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 /* ip_fragment doesn't copy the MAC header */
45 if (nf_bridge_maybe_copy_header(skb) ||
46 (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))) {
49 skb_push(skb, ETH_HLEN);
56 int br_forward_finish(struct sk_buff *skb)
58 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
59 br_dev_queue_push_xmit);
63 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
67 if (unlikely(netpoll_tx_running(to->dev))) {
68 if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
71 skb_push(skb, ETH_HLEN);
72 br_netpoll_send_skb(to, skb);
77 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
81 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
83 struct net_device *indev;
85 if (skb_warn_if_lro(skb)) {
92 skb_forward_csum(skb);
94 NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
98 /* called with rcu_read_lock */
99 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
101 if (to && should_deliver(to, skb)) {
102 __br_deliver(to, skb);
109 /* called with rcu_read_lock */
110 void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
112 if (should_deliver(to, skb)) {
114 deliver_clone(to, skb, __br_forward);
116 __br_forward(to, skb);
124 static int deliver_clone(const struct net_bridge_port *prev,
126 void (*__packet_hook)(const struct net_bridge_port *p,
127 struct sk_buff *skb))
129 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
131 skb = skb_clone(skb, GFP_ATOMIC);
133 dev->stats.tx_dropped++;
137 __packet_hook(prev, skb);
141 static struct net_bridge_port *maybe_deliver(
142 struct net_bridge_port *prev, struct net_bridge_port *p,
144 void (*__packet_hook)(const struct net_bridge_port *p,
145 struct sk_buff *skb))
149 if (!should_deliver(p, skb))
155 err = deliver_clone(prev, skb, __packet_hook);
163 /* called under bridge lock */
164 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
165 struct sk_buff *skb0,
166 void (*__packet_hook)(const struct net_bridge_port *p,
167 struct sk_buff *skb))
169 struct net_bridge_port *p;
170 struct net_bridge_port *prev;
174 list_for_each_entry_rcu(p, &br->port_list, list) {
175 prev = maybe_deliver(prev, p, skb, __packet_hook);
184 deliver_clone(prev, skb, __packet_hook);
186 __packet_hook(prev, skb);
195 /* called with rcu_read_lock */
196 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb)
198 br_flood(br, skb, NULL, __br_deliver);
201 /* called under bridge lock */
202 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
203 struct sk_buff *skb2)
205 br_flood(br, skb, skb2, __br_forward);
208 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
209 /* called with rcu_read_lock */
210 static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
211 struct sk_buff *skb, struct sk_buff *skb0,
212 void (*__packet_hook)(
213 const struct net_bridge_port *p,
214 struct sk_buff *skb))
216 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
217 struct net_bridge *br = netdev_priv(dev);
218 struct net_bridge_port *prev = NULL;
219 struct net_bridge_port_group *p;
220 struct hlist_node *rp;
222 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
223 p = mdst ? rcu_dereference(mdst->ports) : NULL;
225 struct net_bridge_port *port, *lport, *rport;
227 lport = p ? p->port : NULL;
228 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
231 port = (unsigned long)lport > (unsigned long)rport ?
234 prev = maybe_deliver(prev, port, skb, __packet_hook);
238 if ((unsigned long)lport >= (unsigned long)port)
239 p = rcu_dereference(p->next);
240 if ((unsigned long)rport >= (unsigned long)port)
241 rp = rcu_dereference(hlist_next_rcu(rp));
248 deliver_clone(prev, skb, __packet_hook);
250 __packet_hook(prev, skb);
258 /* called with rcu_read_lock */
259 void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
262 br_multicast_flood(mdst, skb, NULL, __br_deliver);
265 /* called with rcu_read_lock */
266 void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
267 struct sk_buff *skb, struct sk_buff *skb2)
269 br_multicast_flood(mdst, skb, skb2, __br_forward);