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 sk_buff *skb)
40 /* ip_fragment doesn't copy the MAC header */
41 if (nf_bridge_maybe_copy_header(skb) ||
42 !is_skb_forwardable(skb->dev, skb)) {
45 skb_push(skb, ETH_HLEN);
46 br_drop_fake_rtable(skb);
52 EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
54 int br_forward_finish(struct sk_buff *skb)
56 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
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, skb, NULL, skb->dev,
84 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
86 struct net_device *indev;
88 if (skb_warn_if_lro(skb)) {
93 skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
99 skb_forward_csum(skb);
101 NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
105 /* called with rcu_read_lock */
106 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
108 if (to && should_deliver(to, skb)) {
109 __br_deliver(to, skb);
116 /* called with rcu_read_lock */
117 void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
119 if (should_deliver(to, skb)) {
121 deliver_clone(to, skb, __br_forward);
123 __br_forward(to, skb);
131 static int deliver_clone(const struct net_bridge_port *prev,
133 void (*__packet_hook)(const struct net_bridge_port *p,
134 struct sk_buff *skb))
136 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
138 skb = skb_clone(skb, GFP_ATOMIC);
140 dev->stats.tx_dropped++;
144 __packet_hook(prev, skb);
148 static struct net_bridge_port *maybe_deliver(
149 struct net_bridge_port *prev, struct net_bridge_port *p,
151 void (*__packet_hook)(const struct net_bridge_port *p,
152 struct sk_buff *skb))
156 if (!should_deliver(p, skb))
162 err = deliver_clone(prev, skb, __packet_hook);
170 /* called under bridge lock */
171 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
172 struct sk_buff *skb0,
173 void (*__packet_hook)(const struct net_bridge_port *p,
174 struct sk_buff *skb),
177 struct net_bridge_port *p;
178 struct net_bridge_port *prev;
182 list_for_each_entry_rcu(p, &br->port_list, list) {
183 /* Do not flood unicast traffic to ports that turn it off */
184 if (unicast && !(p->flags & BR_FLOOD))
186 prev = maybe_deliver(prev, p, skb, __packet_hook);
195 deliver_clone(prev, skb, __packet_hook);
197 __packet_hook(prev, skb);
206 /* called with rcu_read_lock */
207 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast)
209 br_flood(br, skb, NULL, __br_deliver, unicast);
212 /* called under bridge lock */
213 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
214 struct sk_buff *skb2, bool unicast)
216 br_flood(br, skb, skb2, __br_forward, unicast);
219 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
220 /* called with rcu_read_lock */
221 static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
222 struct sk_buff *skb, struct sk_buff *skb0,
223 void (*__packet_hook)(
224 const struct net_bridge_port *p,
225 struct sk_buff *skb))
227 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
228 struct net_bridge *br = netdev_priv(dev);
229 struct net_bridge_port *prev = NULL;
230 struct net_bridge_port_group *p;
231 struct hlist_node *rp;
233 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
234 p = mdst ? rcu_dereference(mdst->ports) : NULL;
236 struct net_bridge_port *port, *lport, *rport;
238 lport = p ? p->port : NULL;
239 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
242 port = (unsigned long)lport > (unsigned long)rport ?
245 prev = maybe_deliver(prev, port, skb, __packet_hook);
249 if ((unsigned long)lport >= (unsigned long)port)
250 p = rcu_dereference(p->next);
251 if ((unsigned long)rport >= (unsigned long)port)
252 rp = rcu_dereference(hlist_next_rcu(rp));
259 deliver_clone(prev, skb, __packet_hook);
261 __packet_hook(prev, skb);
269 /* called with rcu_read_lock */
270 void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
273 br_multicast_flood(mdst, skb, NULL, __br_deliver);
276 /* called with rcu_read_lock */
277 void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
278 struct sk_buff *skb, struct sk_buff *skb2)
280 br_multicast_flood(mdst, skb, skb2, __br_forward);