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);
53 int br_forward_finish(struct sk_buff *skb)
55 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
56 br_dev_queue_push_xmit);
60 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
62 skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
68 if (unlikely(netpoll_tx_running(to->br->dev))) {
69 if (!is_skb_forwardable(skb->dev, skb))
72 skb_push(skb, ETH_HLEN);
73 br_netpoll_send_skb(to, skb);
78 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
82 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
84 struct net_device *indev;
86 if (skb_warn_if_lro(skb)) {
91 skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
97 skb_forward_csum(skb);
99 NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
103 /* called with rcu_read_lock */
104 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
106 if (to && should_deliver(to, skb)) {
107 __br_deliver(to, skb);
114 /* called with rcu_read_lock */
115 void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
117 if (should_deliver(to, skb)) {
119 deliver_clone(to, skb, __br_forward);
121 __br_forward(to, skb);
129 static int deliver_clone(const struct net_bridge_port *prev,
131 void (*__packet_hook)(const struct net_bridge_port *p,
132 struct sk_buff *skb))
134 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
136 skb = skb_clone(skb, GFP_ATOMIC);
138 dev->stats.tx_dropped++;
142 __packet_hook(prev, skb);
146 static struct net_bridge_port *maybe_deliver(
147 struct net_bridge_port *prev, struct net_bridge_port *p,
149 void (*__packet_hook)(const struct net_bridge_port *p,
150 struct sk_buff *skb))
154 if (!should_deliver(p, skb))
160 err = deliver_clone(prev, skb, __packet_hook);
168 /* called under bridge lock */
169 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
170 struct sk_buff *skb0,
171 void (*__packet_hook)(const struct net_bridge_port *p,
172 struct sk_buff *skb),
175 struct net_bridge_port *p;
176 struct net_bridge_port *prev;
180 list_for_each_entry_rcu(p, &br->port_list, list) {
181 /* Do not flood unicast traffic to ports that turn it off */
182 if (unicast && !(p->flags & BR_FLOOD))
184 prev = maybe_deliver(prev, p, skb, __packet_hook);
193 deliver_clone(prev, skb, __packet_hook);
195 __packet_hook(prev, skb);
204 /* called with rcu_read_lock */
205 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast)
207 br_flood(br, skb, NULL, __br_deliver, unicast);
210 /* called under bridge lock */
211 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
212 struct sk_buff *skb2, bool unicast)
214 br_flood(br, skb, skb2, __br_forward, unicast);
217 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
218 /* called with rcu_read_lock */
219 static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
220 struct sk_buff *skb, struct sk_buff *skb0,
221 void (*__packet_hook)(
222 const struct net_bridge_port *p,
223 struct sk_buff *skb))
225 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
226 struct net_bridge *br = netdev_priv(dev);
227 struct net_bridge_port *prev = NULL;
228 struct net_bridge_port_group *p;
229 struct hlist_node *rp;
231 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
232 p = mdst ? rcu_dereference(mdst->ports) : NULL;
234 struct net_bridge_port *port, *lport, *rport;
236 lport = p ? p->port : NULL;
237 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
240 port = (unsigned long)lport > (unsigned long)rport ?
243 prev = maybe_deliver(prev, port, skb, __packet_hook);
247 if ((unsigned long)lport >= (unsigned long)port)
248 p = rcu_dereference(p->next);
249 if ((unsigned long)rport >= (unsigned long)port)
250 rp = rcu_dereference(hlist_next_rcu(rp));
257 deliver_clone(prev, skb, __packet_hook);
259 __packet_hook(prev, skb);
267 /* called with rcu_read_lock */
268 void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
271 br_multicast_flood(mdst, skb, NULL, __br_deliver);
274 /* called with rcu_read_lock */
275 void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
276 struct sk_buff *skb, struct sk_buff *skb2)
278 br_multicast_flood(mdst, skb, skb2, __br_forward);