diff mbox series

[net-next,12/12] net: bridge: fdb: avoid VLAN lookups in unicast forwarding

Message ID 20260930071411.2786201-13-razor@blackwall.org
State New
Headers show
Series None | expand

Commit Message

Nikolay Aleksandrov Sept. 30, 2026, 7:14 a.m. UTC
Pass the complete fdb destination to br_forward(). The tagged value is
decoded once into br_fwd_dst on entry so all subsequent forwarding checks
use the decoded port and VLAN. A cached port-VLAN is then used to avoid two
VLAN hash lookups in the standard unicast forwarding path. A backup-port
redirect also uses a raw destination because the cached VLAN belongs to the
original port.

[1] 64 byte vlan packets, 4k randomized fdb hits with 4k fdbs, 5 million
    packets passed 5 times for every case
 VIDs  Ports       Mpps                 Gbps             CPU1 cycles/input
                before    after   gain  before   after   before   after  reduction
   64    8/2  2.375486 2.635811  11.0%   1.216   1.350   1724.6  1553.7    9.9%
   64    8/4  2.376731 2.636459  10.9%   1.217   1.350   1714.8  1554.7    9.3%
   64    8/8  2.376621 2.635783  10.9%   1.217   1.350   1722.6  1553.2    9.8%
   64   32/2  2.375876 2.637897  11.0%   1.216   1.351   1726.7  1552.3   10.1%
   64  32/16  2.376442 2.636426  10.9%   1.217   1.350   1721.3  1554.2    9.7%
   64  32/32  2.376763 2.636268  10.9%   1.217   1.350   1726.8  1553.5   10.0%
   64   64/2  2.375678 2.638707  11.1%   1.216   1.351   1725.0  1552.1   10.0%
   64  64/32  2.376681 2.637359  11.0%   1.217   1.350   1725.1  1555.9    9.8%
   64  64/64  2.376787 2.638396  11.0%   1.217   1.351   1722.8  1550.9   10.0%
 1024    8/2  2.263768 2.498881  10.4%   1.159   1.279   1808.5  1637.1    9.5%
 1024    8/4  2.264519 2.499075  10.4%   1.159   1.280   1807.6  1638.8    9.3%
 1024    8/8  2.263551 2.499231  10.4%   1.159   1.280   1812.0  1640.2    9.5%
 1024   32/2  2.263841 2.499120  10.4%   1.159   1.280   1806.8  1639.6    9.3%
 1024  32/16  2.263990 2.499562  10.4%   1.159   1.280   1806.1  1639.2    9.2%
 1024  32/32  2.263719 2.498905  10.4%   1.159   1.279   1807.7  1639.3    9.3%
 1024   64/2  2.263635 2.501889  10.5%   1.159   1.281   1809.4  1635.6    9.6%
 1024  64/32  2.264467 2.500359  10.4%   1.159   1.280   1806.5  1633.0    9.6%
 1024  64/64  2.240494 2.470246  10.3%   1.147   1.265   1810.0  1637.1    9.6%

Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
CC: Pablo Neira Ayuso <pablo@netfilter.org>
CC: Florian Westphal <fw@strlen.de>
CC: Phil Sutter <phil@nwl.cc>
CC: netfilter-devel@vger.kernel.org
CC: coreteam@netfilter.org

 net/bridge/br_device.c                   |  2 +-
 net/bridge/br_forward.c                  | 24 +++++++++++++-----------
 net/bridge/br_input.c                    |  2 +-
 net/bridge/br_mrp.c                      |  6 +++---
 net/bridge/br_private.h                  |  2 +-
 net/bridge/netfilter/nft_reject_bridge.c |  8 ++++----
 6 files changed, 23 insertions(+), 21 deletions(-)
diff mbox series

Patch

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 2423d69f2498..0a1ce9e59a4d 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -108,7 +108,7 @@  netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 		else
 			br_flood(br, vlan, skb, BR_PKT_MULTICAST, false, true);
 	} else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
-		br_forward(br_fdb_dst_port(dst), skb, false, true);
+		br_forward(br_fdb_dst_read(dst), skb, false, true);
 	} else {
 		br_flood(br, vlan, skb, BR_PKT_UNICAST, false, true);
 	}
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index b5eece1ff9e8..82645db32efb 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -17,7 +17,7 @@ 
 #include "br_private.h"
 
 struct br_fwd_dst {
-	const struct net_bridge_port *port;
+	struct net_bridge_port *port;
 	struct net_bridge_vlan *vlan;
 };
 
@@ -149,35 +149,37 @@  static int deliver_clone(const struct br_fwd_dst *fwd,
 
 /**
  * br_forward - forward a packet to a specific port
- * @to: destination port
+ * @dst: bridge destination
  * @skb: packet being forwarded
  * @local_rcv: packet will be received locally after forwarding
  * @local_orig: packet is locally originated
  *
  * Should be called with rcu_read_lock.
  */
-void br_forward(const struct net_bridge_port *to,
+void br_forward(struct net_bridge_dst dst,
 		struct sk_buff *skb, bool local_rcv, bool local_orig)
 {
 	struct br_fwd_dst fwd;
 
-	if (unlikely(!to))
+	br_dst_decode(dst, &fwd.port, &fwd.vlan);
+
+	if (unlikely(!fwd.port))
 		goto out;
 
 	/* redirect to backup link if the destination port is down */
-	if (rcu_access_pointer(to->backup_port) &&
-	    (!netif_carrier_ok(to->dev) || !netif_running(to->dev))) {
+	if (rcu_access_pointer(fwd.port->backup_port) &&
+	    (!netif_carrier_ok(fwd.port->dev) ||
+	     !netif_running(fwd.port->dev))) {
 		struct net_bridge_port *backup_port;
 
-		backup_port = rcu_dereference(to->backup_port);
+		backup_port = rcu_dereference(fwd.port->backup_port);
 		if (unlikely(!backup_port))
 			goto out;
-		BR_INPUT_SKB_CB(skb)->backup_nhid = READ_ONCE(to->backup_nhid);
-		to = backup_port;
+		BR_INPUT_SKB_CB(skb)->backup_nhid = READ_ONCE(fwd.port->backup_nhid);
+		fwd.port = backup_port;
+		fwd.vlan = NULL;
 	}
 
-	fwd.port = to;
-	fwd.vlan = NULL;
 	if (should_deliver(&fwd, skb)) {
 		if (local_rcv)
 			deliver_clone(&fwd, skb, local_orig);
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 44a217d65e7f..fc2e381c4fe0 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -225,7 +225,7 @@  int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
 
 		if (now != READ_ONCE(dst->used))
 			WRITE_ONCE(dst->used, now);
-		br_forward(br_fdb_dst_port(dst), skb, local_rcv, false);
+		br_forward(br_fdb_dst_read(dst), skb, local_rcv, false);
 	} else {
 		if (!mcast_hit)
 			br_flood(br, vlan, skb, pkt_type, local_rcv, false);
diff --git a/net/bridge/br_mrp.c b/net/bridge/br_mrp.c
index dce6efa96c4c..c8cd5b4f3af8 100644
--- a/net/bridge/br_mrp.c
+++ b/net/bridge/br_mrp.c
@@ -1219,11 +1219,11 @@  static int br_mrp_rcv(struct net_bridge_port *p,
 
 forward:
 	if (p_dst)
-		br_forward(p_dst, skb, true, false);
+		br_forward(br_port_to_dst(p_dst), skb, true, false);
 	if (s_dst)
-		br_forward(s_dst, skb, true, false);
+		br_forward(br_port_to_dst(s_dst), skb, true, false);
 	if (i_dst)
-		br_forward(i_dst, skb, true, false);
+		br_forward(br_port_to_dst(i_dst), skb, true, false);
 
 no_forward:
 	return 1;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index a1c5b1abc1ef..05921192ebda 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1045,7 +1045,7 @@  enum br_pkt_type {
 	BR_PKT_BROADCAST
 };
 int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb);
-void br_forward(const struct net_bridge_port *to, struct sk_buff *skb,
+void br_forward(struct net_bridge_dst dst, struct sk_buff *skb,
 		bool local_rcv, bool local_orig);
 int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
 void br_flood(struct net_bridge *br, struct net_bridge_vlan *v,
diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c
index cd2b04236a99..92b488793914 100644
--- a/net/bridge/netfilter/nft_reject_bridge.c
+++ b/net/bridge/netfilter/nft_reject_bridge.c
@@ -55,7 +55,7 @@  static void nft_reject_br_send_v4_tcp_reset(struct net *net,
 
 	nft_reject_br_push_etherhdr(oldskb, nskb);
 
-	br_forward(br_port_get_rcu(dev), nskb, false, true);
+	br_forward(br_port_to_dst(br_port_get_rcu(dev)), nskb, false, true);
 }
 
 static void nft_reject_br_send_v4_unreach(struct net *net,
@@ -71,7 +71,7 @@  static void nft_reject_br_send_v4_unreach(struct net *net,
 
 	nft_reject_br_push_etherhdr(oldskb, nskb);
 
-	br_forward(br_port_get_rcu(dev), nskb, false, true);
+	br_forward(br_port_to_dst(br_port_get_rcu(dev)), nskb, false, true);
 }
 
 static void nft_reject_br_send_v6_tcp_reset(struct net *net,
@@ -87,7 +87,7 @@  static void nft_reject_br_send_v6_tcp_reset(struct net *net,
 
 	nft_reject_br_push_etherhdr(oldskb, nskb);
 
-	br_forward(br_port_get_rcu(dev), nskb, false, true);
+	br_forward(br_port_to_dst(br_port_get_rcu(dev)), nskb, false, true);
 }
 
 
@@ -104,7 +104,7 @@  static void nft_reject_br_send_v6_unreach(struct net *net,
 
 	nft_reject_br_push_etherhdr(oldskb, nskb);
 
-	br_forward(br_port_get_rcu(dev), nskb, false, true);
+	br_forward(br_port_to_dst(br_port_get_rcu(dev)), nskb, false, true);
 }
 
 static void nft_reject_bridge_eval(const struct nft_expr *expr,