drivers/uwb/wlp/wss-lc.c

   1 /*
   2  * WiMedia Logical Link Control Protocol (WLP)
   3  *
   4  * Copyright (C) 2007 Intel Corporation
   5  * Reinette Chatre <reinette.chatre@intel.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License version
   9  * 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19  * 02110-1301, USA.
  20  *
  21  *
  22  * Implementation of the WLP association protocol.
  23  *
  24  * FIXME: Docs
  25  *
  26  * A UWB network interface will configure a WSS through wlp_wss_setup() after
  27  * the interface has been assigned a MAC address, typically after
  28  * "ifconfig" has been called. When the interface goes down it should call
  29  * wlp_wss_remove().
  30  *
  31  * When the WSS is ready for use the user interacts via sysfs to create,
  32  * discover, and activate WSS.
  33  *
  34  * wlp_wss_enroll_activate()
  35  *
  36  * wlp_wss_create_activate()
  37  *      wlp_wss_set_wssid_hash()
  38  *              wlp_wss_comp_wssid_hash()
  39  *      wlp_wss_sel_bcast_addr()
  40  *      wlp_wss_sysfs_add()
  41  *
  42  * Called when no more references to WSS exist:
  43  *      wlp_wss_release()
  44  *              wlp_wss_reset()
  45  */
  46 #include <linux/etherdevice.h> /* for is_valid_ether_addr */
  47 #include <linux/skbuff.h>
  48 #include <linux/wlp.h>
  49
  50 #include "wlp-internal.h"
  51
  52 size_t wlp_wss_key_print(char *buf, size_t bufsize, u8 *key)
  53 {
  54         size_t result;
  55
  56         result = scnprintf(buf, bufsize,
  57                           "%02x %02x %02x %02x %02x %02x "
  58                           "%02x %02x %02x %02x %02x %02x "
  59                           "%02x %02x %02x %02x",
  60                           key[0], key[1], key[2], key[3],
  61                           key[4], key[5], key[6], key[7],
  62                           key[8], key[9], key[10], key[11],
  63                           key[12], key[13], key[14], key[15]);
  64         return result;
  65 }
  66
  67 /**
  68  * Compute WSSID hash
  69  * WLP Draft 0.99 [7.2.1]
  70  *
  71  * The WSSID hash for a WSSID is the result of an octet-wise exclusive-OR
  72  * of all octets in the WSSID.
  73  */
  74 static
  75 u8 wlp_wss_comp_wssid_hash(struct wlp_uuid *wssid)
  76 {
  77         return wssid->data[0]  ^ wssid->data[1]  ^ wssid->data[2]
  78                ^ wssid->data[3]  ^ wssid->data[4]  ^ wssid->data[5]
  79                ^ wssid->data[6]  ^ wssid->data[7]  ^ wssid->data[8]
  80                ^ wssid->data[9]  ^ wssid->data[10] ^ wssid->data[11]
  81                ^ wssid->data[12] ^ wssid->data[13] ^ wssid->data[14]
  82                ^ wssid->data[15];
  83 }
  84
  85 /**
  86  * Select a multicast EUI-48 for the WSS broadcast address.
  87  * WLP Draft 0.99 [7.2.1]
  88  *
  89  * Selected based on the WiMedia Alliance OUI, 00-13-88, within the WLP
  90  * range, [01-13-88-00-01-00, 01-13-88-00-01-FF] inclusive.
  91  *
  92  * This address is currently hardcoded.
  93  * FIXME?
  94  */
  95 static
  96 struct uwb_mac_addr wlp_wss_sel_bcast_addr(struct wlp_wss *wss)
  97 {
  98         struct uwb_mac_addr bcast = {
  99                 .data = { 0x01, 0x13, 0x88, 0x00, 0x01, 0x00 }
 100         };
 101         return bcast;
 102 }
 103
 104 /**
 105  * Clear the contents of the WSS structure - all except kobj, mutex, virtual
 106  *
 107  * We do not want to reinitialize - the internal kobj should not change as
 108  * it still points to the parent received during setup. The mutex should
 109  * remain also. We thus just reset values individually.
 110  * The virutal address assigned to WSS will remain the same for the
 111  * lifetime of the WSS. We only reset the fields that can change during its
 112  * lifetime.
 113  */
 114 void wlp_wss_reset(struct wlp_wss *wss)
 115 {
 116         memset(&wss->wssid, 0, sizeof(wss->wssid));
 117         wss->hash = 0;
 118         memset(&wss->name[0], 0, sizeof(wss->name));
 119         memset(&wss->bcast, 0, sizeof(wss->bcast));
 120         wss->secure_status = WLP_WSS_UNSECURE;
 121         memset(&wss->master_key[0], 0, sizeof(wss->master_key));
 122         wss->tag = 0;
 123         wss->state = WLP_WSS_STATE_NONE;
 124 }
 125
 126 /**
 127  * Create sysfs infrastructure for WSS
 128  *
 129  * The WSS is configured to have the interface as parent (see wlp_wss_setup())
 130  * a new sysfs directory that includes wssid as its name is created in the
 131  * interface's sysfs directory. The group of files interacting with WSS are
 132  * created also.
 133  */
 134 static
 135 int wlp_wss_sysfs_add(struct wlp_wss *wss, char *wssid_str)
 136 {
 137         struct wlp *wlp = container_of(wss, struct wlp, wss);
 138         struct device *dev = &wlp->rc->uwb_dev.dev;
 139         int result;
 140
 141         result = kobject_set_name(&wss->kobj, "wss-%s", wssid_str);
 142         if (result < 0)
 143                 return result;
 144         wss->kobj.ktype = &wss_ktype;
 145         result = kobject_init_and_add(&wss->kobj,
 146                         &wss_ktype, wss->kobj.parent, "wlp");
 147         if (result < 0) {
 148                 dev_err(dev, "WLP: Cannot register WSS kobject.\n");
 149                 goto error_kobject_register;
 150         }
 151         result = sysfs_create_group(&wss->kobj, &wss_attr_group);
 152         if (result < 0) {
 153                 dev_err(dev, "WLP: Cannot register WSS attributes: %d\n",
 154                         result);
 155                 goto error_sysfs_create_group;
 156         }
 157         return 0;
 158 error_sysfs_create_group:
 159
 160         kobject_put(&wss->kobj); /* will free name if needed */
 161         return result;
 162 error_kobject_register:
 163         kfree(wss->kobj.name);
 164         wss->kobj.name = NULL;
 165         wss->kobj.ktype = NULL;
 166         return result;
 167 }
 168
 169
 170 /**
 171  * Release WSS
 172  *
 173  * No more references exist to this WSS. We should undo everything that was
 174  * done in wlp_wss_create_activate() except removing the group. The group
 175  * is not removed because an object can be unregistered before the group is
 176  * created. We also undo any additional operations on the WSS after this
 177  * (addition of members).
 178  *
 179  * If memory was allocated for the kobject's name then it will
 180  * be freed by the kobject system during this time.
 181  *
 182  * The EDA cache is removed and reinitilized when the WSS is removed. We
 183  * thus loose knowledge of members of this WSS at that time and need not do
 184  * it here.
 185  */
 186 void wlp_wss_release(struct kobject *kobj)
 187 {
 188         struct wlp_wss *wss = container_of(kobj, struct wlp_wss, kobj);
 189
 190         wlp_wss_reset(wss);
 191 }
 192
 193 /**
 194  * Enroll into a WSS using provided neighbor as registrar
 195  *
 196  * First search the neighborhood information to learn which neighbor is
 197  * referred to, next proceed with enrollment.
 198  *
 199  * &wss->mutex is held
 200  */
 201 static
 202 int wlp_wss_enroll_target(struct wlp_wss *wss, struct wlp_uuid *wssid,
 203                           struct uwb_dev_addr *dest)
 204 {
 205         struct wlp *wlp = container_of(wss, struct wlp, wss);
 206         struct device *dev = &wlp->rc->uwb_dev.dev;
 207         struct wlp_neighbor_e *neighbor;
 208         int result = -ENXIO;
 209         struct uwb_dev_addr *dev_addr;
 210
 211         mutex_lock(&wlp->nbmutex);
 212         list_for_each_entry(neighbor, &wlp->neighbors, node) {
 213                 dev_addr = &neighbor->uwb_dev->dev_addr;
 214                 if (!memcmp(dest, dev_addr, sizeof(*dest))) {
 215                         result = wlp_enroll_neighbor(wlp, neighbor, wss, wssid);
 216                         break;
 217                 }
 218         }
 219         if (result == -ENXIO)
 220                 dev_err(dev, "WLP: Cannot find neighbor %02x:%02x. \n",
 221                         dest->data[1], dest->data[0]);
 222         mutex_unlock(&wlp->nbmutex);
 223         return result;
 224 }
 225
 226 /**
 227  * Enroll into a WSS previously discovered
 228  *
 229  * User provides WSSID of WSS, search for neighbor that has this WSS
 230  * activated and attempt to enroll.
 231  *
 232  * &wss->mutex is held
 233  */
 234 static
 235 int wlp_wss_enroll_discovered(struct wlp_wss *wss, struct wlp_uuid *wssid)
 236 {
 237         struct wlp *wlp = container_of(wss, struct wlp, wss);
 238         struct device *dev = &wlp->rc->uwb_dev.dev;
 239         struct wlp_neighbor_e *neighbor;
 240         struct wlp_wssid_e *wssid_e;
 241         char buf[WLP_WSS_UUID_STRSIZE];
 242         int result = -ENXIO;
 243
 244
 245         mutex_lock(&wlp->nbmutex);
 246         list_for_each_entry(neighbor, &wlp->neighbors, node) {
 247                 list_for_each_entry(wssid_e, &neighbor->wssid, node) {
 248                         if (!memcmp(wssid, &wssid_e->wssid, sizeof(*wssid))) {
 249                                 result = wlp_enroll_neighbor(wlp, neighbor,
 250                                                              wss, wssid);
 251                                 if (result == 0) /* enrollment success */
 252                                         goto out;
 253                                 break;
 254                         }
 255                 }
 256         }
 257 out:
 258         if (result == -ENXIO) {
 259                 wlp_wss_uuid_print(buf, sizeof(buf), wssid);
 260                 dev_err(dev, "WLP: Cannot find WSSID %s in cache. \n", buf);
 261         }
 262         mutex_unlock(&wlp->nbmutex);
 263         return result;
 264 }
 265
 266 /**
 267  * Enroll into WSS with provided WSSID, registrar may be provided
 268  *
 269  * @wss: out WSS that will be enrolled
 270  * @wssid: wssid of neighboring WSS that we want to enroll in
 271  * @devaddr: registrar can be specified, will be broadcast (ff:ff) if any
 272  *           neighbor can be used as registrar.
 273  *
 274  * &wss->mutex is held
 275  */
 276 static
 277 int wlp_wss_enroll(struct wlp_wss *wss, struct wlp_uuid *wssid,
 278                    struct uwb_dev_addr *devaddr)
 279 {
 280         int result;
 281         struct wlp *wlp = container_of(wss, struct wlp, wss);
 282         struct device *dev = &wlp->rc->uwb_dev.dev;
 283         char buf[WLP_WSS_UUID_STRSIZE];
 284         struct uwb_dev_addr bcast = {.data = {0xff, 0xff} };
 285
 286         wlp_wss_uuid_print(buf, sizeof(buf), wssid);
 287
 288         if (wss->state != WLP_WSS_STATE_NONE) {
 289                 dev_err(dev, "WLP: Already enrolled in WSS %s.\n", buf);
 290                 result = -EEXIST;
 291                 goto error;
 292         }
 293         if (!memcmp(&bcast, devaddr, sizeof(bcast)))
 294                 result = wlp_wss_enroll_discovered(wss, wssid);
 295         else
 296                 result = wlp_wss_enroll_target(wss, wssid, devaddr);
 297         if (result < 0) {
 298                 dev_err(dev, "WLP: Unable to enroll into WSS %s, result %d \n",
 299                         buf, result);
 300                 goto error;
 301         }
 302         dev_dbg(dev, "Successfully enrolled into WSS %s \n", buf);
 303         result = wlp_wss_sysfs_add(wss, buf);
 304         if (result < 0) {
 305                 dev_err(dev, "WLP: Unable to set up sysfs for WSS kobject.\n");
 306                 wlp_wss_reset(wss);
 307         }
 308 error:
 309         return result;
 310
 311 }
 312
 313 /**
 314  * Activate given WSS
 315  *
 316  * Prior to activation a WSS must be enrolled. To activate a WSS a device
 317  * includes the WSS hash in the WLP IE in its beacon in each superframe.
 318  * WLP 0.99 [7.2.5].
 319  *
 320  * The WSS tag is also computed at this time. We only support one activated
 321  * WSS so we can use the hash as a tag - there will never be a conflict.
 322  *
 323  * We currently only support one activated WSS so only one WSS hash is
 324  * included in the WLP IE.
 325  */
 326 static
 327 int wlp_wss_activate(struct wlp_wss *wss)
 328 {
 329         struct wlp *wlp = container_of(wss, struct wlp, wss);
 330         struct device *dev = &wlp->rc->uwb_dev.dev;
 331         struct uwb_rc *uwb_rc = wlp->rc;
 332         int result;
 333         struct {
 334                 struct wlp_ie wlp_ie;
 335                 u8 hash; /* only include one hash */
 336         } ie_data;
 337
 338         BUG_ON(wss->state != WLP_WSS_STATE_ENROLLED);
 339         wss->hash = wlp_wss_comp_wssid_hash(&wss->wssid);
 340         wss->tag = wss->hash;
 341         memset(&ie_data, 0, sizeof(ie_data));
 342         ie_data.wlp_ie.hdr.element_id = UWB_IE_WLP;
 343         ie_data.wlp_ie.hdr.length = sizeof(ie_data) - sizeof(struct uwb_ie_hdr);
 344         wlp_ie_set_hash_length(&ie_data.wlp_ie, sizeof(ie_data.hash));
 345         ie_data.hash = wss->hash;
 346         result = uwb_rc_ie_add(uwb_rc, &ie_data.wlp_ie.hdr,
 347                                sizeof(ie_data));
 348         if (result < 0) {
 349                 dev_err(dev, "WLP: Unable to add WLP IE to beacon. "
 350                         "result = %d.\n", result);
 351                 goto error_wlp_ie;
 352         }
 353         wss->state = WLP_WSS_STATE_ACTIVE;
 354         result = 0;
 355 error_wlp_ie:
 356         return result;
 357 }
 358
 359 /**
 360  * Enroll in and activate WSS identified by provided WSSID
 361  *
 362  * The neighborhood cache should contain a list of all neighbors and the
 363  * WSS they have activated. Based on that cache we search which neighbor we
 364  * can perform the association process with. The user also has option to
 365  * specify which neighbor it prefers as registrar.
 366  * Successful enrollment is followed by activation.
 367  * Successful activation will create the sysfs directory containing
 368  * specific information regarding this WSS.
 369  */
 370 int wlp_wss_enroll_activate(struct wlp_wss *wss, struct wlp_uuid *wssid,
 371                             struct uwb_dev_addr *devaddr)
 372 {
 373         struct wlp *wlp = container_of(wss, struct wlp, wss);
 374         struct device *dev = &wlp->rc->uwb_dev.dev;
 375         int result = 0;
 376         char buf[WLP_WSS_UUID_STRSIZE];
 377
 378         mutex_lock(&wss->mutex);
 379         result = wlp_wss_enroll(wss, wssid, devaddr);
 380         if (result < 0) {
 381                 wlp_wss_uuid_print(buf, sizeof(buf), &wss->wssid);
 382                 dev_err(dev, "WLP: Enrollment into WSS %s failed.\n", buf);
 383                 goto error_enroll;
 384         }
 385         result = wlp_wss_activate(wss);
 386         if (result < 0) {
 387                 dev_err(dev, "WLP: Unable to activate WSS. Undoing enrollment "
 388                         "result = %d \n", result);
 389                 /* Undo enrollment */
 390                 wlp_wss_reset(wss);
 391                 goto error_activate;
 392         }
 393 error_activate:
 394 error_enroll:
 395         mutex_unlock(&wss->mutex);
 396         return result;
 397 }
 398
 399 /**
 400  * Create, enroll, and activate a new WSS
 401  *
 402  * @wssid: new wssid provided by user
 403  * @name:  WSS name requested by used.
 404  * @sec_status: security status requested by user
 405  *
 406  * A user requested the creation of a new WSS. All operations are done
 407  * locally. The new WSS will be stored locally, the hash will be included
 408  * in the WLP IE, and the sysfs infrastructure for this WSS will be
 409  * created.
 410  */
 411 int wlp_wss_create_activate(struct wlp_wss *wss, struct wlp_uuid *wssid,
 412                             char *name, unsigned sec_status, unsigned accept)
 413 {
 414         struct wlp *wlp = container_of(wss, struct wlp, wss);
 415         struct device *dev = &wlp->rc->uwb_dev.dev;
 416         int result = 0;
 417         char buf[WLP_WSS_UUID_STRSIZE];
 418
 419         result = wlp_wss_uuid_print(buf, sizeof(buf), wssid);
 420
 421         if (!mutex_trylock(&wss->mutex)) {
 422                 dev_err(dev, "WLP: WLP association session in progress.\n");
 423                 return -EBUSY;
 424         }
 425         if (wss->state != WLP_WSS_STATE_NONE) {
 426                 dev_err(dev, "WLP: WSS already exists. Not creating new.\n");
 427                 result = -EEXIST;
 428                 goto out;
 429         }
 430         if (wss->kobj.parent == NULL) {
 431                 dev_err(dev, "WLP: WSS parent not ready. Is network interface "
 432                        "up?\n");
 433                 result = -ENXIO;
 434                 goto out;
 435         }
 436         if (sec_status == WLP_WSS_SECURE) {
 437                 dev_err(dev, "WLP: FIXME Creation of secure WSS not "
 438                         "supported yet.\n");
 439                 result = -EINVAL;
 440                 goto out;
 441         }
 442         wss->wssid = *wssid;
 443         memcpy(wss->name, name, sizeof(wss->name));
 444         wss->bcast = wlp_wss_sel_bcast_addr(wss);
 445         wss->secure_status = sec_status;
 446         wss->accept_enroll = accept;
 447         /*wss->virtual_addr is initialized in call to wlp_wss_setup*/
 448         /* sysfs infrastructure */
 449         result = wlp_wss_sysfs_add(wss, buf);
 450         if (result < 0) {
 451                 dev_err(dev, "Cannot set up sysfs for WSS kobject.\n");
 452                 wlp_wss_reset(wss);
 453                 goto out;
 454         } else
 455                 result = 0;
 456         wss->state = WLP_WSS_STATE_ENROLLED;
 457         result = wlp_wss_activate(wss);
 458         if (result < 0) {
 459                 dev_err(dev, "WLP: Unable to activate WSS. Undoing "
 460                         "enrollment\n");
 461                 wlp_wss_reset(wss);
 462                 goto out;
 463         }
 464         result = 0;
 465 out:
 466         mutex_unlock(&wss->mutex);
 467         return result;
 468 }
 469
 470 /**
 471  * Determine if neighbor has WSS activated
 472  *
 473  * @returns: 1 if neighbor has WSS activated, zero otherwise
 474  *
 475  * This can be done in two ways:
 476  * - send a C1 frame, parse C2/F0 response
 477  * - examine the WLP IE sent by the neighbor
 478  *
 479  * The WLP IE is not fully supported in hardware so we use the C1/C2 frame
 480  * exchange to determine if a WSS is activated. Using the WLP IE should be
 481  * faster and should be used when it becomes possible.
 482  */
 483 int wlp_wss_is_active(struct wlp *wlp, struct wlp_wss *wss,
 484                       struct uwb_dev_addr *dev_addr)
 485 {
 486         int result = 0;
 487         struct device *dev = &wlp->rc->uwb_dev.dev;
 488         DECLARE_COMPLETION_ONSTACK(completion);
 489         struct wlp_session session;
 490         struct sk_buff  *skb;
 491         struct wlp_frame_assoc *resp;
 492         struct wlp_uuid wssid;
 493
 494         mutex_lock(&wlp->mutex);
 495         /* Send C1 association frame */
 496         result = wlp_send_assoc_frame(wlp, wss, dev_addr, WLP_ASSOC_C1);
 497         if (result < 0) {
 498                 dev_err(dev, "Unable to send C1 frame to neighbor "
 499                         "%02x:%02x (%d)\n", dev_addr->data[1],
 500                         dev_addr->data[0], result);
 501                 result = 0;
 502                 goto out;
 503         }
 504         /* Create session, wait for response */
 505         session.exp_message = WLP_ASSOC_C2;
 506         session.cb = wlp_session_cb;
 507         session.cb_priv = &completion;
 508         session.neighbor_addr = *dev_addr;
 509         BUG_ON(wlp->session != NULL);
 510         wlp->session = &session;
 511         /* Wait for C2/F0 frame */
 512         result = wait_for_completion_interruptible_timeout(&completion,
 513                                                    WLP_PER_MSG_TIMEOUT * HZ);
 514         if (result == 0) {
 515                 dev_err(dev, "Timeout while sending C1 to neighbor "
 516                              "%02x:%02x.\n", dev_addr->data[1],
 517                              dev_addr->data[0]);
 518                 goto out;
 519         }
 520         if (result < 0) {
 521                 dev_err(dev, "Unable to send C1 to neighbor %02x:%02x.\n",
 522                         dev_addr->data[1], dev_addr->data[0]);
 523                 result = 0;
 524                 goto out;
 525         }
 526         /* Parse message in session->data: it will be either C2 or F0 */
 527         skb = session.data;
 528         resp = (void *) skb->data;
 529         if (resp->type == WLP_ASSOC_F0) {
 530                 result = wlp_parse_f0(wlp, skb);
 531                 if (result < 0)
 532                         dev_err(dev, "WLP:  unable to parse incoming F0 "
 533                                 "frame from neighbor %02x:%02x.\n",
 534                                 dev_addr->data[1], dev_addr->data[0]);
 535                 result = 0;
 536                 goto error_resp_parse;
 537         }
 538         /* WLP version and message type fields have already been parsed */
 539         result = wlp_get_wssid(wlp, (void *)resp + sizeof(*resp), &wssid,
 540                                skb->len - sizeof(*resp));
 541         if (result < 0) {
 542                 dev_err(dev, "WLP: unable to obtain WSSID from C2 frame.\n");
 543                 result = 0;
 544                 goto error_resp_parse;
 545         }
 546         if (!memcmp(&wssid, &wss->wssid, sizeof(wssid)))
 547                 result = 1;
 548         else {
 549                 dev_err(dev, "WLP: Received a C2 frame without matching "
 550                         "WSSID.\n");
 551                 result = 0;
 552         }
 553 error_resp_parse:
 554         kfree_skb(skb);
 555 out:
 556         wlp->session = NULL;
 557         mutex_unlock(&wlp->mutex);
 558         return result;
 559 }
 560
 561 /**
 562  * Activate connection with neighbor by updating EDA cache
 563  *
 564  * @wss:       local WSS to which neighbor wants to connect
 565  * @dev_addr:  neighbor's address
 566  * @wssid:     neighbor's WSSID - must be same as our WSS's WSSID
 567  * @tag:       neighbor's WSS tag used to identify frames transmitted by it
 568  * @virt_addr: neighbor's virtual EUI-48
 569  */
 570 static
 571 int wlp_wss_activate_connection(struct wlp *wlp, struct wlp_wss *wss,
 572                                 struct uwb_dev_addr *dev_addr,
 573                                 struct wlp_uuid *wssid, u8 *tag,
 574                                 struct uwb_mac_addr *virt_addr)
 575 {
 576         struct device *dev = &wlp->rc->uwb_dev.dev;
 577         int result = 0;
 578
 579         if (!memcmp(wssid, &wss->wssid, sizeof(*wssid))) {
 580                 /* Update EDA cache */
 581                 result = wlp_eda_update_node(&wlp->eda, dev_addr, wss,
 582                                              (void *) virt_addr->data, *tag,
 583                                              WLP_WSS_CONNECTED);
 584                 if (result < 0)
 585                         dev_err(dev, "WLP: Unable to update EDA cache "
 586                                 "with new connected neighbor information.\n");
 587         } else {
 588                 dev_err(dev, "WLP: Neighbor does not have matching WSSID.\n");
 589                 result = -EINVAL;
 590         }
 591         return result;
 592 }
 593
 594 /**
 595  * Connect to WSS neighbor
 596  *
 597  * Use C3/C4 exchange to determine if neighbor has WSS activated and
 598  * retrieve the WSS tag and virtual EUI-48 of the neighbor.
 599  */
 600 static
 601 int wlp_wss_connect_neighbor(struct wlp *wlp, struct wlp_wss *wss,
 602                              struct uwb_dev_addr *dev_addr)
 603 {
 604         int result;
 605         struct device *dev = &wlp->rc->uwb_dev.dev;
 606         struct wlp_uuid wssid;
 607         u8 tag;
 608         struct uwb_mac_addr virt_addr;
 609         DECLARE_COMPLETION_ONSTACK(completion);
 610         struct wlp_session session;
 611         struct wlp_frame_assoc *resp;
 612         struct sk_buff *skb;
 613
 614         mutex_lock(&wlp->mutex);
 615         /* Send C3 association frame */
 616         result = wlp_send_assoc_frame(wlp, wss, dev_addr, WLP_ASSOC_C3);
 617         if (result < 0) {
 618                 dev_err(dev, "Unable to send C3 frame to neighbor "
 619                         "%02x:%02x (%d)\n", dev_addr->data[1],
 620                         dev_addr->data[0], result);
 621                 goto out;
 622         }
 623         /* Create session, wait for response */
 624         session.exp_message = WLP_ASSOC_C4;
 625         session.cb = wlp_session_cb;
 626         session.cb_priv = &completion;
 627         session.neighbor_addr = *dev_addr;
 628         BUG_ON(wlp->session != NULL);
 629         wlp->session = &session;
 630         /* Wait for C4/F0 frame */
 631         result = wait_for_completion_interruptible_timeout(&completion,
 632                                                    WLP_PER_MSG_TIMEOUT * HZ);
 633         if (result == 0) {
 634                 dev_err(dev, "Timeout while sending C3 to neighbor "
 635                              "%02x:%02x.\n", dev_addr->data[1],
 636                              dev_addr->data[0]);
 637                 result = -ETIMEDOUT;
 638                 goto out;
 639         }
 640         if (result < 0) {
 641                 dev_err(dev, "Unable to send C3 to neighbor %02x:%02x.\n",
 642                         dev_addr->data[1], dev_addr->data[0]);
 643                 goto out;
 644         }
 645         /* Parse message in session->data: it will be either C4 or F0 */
 646         skb = session.data;
 647         resp = (void *) skb->data;
 648         if (resp->type == WLP_ASSOC_F0) {
 649                 result = wlp_parse_f0(wlp, skb);
 650                 if (result < 0)
 651                         dev_err(dev, "WLP: unable to parse incoming F0 "
 652                                 "frame from neighbor %02x:%02x.\n",
 653                                 dev_addr->data[1], dev_addr->data[0]);
 654                 result = -EINVAL;
 655                 goto error_resp_parse;
 656         }
 657         result = wlp_parse_c3c4_frame(wlp, skb, &wssid, &tag, &virt_addr);
 658         if (result < 0) {
 659                 dev_err(dev, "WLP: Unable to parse C4 frame from neighbor.\n");
 660                 goto error_resp_parse;
 661         }
 662         result = wlp_wss_activate_connection(wlp, wss, dev_addr, &wssid, &tag,
 663                                              &virt_addr);
 664         if (result < 0) {
 665                 dev_err(dev, "WLP: Unable to activate connection to "
 666                         "neighbor %02x:%02x.\n", dev_addr->data[1],
 667                         dev_addr->data[0]);
 668                 goto error_resp_parse;
 669         }
 670 error_resp_parse:
 671         kfree_skb(skb);
 672 out:
 673         /* Record that we unsuccessfully tried to connect to this neighbor */
 674         if (result < 0)
 675                 wlp_eda_update_node_state(&wlp->eda, dev_addr,
 676                                           WLP_WSS_CONNECT_FAILED);
 677         wlp->session = NULL;
 678         mutex_unlock(&wlp->mutex);
 679         return result;
 680 }
 681
 682 /**
 683  * Connect to neighbor with common WSS, send pending frame
 684  *
 685  * This function is scheduled when a frame is destined to a neighbor with
 686  * which we do not have a connection. A copy of the EDA cache entry is
 687  * provided - not the actual cache entry (because it is protected by a
 688  * spinlock).
 689  *
 690  * First determine if neighbor has the same WSS activated, connect if it
 691  * does. The C3/C4 exchange is dual purpose to determine if neighbor has
 692  * WSS activated and proceed with the connection.
 693  *
 694  * The frame that triggered the connection setup is sent after connection
 695  * setup.
 696  *
 697  * network queue is stopped - we need to restart when done
 698  *
 699  */
 700 static
 701 void wlp_wss_connect_send(struct work_struct *ws)
 702 {
 703         struct wlp_assoc_conn_ctx *conn_ctx = container_of(ws,
 704                                                   struct wlp_assoc_conn_ctx,
 705                                                   ws);
 706         struct wlp *wlp = conn_ctx->wlp;
 707         struct sk_buff *skb = conn_ctx->skb;
 708         struct wlp_eda_node *eda_entry = &conn_ctx->eda_entry;
 709         struct uwb_dev_addr *dev_addr = &eda_entry->dev_addr;
 710         struct wlp_wss *wss = &wlp->wss;
 711         int result;
 712         struct device *dev = &wlp->rc->uwb_dev.dev;
 713
 714         mutex_lock(&wss->mutex);
 715         if (wss->state < WLP_WSS_STATE_ACTIVE) {
 716                 if (printk_ratelimit())
 717                         dev_err(dev, "WLP: Attempting to connect with "
 718                                 "WSS that is not active or connected.\n");
 719                 dev_kfree_skb(skb);
 720                 goto out;
 721         }
 722         /* Establish connection - send C3 rcv C4 */
 723         result = wlp_wss_connect_neighbor(wlp, wss, dev_addr);
 724         if (result < 0) {
 725                 if (printk_ratelimit())
 726                         dev_err(dev, "WLP: Unable to establish connection "
 727                                 "with neighbor %02x:%02x.\n",
 728                                 dev_addr->data[1], dev_addr->data[0]);
 729                 dev_kfree_skb(skb);
 730                 goto out;
 731         }
 732         /* EDA entry changed, update the local copy being used */
 733         result = wlp_copy_eda_node(&wlp->eda, dev_addr, eda_entry);
 734         if (result < 0) {
 735                 if (printk_ratelimit())
 736                         dev_err(dev, "WLP: Cannot find EDA entry for "
 737                                 "neighbor %02x:%02x \n",
 738                                 dev_addr->data[1], dev_addr->data[0]);
 739         }
 740         result = wlp_wss_prep_hdr(wlp, eda_entry, skb);
 741         if (result < 0) {
 742                 if (printk_ratelimit())
 743                         dev_err(dev, "WLP: Unable to prepare frame header for "
 744                                 "transmission (neighbor %02x:%02x). \n",
 745                                 dev_addr->data[1], dev_addr->data[0]);
 746                 dev_kfree_skb(skb);
 747                 goto out;
 748         }
 749         BUG_ON(wlp->xmit_frame == NULL);
 750         result = wlp->xmit_frame(wlp, skb, dev_addr);
 751         if (result < 0) {
 752                 if (printk_ratelimit())
 753                         dev_err(dev, "WLP: Unable to transmit frame: %d\n",
 754                                 result);
 755                 if (result == -ENXIO)
 756                         dev_err(dev, "WLP: Is network interface up? \n");
 757                 /* We could try again ... */
 758                 dev_kfree_skb(skb);/*we need to free if tx fails */
 759         }
 760 out:
 761         kfree(conn_ctx);
 762         BUG_ON(wlp->start_queue == NULL);
 763         wlp->start_queue(wlp);
 764         mutex_unlock(&wss->mutex);
 765 }
 766
 767 /**
 768  * Add WLP header to outgoing skb
 769  *
 770  * @eda_entry: pointer to neighbor's entry in the EDA cache
 771  * @_skb:      skb containing data destined to the neighbor
 772  */
 773 int wlp_wss_prep_hdr(struct wlp *wlp, struct wlp_eda_node *eda_entry,
 774                      void *_skb)
 775 {
 776         struct device *dev = &wlp->rc->uwb_dev.dev;
 777         int result = 0;
 778         unsigned char *eth_addr = eda_entry->eth_addr;
 779         struct uwb_dev_addr *dev_addr = &eda_entry->dev_addr;
 780         struct sk_buff *skb = _skb;
 781         struct wlp_frame_std_abbrv_hdr *std_hdr;
 782
 783         if (eda_entry->state == WLP_WSS_CONNECTED) {
 784                 /* Add WLP header */
 785                 BUG_ON(skb_headroom(skb) < sizeof(*std_hdr));
 786                 std_hdr = (void *) __skb_push(skb, sizeof(*std_hdr));
 787                 std_hdr->hdr.mux_hdr = cpu_to_le16(WLP_PROTOCOL_ID);
 788                 std_hdr->hdr.type = WLP_FRAME_STANDARD;
 789                 std_hdr->tag = eda_entry->wss->tag;
 790         } else {
 791                 if (printk_ratelimit())
 792                         dev_err(dev, "WLP: Destination neighbor (Ethernet: "
 793                                 "%02x:%02x:%02x:%02x:%02x:%02x, Dev: "
 794                                 "%02x:%02x) is not connected. \n", eth_addr[0],
 795                                 eth_addr[1], eth_addr[2], eth_addr[3],
 796                                 eth_addr[4], eth_addr[5], dev_addr->data[1],
 797                                 dev_addr->data[0]);
 798                 result = -EINVAL;
 799         }
 800         return result;
 801 }
 802
 803
 804 /**
 805  * Prepare skb for neighbor: connect if not already and prep WLP header
 806  *
 807  * This function is called in interrupt context, but it needs to sleep. We
 808  * temporarily stop the net queue to establish the WLP connection.
 809  * Setup of the WLP connection and restart of queue is scheduled
 810  * on the default work queue.
 811  *
 812  * run with eda->lock held (spinlock)
 813  */
 814 int wlp_wss_connect_prep(struct wlp *wlp, struct wlp_eda_node *eda_entry,
 815                          void *_skb)
 816 {
 817         int result = 0;
 818         struct device *dev = &wlp->rc->uwb_dev.dev;
 819         struct sk_buff *skb = _skb;
 820         struct wlp_assoc_conn_ctx *conn_ctx;
 821
 822         if (eda_entry->state == WLP_WSS_UNCONNECTED) {
 823                 /* We don't want any more packets while we set up connection */
 824                 BUG_ON(wlp->stop_queue == NULL);
 825                 wlp->stop_queue(wlp);
 826                 conn_ctx = kmalloc(sizeof(*conn_ctx), GFP_ATOMIC);
 827                 if (conn_ctx == NULL) {
 828                         if (printk_ratelimit())
 829                                 dev_err(dev, "WLP: Unable to allocate memory "
 830                                         "for connection handling.\n");
 831                         result = -ENOMEM;
 832                         goto out;
 833                 }
 834                 conn_ctx->wlp = wlp;
 835                 conn_ctx->skb = skb;
 836                 conn_ctx->eda_entry = *eda_entry;
 837                 INIT_WORK(&conn_ctx->ws, wlp_wss_connect_send);
 838                 schedule_work(&conn_ctx->ws);
 839                 result = 1;
 840         } else if (eda_entry->state == WLP_WSS_CONNECT_FAILED) {
 841                 /* Previous connection attempts failed, don't retry - see
 842                  * conditions for connection in WLP 0.99 [7.6.2] */
 843                 if (printk_ratelimit())
 844                         dev_err(dev, "Could not connect to neighbor "
 845                          "previously. Not retrying. \n");
 846                 result = -ENONET;
 847                 goto out;
 848         } else /* eda_entry->state == WLP_WSS_CONNECTED */
 849                 result = wlp_wss_prep_hdr(wlp, eda_entry, skb);
 850 out:
 851         return result;
 852 }
 853
 854 /**
 855  * Emulate broadcast: copy skb, send copy to neighbor (connect if not already)
 856  *
 857  * We need to copy skbs in the case where we emulate broadcast through
 858  * unicast. We copy instead of clone because we are modifying the data of
 859  * the frame after copying ... clones share data so we cannot emulate
 860  * broadcast using clones.
 861  *
 862  * run with eda->lock held (spinlock)
 863  */
 864 int wlp_wss_send_copy(struct wlp *wlp, struct wlp_eda_node *eda_entry,
 865                       void *_skb)
 866 {
 867         int result = -ENOMEM;
 868         struct device *dev = &wlp->rc->uwb_dev.dev;
 869         struct sk_buff *skb = _skb;
 870         struct sk_buff *copy;
 871         struct uwb_dev_addr *dev_addr = &eda_entry->dev_addr;
 872
 873         copy = skb_copy(skb, GFP_ATOMIC);
 874         if (copy == NULL) {
 875                 if (printk_ratelimit())
 876                         dev_err(dev, "WLP: Unable to copy skb for "
 877                                 "transmission.\n");
 878                 goto out;
 879         }
 880         result = wlp_wss_connect_prep(wlp, eda_entry, copy);
 881         if (result < 0) {
 882                 if (printk_ratelimit())
 883                         dev_err(dev, "WLP: Unable to connect/send skb "
 884                                 "to neighbor.\n");
 885                 dev_kfree_skb_irq(copy);
 886                 goto out;
 887         } else if (result == 1)
 888                 /* Frame will be transmitted separately */
 889                 goto out;
 890         BUG_ON(wlp->xmit_frame == NULL);
 891         result = wlp->xmit_frame(wlp, copy, dev_addr);
 892         if (result < 0) {
 893                 if (printk_ratelimit())
 894                         dev_err(dev, "WLP: Unable to transmit frame: %d\n",
 895                                 result);
 896                 if ((result == -ENXIO) && printk_ratelimit())
 897                         dev_err(dev, "WLP: Is network interface up? \n");
 898                 /* We could try again ... */
 899                 dev_kfree_skb_irq(copy);/*we need to free if tx fails */
 900         }
 901 out:
 902         return result;
 903 }
 904
 905
 906 /**
 907  * Setup WSS
 908  *
 909  * Should be called by network driver after the interface has been given a
 910  * MAC address.
 911  */
 912 int wlp_wss_setup(struct net_device *net_dev, struct wlp_wss *wss)
 913 {
 914         struct wlp *wlp = container_of(wss, struct wlp, wss);
 915         struct device *dev = &wlp->rc->uwb_dev.dev;
 916         int result = 0;
 917
 918         mutex_lock(&wss->mutex);
 919         wss->kobj.parent = &net_dev->dev.kobj;
 920         if (!is_valid_ether_addr(net_dev->dev_addr)) {
 921                 dev_err(dev, "WLP: Invalid MAC address. Cannot use for"
 922                        "virtual.\n");
 923                 result = -EINVAL;
 924                 goto out;
 925         }
 926         memcpy(wss->virtual_addr.data, net_dev->dev_addr,
 927                sizeof(wss->virtual_addr.data));
 928 out:
 929         mutex_unlock(&wss->mutex);
 930         return result;
 931 }
 932 EXPORT_SYMBOL_GPL(wlp_wss_setup);
 933
 934 /**
 935  * Remove WSS
 936  *
 937  * Called by client that configured WSS through wlp_wss_setup(). This
 938  * function is called when client no longer needs WSS, eg. client shuts
 939  * down.
 940  *
 941  * We remove the WLP IE from the beacon before initiating local cleanup.
 942  */
 943 void wlp_wss_remove(struct wlp_wss *wss)
 944 {
 945         struct wlp *wlp = container_of(wss, struct wlp, wss);
 946
 947         mutex_lock(&wss->mutex);
 948         if (wss->state == WLP_WSS_STATE_ACTIVE)
 949                 uwb_rc_ie_rm(wlp->rc, UWB_IE_WLP);
 950         if (wss->state != WLP_WSS_STATE_NONE) {
 951                 sysfs_remove_group(&wss->kobj, &wss_attr_group);
 952                 kobject_put(&wss->kobj);
 953         }
 954         wss->kobj.parent = NULL;
 955         memset(&wss->virtual_addr, 0, sizeof(wss->virtual_addr));
 956         /* Cleanup EDA cache */
 957         wlp_eda_release(&wlp->eda);
 958         wlp_eda_init(&wlp->eda);
 959         mutex_unlock(&wss->mutex);
 960 }
 961 EXPORT_SYMBOL_GPL(wlp_wss_remove);