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/skbuff.h>
19 #include <linux/if_vlan.h>
20 #include <linux/netfilter_bridge.h>
21 #include "br_private.h"
23 static int deliver_clone(const struct net_bridge_port *prev,
25 void (*__packet_hook)(const struct net_bridge_port *p,
26 struct sk_buff *skb));
28 /* Don't forward packets to originating port or forwarding diasabled */
29 static inline int should_deliver(const struct net_bridge_port *p,
30 const struct sk_buff *skb)
32 return (((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
33 p->state == BR_STATE_FORWARDING);
36 static inline unsigned packet_length(const struct sk_buff *skb)
38 return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
41 int br_dev_queue_push_xmit(struct sk_buff *skb)
43 /* drop mtu oversized packets except gso */
44 if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
47 /* ip_fragment doesn't copy the MAC header */
48 if (nf_bridge_maybe_copy_header(skb))
51 skb_push(skb, ETH_HLEN);
60 int br_forward_finish(struct sk_buff *skb)
62 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
63 br_dev_queue_push_xmit);
67 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
70 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
74 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
76 struct net_device *indev;
78 if (skb_warn_if_lro(skb)) {
85 skb_forward_csum(skb);
87 NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
91 /* called with rcu_read_lock */
92 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
94 if (should_deliver(to, skb)) {
95 __br_deliver(to, skb);
102 /* called with rcu_read_lock */
103 void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
105 if (should_deliver(to, skb)) {
107 deliver_clone(to, skb, __br_forward);
109 __br_forward(to, skb);
117 static int deliver_clone(const struct net_bridge_port *prev,
119 void (*__packet_hook)(const struct net_bridge_port *p,
120 struct sk_buff *skb))
122 skb = skb_clone(skb, GFP_ATOMIC);
124 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
126 dev->stats.tx_dropped++;
130 __packet_hook(prev, skb);
134 static struct net_bridge_port *maybe_deliver(
135 struct net_bridge_port *prev, struct net_bridge_port *p,
137 void (*__packet_hook)(const struct net_bridge_port *p,
138 struct sk_buff *skb))
142 if (!should_deliver(p, skb))
148 err = deliver_clone(prev, skb, __packet_hook);
156 /* called under bridge lock */
157 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
158 struct sk_buff *skb0,
159 void (*__packet_hook)(const struct net_bridge_port *p,
160 struct sk_buff *skb))
162 struct net_bridge_port *p;
163 struct net_bridge_port *prev;
167 list_for_each_entry_rcu(p, &br->port_list, list) {
168 prev = maybe_deliver(prev, p, skb, __packet_hook);
177 deliver_clone(prev, skb, __packet_hook);
179 __packet_hook(prev, skb);
188 /* called with rcu_read_lock */
189 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb)
191 br_flood(br, skb, NULL, __br_deliver);
194 /* called under bridge lock */
195 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
196 struct sk_buff *skb2)
198 br_flood(br, skb, skb2, __br_forward);
201 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
202 /* called with rcu_read_lock */
203 static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
204 struct sk_buff *skb, struct sk_buff *skb0,
205 void (*__packet_hook)(
206 const struct net_bridge_port *p,
207 struct sk_buff *skb))
209 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
210 struct net_bridge *br = netdev_priv(dev);
211 struct net_bridge_port *port;
212 struct net_bridge_port *lport, *rport;
213 struct net_bridge_port *prev;
214 struct net_bridge_port_group *p;
215 struct hlist_node *rp;
219 rp = br->router_list.first;
220 p = mdst ? mdst->ports : NULL;
222 lport = p ? p->port : NULL;
223 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
226 port = (unsigned long)lport > (unsigned long)rport ?
229 prev = maybe_deliver(prev, port, skb, __packet_hook);
233 if ((unsigned long)lport >= (unsigned long)port)
235 if ((unsigned long)rport >= (unsigned long)port)
243 deliver_clone(prev, skb, __packet_hook);
245 __packet_hook(prev, skb);
253 /* called with rcu_read_lock */
254 void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
257 br_multicast_flood(mdst, skb, NULL, __br_deliver);
260 /* called with rcu_read_lock */
261 void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
262 struct sk_buff *skb, struct sk_buff *skb2)
264 br_multicast_flood(mdst, skb, skb2, __br_forward);