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)
69 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
70 net, sk, skb, NULL, skb->dev,
71 br_dev_queue_push_xmit);
74 EXPORT_SYMBOL_GPL(br_forward_finish);
76 static void __br_forward(const struct net_bridge_port *to,
77 struct sk_buff *skb, bool local_orig)
79 struct net_bridge_vlan_group *vg;
80 struct net_device *indev;
84 vg = nbp_vlan_group_rcu(to);
85 skb = br_handle_vlan(to->br, to, vg, skb);
92 if (skb_warn_if_lro(skb)) {
96 br_hook = NF_BR_FORWARD;
97 skb_forward_csum(skb);
100 if (unlikely(netpoll_tx_running(to->br->dev))) {
101 if (!is_skb_forwardable(skb->dev, skb)) {
104 skb_push(skb, ETH_HLEN);
105 br_netpoll_send_skb(to, skb);
109 br_hook = NF_BR_LOCAL_OUT;
110 net = dev_net(skb->dev);
114 NF_HOOK(NFPROTO_BRIDGE, br_hook,
115 net, NULL, skb, indev, skb->dev,
119 static int deliver_clone(const struct net_bridge_port *prev,
120 struct sk_buff *skb, bool local_orig)
122 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
124 skb = skb_clone(skb, GFP_ATOMIC);
126 dev->stats.tx_dropped++;
130 __br_forward(prev, skb, local_orig);
135 * br_forward - forward a packet to a specific port
136 * @to: destination port
137 * @skb: packet being forwarded
138 * @local_rcv: packet will be received locally after forwarding
139 * @local_orig: packet is locally originated
141 * Should be called with rcu_read_lock.
143 void br_forward(const struct net_bridge_port *to,
144 struct sk_buff *skb, bool local_rcv, bool local_orig)
149 /* redirect to backup link if the destination port is down */
150 if (rcu_access_pointer(to->backup_port) && !netif_carrier_ok(to->dev)) {
151 struct net_bridge_port *backup_port;
153 backup_port = rcu_dereference(to->backup_port);
154 if (unlikely(!backup_port))
159 if (should_deliver(to, skb)) {
161 deliver_clone(to, skb, local_orig);
163 __br_forward(to, skb, local_orig);
171 EXPORT_SYMBOL_GPL(br_forward);
173 static struct net_bridge_port *maybe_deliver(
174 struct net_bridge_port *prev, struct net_bridge_port *p,
175 struct sk_buff *skb, bool local_orig)
179 if (!should_deliver(p, skb))
185 err = deliver_clone(prev, skb, local_orig);
193 /* called under rcu_read_lock */
194 void br_flood(struct net_bridge *br, struct sk_buff *skb,
195 enum br_pkt_type pkt_type, bool local_rcv, bool local_orig)
197 u8 igmp_type = br_multicast_igmp_type(skb);
198 struct net_bridge_port *prev = NULL;
199 struct net_bridge_port *p;
201 list_for_each_entry_rcu(p, &br->port_list, list) {
202 /* Do not flood unicast traffic to ports that turn it off, nor
203 * other traffic if flood off, except for traffic we originate
207 if (!(p->flags & BR_FLOOD))
210 case BR_PKT_MULTICAST:
211 if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev)
214 case BR_PKT_BROADCAST:
215 if (!(p->flags & BR_BCAST_FLOOD) && skb->dev != br->dev)
220 /* Do not flood to ports that enable proxy ARP */
221 if (p->flags & BR_PROXYARP)
223 if ((p->flags & (BR_PROXYARP_WIFI | BR_NEIGH_SUPPRESS)) &&
224 BR_INPUT_SKB_CB(skb)->proxyarp_replied)
227 prev = maybe_deliver(prev, p, skb, local_orig);
231 br_multicast_count(p->br, p, skb, igmp_type,
239 deliver_clone(prev, skb, local_orig);
241 __br_forward(prev, skb, local_orig);
249 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
250 static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb,
251 const unsigned char *addr, bool local_orig)
253 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
254 const unsigned char *src = eth_hdr(skb)->h_source;
256 if (!should_deliver(p, skb))
259 /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
260 if (skb->dev == p->dev && ether_addr_equal(src, addr))
263 skb = skb_copy(skb, GFP_ATOMIC);
265 dev->stats.tx_dropped++;
269 if (!is_broadcast_ether_addr(addr))
270 memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
272 __br_forward(p, skb, local_orig);
275 /* called with rcu_read_lock */
276 void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
278 bool local_rcv, bool local_orig)
280 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
281 u8 igmp_type = br_multicast_igmp_type(skb);
282 struct net_bridge *br = netdev_priv(dev);
283 struct net_bridge_port *prev = NULL;
284 struct net_bridge_port_group *p;
285 struct hlist_node *rp;
287 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
288 p = mdst ? rcu_dereference(mdst->ports) : NULL;
290 struct net_bridge_port *port, *lport, *rport;
292 lport = p ? p->port : NULL;
293 rport = hlist_entry_safe(rp, struct net_bridge_port, rlist);
295 if ((unsigned long)lport > (unsigned long)rport) {
298 if (port->flags & BR_MULTICAST_TO_UNICAST) {
299 maybe_deliver_addr(lport, skb, p->eth_addr,
307 prev = maybe_deliver(prev, port, skb, local_orig);
312 br_multicast_count(port->br, port, skb, igmp_type,
315 if ((unsigned long)lport >= (unsigned long)port)
316 p = rcu_dereference(p->next);
317 if ((unsigned long)rport >= (unsigned long)port)
318 rp = rcu_dereference(hlist_next_rcu(rp));
325 deliver_clone(prev, skb, local_orig);
327 __br_forward(prev, skb, local_orig);