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