net/bridge/br_ioctl.c

   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
  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 */
  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  */
  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 */
  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  */
 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
 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
 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 }