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
21 static 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 */
39 static 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 */
56 static 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 */
85 static 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
107 static 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;
135 fault:
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 */
144 int 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
339 static 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
397 int 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
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