1 /*
2 * The iPXE 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., 51 Franklin Street, Fifth Floor, Boston, MA
19 * 02110-1301, USA.
20 */
21
22 FILE_LICENCE ( GPL2_OR_LATER );
23
24 #include <string.h>
25 #include <byteswap.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28 #include <errno.h>
29 #include <ipxe/settings.h>
30 #include <ipxe/if_arp.h>
31 #include <ipxe/ethernet.h>
32 #include <ipxe/ieee80211.h>
33 #include <ipxe/netdevice.h>
34 #include <ipxe/net80211.h>
35 #include <ipxe/sec80211.h>
36 #include <ipxe/timer.h>
37 #include <ipxe/nap.h>
38 #include <ipxe/errortab.h>
39 #include <ipxe/net80211_err.h>
40
41 /** @file
42 *
43 * 802.11 device management
44 */
45
46 /** List of 802.11 devices */
47 static struct list_head net80211_devices = LIST_HEAD_INIT ( net80211_devices );
48
49 /** Set of device operations that does nothing */
50 static struct net80211_device_operations net80211_null_ops;
51
52 /** Information associated with a received management packet
53 *
54 * This is used to keep beacon signal strengths in a parallel queue to
55 * the beacons themselves.
56 */
57 struct net80211_rx_info {
58 int signal;
59 struct list_head list;
60 };
61
62 /** Context for a probe operation */
63 struct net80211_probe_ctx {
64 /** 802.11 device to probe on */
65 struct net80211_device *dev;
66
67 /** Value of keep_mgmt before probe was started */
68 int old_keep_mgmt;
69
70 /** If scanning actively, pointer to probe packet to send */
71 struct io_buffer *probe;
72
73 /** If non-"", the ESSID to limit ourselves to */
74 const char *essid;
75
76 /** Time probe was started */
77 u32 ticks_start;
78
79 /** Time last useful beacon was received */
80 u32 ticks_beacon;
81
82 /** Time channel was last changed */
83 u32 ticks_channel;
84
85 /** Time to stay on each channel */
86 u32 hop_time;
87
88 /** Channels to hop by when changing channel */
89 int hop_step;
90
91 /** List of best beacons for each network found so far */
92 struct list_head *beacons;
93 };
94
95 /** Context for the association task */
96 struct net80211_assoc_ctx {
97 /** Next authentication method to try using */
98 int method;
99
100 /** Time (in ticks) of the last sent association-related packet */
101 int last_packet;
102
103 /** Number of times we have tried sending it */
104 int times_tried;
105 };
106
107 /**
108 * Detect secure 802.11 network when security support is not available
109 *
110 * @return -ENOTSUP, always.
111 */
sec80211_detect(struct io_buffer * iob __unused,enum net80211_security_proto * secprot __unused,enum net80211_crypto_alg * crypt __unused)112 __weak int sec80211_detect ( struct io_buffer *iob __unused,
113 enum net80211_security_proto *secprot __unused,
114 enum net80211_crypto_alg *crypt __unused ) {
115 return -ENOTSUP;
116 }
117
118 /**
119 * @defgroup net80211_netdev Network device interface functions
120 * @{
121 */
122 static int net80211_netdev_open ( struct net_device *netdev );
123 static void net80211_netdev_close ( struct net_device *netdev );
124 static int net80211_netdev_transmit ( struct net_device *netdev,
125 struct io_buffer *iobuf );
126 static void net80211_netdev_poll ( struct net_device *netdev );
127 static void net80211_netdev_irq ( struct net_device *netdev, int enable );
128 /** @} */
129
130 /**
131 * @defgroup net80211_linklayer 802.11 link-layer protocol functions
132 * @{
133 */
134 static int net80211_ll_push ( struct net_device *netdev,
135 struct io_buffer *iobuf, const void *ll_dest,
136 const void *ll_source, uint16_t net_proto );
137 static int net80211_ll_pull ( struct net_device *netdev,
138 struct io_buffer *iobuf, const void **ll_dest,
139 const void **ll_source, uint16_t * net_proto,
140 unsigned int *flags );
141 /** @} */
142
143 /**
144 * @defgroup net80211_help 802.11 helper functions
145 * @{
146 */
147 static void net80211_add_channels ( struct net80211_device *dev, int start,
148 int len, int txpower );
149 static void net80211_filter_hw_channels ( struct net80211_device *dev );
150 static void net80211_set_rtscts_rate ( struct net80211_device *dev );
151 static int net80211_process_capab ( struct net80211_device *dev,
152 u16 capab );
153 static int net80211_process_ie ( struct net80211_device *dev,
154 union ieee80211_ie *ie, void *ie_end );
155 static union ieee80211_ie *
156 net80211_marshal_request_info ( struct net80211_device *dev,
157 union ieee80211_ie *ie );
158 /** @} */
159
160 /**
161 * @defgroup net80211_assoc_ll 802.11 association handling functions
162 * @{
163 */
164 static void net80211_step_associate ( struct net80211_device *dev );
165 static void net80211_handle_auth ( struct net80211_device *dev,
166 struct io_buffer *iob );
167 static void net80211_handle_assoc_reply ( struct net80211_device *dev,
168 struct io_buffer *iob );
169 static int net80211_send_disassoc ( struct net80211_device *dev, int reason,
170 int deauth );
171 static void net80211_handle_mgmt ( struct net80211_device *dev,
172 struct io_buffer *iob, int signal );
173 /** @} */
174
175 /**
176 * @defgroup net80211_frag 802.11 fragment handling functions
177 * @{
178 */
179 static void net80211_free_frags ( struct net80211_device *dev, int fcid );
180 static struct io_buffer *net80211_accum_frags ( struct net80211_device *dev,
181 int fcid, int nfrags, int size );
182 static void net80211_rx_frag ( struct net80211_device *dev,
183 struct io_buffer *iob, int signal );
184 /** @} */
185
186 /**
187 * @defgroup net80211_settings 802.11 settings handlers
188 * @{
189 */
190 static int net80211_check_settings_update ( void );
191
192 /** 802.11 settings applicator
193 *
194 * When the SSID is changed, this will cause any open devices to
195 * re-associate; when the encryption key is changed, we similarly
196 * update their state.
197 */
198 struct settings_applicator net80211_applicator __settings_applicator = {
199 .apply = net80211_check_settings_update,
200 };
201
202 /** The network name to associate with
203 *
204 * If this is blank, we scan for all networks and use the one with the
205 * greatest signal strength.
206 */
207 const struct setting net80211_ssid_setting __setting ( SETTING_NETDEV_EXTRA,
208 ssid ) = {
209 .name = "ssid",
210 .description = "Wireless SSID",
211 .type = &setting_type_string,
212 };
213
214 /** Whether to use active scanning
215 *
216 * In order to associate with a hidden SSID, it's necessary to use an
217 * active scan (send probe packets). If this setting is nonzero, an
218 * active scan on the 2.4GHz band will be used to associate.
219 */
220 const struct setting net80211_active_setting __setting ( SETTING_NETDEV_EXTRA,
221 active-scan ) = {
222 .name = "active-scan",
223 .description = "Actively scan for wireless networks",
224 .type = &setting_type_int8,
225 };
226
227 /** The cryptographic key to use
228 *
229 * For hex WEP keys, as is common, this must be entered using the
230 * normal iPXE method for entering hex settings; an ASCII string of
231 * hex characters will not behave as expected.
232 */
233 const struct setting net80211_key_setting __setting ( SETTING_NETDEV_EXTRA,
234 key ) = {
235 .name = "key",
236 .description = "Wireless encryption key",
237 .type = &setting_type_string,
238 };
239
240 /** @} */
241
242
243 /* ---------- net_device wrapper ---------- */
244
245 /**
246 * Open 802.11 device and start association
247 *
248 * @v netdev Wrapping network device
249 * @ret rc Return status code
250 *
251 * This sets up a default conservative set of channels for probing,
252 * and starts the auto-association task unless the @c
253 * NET80211_NO_ASSOC flag is set in the wrapped 802.11 device's @c
254 * state field.
255 */
net80211_netdev_open(struct net_device * netdev)256 static int net80211_netdev_open ( struct net_device *netdev )
257 {
258 struct net80211_device *dev = netdev->priv;
259 int rc = 0;
260
261 if ( dev->op == &net80211_null_ops )
262 return -EFAULT;
263
264 if ( dev->op->open )
265 rc = dev->op->open ( dev );
266
267 if ( rc < 0 )
268 return rc;
269
270 if ( ! ( dev->state & NET80211_NO_ASSOC ) )
271 net80211_autoassociate ( dev );
272
273 return 0;
274 }
275
276 /**
277 * Close 802.11 device
278 *
279 * @v netdev Wrapping network device.
280 *
281 * If the association task is running, this will stop it.
282 */
net80211_netdev_close(struct net_device * netdev)283 static void net80211_netdev_close ( struct net_device *netdev )
284 {
285 struct net80211_device *dev = netdev->priv;
286
287 if ( dev->state & NET80211_WORKING )
288 process_del ( &dev->proc_assoc );
289
290 /* Send disassociation frame to AP, to be polite */
291 if ( dev->state & NET80211_ASSOCIATED )
292 net80211_send_disassoc ( dev, IEEE80211_REASON_LEAVING, 0 );
293
294 if ( dev->handshaker && dev->handshaker->stop &&
295 dev->handshaker->started )
296 dev->handshaker->stop ( dev );
297
298 free ( dev->crypto );
299 free ( dev->handshaker );
300 dev->crypto = NULL;
301 dev->handshaker = NULL;
302
303 netdev_link_down ( netdev );
304 dev->state = 0;
305
306 if ( dev->op->close )
307 dev->op->close ( dev );
308 }
309
310 /**
311 * Transmit packet on 802.11 device
312 *
313 * @v netdev Wrapping network device
314 * @v iobuf I/O buffer
315 * @ret rc Return status code
316 *
317 * If encryption is enabled for the currently associated network, the
318 * packet will be encrypted prior to transmission.
319 */
net80211_netdev_transmit(struct net_device * netdev,struct io_buffer * iobuf)320 static int net80211_netdev_transmit ( struct net_device *netdev,
321 struct io_buffer *iobuf )
322 {
323 struct net80211_device *dev = netdev->priv;
324 struct ieee80211_frame *hdr = iobuf->data;
325 int rc = -ENOSYS;
326
327 if ( dev->crypto && ! ( hdr->fc & IEEE80211_FC_PROTECTED ) &&
328 ( ( hdr->fc & IEEE80211_FC_TYPE ) == IEEE80211_TYPE_DATA ) ) {
329 struct io_buffer *niob = dev->crypto->encrypt ( dev->crypto,
330 iobuf );
331 if ( ! niob )
332 return -ENOMEM; /* only reason encryption could fail */
333
334 /* Free the non-encrypted iob */
335 netdev_tx_complete ( netdev, iobuf );
336
337 /* Transmit the encrypted iob; the Protected flag is
338 set, so we won't recurse into here again */
339 netdev_tx ( netdev, niob );
340
341 /* Don't transmit the freed packet */
342 return 0;
343 }
344
345 if ( dev->op->transmit )
346 rc = dev->op->transmit ( dev, iobuf );
347
348 return rc;
349 }
350
351 /**
352 * Poll 802.11 device for received packets and completed transmissions
353 *
354 * @v netdev Wrapping network device
355 */
net80211_netdev_poll(struct net_device * netdev)356 static void net80211_netdev_poll ( struct net_device *netdev )
357 {
358 struct net80211_device *dev = netdev->priv;
359
360 if ( dev->op->poll )
361 dev->op->poll ( dev );
362 }
363
364 /**
365 * Enable or disable interrupts for 802.11 device
366 *
367 * @v netdev Wrapping network device
368 * @v enable Whether to enable interrupts
369 */
net80211_netdev_irq(struct net_device * netdev,int enable)370 static void net80211_netdev_irq ( struct net_device *netdev, int enable )
371 {
372 struct net80211_device *dev = netdev->priv;
373
374 if ( dev->op->irq )
375 dev->op->irq ( dev, enable );
376 }
377
378 /** Network device operations for a wrapped 802.11 device */
379 static struct net_device_operations net80211_netdev_ops = {
380 .open = net80211_netdev_open,
381 .close = net80211_netdev_close,
382 .transmit = net80211_netdev_transmit,
383 .poll = net80211_netdev_poll,
384 .irq = net80211_netdev_irq,
385 };
386
387
388 /* ---------- 802.11 link-layer protocol ---------- */
389
390 /**
391 * Determine whether a transmission rate uses ERP/OFDM
392 *
393 * @v rate Rate in 100 kbps units
394 * @ret is_erp TRUE if the rate is an ERP/OFDM rate
395 *
396 * 802.11b supports rates of 1.0, 2.0, 5.5, and 11.0 Mbps; any other
397 * rate than these on the 2.4GHz spectrum is an ERP (802.11g) rate.
398 */
net80211_rate_is_erp(u16 rate)399 static inline int net80211_rate_is_erp ( u16 rate )
400 {
401 if ( rate == 10 || rate == 20 || rate == 55 || rate == 110 )
402 return 0;
403 return 1;
404 }
405
406
407 /**
408 * Calculate one frame's contribution to 802.11 duration field
409 *
410 * @v dev 802.11 device
411 * @v bytes Amount of data to calculate duration for
412 * @ret dur Duration field in microseconds
413 *
414 * To avoid multiple stations attempting to transmit at once, 802.11
415 * provides that every packet shall include a duration field
416 * specifying a length of time for which the wireless medium will be
417 * reserved after it is transmitted. The duration is measured in
418 * microseconds and is calculated with respect to the current
419 * physical-layer parameters of the 802.11 device.
420 *
421 * For an unfragmented data or management frame, or the last fragment
422 * of a fragmented frame, the duration captures only the 10 data bytes
423 * of one ACK; call once with bytes = 10.
424 *
425 * For a fragment of a data or management rame that will be followed
426 * by more fragments, the duration captures an ACK, the following
427 * fragment, and its ACK; add the results of three calls, two with
428 * bytes = 10 and one with bytes set to the next fragment's size.
429 *
430 * For an RTS control frame, the duration captures the responding CTS,
431 * the frame being sent, and its ACK; add the results of three calls,
432 * two with bytes = 10 and one with bytes set to the next frame's size
433 * (assuming unfragmented).
434 *
435 * For a CTS-to-self control frame, the duration captures the frame
436 * being protected and its ACK; add the results of two calls, one with
437 * bytes = 10 and one with bytes set to the next frame's size.
438 *
439 * No other frame types are currently supported by iPXE.
440 */
net80211_duration(struct net80211_device * dev,int bytes,u16 rate)441 u16 net80211_duration ( struct net80211_device *dev, int bytes, u16 rate )
442 {
443 struct net80211_channel *chan = &dev->channels[dev->channel];
444 u32 kbps = rate * 100;
445
446 if ( chan->band == NET80211_BAND_5GHZ || net80211_rate_is_erp ( rate ) ) {
447 /* OFDM encoding (802.11a/g) */
448 int bits_per_symbol = ( kbps * 4 ) / 1000; /* 4us/symbol */
449 int bits = 22 + ( bytes << 3 ); /* 22-bit PLCP */
450 int symbols = ( bits + bits_per_symbol - 1 ) / bits_per_symbol;
451
452 return 16 + 20 + ( symbols * 4 ); /* 16us SIFS, 20us preamble */
453 } else {
454 /* CCK encoding (802.11b) */
455 int phy_time = 144 + 48; /* preamble + PLCP */
456 int bits = bytes << 3;
457 int data_time = ( bits * 1000 + kbps - 1 ) / kbps;
458
459 if ( dev->phy_flags & NET80211_PHY_USE_SHORT_PREAMBLE )
460 phy_time >>= 1;
461
462 return 10 + phy_time + data_time; /* 10us SIFS */
463 }
464 }
465
466 /**
467 * Add 802.11 link-layer header
468 *
469 * @v netdev Wrapping network device
470 * @v iobuf I/O buffer
471 * @v ll_dest Link-layer destination address
472 * @v ll_source Link-layer source address
473 * @v net_proto Network-layer protocol, in network byte order
474 * @ret rc Return status code
475 *
476 * This adds both the 802.11 frame header and the 802.2 LLC/SNAP
477 * header used on data packets.
478 *
479 * We also check here for state of the link that would make it invalid
480 * to send a data packet; every data packet must pass through here,
481 * and no non-data packet (e.g. management frame) should.
482 */
net80211_ll_push(struct net_device * netdev,struct io_buffer * iobuf,const void * ll_dest,const void * ll_source,uint16_t net_proto)483 static int net80211_ll_push ( struct net_device *netdev,
484 struct io_buffer *iobuf, const void *ll_dest,
485 const void *ll_source, uint16_t net_proto )
486 {
487 struct net80211_device *dev = netdev->priv;
488 struct ieee80211_frame *hdr = iob_push ( iobuf,
489 IEEE80211_LLC_HEADER_LEN +
490 IEEE80211_TYP_FRAME_HEADER_LEN );
491 struct ieee80211_llc_snap_header *lhdr =
492 ( void * ) hdr + IEEE80211_TYP_FRAME_HEADER_LEN;
493
494 /* We can't send data packets if we're not associated. */
495 if ( ! ( dev->state & NET80211_ASSOCIATED ) ) {
496 if ( dev->assoc_rc )
497 return dev->assoc_rc;
498 return -ENETUNREACH;
499 }
500
501 hdr->fc = IEEE80211_THIS_VERSION | IEEE80211_TYPE_DATA |
502 IEEE80211_STYPE_DATA | IEEE80211_FC_TODS;
503
504 /* We don't send fragmented frames, so duration is the time
505 for an SIFS + 10-byte ACK. */
506 hdr->duration = net80211_duration ( dev, 10, dev->rates[dev->rate] );
507
508 memcpy ( hdr->addr1, dev->bssid, ETH_ALEN );
509 memcpy ( hdr->addr2, ll_source, ETH_ALEN );
510 memcpy ( hdr->addr3, ll_dest, ETH_ALEN );
511
512 hdr->seq = IEEE80211_MAKESEQ ( ++dev->last_tx_seqnr, 0 );
513
514 lhdr->dsap = IEEE80211_LLC_DSAP;
515 lhdr->ssap = IEEE80211_LLC_SSAP;
516 lhdr->ctrl = IEEE80211_LLC_CTRL;
517 memset ( lhdr->oui, 0x00, 3 );
518 lhdr->ethertype = net_proto;
519
520 return 0;
521 }
522
523 /**
524 * Remove 802.11 link-layer header
525 *
526 * @v netdev Wrapping network device
527 * @v iobuf I/O buffer
528 * @ret ll_dest Link-layer destination address
529 * @ret ll_source Link-layer source
530 * @ret net_proto Network-layer protocol, in network byte order
531 * @ret flags Packet flags
532 * @ret rc Return status code
533 *
534 * This expects and removes both the 802.11 frame header and the 802.2
535 * LLC/SNAP header that are used on data packets.
536 */
net80211_ll_pull(struct net_device * netdev __unused,struct io_buffer * iobuf,const void ** ll_dest,const void ** ll_source,uint16_t * net_proto,unsigned int * flags)537 static int net80211_ll_pull ( struct net_device *netdev __unused,
538 struct io_buffer *iobuf,
539 const void **ll_dest, const void **ll_source,
540 uint16_t * net_proto, unsigned int *flags )
541 {
542 struct ieee80211_frame *hdr = iobuf->data;
543 struct ieee80211_llc_snap_header *lhdr =
544 ( void * ) hdr + IEEE80211_TYP_FRAME_HEADER_LEN;
545
546 /* Bunch of sanity checks */
547 if ( iob_len ( iobuf ) < IEEE80211_TYP_FRAME_HEADER_LEN +
548 IEEE80211_LLC_HEADER_LEN ) {
549 DBGC ( netdev->priv, "802.11 %p packet too short (%zd bytes)\n",
550 netdev->priv, iob_len ( iobuf ) );
551 return -EINVAL_PKT_TOO_SHORT;
552 }
553
554 if ( ( hdr->fc & IEEE80211_FC_VERSION ) != IEEE80211_THIS_VERSION ) {
555 DBGC ( netdev->priv, "802.11 %p packet invalid version %04x\n",
556 netdev->priv, hdr->fc & IEEE80211_FC_VERSION );
557 return -EINVAL_PKT_VERSION;
558 }
559
560 if ( ( hdr->fc & IEEE80211_FC_TYPE ) != IEEE80211_TYPE_DATA ||
561 ( hdr->fc & IEEE80211_FC_SUBTYPE ) != IEEE80211_STYPE_DATA ) {
562 DBGC ( netdev->priv, "802.11 %p packet not data/data (fc=%04x)\n",
563 netdev->priv, hdr->fc );
564 return -EINVAL_PKT_NOT_DATA;
565 }
566
567 if ( ( hdr->fc & ( IEEE80211_FC_TODS | IEEE80211_FC_FROMDS ) ) !=
568 IEEE80211_FC_FROMDS ) {
569 DBGC ( netdev->priv, "802.11 %p packet not from DS (fc=%04x)\n",
570 netdev->priv, hdr->fc );
571 return -EINVAL_PKT_NOT_FROMDS;
572 }
573
574 if ( lhdr->dsap != IEEE80211_LLC_DSAP || lhdr->ssap != IEEE80211_LLC_SSAP ||
575 lhdr->ctrl != IEEE80211_LLC_CTRL || lhdr->oui[0] || lhdr->oui[1] ||
576 lhdr->oui[2] ) {
577 DBGC ( netdev->priv, "802.11 %p LLC header is not plain EtherType "
578 "encapsulator: %02x->%02x [%02x] %02x:%02x:%02x %04x\n",
579 netdev->priv, lhdr->dsap, lhdr->ssap, lhdr->ctrl,
580 lhdr->oui[0], lhdr->oui[1], lhdr->oui[2], lhdr->ethertype );
581 return -EINVAL_PKT_LLC_HEADER;
582 }
583
584 iob_pull ( iobuf, sizeof ( *hdr ) + sizeof ( *lhdr ) );
585
586 *ll_dest = hdr->addr1;
587 *ll_source = hdr->addr3;
588 *net_proto = lhdr->ethertype;
589 *flags = ( ( is_multicast_ether_addr ( hdr->addr1 ) ?
590 LL_MULTICAST : 0 ) |
591 ( is_broadcast_ether_addr ( hdr->addr1 ) ?
592 LL_BROADCAST : 0 ) );
593 return 0;
594 }
595
596 /** 802.11 link-layer protocol */
597 static struct ll_protocol net80211_ll_protocol __ll_protocol = {
598 .name = "802.11",
599 .push = net80211_ll_push,
600 .pull = net80211_ll_pull,
601 .init_addr = eth_init_addr,
602 .ntoa = eth_ntoa,
603 .mc_hash = eth_mc_hash,
604 .eth_addr = eth_eth_addr,
605 .eui64 = eth_eui64,
606 .ll_proto = htons ( ARPHRD_ETHER ), /* "encapsulated Ethernet" */
607 .hw_addr_len = ETH_ALEN,
608 .ll_addr_len = ETH_ALEN,
609 .ll_header_len = IEEE80211_TYP_FRAME_HEADER_LEN +
610 IEEE80211_LLC_HEADER_LEN,
611 };
612
613
614 /* ---------- 802.11 network management API ---------- */
615
616 /**
617 * Get 802.11 device from wrapping network device
618 *
619 * @v netdev Wrapping network device
620 * @ret dev 802.11 device wrapped by network device, or NULL
621 *
622 * Returns NULL if the network device does not wrap an 802.11 device.
623 */
net80211_get(struct net_device * netdev)624 struct net80211_device * net80211_get ( struct net_device *netdev )
625 {
626 struct net80211_device *dev;
627
628 list_for_each_entry ( dev, &net80211_devices, list ) {
629 if ( netdev->priv == dev )
630 return netdev->priv;
631 }
632
633 return NULL;
634 }
635
636 /**
637 * Set state of 802.11 device keeping management frames
638 *
639 * @v dev 802.11 device
640 * @v enable Whether to keep management frames
641 * @ret oldenab Whether management frames were enabled before this call
642 *
643 * If enable is TRUE, beacon, probe, and action frames will be kept
644 * and may be retrieved by calling net80211_mgmt_dequeue().
645 */
net80211_keep_mgmt(struct net80211_device * dev,int enable)646 int net80211_keep_mgmt ( struct net80211_device *dev, int enable )
647 {
648 int oldenab = dev->keep_mgmt;
649
650 dev->keep_mgmt = enable;
651 return oldenab;
652 }
653
654 /**
655 * Get 802.11 management frame
656 *
657 * @v dev 802.11 device
658 * @ret signal Signal strength of returned management frame
659 * @ret iob I/O buffer, or NULL if no management frame is queued
660 *
661 * Frames will only be returned by this function if
662 * net80211_keep_mgmt() has been previously called with enable set to
663 * TRUE.
664 *
665 * The calling function takes ownership of the returned I/O buffer.
666 */
net80211_mgmt_dequeue(struct net80211_device * dev,int * signal)667 struct io_buffer * net80211_mgmt_dequeue ( struct net80211_device *dev,
668 int *signal )
669 {
670 struct io_buffer *iobuf;
671 struct net80211_rx_info *rxi;
672
673 list_for_each_entry ( rxi, &dev->mgmt_info_queue, list ) {
674 list_del ( &rxi->list );
675 if ( signal )
676 *signal = rxi->signal;
677 free ( rxi );
678
679 assert ( ! list_empty ( &dev->mgmt_queue ) );
680 iobuf = list_first_entry ( &dev->mgmt_queue, struct io_buffer,
681 list );
682 list_del ( &iobuf->list );
683 return iobuf;
684 }
685
686 return NULL;
687 }
688
689 /**
690 * Transmit 802.11 management frame
691 *
692 * @v dev 802.11 device
693 * @v fc Frame Control flags for management frame
694 * @v dest Destination access point
695 * @v iob I/O buffer
696 * @ret rc Return status code
697 *
698 * The @a fc argument must contain at least an IEEE 802.11 management
699 * subtype number (e.g. IEEE80211_STYPE_PROBE_REQ). If it contains
700 * IEEE80211_FC_PROTECTED, the frame will be encrypted prior to
701 * transmission.
702 *
703 * It is required that @a iob have at least 24 bytes of headroom
704 * reserved before its data start.
705 */
net80211_tx_mgmt(struct net80211_device * dev,u16 fc,u8 dest[6],struct io_buffer * iob)706 int net80211_tx_mgmt ( struct net80211_device *dev, u16 fc, u8 dest[6],
707 struct io_buffer *iob )
708 {
709 struct ieee80211_frame *hdr = iob_push ( iob,
710 IEEE80211_TYP_FRAME_HEADER_LEN );
711
712 hdr->fc = IEEE80211_THIS_VERSION | IEEE80211_TYPE_MGMT |
713 ( fc & ~IEEE80211_FC_PROTECTED );
714 hdr->duration = net80211_duration ( dev, 10, dev->rates[dev->rate] );
715 hdr->seq = IEEE80211_MAKESEQ ( ++dev->last_tx_seqnr, 0 );
716
717 memcpy ( hdr->addr1, dest, ETH_ALEN ); /* DA = RA */
718 memcpy ( hdr->addr2, dev->netdev->ll_addr, ETH_ALEN ); /* SA = TA */
719 memcpy ( hdr->addr3, dest, ETH_ALEN ); /* BSSID */
720
721 if ( fc & IEEE80211_FC_PROTECTED ) {
722 if ( ! dev->crypto )
723 return -EINVAL_CRYPTO_REQUEST;
724
725 struct io_buffer *eiob = dev->crypto->encrypt ( dev->crypto,
726 iob );
727 free_iob ( iob );
728 iob = eiob;
729 }
730
731 return netdev_tx ( dev->netdev, iob );
732 }
733
734
735 /* ---------- Driver API ---------- */
736
737 /** 802.11 association process descriptor */
738 static struct process_descriptor net80211_process_desc =
739 PROC_DESC ( struct net80211_device, proc_assoc,
740 net80211_step_associate );
741
742 /**
743 * Allocate 802.11 device
744 *
745 * @v priv_size Size of driver-private allocation area
746 * @ret dev Newly allocated 802.11 device
747 *
748 * This function allocates a net_device with space in its private area
749 * for both the net80211_device it will wrap and the driver-private
750 * data space requested. It initializes the link-layer-specific parts
751 * of the net_device, and links the net80211_device to the net_device
752 * appropriately.
753 */
net80211_alloc(size_t priv_size)754 struct net80211_device * net80211_alloc ( size_t priv_size )
755 {
756 struct net80211_device *dev;
757 struct net_device *netdev =
758 alloc_netdev ( sizeof ( *dev ) + priv_size );
759
760 if ( ! netdev )
761 return NULL;
762
763 netdev->ll_protocol = &net80211_ll_protocol;
764 netdev->ll_broadcast = eth_broadcast;
765 netdev->max_pkt_len = IEEE80211_MAX_DATA_LEN;
766 netdev_init ( netdev, &net80211_netdev_ops );
767
768 dev = netdev->priv;
769 dev->netdev = netdev;
770 dev->priv = ( u8 * ) dev + sizeof ( *dev );
771 dev->op = &net80211_null_ops;
772
773 process_init_stopped ( &dev->proc_assoc, &net80211_process_desc,
774 &netdev->refcnt );
775 INIT_LIST_HEAD ( &dev->mgmt_queue );
776 INIT_LIST_HEAD ( &dev->mgmt_info_queue );
777
778 return dev;
779 }
780
781 /**
782 * Register 802.11 device with network stack
783 *
784 * @v dev 802.11 device
785 * @v ops 802.11 device operations
786 * @v hw 802.11 hardware information
787 *
788 * This also registers the wrapping net_device with the higher network
789 * layers.
790 */
net80211_register(struct net80211_device * dev,struct net80211_device_operations * ops,struct net80211_hw_info * hw)791 int net80211_register ( struct net80211_device *dev,
792 struct net80211_device_operations *ops,
793 struct net80211_hw_info *hw )
794 {
795 dev->op = ops;
796 dev->hw = malloc ( sizeof ( *hw ) );
797 if ( ! dev->hw )
798 return -ENOMEM;
799
800 memcpy ( dev->hw, hw, sizeof ( *hw ) );
801 memcpy ( dev->netdev->hw_addr, hw->hwaddr, ETH_ALEN );
802
803 /* Set some sensible channel defaults for driver's open() function */
804 memcpy ( dev->channels, dev->hw->channels,
805 NET80211_MAX_CHANNELS * sizeof ( dev->channels[0] ) );
806 dev->channel = 0;
807
808 /* Mark device as not supporting interrupts, if applicable */
809 if ( ! ops->irq )
810 dev->netdev->state |= NETDEV_IRQ_UNSUPPORTED;
811
812 list_add_tail ( &dev->list, &net80211_devices );
813 return register_netdev ( dev->netdev );
814 }
815
816 /**
817 * Unregister 802.11 device from network stack
818 *
819 * @v dev 802.11 device
820 *
821 * After this call, the device operations are cleared so that they
822 * will not be called.
823 */
net80211_unregister(struct net80211_device * dev)824 void net80211_unregister ( struct net80211_device *dev )
825 {
826 unregister_netdev ( dev->netdev );
827 list_del ( &dev->list );
828 dev->op = &net80211_null_ops;
829 }
830
831 /**
832 * Free 802.11 device
833 *
834 * @v dev 802.11 device
835 *
836 * The device should be unregistered before this function is called.
837 */
net80211_free(struct net80211_device * dev)838 void net80211_free ( struct net80211_device *dev )
839 {
840 free ( dev->hw );
841 rc80211_free ( dev->rctl );
842 netdev_nullify ( dev->netdev );
843 netdev_put ( dev->netdev );
844 }
845
846
847 /* ---------- 802.11 network management workhorse code ---------- */
848
849 /**
850 * Set state of 802.11 device
851 *
852 * @v dev 802.11 device
853 * @v clear Bitmask of flags to clear
854 * @v set Bitmask of flags to set
855 * @v status Status or reason code for most recent operation
856 *
857 * If @a status represents a reason code, it should be OR'ed with
858 * NET80211_IS_REASON.
859 *
860 * Clearing authentication also clears association; clearing
861 * association also clears security handshaking state. Clearing
862 * association removes the link-up flag from the wrapping net_device,
863 * but setting it does not automatically set the flag; that is left to
864 * the judgment of higher-level code.
865 */
net80211_set_state(struct net80211_device * dev,short clear,short set,u16 status)866 static inline void net80211_set_state ( struct net80211_device *dev,
867 short clear, short set,
868 u16 status )
869 {
870 /* The conditions in this function are deliberately formulated
871 to be decidable at compile-time in most cases. Since clear
872 and set are generally passed as constants, the body of this
873 function can be reduced down to a few statements by the
874 compiler. */
875
876 const int statmsk = NET80211_STATUS_MASK | NET80211_IS_REASON;
877
878 if ( clear & NET80211_PROBED )
879 clear |= NET80211_AUTHENTICATED;
880
881 if ( clear & NET80211_AUTHENTICATED )
882 clear |= NET80211_ASSOCIATED;
883
884 if ( clear & NET80211_ASSOCIATED )
885 clear |= NET80211_CRYPTO_SYNCED;
886
887 dev->state = ( dev->state & ~clear ) | set;
888 dev->state = ( dev->state & ~statmsk ) | ( status & statmsk );
889
890 if ( clear & NET80211_ASSOCIATED )
891 netdev_link_down ( dev->netdev );
892
893 if ( ( clear | set ) & NET80211_ASSOCIATED )
894 dev->op->config ( dev, NET80211_CFG_ASSOC );
895
896 if ( status != 0 ) {
897 if ( status & NET80211_IS_REASON )
898 dev->assoc_rc = -E80211_REASON ( status );
899 else
900 dev->assoc_rc = -E80211_STATUS ( status );
901 netdev_link_err ( dev->netdev, dev->assoc_rc );
902 }
903 }
904
905 /**
906 * Add channels to 802.11 device
907 *
908 * @v dev 802.11 device
909 * @v start First channel number to add
910 * @v len Number of channels to add
911 * @v txpower TX power (dBm) to allow on added channels
912 *
913 * To replace the current list of channels instead of adding to it,
914 * set the nr_channels field of the 802.11 device to 0 before calling
915 * this function.
916 */
net80211_add_channels(struct net80211_device * dev,int start,int len,int txpower)917 static void net80211_add_channels ( struct net80211_device *dev, int start,
918 int len, int txpower )
919 {
920 int i, chan = start;
921
922 for ( i = dev->nr_channels; len-- && i < NET80211_MAX_CHANNELS; i++ ) {
923 dev->channels[i].channel_nr = chan;
924 dev->channels[i].maxpower = txpower;
925 dev->channels[i].hw_value = 0;
926
927 if ( chan >= 1 && chan <= 14 ) {
928 dev->channels[i].band = NET80211_BAND_2GHZ;
929 if ( chan == 14 )
930 dev->channels[i].center_freq = 2484;
931 else
932 dev->channels[i].center_freq = 2407 + 5 * chan;
933 chan++;
934 } else {
935 dev->channels[i].band = NET80211_BAND_5GHZ;
936 dev->channels[i].center_freq = 5000 + 5 * chan;
937 chan += 4;
938 }
939 }
940
941 dev->nr_channels = i;
942 }
943
944 /**
945 * Filter 802.11 device channels for hardware capabilities
946 *
947 * @v dev 802.11 device
948 *
949 * Hardware may support fewer channels than regulatory restrictions
950 * allow; this function filters out channels in dev->channels that are
951 * not supported by the hardware list in dev->hwinfo. It also copies
952 * over the net80211_channel::hw_value and limits maximum TX power
953 * appropriately.
954 *
955 * Channels are matched based on center frequency, ignoring band and
956 * channel number.
957 *
958 * If the driver specifies no supported channels, the effect will be
959 * as though all were supported.
960 */
net80211_filter_hw_channels(struct net80211_device * dev)961 static void net80211_filter_hw_channels ( struct net80211_device *dev )
962 {
963 int delta = 0, i = 0;
964 int old_freq = dev->channels[dev->channel].center_freq;
965 struct net80211_channel *chan, *hwchan;
966
967 if ( ! dev->hw->nr_channels )
968 return;
969
970 dev->channel = 0;
971 for ( chan = dev->channels; chan < dev->channels + dev->nr_channels;
972 chan++, i++ ) {
973 int ok = 0;
974 for ( hwchan = dev->hw->channels;
975 hwchan < dev->hw->channels + dev->hw->nr_channels;
976 hwchan++ ) {
977 if ( hwchan->center_freq == chan->center_freq ) {
978 ok = 1;
979 break;
980 }
981 }
982
983 if ( ! ok )
984 delta++;
985 else {
986 chan->hw_value = hwchan->hw_value;
987 if ( hwchan->maxpower != 0 &&
988 chan->maxpower > hwchan->maxpower )
989 chan->maxpower = hwchan->maxpower;
990 if ( old_freq == chan->center_freq )
991 dev->channel = i - delta;
992 if ( delta )
993 chan[-delta] = *chan;
994 }
995 }
996
997 dev->nr_channels -= delta;
998
999 if ( dev->channels[dev->channel].center_freq != old_freq )
1000 dev->op->config ( dev, NET80211_CFG_CHANNEL );
1001 }
1002
1003 /**
1004 * Update 802.11 device state to reflect received capabilities field
1005 *
1006 * @v dev 802.11 device
1007 * @v capab Capabilities field in beacon, probe, or association frame
1008 * @ret rc Return status code
1009 */
net80211_process_capab(struct net80211_device * dev,u16 capab)1010 static int net80211_process_capab ( struct net80211_device *dev,
1011 u16 capab )
1012 {
1013 u16 old_phy = dev->phy_flags;
1014
1015 if ( ( capab & ( IEEE80211_CAPAB_MANAGED | IEEE80211_CAPAB_ADHOC ) ) !=
1016 IEEE80211_CAPAB_MANAGED ) {
1017 DBGC ( dev, "802.11 %p cannot handle IBSS network\n", dev );
1018 return -ENOSYS;
1019 }
1020
1021 dev->phy_flags &= ~( NET80211_PHY_USE_SHORT_PREAMBLE |
1022 NET80211_PHY_USE_SHORT_SLOT );
1023
1024 if ( capab & IEEE80211_CAPAB_SHORT_PMBL )
1025 dev->phy_flags |= NET80211_PHY_USE_SHORT_PREAMBLE;
1026
1027 if ( capab & IEEE80211_CAPAB_SHORT_SLOT )
1028 dev->phy_flags |= NET80211_PHY_USE_SHORT_SLOT;
1029
1030 if ( old_phy != dev->phy_flags )
1031 dev->op->config ( dev, NET80211_CFG_PHY_PARAMS );
1032
1033 return 0;
1034 }
1035
1036 /**
1037 * Update 802.11 device state to reflect received information elements
1038 *
1039 * @v dev 802.11 device
1040 * @v ie Pointer to first information element
1041 * @v ie_end Pointer to tail of packet I/O buffer
1042 * @ret rc Return status code
1043 */
net80211_process_ie(struct net80211_device * dev,union ieee80211_ie * ie,void * ie_end)1044 static int net80211_process_ie ( struct net80211_device *dev,
1045 union ieee80211_ie *ie, void *ie_end )
1046 {
1047 u16 old_rate = dev->rates[dev->rate];
1048 u16 old_phy = dev->phy_flags;
1049 int have_rates = 0, i;
1050 int ds_channel = 0;
1051 int changed = 0;
1052 int band = dev->channels[dev->channel].band;
1053
1054 if ( ! ieee80211_ie_bound ( ie, ie_end ) )
1055 return 0;
1056
1057 for ( ; ie; ie = ieee80211_next_ie ( ie, ie_end ) ) {
1058 switch ( ie->id ) {
1059 case IEEE80211_IE_SSID:
1060 if ( ie->len <= 32 ) {
1061 memcpy ( dev->essid, ie->ssid, ie->len );
1062 dev->essid[ie->len] = 0;
1063 }
1064 break;
1065
1066 case IEEE80211_IE_RATES:
1067 case IEEE80211_IE_EXT_RATES:
1068 if ( ! have_rates ) {
1069 dev->nr_rates = 0;
1070 dev->basic_rates = 0;
1071 have_rates = 1;
1072 }
1073 for ( i = 0; i < ie->len &&
1074 dev->nr_rates < NET80211_MAX_RATES; i++ ) {
1075 u8 rid = ie->rates[i];
1076 u16 rate = ( rid & 0x7f ) * 5;
1077
1078 if ( rid & 0x80 )
1079 dev->basic_rates |=
1080 ( 1 << dev->nr_rates );
1081
1082 dev->rates[dev->nr_rates++] = rate;
1083 }
1084
1085 break;
1086
1087 case IEEE80211_IE_DS_PARAM:
1088 if ( dev->channel < dev->nr_channels && ds_channel ==
1089 dev->channels[dev->channel].channel_nr )
1090 break;
1091 ds_channel = ie->ds_param.current_channel;
1092 net80211_change_channel ( dev, ds_channel );
1093 break;
1094
1095 case IEEE80211_IE_COUNTRY:
1096 dev->nr_channels = 0;
1097
1098 DBGC ( dev, "802.11 %p setting country regulations "
1099 "for %c%c\n", dev, ie->country.name[0],
1100 ie->country.name[1] );
1101 for ( i = 0; i < ( ie->len - 3 ) / 3; i++ ) {
1102 union ieee80211_ie_country_triplet *t =
1103 &ie->country.triplet[i];
1104 if ( t->first > 200 ) {
1105 DBGC ( dev, "802.11 %p ignoring regulatory "
1106 "extension information\n", dev );
1107 } else {
1108 net80211_add_channels ( dev,
1109 t->band.first_channel,
1110 t->band.nr_channels,
1111 t->band.max_txpower );
1112 }
1113 }
1114 net80211_filter_hw_channels ( dev );
1115 break;
1116
1117 case IEEE80211_IE_ERP_INFO:
1118 dev->phy_flags &= ~( NET80211_PHY_USE_PROTECTION |
1119 NET80211_PHY_USE_SHORT_PREAMBLE );
1120 if ( ie->erp_info & IEEE80211_ERP_USE_PROTECTION )
1121 dev->phy_flags |= NET80211_PHY_USE_PROTECTION;
1122 if ( ! ( ie->erp_info & IEEE80211_ERP_BARKER_LONG ) )
1123 dev->phy_flags |= NET80211_PHY_USE_SHORT_PREAMBLE;
1124 break;
1125 }
1126 }
1127
1128 if ( have_rates ) {
1129 /* Allow only those rates that are also supported by
1130 the hardware. */
1131 int delta = 0, j;
1132
1133 dev->rate = 0;
1134 for ( i = 0; i < dev->nr_rates; i++ ) {
1135 int ok = 0;
1136 for ( j = 0; j < dev->hw->nr_rates[band]; j++ ) {
1137 if ( dev->hw->rates[band][j] == dev->rates[i] ){
1138 ok = 1;
1139 break;
1140 }
1141 }
1142
1143 if ( ! ok )
1144 delta++;
1145 else {
1146 dev->rates[i - delta] = dev->rates[i];
1147 if ( old_rate == dev->rates[i] )
1148 dev->rate = i - delta;
1149 }
1150 }
1151
1152 dev->nr_rates -= delta;
1153
1154 /* Sort available rates - sorted subclumps tend to already
1155 exist, so insertion sort works well. */
1156 for ( i = 1; i < dev->nr_rates; i++ ) {
1157 u16 rate = dev->rates[i];
1158 u32 tmp, br, mask;
1159
1160 for ( j = i - 1; j >= 0 && dev->rates[j] >= rate; j-- )
1161 dev->rates[j + 1] = dev->rates[j];
1162 dev->rates[j + 1] = rate;
1163
1164 /* Adjust basic_rates to match by rotating the
1165 bits from bit j+1 to bit i left one position. */
1166 mask = ( ( 1 << i ) - 1 ) & ~( ( 1 << ( j + 1 ) ) - 1 );
1167 br = dev->basic_rates;
1168 tmp = br & ( 1 << i );
1169 br = ( br & ~( mask | tmp ) ) | ( ( br & mask ) << 1 );
1170 br |= ( tmp >> ( i - j - 1 ) );
1171 dev->basic_rates = br;
1172 }
1173
1174 net80211_set_rtscts_rate ( dev );
1175
1176 if ( dev->rates[dev->rate] != old_rate )
1177 changed |= NET80211_CFG_RATE;
1178 }
1179
1180 if ( dev->hw->flags & NET80211_HW_NO_SHORT_PREAMBLE )
1181 dev->phy_flags &= ~NET80211_PHY_USE_SHORT_PREAMBLE;
1182 if ( dev->hw->flags & NET80211_HW_NO_SHORT_SLOT )
1183 dev->phy_flags &= ~NET80211_PHY_USE_SHORT_SLOT;
1184
1185 if ( old_phy != dev->phy_flags )
1186 changed |= NET80211_CFG_PHY_PARAMS;
1187
1188 if ( changed )
1189 dev->op->config ( dev, changed );
1190
1191 return 0;
1192 }
1193
1194 /**
1195 * Create information elements for outgoing probe or association packet
1196 *
1197 * @v dev 802.11 device
1198 * @v ie Pointer to start of information element area
1199 * @ret next_ie Pointer to first byte after added information elements
1200 */
1201 static union ieee80211_ie *
net80211_marshal_request_info(struct net80211_device * dev,union ieee80211_ie * ie)1202 net80211_marshal_request_info ( struct net80211_device *dev,
1203 union ieee80211_ie *ie )
1204 {
1205 int i;
1206
1207 ie->id = IEEE80211_IE_SSID;
1208 ie->len = strlen ( dev->essid );
1209 memcpy ( ie->ssid, dev->essid, ie->len );
1210
1211 ie = ieee80211_next_ie ( ie, NULL );
1212
1213 ie->id = IEEE80211_IE_RATES;
1214 ie->len = dev->nr_rates;
1215 if ( ie->len > 8 )
1216 ie->len = 8;
1217
1218 for ( i = 0; i < ie->len; i++ ) {
1219 ie->rates[i] = dev->rates[i] / 5;
1220 if ( dev->basic_rates & ( 1 << i ) )
1221 ie->rates[i] |= 0x80;
1222 }
1223
1224 ie = ieee80211_next_ie ( ie, NULL );
1225
1226 if ( dev->rsn_ie && dev->rsn_ie->id == IEEE80211_IE_RSN ) {
1227 memcpy ( ie, dev->rsn_ie, dev->rsn_ie->len + 2 );
1228 ie = ieee80211_next_ie ( ie, NULL );
1229 }
1230
1231 if ( dev->nr_rates > 8 ) {
1232 /* 802.11 requires we use an Extended Basic Rates IE
1233 for the rates beyond the eighth. */
1234
1235 ie->id = IEEE80211_IE_EXT_RATES;
1236 ie->len = dev->nr_rates - 8;
1237
1238 for ( ; i < dev->nr_rates; i++ ) {
1239 ie->rates[i - 8] = dev->rates[i] / 5;
1240 if ( dev->basic_rates & ( 1 << i ) )
1241 ie->rates[i - 8] |= 0x80;
1242 }
1243
1244 ie = ieee80211_next_ie ( ie, NULL );
1245 }
1246
1247 if ( dev->rsn_ie && dev->rsn_ie->id == IEEE80211_IE_VENDOR ) {
1248 memcpy ( ie, dev->rsn_ie, dev->rsn_ie->len + 2 );
1249 ie = ieee80211_next_ie ( ie, NULL );
1250 }
1251
1252 return ie;
1253 }
1254
1255 /** Seconds to wait after finding a network, to possibly find better APs for it
1256 *
1257 * This is used when a specific SSID to scan for is specified.
1258 */
1259 #define NET80211_PROBE_GATHER 1
1260
1261 /** Seconds to wait after finding a network, to possibly find other networks
1262 *
1263 * This is used when an empty SSID is specified, to scan for all
1264 * networks.
1265 */
1266 #define NET80211_PROBE_GATHER_ALL 2
1267
1268 /** Seconds to allow a probe to take if no network has been found */
1269 #define NET80211_PROBE_TIMEOUT 6
1270
1271 /**
1272 * Begin probe of 802.11 networks
1273 *
1274 * @v dev 802.11 device
1275 * @v essid SSID to probe for, or "" to accept any (may not be NULL)
1276 * @v active Whether to use active scanning
1277 * @ret ctx Probe context
1278 *
1279 * Active scanning may only be used on channels 1-11 in the 2.4GHz
1280 * band, due to iPXE's lack of a complete regulatory database. If
1281 * active scanning is used, probe packets will be sent on each
1282 * channel; this can allow association with hidden-SSID networks if
1283 * the SSID is properly specified.
1284 *
1285 * A @c NULL return indicates an out-of-memory condition.
1286 *
1287 * The returned context must be periodically passed to
1288 * net80211_probe_step() until that function returns zero.
1289 */
net80211_probe_start(struct net80211_device * dev,const char * essid,int active)1290 struct net80211_probe_ctx * net80211_probe_start ( struct net80211_device *dev,
1291 const char *essid,
1292 int active )
1293 {
1294 struct net80211_probe_ctx *ctx = zalloc ( sizeof ( *ctx ) );
1295
1296 if ( ! ctx )
1297 return NULL;
1298
1299 assert ( netdev_is_open ( dev->netdev ) );
1300
1301 ctx->dev = dev;
1302 ctx->old_keep_mgmt = net80211_keep_mgmt ( dev, 1 );
1303 ctx->essid = essid;
1304 if ( dev->essid != ctx->essid )
1305 strcpy ( dev->essid, ctx->essid );
1306
1307 if ( active ) {
1308 struct ieee80211_probe_req *probe_req;
1309 union ieee80211_ie *ie;
1310
1311 ctx->probe = alloc_iob ( 128 );
1312 iob_reserve ( ctx->probe, IEEE80211_TYP_FRAME_HEADER_LEN );
1313 probe_req = ctx->probe->data;
1314
1315 ie = net80211_marshal_request_info ( dev,
1316 probe_req->info_element );
1317
1318 iob_put ( ctx->probe, ( void * ) ie - ctx->probe->data );
1319 }
1320
1321 ctx->ticks_start = currticks();
1322 ctx->ticks_beacon = 0;
1323 ctx->ticks_channel = currticks();
1324 ctx->hop_time = TICKS_PER_SEC / ( active ? 2 : 6 );
1325
1326 /*
1327 * Channels on 2.4GHz overlap, and the most commonly used
1328 * are 1, 6, and 11. We'll get a result faster if we check
1329 * every 5 channels, but in order to hit all of them the
1330 * number of channels must be relatively prime to 5. If it's
1331 * not, tweak the hop.
1332 */
1333 ctx->hop_step = 5;
1334 while ( dev->nr_channels % ctx->hop_step == 0 && ctx->hop_step > 1 )
1335 ctx->hop_step--;
1336
1337 ctx->beacons = malloc ( sizeof ( *ctx->beacons ) );
1338 INIT_LIST_HEAD ( ctx->beacons );
1339
1340 dev->channel = 0;
1341 dev->op->config ( dev, NET80211_CFG_CHANNEL );
1342
1343 return ctx;
1344 }
1345
1346 /**
1347 * Continue probe of 802.11 networks
1348 *
1349 * @v ctx Probe context returned by net80211_probe_start()
1350 * @ret rc Probe status
1351 *
1352 * The return code will be 0 if the probe is still going on (and this
1353 * function should be called again), a positive number if the probe
1354 * completed successfully, or a negative error code if the probe
1355 * failed for that reason.
1356 *
1357 * Whether the probe succeeded or failed, you must call
1358 * net80211_probe_finish_all() or net80211_probe_finish_best()
1359 * (depending on whether you want information on all networks or just
1360 * the best-signal one) in order to release the probe context. A
1361 * failed probe may still have acquired some valid data.
1362 */
net80211_probe_step(struct net80211_probe_ctx * ctx)1363 int net80211_probe_step ( struct net80211_probe_ctx *ctx )
1364 {
1365 struct net80211_device *dev = ctx->dev;
1366 u32 start_timeout = NET80211_PROBE_TIMEOUT * TICKS_PER_SEC;
1367 u32 gather_timeout = TICKS_PER_SEC;
1368 u32 now = currticks();
1369 struct io_buffer *iob;
1370 int signal;
1371 int rc;
1372 char ssid[IEEE80211_MAX_SSID_LEN + 1];
1373
1374 gather_timeout *= ( ctx->essid[0] ? NET80211_PROBE_GATHER :
1375 NET80211_PROBE_GATHER_ALL );
1376
1377 /* Time out if necessary */
1378 if ( now >= ctx->ticks_start + start_timeout )
1379 return list_empty ( ctx->beacons ) ? -ETIMEDOUT : +1;
1380
1381 if ( ctx->ticks_beacon > 0 && now >= ctx->ticks_start + gather_timeout )
1382 return +1;
1383
1384 /* Change channels if necessary */
1385 if ( now >= ctx->ticks_channel + ctx->hop_time ) {
1386 dev->channel = ( dev->channel + ctx->hop_step )
1387 % dev->nr_channels;
1388 dev->op->config ( dev, NET80211_CFG_CHANNEL );
1389 udelay ( dev->hw->channel_change_time );
1390
1391 ctx->ticks_channel = now;
1392
1393 if ( ctx->probe ) {
1394 struct io_buffer *siob = ctx->probe; /* to send */
1395
1396 /* make a copy for future use */
1397 iob = alloc_iob ( siob->tail - siob->head );
1398 iob_reserve ( iob, iob_headroom ( siob ) );
1399 memcpy ( iob_put ( iob, iob_len ( siob ) ),
1400 siob->data, iob_len ( siob ) );
1401
1402 ctx->probe = iob;
1403 rc = net80211_tx_mgmt ( dev, IEEE80211_STYPE_PROBE_REQ,
1404 eth_broadcast,
1405 iob_disown ( siob ) );
1406 if ( rc ) {
1407 DBGC ( dev, "802.11 %p send probe failed: "
1408 "%s\n", dev, strerror ( rc ) );
1409 return rc;
1410 }
1411 }
1412 }
1413
1414 /* Check for new management packets */
1415 while ( ( iob = net80211_mgmt_dequeue ( dev, &signal ) ) != NULL ) {
1416 struct ieee80211_frame *hdr;
1417 struct ieee80211_beacon *beacon;
1418 union ieee80211_ie *ie;
1419 struct net80211_wlan *wlan;
1420 u16 type;
1421
1422 hdr = iob->data;
1423 type = hdr->fc & IEEE80211_FC_SUBTYPE;
1424 beacon = ( struct ieee80211_beacon * ) hdr->data;
1425
1426 if ( type != IEEE80211_STYPE_BEACON &&
1427 type != IEEE80211_STYPE_PROBE_RESP ) {
1428 DBGC2 ( dev, "802.11 %p probe: non-beacon\n", dev );
1429 goto drop;
1430 }
1431
1432 if ( ( void * ) beacon->info_element >= iob->tail ) {
1433 DBGC ( dev, "802.11 %p probe: beacon with no IEs\n",
1434 dev );
1435 goto drop;
1436 }
1437
1438 ie = beacon->info_element;
1439
1440 if ( ! ieee80211_ie_bound ( ie, iob->tail ) )
1441 ie = NULL;
1442
1443 while ( ie && ie->id != IEEE80211_IE_SSID )
1444 ie = ieee80211_next_ie ( ie, iob->tail );
1445
1446 if ( ! ie ) {
1447 DBGC ( dev, "802.11 %p probe: beacon with no SSID\n",
1448 dev );
1449 goto drop;
1450 }
1451
1452 memcpy ( ssid, ie->ssid, ie->len );
1453 ssid[ie->len] = 0;
1454
1455 if ( ctx->essid[0] && strcmp ( ctx->essid, ssid ) != 0 ) {
1456 DBGC2 ( dev, "802.11 %p probe: beacon with wrong SSID "
1457 "(%s)\n", dev, ssid );
1458 goto drop;
1459 }
1460
1461 /* See if we've got an entry for this network */
1462 list_for_each_entry ( wlan, ctx->beacons, list ) {
1463 if ( strcmp ( wlan->essid, ssid ) != 0 )
1464 continue;
1465
1466 if ( signal < wlan->signal ) {
1467 DBGC2 ( dev, "802.11 %p probe: beacon for %s "
1468 "(%s) with weaker signal %d\n", dev,
1469 ssid, eth_ntoa ( hdr->addr3 ), signal );
1470 goto drop;
1471 }
1472
1473 goto fill;
1474 }
1475
1476 /* No entry yet - make one */
1477 wlan = zalloc ( sizeof ( *wlan ) );
1478 strcpy ( wlan->essid, ssid );
1479 list_add_tail ( &wlan->list, ctx->beacons );
1480
1481 /* Whether we're using an old entry or a new one, fill
1482 it with new data. */
1483 fill:
1484 memcpy ( wlan->bssid, hdr->addr3, ETH_ALEN );
1485 wlan->signal = signal;
1486 wlan->channel = dev->channels[dev->channel].channel_nr;
1487
1488 /* Copy this I/O buffer into a new wlan->beacon; the
1489 * iob we've got probably came from the device driver
1490 * and may have the full 2.4k allocation, which we
1491 * don't want to keep around wasting memory.
1492 */
1493 free_iob ( wlan->beacon );
1494 wlan->beacon = alloc_iob ( iob_len ( iob ) );
1495 memcpy ( iob_put ( wlan->beacon, iob_len ( iob ) ),
1496 iob->data, iob_len ( iob ) );
1497
1498 if ( ( rc = sec80211_detect ( wlan->beacon, &wlan->handshaking,
1499 &wlan->crypto ) ) == -ENOTSUP ) {
1500 struct ieee80211_beacon *beacon =
1501 ( struct ieee80211_beacon * ) hdr->data;
1502
1503 if ( beacon->capability & IEEE80211_CAPAB_PRIVACY ) {
1504 DBG ( "802.11 %p probe: secured network %s but "
1505 "encryption support not compiled in\n",
1506 dev, wlan->essid );
1507 wlan->handshaking = NET80211_SECPROT_UNKNOWN;
1508 wlan->crypto = NET80211_CRYPT_UNKNOWN;
1509 } else {
1510 wlan->handshaking = NET80211_SECPROT_NONE;
1511 wlan->crypto = NET80211_CRYPT_NONE;
1512 }
1513 } else if ( rc != 0 ) {
1514 DBGC ( dev, "802.11 %p probe warning: network "
1515 "%s with unidentifiable security "
1516 "settings: %s\n", dev, wlan->essid,
1517 strerror ( rc ) );
1518 }
1519
1520 ctx->ticks_beacon = now;
1521
1522 DBGC2 ( dev, "802.11 %p probe: good beacon for %s (%s)\n",
1523 dev, wlan->essid, eth_ntoa ( wlan->bssid ) );
1524
1525 drop:
1526 free_iob ( iob );
1527 }
1528
1529 return 0;
1530 }
1531
1532
1533 /**
1534 * Finish probe of 802.11 networks, returning best-signal network found
1535 *
1536 * @v ctx Probe context
1537 * @ret wlan Best-signal network found, or @c NULL if none were found
1538 *
1539 * If net80211_probe_start() was called with a particular SSID
1540 * parameter as filter, only a network with that SSID (matching
1541 * case-sensitively) can be returned from this function.
1542 */
1543 struct net80211_wlan *
net80211_probe_finish_best(struct net80211_probe_ctx * ctx)1544 net80211_probe_finish_best ( struct net80211_probe_ctx *ctx )
1545 {
1546 struct net80211_wlan *best = NULL, *wlan;
1547
1548 if ( ! ctx )
1549 return NULL;
1550
1551 list_for_each_entry ( wlan, ctx->beacons, list ) {
1552 if ( ! best || best->signal < wlan->signal )
1553 best = wlan;
1554 }
1555
1556 if ( best )
1557 list_del ( &best->list );
1558 else
1559 DBGC ( ctx->dev, "802.11 %p probe: found nothing for '%s'\n",
1560 ctx->dev, ctx->essid );
1561
1562 net80211_free_wlanlist ( ctx->beacons );
1563
1564 net80211_keep_mgmt ( ctx->dev, ctx->old_keep_mgmt );
1565
1566 if ( ctx->probe )
1567 free_iob ( ctx->probe );
1568
1569 free ( ctx );
1570
1571 return best;
1572 }
1573
1574
1575 /**
1576 * Finish probe of 802.11 networks, returning all networks found
1577 *
1578 * @v ctx Probe context
1579 * @ret list List of net80211_wlan detailing networks found
1580 *
1581 * If net80211_probe_start() was called with a particular SSID
1582 * parameter as filter, this will always return either an empty or a
1583 * one-element list.
1584 */
net80211_probe_finish_all(struct net80211_probe_ctx * ctx)1585 struct list_head *net80211_probe_finish_all ( struct net80211_probe_ctx *ctx )
1586 {
1587 struct list_head *beacons = ctx->beacons;
1588
1589 net80211_keep_mgmt ( ctx->dev, ctx->old_keep_mgmt );
1590
1591 if ( ctx->probe )
1592 free_iob ( ctx->probe );
1593
1594 free ( ctx );
1595
1596 return beacons;
1597 }
1598
1599
1600 /**
1601 * Free WLAN structure
1602 *
1603 * @v wlan WLAN structure to free
1604 */
net80211_free_wlan(struct net80211_wlan * wlan)1605 void net80211_free_wlan ( struct net80211_wlan *wlan )
1606 {
1607 if ( wlan ) {
1608 free_iob ( wlan->beacon );
1609 free ( wlan );
1610 }
1611 }
1612
1613
1614 /**
1615 * Free list of WLAN structures
1616 *
1617 * @v list List of WLAN structures to free
1618 */
net80211_free_wlanlist(struct list_head * list)1619 void net80211_free_wlanlist ( struct list_head *list )
1620 {
1621 struct net80211_wlan *wlan, *tmp;
1622
1623 if ( ! list )
1624 return;
1625
1626 list_for_each_entry_safe ( wlan, tmp, list, list ) {
1627 list_del ( &wlan->list );
1628 net80211_free_wlan ( wlan );
1629 }
1630
1631 free ( list );
1632 }
1633
1634
1635 /** Number of ticks to wait for replies to association management frames */
1636 #define ASSOC_TIMEOUT TICKS_PER_SEC
1637
1638 /** Number of times to try sending a particular association management frame */
1639 #define ASSOC_RETRIES 2
1640
1641 /**
1642 * Step 802.11 association process
1643 *
1644 * @v dev 802.11 device
1645 */
net80211_step_associate(struct net80211_device * dev)1646 static void net80211_step_associate ( struct net80211_device *dev )
1647 {
1648 int rc = 0;
1649 int status = dev->state & NET80211_STATUS_MASK;
1650
1651 /*
1652 * We use a sort of state machine implemented using bits in
1653 * the dev->state variable. At each call, we take the
1654 * logically first step that has not yet succeeded; either it
1655 * has not been tried yet, it's being retried, or it failed.
1656 * If it failed, we return an error indication; otherwise we
1657 * perform the step. If it succeeds, RX handling code will set
1658 * the appropriate status bit for us.
1659 *
1660 * Probe works a bit differently, since we have to step it
1661 * on every call instead of waiting for a packet to arrive
1662 * that will set the completion bit for us.
1663 */
1664
1665 /* If we're waiting for a reply, check for timeout condition */
1666 if ( dev->state & NET80211_WAITING ) {
1667 /* Sanity check */
1668 if ( ! dev->associating )
1669 return;
1670
1671 if ( currticks() - dev->ctx.assoc->last_packet > ASSOC_TIMEOUT ) {
1672 /* Timed out - fail if too many retries, or retry */
1673 dev->ctx.assoc->times_tried++;
1674 if ( ++dev->ctx.assoc->times_tried > ASSOC_RETRIES ) {
1675 rc = -ETIMEDOUT;
1676 goto fail;
1677 }
1678 } else {
1679 /* Didn't time out - let it keep going */
1680 return;
1681 }
1682 } else {
1683 if ( dev->state & NET80211_PROBED )
1684 dev->ctx.assoc->times_tried = 0;
1685 }
1686
1687 if ( ! ( dev->state & NET80211_PROBED ) ) {
1688 /* state: probe */
1689
1690 if ( ! dev->ctx.probe ) {
1691 /* start probe */
1692 int active = fetch_intz_setting ( NULL,
1693 &net80211_active_setting );
1694 int band = dev->hw->bands;
1695
1696 if ( active )
1697 band &= ~NET80211_BAND_BIT_5GHZ;
1698
1699 rc = net80211_prepare_probe ( dev, band, active );
1700 if ( rc )
1701 goto fail;
1702
1703 dev->ctx.probe = net80211_probe_start ( dev, dev->essid,
1704 active );
1705 if ( ! dev->ctx.probe ) {
1706 dev->assoc_rc = -ENOMEM;
1707 goto fail;
1708 }
1709 }
1710
1711 rc = net80211_probe_step ( dev->ctx.probe );
1712 if ( ! rc ) {
1713 return; /* still going */
1714 }
1715
1716 dev->associating = net80211_probe_finish_best ( dev->ctx.probe );
1717 dev->ctx.probe = NULL;
1718 if ( ! dev->associating ) {
1719 if ( rc > 0 ) /* "successful" probe found nothing */
1720 rc = -ETIMEDOUT;
1721 goto fail;
1722 }
1723
1724 /* If we probed using a broadcast SSID, record that
1725 fact for the settings applicator before we clobber
1726 it with the specific SSID we've chosen. */
1727 if ( ! dev->essid[0] )
1728 dev->state |= NET80211_AUTO_SSID;
1729
1730 DBGC ( dev, "802.11 %p found network %s (%s)\n", dev,
1731 dev->associating->essid,
1732 eth_ntoa ( dev->associating->bssid ) );
1733
1734 dev->ctx.assoc = zalloc ( sizeof ( *dev->ctx.assoc ) );
1735 if ( ! dev->ctx.assoc ) {
1736 rc = -ENOMEM;
1737 goto fail;
1738 }
1739
1740 dev->state |= NET80211_PROBED;
1741 dev->ctx.assoc->method = IEEE80211_AUTH_OPEN_SYSTEM;
1742
1743 return;
1744 }
1745
1746 /* Record time of sending the packet we're about to send, for timeout */
1747 dev->ctx.assoc->last_packet = currticks();
1748
1749 if ( ! ( dev->state & NET80211_AUTHENTICATED ) ) {
1750 /* state: prepare and authenticate */
1751
1752 if ( status != IEEE80211_STATUS_SUCCESS ) {
1753 /* we tried authenticating already, but failed */
1754 int method = dev->ctx.assoc->method;
1755
1756 if ( method == IEEE80211_AUTH_OPEN_SYSTEM &&
1757 ( status == IEEE80211_STATUS_AUTH_CHALL_INVALID ||
1758 status == IEEE80211_STATUS_AUTH_ALGO_UNSUPP ) ) {
1759 /* Maybe this network uses Shared Key? */
1760 dev->ctx.assoc->method =
1761 IEEE80211_AUTH_SHARED_KEY;
1762 } else {
1763 goto fail;
1764 }
1765 }
1766
1767 DBGC ( dev, "802.11 %p authenticating with method %d\n", dev,
1768 dev->ctx.assoc->method );
1769
1770 rc = net80211_prepare_assoc ( dev, dev->associating );
1771 if ( rc )
1772 goto fail;
1773
1774 rc = net80211_send_auth ( dev, dev->associating,
1775 dev->ctx.assoc->method );
1776 if ( rc )
1777 goto fail;
1778
1779 return;
1780 }
1781
1782 if ( ! ( dev->state & NET80211_ASSOCIATED ) ) {
1783 /* state: associate */
1784
1785 if ( status != IEEE80211_STATUS_SUCCESS )
1786 goto fail;
1787
1788 DBGC ( dev, "802.11 %p associating\n", dev );
1789
1790 if ( dev->handshaker && dev->handshaker->start &&
1791 ! dev->handshaker->started ) {
1792 rc = dev->handshaker->start ( dev );
1793 if ( rc < 0 )
1794 goto fail;
1795 dev->handshaker->started = 1;
1796 }
1797
1798 rc = net80211_send_assoc ( dev, dev->associating );
1799 if ( rc )
1800 goto fail;
1801
1802 return;
1803 }
1804
1805 if ( ! ( dev->state & NET80211_CRYPTO_SYNCED ) ) {
1806 /* state: crypto sync */
1807 DBGC ( dev, "802.11 %p security handshaking\n", dev );
1808
1809 if ( ! dev->handshaker || ! dev->handshaker->step ) {
1810 dev->state |= NET80211_CRYPTO_SYNCED;
1811 return;
1812 }
1813
1814 rc = dev->handshaker->step ( dev );
1815
1816 if ( rc < 0 ) {
1817 /* Only record the returned error if we're
1818 still marked as associated, because an
1819 asynchronous error will have already been
1820 reported to net80211_deauthenticate() and
1821 assoc_rc thereby set. */
1822 if ( dev->state & NET80211_ASSOCIATED )
1823 dev->assoc_rc = rc;
1824 rc = 0;
1825 goto fail;
1826 }
1827
1828 if ( rc > 0 ) {
1829 dev->assoc_rc = 0;
1830 dev->state |= NET80211_CRYPTO_SYNCED;
1831 }
1832 return;
1833 }
1834
1835 /* state: done! */
1836 netdev_link_up ( dev->netdev );
1837 dev->assoc_rc = 0;
1838 dev->state &= ~NET80211_WORKING;
1839
1840 free ( dev->ctx.assoc );
1841 dev->ctx.assoc = NULL;
1842
1843 net80211_free_wlan ( dev->associating );
1844 dev->associating = NULL;
1845
1846 dev->rctl = rc80211_init ( dev );
1847
1848 process_del ( &dev->proc_assoc );
1849
1850 DBGC ( dev, "802.11 %p associated with %s (%s)\n", dev,
1851 dev->essid, eth_ntoa ( dev->bssid ) );
1852
1853 return;
1854
1855 fail:
1856 dev->state &= ~( NET80211_WORKING | NET80211_WAITING );
1857 if ( rc )
1858 dev->assoc_rc = rc;
1859
1860 netdev_link_err ( dev->netdev, dev->assoc_rc );
1861
1862 /* We never reach here from the middle of a probe, so we don't
1863 need to worry about freeing dev->ctx.probe. */
1864
1865 if ( dev->state & NET80211_PROBED ) {
1866 free ( dev->ctx.assoc );
1867 dev->ctx.assoc = NULL;
1868 }
1869
1870 net80211_free_wlan ( dev->associating );
1871 dev->associating = NULL;
1872
1873 process_del ( &dev->proc_assoc );
1874
1875 DBGC ( dev, "802.11 %p association failed (state=%04x): "
1876 "%s\n", dev, dev->state, strerror ( dev->assoc_rc ) );
1877
1878 /* Try it again: */
1879 net80211_autoassociate ( dev );
1880 }
1881
1882 /**
1883 * Check for 802.11 SSID or key updates
1884 *
1885 * This acts as a settings applicator; if the user changes netX/ssid,
1886 * and netX is currently open, the association task will be invoked
1887 * again. If the user changes the encryption key, the current security
1888 * handshaker will be asked to update its state to match; if that is
1889 * impossible without reassociation, we reassociate.
1890 */
net80211_check_settings_update(void)1891 static int net80211_check_settings_update ( void )
1892 {
1893 struct net80211_device *dev;
1894 char ssid[IEEE80211_MAX_SSID_LEN + 1];
1895 int key_reassoc;
1896
1897 list_for_each_entry ( dev, &net80211_devices, list ) {
1898 if ( ! netdev_is_open ( dev->netdev ) )
1899 continue;
1900
1901 key_reassoc = 0;
1902 if ( dev->handshaker && dev->handshaker->change_key &&
1903 dev->handshaker->change_key ( dev ) < 0 )
1904 key_reassoc = 1;
1905
1906 fetch_string_setting ( netdev_settings ( dev->netdev ),
1907 &net80211_ssid_setting, ssid,
1908 IEEE80211_MAX_SSID_LEN + 1 );
1909
1910 if ( key_reassoc ||
1911 ( ! ( ! ssid[0] && ( dev->state & NET80211_AUTO_SSID ) ) &&
1912 strcmp ( ssid, dev->essid ) != 0 ) ) {
1913 DBGC ( dev, "802.11 %p updating association: "
1914 "%s -> %s\n", dev, dev->essid, ssid );
1915 net80211_autoassociate ( dev );
1916 }
1917 }
1918
1919 return 0;
1920 }
1921
1922 /**
1923 * Start 802.11 association process
1924 *
1925 * @v dev 802.11 device
1926 *
1927 * If the association process is running, it will be restarted.
1928 */
net80211_autoassociate(struct net80211_device * dev)1929 void net80211_autoassociate ( struct net80211_device *dev )
1930 {
1931 if ( ! ( dev->state & NET80211_WORKING ) ) {
1932 DBGC2 ( dev, "802.11 %p spawning association process\n", dev );
1933 process_add ( &dev->proc_assoc );
1934 } else {
1935 DBGC2 ( dev, "802.11 %p restarting association\n", dev );
1936 }
1937
1938 /* Clean up everything an earlier association process might
1939 have been in the middle of using */
1940 if ( dev->associating )
1941 net80211_free_wlan ( dev->associating );
1942
1943 if ( ! ( dev->state & NET80211_PROBED ) )
1944 net80211_free_wlan (
1945 net80211_probe_finish_best ( dev->ctx.probe ) );
1946 else
1947 free ( dev->ctx.assoc );
1948
1949 /* Reset to a clean state */
1950 fetch_string_setting ( netdev_settings ( dev->netdev ),
1951 &net80211_ssid_setting, dev->essid,
1952 IEEE80211_MAX_SSID_LEN + 1 );
1953 dev->ctx.probe = NULL;
1954 dev->associating = NULL;
1955 dev->assoc_rc = 0;
1956 net80211_set_state ( dev, NET80211_PROBED, NET80211_WORKING, 0 );
1957 }
1958
1959 /**
1960 * Pick TX rate for RTS/CTS packets based on data rate
1961 *
1962 * @v dev 802.11 device
1963 *
1964 * The RTS/CTS rate is the fastest TX rate marked as "basic" that is
1965 * not faster than the data rate.
1966 */
net80211_set_rtscts_rate(struct net80211_device * dev)1967 static void net80211_set_rtscts_rate ( struct net80211_device *dev )
1968 {
1969 u16 datarate = dev->rates[dev->rate];
1970 u16 rtsrate = 0;
1971 int rts_idx = -1;
1972 int i;
1973
1974 for ( i = 0; i < dev->nr_rates; i++ ) {
1975 u16 rate = dev->rates[i];
1976
1977 if ( ! ( dev->basic_rates & ( 1 << i ) ) || rate > datarate )
1978 continue;
1979
1980 if ( rate > rtsrate ) {
1981 rtsrate = rate;
1982 rts_idx = i;
1983 }
1984 }
1985
1986 /* If this is in initialization, we might not have any basic
1987 rates; just use the first data rate in that case. */
1988 if ( rts_idx < 0 )
1989 rts_idx = 0;
1990
1991 dev->rtscts_rate = rts_idx;
1992 }
1993
1994 /**
1995 * Set data transmission rate for 802.11 device
1996 *
1997 * @v dev 802.11 device
1998 * @v rate Rate to set, as index into @c dev->rates array
1999 */
net80211_set_rate_idx(struct net80211_device * dev,int rate)2000 void net80211_set_rate_idx ( struct net80211_device *dev, int rate )
2001 {
2002 assert ( netdev_is_open ( dev->netdev ) );
2003
2004 if ( rate >= 0 && rate < dev->nr_rates && rate != dev->rate ) {
2005 DBGC2 ( dev, "802.11 %p changing rate from %d->%d Mbps\n",
2006 dev, dev->rates[dev->rate] / 10,
2007 dev->rates[rate] / 10 );
2008
2009 dev->rate = rate;
2010 net80211_set_rtscts_rate ( dev );
2011 dev->op->config ( dev, NET80211_CFG_RATE );
2012 }
2013 }
2014
2015 /**
2016 * Configure 802.11 device to transmit on a certain channel
2017 *
2018 * @v dev 802.11 device
2019 * @v channel Channel number (1-11 for 2.4GHz) to transmit on
2020 */
net80211_change_channel(struct net80211_device * dev,int channel)2021 int net80211_change_channel ( struct net80211_device *dev, int channel )
2022 {
2023 int i, oldchan = dev->channel;
2024
2025 assert ( netdev_is_open ( dev->netdev ) );
2026
2027 for ( i = 0; i < dev->nr_channels; i++ ) {
2028 if ( dev->channels[i].channel_nr == channel ) {
2029 dev->channel = i;
2030 break;
2031 }
2032 }
2033
2034 if ( i == dev->nr_channels )
2035 return -ENOENT;
2036
2037 if ( i != oldchan )
2038 return dev->op->config ( dev, NET80211_CFG_CHANNEL );
2039
2040 return 0;
2041 }
2042
2043 /**
2044 * Prepare 802.11 device channel and rate set for scanning
2045 *
2046 * @v dev 802.11 device
2047 * @v band RF band(s) on which to prepare for scanning
2048 * @v active Whether the scanning will be active
2049 * @ret rc Return status code
2050 */
net80211_prepare_probe(struct net80211_device * dev,int band,int active)2051 int net80211_prepare_probe ( struct net80211_device *dev, int band,
2052 int active )
2053 {
2054 assert ( netdev_is_open ( dev->netdev ) );
2055
2056 if ( active && ( band & NET80211_BAND_BIT_5GHZ ) ) {
2057 DBGC ( dev, "802.11 %p cannot perform active scanning on "
2058 "5GHz band\n", dev );
2059 return -EINVAL_ACTIVE_SCAN;
2060 }
2061
2062 if ( band == 0 ) {
2063 /* This can happen for a 5GHz-only card with 5GHz
2064 scanning masked out by an active request. */
2065 DBGC ( dev, "802.11 %p asked to prepare for scanning nothing\n",
2066 dev );
2067 return -EINVAL_ACTIVE_SCAN;
2068 }
2069
2070 dev->nr_channels = 0;
2071
2072 if ( active )
2073 net80211_add_channels ( dev, 1, 11, NET80211_REG_TXPOWER );
2074 else {
2075 if ( band & NET80211_BAND_BIT_2GHZ )
2076 net80211_add_channels ( dev, 1, 14,
2077 NET80211_REG_TXPOWER );
2078 if ( band & NET80211_BAND_BIT_5GHZ )
2079 net80211_add_channels ( dev, 36, 8,
2080 NET80211_REG_TXPOWER );
2081 }
2082
2083 net80211_filter_hw_channels ( dev );
2084
2085 /* Use channel 1 for now */
2086 dev->channel = 0;
2087 dev->op->config ( dev, NET80211_CFG_CHANNEL );
2088
2089 /* Always do active probes at lowest (presumably first) speed */
2090 dev->rate = 0;
2091 dev->nr_rates = 1;
2092 dev->rates[0] = dev->hw->rates[dev->channels[0].band][0];
2093 dev->op->config ( dev, NET80211_CFG_RATE );
2094
2095 return 0;
2096 }
2097
2098 /**
2099 * Prepare 802.11 device channel and rate set for communication
2100 *
2101 * @v dev 802.11 device
2102 * @v wlan WLAN to prepare for communication with
2103 * @ret rc Return status code
2104 */
net80211_prepare_assoc(struct net80211_device * dev,struct net80211_wlan * wlan)2105 int net80211_prepare_assoc ( struct net80211_device *dev,
2106 struct net80211_wlan *wlan )
2107 {
2108 struct ieee80211_frame *hdr = wlan->beacon->data;
2109 struct ieee80211_beacon *beacon =
2110 ( struct ieee80211_beacon * ) hdr->data;
2111 struct net80211_handshaker *handshaker;
2112 int rc;
2113
2114 assert ( netdev_is_open ( dev->netdev ) );
2115
2116 net80211_set_state ( dev, NET80211_ASSOCIATED, 0, 0 );
2117 memcpy ( dev->bssid, wlan->bssid, ETH_ALEN );
2118 strcpy ( dev->essid, wlan->essid );
2119
2120 free ( dev->rsn_ie );
2121 dev->rsn_ie = NULL;
2122
2123 dev->last_beacon_timestamp = beacon->timestamp;
2124 dev->tx_beacon_interval = 1024 * beacon->beacon_interval;
2125
2126 /* Barring an IE that tells us the channel outright, assume
2127 the channel we heard this AP best on is the channel it's
2128 communicating on. */
2129 net80211_change_channel ( dev, wlan->channel );
2130
2131 rc = net80211_process_capab ( dev, beacon->capability );
2132 if ( rc )
2133 return rc;
2134
2135 rc = net80211_process_ie ( dev, beacon->info_element,
2136 wlan->beacon->tail );
2137 if ( rc )
2138 return rc;
2139
2140 /* Associate at the lowest rate so we know it'll get through */
2141 dev->rate = 0;
2142 dev->op->config ( dev, NET80211_CFG_RATE );
2143
2144 /* Free old handshaker and crypto, if they exist */
2145 if ( dev->handshaker && dev->handshaker->stop &&
2146 dev->handshaker->started )
2147 dev->handshaker->stop ( dev );
2148 free ( dev->handshaker );
2149 dev->handshaker = NULL;
2150 free ( dev->crypto );
2151 free ( dev->gcrypto );
2152 dev->crypto = dev->gcrypto = NULL;
2153
2154 /* Find new security handshaker to use */
2155 for_each_table_entry ( handshaker, NET80211_HANDSHAKERS ) {
2156 if ( handshaker->protocol == wlan->handshaking ) {
2157 dev->handshaker = zalloc ( sizeof ( *handshaker ) +
2158 handshaker->priv_len );
2159 if ( ! dev->handshaker )
2160 return -ENOMEM;
2161
2162 memcpy ( dev->handshaker, handshaker,
2163 sizeof ( *handshaker ) );
2164 dev->handshaker->priv = ( ( void * ) dev->handshaker +
2165 sizeof ( *handshaker ) );
2166 break;
2167 }
2168 }
2169
2170 if ( ( wlan->handshaking != NET80211_SECPROT_NONE ) &&
2171 ! dev->handshaker ) {
2172 DBGC ( dev, "802.11 %p no support for handshaking scheme %d\n",
2173 dev, wlan->handshaking );
2174 return -( ENOTSUP | ( wlan->handshaking << 8 ) );
2175 }
2176
2177 /* Initialize security handshaker */
2178 if ( dev->handshaker ) {
2179 rc = dev->handshaker->init ( dev );
2180 if ( rc < 0 )
2181 return rc;
2182 }
2183
2184 return 0;
2185 }
2186
2187 /**
2188 * Send 802.11 initial authentication frame
2189 *
2190 * @v dev 802.11 device
2191 * @v wlan WLAN to authenticate with
2192 * @v method Authentication method
2193 * @ret rc Return status code
2194 *
2195 * @a method may be 0 for Open System authentication or 1 for Shared
2196 * Key authentication. Open System provides no security in association
2197 * whatsoever, relying on encryption for confidentiality, but Shared
2198 * Key actively introduces security problems and is very rarely used.
2199 */
net80211_send_auth(struct net80211_device * dev,struct net80211_wlan * wlan,int method)2200 int net80211_send_auth ( struct net80211_device *dev,
2201 struct net80211_wlan *wlan, int method )
2202 {
2203 struct io_buffer *iob = alloc_iob ( 64 );
2204 struct ieee80211_auth *auth;
2205
2206 net80211_set_state ( dev, 0, NET80211_WAITING, 0 );
2207 iob_reserve ( iob, IEEE80211_TYP_FRAME_HEADER_LEN );
2208 auth = iob_put ( iob, sizeof ( *auth ) );
2209 auth->algorithm = method;
2210 auth->tx_seq = 1;
2211 auth->status = 0;
2212
2213 return net80211_tx_mgmt ( dev, IEEE80211_STYPE_AUTH, wlan->bssid, iob );
2214 }
2215
2216 /**
2217 * Handle receipt of 802.11 authentication frame
2218 *
2219 * @v dev 802.11 device
2220 * @v iob I/O buffer
2221 *
2222 * If the authentication method being used is Shared Key, and the
2223 * frame that was received included challenge text, the frame is
2224 * encrypted using the cryptosystem currently in effect and sent back
2225 * to the AP to complete the authentication.
2226 */
net80211_handle_auth(struct net80211_device * dev,struct io_buffer * iob)2227 static void net80211_handle_auth ( struct net80211_device *dev,
2228 struct io_buffer *iob )
2229 {
2230 struct ieee80211_frame *hdr = iob->data;
2231 struct ieee80211_auth *auth =
2232 ( struct ieee80211_auth * ) hdr->data;
2233
2234 if ( auth->tx_seq & 1 ) {
2235 DBGC ( dev, "802.11 %p authentication received improperly "
2236 "directed frame (seq. %d)\n", dev, auth->tx_seq );
2237 net80211_set_state ( dev, NET80211_WAITING, 0,
2238 IEEE80211_STATUS_FAILURE );
2239 return;
2240 }
2241
2242 if ( auth->status != IEEE80211_STATUS_SUCCESS ) {
2243 DBGC ( dev, "802.11 %p authentication failed: status %d\n",
2244 dev, auth->status );
2245 net80211_set_state ( dev, NET80211_WAITING, 0,
2246 auth->status );
2247 return;
2248 }
2249
2250 if ( auth->algorithm == IEEE80211_AUTH_SHARED_KEY && ! dev->crypto ) {
2251 DBGC ( dev, "802.11 %p can't perform shared-key authentication "
2252 "without a cryptosystem\n", dev );
2253 net80211_set_state ( dev, NET80211_WAITING, 0,
2254 IEEE80211_STATUS_FAILURE );
2255 return;
2256 }
2257
2258 if ( auth->algorithm == IEEE80211_AUTH_SHARED_KEY &&
2259 auth->tx_seq == 2 ) {
2260 /* Since the iob we got is going to be freed as soon
2261 as we return, we can do some in-place
2262 modification. */
2263 auth->tx_seq = 3;
2264 auth->status = 0;
2265
2266 memcpy ( hdr->addr2, hdr->addr1, ETH_ALEN );
2267 memcpy ( hdr->addr1, hdr->addr3, ETH_ALEN );
2268
2269 netdev_tx ( dev->netdev,
2270 dev->crypto->encrypt ( dev->crypto, iob ) );
2271 return;
2272 }
2273
2274 net80211_set_state ( dev, NET80211_WAITING, NET80211_AUTHENTICATED,
2275 IEEE80211_STATUS_SUCCESS );
2276
2277 return;
2278 }
2279
2280 /**
2281 * Send 802.11 association frame
2282 *
2283 * @v dev 802.11 device
2284 * @v wlan WLAN to associate with
2285 * @ret rc Return status code
2286 */
net80211_send_assoc(struct net80211_device * dev,struct net80211_wlan * wlan)2287 int net80211_send_assoc ( struct net80211_device *dev,
2288 struct net80211_wlan *wlan )
2289 {
2290 struct io_buffer *iob = alloc_iob ( 128 );
2291 struct ieee80211_assoc_req *assoc;
2292 union ieee80211_ie *ie;
2293
2294 net80211_set_state ( dev, 0, NET80211_WAITING, 0 );
2295
2296 iob_reserve ( iob, IEEE80211_TYP_FRAME_HEADER_LEN );
2297 assoc = iob->data;
2298
2299 assoc->capability = IEEE80211_CAPAB_MANAGED;
2300 if ( ! ( dev->hw->flags & NET80211_HW_NO_SHORT_PREAMBLE ) )
2301 assoc->capability |= IEEE80211_CAPAB_SHORT_PMBL;
2302 if ( ! ( dev->hw->flags & NET80211_HW_NO_SHORT_SLOT ) )
2303 assoc->capability |= IEEE80211_CAPAB_SHORT_SLOT;
2304 if ( wlan->crypto )
2305 assoc->capability |= IEEE80211_CAPAB_PRIVACY;
2306
2307 assoc->listen_interval = 1;
2308
2309 ie = net80211_marshal_request_info ( dev, assoc->info_element );
2310
2311 DBGP ( "802.11 %p about to send association request:\n", dev );
2312 DBGP_HD ( iob->data, ( void * ) ie - iob->data );
2313
2314 iob_put ( iob, ( void * ) ie - iob->data );
2315
2316 return net80211_tx_mgmt ( dev, IEEE80211_STYPE_ASSOC_REQ,
2317 wlan->bssid, iob );
2318 }
2319
2320 /**
2321 * Handle receipt of 802.11 association reply frame
2322 *
2323 * @v dev 802.11 device
2324 * @v iob I/O buffer
2325 */
net80211_handle_assoc_reply(struct net80211_device * dev,struct io_buffer * iob)2326 static void net80211_handle_assoc_reply ( struct net80211_device *dev,
2327 struct io_buffer *iob )
2328 {
2329 struct ieee80211_frame *hdr = iob->data;
2330 struct ieee80211_assoc_resp *assoc =
2331 ( struct ieee80211_assoc_resp * ) hdr->data;
2332
2333 net80211_process_capab ( dev, assoc->capability );
2334 net80211_process_ie ( dev, assoc->info_element, iob->tail );
2335
2336 if ( assoc->status != IEEE80211_STATUS_SUCCESS ) {
2337 DBGC ( dev, "802.11 %p association failed: status %d\n",
2338 dev, assoc->status );
2339 net80211_set_state ( dev, NET80211_WAITING, 0,
2340 assoc->status );
2341 return;
2342 }
2343
2344 /* ESSID was filled before the association request was sent */
2345 memcpy ( dev->bssid, hdr->addr3, ETH_ALEN );
2346 dev->aid = assoc->aid;
2347
2348 net80211_set_state ( dev, NET80211_WAITING, NET80211_ASSOCIATED,
2349 IEEE80211_STATUS_SUCCESS );
2350 }
2351
2352
2353 /**
2354 * Send 802.11 disassociation frame
2355 *
2356 * @v dev 802.11 device
2357 * @v reason Reason for disassociation
2358 * @v deauth If TRUE, send deauthentication instead of disassociation
2359 * @ret rc Return status code
2360 */
net80211_send_disassoc(struct net80211_device * dev,int reason,int deauth)2361 static int net80211_send_disassoc ( struct net80211_device *dev, int reason,
2362 int deauth )
2363 {
2364 struct io_buffer *iob = alloc_iob ( 64 );
2365 struct ieee80211_disassoc *disassoc;
2366
2367 if ( ! ( dev->state & NET80211_ASSOCIATED ) )
2368 return -EINVAL;
2369
2370 net80211_set_state ( dev, NET80211_ASSOCIATED, 0, 0 );
2371 iob_reserve ( iob, IEEE80211_TYP_FRAME_HEADER_LEN );
2372 disassoc = iob_put ( iob, sizeof ( *disassoc ) );
2373 disassoc->reason = reason;
2374
2375 return net80211_tx_mgmt ( dev, deauth ? IEEE80211_STYPE_DEAUTH :
2376 IEEE80211_STYPE_DISASSOC, dev->bssid, iob );
2377 }
2378
2379
2380 /**
2381 * Deauthenticate from current network and try again
2382 *
2383 * @v dev 802.11 device
2384 * @v rc Return status code indicating reason
2385 *
2386 * The deauthentication will be sent using an 802.11 "unspecified
2387 * reason", as is common, but @a rc will be set as a link-up
2388 * error to aid the user in debugging.
2389 */
net80211_deauthenticate(struct net80211_device * dev,int rc)2390 void net80211_deauthenticate ( struct net80211_device *dev, int rc )
2391 {
2392 net80211_send_disassoc ( dev, IEEE80211_REASON_UNSPECIFIED, 1 );
2393 dev->assoc_rc = rc;
2394 netdev_link_err ( dev->netdev, rc );
2395
2396 net80211_autoassociate ( dev );
2397 }
2398
2399
2400 /** Smoothing factor (1-7) for link quality calculation */
2401 #define LQ_SMOOTH 7
2402
2403 /**
2404 * Update link quality information based on received beacon
2405 *
2406 * @v dev 802.11 device
2407 * @v iob I/O buffer containing beacon
2408 * @ret rc Return status code
2409 */
net80211_update_link_quality(struct net80211_device * dev,struct io_buffer * iob)2410 static void net80211_update_link_quality ( struct net80211_device *dev,
2411 struct io_buffer *iob )
2412 {
2413 struct ieee80211_frame *hdr = iob->data;
2414 struct ieee80211_beacon *beacon;
2415 u32 dt, rxi;
2416
2417 if ( ! ( dev->state & NET80211_ASSOCIATED ) )
2418 return;
2419
2420 beacon = ( struct ieee80211_beacon * ) hdr->data;
2421 dt = ( u32 ) ( beacon->timestamp - dev->last_beacon_timestamp );
2422 rxi = dev->rx_beacon_interval;
2423
2424 rxi = ( LQ_SMOOTH * rxi ) + ( ( 8 - LQ_SMOOTH ) * dt );
2425 dev->rx_beacon_interval = rxi >> 3;
2426
2427 dev->last_beacon_timestamp = beacon->timestamp;
2428 }
2429
2430
2431 /**
2432 * Handle receipt of 802.11 management frame
2433 *
2434 * @v dev 802.11 device
2435 * @v iob I/O buffer
2436 * @v signal Signal strength of received frame
2437 */
net80211_handle_mgmt(struct net80211_device * dev,struct io_buffer * iob,int signal)2438 static void net80211_handle_mgmt ( struct net80211_device *dev,
2439 struct io_buffer *iob, int signal )
2440 {
2441 struct ieee80211_frame *hdr = iob->data;
2442 struct ieee80211_disassoc *disassoc;
2443 u16 stype = hdr->fc & IEEE80211_FC_SUBTYPE;
2444 int keep = 0;
2445 int is_deauth = ( stype == IEEE80211_STYPE_DEAUTH );
2446
2447 if ( ( hdr->fc & IEEE80211_FC_TYPE ) != IEEE80211_TYPE_MGMT ) {
2448 free_iob ( iob );
2449 return; /* only handle management frames */
2450 }
2451
2452 switch ( stype ) {
2453 /* We reconnect on deauthentication and disassociation. */
2454 case IEEE80211_STYPE_DEAUTH:
2455 case IEEE80211_STYPE_DISASSOC:
2456 disassoc = ( struct ieee80211_disassoc * ) hdr->data;
2457 net80211_set_state ( dev, is_deauth ? NET80211_AUTHENTICATED :
2458 NET80211_ASSOCIATED, 0,
2459 NET80211_IS_REASON | disassoc->reason );
2460 DBGC ( dev, "802.11 %p %s: reason %d\n",
2461 dev, is_deauth ? "deauthenticated" : "disassociated",
2462 disassoc->reason );
2463
2464 /* Try to reassociate, in case it's transient. */
2465 net80211_autoassociate ( dev );
2466
2467 break;
2468
2469 /* We handle authentication and association. */
2470 case IEEE80211_STYPE_AUTH:
2471 if ( ! ( dev->state & NET80211_AUTHENTICATED ) )
2472 net80211_handle_auth ( dev, iob );
2473 break;
2474
2475 case IEEE80211_STYPE_ASSOC_RESP:
2476 case IEEE80211_STYPE_REASSOC_RESP:
2477 if ( ! ( dev->state & NET80211_ASSOCIATED ) )
2478 net80211_handle_assoc_reply ( dev, iob );
2479 break;
2480
2481 /* We pass probes and beacons onto network scanning
2482 code. Pass actions for future extensibility. */
2483 case IEEE80211_STYPE_BEACON:
2484 net80211_update_link_quality ( dev, iob );
2485 /* fall through */
2486 case IEEE80211_STYPE_PROBE_RESP:
2487 case IEEE80211_STYPE_ACTION:
2488 if ( dev->keep_mgmt ) {
2489 struct net80211_rx_info *rxinf;
2490 rxinf = zalloc ( sizeof ( *rxinf ) );
2491 if ( ! rxinf ) {
2492 DBGC ( dev, "802.11 %p out of memory\n", dev );
2493 break;
2494 }
2495 rxinf->signal = signal;
2496 list_add_tail ( &iob->list, &dev->mgmt_queue );
2497 list_add_tail ( &rxinf->list, &dev->mgmt_info_queue );
2498 keep = 1;
2499 }
2500 break;
2501
2502 case IEEE80211_STYPE_PROBE_REQ:
2503 /* Some nodes send these broadcast. Ignore them. */
2504 break;
2505
2506 case IEEE80211_STYPE_ASSOC_REQ:
2507 case IEEE80211_STYPE_REASSOC_REQ:
2508 /* We should never receive these, only send them. */
2509 DBGC ( dev, "802.11 %p received strange management request "
2510 "(%04x)\n", dev, stype );
2511 break;
2512
2513 default:
2514 DBGC ( dev, "802.11 %p received unimplemented management "
2515 "packet (%04x)\n", dev, stype );
2516 break;
2517 }
2518
2519 if ( ! keep )
2520 free_iob ( iob );
2521 }
2522
2523 /* ---------- Packet handling functions ---------- */
2524
2525 /**
2526 * Free buffers used by 802.11 fragment cache entry
2527 *
2528 * @v dev 802.11 device
2529 * @v fcid Fragment cache entry index
2530 *
2531 * After this function, the referenced entry will be marked unused.
2532 */
net80211_free_frags(struct net80211_device * dev,int fcid)2533 static void net80211_free_frags ( struct net80211_device *dev, int fcid )
2534 {
2535 int j;
2536 struct net80211_frag_cache *frag = &dev->frags[fcid];
2537
2538 for ( j = 0; j < 16; j++ ) {
2539 if ( frag->iob[j] ) {
2540 free_iob ( frag->iob[j] );
2541 frag->iob[j] = NULL;
2542 }
2543 }
2544
2545 frag->seqnr = 0;
2546 frag->start_ticks = 0;
2547 frag->in_use = 0;
2548 }
2549
2550 /**
2551 * Accumulate 802.11 fragments into one I/O buffer
2552 *
2553 * @v dev 802.11 device
2554 * @v fcid Fragment cache entry index
2555 * @v nfrags Number of fragments received
2556 * @v size Sum of sizes of all fragments, including headers
2557 * @ret iob I/O buffer containing reassembled packet
2558 *
2559 * This function does not free the fragment buffers.
2560 */
net80211_accum_frags(struct net80211_device * dev,int fcid,int nfrags,int size)2561 static struct io_buffer *net80211_accum_frags ( struct net80211_device *dev,
2562 int fcid, int nfrags, int size )
2563 {
2564 struct net80211_frag_cache *frag = &dev->frags[fcid];
2565 int hdrsize = IEEE80211_TYP_FRAME_HEADER_LEN;
2566 int nsize = size - hdrsize * ( nfrags - 1 );
2567 int i;
2568
2569 struct io_buffer *niob = alloc_iob ( nsize );
2570 struct ieee80211_frame *hdr;
2571
2572 /* Add the header from the first one... */
2573 memcpy ( iob_put ( niob, hdrsize ), frag->iob[0]->data, hdrsize );
2574
2575 /* ... and all the data from all of them. */
2576 for ( i = 0; i < nfrags; i++ ) {
2577 int len = iob_len ( frag->iob[i] ) - hdrsize;
2578 memcpy ( iob_put ( niob, len ),
2579 frag->iob[i]->data + hdrsize, len );
2580 }
2581
2582 /* Turn off the fragment bit. */
2583 hdr = niob->data;
2584 hdr->fc &= ~IEEE80211_FC_MORE_FRAG;
2585
2586 return niob;
2587 }
2588
2589 /**
2590 * Handle receipt of 802.11 fragment
2591 *
2592 * @v dev 802.11 device
2593 * @v iob I/O buffer containing fragment
2594 * @v signal Signal strength with which fragment was received
2595 */
net80211_rx_frag(struct net80211_device * dev,struct io_buffer * iob,int signal)2596 static void net80211_rx_frag ( struct net80211_device *dev,
2597 struct io_buffer *iob, int signal )
2598 {
2599 struct ieee80211_frame *hdr = iob->data;
2600 int fragnr = IEEE80211_FRAG ( hdr->seq );
2601
2602 if ( fragnr == 0 && ( hdr->fc & IEEE80211_FC_MORE_FRAG ) ) {
2603 /* start a frag cache entry */
2604 int i, newest = -1;
2605 u32 curr_ticks = currticks(), newest_ticks = 0;
2606 u32 timeout = TICKS_PER_SEC * NET80211_FRAG_TIMEOUT;
2607
2608 for ( i = 0; i < NET80211_NR_CONCURRENT_FRAGS; i++ ) {
2609 if ( dev->frags[i].in_use == 0 )
2610 break;
2611
2612 if ( dev->frags[i].start_ticks + timeout >=
2613 curr_ticks ) {
2614 net80211_free_frags ( dev, i );
2615 break;
2616 }
2617
2618 if ( dev->frags[i].start_ticks > newest_ticks ) {
2619 newest = i;
2620 newest_ticks = dev->frags[i].start_ticks;
2621 }
2622 }
2623
2624 /* If we're being sent more concurrent fragmented
2625 packets than we can handle, drop the newest so the
2626 older ones have time to complete. */
2627 if ( i == NET80211_NR_CONCURRENT_FRAGS ) {
2628 i = newest;
2629 net80211_free_frags ( dev, i );
2630 }
2631
2632 dev->frags[i].in_use = 1;
2633 dev->frags[i].seqnr = IEEE80211_SEQNR ( hdr->seq );
2634 dev->frags[i].start_ticks = currticks();
2635 dev->frags[i].iob[0] = iob;
2636 return;
2637 } else {
2638 int i;
2639 for ( i = 0; i < NET80211_NR_CONCURRENT_FRAGS; i++ ) {
2640 if ( dev->frags[i].in_use && dev->frags[i].seqnr ==
2641 IEEE80211_SEQNR ( hdr->seq ) )
2642 break;
2643 }
2644 if ( i == NET80211_NR_CONCURRENT_FRAGS ) {
2645 /* Drop non-first not-in-cache fragments */
2646 DBGC ( dev, "802.11 %p dropped fragment fc=%04x "
2647 "seq=%04x\n", dev, hdr->fc, hdr->seq );
2648 free_iob ( iob );
2649 return;
2650 }
2651
2652 dev->frags[i].iob[fragnr] = iob;
2653
2654 if ( ! ( hdr->fc & IEEE80211_FC_MORE_FRAG ) ) {
2655 int j, size = 0;
2656 for ( j = 0; j < fragnr; j++ ) {
2657 size += iob_len ( dev->frags[i].iob[j] );
2658 if ( dev->frags[i].iob[j] == NULL )
2659 break;
2660 }
2661 if ( j == fragnr ) {
2662 /* We've got everything */
2663 struct io_buffer *niob =
2664 net80211_accum_frags ( dev, i, fragnr,
2665 size );
2666 net80211_free_frags ( dev, i );
2667 net80211_rx ( dev, niob, signal, 0 );
2668 } else {
2669 DBGC ( dev, "802.11 %p dropping fragmented "
2670 "packet due to out-of-order arrival, "
2671 "fc=%04x seq=%04x\n", dev, hdr->fc,
2672 hdr->seq );
2673 net80211_free_frags ( dev, i );
2674 }
2675 }
2676 }
2677 }
2678
2679 /**
2680 * Handle receipt of 802.11 frame
2681 *
2682 * @v dev 802.11 device
2683 * @v iob I/O buffer
2684 * @v signal Received signal strength
2685 * @v rate Bitrate at which frame was received, in 100 kbps units
2686 *
2687 * If the rate or signal is unknown, 0 should be passed.
2688 */
net80211_rx(struct net80211_device * dev,struct io_buffer * iob,int signal,u16 rate)2689 void net80211_rx ( struct net80211_device *dev, struct io_buffer *iob,
2690 int signal, u16 rate )
2691 {
2692 struct ieee80211_frame *hdr = iob->data;
2693 u16 type = hdr->fc & IEEE80211_FC_TYPE;
2694 if ( ( hdr->fc & IEEE80211_FC_VERSION ) != IEEE80211_THIS_VERSION )
2695 goto drop; /* drop invalid-version packets */
2696
2697 if ( type == IEEE80211_TYPE_CTRL )
2698 goto drop; /* we don't handle control packets,
2699 the hardware does */
2700
2701 if ( dev->last_rx_seq == hdr->seq )
2702 goto drop; /* avoid duplicate packet */
2703 dev->last_rx_seq = hdr->seq;
2704
2705 if ( dev->hw->flags & NET80211_HW_RX_HAS_FCS ) {
2706 /* discard the FCS */
2707 iob_unput ( iob, 4 );
2708 }
2709
2710 /* Only decrypt packets from our BSSID, to avoid spurious errors */
2711 if ( ( hdr->fc & IEEE80211_FC_PROTECTED ) &&
2712 ! memcmp ( hdr->addr2, dev->bssid, ETH_ALEN ) ) {
2713 /* Decrypt packet; record and drop if it fails */
2714 struct io_buffer *niob;
2715 struct net80211_crypto *crypto = dev->crypto;
2716
2717 if ( ! dev->crypto ) {
2718 DBGC ( dev, "802.11 %p cannot decrypt packet "
2719 "without a cryptosystem\n", dev );
2720 goto drop_crypt;
2721 }
2722
2723 if ( ( hdr->addr1[0] & 1 ) && dev->gcrypto ) {
2724 /* Use group decryption if needed */
2725 crypto = dev->gcrypto;
2726 }
2727
2728 niob = crypto->decrypt ( crypto, iob );
2729 if ( ! niob ) {
2730 DBGC ( dev, "802.11 %p decryption error\n", dev );
2731 goto drop_crypt;
2732 }
2733 free_iob ( iob );
2734 iob = niob;
2735 hdr = iob->data;
2736 }
2737
2738 dev->last_signal = signal;
2739
2740 /* Fragments go into the frag cache or get dropped. */
2741 if ( IEEE80211_FRAG ( hdr->seq ) != 0
2742 || ( hdr->fc & IEEE80211_FC_MORE_FRAG ) ) {
2743 net80211_rx_frag ( dev, iob, signal );
2744 return;
2745 }
2746
2747 /* Management frames get handled, enqueued, or dropped. */
2748 if ( type == IEEE80211_TYPE_MGMT ) {
2749 net80211_handle_mgmt ( dev, iob, signal );
2750 return;
2751 }
2752
2753 /* Data frames get dropped or sent to the net_device. */
2754 if ( ( hdr->fc & IEEE80211_FC_SUBTYPE ) != IEEE80211_STYPE_DATA )
2755 goto drop; /* drop QoS, CFP, or null data packets */
2756
2757 /* Update rate-control algorithm */
2758 if ( dev->rctl )
2759 rc80211_update_rx ( dev, hdr->fc & IEEE80211_FC_RETRY, rate );
2760
2761 /* Pass packet onward */
2762 if ( dev->state & NET80211_ASSOCIATED ) {
2763 netdev_rx ( dev->netdev, iob );
2764 return;
2765 }
2766
2767 /* No association? Drop it. */
2768 goto drop;
2769
2770 drop_crypt:
2771 netdev_rx_err ( dev->netdev, NULL, EINVAL_CRYPTO_REQUEST );
2772 drop:
2773 DBGC2 ( dev, "802.11 %p dropped packet fc=%04x seq=%04x\n", dev,
2774 hdr->fc, hdr->seq );
2775 free_iob ( iob );
2776 return;
2777 }
2778
2779 /** Indicate an error in receiving a packet
2780 *
2781 * @v dev 802.11 device
2782 * @v iob I/O buffer with received packet, or NULL
2783 * @v rc Error code
2784 *
2785 * This logs the error with the wrapping net_device, and frees iob if
2786 * it is passed.
2787 */
net80211_rx_err(struct net80211_device * dev,struct io_buffer * iob,int rc)2788 void net80211_rx_err ( struct net80211_device *dev,
2789 struct io_buffer *iob, int rc )
2790 {
2791 netdev_rx_err ( dev->netdev, iob, rc );
2792 }
2793
2794 /** Indicate the completed transmission of a packet
2795 *
2796 * @v dev 802.11 device
2797 * @v iob I/O buffer of transmitted packet
2798 * @v retries Number of times this packet was retransmitted
2799 * @v rc Error code, or 0 for success
2800 *
2801 * This logs an error with the wrapping net_device if one occurred,
2802 * and removes and frees the I/O buffer from its TX queue. The
2803 * provided retry information is used to tune our transmission rate.
2804 *
2805 * If the packet did not need to be retransmitted because it was
2806 * properly ACKed the first time, @a retries should be 0.
2807 */
net80211_tx_complete(struct net80211_device * dev,struct io_buffer * iob,int retries,int rc)2808 void net80211_tx_complete ( struct net80211_device *dev,
2809 struct io_buffer *iob, int retries, int rc )
2810 {
2811 /* Update rate-control algorithm */
2812 if ( dev->rctl )
2813 rc80211_update_tx ( dev, retries, rc );
2814
2815 /* Pass completion onward */
2816 netdev_tx_complete_err ( dev->netdev, iob, rc );
2817 }
2818
2819 /** Common 802.11 errors */
2820 struct errortab common_wireless_errors[] __errortab = {
2821 __einfo_errortab ( EINFO_EINVAL_CRYPTO_REQUEST ),
2822 __einfo_errortab ( EINFO_ECONNRESET_UNSPECIFIED ),
2823 __einfo_errortab ( EINFO_ECONNRESET_INACTIVITY ),
2824 __einfo_errortab ( EINFO_ECONNRESET_4WAY_TIMEOUT ),
2825 __einfo_errortab ( EINFO_ECONNRESET_8021X_FAILURE ),
2826 __einfo_errortab ( EINFO_ECONNREFUSED_FAILURE ),
2827 __einfo_errortab ( EINFO_ECONNREFUSED_ASSOC_DENIED ),
2828 __einfo_errortab ( EINFO_ECONNREFUSED_AUTH_ALGO_UNSUPP ),
2829 };
2830
2831 /* Drag in objects via net80211_ll_protocol */
2832 REQUIRING_SYMBOL ( net80211_ll_protocol );
2833
2834 /* Drag in 802.11 configuration */
2835 REQUIRE_OBJECT ( config_net80211 );
2836