net/wireless/wext-core.c

   1 /*
   2  * This file implement the Wireless Extensions core API.
   3  *
   4  * Authors :    Jean Tourrilhes - HPL - <jt@hpl.hp.com>
   5  * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
   6  * Copyright    2009 Johannes Berg <johannes@sipsolutions.net>
   7  *
   8  * (As all part of the Linux kernel, this file is GPL)
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/netdevice.h>
  12 #include <linux/rtnetlink.h>
  13 #include <linux/slab.h>
  14 #include <linux/wireless.h>
  15 #include <linux/uaccess.h>
  16 #include <net/cfg80211.h>
  17 #include <net/iw_handler.h>
  18 #include <net/netlink.h>
  19 #include <net/wext.h>
  20 #include <net/net_namespace.h>
  21
  22 typedef int (*wext_ioctl_func)(struct net_device *, struct iwreq *,
  23                                unsigned int, struct iw_request_info *,
  24                                iw_handler);
  25
  26
  27 /*
  28  * Meta-data about all the standard Wireless Extension request we
  29  * know about.
  30  */
  31 static const struct iw_ioctl_description standard_ioctl[] = {
  32         [IW_IOCTL_IDX(SIOCSIWCOMMIT)] = {
  33                 .header_type    = IW_HEADER_TYPE_NULL,
  34         },
  35         [IW_IOCTL_IDX(SIOCGIWNAME)] = {
  36                 .header_type    = IW_HEADER_TYPE_CHAR,
  37                 .flags          = IW_DESCR_FLAG_DUMP,
  38         },
  39         [IW_IOCTL_IDX(SIOCSIWNWID)] = {
  40                 .header_type    = IW_HEADER_TYPE_PARAM,
  41                 .flags          = IW_DESCR_FLAG_EVENT,
  42         },
  43         [IW_IOCTL_IDX(SIOCGIWNWID)] = {
  44                 .header_type    = IW_HEADER_TYPE_PARAM,
  45                 .flags          = IW_DESCR_FLAG_DUMP,
  46         },
  47         [IW_IOCTL_IDX(SIOCSIWFREQ)] = {
  48                 .header_type    = IW_HEADER_TYPE_FREQ,
  49                 .flags          = IW_DESCR_FLAG_EVENT,
  50         },
  51         [IW_IOCTL_IDX(SIOCGIWFREQ)] = {
  52                 .header_type    = IW_HEADER_TYPE_FREQ,
  53                 .flags          = IW_DESCR_FLAG_DUMP,
  54         },
  55         [IW_IOCTL_IDX(SIOCSIWMODE)] = {
  56                 .header_type    = IW_HEADER_TYPE_UINT,
  57                 .flags          = IW_DESCR_FLAG_EVENT,
  58         },
  59         [IW_IOCTL_IDX(SIOCGIWMODE)] = {
  60                 .header_type    = IW_HEADER_TYPE_UINT,
  61                 .flags          = IW_DESCR_FLAG_DUMP,
  62         },
  63         [IW_IOCTL_IDX(SIOCSIWSENS)] = {
  64                 .header_type    = IW_HEADER_TYPE_PARAM,
  65         },
  66         [IW_IOCTL_IDX(SIOCGIWSENS)] = {
  67                 .header_type    = IW_HEADER_TYPE_PARAM,
  68         },
  69         [IW_IOCTL_IDX(SIOCSIWRANGE)] = {
  70                 .header_type    = IW_HEADER_TYPE_NULL,
  71         },
  72         [IW_IOCTL_IDX(SIOCGIWRANGE)] = {
  73                 .header_type    = IW_HEADER_TYPE_POINT,
  74                 .token_size     = 1,
  75                 .max_tokens     = sizeof(struct iw_range),
  76                 .flags          = IW_DESCR_FLAG_DUMP,
  77         },
  78         [IW_IOCTL_IDX(SIOCSIWPRIV)] = {
  79                 .header_type    = IW_HEADER_TYPE_NULL,
  80         },
  81         [IW_IOCTL_IDX(SIOCGIWPRIV)] = { /* (handled directly by us) */
  82                 .header_type    = IW_HEADER_TYPE_POINT,
  83                 .token_size     = sizeof(struct iw_priv_args),
  84                 .max_tokens     = 16,
  85                 .flags          = IW_DESCR_FLAG_NOMAX,
  86         },
  87         [IW_IOCTL_IDX(SIOCSIWSTATS)] = {
  88                 .header_type    = IW_HEADER_TYPE_NULL,
  89         },
  90         [IW_IOCTL_IDX(SIOCGIWSTATS)] = { /* (handled directly by us) */
  91                 .header_type    = IW_HEADER_TYPE_POINT,
  92                 .token_size     = 1,
  93                 .max_tokens     = sizeof(struct iw_statistics),
  94                 .flags          = IW_DESCR_FLAG_DUMP,
  95         },
  96         [IW_IOCTL_IDX(SIOCSIWSPY)] = {
  97                 .header_type    = IW_HEADER_TYPE_POINT,
  98                 .token_size     = sizeof(struct sockaddr),
  99                 .max_tokens     = IW_MAX_SPY,
 100         },
 101         [IW_IOCTL_IDX(SIOCGIWSPY)] = {
 102                 .header_type    = IW_HEADER_TYPE_POINT,
 103                 .token_size     = sizeof(struct sockaddr) +
 104                                   sizeof(struct iw_quality),
 105                 .max_tokens     = IW_MAX_SPY,
 106         },
 107         [IW_IOCTL_IDX(SIOCSIWTHRSPY)] = {
 108                 .header_type    = IW_HEADER_TYPE_POINT,
 109                 .token_size     = sizeof(struct iw_thrspy),
 110                 .min_tokens     = 1,
 111                 .max_tokens     = 1,
 112         },
 113         [IW_IOCTL_IDX(SIOCGIWTHRSPY)] = {
 114                 .header_type    = IW_HEADER_TYPE_POINT,
 115                 .token_size     = sizeof(struct iw_thrspy),
 116                 .min_tokens     = 1,
 117                 .max_tokens     = 1,
 118         },
 119         [IW_IOCTL_IDX(SIOCSIWAP)] = {
 120                 .header_type    = IW_HEADER_TYPE_ADDR,
 121         },
 122         [IW_IOCTL_IDX(SIOCGIWAP)] = {
 123                 .header_type    = IW_HEADER_TYPE_ADDR,
 124                 .flags          = IW_DESCR_FLAG_DUMP,
 125         },
 126         [IW_IOCTL_IDX(SIOCSIWMLME)] = {
 127                 .header_type    = IW_HEADER_TYPE_POINT,
 128                 .token_size     = 1,
 129                 .min_tokens     = sizeof(struct iw_mlme),
 130                 .max_tokens     = sizeof(struct iw_mlme),
 131         },
 132         [IW_IOCTL_IDX(SIOCGIWAPLIST)] = {
 133                 .header_type    = IW_HEADER_TYPE_POINT,
 134                 .token_size     = sizeof(struct sockaddr) +
 135                                   sizeof(struct iw_quality),
 136                 .max_tokens     = IW_MAX_AP,
 137                 .flags          = IW_DESCR_FLAG_NOMAX,
 138         },
 139         [IW_IOCTL_IDX(SIOCSIWSCAN)] = {
 140                 .header_type    = IW_HEADER_TYPE_POINT,
 141                 .token_size     = 1,
 142                 .min_tokens     = 0,
 143                 .max_tokens     = sizeof(struct iw_scan_req),
 144         },
 145         [IW_IOCTL_IDX(SIOCGIWSCAN)] = {
 146                 .header_type    = IW_HEADER_TYPE_POINT,
 147                 .token_size     = 1,
 148                 .max_tokens     = IW_SCAN_MAX_DATA,
 149                 .flags          = IW_DESCR_FLAG_NOMAX,
 150         },
 151         [IW_IOCTL_IDX(SIOCSIWESSID)] = {
 152                 .header_type    = IW_HEADER_TYPE_POINT,
 153                 .token_size     = 1,
 154                 .max_tokens     = IW_ESSID_MAX_SIZE,
 155                 .flags          = IW_DESCR_FLAG_EVENT,
 156         },
 157         [IW_IOCTL_IDX(SIOCGIWESSID)] = {
 158                 .header_type    = IW_HEADER_TYPE_POINT,
 159                 .token_size     = 1,
 160                 .max_tokens     = IW_ESSID_MAX_SIZE,
 161                 .flags          = IW_DESCR_FLAG_DUMP,
 162         },
 163         [IW_IOCTL_IDX(SIOCSIWNICKN)] = {
 164                 .header_type    = IW_HEADER_TYPE_POINT,
 165                 .token_size     = 1,
 166                 .max_tokens     = IW_ESSID_MAX_SIZE,
 167         },
 168         [IW_IOCTL_IDX(SIOCGIWNICKN)] = {
 169                 .header_type    = IW_HEADER_TYPE_POINT,
 170                 .token_size     = 1,
 171                 .max_tokens     = IW_ESSID_MAX_SIZE,
 172         },
 173         [IW_IOCTL_IDX(SIOCSIWRATE)] = {
 174                 .header_type    = IW_HEADER_TYPE_PARAM,
 175         },
 176         [IW_IOCTL_IDX(SIOCGIWRATE)] = {
 177                 .header_type    = IW_HEADER_TYPE_PARAM,
 178         },
 179         [IW_IOCTL_IDX(SIOCSIWRTS)] = {
 180                 .header_type    = IW_HEADER_TYPE_PARAM,
 181         },
 182         [IW_IOCTL_IDX(SIOCGIWRTS)] = {
 183                 .header_type    = IW_HEADER_TYPE_PARAM,
 184         },
 185         [IW_IOCTL_IDX(SIOCSIWFRAG)] = {
 186                 .header_type    = IW_HEADER_TYPE_PARAM,
 187         },
 188         [IW_IOCTL_IDX(SIOCGIWFRAG)] = {
 189                 .header_type    = IW_HEADER_TYPE_PARAM,
 190         },
 191         [IW_IOCTL_IDX(SIOCSIWTXPOW)] = {
 192                 .header_type    = IW_HEADER_TYPE_PARAM,
 193         },
 194         [IW_IOCTL_IDX(SIOCGIWTXPOW)] = {
 195                 .header_type    = IW_HEADER_TYPE_PARAM,
 196         },
 197         [IW_IOCTL_IDX(SIOCSIWRETRY)] = {
 198                 .header_type    = IW_HEADER_TYPE_PARAM,
 199         },
 200         [IW_IOCTL_IDX(SIOCGIWRETRY)] = {
 201                 .header_type    = IW_HEADER_TYPE_PARAM,
 202         },
 203         [IW_IOCTL_IDX(SIOCSIWENCODE)] = {
 204                 .header_type    = IW_HEADER_TYPE_POINT,
 205                 .token_size     = 1,
 206                 .max_tokens     = IW_ENCODING_TOKEN_MAX,
 207                 .flags          = IW_DESCR_FLAG_EVENT | IW_DESCR_FLAG_RESTRICT,
 208         },
 209         [IW_IOCTL_IDX(SIOCGIWENCODE)] = {
 210                 .header_type    = IW_HEADER_TYPE_POINT,
 211                 .token_size     = 1,
 212                 .max_tokens     = IW_ENCODING_TOKEN_MAX,
 213                 .flags          = IW_DESCR_FLAG_DUMP | IW_DESCR_FLAG_RESTRICT,
 214         },
 215         [IW_IOCTL_IDX(SIOCSIWPOWER)] = {
 216                 .header_type    = IW_HEADER_TYPE_PARAM,
 217         },
 218         [IW_IOCTL_IDX(SIOCGIWPOWER)] = {
 219                 .header_type    = IW_HEADER_TYPE_PARAM,
 220         },
 221         [IW_IOCTL_IDX(SIOCSIWGENIE)] = {
 222                 .header_type    = IW_HEADER_TYPE_POINT,
 223                 .token_size     = 1,
 224                 .max_tokens     = IW_GENERIC_IE_MAX,
 225         },
 226         [IW_IOCTL_IDX(SIOCGIWGENIE)] = {
 227                 .header_type    = IW_HEADER_TYPE_POINT,
 228                 .token_size     = 1,
 229                 .max_tokens     = IW_GENERIC_IE_MAX,
 230         },
 231         [IW_IOCTL_IDX(SIOCSIWAUTH)] = {
 232                 .header_type    = IW_HEADER_TYPE_PARAM,
 233         },
 234         [IW_IOCTL_IDX(SIOCGIWAUTH)] = {
 235                 .header_type    = IW_HEADER_TYPE_PARAM,
 236         },
 237         [IW_IOCTL_IDX(SIOCSIWENCODEEXT)] = {
 238                 .header_type    = IW_HEADER_TYPE_POINT,
 239                 .token_size     = 1,
 240                 .min_tokens     = sizeof(struct iw_encode_ext),
 241                 .max_tokens     = sizeof(struct iw_encode_ext) +
 242                                   IW_ENCODING_TOKEN_MAX,
 243         },
 244         [IW_IOCTL_IDX(SIOCGIWENCODEEXT)] = {
 245                 .header_type    = IW_HEADER_TYPE_POINT,
 246                 .token_size     = 1,
 247                 .min_tokens     = sizeof(struct iw_encode_ext),
 248                 .max_tokens     = sizeof(struct iw_encode_ext) +
 249                                   IW_ENCODING_TOKEN_MAX,
 250         },
 251         [IW_IOCTL_IDX(SIOCSIWPMKSA)] = {
 252                 .header_type    = IW_HEADER_TYPE_POINT,
 253                 .token_size     = 1,
 254                 .min_tokens     = sizeof(struct iw_pmksa),
 255                 .max_tokens     = sizeof(struct iw_pmksa),
 256         },
 257 };
 258 static const unsigned standard_ioctl_num = ARRAY_SIZE(standard_ioctl);
 259
 260 /*
 261  * Meta-data about all the additional standard Wireless Extension events
 262  * we know about.
 263  */
 264 static const struct iw_ioctl_description standard_event[] = {
 265         [IW_EVENT_IDX(IWEVTXDROP)] = {
 266                 .header_type    = IW_HEADER_TYPE_ADDR,
 267         },
 268         [IW_EVENT_IDX(IWEVQUAL)] = {
 269                 .header_type    = IW_HEADER_TYPE_QUAL,
 270         },
 271         [IW_EVENT_IDX(IWEVCUSTOM)] = {
 272                 .header_type    = IW_HEADER_TYPE_POINT,
 273                 .token_size     = 1,
 274                 .max_tokens     = IW_CUSTOM_MAX,
 275         },
 276         [IW_EVENT_IDX(IWEVREGISTERED)] = {
 277                 .header_type    = IW_HEADER_TYPE_ADDR,
 278         },
 279         [IW_EVENT_IDX(IWEVEXPIRED)] = {
 280                 .header_type    = IW_HEADER_TYPE_ADDR,
 281         },
 282         [IW_EVENT_IDX(IWEVGENIE)] = {
 283                 .header_type    = IW_HEADER_TYPE_POINT,
 284                 .token_size     = 1,
 285                 .max_tokens     = IW_GENERIC_IE_MAX,
 286         },
 287         [IW_EVENT_IDX(IWEVMICHAELMICFAILURE)] = {
 288                 .header_type    = IW_HEADER_TYPE_POINT,
 289                 .token_size     = 1,
 290                 .max_tokens     = sizeof(struct iw_michaelmicfailure),
 291         },
 292         [IW_EVENT_IDX(IWEVASSOCREQIE)] = {
 293                 .header_type    = IW_HEADER_TYPE_POINT,
 294                 .token_size     = 1,
 295                 .max_tokens     = IW_GENERIC_IE_MAX,
 296         },
 297         [IW_EVENT_IDX(IWEVASSOCRESPIE)] = {
 298                 .header_type    = IW_HEADER_TYPE_POINT,
 299                 .token_size     = 1,
 300                 .max_tokens     = IW_GENERIC_IE_MAX,
 301         },
 302         [IW_EVENT_IDX(IWEVPMKIDCAND)] = {
 303                 .header_type    = IW_HEADER_TYPE_POINT,
 304                 .token_size     = 1,
 305                 .max_tokens     = sizeof(struct iw_pmkid_cand),
 306         },
 307 };
 308 static const unsigned standard_event_num = ARRAY_SIZE(standard_event);
 309
 310 /* Size (in bytes) of various events */
 311 static const int event_type_size[] = {
 312         IW_EV_LCP_LEN,                  /* IW_HEADER_TYPE_NULL */
 313         0,
 314         IW_EV_CHAR_LEN,                 /* IW_HEADER_TYPE_CHAR */
 315         0,
 316         IW_EV_UINT_LEN,                 /* IW_HEADER_TYPE_UINT */
 317         IW_EV_FREQ_LEN,                 /* IW_HEADER_TYPE_FREQ */
 318         IW_EV_ADDR_LEN,                 /* IW_HEADER_TYPE_ADDR */
 319         0,
 320         IW_EV_POINT_LEN,                /* Without variable payload */
 321         IW_EV_PARAM_LEN,                /* IW_HEADER_TYPE_PARAM */
 322         IW_EV_QUAL_LEN,                 /* IW_HEADER_TYPE_QUAL */
 323 };
 324
 325 #ifdef CONFIG_COMPAT
 326 static const int compat_event_type_size[] = {
 327         IW_EV_COMPAT_LCP_LEN,           /* IW_HEADER_TYPE_NULL */
 328         0,
 329         IW_EV_COMPAT_CHAR_LEN,          /* IW_HEADER_TYPE_CHAR */
 330         0,
 331         IW_EV_COMPAT_UINT_LEN,          /* IW_HEADER_TYPE_UINT */
 332         IW_EV_COMPAT_FREQ_LEN,          /* IW_HEADER_TYPE_FREQ */
 333         IW_EV_COMPAT_ADDR_LEN,          /* IW_HEADER_TYPE_ADDR */
 334         0,
 335         IW_EV_COMPAT_POINT_LEN,         /* Without variable payload */
 336         IW_EV_COMPAT_PARAM_LEN,         /* IW_HEADER_TYPE_PARAM */
 337         IW_EV_COMPAT_QUAL_LEN,          /* IW_HEADER_TYPE_QUAL */
 338 };
 339 #endif
 340
 341
 342 /* IW event code */
 343
 344 static int __net_init wext_pernet_init(struct net *net)
 345 {
 346         skb_queue_head_init(&net->wext_nlevents);
 347         return 0;
 348 }
 349
 350 static void __net_exit wext_pernet_exit(struct net *net)
 351 {
 352         skb_queue_purge(&net->wext_nlevents);
 353 }
 354
 355 static struct pernet_operations wext_pernet_ops = {
 356         .init = wext_pernet_init,
 357         .exit = wext_pernet_exit,
 358 };
 359
 360 static int __init wireless_nlevent_init(void)
 361 {
 362         return register_pernet_subsys(&wext_pernet_ops);
 363 }
 364
 365 subsys_initcall(wireless_nlevent_init);
 366
 367 /* Process events generated by the wireless layer or the driver. */
 368 static void wireless_nlevent_process(struct work_struct *work)
 369 {
 370         struct sk_buff *skb;
 371         struct net *net;
 372
 373         rtnl_lock();
 374
 375         for_each_net(net) {
 376                 while ((skb = skb_dequeue(&net->wext_nlevents)))
 377                         rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL,
 378                                     GFP_KERNEL);
 379         }
 380
 381         rtnl_unlock();
 382 }
 383
 384 static DECLARE_WORK(wireless_nlevent_work, wireless_nlevent_process);
 385
 386 static struct nlmsghdr *rtnetlink_ifinfo_prep(struct net_device *dev,
 387                                               struct sk_buff *skb)
 388 {
 389         struct ifinfomsg *r;
 390         struct nlmsghdr  *nlh;
 391
 392         nlh = nlmsg_put(skb, 0, 0, RTM_NEWLINK, sizeof(*r), 0);
 393         if (!nlh)
 394                 return NULL;
 395
 396         r = nlmsg_data(nlh);
 397         r->ifi_family = AF_UNSPEC;
 398         r->__ifi_pad = 0;
 399         r->ifi_type = dev->type;
 400         r->ifi_index = dev->ifindex;
 401         r->ifi_flags = dev_get_flags(dev);
 402         r->ifi_change = 0;      /* Wireless changes don't affect those flags */
 403
 404         NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
 405
 406         return nlh;
 407  nla_put_failure:
 408         nlmsg_cancel(skb, nlh);
 409         return NULL;
 410 }
 411
 412
 413 /*
 414  * Main event dispatcher. Called from other parts and drivers.
 415  * Send the event on the appropriate channels.
 416  * May be called from interrupt context.
 417  */
 418 void wireless_send_event(struct net_device *    dev,
 419                          unsigned int           cmd,
 420                          union iwreq_data *     wrqu,
 421                          const char *           extra)
 422 {
 423         const struct iw_ioctl_description *     descr = NULL;
 424         int extra_len = 0;
 425         struct iw_event  *event;                /* Mallocated whole event */
 426         int event_len;                          /* Its size */
 427         int hdr_len;                            /* Size of the event header */
 428         int wrqu_off = 0;                       /* Offset in wrqu */
 429         /* Don't "optimise" the following variable, it will crash */
 430         unsigned        cmd_index;              /* *MUST* be unsigned */
 431         struct sk_buff *skb;
 432         struct nlmsghdr *nlh;
 433         struct nlattr *nla;
 434 #ifdef CONFIG_COMPAT
 435         struct __compat_iw_event *compat_event;
 436         struct compat_iw_point compat_wrqu;
 437         struct sk_buff *compskb;
 438 #endif
 439
 440         /*
 441          * Nothing in the kernel sends scan events with data, be safe.
 442          * This is necessary because we cannot fix up scan event data
 443          * for compat, due to being contained in 'extra', but normally
 444          * applications are required to retrieve the scan data anyway
 445          * and no data is included in the event, this codifies that
 446          * practice.
 447          */
 448         if (WARN_ON(cmd == SIOCGIWSCAN && extra))
 449                 extra = NULL;
 450
 451         /* Get the description of the Event */
 452         if (cmd <= SIOCIWLAST) {
 453                 cmd_index = IW_IOCTL_IDX(cmd);
 454                 if (cmd_index < standard_ioctl_num)
 455                         descr = &(standard_ioctl[cmd_index]);
 456         } else {
 457                 cmd_index = IW_EVENT_IDX(cmd);
 458                 if (cmd_index < standard_event_num)
 459                         descr = &(standard_event[cmd_index]);
 460         }
 461         /* Don't accept unknown events */
 462         if (descr == NULL) {
 463                 /* Note : we don't return an error to the driver, because
 464                  * the driver would not know what to do about it. It can't
 465                  * return an error to the user, because the event is not
 466                  * initiated by a user request.
 467                  * The best the driver could do is to log an error message.
 468                  * We will do it ourselves instead...
 469                  */
 470                 netdev_err(dev, "(WE) : Invalid/Unknown Wireless Event (0x%04X)\n",
 471                            cmd);
 472                 return;
 473         }
 474
 475         /* Check extra parameters and set extra_len */
 476         if (descr->header_type == IW_HEADER_TYPE_POINT) {
 477                 /* Check if number of token fits within bounds */
 478                 if (wrqu->data.length > descr->max_tokens) {
 479                         netdev_err(dev, "(WE) : Wireless Event too big (%d)\n",
 480                                    wrqu->data.length);
 481                         return;
 482                 }
 483                 if (wrqu->data.length < descr->min_tokens) {
 484                         netdev_err(dev, "(WE) : Wireless Event too small (%d)\n",
 485                                    wrqu->data.length);
 486                         return;
 487                 }
 488                 /* Calculate extra_len - extra is NULL for restricted events */
 489                 if (extra != NULL)
 490                         extra_len = wrqu->data.length * descr->token_size;
 491                 /* Always at an offset in wrqu */
 492                 wrqu_off = IW_EV_POINT_OFF;
 493         }
 494
 495         /* Total length of the event */
 496         hdr_len = event_type_size[descr->header_type];
 497         event_len = hdr_len + extra_len;
 498
 499         /*
 500          * The problem for 64/32 bit.
 501          *
 502          * On 64-bit, a regular event is laid out as follows:
 503          *      |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
 504          *      | event.len | event.cmd |     p a d d i n g     |
 505          *      | wrqu data ... (with the correct size)         |
 506          *
 507          * This padding exists because we manipulate event->u,
 508          * and 'event' is not packed.
 509          *
 510          * An iw_point event is laid out like this instead:
 511          *      |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
 512          *      | event.len | event.cmd |     p a d d i n g     |
 513          *      | iwpnt.len | iwpnt.flg |     p a d d i n g     |
 514          *      | extra data  ...
 515          *
 516          * The second padding exists because struct iw_point is extended,
 517          * but this depends on the platform...
 518          *
 519          * On 32-bit, all the padding shouldn't be there.
 520          */
 521
 522         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
 523         if (!skb)
 524                 return;
 525
 526         /* Send via the RtNetlink event channel */
 527         nlh = rtnetlink_ifinfo_prep(dev, skb);
 528         if (WARN_ON(!nlh)) {
 529                 kfree_skb(skb);
 530                 return;
 531         }
 532
 533         /* Add the wireless events in the netlink packet */
 534         nla = nla_reserve(skb, IFLA_WIRELESS, event_len);
 535         if (!nla) {
 536                 kfree_skb(skb);
 537                 return;
 538         }
 539         event = nla_data(nla);
 540
 541         /* Fill event - first clear to avoid data leaking */
 542         memset(event, 0, hdr_len);
 543         event->len = event_len;
 544         event->cmd = cmd;
 545         memcpy(&event->u, ((char *) wrqu) + wrqu_off, hdr_len - IW_EV_LCP_LEN);
 546         if (extra_len)
 547                 memcpy(((char *) event) + hdr_len, extra, extra_len);
 548
 549         nlmsg_end(skb, nlh);
 550 #ifdef CONFIG_COMPAT
 551         hdr_len = compat_event_type_size[descr->header_type];
 552         event_len = hdr_len + extra_len;
 553
 554         compskb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
 555         if (!compskb) {
 556                 kfree_skb(skb);
 557                 return;
 558         }
 559
 560         /* Send via the RtNetlink event channel */
 561         nlh = rtnetlink_ifinfo_prep(dev, compskb);
 562         if (WARN_ON(!nlh)) {
 563                 kfree_skb(skb);
 564                 kfree_skb(compskb);
 565                 return;
 566         }
 567
 568         /* Add the wireless events in the netlink packet */
 569         nla = nla_reserve(compskb, IFLA_WIRELESS, event_len);
 570         if (!nla) {
 571                 kfree_skb(skb);
 572                 kfree_skb(compskb);
 573                 return;
 574         }
 575         compat_event = nla_data(nla);
 576
 577         compat_event->len = event_len;
 578         compat_event->cmd = cmd;
 579         if (descr->header_type == IW_HEADER_TYPE_POINT) {
 580                 compat_wrqu.length = wrqu->data.length;
 581                 compat_wrqu.flags = wrqu->data.flags;
 582                 memcpy(&compat_event->pointer,
 583                         ((char *) &compat_wrqu) + IW_EV_COMPAT_POINT_OFF,
 584                         hdr_len - IW_EV_COMPAT_LCP_LEN);
 585                 if (extra_len)
 586                         memcpy(((char *) compat_event) + hdr_len,
 587                                 extra, extra_len);
 588         } else {
 589                 /* extra_len must be zero, so no if (extra) needed */
 590                 memcpy(&compat_event->pointer, wrqu,
 591                         hdr_len - IW_EV_COMPAT_LCP_LEN);
 592         }
 593
 594         nlmsg_end(compskb, nlh);
 595
 596         skb_shinfo(skb)->frag_list = compskb;
 597 #endif
 598         skb_queue_tail(&dev_net(dev)->wext_nlevents, skb);
 599         schedule_work(&wireless_nlevent_work);
 600 }
 601 EXPORT_SYMBOL(wireless_send_event);
 602
 603
 604
 605 /* IW handlers */
 606
 607 struct iw_statistics *get_wireless_stats(struct net_device *dev)
 608 {
 609 #ifdef CONFIG_WIRELESS_EXT
 610         if ((dev->wireless_handlers != NULL) &&
 611            (dev->wireless_handlers->get_wireless_stats != NULL))
 612                 return dev->wireless_handlers->get_wireless_stats(dev);
 613 #endif
 614
 615 #ifdef CONFIG_CFG80211_WEXT
 616         if (dev->ieee80211_ptr &&
 617             dev->ieee80211_ptr->wiphy &&
 618             dev->ieee80211_ptr->wiphy->wext &&
 619             dev->ieee80211_ptr->wiphy->wext->get_wireless_stats)
 620                 return dev->ieee80211_ptr->wiphy->wext->get_wireless_stats(dev);
 621 #endif
 622
 623         /* not found */
 624         return NULL;
 625 }
 626
 627 static int iw_handler_get_iwstats(struct net_device *           dev,
 628                                   struct iw_request_info *      info,
 629                                   union iwreq_data *            wrqu,
 630                                   char *                        extra)
 631 {
 632         /* Get stats from the driver */
 633         struct iw_statistics *stats;
 634
 635         stats = get_wireless_stats(dev);
 636         if (stats) {
 637                 /* Copy statistics to extra */
 638                 memcpy(extra, stats, sizeof(struct iw_statistics));
 639                 wrqu->data.length = sizeof(struct iw_statistics);
 640
 641                 /* Check if we need to clear the updated flag */
 642                 if (wrqu->data.flags != 0)
 643                         stats->qual.updated &= ~IW_QUAL_ALL_UPDATED;
 644                 return 0;
 645         } else
 646                 return -EOPNOTSUPP;
 647 }
 648
 649 static iw_handler get_handler(struct net_device *dev, unsigned int cmd)
 650 {
 651         /* Don't "optimise" the following variable, it will crash */
 652         unsigned int    index;          /* *MUST* be unsigned */
 653         const struct iw_handler_def *handlers = NULL;
 654
 655 #ifdef CONFIG_CFG80211_WEXT
 656         if (dev->ieee80211_ptr && dev->ieee80211_ptr->wiphy)
 657                 handlers = dev->ieee80211_ptr->wiphy->wext;
 658 #endif
 659 #ifdef CONFIG_WIRELESS_EXT
 660         if (dev->wireless_handlers)
 661                 handlers = dev->wireless_handlers;
 662 #endif
 663
 664         if (!handlers)
 665                 return NULL;
 666
 667         /* Try as a standard command */
 668         index = IW_IOCTL_IDX(cmd);
 669         if (index < handlers->num_standard)
 670                 return handlers->standard[index];
 671
 672 #ifdef CONFIG_WEXT_PRIV
 673         /* Try as a private command */
 674         index = cmd - SIOCIWFIRSTPRIV;
 675         if (index < handlers->num_private)
 676                 return handlers->private[index];
 677 #endif
 678
 679         /* Not found */
 680         return NULL;
 681 }
 682
 683 static int ioctl_standard_iw_point(struct iw_point *iwp, unsigned int cmd,
 684                                    const struct iw_ioctl_description *descr,
 685                                    iw_handler handler, struct net_device *dev,
 686                                    struct iw_request_info *info)
 687 {
 688         int err, extra_size, user_length = 0, essid_compat = 0;
 689         char *extra;
 690
 691         /* Calculate space needed by arguments. Always allocate
 692          * for max space.
 693          */
 694         extra_size = descr->max_tokens * descr->token_size;
 695
 696         /* Check need for ESSID compatibility for WE < 21 */
 697         switch (cmd) {
 698         case SIOCSIWESSID:
 699         case SIOCGIWESSID:
 700         case SIOCSIWNICKN:
 701         case SIOCGIWNICKN:
 702                 if (iwp->length == descr->max_tokens + 1)
 703                         essid_compat = 1;
 704                 else if (IW_IS_SET(cmd) && (iwp->length != 0)) {
 705                         char essid[IW_ESSID_MAX_SIZE + 1];
 706                         unsigned int len;
 707                         len = iwp->length * descr->token_size;
 708
 709                         if (len > IW_ESSID_MAX_SIZE)
 710                                 return -EFAULT;
 711
 712                         err = copy_from_user(essid, iwp->pointer, len);
 713                         if (err)
 714                                 return -EFAULT;
 715
 716                         if (essid[iwp->length - 1] == '\0')
 717                                 essid_compat = 1;
 718                 }
 719                 break;
 720         default:
 721                 break;
 722         }
 723
 724         iwp->length -= essid_compat;
 725
 726         /* Check what user space is giving us */
 727         if (IW_IS_SET(cmd)) {
 728                 /* Check NULL pointer */
 729                 if (!iwp->pointer && iwp->length != 0)
 730                         return -EFAULT;
 731                 /* Check if number of token fits within bounds */
 732                 if (iwp->length > descr->max_tokens)
 733                         return -E2BIG;
 734                 if (iwp->length < descr->min_tokens)
 735                         return -EINVAL;
 736         } else {
 737                 /* Check NULL pointer */
 738                 if (!iwp->pointer)
 739                         return -EFAULT;
 740                 /* Save user space buffer size for checking */
 741                 user_length = iwp->length;
 742
 743                 /* Don't check if user_length > max to allow forward
 744                  * compatibility. The test user_length < min is
 745                  * implied by the test at the end.
 746                  */
 747
 748                 /* Support for very large requests */
 749                 if ((descr->flags & IW_DESCR_FLAG_NOMAX) &&
 750                     (user_length > descr->max_tokens)) {
 751                         /* Allow userspace to GET more than max so
 752                          * we can support any size GET requests.
 753                          * There is still a limit : -ENOMEM.
 754                          */
 755                         extra_size = user_length * descr->token_size;
 756
 757                         /* Note : user_length is originally a __u16,
 758                          * and token_size is controlled by us,
 759                          * so extra_size won't get negative and
 760                          * won't overflow...
 761                          */
 762                 }
 763         }
 764
 765         /* kzalloc() ensures NULL-termination for essid_compat. */
 766         extra = kzalloc(extra_size, GFP_KERNEL);
 767         if (!extra)
 768                 return -ENOMEM;
 769
 770         /* If it is a SET, get all the extra data in here */
 771         if (IW_IS_SET(cmd) && (iwp->length != 0)) {
 772                 if (copy_from_user(extra, iwp->pointer,
 773                                    iwp->length *
 774                                    descr->token_size)) {
 775                         err = -EFAULT;
 776                         goto out;
 777                 }
 778
 779                 if (cmd == SIOCSIWENCODEEXT) {
 780                         struct iw_encode_ext *ee = (void *) extra;
 781
 782                         if (iwp->length < sizeof(*ee) + ee->key_len)
 783                                 return -EFAULT;
 784                 }
 785         }
 786
 787         if (IW_IS_GET(cmd) && !(descr->flags & IW_DESCR_FLAG_NOMAX)) {
 788                 /*
 789                  * If this is a GET, but not NOMAX, it means that the extra
 790                  * data is not bounded by userspace, but by max_tokens. Thus
 791                  * set the length to max_tokens. This matches the extra data
 792                  * allocation.
 793                  * The driver should fill it with the number of tokens it
 794                  * provided, and it may check iwp->length rather than having
 795                  * knowledge of max_tokens. If the driver doesn't change the
 796                  * iwp->length, this ioctl just copies back max_token tokens
 797                  * filled with zeroes. Hopefully the driver isn't claiming
 798                  * them to be valid data.
 799                  */
 800                 iwp->length = descr->max_tokens;
 801         }
 802
 803         err = handler(dev, info, (union iwreq_data *) iwp, extra);
 804
 805         iwp->length += essid_compat;
 806
 807         /* If we have something to return to the user */
 808         if (!err && IW_IS_GET(cmd)) {
 809                 /* Check if there is enough buffer up there */
 810                 if (user_length < iwp->length) {
 811                         err = -E2BIG;
 812                         goto out;
 813                 }
 814
 815                 if (copy_to_user(iwp->pointer, extra,
 816                                  iwp->length *
 817                                  descr->token_size)) {
 818                         err = -EFAULT;
 819                         goto out;
 820                 }
 821         }
 822
 823         /* Generate an event to notify listeners of the change */
 824         if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
 825             ((err == 0) || (err == -EIWCOMMIT))) {
 826                 union iwreq_data *data = (union iwreq_data *) iwp;
 827
 828                 if (descr->flags & IW_DESCR_FLAG_RESTRICT)
 829                         /* If the event is restricted, don't
 830                          * export the payload.
 831                          */
 832                         wireless_send_event(dev, cmd, data, NULL);
 833                 else
 834                         wireless_send_event(dev, cmd, data, extra);
 835         }
 836
 837 out:
 838         kfree(extra);
 839         return err;
 840 }
 841
 842 /*
 843  * Call the commit handler in the driver
 844  * (if exist and if conditions are right)
 845  *
 846  * Note : our current commit strategy is currently pretty dumb,
 847  * but we will be able to improve on that...
 848  * The goal is to try to agreagate as many changes as possible
 849  * before doing the commit. Drivers that will define a commit handler
 850  * are usually those that need a reset after changing parameters, so
 851  * we want to minimise the number of reset.
 852  * A cool idea is to use a timer : at each "set" command, we re-set the
 853  * timer, when the timer eventually fires, we call the driver.
 854  * Hopefully, more on that later.
 855  *
 856  * Also, I'm waiting to see how many people will complain about the
 857  * netif_running(dev) test. I'm open on that one...
 858  * Hopefully, the driver will remember to do a commit in "open()" ;-)
 859  */
 860 int call_commit_handler(struct net_device *dev)
 861 {
 862 #ifdef CONFIG_WIRELESS_EXT
 863         if ((netif_running(dev)) &&
 864            (dev->wireless_handlers->standard[0] != NULL))
 865                 /* Call the commit handler on the driver */
 866                 return dev->wireless_handlers->standard[0](dev, NULL,
 867                                                            NULL, NULL);
 868         else
 869                 return 0;               /* Command completed successfully */
 870 #else
 871         /* cfg80211 has no commit */
 872         return 0;
 873 #endif
 874 }
 875
 876 /*
 877  * Main IOCTl dispatcher.
 878  * Check the type of IOCTL and call the appropriate wrapper...
 879  */
 880 static int wireless_process_ioctl(struct net *net, struct ifreq *ifr,
 881                                   unsigned int cmd,
 882                                   struct iw_request_info *info,
 883                                   wext_ioctl_func standard,
 884                                   wext_ioctl_func private)
 885 {
 886         struct iwreq *iwr = (struct iwreq *) ifr;
 887         struct net_device *dev;
 888         iw_handler      handler;
 889
 890         /* Permissions are already checked in dev_ioctl() before calling us.
 891          * The copy_to/from_user() of ifr is also dealt with in there */
 892
 893         /* Make sure the device exist */
 894         if ((dev = __dev_get_by_name(net, ifr->ifr_name)) == NULL)
 895                 return -ENODEV;
 896
 897         /* A bunch of special cases, then the generic case...
 898          * Note that 'cmd' is already filtered in dev_ioctl() with
 899          * (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) */
 900         if (cmd == SIOCGIWSTATS)
 901                 return standard(dev, iwr, cmd, info,
 902                                 &iw_handler_get_iwstats);
 903
 904 #ifdef CONFIG_WEXT_PRIV
 905         if (cmd == SIOCGIWPRIV && dev->wireless_handlers)
 906                 return standard(dev, iwr, cmd, info,
 907                                 iw_handler_get_private);
 908 #endif
 909
 910         /* Basic check */
 911         if (!netif_device_present(dev))
 912                 return -ENODEV;
 913
 914         /* New driver API : try to find the handler */
 915         handler = get_handler(dev, cmd);
 916         if (handler) {
 917                 /* Standard and private are not the same */
 918                 if (cmd < SIOCIWFIRSTPRIV)
 919                         return standard(dev, iwr, cmd, info, handler);
 920                 else if (private)
 921                         return private(dev, iwr, cmd, info, handler);
 922         }
 923         /* Old driver API : call driver ioctl handler */
 924         if (dev->netdev_ops->ndo_do_ioctl)
 925                 return dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd);
 926         return -EOPNOTSUPP;
 927 }
 928
 929 /* If command is `set a parameter', or `get the encoding parameters',
 930  * check if the user has the right to do it.
 931  */
 932 static int wext_permission_check(unsigned int cmd)
 933 {
 934         if ((IW_IS_SET(cmd) || cmd == SIOCGIWENCODE ||
 935              cmd == SIOCGIWENCODEEXT) &&
 936             !capable(CAP_NET_ADMIN))
 937                 return -EPERM;
 938
 939         return 0;
 940 }
 941
 942 /* entry point from dev ioctl */
 943 static int wext_ioctl_dispatch(struct net *net, struct ifreq *ifr,
 944                                unsigned int cmd, struct iw_request_info *info,
 945                                wext_ioctl_func standard,
 946                                wext_ioctl_func private)
 947 {
 948         int ret = wext_permission_check(cmd);
 949
 950         if (ret)
 951                 return ret;
 952
 953         dev_load(net, ifr->ifr_name);
 954         rtnl_lock();
 955         ret = wireless_process_ioctl(net, ifr, cmd, info, standard, private);
 956         rtnl_unlock();
 957
 958         return ret;
 959 }
 960
 961 /*
 962  * Wrapper to call a standard Wireless Extension handler.
 963  * We do various checks and also take care of moving data between
 964  * user space and kernel space.
 965  */
 966 static int ioctl_standard_call(struct net_device *      dev,
 967                                struct iwreq             *iwr,
 968                                unsigned int             cmd,
 969                                struct iw_request_info   *info,
 970                                iw_handler               handler)
 971 {
 972         const struct iw_ioctl_description *     descr;
 973         int                                     ret = -EINVAL;
 974
 975         /* Get the description of the IOCTL */
 976         if (IW_IOCTL_IDX(cmd) >= standard_ioctl_num)
 977                 return -EOPNOTSUPP;
 978         descr = &(standard_ioctl[IW_IOCTL_IDX(cmd)]);
 979
 980         /* Check if we have a pointer to user space data or not */
 981         if (descr->header_type != IW_HEADER_TYPE_POINT) {
 982
 983                 /* No extra arguments. Trivial to handle */
 984                 ret = handler(dev, info, &(iwr->u), NULL);
 985
 986                 /* Generate an event to notify listeners of the change */
 987                 if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
 988                    ((ret == 0) || (ret == -EIWCOMMIT)))
 989                         wireless_send_event(dev, cmd, &(iwr->u), NULL);
 990         } else {
 991                 ret = ioctl_standard_iw_point(&iwr->u.data, cmd, descr,
 992                                               handler, dev, info);
 993         }
 994
 995         /* Call commit handler if needed and defined */
 996         if (ret == -EIWCOMMIT)
 997                 ret = call_commit_handler(dev);
 998
 999         /* Here, we will generate the appropriate event if needed */
1000
1001         return ret;
1002 }
1003
1004
1005 int wext_handle_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd,
1006                       void __user *arg)
1007 {
1008         struct iw_request_info info = { .cmd = cmd, .flags = 0 };
1009         int ret;
1010
1011         ret = wext_ioctl_dispatch(net, ifr, cmd, &info,
1012                                   ioctl_standard_call,
1013                                   ioctl_private_call);
1014         if (ret >= 0 &&
1015             IW_IS_GET(cmd) &&
1016             copy_to_user(arg, ifr, sizeof(struct iwreq)))
1017                 return -EFAULT;
1018
1019         return ret;
1020 }
1021
1022 #ifdef CONFIG_COMPAT
1023 static int compat_standard_call(struct net_device       *dev,
1024                                 struct iwreq            *iwr,
1025                                 unsigned int            cmd,
1026                                 struct iw_request_info  *info,
1027                                 iw_handler              handler)
1028 {
1029         const struct iw_ioctl_description *descr;
1030         struct compat_iw_point *iwp_compat;
1031         struct iw_point iwp;
1032         int err;
1033
1034         descr = standard_ioctl + IW_IOCTL_IDX(cmd);
1035
1036         if (descr->header_type != IW_HEADER_TYPE_POINT)
1037                 return ioctl_standard_call(dev, iwr, cmd, info, handler);
1038
1039         iwp_compat = (struct compat_iw_point *) &iwr->u.data;
1040         iwp.pointer = compat_ptr(iwp_compat->pointer);
1041         iwp.length = iwp_compat->length;
1042         iwp.flags = iwp_compat->flags;
1043
1044         err = ioctl_standard_iw_point(&iwp, cmd, descr, handler, dev, info);
1045
1046         iwp_compat->pointer = ptr_to_compat(iwp.pointer);
1047         iwp_compat->length = iwp.length;
1048         iwp_compat->flags = iwp.flags;
1049
1050         return err;
1051 }
1052
1053 int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
1054                              unsigned long arg)
1055 {
1056         void __user *argp = (void __user *)arg;
1057         struct iw_request_info info;
1058         struct iwreq iwr;
1059         char *colon;
1060         int ret;
1061
1062         if (copy_from_user(&iwr, argp, sizeof(struct iwreq)))
1063                 return -EFAULT;
1064
1065         iwr.ifr_name[IFNAMSIZ-1] = 0;
1066         colon = strchr(iwr.ifr_name, ':');
1067         if (colon)
1068                 *colon = 0;
1069
1070         info.cmd = cmd;
1071         info.flags = IW_REQUEST_FLAG_COMPAT;
1072
1073         ret = wext_ioctl_dispatch(net, (struct ifreq *) &iwr, cmd, &info,
1074                                   compat_standard_call,
1075                                   compat_private_call);
1076
1077         if (ret >= 0 &&
1078             IW_IS_GET(cmd) &&
1079             copy_to_user(argp, &iwr, sizeof(struct iwreq)))
1080                 return -EFAULT;
1081
1082         return ret;
1083 }
1084 #endif