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) &&
34 !br_skb_isolated(p, skb);
37 int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
39 if (!is_skb_forwardable(skb->dev, skb))
42 skb_push(skb, ETH_HLEN);
43 br_drop_fake_rtable(skb);
45 if (skb->ip_summed == CHECKSUM_PARTIAL &&
46 (skb->protocol == htons(ETH_P_8021Q) ||
47 skb->protocol == htons(ETH_P_8021AD))) {
50 if (!__vlan_get_protocol(skb, skb->protocol, &depth))
53 skb_set_network_header(skb, depth);
64 EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
66 int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
68 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
69 net, sk, skb, NULL, skb->dev,
70 br_dev_queue_push_xmit);
73 EXPORT_SYMBOL_GPL(br_forward_finish);
75 static void __br_forward(const struct net_bridge_port *to,
76 struct sk_buff *skb, bool local_orig)
78 struct net_bridge_vlan_group *vg;
79 struct net_device *indev;
83 vg = nbp_vlan_group_rcu(to);
84 skb = br_handle_vlan(to->br, to, vg, skb);
91 if (skb_warn_if_lro(skb)) {
95 br_hook = NF_BR_FORWARD;
96 skb_forward_csum(skb);
99 if (unlikely(netpoll_tx_running(to->br->dev))) {
100 if (!is_skb_forwardable(skb->dev, skb)) {
103 skb_push(skb, ETH_HLEN);
104 br_netpoll_send_skb(to, skb);
108 br_hook = NF_BR_LOCAL_OUT;
109 net = dev_net(skb->dev);
113 NF_HOOK(NFPROTO_BRIDGE, br_hook,
114 net, NULL, skb, indev, skb->dev,
118 static int deliver_clone(const struct net_bridge_port *prev,
119 struct sk_buff *skb, bool local_orig)
121 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
123 skb = skb_clone(skb, GFP_ATOMIC);
125 dev->stats.tx_dropped++;
129 __br_forward(prev, skb, local_orig);
134 * br_forward - forward a packet to a specific port
135 * @to: destination port
136 * @skb: packet being forwarded
137 * @local_rcv: packet will be received locally after forwarding
138 * @local_orig: packet is locally originated
140 * Should be called with rcu_read_lock.
142 void br_forward(const struct net_bridge_port *to,
143 struct sk_buff *skb, bool local_rcv, bool local_orig)
148 /* redirect to backup link if the destination port is down */
149 if (rcu_access_pointer(to->backup_port) && !netif_carrier_ok(to->dev)) {
150 struct net_bridge_port *backup_port;
152 backup_port = rcu_dereference(to->backup_port);
153 if (unlikely(!backup_port))
158 if (should_deliver(to, skb)) {
160 deliver_clone(to, skb, local_orig);
162 __br_forward(to, skb, local_orig);
170 EXPORT_SYMBOL_GPL(br_forward);
172 static struct net_bridge_port *maybe_deliver(
173 struct net_bridge_port *prev, struct net_bridge_port *p,
174 struct sk_buff *skb, bool local_orig)
178 if (!should_deliver(p, skb))
184 err = deliver_clone(prev, skb, local_orig);
192 /* called under rcu_read_lock */
193 void br_flood(struct net_bridge *br, struct sk_buff *skb,
194 enum br_pkt_type pkt_type, bool local_rcv, bool local_orig)
196 u8 igmp_type = br_multicast_igmp_type(skb);
197 struct net_bridge_port *prev = NULL;
198 struct net_bridge_port *p;
200 list_for_each_entry_rcu(p, &br->port_list, list) {
201 /* Do not flood unicast traffic to ports that turn it off, nor
202 * other traffic if flood off, except for traffic we originate
206 if (!(p->flags & BR_FLOOD))
209 case BR_PKT_MULTICAST:
210 if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev)
213 case BR_PKT_BROADCAST:
214 if (!(p->flags & BR_BCAST_FLOOD) && skb->dev != br->dev)
219 /* Do not flood to ports that enable proxy ARP */
220 if (p->flags & BR_PROXYARP)
222 if ((p->flags & (BR_PROXYARP_WIFI | BR_NEIGH_SUPPRESS)) &&
223 BR_INPUT_SKB_CB(skb)->proxyarp_replied)
226 prev = maybe_deliver(prev, p, skb, local_orig);
230 br_multicast_count(p->br, p, skb, igmp_type,
238 deliver_clone(prev, skb, local_orig);
240 __br_forward(prev, skb, local_orig);
248 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
249 static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb,
250 const unsigned char *addr, bool local_orig)
252 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
253 const unsigned char *src = eth_hdr(skb)->h_source;
255 if (!should_deliver(p, skb))
258 /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
259 if (skb->dev == p->dev && ether_addr_equal(src, addr))
262 skb = skb_copy(skb, GFP_ATOMIC);
264 dev->stats.tx_dropped++;
268 if (!is_broadcast_ether_addr(addr))
269 memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
271 __br_forward(p, skb, local_orig);
274 /* called with rcu_read_lock */
275 void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
277 bool local_rcv, bool local_orig)
279 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
280 u8 igmp_type = br_multicast_igmp_type(skb);
281 struct net_bridge *br = netdev_priv(dev);
282 struct net_bridge_port *prev = NULL;
283 struct net_bridge_port_group *p;
284 struct hlist_node *rp;
286 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
287 p = mdst ? rcu_dereference(mdst->ports) : NULL;
289 struct net_bridge_port *port, *lport, *rport;
291 lport = p ? p->port : NULL;
292 rport = hlist_entry_safe(rp, struct net_bridge_port, rlist);
294 if ((unsigned long)lport > (unsigned long)rport) {
297 if (port->flags & BR_MULTICAST_TO_UNICAST) {
298 maybe_deliver_addr(lport, skb, p->eth_addr,
306 prev = maybe_deliver(prev, port, skb, local_orig);
311 br_multicast_count(port->br, port, skb, igmp_type,
314 if ((unsigned long)lport >= (unsigned long)port)
315 p = rcu_dereference(p->next);
316 if ((unsigned long)rport >= (unsigned long)port)
317 rp = rcu_dereference(hlist_next_rcu(rp));
324 deliver_clone(prev, skb, local_orig);
326 __br_forward(prev, skb, local_orig);