bridge: Extend Proxy ARP design to allow optional rules for Wi-Fi
This extends the design in commit 958501163ddd ("bridge: Add support for
IEEE 802.11 Proxy ARP") with optional set of rules that are needed to
meet the IEEE 802.11 and Hotspot 2.0 requirements for ProxyARP. The
previously added BR_PROXYARP behavior is left as-is and a new
BR_PROXYARP_WIFI alternative is added so that this behavior can be
configured from user space when required.
In addition, this enables proxyarp functionality for unicast ARP
requests for both BR_PROXYARP and BR_PROXYARP_WIFI since it is possible
to use unicast as well as broadcast for these frames.
The key differences in functionality:
BR_PROXYARP:
- uses the flag on the bridge port on which the request frame was
received to determine whether to reply
- block bridge port flooding completely on ports that enable proxy ARP
BR_PROXYARP_WIFI:
- uses the flag on the bridge port to which the target device of the
request belongs
- block bridge port flooding selectively based on whether the proxyarp
functionality replied
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
index a57bca2..dad8b00 100644
--- a/include/linux/if_bridge.h
+++ b/include/linux/if_bridge.h
@@ -44,6 +44,7 @@
#define BR_PROMISC BIT(7)
#define BR_PROXYARP BIT(8)
#define BR_LEARNING_SYNC BIT(9)
+#define BR_PROXYARP_WIFI BIT(10)
extern void brioctl_set(int (*ioctl_hook)(struct net *, unsigned int, void __user *));
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index dfd0bb2..756436e 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -247,6 +247,7 @@
IFLA_BRPORT_UNICAST_FLOOD, /* flood unicast traffic */
IFLA_BRPORT_PROXYARP, /* proxy ARP */
IFLA_BRPORT_LEARNING_SYNC, /* mac learning sync from device */
+ IFLA_BRPORT_PROXYARP_WIFI, /* proxy ARP for Wi-Fi */
__IFLA_BRPORT_MAX
};
#define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1)
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index f96933a..1238fab 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -188,6 +188,9 @@
/* Do not flood to ports that enable proxy ARP */
if (p->flags & BR_PROXYARP)
continue;
+ if ((p->flags & BR_PROXYARP_WIFI) &&
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied)
+ continue;
prev = maybe_deliver(prev, p, skb, __packet_hook);
if (IS_ERR(prev))
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index e2aa7be..052c5eb 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -60,7 +60,7 @@
}
static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
- u16 vid)
+ u16 vid, struct net_bridge_port *p)
{
struct net_device *dev = br->dev;
struct neighbour *n;
@@ -68,6 +68,8 @@
u8 *arpptr, *sha;
__be32 sip, tip;
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
+
if (dev->flags & IFF_NOARP)
return;
@@ -105,9 +107,12 @@
}
f = __br_fdb_get(br, n->ha, vid);
- if (f)
+ if (f && ((p->flags & BR_PROXYARP) ||
+ (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)))) {
arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip,
sha, n->ha, sha);
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
+ }
neigh_release(n);
}
@@ -153,12 +158,10 @@
dst = NULL;
- if (is_broadcast_ether_addr(dest)) {
- if (IS_ENABLED(CONFIG_INET) &&
- p->flags & BR_PROXYARP &&
- skb->protocol == htons(ETH_P_ARP))
- br_do_proxy_arp(skb, br, vid);
+ if (IS_ENABLED(CONFIG_INET) && skb->protocol == htons(ETH_P_ARP))
+ br_do_proxy_arp(skb, br, vid, p);
+ if (is_broadcast_ether_addr(dest)) {
skb2 = skb;
unicast = false;
} else if (is_multicast_ether_addr(dest)) {
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index c720839..8bc6b67 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -143,7 +143,9 @@
nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE, !!(p->flags & BR_MULTICAST_FAST_LEAVE)) ||
nla_put_u8(skb, IFLA_BRPORT_LEARNING, !!(p->flags & BR_LEARNING)) ||
nla_put_u8(skb, IFLA_BRPORT_UNICAST_FLOOD, !!(p->flags & BR_FLOOD)) ||
- nla_put_u8(skb, IFLA_BRPORT_PROXYARP, !!(p->flags & BR_PROXYARP)))
+ nla_put_u8(skb, IFLA_BRPORT_PROXYARP, !!(p->flags & BR_PROXYARP)) ||
+ nla_put_u8(skb, IFLA_BRPORT_PROXYARP_WIFI,
+ !!(p->flags & BR_PROXYARP_WIFI)))
return -EMSGSIZE;
return 0;
@@ -553,6 +555,7 @@
br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP, BR_PROXYARP);
+ br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP_WIFI, BR_PROXYARP_WIFI);
if (tb[IFLA_BRPORT_COST]) {
err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index de09199..c32e279 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -305,6 +305,7 @@
#endif
u16 frag_max_size;
+ bool proxyarp_replied;
#ifdef CONFIG_BRIDGE_VLAN_FILTERING
bool vlan_filtered;
diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
index 2de5d91..4905845 100644
--- a/net/bridge/br_sysfs_if.c
+++ b/net/bridge/br_sysfs_if.c
@@ -171,6 +171,7 @@
BRPORT_ATTR_FLAG(learning, BR_LEARNING);
BRPORT_ATTR_FLAG(unicast_flood, BR_FLOOD);
BRPORT_ATTR_FLAG(proxyarp, BR_PROXYARP);
+BRPORT_ATTR_FLAG(proxyarp_wifi, BR_PROXYARP_WIFI);
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
static ssize_t show_multicast_router(struct net_bridge_port *p, char *buf)
@@ -215,6 +216,7 @@
&brport_attr_multicast_fast_leave,
#endif
&brport_attr_proxyarp,
+ &brport_attr_proxyarp_wifi,
NULL
};