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 */
old_dev_ioctl(struct net_device * dev,struct ifreq * rq,int cmd)109 static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
110 {
111 struct net_bridge *br = netdev_priv(dev);
112 struct net_bridge_port *p = NULL;
113 unsigned long args[4];
114 int ret = -EOPNOTSUPP;
115
116 if (copy_from_user(args, rq->ifr_data, sizeof(args)))
117 return -EFAULT;
118
119 switch (args[0]) {
120 case BRCTL_ADD_IF:
121 case BRCTL_DEL_IF:
122 return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);
123
124 case BRCTL_GET_BRIDGE_INFO:
125 {
126 struct __bridge_info b;
127
128 memset(&b, 0, sizeof(struct __bridge_info));
129 rcu_read_lock();
130 memcpy(&b.designated_root, &br->designated_root, 8);
131 memcpy(&b.bridge_id, &br->bridge_id, 8);
132 b.root_path_cost = br->root_path_cost;
133 b.max_age = jiffies_to_clock_t(br->max_age);
134 b.hello_time = jiffies_to_clock_t(br->hello_time);
135 b.forward_delay = br->forward_delay;
136 b.bridge_max_age = br->bridge_max_age;
137 b.bridge_hello_time = br->bridge_hello_time;
138 b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay);
139 b.topology_change = br->topology_change;
140 b.topology_change_detected = br->topology_change_detected;
141 b.root_port = br->root_port;
142
143 b.stp_enabled = (br->stp_enabled != BR_NO_STP);
144 b.ageing_time = jiffies_to_clock_t(br->ageing_time);
145 b.hello_timer_value = br_timer_value(&br->hello_timer);
146 b.tcn_timer_value = br_timer_value(&br->tcn_timer);
147 b.topology_change_timer_value = br_timer_value(&br->topology_change_timer);
148 b.gc_timer_value = br_timer_value(&br->gc_work.timer);
149 rcu_read_unlock();
150
151 if (copy_to_user((void __user *)args[1], &b, sizeof(b)))
152 return -EFAULT;
153
154 return 0;
155 }
156
157 case BRCTL_GET_PORT_LIST:
158 {
159 int num, *indices;
160
161 num = args[2];
162 if (num < 0)
163 return -EINVAL;
164 if (num == 0)
165 num = 256;
166 if (num > BR_MAX_PORTS)
167 num = BR_MAX_PORTS;
168
169 indices = kcalloc(num, sizeof(int), GFP_KERNEL);
170 if (indices == NULL)
171 return -ENOMEM;
172
173 get_port_ifindices(br, indices, num);
174 if (copy_to_user((void __user *)args[1], indices, num*sizeof(int)))
175 num = -EFAULT;
176 kfree(indices);
177 return num;
178 }
179
180 case BRCTL_SET_BRIDGE_FORWARD_DELAY:
181 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
182 return -EPERM;
183
184 ret = br_set_forward_delay(br, args[1]);
185 break;
186
187 case BRCTL_SET_BRIDGE_HELLO_TIME:
188 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
189 return -EPERM;
190
191 ret = br_set_hello_time(br, args[1]);
192 break;
193
194 case BRCTL_SET_BRIDGE_MAX_AGE:
195 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
196 return -EPERM;
197
198 ret = br_set_max_age(br, args[1]);
199 break;
200
201 case BRCTL_SET_AGEING_TIME:
202 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
203 return -EPERM;
204
205 ret = br_set_ageing_time(br, args[1]);
206 break;
207
208 case BRCTL_GET_PORT_INFO:
209 {
210 struct __port_info p;
211 struct net_bridge_port *pt;
212
213 rcu_read_lock();
214 if ((pt = br_get_port(br, args[2])) == NULL) {
215 rcu_read_unlock();
216 return -EINVAL;
217 }
218
219 memset(&p, 0, sizeof(struct __port_info));
220 memcpy(&p.designated_root, &pt->designated_root, 8);
221 memcpy(&p.designated_bridge, &pt->designated_bridge, 8);
222 p.port_id = pt->port_id;
223 p.designated_port = pt->designated_port;
224 p.path_cost = pt->path_cost;
225 p.designated_cost = pt->designated_cost;
226 p.state = pt->state;
227 p.top_change_ack = pt->topology_change_ack;
228 p.config_pending = pt->config_pending;
229 p.message_age_timer_value = br_timer_value(&pt->message_age_timer);
230 p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer);
231 p.hold_timer_value = br_timer_value(&pt->hold_timer);
232
233 rcu_read_unlock();
234
235 if (copy_to_user((void __user *)args[1], &p, sizeof(p)))
236 return -EFAULT;
237
238 return 0;
239 }
240
241 case BRCTL_SET_BRIDGE_STP_STATE:
242 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
243 return -EPERM;
244
245 ret = br_stp_set_enabled(br, args[1], NULL);
246 break;
247
248 case BRCTL_SET_BRIDGE_PRIORITY:
249 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
250 return -EPERM;
251
252 br_stp_set_bridge_priority(br, args[1]);
253 ret = 0;
254 break;
255
256 case BRCTL_SET_PORT_PRIORITY:
257 {
258 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
259 return -EPERM;
260
261 spin_lock_bh(&br->lock);
262 if ((p = br_get_port(br, args[1])) == NULL)
263 ret = -EINVAL;
264 else
265 ret = br_stp_set_port_priority(p, args[2]);
266 spin_unlock_bh(&br->lock);
267 break;
268 }
269
270 case BRCTL_SET_PATH_COST:
271 {
272 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
273 return -EPERM;
274
275 spin_lock_bh(&br->lock);
276 if ((p = br_get_port(br, args[1])) == NULL)
277 ret = -EINVAL;
278 else
279 ret = br_stp_set_path_cost(p, args[2]);
280 spin_unlock_bh(&br->lock);
281 break;
282 }
283
284 case BRCTL_GET_FDB_ENTRIES:
285 return get_fdb_entries(br, (void __user *)args[1],
286 args[2], args[3]);
287 }
288
289 if (!ret) {
290 if (p)
291 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
292 else
293 netdev_state_change(br->dev);
294 }
295
296 return ret;
297 }
298
old_deviceless(struct net * net,void __user * uarg)299 static int old_deviceless(struct net *net, void __user *uarg)
300 {
301 unsigned long args[3];
302
303 if (copy_from_user(args, uarg, sizeof(args)))
304 return -EFAULT;
305
306 switch (args[0]) {
307 case BRCTL_GET_VERSION:
308 return BRCTL_VERSION;
309
310 case BRCTL_GET_BRIDGES:
311 {
312 int *indices;
313 int ret = 0;
314
315 if (args[2] >= 2048)
316 return -ENOMEM;
317 indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
318 if (indices == NULL)
319 return -ENOMEM;
320
321 args[2] = get_bridge_ifindices(net, indices, args[2]);
322
323 ret = copy_to_user((void __user *)args[1], indices, args[2]*sizeof(int))
324 ? -EFAULT : args[2];
325
326 kfree(indices);
327 return ret;
328 }
329
330 case BRCTL_ADD_BRIDGE:
331 case BRCTL_DEL_BRIDGE:
332 {
333 char buf[IFNAMSIZ];
334
335 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
336 return -EPERM;
337
338 if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
339 return -EFAULT;
340
341 buf[IFNAMSIZ-1] = 0;
342
343 if (args[0] == BRCTL_ADD_BRIDGE)
344 return br_add_bridge(net, buf);
345
346 return br_del_bridge(net, buf);
347 }
348 }
349
350 return -EOPNOTSUPP;
351 }
352
br_ioctl_deviceless_stub(struct net * net,unsigned int cmd,void __user * uarg)353 int br_ioctl_deviceless_stub(struct net *net, unsigned int cmd, void __user *uarg)
354 {
355 switch (cmd) {
356 case SIOCGIFBR:
357 case SIOCSIFBR:
358 return old_deviceless(net, uarg);
359
360 case SIOCBRADDBR:
361 case SIOCBRDELBR:
362 {
363 char buf[IFNAMSIZ];
364
365 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
366 return -EPERM;
367
368 if (copy_from_user(buf, uarg, IFNAMSIZ))
369 return -EFAULT;
370
371 buf[IFNAMSIZ-1] = 0;
372 if (cmd == SIOCBRADDBR)
373 return br_add_bridge(net, buf);
374
375 return br_del_bridge(net, buf);
376 }
377 }
378 return -EOPNOTSUPP;
379 }
380
br_dev_ioctl(struct net_device * dev,struct ifreq * rq,int cmd)381 int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
382 {
383 struct net_bridge *br = netdev_priv(dev);
384
385 switch (cmd) {
386 case SIOCDEVPRIVATE:
387 return old_dev_ioctl(dev, rq, cmd);
388
389 case SIOCBRADDIF:
390 case SIOCBRDELIF:
391 return add_del_if(br, rq->ifr_ifindex, cmd == SIOCBRADDIF);
392
393 }
394
395 br_debug(br, "Bridge does not support ioctl 0x%x\n", cmd);
396 return -EOPNOTSUPP;
397 }
398