From a398b9ea0c3b791b7a0f4c6029a62cf628f97f22 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 1 Jul 2023 01:20:10 +0300 Subject: net: dsa: tag_sja1105: fix source port decoding in vlan_filtering=0 bridge mode 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 Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- net/dsa/tag_sja1105.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net/dsa') diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c index 92a626a05e82..db0a6ac67470 100644 --- a/net/dsa/tag_sja1105.c +++ b/net/dsa/tag_sja1105.c @@ -573,11 +573,14 @@ 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 -- cgit