1 /*
2 * The gPXE 802.11 MAC layer.
3 *
4 * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation; either version 2 of the
9 * License, or any later version.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 FILE_LICENCE ( GPL2_OR_LATER );
22
23 #include <string.h>
24 #include <byteswap.h>
25 #include <stdlib.h>
26 #include <gpxe/settings.h>
27 #include <gpxe/if_arp.h>
28 #include <gpxe/ethernet.h>
29 #include <gpxe/ieee80211.h>
30 #include <gpxe/netdevice.h>
31 #include <gpxe/net80211.h>
32 #include <gpxe/sec80211.h>
33 #include <gpxe/timer.h>
34 #include <gpxe/nap.h>
35 #include <unistd.h>
36 #include <errno.h>
37
38 /** @file
39 *
40 * 802.11 device management
41 */
42
43 /* Disambiguate the EINVAL's a bit */
44 #define EINVAL_PKT_TOO_SHORT ( EINVAL | EUNIQ_01 )
45 #define EINVAL_PKT_VERSION ( EINVAL | EUNIQ_02 )
46 #define EINVAL_PKT_NOT_DATA ( EINVAL | EUNIQ_03 )
47 #define EINVAL_PKT_NOT_FROMDS ( EINVAL | EUNIQ_04 )
48 #define EINVAL_PKT_LLC_HEADER ( EINVAL | EUNIQ_05 )
49 #define EINVAL_CRYPTO_REQUEST ( EINVAL | EUNIQ_06 )
50 #define EINVAL_ACTIVE_SCAN ( EINVAL | EUNIQ_07 )
51
52 /*
53 * 802.11 error codes: The AP can give us a status code explaining why
54 * authentication failed, or a reason code explaining why we were
55 * deauthenticated/disassociated. These codes range from 0-63 (the
56 * field is 16 bits wide, but only up to 45 or so are defined yet; we
57 * allow up to 63 for extensibility). This is encoded into an error
58 * code as such:
59 *
60 * status & 0x1f goes here --vv--
61 * Status code 0-31: ECONNREFUSED | EUNIQ_(status & 0x1f) (0e1a6038)
62 * Status code 32-63: EHOSTUNREACH | EUNIQ_(status & 0x1f) (171a6011)
63 * Reason code 0-31: ECONNRESET | EUNIQ_(reason & 0x1f) (0f1a6039)
64 * Reason code 32-63: ENETRESET | EUNIQ_(reason & 0x1f) (271a6001)
65 *
66 * The POSIX error codes more or less convey the appropriate message
67 * (status codes occur when we can't associate at all, reason codes
68 * when we lose association unexpectedly) and let us extract the
69 * complete 802.11 error code from the rc value.
70 */
71
72 /** Make return status code from 802.11 status code */
73 #define E80211_STATUS( stat ) ( ((stat & 0x20)? EHOSTUNREACH : ECONNREFUSED) \
74 | ((stat & 0x1f) << 8) )
75
76 /** Make return status code from 802.11 reason code */
77 #define E80211_REASON( reas ) ( ((reas & 0x20)? ENETRESET : ECONNRESET) \
78 | ((reas & 0x1f) << 8) )
79
80
81 /** List of 802.11 devices */
82 static struct list_head net80211_devices = LIST_HEAD_INIT ( net80211_devices );
83
84 /** Set of device operations that does nothing */
85 static struct net80211_device_operations net80211_null_ops;
86
87 /** Information associated with a received management packet
88 *
89 * This is used to keep beacon signal strengths in a parallel queue to
90 * the beacons themselves.
91 */
92 struct net80211_rx_info {
93 int signal;
94 struct list_head list;
95 };
96
97 /** Context for a probe operation */
98 struct net80211_probe_ctx {
99 /** 802.11 device to probe on */
100 struct net80211_device *dev;
101
102 /** Value of keep_mgmt before probe was started */
103 int old_keep_mgmt;
104
105 /** If scanning actively, pointer to probe packet to send */
106 struct io_buffer *probe;
107
108 /** If non-"", the ESSID to limit ourselves to */
109 const char *essid;
110
111 /** Time probe was started */
112 u32 ticks_start;
113
114 /** Time last useful beacon was received */
115 u32 ticks_beacon;
116
117 /** Time channel was last changed */
118 u32 ticks_channel;
119
120 /** Time to stay on each channel */
121 u32 hop_time;
122
123 /** Channels to hop by when changing channel */
124 int hop_step;
125
126 /** List of best beacons for each network found so far */
127 struct list_head *beacons;
128 };
129
130 /** Context for the association task */
131 struct net80211_assoc_ctx {
132 /** Next authentication method to try using */
133 int method;
134
135 /** Time (in ticks) of the last sent association-related packet */
136 int last_packet;
137
138 /** Number of times we have tried sending it */
139 int times_tried;
140 };
141
142 /**
143 * @defgroup net80211_netdev Network device interface functions
144 * @{
145 */
146 static int net80211_netdev_open ( struct net_device *netdev );
147 static void net80211_netdev_close ( struct net_device *netdev );
148 static int net80211_netdev_transmit ( struct net_device *netdev,
149 struct io_buffer *iobuf );
150 static void net80211_netdev_poll ( struct net_device *netdev );
151 static void net80211_netdev_irq ( struct net_device *netdev, int enable );
152 /** @} */
153
154 /**
155 * @defgroup net80211_linklayer 802.11 link-layer protocol functions
156 * @{
157 */
158 static int net80211_ll_push ( struct net_device *netdev,
159 struct io_buffer *iobuf, const void *ll_dest,
160 const void *ll_source, uint16_t net_proto );
161 static int net80211_ll_pull ( struct net_device *netdev,
162 struct io_buffer *iobuf, const void **ll_dest,
163 const void **ll_source, uint16_t * net_proto );
164 /** @} */
165
166 /**
167 * @defgroup net80211_help 802.11 helper functions
168 * @{
169 */
170 static void net80211_add_channels ( struct net80211_device *dev, int start,
171 int len, int txpower );
172 static void net80211_filter_hw_channels ( struct net80211_device *dev );
173 static void net80211_set_rtscts_rate ( struct net80211_device *dev );
174 static int net80211_process_capab ( struct net80211_device *dev,
175 u16 capab );
176 static int net80211_process_ie ( struct net80211_device *dev,
177 union ieee80211_ie *ie, void *ie_end );
178 static union ieee80211_ie *
179 net80211_marshal_request_info ( struct net80211_device *dev,
180 union ieee80211_ie *ie );
181 /** @} */
182
183 /**
184 * @defgroup net80211_assoc_ll 802.11 association handling functions
185 * @{
186 */
187 static void net80211_step_associate ( struct process *proc );
188 static void net80211_handle_auth ( struct net80211_device *dev,
189 struct io_buffer *iob );
190 static void net80211_handle_assoc_reply ( struct net80211_device *dev,
191 struct io_buffer *iob );
192 static int net80211_send_disassoc ( struct net80211_device *dev, int reason,
193 int deauth );
194 static void net80211_handle_mgmt ( struct net80211_device *dev,
195 struct io_buffer *iob, int signal );
196 /** @} */
197
198 /**
199 * @defgroup net80211_frag 802.11 fragment handling functions
200 * @{
201 */
202 static void net80211_free_frags ( struct net80211_device *dev, int fcid );
203 static struct io_buffer *net80211_accum_frags ( struct net80211_device *dev,
204 int fcid, int nfrags, int size );
205 static void net80211_rx_frag ( struct net80211_device *dev,
206 struct io_buffer *iob, int signal );
207 /** @} */
208
209 /**
210 * @defgroup net80211_settings 802.11 settings handlers
211 * @{
212 */
213 static int net80211_check_settings_update ( void );
214
215 /** 802.11 settings applicator
216 *
217 * When the SSID is changed, this will cause any open devices to
218 * re-associate; when the encryption key is changed, we similarly
219 * update their state.
220 */
221 struct settings_applicator net80211_applicator __settings_applicator = {
222 .apply = net80211_check_settings_update,
223 };
224
225 /** The network name to associate with
226 *
227 * If this is blank, we scan for all networks and use the one with the
228 * greatest signal strength.
229 */
230 struct setting net80211_ssid_setting __setting = {
231 .name = "ssid",
232 .description = "802.11 SSID (network name)",
233 .type = &setting_type_string,
234 };
235
236 /** Whether to use active scanning
237 *
238 * In order to associate with a hidden SSID, it's necessary to use an
239 * active scan (send probe packets). If this setting is nonzero, an
240 * active scan on the 2.4GHz band will be used to associate.
241 */
242 struct setting net80211_active_setting __setting = {
243 .name = "active-scan",
244 .description = "Use an active scan during 802.11 association",
245 .type = &setting_type_int8,
246 };
247
248 /** The cryptographic key to use
249 *
250 * For hex WEP keys, as is common, this must be entered using the
251 * normal gPXE method for entering hex settings; an ASCII string of
252 * hex characters will not behave as expected.
253 */
254 struct setting net80211_key_setting __setting = {
255 .name = "key",
256 .description = "Encryption key for protected 802.11 networks",
257 .type = &setting_type_string,
258 };
259
260 /** @} */
261
262
263 /* ---------- net_device wrapper ---------- */
264
265 /**
266 * Open 802.11 device and start association
267 *
268 * @v netdev Wrapping network device
269 * @ret rc Return status code
270 *
271 * This sets up a default conservative set of channels for probing,
272 * and starts the auto-association task unless the @c
273 * NET80211_NO_ASSOC flag is set in the wrapped 802.11 device's @c
274 * state field.
275 */
net80211_netdev_open(struct net_device * netdev)276 static int net80211_netdev_open ( struct net_device *netdev )
277 {
278 struct net80211_device *dev = netdev->priv;
279 int rc = 0;
280
281 if ( dev->op == &net80211_null_ops )
282 return -EFAULT;
283
284 if ( dev->op->open )
285 rc = dev->op->open ( dev );
286
287 if ( rc < 0 )
288 return rc;
289
290 if ( ! ( dev->state & NET80211_NO_ASSOC ) )
291 net80211_autoassociate ( dev );
292
293 return 0;
294 }
295
296 /**
297 * Close 802.11 device
298 *
299 * @v netdev Wrapping network device.
300 *
301 * If the association task is running, this will stop it.
302 */
net80211_netdev_close(struct net_device * netdev)303 static void net80211_netdev_close ( struct net_device *netdev )
304 {
305 struct net80211_device *dev = netdev->priv;
306
307 if ( dev->state & NET80211_WORKING )
308 process_del ( &dev->proc_assoc );
309
310 /* Send disassociation frame to AP, to be polite */
311 if ( dev->state & NET80211_ASSOCIATED )
312 net80211_send_disassoc ( dev, IEEE80211_REASON_LEAVING, 0 );
313
314 if ( dev->handshaker && dev->handshaker->stop &&
315 dev->handshaker->started )
316 dev->handshaker->stop ( dev );
317
318 free ( dev->crypto );
319 free ( dev->handshaker );
320 dev->crypto = NULL;
321 dev->handshaker = NULL;
322
323 netdev_link_down ( netdev );
324 dev->state = 0;
325
326 if ( dev->op->close )
327 dev->op->close ( dev );
328 }
329
330 /**
331 * Transmit packet on 802.11 device
332 *
333 * @v netdev Wrapping network device
334 * @v iobuf I/O buffer
335 * @ret rc Return status code
336 *
337 * If encryption is enabled for the currently associated network, the
338 * packet will be encrypted prior to transmission.
339 */
net80211_netdev_transmit(struct net_device * netdev,struct io_buffer * iobuf)340 static int net80211_netdev_transmit ( struct net_device *netdev,
341 struct io_buffer *iobuf )
342 {
343 struct net80211_device *dev = netdev->priv;
344 struct ieee80211_frame *hdr = iobuf->data;
345 int rc = -ENOSYS;
346
347 if ( dev->crypto && ! ( hdr->fc & IEEE80211_FC_PROTECTED ) &&
348 ( ( hdr->fc & IEEE80211_FC_TYPE ) == IEEE80211_TYPE_DATA ) ) {
349 struct io_buffer *niob = dev->crypto->encrypt ( dev->crypto,
350 iobuf );
351 if ( ! niob )
352 return -ENOMEM; /* only reason encryption could fail */
353
354 /* Free the non-encrypted iob */
355 netdev_tx_complete ( netdev, iobuf );
356
357 /* Transmit the encrypted iob; the Protected flag is
358 set, so we won't recurse into here again */
359 netdev_tx ( netdev, niob );
360
361 /* Don't transmit the freed packet */
362 return 0;
363 }
364
365 if ( dev->op->transmit )
366 rc = dev->op->transmit ( dev, iobuf );
367
368 return rc;
369 }
370
371 /**
372 * Poll 802.11 device for received packets and completed transmissions
373 *
374 * @v netdev Wrapping network device
375 */
net80211_netdev_poll(struct net_device * netdev)376 static void net80211_netdev_poll ( struct net_device *netdev )
377 {
378 struct net80211_device *dev = netdev->priv;
379
380 if ( dev->op->poll )
381 dev->op->poll ( dev );
382 }
383
384 /**
385 * Enable or disable interrupts for 802.11 device
386 *
387 * @v netdev Wrapping network device
388 * @v enable Whether to enable interrupts
389 */
net80211_netdev_irq(struct net_device * netdev,int enable)390 static void net80211_netdev_irq ( struct net_device *netdev, int enable )
391 {
392 struct net80211_device *dev = netdev->priv;
393
394 if ( dev->op->irq )
395 dev->op->irq ( dev, enable );
396 }
397
398 /** Network device operations for a wrapped 802.11 device */
399 static struct net_device_operations net80211_netdev_ops = {
400 .open = net80211_netdev_open,
401 .close = net80211_netdev_close,
402 .transmit = net80211_netdev_transmit,
403 .poll = net80211_netdev_poll,
404 .irq = net80211_netdev_irq,
405 };
406
407
408 /* ---------- 802.11 link-layer protocol ---------- */
409
410 /** 802.11 broadcast MAC address */
411 static u8 net80211_ll_broadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
412
413 /**
414 * Determine whether a transmission rate uses ERP/OFDM
415 *
416 * @v rate Rate in 100 kbps units
417 * @ret is_erp TRUE if the rate is an ERP/OFDM rate
418 *
419 * 802.11b supports rates of 1.0, 2.0, 5.5, and 11.0 Mbps; any other
420 * rate than these on the 2.4GHz spectrum is an ERP (802.11g) rate.
421 */
net80211_rate_is_erp(u16 rate)422 static inline int net80211_rate_is_erp ( u16 rate )
423 {
424 if ( rate == 10 || rate == 20 || rate == 55 || rate == 110 )
425 return 0;
426 return 1;
427 }
428
429
430 /**
431 * Calculate one frame's contribution to 802.11 duration field
432 *
433 * @v dev 802.11 device
434 * @v bytes Amount of data to calculate duration for
435 * @ret dur Duration field in microseconds
436 *
437 * To avoid multiple stations attempting to transmit at once, 802.11
438 * provides that every packet shall include a duration field
439 * specifying a length of time for which the wireless medium will be
440 * reserved after it is transmitted. The duration is measured in
441 * microseconds and is calculated with respect to the current
442 * physical-layer parameters of the 802.11 device.
443 *
444 * For an unfragmented data or management frame, or the last fragment
445 * of a fragmented frame, the duration captures only the 10 data bytes
446 * of one ACK; call once with bytes = 10.
447 *
448 * For a fragment of a data or management rame that will be followed
449 * by more fragments, the duration captures an ACK, the following
450 * fragment, and its ACK; add the results of three calls, two with
451 * bytes = 10 and one with bytes set to the next fragment's size.
452 *
453 * For an RTS control frame, the duration captures the responding CTS,
454 * the frame being sent, and its ACK; add the results of three calls,
455 * two with bytes = 10 and one with bytes set to the next frame's size
456 * (assuming unfragmented).
457 *
458 * For a CTS-to-self control frame, the duration captures the frame
459 * being protected and its ACK; add the results of two calls, one with
460 * bytes = 10 and one with bytes set to the next frame's size.
461 *
462 * No other frame types are currently supported by gPXE.
463 */
net80211_duration(struct net80211_device * dev,int bytes,u16 rate)464 u16 net80211_duration ( struct net80211_device *dev, int bytes, u16 rate )
465 {
466 struct net80211_channel *chan = &dev->channels[dev->channel];
467 u32 kbps = rate * 100;
468
469 if ( chan->band == NET80211_BAND_5GHZ || net80211_rate_is_erp ( rate ) ) {
470 /* OFDM encoding (802.11a/g) */
471 int bits_per_symbol = ( kbps * 4 ) / 1000; /* 4us/symbol */
472 int bits = 22 + ( bytes << 3 ); /* 22-bit PLCP */
473 int symbols = ( bits + bits_per_symbol - 1 ) / bits_per_symbol;
474
475 return 16 + 20 + ( symbols * 4 ); /* 16us SIFS, 20us preamble */
476 } else {
477 /* CCK encoding (802.11b) */
478 int phy_time = 144 + 48; /* preamble + PLCP */
479 int bits = bytes << 3;
480 int data_time = ( bits * 1000 + kbps - 1 ) / kbps;
481
482 if ( dev->phy_flags & NET80211_PHY_USE_SHORT_PREAMBLE )
483 phy_time >>= 1;
484
485 return 10 + phy_time + data_time; /* 10us SIFS */
486 }
487 }
488
489 /**
490 * Add 802.11 link-layer header
491 *
492 * @v netdev Wrapping network device
493 * @v iobuf I/O buffer
494 * @v ll_dest Link-layer destination address
495 * @v ll_source Link-layer source address
496 * @v net_proto Network-layer protocol, in network byte order
497 * @ret rc Return status code
498 *
499 * This adds both the 802.11 frame header and the 802.2 LLC/SNAP
500 * header used on data packets.
501 *
502 * We also check here for state of the link that would make it invalid
503 * to send a data packet; every data packet must pass through here,
504 * and no non-data packet (e.g. management frame) should.
505 */
net80211_ll_push(struct net_device * netdev,struct io_buffer * iobuf,const void * ll_dest,const void * ll_source,uint16_t net_proto)506 static int net80211_ll_push ( struct net_device *netdev,
507 struct io_buffer *iobuf, const void *ll_dest,
508 const void *ll_source, uint16_t net_proto )
509 {
510 struct net80211_device *dev = netdev->priv;
511 struct ieee80211_frame *hdr = iob_push ( iobuf,
512 IEEE80211_LLC_HEADER_LEN +
513 IEEE80211_TYP_FRAME_HEADER_LEN );
514 struct ieee80211_llc_snap_header *lhdr =
515 ( void * ) hdr + IEEE80211_TYP_FRAME_HEADER_LEN;
516
517 /* We can't send data packets if we're not associated. */
518 if ( ! ( dev->state & NET80211_ASSOCIATED ) ) {
519 if ( dev->assoc_rc )
520 return dev->assoc_rc;
521 return -ENETUNREACH;
522 }
523
524 hdr->fc = IEEE80211_THIS_VERSION | IEEE80211_TYPE_DATA |
525 IEEE80211_STYPE_DATA | IEEE80211_FC_TODS;
526
527 /* We don't send fragmented frames, so duration is the time
528 for an SIFS + 10-byte ACK. */
529 hdr->duration = net80211_duration ( dev, 10, dev->rates[dev->rate] );
530
531 memcpy ( hdr->addr1, dev->bssid, ETH_ALEN );
532 memcpy ( hdr->addr2, ll_source, ETH_ALEN );
533 memcpy ( hdr->addr3, ll_dest, ETH_ALEN );
534
535 hdr->seq = IEEE80211_MAKESEQ ( ++dev->last_tx_seqnr, 0 );
536
537 lhdr->dsap = IEEE80211_LLC_DSAP;
538 lhdr->ssap = IEEE80211_LLC_SSAP;
539 lhdr->ctrl = IEEE80211_LLC_CTRL;
540 memset ( lhdr->oui, 0x00, 3 );
541 lhdr->ethertype = net_proto;
542
543 return 0;
544 }
545
546 /**
547 * Remove 802.11 link-layer header
548 *
549 * @v netdev Wrapping network device
550 * @v iobuf I/O buffer
551 * @ret ll_dest Link-layer destination address
552 * @ret ll_source Link-layer source
553 * @ret net_proto Network-layer protocol, in network byte order
554 * @ret rc Return status code
555 *
556 * This expects and removes both the 802.11 frame header and the 802.2
557 * LLC/SNAP header that are used on data packets.
558 */
net80211_ll_pull(struct net_device * netdev __unused,struct io_buffer * iobuf,const void ** ll_dest,const void ** ll_source,uint16_t * net_proto)559 static int net80211_ll_pull ( struct net_device *netdev __unused,
560 struct io_buffer *iobuf,
561 const void **ll_dest, const void **ll_source,
562 uint16_t * net_proto )
563 {
564 struct ieee80211_frame *hdr = iobuf->data;
565 struct ieee80211_llc_snap_header *lhdr =
566 ( void * ) hdr + IEEE80211_TYP_FRAME_HEADER_LEN;
567
568 /* Bunch of sanity checks */
569 if ( iob_len ( iobuf ) < IEEE80211_TYP_FRAME_HEADER_LEN +
570 IEEE80211_LLC_HEADER_LEN ) {
571 DBGC ( netdev->priv, "802.11 %p packet too short (%zd bytes)\n",
572 netdev->priv, iob_len ( iobuf ) );
573 return -EINVAL_PKT_TOO_SHORT;
574 }
575
576 if ( ( hdr->fc & IEEE80211_FC_VERSION ) != IEEE80211_THIS_VERSION ) {
577 DBGC ( netdev->priv, "802.11 %p packet invalid version %04x\n",
578 netdev->priv, hdr->fc & IEEE80211_FC_VERSION );
579 return -EINVAL_PKT_VERSION;
580 }
581
582 if ( ( hdr->fc & IEEE80211_FC_TYPE ) != IEEE80211_TYPE_DATA ||
583 ( hdr->fc & IEEE80211_FC_SUBTYPE ) != IEEE80211_STYPE_DATA ) {
584 DBGC ( netdev->priv, "802.11 %p packet not data/data (fc=%04x)\n",
585 netdev->priv, hdr->fc );
586 return -EINVAL_PKT_NOT_DATA;
587 }
588
589 if ( ( hdr->fc & ( IEEE80211_FC_TODS | IEEE80211_FC_FROMDS ) ) !=
590 IEEE80211_FC_FROMDS ) {
591 DBGC ( netdev->priv, "802.11 %p packet not from DS (fc=%04x)\n",
592 netdev->priv, hdr->fc );
593 return -EINVAL_PKT_NOT_FROMDS;
594 }
595
596 if ( lhdr->dsap != IEEE80211_LLC_DSAP || lhdr->ssap != IEEE80211_LLC_SSAP ||
597 lhdr->ctrl != IEEE80211_LLC_CTRL || lhdr->oui[0] || lhdr->oui[1] ||
598 lhdr->oui[2] ) {
599 DBGC ( netdev->priv, "802.11 %p LLC header is not plain EtherType "
600 "encapsulator: %02x->%02x [%02x] %02x:%02x:%02x %04x\n",
601 netdev->priv, lhdr->dsap, lhdr->ssap, lhdr->ctrl,
602 lhdr->oui[0], lhdr->oui[1], lhdr->oui[2], lhdr->ethertype );
603 return -EINVAL_PKT_LLC_HEADER;
604 }
605
606 iob_pull ( iobuf, sizeof ( *hdr ) + sizeof ( *lhdr ) );
607
608 *ll_dest = hdr->addr1;
609 *ll_source = hdr->addr3;
610 *net_proto = lhdr->ethertype;
611 return 0;
612 }
613
614 /** 802.11 link-layer protocol */
615 static struct ll_protocol net80211_ll_protocol __ll_protocol = {
616 .name = "802.11",
617 .push = net80211_ll_push,
618 .pull = net80211_ll_pull,
619 .init_addr = eth_init_addr,
620 .ntoa = eth_ntoa,
621 .mc_hash = eth_mc_hash,
622 .eth_addr = eth_eth_addr,
623 .ll_proto = htons ( ARPHRD_ETHER ), /* "encapsulated Ethernet" */
624 .hw_addr_len = ETH_ALEN,
625 .ll_addr_len = ETH_ALEN,
626 .ll_header_len = IEEE80211_TYP_FRAME_HEADER_LEN +
627 IEEE80211_LLC_HEADER_LEN,
628 };
629
630
631 /* ---------- 802.11 network management API ---------- */
632
633 /**
634 * Get 802.11 device from wrapping network device
635 *
636 * @v netdev Wrapping network device
637 * @ret dev 802.11 device wrapped by network device, or NULL
638 *
639 * Returns NULL if the network device does not wrap an 802.11 device.
640 */
net80211_get(struct net_device * netdev)641 struct net80211_device * net80211_get ( struct net_device *netdev )
642 {
643 struct net80211_device *dev;
644
645 list_for_each_entry ( dev, &net80211_devices, list ) {
646 if ( netdev->priv == dev )
647 return netdev->priv;
648 }
649
650 return NULL;
651 }
652
653 /**
654 * Set state of 802.11 device keeping management frames
655 *
656 * @v dev 802.11 device
657 * @v enable Whether to keep management frames
658 * @ret oldenab Whether management frames were enabled before this call
659 *
660 * If enable is TRUE, beacon, probe, and action frames will be kept
661 * and may be retrieved by calling net80211_mgmt_dequeue().
662 */
net80211_keep_mgmt(struct net80211_device * dev,int enable)663 int net80211_keep_mgmt ( struct net80211_device *dev, int enable )
664 {
665 int oldenab = dev->keep_mgmt;
666
667 dev->keep_mgmt = enable;
668 return oldenab;
669 }
670
671 /**
672 * Get 802.11 management frame
673 *
674 * @v dev 802.11 device
675 * @ret signal Signal strength of returned management frame
676 * @ret iob I/O buffer, or NULL if no management frame is queued
677 *
678 * Frames will only be returned by this function if
679 * net80211_keep_mgmt() has been previously called with enable set to
680 * TRUE.
681 *
682 * The calling function takes ownership of the returned I/O buffer.
683 */
net80211_mgmt_dequeue(struct net80211_device * dev,int * signal)684 struct io_buffer * net80211_mgmt_dequeue ( struct net80211_device *dev,
685 int *signal )
686 {
687 struct io_buffer *iobuf;
688 struct net80211_rx_info *rxi;
689
690 list_for_each_entry ( rxi, &dev->mgmt_info_queue, list ) {
691 list_del ( &rxi->list );
692 if ( signal )
693 *signal = rxi->signal;
694 free ( rxi );
695
696 list_for_each_entry ( iobuf, &dev->mgmt_queue, list ) {
697 list_del ( &iobuf->list );
698 return iobuf;
699 }
700 assert ( 0 );
701 }
702
703 return NULL;
704 }
705
706 /**
707 * Transmit 802.11 management frame
708 *
709 * @v dev 802.11 device
710 * @v fc Frame Control flags for management frame
711 * @v dest Destination access point
712 * @v iob I/O buffer
713 * @ret rc Return status code
714 *
715 * The @a fc argument must contain at least an IEEE 802.11 management
716 * subtype number (e.g. IEEE80211_STYPE_PROBE_REQ). If it contains
717 * IEEE80211_FC_PROTECTED, the frame will be encrypted prior to
718 * transmission.
719 *
720 * It is required that @a iob have at least 24 bytes of headroom
721 * reserved before its data start.
722 */
net80211_tx_mgmt(struct net80211_device * dev,u16 fc,u8 dest[6],struct io_buffer * iob)723 int net80211_tx_mgmt ( struct net80211_device *dev, u16 fc, u8 dest[6],
724 struct io_buffer *iob )
725 {
726 struct ieee80211_frame *hdr = iob_push ( iob,
727 IEEE80211_TYP_FRAME_HEADER_LEN );
728
729 hdr->fc = IEEE80211_THIS_VERSION | IEEE80211_TYPE_MGMT |
730 ( fc & ~IEEE80211_FC_PROTECTED );
731 hdr->duration = net80211_duration ( dev, 10, dev->rates[dev->rate] );
732 hdr->seq = IEEE80211_MAKESEQ ( ++dev->last_tx_seqnr, 0 );
733
734 memcpy ( hdr->addr1, dest, ETH_ALEN ); /* DA = RA */
735 memcpy ( hdr->addr2, dev->netdev->ll_addr, ETH_ALEN ); /* SA = TA */
736 memcpy ( hdr->addr3, dest, ETH_ALEN ); /* BSSID */
737
738 if ( fc & IEEE80211_FC_PROTECTED ) {
739 if ( ! dev->crypto )
740 return -EINVAL_CRYPTO_REQUEST;
741
742 struct io_buffer *eiob = dev->crypto->encrypt ( dev->crypto,
743 iob );
744 free_iob ( iob );
745 iob = eiob;
746 }
747
748 return netdev_tx ( dev->netdev, iob );
749 }
750
751
752 /* ---------- Driver API ---------- */
753
754 /**
755 * Allocate 802.11 device
756 *
757 * @v priv_size Size of driver-private allocation area
758 * @ret dev Newly allocated 802.11 device
759 *
760 * This function allocates a net_device with space in its private area
761 * for both the net80211_device it will wrap and the driver-private
762 * data space requested. It initializes the link-layer-specific parts
763 * of the net_device, and links the net80211_device to the net_device
764 * appropriately.
765 */
net80211_alloc(size_t priv_size)766 struct net80211_device * net80211_alloc ( size_t priv_size )
767 {
768 struct net80211_device *dev;
769 struct net_device *netdev =
770 alloc_netdev ( sizeof ( *dev ) + priv_size );
771
772 if ( ! netdev )
773 return NULL;
774
775 netdev->ll_protocol = &net80211_ll_protocol;
776 netdev->ll_broadcast = net80211_ll_broadcast;
777 netdev->max_pkt_len = IEEE80211_MAX_DATA_LEN;
778 netdev_init ( netdev, &net80211_netdev_ops );
779
780 dev = netdev->priv;
781 dev->netdev = netdev;
782 dev->priv = ( u8 * ) dev + sizeof ( *dev );
783 dev->op = &net80211_null_ops;
784
785 process_init_stopped ( &dev->proc_assoc, net80211_step_associate,
786 &netdev->refcnt );
787 INIT_LIST_HEAD ( &dev->mgmt_queue );
788 INIT_LIST_HEAD ( &dev->mgmt_info_queue );
789
790 return dev;
791 }
792
793 /**
794 * Register 802.11 device with network stack
795 *
796 * @v dev 802.11 device
797 * @v ops 802.11 device operations
798 * @v hw 802.11 hardware information
799 *
800 * This also registers the wrapping net_device with the higher network
801 * layers.
802 */
net80211_register(struct net80211_device * dev,struct net80211_device_operations * ops,struct net80211_hw_info * hw)803 int net80211_register ( struct net80211_device *dev,
804 struct net80211_device_operations *ops,
805 struct net80211_hw_info *hw )
806 {
807 dev->op = ops;
808 dev->hw = malloc ( sizeof ( *hw ) );
809 if ( ! dev->hw )
810 return -ENOMEM;
811
812 memcpy ( dev->hw, hw, sizeof ( *hw ) );
813 memcpy ( dev->netdev->hw_addr, hw->hwaddr, ETH_ALEN );
814
815 /* Set some sensible channel defaults for driver's open() function */
816 memcpy ( dev->channels, dev->hw->channels,
817 NET80211_MAX_CHANNELS * sizeof ( dev->channels[0] ) );
818 dev->channel = 0;
819
820 list_add_tail ( &dev->list, &net80211_devices );
821 return register_netdev ( dev->netdev );
822 }
823
824 /**
825 * Unregister 802.11 device from network stack
826 *
827 * @v dev 802.11 device
828 *
829 * After this call, the device operations are cleared so that they
830 * will not be called.
831 */
net80211_unregister(struct net80211_device * dev)832 void net80211_unregister ( struct net80211_device *dev )
833 {
834 unregister_netdev ( dev->netdev );
835 list_del ( &dev->list );
836 dev->op = &net80211_null_ops;
837 }
838
839 /**
840 * Free 802.11 device
841 *
842 * @v dev 802.11 device
843 *
844 * The device should be unregistered before this function is called.
845 */
net80211_free(struct net80211_device * dev)846 void net80211_free ( struct net80211_device *dev )
847 {
848 free ( dev->hw );
849 rc80211_free ( dev->rctl );
850 netdev_nullify ( dev->netdev );
851 netdev_put ( dev->netdev );
852 }
853
854
855 /* ---------- 802.11 network management workhorse code ---------- */
856
857 /**
858 * Set state of 802.11 device
859 *
860 * @v dev 802.11 device
861 * @v clear Bitmask of flags to clear
862 * @v set Bitmask of flags to set
863 * @v status Status or reason code for most recent operation
864 *
865 * If @a status represents a reason code, it should be OR'ed with
866 * NET80211_IS_REASON.
867 *
868 * Clearing authentication also clears association; clearing
869 * association also clears security handshaking state. Clearing
870 * association removes the link-up flag from the wrapping net_device,
871 * but setting it does not automatically set the flag; that is left to
872 * the judgment of higher-level code.
873 */
net80211_set_state(struct net80211_device * dev,short clear,short set,u16 status)874 static inline void net80211_set_state ( struct net80211_device *dev,
875 short clear, short set,
876 u16 status )
877 {
878 /* The conditions in this function are deliberately formulated
879 to be decidable at compile-time in most cases. Since clear
880 and set are generally passed as constants, the body of this
881 function can be reduced down to a few statements by the
882 compiler. */
883
884 const int statmsk = NET80211_STATUS_MASK | NET80211_IS_REASON;
885
886 if ( clear & NET80211_PROBED )
887 clear |= NET80211_AUTHENTICATED;
888
889 if ( clear & NET80211_AUTHENTICATED )
890 clear |= NET80211_ASSOCIATED;
891
892 if ( clear & NET80211_ASSOCIATED )
893 clear |= NET80211_CRYPTO_SYNCED;
894
895 dev->state = ( dev->state & ~clear ) | set;
896 dev->state = ( dev->state & ~statmsk ) | ( status & statmsk );
897
898 if ( clear & NET80211_ASSOCIATED )
899 netdev_link_down ( dev->netdev );
900
901 if ( ( clear | set ) & NET80211_ASSOCIATED )
902 dev->op->config ( dev, NET80211_CFG_ASSOC );
903
904 if ( status != 0 ) {
905 if ( status & NET80211_IS_REASON )
906 dev->assoc_rc = -E80211_REASON ( status );
907 else
908 dev->assoc_rc = -E80211_STATUS ( status );
909 netdev_link_err ( dev->netdev, dev->assoc_rc );
910 }
911 }
912
913 /**
914 * Add channels to 802.11 device
915 *
916 * @v dev 802.11 device
917 * @v start First channel number to add
918 * @v len Number of channels to add
919 * @v txpower TX power (dBm) to allow on added channels
920 *
921 * To replace the current list of channels instead of adding to it,
922 * set the nr_channels field of the 802.11 device to 0 before calling
923 * this function.
924 */
net80211_add_channels(struct net80211_device * dev,int start,int len,int txpower)925 static void net80211_add_channels ( struct net80211_device *dev, int start,
926 int len, int txpower )
927 {
928 int i, chan = start;
929
930 for ( i = dev->nr_channels; len-- && i < NET80211_MAX_CHANNELS; i++ ) {
931 dev->channels[i].channel_nr = chan;
932 dev->channels[i].maxpower = txpower;
933 dev->channels[i].hw_value = 0;
934
935 if ( chan >= 1 && chan <= 14 ) {
936 dev->channels[i].band = NET80211_BAND_2GHZ;
937 if ( chan == 14 )
938 dev->channels[i].center_freq = 2484;
939 else
940 dev->channels[i].center_freq = 2407 + 5 * chan;
941 chan++;
942 } else {
943 dev->channels[i].band = NET80211_BAND_5GHZ;
944 dev->channels[i].center_freq = 5000 + 5 * chan;
945 chan += 4;
946 }
947 }
948
949 dev->nr_channels = i;
950 }
951
952 /**
953 * Filter 802.11 device channels for hardware capabilities
954 *
955 * @v dev 802.11 device
956 *
957 * Hardware may support fewer channels than regulatory restrictions
958 * allow; this function filters out channels in dev->channels that are
959 * not supported by the hardware list in dev->hwinfo. It also copies
960 * over the net80211_channel::hw_value and limits maximum TX power
961 * appropriately.
962 *
963 * Channels are matched based on center frequency, ignoring band and
964 * channel number.
965 *
966 * If the driver specifies no supported channels, the effect will be
967 * as though all were supported.
968 */
net80211_filter_hw_channels(struct net80211_device * dev)969 static void net80211_filter_hw_channels ( struct net80211_device *dev )
970 {
971 int delta = 0, i = 0;
972 int old_freq = dev->channels[dev->channel].center_freq;
973 struct net80211_channel *chan, *hwchan;
974
975 if ( ! dev->hw->nr_channels )
976 return;
977
978 dev->channel = 0;
979 for ( chan = dev->channels; chan < dev->channels + dev->nr_channels;
980 chan++, i++ ) {
981 int ok = 0;
982 for ( hwchan = dev->hw->channels;
983 hwchan < dev->hw->channels + dev->hw->nr_channels;
984 hwchan++ ) {
985 if ( hwchan->center_freq == chan->center_freq ) {
986 ok = 1;
987 break;
988 }
989 }
990
991 if ( ! ok )
992 delta++;
993 else {
994 chan->hw_value = hwchan->hw_value;
995 if ( hwchan->maxpower != 0 &&
996 chan->maxpower > hwchan->maxpower )
997 chan->maxpower = hwchan->maxpower;
998 if ( old_freq == chan->center_freq )
999 dev->channel = i - delta;
1000 if ( delta )
1001 chan[-delta] = *chan;
1002 }
1003 }
1004
1005 dev->nr_channels -= delta;
1006
1007 if ( dev->channels[dev->channel].center_freq != old_freq )
1008 dev->op->config ( dev, NET80211_CFG_CHANNEL );
1009 }
1010
1011 /**
1012 * Update 802.11 device state to reflect received capabilities field
1013 *
1014 * @v dev 802.11 device
1015 * @v capab Capabilities field in beacon, probe, or association frame
1016 * @ret rc Return status code
1017 */
net80211_process_capab(struct net80211_device * dev,u16 capab)1018 static int net80211_process_capab ( struct net80211_device *dev,
1019 u16 capab )
1020 {
1021 u16 old_phy = dev->phy_flags;
1022
1023 if ( ( capab & ( IEEE80211_CAPAB_MANAGED | IEEE80211_CAPAB_ADHOC ) ) !=
1024 IEEE80211_CAPAB_MANAGED ) {
1025 DBGC ( dev, "802.11 %p cannot handle IBSS network\n", dev );
1026 return -ENOSYS;
1027 }
1028
1029 dev->phy_flags &= ~( NET80211_PHY_USE_SHORT_PREAMBLE |
1030 NET80211_PHY_USE_SHORT_SLOT );
1031
1032 if ( capab & IEEE80211_CAPAB_SHORT_PMBL )
1033 dev->phy_flags |= NET80211_PHY_USE_SHORT_PREAMBLE;
1034
1035 if ( capab & IEEE80211_CAPAB_SHORT_SLOT )
1036 dev->phy_flags |= NET80211_PHY_USE_SHORT_SLOT;
1037
1038 if ( old_phy != dev->phy_flags )
1039 dev->op->config ( dev, NET80211_CFG_PHY_PARAMS );
1040
1041 return 0;
1042 }
1043
1044 /**
1045 * Update 802.11 device state to reflect received information elements
1046 *
1047 * @v dev 802.11 device
1048 * @v ie Pointer to first information element
1049 * @v ie_end Pointer to tail of packet I/O buffer
1050 * @ret rc Return status code
1051 */
net80211_process_ie(struct net80211_device * dev,union ieee80211_ie * ie,void * ie_end)1052 static int net80211_process_ie ( struct net80211_device *dev,
1053 union ieee80211_ie *ie, void *ie_end )
1054 {
1055 u16 old_rate = dev->rates[dev->rate];
1056 u16 old_phy = dev->phy_flags;
1057 int have_rates = 0, i;
1058 int ds_channel = 0;
1059 int changed = 0;
1060 int band = dev->channels[dev->channel].band;
1061
1062 if ( ! ieee80211_ie_bound ( ie, ie_end ) )
1063 return 0;
1064
1065 for ( ; ie; ie = ieee80211_next_ie ( ie, ie_end ) ) {
1066 switch ( ie->id ) {
1067 case IEEE80211_IE_SSID:
1068 if ( ie->len <= 32 ) {
1069 memcpy ( dev->essid, ie->ssid, ie->len );
1070 dev->essid[ie->len] = 0;
1071 }
1072 break;
1073
1074 case IEEE80211_IE_RATES:
1075 case IEEE80211_IE_EXT_RATES:
1076 if ( ! have_rates ) {
1077 dev->nr_rates = 0;
1078 dev->basic_rates = 0;
1079 have_rates = 1;
1080 }
1081 for ( i = 0; i < ie->len &&
1082 dev->nr_rates < NET80211_MAX_RATES; i++ ) {
1083 u8 rid = ie->rates[i];
1084 u16 rate = ( rid & 0x7f ) * 5;
1085
1086 if ( rid & 0x80 )
1087 dev->basic_rates |=
1088 ( 1 << dev->nr_rates );
1089
1090 dev->rates[dev->nr_rates++] = rate;
1091 }
1092
1093 break;
1094
1095 case IEEE80211_IE_DS_PARAM:
1096 if ( dev->channel < dev->nr_channels && ds_channel ==
1097 dev->channels[dev->channel].channel_nr )
1098 break;
1099 ds_channel = ie->ds_param.current_channel;
1100 net80211_change_channel ( dev, ds_channel );
1101 break;
1102
1103 case IEEE80211_IE_COUNTRY:
1104 dev->nr_channels = 0;
1105
1106 DBGC ( dev, "802.11 %p setting country regulations "
1107 "for %c%c\n", dev, ie->country.name[0],
1108 ie->country.name[1] );
1109 for ( i = 0; i < ( ie->len - 3 ) / 3; i++ ) {
1110 union ieee80211_ie_country_triplet *t =
1111 &ie->country.triplet[i];
1112 if ( t->first > 200 ) {
1113 DBGC ( dev, "802.11 %p ignoring regulatory "
1114 "extension information\n", dev );
1115 } else {
1116 net80211_add_channels ( dev,
1117 t->band.first_channel,
1118 t->band.nr_channels,
1119 t->band.max_txpower );
1120 }
1121 }
1122 net80211_filter_hw_channels ( dev );
1123 break;
1124
1125 case IEEE80211_IE_ERP_INFO:
1126 dev->phy_flags &= ~( NET80211_PHY_USE_PROTECTION |
1127 NET80211_PHY_USE_SHORT_PREAMBLE );
1128 if ( ie->erp_info & IEEE80211_ERP_USE_PROTECTION )
1129 dev->phy_flags |= NET80211_PHY_USE_PROTECTION;
1130 if ( ! ( ie->erp_info & IEEE80211_ERP_BARKER_LONG ) )
1131 dev->phy_flags |= NET80211_PHY_USE_SHORT_PREAMBLE;
1132 break;
1133 }
1134 }
1135
1136 if ( have_rates ) {
1137 /* Allow only those rates that are also supported by
1138 the hardware. */
1139 int delta = 0, j;
1140
1141 dev->rate = 0;
1142 for ( i = 0; i < dev->nr_rates; i++ ) {
1143 int ok = 0;
1144 for ( j = 0; j < dev->hw->nr_rates[band]; j++ ) {
1145 if ( dev->hw->rates[band][j] == dev->rates[i] ){
1146 ok = 1;
1147 break;
1148 }
1149 }
1150
1151 if ( ! ok )
1152 delta++;
1153 else {
1154 dev->rates[i - delta] = dev->rates[i];
1155 if ( old_rate == dev->rates[i] )
1156 dev->rate = i - delta;
1157 }
1158 }
1159
1160 dev->nr_rates -= delta;
1161
1162 /* Sort available rates - sorted subclumps tend to already
1163 exist, so insertion sort works well. */
1164 for ( i = 1; i < dev->nr_rates; i++ ) {
1165 u16 rate = dev->rates[i];
1166 u32 tmp, br, mask;
1167
1168 for ( j = i - 1; j >= 0 && dev->rates[j] >= rate; j-- )
1169 dev->rates[j + 1] = dev->rates[j];
1170 dev->rates[j + 1] = rate;
1171
1172 /* Adjust basic_rates to match by rotating the
1173 bits from bit j+1 to bit i left one position. */
1174 mask = ( ( 1 << i ) - 1 ) & ~( ( 1 << ( j + 1 ) ) - 1 );
1175 br = dev->basic_rates;
1176 tmp = br & ( 1 << i );
1177 br = ( br & ~( mask | tmp ) ) | ( ( br & mask ) << 1 );
1178 br |= ( tmp >> ( i - j - 1 ) );
1179 dev->basic_rates = br;
1180 }
1181
1182 net80211_set_rtscts_rate ( dev );
1183
1184 if ( dev->rates[dev->rate] != old_rate )
1185 changed |= NET80211_CFG_RATE;
1186 }
1187
1188 if ( dev->hw->flags & NET80211_HW_NO_SHORT_PREAMBLE )
1189 dev->phy_flags &= ~NET80211_PHY_USE_SHORT_PREAMBLE;
1190 if ( dev->hw->flags & NET80211_HW_NO_SHORT_SLOT )
1191 dev->phy_flags &= ~NET80211_PHY_USE_SHORT_SLOT;
1192
1193 if ( old_phy != dev->phy_flags )
1194 changed |= NET80211_CFG_PHY_PARAMS;
1195
1196 if ( changed )
1197 dev->op->config ( dev, changed );
1198
1199 return 0;
1200 }
1201
1202 /**
1203 * Create information elements for outgoing probe or association packet
1204 *
1205 * @v dev 802.11 device
1206 * @v ie Pointer to start of information element area
1207 * @ret next_ie Pointer to first byte after added information elements
1208 */
1209 static union ieee80211_ie *
net80211_marshal_request_info(struct net80211_device * dev,union ieee80211_ie * ie)1210 net80211_marshal_request_info ( struct net80211_device *dev,
1211 union ieee80211_ie *ie )
1212 {
1213 int i;
1214
1215 ie->id = IEEE80211_IE_SSID;
1216 ie->len = strlen ( dev->essid );
1217 memcpy ( ie->ssid, dev->essid, ie->len );
1218
1219 ie = ieee80211_next_ie ( ie, NULL );
1220
1221 ie->id = IEEE80211_IE_RATES;
1222 ie->len = dev->nr_rates;
1223 if ( ie->len > 8 )
1224 ie->len = 8;
1225
1226 for ( i = 0; i < ie->len; i++ ) {
1227 ie->rates[i] = dev->rates[i] / 5;
1228 if ( dev->basic_rates & ( 1 << i ) )
1229 ie->rates[i] |= 0x80;
1230 }
1231
1232 ie = ieee80211_next_ie ( ie, NULL );
1233
1234 if ( dev->rsn_ie && dev->rsn_ie->id == IEEE80211_IE_RSN ) {
1235 memcpy ( ie, dev->rsn_ie, dev->rsn_ie->len + 2 );
1236 ie = ieee80211_next_ie ( ie, NULL );
1237 }
1238
1239 if ( dev->nr_rates > 8 ) {
1240 /* 802.11 requires we use an Extended Basic Rates IE
1241 for the rates beyond the eighth. */
1242
1243 ie->id = IEEE80211_IE_EXT_RATES;
1244 ie->len = dev->nr_rates - 8;
1245
1246 for ( ; i < dev->nr_rates; i++ ) {
1247 ie->rates[i - 8] = dev->rates[i] / 5;
1248 if ( dev->basic_rates & ( 1 << i ) )
1249 ie->rates[i - 8] |= 0x80;
1250 }
1251
1252 ie = ieee80211_next_ie ( ie, NULL );
1253 }
1254
1255 if ( dev->rsn_ie && dev->rsn_ie->id == IEEE80211_IE_VENDOR ) {
1256 memcpy ( ie, dev->rsn_ie, dev->rsn_ie->len + 2 );
1257 ie = ieee80211_next_ie ( ie, NULL );
1258 }
1259
1260 return ie;
1261 }
1262
1263 /** Seconds to wait after finding a network, to possibly find better APs for it
1264 *
1265 * This is used when a specific SSID to scan for is specified.
1266 */
1267 #define NET80211_PROBE_GATHER 1
1268
1269 /** Seconds to wait after finding a network, to possibly find other networks
1270 *
1271 * This is used when an empty SSID is specified, to scan for all
1272 * networks.
1273 */
1274 #define NET80211_PROBE_GATHER_ALL 2
1275
1276 /** Seconds to allow a probe to take if no network has been found */
1277 #define NET80211_PROBE_TIMEOUT 6
1278
1279 /**
1280 * Begin probe of 802.11 networks
1281 *
1282 * @v dev 802.11 device
1283 * @v essid SSID to probe for, or "" to accept any (may not be NULL)
1284 * @v active Whether to use active scanning
1285 * @ret ctx Probe context
1286 *
1287 * Active scanning may only be used on channels 1-11 in the 2.4GHz
1288 * band, due to gPXE's lack of a complete regulatory database. If
1289 * active scanning is used, probe packets will be sent on each
1290 * channel; this can allow association with hidden-SSID networks if
1291 * the SSID is properly specified.
1292 *
1293 * A @c NULL return indicates an out-of-memory condition.
1294 *
1295 * The returned context must be periodically passed to
1296 * net80211_probe_step() until that function returns zero.
1297 */
net80211_probe_start(struct net80211_device * dev,const char * essid,int active)1298 struct net80211_probe_ctx * net80211_probe_start ( struct net80211_device *dev,
1299 const char *essid,
1300 int active )
1301 {
1302 struct net80211_probe_ctx *ctx = zalloc ( sizeof ( *ctx ) );
1303
1304 if ( ! ctx )
1305 return NULL;
1306
1307 assert ( dev->netdev->state & NETDEV_OPEN );
1308
1309 ctx->dev = dev;
1310 ctx->old_keep_mgmt = net80211_keep_mgmt ( dev, 1 );
1311 ctx->essid = essid;
1312 if ( dev->essid != ctx->essid )
1313 strcpy ( dev->essid, ctx->essid );
1314
1315 if ( active ) {
1316 struct ieee80211_probe_req *probe_req;
1317 union ieee80211_ie *ie;
1318
1319 ctx->probe = alloc_iob ( 128 );
1320 iob_reserve ( ctx->probe, IEEE80211_TYP_FRAME_HEADER_LEN );
1321 probe_req = ctx->probe->data;
1322
1323 ie = net80211_marshal_request_info ( dev,
1324 probe_req->info_element );
1325
1326 iob_put ( ctx->probe, ( void * ) ie - ctx->probe->data );
1327 }
1328
1329 ctx->ticks_start = currticks();
1330 ctx->ticks_beacon = 0;
1331 ctx->ticks_channel = currticks();
1332 ctx->hop_time = ticks_per_sec() / ( active ? 2 : 6 );
1333
1334 /*
1335 * Channels on 2.4GHz overlap, and the most commonly used
1336 * are 1, 6, and 11. We'll get a result faster if we check
1337 * every 5 channels, but in order to hit all of them the
1338 * number of channels must be relatively prime to 5. If it's
1339 * not, tweak the hop.
1340 */
1341 ctx->hop_step = 5;
1342 while ( dev->nr_channels % ctx->hop_step == 0 && ctx->hop_step > 1 )
1343 ctx->hop_step--;
1344
1345 ctx->beacons = malloc ( sizeof ( *ctx->beacons ) );
1346 INIT_LIST_HEAD ( ctx->beacons );
1347
1348 dev->channel = 0;
1349 dev->op->config ( dev, NET80211_CFG_CHANNEL );
1350
1351 return ctx;
1352 }
1353
1354 /**
1355 * Continue probe of 802.11 networks
1356 *
1357 * @v ctx Probe context returned by net80211_probe_start()
1358 * @ret rc Probe status
1359 *
1360 * The return code will be 0 if the probe is still going on (and this
1361 * function should be called again), a positive number if the probe
1362 * completed successfully, or a negative error code if the probe
1363 * failed for that reason.
1364 *
1365 * Whether the probe succeeded or failed, you must call
1366 * net80211_probe_finish_all() or net80211_probe_finish_best()
1367 * (depending on whether you want information on all networks or just
1368 * the best-signal one) in order to release the probe context. A
1369 * failed probe may still have acquired some valid data.
1370 */
net80211_probe_step(struct net80211_probe_ctx * ctx)1371 int net80211_probe_step ( struct net80211_probe_ctx *ctx )
1372 {
1373 struct net80211_device *dev = ctx->dev;
1374 u32 start_timeout = NET80211_PROBE_TIMEOUT * ticks_per_sec();
1375 u32 gather_timeout = ticks_per_sec();
1376 u32 now = currticks();
1377 struct io_buffer *iob;
1378 int signal;
1379 int rc;
1380 char ssid[IEEE80211_MAX_SSID_LEN + 1];
1381
1382 gather_timeout *= ( ctx->essid[0] ? NET80211_PROBE_GATHER :
1383 NET80211_PROBE_GATHER_ALL );
1384
1385 /* Time out if necessary */
1386 if ( now >= ctx->ticks_start + start_timeout )
1387 return list_empty ( ctx->beacons ) ? -ETIMEDOUT : +1;
1388
1389 if ( ctx->ticks_beacon > 0 && now >= ctx->ticks_start + gather_timeout )
1390 return +1;
1391
1392 /* Change channels if necessary */
1393 if ( now >= ctx->ticks_channel + ctx->hop_time ) {
1394 dev->channel = ( dev->channel + ctx->hop_step )
1395 % dev->nr_channels;
1396 dev->op->config ( dev, NET80211_CFG_CHANNEL );
1397 udelay ( dev->hw->channel_change_time );
1398
1399 ctx->ticks_channel = now;
1400
1401 if ( ctx->probe ) {
1402 struct io_buffer *siob = ctx->probe; /* to send */
1403
1404 /* make a copy for future use */
1405 iob = alloc_iob ( siob->tail - siob->head );
1406 iob_reserve ( iob, iob_headroom ( siob ) );
1407 memcpy ( iob_put ( iob, iob_len ( siob ) ),
1408 siob->data, iob_len ( siob ) );
1409
1410 ctx->probe = iob;
1411 rc = net80211_tx_mgmt ( dev, IEEE80211_STYPE_PROBE_REQ,
1412 net80211_ll_broadcast,
1413 iob_disown ( siob ) );
1414 if ( rc ) {
1415 DBGC ( dev, "802.11 %p send probe failed: "
1416 "%s\n", dev, strerror ( rc ) );
1417 return rc;
1418 }
1419 }
1420 }
1421
1422 /* Check for new management packets */
1423 while ( ( iob = net80211_mgmt_dequeue ( dev, &signal ) ) != NULL ) {
1424 struct ieee80211_frame *hdr;
1425 struct ieee80211_beacon *beacon;
1426 union ieee80211_ie *ie;
1427 struct net80211_wlan *wlan;
1428 u16 type;
1429
1430 hdr = iob->data;
1431 type = hdr->fc & IEEE80211_FC_SUBTYPE;
1432 beacon = ( struct ieee80211_beacon * ) hdr->data;
1433
1434 if ( type != IEEE80211_STYPE_BEACON &&
1435 type != IEEE80211_STYPE_PROBE_RESP ) {
1436 DBGC2 ( dev, "802.11 %p probe: non-beacon\n", dev );
1437 goto drop;
1438 }
1439
1440 if ( ( void * ) beacon->info_element >= iob->tail ) {
1441 DBGC ( dev, "802.11 %p probe: beacon with no IEs\n",
1442 dev );
1443 goto drop;
1444 }
1445
1446 ie = beacon->info_element;
1447
1448 if ( ! ieee80211_ie_bound ( ie, iob->tail ) )
1449 ie = NULL;
1450
1451 while ( ie && ie->id != IEEE80211_IE_SSID )
1452 ie = ieee80211_next_ie ( ie, iob->tail );
1453
1454 if ( ! ie ) {
1455 DBGC ( dev, "802.11 %p probe: beacon with no SSID\n",
1456 dev );
1457 goto drop;
1458 }
1459
1460 memcpy ( ssid, ie->ssid, ie->len );
1461 ssid[ie->len] = 0;
1462
1463 if ( ctx->essid[0] && strcmp ( ctx->essid, ssid ) != 0 ) {
1464 DBGC2 ( dev, "802.11 %p probe: beacon with wrong SSID "
1465 "(%s)\n", dev, ssid );
1466 goto drop;
1467 }
1468
1469 /* See if we've got an entry for this network */
1470 list_for_each_entry ( wlan, ctx->beacons, list ) {
1471 if ( strcmp ( wlan->essid, ssid ) != 0 )
1472 continue;
1473
1474 if ( signal < wlan->signal ) {
1475 DBGC2 ( dev, "802.11 %p probe: beacon for %s "
1476 "(%s) with weaker signal %d\n", dev,
1477 ssid, eth_ntoa ( hdr->addr3 ), signal );
1478 goto drop;
1479 }
1480
1481 goto fill;
1482 }
1483
1484 /* No entry yet - make one */
1485 wlan = zalloc ( sizeof ( *wlan ) );
1486 strcpy ( wlan->essid, ssid );
1487 list_add_tail ( &wlan->list, ctx->beacons );
1488
1489 /* Whether we're using an old entry or a new one, fill
1490 it with new data. */
1491 fill:
1492 memcpy ( wlan->bssid, hdr->addr3, ETH_ALEN );
1493 wlan->signal = signal;
1494 wlan->channel = dev->channels[dev->channel].channel_nr;
1495
1496 /* Copy this I/O buffer into a new wlan->beacon; the
1497 * iob we've got probably came from the device driver
1498 * and may have the full 2.4k allocation, which we
1499 * don't want to keep around wasting memory.
1500 */
1501 free_iob ( wlan->beacon );
1502 wlan->beacon = alloc_iob ( iob_len ( iob ) );
1503 memcpy ( iob_put ( wlan->beacon, iob_len ( iob ) ),
1504 iob->data, iob_len ( iob ) );
1505
1506 if ( ( rc = sec80211_detect ( wlan->beacon, &wlan->handshaking,
1507 &wlan->crypto ) ) == -ENOTSUP ) {
1508 struct ieee80211_beacon *beacon =
1509 ( struct ieee80211_beacon * ) hdr->data;
1510
1511 if ( beacon->capability & IEEE80211_CAPAB_PRIVACY ) {
1512 DBG ( "802.11 %p probe: secured network %s but "
1513 "encryption support not compiled in\n",
1514 dev, wlan->essid );
1515 wlan->handshaking = NET80211_SECPROT_UNKNOWN;
1516 wlan->crypto = NET80211_CRYPT_UNKNOWN;
1517 } else {
1518 wlan->handshaking = NET80211_SECPROT_NONE;
1519 wlan->crypto = NET80211_CRYPT_NONE;
1520 }
1521 } else if ( rc != 0 ) {
1522 DBGC ( dev, "802.11 %p probe warning: network "
1523 "%s with unidentifiable security "
1524 "settings: %s\n", dev, wlan->essid,
1525 strerror ( rc ) );
1526 }
1527
1528 ctx->ticks_beacon = now;
1529
1530 DBGC2 ( dev, "802.11 %p probe: good beacon for %s (%s)\n",
1531 dev, wlan->essid, eth_ntoa ( wlan->bssid ) );
1532
1533 drop:
1534 free_iob ( iob );
1535 }
1536
1537 return 0;
1538 }
1539
1540
1541 /**
1542 * Finish probe of 802.11 networks, returning best-signal network found
1543 *
1544 * @v ctx Probe context
1545 * @ret wlan Best-signal network found, or @c NULL if none were found
1546 *
1547 * If net80211_probe_start() was called with a particular SSID
1548 * parameter as filter, only a network with that SSID (matching
1549 * case-sensitively) can be returned from this function.
1550 */
1551 struct net80211_wlan *
net80211_probe_finish_best(struct net80211_probe_ctx * ctx)1552 net80211_probe_finish_best ( struct net80211_probe_ctx *ctx )
1553 {
1554 struct net80211_wlan *best = NULL, *wlan;
1555
1556 if ( ! ctx )
1557 return NULL;
1558
1559 list_for_each_entry ( wlan, ctx->beacons, list ) {
1560 if ( ! best || best->signal < wlan->signal )
1561 best = wlan;
1562 }
1563
1564 if ( best )
1565 list_del ( &best->list );
1566 else
1567 DBGC ( ctx->dev, "802.11 %p probe: found nothing for '%s'\n",
1568 ctx->dev, ctx->essid );
1569
1570 net80211_free_wlanlist ( ctx->beacons );
1571
1572 net80211_keep_mgmt ( ctx->dev, ctx->old_keep_mgmt );
1573
1574 if ( ctx->probe )
1575 free_iob ( ctx->probe );
1576
1577 free ( ctx );
1578
1579 return best;
1580 }
1581
1582
1583 /**
1584 * Finish probe of 802.11 networks, returning all networks found
1585 *
1586 * @v ctx Probe context
1587 * @ret list List of net80211_wlan detailing networks found
1588 *
1589 * If net80211_probe_start() was called with a particular SSID
1590 * parameter as filter, this will always return either an empty or a
1591 * one-element list.
1592 */
net80211_probe_finish_all(struct net80211_probe_ctx * ctx)1593 struct list_head *net80211_probe_finish_all ( struct net80211_probe_ctx *ctx )
1594 {
1595 struct list_head *beacons = ctx->beacons;
1596
1597 if ( ! ctx )
1598 return NULL;
1599
1600 net80211_keep_mgmt ( ctx->dev, ctx->old_keep_mgmt );
1601
1602 if ( ctx->probe )
1603 free_iob ( ctx->probe );
1604
1605 free ( ctx );
1606
1607 return beacons;
1608 }
1609
1610
1611 /**
1612 * Free WLAN structure
1613 *
1614 * @v wlan WLAN structure to free
1615 */
net80211_free_wlan(struct net80211_wlan * wlan)1616 void net80211_free_wlan ( struct net80211_wlan *wlan )
1617 {
1618 if ( wlan ) {
1619 free_iob ( wlan->beacon );
1620 free ( wlan );
1621 }
1622 }
1623
1624
1625 /**
1626 * Free list of WLAN structures
1627 *
1628 * @v list List of WLAN structures to free
1629 */
net80211_free_wlanlist(struct list_head * list)1630 void net80211_free_wlanlist ( struct list_head *list )
1631 {
1632 struct net80211_wlan *wlan, *tmp;
1633
1634 if ( ! list )
1635 return;
1636
1637 list_for_each_entry_safe ( wlan, tmp, list, list ) {
1638 list_del ( &wlan->list );
1639 net80211_free_wlan ( wlan );
1640 }
1641
1642 free ( list );
1643 }
1644
1645
1646 /** Number of ticks to wait for replies to association management frames */
1647 #define ASSOC_TIMEOUT TICKS_PER_SEC
1648
1649 /** Number of times to try sending a particular association management frame */
1650 #define ASSOC_RETRIES 2
1651
1652 /**
1653 * Step 802.11 association process
1654 *
1655 * @v proc Association process
1656 */
net80211_step_associate(struct process * proc)1657 static void net80211_step_associate ( struct process *proc )
1658 {
1659 struct net80211_device *dev =
1660 container_of ( proc, struct net80211_device, proc_assoc );
1661 int rc = 0;
1662 int status = dev->state & NET80211_STATUS_MASK;
1663
1664 /*
1665 * We use a sort of state machine implemented using bits in
1666 * the dev->state variable. At each call, we take the
1667 * logically first step that has not yet succeeded; either it
1668 * has not been tried yet, it's being retried, or it failed.
1669 * If it failed, we return an error indication; otherwise we
1670 * perform the step. If it succeeds, RX handling code will set
1671 * the appropriate status bit for us.
1672 *
1673 * Probe works a bit differently, since we have to step it
1674 * on every call instead of waiting for a packet to arrive
1675 * that will set the completion bit for us.
1676 */
1677
1678 /* If we're waiting for a reply, check for timeout condition */
1679 if ( dev->state & NET80211_WAITING ) {
1680 /* Sanity check */
1681 if ( ! dev->associating )
1682 return;
1683
1684 if ( currticks() - dev->ctx.assoc->last_packet > ASSOC_TIMEOUT ) {
1685 /* Timed out - fail if too many retries, or retry */
1686 dev->ctx.assoc->times_tried++;
1687 if ( ++dev->ctx.assoc->times_tried > ASSOC_RETRIES ) {
1688 rc = -ETIMEDOUT;
1689 goto fail;
1690 }
1691 } else {
1692 /* Didn't time out - let it keep going */
1693 return;
1694 }
1695 } else {
1696 if ( dev->state & NET80211_PROBED )
1697 dev->ctx.assoc->times_tried = 0;
1698 }
1699
1700 if ( ! ( dev->state & NET80211_PROBED ) ) {
1701 /* state: probe */
1702
1703 if ( ! dev->ctx.probe ) {
1704 /* start probe */
1705 int active = fetch_intz_setting ( NULL,
1706 &net80211_active_setting );
1707 int band = dev->hw->bands;
1708
1709 if ( active )
1710 band &= ~NET80211_BAND_BIT_5GHZ;
1711
1712 rc = net80211_prepare_probe ( dev, band, active );
1713 if ( rc )
1714 goto fail;
1715
1716 dev->ctx.probe = net80211_probe_start ( dev, dev->essid,
1717 active );
1718 if ( ! dev->ctx.probe ) {
1719 dev->assoc_rc = -ENOMEM;
1720 goto fail;
1721 }
1722 }
1723
1724 rc = net80211_probe_step ( dev->ctx.probe );
1725 if ( ! rc ) {
1726 return; /* still going */
1727 }
1728
1729 dev->associating = net80211_probe_finish_best ( dev->ctx.probe );
1730 dev->ctx.probe = NULL;
1731 if ( ! dev->associating ) {
1732 if ( rc > 0 ) /* "successful" probe found nothing */
1733 rc = -ETIMEDOUT;
1734 goto fail;
1735 }
1736
1737 /* If we probed using a broadcast SSID, record that
1738 fact for the settings applicator before we clobber
1739 it with the specific SSID we've chosen. */
1740 if ( ! dev->essid[0] )
1741 dev->state |= NET80211_AUTO_SSID;
1742
1743 DBGC ( dev, "802.11 %p found network %s (%s)\n", dev,
1744 dev->associating->essid,
1745 eth_ntoa ( dev->associating->bssid ) );
1746
1747 dev->ctx.assoc = zalloc ( sizeof ( *dev->ctx.assoc ) );
1748 if ( ! dev->ctx.assoc ) {
1749 rc = -ENOMEM;
1750 goto fail;
1751 }
1752
1753 dev->state |= NET80211_PROBED;
1754 dev->ctx.assoc->method = IEEE80211_AUTH_OPEN_SYSTEM;
1755
1756 return;
1757 }
1758
1759 /* Record time of sending the packet we're about to send, for timeout */
1760 dev->ctx.assoc->last_packet = currticks();
1761
1762 if ( ! ( dev->state & NET80211_AUTHENTICATED ) ) {
1763 /* state: prepare and authenticate */
1764
1765 if ( status != IEEE80211_STATUS_SUCCESS ) {
1766 /* we tried authenticating already, but failed */
1767 int method = dev->ctx.assoc->method;
1768
1769 if ( method == IEEE80211_AUTH_OPEN_SYSTEM &&
1770 ( status == IEEE80211_STATUS_AUTH_CHALL_INVALID ||
1771 status == IEEE80211_STATUS_AUTH_ALGO_UNSUPP ) ) {
1772 /* Maybe this network uses Shared Key? */
1773 dev->ctx.assoc->method =
1774 IEEE80211_AUTH_SHARED_KEY;
1775 } else {
1776 goto fail;
1777 }
1778 }
1779
1780 DBGC ( dev, "802.11 %p authenticating with method %d\n", dev,
1781 dev->ctx.assoc->method );
1782
1783 rc = net80211_prepare_assoc ( dev, dev->associating );
1784 if ( rc )
1785 goto fail;
1786
1787 rc = net80211_send_auth ( dev, dev->associating,
1788 dev->ctx.assoc->method );
1789 if ( rc )
1790 goto fail;
1791
1792 return;
1793 }
1794
1795 if ( ! ( dev->state & NET80211_ASSOCIATED ) ) {
1796 /* state: associate */
1797
1798 if ( status != IEEE80211_STATUS_SUCCESS )
1799 goto fail;
1800
1801 DBGC ( dev, "802.11 %p associating\n", dev );
1802
1803 if ( dev->handshaker && dev->handshaker->start &&
1804 ! dev->handshaker->started ) {
1805 rc = dev->handshaker->start ( dev );
1806 if ( rc < 0 )
1807 goto fail;
1808 dev->handshaker->started = 1;
1809 }
1810
1811 rc = net80211_send_assoc ( dev, dev->associating );
1812 if ( rc )
1813 goto fail;
1814
1815 return;
1816 }
1817
1818 if ( ! ( dev->state & NET80211_CRYPTO_SYNCED ) ) {
1819 /* state: crypto sync */
1820 DBGC ( dev, "802.11 %p security handshaking\n", dev );
1821
1822 if ( ! dev->handshaker || ! dev->handshaker->step ) {
1823 dev->state |= NET80211_CRYPTO_SYNCED;
1824 return;
1825 }
1826
1827 rc = dev->handshaker->step ( dev );
1828
1829 if ( rc < 0 ) {
1830 /* Only record the returned error if we're
1831 still marked as associated, because an
1832 asynchronous error will have already been
1833 reported to net80211_deauthenticate() and
1834 assoc_rc thereby set. */
1835 if ( dev->state & NET80211_ASSOCIATED )
1836 dev->assoc_rc = rc;
1837 rc = 0;
1838 goto fail;
1839 }
1840
1841 if ( rc > 0 ) {
1842 dev->assoc_rc = 0;
1843 dev->state |= NET80211_CRYPTO_SYNCED;
1844 }
1845 return;
1846 }
1847
1848 /* state: done! */
1849 netdev_link_up ( dev->netdev );
1850 dev->assoc_rc = 0;
1851 dev->state &= ~NET80211_WORKING;
1852
1853 free ( dev->ctx.assoc );
1854 dev->ctx.assoc = NULL;
1855
1856 net80211_free_wlan ( dev->associating );
1857 dev->associating = NULL;
1858
1859 dev->rctl = rc80211_init ( dev );
1860
1861 process_del ( proc );
1862
1863 DBGC ( dev, "802.11 %p associated with %s (%s)\n", dev,
1864 dev->essid, eth_ntoa ( dev->bssid ) );
1865
1866 return;
1867
1868 fail:
1869 dev->state &= ~( NET80211_WORKING | NET80211_WAITING );
1870 if ( rc )
1871 dev->assoc_rc = rc;
1872
1873 netdev_link_err ( dev->netdev, dev->assoc_rc );
1874
1875 /* We never reach here from the middle of a probe, so we don't
1876 need to worry about freeing dev->ctx.probe. */
1877
1878 if ( dev->state & NET80211_PROBED ) {
1879 free ( dev->ctx.assoc );
1880 dev->ctx.assoc = NULL;
1881 }
1882
1883 net80211_free_wlan ( dev->associating );
1884 dev->associating = NULL;
1885
1886 process_del ( proc );
1887
1888 DBGC ( dev, "802.11 %p association failed (state=%04x): "
1889 "%s\n", dev, dev->state, strerror ( dev->assoc_rc ) );
1890
1891 /* Try it again: */
1892 net80211_autoassociate ( dev );
1893 }
1894
1895 /**
1896 * Check for 802.11 SSID or key updates
1897 *
1898 * This acts as a settings applicator; if the user changes netX/ssid,
1899 * and netX is currently open, the association task will be invoked
1900 * again. If the user changes the encryption key, the current security
1901 * handshaker will be asked to update its state to match; if that is
1902 * impossible without reassociation, we reassociate.
1903 */
net80211_check_settings_update(void)1904 static int net80211_check_settings_update ( void )
1905 {
1906 struct net80211_device *dev;
1907 char ssid[IEEE80211_MAX_SSID_LEN + 1];
1908 int key_reassoc;
1909
1910 list_for_each_entry ( dev, &net80211_devices, list ) {
1911 if ( ! ( dev->netdev->state & NETDEV_OPEN ) )
1912 continue;
1913
1914 key_reassoc = 0;
1915 if ( dev->handshaker && dev->handshaker->change_key &&
1916 dev->handshaker->change_key ( dev ) < 0 )
1917 key_reassoc = 1;
1918
1919 fetch_string_setting ( netdev_settings ( dev->netdev ),
1920 &net80211_ssid_setting, ssid,
1921 IEEE80211_MAX_SSID_LEN + 1 );
1922
1923 if ( key_reassoc ||
1924 ( ! ( ! ssid[0] && ( dev->state & NET80211_AUTO_SSID ) ) &&
1925 strcmp ( ssid, dev->essid ) != 0 ) ) {
1926 DBGC ( dev, "802.11 %p updating association: "
1927 "%s -> %s\n", dev, dev->essid, ssid );
1928 net80211_autoassociate ( dev );
1929 }
1930 }
1931
1932 return 0;
1933 }
1934
1935 /**
1936 * Start 802.11 association process
1937 *
1938 * @v dev 802.11 device
1939 *
1940 * If the association process is running, it will be restarted.
1941 */
net80211_autoassociate(struct net80211_device * dev)1942 void net80211_autoassociate ( struct net80211_device *dev )
1943 {
1944 if ( ! ( dev->state & NET80211_WORKING ) ) {
1945 DBGC2 ( dev, "802.11 %p spawning association process\n", dev );
1946 process_add ( &dev->proc_assoc );
1947 } else {
1948 DBGC2 ( dev, "802.11 %p restarting association\n", dev );
1949 }
1950
1951 /* Clean up everything an earlier association process might
1952 have been in the middle of using */
1953 if ( dev->associating )
1954 net80211_free_wlan ( dev->associating );
1955
1956 if ( ! ( dev->state & NET80211_PROBED ) )
1957 net80211_free_wlan (
1958 net80211_probe_finish_best ( dev->ctx.probe ) );
1959 else
1960 free ( dev->ctx.assoc );
1961
1962 /* Reset to a clean state */
1963 fetch_string_setting ( netdev_settings ( dev->netdev ),
1964 &net80211_ssid_setting, dev->essid,
1965 IEEE80211_MAX_SSID_LEN + 1 );
1966 dev->ctx.probe = NULL;
1967 dev->associating = NULL;
1968 dev->assoc_rc = 0;
1969 net80211_set_state ( dev, NET80211_PROBED, NET80211_WORKING, 0 );
1970 }
1971
1972 /**
1973 * Pick TX rate for RTS/CTS packets based on data rate
1974 *
1975 * @v dev 802.11 device
1976 *
1977 * The RTS/CTS rate is the fastest TX rate marked as "basic" that is
1978 * not faster than the data rate.
1979 */
net80211_set_rtscts_rate(struct net80211_device * dev)1980 static void net80211_set_rtscts_rate ( struct net80211_device *dev )
1981 {
1982 u16 datarate = dev->rates[dev->rate];
1983 u16 rtsrate = 0;
1984 int rts_idx = -1;
1985 int i;
1986
1987 for ( i = 0; i < dev->nr_rates; i++ ) {
1988 u16 rate = dev->rates[i];
1989
1990 if ( ! ( dev->basic_rates & ( 1 << i ) ) || rate > datarate )
1991 continue;
1992
1993 if ( rate > rtsrate ) {
1994 rtsrate = rate;
1995 rts_idx = i;
1996 }
1997 }
1998
1999 /* If this is in initialization, we might not have any basic
2000 rates; just use the first data rate in that case. */
2001 if ( rts_idx < 0 )
2002 rts_idx = 0;
2003
2004 dev->rtscts_rate = rts_idx;
2005 }
2006
2007 /**
2008 * Set data transmission rate for 802.11 device
2009 *
2010 * @v dev 802.11 device
2011 * @v rate Rate to set, as index into @c dev->rates array
2012 */
net80211_set_rate_idx(struct net80211_device * dev,int rate)2013 void net80211_set_rate_idx ( struct net80211_device *dev, int rate )
2014 {
2015 assert ( dev->netdev->state & NETDEV_OPEN );
2016
2017 if ( rate >= 0 && rate < dev->nr_rates && rate != dev->rate ) {
2018 DBGC2 ( dev, "802.11 %p changing rate from %d->%d Mbps\n",
2019 dev, dev->rates[dev->rate] / 10,
2020 dev->rates[rate] / 10 );
2021
2022 dev->rate = rate;
2023 net80211_set_rtscts_rate ( dev );
2024 dev->op->config ( dev, NET80211_CFG_RATE );
2025 }
2026 }
2027
2028 /**
2029 * Configure 802.11 device to transmit on a certain channel
2030 *
2031 * @v dev 802.11 device
2032 * @v channel Channel number (1-11 for 2.4GHz) to transmit on
2033 */
net80211_change_channel(struct net80211_device * dev,int channel)2034 int net80211_change_channel ( struct net80211_device *dev, int channel )
2035 {
2036 int i, oldchan = dev->channel;
2037
2038 assert ( dev->netdev->state & NETDEV_OPEN );
2039
2040 for ( i = 0; i < dev->nr_channels; i++ ) {
2041 if ( dev->channels[i].channel_nr == channel ) {
2042 dev->channel = i;
2043 break;
2044 }
2045 }
2046
2047 if ( i == dev->nr_channels )
2048 return -ENOENT;
2049
2050 if ( i != oldchan )
2051 return dev->op->config ( dev, NET80211_CFG_CHANNEL );
2052
2053 return 0;
2054 }
2055
2056 /**
2057 * Prepare 802.11 device channel and rate set for scanning
2058 *
2059 * @v dev 802.11 device
2060 * @v band RF band(s) on which to prepare for scanning
2061 * @v active Whether the scanning will be active
2062 * @ret rc Return status code
2063 */
net80211_prepare_probe(struct net80211_device * dev,int band,int active)2064 int net80211_prepare_probe ( struct net80211_device *dev, int band,
2065 int active )
2066 {
2067 assert ( dev->netdev->state & NETDEV_OPEN );
2068
2069 if ( active && ( band & NET80211_BAND_BIT_5GHZ ) ) {
2070 DBGC ( dev, "802.11 %p cannot perform active scanning on "
2071 "5GHz band\n", dev );
2072 return -EINVAL_ACTIVE_SCAN;
2073 }
2074
2075 if ( band == 0 ) {
2076 /* This can happen for a 5GHz-only card with 5GHz
2077 scanning masked out by an active request. */
2078 DBGC ( dev, "802.11 %p asked to prepare for scanning nothing\n",
2079 dev );
2080 return -EINVAL_ACTIVE_SCAN;
2081 }
2082
2083 dev->nr_channels = 0;
2084
2085 if ( active )
2086 net80211_add_channels ( dev, 1, 11, NET80211_REG_TXPOWER );
2087 else {
2088 if ( band & NET80211_BAND_BIT_2GHZ )
2089 net80211_add_channels ( dev, 1, 14,
2090 NET80211_REG_TXPOWER );
2091 if ( band & NET80211_BAND_BIT_5GHZ )
2092 net80211_add_channels ( dev, 36, 8,
2093 NET80211_REG_TXPOWER );
2094 }
2095
2096 net80211_filter_hw_channels ( dev );
2097
2098 /* Use channel 1 for now */
2099 dev->channel = 0;
2100 dev->op->config ( dev, NET80211_CFG_CHANNEL );
2101
2102 /* Always do active probes at lowest (presumably first) speed */
2103 dev->rate = 0;
2104 dev->nr_rates = 1;
2105 dev->rates[0] = dev->hw->rates[dev->channels[0].band][0];
2106 dev->op->config ( dev, NET80211_CFG_RATE );
2107
2108 return 0;
2109 }
2110
2111 /**
2112 * Prepare 802.11 device channel and rate set for communication
2113 *
2114 * @v dev 802.11 device
2115 * @v wlan WLAN to prepare for communication with
2116 * @ret rc Return status code
2117 */
net80211_prepare_assoc(struct net80211_device * dev,struct net80211_wlan * wlan)2118 int net80211_prepare_assoc ( struct net80211_device *dev,
2119 struct net80211_wlan *wlan )
2120 {
2121 struct ieee80211_frame *hdr = wlan->beacon->data;
2122 struct ieee80211_beacon *beacon =
2123 ( struct ieee80211_beacon * ) hdr->data;
2124 struct net80211_handshaker *handshaker;
2125 int rc;
2126
2127 assert ( dev->netdev->state & NETDEV_OPEN );
2128
2129 net80211_set_state ( dev, NET80211_ASSOCIATED, 0, 0 );
2130 memcpy ( dev->bssid, wlan->bssid, ETH_ALEN );
2131 strcpy ( dev->essid, wlan->essid );
2132
2133 free ( dev->rsn_ie );
2134 dev->rsn_ie = NULL;
2135
2136 dev->last_beacon_timestamp = beacon->timestamp;
2137 dev->tx_beacon_interval = 1024 * beacon->beacon_interval;
2138
2139 /* Barring an IE that tells us the channel outright, assume
2140 the channel we heard this AP best on is the channel it's
2141 communicating on. */
2142 net80211_change_channel ( dev, wlan->channel );
2143
2144 rc = net80211_process_capab ( dev, beacon->capability );
2145 if ( rc )
2146 return rc;
2147
2148 rc = net80211_process_ie ( dev, beacon->info_element,
2149 wlan->beacon->tail );
2150 if ( rc )
2151 return rc;
2152
2153 /* Associate at the lowest rate so we know it'll get through */
2154 dev->rate = 0;
2155 dev->op->config ( dev, NET80211_CFG_RATE );
2156
2157 /* Free old handshaker and crypto, if they exist */
2158 if ( dev->handshaker && dev->handshaker->stop &&
2159 dev->handshaker->started )
2160 dev->handshaker->stop ( dev );
2161 free ( dev->handshaker );
2162 dev->handshaker = NULL;
2163 free ( dev->crypto );
2164 free ( dev->gcrypto );
2165 dev->crypto = dev->gcrypto = NULL;
2166
2167 /* Find new security handshaker to use */
2168 for_each_table_entry ( handshaker, NET80211_HANDSHAKERS ) {
2169 if ( handshaker->protocol == wlan->handshaking ) {
2170 dev->handshaker = zalloc ( sizeof ( *handshaker ) +
2171 handshaker->priv_len );
2172 if ( ! dev->handshaker )
2173 return -ENOMEM;
2174
2175 memcpy ( dev->handshaker, handshaker,
2176 sizeof ( *handshaker ) );
2177 dev->handshaker->priv = ( ( void * ) dev->handshaker +
2178 sizeof ( *handshaker ) );
2179 break;
2180 }
2181 }
2182
2183 if ( ( wlan->handshaking != NET80211_SECPROT_NONE ) &&
2184 ! dev->handshaker ) {
2185 DBGC ( dev, "802.11 %p no support for handshaking scheme %d\n",
2186 dev, wlan->handshaking );
2187 return -( ENOTSUP | ( wlan->handshaking << 8 ) );
2188 }
2189
2190 /* Initialize security handshaker */
2191 if ( dev->handshaker ) {
2192 rc = dev->handshaker->init ( dev );
2193 if ( rc < 0 )
2194 return rc;
2195 }
2196
2197 return 0;
2198 }
2199
2200 /**
2201 * Send 802.11 initial authentication frame
2202 *
2203 * @v dev 802.11 device
2204 * @v wlan WLAN to authenticate with
2205 * @v method Authentication method
2206 * @ret rc Return status code
2207 *
2208 * @a method may be 0 for Open System authentication or 1 for Shared
2209 * Key authentication. Open System provides no security in association
2210 * whatsoever, relying on encryption for confidentiality, but Shared
2211 * Key actively introduces security problems and is very rarely used.
2212 */
net80211_send_auth(struct net80211_device * dev,struct net80211_wlan * wlan,int method)2213 int net80211_send_auth ( struct net80211_device *dev,
2214 struct net80211_wlan *wlan, int method )
2215 {
2216 struct io_buffer *iob = alloc_iob ( 64 );
2217 struct ieee80211_auth *auth;
2218
2219 net80211_set_state ( dev, 0, NET80211_WAITING, 0 );
2220 iob_reserve ( iob, IEEE80211_TYP_FRAME_HEADER_LEN );
2221 auth = iob_put ( iob, sizeof ( *auth ) );
2222 auth->algorithm = method;
2223 auth->tx_seq = 1;
2224 auth->status = 0;
2225
2226 return net80211_tx_mgmt ( dev, IEEE80211_STYPE_AUTH, wlan->bssid, iob );
2227 }
2228
2229 /**
2230 * Handle receipt of 802.11 authentication frame
2231 *
2232 * @v dev 802.11 device
2233 * @v iob I/O buffer
2234 *
2235 * If the authentication method being used is Shared Key, and the
2236 * frame that was received included challenge text, the frame is
2237 * encrypted using the cryptosystem currently in effect and sent back
2238 * to the AP to complete the authentication.
2239 */
net80211_handle_auth(struct net80211_device * dev,struct io_buffer * iob)2240 static void net80211_handle_auth ( struct net80211_device *dev,
2241 struct io_buffer *iob )
2242 {
2243 struct ieee80211_frame *hdr = iob->data;
2244 struct ieee80211_auth *auth =
2245 ( struct ieee80211_auth * ) hdr->data;
2246
2247 if ( auth->tx_seq & 1 ) {
2248 DBGC ( dev, "802.11 %p authentication received improperly "
2249 "directed frame (seq. %d)\n", dev, auth->tx_seq );
2250 net80211_set_state ( dev, NET80211_WAITING, 0,
2251 IEEE80211_STATUS_FAILURE );
2252 return;
2253 }
2254
2255 if ( auth->status != IEEE80211_STATUS_SUCCESS ) {
2256 DBGC ( dev, "802.11 %p authentication failed: status %d\n",
2257 dev, auth->status );
2258 net80211_set_state ( dev, NET80211_WAITING, 0,
2259 auth->status );
2260 return;
2261 }
2262
2263 if ( auth->algorithm == IEEE80211_AUTH_SHARED_KEY && ! dev->crypto ) {
2264 DBGC ( dev, "802.11 %p can't perform shared-key authentication "
2265 "without a cryptosystem\n", dev );
2266 net80211_set_state ( dev, NET80211_WAITING, 0,
2267 IEEE80211_STATUS_FAILURE );
2268 return;
2269 }
2270
2271 if ( auth->algorithm == IEEE80211_AUTH_SHARED_KEY &&
2272 auth->tx_seq == 2 ) {
2273 /* Since the iob we got is going to be freed as soon
2274 as we return, we can do some in-place
2275 modification. */
2276 auth->tx_seq = 3;
2277 auth->status = 0;
2278
2279 memcpy ( hdr->addr2, hdr->addr1, ETH_ALEN );
2280 memcpy ( hdr->addr1, hdr->addr3, ETH_ALEN );
2281
2282 netdev_tx ( dev->netdev,
2283 dev->crypto->encrypt ( dev->crypto, iob ) );
2284 return;
2285 }
2286
2287 net80211_set_state ( dev, NET80211_WAITING, NET80211_AUTHENTICATED,
2288 IEEE80211_STATUS_SUCCESS );
2289
2290 return;
2291 }
2292
2293 /**
2294 * Send 802.11 association frame
2295 *
2296 * @v dev 802.11 device
2297 * @v wlan WLAN to associate with
2298 * @ret rc Return status code
2299 */
net80211_send_assoc(struct net80211_device * dev,struct net80211_wlan * wlan)2300 int net80211_send_assoc ( struct net80211_device *dev,
2301 struct net80211_wlan *wlan )
2302 {
2303 struct io_buffer *iob = alloc_iob ( 128 );
2304 struct ieee80211_assoc_req *assoc;
2305 union ieee80211_ie *ie;
2306
2307 net80211_set_state ( dev, 0, NET80211_WAITING, 0 );
2308
2309 iob_reserve ( iob, IEEE80211_TYP_FRAME_HEADER_LEN );
2310 assoc = iob->data;
2311
2312 assoc->capability = IEEE80211_CAPAB_MANAGED;
2313 if ( ! ( dev->hw->flags & NET80211_HW_NO_SHORT_PREAMBLE ) )
2314 assoc->capability |= IEEE80211_CAPAB_SHORT_PMBL;
2315 if ( ! ( dev->hw->flags & NET80211_HW_NO_SHORT_SLOT ) )
2316 assoc->capability |= IEEE80211_CAPAB_SHORT_SLOT;
2317 if ( wlan->crypto )
2318 assoc->capability |= IEEE80211_CAPAB_PRIVACY;
2319
2320 assoc->listen_interval = 1;
2321
2322 ie = net80211_marshal_request_info ( dev, assoc->info_element );
2323
2324 DBGP ( "802.11 %p about to send association request:\n", dev );
2325 DBGP_HD ( iob->data, ( void * ) ie - iob->data );
2326
2327 iob_put ( iob, ( void * ) ie - iob->data );
2328
2329 return net80211_tx_mgmt ( dev, IEEE80211_STYPE_ASSOC_REQ,
2330 wlan->bssid, iob );
2331 }
2332
2333 /**
2334 * Handle receipt of 802.11 association reply frame
2335 *
2336 * @v dev 802.11 device
2337 * @v iob I/O buffer
2338 */
net80211_handle_assoc_reply(struct net80211_device * dev,struct io_buffer * iob)2339 static void net80211_handle_assoc_reply ( struct net80211_device *dev,
2340 struct io_buffer *iob )
2341 {
2342 struct ieee80211_frame *hdr = iob->data;
2343 struct ieee80211_assoc_resp *assoc =
2344 ( struct ieee80211_assoc_resp * ) hdr->data;
2345
2346 net80211_process_capab ( dev, assoc->capability );
2347 net80211_process_ie ( dev, assoc->info_element, iob->tail );
2348
2349 if ( assoc->status != IEEE80211_STATUS_SUCCESS ) {
2350 DBGC ( dev, "802.11 %p association failed: status %d\n",
2351 dev, assoc->status );
2352 net80211_set_state ( dev, NET80211_WAITING, 0,
2353 assoc->status );
2354 return;
2355 }
2356
2357 /* ESSID was filled before the association request was sent */
2358 memcpy ( dev->bssid, hdr->addr3, ETH_ALEN );
2359 dev->aid = assoc->aid;
2360
2361 net80211_set_state ( dev, NET80211_WAITING, NET80211_ASSOCIATED,
2362 IEEE80211_STATUS_SUCCESS );
2363 }
2364
2365
2366 /**
2367 * Send 802.11 disassociation frame
2368 *
2369 * @v dev 802.11 device
2370 * @v reason Reason for disassociation
2371 * @v deauth If TRUE, send deauthentication instead of disassociation
2372 * @ret rc Return status code
2373 */
net80211_send_disassoc(struct net80211_device * dev,int reason,int deauth)2374 static int net80211_send_disassoc ( struct net80211_device *dev, int reason,
2375 int deauth )
2376 {
2377 struct io_buffer *iob = alloc_iob ( 64 );
2378 struct ieee80211_disassoc *disassoc;
2379
2380 if ( ! ( dev->state & NET80211_ASSOCIATED ) )
2381 return -EINVAL;
2382
2383 net80211_set_state ( dev, NET80211_ASSOCIATED, 0, 0 );
2384 iob_reserve ( iob, IEEE80211_TYP_FRAME_HEADER_LEN );
2385 disassoc = iob_put ( iob, sizeof ( *disassoc ) );
2386 disassoc->reason = reason;
2387
2388 return net80211_tx_mgmt ( dev, deauth ? IEEE80211_STYPE_DEAUTH :
2389 IEEE80211_STYPE_DISASSOC, dev->bssid, iob );
2390 }
2391
2392
2393 /**
2394 * Deauthenticate from current network and try again
2395 *
2396 * @v dev 802.11 device
2397 * @v rc Return status code indicating reason
2398 *
2399 * The deauthentication will be sent using an 802.11 "unspecified
2400 * reason", as is common, but @a rc will be set as a link-up
2401 * error to aid the user in debugging.
2402 */
net80211_deauthenticate(struct net80211_device * dev,int rc)2403 void net80211_deauthenticate ( struct net80211_device *dev, int rc )
2404 {
2405 net80211_send_disassoc ( dev, IEEE80211_REASON_UNSPECIFIED, 1 );
2406 dev->assoc_rc = rc;
2407 netdev_link_err ( dev->netdev, rc );
2408
2409 net80211_autoassociate ( dev );
2410 }
2411
2412
2413 /** Smoothing factor (1-7) for link quality calculation */
2414 #define LQ_SMOOTH 7
2415
2416 /**
2417 * Update link quality information based on received beacon
2418 *
2419 * @v dev 802.11 device
2420 * @v iob I/O buffer containing beacon
2421 * @ret rc Return status code
2422 */
net80211_update_link_quality(struct net80211_device * dev,struct io_buffer * iob)2423 static void net80211_update_link_quality ( struct net80211_device *dev,
2424 struct io_buffer *iob )
2425 {
2426 struct ieee80211_frame *hdr = iob->data;
2427 struct ieee80211_beacon *beacon;
2428 u32 dt, rxi;
2429
2430 if ( ! ( dev->state & NET80211_ASSOCIATED ) )
2431 return;
2432
2433 beacon = ( struct ieee80211_beacon * ) hdr->data;
2434 dt = ( u32 ) ( beacon->timestamp - dev->last_beacon_timestamp );
2435 rxi = dev->rx_beacon_interval;
2436
2437 rxi = ( LQ_SMOOTH * rxi ) + ( ( 8 - LQ_SMOOTH ) * dt );
2438 dev->rx_beacon_interval = rxi >> 3;
2439
2440 dev->last_beacon_timestamp = beacon->timestamp;
2441 }
2442
2443
2444 /**
2445 * Handle receipt of 802.11 management frame
2446 *
2447 * @v dev 802.11 device
2448 * @v iob I/O buffer
2449 * @v signal Signal strength of received frame
2450 */
net80211_handle_mgmt(struct net80211_device * dev,struct io_buffer * iob,int signal)2451 static void net80211_handle_mgmt ( struct net80211_device *dev,
2452 struct io_buffer *iob, int signal )
2453 {
2454 struct ieee80211_frame *hdr = iob->data;
2455 struct ieee80211_disassoc *disassoc;
2456 u16 stype = hdr->fc & IEEE80211_FC_SUBTYPE;
2457 int keep = 0;
2458 int is_deauth = ( stype == IEEE80211_STYPE_DEAUTH );
2459
2460 if ( ( hdr->fc & IEEE80211_FC_TYPE ) != IEEE80211_TYPE_MGMT ) {
2461 free_iob ( iob );
2462 return; /* only handle management frames */
2463 }
2464
2465 switch ( stype ) {
2466 /* We reconnect on deauthentication and disassociation. */
2467 case IEEE80211_STYPE_DEAUTH:
2468 case IEEE80211_STYPE_DISASSOC:
2469 disassoc = ( struct ieee80211_disassoc * ) hdr->data;
2470 net80211_set_state ( dev, is_deauth ? NET80211_AUTHENTICATED :
2471 NET80211_ASSOCIATED, 0,
2472 NET80211_IS_REASON | disassoc->reason );
2473 DBGC ( dev, "802.11 %p %s: reason %d\n",
2474 dev, is_deauth ? "deauthenticated" : "disassociated",
2475 disassoc->reason );
2476
2477 /* Try to reassociate, in case it's transient. */
2478 net80211_autoassociate ( dev );
2479
2480 break;
2481
2482 /* We handle authentication and association. */
2483 case IEEE80211_STYPE_AUTH:
2484 if ( ! ( dev->state & NET80211_AUTHENTICATED ) )
2485 net80211_handle_auth ( dev, iob );
2486 break;
2487
2488 case IEEE80211_STYPE_ASSOC_RESP:
2489 case IEEE80211_STYPE_REASSOC_RESP:
2490 if ( ! ( dev->state & NET80211_ASSOCIATED ) )
2491 net80211_handle_assoc_reply ( dev, iob );
2492 break;
2493
2494 /* We pass probes and beacons onto network scanning
2495 code. Pass actions for future extensibility. */
2496 case IEEE80211_STYPE_BEACON:
2497 net80211_update_link_quality ( dev, iob );
2498 /* fall through */
2499 case IEEE80211_STYPE_PROBE_RESP:
2500 case IEEE80211_STYPE_ACTION:
2501 if ( dev->keep_mgmt ) {
2502 struct net80211_rx_info *rxinf;
2503 rxinf = zalloc ( sizeof ( *rxinf ) );
2504 if ( ! rxinf ) {
2505 DBGC ( dev, "802.11 %p out of memory\n", dev );
2506 break;
2507 }
2508 rxinf->signal = signal;
2509 list_add_tail ( &iob->list, &dev->mgmt_queue );
2510 list_add_tail ( &rxinf->list, &dev->mgmt_info_queue );
2511 keep = 1;
2512 }
2513 break;
2514
2515 case IEEE80211_STYPE_PROBE_REQ:
2516 /* Some nodes send these broadcast. Ignore them. */
2517 break;
2518
2519 case IEEE80211_STYPE_ASSOC_REQ:
2520 case IEEE80211_STYPE_REASSOC_REQ:
2521 /* We should never receive these, only send them. */
2522 DBGC ( dev, "802.11 %p received strange management request "
2523 "(%04x)\n", dev, stype );
2524 break;
2525
2526 default:
2527 DBGC ( dev, "802.11 %p received unimplemented management "
2528 "packet (%04x)\n", dev, stype );
2529 break;
2530 }
2531
2532 if ( ! keep )
2533 free_iob ( iob );
2534 }
2535
2536 /* ---------- Packet handling functions ---------- */
2537
2538 /**
2539 * Free buffers used by 802.11 fragment cache entry
2540 *
2541 * @v dev 802.11 device
2542 * @v fcid Fragment cache entry index
2543 *
2544 * After this function, the referenced entry will be marked unused.
2545 */
net80211_free_frags(struct net80211_device * dev,int fcid)2546 static void net80211_free_frags ( struct net80211_device *dev, int fcid )
2547 {
2548 int j;
2549 struct net80211_frag_cache *frag = &dev->frags[fcid];
2550
2551 for ( j = 0; j < 16; j++ ) {
2552 if ( frag->iob[j] ) {
2553 free_iob ( frag->iob[j] );
2554 frag->iob[j] = NULL;
2555 }
2556 }
2557
2558 frag->seqnr = 0;
2559 frag->start_ticks = 0;
2560 frag->in_use = 0;
2561 }
2562
2563 /**
2564 * Accumulate 802.11 fragments into one I/O buffer
2565 *
2566 * @v dev 802.11 device
2567 * @v fcid Fragment cache entry index
2568 * @v nfrags Number of fragments received
2569 * @v size Sum of sizes of all fragments, including headers
2570 * @ret iob I/O buffer containing reassembled packet
2571 *
2572 * This function does not free the fragment buffers.
2573 */
net80211_accum_frags(struct net80211_device * dev,int fcid,int nfrags,int size)2574 static struct io_buffer *net80211_accum_frags ( struct net80211_device *dev,
2575 int fcid, int nfrags, int size )
2576 {
2577 struct net80211_frag_cache *frag = &dev->frags[fcid];
2578 int hdrsize = IEEE80211_TYP_FRAME_HEADER_LEN;
2579 int nsize = size - hdrsize * ( nfrags - 1 );
2580 int i;
2581
2582 struct io_buffer *niob = alloc_iob ( nsize );
2583 struct ieee80211_frame *hdr;
2584
2585 /* Add the header from the first one... */
2586 memcpy ( iob_put ( niob, hdrsize ), frag->iob[0]->data, hdrsize );
2587
2588 /* ... and all the data from all of them. */
2589 for ( i = 0; i < nfrags; i++ ) {
2590 int len = iob_len ( frag->iob[i] ) - hdrsize;
2591 memcpy ( iob_put ( niob, len ),
2592 frag->iob[i]->data + hdrsize, len );
2593 }
2594
2595 /* Turn off the fragment bit. */
2596 hdr = niob->data;
2597 hdr->fc &= ~IEEE80211_FC_MORE_FRAG;
2598
2599 return niob;
2600 }
2601
2602 /**
2603 * Handle receipt of 802.11 fragment
2604 *
2605 * @v dev 802.11 device
2606 * @v iob I/O buffer containing fragment
2607 * @v signal Signal strength with which fragment was received
2608 */
net80211_rx_frag(struct net80211_device * dev,struct io_buffer * iob,int signal)2609 static void net80211_rx_frag ( struct net80211_device *dev,
2610 struct io_buffer *iob, int signal )
2611 {
2612 struct ieee80211_frame *hdr = iob->data;
2613 int fragnr = IEEE80211_FRAG ( hdr->seq );
2614
2615 if ( fragnr == 0 && ( hdr->fc & IEEE80211_FC_MORE_FRAG ) ) {
2616 /* start a frag cache entry */
2617 int i, newest = -1;
2618 u32 curr_ticks = currticks(), newest_ticks = 0;
2619 u32 timeout = ticks_per_sec() * NET80211_FRAG_TIMEOUT;
2620
2621 for ( i = 0; i < NET80211_NR_CONCURRENT_FRAGS; i++ ) {
2622 if ( dev->frags[i].in_use == 0 )
2623 break;
2624
2625 if ( dev->frags[i].start_ticks + timeout >=
2626 curr_ticks ) {
2627 net80211_free_frags ( dev, i );
2628 break;
2629 }
2630
2631 if ( dev->frags[i].start_ticks > newest_ticks ) {
2632 newest = i;
2633 newest_ticks = dev->frags[i].start_ticks;
2634 }
2635 }
2636
2637 /* If we're being sent more concurrent fragmented
2638 packets than we can handle, drop the newest so the
2639 older ones have time to complete. */
2640 if ( i == NET80211_NR_CONCURRENT_FRAGS ) {
2641 i = newest;
2642 net80211_free_frags ( dev, i );
2643 }
2644
2645 dev->frags[i].in_use = 1;
2646 dev->frags[i].seqnr = IEEE80211_SEQNR ( hdr->seq );
2647 dev->frags[i].start_ticks = currticks();
2648 dev->frags[i].iob[0] = iob;
2649 return;
2650 } else {
2651 int i;
2652 for ( i = 0; i < NET80211_NR_CONCURRENT_FRAGS; i++ ) {
2653 if ( dev->frags[i].in_use && dev->frags[i].seqnr ==
2654 IEEE80211_SEQNR ( hdr->seq ) )
2655 break;
2656 }
2657 if ( i == NET80211_NR_CONCURRENT_FRAGS ) {
2658 /* Drop non-first not-in-cache fragments */
2659 DBGC ( dev, "802.11 %p dropped fragment fc=%04x "
2660 "seq=%04x\n", dev, hdr->fc, hdr->seq );
2661 free_iob ( iob );
2662 return;
2663 }
2664
2665 dev->frags[i].iob[fragnr] = iob;
2666
2667 if ( ! ( hdr->fc & IEEE80211_FC_MORE_FRAG ) ) {
2668 int j, size = 0;
2669 for ( j = 0; j < fragnr; j++ ) {
2670 size += iob_len ( dev->frags[i].iob[j] );
2671 if ( dev->frags[i].iob[j] == NULL )
2672 break;
2673 }
2674 if ( j == fragnr ) {
2675 /* We've got everything */
2676 struct io_buffer *niob =
2677 net80211_accum_frags ( dev, i, fragnr,
2678 size );
2679 net80211_free_frags ( dev, i );
2680 net80211_rx ( dev, niob, signal, 0 );
2681 } else {
2682 DBGC ( dev, "802.11 %p dropping fragmented "
2683 "packet due to out-of-order arrival, "
2684 "fc=%04x seq=%04x\n", dev, hdr->fc,
2685 hdr->seq );
2686 net80211_free_frags ( dev, i );
2687 }
2688 }
2689 }
2690 }
2691
2692 /**
2693 * Handle receipt of 802.11 frame
2694 *
2695 * @v dev 802.11 device
2696 * @v iob I/O buffer
2697 * @v signal Received signal strength
2698 * @v rate Bitrate at which frame was received, in 100 kbps units
2699 *
2700 * If the rate or signal is unknown, 0 should be passed.
2701 */
net80211_rx(struct net80211_device * dev,struct io_buffer * iob,int signal,u16 rate)2702 void net80211_rx ( struct net80211_device *dev, struct io_buffer *iob,
2703 int signal, u16 rate )
2704 {
2705 struct ieee80211_frame *hdr = iob->data;
2706 u16 type = hdr->fc & IEEE80211_FC_TYPE;
2707 if ( ( hdr->fc & IEEE80211_FC_VERSION ) != IEEE80211_THIS_VERSION )
2708 goto drop; /* drop invalid-version packets */
2709
2710 if ( type == IEEE80211_TYPE_CTRL )
2711 goto drop; /* we don't handle control packets,
2712 the hardware does */
2713
2714 if ( dev->last_rx_seq == hdr->seq )
2715 goto drop; /* avoid duplicate packet */
2716 dev->last_rx_seq = hdr->seq;
2717
2718 if ( dev->hw->flags & NET80211_HW_RX_HAS_FCS ) {
2719 /* discard the FCS */
2720 iob_unput ( iob, 4 );
2721 }
2722
2723 /* Only decrypt packets from our BSSID, to avoid spurious errors */
2724 if ( ( hdr->fc & IEEE80211_FC_PROTECTED ) &&
2725 ! memcmp ( hdr->addr2, dev->bssid, ETH_ALEN ) ) {
2726 /* Decrypt packet; record and drop if it fails */
2727 struct io_buffer *niob;
2728 struct net80211_crypto *crypto = dev->crypto;
2729
2730 if ( ! dev->crypto ) {
2731 DBGC ( dev, "802.11 %p cannot decrypt packet "
2732 "without a cryptosystem\n", dev );
2733 goto drop_crypt;
2734 }
2735
2736 if ( ( hdr->addr1[0] & 1 ) && dev->gcrypto ) {
2737 /* Use group decryption if needed */
2738 crypto = dev->gcrypto;
2739 }
2740
2741 niob = crypto->decrypt ( crypto, iob );
2742 if ( ! niob ) {
2743 DBGC ( dev, "802.11 %p decryption error\n", dev );
2744 goto drop_crypt;
2745 }
2746 free_iob ( iob );
2747 iob = niob;
2748 }
2749
2750 dev->last_signal = signal;
2751
2752 /* Fragments go into the frag cache or get dropped. */
2753 if ( IEEE80211_FRAG ( hdr->seq ) != 0
2754 || ( hdr->fc & IEEE80211_FC_MORE_FRAG ) ) {
2755 net80211_rx_frag ( dev, iob, signal );
2756 return;
2757 }
2758
2759 /* Management frames get handled, enqueued, or dropped. */
2760 if ( type == IEEE80211_TYPE_MGMT ) {
2761 net80211_handle_mgmt ( dev, iob, signal );
2762 return;
2763 }
2764
2765 /* Data frames get dropped or sent to the net_device. */
2766 if ( ( hdr->fc & IEEE80211_FC_SUBTYPE ) != IEEE80211_STYPE_DATA )
2767 goto drop; /* drop QoS, CFP, or null data packets */
2768
2769 /* Update rate-control algorithm */
2770 if ( dev->rctl )
2771 rc80211_update_rx ( dev, hdr->fc & IEEE80211_FC_RETRY, rate );
2772
2773 /* Pass packet onward */
2774 if ( dev->state & NET80211_ASSOCIATED ) {
2775 netdev_rx ( dev->netdev, iob );
2776 return;
2777 }
2778
2779 /* No association? Drop it. */
2780 goto drop;
2781
2782 drop_crypt:
2783 netdev_rx_err ( dev->netdev, NULL, EINVAL_CRYPTO_REQUEST );
2784 drop:
2785 DBGC2 ( dev, "802.11 %p dropped packet fc=%04x seq=%04x\n", dev,
2786 hdr->fc, hdr->seq );
2787 free_iob ( iob );
2788 return;
2789 }
2790
2791 /** Indicate an error in receiving a packet
2792 *
2793 * @v dev 802.11 device
2794 * @v iob I/O buffer with received packet, or NULL
2795 * @v rc Error code
2796 *
2797 * This logs the error with the wrapping net_device, and frees iob if
2798 * it is passed.
2799 */
net80211_rx_err(struct net80211_device * dev,struct io_buffer * iob,int rc)2800 void net80211_rx_err ( struct net80211_device *dev,
2801 struct io_buffer *iob, int rc )
2802 {
2803 netdev_rx_err ( dev->netdev, iob, rc );
2804 }
2805
2806 /** Indicate the completed transmission of a packet
2807 *
2808 * @v dev 802.11 device
2809 * @v iob I/O buffer of transmitted packet
2810 * @v retries Number of times this packet was retransmitted
2811 * @v rc Error code, or 0 for success
2812 *
2813 * This logs an error with the wrapping net_device if one occurred,
2814 * and removes and frees the I/O buffer from its TX queue. The
2815 * provided retry information is used to tune our transmission rate.
2816 *
2817 * If the packet did not need to be retransmitted because it was
2818 * properly ACKed the first time, @a retries should be 0.
2819 */
net80211_tx_complete(struct net80211_device * dev,struct io_buffer * iob,int retries,int rc)2820 void net80211_tx_complete ( struct net80211_device *dev,
2821 struct io_buffer *iob, int retries, int rc )
2822 {
2823 /* Update rate-control algorithm */
2824 if ( dev->rctl )
2825 rc80211_update_tx ( dev, retries, rc );
2826
2827 /* Pass completion onward */
2828 netdev_tx_complete_err ( dev->netdev, iob, rc );
2829 }
2830