vcs.maemo.org Git - wpasupplicant/blob - wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2008, 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 "eloop.h"
  19 #include "config.h"
  20 #include "wpa_supplicant_i.h"
  21 #include "driver_i.h"
  22 #include "mlme.h"
  23 #include "wps_supplicant.h"
  24
  25
  26 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  27 {
  28         struct wpa_ssid *ssid;
  29         union wpa_event_data data;
  30
  31         ssid = wpa_supplicant_get_ssid(wpa_s);
  32         if (ssid == NULL)
  33                 return;
  34
  35         if (wpa_s->current_ssid == NULL)
  36                 wpa_s->current_ssid = ssid;
  37         wpa_supplicant_initiate_eapol(wpa_s);
  38         wpa_printf(MSG_DEBUG, "Already associated with a configured network - "
  39                    "generating associated event");
  40         os_memset(&data, 0, sizeof(data));
  41         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  42 }
  43
  44
  45 #ifdef CONFIG_WPS
  46 static int wpas_wps_in_use(struct wpa_config *conf,
  47                            enum wps_request_type *req_type)
  48 {
  49         struct wpa_ssid *ssid;
  50         int wps = 0;
  51
  52         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
  53                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  54                         continue;
  55
  56                 wps = 1;
  57                 *req_type = wpas_wps_get_req_type(ssid);
  58                 if (!ssid->eap.phase1)
  59                         continue;
  60
  61                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  62                         return 2;
  63         }
  64
  65         return wps;
  66 }
  67 #endif /* CONFIG_WPS */
  68
  69
  70 static int wpa_supplicant_enabled_networks(struct wpa_config *conf)
  71 {
  72         struct wpa_ssid *ssid = conf->ssid;
  73         while (ssid) {
  74                 if (!ssid->disabled)
  75                         return 1;
  76                 ssid = ssid->next;
  77         }
  78         return 0;
  79 }
  80
  81
  82 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
  83                                      struct wpa_ssid *ssid)
  84 {
  85         while (ssid) {
  86                 if (!ssid->disabled)
  87                         break;
  88                 ssid = ssid->next;
  89         }
  90
  91         /* ap_scan=2 mode - try to associate with each SSID. */
  92         if (ssid == NULL) {
  93                 wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
  94                            "end of scan list - go back to beginning");
  95                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
  96                 wpa_supplicant_req_scan(wpa_s, 0, 0);
  97                 return;
  98         }
  99         if (ssid->next) {
 100                 /* Continue from the next SSID on the next attempt. */
 101                 wpa_s->prev_scan_ssid = ssid;
 102         } else {
 103                 /* Start from the beginning of the SSID list. */
 104                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 105         }
 106         wpa_supplicant_associate(wpa_s, NULL, ssid);
 107 }
 108
 109
 110 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 111 {
 112         struct wpa_supplicant *wpa_s = eloop_ctx;
 113         struct wpa_ssid *ssid;
 114         int scan_req = 0, ret;
 115         struct wpabuf *wps_ie = NULL;
 116         int wps = 0;
 117 #ifdef CONFIG_WPS
 118         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 119 #endif /* CONFIG_WPS */
 120         struct wpa_driver_scan_params params;
 121         size_t max_ssids;
 122
 123         if (wpa_s->disconnected && !wpa_s->scan_req)
 124                 return;
 125
 126         if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
 127             !wpa_s->scan_req) {
 128                 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
 129                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 130                 return;
 131         }
 132
 133         if (wpa_s->conf->ap_scan != 0 &&
 134             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 135                 wpa_printf(MSG_DEBUG, "Using wired authentication - "
 136                            "overriding ap_scan configuration");
 137                 wpa_s->conf->ap_scan = 0;
 138         }
 139
 140         if (wpa_s->conf->ap_scan == 0) {
 141                 wpa_supplicant_gen_assoc_event(wpa_s);
 142                 return;
 143         }
 144
 145         if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
 146             wpa_s->conf->ap_scan == 2)
 147                 max_ssids = 1;
 148         else {
 149                 max_ssids = wpa_s->max_scan_ssids;
 150                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 151                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 152         }
 153
 154 #ifdef CONFIG_WPS
 155         wps = wpas_wps_in_use(wpa_s->conf, &req_type);
 156 #endif /* CONFIG_WPS */
 157
 158         if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
 159             !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) &&
 160             wps != 2) {
 161                 wpa_s->scan_res_tried++;
 162                 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
 163                            "first without requesting a new scan to speed up "
 164                            "initial association");
 165                 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
 166                 return;
 167         }
 168
 169         scan_req = wpa_s->scan_req;
 170         wpa_s->scan_req = 0;
 171
 172         os_memset(&params, 0, sizeof(params));
 173
 174         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 175             wpa_s->wpa_state == WPA_INACTIVE)
 176                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 177
 178         /* Find the starting point from which to continue scanning */
 179         ssid = wpa_s->conf->ssid;
 180         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 181                 while (ssid) {
 182                         if (ssid == wpa_s->prev_scan_ssid) {
 183                                 ssid = ssid->next;
 184                                 break;
 185                         }
 186                         ssid = ssid->next;
 187                 }
 188         }
 189
 190         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 191                 wpa_supplicant_assoc_try(wpa_s, ssid);
 192                 return;
 193         } else if (wpa_s->conf->ap_scan == 2) {
 194                 /*
 195                  * User-initiated scan request in ap_scan == 2; scan with
 196                  * wildcard SSID.
 197                  */
 198                 ssid = NULL;
 199         } else {
 200                 struct wpa_ssid *start = ssid;
 201                 if (ssid == NULL && max_ssids > 1)
 202                         ssid = wpa_s->conf->ssid;
 203                 while (ssid) {
 204                         if (!ssid->disabled && ssid->scan_ssid) {
 205                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 206                                                   ssid->ssid, ssid->ssid_len);
 207                                 params.ssids[params.num_ssids].ssid =
 208                                         ssid->ssid;
 209                                 params.ssids[params.num_ssids].ssid_len =
 210                                         ssid->ssid_len;
 211                                 params.num_ssids++;
 212                                 if (params.num_ssids + 1 >= max_ssids)
 213                                         break;
 214                         }
 215                         ssid = ssid->next;
 216                         if (ssid == start)
 217                                 break;
 218                         if (ssid == NULL && max_ssids > 1 &&
 219                             start != wpa_s->conf->ssid)
 220                                 ssid = wpa_s->conf->ssid;
 221                 }
 222         }
 223
 224         if (ssid) {
 225                 wpa_s->prev_scan_ssid = ssid;
 226                 if (max_ssids > 1) {
 227                         wpa_printf(MSG_DEBUG, "Include wildcard SSID in the "
 228                                    "scan request");
 229                         params.num_ssids++;
 230                 }
 231                 wpa_printf(MSG_DEBUG, "Starting AP scan for specific SSID(s)");
 232         } else {
 233                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 234                 params.num_ssids++;
 235                 wpa_printf(MSG_DEBUG, "Starting AP scan for wildcard SSID");
 236         }
 237
 238 #ifdef CONFIG_WPS
 239         if (wps) {
 240                 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 241                                                 wpa_s->wps->uuid, req_type);
 242                 if (wps_ie) {
 243                         params.extra_ies = wpabuf_head(wps_ie);
 244                         params.extra_ies_len = wpabuf_len(wps_ie);
 245                 }
 246         }
 247 #endif /* CONFIG_WPS */
 248
 249         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) {
 250                 ieee80211_sta_set_probe_req_ie(wpa_s, params.extra_ies,
 251                                                params.extra_ies_len);
 252                 ret = ieee80211_sta_req_scan(wpa_s, params.ssids[0].ssid,
 253                                              params.ssids[0].ssid_len);
 254         } else {
 255                 wpa_drv_set_probe_req_ie(wpa_s, params.extra_ies,
 256                                          params.extra_ies_len);
 257                 ret = wpa_drv_scan(wpa_s, &params);
 258         }
 259
 260         wpabuf_free(wps_ie);
 261
 262         if (ret) {
 263                 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
 264                 wpa_supplicant_req_scan(wpa_s, 10, 0);
 265         } else
 266                 wpa_s->scan_runs++;
 267 }
 268
 269
 270 /**
 271  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 272  * @wpa_s: Pointer to wpa_supplicant data
 273  * @sec: Number of seconds after which to scan
 274  * @usec: Number of microseconds after which to scan
 275  *
 276  * This function is used to schedule a scan for neighboring access points after
 277  * the specified time.
 278  */
 279 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 280 {
 281         /* If there's at least one network that should be specifically scanned
 282          * then don't cancel the scan and reschedule.  Some drivers do
 283          * background scanning which generates frequent scan results, and that
 284          * causes the specific SSID scan to get continually pushed back and
 285          * never happen, which causes hidden APs to never get probe-scanned.
 286          */
 287         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 288             wpa_s->conf->ap_scan == 1) {
 289                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 290
 291                 while (ssid) {
 292                         if (!ssid->disabled && ssid->scan_ssid)
 293                                 break;
 294                         ssid = ssid->next;
 295                 }
 296                 if (ssid) {
 297                         wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 298                                 "ensure that specific SSID scans occur");
 299                         return;
 300                 }
 301         }
 302
 303         wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 304                 sec, usec);
 305         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 306         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 307 }
 308
 309
 310 /**
 311  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 312  * @wpa_s: Pointer to wpa_supplicant data
 313  *
 314  * This function is used to cancel a scan request scheduled with
 315  * wpa_supplicant_req_scan().
 316  */
 317 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 318 {
 319         wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 320         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 321 }