drivers/usb/wusbcore/security.c

   1 /*
   2  * Wireless USB Host Controller
   3  * Security support: encryption enablement, etc
   4  *
   5  * Copyright (C) 2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   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 version
  10  * 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301, USA.
  21  *
  22  *
  23  * FIXME: docs
  24  */
  25 #include <linux/types.h>
  26 #include <linux/slab.h>
  27 #include <linux/usb/ch9.h>
  28 #include <linux/random.h>
  29 #include <linux/export.h>
  30 #include "wusbhc.h"
  31
  32 static void wusbhc_set_gtk_callback(struct urb *urb);
  33 static void wusbhc_gtk_rekey_done_work(struct work_struct *work);
  34
  35 int wusbhc_sec_create(struct wusbhc *wusbhc)
  36 {
  37         wusbhc->gtk.descr.bLength = sizeof(wusbhc->gtk.descr) + sizeof(wusbhc->gtk.data);
  38         wusbhc->gtk.descr.bDescriptorType = USB_DT_KEY;
  39         wusbhc->gtk.descr.bReserved = 0;
  40
  41         wusbhc->gtk_index = wusb_key_index(0, WUSB_KEY_INDEX_TYPE_GTK,
  42                                            WUSB_KEY_INDEX_ORIGINATOR_HOST);
  43
  44         INIT_WORK(&wusbhc->gtk_rekey_done_work, wusbhc_gtk_rekey_done_work);
  45
  46         return 0;
  47 }
  48
  49
  50 /* Called when the HC is destroyed */
  51 void wusbhc_sec_destroy(struct wusbhc *wusbhc)
  52 {
  53 }
  54
  55
  56 /**
  57  * wusbhc_next_tkid - generate a new, currently unused, TKID
  58  * @wusbhc:   the WUSB host controller
  59  * @wusb_dev: the device whose PTK the TKID is for
  60  *            (or NULL for a TKID for a GTK)
  61  *
  62  * The generated TKID consist of two parts: the device's authenicated
  63  * address (or 0 or a GTK); and an incrementing number.  This ensures
  64  * that TKIDs cannot be shared between devices and by the time the
  65  * incrementing number wraps around the older TKIDs will no longer be
  66  * in use (a maximum of two keys may be active at any one time).
  67  */
  68 static u32 wusbhc_next_tkid(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
  69 {
  70         u32 *tkid;
  71         u32 addr;
  72
  73         if (wusb_dev == NULL) {
  74                 tkid = &wusbhc->gtk_tkid;
  75                 addr = 0;
  76         } else {
  77                 tkid = &wusb_port_by_idx(wusbhc, wusb_dev->port_idx)->ptk_tkid;
  78                 addr = wusb_dev->addr & 0x7f;
  79         }
  80
  81         *tkid = (addr << 8) | ((*tkid + 1) & 0xff);
  82
  83         return *tkid;
  84 }
  85
  86 static void wusbhc_generate_gtk(struct wusbhc *wusbhc)
  87 {
  88         const size_t key_size = sizeof(wusbhc->gtk.data);
  89         u32 tkid;
  90
  91         tkid = wusbhc_next_tkid(wusbhc, NULL);
  92
  93         wusbhc->gtk.descr.tTKID[0] = (tkid >>  0) & 0xff;
  94         wusbhc->gtk.descr.tTKID[1] = (tkid >>  8) & 0xff;
  95         wusbhc->gtk.descr.tTKID[2] = (tkid >> 16) & 0xff;
  96
  97         get_random_bytes(wusbhc->gtk.descr.bKeyData, key_size);
  98 }
  99
 100 /**
 101  * wusbhc_sec_start - start the security management process
 102  * @wusbhc: the WUSB host controller
 103  *
 104  * Generate and set an initial GTK on the host controller.
 105  *
 106  * Called when the HC is started.
 107  */
 108 int wusbhc_sec_start(struct wusbhc *wusbhc)
 109 {
 110         const size_t key_size = sizeof(wusbhc->gtk.data);
 111         int result;
 112
 113         wusbhc_generate_gtk(wusbhc);
 114
 115         result = wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid,
 116                                  &wusbhc->gtk.descr.bKeyData, key_size);
 117         if (result < 0)
 118                 dev_err(wusbhc->dev, "cannot set GTK for the host: %d\n",
 119                         result);
 120
 121         return result;
 122 }
 123
 124 /**
 125  * wusbhc_sec_stop - stop the security management process
 126  * @wusbhc: the WUSB host controller
 127  *
 128  * Wait for any pending GTK rekeys to stop.
 129  */
 130 void wusbhc_sec_stop(struct wusbhc *wusbhc)
 131 {
 132         cancel_work_sync(&wusbhc->gtk_rekey_done_work);
 133 }
 134
 135
 136 /** @returns encryption type name */
 137 const char *wusb_et_name(u8 x)
 138 {
 139         switch (x) {
 140         case USB_ENC_TYPE_UNSECURE:     return "unsecure";
 141         case USB_ENC_TYPE_WIRED:        return "wired";
 142         case USB_ENC_TYPE_CCM_1:        return "CCM-1";
 143         case USB_ENC_TYPE_RSA_1:        return "RSA-1";
 144         default:                        return "unknown";
 145         }
 146 }
 147 EXPORT_SYMBOL_GPL(wusb_et_name);
 148
 149 /*
 150  * Set the device encryption method
 151  *
 152  * We tell the device which encryption method to use; we do this when
 153  * setting up the device's security.
 154  */
 155 static int wusb_dev_set_encryption(struct usb_device *usb_dev, int value)
 156 {
 157         int result;
 158         struct device *dev = &usb_dev->dev;
 159         struct wusb_dev *wusb_dev = usb_dev->wusb_dev;
 160
 161         if (value) {
 162                 value = wusb_dev->ccm1_etd.bEncryptionValue;
 163         } else {
 164                 /* FIXME: should be wusb_dev->etd[UNSECURE].bEncryptionValue */
 165                 value = 0;
 166         }
 167         /* Set device's */
 168         result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
 169                         USB_REQ_SET_ENCRYPTION,
 170                         USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 171                         value, 0, NULL, 0, 1000 /* FIXME: arbitrary */);
 172         if (result < 0)
 173                 dev_err(dev, "Can't set device's WUSB encryption to "
 174                         "%s (value %d): %d\n",
 175                         wusb_et_name(wusb_dev->ccm1_etd.bEncryptionType),
 176                         wusb_dev->ccm1_etd.bEncryptionValue,  result);
 177         return result;
 178 }
 179
 180 /*
 181  * Set the GTK to be used by a device.
 182  *
 183  * The device must be authenticated.
 184  */
 185 static int wusb_dev_set_gtk(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
 186 {
 187         struct usb_device *usb_dev = wusb_dev->usb_dev;
 188
 189         return usb_control_msg(
 190                 usb_dev, usb_sndctrlpipe(usb_dev, 0),
 191                 USB_REQ_SET_DESCRIPTOR,
 192                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 193                 USB_DT_KEY << 8 | wusbhc->gtk_index, 0,
 194                 &wusbhc->gtk.descr, wusbhc->gtk.descr.bLength,
 195                 1000);
 196 }
 197
 198
 199 /* FIXME: prototype for adding security */
 200 int wusb_dev_sec_add(struct wusbhc *wusbhc,
 201                      struct usb_device *usb_dev, struct wusb_dev *wusb_dev)
 202 {
 203         int result, bytes, secd_size;
 204         struct device *dev = &usb_dev->dev;
 205         struct usb_security_descriptor *secd;
 206         const struct usb_encryption_descriptor *etd, *ccm1_etd = NULL;
 207         const void *itr, *top;
 208         char buf[64];
 209
 210         secd = kmalloc(sizeof(*secd), GFP_KERNEL);
 211         if (secd == NULL) {
 212                 result = -ENOMEM;
 213                 goto out;
 214         }
 215
 216         result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
 217                                     0, secd, sizeof(*secd));
 218         if (result < sizeof(*secd)) {
 219                 dev_err(dev, "Can't read security descriptor or "
 220                         "not enough data: %d\n", result);
 221                 goto out;
 222         }
 223         secd_size = le16_to_cpu(secd->wTotalLength);
 224         secd = krealloc(secd, secd_size, GFP_KERNEL);
 225         if (secd == NULL) {
 226                 dev_err(dev, "Can't allocate space for security descriptors\n");
 227                 goto out;
 228         }
 229         result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
 230                                     0, secd, secd_size);
 231         if (result < secd_size) {
 232                 dev_err(dev, "Can't read security descriptor or "
 233                         "not enough data: %d\n", result);
 234                 goto out;
 235         }
 236         bytes = 0;
 237         itr = &secd[1];
 238         top = (void *)secd + result;
 239         while (itr < top) {
 240                 etd = itr;
 241                 if (top - itr < sizeof(*etd)) {
 242                         dev_err(dev, "BUG: bad device security descriptor; "
 243                                 "not enough data (%zu vs %zu bytes left)\n",
 244                                 top - itr, sizeof(*etd));
 245                         break;
 246                 }
 247                 if (etd->bLength < sizeof(*etd)) {
 248                         dev_err(dev, "BUG: bad device encryption descriptor; "
 249                                 "descriptor is too short "
 250                                 "(%u vs %zu needed)\n",
 251                                 etd->bLength, sizeof(*etd));
 252                         break;
 253                 }
 254                 itr += etd->bLength;
 255                 bytes += snprintf(buf + bytes, sizeof(buf) - bytes,
 256                                   "%s (0x%02x/%02x) ",
 257                                   wusb_et_name(etd->bEncryptionType),
 258                                   etd->bEncryptionValue, etd->bAuthKeyIndex);
 259                 if (etd->bEncryptionType == USB_ENC_TYPE_CCM_1)
 260                         ccm1_etd = etd;
 261         }
 262         /* This code only supports CCM1 as of now. */
 263         /* FIXME: user has to choose which sec mode to use?
 264          * In theory we want CCM */
 265         if (ccm1_etd == NULL) {
 266                 dev_err(dev, "WUSB device doesn't support CCM1 encryption, "
 267                         "can't use!\n");
 268                 result = -EINVAL;
 269                 goto out;
 270         }
 271         wusb_dev->ccm1_etd = *ccm1_etd;
 272         dev_dbg(dev, "supported encryption: %s; using %s (0x%02x/%02x)\n",
 273                 buf, wusb_et_name(ccm1_etd->bEncryptionType),
 274                 ccm1_etd->bEncryptionValue, ccm1_etd->bAuthKeyIndex);
 275         result = 0;
 276 out:
 277         kfree(secd);
 278         return result;
 279 }
 280
 281 void wusb_dev_sec_rm(struct wusb_dev *wusb_dev)
 282 {
 283         /* Nothing so far */
 284 }
 285
 286 /**
 287  * Update the address of an unauthenticated WUSB device
 288  *
 289  * Once we have successfully authenticated, we take it to addr0 state
 290  * and then to a normal address.
 291  *
 292  * Before the device's address (as known by it) was usb_dev->devnum |
 293  * 0x80 (unauthenticated address). With this we update it to usb_dev->devnum.
 294  */
 295 int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
 296 {
 297         int result = -ENOMEM;
 298         struct usb_device *usb_dev = wusb_dev->usb_dev;
 299         struct device *dev = &usb_dev->dev;
 300         u8 new_address = wusb_dev->addr & 0x7F;
 301
 302         /* Set address 0 */
 303         result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
 304                                  USB_REQ_SET_ADDRESS, 0,
 305                                  0, 0, NULL, 0, 1000 /* FIXME: arbitrary */);
 306         if (result < 0) {
 307                 dev_err(dev, "auth failed: can't set address 0: %d\n",
 308                         result);
 309                 goto error_addr0;
 310         }
 311         result = wusb_set_dev_addr(wusbhc, wusb_dev, 0);
 312         if (result < 0)
 313                 goto error_addr0;
 314         usb_set_device_state(usb_dev, USB_STATE_DEFAULT);
 315         usb_ep0_reinit(usb_dev);
 316
 317         /* Set new (authenticated) address. */
 318         result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
 319                                  USB_REQ_SET_ADDRESS, 0,
 320                                  new_address, 0, NULL, 0,
 321                                  1000 /* FIXME: arbitrary */);
 322         if (result < 0) {
 323                 dev_err(dev, "auth failed: can't set address %u: %d\n",
 324                         new_address, result);
 325                 goto error_addr;
 326         }
 327         result = wusb_set_dev_addr(wusbhc, wusb_dev, new_address);
 328         if (result < 0)
 329                 goto error_addr;
 330         usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
 331         usb_ep0_reinit(usb_dev);
 332         usb_dev->authenticated = 1;
 333 error_addr:
 334 error_addr0:
 335         return result;
 336 }
 337
 338 /*
 339  *
 340  *
 341  */
 342 /* FIXME: split and cleanup */
 343 int wusb_dev_4way_handshake(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev,
 344                             struct wusb_ckhdid *ck)
 345 {
 346         int result = -ENOMEM;
 347         struct usb_device *usb_dev = wusb_dev->usb_dev;
 348         struct device *dev = &usb_dev->dev;
 349         u32 tkid;
 350         __le32 tkid_le;
 351         struct usb_handshake *hs;
 352         struct aes_ccm_nonce ccm_n;
 353         u8 mic[8];
 354         struct wusb_keydvt_in keydvt_in;
 355         struct wusb_keydvt_out keydvt_out;
 356
 357         hs = kzalloc(3*sizeof(hs[0]), GFP_KERNEL);
 358         if (hs == NULL) {
 359                 dev_err(dev, "can't allocate handshake data\n");
 360                 goto error_kzalloc;
 361         }
 362
 363         /* We need to turn encryption before beginning the 4way
 364          * hshake (WUSB1.0[.3.2.2]) */
 365         result = wusb_dev_set_encryption(usb_dev, 1);
 366         if (result < 0)
 367                 goto error_dev_set_encryption;
 368
 369         tkid = wusbhc_next_tkid(wusbhc, wusb_dev);
 370         tkid_le = cpu_to_le32(tkid);
 371
 372         hs[0].bMessageNumber = 1;
 373         hs[0].bStatus = 0;
 374         memcpy(hs[0].tTKID, &tkid_le, sizeof(hs[0].tTKID));
 375         hs[0].bReserved = 0;
 376         memcpy(hs[0].CDID, &wusb_dev->cdid, sizeof(hs[0].CDID));
 377         get_random_bytes(&hs[0].nonce, sizeof(hs[0].nonce));
 378         memset(hs[0].MIC, 0, sizeof(hs[0].MIC));        /* Per WUSB1.0[T7-22] */
 379
 380         result = usb_control_msg(
 381                 usb_dev, usb_sndctrlpipe(usb_dev, 0),
 382                 USB_REQ_SET_HANDSHAKE,
 383                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 384                 1, 0, &hs[0], sizeof(hs[0]), 1000 /* FIXME: arbitrary */);
 385         if (result < 0) {
 386                 dev_err(dev, "Handshake1: request failed: %d\n", result);
 387                 goto error_hs1;
 388         }
 389
 390         /* Handshake 2, from the device -- need to verify fields */
 391         result = usb_control_msg(
 392                 usb_dev, usb_rcvctrlpipe(usb_dev, 0),
 393                 USB_REQ_GET_HANDSHAKE,
 394                 USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 395                 2, 0, &hs[1], sizeof(hs[1]), 1000 /* FIXME: arbitrary */);
 396         if (result < 0) {
 397                 dev_err(dev, "Handshake2: request failed: %d\n", result);
 398                 goto error_hs2;
 399         }
 400
 401         result = -EINVAL;
 402         if (hs[1].bMessageNumber != 2) {
 403                 dev_err(dev, "Handshake2 failed: bad message number %u\n",
 404                         hs[1].bMessageNumber);
 405                 goto error_hs2;
 406         }
 407         if (hs[1].bStatus != 0) {
 408                 dev_err(dev, "Handshake2 failed: bad status %u\n",
 409                         hs[1].bStatus);
 410                 goto error_hs2;
 411         }
 412         if (memcmp(hs[0].tTKID, hs[1].tTKID, sizeof(hs[0].tTKID))) {
 413                 dev_err(dev, "Handshake2 failed: TKID mismatch "
 414                         "(#1 0x%02x%02x%02x vs #2 0x%02x%02x%02x)\n",
 415                         hs[0].tTKID[0], hs[0].tTKID[1], hs[0].tTKID[2],
 416                         hs[1].tTKID[0], hs[1].tTKID[1], hs[1].tTKID[2]);
 417                 goto error_hs2;
 418         }
 419         if (memcmp(hs[0].CDID, hs[1].CDID, sizeof(hs[0].CDID))) {
 420                 dev_err(dev, "Handshake2 failed: CDID mismatch\n");
 421                 goto error_hs2;
 422         }
 423
 424         /* Setup the CCM nonce */
 425         memset(&ccm_n.sfn, 0, sizeof(ccm_n.sfn));       /* Per WUSB1.0[6.5.2] */
 426         memcpy(ccm_n.tkid, &tkid_le, sizeof(ccm_n.tkid));
 427         ccm_n.src_addr = wusbhc->uwb_rc->uwb_dev.dev_addr;
 428         ccm_n.dest_addr.data[0] = wusb_dev->addr;
 429         ccm_n.dest_addr.data[1] = 0;
 430
 431         /* Derive the KCK and PTK from CK, the CCM, H and D nonces */
 432         memcpy(keydvt_in.hnonce, hs[0].nonce, sizeof(keydvt_in.hnonce));
 433         memcpy(keydvt_in.dnonce, hs[1].nonce, sizeof(keydvt_in.dnonce));
 434         result = wusb_key_derive(&keydvt_out, ck->data, &ccm_n, &keydvt_in);
 435         if (result < 0) {
 436                 dev_err(dev, "Handshake2 failed: cannot derive keys: %d\n",
 437                         result);
 438                 goto error_hs2;
 439         }
 440
 441         /* Compute MIC and verify it */
 442         result = wusb_oob_mic(mic, keydvt_out.kck, &ccm_n, &hs[1]);
 443         if (result < 0) {
 444                 dev_err(dev, "Handshake2 failed: cannot compute MIC: %d\n",
 445                         result);
 446                 goto error_hs2;
 447         }
 448
 449         if (memcmp(hs[1].MIC, mic, sizeof(hs[1].MIC))) {
 450                 dev_err(dev, "Handshake2 failed: MIC mismatch\n");
 451                 goto error_hs2;
 452         }
 453
 454         /* Send Handshake3 */
 455         hs[2].bMessageNumber = 3;
 456         hs[2].bStatus = 0;
 457         memcpy(hs[2].tTKID, &tkid_le, sizeof(hs[2].tTKID));
 458         hs[2].bReserved = 0;
 459         memcpy(hs[2].CDID, &wusb_dev->cdid, sizeof(hs[2].CDID));
 460         memcpy(hs[2].nonce, hs[0].nonce, sizeof(hs[2].nonce));
 461         result = wusb_oob_mic(hs[2].MIC, keydvt_out.kck, &ccm_n, &hs[2]);
 462         if (result < 0) {
 463                 dev_err(dev, "Handshake3 failed: cannot compute MIC: %d\n",
 464                         result);
 465                 goto error_hs2;
 466         }
 467
 468         result = usb_control_msg(
 469                 usb_dev, usb_sndctrlpipe(usb_dev, 0),
 470                 USB_REQ_SET_HANDSHAKE,
 471                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 472                 3, 0, &hs[2], sizeof(hs[2]), 1000 /* FIXME: arbitrary */);
 473         if (result < 0) {
 474                 dev_err(dev, "Handshake3: request failed: %d\n", result);
 475                 goto error_hs3;
 476         }
 477
 478         result = wusbhc->set_ptk(wusbhc, wusb_dev->port_idx, tkid,
 479                                  keydvt_out.ptk, sizeof(keydvt_out.ptk));
 480         if (result < 0)
 481                 goto error_wusbhc_set_ptk;
 482
 483         result = wusb_dev_set_gtk(wusbhc, wusb_dev);
 484         if (result < 0) {
 485                 dev_err(dev, "Set GTK for device: request failed: %d\n",
 486                         result);
 487                 goto error_wusbhc_set_gtk;
 488         }
 489
 490         /* Update the device's address from unauth to auth */
 491         if (usb_dev->authenticated == 0) {
 492                 result = wusb_dev_update_address(wusbhc, wusb_dev);
 493                 if (result < 0)
 494                         goto error_dev_update_address;
 495         }
 496         result = 0;
 497         dev_info(dev, "device authenticated\n");
 498
 499 error_dev_update_address:
 500 error_wusbhc_set_gtk:
 501 error_wusbhc_set_ptk:
 502 error_hs3:
 503 error_hs2:
 504 error_hs1:
 505         memset(hs, 0, 3*sizeof(hs[0]));
 506         memset(&keydvt_out, 0, sizeof(keydvt_out));
 507         memset(&keydvt_in, 0, sizeof(keydvt_in));
 508         memset(&ccm_n, 0, sizeof(ccm_n));
 509         memset(mic, 0, sizeof(mic));
 510         if (result < 0)
 511                 wusb_dev_set_encryption(usb_dev, 0);
 512 error_dev_set_encryption:
 513         kfree(hs);
 514 error_kzalloc:
 515         return result;
 516 }
 517
 518 /*
 519  * Once all connected and authenticated devices have received the new
 520  * GTK, switch the host to using it.
 521  */
 522 static void wusbhc_gtk_rekey_done_work(struct work_struct *work)
 523 {
 524         struct wusbhc *wusbhc = container_of(work, struct wusbhc, gtk_rekey_done_work);
 525         size_t key_size = sizeof(wusbhc->gtk.data);
 526
 527         mutex_lock(&wusbhc->mutex);
 528
 529         if (--wusbhc->pending_set_gtks == 0)
 530                 wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid, &wusbhc->gtk.descr.bKeyData, key_size);
 531
 532         mutex_unlock(&wusbhc->mutex);
 533 }
 534
 535 static void wusbhc_set_gtk_callback(struct urb *urb)
 536 {
 537         struct wusbhc *wusbhc = urb->context;
 538
 539         queue_work(wusbd, &wusbhc->gtk_rekey_done_work);
 540 }
 541
 542 /**
 543  * wusbhc_gtk_rekey - generate and distribute a new GTK
 544  * @wusbhc: the WUSB host controller
 545  *
 546  * Generate a new GTK and distribute it to all connected and
 547  * authenticated devices.  When all devices have the new GTK, the host
 548  * starts using it.
 549  *
 550  * This must be called after every device disconnect (see [WUSB]
 551  * section 6.2.11.2).
 552  */
 553 void wusbhc_gtk_rekey(struct wusbhc *wusbhc)
 554 {
 555         static const size_t key_size = sizeof(wusbhc->gtk.data);
 556         int p;
 557
 558         wusbhc_generate_gtk(wusbhc);
 559
 560         for (p = 0; p < wusbhc->ports_max; p++) {
 561                 struct wusb_dev *wusb_dev;
 562
 563                 wusb_dev = wusbhc->port[p].wusb_dev;
 564                 if (!wusb_dev || !wusb_dev->usb_dev || !wusb_dev->usb_dev->authenticated)
 565                         continue;
 566
 567                 usb_fill_control_urb(wusb_dev->set_gtk_urb, wusb_dev->usb_dev,
 568                                      usb_sndctrlpipe(wusb_dev->usb_dev, 0),
 569                                      (void *)wusb_dev->set_gtk_req,
 570                                      &wusbhc->gtk.descr, wusbhc->gtk.descr.bLength,
 571                                      wusbhc_set_gtk_callback, wusbhc);
 572                 if (usb_submit_urb(wusb_dev->set_gtk_urb, GFP_KERNEL) == 0)
 573                         wusbhc->pending_set_gtks++;
 574         }
 575         if (wusbhc->pending_set_gtks == 0)
 576                 wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid, &wusbhc->gtk.descr.bKeyData, key_size);
 577 }