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/* net device transmit always called with BH disabled */
26netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
27{
28	struct net_bridge *br = netdev_priv(dev);
29	const unsigned char *dest = skb->data;
30	struct net_bridge_fdb_entry *dst;
31	struct net_bridge_mdb_entry *mdst;
32	struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
33	u16 vid = 0;
34
35	rcu_read_lock();
36#ifdef CONFIG_BRIDGE_NETFILTER
37	if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
38		br_nf_pre_routing_finish_bridge_slow(skb);
39		rcu_read_unlock();
40		return NETDEV_TX_OK;
41	}
42#endif
43
44	if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid))
45		goto out;
46
47	BR_INPUT_SKB_CB(skb)->brdev = dev;
48
49	skb_reset_mac_header(skb);
50	skb_pull(skb, ETH_HLEN);
51
52	u64_stats_update_begin(&brstats->syncp);
53	brstats->tx_packets++;
54	/* Exclude ETH_HLEN from byte stats for consistency with Rx chain */
55	brstats->tx_bytes += skb->len;
56	u64_stats_update_end(&brstats->syncp);
57
58	if (is_broadcast_ether_addr(dest))
59		br_flood_deliver(br, skb);
60	else if (is_multicast_ether_addr(dest)) {
61		if (unlikely(netpoll_tx_running(dev))) {
62			br_flood_deliver(br, skb);
63			goto out;
64		}
65		if (br_multicast_rcv(br, NULL, skb)) {
66			kfree_skb(skb);
67			goto out;
68		}
69
70		mdst = br_mdb_get(br, skb, vid);
71		if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb))
72			br_multicast_deliver(mdst, skb);
73		else
74			br_flood_deliver(br, skb);
75	} else if ((dst = __br_fdb_get(br, dest, vid)) != NULL)
76		br_deliver(dst->dst, skb);
77	else
78		br_flood_deliver(br, skb);
79
80out:
81	rcu_read_unlock();
82	return NETDEV_TX_OK;
83}
84
85static int br_dev_init(struct net_device *dev)
86{
87	struct net_bridge *br = netdev_priv(dev);
88
89	br->stats = alloc_percpu(struct br_cpu_netstats);
90	if (!br->stats)
91		return -ENOMEM;
92
93	return 0;
94}
95
96static int br_dev_open(struct net_device *dev)
97{
98	struct net_bridge *br = netdev_priv(dev);
99
100	netdev_update_features(dev);
101	netif_start_queue(dev);
102	br_stp_enable_bridge(br);
103	br_multicast_open(br);
104
105	return 0;
106}
107
108static void br_dev_set_multicast_list(struct net_device *dev)
109{
110}
111
112static int br_dev_stop(struct net_device *dev)
113{
114	struct net_bridge *br = netdev_priv(dev);
115
116	br_stp_disable_bridge(br);
117	br_multicast_stop(br);
118
119	netif_stop_queue(dev);
120
121	return 0;
122}
123
124static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
125						struct rtnl_link_stats64 *stats)
126{
127	struct net_bridge *br = netdev_priv(dev);
128	struct br_cpu_netstats tmp, sum = { 0 };
129	unsigned int cpu;
130
131	for_each_possible_cpu(cpu) {
132		unsigned int start;
133		const struct br_cpu_netstats *bstats
134			= per_cpu_ptr(br->stats, cpu);
135		do {
136			start = u64_stats_fetch_begin_bh(&bstats->syncp);
137			memcpy(&tmp, bstats, sizeof(tmp));
138		} while (u64_stats_fetch_retry_bh(&bstats->syncp, start));
139		sum.tx_bytes   += tmp.tx_bytes;
140		sum.tx_packets += tmp.tx_packets;
141		sum.rx_bytes   += tmp.rx_bytes;
142		sum.rx_packets += tmp.rx_packets;
143	}
144
145	stats->tx_bytes   = sum.tx_bytes;
146	stats->tx_packets = sum.tx_packets;
147	stats->rx_bytes   = sum.rx_bytes;
148	stats->rx_packets = sum.rx_packets;
149
150	return stats;
151}
152
153static int br_change_mtu(struct net_device *dev, int new_mtu)
154{
155	struct net_bridge *br = netdev_priv(dev);
156	if (new_mtu < 68 || new_mtu > br_min_mtu(br))
157		return -EINVAL;
158
159	dev->mtu = new_mtu;
160
161#ifdef CONFIG_BRIDGE_NETFILTER
162	/* remember the MTU in the rtable for PMTU */
163	dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
164#endif
165
166	return 0;
167}
168
169/* Allow setting mac address to any valid ethernet address. */
170static int br_set_mac_address(struct net_device *dev, void *p)
171{
172	struct net_bridge *br = netdev_priv(dev);
173	struct sockaddr *addr = p;
174
175	if (!is_valid_ether_addr(addr->sa_data))
176		return -EADDRNOTAVAIL;
177
178	spin_lock_bh(&br->lock);
179	if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
180		memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
181		br_fdb_change_mac_address(br, addr->sa_data);
182		br_stp_change_bridge_id(br, addr->sa_data);
183	}
184	spin_unlock_bh(&br->lock);
185
186	return 0;
187}
188
189static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
190{
191	strlcpy(info->driver, "bridge", sizeof(info->driver));
192	strlcpy(info->version, BR_VERSION, sizeof(info->version));
193	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
194	strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
195}
196
197static netdev_features_t br_fix_features(struct net_device *dev,
198	netdev_features_t features)
199{
200	struct net_bridge *br = netdev_priv(dev);
201
202	return br_features_recompute(br, features);
203}
204
205#ifdef CONFIG_NET_POLL_CONTROLLER
206static void br_poll_controller(struct net_device *br_dev)
207{
208}
209
210static void br_netpoll_cleanup(struct net_device *dev)
211{
212	struct net_bridge *br = netdev_priv(dev);
213	struct net_bridge_port *p;
214
215	list_for_each_entry(p, &br->port_list, list)
216		br_netpoll_disable(p);
217}
218
219static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni,
220			    gfp_t gfp)
221{
222	struct net_bridge *br = netdev_priv(dev);
223	struct net_bridge_port *p;
224	int err = 0;
225
226	list_for_each_entry(p, &br->port_list, list) {
227		if (!p->dev)
228			continue;
229		err = br_netpoll_enable(p, gfp);
230		if (err)
231			goto fail;
232	}
233
234out:
235	return err;
236
237fail:
238	br_netpoll_cleanup(dev);
239	goto out;
240}
241
242int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp)
243{
244	struct netpoll *np;
245	int err = 0;
246
247	np = kzalloc(sizeof(*p->np), gfp);
248	err = -ENOMEM;
249	if (!np)
250		goto out;
251
252	err = __netpoll_setup(np, p->dev, gfp);
253	if (err) {
254		kfree(np);
255		goto out;
256	}
257
258	p->np = np;
259
260out:
261	return err;
262}
263
264void br_netpoll_disable(struct net_bridge_port *p)
265{
266	struct netpoll *np = p->np;
267
268	if (!np)
269		return;
270
271	p->np = NULL;
272
273	__netpoll_free_async(np);
274}
275
276#endif
277
278static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
279
280{
281	struct net_bridge *br = netdev_priv(dev);
282
283	return br_add_if(br, slave_dev);
284}
285
286static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
287{
288	struct net_bridge *br = netdev_priv(dev);
289
290	return br_del_if(br, slave_dev);
291}
292
293static const struct ethtool_ops br_ethtool_ops = {
294	.get_drvinfo    = br_getinfo,
295	.get_link	= ethtool_op_get_link,
296};
297
298static const struct net_device_ops br_netdev_ops = {
299	.ndo_open		 = br_dev_open,
300	.ndo_stop		 = br_dev_stop,
301	.ndo_init		 = br_dev_init,
302	.ndo_start_xmit		 = br_dev_xmit,
303	.ndo_get_stats64	 = br_get_stats64,
304	.ndo_set_mac_address	 = br_set_mac_address,
305	.ndo_set_rx_mode	 = br_dev_set_multicast_list,
306	.ndo_change_mtu		 = br_change_mtu,
307	.ndo_do_ioctl		 = br_dev_ioctl,
308#ifdef CONFIG_NET_POLL_CONTROLLER
309	.ndo_netpoll_setup	 = br_netpoll_setup,
310	.ndo_netpoll_cleanup	 = br_netpoll_cleanup,
311	.ndo_poll_controller	 = br_poll_controller,
312#endif
313	.ndo_add_slave		 = br_add_slave,
314	.ndo_del_slave		 = br_del_slave,
315	.ndo_fix_features        = br_fix_features,
316	.ndo_fdb_add		 = br_fdb_add,
317	.ndo_fdb_del		 = br_fdb_delete,
318	.ndo_fdb_dump		 = br_fdb_dump,
319	.ndo_bridge_getlink	 = br_getlink,
320	.ndo_bridge_setlink	 = br_setlink,
321	.ndo_bridge_dellink	 = br_dellink,
322};
323
324static void br_dev_free(struct net_device *dev)
325{
326	struct net_bridge *br = netdev_priv(dev);
327
328	free_percpu(br->stats);
329	free_netdev(dev);
330}
331
332static struct device_type br_type = {
333	.name	= "bridge",
334};
335
336void br_dev_setup(struct net_device *dev)
337{
338	struct net_bridge *br = netdev_priv(dev);
339
340	eth_hw_addr_random(dev);
341	ether_setup(dev);
342
343	dev->netdev_ops = &br_netdev_ops;
344	dev->destructor = br_dev_free;
345	SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
346	SET_NETDEV_DEVTYPE(dev, &br_type);
347	dev->tx_queue_len = 0;
348	dev->priv_flags = IFF_EBRIDGE;
349
350	dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
351			NETIF_F_GSO_MASK | NETIF_F_HW_CSUM | NETIF_F_LLTX |
352			NETIF_F_NETNS_LOCAL | NETIF_F_HW_VLAN_CTAG_TX;
353	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
354			   NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
355			   NETIF_F_HW_VLAN_CTAG_TX;
356
357	br->dev = dev;
358	spin_lock_init(&br->lock);
359	INIT_LIST_HEAD(&br->port_list);
360	spin_lock_init(&br->hash_lock);
361
362	br->bridge_id.prio[0] = 0x80;
363	br->bridge_id.prio[1] = 0x00;
364
365	memcpy(br->group_addr, eth_reserved_addr_base, ETH_ALEN);
366
367	br->stp_enabled = BR_NO_STP;
368	br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
369
370	br->designated_root = br->bridge_id;
371	br->bridge_max_age = br->max_age = 20 * HZ;
372	br->bridge_hello_time = br->hello_time = 2 * HZ;
373	br->bridge_forward_delay = br->forward_delay = 15 * HZ;
374	br->ageing_time = 300 * HZ;
375
376	br_netfilter_rtable_init(br);
377	br_stp_timer_init(br);
378	br_multicast_init(br);
379}
380