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 to
 107  * to do the translation for 32/64bit ioctl compatibility.
 108  */
 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                 br_stp_set_enabled(br, args[1]);
 246                 ret = 0;
 247                 break;
 248
 249         case BRCTL_SET_BRIDGE_PRIORITY:
 250                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 251                         return -EPERM;
 252
 253                 br_stp_set_bridge_priority(br, args[1]);
 254                 ret = 0;
 255                 break;
 256
 257         case BRCTL_SET_PORT_PRIORITY:
 258         {
 259                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 260                         return -EPERM;
 261
 262                 spin_lock_bh(&br->lock);
 263                 if ((p = br_get_port(br, args[1])) == NULL)
 264                         ret = -EINVAL;
 265                 else
 266                         ret = br_stp_set_port_priority(p, args[2]);
 267                 spin_unlock_bh(&br->lock);
 268                 break;
 269         }
 270
 271         case BRCTL_SET_PATH_COST:
 272         {
 273                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 274                         return -EPERM;
 275
 276                 spin_lock_bh(&br->lock);
 277                 if ((p = br_get_port(br, args[1])) == NULL)
 278                         ret = -EINVAL;
 279                 else
 280                         ret = br_stp_set_path_cost(p, args[2]);
 281                 spin_unlock_bh(&br->lock);
 282                 break;
 283         }
 284
 285         case BRCTL_GET_FDB_ENTRIES:
 286                 return get_fdb_entries(br, (void __user *)args[1],
 287                                        args[2], args[3]);
 288         }
 289
 290         if (!ret) {
 291                 if (p)
 292                         br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 293                 else
 294                         netdev_state_change(br->dev);
 295         }
 296
 297         return ret;
 298 }
 299
 300 static int old_deviceless(struct net *net, void __user *uarg)
 301 {
 302         unsigned long args[3];
 303
 304         if (copy_from_user(args, uarg, sizeof(args)))
 305                 return -EFAULT;
 306
 307         switch (args[0]) {
 308         case BRCTL_GET_VERSION:
 309                 return BRCTL_VERSION;
 310
 311         case BRCTL_GET_BRIDGES:
 312         {
 313                 int *indices;
 314                 int ret = 0;
 315
 316                 if (args[2] >= 2048)
 317                         return -ENOMEM;
 318                 indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
 319                 if (indices == NULL)
 320                         return -ENOMEM;
 321
 322                 args[2] = get_bridge_ifindices(net, indices, args[2]);
 323
 324                 ret = copy_to_user((void __user *)args[1], indices, args[2]*sizeof(int))
 325                         ? -EFAULT : args[2];
 326
 327                 kfree(indices);
 328                 return ret;
 329         }
 330
 331         case BRCTL_ADD_BRIDGE:
 332         case BRCTL_DEL_BRIDGE:
 333         {
 334                 char buf[IFNAMSIZ];
 335
 336                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 337                         return -EPERM;
 338
 339                 if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
 340                         return -EFAULT;
 341
 342                 buf[IFNAMSIZ-1] = 0;
 343
 344                 if (args[0] == BRCTL_ADD_BRIDGE)
 345                         return br_add_bridge(net, buf);
 346
 347                 return br_del_bridge(net, buf);
 348         }
 349         }
 350
 351         return -EOPNOTSUPP;
 352 }
 353
 354 int br_ioctl_deviceless_stub(struct net *net, unsigned int cmd, void __user *uarg)
 355 {
 356         switch (cmd) {
 357         case SIOCGIFBR:
 358         case SIOCSIFBR:
 359                 return old_deviceless(net, uarg);
 360
 361         case SIOCBRADDBR:
 362         case SIOCBRDELBR:
 363         {
 364                 char buf[IFNAMSIZ];
 365
 366                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 367                         return -EPERM;
 368
 369                 if (copy_from_user(buf, uarg, IFNAMSIZ))
 370                         return -EFAULT;
 371
 372                 buf[IFNAMSIZ-1] = 0;
 373                 if (cmd == SIOCBRADDBR)
 374                         return br_add_bridge(net, buf);
 375
 376                 return br_del_bridge(net, buf);
 377         }
 378         }
 379         return -EOPNOTSUPP;
 380 }
 381
 382 int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 383 {
 384         struct net_bridge *br = netdev_priv(dev);
 385
 386         switch (cmd) {
 387         case SIOCDEVPRIVATE:
 388                 return old_dev_ioctl(dev, rq, cmd);
 389
 390         case SIOCBRADDIF:
 391         case SIOCBRDELIF:
 392                 return add_del_if(br, rq->ifr_ifindex, cmd == SIOCBRADDIF);
 393
 394         }
 395
 396         br_debug(br, "Bridge does not support ioctl 0x%x\n", cmd);
 397         return -EOPNOTSUPP;
 398 }