linux/net/bridge/br_ioctl.c
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   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
  20static 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 */
  38static 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 */
  55static 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 */
  83static 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 */
 109int 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
 315static 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
 369int 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}
 413