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 /* Don't forward packets to originating port or forwarding disabled */
25 static inline int should_deliver(const struct net_bridge_port *p,
26 const struct sk_buff *skb)
28 struct net_bridge_vlan_group *vg;
30 vg = nbp_vlan_group_rcu(p);
31 return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
32 br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING &&
33 nbp_switchdev_allowed_egress(p, skb);
36 int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
38 skb_push(skb, ETH_HLEN);
39 if (!is_skb_forwardable(skb->dev, skb))
42 br_drop_fake_rtable(skb);
44 if (skb->ip_summed == CHECKSUM_PARTIAL &&
45 (skb->protocol == htons(ETH_P_8021Q) ||
46 skb->protocol == htons(ETH_P_8021AD))) {
49 if (!__vlan_get_protocol(skb, skb->protocol, &depth))
52 skb_set_network_header(skb, depth);
63 EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
65 int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
67 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
68 net, sk, skb, NULL, skb->dev,
69 br_dev_queue_push_xmit);
72 EXPORT_SYMBOL_GPL(br_forward_finish);
74 static void __br_forward(const struct net_bridge_port *to,
75 struct sk_buff *skb, bool local_orig)
77 struct net_bridge_vlan_group *vg;
78 struct net_device *indev;
82 vg = nbp_vlan_group_rcu(to);
83 skb = br_handle_vlan(to->br, to, vg, skb);
90 if (skb_warn_if_lro(skb)) {
94 br_hook = NF_BR_FORWARD;
95 skb_forward_csum(skb);
98 if (unlikely(netpoll_tx_running(to->br->dev))) {
99 skb_push(skb, ETH_HLEN);
100 if (!is_skb_forwardable(skb->dev, skb))
103 br_netpoll_send_skb(to, skb);
106 br_hook = NF_BR_LOCAL_OUT;
107 net = dev_net(skb->dev);
111 NF_HOOK(NFPROTO_BRIDGE, br_hook,
112 net, NULL, skb, indev, skb->dev,
116 static int deliver_clone(const struct net_bridge_port *prev,
117 struct sk_buff *skb, bool local_orig)
119 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
121 skb = skb_clone(skb, GFP_ATOMIC);
123 dev->stats.tx_dropped++;
127 __br_forward(prev, skb, local_orig);
132 * br_forward - forward a packet to a specific port
133 * @to: destination port
134 * @skb: packet being forwarded
135 * @local_rcv: packet will be received locally after forwarding
136 * @local_orig: packet is locally originated
138 * Should be called with rcu_read_lock.
140 void br_forward(const struct net_bridge_port *to,
141 struct sk_buff *skb, bool local_rcv, bool local_orig)
143 if (to && should_deliver(to, skb)) {
145 deliver_clone(to, skb, local_orig);
147 __br_forward(to, skb, local_orig);
154 EXPORT_SYMBOL_GPL(br_forward);
156 static struct net_bridge_port *maybe_deliver(
157 struct net_bridge_port *prev, struct net_bridge_port *p,
158 struct sk_buff *skb, bool local_orig)
162 if (!should_deliver(p, skb))
168 err = deliver_clone(prev, skb, local_orig);
176 /* called under rcu_read_lock */
177 void br_flood(struct net_bridge *br, struct sk_buff *skb,
178 enum br_pkt_type pkt_type, bool local_rcv, bool local_orig)
180 u8 igmp_type = br_multicast_igmp_type(skb);
181 struct net_bridge_port *prev = NULL;
182 struct net_bridge_port *p;
184 list_for_each_entry_rcu(p, &br->port_list, list) {
185 /* Do not flood unicast traffic to ports that turn it off, nor
186 * other traffic if flood off, except for traffic we originate
190 if (!(p->flags & BR_FLOOD))
193 case BR_PKT_MULTICAST:
194 if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev)
197 case BR_PKT_BROADCAST:
198 if (!(p->flags & BR_BCAST_FLOOD) && skb->dev != br->dev)
203 /* Do not flood to ports that enable proxy ARP */
204 if (p->flags & BR_PROXYARP)
206 if ((p->flags & BR_PROXYARP_WIFI) &&
207 BR_INPUT_SKB_CB(skb)->proxyarp_replied)
210 prev = maybe_deliver(prev, p, skb, local_orig);
214 br_multicast_count(p->br, p, skb, igmp_type,
222 deliver_clone(prev, skb, local_orig);
224 __br_forward(prev, skb, local_orig);
232 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
233 static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb,
234 const unsigned char *addr, bool local_orig)
236 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
237 const unsigned char *src = eth_hdr(skb)->h_source;
239 if (!should_deliver(p, skb))
242 /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
243 if (skb->dev == p->dev && ether_addr_equal(src, addr))
246 skb = skb_copy(skb, GFP_ATOMIC);
248 dev->stats.tx_dropped++;
252 if (!is_broadcast_ether_addr(addr))
253 memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
255 __br_forward(p, skb, local_orig);
258 /* called with rcu_read_lock */
259 void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
261 bool local_rcv, bool local_orig)
263 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
264 u8 igmp_type = br_multicast_igmp_type(skb);
265 struct net_bridge *br = netdev_priv(dev);
266 struct net_bridge_port *prev = NULL;
267 struct net_bridge_port_group *p;
268 struct hlist_node *rp;
270 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
271 p = mdst ? rcu_dereference(mdst->ports) : NULL;
273 struct net_bridge_port *port, *lport, *rport;
275 lport = p ? p->port : NULL;
276 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
279 if ((unsigned long)lport > (unsigned long)rport) {
282 if (port->flags & BR_MULTICAST_TO_UNICAST) {
283 maybe_deliver_addr(lport, skb, p->eth_addr,
291 prev = maybe_deliver(prev, port, skb, local_orig);
296 br_multicast_count(port->br, port, skb, igmp_type,
299 if ((unsigned long)lport >= (unsigned long)port)
300 p = rcu_dereference(p->next);
301 if ((unsigned long)rport >= (unsigned long)port)
302 rp = rcu_dereference(hlist_next_rcu(rp));
309 deliver_clone(prev, skb, local_orig);
311 __br_forward(prev, skb, local_orig);