3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #include <linux/err.h>
15 #include <linux/slab.h>
16 #include <linux/kernel.h>
17 #include <linux/netdevice.h>
18 #include <linux/netpoll.h>
19 #include <linux/skbuff.h>
20 #include <linux/if_vlan.h>
21 #include <linux/netfilter_bridge.h>
22 #include "br_private.h"
24 static int deliver_clone(const struct net_bridge_port *prev,
26 void (*__packet_hook)(const struct net_bridge_port *p,
27 struct sk_buff *skb));
29 /* Don't forward packets to originating port or forwarding disabled */
30 static inline int should_deliver(const struct net_bridge_port *p,
31 const struct sk_buff *skb)
33 return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
34 br_allowed_egress(p->br, nbp_get_vlan_info(p), skb) &&
35 p->state == BR_STATE_FORWARDING;
38 int br_dev_queue_push_xmit(struct sock *sk, struct sk_buff *skb)
40 if (!is_skb_forwardable(skb->dev, skb)) {
43 skb_push(skb, ETH_HLEN);
44 br_drop_fake_rtable(skb);
45 skb_sender_cpu_clear(skb);
51 EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
53 int br_forward_finish(struct sock *sk, struct sk_buff *skb)
55 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, sk, skb,
57 br_dev_queue_push_xmit);
60 EXPORT_SYMBOL_GPL(br_forward_finish);
62 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
64 skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
70 if (unlikely(netpoll_tx_running(to->br->dev))) {
71 if (!is_skb_forwardable(skb->dev, skb))
74 skb_push(skb, ETH_HLEN);
75 br_netpoll_send_skb(to, skb);
80 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, NULL, skb,
85 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
87 struct net_device *indev;
89 if (skb_warn_if_lro(skb)) {
94 skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
100 skb_forward_csum(skb);
102 NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, NULL, skb,
107 /* called with rcu_read_lock */
108 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
110 if (to && should_deliver(to, skb)) {
111 __br_deliver(to, skb);
117 EXPORT_SYMBOL_GPL(br_deliver);
119 /* called with rcu_read_lock */
120 void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
122 if (should_deliver(to, skb)) {
124 deliver_clone(to, skb, __br_forward);
126 __br_forward(to, skb);
134 static int deliver_clone(const struct net_bridge_port *prev,
136 void (*__packet_hook)(const struct net_bridge_port *p,
137 struct sk_buff *skb))
139 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
141 skb = skb_clone(skb, GFP_ATOMIC);
143 dev->stats.tx_dropped++;
147 __packet_hook(prev, skb);
151 static struct net_bridge_port *maybe_deliver(
152 struct net_bridge_port *prev, struct net_bridge_port *p,
154 void (*__packet_hook)(const struct net_bridge_port *p,
155 struct sk_buff *skb))
159 if (!should_deliver(p, skb))
165 err = deliver_clone(prev, skb, __packet_hook);
173 /* called under bridge lock */
174 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
175 struct sk_buff *skb0,
176 void (*__packet_hook)(const struct net_bridge_port *p,
177 struct sk_buff *skb),
180 struct net_bridge_port *p;
181 struct net_bridge_port *prev;
185 list_for_each_entry_rcu(p, &br->port_list, list) {
186 /* Do not flood unicast traffic to ports that turn it off */
187 if (unicast && !(p->flags & BR_FLOOD))
190 /* Do not flood to ports that enable proxy ARP */
191 if (p->flags & BR_PROXYARP)
193 if ((p->flags & BR_PROXYARP_WIFI) &&
194 BR_INPUT_SKB_CB(skb)->proxyarp_replied)
197 prev = maybe_deliver(prev, p, skb, __packet_hook);
206 deliver_clone(prev, skb, __packet_hook);
208 __packet_hook(prev, skb);
217 /* called with rcu_read_lock */
218 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast)
220 br_flood(br, skb, NULL, __br_deliver, unicast);
223 /* called under bridge lock */
224 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
225 struct sk_buff *skb2, bool unicast)
227 br_flood(br, skb, skb2, __br_forward, unicast);
230 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
231 /* called with rcu_read_lock */
232 static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
233 struct sk_buff *skb, struct sk_buff *skb0,
234 void (*__packet_hook)(
235 const struct net_bridge_port *p,
236 struct sk_buff *skb))
238 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
239 struct net_bridge *br = netdev_priv(dev);
240 struct net_bridge_port *prev = NULL;
241 struct net_bridge_port_group *p;
242 struct hlist_node *rp;
244 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
245 p = mdst ? rcu_dereference(mdst->ports) : NULL;
247 struct net_bridge_port *port, *lport, *rport;
249 lport = p ? p->port : NULL;
250 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
253 port = (unsigned long)lport > (unsigned long)rport ?
256 prev = maybe_deliver(prev, port, skb, __packet_hook);
260 if ((unsigned long)lport >= (unsigned long)port)
261 p = rcu_dereference(p->next);
262 if ((unsigned long)rport >= (unsigned long)port)
263 rp = rcu_dereference(hlist_next_rcu(rp));
270 deliver_clone(prev, skb, __packet_hook);
272 __packet_hook(prev, skb);
280 /* called with rcu_read_lock */
281 void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
284 br_multicast_flood(mdst, skb, NULL, __br_deliver);
287 /* called with rcu_read_lock */
288 void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
289 struct sk_buff *skb, struct sk_buff *skb2)
291 br_multicast_flood(mdst, skb, skb2, __br_forward);