net/core/dev_ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/kmod.h>
   3 #include <linux/netdevice.h>
   4 #include <linux/inetdevice.h>
   5 #include <linux/etherdevice.h>
   6 #include <linux/rtnetlink.h>
   7 #include <linux/net_tstamp.h>
   8 #include <linux/phylib_stubs.h>
   9 #include <linux/wireless.h>
  10 #include <linux/if_bridge.h>
  11 #include <net/dsa_stubs.h>
  12 #include <net/wext.h>
  13
  14 #include "dev.h"
  15
  16 /*
  17  *      Map an interface index to its name (SIOCGIFNAME)
  18  */
  19
  20 /*
  21  *      We need this ioctl for efficient implementation of the
  22  *      if_indextoname() function required by the IPv6 API.  Without
  23  *      it, we would have to search all the interfaces to find a
  24  *      match.  --pb
  25  */
  26
  27 static int dev_ifname(struct net *net, struct ifreq *ifr)
  28 {
  29         ifr->ifr_name[IFNAMSIZ-1] = 0;
  30         return netdev_get_name(net, ifr->ifr_name, ifr->ifr_ifindex);
  31 }
  32
  33 /*
  34  *      Perform a SIOCGIFCONF call. This structure will change
  35  *      size eventually, and there is nothing I can do about it.
  36  *      Thus we will need a 'compatibility mode'.
  37  */
  38 int dev_ifconf(struct net *net, struct ifconf __user *uifc)
  39 {
  40         struct net_device *dev;
  41         void __user *pos;
  42         size_t size;
  43         int len, total = 0, done;
  44
  45         /* both the ifconf and the ifreq structures are slightly different */
  46         if (in_compat_syscall()) {
  47                 struct compat_ifconf ifc32;
  48
  49                 if (copy_from_user(&ifc32, uifc, sizeof(struct compat_ifconf)))
  50                         return -EFAULT;
  51
  52                 pos = compat_ptr(ifc32.ifcbuf);
  53                 len = ifc32.ifc_len;
  54                 size = sizeof(struct compat_ifreq);
  55         } else {
  56                 struct ifconf ifc;
  57
  58                 if (copy_from_user(&ifc, uifc, sizeof(struct ifconf)))
  59                         return -EFAULT;
  60
  61                 pos = ifc.ifc_buf;
  62                 len = ifc.ifc_len;
  63                 size = sizeof(struct ifreq);
  64         }
  65
  66         /* Loop over the interfaces, and write an info block for each. */
  67         rtnl_lock();
  68         for_each_netdev(net, dev) {
  69                 if (!pos)
  70                         done = inet_gifconf(dev, NULL, 0, size);
  71                 else
  72                         done = inet_gifconf(dev, pos + total,
  73                                             len - total, size);
  74                 if (done < 0) {
  75                         rtnl_unlock();
  76                         return -EFAULT;
  77                 }
  78                 total += done;
  79         }
  80         rtnl_unlock();
  81
  82         return put_user(total, &uifc->ifc_len);
  83 }
  84
  85 static int dev_getifmap(struct net_device *dev, struct ifreq *ifr)
  86 {
  87         struct ifmap *ifmap = &ifr->ifr_map;
  88
  89         if (in_compat_syscall()) {
  90                 struct compat_ifmap *cifmap = (struct compat_ifmap *)ifmap;
  91
  92                 cifmap->mem_start = dev->mem_start;
  93                 cifmap->mem_end   = dev->mem_end;
  94                 cifmap->base_addr = dev->base_addr;
  95                 cifmap->irq       = dev->irq;
  96                 cifmap->dma       = dev->dma;
  97                 cifmap->port      = dev->if_port;
  98
  99                 return 0;
 100         }
 101
 102         ifmap->mem_start  = dev->mem_start;
 103         ifmap->mem_end    = dev->mem_end;
 104         ifmap->base_addr  = dev->base_addr;
 105         ifmap->irq        = dev->irq;
 106         ifmap->dma        = dev->dma;
 107         ifmap->port       = dev->if_port;
 108
 109         return 0;
 110 }
 111
 112 static int dev_setifmap(struct net_device *dev, struct ifreq *ifr)
 113 {
 114         struct compat_ifmap *cifmap = (struct compat_ifmap *)&ifr->ifr_map;
 115
 116         if (!dev->netdev_ops->ndo_set_config)
 117                 return -EOPNOTSUPP;
 118
 119         if (in_compat_syscall()) {
 120                 struct ifmap ifmap = {
 121                         .mem_start  = cifmap->mem_start,
 122                         .mem_end    = cifmap->mem_end,
 123                         .base_addr  = cifmap->base_addr,
 124                         .irq        = cifmap->irq,
 125                         .dma        = cifmap->dma,
 126                         .port       = cifmap->port,
 127                 };
 128
 129                 return dev->netdev_ops->ndo_set_config(dev, &ifmap);
 130         }
 131
 132         return dev->netdev_ops->ndo_set_config(dev, &ifr->ifr_map);
 133 }
 134
 135 /*
 136  *      Perform the SIOCxIFxxx calls, inside rcu_read_lock()
 137  */
 138 static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
 139 {
 140         int err;
 141         struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
 142
 143         if (!dev)
 144                 return -ENODEV;
 145
 146         switch (cmd) {
 147         case SIOCGIFFLAGS:      /* Get interface flags */
 148                 ifr->ifr_flags = (short) dev_get_flags(dev);
 149                 return 0;
 150
 151         case SIOCGIFMETRIC:     /* Get the metric on the interface
 152                                    (currently unused) */
 153                 ifr->ifr_metric = 0;
 154                 return 0;
 155
 156         case SIOCGIFMTU:        /* Get the MTU of a device */
 157                 ifr->ifr_mtu = dev->mtu;
 158                 return 0;
 159
 160         case SIOCGIFSLAVE:
 161                 err = -EINVAL;
 162                 break;
 163
 164         case SIOCGIFMAP:
 165                 return dev_getifmap(dev, ifr);
 166
 167         case SIOCGIFINDEX:
 168                 ifr->ifr_ifindex = dev->ifindex;
 169                 return 0;
 170
 171         case SIOCGIFTXQLEN:
 172                 ifr->ifr_qlen = dev->tx_queue_len;
 173                 return 0;
 174
 175         default:
 176                 /* dev_ioctl() should ensure this case
 177                  * is never reached
 178                  */
 179                 WARN_ON(1);
 180                 err = -ENOTTY;
 181                 break;
 182
 183         }
 184         return err;
 185 }
 186
 187 static int net_hwtstamp_validate(const struct kernel_hwtstamp_config *cfg)
 188 {
 189         enum hwtstamp_tx_types tx_type;
 190         enum hwtstamp_rx_filters rx_filter;
 191         int tx_type_valid = 0;
 192         int rx_filter_valid = 0;
 193
 194         if (cfg->flags & ~HWTSTAMP_FLAG_MASK)
 195                 return -EINVAL;
 196
 197         tx_type = cfg->tx_type;
 198         rx_filter = cfg->rx_filter;
 199
 200         switch (tx_type) {
 201         case HWTSTAMP_TX_OFF:
 202         case HWTSTAMP_TX_ON:
 203         case HWTSTAMP_TX_ONESTEP_SYNC:
 204         case HWTSTAMP_TX_ONESTEP_P2P:
 205                 tx_type_valid = 1;
 206                 break;
 207         case __HWTSTAMP_TX_CNT:
 208                 /* not a real value */
 209                 break;
 210         }
 211
 212         switch (rx_filter) {
 213         case HWTSTAMP_FILTER_NONE:
 214         case HWTSTAMP_FILTER_ALL:
 215         case HWTSTAMP_FILTER_SOME:
 216         case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
 217         case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
 218         case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
 219         case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
 220         case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
 221         case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
 222         case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
 223         case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
 224         case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
 225         case HWTSTAMP_FILTER_PTP_V2_EVENT:
 226         case HWTSTAMP_FILTER_PTP_V2_SYNC:
 227         case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
 228         case HWTSTAMP_FILTER_NTP_ALL:
 229                 rx_filter_valid = 1;
 230                 break;
 231         case __HWTSTAMP_FILTER_CNT:
 232                 /* not a real value */
 233                 break;
 234         }
 235
 236         if (!tx_type_valid || !rx_filter_valid)
 237                 return -ERANGE;
 238
 239         return 0;
 240 }
 241
 242 static int dev_eth_ioctl(struct net_device *dev,
 243                          struct ifreq *ifr, unsigned int cmd)
 244 {
 245         const struct net_device_ops *ops = dev->netdev_ops;
 246
 247         if (!ops->ndo_eth_ioctl)
 248                 return -EOPNOTSUPP;
 249
 250         if (!netif_device_present(dev))
 251                 return -ENODEV;
 252
 253         return ops->ndo_eth_ioctl(dev, ifr, cmd);
 254 }
 255
 256 /**
 257  * dev_get_hwtstamp_phylib() - Get hardware timestamping settings of NIC
 258  *      or of attached phylib PHY
 259  * @dev: Network device
 260  * @cfg: Timestamping configuration structure
 261  *
 262  * Helper for calling the default hardware provider timestamping.
 263  *
 264  * Note: phy_mii_ioctl() only handles SIOCSHWTSTAMP (not SIOCGHWTSTAMP), and
 265  * there only exists a phydev->mii_ts->hwtstamp() method. So this will return
 266  * -EOPNOTSUPP for phylib for now, which is still more accurate than letting
 267  * the netdev handle the GET request.
 268  */
 269 static int dev_get_hwtstamp_phylib(struct net_device *dev,
 270                                    struct kernel_hwtstamp_config *cfg)
 271 {
 272         if (phy_is_default_hwtstamp(dev->phydev))
 273                 return phy_hwtstamp_get(dev->phydev, cfg);
 274
 275         return dev->netdev_ops->ndo_hwtstamp_get(dev, cfg);
 276 }
 277
 278 static int dev_get_hwtstamp(struct net_device *dev, struct ifreq *ifr)
 279 {
 280         const struct net_device_ops *ops = dev->netdev_ops;
 281         struct kernel_hwtstamp_config kernel_cfg = {};
 282         struct hwtstamp_config cfg;
 283         int err;
 284
 285         if (!ops->ndo_hwtstamp_get)
 286                 return dev_eth_ioctl(dev, ifr, SIOCGHWTSTAMP); /* legacy */
 287
 288         if (!netif_device_present(dev))
 289                 return -ENODEV;
 290
 291         kernel_cfg.ifr = ifr;
 292         err = dev_get_hwtstamp_phylib(dev, &kernel_cfg);
 293         if (err)
 294                 return err;
 295
 296         /* If the request was resolved through an unconverted driver, omit
 297          * the copy_to_user(), since the implementation has already done that
 298          */
 299         if (!kernel_cfg.copied_to_user) {
 300                 hwtstamp_config_from_kernel(&cfg, &kernel_cfg);
 301
 302                 if (copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)))
 303                         return -EFAULT;
 304         }
 305
 306         return 0;
 307 }
 308
 309 /**
 310  * dev_set_hwtstamp_phylib() - Change hardware timestamping of NIC
 311  *      or of attached phylib PHY
 312  * @dev: Network device
 313  * @cfg: Timestamping configuration structure
 314  * @extack: Netlink extended ack message structure, for error reporting
 315  *
 316  * Helper for enforcing a common policy that phylib timestamping, if available,
 317  * should take precedence in front of hardware timestamping provided by the
 318  * netdev. If the netdev driver needs to perform specific actions even for PHY
 319  * timestamping to work properly (a switch port must trap the timestamped
 320  * frames and not forward them), it must set dev->see_all_hwtstamp_requests.
 321  */
 322 int dev_set_hwtstamp_phylib(struct net_device *dev,
 323                             struct kernel_hwtstamp_config *cfg,
 324                             struct netlink_ext_ack *extack)
 325 {
 326         const struct net_device_ops *ops = dev->netdev_ops;
 327         bool phy_ts = phy_is_default_hwtstamp(dev->phydev);
 328         struct kernel_hwtstamp_config old_cfg = {};
 329         bool changed = false;
 330         int err;
 331
 332         cfg->source = phy_ts ? HWTSTAMP_SOURCE_PHYLIB : HWTSTAMP_SOURCE_NETDEV;
 333
 334         if (phy_ts && dev->see_all_hwtstamp_requests) {
 335                 err = ops->ndo_hwtstamp_get(dev, &old_cfg);
 336                 if (err)
 337                         return err;
 338         }
 339
 340         if (!phy_ts || dev->see_all_hwtstamp_requests) {
 341                 err = ops->ndo_hwtstamp_set(dev, cfg, extack);
 342                 if (err) {
 343                         if (extack->_msg)
 344                                 netdev_err(dev, "%s\n", extack->_msg);
 345                         return err;
 346                 }
 347         }
 348
 349         if (phy_ts && dev->see_all_hwtstamp_requests)
 350                 changed = kernel_hwtstamp_config_changed(&old_cfg, cfg);
 351
 352         if (phy_ts) {
 353                 err = phy_hwtstamp_set(dev->phydev, cfg, extack);
 354                 if (err) {
 355                         if (changed)
 356                                 ops->ndo_hwtstamp_set(dev, &old_cfg, NULL);
 357                         return err;
 358                 }
 359         }
 360
 361         return 0;
 362 }
 363
 364 static int dev_set_hwtstamp(struct net_device *dev, struct ifreq *ifr)
 365 {
 366         const struct net_device_ops *ops = dev->netdev_ops;
 367         struct kernel_hwtstamp_config kernel_cfg = {};
 368         struct netlink_ext_ack extack = {};
 369         struct hwtstamp_config cfg;
 370         int err;
 371
 372         if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
 373                 return -EFAULT;
 374
 375         hwtstamp_config_to_kernel(&kernel_cfg, &cfg);
 376         kernel_cfg.ifr = ifr;
 377
 378         err = net_hwtstamp_validate(&kernel_cfg);
 379         if (err)
 380                 return err;
 381
 382         err = dsa_conduit_hwtstamp_validate(dev, &kernel_cfg, &extack);
 383         if (err) {
 384                 if (extack._msg)
 385                         netdev_err(dev, "%s\n", extack._msg);
 386                 return err;
 387         }
 388
 389         if (!ops->ndo_hwtstamp_set)
 390                 return dev_eth_ioctl(dev, ifr, SIOCSHWTSTAMP); /* legacy */
 391
 392         if (!netif_device_present(dev))
 393                 return -ENODEV;
 394
 395         err = dev_set_hwtstamp_phylib(dev, &kernel_cfg, &extack);
 396         if (err)
 397                 return err;
 398
 399         /* The driver may have modified the configuration, so copy the
 400          * updated version of it back to user space
 401          */
 402         if (!kernel_cfg.copied_to_user) {
 403                 hwtstamp_config_from_kernel(&cfg, &kernel_cfg);
 404
 405                 if (copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)))
 406                         return -EFAULT;
 407         }
 408
 409         return 0;
 410 }
 411
 412 static int generic_hwtstamp_ioctl_lower(struct net_device *dev, int cmd,
 413                                         struct kernel_hwtstamp_config *kernel_cfg)
 414 {
 415         struct ifreq ifrr;
 416         int err;
 417
 418         strscpy_pad(ifrr.ifr_name, dev->name, IFNAMSIZ);
 419         ifrr.ifr_ifru = kernel_cfg->ifr->ifr_ifru;
 420
 421         err = dev_eth_ioctl(dev, &ifrr, cmd);
 422         if (err)
 423                 return err;
 424
 425         kernel_cfg->ifr->ifr_ifru = ifrr.ifr_ifru;
 426         kernel_cfg->copied_to_user = true;
 427
 428         return 0;
 429 }
 430
 431 int generic_hwtstamp_get_lower(struct net_device *dev,
 432                                struct kernel_hwtstamp_config *kernel_cfg)
 433 {
 434         const struct net_device_ops *ops = dev->netdev_ops;
 435
 436         if (!netif_device_present(dev))
 437                 return -ENODEV;
 438
 439         if (ops->ndo_hwtstamp_get)
 440                 return dev_get_hwtstamp_phylib(dev, kernel_cfg);
 441
 442         /* Legacy path: unconverted lower driver */
 443         return generic_hwtstamp_ioctl_lower(dev, SIOCGHWTSTAMP, kernel_cfg);
 444 }
 445 EXPORT_SYMBOL(generic_hwtstamp_get_lower);
 446
 447 int generic_hwtstamp_set_lower(struct net_device *dev,
 448                                struct kernel_hwtstamp_config *kernel_cfg,
 449                                struct netlink_ext_ack *extack)
 450 {
 451         const struct net_device_ops *ops = dev->netdev_ops;
 452
 453         if (!netif_device_present(dev))
 454                 return -ENODEV;
 455
 456         if (ops->ndo_hwtstamp_set)
 457                 return dev_set_hwtstamp_phylib(dev, kernel_cfg, extack);
 458
 459         /* Legacy path: unconverted lower driver */
 460         return generic_hwtstamp_ioctl_lower(dev, SIOCSHWTSTAMP, kernel_cfg);
 461 }
 462 EXPORT_SYMBOL(generic_hwtstamp_set_lower);
 463
 464 static int dev_siocbond(struct net_device *dev,
 465                         struct ifreq *ifr, unsigned int cmd)
 466 {
 467         const struct net_device_ops *ops = dev->netdev_ops;
 468
 469         if (ops->ndo_siocbond) {
 470                 if (netif_device_present(dev))
 471                         return ops->ndo_siocbond(dev, ifr, cmd);
 472                 else
 473                         return -ENODEV;
 474         }
 475
 476         return -EOPNOTSUPP;
 477 }
 478
 479 static int dev_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
 480                               void __user *data, unsigned int cmd)
 481 {
 482         const struct net_device_ops *ops = dev->netdev_ops;
 483
 484         if (ops->ndo_siocdevprivate) {
 485                 if (netif_device_present(dev))
 486                         return ops->ndo_siocdevprivate(dev, ifr, data, cmd);
 487                 else
 488                         return -ENODEV;
 489         }
 490
 491         return -EOPNOTSUPP;
 492 }
 493
 494 static int dev_siocwandev(struct net_device *dev, struct if_settings *ifs)
 495 {
 496         const struct net_device_ops *ops = dev->netdev_ops;
 497
 498         if (ops->ndo_siocwandev) {
 499                 if (netif_device_present(dev))
 500                         return ops->ndo_siocwandev(dev, ifs);
 501                 else
 502                         return -ENODEV;
 503         }
 504
 505         return -EOPNOTSUPP;
 506 }
 507
 508 /*
 509  *      Perform the SIOCxIFxxx calls, inside rtnl_lock()
 510  */
 511 static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
 512                       unsigned int cmd)
 513 {
 514         int err;
 515         struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
 516         const struct net_device_ops *ops;
 517         netdevice_tracker dev_tracker;
 518
 519         if (!dev)
 520                 return -ENODEV;
 521
 522         ops = dev->netdev_ops;
 523
 524         switch (cmd) {
 525         case SIOCSIFFLAGS:      /* Set interface flags */
 526                 return dev_change_flags(dev, ifr->ifr_flags, NULL);
 527
 528         case SIOCSIFMETRIC:     /* Set the metric on the interface
 529                                    (currently unused) */
 530                 return -EOPNOTSUPP;
 531
 532         case SIOCSIFMTU:        /* Set the MTU of a device */
 533                 return dev_set_mtu(dev, ifr->ifr_mtu);
 534
 535         case SIOCSIFHWADDR:
 536                 if (dev->addr_len > sizeof(struct sockaddr))
 537                         return -EINVAL;
 538                 return dev_set_mac_address_user(dev, &ifr->ifr_hwaddr, NULL);
 539
 540         case SIOCSIFHWBROADCAST:
 541                 if (ifr->ifr_hwaddr.sa_family != dev->type)
 542                         return -EINVAL;
 543                 memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
 544                        min(sizeof(ifr->ifr_hwaddr.sa_data_min),
 545                            (size_t)dev->addr_len));
 546                 call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
 547                 return 0;
 548
 549         case SIOCSIFMAP:
 550                 return dev_setifmap(dev, ifr);
 551
 552         case SIOCADDMULTI:
 553                 if (!ops->ndo_set_rx_mode ||
 554                     ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
 555                         return -EINVAL;
 556                 if (!netif_device_present(dev))
 557                         return -ENODEV;
 558                 return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
 559
 560         case SIOCDELMULTI:
 561                 if (!ops->ndo_set_rx_mode ||
 562                     ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
 563                         return -EINVAL;
 564                 if (!netif_device_present(dev))
 565                         return -ENODEV;
 566                 return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
 567
 568         case SIOCSIFTXQLEN:
 569                 if (ifr->ifr_qlen < 0)
 570                         return -EINVAL;
 571                 return dev_change_tx_queue_len(dev, ifr->ifr_qlen);
 572
 573         case SIOCSIFNAME:
 574                 ifr->ifr_newname[IFNAMSIZ-1] = '\0';
 575                 return dev_change_name(dev, ifr->ifr_newname);
 576
 577         case SIOCWANDEV:
 578                 return dev_siocwandev(dev, &ifr->ifr_settings);
 579
 580         case SIOCBRADDIF:
 581         case SIOCBRDELIF:
 582                 if (!netif_device_present(dev))
 583                         return -ENODEV;
 584                 if (!netif_is_bridge_master(dev))
 585                         return -EOPNOTSUPP;
 586                 netdev_hold(dev, &dev_tracker, GFP_KERNEL);
 587                 rtnl_unlock();
 588                 err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL);
 589                 netdev_put(dev, &dev_tracker);
 590                 rtnl_lock();
 591                 return err;
 592
 593         case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15:
 594                 return dev_siocdevprivate(dev, ifr, data, cmd);
 595
 596         case SIOCSHWTSTAMP:
 597                 return dev_set_hwtstamp(dev, ifr);
 598
 599         case SIOCGHWTSTAMP:
 600                 return dev_get_hwtstamp(dev, ifr);
 601
 602         case SIOCGMIIPHY:
 603         case SIOCGMIIREG:
 604         case SIOCSMIIREG:
 605                 return dev_eth_ioctl(dev, ifr, cmd);
 606
 607         case SIOCBONDENSLAVE:
 608         case SIOCBONDRELEASE:
 609         case SIOCBONDSETHWADDR:
 610         case SIOCBONDSLAVEINFOQUERY:
 611         case SIOCBONDINFOQUERY:
 612         case SIOCBONDCHANGEACTIVE:
 613                 return dev_siocbond(dev, ifr, cmd);
 614
 615         /* Unknown ioctl */
 616         default:
 617                 err = -EINVAL;
 618         }
 619         return err;
 620 }
 621
 622 /**
 623  *      dev_load        - load a network module
 624  *      @net: the applicable net namespace
 625  *      @name: name of interface
 626  *
 627  *      If a network interface is not present and the process has suitable
 628  *      privileges this function loads the module. If module loading is not
 629  *      available in this kernel then it becomes a nop.
 630  */
 631
 632 void dev_load(struct net *net, const char *name)
 633 {
 634         struct net_device *dev;
 635         int no_module;
 636
 637         rcu_read_lock();
 638         dev = dev_get_by_name_rcu(net, name);
 639         rcu_read_unlock();
 640
 641         no_module = !dev;
 642         if (no_module && capable(CAP_NET_ADMIN))
 643                 no_module = request_module("netdev-%s", name);
 644         if (no_module && capable(CAP_SYS_MODULE))
 645                 request_module("%s", name);
 646 }
 647 EXPORT_SYMBOL(dev_load);
 648
 649 /*
 650  *      This function handles all "interface"-type I/O control requests. The actual
 651  *      'doing' part of this is dev_ifsioc above.
 652  */
 653
 654 /**
 655  *      dev_ioctl       -       network device ioctl
 656  *      @net: the applicable net namespace
 657  *      @cmd: command to issue
 658  *      @ifr: pointer to a struct ifreq in user space
 659  *      @data: data exchanged with userspace
 660  *      @need_copyout: whether or not copy_to_user() should be called
 661  *
 662  *      Issue ioctl functions to devices. This is normally called by the
 663  *      user space syscall interfaces but can sometimes be useful for
 664  *      other purposes. The return value is the return from the syscall if
 665  *      positive or a negative errno code on error.
 666  */
 667
 668 int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
 669               void __user *data, bool *need_copyout)
 670 {
 671         int ret;
 672         char *colon;
 673
 674         if (need_copyout)
 675                 *need_copyout = true;
 676         if (cmd == SIOCGIFNAME)
 677                 return dev_ifname(net, ifr);
 678
 679         ifr->ifr_name[IFNAMSIZ-1] = 0;
 680
 681         colon = strchr(ifr->ifr_name, ':');
 682         if (colon)
 683                 *colon = 0;
 684
 685         /*
 686          *      See which interface the caller is talking about.
 687          */
 688
 689         switch (cmd) {
 690         case SIOCGIFHWADDR:
 691                 dev_load(net, ifr->ifr_name);
 692                 ret = dev_get_mac_address(&ifr->ifr_hwaddr, net, ifr->ifr_name);
 693                 if (colon)
 694                         *colon = ':';
 695                 return ret;
 696         /*
 697          *      These ioctl calls:
 698          *      - can be done by all.
 699          *      - atomic and do not require locking.
 700          *      - return a value
 701          */
 702         case SIOCGIFFLAGS:
 703         case SIOCGIFMETRIC:
 704         case SIOCGIFMTU:
 705         case SIOCGIFSLAVE:
 706         case SIOCGIFMAP:
 707         case SIOCGIFINDEX:
 708         case SIOCGIFTXQLEN:
 709                 dev_load(net, ifr->ifr_name);
 710                 rcu_read_lock();
 711                 ret = dev_ifsioc_locked(net, ifr, cmd);
 712                 rcu_read_unlock();
 713                 if (colon)
 714                         *colon = ':';
 715                 return ret;
 716
 717         case SIOCETHTOOL:
 718                 dev_load(net, ifr->ifr_name);
 719                 ret = dev_ethtool(net, ifr, data);
 720                 if (colon)
 721                         *colon = ':';
 722                 return ret;
 723
 724         /*
 725          *      These ioctl calls:
 726          *      - require superuser power.
 727          *      - require strict serialization.
 728          *      - return a value
 729          */
 730         case SIOCGMIIPHY:
 731         case SIOCGMIIREG:
 732         case SIOCSIFNAME:
 733                 dev_load(net, ifr->ifr_name);
 734                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 735                         return -EPERM;
 736                 rtnl_lock();
 737                 ret = dev_ifsioc(net, ifr, data, cmd);
 738                 rtnl_unlock();
 739                 if (colon)
 740                         *colon = ':';
 741                 return ret;
 742
 743         /*
 744          *      These ioctl calls:
 745          *      - require superuser power.
 746          *      - require strict serialization.
 747          *      - do not return a value
 748          */
 749         case SIOCSIFMAP:
 750         case SIOCSIFTXQLEN:
 751                 if (!capable(CAP_NET_ADMIN))
 752                         return -EPERM;
 753                 fallthrough;
 754         /*
 755          *      These ioctl calls:
 756          *      - require local superuser power.
 757          *      - require strict serialization.
 758          *      - do not return a value
 759          */
 760         case SIOCSIFFLAGS:
 761         case SIOCSIFMETRIC:
 762         case SIOCSIFMTU:
 763         case SIOCSIFHWADDR:
 764         case SIOCSIFSLAVE:
 765         case SIOCADDMULTI:
 766         case SIOCDELMULTI:
 767         case SIOCSIFHWBROADCAST:
 768         case SIOCSMIIREG:
 769         case SIOCBONDENSLAVE:
 770         case SIOCBONDRELEASE:
 771         case SIOCBONDSETHWADDR:
 772         case SIOCBONDCHANGEACTIVE:
 773         case SIOCBRADDIF:
 774         case SIOCBRDELIF:
 775         case SIOCSHWTSTAMP:
 776                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 777                         return -EPERM;
 778                 fallthrough;
 779         case SIOCBONDSLAVEINFOQUERY:
 780         case SIOCBONDINFOQUERY:
 781                 dev_load(net, ifr->ifr_name);
 782                 rtnl_lock();
 783                 ret = dev_ifsioc(net, ifr, data, cmd);
 784                 rtnl_unlock();
 785                 if (need_copyout)
 786                         *need_copyout = false;
 787                 return ret;
 788
 789         case SIOCGIFMEM:
 790                 /* Get the per device memory space. We can add this but
 791                  * currently do not support it */
 792         case SIOCSIFMEM:
 793                 /* Set the per device memory buffer space.
 794                  * Not applicable in our case */
 795         case SIOCSIFLINK:
 796                 return -ENOTTY;
 797
 798         /*
 799          *      Unknown or private ioctl.
 800          */
 801         default:
 802                 if (cmd == SIOCWANDEV ||
 803                     cmd == SIOCGHWTSTAMP ||
 804                     (cmd >= SIOCDEVPRIVATE &&
 805                      cmd <= SIOCDEVPRIVATE + 15)) {
 806                         dev_load(net, ifr->ifr_name);
 807                         rtnl_lock();
 808                         ret = dev_ifsioc(net, ifr, data, cmd);
 809                         rtnl_unlock();
 810                         return ret;
 811                 }
 812                 return -ENOTTY;
 813         }
 814 }