Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | #include <linux/module.h> | |
18 | ||
19 | #include <asm/system.h> | |
20 | #include <asm/uaccess.h> | |
21 | #include <linux/bitops.h> | |
22 | #include <linux/string.h> | |
23 | #include <linux/mm.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/in.h> | |
26 | #include <linux/tty.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/netdevice.h> | |
29 | #include <linux/etherdevice.h> | |
30 | #include <linux/skbuff.h> | |
31 | #include <linux/if_arp.h> | |
32 | #include <linux/x25.h> | |
33 | #include <linux/lapb.h> | |
34 | #include <linux/init.h> | |
35 | #include "x25_asy.h" | |
36 | ||
37 | #include <net/x25device.h> | |
38 | ||
39 | static struct net_device **x25_asy_devs; | |
40 | static int x25_asy_maxdev = SL_NRUNIT; | |
41 | ||
42 | module_param(x25_asy_maxdev, int, 0); | |
43 | MODULE_LICENSE("GPL"); | |
44 | ||
45 | static int x25_asy_esc(unsigned char *p, unsigned char *d, int len); | |
46 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char c); | |
47 | static void x25_asy_setup(struct net_device *dev); | |
48 | ||
49 | /* Find a free X.25 channel, and link in this `tty' line. */ | |
50 | static struct x25_asy *x25_asy_alloc(void) | |
51 | { | |
52 | struct net_device *dev = NULL; | |
53 | struct x25_asy *sl; | |
54 | int i; | |
55 | ||
56 | if (x25_asy_devs == NULL) | |
57 | return NULL; /* Master array missing ! */ | |
58 | ||
59 | for (i = 0; i < x25_asy_maxdev; i++) { | |
60 | dev = x25_asy_devs[i]; | |
61 | ||
62 | /* Not allocated ? */ | |
63 | if (dev == NULL) | |
64 | break; | |
65 | ||
66 | sl = dev->priv; | |
67 | /* Not in use ? */ | |
68 | if (!test_and_set_bit(SLF_INUSE, &sl->flags)) | |
69 | return sl; | |
70 | } | |
71 | ||
72 | ||
73 | /* Sorry, too many, all slots in use */ | |
74 | if (i >= x25_asy_maxdev) | |
75 | return NULL; | |
76 | ||
77 | /* If no channels are available, allocate one */ | |
78 | if (!dev) { | |
79 | char name[IFNAMSIZ]; | |
80 | sprintf(name, "x25asy%d", i); | |
81 | ||
82 | dev = alloc_netdev(sizeof(struct x25_asy), | |
83 | name, x25_asy_setup); | |
84 | if (!dev) | |
85 | return NULL; | |
86 | ||
87 | /* Initialize channel control data */ | |
88 | sl = dev->priv; | |
89 | dev->base_addr = i; | |
90 | ||
91 | /* register device so that it can be ifconfig'ed */ | |
92 | if (register_netdev(dev) == 0) { | |
93 | /* (Re-)Set the INUSE bit. Very Important! */ | |
94 | set_bit(SLF_INUSE, &sl->flags); | |
95 | x25_asy_devs[i] = dev; | |
96 | return sl; | |
97 | } else { | |
98 | printk("x25_asy_alloc() - register_netdev() failure.\n"); | |
99 | free_netdev(dev); | |
100 | } | |
101 | } | |
102 | return NULL; | |
103 | } | |
104 | ||
105 | ||
106 | /* Free an X.25 channel. */ | |
107 | static void x25_asy_free(struct x25_asy *sl) | |
108 | { | |
109 | /* Free all X.25 frame buffers. */ | |
110 | if (sl->rbuff) { | |
111 | kfree(sl->rbuff); | |
112 | } | |
113 | sl->rbuff = NULL; | |
114 | if (sl->xbuff) { | |
115 | kfree(sl->xbuff); | |
116 | } | |
117 | sl->xbuff = NULL; | |
118 | ||
119 | if (!test_and_clear_bit(SLF_INUSE, &sl->flags)) { | |
120 | printk("%s: x25_asy_free for already free unit.\n", sl->dev->name); | |
121 | } | |
122 | } | |
123 | ||
124 | static int x25_asy_change_mtu(struct net_device *dev, int newmtu) | |
125 | { | |
126 | struct x25_asy *sl = dev->priv; | |
127 | unsigned char *xbuff, *rbuff; | |
128 | int len = 2* newmtu; | |
129 | ||
130 | xbuff = (unsigned char *) kmalloc (len + 4, GFP_ATOMIC); | |
131 | rbuff = (unsigned char *) kmalloc (len + 4, GFP_ATOMIC); | |
132 | ||
133 | if (xbuff == NULL || rbuff == NULL) | |
134 | { | |
135 | printk("%s: unable to grow X.25 buffers, MTU change cancelled.\n", | |
136 | dev->name); | |
137 | if (xbuff != NULL) | |
138 | kfree(xbuff); | |
139 | if (rbuff != NULL) | |
140 | kfree(rbuff); | |
141 | return -ENOMEM; | |
142 | } | |
143 | ||
144 | spin_lock_bh(&sl->lock); | |
145 | xbuff = xchg(&sl->xbuff, xbuff); | |
146 | if (sl->xleft) { | |
147 | if (sl->xleft <= len) { | |
148 | memcpy(sl->xbuff, sl->xhead, sl->xleft); | |
149 | } else { | |
150 | sl->xleft = 0; | |
151 | sl->stats.tx_dropped++; | |
152 | } | |
153 | } | |
154 | sl->xhead = sl->xbuff; | |
155 | ||
156 | rbuff = xchg(&sl->rbuff, rbuff); | |
157 | if (sl->rcount) { | |
158 | if (sl->rcount <= len) { | |
159 | memcpy(sl->rbuff, rbuff, sl->rcount); | |
160 | } else { | |
161 | sl->rcount = 0; | |
162 | sl->stats.rx_over_errors++; | |
163 | set_bit(SLF_ERROR, &sl->flags); | |
164 | } | |
165 | } | |
166 | ||
167 | dev->mtu = newmtu; | |
168 | sl->buffsize = len; | |
169 | ||
170 | spin_unlock_bh(&sl->lock); | |
171 | ||
172 | if (xbuff != NULL) | |
173 | kfree(xbuff); | |
174 | if (rbuff != NULL) | |
175 | kfree(rbuff); | |
176 | return 0; | |
177 | } | |
178 | ||
179 | ||
180 | /* Set the "sending" flag. This must be atomic, hence the ASM. */ | |
181 | ||
182 | static inline void x25_asy_lock(struct x25_asy *sl) | |
183 | { | |
184 | netif_stop_queue(sl->dev); | |
185 | } | |
186 | ||
187 | ||
188 | /* Clear the "sending" flag. This must be atomic, hence the ASM. */ | |
189 | ||
190 | static inline void x25_asy_unlock(struct x25_asy *sl) | |
191 | { | |
192 | netif_wake_queue(sl->dev); | |
193 | } | |
194 | ||
195 | /* Send one completely decapsulated IP datagram to the IP layer. */ | |
196 | ||
197 | static void x25_asy_bump(struct x25_asy *sl) | |
198 | { | |
199 | struct sk_buff *skb; | |
200 | int count; | |
201 | int err; | |
202 | ||
203 | count = sl->rcount; | |
204 | sl->stats.rx_bytes+=count; | |
205 | ||
206 | skb = dev_alloc_skb(count+1); | |
207 | if (skb == NULL) | |
208 | { | |
209 | printk("%s: memory squeeze, dropping packet.\n", sl->dev->name); | |
210 | sl->stats.rx_dropped++; | |
211 | return; | |
212 | } | |
213 | skb_push(skb,1); /* LAPB internal control */ | |
214 | memcpy(skb_put(skb,count), sl->rbuff, count); | |
215 | skb->protocol = x25_type_trans(skb, sl->dev); | |
216 | if((err=lapb_data_received(skb->dev, skb))!=LAPB_OK) | |
217 | { | |
218 | kfree_skb(skb); | |
219 | printk(KERN_DEBUG "x25_asy: data received err - %d\n",err); | |
220 | } | |
221 | else | |
222 | { | |
223 | netif_rx(skb); | |
224 | sl->dev->last_rx = jiffies; | |
225 | sl->stats.rx_packets++; | |
226 | } | |
227 | } | |
228 | ||
229 | /* Encapsulate one IP datagram and stuff into a TTY queue. */ | |
230 | static void x25_asy_encaps(struct x25_asy *sl, unsigned char *icp, int len) | |
231 | { | |
232 | unsigned char *p; | |
233 | int actual, count, mtu = sl->dev->mtu; | |
234 | ||
235 | if (len > mtu) | |
236 | { /* Sigh, shouldn't occur BUT ... */ | |
237 | len = mtu; | |
238 | printk ("%s: truncating oversized transmit packet!\n", sl->dev->name); | |
239 | sl->stats.tx_dropped++; | |
240 | x25_asy_unlock(sl); | |
241 | return; | |
242 | } | |
243 | ||
244 | p = icp; | |
245 | count = x25_asy_esc(p, (unsigned char *) sl->xbuff, len); | |
246 | ||
247 | /* Order of next two lines is *very* important. | |
248 | * When we are sending a little amount of data, | |
249 | * the transfer may be completed inside driver.write() | |
250 | * routine, because it's running with interrupts enabled. | |
251 | * In this case we *never* got WRITE_WAKEUP event, | |
252 | * if we did not request it before write operation. | |
253 | * 14 Oct 1994 Dmitry Gorodchanin. | |
254 | */ | |
255 | sl->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP); | |
256 | actual = sl->tty->driver->write(sl->tty, sl->xbuff, count); | |
257 | sl->xleft = count - actual; | |
258 | sl->xhead = sl->xbuff + actual; | |
259 | /* VSV */ | |
260 | clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */ | |
261 | } | |
262 | ||
263 | /* | |
264 | * Called by the driver when there's room for more data. If we have | |
265 | * more packets to send, we send them here. | |
266 | */ | |
267 | static void x25_asy_write_wakeup(struct tty_struct *tty) | |
268 | { | |
269 | int actual; | |
270 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
271 | ||
272 | /* First make sure we're connected. */ | |
273 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) | |
274 | return; | |
275 | ||
276 | if (sl->xleft <= 0) | |
277 | { | |
278 | /* Now serial buffer is almost free & we can start | |
279 | * transmission of another packet */ | |
280 | sl->stats.tx_packets++; | |
281 | tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); | |
282 | x25_asy_unlock(sl); | |
283 | return; | |
284 | } | |
285 | ||
286 | actual = tty->driver->write(tty, sl->xhead, sl->xleft); | |
287 | sl->xleft -= actual; | |
288 | sl->xhead += actual; | |
289 | } | |
290 | ||
291 | static void x25_asy_timeout(struct net_device *dev) | |
292 | { | |
293 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
294 | ||
295 | spin_lock(&sl->lock); | |
296 | if (netif_queue_stopped(dev)) { | |
297 | /* May be we must check transmitter timeout here ? | |
298 | * 14 Oct 1994 Dmitry Gorodchanin. | |
299 | */ | |
300 | printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name, | |
301 | (sl->tty->driver->chars_in_buffer(sl->tty) || sl->xleft) ? | |
302 | "bad line quality" : "driver error"); | |
303 | sl->xleft = 0; | |
304 | sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); | |
305 | x25_asy_unlock(sl); | |
306 | } | |
307 | spin_unlock(&sl->lock); | |
308 | } | |
309 | ||
310 | /* Encapsulate an IP datagram and kick it into a TTY queue. */ | |
311 | ||
312 | static int x25_asy_xmit(struct sk_buff *skb, struct net_device *dev) | |
313 | { | |
314 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
315 | int err; | |
316 | ||
317 | if (!netif_running(sl->dev)) { | |
318 | printk("%s: xmit call when iface is down\n", dev->name); | |
319 | kfree_skb(skb); | |
320 | return 0; | |
321 | } | |
322 | ||
323 | switch(skb->data[0]) | |
324 | { | |
325 | case 0x00:break; | |
326 | case 0x01: /* Connection request .. do nothing */ | |
327 | if((err=lapb_connect_request(dev))!=LAPB_OK) | |
328 | printk(KERN_ERR "x25_asy: lapb_connect_request error - %d\n", err); | |
329 | kfree_skb(skb); | |
330 | return 0; | |
331 | case 0x02: /* Disconnect request .. do nothing - hang up ?? */ | |
332 | if((err=lapb_disconnect_request(dev))!=LAPB_OK) | |
333 | printk(KERN_ERR "x25_asy: lapb_disconnect_request error - %d\n", err); | |
334 | default: | |
335 | kfree_skb(skb); | |
336 | return 0; | |
337 | } | |
338 | skb_pull(skb,1); /* Remove control byte */ | |
339 | /* | |
340 | * If we are busy already- too bad. We ought to be able | |
341 | * to queue things at this point, to allow for a little | |
342 | * frame buffer. Oh well... | |
343 | * ----------------------------------------------------- | |
344 | * I hate queues in X.25 driver. May be it's efficient, | |
345 | * but for me latency is more important. ;) | |
346 | * So, no queues ! | |
347 | * 14 Oct 1994 Dmitry Gorodchanin. | |
348 | */ | |
349 | ||
350 | if((err=lapb_data_request(dev,skb))!=LAPB_OK) | |
351 | { | |
352 | printk(KERN_ERR "lapbeth: lapb_data_request error - %d\n", err); | |
353 | kfree_skb(skb); | |
354 | return 0; | |
355 | } | |
356 | return 0; | |
357 | } | |
358 | ||
359 | ||
360 | /* | |
361 | * LAPB interface boilerplate | |
362 | */ | |
363 | ||
364 | /* | |
365 | * Called when I frame data arrives. We did the work above - throw it | |
366 | * at the net layer. | |
367 | */ | |
368 | ||
369 | static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb) | |
370 | { | |
371 | skb->dev->last_rx = jiffies; | |
372 | return netif_rx(skb); | |
373 | } | |
374 | ||
375 | /* | |
376 | * Data has emerged from the LAPB protocol machine. We don't handle | |
377 | * busy cases too well. Its tricky to see how to do this nicely - | |
378 | * perhaps lapb should allow us to bounce this ? | |
379 | */ | |
380 | ||
381 | static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb) | |
382 | { | |
383 | struct x25_asy *sl=dev->priv; | |
384 | ||
385 | spin_lock(&sl->lock); | |
386 | if (netif_queue_stopped(sl->dev) || sl->tty == NULL) | |
387 | { | |
388 | spin_unlock(&sl->lock); | |
389 | printk(KERN_ERR "x25_asy: tbusy drop\n"); | |
390 | kfree_skb(skb); | |
391 | return; | |
392 | } | |
393 | /* We were not busy, so we are now... :-) */ | |
394 | if (skb != NULL) | |
395 | { | |
396 | x25_asy_lock(sl); | |
397 | sl->stats.tx_bytes+=skb->len; | |
398 | x25_asy_encaps(sl, skb->data, skb->len); | |
399 | dev_kfree_skb(skb); | |
400 | } | |
401 | spin_unlock(&sl->lock); | |
402 | } | |
403 | ||
404 | /* | |
405 | * LAPB connection establish/down information. | |
406 | */ | |
407 | ||
408 | static void x25_asy_connected(struct net_device *dev, int reason) | |
409 | { | |
410 | struct x25_asy *sl = dev->priv; | |
411 | struct sk_buff *skb; | |
412 | unsigned char *ptr; | |
413 | ||
414 | if ((skb = dev_alloc_skb(1)) == NULL) { | |
415 | printk(KERN_ERR "lapbeth: out of memory\n"); | |
416 | return; | |
417 | } | |
418 | ||
419 | ptr = skb_put(skb, 1); | |
420 | *ptr = 0x01; | |
421 | ||
422 | skb->protocol = x25_type_trans(skb, sl->dev); | |
423 | netif_rx(skb); | |
424 | sl->dev->last_rx = jiffies; | |
425 | } | |
426 | ||
427 | static void x25_asy_disconnected(struct net_device *dev, int reason) | |
428 | { | |
429 | struct x25_asy *sl = dev->priv; | |
430 | struct sk_buff *skb; | |
431 | unsigned char *ptr; | |
432 | ||
433 | if ((skb = dev_alloc_skb(1)) == NULL) { | |
434 | printk(KERN_ERR "x25_asy: out of memory\n"); | |
435 | return; | |
436 | } | |
437 | ||
438 | ptr = skb_put(skb, 1); | |
439 | *ptr = 0x02; | |
440 | ||
441 | skb->protocol = x25_type_trans(skb, sl->dev); | |
442 | netif_rx(skb); | |
443 | sl->dev->last_rx = jiffies; | |
444 | } | |
445 | ||
446 | static struct lapb_register_struct x25_asy_callbacks = { | |
447 | .connect_confirmation = x25_asy_connected, | |
448 | .connect_indication = x25_asy_connected, | |
449 | .disconnect_confirmation = x25_asy_disconnected, | |
450 | .disconnect_indication = x25_asy_disconnected, | |
451 | .data_indication = x25_asy_data_indication, | |
452 | .data_transmit = x25_asy_data_transmit, | |
453 | ||
454 | }; | |
455 | ||
456 | ||
457 | /* Open the low-level part of the X.25 channel. Easy! */ | |
458 | static int x25_asy_open(struct net_device *dev) | |
459 | { | |
460 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
461 | unsigned long len; | |
462 | int err; | |
463 | ||
464 | if (sl->tty == NULL) | |
465 | return -ENODEV; | |
466 | ||
467 | /* | |
468 | * Allocate the X.25 frame buffers: | |
469 | * | |
470 | * rbuff Receive buffer. | |
471 | * xbuff Transmit buffer. | |
472 | */ | |
473 | ||
474 | len = dev->mtu * 2; | |
475 | ||
476 | sl->rbuff = (unsigned char *) kmalloc(len + 4, GFP_KERNEL); | |
477 | if (sl->rbuff == NULL) { | |
478 | goto norbuff; | |
479 | } | |
480 | sl->xbuff = (unsigned char *) kmalloc(len + 4, GFP_KERNEL); | |
481 | if (sl->xbuff == NULL) { | |
482 | goto noxbuff; | |
483 | } | |
484 | ||
485 | sl->buffsize = len; | |
486 | sl->rcount = 0; | |
487 | sl->xleft = 0; | |
488 | sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */ | |
489 | ||
490 | netif_start_queue(dev); | |
491 | ||
492 | /* | |
493 | * Now attach LAPB | |
494 | */ | |
495 | if((err=lapb_register(dev, &x25_asy_callbacks))==LAPB_OK) | |
496 | return 0; | |
497 | ||
498 | /* Cleanup */ | |
499 | kfree(sl->xbuff); | |
500 | noxbuff: | |
501 | kfree(sl->rbuff); | |
502 | norbuff: | |
503 | return -ENOMEM; | |
504 | } | |
505 | ||
506 | ||
507 | /* Close the low-level part of the X.25 channel. Easy! */ | |
508 | static int x25_asy_close(struct net_device *dev) | |
509 | { | |
510 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
511 | int err; | |
512 | ||
513 | spin_lock(&sl->lock); | |
514 | if (sl->tty) | |
515 | sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); | |
516 | ||
517 | netif_stop_queue(dev); | |
518 | sl->rcount = 0; | |
519 | sl->xleft = 0; | |
520 | if((err=lapb_unregister(dev))!=LAPB_OK) | |
521 | printk(KERN_ERR "x25_asy_close: lapb_unregister error -%d\n",err); | |
522 | spin_unlock(&sl->lock); | |
523 | return 0; | |
524 | } | |
525 | ||
526 | static int x25_asy_receive_room(struct tty_struct *tty) | |
527 | { | |
528 | return 65536; /* We can handle an infinite amount of data. :-) */ | |
529 | } | |
530 | ||
531 | /* | |
532 | * Handle the 'receiver data ready' interrupt. | |
533 | * This function is called by the 'tty_io' module in the kernel when | |
534 | * a block of X.25 data has been received, which can now be decapsulated | |
535 | * and sent on to some IP layer for further processing. | |
536 | */ | |
537 | ||
538 | static void x25_asy_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) | |
539 | { | |
540 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
541 | ||
542 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) | |
543 | return; | |
544 | ||
545 | ||
546 | /* Read the characters out of the buffer */ | |
547 | while (count--) { | |
548 | if (fp && *fp++) { | |
549 | if (!test_and_set_bit(SLF_ERROR, &sl->flags)) { | |
550 | sl->stats.rx_errors++; | |
551 | } | |
552 | cp++; | |
553 | continue; | |
554 | } | |
555 | x25_asy_unesc(sl, *cp++); | |
556 | } | |
557 | } | |
558 | ||
559 | /* | |
560 | * Open the high-level part of the X.25 channel. | |
561 | * This function is called by the TTY module when the | |
562 | * X.25 line discipline is called for. Because we are | |
563 | * sure the tty line exists, we only have to link it to | |
564 | * a free X.25 channel... | |
565 | */ | |
566 | ||
567 | static int x25_asy_open_tty(struct tty_struct *tty) | |
568 | { | |
569 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
570 | int err; | |
571 | ||
572 | /* First make sure we're not already connected. */ | |
573 | if (sl && sl->magic == X25_ASY_MAGIC) { | |
574 | return -EEXIST; | |
575 | } | |
576 | ||
577 | /* OK. Find a free X.25 channel to use. */ | |
578 | if ((sl = x25_asy_alloc()) == NULL) { | |
579 | return -ENFILE; | |
580 | } | |
581 | ||
582 | sl->tty = tty; | |
583 | tty->disc_data = sl; | |
584 | if (tty->driver->flush_buffer) { | |
585 | tty->driver->flush_buffer(tty); | |
586 | } | |
587 | if (tty->ldisc.flush_buffer) { | |
588 | tty->ldisc.flush_buffer(tty); | |
589 | } | |
590 | ||
591 | /* Restore default settings */ | |
592 | sl->dev->type = ARPHRD_X25; | |
593 | ||
594 | /* Perform the low-level X.25 async init */ | |
595 | if ((err = x25_asy_open(sl->dev))) | |
596 | return err; | |
597 | ||
598 | /* Done. We have linked the TTY line to a channel. */ | |
599 | return sl->dev->base_addr; | |
600 | } | |
601 | ||
602 | ||
603 | /* | |
604 | * Close down an X.25 channel. | |
605 | * This means flushing out any pending queues, and then restoring the | |
606 | * TTY line discipline to what it was before it got hooked to X.25 | |
607 | * (which usually is TTY again). | |
608 | */ | |
609 | static void x25_asy_close_tty(struct tty_struct *tty) | |
610 | { | |
611 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
612 | ||
613 | /* First make sure we're connected. */ | |
614 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
615 | return; | |
616 | ||
617 | if (sl->dev->flags & IFF_UP) | |
618 | { | |
619 | (void) dev_close(sl->dev); | |
620 | } | |
621 | ||
622 | tty->disc_data = NULL; | |
623 | sl->tty = NULL; | |
624 | x25_asy_free(sl); | |
625 | } | |
626 | ||
627 | ||
628 | static struct net_device_stats *x25_asy_get_stats(struct net_device *dev) | |
629 | { | |
630 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
631 | ||
632 | return &sl->stats; | |
633 | } | |
634 | ||
635 | ||
636 | /************************************************************************ | |
637 | * STANDARD X.25 ENCAPSULATION * | |
638 | ************************************************************************/ | |
639 | ||
640 | int x25_asy_esc(unsigned char *s, unsigned char *d, int len) | |
641 | { | |
642 | unsigned char *ptr = d; | |
643 | unsigned char c; | |
644 | ||
645 | /* | |
646 | * Send an initial END character to flush out any | |
647 | * data that may have accumulated in the receiver | |
648 | * due to line noise. | |
649 | */ | |
650 | ||
651 | *ptr++ = X25_END; /* Send 10111110 bit seq */ | |
652 | ||
653 | /* | |
654 | * For each byte in the packet, send the appropriate | |
655 | * character sequence, according to the X.25 protocol. | |
656 | */ | |
657 | ||
658 | while (len-- > 0) | |
659 | { | |
660 | switch(c = *s++) | |
661 | { | |
662 | case X25_END: | |
663 | *ptr++ = X25_ESC; | |
664 | *ptr++ = X25_ESCAPE(X25_END); | |
665 | break; | |
666 | case X25_ESC: | |
667 | *ptr++ = X25_ESC; | |
668 | *ptr++ = X25_ESCAPE(X25_ESC); | |
669 | break; | |
670 | default: | |
671 | *ptr++ = c; | |
672 | break; | |
673 | } | |
674 | } | |
675 | *ptr++ = X25_END; | |
676 | return (ptr - d); | |
677 | } | |
678 | ||
679 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char s) | |
680 | { | |
681 | ||
682 | switch(s) | |
683 | { | |
684 | case X25_END: | |
685 | if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && (sl->rcount > 2)) | |
686 | { | |
687 | x25_asy_bump(sl); | |
688 | } | |
689 | clear_bit(SLF_ESCAPE, &sl->flags); | |
690 | sl->rcount = 0; | |
691 | return; | |
692 | ||
693 | case X25_ESC: | |
694 | set_bit(SLF_ESCAPE, &sl->flags); | |
695 | return; | |
696 | ||
697 | case X25_ESCAPE(X25_ESC): | |
698 | case X25_ESCAPE(X25_END): | |
699 | if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) | |
700 | s = X25_UNESCAPE(s); | |
701 | break; | |
702 | } | |
703 | if (!test_bit(SLF_ERROR, &sl->flags)) | |
704 | { | |
705 | if (sl->rcount < sl->buffsize) | |
706 | { | |
707 | sl->rbuff[sl->rcount++] = s; | |
708 | return; | |
709 | } | |
710 | sl->stats.rx_over_errors++; | |
711 | set_bit(SLF_ERROR, &sl->flags); | |
712 | } | |
713 | } | |
714 | ||
715 | ||
716 | /* Perform I/O control on an active X.25 channel. */ | |
717 | static int x25_asy_ioctl(struct tty_struct *tty, struct file *file, | |
718 | unsigned int cmd, unsigned long arg) | |
719 | { | |
720 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
721 | ||
722 | /* First make sure we're connected. */ | |
723 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
724 | return -EINVAL; | |
725 | ||
726 | switch(cmd) { | |
727 | case SIOCGIFNAME: | |
728 | if (copy_to_user((void __user *)arg, sl->dev->name, | |
729 | strlen(sl->dev->name) + 1)) | |
730 | return -EFAULT; | |
731 | return 0; | |
732 | case SIOCSIFHWADDR: | |
733 | return -EINVAL; | |
734 | /* Allow stty to read, but not set, the serial port */ | |
735 | case TCGETS: | |
736 | case TCGETA: | |
737 | return n_tty_ioctl(tty, file, cmd, arg); | |
738 | default: | |
739 | return -ENOIOCTLCMD; | |
740 | } | |
741 | } | |
742 | ||
743 | static int x25_asy_open_dev(struct net_device *dev) | |
744 | { | |
745 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
746 | if(sl->tty==NULL) | |
747 | return -ENODEV; | |
748 | return 0; | |
749 | } | |
750 | ||
751 | /* Initialise the X.25 driver. Called by the device init code */ | |
752 | static void x25_asy_setup(struct net_device *dev) | |
753 | { | |
754 | struct x25_asy *sl = dev->priv; | |
755 | ||
756 | sl->magic = X25_ASY_MAGIC; | |
757 | sl->dev = dev; | |
758 | spin_lock_init(&sl->lock); | |
759 | set_bit(SLF_INUSE, &sl->flags); | |
760 | ||
761 | /* | |
762 | * Finish setting up the DEVICE info. | |
763 | */ | |
764 | ||
765 | dev->mtu = SL_MTU; | |
766 | dev->hard_start_xmit = x25_asy_xmit; | |
767 | dev->tx_timeout = x25_asy_timeout; | |
768 | dev->watchdog_timeo = HZ*20; | |
769 | dev->open = x25_asy_open_dev; | |
770 | dev->stop = x25_asy_close; | |
771 | dev->get_stats = x25_asy_get_stats; | |
772 | dev->change_mtu = x25_asy_change_mtu; | |
773 | dev->hard_header_len = 0; | |
774 | dev->addr_len = 0; | |
775 | dev->type = ARPHRD_X25; | |
776 | dev->tx_queue_len = 10; | |
777 | ||
778 | /* New-style flags. */ | |
779 | dev->flags = IFF_NOARP; | |
780 | } | |
781 | ||
782 | static struct tty_ldisc x25_ldisc = { | |
783 | .owner = THIS_MODULE, | |
784 | .magic = TTY_LDISC_MAGIC, | |
785 | .name = "X.25", | |
786 | .open = x25_asy_open_tty, | |
787 | .close = x25_asy_close_tty, | |
788 | .ioctl = x25_asy_ioctl, | |
789 | .receive_buf = x25_asy_receive_buf, | |
790 | .receive_room = x25_asy_receive_room, | |
791 | .write_wakeup = x25_asy_write_wakeup, | |
792 | }; | |
793 | ||
794 | static int __init init_x25_asy(void) | |
795 | { | |
796 | if (x25_asy_maxdev < 4) | |
797 | x25_asy_maxdev = 4; /* Sanity */ | |
798 | ||
799 | printk(KERN_INFO "X.25 async: version 0.00 ALPHA " | |
800 | "(dynamic channels, max=%d).\n", x25_asy_maxdev ); | |
801 | ||
802 | x25_asy_devs = kmalloc(sizeof(struct net_device *)*x25_asy_maxdev, | |
803 | GFP_KERNEL); | |
804 | if (!x25_asy_devs) { | |
805 | printk(KERN_WARNING "X25 async: Can't allocate x25_asy_ctrls[] " | |
806 | "array! Uaargh! (-> No X.25 available)\n"); | |
807 | return -ENOMEM; | |
808 | } | |
809 | memset(x25_asy_devs, 0, sizeof(struct net_device *)*x25_asy_maxdev); | |
810 | ||
811 | return tty_register_ldisc(N_X25, &x25_ldisc); | |
812 | } | |
813 | ||
814 | ||
815 | static void __exit exit_x25_asy(void) | |
816 | { | |
817 | struct net_device *dev; | |
818 | int i; | |
819 | ||
820 | for (i = 0; i < x25_asy_maxdev; i++) { | |
821 | dev = x25_asy_devs[i]; | |
822 | if (dev) { | |
823 | struct x25_asy *sl = dev->priv; | |
824 | ||
825 | spin_lock_bh(&sl->lock); | |
826 | if (sl->tty) | |
827 | tty_hangup(sl->tty); | |
828 | ||
829 | spin_unlock_bh(&sl->lock); | |
830 | /* | |
831 | * VSV = if dev->start==0, then device | |
832 | * unregistered while close proc. | |
833 | */ | |
834 | unregister_netdev(dev); | |
835 | free_netdev(dev); | |
836 | } | |
837 | } | |
838 | ||
839 | kfree(x25_asy_devs); | |
840 | tty_register_ldisc(N_X25, NULL); | |
841 | } | |
842 | ||
843 | module_init(init_x25_asy); | |
844 | module_exit(exit_x25_asy); |