From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 728db843df88753aeb7224314807a203afa8eb32 ]
Currently, when sja1105pqrs_fdb_add() is called for a host-joined IPv6 MDB entry such as 33:33:00:00:00:6a, the search for that address will return the FDB entry for SJA1105_UNKNOWN_MULTICAST, which has a destination MAC of 01:00:00:00:00:00 and a mask of 01:00:00:00:00:00. It returns that entry because, well, it matches, in the sense that unknown multicast is supposed by design to match it...
But the issue is that we then proceed to overwrite this entry with the one for our precise host-joined multicast address, and the unknown multicast entry is no longer there - unknown multicast is now flooded to the same group of ports as broadcast, which does not look up the FDB.
To solve this problem, we should ignore searches that return the unknown multicast address as the match, and treat them as "no match" which will result in the entry being installed to hardware.
For this to work properly, we need to put the result of the FDB search in a temporary variable in order to avoid overwriting the l2_lookup entry we want to program. The l2_lookup entry returned by the search might not have the same set of DESTPORTS and not even the same MACADDR as the entry we're trying to add.
Fixes: 4d9423549501 ("net: dsa: sja1105: offload bridge port flags to device") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/dsa/sja1105/sja1105_main.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index 5e88632e10b9..edc9462c6d4e 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -1446,14 +1446,19 @@ int sja1105pqrs_fdb_add(struct dsa_switch *ds, int port, } l2_lookup.destports = BIT(port);
+ tmp = l2_lookup; + rc = sja1105_dynamic_config_read(priv, BLK_IDX_L2_LOOKUP, - SJA1105_SEARCH, &l2_lookup); - if (rc == 0) { + SJA1105_SEARCH, &tmp); + if (rc == 0 && tmp.index != SJA1105_MAX_L2_LOOKUP_COUNT - 1) { /* Found a static entry and this port is already in the entry's * port mask => job done */ - if ((l2_lookup.destports & BIT(port)) && l2_lookup.lockeds) + if ((tmp.destports & BIT(port)) && tmp.lockeds) return 0; + + l2_lookup = tmp; + /* l2_lookup.index is populated by the switch in case it * found something. */