1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *	Ioctl handler
4 *	Linux ethernet bridge
5 *
6 *	Authors:
7 *	Lennert Buytenhek		<buytenh@gnu.org>
8 */
9
10#include <linux/capability.h>
11#include <linux/compat.h>
12#include <linux/kernel.h>
13#include <linux/if_bridge.h>
14#include <linux/netdevice.h>
15#include <linux/slab.h>
16#include <linux/times.h>
17#include <net/net_namespace.h>
18#include <linux/uaccess.h>
19#include "br_private.h"
20
21static int get_bridge_ifindices(struct net *net, int *indices, int num)
22{
23	struct net_device *dev;
24	int i = 0;
25
26	rcu_read_lock();
27	for_each_netdev_rcu(net, dev) {
28		if (i >= num)
29			break;
30		if (netif_is_bridge_master(dev))
31			indices[i++] = dev->ifindex;
32	}
33	rcu_read_unlock();
34
35	return i;
36}
37
38/* called with RTNL */
39static void get_port_ifindices(struct net_bridge *br, int *ifindices, int num)
40{
41	struct net_bridge_port *p;
42
43	list_for_each_entry(p, &br->port_list, list) {
44		if (p->port_no < num)
45			ifindices[p->port_no] = p->dev->ifindex;
46	}
47}
48
49/*
50 * Format up to a page worth of forwarding table entries
51 * userbuf -- where to copy result
52 * maxnum  -- maximum number of entries desired
53 *            (limited to a page for sanity)
54 * offset  -- number of records to skip
55 */
56static int get_fdb_entries(struct net_bridge *br, void __user *userbuf,
57			   unsigned long maxnum, unsigned long offset)
58{
59	int num;
60	void *buf;
61	size_t size;
62
63	/* Clamp size to PAGE_SIZE, test maxnum to avoid overflow */
64	if (maxnum > PAGE_SIZE/sizeof(struct __fdb_entry))
65		maxnum = PAGE_SIZE/sizeof(struct __fdb_entry);
66
67	size = maxnum * sizeof(struct __fdb_entry);
68
69	buf = kmalloc(size, GFP_USER);
70	if (!buf)
71		return -ENOMEM;
72
73	num = br_fdb_fillbuf(br, buf, maxnum, offset);
74	if (num > 0) {
75		if (copy_to_user(userbuf, buf,
76				 array_size(num, sizeof(struct __fdb_entry))))
77			num = -EFAULT;
78	}
79	kfree(buf);
80
81	return num;
82}
83
84/* called with RTNL */
85static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
86{
87	struct net *net = dev_net(br->dev);
88	struct net_device *dev;
89	int ret;
90
91	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
92		return -EPERM;
93
94	dev = __dev_get_by_index(net, ifindex);
95	if (dev == NULL)
96		return -EINVAL;
97
98	if (isadd)
99		ret = br_add_if(br, dev, NULL);
100	else
101		ret = br_del_if(br, dev);
102
103	return ret;
104}
105
106#define BR_UARGS_MAX 4
107static int br_dev_read_uargs(unsigned long *args, size_t nr_args,
108			     void __user **argp, void __user *data)
109{
110	int ret;
111
112	if (nr_args < 2 || nr_args > BR_UARGS_MAX)
113		return -EINVAL;
114
115	if (in_compat_syscall()) {
116		unsigned int cargs[BR_UARGS_MAX];
117		int i;
118
119		ret = copy_from_user(cargs, data, nr_args * sizeof(*cargs));
120		if (ret)
121			goto fault;
122
123		for (i = 0; i < nr_args; ++i)
124			args[i] = cargs[i];
125
126		*argp = compat_ptr(args[1]);
127	} else {
128		ret = copy_from_user(args, data, nr_args * sizeof(*args));
129		if (ret)
130			goto fault;
131		*argp = (void __user *)args[1];
132	}
133
134	return 0;
135fault:
136	return -EFAULT;
137}
138
139/*
140 * Legacy ioctl's through SIOCDEVPRIVATE
141 * This interface is deprecated because it was too difficult
142 * to do the translation for 32/64bit ioctl compatibility.
143 */
144int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq,
145			  void __user *data, int cmd)
146{
147	struct net_bridge *br = netdev_priv(dev);
148	struct net_bridge_port *p = NULL;
149	unsigned long args[4];
150	void __user *argp;
151	int ret;
152
153	ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data);
154	if (ret)
155		return ret;
156
157	switch (args[0]) {
158	case BRCTL_ADD_IF:
159	case BRCTL_DEL_IF:
160		return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);
161
162	case BRCTL_GET_BRIDGE_INFO:
163	{
164		struct __bridge_info b;
165
166		memset(&b, 0, sizeof(struct __bridge_info));
167		rcu_read_lock();
168		memcpy(&b.designated_root, &br->designated_root, 8);
169		memcpy(&b.bridge_id, &br->bridge_id, 8);
170		b.root_path_cost = br->root_path_cost;
171		b.max_age = jiffies_to_clock_t(br->max_age);
172		b.hello_time = jiffies_to_clock_t(br->hello_time);
173		b.forward_delay = br->forward_delay;
174		b.bridge_max_age = br->bridge_max_age;
175		b.bridge_hello_time = br->bridge_hello_time;
176		b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay);
177		b.topology_change = br->topology_change;
178		b.topology_change_detected = br->topology_change_detected;
179		b.root_port = br->root_port;
180
181		b.stp_enabled = (br->stp_enabled != BR_NO_STP);
182		b.ageing_time = jiffies_to_clock_t(br->ageing_time);
183		b.hello_timer_value = br_timer_value(&br->hello_timer);
184		b.tcn_timer_value = br_timer_value(&br->tcn_timer);
185		b.topology_change_timer_value = br_timer_value(&br->topology_change_timer);
186		b.gc_timer_value = br_timer_value(&br->gc_work.timer);
187		rcu_read_unlock();
188
189		if (copy_to_user((void __user *)args[1], &b, sizeof(b)))
190			return -EFAULT;
191
192		return 0;
193	}
194
195	case BRCTL_GET_PORT_LIST:
196	{
197		int num, *indices;
198
199		num = args[2];
200		if (num < 0)
201			return -EINVAL;
202		if (num == 0)
203			num = 256;
204		if (num > BR_MAX_PORTS)
205			num = BR_MAX_PORTS;
206
207		indices = kcalloc(num, sizeof(int), GFP_KERNEL);
208		if (indices == NULL)
209			return -ENOMEM;
210
211		get_port_ifindices(br, indices, num);
212		if (copy_to_user(argp, indices, array_size(num, sizeof(int))))
213			num =  -EFAULT;
214		kfree(indices);
215		return num;
216	}
217
218	case BRCTL_SET_BRIDGE_FORWARD_DELAY:
219		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
220			return -EPERM;
221
222		ret = br_set_forward_delay(br, args[1]);
223		break;
224
225	case BRCTL_SET_BRIDGE_HELLO_TIME:
226		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
227			return -EPERM;
228
229		ret = br_set_hello_time(br, args[1]);
230		break;
231
232	case BRCTL_SET_BRIDGE_MAX_AGE:
233		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
234			return -EPERM;
235
236		ret = br_set_max_age(br, args[1]);
237		break;
238
239	case BRCTL_SET_AGEING_TIME:
240		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
241			return -EPERM;
242
243		ret = br_set_ageing_time(br, args[1]);
244		break;
245
246	case BRCTL_GET_PORT_INFO:
247	{
248		struct __port_info p;
249		struct net_bridge_port *pt;
250
251		rcu_read_lock();
252		if ((pt = br_get_port(br, args[2])) == NULL) {
253			rcu_read_unlock();
254			return -EINVAL;
255		}
256
257		memset(&p, 0, sizeof(struct __port_info));
258		memcpy(&p.designated_root, &pt->designated_root, 8);
259		memcpy(&p.designated_bridge, &pt->designated_bridge, 8);
260		p.port_id = pt->port_id;
261		p.designated_port = pt->designated_port;
262		p.path_cost = pt->path_cost;
263		p.designated_cost = pt->designated_cost;
264		p.state = pt->state;
265		p.top_change_ack = pt->topology_change_ack;
266		p.config_pending = pt->config_pending;
267		p.message_age_timer_value = br_timer_value(&pt->message_age_timer);
268		p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer);
269		p.hold_timer_value = br_timer_value(&pt->hold_timer);
270
271		rcu_read_unlock();
272
273		if (copy_to_user(argp, &p, sizeof(p)))
274			return -EFAULT;
275
276		return 0;
277	}
278
279	case BRCTL_SET_BRIDGE_STP_STATE:
280		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
281			return -EPERM;
282
283		ret = br_stp_set_enabled(br, args[1], NULL);
284		break;
285
286	case BRCTL_SET_BRIDGE_PRIORITY:
287		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
288			return -EPERM;
289
290		br_stp_set_bridge_priority(br, args[1]);
291		ret = 0;
292		break;
293
294	case BRCTL_SET_PORT_PRIORITY:
295	{
296		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
297			return -EPERM;
298
299		spin_lock_bh(&br->lock);
300		if ((p = br_get_port(br, args[1])) == NULL)
301			ret = -EINVAL;
302		else
303			ret = br_stp_set_port_priority(p, args[2]);
304		spin_unlock_bh(&br->lock);
305		break;
306	}
307
308	case BRCTL_SET_PATH_COST:
309	{
310		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
311			return -EPERM;
312
313		spin_lock_bh(&br->lock);
314		if ((p = br_get_port(br, args[1])) == NULL)
315			ret = -EINVAL;
316		else
317			ret = br_stp_set_path_cost(p, args[2]);
318		spin_unlock_bh(&br->lock);
319		break;
320	}
321
322	case BRCTL_GET_FDB_ENTRIES:
323		return get_fdb_entries(br, argp, args[2], args[3]);
324
325	default:
326		ret = -EOPNOTSUPP;
327	}
328
329	if (!ret) {
330		if (p)
331			br_ifinfo_notify(RTM_NEWLINK, NULL, p);
332		else
333			netdev_state_change(br->dev);
334	}
335
336	return ret;
337}
338
339static int old_deviceless(struct net *net, void __user *data)
340{
341	unsigned long args[3];
342	void __user *argp;
343	int ret;
344
345	ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data);
346	if (ret)
347		return ret;
348
349	switch (args[0]) {
350	case BRCTL_GET_VERSION:
351		return BRCTL_VERSION;
352
353	case BRCTL_GET_BRIDGES:
354	{
355		int *indices;
356		int ret = 0;
357
358		if (args[2] >= 2048)
359			return -ENOMEM;
360		indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
361		if (indices == NULL)
362			return -ENOMEM;
363
364		args[2] = get_bridge_ifindices(net, indices, args[2]);
365
366		ret = copy_to_user(argp, indices,
367				   array_size(args[2], sizeof(int)))
368			? -EFAULT : args[2];
369
370		kfree(indices);
371		return ret;
372	}
373
374	case BRCTL_ADD_BRIDGE:
375	case BRCTL_DEL_BRIDGE:
376	{
377		char buf[IFNAMSIZ];
378
379		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
380			return -EPERM;
381
382		if (copy_from_user(buf, argp, IFNAMSIZ))
383			return -EFAULT;
384
385		buf[IFNAMSIZ-1] = 0;
386
387		if (args[0] == BRCTL_ADD_BRIDGE)
388			return br_add_bridge(net, buf);
389
390		return br_del_bridge(net, buf);
391	}
392	}
393
394	return -EOPNOTSUPP;
395}
396
397int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd,
398		  struct ifreq *ifr, void __user *uarg)
399{
400	int ret = -EOPNOTSUPP;
401
402	rtnl_lock();
403
404	switch (cmd) {
405	case SIOCGIFBR:
406	case SIOCSIFBR:
407		ret = old_deviceless(net, uarg);
408		break;
409	case SIOCBRADDBR:
410	case SIOCBRDELBR:
411	{
412		char buf[IFNAMSIZ];
413
414		if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) {
415			ret = -EPERM;
416			break;
417		}
418
419		if (copy_from_user(buf, uarg, IFNAMSIZ)) {
420			ret = -EFAULT;
421			break;
422		}
423
424		buf[IFNAMSIZ-1] = 0;
425		if (cmd == SIOCBRADDBR)
426			ret = br_add_bridge(net, buf);
427		else
428			ret = br_del_bridge(net, buf);
429	}
430		break;
431	case SIOCBRADDIF:
432	case SIOCBRDELIF:
433		ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF);
434		break;
435	}
436
437	rtnl_unlock();
438
439	return ret;
440}
441