6.11-stable review patch. If anyone has any objections, please let me know.
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From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 8c924369cb56c3054dca504c2c9c3eb208272865 ]
In case of a tc mirred action from one switch to another, the behavior is not correct. We simply tell the source switch driver to program a mirroring entry towards mirror->to_local_port = to_dp->index, but it is not even guaranteed that the to_dp belongs to the same switch as dp.
For proper cross-chip support, we would need to go through the cross-chip notifier layer in switch.c, program the entry on cascade ports, and introduce new, explicit API for cross-chip mirroring, given that intermediary switches should have introspection into the DSA tags passed through the cascade port (and not just program a port mirror on the entire cascade port). None of that exists today.
Reject what is not implemented so that user space is not misled into thinking it works.
Fixes: f50f212749e8 ("net: dsa: Add plumbing for port mirroring") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Andrew Lunn andrew@lunn.ch Link: https://patch.msgid.link/20241008094320.3340980-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/dsa/user.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/net/dsa/user.c b/net/dsa/user.c index f5adfa1d978a2..ac34d5d1deb09 100644 --- a/net/dsa/user.c +++ b/net/dsa/user.c @@ -1392,6 +1392,14 @@ dsa_user_add_cls_matchall_mirred(struct net_device *dev, if (!dsa_user_dev_check(act->dev)) return -EOPNOTSUPP;
+ to_dp = dsa_user_to_port(act->dev); + + if (dp->ds != to_dp->ds) { + NL_SET_ERR_MSG_MOD(extack, + "Cross-chip mirroring not implemented"); + return -EOPNOTSUPP; + } + mall_tc_entry = kzalloc(sizeof(*mall_tc_entry), GFP_KERNEL); if (!mall_tc_entry) return -ENOMEM; @@ -1399,9 +1407,6 @@ dsa_user_add_cls_matchall_mirred(struct net_device *dev, mall_tc_entry->cookie = cls->cookie; mall_tc_entry->type = DSA_PORT_MALL_MIRROR; mirror = &mall_tc_entry->mirror; - - to_dp = dsa_user_to_port(act->dev); - mirror->to_local_port = to_dp->index; mirror->ingress = ingress;