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, num*sizeof(struct __fdb_entry)))
  75                         num = -EFAULT;
  76         }
  77         kfree(buf);
  78
  79         return num;
  80 }
  81
  82 /* called with RTNL */
  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  */
 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
 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
 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 }