blob: d67e208ab3759941c6be1344d63114af8e8d3d14 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Alan Coxf34d7a52008-04-30 00:54:13 -070020#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#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>
Ben Hutchings3e3cda92008-05-06 19:41:48 +010035#include <linux/rtnetlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include "x25_asy.h"
37
38#include <net/x25device.h>
39
40static struct net_device **x25_asy_devs;
41static int x25_asy_maxdev = SL_NRUNIT;
42
43module_param(x25_asy_maxdev, int, 0);
44MODULE_LICENSE("GPL");
45
46static int x25_asy_esc(unsigned char *p, unsigned char *d, int len);
47static void x25_asy_unesc(struct x25_asy *sl, unsigned char c);
48static void x25_asy_setup(struct net_device *dev);
49
50/* Find a free X.25 channel, and link in this `tty' line. */
51static 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
Wang Chen8f15ea42008-11-12 23:38:36 -080067 sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 /* 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 */
Wang Chen8f15ea42008-11-12 23:38:36 -080089 sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 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 {
Alan Coxf34d7a52008-04-30 00:54:13 -070099 printk(KERN_WARNING "x25_asy_alloc() - register_netdev() failure.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 free_netdev(dev);
101 }
102 }
103 return NULL;
104}
105
106
107/* Free an X.25 channel. */
108static void x25_asy_free(struct x25_asy *sl)
109{
110 /* Free all X.25 frame buffers. */
Jesper Juhl6a5d3622005-05-03 14:33:27 -0700111 kfree(sl->rbuff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 sl->rbuff = NULL;
Jesper Juhl6a5d3622005-05-03 14:33:27 -0700113 kfree(sl->xbuff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 sl->xbuff = NULL;
115
Alan Coxf34d7a52008-04-30 00:54:13 -0700116 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119}
120
121static int x25_asy_change_mtu(struct net_device *dev, int newmtu)
122{
Wang Chen8f15ea42008-11-12 23:38:36 -0800123 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 unsigned char *xbuff, *rbuff;
Alan Coxf34d7a52008-04-30 00:54:13 -0700125 int len = 2 * newmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
Robert P. J. Day5cbded52006-12-13 00:35:56 -0800127 xbuff = kmalloc(len + 4, GFP_ATOMIC);
128 rbuff = kmalloc(len + 4, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129
Alan Coxf34d7a52008-04-30 00:54:13 -0700130 if (xbuff == NULL || rbuff == NULL) {
131 printk(KERN_WARNING "%s: unable to grow X.25 buffers, MTU change cancelled.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 dev->name);
Jesper Juhl6a5d3622005-05-03 14:33:27 -0700133 kfree(xbuff);
134 kfree(rbuff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 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;
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000145 dev->stats.tx_dropped++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
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;
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000156 dev->stats.rx_over_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 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
Jesper Juhl6a5d3622005-05-03 14:33:27 -0700166 kfree(xbuff);
167 kfree(rbuff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 return 0;
169}
170
171
172/* Set the "sending" flag. This must be atomic, hence the ASM. */
173
174static 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
182static 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
189static void x25_asy_bump(struct x25_asy *sl)
190{
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000191 struct net_device *dev = sl->dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 struct sk_buff *skb;
193 int count;
194 int err;
195
196 count = sl->rcount;
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000197 dev->stats.rx_bytes += count;
Alan Coxf34d7a52008-04-30 00:54:13 -0700198
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 skb = dev_alloc_skb(count+1);
Alan Coxf34d7a52008-04-30 00:54:13 -0700200 if (skb == NULL) {
201 printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n",
202 sl->dev->name);
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000203 dev->stats.rx_dropped++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 return;
205 }
Alan Coxf34d7a52008-04-30 00:54:13 -0700206 skb_push(skb, 1); /* LAPB internal control */
207 memcpy(skb_put(skb, count), sl->rbuff, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 skb->protocol = x25_type_trans(skb, sl->dev);
Alan Coxf34d7a52008-04-30 00:54:13 -0700209 err = lapb_data_received(skb->dev, skb);
210 if (err != LAPB_OK) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 kfree_skb(skb);
Alan Coxf34d7a52008-04-30 00:54:13 -0700212 printk(KERN_DEBUG "x25_asy: data received err - %d\n", err);
213 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 netif_rx(skb);
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000215 dev->stats.rx_packets++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 }
217}
218
219/* Encapsulate one IP datagram and stuff into a TTY queue. */
220static void x25_asy_encaps(struct x25_asy *sl, unsigned char *icp, int len)
221{
222 unsigned char *p;
223 int actual, count, mtu = sl->dev->mtu;
224
Alan Coxf34d7a52008-04-30 00:54:13 -0700225 if (len > mtu) {
226 /* Sigh, shouldn't occur BUT ... */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 len = mtu;
Alan Coxf34d7a52008-04-30 00:54:13 -0700228 printk(KERN_DEBUG "%s: truncating oversized transmit packet!\n",
229 sl->dev->name);
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000230 sl->dev->stats.tx_dropped++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 x25_asy_unlock(sl);
232 return;
233 }
234
235 p = icp;
236 count = x25_asy_esc(p, (unsigned char *) sl->xbuff, len);
237
238 /* Order of next two lines is *very* important.
239 * When we are sending a little amount of data,
240 * the transfer may be completed inside driver.write()
241 * routine, because it's running with interrupts enabled.
242 * In this case we *never* got WRITE_WAKEUP event,
243 * if we did not request it before write operation.
244 * 14 Oct 1994 Dmitry Gorodchanin.
245 */
Alan Cox8a1ec212008-12-05 22:31:52 -0800246 set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
Alan Coxf34d7a52008-04-30 00:54:13 -0700247 actual = sl->tty->ops->write(sl->tty, sl->xbuff, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 sl->xleft = count - actual;
249 sl->xhead = sl->xbuff + actual;
250 /* VSV */
251 clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */
252}
253
254/*
255 * Called by the driver when there's room for more data. If we have
256 * more packets to send, we send them here.
257 */
258static void x25_asy_write_wakeup(struct tty_struct *tty)
259{
260 int actual;
Alan Coxd2b88812008-12-05 22:32:22 -0800261 struct x25_asy *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 /* First make sure we're connected. */
264 if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
265 return;
266
Alan Coxf34d7a52008-04-30 00:54:13 -0700267 if (sl->xleft <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 /* Now serial buffer is almost free & we can start
269 * transmission of another packet */
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000270 sl->dev->stats.tx_packets++;
Alan Cox8a1ec212008-12-05 22:31:52 -0800271 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 x25_asy_unlock(sl);
273 return;
274 }
275
Alan Coxf34d7a52008-04-30 00:54:13 -0700276 actual = tty->ops->write(tty, sl->xhead, sl->xleft);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 sl->xleft -= actual;
278 sl->xhead += actual;
279}
280
281static void x25_asy_timeout(struct net_device *dev)
282{
Wang Chen8f15ea42008-11-12 23:38:36 -0800283 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
285 spin_lock(&sl->lock);
286 if (netif_queue_stopped(dev)) {
287 /* May be we must check transmitter timeout here ?
288 * 14 Oct 1994 Dmitry Gorodchanin.
289 */
290 printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name,
Alan Coxf34d7a52008-04-30 00:54:13 -0700291 (tty_chars_in_buffer(sl->tty) || sl->xleft) ?
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 "bad line quality" : "driver error");
293 sl->xleft = 0;
Alan Cox8a1ec212008-12-05 22:31:52 -0800294 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 x25_asy_unlock(sl);
296 }
297 spin_unlock(&sl->lock);
298}
299
300/* Encapsulate an IP datagram and kick it into a TTY queue. */
301
302static int x25_asy_xmit(struct sk_buff *skb, struct net_device *dev)
303{
Wang Chen8f15ea42008-11-12 23:38:36 -0800304 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 int err;
306
307 if (!netif_running(sl->dev)) {
Alan Coxf34d7a52008-04-30 00:54:13 -0700308 printk(KERN_ERR "%s: xmit call when iface is down\n",
309 dev->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 kfree_skb(skb);
311 return 0;
312 }
Alan Coxf34d7a52008-04-30 00:54:13 -0700313
314 switch (skb->data[0]) {
315 case 0x00:
316 break;
317 case 0x01: /* Connection request .. do nothing */
318 err = lapb_connect_request(dev);
319 if (err != 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 err = lapb_disconnect_request(dev);
325 if (err != LAPB_OK)
326 printk(KERN_ERR "x25_asy: lapb_disconnect_request error - %d\n", err);
327 default:
328 kfree_skb(skb);
329 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 }
Alan Coxf34d7a52008-04-30 00:54:13 -0700331 skb_pull(skb, 1); /* Remove control byte */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 /*
333 * If we are busy already- too bad. We ought to be able
334 * to queue things at this point, to allow for a little
335 * frame buffer. Oh well...
336 * -----------------------------------------------------
337 * I hate queues in X.25 driver. May be it's efficient,
338 * but for me latency is more important. ;)
339 * So, no queues !
340 * 14 Oct 1994 Dmitry Gorodchanin.
341 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700342
343 err = lapb_data_request(dev, skb);
344 if (err != LAPB_OK) {
345 printk(KERN_ERR "x25_asy: lapb_data_request error - %d\n", err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 kfree_skb(skb);
347 return 0;
348 }
349 return 0;
350}
351
352
353/*
354 * LAPB interface boilerplate
355 */
356
357/*
358 * Called when I frame data arrives. We did the work above - throw it
359 * at the net layer.
360 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700361
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb)
363{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 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 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700372
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb)
374{
Wang Chen8f15ea42008-11-12 23:38:36 -0800375 struct x25_asy *sl = netdev_priv(dev);
Alan Coxf34d7a52008-04-30 00:54:13 -0700376
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 spin_lock(&sl->lock);
Alan Coxf34d7a52008-04-30 00:54:13 -0700378 if (netif_queue_stopped(sl->dev) || sl->tty == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 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... :-) */
Alan Coxf34d7a52008-04-30 00:54:13 -0700385 if (skb != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 x25_asy_lock(sl);
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000387 dev->stats.tx_bytes += skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 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 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700397
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398static void x25_asy_connected(struct net_device *dev, int reason)
399{
Wang Chen8f15ea42008-11-12 23:38:36 -0800400 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 struct sk_buff *skb;
402 unsigned char *ptr;
403
Alan Coxf34d7a52008-04-30 00:54:13 -0700404 skb = dev_alloc_skb(1);
405 if (skb == NULL) {
406 printk(KERN_ERR "x25_asy: out of memory\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415}
416
417static void x25_asy_disconnected(struct net_device *dev, int reason)
418{
Wang Chen8f15ea42008-11-12 23:38:36 -0800419 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 struct sk_buff *skb;
421 unsigned char *ptr;
422
Alan Coxf34d7a52008-04-30 00:54:13 -0700423 skb = dev_alloc_skb(1);
424 if (skb == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 printk(KERN_ERR "x25_asy: out of memory\n");
426 return;
427 }
428
429 ptr = skb_put(skb, 1);
430 *ptr = 0x02;
431
432 skb->protocol = x25_type_trans(skb, sl->dev);
433 netif_rx(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434}
435
436static struct lapb_register_struct x25_asy_callbacks = {
437 .connect_confirmation = x25_asy_connected,
438 .connect_indication = x25_asy_connected,
439 .disconnect_confirmation = x25_asy_disconnected,
440 .disconnect_indication = x25_asy_disconnected,
441 .data_indication = x25_asy_data_indication,
442 .data_transmit = x25_asy_data_transmit,
443
444};
445
446
447/* Open the low-level part of the X.25 channel. Easy! */
448static int x25_asy_open(struct net_device *dev)
449{
Wang Chen8f15ea42008-11-12 23:38:36 -0800450 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 unsigned long len;
452 int err;
453
454 if (sl->tty == NULL)
455 return -ENODEV;
456
457 /*
458 * Allocate the X.25 frame buffers:
459 *
460 * rbuff Receive buffer.
461 * xbuff Transmit buffer.
462 */
463
464 len = dev->mtu * 2;
465
Robert P. J. Day5cbded52006-12-13 00:35:56 -0800466 sl->rbuff = kmalloc(len + 4, GFP_KERNEL);
Alan Coxf34d7a52008-04-30 00:54:13 -0700467 if (sl->rbuff == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 goto norbuff;
Robert P. J. Day5cbded52006-12-13 00:35:56 -0800469 sl->xbuff = kmalloc(len + 4, GFP_KERNEL);
Alan Coxf34d7a52008-04-30 00:54:13 -0700470 if (sl->xbuff == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 goto noxbuff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
473 sl->buffsize = len;
474 sl->rcount = 0;
475 sl->xleft = 0;
476 sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */
477
478 netif_start_queue(dev);
Alan Coxf34d7a52008-04-30 00:54:13 -0700479
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 /*
481 * Now attach LAPB
482 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700483 err = lapb_register(dev, &x25_asy_callbacks);
484 if (err == LAPB_OK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 return 0;
486
487 /* Cleanup */
488 kfree(sl->xbuff);
489noxbuff:
490 kfree(sl->rbuff);
491norbuff:
492 return -ENOMEM;
493}
494
495
496/* Close the low-level part of the X.25 channel. Easy! */
497static int x25_asy_close(struct net_device *dev)
498{
Wang Chen8f15ea42008-11-12 23:38:36 -0800499 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 int err;
501
502 spin_lock(&sl->lock);
Alan Coxf34d7a52008-04-30 00:54:13 -0700503 if (sl->tty)
Alan Cox8a1ec212008-12-05 22:31:52 -0800504 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505
506 netif_stop_queue(dev);
507 sl->rcount = 0;
508 sl->xleft = 0;
Alan Coxf34d7a52008-04-30 00:54:13 -0700509 err = lapb_unregister(dev);
510 if (err != LAPB_OK)
511 printk(KERN_ERR "x25_asy_close: lapb_unregister error -%d\n",
512 err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 spin_unlock(&sl->lock);
514 return 0;
515}
516
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517/*
518 * Handle the 'receiver data ready' interrupt.
519 * This function is called by the 'tty_io' module in the kernel when
520 * a block of X.25 data has been received, which can now be decapsulated
521 * and sent on to some IP layer for further processing.
522 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700523
524static void x25_asy_receive_buf(struct tty_struct *tty,
525 const unsigned char *cp, char *fp, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526{
Alan Coxd2b88812008-12-05 22:32:22 -0800527 struct x25_asy *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
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++) {
Alan Coxf34d7a52008-04-30 00:54:13 -0700536 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000537 sl->dev->stats.rx_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 cp++;
539 continue;
540 }
541 x25_asy_unesc(sl, *cp++);
542 }
543}
544
545/*
546 * Open the high-level part of the X.25 channel.
547 * This function is called by the TTY module when the
548 * X.25 line discipline is called for. Because we are
549 * sure the tty line exists, we only have to link it to
550 * a free X.25 channel...
551 */
552
553static int x25_asy_open_tty(struct tty_struct *tty)
554{
Alan Coxd2b88812008-12-05 22:32:22 -0800555 struct x25_asy *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 int err;
557
Alan Coxf34d7a52008-04-30 00:54:13 -0700558 if (tty->ops->write == NULL)
559 return -EOPNOTSUPP;
560
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 /* First make sure we're not already connected. */
Alan Coxf34d7a52008-04-30 00:54:13 -0700562 if (sl && sl->magic == X25_ASY_MAGIC)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 return -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564
565 /* OK. Find a free X.25 channel to use. */
Alan Coxf34d7a52008-04-30 00:54:13 -0700566 sl = x25_asy_alloc();
567 if (sl == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 return -ENFILE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
570 sl->tty = tty;
571 tty->disc_data = sl;
Alan Cox33f0f882006-01-09 20:54:13 -0800572 tty->receive_room = 65536;
Alan Coxf34d7a52008-04-30 00:54:13 -0700573 tty_driver_flush_buffer(tty);
Alan Cox11b0cc32008-02-08 15:00:48 -0800574 tty_ldisc_flush(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575
576 /* Restore default settings */
577 sl->dev->type = ARPHRD_X25;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
Alan Coxf34d7a52008-04-30 00:54:13 -0700579 /* Perform the low-level X.25 async init */
580 err = x25_asy_open(sl->dev);
581 if (err)
582 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 /* Done. We have linked the TTY line to a channel. */
584 return sl->dev->base_addr;
585}
586
587
588/*
589 * Close down an X.25 channel.
590 * This means flushing out any pending queues, and then restoring the
591 * TTY line discipline to what it was before it got hooked to X.25
592 * (which usually is TTY again).
593 */
594static void x25_asy_close_tty(struct tty_struct *tty)
595{
Alan Coxd2b88812008-12-05 22:32:22 -0800596 struct x25_asy *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
598 /* First make sure we're connected. */
599 if (!sl || sl->magic != X25_ASY_MAGIC)
600 return;
601
Ben Hutchings3e3cda92008-05-06 19:41:48 +0100602 rtnl_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 if (sl->dev->flags & IFF_UP)
Alan Coxf34d7a52008-04-30 00:54:13 -0700604 dev_close(sl->dev);
Ben Hutchings3e3cda92008-05-06 19:41:48 +0100605 rtnl_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
607 tty->disc_data = NULL;
608 sl->tty = NULL;
609 x25_asy_free(sl);
610}
611
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 /************************************************************************
613 * STANDARD X.25 ENCAPSULATION *
614 ************************************************************************/
615
Hannes Eder7b3dfa12008-12-26 00:11:21 -0800616static int x25_asy_esc(unsigned char *s, unsigned char *d, int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617{
618 unsigned char *ptr = d;
619 unsigned char c;
620
621 /*
622 * Send an initial END character to flush out any
623 * data that may have accumulated in the receiver
624 * due to line noise.
625 */
626
627 *ptr++ = X25_END; /* Send 10111110 bit seq */
628
629 /*
630 * For each byte in the packet, send the appropriate
631 * character sequence, according to the X.25 protocol.
632 */
633
Alan Coxf34d7a52008-04-30 00:54:13 -0700634 while (len-- > 0) {
635 switch (c = *s++) {
636 case X25_END:
637 *ptr++ = X25_ESC;
638 *ptr++ = X25_ESCAPE(X25_END);
639 break;
640 case X25_ESC:
641 *ptr++ = X25_ESC;
642 *ptr++ = X25_ESCAPE(X25_ESC);
643 break;
644 default:
645 *ptr++ = c;
646 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 }
648 }
649 *ptr++ = X25_END;
650 return (ptr - d);
651}
652
653static void x25_asy_unesc(struct x25_asy *sl, unsigned char s)
654{
655
Alan Coxf34d7a52008-04-30 00:54:13 -0700656 switch (s) {
657 case X25_END:
658 if (!test_and_clear_bit(SLF_ERROR, &sl->flags)
659 && sl->rcount > 2)
660 x25_asy_bump(sl);
661 clear_bit(SLF_ESCAPE, &sl->flags);
662 sl->rcount = 0;
663 return;
664 case X25_ESC:
665 set_bit(SLF_ESCAPE, &sl->flags);
666 return;
667 case X25_ESCAPE(X25_ESC):
668 case X25_ESCAPE(X25_END):
669 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
670 s = X25_UNESCAPE(s);
671 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 }
Alan Coxf34d7a52008-04-30 00:54:13 -0700673 if (!test_bit(SLF_ERROR, &sl->flags)) {
674 if (sl->rcount < sl->buffsize) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 sl->rbuff[sl->rcount++] = s;
676 return;
677 }
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000678 sl->dev->stats.rx_over_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 set_bit(SLF_ERROR, &sl->flags);
680 }
681}
682
683
684/* Perform I/O control on an active X.25 channel. */
685static int x25_asy_ioctl(struct tty_struct *tty, struct file *file,
686 unsigned int cmd, unsigned long arg)
687{
Alan Coxd2b88812008-12-05 22:32:22 -0800688 struct x25_asy *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
690 /* First make sure we're connected. */
691 if (!sl || sl->magic != X25_ASY_MAGIC)
692 return -EINVAL;
693
Alan Coxf34d7a52008-04-30 00:54:13 -0700694 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 case SIOCGIFNAME:
696 if (copy_to_user((void __user *)arg, sl->dev->name,
697 strlen(sl->dev->name) + 1))
698 return -EFAULT;
699 return 0;
700 case SIOCSIFHWADDR:
701 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 default:
Alan Coxd0127532007-11-07 01:27:34 -0800703 return tty_mode_ioctl(tty, file, cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 }
705}
706
707static int x25_asy_open_dev(struct net_device *dev)
708{
Wang Chen8f15ea42008-11-12 23:38:36 -0800709 struct x25_asy *sl = netdev_priv(dev);
Alan Coxf34d7a52008-04-30 00:54:13 -0700710 if (sl->tty == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 return -ENODEV;
712 return 0;
713}
714
Stephen Hemminger48f26ad2009-03-20 19:36:13 +0000715static const struct net_device_ops x25_asy_netdev_ops = {
716 .ndo_open = x25_asy_open_dev,
717 .ndo_stop = x25_asy_close,
718 .ndo_start_xmit = x25_asy_xmit,
719 .ndo_tx_timeout = x25_asy_timeout,
720 .ndo_change_mtu = x25_asy_change_mtu,
721};
722
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723/* Initialise the X.25 driver. Called by the device init code */
724static void x25_asy_setup(struct net_device *dev)
725{
Wang Chen8f15ea42008-11-12 23:38:36 -0800726 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727
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 /*
Alan Coxf34d7a52008-04-30 00:54:13 -0700734 * Finish setting up the DEVICE info.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700736
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 dev->mtu = SL_MTU;
Stephen Hemminger48f26ad2009-03-20 19:36:13 +0000738 dev->netdev_ops = &x25_asy_netdev_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 dev->watchdog_timeo = HZ*20;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 dev->hard_header_len = 0;
741 dev->addr_len = 0;
742 dev->type = ARPHRD_X25;
743 dev->tx_queue_len = 10;
744
745 /* New-style flags. */
746 dev->flags = IFF_NOARP;
747}
748
Alan Coxa352def2008-07-16 21:53:12 +0100749static struct tty_ldisc_ops x25_ldisc = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 .owner = THIS_MODULE,
751 .magic = TTY_LDISC_MAGIC,
752 .name = "X.25",
753 .open = x25_asy_open_tty,
754 .close = x25_asy_close_tty,
755 .ioctl = x25_asy_ioctl,
756 .receive_buf = x25_asy_receive_buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 .write_wakeup = x25_asy_write_wakeup,
758};
759
760static int __init init_x25_asy(void)
761{
762 if (x25_asy_maxdev < 4)
763 x25_asy_maxdev = 4; /* Sanity */
764
765 printk(KERN_INFO "X.25 async: version 0.00 ALPHA "
Alan Coxf34d7a52008-04-30 00:54:13 -0700766 "(dynamic channels, max=%d).\n", x25_asy_maxdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767
Alan Coxf34d7a52008-04-30 00:54:13 -0700768 x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device *),
769 GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 if (!x25_asy_devs) {
771 printk(KERN_WARNING "X25 async: Can't allocate x25_asy_ctrls[] "
772 "array! Uaargh! (-> No X.25 available)\n");
773 return -ENOMEM;
774 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775
776 return tty_register_ldisc(N_X25, &x25_ldisc);
777}
778
779
780static void __exit exit_x25_asy(void)
781{
782 struct net_device *dev;
783 int i;
784
785 for (i = 0; i < x25_asy_maxdev; i++) {
786 dev = x25_asy_devs[i];
787 if (dev) {
Wang Chen8f15ea42008-11-12 23:38:36 -0800788 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789
790 spin_lock_bh(&sl->lock);
Alan Coxf34d7a52008-04-30 00:54:13 -0700791 if (sl->tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 tty_hangup(sl->tty);
793
794 spin_unlock_bh(&sl->lock);
795 /*
796 * VSV = if dev->start==0, then device
797 * unregistered while close proc.
798 */
799 unregister_netdev(dev);
800 free_netdev(dev);
801 }
802 }
803
804 kfree(x25_asy_devs);
Alexey Dobriyan64ccd712005-06-23 00:10:33 -0700805 tty_unregister_ldisc(N_X25);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806}
807
808module_init(init_x25_asy);
809module_exit(exit_x25_asy);