bridge: Extend Proxy ARP design to allow optional rules for Wi-Fi

This extends the design in commit 958501163d ("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>
This commit is contained in:
Jouni Malinen 2015-03-04 12:54:21 +02:00 committed by David S. Miller
parent 787fb2bd42
commit 842a9ae08a
7 changed files with 22 additions and 8 deletions

View File

@ -44,6 +44,7 @@ struct br_ip_list {
#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 *));

View File

@ -247,6 +247,7 @@ enum {
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)

View File

@ -188,6 +188,9 @@ static void br_flood(struct net_bridge *br, struct sk_buff *skb,
/* 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))

View File

@ -60,7 +60,7 @@ static int br_pass_frame_up(struct sk_buff *skb)
}
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 @@ static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
u8 *arpptr, *sha;
__be32 sip, tip;
BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
if (dev->flags & IFF_NOARP)
return;
@ -105,9 +107,12 @@ static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
}
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 @@ int br_handle_frame_finish(struct sk_buff *skb)
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)) {

View File

@ -143,7 +143,9 @@ static int br_port_fill_attrs(struct sk_buff *skb,
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 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
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]));

View File

@ -305,6 +305,7 @@ struct br_input_skb_cb {
#endif
u16 frag_max_size;
bool proxyarp_replied;
#ifdef CONFIG_BRIDGE_VLAN_FILTERING
bool vlan_filtered;

View File

@ -171,6 +171,7 @@ BRPORT_ATTR_FLAG(root_block, BR_ROOT_BLOCK);
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 @@ static const struct brport_attribute *brport_attrs[] = {
&brport_attr_multicast_fast_leave,
#endif
&brport_attr_proxyarp,
&brport_attr_proxyarp_wifi,
NULL
};