1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Linux ethernet bridge
7 * Lennert Buytenhek <buytenh@gnu.org>
10 #include <linux/err.h>
11 #include <linux/slab.h>
12 #include <linux/kernel.h>
13 #include <linux/netdevice.h>
14 #include <linux/netpoll.h>
15 #include <linux/skbuff.h>
16 #include <linux/if_vlan.h>
17 #include <linux/netfilter_bridge.h>
18 #include "br_private.h"
20 /* Don't forward packets to originating port or forwarding disabled */
21 static inline int should_deliver(const struct net_bridge_port *p,
22 const struct sk_buff *skb)
24 struct net_bridge_vlan_group *vg;
26 vg = nbp_vlan_group_rcu(p);
27 return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
28 p->state == BR_STATE_FORWARDING && br_allowed_egress(vg, skb) &&
29 nbp_switchdev_allowed_egress(p, skb) &&
30 !br_skb_isolated(p, skb);
33 int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
35 skb_push(skb, ETH_HLEN);
36 if (!is_skb_forwardable(skb->dev, skb))
39 br_drop_fake_rtable(skb);
41 if (skb->ip_summed == CHECKSUM_PARTIAL &&
42 (skb->protocol == htons(ETH_P_8021Q) ||
43 skb->protocol == htons(ETH_P_8021AD))) {
46 if (!__vlan_get_protocol(skb, skb->protocol, &depth))
49 skb_set_network_header(skb, depth);
60 EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
62 int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
65 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
66 net, sk, skb, NULL, skb->dev,
67 br_dev_queue_push_xmit);
70 EXPORT_SYMBOL_GPL(br_forward_finish);
72 static void __br_forward(const struct net_bridge_port *to,
73 struct sk_buff *skb, bool local_orig)
75 struct net_bridge_vlan_group *vg;
76 struct net_device *indev;
80 vg = nbp_vlan_group_rcu(to);
81 skb = br_handle_vlan(to->br, to, vg, skb);
88 if (skb_warn_if_lro(skb)) {
92 br_hook = NF_BR_FORWARD;
93 skb_forward_csum(skb);
96 if (unlikely(netpoll_tx_running(to->br->dev))) {
97 skb_push(skb, ETH_HLEN);
98 if (!is_skb_forwardable(skb->dev, skb))
101 br_netpoll_send_skb(to, skb);
104 br_hook = NF_BR_LOCAL_OUT;
105 net = dev_net(skb->dev);
109 NF_HOOK(NFPROTO_BRIDGE, br_hook,
110 net, NULL, skb, indev, skb->dev,
114 static int deliver_clone(const struct net_bridge_port *prev,
115 struct sk_buff *skb, bool local_orig)
117 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
119 skb = skb_clone(skb, GFP_ATOMIC);
121 dev->stats.tx_dropped++;
125 __br_forward(prev, skb, local_orig);
130 * br_forward - forward a packet to a specific port
131 * @to: destination port
132 * @skb: packet being forwarded
133 * @local_rcv: packet will be received locally after forwarding
134 * @local_orig: packet is locally originated
136 * Should be called with rcu_read_lock.
138 void br_forward(const struct net_bridge_port *to,
139 struct sk_buff *skb, bool local_rcv, bool local_orig)
144 /* redirect to backup link if the destination port is down */
145 if (rcu_access_pointer(to->backup_port) && !netif_carrier_ok(to->dev)) {
146 struct net_bridge_port *backup_port;
148 backup_port = rcu_dereference(to->backup_port);
149 if (unlikely(!backup_port))
154 if (should_deliver(to, skb)) {
156 deliver_clone(to, skb, local_orig);
158 __br_forward(to, skb, local_orig);
166 EXPORT_SYMBOL_GPL(br_forward);
168 static struct net_bridge_port *maybe_deliver(
169 struct net_bridge_port *prev, struct net_bridge_port *p,
170 struct sk_buff *skb, bool local_orig)
172 u8 igmp_type = br_multicast_igmp_type(skb);
175 if (!should_deliver(p, skb))
181 err = deliver_clone(prev, skb, local_orig);
185 br_multicast_count(p->br, p, skb, igmp_type, BR_MCAST_DIR_TX);
190 /* called under rcu_read_lock */
191 void br_flood(struct net_bridge *br, struct sk_buff *skb,
192 enum br_pkt_type pkt_type, bool local_rcv, bool local_orig)
194 struct net_bridge_port *prev = NULL;
195 struct net_bridge_port *p;
197 list_for_each_entry_rcu(p, &br->port_list, list) {
198 /* Do not flood unicast traffic to ports that turn it off, nor
199 * other traffic if flood off, except for traffic we originate
203 if (!(p->flags & BR_FLOOD))
206 case BR_PKT_MULTICAST:
207 if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev)
210 case BR_PKT_BROADCAST:
211 if (!(p->flags & BR_BCAST_FLOOD) && skb->dev != br->dev)
216 /* Do not flood to ports that enable proxy ARP */
217 if (p->flags & BR_PROXYARP)
219 if ((p->flags & (BR_PROXYARP_WIFI | BR_NEIGH_SUPPRESS)) &&
220 BR_INPUT_SKB_CB(skb)->proxyarp_replied)
223 prev = maybe_deliver(prev, p, skb, local_orig);
232 deliver_clone(prev, skb, local_orig);
234 __br_forward(prev, skb, local_orig);
242 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
243 static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb,
244 const unsigned char *addr, bool local_orig)
246 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
247 const unsigned char *src = eth_hdr(skb)->h_source;
249 if (!should_deliver(p, skb))
252 /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
253 if (skb->dev == p->dev && ether_addr_equal(src, addr))
256 skb = skb_copy(skb, GFP_ATOMIC);
258 dev->stats.tx_dropped++;
262 if (!is_broadcast_ether_addr(addr))
263 memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
265 __br_forward(p, skb, local_orig);
268 /* called with rcu_read_lock */
269 void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
271 bool local_rcv, bool local_orig)
273 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
274 struct net_bridge *br = netdev_priv(dev);
275 struct net_bridge_port *prev = NULL;
276 struct net_bridge_port_group *p;
277 struct hlist_node *rp;
279 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
280 p = mdst ? rcu_dereference(mdst->ports) : NULL;
282 struct net_bridge_port *port, *lport, *rport;
284 lport = p ? p->port : NULL;
285 rport = hlist_entry_safe(rp, struct net_bridge_port, rlist);
287 if ((unsigned long)lport > (unsigned long)rport) {
290 if (port->flags & BR_MULTICAST_TO_UNICAST) {
291 maybe_deliver_addr(lport, skb, p->eth_addr,
299 prev = maybe_deliver(prev, port, skb, local_orig);
303 if ((unsigned long)lport >= (unsigned long)port)
304 p = rcu_dereference(p->next);
305 if ((unsigned long)rport >= (unsigned long)port)
306 rp = rcu_dereference(hlist_next_rcu(rp));
313 deliver_clone(prev, skb, local_orig);
315 __br_forward(prev, skb, local_orig);