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 if (!is_skb_forwardable(skb->dev, skb))
41 skb_push(skb, ETH_HLEN);
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 if (!is_skb_forwardable(skb->dev, skb)) {
102 skb_push(skb, ETH_HLEN);
103 br_netpoll_send_skb(to, skb);
107 br_hook = NF_BR_LOCAL_OUT;
108 net = dev_net(skb->dev);
112 NF_HOOK(NFPROTO_BRIDGE, br_hook,
113 net, NULL, skb, indev, skb->dev,
117 static int deliver_clone(const struct net_bridge_port *prev,
118 struct sk_buff *skb, bool local_orig)
120 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
122 skb = skb_clone(skb, GFP_ATOMIC);
124 dev->stats.tx_dropped++;
128 __br_forward(prev, skb, local_orig);
133 * br_forward - forward a packet to a specific port
134 * @to: destination port
135 * @skb: packet being forwarded
136 * @local_rcv: packet will be received locally after forwarding
137 * @local_orig: packet is locally originated
139 * Should be called with rcu_read_lock.
141 void br_forward(const struct net_bridge_port *to,
142 struct sk_buff *skb, bool local_rcv, bool local_orig)
144 if (to && should_deliver(to, skb)) {
146 deliver_clone(to, skb, local_orig);
148 __br_forward(to, skb, local_orig);
155 EXPORT_SYMBOL_GPL(br_forward);
157 static struct net_bridge_port *maybe_deliver(
158 struct net_bridge_port *prev, struct net_bridge_port *p,
159 struct sk_buff *skb, bool local_orig)
163 if (!should_deliver(p, skb))
169 err = deliver_clone(prev, skb, local_orig);
177 /* called under rcu_read_lock */
178 void br_flood(struct net_bridge *br, struct sk_buff *skb,
179 enum br_pkt_type pkt_type, bool local_rcv, bool local_orig)
181 u8 igmp_type = br_multicast_igmp_type(skb);
182 struct net_bridge_port *prev = NULL;
183 struct net_bridge_port *p;
185 list_for_each_entry_rcu(p, &br->port_list, list) {
186 /* Do not flood unicast traffic to ports that turn it off */
187 if (pkt_type == BR_PKT_UNICAST && !(p->flags & BR_FLOOD))
189 if (pkt_type == BR_PKT_MULTICAST &&
190 !(p->flags & BR_MCAST_FLOOD))
193 /* Do not flood to ports that enable proxy ARP */
194 if (p->flags & BR_PROXYARP)
196 if ((p->flags & BR_PROXYARP_WIFI) &&
197 BR_INPUT_SKB_CB(skb)->proxyarp_replied)
200 prev = maybe_deliver(prev, p, skb, local_orig);
204 br_multicast_count(p->br, p, skb, igmp_type,
212 deliver_clone(prev, skb, local_orig);
214 __br_forward(prev, skb, local_orig);
222 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
223 static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb,
224 const unsigned char *addr, bool local_orig)
226 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
227 const unsigned char *src = eth_hdr(skb)->h_source;
229 if (!should_deliver(p, skb))
232 /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
233 if (skb->dev == p->dev && ether_addr_equal(src, addr))
236 skb = skb_copy(skb, GFP_ATOMIC);
238 dev->stats.tx_dropped++;
242 if (!is_broadcast_ether_addr(addr))
243 memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
245 __br_forward(p, skb, local_orig);
248 /* called with rcu_read_lock */
249 void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
251 bool local_rcv, bool local_orig)
253 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
254 u8 igmp_type = br_multicast_igmp_type(skb);
255 struct net_bridge *br = netdev_priv(dev);
256 struct net_bridge_port *prev = NULL;
257 struct net_bridge_port_group *p;
258 struct hlist_node *rp;
260 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
261 p = mdst ? rcu_dereference(mdst->ports) : NULL;
263 struct net_bridge_port *port, *lport, *rport;
265 lport = p ? p->port : NULL;
266 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
269 if ((unsigned long)lport > (unsigned long)rport) {
272 if (port->flags & BR_MULTICAST_TO_UNICAST) {
273 maybe_deliver_addr(lport, skb, p->eth_addr,
281 prev = maybe_deliver(prev, port, skb, local_orig);
286 br_multicast_count(port->br, port, skb, igmp_type,
289 if ((unsigned long)lport >= (unsigned long)port)
290 p = rcu_dereference(p->next);
291 if ((unsigned long)rport >= (unsigned long)port)
292 rp = rcu_dereference(hlist_next_rcu(rp));
299 deliver_clone(prev, skb, local_orig);
301 __br_forward(prev, skb, local_orig);