#include <linux/netfilter_bridge.h>
#include "br_private.h"
-const unsigned char bridge_ula[6] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
-
-static int br_pass_frame_up_finish(struct sk_buff *skb)
-{
-#ifdef CONFIG_NETFILTER_DEBUG
- skb->nf_debug = 0;
-#endif
- netif_rx(skb);
-
- return 0;
-}
+/* Bridge group multicast address 802.1d (pg 51). */
+const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb)
{
skb->dev = br->dev;
NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
- br_pass_frame_up_finish);
+ netif_receive_skb);
}
+/* note: already called with rcu_read_lock (preempt_disabled) */
int br_handle_frame_finish(struct sk_buff *skb)
{
+ const unsigned char *dest = eth_hdr(skb)->h_dest;
+ struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
struct net_bridge *br;
- unsigned char *dest;
struct net_bridge_fdb_entry *dst;
- struct net_bridge_port *p;
- int passedup;
+ int passedup = 0;
- dest = skb->mac.ethernet->h_dest;
+ if (!p || p->state == BR_STATE_DISABLED)
+ goto drop;
- rcu_read_lock();
- p = skb->dev->br_port;
- smp_read_barrier_depends();
+ /* insert into forwarding database after filtering to avoid spoofing */
+ br = p->br;
+ br_fdb_update(br, p, eth_hdr(skb)->h_source);
- if (p == NULL || p->state == BR_STATE_DISABLED) {
- kfree_skb(skb);
- goto out;
- }
+ if (p->state == BR_STATE_LEARNING)
+ goto drop;
- br = p->br;
- passedup = 0;
if (br->dev->flags & IFF_PROMISC) {
struct sk_buff *skb2;
}
}
- if (dest[0] & 1) {
+ if (is_multicast_ether_addr(dest)) {
+ br->statistics.multicast++;
br_flood_forward(br, skb, !passedup);
if (!passedup)
br_pass_frame_up(br, skb);
goto out;
}
- dst = br_fdb_get(br, dest);
+ dst = __br_fdb_get(br, dest);
if (dst != NULL && dst->is_local) {
if (!passedup)
br_pass_frame_up(br, skb);
else
kfree_skb(skb);
- br_fdb_put(dst);
goto out;
}
if (dst != NULL) {
br_forward(dst->dst, skb);
- br_fdb_put(dst);
goto out;
}
br_flood_forward(br, skb, 0);
out:
- rcu_read_unlock();
return 0;
+drop:
+ kfree_skb(skb);
+ goto out;
}
-int br_handle_frame(struct sk_buff *skb)
+/* note: already called with rcu_read_lock (preempt_disabled) */
+static int br_handle_local_finish(struct sk_buff *skb)
{
- unsigned char *dest;
- struct net_bridge_port *p;
+ struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
- dest = skb->mac.ethernet->h_dest;
+ if (p && p->state != BR_STATE_DISABLED)
+ br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
- rcu_read_lock();
- p = skb->dev->br_port;
- if (p == NULL || p->state == BR_STATE_DISABLED)
- goto err;
+ return 0; /* process further */
+}
+
+/* Does address match the link local multicast address.
+ * 01:80:c2:00:00:0X
+ */
+static inline int is_link_local(const unsigned char *dest)
+{
+ return memcmp(dest, br_group_address, 5) == 0 && (dest[5] & 0xf0) == 0;
+}
- if (skb->mac.ethernet->h_source[0] & 1)
+/*
+ * Called via br_handle_frame_hook.
+ * Return 0 if *pskb should be processed furthur
+ * 1 if *pskb is handled
+ * note: already called with rcu_read_lock (preempt_disabled)
+ */
+int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
+{
+ struct sk_buff *skb = *pskb;
+ const unsigned char *dest = eth_hdr(skb)->h_dest;
+
+ if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
goto err;
- if (p->state == BR_STATE_LEARNING ||
- p->state == BR_STATE_FORWARDING)
- br_fdb_insert(p->br, p, skb->mac.ethernet->h_source, 0);
-
- if (p->br->stp_enabled &&
- !memcmp(dest, bridge_ula, 5) &&
- !(dest[5] & 0xF0)) {
- if (!dest[5]) {
- NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
- NULL, br_stp_handle_bpdu);
- rcu_read_unlock();
- return 0;
- }
+ if (unlikely(is_link_local(dest))) {
+ skb->pkt_type = PACKET_HOST;
+ return NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
+ NULL, br_handle_local_finish) != 0;
}
- else if (p->state == BR_STATE_FORWARDING) {
- if (br_should_route_hook && br_should_route_hook(&skb)) {
- rcu_read_unlock();
- return -1;
+ if (p->state == BR_STATE_FORWARDING || p->state == BR_STATE_LEARNING) {
+ if (br_should_route_hook) {
+ if (br_should_route_hook(pskb))
+ return 0;
+ skb = *pskb;
+ dest = eth_hdr(skb)->h_dest;
}
- if (!memcmp(p->br->dev->dev_addr, dest, ETH_ALEN))
+ if (!compare_ether_addr(p->br->dev->dev_addr, dest))
skb->pkt_type = PACKET_HOST;
NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
br_handle_frame_finish);
- rcu_read_unlock();
- return 0;
+ return 1;
}
err:
- rcu_read_unlock();
kfree_skb(skb);
- return 0;
+ return 1;
}