wpa_supplicant/offchannel.c

   1 /*
   2  * wpa_supplicant - Off-channel Action frame TX/RX
   3  * Copyright (c) 2009-2010, Atheros Communications
   4  * Copyright (c) 2011, Qualcomm Atheros
   5  *
   6  * This software may be distributed under the terms of the BSD license.
   7  * See README for more details.
   8  */
   9
  10 #include "includes.h"
  11
  12 #include "common.h"
  13 #include "utils/eloop.h"
  14 #include "wpa_supplicant_i.h"
  15 #include "driver_i.h"
  16 #include "offchannel.h"
  17
  18
  19
  20 static struct wpa_supplicant *
  21 wpas_get_tx_interface(struct wpa_supplicant *wpa_s, const u8 *src)
  22 {
  23         struct wpa_supplicant *iface;
  24
  25         if (os_memcmp(src, wpa_s->own_addr, ETH_ALEN) == 0)
  26                 return wpa_s;
  27
  28         /*
  29          * Try to find a group interface that matches with the source address.
  30          */
  31         iface = wpa_s->global->ifaces;
  32         while (iface) {
  33                 if (os_memcmp(wpa_s->pending_action_src,
  34                               iface->own_addr, ETH_ALEN) == 0)
  35                         break;
  36                 iface = iface->next;
  37         }
  38         if (iface) {
  39                 wpa_printf(MSG_DEBUG, "P2P: Use group interface %s "
  40                            "instead of interface %s for Action TX",
  41                            iface->ifname, wpa_s->ifname);
  42                 return iface;
  43         }
  44
  45         return wpa_s;
  46 }
  47
  48
  49 static void wpas_send_action_cb(void *eloop_ctx, void *timeout_ctx)
  50 {
  51         struct wpa_supplicant *wpa_s = eloop_ctx;
  52         struct wpa_supplicant *iface;
  53         int res;
  54         int without_roc;
  55
  56         without_roc = wpa_s->pending_action_without_roc;
  57         wpa_s->pending_action_without_roc = 0;
  58         wpa_printf(MSG_DEBUG, "Off-channel: Send Action callback "
  59                    "(without_roc=%d pending_action_tx=%p)",
  60                    without_roc, wpa_s->pending_action_tx);
  61
  62         if (wpa_s->pending_action_tx == NULL)
  63                 return;
  64
  65         /*
  66          * This call is likely going to be on the P2P device instance if the
  67          * driver uses a separate interface for that purpose. However, some
  68          * Action frames are actually sent within a P2P Group and when that is
  69          * the case, we need to follow power saving (e.g., GO buffering the
  70          * frame for a client in PS mode or a client following the advertised
  71          * NoA from its GO). To make that easier for the driver, select the
  72          * correct group interface here.
  73          */
  74         iface = wpas_get_tx_interface(wpa_s, wpa_s->pending_action_src);
  75
  76         if (wpa_s->off_channel_freq != wpa_s->pending_action_freq &&
  77             wpa_s->pending_action_freq != 0 &&
  78             wpa_s->pending_action_freq != iface->assoc_freq) {
  79                 wpa_printf(MSG_DEBUG, "Off-channel: Pending Action frame TX "
  80                            "waiting for another freq=%u (off_channel_freq=%u "
  81                            "assoc_freq=%u)",
  82                            wpa_s->pending_action_freq,
  83                            wpa_s->off_channel_freq,
  84                            iface->assoc_freq);
  85                 if (without_roc && wpa_s->off_channel_freq == 0) {
  86                         /*
  87                          * We may get here if wpas_send_action() found us to be
  88                          * on the correct channel, but remain-on-channel cancel
  89                          * event was received before getting here.
  90                          */
  91                         wpa_printf(MSG_DEBUG, "Off-channel: Schedule "
  92                                    "remain-on-channel to send Action frame");
  93                         if (wpa_drv_remain_on_channel(
  94                                     wpa_s, wpa_s->pending_action_freq, 200) <
  95                             0) {
  96                                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to "
  97                                            "request driver to remain on "
  98                                            "channel (%u MHz) for Action Frame "
  99                                            "TX", wpa_s->pending_action_freq);
 100                         } else {
 101                                 wpa_s->off_channel_freq = 0;
 102                                 wpa_s->roc_waiting_drv_freq =
 103                                         wpa_s->pending_action_freq;
 104                         }
 105                 }
 106                 return;
 107         }
 108
 109         wpa_printf(MSG_DEBUG, "Off-channel: Sending pending Action frame to "
 110                    MACSTR " using interface %s",
 111                    MAC2STR(wpa_s->pending_action_dst), iface->ifname);
 112         res = wpa_drv_send_action(iface, wpa_s->pending_action_freq, 0,
 113                                   wpa_s->pending_action_dst,
 114                                   wpa_s->pending_action_src,
 115                                   wpa_s->pending_action_bssid,
 116                                   wpabuf_head(wpa_s->pending_action_tx),
 117                                   wpabuf_len(wpa_s->pending_action_tx),
 118                                   wpa_s->pending_action_no_cck);
 119         if (res) {
 120                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to send the "
 121                            "pending Action frame");
 122                 /*
 123                  * Use fake TX status event to allow state machines to
 124                  * continue.
 125                  */
 126                 offchannel_send_action_tx_status(
 127                         wpa_s, wpa_s->pending_action_dst,
 128                         wpabuf_head(wpa_s->pending_action_tx),
 129                         wpabuf_len(wpa_s->pending_action_tx),
 130                         OFFCHANNEL_SEND_ACTION_FAILED);
 131         }
 132 }
 133
 134
 135 void offchannel_send_action_tx_status(
 136         struct wpa_supplicant *wpa_s, const u8 *dst, const u8 *data,
 137         size_t data_len, enum offchannel_send_action_result result)
 138 {
 139         if (wpa_s->pending_action_tx == NULL) {
 140                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 141                            "no pending operation");
 142                 return;
 143         }
 144
 145         if (os_memcmp(dst, wpa_s->pending_action_dst, ETH_ALEN) != 0) {
 146                 wpa_printf(MSG_DEBUG, "Off-channel: Ignore Action TX status - "
 147                            "unknown destination address");
 148                 return;
 149         }
 150
 151         wpabuf_free(wpa_s->pending_action_tx);
 152         wpa_s->pending_action_tx = NULL;
 153
 154         wpa_printf(MSG_DEBUG, "Off-channel: TX status result=%d cb=%p",
 155                    result, wpa_s->pending_action_tx_status_cb);
 156
 157         if (wpa_s->pending_action_tx_status_cb) {
 158                 wpa_s->pending_action_tx_status_cb(
 159                         wpa_s, wpa_s->pending_action_freq,
 160                         wpa_s->pending_action_dst, wpa_s->pending_action_src,
 161                         wpa_s->pending_action_bssid,
 162                         data, data_len, result);
 163         }
 164 }
 165
 166
 167 int offchannel_send_action(struct wpa_supplicant *wpa_s, unsigned int freq,
 168                            const u8 *dst, const u8 *src, const u8 *bssid,
 169                            const u8 *buf, size_t len, unsigned int wait_time,
 170                            void (*tx_cb)(struct wpa_supplicant *wpa_s,
 171                                          unsigned int freq, const u8 *dst,
 172                                          const u8 *src, const u8 *bssid,
 173                                          const u8 *data, size_t data_len,
 174                                          enum offchannel_send_action_result
 175                                          result),
 176                            int no_cck)
 177 {
 178         wpa_printf(MSG_DEBUG, "Off-channel: Send action frame: freq=%d dst="
 179                    MACSTR " src=" MACSTR " bssid=" MACSTR " len=%d",
 180                    freq, MAC2STR(dst), MAC2STR(src), MAC2STR(bssid),
 181                    (int) len);
 182
 183         wpa_s->pending_action_tx_status_cb = tx_cb;
 184
 185         if (wpa_s->pending_action_tx) {
 186                 wpa_printf(MSG_DEBUG, "Off-channel: Dropped pending Action "
 187                            "frame TX to " MACSTR,
 188                            MAC2STR(wpa_s->pending_action_dst));
 189                 wpabuf_free(wpa_s->pending_action_tx);
 190         }
 191         wpa_s->pending_action_tx = wpabuf_alloc(len);
 192         if (wpa_s->pending_action_tx == NULL) {
 193                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to allocate Action "
 194                            "frame TX buffer (len=%llu)",
 195                            (unsigned long long) len);
 196                 return -1;
 197         }
 198         wpabuf_put_data(wpa_s->pending_action_tx, buf, len);
 199         os_memcpy(wpa_s->pending_action_src, src, ETH_ALEN);
 200         os_memcpy(wpa_s->pending_action_dst, dst, ETH_ALEN);
 201         os_memcpy(wpa_s->pending_action_bssid, bssid, ETH_ALEN);
 202         wpa_s->pending_action_freq = freq;
 203         wpa_s->pending_action_no_cck = no_cck;
 204
 205         if (freq != 0 && wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX) {
 206                 struct wpa_supplicant *iface;
 207
 208                 iface = wpas_get_tx_interface(wpa_s,
 209                                               wpa_s->pending_action_src);
 210                 wpa_s->action_tx_wait_time = wait_time;
 211
 212                 return wpa_drv_send_action(
 213                         iface, wpa_s->pending_action_freq,
 214                         wait_time, wpa_s->pending_action_dst,
 215                         wpa_s->pending_action_src, wpa_s->pending_action_bssid,
 216                         wpabuf_head(wpa_s->pending_action_tx),
 217                         wpabuf_len(wpa_s->pending_action_tx),
 218                         wpa_s->pending_action_no_cck);
 219         }
 220
 221         if (freq) {
 222                 struct wpa_supplicant *tx_iface;
 223                 tx_iface = wpas_get_tx_interface(wpa_s, src);
 224                 if (tx_iface->assoc_freq == freq) {
 225                         wpa_printf(MSG_DEBUG, "Off-channel: Already on "
 226                                    "requested channel (TX interface operating "
 227                                    "channel)");
 228                         freq = 0;
 229                 }
 230         }
 231
 232         if (wpa_s->off_channel_freq == freq || freq == 0) {
 233                 wpa_printf(MSG_DEBUG, "Off-channel: Already on requested "
 234                            "channel; send Action frame immediately");
 235                 /* TODO: Would there ever be need to extend the current
 236                  * duration on the channel? */
 237                 wpa_s->pending_action_without_roc = 1;
 238                 eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
 239                 eloop_register_timeout(0, 0, wpas_send_action_cb, wpa_s, NULL);
 240                 return 0;
 241         }
 242         wpa_s->pending_action_without_roc = 0;
 243
 244         if (wpa_s->roc_waiting_drv_freq == freq) {
 245                 wpa_printf(MSG_DEBUG, "Off-channel: Already waiting for "
 246                            "driver to get to frequency %u MHz; continue "
 247                            "waiting to send the Action frame", freq);
 248                 return 0;
 249         }
 250
 251         wpa_printf(MSG_DEBUG, "Off-channel: Schedule Action frame to be "
 252                    "transmitted once the driver gets to the requested "
 253                    "channel");
 254         if (wait_time > wpa_s->max_remain_on_chan)
 255                 wait_time = wpa_s->max_remain_on_chan;
 256         if (wpa_drv_remain_on_channel(wpa_s, freq, wait_time) < 0) {
 257                 wpa_printf(MSG_DEBUG, "Off-channel: Failed to request driver "
 258                            "to remain on channel (%u MHz) for Action "
 259                            "Frame TX", freq);
 260                 return -1;
 261         }
 262         wpa_s->off_channel_freq = 0;
 263         wpa_s->roc_waiting_drv_freq = freq;
 264
 265         return 0;
 266 }
 267
 268
 269 void offchannel_send_action_done(struct wpa_supplicant *wpa_s)
 270 {
 271         wpa_printf(MSG_DEBUG, "Off-channel: Action frame sequence done "
 272                    "notification");
 273         wpabuf_free(wpa_s->pending_action_tx);
 274         wpa_s->pending_action_tx = NULL;
 275         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_OFFCHANNEL_TX &&
 276             wpa_s->action_tx_wait_time)
 277                 wpa_drv_send_action_cancel_wait(wpa_s);
 278
 279         if (wpa_s->off_channel_freq || wpa_s->roc_waiting_drv_freq) {
 280                 wpa_drv_cancel_remain_on_channel(wpa_s);
 281                 wpa_s->off_channel_freq = 0;
 282                 wpa_s->roc_waiting_drv_freq = 0;
 283         }
 284 }
 285
 286
 287 void offchannel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
 288                                      unsigned int freq, unsigned int duration)
 289 {
 290         wpa_s->roc_waiting_drv_freq = 0;
 291         wpa_s->off_channel_freq = freq;
 292         wpas_send_action_cb(wpa_s, NULL);
 293 }
 294
 295
 296 void offchannel_cancel_remain_on_channel_cb(struct wpa_supplicant *wpa_s,
 297                                             unsigned int freq)
 298 {
 299         wpa_s->off_channel_freq = 0;
 300 }
 301
 302
 303 void offchannel_deinit(struct wpa_supplicant *wpa_s)
 304 {
 305         wpabuf_free(wpa_s->pending_action_tx);
 306         wpa_s->pending_action_tx = NULL;
 307         eloop_cancel_timeout(wpas_send_action_cb, wpa_s, NULL);
 308 }