net/bridge/br_ioctl.c

   1 /*
   2  *      Ioctl handler
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <buytenh@gnu.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/capability.h>
  15 #include <linux/kernel.h>
  16 #include <linux/if_bridge.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/slab.h>
  19 #include <linux/times.h>
  20 #include <net/net_namespace.h>
  21 #include <linux/uaccess.h>
  22 #include "br_private.h"
  23
  24 static int get_bridge_ifindices(struct net *net, int *indices, int num)
  25 {
  26         struct net_device *dev;
  27         int i = 0;
  28
  29         rcu_read_lock();
  30         for_each_netdev_rcu(net, dev) {
  31                 if (i >= num)
  32                         break;
  33                 if (dev->priv_flags & IFF_EBRIDGE)
  34                         indices[i++] = dev->ifindex;
  35         }
  36         rcu_read_unlock();
  37
  38         return i;
  39 }
  40
  41 /* called with RTNL */
  42 static void get_port_ifindices(struct net_bridge *br, int *ifindices, int num)
  43 {
  44         struct net_bridge_port *p;
  45
  46         list_for_each_entry(p, &br->port_list, list) {
  47                 if (p->port_no < num)
  48                         ifindices[p->port_no] = p->dev->ifindex;
  49         }
  50 }
  51
  52 /*
  53  * Format up to a page worth of forwarding table entries
  54  * userbuf -- where to copy result
  55  * maxnum  -- maximum number of entries desired
  56  *            (limited to a page for sanity)
  57  * offset  -- number of records to skip
  58  */
  59 static int get_fdb_entries(struct net_bridge *br, void __user *userbuf,
  60                            unsigned long maxnum, unsigned long offset)
  61 {
  62         int num;
  63         void *buf;
  64         size_t size;
  65
  66         /* Clamp size to PAGE_SIZE, test maxnum to avoid overflow */
  67         if (maxnum > PAGE_SIZE/sizeof(struct __fdb_entry))
  68                 maxnum = PAGE_SIZE/sizeof(struct __fdb_entry);
  69
  70         size = maxnum * sizeof(struct __fdb_entry);
  71
  72         buf = kmalloc(size, GFP_USER);
  73         if (!buf)
  74                 return -ENOMEM;
  75
  76         num = br_fdb_fillbuf(br, buf, maxnum, offset);
  77         if (num > 0) {
  78                 if (copy_to_user(userbuf, buf, num*sizeof(struct __fdb_entry)))
  79                         num = -EFAULT;
  80         }
  81         kfree(buf);
  82
  83         return num;
  84 }
  85
  86 /* called with RTNL */
  87 static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
  88 {
  89         struct net *net = dev_net(br->dev);
  90         struct net_device *dev;
  91         int ret;
  92
  93         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
  94                 return -EPERM;
  95
  96         dev = __dev_get_by_index(net, ifindex);
  97         if (dev == NULL)
  98                 return -EINVAL;
  99
 100         if (isadd)
 101                 ret = br_add_if(br, dev, NULL);
 102         else
 103                 ret = br_del_if(br, dev);
 104
 105         return ret;
 106 }
 107
 108 /*
 109  * Legacy ioctl's through SIOCDEVPRIVATE
 110  * This interface is deprecated because it was too difficult to
 111  * to do the translation for 32/64bit ioctl compatibility.
 112  */
 113 static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 114 {
 115         struct net_bridge *br = netdev_priv(dev);
 116         struct net_bridge_port *p = NULL;
 117         unsigned long args[4];
 118         int ret = -EOPNOTSUPP;
 119
 120         if (copy_from_user(args, rq->ifr_data, sizeof(args)))
 121                 return -EFAULT;
 122
 123         switch (args[0]) {
 124         case BRCTL_ADD_IF:
 125         case BRCTL_DEL_IF:
 126                 return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);
 127
 128         case BRCTL_GET_BRIDGE_INFO:
 129         {
 130                 struct __bridge_info b;
 131
 132                 memset(&b, 0, sizeof(struct __bridge_info));
 133                 rcu_read_lock();
 134                 memcpy(&b.designated_root, &br->designated_root, 8);
 135                 memcpy(&b.bridge_id, &br->bridge_id, 8);
 136                 b.root_path_cost = br->root_path_cost;
 137                 b.max_age = jiffies_to_clock_t(br->max_age);
 138                 b.hello_time = jiffies_to_clock_t(br->hello_time);
 139                 b.forward_delay = br->forward_delay;
 140                 b.bridge_max_age = br->bridge_max_age;
 141                 b.bridge_hello_time = br->bridge_hello_time;
 142                 b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay);
 143                 b.topology_change = br->topology_change;
 144                 b.topology_change_detected = br->topology_change_detected;
 145                 b.root_port = br->root_port;
 146
 147                 b.stp_enabled = (br->stp_enabled != BR_NO_STP);
 148                 b.ageing_time = jiffies_to_clock_t(br->ageing_time);
 149                 b.hello_timer_value = br_timer_value(&br->hello_timer);
 150                 b.tcn_timer_value = br_timer_value(&br->tcn_timer);
 151                 b.topology_change_timer_value = br_timer_value(&br->topology_change_timer);
 152                 b.gc_timer_value = br_timer_value(&br->gc_work.timer);
 153                 rcu_read_unlock();
 154
 155                 if (copy_to_user((void __user *)args[1], &b, sizeof(b)))
 156                         return -EFAULT;
 157
 158                 return 0;
 159         }
 160
 161         case BRCTL_GET_PORT_LIST:
 162         {
 163                 int num, *indices;
 164
 165                 num = args[2];
 166                 if (num < 0)
 167                         return -EINVAL;
 168                 if (num == 0)
 169                         num = 256;
 170                 if (num > BR_MAX_PORTS)
 171                         num = BR_MAX_PORTS;
 172
 173                 indices = kcalloc(num, sizeof(int), GFP_KERNEL);
 174                 if (indices == NULL)
 175                         return -ENOMEM;
 176
 177                 get_port_ifindices(br, indices, num);
 178                 if (copy_to_user((void __user *)args[1], indices, num*sizeof(int)))
 179                         num =  -EFAULT;
 180                 kfree(indices);
 181                 return num;
 182         }
 183
 184         case BRCTL_SET_BRIDGE_FORWARD_DELAY:
 185                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 186                         return -EPERM;
 187
 188                 ret = br_set_forward_delay(br, args[1]);
 189                 break;
 190
 191         case BRCTL_SET_BRIDGE_HELLO_TIME:
 192                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 193                         return -EPERM;
 194
 195                 ret = br_set_hello_time(br, args[1]);
 196                 break;
 197
 198         case BRCTL_SET_BRIDGE_MAX_AGE:
 199                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 200                         return -EPERM;
 201
 202                 ret = br_set_max_age(br, args[1]);
 203                 break;
 204
 205         case BRCTL_SET_AGEING_TIME:
 206                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 207                         return -EPERM;
 208
 209                 ret = br_set_ageing_time(br, args[1]);
 210                 break;
 211
 212         case BRCTL_GET_PORT_INFO:
 213         {
 214                 struct __port_info p;
 215                 struct net_bridge_port *pt;
 216
 217                 rcu_read_lock();
 218                 if ((pt = br_get_port(br, args[2])) == NULL) {
 219                         rcu_read_unlock();
 220                         return -EINVAL;
 221                 }
 222
 223                 memset(&p, 0, sizeof(struct __port_info));
 224                 memcpy(&p.designated_root, &pt->designated_root, 8);
 225                 memcpy(&p.designated_bridge, &pt->designated_bridge, 8);
 226                 p.port_id = pt->port_id;
 227                 p.designated_port = pt->designated_port;
 228                 p.path_cost = pt->path_cost;
 229                 p.designated_cost = pt->designated_cost;
 230                 p.state = pt->state;
 231                 p.top_change_ack = pt->topology_change_ack;
 232                 p.config_pending = pt->config_pending;
 233                 p.message_age_timer_value = br_timer_value(&pt->message_age_timer);
 234                 p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer);
 235                 p.hold_timer_value = br_timer_value(&pt->hold_timer);
 236
 237                 rcu_read_unlock();
 238
 239                 if (copy_to_user((void __user *)args[1], &p, sizeof(p)))
 240                         return -EFAULT;
 241
 242                 return 0;
 243         }
 244
 245         case BRCTL_SET_BRIDGE_STP_STATE:
 246                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 247                         return -EPERM;
 248
 249                 br_stp_set_enabled(br, args[1]);
 250                 ret = 0;
 251                 break;
 252
 253         case BRCTL_SET_BRIDGE_PRIORITY:
 254                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 255                         return -EPERM;
 256
 257                 br_stp_set_bridge_priority(br, args[1]);
 258                 ret = 0;
 259                 break;
 260
 261         case BRCTL_SET_PORT_PRIORITY:
 262         {
 263                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 264                         return -EPERM;
 265
 266                 spin_lock_bh(&br->lock);
 267                 if ((p = br_get_port(br, args[1])) == NULL)
 268                         ret = -EINVAL;
 269                 else
 270                         ret = br_stp_set_port_priority(p, args[2]);
 271                 spin_unlock_bh(&br->lock);
 272                 break;
 273         }
 274
 275         case BRCTL_SET_PATH_COST:
 276         {
 277                 if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 278                         return -EPERM;
 279
 280                 spin_lock_bh(&br->lock);
 281                 if ((p = br_get_port(br, args[1])) == NULL)
 282                         ret = -EINVAL;
 283                 else
 284                         ret = br_stp_set_path_cost(p, args[2]);
 285                 spin_unlock_bh(&br->lock);
 286                 break;
 287         }
 288
 289         case BRCTL_GET_FDB_ENTRIES:
 290                 return get_fdb_entries(br, (void __user *)args[1],
 291                                        args[2], args[3]);
 292         }
 293
 294         if (!ret) {
 295                 if (p)
 296                         br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 297                 else
 298                         netdev_state_change(br->dev);
 299         }
 300
 301         return ret;
 302 }
 303
 304 static int old_deviceless(struct net *net, void __user *uarg)
 305 {
 306         unsigned long args[3];
 307
 308         if (copy_from_user(args, uarg, sizeof(args)))
 309                 return -EFAULT;
 310
 311         switch (args[0]) {
 312         case BRCTL_GET_VERSION:
 313                 return BRCTL_VERSION;
 314
 315         case BRCTL_GET_BRIDGES:
 316         {
 317                 int *indices;
 318                 int ret = 0;
 319
 320                 if (args[2] >= 2048)
 321                         return -ENOMEM;
 322                 indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
 323                 if (indices == NULL)
 324                         return -ENOMEM;
 325
 326                 args[2] = get_bridge_ifindices(net, indices, args[2]);
 327
 328                 ret = copy_to_user((void __user *)args[1], indices, args[2]*sizeof(int))
 329                         ? -EFAULT : args[2];
 330
 331                 kfree(indices);
 332                 return ret;
 333         }
 334
 335         case BRCTL_ADD_BRIDGE:
 336         case BRCTL_DEL_BRIDGE:
 337         {
 338                 char buf[IFNAMSIZ];
 339
 340                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 341                         return -EPERM;
 342
 343                 if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
 344                         return -EFAULT;
 345
 346                 buf[IFNAMSIZ-1] = 0;
 347
 348                 if (args[0] == BRCTL_ADD_BRIDGE)
 349                         return br_add_bridge(net, buf);
 350
 351                 return br_del_bridge(net, buf);
 352         }
 353         }
 354
 355         return -EOPNOTSUPP;
 356 }
 357
 358 int br_ioctl_deviceless_stub(struct net *net, unsigned int cmd, void __user *uarg)
 359 {
 360         switch (cmd) {
 361         case SIOCGIFBR:
 362         case SIOCSIFBR:
 363                 return old_deviceless(net, uarg);
 364
 365         case SIOCBRADDBR:
 366         case SIOCBRDELBR:
 367         {
 368                 char buf[IFNAMSIZ];
 369
 370                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 371                         return -EPERM;
 372
 373                 if (copy_from_user(buf, uarg, IFNAMSIZ))
 374                         return -EFAULT;
 375
 376                 buf[IFNAMSIZ-1] = 0;
 377                 if (cmd == SIOCBRADDBR)
 378                         return br_add_bridge(net, buf);
 379
 380                 return br_del_bridge(net, buf);
 381         }
 382         }
 383         return -EOPNOTSUPP;
 384 }
 385
 386 int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 387 {
 388         struct net_bridge *br = netdev_priv(dev);
 389
 390         switch (cmd) {
 391         case SIOCDEVPRIVATE:
 392                 return old_dev_ioctl(dev, rq, cmd);
 393
 394         case SIOCBRADDIF:
 395         case SIOCBRDELIF:
 396                 return add_del_if(br, rq->ifr_ifindex, cmd == SIOCBRADDIF);
 397
 398         }
 399
 400         br_debug(br, "Bridge does not support ioctl 0x%x\n", cmd);
 401         return -EOPNOTSUPP;
 402 }