src/wps/wps.c

   1 /*
   2  * Wi-Fi Protected Setup
   3  * Copyright (c) 2007-2009, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "crypto/dh_group5.h"
  19 #include "common/ieee802_11_defs.h"
  20 #include "wps_i.h"
  21 #include "wps_dev_attr.h"
  22
  23
  24 #ifdef CONFIG_WPS_TESTING
  25 int wps_version_number = 0x20;
  26 int wps_testing_dummy_cred = 0;
  27 #endif /* CONFIG_WPS_TESTING */
  28
  29
  30 /**
  31  * wps_init - Initialize WPS Registration protocol data
  32  * @cfg: WPS configuration
  33  * Returns: Pointer to allocated data or %NULL on failure
  34  *
  35  * This function is used to initialize WPS data for a registration protocol
  36  * instance (i.e., each run of registration protocol as a Registrar of
  37  * Enrollee. The caller is responsible for freeing this data after the
  38  * registration run has been completed by calling wps_deinit().
  39  */
  40 struct wps_data * wps_init(const struct wps_config *cfg)
  41 {
  42         struct wps_data *data = os_zalloc(sizeof(*data));
  43         if (data == NULL)
  44                 return NULL;
  45         data->wps = cfg->wps;
  46         data->registrar = cfg->registrar;
  47         if (cfg->registrar) {
  48                 os_memcpy(data->uuid_r, cfg->wps->uuid, WPS_UUID_LEN);
  49         } else {
  50                 os_memcpy(data->mac_addr_e, cfg->wps->dev.mac_addr, ETH_ALEN);
  51                 os_memcpy(data->uuid_e, cfg->wps->uuid, WPS_UUID_LEN);
  52         }
  53         if (cfg->pin) {
  54                 data->dev_pw_id = data->wps->oob_dev_pw_id == 0 ?
  55                         cfg->dev_pw_id : data->wps->oob_dev_pw_id;
  56                 data->dev_password = os_malloc(cfg->pin_len);
  57                 if (data->dev_password == NULL) {
  58                         os_free(data);
  59                         return NULL;
  60                 }
  61                 os_memcpy(data->dev_password, cfg->pin, cfg->pin_len);
  62                 data->dev_password_len = cfg->pin_len;
  63         }
  64
  65         data->pbc = cfg->pbc;
  66         if (cfg->pbc) {
  67                 /* Use special PIN '00000000' for PBC */
  68                 data->dev_pw_id = DEV_PW_PUSHBUTTON;
  69                 os_free(data->dev_password);
  70                 data->dev_password = os_malloc(8);
  71                 if (data->dev_password == NULL) {
  72                         os_free(data);
  73                         return NULL;
  74                 }
  75                 os_memset(data->dev_password, '0', 8);
  76                 data->dev_password_len = 8;
  77         }
  78
  79         data->state = data->registrar ? RECV_M1 : SEND_M1;
  80
  81         if (cfg->assoc_wps_ie) {
  82                 struct wps_parse_attr attr;
  83                 wpa_hexdump_buf(MSG_DEBUG, "WPS: WPS IE from (Re)AssocReq",
  84                                 cfg->assoc_wps_ie);
  85                 if (wps_parse_msg(cfg->assoc_wps_ie, &attr) < 0) {
  86                         wpa_printf(MSG_DEBUG, "WPS: Failed to parse WPS IE "
  87                                    "from (Re)AssocReq");
  88                 } else if (attr.request_type == NULL) {
  89                         wpa_printf(MSG_DEBUG, "WPS: No Request Type attribute "
  90                                    "in (Re)AssocReq WPS IE");
  91                 } else {
  92                         wpa_printf(MSG_DEBUG, "WPS: Request Type (from WPS IE "
  93                                    "in (Re)AssocReq WPS IE): %d",
  94                                    *attr.request_type);
  95                         data->request_type = *attr.request_type;
  96                 }
  97         }
  98
  99         if (cfg->new_ap_settings) {
 100                 data->new_ap_settings =
 101                         os_malloc(sizeof(*data->new_ap_settings));
 102                 if (data->new_ap_settings == NULL) {
 103                         os_free(data);
 104                         return NULL;
 105                 }
 106                 os_memcpy(data->new_ap_settings, cfg->new_ap_settings,
 107                           sizeof(*data->new_ap_settings));
 108         }
 109
 110         if (cfg->peer_addr)
 111                 os_memcpy(data->peer_dev.mac_addr, cfg->peer_addr, ETH_ALEN);
 112         if (cfg->p2p_dev_addr)
 113                 os_memcpy(data->p2p_dev_addr, cfg->p2p_dev_addr, ETH_ALEN);
 114
 115         data->use_psk_key = cfg->use_psk_key;
 116         data->pbc_in_m1 = cfg->pbc_in_m1;
 117
 118         return data;
 119 }
 120
 121
 122 /**
 123  * wps_deinit - Deinitialize WPS Registration protocol data
 124  * @data: WPS Registration protocol data from wps_init()
 125  */
 126 void wps_deinit(struct wps_data *data)
 127 {
 128         if (data->wps_pin_revealed) {
 129                 wpa_printf(MSG_DEBUG, "WPS: Full PIN information revealed and "
 130                            "negotiation failed");
 131                 if (data->registrar)
 132                         wps_registrar_invalidate_pin(data->wps->registrar,
 133                                                      data->uuid_e);
 134         } else if (data->registrar)
 135                 wps_registrar_unlock_pin(data->wps->registrar, data->uuid_e);
 136
 137         wpabuf_free(data->dh_privkey);
 138         wpabuf_free(data->dh_pubkey_e);
 139         wpabuf_free(data->dh_pubkey_r);
 140         wpabuf_free(data->last_msg);
 141         os_free(data->dev_password);
 142         os_free(data->new_psk);
 143         wps_device_data_free(&data->peer_dev);
 144         os_free(data->new_ap_settings);
 145         dh5_free(data->dh_ctx);
 146         os_free(data);
 147 }
 148
 149
 150 /**
 151  * wps_process_msg - Process a WPS message
 152  * @wps: WPS Registration protocol data from wps_init()
 153  * @op_code: Message OP Code
 154  * @msg: Message data
 155  * Returns: Processing result
 156  *
 157  * This function is used to process WPS messages with OP Codes WSC_ACK,
 158  * WSC_NACK, WSC_MSG, and WSC_Done. The caller (e.g., EAP server/peer) is
 159  * responsible for reassembling the messages before calling this function.
 160  * Response to this message is built by calling wps_get_msg().
 161  */
 162 enum wps_process_res wps_process_msg(struct wps_data *wps,
 163                                      enum wsc_op_code op_code,
 164                                      const struct wpabuf *msg)
 165 {
 166         if (wps->registrar)
 167                 return wps_registrar_process_msg(wps, op_code, msg);
 168         else
 169                 return wps_enrollee_process_msg(wps, op_code, msg);
 170 }
 171
 172
 173 /**
 174  * wps_get_msg - Build a WPS message
 175  * @wps: WPS Registration protocol data from wps_init()
 176  * @op_code: Buffer for returning message OP Code
 177  * Returns: The generated WPS message or %NULL on failure
 178  *
 179  * This function is used to build a response to a message processed by calling
 180  * wps_process_msg(). The caller is responsible for freeing the buffer.
 181  */
 182 struct wpabuf * wps_get_msg(struct wps_data *wps, enum wsc_op_code *op_code)
 183 {
 184         if (wps->registrar)
 185                 return wps_registrar_get_msg(wps, op_code);
 186         else
 187                 return wps_enrollee_get_msg(wps, op_code);
 188 }
 189
 190
 191 /**
 192  * wps_is_selected_pbc_registrar - Check whether WPS IE indicates active PBC
 193  * @msg: WPS IE contents from Beacon or Probe Response frame
 194  * Returns: 1 if PBC Registrar is active, 0 if not
 195  */
 196 int wps_is_selected_pbc_registrar(const struct wpabuf *msg)
 197 {
 198         struct wps_parse_attr attr;
 199
 200         /*
 201          * In theory, this could also verify that attr.sel_reg_config_methods
 202          * includes WPS_CONFIG_PUSHBUTTON, but some deployed AP implementations
 203          * do not set Selected Registrar Config Methods attribute properly, so
 204          * it is safer to just use Device Password ID here.
 205          */
 206
 207         if (wps_parse_msg(msg, &attr) < 0 ||
 208             !attr.selected_registrar || *attr.selected_registrar == 0 ||
 209             !attr.dev_password_id ||
 210             WPA_GET_BE16(attr.dev_password_id) != DEV_PW_PUSHBUTTON)
 211                 return 0;
 212
 213 #ifdef CONFIG_WPS_STRICT
 214         if (!attr.sel_reg_config_methods ||
 215             !(WPA_GET_BE16(attr.sel_reg_config_methods) &
 216               WPS_CONFIG_PUSHBUTTON))
 217                 return 0;
 218 #endif /* CONFIG_WPS_STRICT */
 219
 220         return 1;
 221 }
 222
 223
 224 static int is_selected_pin_registrar(struct wps_parse_attr *attr)
 225 {
 226         /*
 227          * In theory, this could also verify that attr.sel_reg_config_methods
 228          * includes WPS_CONFIG_LABEL, WPS_CONFIG_DISPLAY, or WPS_CONFIG_KEYPAD,
 229          * but some deployed AP implementations do not set Selected Registrar
 230          * Config Methods attribute properly, so it is safer to just use
 231          * Device Password ID here.
 232          */
 233
 234         if (!attr->selected_registrar || *attr->selected_registrar == 0)
 235                 return 0;
 236
 237         if (attr->dev_password_id != NULL &&
 238             WPA_GET_BE16(attr->dev_password_id) == DEV_PW_PUSHBUTTON)
 239                 return 0;
 240
 241 #ifdef CONFIG_WPS_STRICT
 242         if (!attr->sel_reg_config_methods ||
 243             !(WPA_GET_BE16(attr->sel_reg_config_methods) &
 244               (WPS_CONFIG_LABEL | WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD)))
 245                 return 0;
 246 #endif /* CONFIG_WPS_STRICT */
 247
 248         return 1;
 249 }
 250
 251
 252 /**
 253  * wps_is_selected_pin_registrar - Check whether WPS IE indicates active PIN
 254  * @msg: WPS IE contents from Beacon or Probe Response frame
 255  * Returns: 1 if PIN Registrar is active, 0 if not
 256  */
 257 int wps_is_selected_pin_registrar(const struct wpabuf *msg)
 258 {
 259         struct wps_parse_attr attr;
 260
 261         if (wps_parse_msg(msg, &attr) < 0)
 262                 return 0;
 263
 264         return is_selected_pin_registrar(&attr);
 265 }
 266
 267
 268 /**
 269  * wps_is_addr_authorized - Check whether WPS IE authorizes MAC address
 270  * @msg: WPS IE contents from Beacon or Probe Response frame
 271  * @addr: MAC address to search for
 272  * @ver1_compat: Whether to use version 1 compatibility mode
 273  * Returns: 1 if address is authorized, 0 if not
 274  */
 275 int wps_is_addr_authorized(const struct wpabuf *msg, const u8 *addr,
 276                            int ver1_compat)
 277 {
 278         struct wps_parse_attr attr;
 279         unsigned int i;
 280         const u8 *pos;
 281         const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 282
 283         if (wps_parse_msg(msg, &attr) < 0)
 284                 return 0;
 285
 286         if (!attr.version2 && ver1_compat) {
 287                 /*
 288                  * Version 1.0 AP - AuthorizedMACs not used, so revert back to
 289                  * old mechanism of using SelectedRegistrar.
 290                  */
 291                 return is_selected_pin_registrar(&attr);
 292         }
 293
 294         if (!attr.authorized_macs)
 295                 return 0;
 296
 297         pos = attr.authorized_macs;
 298         for (i = 0; i < attr.authorized_macs_len / ETH_ALEN; i++) {
 299                 if (os_memcmp(pos, addr, ETH_ALEN) == 0 ||
 300                     os_memcmp(pos, bcast, ETH_ALEN) == 0)
 301                         return 1;
 302                 pos += ETH_ALEN;
 303         }
 304
 305         return 0;
 306 }
 307
 308
 309 /**
 310  * wps_ap_priority_compar - Prioritize WPS IE from two APs
 311  * @wps_a: WPS IE contents from Beacon or Probe Response frame
 312  * @wps_b: WPS IE contents from Beacon or Probe Response frame
 313  * Returns: 1 if wps_b is considered more likely selection for WPS
 314  * provisioning, -1 if wps_a is considered more like, or 0 if no preference
 315  */
 316 int wps_ap_priority_compar(const struct wpabuf *wps_a,
 317                            const struct wpabuf *wps_b)
 318 {
 319         struct wps_parse_attr attr_a, attr_b;
 320         int sel_a, sel_b;
 321
 322         if (wps_a == NULL || wps_parse_msg(wps_a, &attr_a) < 0)
 323                 return 1;
 324         if (wps_b == NULL || wps_parse_msg(wps_b, &attr_b) < 0)
 325                 return -1;
 326
 327         sel_a = attr_a.selected_registrar && *attr_a.selected_registrar != 0;
 328         sel_b = attr_b.selected_registrar && *attr_b.selected_registrar != 0;
 329
 330         if (sel_a && !sel_b)
 331                 return -1;
 332         if (!sel_a && sel_b)
 333                 return 1;
 334
 335         return 0;
 336 }
 337
 338
 339 /**
 340  * wps_get_uuid_e - Get UUID-E from WPS IE
 341  * @msg: WPS IE contents from Beacon or Probe Response frame
 342  * Returns: Pointer to UUID-E or %NULL if not included
 343  *
 344  * The returned pointer is to the msg contents and it remains valid only as
 345  * long as the msg buffer is valid.
 346  */
 347 const u8 * wps_get_uuid_e(const struct wpabuf *msg)
 348 {
 349         struct wps_parse_attr attr;
 350
 351         if (wps_parse_msg(msg, &attr) < 0)
 352                 return NULL;
 353         return attr.uuid_e;
 354 }
 355
 356
 357 /**
 358  * wps_build_assoc_req_ie - Build WPS IE for (Re)Association Request
 359  * @req_type: Value for Request Type attribute
 360  * Returns: WPS IE or %NULL on failure
 361  *
 362  * The caller is responsible for freeing the buffer.
 363  */
 364 struct wpabuf * wps_build_assoc_req_ie(enum wps_request_type req_type)
 365 {
 366         struct wpabuf *ie;
 367         u8 *len;
 368
 369         wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for (Re)Association "
 370                    "Request");
 371         ie = wpabuf_alloc(100);
 372         if (ie == NULL)
 373                 return NULL;
 374
 375         wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
 376         len = wpabuf_put(ie, 1);
 377         wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
 378
 379         if (wps_build_version(ie) ||
 380             wps_build_req_type(ie, req_type) ||
 381             wps_build_wfa_ext(ie, 0, NULL, 0)) {
 382                 wpabuf_free(ie);
 383                 return NULL;
 384         }
 385
 386         *len = wpabuf_len(ie) - 2;
 387
 388         return ie;
 389 }
 390
 391
 392 /**
 393  * wps_build_assoc_resp_ie - Build WPS IE for (Re)Association Response
 394  * Returns: WPS IE or %NULL on failure
 395  *
 396  * The caller is responsible for freeing the buffer.
 397  */
 398 struct wpabuf * wps_build_assoc_resp_ie(void)
 399 {
 400         struct wpabuf *ie;
 401         u8 *len;
 402
 403         wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for (Re)Association "
 404                    "Response");
 405         ie = wpabuf_alloc(100);
 406         if (ie == NULL)
 407                 return NULL;
 408
 409         wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
 410         len = wpabuf_put(ie, 1);
 411         wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
 412
 413         if (wps_build_version(ie) ||
 414             wps_build_resp_type(ie, WPS_RESP_AP) ||
 415             wps_build_wfa_ext(ie, 0, NULL, 0)) {
 416                 wpabuf_free(ie);
 417                 return NULL;
 418         }
 419
 420         *len = wpabuf_len(ie) - 2;
 421
 422         return ie;
 423 }
 424
 425
 426 /**
 427  * wps_build_probe_req_ie - Build WPS IE for Probe Request
 428  * @pbc: Whether searching for PBC mode APs
 429  * @dev: Device attributes
 430  * @uuid: Own UUID
 431  * @req_type: Value for Request Type attribute
 432  * @num_req_dev_types: Number of requested device types
 433  * @req_dev_types: Requested device types (8 * num_req_dev_types octets) or
 434  *      %NULL if none
 435  * Returns: WPS IE or %NULL on failure
 436  *
 437  * The caller is responsible for freeing the buffer.
 438  */
 439 struct wpabuf * wps_build_probe_req_ie(int pbc, struct wps_device_data *dev,
 440                                        const u8 *uuid,
 441                                        enum wps_request_type req_type,
 442                                        unsigned int num_req_dev_types,
 443                                        const u8 *req_dev_types)
 444 {
 445         struct wpabuf *ie;
 446         u16 methods = 0;
 447
 448         wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for Probe Request");
 449
 450         ie = wpabuf_alloc(500);
 451         if (ie == NULL)
 452                 return NULL;
 453
 454         methods |= WPS_CONFIG_PUSHBUTTON;
 455 #ifdef CONFIG_WPS2
 456         /*
 457          * TODO: Should figure out whether this device has a physical or
 458          * virtual pushbutton.
 459          */
 460         methods |= WPS_CONFIG_VIRT_PUSHBUTTON;
 461 #endif /* CONFIG_WPS2 */
 462
 463         /*
 464          * TODO: Should figure out whether this Probe Request was triggered
 465          * using physical or virtual display. Also, if the device has a PIN on
 466          * a label, that should be indicated here.
 467          */
 468         methods |= WPS_CONFIG_DISPLAY |
 469 #ifdef CONFIG_WPS2
 470                 WPS_CONFIG_VIRT_DISPLAY |
 471 #endif /* CONFIG_WPS2 */
 472                 WPS_CONFIG_KEYPAD;
 473 #ifdef CONFIG_WPS_UFD
 474         methods |= WPS_CONFIG_USBA;
 475 #endif /* CONFIG_WPS_UFD */
 476 #ifdef CONFIG_WPS_NFC
 477         methods |= WPS_CONFIG_NFC_INTERFACE;
 478 #endif /* CONFIG_WPS_NFC */
 479
 480         if (wps_build_version(ie) ||
 481             wps_build_req_type(ie, req_type) ||
 482             wps_build_config_methods(ie, methods) ||
 483             wps_build_uuid_e(ie, uuid) ||
 484             wps_build_primary_dev_type(dev, ie) ||
 485             wps_build_rf_bands(dev, ie) ||
 486             wps_build_assoc_state(NULL, ie) ||
 487             wps_build_config_error(ie, WPS_CFG_NO_ERROR) ||
 488             wps_build_dev_password_id(ie, pbc ? DEV_PW_PUSHBUTTON :
 489                                       DEV_PW_DEFAULT) ||
 490 #ifdef CONFIG_WPS2
 491             wps_build_manufacturer(dev, ie) ||
 492             wps_build_model_name(dev, ie) ||
 493             wps_build_model_number(dev, ie) ||
 494             wps_build_dev_name(dev, ie) ||
 495             wps_build_wfa_ext(ie, req_type == WPS_REQ_ENROLLEE, NULL, 0) ||
 496 #endif /* CONFIG_WPS2 */
 497             wps_build_req_dev_type(dev, ie, num_req_dev_types, req_dev_types)
 498             ||
 499             wps_build_secondary_dev_type(dev, ie)
 500                 ) {
 501                 wpabuf_free(ie);
 502                 return NULL;
 503         }
 504
 505 #ifndef CONFIG_WPS2
 506         if (dev->p2p && wps_build_dev_name(dev, ie)) {
 507                 wpabuf_free(ie);
 508                 return NULL;
 509         }
 510 #endif /* CONFIG_WPS2 */
 511
 512         return wps_ie_encapsulate(ie);
 513 }
 514
 515
 516 void wps_free_pending_msgs(struct upnp_pending_message *msgs)
 517 {
 518         struct upnp_pending_message *p, *prev;
 519         p = msgs;
 520         while (p) {
 521                 prev = p;
 522                 p = p->next;
 523                 wpabuf_free(prev->msg);
 524                 os_free(prev);
 525         }
 526 }
 527
 528
 529 int wps_attr_text(struct wpabuf *data, char *buf, char *end)
 530 {
 531         struct wps_parse_attr attr;
 532         char *pos = buf;
 533         int ret;
 534
 535         if (wps_parse_msg(data, &attr) < 0)
 536                 return -1;
 537
 538         if (attr.wps_state) {
 539                 if (*attr.wps_state == WPS_STATE_NOT_CONFIGURED)
 540                         ret = os_snprintf(pos, end - pos,
 541                                           "wps_state=unconfigured\n");
 542                 else if (*attr.wps_state == WPS_STATE_CONFIGURED)
 543                         ret = os_snprintf(pos, end - pos,
 544                                           "wps_state=configured\n");
 545                 else
 546                         ret = 0;
 547                 if (ret < 0 || ret >= end - pos)
 548                         return pos - buf;
 549                 pos += ret;
 550         }
 551
 552         if (attr.ap_setup_locked && *attr.ap_setup_locked) {
 553                 ret = os_snprintf(pos, end - pos,
 554                                   "wps_ap_setup_locked=1\n");
 555                 if (ret < 0 || ret >= end - pos)
 556                         return pos - buf;
 557                 pos += ret;
 558         }
 559
 560         if (attr.selected_registrar && *attr.selected_registrar) {
 561                 ret = os_snprintf(pos, end - pos,
 562                                   "wps_selected_registrar=1\n");
 563                 if (ret < 0 || ret >= end - pos)
 564                         return pos - buf;
 565                 pos += ret;
 566         }
 567
 568         if (attr.dev_password_id) {
 569                 ret = os_snprintf(pos, end - pos,
 570                                   "wps_device_password_id=%u\n",
 571                                   WPA_GET_BE16(attr.dev_password_id));
 572                 if (ret < 0 || ret >= end - pos)
 573                         return pos - buf;
 574                 pos += ret;
 575         }
 576
 577         if (attr.sel_reg_config_methods) {
 578                 ret = os_snprintf(pos, end - pos,
 579                                   "wps_selected_registrar_config_methods="
 580                                   "0x%04x\n",
 581                                   WPA_GET_BE16(attr.sel_reg_config_methods));
 582                 if (ret < 0 || ret >= end - pos)
 583                         return pos - buf;
 584                 pos += ret;
 585         }
 586
 587         if (attr.primary_dev_type) {
 588                 char devtype[WPS_DEV_TYPE_BUFSIZE];
 589                 ret = os_snprintf(pos, end - pos,
 590                                   "wps_primary_device_type=%s\n",
 591                                   wps_dev_type_bin2str(attr.primary_dev_type,
 592                                                        devtype,
 593                                                        sizeof(devtype)));
 594                 if (ret < 0 || ret >= end - pos)
 595                         return pos - buf;
 596                 pos += ret;
 597         }
 598
 599         if (attr.dev_name) {
 600                 char *str = os_malloc(attr.dev_name_len + 1);
 601                 size_t i;
 602                 if (str == NULL)
 603                         return pos - buf;
 604                 for (i = 0; i < attr.dev_name_len; i++) {
 605                         if (attr.dev_name[i] < 32)
 606                                 str[i] = '_';
 607                         else
 608                                 str[i] = attr.dev_name[i];
 609                 }
 610                 str[i] = '\0';
 611                 ret = os_snprintf(pos, end - pos, "wps_device_name=%s\n", str);
 612                 os_free(str);
 613                 if (ret < 0 || ret >= end - pos)
 614                         return pos - buf;
 615                 pos += ret;
 616         }
 617
 618         if (attr.config_methods) {
 619                 ret = os_snprintf(pos, end - pos,
 620                                   "wps_config_methods=0x%04x\n",
 621                                   WPA_GET_BE16(attr.config_methods));
 622                 if (ret < 0 || ret >= end - pos)
 623                         return pos - buf;
 624                 pos += ret;
 625         }
 626
 627         return pos - buf;
 628 }