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> | |
f34d7a5b | 20 | #include <linux/uaccess.h> |
1da177e4 LT |
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 { | |
f34d7a5b | 98 | printk(KERN_WARNING "x25_asy_alloc() - register_netdev() failure.\n"); |
1da177e4 LT |
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 | ||
f34d7a5b AC |
115 | if (!test_and_clear_bit(SLF_INUSE, &sl->flags)) |
116 | printk(KERN_ERR "%s: x25_asy_free for already free unit.\n", | |
117 | sl->dev->name); | |
1da177e4 LT |
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; | |
f34d7a5b | 124 | int len = 2 * newmtu; |
1da177e4 | 125 | |
5cbded58 RD |
126 | xbuff = kmalloc(len + 4, GFP_ATOMIC); |
127 | rbuff = kmalloc(len + 4, GFP_ATOMIC); | |
1da177e4 | 128 | |
f34d7a5b AC |
129 | if (xbuff == NULL || rbuff == NULL) { |
130 | printk(KERN_WARNING "%s: unable to grow X.25 buffers, MTU change cancelled.\n", | |
1da177e4 | 131 | dev->name); |
6a5d3621 JJ |
132 | kfree(xbuff); |
133 | kfree(rbuff); | |
1da177e4 LT |
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 | sl->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 | sl->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 | ||
6a5d3621 JJ |
165 | kfree(xbuff); |
166 | kfree(rbuff); | |
1da177e4 LT |
167 | return 0; |
168 | } | |
169 | ||
170 | ||
171 | /* Set the "sending" flag. This must be atomic, hence the ASM. */ | |
172 | ||
173 | static 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 | ||
181 | static 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 | ||
188 | static void x25_asy_bump(struct x25_asy *sl) | |
189 | { | |
190 | struct sk_buff *skb; | |
191 | int count; | |
192 | int err; | |
193 | ||
194 | count = sl->rcount; | |
f34d7a5b AC |
195 | sl->stats.rx_bytes += count; |
196 | ||
1da177e4 | 197 | skb = dev_alloc_skb(count+1); |
f34d7a5b AC |
198 | if (skb == NULL) { |
199 | printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", | |
200 | sl->dev->name); | |
1da177e4 LT |
201 | sl->stats.rx_dropped++; |
202 | return; | |
203 | } | |
f34d7a5b AC |
204 | skb_push(skb, 1); /* LAPB internal control */ |
205 | memcpy(skb_put(skb, count), sl->rbuff, count); | |
1da177e4 | 206 | skb->protocol = x25_type_trans(skb, sl->dev); |
f34d7a5b AC |
207 | err = lapb_data_received(skb->dev, skb); |
208 | if (err != LAPB_OK) { | |
1da177e4 | 209 | kfree_skb(skb); |
f34d7a5b AC |
210 | printk(KERN_DEBUG "x25_asy: data received err - %d\n", err); |
211 | } else { | |
1da177e4 LT |
212 | netif_rx(skb); |
213 | sl->dev->last_rx = jiffies; | |
214 | sl->stats.rx_packets++; | |
215 | } | |
216 | } | |
217 | ||
218 | /* Encapsulate one IP datagram and stuff into a TTY queue. */ | |
219 | static 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 | ||
f34d7a5b AC |
224 | if (len > mtu) { |
225 | /* Sigh, shouldn't occur BUT ... */ | |
1da177e4 | 226 | len = mtu; |
f34d7a5b AC |
227 | printk(KERN_DEBUG "%s: truncating oversized transmit packet!\n", |
228 | sl->dev->name); | |
1da177e4 LT |
229 | sl->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 | sl->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP); | |
f34d7a5b | 246 | actual = sl->tty->ops->write(sl->tty, sl->xbuff, count); |
1da177e4 LT |
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 | */ | |
257 | static void x25_asy_write_wakeup(struct tty_struct *tty) | |
258 | { | |
259 | int actual; | |
260 | struct x25_asy *sl = (struct x25_asy *) 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 | ||
f34d7a5b | 266 | if (sl->xleft <= 0) { |
1da177e4 LT |
267 | /* Now serial buffer is almost free & we can start |
268 | * transmission of another packet */ | |
269 | sl->stats.tx_packets++; | |
270 | tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); | |
271 | x25_asy_unlock(sl); | |
272 | return; | |
273 | } | |
274 | ||
f34d7a5b | 275 | actual = tty->ops->write(tty, sl->xhead, sl->xleft); |
1da177e4 LT |
276 | sl->xleft -= actual; |
277 | sl->xhead += actual; | |
278 | } | |
279 | ||
280 | static void x25_asy_timeout(struct net_device *dev) | |
281 | { | |
f34d7a5b | 282 | struct x25_asy *sl = dev->priv; |
1da177e4 LT |
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 | printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name, | |
f34d7a5b | 290 | (tty_chars_in_buffer(sl->tty) || sl->xleft) ? |
1da177e4 LT |
291 | "bad line quality" : "driver error"); |
292 | sl->xleft = 0; | |
293 | sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); | |
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 | ||
301 | static int x25_asy_xmit(struct sk_buff *skb, struct net_device *dev) | |
302 | { | |
f34d7a5b | 303 | struct x25_asy *sl = dev->priv; |
1da177e4 LT |
304 | int err; |
305 | ||
306 | if (!netif_running(sl->dev)) { | |
f34d7a5b AC |
307 | printk(KERN_ERR "%s: xmit call when iface is down\n", |
308 | dev->name); | |
1da177e4 LT |
309 | kfree_skb(skb); |
310 | return 0; | |
311 | } | |
f34d7a5b AC |
312 | |
313 | switch (skb->data[0]) { | |
314 | case 0x00: | |
315 | break; | |
316 | case 0x01: /* Connection request .. do nothing */ | |
317 | err = lapb_connect_request(dev); | |
318 | if (err != LAPB_OK) | |
319 | printk(KERN_ERR "x25_asy: lapb_connect_request error - %d\n", err); | |
320 | kfree_skb(skb); | |
321 | return 0; | |
322 | case 0x02: /* Disconnect request .. do nothing - hang up ?? */ | |
323 | err = lapb_disconnect_request(dev); | |
324 | if (err != LAPB_OK) | |
325 | printk(KERN_ERR "x25_asy: lapb_disconnect_request error - %d\n", err); | |
326 | default: | |
327 | kfree_skb(skb); | |
328 | return 0; | |
1da177e4 | 329 | } |
f34d7a5b | 330 | skb_pull(skb, 1); /* Remove control byte */ |
1da177e4 LT |
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 | */ | |
f34d7a5b AC |
341 | |
342 | err = lapb_data_request(dev, skb); | |
343 | if (err != LAPB_OK) { | |
344 | printk(KERN_ERR "x25_asy: lapb_data_request error - %d\n", err); | |
1da177e4 LT |
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 | */ | |
f34d7a5b | 360 | |
1da177e4 LT |
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 | */ | |
f34d7a5b | 372 | |
1da177e4 LT |
373 | static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb) |
374 | { | |
f34d7a5b AC |
375 | struct x25_asy *sl = dev->priv; |
376 | ||
1da177e4 | 377 | spin_lock(&sl->lock); |
f34d7a5b | 378 | if (netif_queue_stopped(sl->dev) || sl->tty == NULL) { |
1da177e4 LT |
379 | spin_unlock(&sl->lock); |
380 | printk(KERN_ERR "x25_asy: tbusy drop\n"); | |
381 | kfree_skb(skb); | |
382 | return; | |
383 | } | |
384 | /* We were not busy, so we are now... :-) */ | |
f34d7a5b | 385 | if (skb != NULL) { |
1da177e4 | 386 | x25_asy_lock(sl); |
f34d7a5b | 387 | sl->stats.tx_bytes += skb->len; |
1da177e4 LT |
388 | x25_asy_encaps(sl, skb->data, skb->len); |
389 | dev_kfree_skb(skb); | |
390 | } | |
391 | spin_unlock(&sl->lock); | |
392 | } | |
393 | ||
394 | /* | |
395 | * LAPB connection establish/down information. | |
396 | */ | |
f34d7a5b | 397 | |
1da177e4 LT |
398 | static void x25_asy_connected(struct net_device *dev, int reason) |
399 | { | |
400 | struct x25_asy *sl = dev->priv; | |
401 | struct sk_buff *skb; | |
402 | unsigned char *ptr; | |
403 | ||
f34d7a5b AC |
404 | skb = dev_alloc_skb(1); |
405 | if (skb == NULL) { | |
406 | printk(KERN_ERR "x25_asy: out of memory\n"); | |
1da177e4 LT |
407 | return; |
408 | } | |
409 | ||
410 | ptr = skb_put(skb, 1); | |
411 | *ptr = 0x01; | |
412 | ||
413 | skb->protocol = x25_type_trans(skb, sl->dev); | |
414 | netif_rx(skb); | |
415 | sl->dev->last_rx = jiffies; | |
416 | } | |
417 | ||
418 | static void x25_asy_disconnected(struct net_device *dev, int reason) | |
419 | { | |
420 | struct x25_asy *sl = dev->priv; | |
421 | struct sk_buff *skb; | |
422 | unsigned char *ptr; | |
423 | ||
f34d7a5b AC |
424 | skb = dev_alloc_skb(1); |
425 | if (skb == NULL) { | |
1da177e4 LT |
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 | { | |
f34d7a5b | 452 | struct x25_asy *sl = dev->priv; |
1da177e4 LT |
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); |
f34d7a5b | 469 | if (sl->rbuff == NULL) |
1da177e4 | 470 | goto norbuff; |
5cbded58 | 471 | sl->xbuff = kmalloc(len + 4, GFP_KERNEL); |
f34d7a5b | 472 | if (sl->xbuff == NULL) |
1da177e4 | 473 | goto noxbuff; |
1da177e4 LT |
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); | |
f34d7a5b | 481 | |
1da177e4 LT |
482 | /* |
483 | * Now attach LAPB | |
484 | */ | |
f34d7a5b AC |
485 | err = lapb_register(dev, &x25_asy_callbacks); |
486 | if (err == LAPB_OK) | |
1da177e4 LT |
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 | { | |
f34d7a5b | 501 | struct x25_asy *sl = dev->priv; |
1da177e4 LT |
502 | int err; |
503 | ||
504 | spin_lock(&sl->lock); | |
f34d7a5b | 505 | if (sl->tty) |
1da177e4 LT |
506 | sl->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); |
507 | ||
508 | netif_stop_queue(dev); | |
509 | sl->rcount = 0; | |
510 | sl->xleft = 0; | |
f34d7a5b AC |
511 | err = lapb_unregister(dev); |
512 | if (err != LAPB_OK) | |
513 | printk(KERN_ERR "x25_asy_close: lapb_unregister error -%d\n", | |
514 | err); | |
1da177e4 LT |
515 | spin_unlock(&sl->lock); |
516 | return 0; | |
517 | } | |
518 | ||
1da177e4 LT |
519 | /* |
520 | * Handle the 'receiver data ready' interrupt. | |
521 | * This function is called by the 'tty_io' module in the kernel when | |
522 | * a block of X.25 data has been received, which can now be decapsulated | |
523 | * and sent on to some IP layer for further processing. | |
524 | */ | |
f34d7a5b AC |
525 | |
526 | static void x25_asy_receive_buf(struct tty_struct *tty, | |
527 | const unsigned char *cp, char *fp, int count) | |
1da177e4 LT |
528 | { |
529 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
530 | ||
531 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) | |
532 | return; | |
533 | ||
534 | ||
535 | /* Read the characters out of the buffer */ | |
536 | while (count--) { | |
537 | if (fp && *fp++) { | |
f34d7a5b | 538 | if (!test_and_set_bit(SLF_ERROR, &sl->flags)) |
1da177e4 | 539 | sl->stats.rx_errors++; |
1da177e4 LT |
540 | cp++; |
541 | continue; | |
542 | } | |
543 | x25_asy_unesc(sl, *cp++); | |
544 | } | |
545 | } | |
546 | ||
547 | /* | |
548 | * Open the high-level part of the X.25 channel. | |
549 | * This function is called by the TTY module when the | |
550 | * X.25 line discipline is called for. Because we are | |
551 | * sure the tty line exists, we only have to link it to | |
552 | * a free X.25 channel... | |
553 | */ | |
554 | ||
555 | static int x25_asy_open_tty(struct tty_struct *tty) | |
556 | { | |
557 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
558 | int err; | |
559 | ||
f34d7a5b AC |
560 | if (tty->ops->write == NULL) |
561 | return -EOPNOTSUPP; | |
562 | ||
1da177e4 | 563 | /* First make sure we're not already connected. */ |
f34d7a5b | 564 | if (sl && sl->magic == X25_ASY_MAGIC) |
1da177e4 | 565 | return -EEXIST; |
1da177e4 LT |
566 | |
567 | /* OK. Find a free X.25 channel to use. */ | |
f34d7a5b AC |
568 | sl = x25_asy_alloc(); |
569 | if (sl == NULL) | |
1da177e4 | 570 | return -ENFILE; |
1da177e4 LT |
571 | |
572 | sl->tty = tty; | |
573 | tty->disc_data = sl; | |
33f0f88f | 574 | tty->receive_room = 65536; |
f34d7a5b | 575 | tty_driver_flush_buffer(tty); |
11b0cc3a | 576 | tty_ldisc_flush(tty); |
1da177e4 LT |
577 | |
578 | /* Restore default settings */ | |
579 | sl->dev->type = ARPHRD_X25; | |
f34d7a5b | 580 | |
1da177e4 | 581 | /* Perform the low-level X.25 async init */ |
f34d7a5b AC |
582 | err = x25_asy_open(sl->dev); |
583 | if (err) | |
1da177e4 | 584 | return err; |
1da177e4 LT |
585 | /* Done. We have linked the TTY line to a channel. */ |
586 | return sl->dev->base_addr; | |
587 | } | |
588 | ||
589 | ||
590 | /* | |
591 | * Close down an X.25 channel. | |
592 | * This means flushing out any pending queues, and then restoring the | |
593 | * TTY line discipline to what it was before it got hooked to X.25 | |
594 | * (which usually is TTY again). | |
595 | */ | |
596 | static void x25_asy_close_tty(struct tty_struct *tty) | |
597 | { | |
598 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
599 | ||
600 | /* First make sure we're connected. */ | |
601 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
602 | return; | |
603 | ||
604 | if (sl->dev->flags & IFF_UP) | |
f34d7a5b | 605 | dev_close(sl->dev); |
1da177e4 LT |
606 | |
607 | tty->disc_data = NULL; | |
608 | sl->tty = NULL; | |
609 | x25_asy_free(sl); | |
610 | } | |
611 | ||
612 | ||
613 | static struct net_device_stats *x25_asy_get_stats(struct net_device *dev) | |
614 | { | |
f34d7a5b | 615 | struct x25_asy *sl = dev->priv; |
1da177e4 LT |
616 | return &sl->stats; |
617 | } | |
618 | ||
619 | ||
620 | /************************************************************************ | |
621 | * STANDARD X.25 ENCAPSULATION * | |
622 | ************************************************************************/ | |
623 | ||
624 | int x25_asy_esc(unsigned char *s, unsigned char *d, int len) | |
625 | { | |
626 | unsigned char *ptr = d; | |
627 | unsigned char c; | |
628 | ||
629 | /* | |
630 | * Send an initial END character to flush out any | |
631 | * data that may have accumulated in the receiver | |
632 | * due to line noise. | |
633 | */ | |
634 | ||
635 | *ptr++ = X25_END; /* Send 10111110 bit seq */ | |
636 | ||
637 | /* | |
638 | * For each byte in the packet, send the appropriate | |
639 | * character sequence, according to the X.25 protocol. | |
640 | */ | |
641 | ||
f34d7a5b AC |
642 | while (len-- > 0) { |
643 | switch (c = *s++) { | |
644 | case X25_END: | |
645 | *ptr++ = X25_ESC; | |
646 | *ptr++ = X25_ESCAPE(X25_END); | |
647 | break; | |
648 | case X25_ESC: | |
649 | *ptr++ = X25_ESC; | |
650 | *ptr++ = X25_ESCAPE(X25_ESC); | |
651 | break; | |
652 | default: | |
653 | *ptr++ = c; | |
654 | break; | |
1da177e4 LT |
655 | } |
656 | } | |
657 | *ptr++ = X25_END; | |
658 | return (ptr - d); | |
659 | } | |
660 | ||
661 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char s) | |
662 | { | |
663 | ||
f34d7a5b AC |
664 | switch (s) { |
665 | case X25_END: | |
666 | if (!test_and_clear_bit(SLF_ERROR, &sl->flags) | |
667 | && sl->rcount > 2) | |
668 | x25_asy_bump(sl); | |
669 | clear_bit(SLF_ESCAPE, &sl->flags); | |
670 | sl->rcount = 0; | |
671 | return; | |
672 | case X25_ESC: | |
673 | set_bit(SLF_ESCAPE, &sl->flags); | |
674 | return; | |
675 | case X25_ESCAPE(X25_ESC): | |
676 | case X25_ESCAPE(X25_END): | |
677 | if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) | |
678 | s = X25_UNESCAPE(s); | |
679 | break; | |
680 | } | |
681 | if (!test_bit(SLF_ERROR, &sl->flags)) { | |
682 | if (sl->rcount < sl->buffsize) { | |
1da177e4 LT |
683 | sl->rbuff[sl->rcount++] = s; |
684 | return; | |
685 | } | |
686 | sl->stats.rx_over_errors++; | |
687 | set_bit(SLF_ERROR, &sl->flags); | |
688 | } | |
689 | } | |
690 | ||
691 | ||
692 | /* Perform I/O control on an active X.25 channel. */ | |
693 | static int x25_asy_ioctl(struct tty_struct *tty, struct file *file, | |
694 | unsigned int cmd, unsigned long arg) | |
695 | { | |
696 | struct x25_asy *sl = (struct x25_asy *) tty->disc_data; | |
697 | ||
698 | /* First make sure we're connected. */ | |
699 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
700 | return -EINVAL; | |
701 | ||
f34d7a5b | 702 | switch (cmd) { |
1da177e4 LT |
703 | case SIOCGIFNAME: |
704 | if (copy_to_user((void __user *)arg, sl->dev->name, | |
705 | strlen(sl->dev->name) + 1)) | |
706 | return -EFAULT; | |
707 | return 0; | |
708 | case SIOCSIFHWADDR: | |
709 | return -EINVAL; | |
1da177e4 | 710 | default: |
d0127539 | 711 | return tty_mode_ioctl(tty, file, cmd, arg); |
1da177e4 LT |
712 | } |
713 | } | |
714 | ||
715 | static int x25_asy_open_dev(struct net_device *dev) | |
716 | { | |
f34d7a5b AC |
717 | struct x25_asy *sl = dev->priv; |
718 | if (sl->tty == NULL) | |
1da177e4 LT |
719 | return -ENODEV; |
720 | return 0; | |
721 | } | |
722 | ||
723 | /* Initialise the X.25 driver. Called by the device init code */ | |
724 | static void x25_asy_setup(struct net_device *dev) | |
725 | { | |
726 | struct x25_asy *sl = dev->priv; | |
727 | ||
728 | sl->magic = X25_ASY_MAGIC; | |
729 | sl->dev = dev; | |
730 | spin_lock_init(&sl->lock); | |
731 | set_bit(SLF_INUSE, &sl->flags); | |
732 | ||
733 | /* | |
f34d7a5b | 734 | * Finish setting up the DEVICE info. |
1da177e4 | 735 | */ |
f34d7a5b | 736 | |
1da177e4 LT |
737 | dev->mtu = SL_MTU; |
738 | dev->hard_start_xmit = x25_asy_xmit; | |
739 | dev->tx_timeout = x25_asy_timeout; | |
740 | dev->watchdog_timeo = HZ*20; | |
741 | dev->open = x25_asy_open_dev; | |
742 | dev->stop = x25_asy_close; | |
743 | dev->get_stats = x25_asy_get_stats; | |
744 | dev->change_mtu = x25_asy_change_mtu; | |
745 | dev->hard_header_len = 0; | |
746 | dev->addr_len = 0; | |
747 | dev->type = ARPHRD_X25; | |
748 | dev->tx_queue_len = 10; | |
749 | ||
750 | /* New-style flags. */ | |
751 | dev->flags = IFF_NOARP; | |
752 | } | |
753 | ||
754 | static struct tty_ldisc x25_ldisc = { | |
755 | .owner = THIS_MODULE, | |
756 | .magic = TTY_LDISC_MAGIC, | |
757 | .name = "X.25", | |
758 | .open = x25_asy_open_tty, | |
759 | .close = x25_asy_close_tty, | |
760 | .ioctl = x25_asy_ioctl, | |
761 | .receive_buf = x25_asy_receive_buf, | |
1da177e4 LT |
762 | .write_wakeup = x25_asy_write_wakeup, |
763 | }; | |
764 | ||
765 | static int __init init_x25_asy(void) | |
766 | { | |
767 | if (x25_asy_maxdev < 4) | |
768 | x25_asy_maxdev = 4; /* Sanity */ | |
769 | ||
770 | printk(KERN_INFO "X.25 async: version 0.00 ALPHA " | |
f34d7a5b | 771 | "(dynamic channels, max=%d).\n", x25_asy_maxdev); |
1da177e4 | 772 | |
f34d7a5b AC |
773 | x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device *), |
774 | GFP_KERNEL); | |
1da177e4 LT |
775 | if (!x25_asy_devs) { |
776 | printk(KERN_WARNING "X25 async: Can't allocate x25_asy_ctrls[] " | |
777 | "array! Uaargh! (-> No X.25 available)\n"); | |
778 | return -ENOMEM; | |
779 | } | |
1da177e4 LT |
780 | |
781 | return tty_register_ldisc(N_X25, &x25_ldisc); | |
782 | } | |
783 | ||
784 | ||
785 | static void __exit exit_x25_asy(void) | |
786 | { | |
787 | struct net_device *dev; | |
788 | int i; | |
789 | ||
790 | for (i = 0; i < x25_asy_maxdev; i++) { | |
791 | dev = x25_asy_devs[i]; | |
792 | if (dev) { | |
793 | struct x25_asy *sl = dev->priv; | |
794 | ||
795 | spin_lock_bh(&sl->lock); | |
f34d7a5b | 796 | if (sl->tty) |
1da177e4 LT |
797 | tty_hangup(sl->tty); |
798 | ||
799 | spin_unlock_bh(&sl->lock); | |
800 | /* | |
801 | * VSV = if dev->start==0, then device | |
802 | * unregistered while close proc. | |
803 | */ | |
804 | unregister_netdev(dev); | |
805 | free_netdev(dev); | |
806 | } | |
807 | } | |
808 | ||
809 | kfree(x25_asy_devs); | |
64ccd715 | 810 | tty_unregister_ldisc(N_X25); |
1da177e4 LT |
811 | } |
812 | ||
813 | module_init(init_x25_asy); | |
814 | module_exit(exit_x25_asy); |