* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
*
- * $Id: br_input.c,v 1.10 2001/12/24 04:50:20 davem Exp $
- *
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
#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_receive_skb(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)
{
- struct net_device *indev;
+ struct net_device *indev, *brdev = br->dev;
- br->statistics.rx_packets++;
- br->statistics.rx_bytes += skb->len;
+ brdev->stats.rx_packets++;
+ brdev->stats.rx_bytes += skb->len;
indev = skb->dev;
- skb->dev = br->dev;
+ skb->dev = brdev;
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 = skb->dev->br_port;
- struct net_bridge *br = p->br;
+ struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
+ struct net_bridge *br;
struct net_bridge_fdb_entry *dst;
- int passedup = 0;
+ struct sk_buff *skb2;
+
+ if (!p || p->state == BR_STATE_DISABLED)
+ goto drop;
/* insert into forwarding database after filtering to avoid spoofing */
- br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
+ br = p->br;
+ br_fdb_update(br, p, eth_hdr(skb)->h_source);
- if (br->dev->flags & IFF_PROMISC) {
- struct sk_buff *skb2;
+ if (p->state == BR_STATE_LEARNING)
+ goto drop;
- skb2 = skb_clone(skb, GFP_ATOMIC);
- if (skb2 != NULL) {
- passedup = 1;
- br_pass_frame_up(br, skb2);
- }
- }
+ /* The packet skb2 goes to the local host (NULL to skip). */
+ skb2 = NULL;
- if (dest[0] & 1) {
- br_flood_forward(br, skb, !passedup);
- if (!passedup)
- br_pass_frame_up(br, skb);
- goto out;
- }
+ if (br->dev->flags & IFF_PROMISC)
+ skb2 = skb;
- dst = __br_fdb_get(br, dest);
- if (dst != NULL && dst->is_local) {
- if (!passedup)
- br_pass_frame_up(br, skb);
- else
- kfree_skb(skb);
- goto out;
- }
+ dst = NULL;
- if (dst != NULL) {
- br_forward(dst->dst, skb);
- goto out;
+ if (is_multicast_ether_addr(dest)) {
+ br->dev->stats.multicast++;
+ skb2 = skb;
+ } else if ((dst = __br_fdb_get(br, dest)) && dst->is_local) {
+ skb2 = skb;
+ /* Do not forward the packet since it's local. */
+ skb = NULL;
}
- br_flood_forward(br, skb, 0);
+ if (skb2 == skb)
+ skb2 = skb_clone(skb, GFP_ATOMIC);
+
+ if (skb2)
+ br_pass_frame_up(br, skb2);
+
+ if (skb) {
+ if (dst)
+ br_forward(dst->dst, skb);
+ else
+ br_flood_forward(br, skb);
+ }
out:
return 0;
+drop:
+ kfree_skb(skb);
+ goto out;
+}
+
+/* note: already called with rcu_read_lock (preempt_disabled) */
+static int br_handle_local_finish(struct sk_buff *skb)
+{
+ struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
+
+ if (p)
+ br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
+ 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)
+{
+ __be16 *a = (__be16 *)dest;
+ static const __be16 *b = (const __be16 *)br_group_address;
+ static const __be16 m = cpu_to_be16(0xfff0);
+
+ return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
}
/*
* 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)
+ * Return NULL if skb 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 *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb)
{
- struct sk_buff *skb = *pskb;
const unsigned char *dest = eth_hdr(skb)->h_dest;
-
- if (p->state == BR_STATE_DISABLED)
- goto err;
+ int (*rhook)(struct sk_buff *skb);
if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
- goto err;
+ goto drop;
- if (p->state == BR_STATE_LEARNING)
- br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (!skb)
+ return NULL;
- 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);
- return 1;
- }
+ if (unlikely(is_link_local(dest))) {
+ /* Pause frames shouldn't be passed up by driver anyway */
+ if (skb->protocol == htons(ETH_P_PAUSE))
+ goto drop;
+
+ /* If STP is turned off, then forward */
+ if (p->br->stp_enabled == BR_NO_STP && dest[5] == 0)
+ goto forward;
+
+ if (NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
+ NULL, br_handle_local_finish))
+ return NULL; /* frame consumed by filter */
+ else
+ return skb; /* continue processing */
}
- else if (p->state == BR_STATE_FORWARDING) {
- if (br_should_route_hook) {
- if (br_should_route_hook(pskb))
- return 0;
- skb = *pskb;
+forward:
+ switch (p->state) {
+ case BR_STATE_FORWARDING:
+ rhook = rcu_dereference(br_should_route_hook);
+ if (rhook != NULL) {
+ if (rhook(skb))
+ return skb;
dest = eth_hdr(skb)->h_dest;
}
-
- if (!memcmp(p->br->dev->dev_addr, dest, ETH_ALEN))
+ /* fall through */
+ case BR_STATE_LEARNING:
+ 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);
- return 1;
+ break;
+ default:
+drop:
+ kfree_skb(skb);
}
-
-err:
- kfree_skb(skb);
- return 1;
+ return NULL;
}