From dcfe7673787b4bfea2c213df443d312aa754757b Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 13 Jul 2024 23:16:09 +0200 Subject: [PATCH] net: dsa: tag_sja1105: absorb logic for not overwriting precise info into dsa_8021q_rcv() In both sja1105_rcv() and sja1110_rcv(), we may have precise source port information coming from parallel hardware mechanisms, in addition to the tag_8021q header. Only sja1105_rcv() has extra logic to not overwrite that precise info with what's present in the VLAN tag. This is because sja1110_rcv() gets by, by having a reversed set of checks when assigning skb->dev. When the source port is imprecise (vbid >=1), source_port and switch_id will be set to zeroes by dsa_8021q_rcv(), which might be problematic. But by checking for vbid >= 1 first, sja1110_rcv() fends that off. We would like to make more code common between sja1105_rcv() and sja1110_rcv(), and for that, we need to make sure that sja1110_rcv() also goes through the precise source port preservation logic. Signed-off-by: Vladimir Oltean Signed-off-by: Pawel Dembicki Reviewed-by: Vladimir Oltean Tested-by: Vladimir Oltean Link: https://patch.msgid.link/20240713211620.1125910-4-paweldembicki@gmail.com Signed-off-by: Jakub Kicinski --- net/dsa/tag_8021q.c | 32 +++++++++++++++++++++++++++++--- net/dsa/tag_sja1105.c | 23 +++-------------------- 2 files changed, 32 insertions(+), 23 deletions(-) diff --git a/net/dsa/tag_8021q.c b/net/dsa/tag_8021q.c index 71b26ae6db39..3cb0293793a5 100644 --- a/net/dsa/tag_8021q.c +++ b/net/dsa/tag_8021q.c @@ -497,9 +497,21 @@ struct net_device *dsa_tag_8021q_find_port_by_vbid(struct net_device *conduit, } EXPORT_SYMBOL_GPL(dsa_tag_8021q_find_port_by_vbid); +/** + * dsa_8021q_rcv - Decode source information from tag_8021q header + * @skb: RX socket buffer + * @source_port: pointer to storage for precise source port information. + * If this is known already from outside tag_8021q, the pre-initialized + * value is preserved. If not known, pass -1. + * @switch_id: similar to source_port. + * @vbid: pointer to storage for imprecise bridge ID. Must be pre-initialized + * with -1. If a positive value is returned, the source_port and switch_id + * are invalid. + */ void dsa_8021q_rcv(struct sk_buff *skb, int *source_port, int *switch_id, int *vbid) { + int tmp_source_port, tmp_switch_id, tmp_vbid; u16 vid, tci; if (skb_vlan_tag_present(skb)) { @@ -513,11 +525,25 @@ void dsa_8021q_rcv(struct sk_buff *skb, int *source_port, int *switch_id, vid = tci & VLAN_VID_MASK; - *source_port = dsa_8021q_rx_source_port(vid); - *switch_id = dsa_8021q_rx_switch_id(vid); + tmp_source_port = dsa_8021q_rx_source_port(vid); + tmp_switch_id = dsa_8021q_rx_switch_id(vid); + tmp_vbid = dsa_tag_8021q_rx_vbid(vid); + + /* Precise source port information is unknown when receiving from a + * VLAN-unaware bridging domain, and tmp_source_port and tmp_switch_id + * are zeroes in this case. + * + * Preserve the source information from hardware-specific mechanisms, + * if available. This allows us to not overwrite a valid source port + * and switch ID with less precise values. + */ + if (tmp_vbid == 0 && *source_port == -1) + *source_port = tmp_source_port; + if (tmp_vbid == 0 && *switch_id == -1) + *switch_id = tmp_switch_id; if (vbid) - *vbid = dsa_tag_8021q_rx_vbid(vid); + *vbid = tmp_vbid; skb->priority = (tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; } diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c index 1aba1d05c27a..48886d4b7e3e 100644 --- a/net/dsa/tag_sja1105.c +++ b/net/dsa/tag_sja1105.c @@ -524,30 +524,13 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb, /* 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). 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 (vbid == 0 && source_port == -1) - source_port = tmp_source_port; - if (vbid == 0 && switch_id == -1) - switch_id = tmp_switch_id; - } else if (source_port == -1 && switch_id == -1) { + if (sja1105_skb_has_tag_8021q(skb)) + sja1105_vlan_rcv(skb, &source_port, &switch_id, &vbid, &vid); + else if (source_port == -1 && switch_id == -1) /* Packets with no source information have no chance of * getting accepted, drop them straight away. */ return NULL; - } if (source_port != -1 && switch_id != -1) skb->dev = dsa_conduit_find_user(netdev, switch_id, source_port);