[PATCH 13/16 net-next v2] net: bridge: guard ARP/RARP proxy and suppression with CONFIG_IPV4

From: Fernando Fernandez Mancera

Date: Mon Sep 28 2026 - 15:36:13 EST


Historically, the bridge subsystem relied on CONFIG_INET to guard ARP
and RARP proxy and suppression routines. As CONFIG_IPV4 is decoupled
from the core stack and made optional, relying on CONFIG_INET is no
longer accurate, as ARP and RARP are exclusively IPv4 protocols.

Signed-off-by: Fernando Fernandez Mancera <fmancera@xxxxxxx>
---
net/bridge/br_arp_nd_proxy.c | 2 +-
net/bridge/br_device.c | 2 +-
net/bridge/br_input.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c
index da15f4d7c1ae..d739b8697429 100644
--- a/net/bridge/br_arp_nd_proxy.c
+++ b/net/bridge/br_arp_nd_proxy.c
@@ -39,7 +39,6 @@ void br_recalculate_neigh_suppress_enabled(struct net_bridge *br)
br_opt_toggle(br, BROPT_NEIGH_SUPPRESS_ENABLED, neigh_suppress);
}

-#if IS_ENABLED(CONFIG_INET)
static bool
br_is_neigh_suppress_enabled_vid(const struct net_bridge_port *p, u16 vid)
{
@@ -57,6 +56,7 @@ br_is_neigh_suppress_enabled_vid(const struct net_bridge_port *p, u16 vid)
return br_is_neigh_suppress_enabled(p, v);
}

+#if IS_ENABLED(CONFIG_IPV4)
static void br_arp_send(struct net_bridge *br, struct net_bridge_port *p,
struct net_device *dev, __be32 dest_ip, __be32 src_ip,
const unsigned char *dest_hw,
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index ce9ea9ac3d0a..a3e5a521178f 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -69,7 +69,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
&state, &vlan))
goto out;

- if (IS_ENABLED(CONFIG_INET) &&
+ if (IS_ENABLED(CONFIG_IPV4) &&
(eth_hdr(skb)->h_proto == htons(ETH_P_ARP) ||
eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) &&
br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 4357d78524a6..584ac6c2215c 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -166,7 +166,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
BR_INPUT_SKB_CB(skb)->brdev = br->dev;
BR_INPUT_SKB_CB(skb)->src_port_isolated = test_bit(BR_ISOLATED_BIT, &p->flags);

- if (IS_ENABLED(CONFIG_INET) &&
+ if (IS_ENABLED(CONFIG_IPV4) &&
(skb->protocol == htons(ETH_P_ARP) ||
skb->protocol == htons(ETH_P_RARP))) {
br_do_proxy_suppress_arp(skb, br, vid, p);
--
2.55.0