From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Mon, 4 Nov 2019 11:36:51 +0200
Subject: net: bridge: fdb: eliminate extra port state tests from fast-path
Patch-mainline: v5.5-rc1
Git-commit: 5d1fcaf35d74b4188d238e46f0be37c14a01f169
References: bsc#1154353
When commit df1c0b8468b3 ("[BRIDGE]: Packets leaking out of
disabled/blocked ports.") introduced the port state tests in
br_fdb_update() it was to avoid learning/refreshing from STP BPDUs, it was
also used to avoid learning/refreshing from user-space with NTF_USE. Those
two tests are done for every packet entering the bridge if it's learning,
but for the fast-path we already have them checked in br_handle_frame() and
is unnecessary to do it again. Thus push the checks to the unlikely cases
and drop them from br_fdb_update(), the new nbp_state_should_learn() helper
is used to determine if the port state allows br_fdb_update() to be called.
The two places which need to do it manually are:
- user-space add call with NTF_USE set
- link-local packet learning done in __br_handle_local_finish()
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/bridge/br_fdb.c | 8 +++-----
net/bridge/br_input.c | 1 +
net/bridge/br_private.h | 5 +++++
3 files changed, 9 insertions(+), 5 deletions(-)
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -566,11 +566,6 @@ void br_fdb_update(struct net_bridge *br
if (hold_time(br) == 0)
return;
- /* ignore packets unless we are using this port */
- if (!(source->state == BR_STATE_LEARNING ||
- source->state == BR_STATE_FORWARDING))
- return;
-
fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
if (likely(fdb)) {
/* attempt to update an entry for a local interface */
@@ -886,6 +881,9 @@ static int __br_fdb_add(struct ndmsg *nd
br->dev->name);
return -EINVAL;
}
+ if (!nbp_state_should_learn(p))
+ return 0;
+
local_bh_disable();
rcu_read_lock();
br_fdb_update(br, p, addr, vid, BIT(BR_FDB_ADDED_BY_USER));
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -182,6 +182,7 @@ static void __br_handle_local_finish(str
/* check if vlan is allowed, to avoid spoofing */
if ((p->flags & BR_LEARNING) &&
+ nbp_state_should_learn(p) &&
!br_opt_get(p->br, BROPT_NO_LL_LEARN) &&
br_should_learn(p, skb, &vid))
br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, 0);
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -500,6 +500,11 @@ static inline bool br_vlan_should_use(co
return true;
}
+static inline bool nbp_state_should_learn(const struct net_bridge_port *p)
+{
+ return p->state == BR_STATE_LEARNING || p->state == BR_STATE_FORWARDING;
+}
+
static inline int br_opt_get(const struct net_bridge *br,
enum net_bridge_opts opt)
{