Messages in this thread Patch in this message | | | From | Vladimir Oltean <> | Subject | [PATCH net] net: dsa: tag_sja1105: fix source port decoding in vlan_filtering=0 bridge mode | Date | Sat, 1 Jul 2023 01:20:10 +0300 |
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There was a regression introduced by the blamed commit, where pinging to a VLAN-unaware bridge would fail with the repeated message "Couldn't decode source port" coming from the tagging protocol driver.
When receiving packets with a bridge_vid as determined by dsa_tag_8021q_bridge_join(), dsa_8021q_rcv() will decode: - source_port = 0 (which isn't really valid, more like "don't know") - switch_id = 0 (which isn't really valid, more like "don't know") - vbid = value in range 1-7
Since the blamed patch has reversed the order of the checks, we are now going to believe that source_port != -1 and switch_id != -1, so they're valid, but they aren't.
The minimal solution to the problem is to only populate source_port and switch_id with what dsa_8021q_rcv() came up with, if the vbid is zero, i.e. the source port information is trustworthy.
Fixes: c1ae02d87689 ("net: dsa: tag_sja1105: always prefer source port information from INCL_SRCPT") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- net/dsa/tag_sja1105.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c index 796e4b88f63b..f480ffffa8c3 100644 --- a/net/dsa/tag_sja1105.c +++ b/net/dsa/tag_sja1105.c @@ -531,11 +531,14 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb, * 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). + * VLAN-aware bridged port (non-zero vid). Furthermore, the + * tag_8021q source port information is only of trust when the + * vbid is 0 (precise port). Otherwise, tmp_source_port and + * tmp_switch_id will be zeroes. */ - if (source_port == -1) + if (vbid == 0 && source_port == -1) source_port = tmp_source_port; - if (switch_id == -1) + if (vbid == 0 && switch_id == -1) switch_id = tmp_switch_id; } else if (source_port == -1 && switch_id == -1) { /* Packets with no source information have no chance of -- 2.34.1
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