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 diasabled */
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 static inline unsigned int packet_length(const struct sk_buff *skb)
40 return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
43 int br_dev_queue_push_xmit(struct sk_buff *skb)
45 /* ip_fragment doesn't copy the MAC header */
46 if (nf_bridge_maybe_copy_header(skb) ||
47 (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))) {
50 skb_push(skb, ETH_HLEN);
51 br_drop_fake_rtable(skb);
58 int br_forward_finish(struct sk_buff *skb)
60 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
61 br_dev_queue_push_xmit);
65 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
69 if (unlikely(netpoll_tx_running(to->br->dev))) {
70 if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
73 skb_push(skb, ETH_HLEN);
74 br_netpoll_send_skb(to, skb);
79 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
83 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
85 struct net_device *indev;
87 if (skb_warn_if_lro(skb)) {
94 skb_forward_csum(skb);
96 NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
100 /* called with rcu_read_lock */
101 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
103 if (to && should_deliver(to, skb)) {
104 __br_deliver(to, skb);
111 /* called with rcu_read_lock */
112 void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
114 if (should_deliver(to, skb)) {
116 deliver_clone(to, skb, __br_forward);
118 __br_forward(to, skb);
126 static int deliver_clone(const struct net_bridge_port *prev,
128 void (*__packet_hook)(const struct net_bridge_port *p,
129 struct sk_buff *skb))
131 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
133 skb = skb_clone(skb, GFP_ATOMIC);
135 dev->stats.tx_dropped++;
139 __packet_hook(prev, skb);
143 static struct net_bridge_port *maybe_deliver(
144 struct net_bridge_port *prev, struct net_bridge_port *p,
146 void (*__packet_hook)(const struct net_bridge_port *p,
147 struct sk_buff *skb))
151 if (!should_deliver(p, skb))
157 err = deliver_clone(prev, skb, __packet_hook);
165 /* called under bridge lock */
166 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
167 struct sk_buff *skb0,
168 void (*__packet_hook)(const struct net_bridge_port *p,
169 struct sk_buff *skb))
171 struct net_bridge_port *p;
172 struct net_bridge_port *prev;
176 list_for_each_entry_rcu(p, &br->port_list, list) {
177 prev = maybe_deliver(prev, p, skb, __packet_hook);
186 deliver_clone(prev, skb, __packet_hook);
188 __packet_hook(prev, skb);
197 /* called with rcu_read_lock */
198 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb)
200 br_flood(br, skb, NULL, __br_deliver);
203 /* called under bridge lock */
204 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
205 struct sk_buff *skb2)
207 br_flood(br, skb, skb2, __br_forward);
210 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
211 /* called with rcu_read_lock */
212 static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
213 struct sk_buff *skb, struct sk_buff *skb0,
214 void (*__packet_hook)(
215 const struct net_bridge_port *p,
216 struct sk_buff *skb))
218 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
219 struct net_bridge *br = netdev_priv(dev);
220 struct net_bridge_port *prev = NULL;
221 struct net_bridge_port_group *p;
222 struct hlist_node *rp;
224 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
225 p = mdst ? rcu_dereference(mdst->ports) : NULL;
227 struct net_bridge_port *port, *lport, *rport;
229 lport = p ? p->port : NULL;
230 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
233 port = (unsigned long)lport > (unsigned long)rport ?
236 prev = maybe_deliver(prev, port, skb, __packet_hook);
240 if ((unsigned long)lport >= (unsigned long)port)
241 p = rcu_dereference(p->next);
242 if ((unsigned long)rport >= (unsigned long)port)
243 rp = rcu_dereference(hlist_next_rcu(rp));
250 deliver_clone(prev, skb, __packet_hook);
252 __packet_hook(prev, skb);
260 /* called with rcu_read_lock */
261 void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
264 br_multicast_flood(mdst, skb, NULL, __br_deliver);
267 /* called with rcu_read_lock */
268 void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
269 struct sk_buff *skb, struct sk_buff *skb2)
271 br_multicast_flood(mdst, skb, skb2, __br_forward);