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 p->state == BR_STATE_FORWARDING);
37 static inline unsigned packet_length(const struct sk_buff *skb)
39 return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
42 int br_dev_queue_push_xmit(struct sk_buff *skb)
44 /* drop mtu oversized packets except gso */
45 if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
48 /* ip_fragment doesn't copy the MAC header */
49 if (nf_bridge_maybe_copy_header(skb))
52 skb_push(skb, ETH_HLEN);
54 #ifdef CONFIG_NET_POLL_CONTROLLER
55 if (unlikely(skb->dev->priv_flags & IFF_IN_NETPOLL)) {
56 netpoll_send_skb(skb->dev->npinfo->netpoll, skb);
57 skb->dev->priv_flags &= ~IFF_IN_NETPOLL;
67 int br_forward_finish(struct sk_buff *skb)
69 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
70 br_dev_queue_push_xmit);
74 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
76 #ifdef CONFIG_NET_POLL_CONTROLLER
77 struct net_bridge *br = to->br;
78 if (unlikely(br->dev->priv_flags & IFF_IN_NETPOLL)) {
80 to->dev->npinfo = skb->dev->npinfo;
81 np = skb->dev->npinfo->netpoll;
82 np->real_dev = np->dev = to->dev;
83 to->dev->priv_flags |= IFF_IN_NETPOLL;
87 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
89 #ifdef CONFIG_NET_POLL_CONTROLLER
91 skb->dev->npinfo->netpoll->dev = br->dev;
95 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
97 struct net_device *indev;
99 if (skb_warn_if_lro(skb)) {
106 skb_forward_csum(skb);
108 NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
112 /* called with rcu_read_lock */
113 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
115 if (should_deliver(to, skb)) {
116 __br_deliver(to, skb);
123 /* called with rcu_read_lock */
124 void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
126 if (should_deliver(to, skb)) {
128 deliver_clone(to, skb, __br_forward);
130 __br_forward(to, skb);
138 static int deliver_clone(const struct net_bridge_port *prev,
140 void (*__packet_hook)(const struct net_bridge_port *p,
141 struct sk_buff *skb))
143 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
145 skb = skb_clone(skb, GFP_ATOMIC);
147 dev->stats.tx_dropped++;
151 __packet_hook(prev, skb);
155 static struct net_bridge_port *maybe_deliver(
156 struct net_bridge_port *prev, struct net_bridge_port *p,
158 void (*__packet_hook)(const struct net_bridge_port *p,
159 struct sk_buff *skb))
163 if (!should_deliver(p, skb))
169 err = deliver_clone(prev, skb, __packet_hook);
177 /* called under bridge lock */
178 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
179 struct sk_buff *skb0,
180 void (*__packet_hook)(const struct net_bridge_port *p,
181 struct sk_buff *skb))
183 struct net_bridge_port *p;
184 struct net_bridge_port *prev;
188 list_for_each_entry_rcu(p, &br->port_list, list) {
189 prev = maybe_deliver(prev, p, skb, __packet_hook);
198 deliver_clone(prev, skb, __packet_hook);
200 __packet_hook(prev, skb);
209 /* called with rcu_read_lock */
210 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb)
212 br_flood(br, skb, NULL, __br_deliver);
215 /* called under bridge lock */
216 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
217 struct sk_buff *skb2)
219 br_flood(br, skb, skb2, __br_forward);
222 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
223 /* called with rcu_read_lock */
224 static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
225 struct sk_buff *skb, struct sk_buff *skb0,
226 void (*__packet_hook)(
227 const struct net_bridge_port *p,
228 struct sk_buff *skb))
230 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
231 struct net_bridge *br = netdev_priv(dev);
232 struct net_bridge_port *prev = NULL;
233 struct net_bridge_port_group *p;
234 struct hlist_node *rp;
236 rp = rcu_dereference(br->router_list.first);
237 p = mdst ? rcu_dereference(mdst->ports) : NULL;
239 struct net_bridge_port *port, *lport, *rport;
241 lport = p ? p->port : NULL;
242 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
245 port = (unsigned long)lport > (unsigned long)rport ?
248 prev = maybe_deliver(prev, port, skb, __packet_hook);
252 if ((unsigned long)lport >= (unsigned long)port)
253 p = rcu_dereference(p->next);
254 if ((unsigned long)rport >= (unsigned long)port)
255 rp = rcu_dereference(rp->next);
262 deliver_clone(prev, skb, __packet_hook);
264 __packet_hook(prev, skb);
272 /* called with rcu_read_lock */
273 void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
276 br_multicast_flood(mdst, skb, NULL, __br_deliver);
279 /* called with rcu_read_lock */
280 void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
281 struct sk_buff *skb, struct sk_buff *skb2)
283 br_multicast_flood(mdst, skb, skb2, __br_forward);