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Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[deliverable/linux.git] / drivers / net / wan / x25_asy.c
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
41 static struct net_device **x25_asy_devs;
42 static int x25_asy_maxdev = SL_NRUNIT;
43
44 module_param(x25_asy_maxdev, int, 0);
45 MODULE_LICENSE("GPL");
46
47 static int x25_asy_esc(unsigned char *p, unsigned char *d, int len);
48 static void x25_asy_unesc(struct x25_asy *sl, unsigned char c);
49 static void x25_asy_setup(struct net_device *dev);
50
51 /* Find a free X.25 channel, and link in this `tty' line. */
52 static 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. */
109 static 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
121 static 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 if (newmtu > 65534)
128 return -EINVAL;
129
130 len = 2 * newmtu;
131 xbuff = kmalloc(len + 4, GFP_ATOMIC);
132 rbuff = kmalloc(len + 4, GFP_ATOMIC);
133
134 if (xbuff == NULL || rbuff == NULL) {
135 kfree(xbuff);
136 kfree(rbuff);
137 return -ENOMEM;
138 }
139
140 spin_lock_bh(&sl->lock);
141 xbuff = xchg(&sl->xbuff, xbuff);
142 if (sl->xleft) {
143 if (sl->xleft <= len) {
144 memcpy(sl->xbuff, sl->xhead, sl->xleft);
145 } else {
146 sl->xleft = 0;
147 dev->stats.tx_dropped++;
148 }
149 }
150 sl->xhead = sl->xbuff;
151
152 rbuff = xchg(&sl->rbuff, rbuff);
153 if (sl->rcount) {
154 if (sl->rcount <= len) {
155 memcpy(sl->rbuff, rbuff, sl->rcount);
156 } else {
157 sl->rcount = 0;
158 dev->stats.rx_over_errors++;
159 set_bit(SLF_ERROR, &sl->flags);
160 }
161 }
162
163 dev->mtu = newmtu;
164 sl->buffsize = len;
165
166 spin_unlock_bh(&sl->lock);
167
168 kfree(xbuff);
169 kfree(rbuff);
170 return 0;
171 }
172
173
174 /* Set the "sending" flag. This must be atomic, hence the ASM. */
175
176 static inline void x25_asy_lock(struct x25_asy *sl)
177 {
178 netif_stop_queue(sl->dev);
179 }
180
181
182 /* Clear the "sending" flag. This must be atomic, hence the ASM. */
183
184 static inline void x25_asy_unlock(struct x25_asy *sl)
185 {
186 netif_wake_queue(sl->dev);
187 }
188
189 /* Send one completely decapsulated IP datagram to the IP layer. */
190
191 static void x25_asy_bump(struct x25_asy *sl)
192 {
193 struct net_device *dev = sl->dev;
194 struct sk_buff *skb;
195 int count;
196 int err;
197
198 count = sl->rcount;
199 dev->stats.rx_bytes += count;
200
201 skb = dev_alloc_skb(count+1);
202 if (skb == NULL) {
203 netdev_warn(sl->dev, "memory squeeze, dropping packet\n");
204 dev->stats.rx_dropped++;
205 return;
206 }
207 skb_push(skb, 1); /* LAPB internal control */
208 memcpy(skb_put(skb, count), sl->rbuff, count);
209 skb->protocol = x25_type_trans(skb, sl->dev);
210 err = lapb_data_received(skb->dev, skb);
211 if (err != LAPB_OK) {
212 kfree_skb(skb);
213 printk(KERN_DEBUG "x25_asy: data received err - %d\n", err);
214 } else {
215 netif_rx(skb);
216 dev->stats.rx_packets++;
217 }
218 }
219
220 /* Encapsulate one IP datagram and stuff into a TTY queue. */
221 static void x25_asy_encaps(struct x25_asy *sl, unsigned char *icp, int len)
222 {
223 unsigned char *p;
224 int actual, count, mtu = sl->dev->mtu;
225
226 if (len > mtu) {
227 /* Sigh, shouldn't occur BUT ... */
228 len = mtu;
229 printk(KERN_DEBUG "%s: truncating oversized transmit packet!\n",
230 sl->dev->name);
231 sl->dev->stats.tx_dropped++;
232 x25_asy_unlock(sl);
233 return;
234 }
235
236 p = icp;
237 count = x25_asy_esc(p, sl->xbuff, len);
238
239 /* Order of next two lines is *very* important.
240 * When we are sending a little amount of data,
241 * the transfer may be completed inside driver.write()
242 * routine, because it's running with interrupts enabled.
243 * In this case we *never* got WRITE_WAKEUP event,
244 * if we did not request it before write operation.
245 * 14 Oct 1994 Dmitry Gorodchanin.
246 */
247 set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
248 actual = sl->tty->ops->write(sl->tty, sl->xbuff, count);
249 sl->xleft = count - actual;
250 sl->xhead = sl->xbuff + actual;
251 /* VSV */
252 clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */
253 }
254
255 /*
256 * Called by the driver when there's room for more data. If we have
257 * more packets to send, we send them here.
258 */
259 static void x25_asy_write_wakeup(struct tty_struct *tty)
260 {
261 int actual;
262 struct x25_asy *sl = tty->disc_data;
263
264 /* First make sure we're connected. */
265 if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
266 return;
267
268 if (sl->xleft <= 0) {
269 /* Now serial buffer is almost free & we can start
270 * transmission of another packet */
271 sl->dev->stats.tx_packets++;
272 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
273 x25_asy_unlock(sl);
274 return;
275 }
276
277 actual = tty->ops->write(tty, sl->xhead, sl->xleft);
278 sl->xleft -= actual;
279 sl->xhead += actual;
280 }
281
282 static void x25_asy_timeout(struct net_device *dev)
283 {
284 struct x25_asy *sl = netdev_priv(dev);
285
286 spin_lock(&sl->lock);
287 if (netif_queue_stopped(dev)) {
288 /* May be we must check transmitter timeout here ?
289 * 14 Oct 1994 Dmitry Gorodchanin.
290 */
291 netdev_warn(dev, "transmit timed out, %s?\n",
292 (tty_chars_in_buffer(sl->tty) || sl->xleft) ?
293 "bad line quality" : "driver error");
294 sl->xleft = 0;
295 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
296 x25_asy_unlock(sl);
297 }
298 spin_unlock(&sl->lock);
299 }
300
301 /* Encapsulate an IP datagram and kick it into a TTY queue. */
302
303 static netdev_tx_t x25_asy_xmit(struct sk_buff *skb,
304 struct net_device *dev)
305 {
306 struct x25_asy *sl = netdev_priv(dev);
307 int err;
308
309 if (!netif_running(sl->dev)) {
310 netdev_err(dev, "xmit call when iface is down\n");
311 kfree_skb(skb);
312 return NETDEV_TX_OK;
313 }
314
315 switch (skb->data[0]) {
316 case X25_IFACE_DATA:
317 break;
318 case X25_IFACE_CONNECT: /* Connection request .. do nothing */
319 err = lapb_connect_request(dev);
320 if (err != LAPB_OK)
321 netdev_err(dev, "lapb_connect_request error: %d\n",
322 err);
323 kfree_skb(skb);
324 return NETDEV_TX_OK;
325 case X25_IFACE_DISCONNECT: /* do nothing - hang up ?? */
326 err = lapb_disconnect_request(dev);
327 if (err != LAPB_OK)
328 netdev_err(dev, "lapb_disconnect_request error: %d\n",
329 err);
330 default:
331 kfree_skb(skb);
332 return NETDEV_TX_OK;
333 }
334 skb_pull(skb, 1); /* Remove control byte */
335 /*
336 * If we are busy already- too bad. We ought to be able
337 * to queue things at this point, to allow for a little
338 * frame buffer. Oh well...
339 * -----------------------------------------------------
340 * I hate queues in X.25 driver. May be it's efficient,
341 * but for me latency is more important. ;)
342 * So, no queues !
343 * 14 Oct 1994 Dmitry Gorodchanin.
344 */
345
346 err = lapb_data_request(dev, skb);
347 if (err != LAPB_OK) {
348 netdev_err(dev, "lapb_data_request error: %d\n", err);
349 kfree_skb(skb);
350 return NETDEV_TX_OK;
351 }
352 return NETDEV_TX_OK;
353 }
354
355
356 /*
357 * LAPB interface boilerplate
358 */
359
360 /*
361 * Called when I frame data arrives. We did the work above - throw it
362 * at the net layer.
363 */
364
365 static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb)
366 {
367 return netif_rx(skb);
368 }
369
370 /*
371 * Data has emerged from the LAPB protocol machine. We don't handle
372 * busy cases too well. Its tricky to see how to do this nicely -
373 * perhaps lapb should allow us to bounce this ?
374 */
375
376 static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb)
377 {
378 struct x25_asy *sl = netdev_priv(dev);
379
380 spin_lock(&sl->lock);
381 if (netif_queue_stopped(sl->dev) || sl->tty == NULL) {
382 spin_unlock(&sl->lock);
383 netdev_err(dev, "tbusy drop\n");
384 kfree_skb(skb);
385 return;
386 }
387 /* We were not busy, so we are now... :-) */
388 if (skb != NULL) {
389 x25_asy_lock(sl);
390 dev->stats.tx_bytes += skb->len;
391 x25_asy_encaps(sl, skb->data, skb->len);
392 dev_kfree_skb(skb);
393 }
394 spin_unlock(&sl->lock);
395 }
396
397 /*
398 * LAPB connection establish/down information.
399 */
400
401 static void x25_asy_connected(struct net_device *dev, int reason)
402 {
403 struct x25_asy *sl = netdev_priv(dev);
404 struct sk_buff *skb;
405 unsigned char *ptr;
406
407 skb = dev_alloc_skb(1);
408 if (skb == NULL) {
409 netdev_err(dev, "out of memory\n");
410 return;
411 }
412
413 ptr = skb_put(skb, 1);
414 *ptr = X25_IFACE_CONNECT;
415
416 skb->protocol = x25_type_trans(skb, sl->dev);
417 netif_rx(skb);
418 }
419
420 static void x25_asy_disconnected(struct net_device *dev, int reason)
421 {
422 struct x25_asy *sl = netdev_priv(dev);
423 struct sk_buff *skb;
424 unsigned char *ptr;
425
426 skb = dev_alloc_skb(1);
427 if (skb == NULL) {
428 netdev_err(dev, "out of memory\n");
429 return;
430 }
431
432 ptr = skb_put(skb, 1);
433 *ptr = X25_IFACE_DISCONNECT;
434
435 skb->protocol = x25_type_trans(skb, sl->dev);
436 netif_rx(skb);
437 }
438
439 static const struct lapb_register_struct x25_asy_callbacks = {
440 .connect_confirmation = x25_asy_connected,
441 .connect_indication = x25_asy_connected,
442 .disconnect_confirmation = x25_asy_disconnected,
443 .disconnect_indication = x25_asy_disconnected,
444 .data_indication = x25_asy_data_indication,
445 .data_transmit = x25_asy_data_transmit,
446 };
447
448
449 /* Open the low-level part of the X.25 channel. Easy! */
450 static int x25_asy_open(struct net_device *dev)
451 {
452 struct x25_asy *sl = netdev_priv(dev);
453 unsigned long len;
454 int err;
455
456 if (sl->tty == NULL)
457 return -ENODEV;
458
459 /*
460 * Allocate the X.25 frame buffers:
461 *
462 * rbuff Receive buffer.
463 * xbuff Transmit buffer.
464 */
465
466 len = dev->mtu * 2;
467
468 sl->rbuff = kmalloc(len + 4, GFP_KERNEL);
469 if (sl->rbuff == NULL)
470 goto norbuff;
471 sl->xbuff = kmalloc(len + 4, GFP_KERNEL);
472 if (sl->xbuff == NULL)
473 goto noxbuff;
474
475 sl->buffsize = len;
476 sl->rcount = 0;
477 sl->xleft = 0;
478 sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */
479
480 netif_start_queue(dev);
481
482 /*
483 * Now attach LAPB
484 */
485 err = lapb_register(dev, &x25_asy_callbacks);
486 if (err == LAPB_OK)
487 return 0;
488
489 /* Cleanup */
490 kfree(sl->xbuff);
491 noxbuff:
492 kfree(sl->rbuff);
493 norbuff:
494 return -ENOMEM;
495 }
496
497
498 /* Close the low-level part of the X.25 channel. Easy! */
499 static int x25_asy_close(struct net_device *dev)
500 {
501 struct x25_asy *sl = netdev_priv(dev);
502
503 spin_lock(&sl->lock);
504 if (sl->tty)
505 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
506
507 netif_stop_queue(dev);
508 sl->rcount = 0;
509 sl->xleft = 0;
510 spin_unlock(&sl->lock);
511 return 0;
512 }
513
514 /*
515 * Handle the 'receiver data ready' interrupt.
516 * This function is called by the 'tty_io' module in the kernel when
517 * a block of X.25 data has been received, which can now be decapsulated
518 * and sent on to some IP layer for further processing.
519 */
520
521 static void x25_asy_receive_buf(struct tty_struct *tty,
522 const unsigned char *cp, char *fp, int count)
523 {
524 struct x25_asy *sl = tty->disc_data;
525
526 if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
527 return;
528
529
530 /* Read the characters out of the buffer */
531 while (count--) {
532 if (fp && *fp++) {
533 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
534 sl->dev->stats.rx_errors++;
535 cp++;
536 continue;
537 }
538 x25_asy_unesc(sl, *cp++);
539 }
540 }
541
542 /*
543 * Open the high-level part of the X.25 channel.
544 * This function is called by the TTY module when the
545 * X.25 line discipline is called for. Because we are
546 * sure the tty line exists, we only have to link it to
547 * a free X.25 channel...
548 */
549
550 static int x25_asy_open_tty(struct tty_struct *tty)
551 {
552 struct x25_asy *sl;
553 int err;
554
555 if (tty->ops->write == NULL)
556 return -EOPNOTSUPP;
557
558 /* OK. Find a free X.25 channel to use. */
559 sl = x25_asy_alloc();
560 if (sl == NULL)
561 return -ENFILE;
562
563 sl->tty = tty;
564 tty->disc_data = sl;
565 tty->receive_room = 65536;
566 tty_driver_flush_buffer(tty);
567 tty_ldisc_flush(tty);
568
569 /* Restore default settings */
570 sl->dev->type = ARPHRD_X25;
571
572 /* Perform the low-level X.25 async init */
573 err = x25_asy_open(sl->dev);
574 if (err) {
575 x25_asy_free(sl);
576 return err;
577 }
578 /* Done. We have linked the TTY line to a channel. */
579 return 0;
580 }
581
582
583 /*
584 * Close down an X.25 channel.
585 * This means flushing out any pending queues, and then restoring the
586 * TTY line discipline to what it was before it got hooked to X.25
587 * (which usually is TTY again).
588 */
589 static void x25_asy_close_tty(struct tty_struct *tty)
590 {
591 struct x25_asy *sl = tty->disc_data;
592 int err;
593
594 /* First make sure we're connected. */
595 if (!sl || sl->magic != X25_ASY_MAGIC)
596 return;
597
598 rtnl_lock();
599 if (sl->dev->flags & IFF_UP)
600 dev_close(sl->dev);
601 rtnl_unlock();
602
603 err = lapb_unregister(sl->dev);
604 if (err != LAPB_OK)
605 pr_err("x25_asy_close: lapb_unregister error: %d\n",
606 err);
607
608 tty->disc_data = NULL;
609 sl->tty = NULL;
610 x25_asy_free(sl);
611 }
612
613 /************************************************************************
614 * STANDARD X.25 ENCAPSULATION *
615 ************************************************************************/
616
617 static int x25_asy_esc(unsigned char *s, unsigned char *d, int len)
618 {
619 unsigned char *ptr = d;
620 unsigned char c;
621
622 /*
623 * Send an initial END character to flush out any
624 * data that may have accumulated in the receiver
625 * due to line noise.
626 */
627
628 *ptr++ = X25_END; /* Send 10111110 bit seq */
629
630 /*
631 * For each byte in the packet, send the appropriate
632 * character sequence, according to the X.25 protocol.
633 */
634
635 while (len-- > 0) {
636 switch (c = *s++) {
637 case X25_END:
638 *ptr++ = X25_ESC;
639 *ptr++ = X25_ESCAPE(X25_END);
640 break;
641 case X25_ESC:
642 *ptr++ = X25_ESC;
643 *ptr++ = X25_ESCAPE(X25_ESC);
644 break;
645 default:
646 *ptr++ = c;
647 break;
648 }
649 }
650 *ptr++ = X25_END;
651 return ptr - d;
652 }
653
654 static void x25_asy_unesc(struct x25_asy *sl, unsigned char s)
655 {
656
657 switch (s) {
658 case X25_END:
659 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
660 sl->rcount > 2)
661 x25_asy_bump(sl);
662 clear_bit(SLF_ESCAPE, &sl->flags);
663 sl->rcount = 0;
664 return;
665 case X25_ESC:
666 set_bit(SLF_ESCAPE, &sl->flags);
667 return;
668 case X25_ESCAPE(X25_ESC):
669 case X25_ESCAPE(X25_END):
670 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
671 s = X25_UNESCAPE(s);
672 break;
673 }
674 if (!test_bit(SLF_ERROR, &sl->flags)) {
675 if (sl->rcount < sl->buffsize) {
676 sl->rbuff[sl->rcount++] = s;
677 return;
678 }
679 sl->dev->stats.rx_over_errors++;
680 set_bit(SLF_ERROR, &sl->flags);
681 }
682 }
683
684
685 /* Perform I/O control on an active X.25 channel. */
686 static int x25_asy_ioctl(struct tty_struct *tty, struct file *file,
687 unsigned int cmd, unsigned long arg)
688 {
689 struct x25_asy *sl = tty->disc_data;
690
691 /* First make sure we're connected. */
692 if (!sl || sl->magic != X25_ASY_MAGIC)
693 return -EINVAL;
694
695 switch (cmd) {
696 case SIOCGIFNAME:
697 if (copy_to_user((void __user *)arg, sl->dev->name,
698 strlen(sl->dev->name) + 1))
699 return -EFAULT;
700 return 0;
701 case SIOCSIFHWADDR:
702 return -EINVAL;
703 default:
704 return tty_mode_ioctl(tty, file, cmd, arg);
705 }
706 }
707
708 #ifdef CONFIG_COMPAT
709 static long x25_asy_compat_ioctl(struct tty_struct *tty, struct file *file,
710 unsigned int cmd, unsigned long arg)
711 {
712 switch (cmd) {
713 case SIOCGIFNAME:
714 case SIOCSIFHWADDR:
715 return x25_asy_ioctl(tty, file, cmd,
716 (unsigned long)compat_ptr(arg));
717 }
718
719 return -ENOIOCTLCMD;
720 }
721 #endif
722
723 static int x25_asy_open_dev(struct net_device *dev)
724 {
725 struct x25_asy *sl = netdev_priv(dev);
726 if (sl->tty == NULL)
727 return -ENODEV;
728 return 0;
729 }
730
731 static const struct net_device_ops x25_asy_netdev_ops = {
732 .ndo_open = x25_asy_open_dev,
733 .ndo_stop = x25_asy_close,
734 .ndo_start_xmit = x25_asy_xmit,
735 .ndo_tx_timeout = x25_asy_timeout,
736 .ndo_change_mtu = x25_asy_change_mtu,
737 };
738
739 /* Initialise the X.25 driver. Called by the device init code */
740 static void x25_asy_setup(struct net_device *dev)
741 {
742 struct x25_asy *sl = netdev_priv(dev);
743
744 sl->magic = X25_ASY_MAGIC;
745 sl->dev = dev;
746 spin_lock_init(&sl->lock);
747 set_bit(SLF_INUSE, &sl->flags);
748
749 /*
750 * Finish setting up the DEVICE info.
751 */
752
753 dev->mtu = SL_MTU;
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
765 static 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
779 static 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
796 static 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
824 module_init(init_x25_asy);
825 module_exit(exit_x25_asy);
Linux kernel - Deliverables
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