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Commit | Line | Data |
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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. */ | |
6a5d3621 | 110 | kfree(sl->rbuff); |
1da177e4 | 111 | sl->rbuff = NULL; |
6a5d3621 | 112 | kfree(sl->xbuff); |
1da177e4 LT |
113 | sl->xbuff = NULL; |
114 | ||
115 | if (!test_and_clear_bit(SLF_INUSE, &sl->flags)) { | |
116 | printk("%s: x25_asy_free for already free unit.\n", sl->dev->name); | |
117 | } | |
118 | } | |
119 | ||
120 | static int x25_asy_change_mtu(struct net_device *dev, int newmtu) | |
121 | { | |
122 | struct x25_asy *sl = dev->priv; | |
123 | unsigned char *xbuff, *rbuff; | |
124 | int len = 2* newmtu; | |
125 | ||
5cbded58 RD |
126 | xbuff = kmalloc(len + 4, GFP_ATOMIC); |
127 | rbuff = kmalloc(len + 4, GFP_ATOMIC); | |
1da177e4 LT |
128 | |
129 | if (xbuff == NULL || rbuff == NULL) | |
130 | { | |
131 | printk("%s: unable to grow X.25 buffers, MTU change cancelled.\n", | |
132 | dev->name); | |
6a5d3621 JJ |
133 | kfree(xbuff); |
134 | kfree(rbuff); | |
1da177e4 LT |
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 | sl->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 | sl->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 | ||
6a5d3621 JJ |
166 | kfree(xbuff); |
167 | kfree(rbuff); | |
1da177e4 LT |
168 | return 0; |
169 | } | |
170 | ||
171 | ||
172 | /* Set the "sending" flag. This must be atomic, hence the ASM. */ | |
173 | ||
174 | static 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 | ||
182 | static 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 | ||
189 | static void x25_asy_bump(struct x25_asy *sl) | |
190 | { | |
191 | struct sk_buff *skb; | |
192 | int count; | |
193 | int err; | |
194 | ||
195 | count = sl->rcount; | |
196 | sl->stats.rx_bytes+=count; | |
197 | ||
198 | skb = dev_alloc_skb(count+1); | |
199 | if (skb == NULL) | |
200 | { | |
201 | printk("%s: memory squeeze, dropping packet.\n", sl->dev->name); | |
202 | sl->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 | if((err=lapb_data_received(skb->dev, skb))!=LAPB_OK) | |
209 | { | |
210 | kfree_skb(skb); | |
211 | printk(KERN_DEBUG "x25_asy: data received err - %d\n",err); | |
212 | } | |
213 | else | |
214 | { | |
215 | netif_rx(skb); | |
216 | sl->dev->last_rx = jiffies; | |
217 | sl->stats.rx_packets++; | |
218 | } | |
219 | } | |
220 | ||
221 | /* Encapsulate one IP datagram and stuff into a TTY queue. */ | |
222 | static void x25_asy_encaps(struct x25_asy *sl, unsigned char *icp, int len) | |
223 | { | |
224 | unsigned char *p; | |
225 | int actual, count, mtu = sl->dev->mtu; | |
226 | ||
227 | if (len > mtu) | |
228 | { /* Sigh, shouldn't occur BUT ... */ | |
229 | len = mtu; | |
230 | printk ("%s: truncating oversized transmit packet!\n", sl->dev->name); | |
231 | sl->stats.tx_dropped++; | |
232 | x25_asy_unlock(sl); | |
233 | return; | |
234 | } | |
235 | ||
236 | p = icp; | |
237 | count = x25_asy_esc(p, (unsigned char *) 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 | sl->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP); | |
248 | actual = sl->tty->driver->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 = (struct x25_asy *) 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 | { | |
270 | /* Now serial buffer is almost free & we can start | |
271 | * transmission of another packet */ | |
272 | sl->stats.tx_packets++; | |
273 | tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); | |
274 | x25_asy_unlock(sl); | |
275 | return; | |
276 | } | |
277 | ||
278 | actual = tty->driver->write(tty, sl->xhead, sl->xleft); | |
279 | sl->xleft -= actual; | |
280 | sl->xhead += actual; | |
281 | } | |
282 | ||
283 | static void x25_asy_timeout(struct net_device *dev) | |
284 | { | |
285 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
286 | ||
287 | spin_lock(&sl->lock); | |
288 | if (netif_queue_stopped(dev)) { | |
289 | /* May be we must check transmitter timeout here ? | |
290 | * 14 Oct 1994 Dmitry Gorodchanin. | |
291 | */ | |
292 | printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name, | |
293 | (sl->tty->driver->chars_in_buffer(sl->tty) || sl->xleft) ? | |
294 | "bad line quality" : "driver error"); | |
295 | sl->xleft = 0; | |
296 | sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); | |
297 | x25_asy_unlock(sl); | |
298 | } | |
299 | spin_unlock(&sl->lock); | |
300 | } | |
301 | ||
302 | /* Encapsulate an IP datagram and kick it into a TTY queue. */ | |
303 | ||
304 | static int x25_asy_xmit(struct sk_buff *skb, struct net_device *dev) | |
305 | { | |
306 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
307 | int err; | |
308 | ||
309 | if (!netif_running(sl->dev)) { | |
310 | printk("%s: xmit call when iface is down\n", dev->name); | |
311 | kfree_skb(skb); | |
312 | return 0; | |
313 | } | |
314 | ||
315 | switch(skb->data[0]) | |
316 | { | |
317 | case 0x00:break; | |
318 | case 0x01: /* Connection request .. do nothing */ | |
319 | if((err=lapb_connect_request(dev))!=LAPB_OK) | |
320 | printk(KERN_ERR "x25_asy: lapb_connect_request error - %d\n", err); | |
321 | kfree_skb(skb); | |
322 | return 0; | |
323 | case 0x02: /* Disconnect request .. do nothing - hang up ?? */ | |
324 | if((err=lapb_disconnect_request(dev))!=LAPB_OK) | |
325 | printk(KERN_ERR "x25_asy: lapb_disconnect_request error - %d\n", err); | |
326 | default: | |
327 | kfree_skb(skb); | |
328 | return 0; | |
329 | } | |
330 | skb_pull(skb,1); /* Remove control byte */ | |
331 | /* | |
332 | * If we are busy already- too bad. We ought to be able | |
333 | * to queue things at this point, to allow for a little | |
334 | * frame buffer. Oh well... | |
335 | * ----------------------------------------------------- | |
336 | * I hate queues in X.25 driver. May be it's efficient, | |
337 | * but for me latency is more important. ;) | |
338 | * So, no queues ! | |
339 | * 14 Oct 1994 Dmitry Gorodchanin. | |
340 | */ | |
341 | ||
342 | if((err=lapb_data_request(dev,skb))!=LAPB_OK) | |
343 | { | |
344 | printk(KERN_ERR "lapbeth: lapb_data_request error - %d\n", err); | |
345 | kfree_skb(skb); | |
346 | return 0; | |
347 | } | |
348 | return 0; | |
349 | } | |
350 | ||
351 | ||
352 | /* | |
353 | * LAPB interface boilerplate | |
354 | */ | |
355 | ||
356 | /* | |
357 | * Called when I frame data arrives. We did the work above - throw it | |
358 | * at the net layer. | |
359 | */ | |
360 | ||
361 | static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb) | |
362 | { | |
363 | skb->dev->last_rx = jiffies; | |
364 | return netif_rx(skb); | |
365 | } | |
366 | ||
367 | /* | |
368 | * Data has emerged from the LAPB protocol machine. We don't handle | |
369 | * busy cases too well. Its tricky to see how to do this nicely - | |
370 | * perhaps lapb should allow us to bounce this ? | |
371 | */ | |
372 | ||
373 | static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb) | |
374 | { | |
375 | struct x25_asy *sl=dev->priv; | |
376 | ||
377 | spin_lock(&sl->lock); | |
378 | if (netif_queue_stopped(sl->dev) || sl->tty == NULL) | |
379 | { | |
380 | spin_unlock(&sl->lock); | |
381 | printk(KERN_ERR "x25_asy: tbusy drop\n"); | |
382 | kfree_skb(skb); | |
383 | return; | |
384 | } | |
385 | /* We were not busy, so we are now... :-) */ | |
386 | if (skb != NULL) | |
387 | { | |
388 | x25_asy_lock(sl); | |
389 | sl->stats.tx_bytes+=skb->len; | |
390 | x25_asy_encaps(sl, skb->data, skb->len); | |
391 | dev_kfree_skb(skb); | |
392 | } | |
393 | spin_unlock(&sl->lock); | |
394 | } | |
395 | ||
396 | /* | |
397 | * LAPB connection establish/down information. | |
398 | */ | |
399 | ||
400 | static void x25_asy_connected(struct net_device *dev, int reason) | |
401 | { | |
402 | struct x25_asy *sl = dev->priv; | |
403 | struct sk_buff *skb; | |
404 | unsigned char *ptr; | |
405 | ||
406 | if ((skb = dev_alloc_skb(1)) == NULL) { | |
407 | printk(KERN_ERR "lapbeth: out of memory\n"); | |
408 | return; | |
409 | } | |
410 | ||
411 | ptr = skb_put(skb, 1); | |
412 | *ptr = 0x01; | |
413 | ||
414 | skb->protocol = x25_type_trans(skb, sl->dev); | |
415 | netif_rx(skb); | |
416 | sl->dev->last_rx = jiffies; | |
417 | } | |
418 | ||
419 | static void x25_asy_disconnected(struct net_device *dev, int reason) | |
420 | { | |
421 | struct x25_asy *sl = dev->priv; | |
422 | struct sk_buff *skb; | |
423 | unsigned char *ptr; | |
424 | ||
425 | if ((skb = dev_alloc_skb(1)) == NULL) { | |
426 | printk(KERN_ERR "x25_asy: out of memory\n"); | |
427 | return; | |
428 | } | |
429 | ||
430 | ptr = skb_put(skb, 1); | |
431 | *ptr = 0x02; | |
432 | ||
433 | skb->protocol = x25_type_trans(skb, sl->dev); | |
434 | netif_rx(skb); | |
435 | sl->dev->last_rx = jiffies; | |
436 | } | |
437 | ||
438 | static struct lapb_register_struct x25_asy_callbacks = { | |
439 | .connect_confirmation = x25_asy_connected, | |
440 | .connect_indication = x25_asy_connected, | |
441 | .disconnect_confirmation = x25_asy_disconnected, | |
442 | .disconnect_indication = x25_asy_disconnected, | |
443 | .data_indication = x25_asy_data_indication, | |
444 | .data_transmit = x25_asy_data_transmit, | |
445 | ||
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 = (struct x25_asy*)(dev->priv); | |
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 | ||
5cbded58 | 468 | sl->rbuff = kmalloc(len + 4, GFP_KERNEL); |
1da177e4 LT |
469 | if (sl->rbuff == NULL) { |
470 | goto norbuff; | |
471 | } | |
5cbded58 | 472 | sl->xbuff = kmalloc(len + 4, GFP_KERNEL); |
1da177e4 LT |
473 | if (sl->xbuff == NULL) { |
474 | goto noxbuff; | |
475 | } | |
476 | ||
477 | sl->buffsize = len; | |
478 | sl->rcount = 0; | |
479 | sl->xleft = 0; | |
480 | sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */ | |
481 | ||
482 | netif_start_queue(dev); | |
483 | ||
484 | /* | |
485 | * Now attach LAPB | |
486 | */ | |
487 | if((err=lapb_register(dev, &x25_asy_callbacks))==LAPB_OK) | |
488 | return 0; | |
489 | ||
490 | /* Cleanup */ | |
491 | kfree(sl->xbuff); | |
492 | noxbuff: | |
493 | kfree(sl->rbuff); | |
494 | norbuff: | |
495 | return -ENOMEM; | |
496 | } | |
497 | ||
498 | ||
499 | /* Close the low-level part of the X.25 channel. Easy! */ | |
500 | static int x25_asy_close(struct net_device *dev) | |
501 | { | |
502 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
503 | int err; | |
504 | ||
505 | spin_lock(&sl->lock); | |
506 | if (sl->tty) | |
507 | sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); | |
508 | ||
509 | netif_stop_queue(dev); | |
510 | sl->rcount = 0; | |
511 | sl->xleft = 0; | |
512 | if((err=lapb_unregister(dev))!=LAPB_OK) | |
513 | printk(KERN_ERR "x25_asy_close: lapb_unregister error -%d\n",err); | |
514 | spin_unlock(&sl->lock); | |
515 | return 0; | |
516 | } | |
517 | ||
1da177e4 LT |
518 | /* |
519 | * Handle the 'receiver data ready' interrupt. | |
520 | * This function is called by the 'tty_io' module in the kernel when | |
521 | * a block of X.25 data has been received, which can now be decapsulated | |
522 | * and sent on to some IP layer for further processing. | |
523 | */ | |
524 | ||
525 | static void x25_asy_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) | |
526 | { | |
527 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
528 | ||
529 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) | |
530 | return; | |
531 | ||
532 | ||
533 | /* Read the characters out of the buffer */ | |
534 | while (count--) { | |
535 | if (fp && *fp++) { | |
536 | if (!test_and_set_bit(SLF_ERROR, &sl->flags)) { | |
537 | sl->stats.rx_errors++; | |
538 | } | |
539 | cp++; | |
540 | continue; | |
541 | } | |
542 | x25_asy_unesc(sl, *cp++); | |
543 | } | |
544 | } | |
545 | ||
546 | /* | |
547 | * Open the high-level part of the X.25 channel. | |
548 | * This function is called by the TTY module when the | |
549 | * X.25 line discipline is called for. Because we are | |
550 | * sure the tty line exists, we only have to link it to | |
551 | * a free X.25 channel... | |
552 | */ | |
553 | ||
554 | static int x25_asy_open_tty(struct tty_struct *tty) | |
555 | { | |
556 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
557 | int err; | |
558 | ||
559 | /* First make sure we're not already connected. */ | |
560 | if (sl && sl->magic == X25_ASY_MAGIC) { | |
561 | return -EEXIST; | |
562 | } | |
563 | ||
564 | /* OK. Find a free X.25 channel to use. */ | |
565 | if ((sl = x25_asy_alloc()) == NULL) { | |
566 | return -ENFILE; | |
567 | } | |
568 | ||
569 | sl->tty = tty; | |
570 | tty->disc_data = sl; | |
33f0f88f | 571 | tty->receive_room = 65536; |
1da177e4 LT |
572 | if (tty->driver->flush_buffer) { |
573 | tty->driver->flush_buffer(tty); | |
574 | } | |
575 | if (tty->ldisc.flush_buffer) { | |
576 | tty->ldisc.flush_buffer(tty); | |
577 | } | |
578 | ||
579 | /* Restore default settings */ | |
580 | sl->dev->type = ARPHRD_X25; | |
581 | ||
582 | /* Perform the low-level X.25 async init */ | |
583 | if ((err = x25_asy_open(sl->dev))) | |
584 | return err; | |
585 | ||
586 | /* Done. We have linked the TTY line to a channel. */ | |
587 | return sl->dev->base_addr; | |
588 | } | |
589 | ||
590 | ||
591 | /* | |
592 | * Close down an X.25 channel. | |
593 | * This means flushing out any pending queues, and then restoring the | |
594 | * TTY line discipline to what it was before it got hooked to X.25 | |
595 | * (which usually is TTY again). | |
596 | */ | |
597 | static void x25_asy_close_tty(struct tty_struct *tty) | |
598 | { | |
599 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
600 | ||
601 | /* First make sure we're connected. */ | |
602 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
603 | return; | |
604 | ||
605 | if (sl->dev->flags & IFF_UP) | |
606 | { | |
607 | (void) dev_close(sl->dev); | |
608 | } | |
609 | ||
610 | tty->disc_data = NULL; | |
611 | sl->tty = NULL; | |
612 | x25_asy_free(sl); | |
613 | } | |
614 | ||
615 | ||
616 | static struct net_device_stats *x25_asy_get_stats(struct net_device *dev) | |
617 | { | |
618 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
619 | ||
620 | return &sl->stats; | |
621 | } | |
622 | ||
623 | ||
624 | /************************************************************************ | |
625 | * STANDARD X.25 ENCAPSULATION * | |
626 | ************************************************************************/ | |
627 | ||
628 | int x25_asy_esc(unsigned char *s, unsigned char *d, int len) | |
629 | { | |
630 | unsigned char *ptr = d; | |
631 | unsigned char c; | |
632 | ||
633 | /* | |
634 | * Send an initial END character to flush out any | |
635 | * data that may have accumulated in the receiver | |
636 | * due to line noise. | |
637 | */ | |
638 | ||
639 | *ptr++ = X25_END; /* Send 10111110 bit seq */ | |
640 | ||
641 | /* | |
642 | * For each byte in the packet, send the appropriate | |
643 | * character sequence, according to the X.25 protocol. | |
644 | */ | |
645 | ||
646 | while (len-- > 0) | |
647 | { | |
648 | switch(c = *s++) | |
649 | { | |
650 | case X25_END: | |
651 | *ptr++ = X25_ESC; | |
652 | *ptr++ = X25_ESCAPE(X25_END); | |
653 | break; | |
654 | case X25_ESC: | |
655 | *ptr++ = X25_ESC; | |
656 | *ptr++ = X25_ESCAPE(X25_ESC); | |
657 | break; | |
658 | default: | |
659 | *ptr++ = c; | |
660 | break; | |
661 | } | |
662 | } | |
663 | *ptr++ = X25_END; | |
664 | return (ptr - d); | |
665 | } | |
666 | ||
667 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char s) | |
668 | { | |
669 | ||
670 | switch(s) | |
671 | { | |
672 | case X25_END: | |
673 | if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && (sl->rcount > 2)) | |
674 | { | |
675 | x25_asy_bump(sl); | |
676 | } | |
677 | clear_bit(SLF_ESCAPE, &sl->flags); | |
678 | sl->rcount = 0; | |
679 | return; | |
680 | ||
681 | case X25_ESC: | |
682 | set_bit(SLF_ESCAPE, &sl->flags); | |
683 | return; | |
684 | ||
685 | case X25_ESCAPE(X25_ESC): | |
686 | case X25_ESCAPE(X25_END): | |
687 | if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) | |
688 | s = X25_UNESCAPE(s); | |
689 | break; | |
690 | } | |
691 | if (!test_bit(SLF_ERROR, &sl->flags)) | |
692 | { | |
693 | if (sl->rcount < sl->buffsize) | |
694 | { | |
695 | sl->rbuff[sl->rcount++] = s; | |
696 | return; | |
697 | } | |
698 | sl->stats.rx_over_errors++; | |
699 | set_bit(SLF_ERROR, &sl->flags); | |
700 | } | |
701 | } | |
702 | ||
703 | ||
704 | /* Perform I/O control on an active X.25 channel. */ | |
705 | static int x25_asy_ioctl(struct tty_struct *tty, struct file *file, | |
706 | unsigned int cmd, unsigned long arg) | |
707 | { | |
708 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
709 | ||
710 | /* First make sure we're connected. */ | |
711 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
712 | return -EINVAL; | |
713 | ||
714 | switch(cmd) { | |
715 | case SIOCGIFNAME: | |
716 | if (copy_to_user((void __user *)arg, sl->dev->name, | |
717 | strlen(sl->dev->name) + 1)) | |
718 | return -EFAULT; | |
719 | return 0; | |
720 | case SIOCSIFHWADDR: | |
721 | return -EINVAL; | |
722 | /* Allow stty to read, but not set, the serial port */ | |
723 | case TCGETS: | |
724 | case TCGETA: | |
725 | return n_tty_ioctl(tty, file, cmd, arg); | |
726 | default: | |
727 | return -ENOIOCTLCMD; | |
728 | } | |
729 | } | |
730 | ||
731 | static int x25_asy_open_dev(struct net_device *dev) | |
732 | { | |
733 | struct x25_asy *sl = (struct x25_asy*)(dev->priv); | |
734 | if(sl->tty==NULL) | |
735 | return -ENODEV; | |
736 | return 0; | |
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 = dev->priv; | |
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->hard_start_xmit = x25_asy_xmit; | |
755 | dev->tx_timeout = x25_asy_timeout; | |
756 | dev->watchdog_timeo = HZ*20; | |
757 | dev->open = x25_asy_open_dev; | |
758 | dev->stop = x25_asy_close; | |
759 | dev->get_stats = x25_asy_get_stats; | |
760 | dev->change_mtu = x25_asy_change_mtu; | |
761 | dev->hard_header_len = 0; | |
762 | dev->addr_len = 0; | |
763 | dev->type = ARPHRD_X25; | |
764 | dev->tx_queue_len = 10; | |
765 | ||
766 | /* New-style flags. */ | |
767 | dev->flags = IFF_NOARP; | |
768 | } | |
769 | ||
770 | static struct tty_ldisc x25_ldisc = { | |
771 | .owner = THIS_MODULE, | |
772 | .magic = TTY_LDISC_MAGIC, | |
773 | .name = "X.25", | |
774 | .open = x25_asy_open_tty, | |
775 | .close = x25_asy_close_tty, | |
776 | .ioctl = x25_asy_ioctl, | |
777 | .receive_buf = x25_asy_receive_buf, | |
1da177e4 LT |
778 | .write_wakeup = x25_asy_write_wakeup, |
779 | }; | |
780 | ||
781 | static int __init init_x25_asy(void) | |
782 | { | |
783 | if (x25_asy_maxdev < 4) | |
784 | x25_asy_maxdev = 4; /* Sanity */ | |
785 | ||
786 | printk(KERN_INFO "X.25 async: version 0.00 ALPHA " | |
787 | "(dynamic channels, max=%d).\n", x25_asy_maxdev ); | |
788 | ||
dd00cc48 | 789 | x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device*), GFP_KERNEL); |
1da177e4 LT |
790 | if (!x25_asy_devs) { |
791 | printk(KERN_WARNING "X25 async: Can't allocate x25_asy_ctrls[] " | |
792 | "array! Uaargh! (-> No X.25 available)\n"); | |
793 | return -ENOMEM; | |
794 | } | |
1da177e4 LT |
795 | |
796 | return tty_register_ldisc(N_X25, &x25_ldisc); | |
797 | } | |
798 | ||
799 | ||
800 | static void __exit exit_x25_asy(void) | |
801 | { | |
802 | struct net_device *dev; | |
803 | int i; | |
804 | ||
805 | for (i = 0; i < x25_asy_maxdev; i++) { | |
806 | dev = x25_asy_devs[i]; | |
807 | if (dev) { | |
808 | struct x25_asy *sl = dev->priv; | |
809 | ||
810 | spin_lock_bh(&sl->lock); | |
811 | if (sl->tty) | |
812 | tty_hangup(sl->tty); | |
813 | ||
814 | spin_unlock_bh(&sl->lock); | |
815 | /* | |
816 | * VSV = if dev->start==0, then device | |
817 | * unregistered while close proc. | |
818 | */ | |
819 | unregister_netdev(dev); | |
820 | free_netdev(dev); | |
821 | } | |
822 | } | |
823 | ||
824 | kfree(x25_asy_devs); | |
64ccd715 | 825 | tty_unregister_ldisc(N_X25); |
1da177e4 LT |
826 | } |
827 | ||
828 | module_init(init_x25_asy); | |
829 | module_exit(exit_x25_asy); |