xref: /linux/net/bridge/br_ioctl.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
1 /*
2  *	Ioctl handler
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/capability.h>
15 #include <linux/kernel.h>
16 #include <linux/if_bridge.h>
17 #include <linux/netdevice.h>
18 #include <linux/slab.h>
19 #include <linux/times.h>
20 #include <net/net_namespace.h>
21 #include <asm/uaccess.h>
22 #include "br_private.h"
23 
24 static int get_bridge_ifindices(struct net *net, int *indices, int num)
25 {
26 	struct net_device *dev;
27 	int i = 0;
28 
29 	rcu_read_lock();
30 	for_each_netdev_rcu(net, dev) {
31 		if (i >= num)
32 			break;
33 		if (dev->priv_flags & IFF_EBRIDGE)
34 			indices[i++] = dev->ifindex;
35 	}
36 	rcu_read_unlock();
37 
38 	return i;
39 }
40 
41 /* called with RTNL */
42 static void get_port_ifindices(struct net_bridge *br, int *ifindices, int num)
43 {
44 	struct net_bridge_port *p;
45 
46 	list_for_each_entry(p, &br->port_list, list) {
47 		if (p->port_no < num)
48 			ifindices[p->port_no] = p->dev->ifindex;
49 	}
50 }
51 
52 /*
53  * Format up to a page worth of forwarding table entries
54  * userbuf -- where to copy result
55  * maxnum  -- maximum number of entries desired
56  *            (limited to a page for sanity)
57  * offset  -- number of records to skip
58  */
59 static int get_fdb_entries(struct net_bridge *br, void __user *userbuf,
60 			   unsigned long maxnum, unsigned long offset)
61 {
62 	int num;
63 	void *buf;
64 	size_t size;
65 
66 	/* Clamp size to PAGE_SIZE, test maxnum to avoid overflow */
67 	if (maxnum > PAGE_SIZE/sizeof(struct __fdb_entry))
68 		maxnum = PAGE_SIZE/sizeof(struct __fdb_entry);
69 
70 	size = maxnum * sizeof(struct __fdb_entry);
71 
72 	buf = kmalloc(size, GFP_USER);
73 	if (!buf)
74 		return -ENOMEM;
75 
76 	num = br_fdb_fillbuf(br, buf, maxnum, offset);
77 	if (num > 0) {
78 		if (copy_to_user(userbuf, buf, num*sizeof(struct __fdb_entry)))
79 			num = -EFAULT;
80 	}
81 	kfree(buf);
82 
83 	return num;
84 }
85 
86 /* called with RTNL */
87 static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
88 {
89 	struct net *net = dev_net(br->dev);
90 	struct net_device *dev;
91 	int ret;
92 
93 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
94 		return -EPERM;
95 
96 	dev = __dev_get_by_index(net, ifindex);
97 	if (dev == NULL)
98 		return -EINVAL;
99 
100 	if (isadd)
101 		ret = br_add_if(br, dev);
102 	else
103 		ret = br_del_if(br, dev);
104 
105 	return ret;
106 }
107 
108 /*
109  * Legacy ioctl's through SIOCDEVPRIVATE
110  * This interface is deprecated because it was too difficult to
111  * to do the translation for 32/64bit ioctl compatibility.
112  */
113 static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
114 {
115 	struct net_bridge *br = netdev_priv(dev);
116 	struct net_bridge_port *p = NULL;
117 	unsigned long args[4];
118 	int ret = -EOPNOTSUPP;
119 
120 	if (copy_from_user(args, rq->ifr_data, sizeof(args)))
121 		return -EFAULT;
122 
123 	switch (args[0]) {
124 	case BRCTL_ADD_IF:
125 	case BRCTL_DEL_IF:
126 		return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);
127 
128 	case BRCTL_GET_BRIDGE_INFO:
129 	{
130 		struct __bridge_info b;
131 
132 		memset(&b, 0, sizeof(struct __bridge_info));
133 		rcu_read_lock();
134 		memcpy(&b.designated_root, &br->designated_root, 8);
135 		memcpy(&b.bridge_id, &br->bridge_id, 8);
136 		b.root_path_cost = br->root_path_cost;
137 		b.max_age = jiffies_to_clock_t(br->max_age);
138 		b.hello_time = jiffies_to_clock_t(br->hello_time);
139 		b.forward_delay = br->forward_delay;
140 		b.bridge_max_age = br->bridge_max_age;
141 		b.bridge_hello_time = br->bridge_hello_time;
142 		b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay);
143 		b.topology_change = br->topology_change;
144 		b.topology_change_detected = br->topology_change_detected;
145 		b.root_port = br->root_port;
146 
147 		b.stp_enabled = (br->stp_enabled != BR_NO_STP);
148 		b.ageing_time = jiffies_to_clock_t(br->ageing_time);
149 		b.hello_timer_value = br_timer_value(&br->hello_timer);
150 		b.tcn_timer_value = br_timer_value(&br->tcn_timer);
151 		b.topology_change_timer_value = br_timer_value(&br->topology_change_timer);
152 		b.gc_timer_value = br_timer_value(&br->gc_timer);
153 		rcu_read_unlock();
154 
155 		if (copy_to_user((void __user *)args[1], &b, sizeof(b)))
156 			return -EFAULT;
157 
158 		return 0;
159 	}
160 
161 	case BRCTL_GET_PORT_LIST:
162 	{
163 		int num, *indices;
164 
165 		num = args[2];
166 		if (num < 0)
167 			return -EINVAL;
168 		if (num == 0)
169 			num = 256;
170 		if (num > BR_MAX_PORTS)
171 			num = BR_MAX_PORTS;
172 
173 		indices = kcalloc(num, sizeof(int), GFP_KERNEL);
174 		if (indices == NULL)
175 			return -ENOMEM;
176 
177 		get_port_ifindices(br, indices, num);
178 		if (copy_to_user((void __user *)args[1], indices, num*sizeof(int)))
179 			num =  -EFAULT;
180 		kfree(indices);
181 		return num;
182 	}
183 
184 	case BRCTL_SET_BRIDGE_FORWARD_DELAY:
185 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
186 			return -EPERM;
187 
188 		ret = br_set_forward_delay(br, args[1]);
189 		break;
190 
191 	case BRCTL_SET_BRIDGE_HELLO_TIME:
192 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
193 			return -EPERM;
194 
195 		ret = br_set_hello_time(br, args[1]);
196 		break;
197 
198 	case BRCTL_SET_BRIDGE_MAX_AGE:
199 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
200 			return -EPERM;
201 
202 		ret = br_set_max_age(br, args[1]);
203 		break;
204 
205 	case BRCTL_SET_AGEING_TIME:
206 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
207 			return -EPERM;
208 
209 		ret = br_set_ageing_time(br, args[1]);
210 		break;
211 
212 	case BRCTL_GET_PORT_INFO:
213 	{
214 		struct __port_info p;
215 		struct net_bridge_port *pt;
216 
217 		rcu_read_lock();
218 		if ((pt = br_get_port(br, args[2])) == NULL) {
219 			rcu_read_unlock();
220 			return -EINVAL;
221 		}
222 
223 		memset(&p, 0, sizeof(struct __port_info));
224 		memcpy(&p.designated_root, &pt->designated_root, 8);
225 		memcpy(&p.designated_bridge, &pt->designated_bridge, 8);
226 		p.port_id = pt->port_id;
227 		p.designated_port = pt->designated_port;
228 		p.path_cost = pt->path_cost;
229 		p.designated_cost = pt->designated_cost;
230 		p.state = pt->state;
231 		p.top_change_ack = pt->topology_change_ack;
232 		p.config_pending = pt->config_pending;
233 		p.message_age_timer_value = br_timer_value(&pt->message_age_timer);
234 		p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer);
235 		p.hold_timer_value = br_timer_value(&pt->hold_timer);
236 
237 		rcu_read_unlock();
238 
239 		if (copy_to_user((void __user *)args[1], &p, sizeof(p)))
240 			return -EFAULT;
241 
242 		return 0;
243 	}
244 
245 	case BRCTL_SET_BRIDGE_STP_STATE:
246 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
247 			return -EPERM;
248 
249 		br_stp_set_enabled(br, args[1]);
250 		ret = 0;
251 		break;
252 
253 	case BRCTL_SET_BRIDGE_PRIORITY:
254 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
255 			return -EPERM;
256 
257 		br_stp_set_bridge_priority(br, args[1]);
258 		ret = 0;
259 		break;
260 
261 	case BRCTL_SET_PORT_PRIORITY:
262 	{
263 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
264 			return -EPERM;
265 
266 		spin_lock_bh(&br->lock);
267 		if ((p = br_get_port(br, args[1])) == NULL)
268 			ret = -EINVAL;
269 		else
270 			ret = br_stp_set_port_priority(p, args[2]);
271 		spin_unlock_bh(&br->lock);
272 		break;
273 	}
274 
275 	case BRCTL_SET_PATH_COST:
276 	{
277 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
278 			return -EPERM;
279 
280 		spin_lock_bh(&br->lock);
281 		if ((p = br_get_port(br, args[1])) == NULL)
282 			ret = -EINVAL;
283 		else
284 			ret = br_stp_set_path_cost(p, args[2]);
285 		spin_unlock_bh(&br->lock);
286 		break;
287 	}
288 
289 	case BRCTL_GET_FDB_ENTRIES:
290 		return get_fdb_entries(br, (void __user *)args[1],
291 				       args[2], args[3]);
292 	}
293 
294 	if (!ret) {
295 		if (p)
296 			br_ifinfo_notify(RTM_NEWLINK, p);
297 		else
298 			netdev_state_change(br->dev);
299 	}
300 
301 	return ret;
302 }
303 
304 static int old_deviceless(struct net *net, void __user *uarg)
305 {
306 	unsigned long args[3];
307 
308 	if (copy_from_user(args, uarg, sizeof(args)))
309 		return -EFAULT;
310 
311 	switch (args[0]) {
312 	case BRCTL_GET_VERSION:
313 		return BRCTL_VERSION;
314 
315 	case BRCTL_GET_BRIDGES:
316 	{
317 		int *indices;
318 		int ret = 0;
319 
320 		if (args[2] >= 2048)
321 			return -ENOMEM;
322 		indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
323 		if (indices == NULL)
324 			return -ENOMEM;
325 
326 		args[2] = get_bridge_ifindices(net, indices, args[2]);
327 
328 		ret = copy_to_user((void __user *)args[1], indices, args[2]*sizeof(int))
329 			? -EFAULT : args[2];
330 
331 		kfree(indices);
332 		return ret;
333 	}
334 
335 	case BRCTL_ADD_BRIDGE:
336 	case BRCTL_DEL_BRIDGE:
337 	{
338 		char buf[IFNAMSIZ];
339 
340 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
341 			return -EPERM;
342 
343 		if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
344 			return -EFAULT;
345 
346 		buf[IFNAMSIZ-1] = 0;
347 
348 		if (args[0] == BRCTL_ADD_BRIDGE)
349 			return br_add_bridge(net, buf);
350 
351 		return br_del_bridge(net, buf);
352 	}
353 	}
354 
355 	return -EOPNOTSUPP;
356 }
357 
358 int br_ioctl_deviceless_stub(struct net *net, unsigned int cmd, void __user *uarg)
359 {
360 	switch (cmd) {
361 	case SIOCGIFBR:
362 	case SIOCSIFBR:
363 		return old_deviceless(net, uarg);
364 
365 	case SIOCBRADDBR:
366 	case SIOCBRDELBR:
367 	{
368 		char buf[IFNAMSIZ];
369 
370 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
371 			return -EPERM;
372 
373 		if (copy_from_user(buf, uarg, IFNAMSIZ))
374 			return -EFAULT;
375 
376 		buf[IFNAMSIZ-1] = 0;
377 		if (cmd == SIOCBRADDBR)
378 			return br_add_bridge(net, buf);
379 
380 		return br_del_bridge(net, buf);
381 	}
382 	}
383 	return -EOPNOTSUPP;
384 }
385 
386 int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
387 {
388 	struct net_bridge *br = netdev_priv(dev);
389 
390 	switch (cmd) {
391 	case SIOCDEVPRIVATE:
392 		return old_dev_ioctl(dev, rq, cmd);
393 
394 	case SIOCBRADDIF:
395 	case SIOCBRDELIF:
396 		return add_del_if(br, rq->ifr_ifindex, cmd == SIOCBRADDIF);
397 
398 	}
399 
400 	br_debug(br, "Bridge does not support ioctl 0x%x\n", cmd);
401 	return -EOPNOTSUPP;
402 }
403