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15#include <linux/module.h>
16#include <asm/uaccess.h>
17#include <linux/bitops.h>
18#include <linux/string.h>
19#include <linux/mm.h>
20#include <linux/interrupt.h>
21#include <linux/in.h>
22#include <linux/tty.h>
23#include <linux/errno.h>
24#include <linux/netdevice.h>
25#include <linux/timer.h>
26#include <linux/slab.h>
27#include <net/ax25.h>
28#include <linux/etherdevice.h>
29#include <linux/skbuff.h>
30#include <linux/rtnetlink.h>
31#include <linux/spinlock.h>
32#include <linux/if_arp.h>
33#include <linux/init.h>
34#include <linux/ip.h>
35#include <linux/tcp.h>
36#include <linux/semaphore.h>
37#include <linux/compat.h>
38#include <linux/atomic.h>
39
40#define SIXPACK_VERSION "Revision: 0.3.0"
41
42
43#define SIXP_SEOF 0x40
44#define SIXP_TX_URUN 0x48
45#define SIXP_RX_ORUN 0x50
46#define SIXP_RX_BUF_OVL 0x58
47
48#define SIXP_CHKSUM 0xFF
49
50
51
52#define SIXP_CMD_MASK 0xC0
53#define SIXP_CHN_MASK 0x07
54#define SIXP_PRIO_CMD_MASK 0x80
55#define SIXP_STD_CMD_MASK 0x40
56#define SIXP_PRIO_DATA_MASK 0x38
57#define SIXP_TX_MASK 0x20
58#define SIXP_RX_MASK 0x10
59#define SIXP_RX_DCD_MASK 0x18
60#define SIXP_LEDS_ON 0x78
61#define SIXP_LEDS_OFF 0x60
62#define SIXP_CON 0x08
63#define SIXP_STA 0x10
64
65#define SIXP_FOUND_TNC 0xe9
66#define SIXP_CON_ON 0x68
67#define SIXP_DCD_MASK 0x08
68#define SIXP_DAMA_OFF 0
69
70
71#define SIXP_TXDELAY (HZ/4)
72#define SIXP_PERSIST 50
73#define SIXP_SLOTTIME (HZ/10)
74#define SIXP_INIT_RESYNC_TIMEOUT (3*HZ/2)
75#define SIXP_RESYNC_TIMEOUT 5*HZ
76
77
78#define SIXP_NRUNIT 31
79#define SIXP_MTU 256
80
81enum sixpack_flags {
82 SIXPF_ERROR,
83};
84
85struct sixpack {
86
87 struct tty_struct *tty;
88 struct net_device *dev;
89
90
91 unsigned char *rbuff;
92 int rcount;
93 unsigned char *xbuff;
94 unsigned char *xhead;
95 int xleft;
96
97 unsigned char raw_buf[4];
98 unsigned char cooked_buf[400];
99
100 unsigned int rx_count;
101 unsigned int rx_count_cooked;
102
103 int mtu;
104 int buffsize;
105
106 unsigned long flags;
107 unsigned char mode;
108
109
110 unsigned char tx_delay;
111 unsigned char persistence;
112 unsigned char slottime;
113 unsigned char duplex;
114 unsigned char led_state;
115 unsigned char status;
116 unsigned char status1;
117 unsigned char status2;
118 unsigned char tx_enable;
119 unsigned char tnc_state;
120
121 struct timer_list tx_t;
122 struct timer_list resync_t;
123 atomic_t refcnt;
124 struct semaphore dead_sem;
125 spinlock_t lock;
126};
127
128#define AX25_6PACK_HEADER_LEN 0
129
130static void sixpack_decode(struct sixpack *, unsigned char[], int);
131static int encode_sixpack(unsigned char *, unsigned char *, int, unsigned char);
132
133
134
135
136
137
138
139static void sp_xmit_on_air(unsigned long channel)
140{
141 struct sixpack *sp = (struct sixpack *) channel;
142 int actual, when = sp->slottime;
143 static unsigned char random;
144
145 random = random * 17 + 41;
146
147 if (((sp->status1 & SIXP_DCD_MASK) == 0) && (random < sp->persistence)) {
148 sp->led_state = 0x70;
149 sp->tty->ops->write(sp->tty, &sp->led_state, 1);
150 sp->tx_enable = 1;
151 actual = sp->tty->ops->write(sp->tty, sp->xbuff, sp->status2);
152 sp->xleft -= actual;
153 sp->xhead += actual;
154 sp->led_state = 0x60;
155 sp->tty->ops->write(sp->tty, &sp->led_state, 1);
156 sp->status2 = 0;
157 } else
158 mod_timer(&sp->tx_t, jiffies + ((when + 1) * HZ) / 100);
159}
160
161
162
163
164static void sp_encaps(struct sixpack *sp, unsigned char *icp, int len)
165{
166 unsigned char *msg, *p = icp;
167 int actual, count;
168
169 if (len > sp->mtu) {
170 msg = "oversized transmit packet!";
171 goto out_drop;
172 }
173
174 if (len > sp->mtu) {
175 msg = "oversized transmit packet!";
176 goto out_drop;
177 }
178
179 if (p[0] > 5) {
180 msg = "invalid KISS command";
181 goto out_drop;
182 }
183
184 if ((p[0] != 0) && (len > 2)) {
185 msg = "KISS control packet too long";
186 goto out_drop;
187 }
188
189 if ((p[0] == 0) && (len < 15)) {
190 msg = "bad AX.25 packet to transmit";
191 goto out_drop;
192 }
193
194 count = encode_sixpack(p, sp->xbuff, len, sp->tx_delay);
195 set_bit(TTY_DO_WRITE_WAKEUP, &sp->tty->flags);
196
197 switch (p[0]) {
198 case 1: sp->tx_delay = p[1];
199 return;
200 case 2: sp->persistence = p[1];
201 return;
202 case 3: sp->slottime = p[1];
203 return;
204 case 4:
205 return;
206 case 5: sp->duplex = p[1];
207 return;
208 }
209
210 if (p[0] != 0)
211 return;
212
213
214
215
216
217
218
219 if (sp->duplex == 1) {
220 sp->led_state = 0x70;
221 sp->tty->ops->write(sp->tty, &sp->led_state, 1);
222 sp->tx_enable = 1;
223 actual = sp->tty->ops->write(sp->tty, sp->xbuff, count);
224 sp->xleft = count - actual;
225 sp->xhead = sp->xbuff + actual;
226 sp->led_state = 0x60;
227 sp->tty->ops->write(sp->tty, &sp->led_state, 1);
228 } else {
229 sp->xleft = count;
230 sp->xhead = sp->xbuff;
231 sp->status2 = count;
232 sp_xmit_on_air((unsigned long)sp);
233 }
234
235 return;
236
237out_drop:
238 sp->dev->stats.tx_dropped++;
239 netif_start_queue(sp->dev);
240 if (net_ratelimit())
241 printk(KERN_DEBUG "%s: %s - dropped.\n", sp->dev->name, msg);
242}
243
244
245
246static netdev_tx_t sp_xmit(struct sk_buff *skb, struct net_device *dev)
247{
248 struct sixpack *sp = netdev_priv(dev);
249
250 spin_lock_bh(&sp->lock);
251
252 netif_stop_queue(dev);
253 dev->stats.tx_bytes += skb->len;
254 sp_encaps(sp, skb->data, skb->len);
255 spin_unlock_bh(&sp->lock);
256
257 dev_kfree_skb(skb);
258
259 return NETDEV_TX_OK;
260}
261
262static int sp_open_dev(struct net_device *dev)
263{
264 struct sixpack *sp = netdev_priv(dev);
265
266 if (sp->tty == NULL)
267 return -ENODEV;
268 return 0;
269}
270
271
272static int sp_close(struct net_device *dev)
273{
274 struct sixpack *sp = netdev_priv(dev);
275
276 spin_lock_bh(&sp->lock);
277 if (sp->tty) {
278
279 clear_bit(TTY_DO_WRITE_WAKEUP, &sp->tty->flags);
280 }
281 netif_stop_queue(dev);
282 spin_unlock_bh(&sp->lock);
283
284 return 0;
285}
286
287
288static int sp_header(struct sk_buff *skb, struct net_device *dev,
289 unsigned short type, const void *daddr,
290 const void *saddr, unsigned len)
291{
292#ifdef CONFIG_INET
293 if (type != ETH_P_AX25)
294 return ax25_hard_header(skb, dev, type, daddr, saddr, len);
295#endif
296 return 0;
297}
298
299static int sp_set_mac_address(struct net_device *dev, void *addr)
300{
301 struct sockaddr_ax25 *sa = addr;
302
303 netif_tx_lock_bh(dev);
304 netif_addr_lock(dev);
305 memcpy(dev->dev_addr, &sa->sax25_call, AX25_ADDR_LEN);
306 netif_addr_unlock(dev);
307 netif_tx_unlock_bh(dev);
308
309 return 0;
310}
311
312static int sp_rebuild_header(struct sk_buff *skb)
313{
314#ifdef CONFIG_INET
315 return ax25_rebuild_header(skb);
316#else
317 return 0;
318#endif
319}
320
321static const struct header_ops sp_header_ops = {
322 .create = sp_header,
323 .rebuild = sp_rebuild_header,
324};
325
326static const struct net_device_ops sp_netdev_ops = {
327 .ndo_open = sp_open_dev,
328 .ndo_stop = sp_close,
329 .ndo_start_xmit = sp_xmit,
330 .ndo_set_mac_address = sp_set_mac_address,
331};
332
333static void sp_setup(struct net_device *dev)
334{
335
336 dev->netdev_ops = &sp_netdev_ops;
337 dev->destructor = free_netdev;
338 dev->mtu = SIXP_MTU;
339 dev->hard_header_len = AX25_MAX_HEADER_LEN;
340 dev->header_ops = &sp_header_ops;
341
342 dev->addr_len = AX25_ADDR_LEN;
343 dev->type = ARPHRD_AX25;
344 dev->tx_queue_len = 10;
345
346
347 memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
348 memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
349
350 dev->flags = 0;
351}
352
353
354
355
356
357
358
359
360static void sp_bump(struct sixpack *sp, char cmd)
361{
362 struct sk_buff *skb;
363 int count;
364 unsigned char *ptr;
365
366 count = sp->rcount + 1;
367
368 sp->dev->stats.rx_bytes += count;
369
370 if ((skb = dev_alloc_skb(count)) == NULL)
371 goto out_mem;
372
373 ptr = skb_put(skb, count);
374 *ptr++ = cmd;
375
376 memcpy(ptr, sp->cooked_buf + 1, count);
377 skb->protocol = ax25_type_trans(skb, sp->dev);
378 netif_rx(skb);
379 sp->dev->stats.rx_packets++;
380
381 return;
382
383out_mem:
384 sp->dev->stats.rx_dropped++;
385}
386
387
388
389
390
391
392
393
394
395
396
397
398static DEFINE_RWLOCK(disc_data_lock);
399
400static struct sixpack *sp_get(struct tty_struct *tty)
401{
402 struct sixpack *sp;
403
404 read_lock(&disc_data_lock);
405 sp = tty->disc_data;
406 if (sp)
407 atomic_inc(&sp->refcnt);
408 read_unlock(&disc_data_lock);
409
410 return sp;
411}
412
413static void sp_put(struct sixpack *sp)
414{
415 if (atomic_dec_and_test(&sp->refcnt))
416 up(&sp->dead_sem);
417}
418
419
420
421
422
423static void sixpack_write_wakeup(struct tty_struct *tty)
424{
425 struct sixpack *sp = sp_get(tty);
426 int actual;
427
428 if (!sp)
429 return;
430 if (sp->xleft <= 0) {
431
432
433 sp->dev->stats.tx_packets++;
434 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
435 sp->tx_enable = 0;
436 netif_wake_queue(sp->dev);
437 goto out;
438 }
439
440 if (sp->tx_enable) {
441 actual = tty->ops->write(tty, sp->xhead, sp->xleft);
442 sp->xleft -= actual;
443 sp->xhead += actual;
444 }
445
446out:
447 sp_put(sp);
448}
449
450
451
452
453
454
455
456
457
458static void sixpack_receive_buf(struct tty_struct *tty,
459 const unsigned char *cp, char *fp, int count)
460{
461 struct sixpack *sp;
462 unsigned char buf[512];
463 int count1;
464
465 if (!count)
466 return;
467
468 sp = sp_get(tty);
469 if (!sp)
470 return;
471
472 memcpy(buf, cp, count < sizeof(buf) ? count : sizeof(buf));
473
474
475
476 count1 = count;
477 while (count) {
478 count--;
479 if (fp && *fp++) {
480 if (!test_and_set_bit(SIXPF_ERROR, &sp->flags))
481 sp->dev->stats.rx_errors++;
482 continue;
483 }
484 }
485 sixpack_decode(sp, buf, count1);
486
487 sp_put(sp);
488 tty_unthrottle(tty);
489}
490
491
492
493
494
495
496#define TNC_UNINITIALIZED 0
497#define TNC_UNSYNC_STARTUP 1
498#define TNC_UNSYNCED 2
499#define TNC_IN_SYNC 3
500
501static void __tnc_set_sync_state(struct sixpack *sp, int new_tnc_state)
502{
503 char *msg;
504
505 switch (new_tnc_state) {
506 default:
507 case TNC_UNSYNC_STARTUP:
508 msg = "Synchronizing with TNC";
509 break;
510 case TNC_UNSYNCED:
511 msg = "Lost synchronization with TNC\n";
512 break;
513 case TNC_IN_SYNC:
514 msg = "Found TNC";
515 break;
516 }
517
518 sp->tnc_state = new_tnc_state;
519 printk(KERN_INFO "%s: %s\n", sp->dev->name, msg);
520}
521
522static inline void tnc_set_sync_state(struct sixpack *sp, int new_tnc_state)
523{
524 int old_tnc_state = sp->tnc_state;
525
526 if (old_tnc_state != new_tnc_state)
527 __tnc_set_sync_state(sp, new_tnc_state);
528}
529
530static void resync_tnc(unsigned long channel)
531{
532 struct sixpack *sp = (struct sixpack *) channel;
533 static char resync_cmd = 0xe8;
534
535
536
537 sp->rx_count = 0;
538 sp->rx_count_cooked = 0;
539
540
541
542 sp->status = 1;
543 sp->status1 = 1;
544 sp->status2 = 0;
545
546
547
548 sp->led_state = 0x60;
549 sp->tty->ops->write(sp->tty, &sp->led_state, 1);
550 sp->tty->ops->write(sp->tty, &resync_cmd, 1);
551
552
553
554
555 del_timer(&sp->resync_t);
556 sp->resync_t.data = (unsigned long) sp;
557 sp->resync_t.function = resync_tnc;
558 sp->resync_t.expires = jiffies + SIXP_RESYNC_TIMEOUT;
559 add_timer(&sp->resync_t);
560}
561
562static inline int tnc_init(struct sixpack *sp)
563{
564 unsigned char inbyte = 0xe8;
565
566 tnc_set_sync_state(sp, TNC_UNSYNC_STARTUP);
567
568 sp->tty->ops->write(sp->tty, &inbyte, 1);
569
570 del_timer(&sp->resync_t);
571 sp->resync_t.data = (unsigned long) sp;
572 sp->resync_t.function = resync_tnc;
573 sp->resync_t.expires = jiffies + SIXP_RESYNC_TIMEOUT;
574 add_timer(&sp->resync_t);
575
576 return 0;
577}
578
579
580
581
582
583
584
585
586static int sixpack_open(struct tty_struct *tty)
587{
588 char *rbuff = NULL, *xbuff = NULL;
589 struct net_device *dev;
590 struct sixpack *sp;
591 unsigned long len;
592 int err = 0;
593
594 if (!capable(CAP_NET_ADMIN))
595 return -EPERM;
596 if (tty->ops->write == NULL)
597 return -EOPNOTSUPP;
598
599 dev = alloc_netdev(sizeof(struct sixpack), "sp%d", sp_setup);
600 if (!dev) {
601 err = -ENOMEM;
602 goto out;
603 }
604
605 sp = netdev_priv(dev);
606 sp->dev = dev;
607
608 spin_lock_init(&sp->lock);
609 atomic_set(&sp->refcnt, 1);
610 sema_init(&sp->dead_sem, 0);
611
612
613
614 len = dev->mtu * 2;
615
616 rbuff = kmalloc(len + 4, GFP_KERNEL);
617 xbuff = kmalloc(len + 4, GFP_KERNEL);
618
619 if (rbuff == NULL || xbuff == NULL) {
620 err = -ENOBUFS;
621 goto out_free;
622 }
623
624 spin_lock_bh(&sp->lock);
625
626 sp->tty = tty;
627
628 sp->rbuff = rbuff;
629 sp->xbuff = xbuff;
630
631 sp->mtu = AX25_MTU + 73;
632 sp->buffsize = len;
633 sp->rcount = 0;
634 sp->rx_count = 0;
635 sp->rx_count_cooked = 0;
636 sp->xleft = 0;
637
638 sp->flags = 0;
639
640 sp->duplex = 0;
641 sp->tx_delay = SIXP_TXDELAY;
642 sp->persistence = SIXP_PERSIST;
643 sp->slottime = SIXP_SLOTTIME;
644 sp->led_state = 0x60;
645 sp->status = 1;
646 sp->status1 = 1;
647 sp->status2 = 0;
648 sp->tx_enable = 0;
649
650 netif_start_queue(dev);
651
652 init_timer(&sp->tx_t);
653 sp->tx_t.function = sp_xmit_on_air;
654 sp->tx_t.data = (unsigned long) sp;
655
656 init_timer(&sp->resync_t);
657
658 spin_unlock_bh(&sp->lock);
659
660
661 tty->disc_data = sp;
662 tty->receive_room = 65536;
663
664
665 if (register_netdev(dev))
666 goto out_free;
667
668 tnc_init(sp);
669
670 return 0;
671
672out_free:
673 kfree(xbuff);
674 kfree(rbuff);
675
676 if (dev)
677 free_netdev(dev);
678
679out:
680 return err;
681}
682
683
684
685
686
687
688
689
690static void sixpack_close(struct tty_struct *tty)
691{
692 struct sixpack *sp;
693
694 write_lock_bh(&disc_data_lock);
695 sp = tty->disc_data;
696 tty->disc_data = NULL;
697 write_unlock_bh(&disc_data_lock);
698 if (!sp)
699 return;
700
701
702
703
704
705 if (!atomic_dec_and_test(&sp->refcnt))
706 down(&sp->dead_sem);
707
708 unregister_netdev(sp->dev);
709
710 del_timer(&sp->tx_t);
711 del_timer(&sp->resync_t);
712
713
714 kfree(sp->rbuff);
715 kfree(sp->xbuff);
716}
717
718
719static int sixpack_ioctl(struct tty_struct *tty, struct file *file,
720 unsigned int cmd, unsigned long arg)
721{
722 struct sixpack *sp = sp_get(tty);
723 struct net_device *dev;
724 unsigned int tmp, err;
725
726 if (!sp)
727 return -ENXIO;
728 dev = sp->dev;
729
730 switch(cmd) {
731 case SIOCGIFNAME:
732 err = copy_to_user((void __user *) arg, dev->name,
733 strlen(dev->name) + 1) ? -EFAULT : 0;
734 break;
735
736 case SIOCGIFENCAP:
737 err = put_user(0, (int __user *) arg);
738 break;
739
740 case SIOCSIFENCAP:
741 if (get_user(tmp, (int __user *) arg)) {
742 err = -EFAULT;
743 break;
744 }
745
746 sp->mode = tmp;
747 dev->addr_len = AX25_ADDR_LEN;
748 dev->hard_header_len = AX25_KISS_HEADER_LEN +
749 AX25_MAX_HEADER_LEN + 3;
750 dev->type = ARPHRD_AX25;
751
752 err = 0;
753 break;
754
755 case SIOCSIFHWADDR: {
756 char addr[AX25_ADDR_LEN];
757
758 if (copy_from_user(&addr,
759 (void __user *) arg, AX25_ADDR_LEN)) {
760 err = -EFAULT;
761 break;
762 }
763
764 netif_tx_lock_bh(dev);
765 memcpy(dev->dev_addr, &addr, AX25_ADDR_LEN);
766 netif_tx_unlock_bh(dev);
767
768 err = 0;
769 break;
770 }
771
772 default:
773 err = tty_mode_ioctl(tty, file, cmd, arg);
774 }
775
776 sp_put(sp);
777
778 return err;
779}
780
781#ifdef CONFIG_COMPAT
782static long sixpack_compat_ioctl(struct tty_struct * tty, struct file * file,
783 unsigned int cmd, unsigned long arg)
784{
785 switch (cmd) {
786 case SIOCGIFNAME:
787 case SIOCGIFENCAP:
788 case SIOCSIFENCAP:
789 case SIOCSIFHWADDR:
790 return sixpack_ioctl(tty, file, cmd,
791 (unsigned long)compat_ptr(arg));
792 }
793
794 return -ENOIOCTLCMD;
795}
796#endif
797
798static struct tty_ldisc_ops sp_ldisc = {
799 .owner = THIS_MODULE,
800 .magic = TTY_LDISC_MAGIC,
801 .name = "6pack",
802 .open = sixpack_open,
803 .close = sixpack_close,
804 .ioctl = sixpack_ioctl,
805#ifdef CONFIG_COMPAT
806 .compat_ioctl = sixpack_compat_ioctl,
807#endif
808 .receive_buf = sixpack_receive_buf,
809 .write_wakeup = sixpack_write_wakeup,
810};
811
812
813
814static const char msg_banner[] __initconst = KERN_INFO \
815 "AX.25: 6pack driver, " SIXPACK_VERSION "\n";
816static const char msg_regfail[] __initconst = KERN_ERR \
817 "6pack: can't register line discipline (err = %d)\n";
818
819static int __init sixpack_init_driver(void)
820{
821 int status;
822
823 printk(msg_banner);
824
825
826 if ((status = tty_register_ldisc(N_6PACK, &sp_ldisc)) != 0)
827 printk(msg_regfail, status);
828
829 return status;
830}
831
832static const char msg_unregfail[] = KERN_ERR \
833 "6pack: can't unregister line discipline (err = %d)\n";
834
835static void __exit sixpack_exit_driver(void)
836{
837 int ret;
838
839 if ((ret = tty_unregister_ldisc(N_6PACK)))
840 printk(msg_unregfail, ret);
841}
842
843
844
845static int encode_sixpack(unsigned char *tx_buf, unsigned char *tx_buf_raw,
846 int length, unsigned char tx_delay)
847{
848 int count = 0;
849 unsigned char checksum = 0, buf[400];
850 int raw_count = 0;
851
852 tx_buf_raw[raw_count++] = SIXP_PRIO_CMD_MASK | SIXP_TX_MASK;
853 tx_buf_raw[raw_count++] = SIXP_SEOF;
854
855 buf[0] = tx_delay;
856 for (count = 1; count < length; count++)
857 buf[count] = tx_buf[count];
858
859 for (count = 0; count < length; count++)
860 checksum += buf[count];
861 buf[length] = (unsigned char) 0xff - checksum;
862
863 for (count = 0; count <= length; count++) {
864 if ((count % 3) == 0) {
865 tx_buf_raw[raw_count++] = (buf[count] & 0x3f);
866 tx_buf_raw[raw_count] = ((buf[count] >> 2) & 0x30);
867 } else if ((count % 3) == 1) {
868 tx_buf_raw[raw_count++] |= (buf[count] & 0x0f);
869 tx_buf_raw[raw_count] = ((buf[count] >> 2) & 0x3c);
870 } else {
871 tx_buf_raw[raw_count++] |= (buf[count] & 0x03);
872 tx_buf_raw[raw_count++] = (buf[count] >> 2);
873 }
874 }
875 if ((length % 3) != 2)
876 raw_count++;
877 tx_buf_raw[raw_count++] = SIXP_SEOF;
878 return raw_count;
879}
880
881
882
883static void decode_data(struct sixpack *sp, unsigned char inbyte)
884{
885 unsigned char *buf;
886
887 if (sp->rx_count != 3) {
888 sp->raw_buf[sp->rx_count++] = inbyte;
889
890 return;
891 }
892
893 buf = sp->raw_buf;
894 sp->cooked_buf[sp->rx_count_cooked++] =
895 buf[0] | ((buf[1] << 2) & 0xc0);
896 sp->cooked_buf[sp->rx_count_cooked++] =
897 (buf[1] & 0x0f) | ((buf[2] << 2) & 0xf0);
898 sp->cooked_buf[sp->rx_count_cooked++] =
899 (buf[2] & 0x03) | (inbyte << 2);
900 sp->rx_count = 0;
901}
902
903
904
905static void decode_prio_command(struct sixpack *sp, unsigned char cmd)
906{
907 unsigned char channel;
908 int actual;
909
910 channel = cmd & SIXP_CHN_MASK;
911 if ((cmd & SIXP_PRIO_DATA_MASK) != 0) {
912
913
914
915
916
917
918
919
920 if (((sp->status & SIXP_DCD_MASK) == 0) &&
921 ((cmd & SIXP_RX_DCD_MASK) == SIXP_RX_DCD_MASK)) {
922 if (sp->status != 1)
923 printk(KERN_DEBUG "6pack: protocol violation\n");
924 else
925 sp->status = 0;
926 cmd &= ~SIXP_RX_DCD_MASK;
927 }
928 sp->status = cmd & SIXP_PRIO_DATA_MASK;
929 } else {
930 if ((sp->status2 != 0) && (sp->duplex == 1)) {
931 sp->led_state = 0x70;
932 sp->tty->ops->write(sp->tty, &sp->led_state, 1);
933 sp->tx_enable = 1;
934 actual = sp->tty->ops->write(sp->tty, sp->xbuff, sp->status2);
935 sp->xleft -= actual;
936 sp->xhead += actual;
937 sp->led_state = 0x60;
938 sp->status2 = 0;
939
940 }
941 }
942
943
944 sp->tty->ops->write(sp->tty, &sp->led_state, 1);
945
946
947
948
949 if (sp->tnc_state == TNC_IN_SYNC) {
950 del_timer(&sp->resync_t);
951 sp->resync_t.data = (unsigned long) sp;
952 sp->resync_t.function = resync_tnc;
953 sp->resync_t.expires = jiffies + SIXP_INIT_RESYNC_TIMEOUT;
954 add_timer(&sp->resync_t);
955 }
956
957 sp->status1 = cmd & SIXP_PRIO_DATA_MASK;
958}
959
960
961
962static void decode_std_command(struct sixpack *sp, unsigned char cmd)
963{
964 unsigned char checksum = 0, rest = 0, channel;
965 short i;
966
967 channel = cmd & SIXP_CHN_MASK;
968 switch (cmd & SIXP_CMD_MASK) {
969 case SIXP_SEOF:
970 if ((sp->rx_count == 0) && (sp->rx_count_cooked == 0)) {
971 if ((sp->status & SIXP_RX_DCD_MASK) ==
972 SIXP_RX_DCD_MASK) {
973 sp->led_state = 0x68;
974 sp->tty->ops->write(sp->tty, &sp->led_state, 1);
975 }
976 } else {
977 sp->led_state = 0x60;
978
979 sp->tty->ops->write(sp->tty, &sp->led_state, 1);
980 rest = sp->rx_count;
981 if (rest != 0)
982 for (i = rest; i <= 3; i++)
983 decode_data(sp, 0);
984 if (rest == 2)
985 sp->rx_count_cooked -= 2;
986 else if (rest == 3)
987 sp->rx_count_cooked -= 1;
988 for (i = 0; i < sp->rx_count_cooked; i++)
989 checksum += sp->cooked_buf[i];
990 if (checksum != SIXP_CHKSUM) {
991 printk(KERN_DEBUG "6pack: bad checksum %2.2x\n", checksum);
992 } else {
993 sp->rcount = sp->rx_count_cooked-2;
994 sp_bump(sp, 0);
995 }
996 sp->rx_count_cooked = 0;
997 }
998 break;
999 case SIXP_TX_URUN: printk(KERN_DEBUG "6pack: TX underrun\n");
1000 break;
1001 case SIXP_RX_ORUN: printk(KERN_DEBUG "6pack: RX overrun\n");
1002 break;
1003 case SIXP_RX_BUF_OVL:
1004 printk(KERN_DEBUG "6pack: RX buffer overflow\n");
1005 }
1006}
1007
1008
1009
1010static void
1011sixpack_decode(struct sixpack *sp, unsigned char *pre_rbuff, int count)
1012{
1013 unsigned char inbyte;
1014 int count1;
1015
1016 for (count1 = 0; count1 < count; count1++) {
1017 inbyte = pre_rbuff[count1];
1018 if (inbyte == SIXP_FOUND_TNC) {
1019 tnc_set_sync_state(sp, TNC_IN_SYNC);
1020 del_timer(&sp->resync_t);
1021 }
1022 if ((inbyte & SIXP_PRIO_CMD_MASK) != 0)
1023 decode_prio_command(sp, inbyte);
1024 else if ((inbyte & SIXP_STD_CMD_MASK) != 0)
1025 decode_std_command(sp, inbyte);
1026 else if ((sp->status & SIXP_RX_DCD_MASK) == SIXP_RX_DCD_MASK)
1027 decode_data(sp, inbyte);
1028 }
1029}
1030
1031MODULE_AUTHOR("Ralf Baechle DO1GRB <ralf@linux-mips.org>");
1032MODULE_DESCRIPTION("6pack driver for AX.25");
1033MODULE_LICENSE("GPL");
1034MODULE_ALIAS_LDISC(N_6PACK);
1035
1036module_init(sixpack_init_driver);
1037module_exit(sixpack_exit_driver);
1038