luck/tmp_suning_uos_patched
1
0
Fork 1
Code Issues Pull Requests Packages Projects Releases Wiki Activity

net: dsa: sja1105: fix broken backpressure in .port_fdb_dump

Browse Source 
[ Upstream commit 21b52fed928e96d2f75d2f6aa9eac7a4b0b55d22 ]

rtnl_fdb_dump() has logic to split a dump of PF_BRIDGE neighbors into
multiple netlink skbs if the buffer provided by user space is too small
(one buffer will typically handle a few hundred FDB entries).

When the current buffer becomes full, nlmsg_put() in
dsa_slave_port_fdb_do_dump() returns -EMSGSIZE and DSA saves the index
of the last dumped FDB entry, returns to rtnl_fdb_dump() up to that
point, and then the dump resumes on the same port with a new skb, and
FDB entries up to the saved index are simply skipped.

Since dsa_slave_port_fdb_do_dump() is pointed to by the "cb" passed to
drivers, then drivers must check for the -EMSGSIZE error code returned
by it. Otherwise, when a netlink skb becomes full, DSA will no longer
save newly dumped FDB entries to it, but the driver will continue
dumping. So FDB entries will be missing from the dump.

Fix the broken backpressure by propagating the "cb" return code and
allow rtnl_fdb_dump() to restart the FDB dump with a new skb.

Fixes: 291d1e72b7 ("net: dsa: sja1105: Add support for FDB and MDB management")
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>
This commit is contained in:
Vladimir Oltean 2021-08-10 14:19:56 +03:00 committed by Greg Kroah-Hartman
parent 56cc3408ff
commit 1cad01aca1
1 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/net/dsa/sja1105/sja1105_main.c
View File

@ -1566,7 +1566,9 @@ static int sja1105_fdb_dump(struct dsa_switch *ds, int port,
/* We need to hide the dsa_8021q VLANs from the user. */
if (priv->vlan_state == SJA1105_VLAN_UNAWARE)
l2_lookup.vlanid = 0;
cb(macaddr, l2_lookup.vlanid, l2_lookup.lockeds, data);
rc = cb(macaddr, l2_lookup.vlanid, l2_lookup.lockeds, data);
if (rc)
return rc;
}
return 0;
}