xref: /openbmc/linux/net/bridge/br.c (revision 4cff79e9)
1 /*
2  *	Generic parts
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/module.h>
15 #include <linux/kernel.h>
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 #include <linux/init.h>
19 #include <linux/llc.h>
20 #include <net/llc.h>
21 #include <net/stp.h>
22 #include <net/switchdev.h>
23 
24 #include "br_private.h"
25 
26 /*
27  * Handle changes in state of network devices enslaved to a bridge.
28  *
29  * Note: don't care about up/down if bridge itself is down, because
30  *     port state is checked when bridge is brought up.
31  */
32 static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
33 {
34 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
35 	struct net_bridge_port *p;
36 	struct net_bridge *br;
37 	bool changed_addr;
38 	int err;
39 
40 	/* register of bridge completed, add sysfs entries */
41 	if ((dev->priv_flags & IFF_EBRIDGE) && event == NETDEV_REGISTER) {
42 		br_sysfs_addbr(dev);
43 		return NOTIFY_DONE;
44 	}
45 
46 	/* not a port of a bridge */
47 	p = br_port_get_rtnl(dev);
48 	if (!p)
49 		return NOTIFY_DONE;
50 
51 	br = p->br;
52 
53 	switch (event) {
54 	case NETDEV_CHANGEMTU:
55 		br_mtu_auto_adjust(br);
56 		break;
57 
58 	case NETDEV_CHANGEADDR:
59 		spin_lock_bh(&br->lock);
60 		br_fdb_changeaddr(p, dev->dev_addr);
61 		changed_addr = br_stp_recalculate_bridge_id(br);
62 		spin_unlock_bh(&br->lock);
63 
64 		if (changed_addr)
65 			call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
66 
67 		break;
68 
69 	case NETDEV_CHANGE:
70 		br_port_carrier_check(p);
71 		break;
72 
73 	case NETDEV_FEAT_CHANGE:
74 		netdev_update_features(br->dev);
75 		break;
76 
77 	case NETDEV_DOWN:
78 		spin_lock_bh(&br->lock);
79 		if (br->dev->flags & IFF_UP)
80 			br_stp_disable_port(p);
81 		spin_unlock_bh(&br->lock);
82 		break;
83 
84 	case NETDEV_UP:
85 		if (netif_running(br->dev) && netif_oper_up(dev)) {
86 			spin_lock_bh(&br->lock);
87 			br_stp_enable_port(p);
88 			spin_unlock_bh(&br->lock);
89 		}
90 		break;
91 
92 	case NETDEV_UNREGISTER:
93 		br_del_if(br, dev);
94 		break;
95 
96 	case NETDEV_CHANGENAME:
97 		err = br_sysfs_renameif(p);
98 		if (err)
99 			return notifier_from_errno(err);
100 		break;
101 
102 	case NETDEV_PRE_TYPE_CHANGE:
103 		/* Forbid underlaying device to change its type. */
104 		return NOTIFY_BAD;
105 
106 	case NETDEV_RESEND_IGMP:
107 		/* Propagate to master device */
108 		call_netdevice_notifiers(event, br->dev);
109 		break;
110 	}
111 
112 	/* Events that may cause spanning tree to refresh */
113 	if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
114 	    event == NETDEV_CHANGE || event == NETDEV_DOWN)
115 		br_ifinfo_notify(RTM_NEWLINK, NULL, p);
116 
117 	return NOTIFY_DONE;
118 }
119 
120 static struct notifier_block br_device_notifier = {
121 	.notifier_call = br_device_event
122 };
123 
124 /* called with RTNL or RCU */
125 static int br_switchdev_event(struct notifier_block *unused,
126 			      unsigned long event, void *ptr)
127 {
128 	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
129 	struct net_bridge_port *p;
130 	struct net_bridge *br;
131 	struct switchdev_notifier_fdb_info *fdb_info;
132 	int err = NOTIFY_DONE;
133 
134 	p = br_port_get_rtnl_rcu(dev);
135 	if (!p)
136 		goto out;
137 
138 	br = p->br;
139 
140 	switch (event) {
141 	case SWITCHDEV_FDB_ADD_TO_BRIDGE:
142 		fdb_info = ptr;
143 		err = br_fdb_external_learn_add(br, p, fdb_info->addr,
144 						fdb_info->vid);
145 		if (err) {
146 			err = notifier_from_errno(err);
147 			break;
148 		}
149 		br_fdb_offloaded_set(br, p, fdb_info->addr,
150 				     fdb_info->vid);
151 		break;
152 	case SWITCHDEV_FDB_DEL_TO_BRIDGE:
153 		fdb_info = ptr;
154 		err = br_fdb_external_learn_del(br, p, fdb_info->addr,
155 						fdb_info->vid);
156 		if (err)
157 			err = notifier_from_errno(err);
158 		break;
159 	case SWITCHDEV_FDB_OFFLOADED:
160 		fdb_info = ptr;
161 		br_fdb_offloaded_set(br, p, fdb_info->addr,
162 				     fdb_info->vid);
163 		break;
164 	}
165 
166 out:
167 	return err;
168 }
169 
170 static struct notifier_block br_switchdev_notifier = {
171 	.notifier_call = br_switchdev_event,
172 };
173 
174 static void __net_exit br_net_exit(struct net *net)
175 {
176 	struct net_device *dev;
177 	LIST_HEAD(list);
178 
179 	rtnl_lock();
180 	for_each_netdev(net, dev)
181 		if (dev->priv_flags & IFF_EBRIDGE)
182 			br_dev_delete(dev, &list);
183 
184 	unregister_netdevice_many(&list);
185 	rtnl_unlock();
186 
187 }
188 
189 static struct pernet_operations br_net_ops = {
190 	.exit	= br_net_exit,
191 };
192 
193 static const struct stp_proto br_stp_proto = {
194 	.rcv	= br_stp_rcv,
195 };
196 
197 static int __init br_init(void)
198 {
199 	int err;
200 
201 	BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));
202 
203 	err = stp_proto_register(&br_stp_proto);
204 	if (err < 0) {
205 		pr_err("bridge: can't register sap for STP\n");
206 		return err;
207 	}
208 
209 	err = br_fdb_init();
210 	if (err)
211 		goto err_out;
212 
213 	err = register_pernet_subsys(&br_net_ops);
214 	if (err)
215 		goto err_out1;
216 
217 	err = br_nf_core_init();
218 	if (err)
219 		goto err_out2;
220 
221 	err = register_netdevice_notifier(&br_device_notifier);
222 	if (err)
223 		goto err_out3;
224 
225 	err = register_switchdev_notifier(&br_switchdev_notifier);
226 	if (err)
227 		goto err_out4;
228 
229 	err = br_netlink_init();
230 	if (err)
231 		goto err_out5;
232 
233 	brioctl_set(br_ioctl_deviceless_stub);
234 
235 #if IS_ENABLED(CONFIG_ATM_LANE)
236 	br_fdb_test_addr_hook = br_fdb_test_addr;
237 #endif
238 
239 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
240 	pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
241 		"by default. Update your scripts to load br_netfilter if you "
242 		"need this.\n");
243 #endif
244 
245 	return 0;
246 
247 err_out5:
248 	unregister_switchdev_notifier(&br_switchdev_notifier);
249 err_out4:
250 	unregister_netdevice_notifier(&br_device_notifier);
251 err_out3:
252 	br_nf_core_fini();
253 err_out2:
254 	unregister_pernet_subsys(&br_net_ops);
255 err_out1:
256 	br_fdb_fini();
257 err_out:
258 	stp_proto_unregister(&br_stp_proto);
259 	return err;
260 }
261 
262 static void __exit br_deinit(void)
263 {
264 	stp_proto_unregister(&br_stp_proto);
265 	br_netlink_fini();
266 	unregister_switchdev_notifier(&br_switchdev_notifier);
267 	unregister_netdevice_notifier(&br_device_notifier);
268 	brioctl_set(NULL);
269 	unregister_pernet_subsys(&br_net_ops);
270 
271 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
272 
273 	br_nf_core_fini();
274 #if IS_ENABLED(CONFIG_ATM_LANE)
275 	br_fdb_test_addr_hook = NULL;
276 #endif
277 	br_fdb_fini();
278 }
279 
280 module_init(br_init)
281 module_exit(br_deinit)
282 MODULE_LICENSE("GPL");
283 MODULE_VERSION(BR_VERSION);
284 MODULE_ALIAS_RTNL_LINK("bridge");
285