1/*
2 *	Device handling code
3 *	Linux ethernet bridge
4 *
5 *	Authors:
6 *	Lennert Buytenhek		<buytenh@gnu.org>
7 *
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.
12 */
13
14#include <linux/kernel.h>
15#include <linux/netdevice.h>
16#include <linux/netpoll.h>
17#include <linux/etherdevice.h>
18#include <linux/ethtool.h>
19#include <linux/list.h>
20#include <linux/netfilter_bridge.h>
21
22#include <asm/uaccess.h>
23#include "br_private.h"
24
25#define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \
26			 NETIF_F_GSO_MASK | NETIF_F_HW_CSUM)
27
28const struct nf_br_ops __rcu *nf_br_ops __read_mostly;
29EXPORT_SYMBOL_GPL(nf_br_ops);
30
31static struct lock_class_key bridge_netdev_addr_lock_key;
32
33/* net device transmit always called with BH disabled */
34netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
35{
36	struct net_bridge *br = netdev_priv(dev);
37	const unsigned char *dest = skb->data;
38	struct net_bridge_fdb_entry *dst;
39	struct net_bridge_mdb_entry *mdst;
40	struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);
41	const struct nf_br_ops *nf_ops;
42	u16 vid = 0;
43
44	rcu_read_lock();
45	nf_ops = rcu_dereference(nf_br_ops);
46	if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
47		rcu_read_unlock();
48		return NETDEV_TX_OK;
49	}
50
51	u64_stats_update_begin(&brstats->syncp);
52	brstats->tx_packets++;
53	brstats->tx_bytes += skb->len;
54	u64_stats_update_end(&brstats->syncp);
55
56	BR_INPUT_SKB_CB(skb)->brdev = dev;
57
58	skb_reset_mac_header(skb);
59	skb_pull(skb, ETH_HLEN);
60
61	if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid))
62		goto out;
63
64	if (is_broadcast_ether_addr(dest))
65		br_flood_deliver(br, skb, false);
66	else if (is_multicast_ether_addr(dest)) {
67		if (unlikely(netpoll_tx_running(dev))) {
68			br_flood_deliver(br, skb, false);
69			goto out;
70		}
71		if (br_multicast_rcv(br, NULL, skb, vid)) {
72			kfree_skb(skb);
73			goto out;
74		}
75
76		mdst = br_mdb_get(br, skb, vid);
77		if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
78		    br_multicast_querier_exists(br, eth_hdr(skb)))
79			br_multicast_deliver(mdst, skb);
80		else
81			br_flood_deliver(br, skb, false);
82	} else if ((dst = __br_fdb_get(br, dest, vid)) != NULL)
83		br_deliver(dst->dst, skb);
84	else
85		br_flood_deliver(br, skb, true);
86
87out:
88	rcu_read_unlock();
89	return NETDEV_TX_OK;
90}
91
92static void br_set_lockdep_class(struct net_device *dev)
93{
94	lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key);
95}
96
97static int br_dev_init(struct net_device *dev)
98{
99	struct net_bridge *br = netdev_priv(dev);
100	int err;
101
102	br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
103	if (!br->stats)
104		return -ENOMEM;
105
106	err = br_vlan_init(br);
107	if (err)
108		free_percpu(br->stats);
109	br_set_lockdep_class(dev);
110
111	return err;
112}
113
114static int br_dev_open(struct net_device *dev)
115{
116	struct net_bridge *br = netdev_priv(dev);
117
118	netdev_update_features(dev);
119	netif_start_queue(dev);
120	br_stp_enable_bridge(br);
121	br_multicast_open(br);
122
123	return 0;
124}
125
126static void br_dev_set_multicast_list(struct net_device *dev)
127{
128}
129
130static void br_dev_change_rx_flags(struct net_device *dev, int change)
131{
132	if (change & IFF_PROMISC)
133		br_manage_promisc(netdev_priv(dev));
134}
135
136static int br_dev_stop(struct net_device *dev)
137{
138	struct net_bridge *br = netdev_priv(dev);
139
140	br_stp_disable_bridge(br);
141	br_multicast_stop(br);
142
143	netif_stop_queue(dev);
144
145	return 0;
146}
147
148static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
149						struct rtnl_link_stats64 *stats)
150{
151	struct net_bridge *br = netdev_priv(dev);
152	struct pcpu_sw_netstats tmp, sum = { 0 };
153	unsigned int cpu;
154
155	for_each_possible_cpu(cpu) {
156		unsigned int start;
157		const struct pcpu_sw_netstats *bstats
158			= per_cpu_ptr(br->stats, cpu);
159		do {
160			start = u64_stats_fetch_begin_irq(&bstats->syncp);
161			memcpy(&tmp, bstats, sizeof(tmp));
162		} while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
163		sum.tx_bytes   += tmp.tx_bytes;
164		sum.tx_packets += tmp.tx_packets;
165		sum.rx_bytes   += tmp.rx_bytes;
166		sum.rx_packets += tmp.rx_packets;
167	}
168
169	stats->tx_bytes   = sum.tx_bytes;
170	stats->tx_packets = sum.tx_packets;
171	stats->rx_bytes   = sum.rx_bytes;
172	stats->rx_packets = sum.rx_packets;
173
174	return stats;
175}
176
177static int br_change_mtu(struct net_device *dev, int new_mtu)
178{
179	struct net_bridge *br = netdev_priv(dev);
180	if (new_mtu < 68 || new_mtu > br_min_mtu(br))
181		return -EINVAL;
182
183	dev->mtu = new_mtu;
184
185#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
186	/* remember the MTU in the rtable for PMTU */
187	dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
188#endif
189
190	return 0;
191}
192
193/* Allow setting mac address to any valid ethernet address. */
194static int br_set_mac_address(struct net_device *dev, void *p)
195{
196	struct net_bridge *br = netdev_priv(dev);
197	struct sockaddr *addr = p;
198
199	if (!is_valid_ether_addr(addr->sa_data))
200		return -EADDRNOTAVAIL;
201
202	spin_lock_bh(&br->lock);
203	if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
204		/* Mac address will be changed in br_stp_change_bridge_id(). */
205		br_stp_change_bridge_id(br, addr->sa_data);
206	}
207	spin_unlock_bh(&br->lock);
208
209	return 0;
210}
211
212static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
213{
214	strlcpy(info->driver, "bridge", sizeof(info->driver));
215	strlcpy(info->version, BR_VERSION, sizeof(info->version));
216	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
217	strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
218}
219
220static netdev_features_t br_fix_features(struct net_device *dev,
221	netdev_features_t features)
222{
223	struct net_bridge *br = netdev_priv(dev);
224
225	return br_features_recompute(br, features);
226}
227
228#ifdef CONFIG_NET_POLL_CONTROLLER
229static void br_poll_controller(struct net_device *br_dev)
230{
231}
232
233static void br_netpoll_cleanup(struct net_device *dev)
234{
235	struct net_bridge *br = netdev_priv(dev);
236	struct net_bridge_port *p;
237
238	list_for_each_entry(p, &br->port_list, list)
239		br_netpoll_disable(p);
240}
241
242static int __br_netpoll_enable(struct net_bridge_port *p)
243{
244	struct netpoll *np;
245	int err;
246
247	np = kzalloc(sizeof(*p->np), GFP_KERNEL);
248	if (!np)
249		return -ENOMEM;
250
251	err = __netpoll_setup(np, p->dev);
252	if (err) {
253		kfree(np);
254		return err;
255	}
256
257	p->np = np;
258	return err;
259}
260
261int br_netpoll_enable(struct net_bridge_port *p)
262{
263	if (!p->br->dev->npinfo)
264		return 0;
265
266	return __br_netpoll_enable(p);
267}
268
269static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
270{
271	struct net_bridge *br = netdev_priv(dev);
272	struct net_bridge_port *p;
273	int err = 0;
274
275	list_for_each_entry(p, &br->port_list, list) {
276		if (!p->dev)
277			continue;
278		err = __br_netpoll_enable(p);
279		if (err)
280			goto fail;
281	}
282
283out:
284	return err;
285
286fail:
287	br_netpoll_cleanup(dev);
288	goto out;
289}
290
291void br_netpoll_disable(struct net_bridge_port *p)
292{
293	struct netpoll *np = p->np;
294
295	if (!np)
296		return;
297
298	p->np = NULL;
299
300	__netpoll_free_async(np);
301}
302
303#endif
304
305static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
306
307{
308	struct net_bridge *br = netdev_priv(dev);
309
310	return br_add_if(br, slave_dev);
311}
312
313static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
314{
315	struct net_bridge *br = netdev_priv(dev);
316
317	return br_del_if(br, slave_dev);
318}
319
320static const struct ethtool_ops br_ethtool_ops = {
321	.get_drvinfo    = br_getinfo,
322	.get_link	= ethtool_op_get_link,
323};
324
325static const struct net_device_ops br_netdev_ops = {
326	.ndo_open		 = br_dev_open,
327	.ndo_stop		 = br_dev_stop,
328	.ndo_init		 = br_dev_init,
329	.ndo_start_xmit		 = br_dev_xmit,
330	.ndo_get_stats64	 = br_get_stats64,
331	.ndo_set_mac_address	 = br_set_mac_address,
332	.ndo_set_rx_mode	 = br_dev_set_multicast_list,
333	.ndo_change_rx_flags	 = br_dev_change_rx_flags,
334	.ndo_change_mtu		 = br_change_mtu,
335	.ndo_do_ioctl		 = br_dev_ioctl,
336#ifdef CONFIG_NET_POLL_CONTROLLER
337	.ndo_netpoll_setup	 = br_netpoll_setup,
338	.ndo_netpoll_cleanup	 = br_netpoll_cleanup,
339	.ndo_poll_controller	 = br_poll_controller,
340#endif
341	.ndo_add_slave		 = br_add_slave,
342	.ndo_del_slave		 = br_del_slave,
343	.ndo_fix_features        = br_fix_features,
344	.ndo_fdb_add		 = br_fdb_add,
345	.ndo_fdb_del		 = br_fdb_delete,
346	.ndo_fdb_dump		 = br_fdb_dump,
347	.ndo_bridge_getlink	 = br_getlink,
348	.ndo_bridge_setlink	 = br_setlink,
349	.ndo_bridge_dellink	 = br_dellink,
350};
351
352static void br_dev_free(struct net_device *dev)
353{
354	struct net_bridge *br = netdev_priv(dev);
355
356	free_percpu(br->stats);
357	free_netdev(dev);
358}
359
360static struct device_type br_type = {
361	.name	= "bridge",
362};
363
364void br_dev_setup(struct net_device *dev)
365{
366	struct net_bridge *br = netdev_priv(dev);
367
368	eth_hw_addr_random(dev);
369	ether_setup(dev);
370
371	dev->netdev_ops = &br_netdev_ops;
372	dev->destructor = br_dev_free;
373	dev->ethtool_ops = &br_ethtool_ops;
374	SET_NETDEV_DEVTYPE(dev, &br_type);
375	dev->tx_queue_len = 0;
376	dev->priv_flags = IFF_EBRIDGE;
377
378	dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
379			NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
380	dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
381			   NETIF_F_HW_VLAN_STAG_TX;
382	dev->vlan_features = COMMON_FEATURES;
383
384	br->dev = dev;
385	spin_lock_init(&br->lock);
386	INIT_LIST_HEAD(&br->port_list);
387	spin_lock_init(&br->hash_lock);
388
389	br->bridge_id.prio[0] = 0x80;
390	br->bridge_id.prio[1] = 0x00;
391
392	ether_addr_copy(br->group_addr, eth_reserved_addr_base);
393
394	br->stp_enabled = BR_NO_STP;
395	br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
396	br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
397
398	br->designated_root = br->bridge_id;
399	br->bridge_max_age = br->max_age = 20 * HZ;
400	br->bridge_hello_time = br->hello_time = 2 * HZ;
401	br->bridge_forward_delay = br->forward_delay = 15 * HZ;
402	br->ageing_time = 300 * HZ;
403
404	br_netfilter_rtable_init(br);
405	br_stp_timer_init(br);
406	br_multicast_init(br);
407}
408