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> | |
3e3cda96 | 35 | #include <linux/rtnetlink.h> |
1da177e4 LT |
36 | #include "x25_asy.h" |
37 | ||
38 | #include <net/x25device.h> | |
39 | ||
40 | static struct net_device **x25_asy_devs; | |
41 | static int x25_asy_maxdev = SL_NRUNIT; | |
42 | ||
43 | module_param(x25_asy_maxdev, int, 0); | |
44 | MODULE_LICENSE("GPL"); | |
45 | ||
46 | static int x25_asy_esc(unsigned char *p, unsigned char *d, int len); | |
47 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char c); | |
48 | static void x25_asy_setup(struct net_device *dev); | |
49 | ||
50 | /* Find a free X.25 channel, and link in this `tty' line. */ | |
51 | static struct x25_asy *x25_asy_alloc(void) | |
52 | { | |
53 | struct net_device *dev = NULL; | |
54 | struct x25_asy *sl; | |
55 | int i; | |
56 | ||
57 | if (x25_asy_devs == NULL) | |
58 | return NULL; /* Master array missing ! */ | |
59 | ||
60 | for (i = 0; i < x25_asy_maxdev; i++) { | |
61 | dev = x25_asy_devs[i]; | |
62 | ||
63 | /* Not allocated ? */ | |
64 | if (dev == NULL) | |
65 | break; | |
66 | ||
8f15ea42 | 67 | sl = netdev_priv(dev); |
1da177e4 LT |
68 | /* Not in use ? */ |
69 | if (!test_and_set_bit(SLF_INUSE, &sl->flags)) | |
70 | return sl; | |
71 | } | |
72 | ||
73 | ||
74 | /* Sorry, too many, all slots in use */ | |
75 | if (i >= x25_asy_maxdev) | |
76 | return NULL; | |
77 | ||
78 | /* If no channels are available, allocate one */ | |
79 | if (!dev) { | |
80 | char name[IFNAMSIZ]; | |
81 | sprintf(name, "x25asy%d", i); | |
82 | ||
83 | dev = alloc_netdev(sizeof(struct x25_asy), | |
84 | name, x25_asy_setup); | |
85 | if (!dev) | |
86 | return NULL; | |
87 | ||
88 | /* Initialize channel control data */ | |
8f15ea42 | 89 | sl = netdev_priv(dev); |
1da177e4 LT |
90 | dev->base_addr = i; |
91 | ||
92 | /* register device so that it can be ifconfig'ed */ | |
93 | if (register_netdev(dev) == 0) { | |
94 | /* (Re-)Set the INUSE bit. Very Important! */ | |
95 | set_bit(SLF_INUSE, &sl->flags); | |
96 | x25_asy_devs[i] = dev; | |
97 | return sl; | |
98 | } else { | |
f34d7a5b | 99 | printk(KERN_WARNING "x25_asy_alloc() - register_netdev() failure.\n"); |
1da177e4 LT |
100 | free_netdev(dev); |
101 | } | |
102 | } | |
103 | return NULL; | |
104 | } | |
105 | ||
106 | ||
107 | /* Free an X.25 channel. */ | |
108 | static void x25_asy_free(struct x25_asy *sl) | |
109 | { | |
110 | /* Free all X.25 frame buffers. */ | |
6a5d3621 | 111 | kfree(sl->rbuff); |
1da177e4 | 112 | sl->rbuff = NULL; |
6a5d3621 | 113 | kfree(sl->xbuff); |
1da177e4 LT |
114 | sl->xbuff = NULL; |
115 | ||
f34d7a5b AC |
116 | if (!test_and_clear_bit(SLF_INUSE, &sl->flags)) |
117 | printk(KERN_ERR "%s: x25_asy_free for already free unit.\n", | |
118 | sl->dev->name); | |
1da177e4 LT |
119 | } |
120 | ||
121 | static int x25_asy_change_mtu(struct net_device *dev, int newmtu) | |
122 | { | |
8f15ea42 | 123 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 | 124 | unsigned char *xbuff, *rbuff; |
f34d7a5b | 125 | int len = 2 * newmtu; |
1da177e4 | 126 | |
5cbded58 RD |
127 | xbuff = kmalloc(len + 4, GFP_ATOMIC); |
128 | rbuff = kmalloc(len + 4, GFP_ATOMIC); | |
1da177e4 | 129 | |
f34d7a5b AC |
130 | if (xbuff == NULL || rbuff == NULL) { |
131 | printk(KERN_WARNING "%s: unable to grow X.25 buffers, MTU change cancelled.\n", | |
1da177e4 | 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; | |
f34d7a5b AC |
196 | sl->stats.rx_bytes += count; |
197 | ||
1da177e4 | 198 | skb = dev_alloc_skb(count+1); |
f34d7a5b AC |
199 | if (skb == NULL) { |
200 | printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", | |
201 | sl->dev->name); | |
1da177e4 LT |
202 | sl->stats.rx_dropped++; |
203 | return; | |
204 | } | |
f34d7a5b AC |
205 | skb_push(skb, 1); /* LAPB internal control */ |
206 | memcpy(skb_put(skb, count), sl->rbuff, count); | |
1da177e4 | 207 | skb->protocol = x25_type_trans(skb, sl->dev); |
f34d7a5b AC |
208 | err = lapb_data_received(skb->dev, skb); |
209 | if (err != LAPB_OK) { | |
1da177e4 | 210 | kfree_skb(skb); |
f34d7a5b AC |
211 | printk(KERN_DEBUG "x25_asy: data received err - %d\n", err); |
212 | } else { | |
1da177e4 | 213 | netif_rx(skb); |
1da177e4 LT |
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 | */ | |
8a1ec21e | 245 | set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
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; | |
d2b88814 | 260 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
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++; | |
8a1ec21e | 270 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
1da177e4 LT |
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 | { | |
8f15ea42 | 282 | struct x25_asy *sl = netdev_priv(dev); |
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; | |
8a1ec21e | 293 | clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
1da177e4 LT |
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 | { | |
8f15ea42 | 303 | struct x25_asy *sl = netdev_priv(dev); |
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 | { | |
1da177e4 LT |
363 | return netif_rx(skb); |
364 | } | |
365 | ||
366 | /* | |
367 | * Data has emerged from the LAPB protocol machine. We don't handle | |
368 | * busy cases too well. Its tricky to see how to do this nicely - | |
369 | * perhaps lapb should allow us to bounce this ? | |
370 | */ | |
f34d7a5b | 371 | |
1da177e4 LT |
372 | static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb) |
373 | { | |
8f15ea42 | 374 | struct x25_asy *sl = netdev_priv(dev); |
f34d7a5b | 375 | |
1da177e4 | 376 | spin_lock(&sl->lock); |
f34d7a5b | 377 | if (netif_queue_stopped(sl->dev) || sl->tty == NULL) { |
1da177e4 LT |
378 | spin_unlock(&sl->lock); |
379 | printk(KERN_ERR "x25_asy: tbusy drop\n"); | |
380 | kfree_skb(skb); | |
381 | return; | |
382 | } | |
383 | /* We were not busy, so we are now... :-) */ | |
f34d7a5b | 384 | if (skb != NULL) { |
1da177e4 | 385 | x25_asy_lock(sl); |
f34d7a5b | 386 | sl->stats.tx_bytes += skb->len; |
1da177e4 LT |
387 | x25_asy_encaps(sl, skb->data, skb->len); |
388 | dev_kfree_skb(skb); | |
389 | } | |
390 | spin_unlock(&sl->lock); | |
391 | } | |
392 | ||
393 | /* | |
394 | * LAPB connection establish/down information. | |
395 | */ | |
f34d7a5b | 396 | |
1da177e4 LT |
397 | static void x25_asy_connected(struct net_device *dev, int reason) |
398 | { | |
8f15ea42 | 399 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
400 | struct sk_buff *skb; |
401 | unsigned char *ptr; | |
402 | ||
f34d7a5b AC |
403 | skb = dev_alloc_skb(1); |
404 | if (skb == NULL) { | |
405 | printk(KERN_ERR "x25_asy: out of memory\n"); | |
1da177e4 LT |
406 | return; |
407 | } | |
408 | ||
409 | ptr = skb_put(skb, 1); | |
410 | *ptr = 0x01; | |
411 | ||
412 | skb->protocol = x25_type_trans(skb, sl->dev); | |
413 | netif_rx(skb); | |
1da177e4 LT |
414 | } |
415 | ||
416 | static void x25_asy_disconnected(struct net_device *dev, int reason) | |
417 | { | |
8f15ea42 | 418 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
419 | struct sk_buff *skb; |
420 | unsigned char *ptr; | |
421 | ||
f34d7a5b AC |
422 | skb = dev_alloc_skb(1); |
423 | if (skb == NULL) { | |
1da177e4 LT |
424 | printk(KERN_ERR "x25_asy: out of memory\n"); |
425 | return; | |
426 | } | |
427 | ||
428 | ptr = skb_put(skb, 1); | |
429 | *ptr = 0x02; | |
430 | ||
431 | skb->protocol = x25_type_trans(skb, sl->dev); | |
432 | netif_rx(skb); | |
1da177e4 LT |
433 | } |
434 | ||
435 | static struct lapb_register_struct x25_asy_callbacks = { | |
436 | .connect_confirmation = x25_asy_connected, | |
437 | .connect_indication = x25_asy_connected, | |
438 | .disconnect_confirmation = x25_asy_disconnected, | |
439 | .disconnect_indication = x25_asy_disconnected, | |
440 | .data_indication = x25_asy_data_indication, | |
441 | .data_transmit = x25_asy_data_transmit, | |
442 | ||
443 | }; | |
444 | ||
445 | ||
446 | /* Open the low-level part of the X.25 channel. Easy! */ | |
447 | static int x25_asy_open(struct net_device *dev) | |
448 | { | |
8f15ea42 | 449 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
450 | unsigned long len; |
451 | int err; | |
452 | ||
453 | if (sl->tty == NULL) | |
454 | return -ENODEV; | |
455 | ||
456 | /* | |
457 | * Allocate the X.25 frame buffers: | |
458 | * | |
459 | * rbuff Receive buffer. | |
460 | * xbuff Transmit buffer. | |
461 | */ | |
462 | ||
463 | len = dev->mtu * 2; | |
464 | ||
5cbded58 | 465 | sl->rbuff = kmalloc(len + 4, GFP_KERNEL); |
f34d7a5b | 466 | if (sl->rbuff == NULL) |
1da177e4 | 467 | goto norbuff; |
5cbded58 | 468 | sl->xbuff = kmalloc(len + 4, GFP_KERNEL); |
f34d7a5b | 469 | if (sl->xbuff == NULL) |
1da177e4 | 470 | goto noxbuff; |
1da177e4 LT |
471 | |
472 | sl->buffsize = len; | |
473 | sl->rcount = 0; | |
474 | sl->xleft = 0; | |
475 | sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */ | |
476 | ||
477 | netif_start_queue(dev); | |
f34d7a5b | 478 | |
1da177e4 LT |
479 | /* |
480 | * Now attach LAPB | |
481 | */ | |
f34d7a5b AC |
482 | err = lapb_register(dev, &x25_asy_callbacks); |
483 | if (err == LAPB_OK) | |
1da177e4 LT |
484 | return 0; |
485 | ||
486 | /* Cleanup */ | |
487 | kfree(sl->xbuff); | |
488 | noxbuff: | |
489 | kfree(sl->rbuff); | |
490 | norbuff: | |
491 | return -ENOMEM; | |
492 | } | |
493 | ||
494 | ||
495 | /* Close the low-level part of the X.25 channel. Easy! */ | |
496 | static int x25_asy_close(struct net_device *dev) | |
497 | { | |
8f15ea42 | 498 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
499 | int err; |
500 | ||
501 | spin_lock(&sl->lock); | |
f34d7a5b | 502 | if (sl->tty) |
8a1ec21e | 503 | clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
1da177e4 LT |
504 | |
505 | netif_stop_queue(dev); | |
506 | sl->rcount = 0; | |
507 | sl->xleft = 0; | |
f34d7a5b AC |
508 | err = lapb_unregister(dev); |
509 | if (err != LAPB_OK) | |
510 | printk(KERN_ERR "x25_asy_close: lapb_unregister error -%d\n", | |
511 | err); | |
1da177e4 LT |
512 | spin_unlock(&sl->lock); |
513 | return 0; | |
514 | } | |
515 | ||
1da177e4 LT |
516 | /* |
517 | * Handle the 'receiver data ready' interrupt. | |
518 | * This function is called by the 'tty_io' module in the kernel when | |
519 | * a block of X.25 data has been received, which can now be decapsulated | |
520 | * and sent on to some IP layer for further processing. | |
521 | */ | |
f34d7a5b AC |
522 | |
523 | static void x25_asy_receive_buf(struct tty_struct *tty, | |
524 | const unsigned char *cp, char *fp, int count) | |
1da177e4 | 525 | { |
d2b88814 | 526 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
527 | |
528 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) | |
529 | return; | |
530 | ||
531 | ||
532 | /* Read the characters out of the buffer */ | |
533 | while (count--) { | |
534 | if (fp && *fp++) { | |
f34d7a5b | 535 | if (!test_and_set_bit(SLF_ERROR, &sl->flags)) |
1da177e4 | 536 | sl->stats.rx_errors++; |
1da177e4 LT |
537 | cp++; |
538 | continue; | |
539 | } | |
540 | x25_asy_unesc(sl, *cp++); | |
541 | } | |
542 | } | |
543 | ||
544 | /* | |
545 | * Open the high-level part of the X.25 channel. | |
546 | * This function is called by the TTY module when the | |
547 | * X.25 line discipline is called for. Because we are | |
548 | * sure the tty line exists, we only have to link it to | |
549 | * a free X.25 channel... | |
550 | */ | |
551 | ||
552 | static int x25_asy_open_tty(struct tty_struct *tty) | |
553 | { | |
d2b88814 | 554 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
555 | int err; |
556 | ||
f34d7a5b AC |
557 | if (tty->ops->write == NULL) |
558 | return -EOPNOTSUPP; | |
559 | ||
1da177e4 | 560 | /* First make sure we're not already connected. */ |
f34d7a5b | 561 | if (sl && sl->magic == X25_ASY_MAGIC) |
1da177e4 | 562 | return -EEXIST; |
1da177e4 LT |
563 | |
564 | /* OK. Find a free X.25 channel to use. */ | |
f34d7a5b AC |
565 | sl = x25_asy_alloc(); |
566 | if (sl == NULL) | |
1da177e4 | 567 | return -ENFILE; |
1da177e4 LT |
568 | |
569 | sl->tty = tty; | |
570 | tty->disc_data = sl; | |
33f0f88f | 571 | tty->receive_room = 65536; |
f34d7a5b | 572 | tty_driver_flush_buffer(tty); |
11b0cc3a | 573 | tty_ldisc_flush(tty); |
1da177e4 LT |
574 | |
575 | /* Restore default settings */ | |
576 | sl->dev->type = ARPHRD_X25; | |
f34d7a5b | 577 | |
1da177e4 | 578 | /* Perform the low-level X.25 async init */ |
f34d7a5b AC |
579 | err = x25_asy_open(sl->dev); |
580 | if (err) | |
1da177e4 | 581 | return err; |
1da177e4 LT |
582 | /* Done. We have linked the TTY line to a channel. */ |
583 | return sl->dev->base_addr; | |
584 | } | |
585 | ||
586 | ||
587 | /* | |
588 | * Close down an X.25 channel. | |
589 | * This means flushing out any pending queues, and then restoring the | |
590 | * TTY line discipline to what it was before it got hooked to X.25 | |
591 | * (which usually is TTY again). | |
592 | */ | |
593 | static void x25_asy_close_tty(struct tty_struct *tty) | |
594 | { | |
d2b88814 | 595 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
596 | |
597 | /* First make sure we're connected. */ | |
598 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
599 | return; | |
600 | ||
3e3cda96 | 601 | rtnl_lock(); |
1da177e4 | 602 | if (sl->dev->flags & IFF_UP) |
f34d7a5b | 603 | dev_close(sl->dev); |
3e3cda96 | 604 | rtnl_unlock(); |
1da177e4 LT |
605 | |
606 | tty->disc_data = NULL; | |
607 | sl->tty = NULL; | |
608 | x25_asy_free(sl); | |
609 | } | |
610 | ||
611 | ||
612 | static struct net_device_stats *x25_asy_get_stats(struct net_device *dev) | |
613 | { | |
8f15ea42 | 614 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
615 | return &sl->stats; |
616 | } | |
617 | ||
618 | ||
619 | /************************************************************************ | |
620 | * STANDARD X.25 ENCAPSULATION * | |
621 | ************************************************************************/ | |
622 | ||
7b3dfa11 | 623 | static int x25_asy_esc(unsigned char *s, unsigned char *d, int len) |
1da177e4 LT |
624 | { |
625 | unsigned char *ptr = d; | |
626 | unsigned char c; | |
627 | ||
628 | /* | |
629 | * Send an initial END character to flush out any | |
630 | * data that may have accumulated in the receiver | |
631 | * due to line noise. | |
632 | */ | |
633 | ||
634 | *ptr++ = X25_END; /* Send 10111110 bit seq */ | |
635 | ||
636 | /* | |
637 | * For each byte in the packet, send the appropriate | |
638 | * character sequence, according to the X.25 protocol. | |
639 | */ | |
640 | ||
f34d7a5b AC |
641 | while (len-- > 0) { |
642 | switch (c = *s++) { | |
643 | case X25_END: | |
644 | *ptr++ = X25_ESC; | |
645 | *ptr++ = X25_ESCAPE(X25_END); | |
646 | break; | |
647 | case X25_ESC: | |
648 | *ptr++ = X25_ESC; | |
649 | *ptr++ = X25_ESCAPE(X25_ESC); | |
650 | break; | |
651 | default: | |
652 | *ptr++ = c; | |
653 | break; | |
1da177e4 LT |
654 | } |
655 | } | |
656 | *ptr++ = X25_END; | |
657 | return (ptr - d); | |
658 | } | |
659 | ||
660 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char s) | |
661 | { | |
662 | ||
f34d7a5b AC |
663 | switch (s) { |
664 | case X25_END: | |
665 | if (!test_and_clear_bit(SLF_ERROR, &sl->flags) | |
666 | && sl->rcount > 2) | |
667 | x25_asy_bump(sl); | |
668 | clear_bit(SLF_ESCAPE, &sl->flags); | |
669 | sl->rcount = 0; | |
670 | return; | |
671 | case X25_ESC: | |
672 | set_bit(SLF_ESCAPE, &sl->flags); | |
673 | return; | |
674 | case X25_ESCAPE(X25_ESC): | |
675 | case X25_ESCAPE(X25_END): | |
676 | if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) | |
677 | s = X25_UNESCAPE(s); | |
678 | break; | |
679 | } | |
680 | if (!test_bit(SLF_ERROR, &sl->flags)) { | |
681 | if (sl->rcount < sl->buffsize) { | |
1da177e4 LT |
682 | sl->rbuff[sl->rcount++] = s; |
683 | return; | |
684 | } | |
685 | sl->stats.rx_over_errors++; | |
686 | set_bit(SLF_ERROR, &sl->flags); | |
687 | } | |
688 | } | |
689 | ||
690 | ||
691 | /* Perform I/O control on an active X.25 channel. */ | |
692 | static int x25_asy_ioctl(struct tty_struct *tty, struct file *file, | |
693 | unsigned int cmd, unsigned long arg) | |
694 | { | |
d2b88814 | 695 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
696 | |
697 | /* First make sure we're connected. */ | |
698 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
699 | return -EINVAL; | |
700 | ||
f34d7a5b | 701 | switch (cmd) { |
1da177e4 LT |
702 | case SIOCGIFNAME: |
703 | if (copy_to_user((void __user *)arg, sl->dev->name, | |
704 | strlen(sl->dev->name) + 1)) | |
705 | return -EFAULT; | |
706 | return 0; | |
707 | case SIOCSIFHWADDR: | |
708 | return -EINVAL; | |
1da177e4 | 709 | default: |
d0127539 | 710 | return tty_mode_ioctl(tty, file, cmd, arg); |
1da177e4 LT |
711 | } |
712 | } | |
713 | ||
714 | static int x25_asy_open_dev(struct net_device *dev) | |
715 | { | |
8f15ea42 | 716 | struct x25_asy *sl = netdev_priv(dev); |
f34d7a5b | 717 | if (sl->tty == NULL) |
1da177e4 LT |
718 | return -ENODEV; |
719 | return 0; | |
720 | } | |
721 | ||
722 | /* Initialise the X.25 driver. Called by the device init code */ | |
723 | static void x25_asy_setup(struct net_device *dev) | |
724 | { | |
8f15ea42 | 725 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
726 | |
727 | sl->magic = X25_ASY_MAGIC; | |
728 | sl->dev = dev; | |
729 | spin_lock_init(&sl->lock); | |
730 | set_bit(SLF_INUSE, &sl->flags); | |
731 | ||
732 | /* | |
f34d7a5b | 733 | * Finish setting up the DEVICE info. |
1da177e4 | 734 | */ |
f34d7a5b | 735 | |
1da177e4 LT |
736 | dev->mtu = SL_MTU; |
737 | dev->hard_start_xmit = x25_asy_xmit; | |
738 | dev->tx_timeout = x25_asy_timeout; | |
739 | dev->watchdog_timeo = HZ*20; | |
740 | dev->open = x25_asy_open_dev; | |
741 | dev->stop = x25_asy_close; | |
742 | dev->get_stats = x25_asy_get_stats; | |
743 | dev->change_mtu = x25_asy_change_mtu; | |
744 | dev->hard_header_len = 0; | |
745 | dev->addr_len = 0; | |
746 | dev->type = ARPHRD_X25; | |
747 | dev->tx_queue_len = 10; | |
748 | ||
749 | /* New-style flags. */ | |
750 | dev->flags = IFF_NOARP; | |
751 | } | |
752 | ||
a352def2 | 753 | static struct tty_ldisc_ops x25_ldisc = { |
1da177e4 LT |
754 | .owner = THIS_MODULE, |
755 | .magic = TTY_LDISC_MAGIC, | |
756 | .name = "X.25", | |
757 | .open = x25_asy_open_tty, | |
758 | .close = x25_asy_close_tty, | |
759 | .ioctl = x25_asy_ioctl, | |
760 | .receive_buf = x25_asy_receive_buf, | |
1da177e4 LT |
761 | .write_wakeup = x25_asy_write_wakeup, |
762 | }; | |
763 | ||
764 | static int __init init_x25_asy(void) | |
765 | { | |
766 | if (x25_asy_maxdev < 4) | |
767 | x25_asy_maxdev = 4; /* Sanity */ | |
768 | ||
769 | printk(KERN_INFO "X.25 async: version 0.00 ALPHA " | |
f34d7a5b | 770 | "(dynamic channels, max=%d).\n", x25_asy_maxdev); |
1da177e4 | 771 | |
f34d7a5b AC |
772 | x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device *), |
773 | GFP_KERNEL); | |
1da177e4 LT |
774 | if (!x25_asy_devs) { |
775 | printk(KERN_WARNING "X25 async: Can't allocate x25_asy_ctrls[] " | |
776 | "array! Uaargh! (-> No X.25 available)\n"); | |
777 | return -ENOMEM; | |
778 | } | |
1da177e4 LT |
779 | |
780 | return tty_register_ldisc(N_X25, &x25_ldisc); | |
781 | } | |
782 | ||
783 | ||
784 | static void __exit exit_x25_asy(void) | |
785 | { | |
786 | struct net_device *dev; | |
787 | int i; | |
788 | ||
789 | for (i = 0; i < x25_asy_maxdev; i++) { | |
790 | dev = x25_asy_devs[i]; | |
791 | if (dev) { | |
8f15ea42 | 792 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
793 | |
794 | spin_lock_bh(&sl->lock); | |
f34d7a5b | 795 | if (sl->tty) |
1da177e4 LT |
796 | tty_hangup(sl->tty); |
797 | ||
798 | spin_unlock_bh(&sl->lock); | |
799 | /* | |
800 | * VSV = if dev->start==0, then device | |
801 | * unregistered while close proc. | |
802 | */ | |
803 | unregister_netdev(dev); | |
804 | free_netdev(dev); | |
805 | } | |
806 | } | |
807 | ||
808 | kfree(x25_asy_devs); | |
64ccd715 | 809 | tty_unregister_ldisc(N_X25); |
1da177e4 LT |
810 | } |
811 | ||
812 | module_init(init_x25_asy); | |
813 | module_exit(exit_x25_asy); |