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 (netif_is_bridge_master(dev))
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,
75 array_size(num, sizeof(struct __fdb_entry))))
76 num = -EFAULT;
77 }
78 kfree(buf);
79
80 return num;
81 }
82
83 /* called with RTNL */
add_del_if(struct net_bridge * br,int ifindex,int isadd)84 static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
85 {
86 struct net *net = dev_net(br->dev);
87 struct net_device *dev;
88 int ret;
89
90 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
91 return -EPERM;
92
93 dev = __dev_get_by_index(net, ifindex);
94 if (dev == NULL)
95 return -EINVAL;
96
97 if (isadd)
98 ret = br_add_if(br, dev, NULL);
99 else
100 ret = br_del_if(br, dev);
101
102 return ret;
103 }
104
105 /*
106 * Legacy ioctl's through SIOCDEVPRIVATE
107 * This interface is deprecated because it was too difficult
108 * to do the translation for 32/64bit ioctl compatibility.
109 */
br_dev_siocdevprivate(struct net_device * dev,struct ifreq * rq,void __user * data,int cmd)110 int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user *data, int cmd)
111 {
112 struct net_bridge *br = netdev_priv(dev);
113 struct net_bridge_port *p = NULL;
114 unsigned long args[4];
115 void __user *argp;
116 int ret = -EOPNOTSUPP;
117
118 if (in_compat_syscall()) {
119 unsigned int cargs[4];
120
121 if (copy_from_user(cargs, data, sizeof(cargs)))
122 return -EFAULT;
123
124 args[0] = cargs[0];
125 args[1] = cargs[1];
126 args[2] = cargs[2];
127 args[3] = cargs[3];
128
129 argp = compat_ptr(args[1]);
130 } else {
131 if (copy_from_user(args, data, sizeof(args)))
132 return -EFAULT;
133
134 argp = (void __user *)args[1];
135 }
136
137 switch (args[0]) {
138 case BRCTL_ADD_IF:
139 case BRCTL_DEL_IF:
140 return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);
141
142 case BRCTL_GET_BRIDGE_INFO:
143 {
144 struct __bridge_info b;
145
146 memset(&b, 0, sizeof(struct __bridge_info));
147 rcu_read_lock();
148 memcpy(&b.designated_root, &br->designated_root, 8);
149 memcpy(&b.bridge_id, &br->bridge_id, 8);
150 b.root_path_cost = br->root_path_cost;
151 b.max_age = jiffies_to_clock_t(br->max_age);
152 b.hello_time = jiffies_to_clock_t(br->hello_time);
153 b.forward_delay = br->forward_delay;
154 b.bridge_max_age = br->bridge_max_age;
155 b.bridge_hello_time = br->bridge_hello_time;
156 b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay);
157 b.topology_change = br->topology_change;
158 b.topology_change_detected = br->topology_change_detected;
159 b.root_port = br->root_port;
160
161 b.stp_enabled = (br->stp_enabled != BR_NO_STP);
162 b.ageing_time = jiffies_to_clock_t(br->ageing_time);
163 b.hello_timer_value = br_timer_value(&br->hello_timer);
164 b.tcn_timer_value = br_timer_value(&br->tcn_timer);
165 b.topology_change_timer_value = br_timer_value(&br->topology_change_timer);
166 b.gc_timer_value = br_timer_value(&br->gc_work.timer);
167 rcu_read_unlock();
168
169 if (copy_to_user((void __user *)args[1], &b, sizeof(b)))
170 return -EFAULT;
171
172 return 0;
173 }
174
175 case BRCTL_GET_PORT_LIST:
176 {
177 int num, *indices;
178
179 num = args[2];
180 if (num < 0)
181 return -EINVAL;
182 if (num == 0)
183 num = 256;
184 if (num > BR_MAX_PORTS)
185 num = BR_MAX_PORTS;
186
187 indices = kcalloc(num, sizeof(int), GFP_KERNEL);
188 if (indices == NULL)
189 return -ENOMEM;
190
191 get_port_ifindices(br, indices, num);
192 if (copy_to_user(argp, indices, array_size(num, sizeof(int))))
193 num = -EFAULT;
194 kfree(indices);
195 return num;
196 }
197
198 case BRCTL_SET_BRIDGE_FORWARD_DELAY:
199 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
200 return -EPERM;
201
202 ret = br_set_forward_delay(br, args[1]);
203 break;
204
205 case BRCTL_SET_BRIDGE_HELLO_TIME:
206 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
207 return -EPERM;
208
209 ret = br_set_hello_time(br, args[1]);
210 break;
211
212 case BRCTL_SET_BRIDGE_MAX_AGE:
213 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
214 return -EPERM;
215
216 ret = br_set_max_age(br, args[1]);
217 break;
218
219 case BRCTL_SET_AGEING_TIME:
220 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
221 return -EPERM;
222
223 ret = br_set_ageing_time(br, args[1]);
224 break;
225
226 case BRCTL_GET_PORT_INFO:
227 {
228 struct __port_info p;
229 struct net_bridge_port *pt;
230
231 rcu_read_lock();
232 if ((pt = br_get_port(br, args[2])) == NULL) {
233 rcu_read_unlock();
234 return -EINVAL;
235 }
236
237 memset(&p, 0, sizeof(struct __port_info));
238 memcpy(&p.designated_root, &pt->designated_root, 8);
239 memcpy(&p.designated_bridge, &pt->designated_bridge, 8);
240 p.port_id = pt->port_id;
241 p.designated_port = pt->designated_port;
242 p.path_cost = pt->path_cost;
243 p.designated_cost = pt->designated_cost;
244 p.state = pt->state;
245 p.top_change_ack = pt->topology_change_ack;
246 p.config_pending = pt->config_pending;
247 p.message_age_timer_value = br_timer_value(&pt->message_age_timer);
248 p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer);
249 p.hold_timer_value = br_timer_value(&pt->hold_timer);
250
251 rcu_read_unlock();
252
253 if (copy_to_user(argp, &p, sizeof(p)))
254 return -EFAULT;
255
256 return 0;
257 }
258
259 case BRCTL_SET_BRIDGE_STP_STATE:
260 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
261 return -EPERM;
262
263 ret = br_stp_set_enabled(br, args[1], NULL);
264 break;
265
266 case BRCTL_SET_BRIDGE_PRIORITY:
267 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
268 return -EPERM;
269
270 br_stp_set_bridge_priority(br, args[1]);
271 ret = 0;
272 break;
273
274 case BRCTL_SET_PORT_PRIORITY:
275 {
276 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
277 return -EPERM;
278
279 spin_lock_bh(&br->lock);
280 if ((p = br_get_port(br, args[1])) == NULL)
281 ret = -EINVAL;
282 else
283 ret = br_stp_set_port_priority(p, args[2]);
284 spin_unlock_bh(&br->lock);
285 break;
286 }
287
288 case BRCTL_SET_PATH_COST:
289 {
290 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
291 return -EPERM;
292
293 spin_lock_bh(&br->lock);
294 if ((p = br_get_port(br, args[1])) == NULL)
295 ret = -EINVAL;
296 else
297 ret = br_stp_set_path_cost(p, args[2]);
298 spin_unlock_bh(&br->lock);
299 break;
300 }
301
302 case BRCTL_GET_FDB_ENTRIES:
303 return get_fdb_entries(br, argp, args[2], args[3]);
304 }
305
306 if (!ret) {
307 if (p)
308 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
309 else
310 netdev_state_change(br->dev);
311 }
312
313 return ret;
314 }
315
old_deviceless(struct net * net,void __user * uarg)316 static int old_deviceless(struct net *net, void __user *uarg)
317 {
318 unsigned long args[3];
319
320 if (copy_from_user(args, uarg, sizeof(args)))
321 return -EFAULT;
322
323 switch (args[0]) {
324 case BRCTL_GET_VERSION:
325 return BRCTL_VERSION;
326
327 case BRCTL_GET_BRIDGES:
328 {
329 int *indices;
330 int ret = 0;
331
332 if (args[2] >= 2048)
333 return -ENOMEM;
334 indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
335 if (indices == NULL)
336 return -ENOMEM;
337
338 args[2] = get_bridge_ifindices(net, indices, args[2]);
339
340 ret = copy_to_user((void __user *)args[1], indices,
341 array_size(args[2], sizeof(int)))
342 ? -EFAULT : args[2];
343
344 kfree(indices);
345 return ret;
346 }
347
348 case BRCTL_ADD_BRIDGE:
349 case BRCTL_DEL_BRIDGE:
350 {
351 char buf[IFNAMSIZ];
352
353 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
354 return -EPERM;
355
356 if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
357 return -EFAULT;
358
359 buf[IFNAMSIZ-1] = 0;
360
361 if (args[0] == BRCTL_ADD_BRIDGE)
362 return br_add_bridge(net, buf);
363
364 return br_del_bridge(net, buf);
365 }
366 }
367
368 return -EOPNOTSUPP;
369 }
370
br_ioctl_stub(struct net * net,struct net_bridge * br,unsigned int cmd,struct ifreq * ifr,void __user * uarg)371 int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd,
372 struct ifreq *ifr, void __user *uarg)
373 {
374 int ret = -EOPNOTSUPP;
375
376 rtnl_lock();
377
378 switch (cmd) {
379 case SIOCGIFBR:
380 case SIOCSIFBR:
381 ret = old_deviceless(net, uarg);
382 break;
383 case SIOCBRADDBR:
384 case SIOCBRDELBR:
385 {
386 char buf[IFNAMSIZ];
387
388 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) {
389 ret = -EPERM;
390 break;
391 }
392
393 if (copy_from_user(buf, uarg, IFNAMSIZ)) {
394 ret = -EFAULT;
395 break;
396 }
397
398 buf[IFNAMSIZ-1] = 0;
399 if (cmd == SIOCBRADDBR)
400 ret = br_add_bridge(net, buf);
401 else
402 ret = br_del_bridge(net, buf);
403 }
404 break;
405 case SIOCBRADDIF:
406 case SIOCBRDELIF:
407 ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF);
408 break;
409 }
410
411 rtnl_unlock();
412
413 return ret;
414 }
415