled (in which case the CPU port > + * will be a member of the VLAN). > + */ > + if (skb->protocol == htons(ETH_P_8021Q) && > + (!br_dev || br_vlan_enabled(br_dev))) {
Conservative patch. If !br_dev, we could/should inject using MV88E6XXX_VID_STANDALONE. But since we use FROM_CPU, the classified VLAN probably does not make a difference that I can see, so there is no reason to change this now (and certainly not in the same patch).
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
> if (extra) { > skb_push(skb, extra); > dsa_alloc_etype_header(skb, extra); > @@ -166,10 +176,9 @@ static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev, > dsa_header[2] &= ~0x10; > } > } else { > - struct net_device *br = dsa_port_bridge_dev_get(dp); > u16 vid; > > - vid = br ? MV88E6XXX_VID_BRIDGED : MV88E6XXX_VID_STANDALONE; > + vid = br_dev ? MV88E6XXX_VID_BRIDGED : MV88E6XXX_VID_STANDALONE; > > skb_push(skb, DSA_HLEN + extra); > dsa_alloc_etype_header(skb, DSA_HLEN + extra); > -- > 2.25.1 >
| |