xref: /openbmc/linux/net/bridge/br.c (revision 92a2c6b2)
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 		dev_set_mtu(br->dev, br_min_mtu(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, 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 static int br_netdev_switch_event(struct notifier_block *unused,
125 				  unsigned long event, void *ptr)
126 {
127 	struct net_device *dev = netdev_switch_notifier_info_to_dev(ptr);
128 	struct net_bridge_port *p;
129 	struct net_bridge *br;
130 	struct netdev_switch_notifier_fdb_info *fdb_info;
131 	int err = NOTIFY_DONE;
132 
133 	rtnl_lock();
134 	p = br_port_get_rtnl(dev);
135 	if (!p)
136 		goto out;
137 
138 	br = p->br;
139 
140 	switch (event) {
141 	case NETDEV_SWITCH_FDB_ADD:
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 	case NETDEV_SWITCH_FDB_DEL:
149 		fdb_info = ptr;
150 		err = br_fdb_external_learn_del(br, p, fdb_info->addr,
151 						fdb_info->vid);
152 		if (err)
153 			err = notifier_from_errno(err);
154 		break;
155 	}
156 
157 out:
158 	rtnl_unlock();
159 	return err;
160 }
161 
162 static struct notifier_block br_netdev_switch_notifier = {
163 	.notifier_call = br_netdev_switch_event,
164 };
165 
166 static void __net_exit br_net_exit(struct net *net)
167 {
168 	struct net_device *dev;
169 	LIST_HEAD(list);
170 
171 	rtnl_lock();
172 	for_each_netdev(net, dev)
173 		if (dev->priv_flags & IFF_EBRIDGE)
174 			br_dev_delete(dev, &list);
175 
176 	unregister_netdevice_many(&list);
177 	rtnl_unlock();
178 
179 }
180 
181 static struct pernet_operations br_net_ops = {
182 	.exit	= br_net_exit,
183 };
184 
185 static const struct stp_proto br_stp_proto = {
186 	.rcv	= br_stp_rcv,
187 };
188 
189 static int __init br_init(void)
190 {
191 	int err;
192 
193 	err = stp_proto_register(&br_stp_proto);
194 	if (err < 0) {
195 		pr_err("bridge: can't register sap for STP\n");
196 		return err;
197 	}
198 
199 	err = br_fdb_init();
200 	if (err)
201 		goto err_out;
202 
203 	err = register_pernet_subsys(&br_net_ops);
204 	if (err)
205 		goto err_out1;
206 
207 	err = br_nf_core_init();
208 	if (err)
209 		goto err_out2;
210 
211 	err = register_netdevice_notifier(&br_device_notifier);
212 	if (err)
213 		goto err_out3;
214 
215 	err = register_netdev_switch_notifier(&br_netdev_switch_notifier);
216 	if (err)
217 		goto err_out4;
218 
219 	err = br_netlink_init();
220 	if (err)
221 		goto err_out5;
222 
223 	brioctl_set(br_ioctl_deviceless_stub);
224 
225 #if IS_ENABLED(CONFIG_ATM_LANE)
226 	br_fdb_test_addr_hook = br_fdb_test_addr;
227 #endif
228 
229 	pr_info("bridge: automatic filtering via arp/ip/ip6tables has been "
230 		"deprecated. Update your scripts to load br_netfilter if you "
231 		"need this.\n");
232 
233 	return 0;
234 
235 err_out5:
236 	unregister_netdev_switch_notifier(&br_netdev_switch_notifier);
237 err_out4:
238 	unregister_netdevice_notifier(&br_device_notifier);
239 err_out3:
240 	br_nf_core_fini();
241 err_out2:
242 	unregister_pernet_subsys(&br_net_ops);
243 err_out1:
244 	br_fdb_fini();
245 err_out:
246 	stp_proto_unregister(&br_stp_proto);
247 	return err;
248 }
249 
250 static void __exit br_deinit(void)
251 {
252 	stp_proto_unregister(&br_stp_proto);
253 	br_netlink_fini();
254 	unregister_netdev_switch_notifier(&br_netdev_switch_notifier);
255 	unregister_netdevice_notifier(&br_device_notifier);
256 	brioctl_set(NULL);
257 	unregister_pernet_subsys(&br_net_ops);
258 
259 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
260 
261 	br_nf_core_fini();
262 #if IS_ENABLED(CONFIG_ATM_LANE)
263 	br_fdb_test_addr_hook = NULL;
264 #endif
265 	br_fdb_fini();
266 }
267 
268 module_init(br_init)
269 module_exit(br_deinit)
270 MODULE_LICENSE("GPL");
271 MODULE_VERSION(BR_VERSION);
272 MODULE_ALIAS_RTNL_LINK("bridge");
273