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1/*
2 * Things to sort out:
3 *
4 * o tbusy handling
5 * o allow users to set the parameters
6 * o sync/async switching ?
7 *
8 * Note: This does _not_ implement CCITT X.25 asynchronous framing
9 * recommendations. Its primarily for testing purposes. If you wanted
10 * to do CCITT then in theory all you need is to nick the HDLC async
11 * checksum routines from ppp.c
12 * Changes:
13 *
14 * 2000-10-29 Henner Eisen lapb_data_indication() return status.
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/module.h>
20
21#include <linux/uaccess.h>
22#include <linux/bitops.h>
23#include <linux/string.h>
24#include <linux/mm.h>
25#include <linux/interrupt.h>
26#include <linux/in.h>
27#include <linux/tty.h>
28#include <linux/errno.h>
29#include <linux/netdevice.h>
30#include <linux/etherdevice.h>
31#include <linux/skbuff.h>
32#include <linux/if_arp.h>
33#include <linux/lapb.h>
34#include <linux/init.h>
35#include <linux/rtnetlink.h>
36#include <linux/compat.h>
37#include <linux/slab.h>
38#include <net/x25device.h>
39#include "x25_asy.h"
40
41static struct net_device **x25_asy_devs;
42static int x25_asy_maxdev = SL_NRUNIT;
43
44module_param(x25_asy_maxdev, int, 0);
45MODULE_LICENSE("GPL");
46
47static int x25_asy_esc(unsigned char *p, unsigned char *d, int len);
48static void x25_asy_unesc(struct x25_asy *sl, unsigned char c);
49static void x25_asy_setup(struct net_device *dev);
50
51/* Find a free X.25 channel, and link in this `tty' line. */
52static struct x25_asy *x25_asy_alloc(void)
53{
54 struct net_device *dev = NULL;
55 struct x25_asy *sl;
56 int i;
57
58 if (x25_asy_devs == NULL)
59 return NULL; /* Master array missing ! */
60
61 for (i = 0; i < x25_asy_maxdev; i++) {
62 dev = x25_asy_devs[i];
63
64 /* Not allocated ? */
65 if (dev == NULL)
66 break;
67
68 sl = netdev_priv(dev);
69 /* Not in use ? */
70 if (!test_and_set_bit(SLF_INUSE, &sl->flags))
71 return sl;
72 }
73
74
75 /* Sorry, too many, all slots in use */
76 if (i >= x25_asy_maxdev)
77 return NULL;
78
79 /* If no channels are available, allocate one */
80 if (!dev) {
81 char name[IFNAMSIZ];
82 sprintf(name, "x25asy%d", i);
83
84 dev = alloc_netdev(sizeof(struct x25_asy), name,
85 NET_NAME_UNKNOWN, x25_asy_setup);
86 if (!dev)
87 return NULL;
88
89 /* Initialize channel control data */
90 sl = netdev_priv(dev);
91 dev->base_addr = i;
92
93 /* register device so that it can be ifconfig'ed */
94 if (register_netdev(dev) == 0) {
95 /* (Re-)Set the INUSE bit. Very Important! */
96 set_bit(SLF_INUSE, &sl->flags);
97 x25_asy_devs[i] = dev;
98 return sl;
99 } else {
100 pr_warn("%s(): register_netdev() failure\n", __func__);
101 free_netdev(dev);
102 }
103 }
104 return NULL;
105}
106
107
108/* Free an X.25 channel. */
109static void x25_asy_free(struct x25_asy *sl)
110{
111 /* Free all X.25 frame buffers. */
112 kfree(sl->rbuff);
113 sl->rbuff = NULL;
114 kfree(sl->xbuff);
115 sl->xbuff = NULL;
116
117 if (!test_and_clear_bit(SLF_INUSE, &sl->flags))
118 netdev_err(sl->dev, "x25_asy_free for already free unit\n");
119}
120
121static int x25_asy_change_mtu(struct net_device *dev, int newmtu)
122{
123 struct x25_asy *sl = netdev_priv(dev);
124 unsigned char *xbuff, *rbuff;
125 int len;
126
127 len = 2 * newmtu;
128 xbuff = kmalloc(len + 4, GFP_ATOMIC);
129 rbuff = kmalloc(len + 4, GFP_ATOMIC);
130
131 if (xbuff == NULL || rbuff == NULL) {
132 kfree(xbuff);
133 kfree(rbuff);
134 return -ENOMEM;
135 }
136
137 spin_lock_bh(&sl->lock);
138 xbuff = xchg(&sl->xbuff, xbuff);
139 if (sl->xleft) {
140 if (sl->xleft <= len) {
141 memcpy(sl->xbuff, sl->xhead, sl->xleft);
142 } else {
143 sl->xleft = 0;
144 dev->stats.tx_dropped++;
145 }
146 }
147 sl->xhead = sl->xbuff;
148
149 rbuff = xchg(&sl->rbuff, rbuff);
150 if (sl->rcount) {
151 if (sl->rcount <= len) {
152 memcpy(sl->rbuff, rbuff, sl->rcount);
153 } else {
154 sl->rcount = 0;
155 dev->stats.rx_over_errors++;
156 set_bit(SLF_ERROR, &sl->flags);
157 }
158 }
159
160 dev->mtu = newmtu;
161 sl->buffsize = len;
162
163 spin_unlock_bh(&sl->lock);
164
165 kfree(xbuff);
166 kfree(rbuff);
167 return 0;
168}
169
170
171/* Set the "sending" flag. This must be atomic, hence the ASM. */
172
173static inline void x25_asy_lock(struct x25_asy *sl)
174{
175 netif_stop_queue(sl->dev);
176}
177
178
179/* Clear the "sending" flag. This must be atomic, hence the ASM. */
180
181static inline void x25_asy_unlock(struct x25_asy *sl)
182{
183 netif_wake_queue(sl->dev);
184}
185
186/* Send one completely decapsulated IP datagram to the IP layer. */
187
188static void x25_asy_bump(struct x25_asy *sl)
189{
190 struct net_device *dev = sl->dev;
191 struct sk_buff *skb;
192 int count;
193 int err;
194
195 count = sl->rcount;
196 dev->stats.rx_bytes += count;
197
198 skb = dev_alloc_skb(count+1);
199 if (skb == NULL) {
200 netdev_warn(sl->dev, "memory squeeze, dropping packet\n");
201 dev->stats.rx_dropped++;
202 return;
203 }
204 skb_push(skb, 1); /* LAPB internal control */
205 skb_put_data(skb, sl->rbuff, count);
206 skb->protocol = x25_type_trans(skb, sl->dev);
207 err = lapb_data_received(skb->dev, skb);
208 if (err != LAPB_OK) {
209 kfree_skb(skb);
210 printk(KERN_DEBUG "x25_asy: data received err - %d\n", err);
211 } else {
212 netif_rx(skb);
213 dev->stats.rx_packets++;
214 }
215}
216
217/* Encapsulate one IP datagram and stuff into a TTY queue. */
218static void x25_asy_encaps(struct x25_asy *sl, unsigned char *icp, int len)
219{
220 unsigned char *p;
221 int actual, count, mtu = sl->dev->mtu;
222
223 if (len > mtu) {
224 /* Sigh, shouldn't occur BUT ... */
225 len = mtu;
226 printk(KERN_DEBUG "%s: truncating oversized transmit packet!\n",
227 sl->dev->name);
228 sl->dev->stats.tx_dropped++;
229 x25_asy_unlock(sl);
230 return;
231 }
232
233 p = icp;
234 count = x25_asy_esc(p, sl->xbuff, len);
235
236 /* Order of next two lines is *very* important.
237 * When we are sending a little amount of data,
238 * the transfer may be completed inside driver.write()
239 * routine, because it's running with interrupts enabled.
240 * In this case we *never* got WRITE_WAKEUP event,
241 * if we did not request it before write operation.
242 * 14 Oct 1994 Dmitry Gorodchanin.
243 */
244 set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
245 actual = sl->tty->ops->write(sl->tty, sl->xbuff, count);
246 sl->xleft = count - actual;
247 sl->xhead = sl->xbuff + actual;
248 /* VSV */
249 clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */
250}
251
252/*
253 * Called by the driver when there's room for more data. If we have
254 * more packets to send, we send them here.
255 */
256static void x25_asy_write_wakeup(struct tty_struct *tty)
257{
258 int actual;
259 struct x25_asy *sl = tty->disc_data;
260
261 /* First make sure we're connected. */
262 if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
263 return;
264
265 if (sl->xleft <= 0) {
266 /* Now serial buffer is almost free & we can start
267 * transmission of another packet */
268 sl->dev->stats.tx_packets++;
269 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
270 x25_asy_unlock(sl);
271 return;
272 }
273
274 actual = tty->ops->write(tty, sl->xhead, sl->xleft);
275 sl->xleft -= actual;
276 sl->xhead += actual;
277}
278
279static void x25_asy_timeout(struct net_device *dev)
280{
281 struct x25_asy *sl = netdev_priv(dev);
282
283 spin_lock(&sl->lock);
284 if (netif_queue_stopped(dev)) {
285 /* May be we must check transmitter timeout here ?
286 * 14 Oct 1994 Dmitry Gorodchanin.
287 */
288 netdev_warn(dev, "transmit timed out, %s?\n",
289 (tty_chars_in_buffer(sl->tty) || sl->xleft) ?
290 "bad line quality" : "driver error");
291 sl->xleft = 0;
292 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
293 x25_asy_unlock(sl);
294 }
295 spin_unlock(&sl->lock);
296}
297
298/* Encapsulate an IP datagram and kick it into a TTY queue. */
299
300static netdev_tx_t x25_asy_xmit(struct sk_buff *skb,
301 struct net_device *dev)
302{
303 struct x25_asy *sl = netdev_priv(dev);
304 int err;
305
306 if (!netif_running(sl->dev)) {
307 netdev_err(dev, "xmit call when iface is down\n");
308 kfree_skb(skb);
309 return NETDEV_TX_OK;
310 }
311
312 switch (skb->data[0]) {
313 case X25_IFACE_DATA:
314 break;
315 case X25_IFACE_CONNECT: /* Connection request .. do nothing */
316 err = lapb_connect_request(dev);
317 if (err != LAPB_OK)
318 netdev_err(dev, "lapb_connect_request error: %d\n",
319 err);
320 kfree_skb(skb);
321 return NETDEV_TX_OK;
322 case X25_IFACE_DISCONNECT: /* do nothing - hang up ?? */
323 err = lapb_disconnect_request(dev);
324 if (err != LAPB_OK)
325 netdev_err(dev, "lapb_disconnect_request error: %d\n",
326 err);
327 /* fall through */
328 default:
329 kfree_skb(skb);
330 return NETDEV_TX_OK;
331 }
332 skb_pull(skb, 1); /* Remove control byte */
333 /*
334 * If we are busy already- too bad. We ought to be able
335 * to queue things at this point, to allow for a little
336 * frame buffer. Oh well...
337 * -----------------------------------------------------
338 * I hate queues in X.25 driver. May be it's efficient,
339 * but for me latency is more important. ;)
340 * So, no queues !
341 * 14 Oct 1994 Dmitry Gorodchanin.
342 */
343
344 err = lapb_data_request(dev, skb);
345 if (err != LAPB_OK) {
346 netdev_err(dev, "lapb_data_request error: %d\n", err);
347 kfree_skb(skb);
348 return NETDEV_TX_OK;
349 }
350 return NETDEV_TX_OK;
351}
352
353
354/*
355 * LAPB interface boilerplate
356 */
357
358/*
359 * Called when I frame data arrives. We did the work above - throw it
360 * at the net layer.
361 */
362
363static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb)
364{
365 return netif_rx(skb);
366}
367
368/*
369 * Data has emerged from the LAPB protocol machine. We don't handle
370 * busy cases too well. Its tricky to see how to do this nicely -
371 * perhaps lapb should allow us to bounce this ?
372 */
373
374static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb)
375{
376 struct x25_asy *sl = netdev_priv(dev);
377
378 spin_lock(&sl->lock);
379 if (netif_queue_stopped(sl->dev) || sl->tty == NULL) {
380 spin_unlock(&sl->lock);
381 netdev_err(dev, "tbusy drop\n");
382 kfree_skb(skb);
383 return;
384 }
385 /* We were not busy, so we are now... :-) */
386 if (skb != NULL) {
387 x25_asy_lock(sl);
388 dev->stats.tx_bytes += skb->len;
389 x25_asy_encaps(sl, skb->data, skb->len);
390 dev_kfree_skb(skb);
391 }
392 spin_unlock(&sl->lock);
393}
394
395/*
396 * LAPB connection establish/down information.
397 */
398
399static void x25_asy_connected(struct net_device *dev, int reason)
400{
401 struct x25_asy *sl = netdev_priv(dev);
402 struct sk_buff *skb;
403 unsigned char *ptr;
404
405 skb = dev_alloc_skb(1);
406 if (skb == NULL) {
407 netdev_err(dev, "out of memory\n");
408 return;
409 }
410
411 ptr = skb_put(skb, 1);
412 *ptr = X25_IFACE_CONNECT;
413
414 skb->protocol = x25_type_trans(skb, sl->dev);
415 netif_rx(skb);
416}
417
418static void x25_asy_disconnected(struct net_device *dev, int reason)
419{
420 struct x25_asy *sl = netdev_priv(dev);
421 struct sk_buff *skb;
422 unsigned char *ptr;
423
424 skb = dev_alloc_skb(1);
425 if (skb == NULL) {
426 netdev_err(dev, "out of memory\n");
427 return;
428 }
429
430 ptr = skb_put(skb, 1);
431 *ptr = X25_IFACE_DISCONNECT;
432
433 skb->protocol = x25_type_trans(skb, sl->dev);
434 netif_rx(skb);
435}
436
437static const struct lapb_register_struct x25_asy_callbacks = {
438 .connect_confirmation = x25_asy_connected,
439 .connect_indication = x25_asy_connected,
440 .disconnect_confirmation = x25_asy_disconnected,
441 .disconnect_indication = x25_asy_disconnected,
442 .data_indication = x25_asy_data_indication,
443 .data_transmit = x25_asy_data_transmit,
444};
445
446
447/* Open the low-level part of the X.25 channel. Easy! */
448static int x25_asy_open(struct net_device *dev)
449{
450 struct x25_asy *sl = netdev_priv(dev);
451 unsigned long len;
452 int err;
453
454 if (sl->tty == NULL)
455 return -ENODEV;
456
457 /*
458 * Allocate the X.25 frame buffers:
459 *
460 * rbuff Receive buffer.
461 * xbuff Transmit buffer.
462 */
463
464 len = dev->mtu * 2;
465
466 sl->rbuff = kmalloc(len + 4, GFP_KERNEL);
467 if (sl->rbuff == NULL)
468 goto norbuff;
469 sl->xbuff = kmalloc(len + 4, GFP_KERNEL);
470 if (sl->xbuff == NULL)
471 goto noxbuff;
472
473 sl->buffsize = len;
474 sl->rcount = 0;
475 sl->xleft = 0;
476 sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */
477
478 netif_start_queue(dev);
479
480 /*
481 * Now attach LAPB
482 */
483 err = lapb_register(dev, &x25_asy_callbacks);
484 if (err == LAPB_OK)
485 return 0;
486
487 /* Cleanup */
488 kfree(sl->xbuff);
489noxbuff:
490 kfree(sl->rbuff);
491norbuff:
492 return -ENOMEM;
493}
494
495
496/* Close the low-level part of the X.25 channel. Easy! */
497static int x25_asy_close(struct net_device *dev)
498{
499 struct x25_asy *sl = netdev_priv(dev);
500
501 spin_lock(&sl->lock);
502 if (sl->tty)
503 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
504
505 netif_stop_queue(dev);
506 sl->rcount = 0;
507 sl->xleft = 0;
508 spin_unlock(&sl->lock);
509 return 0;
510}
511
512/*
513 * Handle the 'receiver data ready' interrupt.
514 * This function is called by the 'tty_io' module in the kernel when
515 * a block of X.25 data has been received, which can now be decapsulated
516 * and sent on to some IP layer for further processing.
517 */
518
519static void x25_asy_receive_buf(struct tty_struct *tty,
520 const unsigned char *cp, char *fp, int count)
521{
522 struct x25_asy *sl = tty->disc_data;
523
524 if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
525 return;
526
527
528 /* Read the characters out of the buffer */
529 while (count--) {
530 if (fp && *fp++) {
531 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
532 sl->dev->stats.rx_errors++;
533 cp++;
534 continue;
535 }
536 x25_asy_unesc(sl, *cp++);
537 }
538}
539
540/*
541 * Open the high-level part of the X.25 channel.
542 * This function is called by the TTY module when the
543 * X.25 line discipline is called for. Because we are
544 * sure the tty line exists, we only have to link it to
545 * a free X.25 channel...
546 */
547
548static int x25_asy_open_tty(struct tty_struct *tty)
549{
550 struct x25_asy *sl;
551 int err;
552
553 if (tty->ops->write == NULL)
554 return -EOPNOTSUPP;
555
556 /* OK. Find a free X.25 channel to use. */
557 sl = x25_asy_alloc();
558 if (sl == NULL)
559 return -ENFILE;
560
561 sl->tty = tty;
562 tty->disc_data = sl;
563 tty->receive_room = 65536;
564 tty_driver_flush_buffer(tty);
565 tty_ldisc_flush(tty);
566
567 /* Restore default settings */
568 sl->dev->type = ARPHRD_X25;
569
570 /* Perform the low-level X.25 async init */
571 err = x25_asy_open(sl->dev);
572 if (err) {
573 x25_asy_free(sl);
574 return err;
575 }
576 /* Done. We have linked the TTY line to a channel. */
577 return 0;
578}
579
580
581/*
582 * Close down an X.25 channel.
583 * This means flushing out any pending queues, and then restoring the
584 * TTY line discipline to what it was before it got hooked to X.25
585 * (which usually is TTY again).
586 */
587static void x25_asy_close_tty(struct tty_struct *tty)
588{
589 struct x25_asy *sl = tty->disc_data;
590 int err;
591
592 /* First make sure we're connected. */
593 if (!sl || sl->magic != X25_ASY_MAGIC)
594 return;
595
596 rtnl_lock();
597 if (sl->dev->flags & IFF_UP)
598 dev_close(sl->dev);
599 rtnl_unlock();
600
601 err = lapb_unregister(sl->dev);
602 if (err != LAPB_OK)
603 pr_err("x25_asy_close: lapb_unregister error: %d\n",
604 err);
605
606 tty->disc_data = NULL;
607 sl->tty = NULL;
608 x25_asy_free(sl);
609}
610
611 /************************************************************************
612 * STANDARD X.25 ENCAPSULATION *
613 ************************************************************************/
614
615static int x25_asy_esc(unsigned char *s, unsigned char *d, int len)
616{
617 unsigned char *ptr = d;
618 unsigned char c;
619
620 /*
621 * Send an initial END character to flush out any
622 * data that may have accumulated in the receiver
623 * due to line noise.
624 */
625
626 *ptr++ = X25_END; /* Send 10111110 bit seq */
627
628 /*
629 * For each byte in the packet, send the appropriate
630 * character sequence, according to the X.25 protocol.
631 */
632
633 while (len-- > 0) {
634 switch (c = *s++) {
635 case X25_END:
636 *ptr++ = X25_ESC;
637 *ptr++ = X25_ESCAPE(X25_END);
638 break;
639 case X25_ESC:
640 *ptr++ = X25_ESC;
641 *ptr++ = X25_ESCAPE(X25_ESC);
642 break;
643 default:
644 *ptr++ = c;
645 break;
646 }
647 }
648 *ptr++ = X25_END;
649 return ptr - d;
650}
651
652static void x25_asy_unesc(struct x25_asy *sl, unsigned char s)
653{
654
655 switch (s) {
656 case X25_END:
657 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
658 sl->rcount > 2)
659 x25_asy_bump(sl);
660 clear_bit(SLF_ESCAPE, &sl->flags);
661 sl->rcount = 0;
662 return;
663 case X25_ESC:
664 set_bit(SLF_ESCAPE, &sl->flags);
665 return;
666 case X25_ESCAPE(X25_ESC):
667 case X25_ESCAPE(X25_END):
668 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
669 s = X25_UNESCAPE(s);
670 break;
671 }
672 if (!test_bit(SLF_ERROR, &sl->flags)) {
673 if (sl->rcount < sl->buffsize) {
674 sl->rbuff[sl->rcount++] = s;
675 return;
676 }
677 sl->dev->stats.rx_over_errors++;
678 set_bit(SLF_ERROR, &sl->flags);
679 }
680}
681
682
683/* Perform I/O control on an active X.25 channel. */
684static int x25_asy_ioctl(struct tty_struct *tty, struct file *file,
685 unsigned int cmd, unsigned long arg)
686{
687 struct x25_asy *sl = tty->disc_data;
688
689 /* First make sure we're connected. */
690 if (!sl || sl->magic != X25_ASY_MAGIC)
691 return -EINVAL;
692
693 switch (cmd) {
694 case SIOCGIFNAME:
695 if (copy_to_user((void __user *)arg, sl->dev->name,
696 strlen(sl->dev->name) + 1))
697 return -EFAULT;
698 return 0;
699 case SIOCSIFHWADDR:
700 return -EINVAL;
701 default:
702 return tty_mode_ioctl(tty, file, cmd, arg);
703 }
704}
705
706#ifdef CONFIG_COMPAT
707static long x25_asy_compat_ioctl(struct tty_struct *tty, struct file *file,
708 unsigned int cmd, unsigned long arg)
709{
710 switch (cmd) {
711 case SIOCGIFNAME:
712 case SIOCSIFHWADDR:
713 return x25_asy_ioctl(tty, file, cmd,
714 (unsigned long)compat_ptr(arg));
715 }
716
717 return -ENOIOCTLCMD;
718}
719#endif
720
721static int x25_asy_open_dev(struct net_device *dev)
722{
723 struct x25_asy *sl = netdev_priv(dev);
724 if (sl->tty == NULL)
725 return -ENODEV;
726 return 0;
727}
728
729static const struct net_device_ops x25_asy_netdev_ops = {
730 .ndo_open = x25_asy_open_dev,
731 .ndo_stop = x25_asy_close,
732 .ndo_start_xmit = x25_asy_xmit,
733 .ndo_tx_timeout = x25_asy_timeout,
734 .ndo_change_mtu = x25_asy_change_mtu,
735};
736
737/* Initialise the X.25 driver. Called by the device init code */
738static void x25_asy_setup(struct net_device *dev)
739{
740 struct x25_asy *sl = netdev_priv(dev);
741
742 sl->magic = X25_ASY_MAGIC;
743 sl->dev = dev;
744 spin_lock_init(&sl->lock);
745 set_bit(SLF_INUSE, &sl->flags);
746
747 /*
748 * Finish setting up the DEVICE info.
749 */
750
751 dev->mtu = SL_MTU;
752 dev->min_mtu = 0;
753 dev->max_mtu = 65534;
754 dev->netdev_ops = &x25_asy_netdev_ops;
755 dev->watchdog_timeo = HZ*20;
756 dev->hard_header_len = 0;
757 dev->addr_len = 0;
758 dev->type = ARPHRD_X25;
759 dev->tx_queue_len = 10;
760
761 /* New-style flags. */
762 dev->flags = IFF_NOARP;
763}
764
765static struct tty_ldisc_ops x25_ldisc = {
766 .owner = THIS_MODULE,
767 .magic = TTY_LDISC_MAGIC,
768 .name = "X.25",
769 .open = x25_asy_open_tty,
770 .close = x25_asy_close_tty,
771 .ioctl = x25_asy_ioctl,
772#ifdef CONFIG_COMPAT
773 .compat_ioctl = x25_asy_compat_ioctl,
774#endif
775 .receive_buf = x25_asy_receive_buf,
776 .write_wakeup = x25_asy_write_wakeup,
777};
778
779static int __init init_x25_asy(void)
780{
781 if (x25_asy_maxdev < 4)
782 x25_asy_maxdev = 4; /* Sanity */
783
784 pr_info("X.25 async: version 0.00 ALPHA (dynamic channels, max=%d)\n",
785 x25_asy_maxdev);
786
787 x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device *),
788 GFP_KERNEL);
789 if (!x25_asy_devs)
790 return -ENOMEM;
791
792 return tty_register_ldisc(N_X25, &x25_ldisc);
793}
794
795
796static void __exit exit_x25_asy(void)
797{
798 struct net_device *dev;
799 int i;
800
801 for (i = 0; i < x25_asy_maxdev; i++) {
802 dev = x25_asy_devs[i];
803 if (dev) {
804 struct x25_asy *sl = netdev_priv(dev);
805
806 spin_lock_bh(&sl->lock);
807 if (sl->tty)
808 tty_hangup(sl->tty);
809
810 spin_unlock_bh(&sl->lock);
811 /*
812 * VSV = if dev->start==0, then device
813 * unregistered while close proc.
814 */
815 unregister_netdev(dev);
816 free_netdev(dev);
817 }
818 }
819
820 kfree(x25_asy_devs);
821 tty_unregister_ldisc(N_X25);
822}
823
824module_init(init_x25_asy);
825module_exit(exit_x25_asy);
1/*
2 * Things to sort out:
3 *
4 * o tbusy handling
5 * o allow users to set the parameters
6 * o sync/async switching ?
7 *
8 * Note: This does _not_ implement CCITT X.25 asynchronous framing
9 * recommendations. Its primarily for testing purposes. If you wanted
10 * to do CCITT then in theory all you need is to nick the HDLC async
11 * checksum routines from ppp.c
12 * Changes:
13 *
14 * 2000-10-29 Henner Eisen lapb_data_indication() return status.
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/module.h>
20
21#include <asm/system.h>
22#include <linux/uaccess.h>
23#include <linux/bitops.h>
24#include <linux/string.h>
25#include <linux/mm.h>
26#include <linux/interrupt.h>
27#include <linux/in.h>
28#include <linux/tty.h>
29#include <linux/errno.h>
30#include <linux/netdevice.h>
31#include <linux/etherdevice.h>
32#include <linux/skbuff.h>
33#include <linux/if_arp.h>
34#include <linux/lapb.h>
35#include <linux/init.h>
36#include <linux/rtnetlink.h>
37#include <linux/compat.h>
38#include <linux/slab.h>
39#include <net/x25device.h>
40#include "x25_asy.h"
41
42static struct net_device **x25_asy_devs;
43static int x25_asy_maxdev = SL_NRUNIT;
44
45module_param(x25_asy_maxdev, int, 0);
46MODULE_LICENSE("GPL");
47
48static int x25_asy_esc(unsigned char *p, unsigned char *d, int len);
49static void x25_asy_unesc(struct x25_asy *sl, unsigned char c);
50static void x25_asy_setup(struct net_device *dev);
51
52/* Find a free X.25 channel, and link in this `tty' line. */
53static struct x25_asy *x25_asy_alloc(void)
54{
55 struct net_device *dev = NULL;
56 struct x25_asy *sl;
57 int i;
58
59 if (x25_asy_devs == NULL)
60 return NULL; /* Master array missing ! */
61
62 for (i = 0; i < x25_asy_maxdev; i++) {
63 dev = x25_asy_devs[i];
64
65 /* Not allocated ? */
66 if (dev == NULL)
67 break;
68
69 sl = netdev_priv(dev);
70 /* Not in use ? */
71 if (!test_and_set_bit(SLF_INUSE, &sl->flags))
72 return sl;
73 }
74
75
76 /* Sorry, too many, all slots in use */
77 if (i >= x25_asy_maxdev)
78 return NULL;
79
80 /* If no channels are available, allocate one */
81 if (!dev) {
82 char name[IFNAMSIZ];
83 sprintf(name, "x25asy%d", i);
84
85 dev = alloc_netdev(sizeof(struct x25_asy),
86 name, x25_asy_setup);
87 if (!dev)
88 return NULL;
89
90 /* Initialize channel control data */
91 sl = netdev_priv(dev);
92 dev->base_addr = i;
93
94 /* register device so that it can be ifconfig'ed */
95 if (register_netdev(dev) == 0) {
96 /* (Re-)Set the INUSE bit. Very Important! */
97 set_bit(SLF_INUSE, &sl->flags);
98 x25_asy_devs[i] = dev;
99 return sl;
100 } else {
101 pr_warn("%s(): register_netdev() failure\n", __func__);
102 free_netdev(dev);
103 }
104 }
105 return NULL;
106}
107
108
109/* Free an X.25 channel. */
110static void x25_asy_free(struct x25_asy *sl)
111{
112 /* Free all X.25 frame buffers. */
113 kfree(sl->rbuff);
114 sl->rbuff = NULL;
115 kfree(sl->xbuff);
116 sl->xbuff = NULL;
117
118 if (!test_and_clear_bit(SLF_INUSE, &sl->flags))
119 netdev_err(sl->dev, "x25_asy_free for already free unit\n");
120}
121
122static int x25_asy_change_mtu(struct net_device *dev, int newmtu)
123{
124 struct x25_asy *sl = netdev_priv(dev);
125 unsigned char *xbuff, *rbuff;
126 int len = 2 * newmtu;
127
128 xbuff = kmalloc(len + 4, GFP_ATOMIC);
129 rbuff = kmalloc(len + 4, GFP_ATOMIC);
130
131 if (xbuff == NULL || rbuff == NULL) {
132 netdev_warn(dev, "unable to grow X.25 buffers, MTU change cancelled\n");
133 kfree(xbuff);
134 kfree(rbuff);
135 return -ENOMEM;
136 }
137
138 spin_lock_bh(&sl->lock);
139 xbuff = xchg(&sl->xbuff, xbuff);
140 if (sl->xleft) {
141 if (sl->xleft <= len) {
142 memcpy(sl->xbuff, sl->xhead, sl->xleft);
143 } else {
144 sl->xleft = 0;
145 dev->stats.tx_dropped++;
146 }
147 }
148 sl->xhead = sl->xbuff;
149
150 rbuff = xchg(&sl->rbuff, rbuff);
151 if (sl->rcount) {
152 if (sl->rcount <= len) {
153 memcpy(sl->rbuff, rbuff, sl->rcount);
154 } else {
155 sl->rcount = 0;
156 dev->stats.rx_over_errors++;
157 set_bit(SLF_ERROR, &sl->flags);
158 }
159 }
160
161 dev->mtu = newmtu;
162 sl->buffsize = len;
163
164 spin_unlock_bh(&sl->lock);
165
166 kfree(xbuff);
167 kfree(rbuff);
168 return 0;
169}
170
171
172/* Set the "sending" flag. This must be atomic, hence the ASM. */
173
174static inline void x25_asy_lock(struct x25_asy *sl)
175{
176 netif_stop_queue(sl->dev);
177}
178
179
180/* Clear the "sending" flag. This must be atomic, hence the ASM. */
181
182static inline void x25_asy_unlock(struct x25_asy *sl)
183{
184 netif_wake_queue(sl->dev);
185}
186
187/* Send one completely decapsulated IP datagram to the IP layer. */
188
189static void x25_asy_bump(struct x25_asy *sl)
190{
191 struct net_device *dev = sl->dev;
192 struct sk_buff *skb;
193 int count;
194 int err;
195
196 count = sl->rcount;
197 dev->stats.rx_bytes += count;
198
199 skb = dev_alloc_skb(count+1);
200 if (skb == NULL) {
201 netdev_warn(sl->dev, "memory squeeze, dropping packet\n");
202 dev->stats.rx_dropped++;
203 return;
204 }
205 skb_push(skb, 1); /* LAPB internal control */
206 memcpy(skb_put(skb, count), sl->rbuff, count);
207 skb->protocol = x25_type_trans(skb, sl->dev);
208 err = lapb_data_received(skb->dev, skb);
209 if (err != LAPB_OK) {
210 kfree_skb(skb);
211 printk(KERN_DEBUG "x25_asy: data received err - %d\n", err);
212 } else {
213 netif_rx(skb);
214 dev->stats.rx_packets++;
215 }
216}
217
218/* Encapsulate one IP datagram and stuff into a TTY queue. */
219static void x25_asy_encaps(struct x25_asy *sl, unsigned char *icp, int len)
220{
221 unsigned char *p;
222 int actual, count, mtu = sl->dev->mtu;
223
224 if (len > mtu) {
225 /* Sigh, shouldn't occur BUT ... */
226 len = mtu;
227 printk(KERN_DEBUG "%s: truncating oversized transmit packet!\n",
228 sl->dev->name);
229 sl->dev->stats.tx_dropped++;
230 x25_asy_unlock(sl);
231 return;
232 }
233
234 p = icp;
235 count = x25_asy_esc(p, (unsigned char *) sl->xbuff, len);
236
237 /* Order of next two lines is *very* important.
238 * When we are sending a little amount of data,
239 * the transfer may be completed inside driver.write()
240 * routine, because it's running with interrupts enabled.
241 * In this case we *never* got WRITE_WAKEUP event,
242 * if we did not request it before write operation.
243 * 14 Oct 1994 Dmitry Gorodchanin.
244 */
245 set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
246 actual = sl->tty->ops->write(sl->tty, sl->xbuff, count);
247 sl->xleft = count - actual;
248 sl->xhead = sl->xbuff + actual;
249 /* VSV */
250 clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */
251}
252
253/*
254 * Called by the driver when there's room for more data. If we have
255 * more packets to send, we send them here.
256 */
257static void x25_asy_write_wakeup(struct tty_struct *tty)
258{
259 int actual;
260 struct x25_asy *sl = tty->disc_data;
261
262 /* First make sure we're connected. */
263 if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
264 return;
265
266 if (sl->xleft <= 0) {
267 /* Now serial buffer is almost free & we can start
268 * transmission of another packet */
269 sl->dev->stats.tx_packets++;
270 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
271 x25_asy_unlock(sl);
272 return;
273 }
274
275 actual = tty->ops->write(tty, sl->xhead, sl->xleft);
276 sl->xleft -= actual;
277 sl->xhead += actual;
278}
279
280static void x25_asy_timeout(struct net_device *dev)
281{
282 struct x25_asy *sl = netdev_priv(dev);
283
284 spin_lock(&sl->lock);
285 if (netif_queue_stopped(dev)) {
286 /* May be we must check transmitter timeout here ?
287 * 14 Oct 1994 Dmitry Gorodchanin.
288 */
289 netdev_warn(dev, "transmit timed out, %s?\n",
290 (tty_chars_in_buffer(sl->tty) || sl->xleft) ?
291 "bad line quality" : "driver error");
292 sl->xleft = 0;
293 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
294 x25_asy_unlock(sl);
295 }
296 spin_unlock(&sl->lock);
297}
298
299/* Encapsulate an IP datagram and kick it into a TTY queue. */
300
301static netdev_tx_t x25_asy_xmit(struct sk_buff *skb,
302 struct net_device *dev)
303{
304 struct x25_asy *sl = netdev_priv(dev);
305 int err;
306
307 if (!netif_running(sl->dev)) {
308 netdev_err(dev, "xmit call when iface is down\n");
309 kfree_skb(skb);
310 return NETDEV_TX_OK;
311 }
312
313 switch (skb->data[0]) {
314 case X25_IFACE_DATA:
315 break;
316 case X25_IFACE_CONNECT: /* Connection request .. do nothing */
317 err = lapb_connect_request(dev);
318 if (err != LAPB_OK)
319 netdev_err(dev, "lapb_connect_request error: %d\n",
320 err);
321 kfree_skb(skb);
322 return NETDEV_TX_OK;
323 case X25_IFACE_DISCONNECT: /* do nothing - hang up ?? */
324 err = lapb_disconnect_request(dev);
325 if (err != LAPB_OK)
326 netdev_err(dev, "lapb_disconnect_request error: %d\n",
327 err);
328 default:
329 kfree_skb(skb);
330 return NETDEV_TX_OK;
331 }
332 skb_pull(skb, 1); /* Remove control byte */
333 /*
334 * If we are busy already- too bad. We ought to be able
335 * to queue things at this point, to allow for a little
336 * frame buffer. Oh well...
337 * -----------------------------------------------------
338 * I hate queues in X.25 driver. May be it's efficient,
339 * but for me latency is more important. ;)
340 * So, no queues !
341 * 14 Oct 1994 Dmitry Gorodchanin.
342 */
343
344 err = lapb_data_request(dev, skb);
345 if (err != LAPB_OK) {
346 netdev_err(dev, "lapb_data_request error: %d\n", err);
347 kfree_skb(skb);
348 return NETDEV_TX_OK;
349 }
350 return NETDEV_TX_OK;
351}
352
353
354/*
355 * LAPB interface boilerplate
356 */
357
358/*
359 * Called when I frame data arrives. We did the work above - throw it
360 * at the net layer.
361 */
362
363static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb)
364{
365 return netif_rx(skb);
366}
367
368/*
369 * Data has emerged from the LAPB protocol machine. We don't handle
370 * busy cases too well. Its tricky to see how to do this nicely -
371 * perhaps lapb should allow us to bounce this ?
372 */
373
374static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb)
375{
376 struct x25_asy *sl = netdev_priv(dev);
377
378 spin_lock(&sl->lock);
379 if (netif_queue_stopped(sl->dev) || sl->tty == NULL) {
380 spin_unlock(&sl->lock);
381 netdev_err(dev, "tbusy drop\n");
382 kfree_skb(skb);
383 return;
384 }
385 /* We were not busy, so we are now... :-) */
386 if (skb != NULL) {
387 x25_asy_lock(sl);
388 dev->stats.tx_bytes += skb->len;
389 x25_asy_encaps(sl, skb->data, skb->len);
390 dev_kfree_skb(skb);
391 }
392 spin_unlock(&sl->lock);
393}
394
395/*
396 * LAPB connection establish/down information.
397 */
398
399static void x25_asy_connected(struct net_device *dev, int reason)
400{
401 struct x25_asy *sl = netdev_priv(dev);
402 struct sk_buff *skb;
403 unsigned char *ptr;
404
405 skb = dev_alloc_skb(1);
406 if (skb == NULL) {
407 netdev_err(dev, "out of memory\n");
408 return;
409 }
410
411 ptr = skb_put(skb, 1);
412 *ptr = X25_IFACE_CONNECT;
413
414 skb->protocol = x25_type_trans(skb, sl->dev);
415 netif_rx(skb);
416}
417
418static void x25_asy_disconnected(struct net_device *dev, int reason)
419{
420 struct x25_asy *sl = netdev_priv(dev);
421 struct sk_buff *skb;
422 unsigned char *ptr;
423
424 skb = dev_alloc_skb(1);
425 if (skb == NULL) {
426 netdev_err(dev, "out of memory\n");
427 return;
428 }
429
430 ptr = skb_put(skb, 1);
431 *ptr = X25_IFACE_DISCONNECT;
432
433 skb->protocol = x25_type_trans(skb, sl->dev);
434 netif_rx(skb);
435}
436
437static struct lapb_register_struct x25_asy_callbacks = {
438 .connect_confirmation = x25_asy_connected,
439 .connect_indication = x25_asy_connected,
440 .disconnect_confirmation = x25_asy_disconnected,
441 .disconnect_indication = x25_asy_disconnected,
442 .data_indication = x25_asy_data_indication,
443 .data_transmit = x25_asy_data_transmit,
444
445};
446
447
448/* Open the low-level part of the X.25 channel. Easy! */
449static int x25_asy_open(struct net_device *dev)
450{
451 struct x25_asy *sl = netdev_priv(dev);
452 unsigned long len;
453 int err;
454
455 if (sl->tty == NULL)
456 return -ENODEV;
457
458 /*
459 * Allocate the X.25 frame buffers:
460 *
461 * rbuff Receive buffer.
462 * xbuff Transmit buffer.
463 */
464
465 len = dev->mtu * 2;
466
467 sl->rbuff = kmalloc(len + 4, GFP_KERNEL);
468 if (sl->rbuff == NULL)
469 goto norbuff;
470 sl->xbuff = kmalloc(len + 4, GFP_KERNEL);
471 if (sl->xbuff == NULL)
472 goto noxbuff;
473
474 sl->buffsize = len;
475 sl->rcount = 0;
476 sl->xleft = 0;
477 sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */
478
479 netif_start_queue(dev);
480
481 /*
482 * Now attach LAPB
483 */
484 err = lapb_register(dev, &x25_asy_callbacks);
485 if (err == LAPB_OK)
486 return 0;
487
488 /* Cleanup */
489 kfree(sl->xbuff);
490noxbuff:
491 kfree(sl->rbuff);
492norbuff:
493 return -ENOMEM;
494}
495
496
497/* Close the low-level part of the X.25 channel. Easy! */
498static int x25_asy_close(struct net_device *dev)
499{
500 struct x25_asy *sl = netdev_priv(dev);
501
502 spin_lock(&sl->lock);
503 if (sl->tty)
504 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
505
506 netif_stop_queue(dev);
507 sl->rcount = 0;
508 sl->xleft = 0;
509 spin_unlock(&sl->lock);
510 return 0;
511}
512
513/*
514 * Handle the 'receiver data ready' interrupt.
515 * This function is called by the 'tty_io' module in the kernel when
516 * a block of X.25 data has been received, which can now be decapsulated
517 * and sent on to some IP layer for further processing.
518 */
519
520static void x25_asy_receive_buf(struct tty_struct *tty,
521 const unsigned char *cp, char *fp, int count)
522{
523 struct x25_asy *sl = tty->disc_data;
524
525 if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
526 return;
527
528
529 /* Read the characters out of the buffer */
530 while (count--) {
531 if (fp && *fp++) {
532 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
533 sl->dev->stats.rx_errors++;
534 cp++;
535 continue;
536 }
537 x25_asy_unesc(sl, *cp++);
538 }
539}
540
541/*
542 * Open the high-level part of the X.25 channel.
543 * This function is called by the TTY module when the
544 * X.25 line discipline is called for. Because we are
545 * sure the tty line exists, we only have to link it to
546 * a free X.25 channel...
547 */
548
549static int x25_asy_open_tty(struct tty_struct *tty)
550{
551 struct x25_asy *sl = tty->disc_data;
552 int err;
553
554 if (tty->ops->write == NULL)
555 return -EOPNOTSUPP;
556
557 /* First make sure we're not already connected. */
558 if (sl && sl->magic == X25_ASY_MAGIC)
559 return -EEXIST;
560
561 /* OK. Find a free X.25 channel to use. */
562 sl = x25_asy_alloc();
563 if (sl == NULL)
564 return -ENFILE;
565
566 sl->tty = tty;
567 tty->disc_data = sl;
568 tty->receive_room = 65536;
569 tty_driver_flush_buffer(tty);
570 tty_ldisc_flush(tty);
571
572 /* Restore default settings */
573 sl->dev->type = ARPHRD_X25;
574
575 /* Perform the low-level X.25 async init */
576 err = x25_asy_open(sl->dev);
577 if (err)
578 return err;
579 /* Done. We have linked the TTY line to a channel. */
580 return 0;
581}
582
583
584/*
585 * Close down an X.25 channel.
586 * This means flushing out any pending queues, and then restoring the
587 * TTY line discipline to what it was before it got hooked to X.25
588 * (which usually is TTY again).
589 */
590static void x25_asy_close_tty(struct tty_struct *tty)
591{
592 struct x25_asy *sl = tty->disc_data;
593 int err;
594
595 /* First make sure we're connected. */
596 if (!sl || sl->magic != X25_ASY_MAGIC)
597 return;
598
599 rtnl_lock();
600 if (sl->dev->flags & IFF_UP)
601 dev_close(sl->dev);
602 rtnl_unlock();
603
604 err = lapb_unregister(sl->dev);
605 if (err != LAPB_OK)
606 pr_err("x25_asy_close: lapb_unregister error: %d\n",
607 err);
608
609 tty->disc_data = NULL;
610 sl->tty = NULL;
611 x25_asy_free(sl);
612}
613
614 /************************************************************************
615 * STANDARD X.25 ENCAPSULATION *
616 ************************************************************************/
617
618static int x25_asy_esc(unsigned char *s, unsigned char *d, int len)
619{
620 unsigned char *ptr = d;
621 unsigned char c;
622
623 /*
624 * Send an initial END character to flush out any
625 * data that may have accumulated in the receiver
626 * due to line noise.
627 */
628
629 *ptr++ = X25_END; /* Send 10111110 bit seq */
630
631 /*
632 * For each byte in the packet, send the appropriate
633 * character sequence, according to the X.25 protocol.
634 */
635
636 while (len-- > 0) {
637 switch (c = *s++) {
638 case X25_END:
639 *ptr++ = X25_ESC;
640 *ptr++ = X25_ESCAPE(X25_END);
641 break;
642 case X25_ESC:
643 *ptr++ = X25_ESC;
644 *ptr++ = X25_ESCAPE(X25_ESC);
645 break;
646 default:
647 *ptr++ = c;
648 break;
649 }
650 }
651 *ptr++ = X25_END;
652 return ptr - d;
653}
654
655static void x25_asy_unesc(struct x25_asy *sl, unsigned char s)
656{
657
658 switch (s) {
659 case X25_END:
660 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
661 sl->rcount > 2)
662 x25_asy_bump(sl);
663 clear_bit(SLF_ESCAPE, &sl->flags);
664 sl->rcount = 0;
665 return;
666 case X25_ESC:
667 set_bit(SLF_ESCAPE, &sl->flags);
668 return;
669 case X25_ESCAPE(X25_ESC):
670 case X25_ESCAPE(X25_END):
671 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
672 s = X25_UNESCAPE(s);
673 break;
674 }
675 if (!test_bit(SLF_ERROR, &sl->flags)) {
676 if (sl->rcount < sl->buffsize) {
677 sl->rbuff[sl->rcount++] = s;
678 return;
679 }
680 sl->dev->stats.rx_over_errors++;
681 set_bit(SLF_ERROR, &sl->flags);
682 }
683}
684
685
686/* Perform I/O control on an active X.25 channel. */
687static int x25_asy_ioctl(struct tty_struct *tty, struct file *file,
688 unsigned int cmd, unsigned long arg)
689{
690 struct x25_asy *sl = tty->disc_data;
691
692 /* First make sure we're connected. */
693 if (!sl || sl->magic != X25_ASY_MAGIC)
694 return -EINVAL;
695
696 switch (cmd) {
697 case SIOCGIFNAME:
698 if (copy_to_user((void __user *)arg, sl->dev->name,
699 strlen(sl->dev->name) + 1))
700 return -EFAULT;
701 return 0;
702 case SIOCSIFHWADDR:
703 return -EINVAL;
704 default:
705 return tty_mode_ioctl(tty, file, cmd, arg);
706 }
707}
708
709#ifdef CONFIG_COMPAT
710static long x25_asy_compat_ioctl(struct tty_struct *tty, struct file *file,
711 unsigned int cmd, unsigned long arg)
712{
713 switch (cmd) {
714 case SIOCGIFNAME:
715 case SIOCSIFHWADDR:
716 return x25_asy_ioctl(tty, file, cmd,
717 (unsigned long)compat_ptr(arg));
718 }
719
720 return -ENOIOCTLCMD;
721}
722#endif
723
724static int x25_asy_open_dev(struct net_device *dev)
725{
726 struct x25_asy *sl = netdev_priv(dev);
727 if (sl->tty == NULL)
728 return -ENODEV;
729 return 0;
730}
731
732static const struct net_device_ops x25_asy_netdev_ops = {
733 .ndo_open = x25_asy_open_dev,
734 .ndo_stop = x25_asy_close,
735 .ndo_start_xmit = x25_asy_xmit,
736 .ndo_tx_timeout = x25_asy_timeout,
737 .ndo_change_mtu = x25_asy_change_mtu,
738};
739
740/* Initialise the X.25 driver. Called by the device init code */
741static void x25_asy_setup(struct net_device *dev)
742{
743 struct x25_asy *sl = netdev_priv(dev);
744
745 sl->magic = X25_ASY_MAGIC;
746 sl->dev = dev;
747 spin_lock_init(&sl->lock);
748 set_bit(SLF_INUSE, &sl->flags);
749
750 /*
751 * Finish setting up the DEVICE info.
752 */
753
754 dev->mtu = SL_MTU;
755 dev->netdev_ops = &x25_asy_netdev_ops;
756 dev->watchdog_timeo = HZ*20;
757 dev->hard_header_len = 0;
758 dev->addr_len = 0;
759 dev->type = ARPHRD_X25;
760 dev->tx_queue_len = 10;
761
762 /* New-style flags. */
763 dev->flags = IFF_NOARP;
764}
765
766static struct tty_ldisc_ops x25_ldisc = {
767 .owner = THIS_MODULE,
768 .magic = TTY_LDISC_MAGIC,
769 .name = "X.25",
770 .open = x25_asy_open_tty,
771 .close = x25_asy_close_tty,
772 .ioctl = x25_asy_ioctl,
773#ifdef CONFIG_COMPAT
774 .compat_ioctl = x25_asy_compat_ioctl,
775#endif
776 .receive_buf = x25_asy_receive_buf,
777 .write_wakeup = x25_asy_write_wakeup,
778};
779
780static int __init init_x25_asy(void)
781{
782 if (x25_asy_maxdev < 4)
783 x25_asy_maxdev = 4; /* Sanity */
784
785 pr_info("X.25 async: version 0.00 ALPHA (dynamic channels, max=%d)\n",
786 x25_asy_maxdev);
787
788 x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device *),
789 GFP_KERNEL);
790 if (!x25_asy_devs) {
791 pr_warn("Can't allocate x25_asy_ctrls[] array! Uaargh! (-> No X.25 available)\n");
792 return -ENOMEM;
793 }
794
795 return tty_register_ldisc(N_X25, &x25_ldisc);
796}
797
798
799static void __exit exit_x25_asy(void)
800{
801 struct net_device *dev;
802 int i;
803
804 for (i = 0; i < x25_asy_maxdev; i++) {
805 dev = x25_asy_devs[i];
806 if (dev) {
807 struct x25_asy *sl = netdev_priv(dev);
808
809 spin_lock_bh(&sl->lock);
810 if (sl->tty)
811 tty_hangup(sl->tty);
812
813 spin_unlock_bh(&sl->lock);
814 /*
815 * VSV = if dev->start==0, then device
816 * unregistered while close proc.
817 */
818 unregister_netdev(dev);
819 free_netdev(dev);
820 }
821 }
822
823 kfree(x25_asy_devs);
824 tty_unregister_ldisc(N_X25);
825}
826
827module_init(init_x25_asy);
828module_exit(exit_x25_asy);