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/compat.h>
  12 #include <linux/kernel.h>
  13 #include <linux/if_bridge.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/slab.h>
  16 #include <linux/times.h>
  17 #include <net/net_namespace.h>
  18 #include <linux/uaccess.h>
  19 #include "br_private.h"
  20
  21 static int get_bridge_ifindices(struct net *net, int *indices, int num)
  22 {
  23         struct net_device *dev;
  24         int i = 0;
  25
  26         rcu_read_lock();
  27         for_each_netdev_rcu(net, dev) {
  28                 if (i >= num)
  29                         break;
  30                 if (netif_is_bridge_master(dev))
  31                         indices[i++] = dev->ifindex;
  32         }
  33         rcu_read_unlock();
  34
  35         return i;
  36 }
  37
  38 /* called with RTNL */
  39 static void get_port_ifindices(struct net_bridge *br, int *ifindices, int num)
  40 {
  41         struct net_bridge_port *p;
  42
  43         list_for_each_entry(p, &br->port_list, list) {
  44                 if (p->port_no < num)
  45                         ifindices[p->port_no] = p->dev->ifindex;
  46         }
  47 }
  48
  49 /*
  50  * Format up to a page worth of forwarding table entries
  51  * userbuf -- where to copy result
  52  * maxnum  -- maximum number of entries desired
  53  *            (limited to a page for sanity)
  54  * offset  -- number of records to skip
  55  */
  56 static int get_fdb_entries(struct net_bridge *br, void __user *userbuf,
  57                            unsigned long maxnum, unsigned long offset)
  58 {
  59         int num;
  60         void *buf;
  61         size_t size;
  62
  63         /* Clamp size to PAGE_SIZE, test maxnum to avoid overflow */
  64         if (maxnum > PAGE_SIZE/sizeof(struct __fdb_entry))
  65                 maxnum = PAGE_SIZE/sizeof(struct __fdb_entry);
  66
  67         size = maxnum * sizeof(struct __fdb_entry);
  68
  69         buf = kmalloc(size, GFP_USER);
  70         if (!buf)
  71                 return -ENOMEM;
  72
  73         num = br_fdb_fillbuf(br, buf, maxnum, offset);
  74         if (num > 0) {
  75                 if (copy_to_user(userbuf, buf,
  76                                  array_size(num, sizeof(struct __fdb_entry))))
  77                         num = -EFAULT;
  78         }
  79         kfree(buf);
  80
  81         return num;
  82 }
  83
  84 /* called with RTNL */
  85 static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
  86 {
  87         struct net *net = dev_net(br->dev);
  88         struct net_device *dev;
  89         int ret;
  90
  91         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
  92                 return -EPERM;
  93
  94         dev = __dev_get_by_index(net, ifindex);
  95         if (dev == NULL)
  96                 return -EINVAL;
  97
  98         if (isadd)
  99                 ret = br_add_if(br, dev, NULL);
 100         else
 101                 ret = br_del_if(br, dev);
 102
 103         return ret;
 104 }
 105
 106 #define BR_UARGS_MAX 4
 107 static int br_dev_read_uargs(unsigned long *args, size_t nr_args,
 108                              void __user **argp, void __user *data)
 109 {
 110         int ret;
 111
 112         if (nr_args < 2 || nr_args > BR_UARGS_MAX)
 113                 return -EINVAL;
 114
 115         if (in_compat_syscall()) {
 116                 unsigned int cargs[BR_UARGS_MAX];
 117                 int i;
 118
 119                 ret = copy_from_user(cargs, data, nr_args * sizeof(*cargs));
 120                 if (ret)
 121                         goto fault;
 122
 123                 for (i = 0; i < nr_args; ++i)
 124                         args[i] = cargs[i];
 125
 126                 *argp = compat_ptr(args[1]);
 127         } else {
 128                 ret = copy_from_user(args, data, nr_args * sizeof(*args));
 129                 if (ret)
 130                         goto fault;
 131                 *argp = (void __user *)args[1];
 132         }
 133
 134         return 0;
 135 fault:
 136         return -EFAULT;
 137 }
 138
 139 /*
 140  * Legacy ioctl's through SIOCDEVPRIVATE
 141  * This interface is deprecated because it was too difficult
 142  * to do the translation for 32/64bit ioctl compatibility.
 143  */
 144 int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq,
 145                           void __user *data, int cmd)
 146 {
 147         struct net_bridge *br = netdev_priv(dev);
 148         struct net_bridge_port *p = NULL;
 149         unsigned long args[4];
 150         void __user *argp;
 151         int ret;
 152
 153         ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data);
 154         if (ret)
 155                 return ret;
 156
 157         switch (args[0]) {
 158         case BRCTL_ADD_IF:
 159         case BRCTL_DEL_IF:
 160                 return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);
 161
 162         case BRCTL_GET_BRIDGE_INFO:
 163         {
 164                 struct __bridge_info b;
 165
 166                 memset(&b, 0, sizeof(struct __bridge_info));
 167                 rcu_read_lock();
 168                 memcpy(&b.designated_root, &br->designated_root, 8);
 169                 memcpy(&b.bridge_id, &br->bridge_id, 8);
 170                 b.root_path_cost = br->root_path_cost;
 171                 b.max_age = jiffies_to_clock_t(br->max_age);
 172                 b.hello_time = jiffies_to_clock_t(br->hello_time);
 173                 b.forward_delay = br->forward_delay;
 174                 b.bridge_max_age = br->bridge_max_age;
 175                 b.bridge_hello_time = br->bridge_hello_time;
 176                 b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay);
 177                 b.topology_change = br->topology_change;
 178                 b.topology_change_detected = br->topology_change_detected;
 179                 b.root_port = br->root_port;
 180
 181                 b.stp_enabled = (br->stp_enabled != BR_NO_STP);
 182                 b.ageing_time = jiffies_to_clock_t(br->ageing_time);
 183                 b.hello_timer_value = br_timer_value(&br->hello_timer);
 184                 b.tcn_timer_value = br_timer_value(&br->tcn_timer);
 185                 b.topology_change_timer_value = br_timer_value(&br->topology_change_timer);
 186                 b.gc_timer_value = br_timer_value(&br->gc_work.timer);
 187                 rcu_read_unlock();
 188
 189                 if (copy_to_user((void __user *)args[1], &b, sizeof(b)))
 190                         return -EFAULT;
 191
 192                 return 0;
 193         }
 194
 195         case BRCTL_GET_PORT_LIST:
 196         {
 197                 int num, *indices;
 198
 199                 num = args[2];
 200                 if (num < 0)
 201                         return -EINVAL;
 202                 if (num == 0)
 203                         num = 256;
 204                 if (num > BR_MAX_PORTS)
 205                         num = BR_MAX_PORTS;
 206
 207                 indices = kcalloc(num, sizeof(int), GFP_KERNEL);
 208                 if (indices == NULL)
 209                         return -ENOMEM;
 210
 211                 get_port_ifindices(br, indices, num);
 212                 if (copy_to_user(argp, indices, array_size(num, sizeof(int))))
 213                         num =  -EFAULT;
 214                 kfree(indices);
 215                 return num;
 216         }
 217
 218         case BRCTL_SET_BRIDGE_FORWARD_DELAY:
 219                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 220                         return -EPERM;
 221
 222                 ret = br_set_forward_delay(br, args[1]);
 223                 break;
 224
 225         case BRCTL_SET_BRIDGE_HELLO_TIME:
 226                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 227                         return -EPERM;
 228
 229                 ret = br_set_hello_time(br, args[1]);
 230                 break;
 231
 232         case BRCTL_SET_BRIDGE_MAX_AGE:
 233                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 234                         return -EPERM;
 235
 236                 ret = br_set_max_age(br, args[1]);
 237                 break;
 238
 239         case BRCTL_SET_AGEING_TIME:
 240                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 241                         return -EPERM;
 242
 243                 ret = br_set_ageing_time(br, args[1]);
 244                 break;
 245
 246         case BRCTL_GET_PORT_INFO:
 247         {
 248                 struct __port_info p;
 249                 struct net_bridge_port *pt;
 250
 251                 rcu_read_lock();
 252                 if ((pt = br_get_port(br, args[2])) == NULL) {
 253                         rcu_read_unlock();
 254                         return -EINVAL;
 255                 }
 256
 257                 memset(&p, 0, sizeof(struct __port_info));
 258                 memcpy(&p.designated_root, &pt->designated_root, 8);
 259                 memcpy(&p.designated_bridge, &pt->designated_bridge, 8);
 260                 p.port_id = pt->port_id;
 261                 p.designated_port = pt->designated_port;
 262                 p.path_cost = pt->path_cost;
 263                 p.designated_cost = pt->designated_cost;
 264                 p.state = pt->state;
 265                 p.top_change_ack = pt->topology_change_ack;
 266                 p.config_pending = pt->config_pending;
 267                 p.message_age_timer_value = br_timer_value(&pt->message_age_timer);
 268                 p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer);
 269                 p.hold_timer_value = br_timer_value(&pt->hold_timer);
 270
 271                 rcu_read_unlock();
 272
 273                 if (copy_to_user(argp, &p, sizeof(p)))
 274                         return -EFAULT;
 275
 276                 return 0;
 277         }
 278
 279         case BRCTL_SET_BRIDGE_STP_STATE:
 280                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 281                         return -EPERM;
 282
 283                 ret = br_stp_set_enabled(br, args[1], NULL);
 284                 break;
 285
 286         case BRCTL_SET_BRIDGE_PRIORITY:
 287                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 288                         return -EPERM;
 289
 290                 br_stp_set_bridge_priority(br, args[1]);
 291                 ret = 0;
 292                 break;
 293
 294         case BRCTL_SET_PORT_PRIORITY:
 295         {
 296                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 297                         return -EPERM;
 298
 299                 spin_lock_bh(&br->lock);
 300                 if ((p = br_get_port(br, args[1])) == NULL)
 301                         ret = -EINVAL;
 302                 else
 303                         ret = br_stp_set_port_priority(p, args[2]);
 304                 spin_unlock_bh(&br->lock);
 305                 break;
 306         }
 307
 308         case BRCTL_SET_PATH_COST:
 309         {
 310                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 311                         return -EPERM;
 312
 313                 spin_lock_bh(&br->lock);
 314                 if ((p = br_get_port(br, args[1])) == NULL)
 315                         ret = -EINVAL;
 316                 else
 317                         ret = br_stp_set_path_cost(p, args[2]);
 318                 spin_unlock_bh(&br->lock);
 319                 break;
 320         }
 321
 322         case BRCTL_GET_FDB_ENTRIES:
 323                 return get_fdb_entries(br, argp, args[2], args[3]);
 324
 325         default:
 326                 ret = -EOPNOTSUPP;
 327         }
 328
 329         if (!ret) {
 330                 if (p)
 331                         br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 332                 else
 333                         netdev_state_change(br->dev);
 334         }
 335
 336         return ret;
 337 }
 338
 339 static int old_deviceless(struct net *net, void __user *data)
 340 {
 341         unsigned long args[3];
 342         void __user *argp;
 343         int ret;
 344
 345         ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data);
 346         if (ret)
 347                 return ret;
 348
 349         switch (args[0]) {
 350         case BRCTL_GET_VERSION:
 351                 return BRCTL_VERSION;
 352
 353         case BRCTL_GET_BRIDGES:
 354         {
 355                 int *indices;
 356                 int ret = 0;
 357
 358                 if (args[2] >= 2048)
 359                         return -ENOMEM;
 360                 indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
 361                 if (indices == NULL)
 362                         return -ENOMEM;
 363
 364                 args[2] = get_bridge_ifindices(net, indices, args[2]);
 365
 366                 ret = copy_to_user(argp, indices,
 367                                    array_size(args[2], sizeof(int)))
 368                         ? -EFAULT : args[2];
 369
 370                 kfree(indices);
 371                 return ret;
 372         }
 373
 374         case BRCTL_ADD_BRIDGE:
 375         case BRCTL_DEL_BRIDGE:
 376         {
 377                 char buf[IFNAMSIZ];
 378
 379                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 380                         return -EPERM;
 381
 382                 if (copy_from_user(buf, argp, IFNAMSIZ))
 383                         return -EFAULT;
 384
 385                 buf[IFNAMSIZ-1] = 0;
 386
 387                 if (args[0] == BRCTL_ADD_BRIDGE)
 388                         return br_add_bridge(net, buf);
 389
 390                 return br_del_bridge(net, buf);
 391         }
 392         }
 393
 394         return -EOPNOTSUPP;
 395 }
 396
 397 int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd,
 398                   struct ifreq *ifr, void __user *uarg)
 399 {
 400         int ret = -EOPNOTSUPP;
 401
 402         rtnl_lock();
 403
 404         switch (cmd) {
 405         case SIOCGIFBR:
 406         case SIOCSIFBR:
 407                 ret = old_deviceless(net, uarg);
 408                 break;
 409         case SIOCBRADDBR:
 410         case SIOCBRDELBR:
 411         {
 412                 char buf[IFNAMSIZ];
 413
 414                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 415                         ret = -EPERM;
 416                         break;
 417                 }
 418
 419                 if (copy_from_user(buf, uarg, IFNAMSIZ)) {
 420                         ret = -EFAULT;
 421                         break;
 422                 }
 423
 424                 buf[IFNAMSIZ-1] = 0;
 425                 if (cmd == SIOCBRADDBR)
 426                         ret = br_add_bridge(net, buf);
 427                 else
 428                         ret = br_del_bridge(net, buf);
 429         }
 430                 break;
 431         case SIOCBRADDIF:
 432         case SIOCBRDELIF:
 433                 ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF);
 434                 break;
 435         }
 436
 437         rtnl_unlock();
 438
 439         return ret;
 440 }