Messages in this thread | | | Date | Mon, 26 Jun 2023 20:11:53 +0200 | From | Simon Horman <> | Subject | Re: [PATCH net 2/2] net: dsa: tag_sja1105: always prefer source port information from INCL_SRCPT |
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On Mon, Jun 26, 2023 at 06:51:12PM +0300, Vladimir Oltean wrote: > Currently the sja1105 tagging protocol prefers using the source port > information from the VLAN header if that is available, falling back to > the INCL_SRCPT option if it isn't. The VLAN header is available for all > frames except for META frames initiated by the switch (containing RX > timestamps), and thus, the "if (is_link_local)" branch is practically > dead. > > The tag_8021q source port identification has become more loose > ("imprecise") and will report a plausible rather than exact bridge port, > when under a bridge (be it VLAN-aware or VLAN-unaware). But link-local > traffic always needs to know the precise source port. With incorrect > source port reporting, for example PTP traffic over 2 bridged ports will > all be seen on sockets opened on the first such port, which is incorrect. > > Now that the tagging protocol has been changed to make link-local frames > always contain source port information, we can reverse the order of the > checks so that we always give precedence to that information (which is > always precise) in lieu of the tag_8021q VID which is only precise for a > standalone port. > > Fixes: d7f9787a763f ("net: dsa: tag_8021q: add support for imprecise RX based on the VBID") > Fixes: 91495f21fcec ("net: dsa: tag_8021q: replace the SVL bridging with VLAN-unaware IVL bridging") > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> > --- > net/dsa/tag_sja1105.c | 35 +++++++++++++++++++++++++---------- > 1 file changed, 25 insertions(+), 10 deletions(-) > > diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c > index a5f3b73da417..0e62eab8f251 100644 > --- a/net/dsa/tag_sja1105.c > +++ b/net/dsa/tag_sja1105.c > @@ -545,10 +545,7 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb, > is_link_local = sja1105_is_link_local(skb); > is_meta = sja1105_is_meta_frame(skb); > > - if (sja1105_skb_has_tag_8021q(skb)) { > - /* Normal traffic path. */ > - sja1105_vlan_rcv(skb, &source_port, &switch_id, &vbid, &vid); > - } else if (is_link_local) { > + if (is_link_local) { > /* Management traffic path. Switch embeds the switch ID and > * port ID into bytes of the destination MAC, courtesy of > * the incl_srcpt options. > @@ -562,16 +559,34 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb, > sja1105_meta_unpack(skb, &meta); > source_port = meta.source_port; > switch_id = meta.switch_id; > - } else { > - return NULL; > } > > - if (vbid >= 1) > + /* Normal data plane traffic and link-local frames are tagged with > + * a tag_8021q VLAN which we have to strip > + */ > + if (sja1105_skb_has_tag_8021q(skb)) { > + int tmp_source_port = -1, tmp_switch_id = -1; > + > + sja1105_vlan_rcv(skb, &tmp_source_port, &tmp_switch_id, &vbid, > + &vid); > + /* Preserve the source information from the INCL_SRCPT option, > + * if available. This allows us to not overwrite a valid source > + * port and switch ID with zeroes when receiving link-local > + * frames from a VLAN-unaware bridged port (non-zero vbid) or a > + * VLAN-aware bridged port (non-zero vid). > + */ > + if (source_port == -1) > + source_port = tmp_source_port; > + if (switch_id == -1) > + switch_id = tmp_switch_id; > + } > + > + if (source_port != -1 && switch_id != -1) > + skb->dev = dsa_master_find_slave(netdev, switch_id, source_port); > + else if (vbid >= 1) > skb->dev = dsa_tag_8021q_find_port_by_vbid(netdev, vbid); > - else if (source_port == -1 || switch_id == -1) > - skb->dev = dsa_find_designated_bridge_port_by_vid(netdev, vid); > else > - skb->dev = dsa_master_find_slave(netdev, switch_id, source_port); > + skb->dev = dsa_find_designated_bridge_port_by_vid(netdev, vid);
Hi Vladimir,
A similar comment to that made for [1], though the code is somewhat different to that case: are you sure vid is initialised here? GCC 12 and Smatch seem unsure about it.
[1] Re: [PATCH net-next v2 4/7] net: dsa: vsc73xx: Add dsa tagging based on 8021q https://lore.kernel.org/all/ZJg2M+Qvg3Fv73CH@corigine.com/
> if (!skb->dev) { > netdev_warn(netdev, "Couldn't decode source port\n"); > return NULL; > -- > 2.34.1 > >
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