6.17-stable review patch. If anyone has any objections, please let me know.
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From: Jonas Gorski jonas.gorski@gmail.com
[ Upstream commit 762e7e174da91cf4babfe77e45bc6b67334b1503 ]
Broadcom switches locally terminate link local traffic and do not forward it, so we should not mark it as offloaded.
In some situations we still want/need to flood this traffic, e.g. if STP is disabled, or it is explicitly enabled via the group_fwd_mask. But if the skb is marked as offloaded, the kernel will assume this was already done in hardware, and the packets never reach other bridge ports.
So ensure that link local traffic is never marked as offloaded, so that the kernel can forward/flood these packets in software if needed.
Since the local termination in not configurable, check the destination MAC, and never mark packets as offloaded if it is a link local ether address.
While modern switches set the tag reason code to BRCM_EG_RC_PROT_TERM for trapped link local traffic, they also set it for link local traffic that is flooded (01:80:c2:00:00:10 to 01:80:c2:00:00:2f), so we cannot use it and need to look at the destination address for them as well.
Fixes: 964dbf186eaa ("net: dsa: tag_brcm: add support for legacy tags") Fixes: 0e62f543bed0 ("net: dsa: Fix duplicate frames flooded by learning") Signed-off-by: Jonas Gorski jonas.gorski@gmail.com Reviewed-by: Vladimir Oltean olteanv@gmail.com Reviewed-by: Florian Fainelli florian.fainelli@broadcom.com Link: https://patch.msgid.link/20251109134635.243951-1-jonas.gorski@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/dsa/tag_brcm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c index d9c77fa553b53..eadb358179ce3 100644 --- a/net/dsa/tag_brcm.c +++ b/net/dsa/tag_brcm.c @@ -176,7 +176,8 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb, /* Remove Broadcom tag and update checksum */ skb_pull_rcsum(skb, BRCM_TAG_LEN);
- dsa_default_offload_fwd_mark(skb); + if (likely(!is_link_local_ether_addr(eth_hdr(skb)->h_dest))) + dsa_default_offload_fwd_mark(skb);
return skb; } @@ -250,7 +251,8 @@ static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb, /* Remove Broadcom tag and update checksum */ skb_pull_rcsum(skb, len);
- dsa_default_offload_fwd_mark(skb); + if (likely(!is_link_local_ether_addr(eth_hdr(skb)->h_dest))) + dsa_default_offload_fwd_mark(skb);
dsa_strip_etype_header(skb, len);