blob: e47f5a986b1c213c7f14e43b38dda541504c8b7d [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/lapb.h>
33#include <linux/init.h>
Ben Hutchings3e3cda92008-05-06 19:41:48 +010034#include <linux/rtnetlink.h>
Arnd Bergmann9646e7c2009-11-06 22:51:16 -080035#include <linux/compat.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090036#include <linux/slab.h>
andrew hendry7eeeacf02010-04-19 13:29:47 +000037#include <net/x25device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include "x25_asy.h"
39
Linus Torvalds1da177e2005-04-16 15:20:36 -070040static 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
Stephen Hemmingerd71a6742009-08-31 19:50:47 +0000302static netdev_tx_t x25_asy_xmit(struct sk_buff *skb,
303 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304{
Wang Chen8f15ea42008-11-12 23:38:36 -0800305 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 int err;
307
308 if (!netif_running(sl->dev)) {
Alan Coxf34d7a52008-04-30 00:54:13 -0700309 printk(KERN_ERR "%s: xmit call when iface is down\n",
310 dev->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 kfree_skb(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000312 return NETDEV_TX_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 }
Alan Coxf34d7a52008-04-30 00:54:13 -0700314
315 switch (skb->data[0]) {
andrew hendry7eeeacf02010-04-19 13:29:47 +0000316 case X25_IFACE_DATA:
Alan Coxf34d7a52008-04-30 00:54:13 -0700317 break;
andrew hendry7eeeacf02010-04-19 13:29:47 +0000318 case X25_IFACE_CONNECT: /* Connection request .. do nothing */
Alan Coxf34d7a52008-04-30 00:54:13 -0700319 err = lapb_connect_request(dev);
320 if (err != LAPB_OK)
321 printk(KERN_ERR "x25_asy: lapb_connect_request error - %d\n", err);
322 kfree_skb(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000323 return NETDEV_TX_OK;
andrew hendry7eeeacf02010-04-19 13:29:47 +0000324 case X25_IFACE_DISCONNECT: /* do nothing - hang up ?? */
Alan Coxf34d7a52008-04-30 00:54:13 -0700325 err = lapb_disconnect_request(dev);
326 if (err != LAPB_OK)
327 printk(KERN_ERR "x25_asy: lapb_disconnect_request error - %d\n", err);
328 default:
329 kfree_skb(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000330 return NETDEV_TX_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 }
Alan Coxf34d7a52008-04-30 00:54:13 -0700332 skb_pull(skb, 1); /* Remove control byte */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 /*
334 * If we are busy already- too bad. We ought to be able
335 * to queue things at this point, to allow for a little
336 * frame buffer. Oh well...
337 * -----------------------------------------------------
338 * I hate queues in X.25 driver. May be it's efficient,
339 * but for me latency is more important. ;)
340 * So, no queues !
341 * 14 Oct 1994 Dmitry Gorodchanin.
342 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700343
344 err = lapb_data_request(dev, skb);
345 if (err != LAPB_OK) {
346 printk(KERN_ERR "x25_asy: lapb_data_request error - %d\n", err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 kfree_skb(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000348 return NETDEV_TX_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 }
Patrick McHardy6ed10652009-06-23 06:03:08 +0000350 return NETDEV_TX_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351}
352
353
354/*
355 * LAPB interface boilerplate
356 */
357
358/*
359 * Called when I frame data arrives. We did the work above - throw it
360 * at the net layer.
361 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700362
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb)
364{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 return netif_rx(skb);
366}
367
368/*
369 * Data has emerged from the LAPB protocol machine. We don't handle
370 * busy cases too well. Its tricky to see how to do this nicely -
371 * perhaps lapb should allow us to bounce this ?
372 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700373
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb)
375{
Wang Chen8f15ea42008-11-12 23:38:36 -0800376 struct x25_asy *sl = netdev_priv(dev);
Alan Coxf34d7a52008-04-30 00:54:13 -0700377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 spin_lock(&sl->lock);
Alan Coxf34d7a52008-04-30 00:54:13 -0700379 if (netif_queue_stopped(sl->dev) || sl->tty == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 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... :-) */
Alan Coxf34d7a52008-04-30 00:54:13 -0700386 if (skb != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 x25_asy_lock(sl);
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000388 dev->stats.tx_bytes += skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 x25_asy_encaps(sl, skb->data, skb->len);
390 dev_kfree_skb(skb);
391 }
392 spin_unlock(&sl->lock);
393}
394
395/*
396 * LAPB connection establish/down information.
397 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700398
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399static void x25_asy_connected(struct net_device *dev, int reason)
400{
Wang Chen8f15ea42008-11-12 23:38:36 -0800401 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 struct sk_buff *skb;
403 unsigned char *ptr;
404
Alan Coxf34d7a52008-04-30 00:54:13 -0700405 skb = dev_alloc_skb(1);
406 if (skb == NULL) {
407 printk(KERN_ERR "x25_asy: out of memory\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 return;
409 }
410
411 ptr = skb_put(skb, 1);
andrew hendry7eeeacf02010-04-19 13:29:47 +0000412 *ptr = X25_IFACE_CONNECT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413
414 skb->protocol = x25_type_trans(skb, sl->dev);
415 netif_rx(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416}
417
418static void x25_asy_disconnected(struct net_device *dev, int reason)
419{
Wang Chen8f15ea42008-11-12 23:38:36 -0800420 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 struct sk_buff *skb;
422 unsigned char *ptr;
423
Alan Coxf34d7a52008-04-30 00:54:13 -0700424 skb = dev_alloc_skb(1);
425 if (skb == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 printk(KERN_ERR "x25_asy: out of memory\n");
427 return;
428 }
429
430 ptr = skb_put(skb, 1);
andrew hendry7eeeacf02010-04-19 13:29:47 +0000431 *ptr = X25_IFACE_DISCONNECT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
433 skb->protocol = x25_type_trans(skb, sl->dev);
434 netif_rx(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435}
436
437static struct lapb_register_struct x25_asy_callbacks = {
438 .connect_confirmation = x25_asy_connected,
439 .connect_indication = x25_asy_connected,
440 .disconnect_confirmation = x25_asy_disconnected,
441 .disconnect_indication = x25_asy_disconnected,
442 .data_indication = x25_asy_data_indication,
443 .data_transmit = x25_asy_data_transmit,
444
445};
446
447
448/* Open the low-level part of the X.25 channel. Easy! */
449static int x25_asy_open(struct net_device *dev)
450{
Wang Chen8f15ea42008-11-12 23:38:36 -0800451 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 unsigned long len;
453 int err;
454
455 if (sl->tty == NULL)
456 return -ENODEV;
457
458 /*
459 * Allocate the X.25 frame buffers:
460 *
461 * rbuff Receive buffer.
462 * xbuff Transmit buffer.
463 */
464
465 len = dev->mtu * 2;
466
Robert P. J. Day5cbded52006-12-13 00:35:56 -0800467 sl->rbuff = kmalloc(len + 4, GFP_KERNEL);
Alan Coxf34d7a52008-04-30 00:54:13 -0700468 if (sl->rbuff == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 goto norbuff;
Robert P. J. Day5cbded52006-12-13 00:35:56 -0800470 sl->xbuff = kmalloc(len + 4, GFP_KERNEL);
Alan Coxf34d7a52008-04-30 00:54:13 -0700471 if (sl->xbuff == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 goto noxbuff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473
474 sl->buffsize = len;
475 sl->rcount = 0;
476 sl->xleft = 0;
477 sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */
478
479 netif_start_queue(dev);
Alan Coxf34d7a52008-04-30 00:54:13 -0700480
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 /*
482 * Now attach LAPB
483 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700484 err = lapb_register(dev, &x25_asy_callbacks);
485 if (err == LAPB_OK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 return 0;
487
488 /* Cleanup */
489 kfree(sl->xbuff);
490noxbuff:
491 kfree(sl->rbuff);
492norbuff:
493 return -ENOMEM;
494}
495
496
497/* Close the low-level part of the X.25 channel. Easy! */
498static int x25_asy_close(struct net_device *dev)
499{
Wang Chen8f15ea42008-11-12 23:38:36 -0800500 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 int err;
502
503 spin_lock(&sl->lock);
Alan Coxf34d7a52008-04-30 00:54:13 -0700504 if (sl->tty)
Alan Cox8a1ec212008-12-05 22:31:52 -0800505 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
507 netif_stop_queue(dev);
508 sl->rcount = 0;
509 sl->xleft = 0;
Alan Coxf34d7a52008-04-30 00:54:13 -0700510 err = lapb_unregister(dev);
511 if (err != LAPB_OK)
512 printk(KERN_ERR "x25_asy_close: lapb_unregister error -%d\n",
513 err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 spin_unlock(&sl->lock);
515 return 0;
516}
517
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518/*
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 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700524
525static void x25_asy_receive_buf(struct tty_struct *tty,
526 const unsigned char *cp, char *fp, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527{
Alan Coxd2b88812008-12-05 22:32:22 -0800528 struct x25_asy *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
530 if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev))
531 return;
532
533
534 /* Read the characters out of the buffer */
535 while (count--) {
536 if (fp && *fp++) {
Alan Coxf34d7a52008-04-30 00:54:13 -0700537 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000538 sl->dev->stats.rx_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 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
554static int x25_asy_open_tty(struct tty_struct *tty)
555{
Alan Coxd2b88812008-12-05 22:32:22 -0800556 struct x25_asy *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 int err;
558
Alan Coxf34d7a52008-04-30 00:54:13 -0700559 if (tty->ops->write == NULL)
560 return -EOPNOTSUPP;
561
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 /* First make sure we're not already connected. */
Alan Coxf34d7a52008-04-30 00:54:13 -0700563 if (sl && sl->magic == X25_ASY_MAGIC)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 return -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
566 /* OK. Find a free X.25 channel to use. */
Alan Coxf34d7a52008-04-30 00:54:13 -0700567 sl = x25_asy_alloc();
568 if (sl == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 return -ENFILE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570
571 sl->tty = tty;
572 tty->disc_data = sl;
Alan Cox33f0f882006-01-09 20:54:13 -0800573 tty->receive_room = 65536;
Alan Coxf34d7a52008-04-30 00:54:13 -0700574 tty_driver_flush_buffer(tty);
Alan Cox11b0cc32008-02-08 15:00:48 -0800575 tty_ldisc_flush(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576
577 /* Restore default settings */
578 sl->dev->type = ARPHRD_X25;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
Alan Coxf34d7a52008-04-30 00:54:13 -0700580 /* Perform the low-level X.25 async init */
581 err = x25_asy_open(sl->dev);
582 if (err)
583 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 /* Done. We have linked the TTY line to a channel. */
585 return sl->dev->base_addr;
586}
587
588
589/*
590 * Close down an X.25 channel.
591 * This means flushing out any pending queues, and then restoring the
592 * TTY line discipline to what it was before it got hooked to X.25
593 * (which usually is TTY again).
594 */
595static void x25_asy_close_tty(struct tty_struct *tty)
596{
Alan Coxd2b88812008-12-05 22:32:22 -0800597 struct x25_asy *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598
599 /* First make sure we're connected. */
600 if (!sl || sl->magic != X25_ASY_MAGIC)
601 return;
602
Ben Hutchings3e3cda92008-05-06 19:41:48 +0100603 rtnl_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 if (sl->dev->flags & IFF_UP)
Alan Coxf34d7a52008-04-30 00:54:13 -0700605 dev_close(sl->dev);
Ben Hutchings3e3cda92008-05-06 19:41:48 +0100606 rtnl_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607
608 tty->disc_data = NULL;
609 sl->tty = NULL;
610 x25_asy_free(sl);
611}
612
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 /************************************************************************
614 * STANDARD X.25 ENCAPSULATION *
615 ************************************************************************/
616
Hannes Eder7b3dfa12008-12-26 00:11:21 -0800617static int x25_asy_esc(unsigned char *s, unsigned char *d, int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618{
619 unsigned char *ptr = d;
620 unsigned char c;
621
622 /*
623 * Send an initial END character to flush out any
624 * data that may have accumulated in the receiver
625 * due to line noise.
626 */
627
628 *ptr++ = X25_END; /* Send 10111110 bit seq */
629
630 /*
631 * For each byte in the packet, send the appropriate
632 * character sequence, according to the X.25 protocol.
633 */
634
Alan Coxf34d7a52008-04-30 00:54:13 -0700635 while (len-- > 0) {
636 switch (c = *s++) {
637 case X25_END:
638 *ptr++ = X25_ESC;
639 *ptr++ = X25_ESCAPE(X25_END);
640 break;
641 case X25_ESC:
642 *ptr++ = X25_ESC;
643 *ptr++ = X25_ESCAPE(X25_ESC);
644 break;
645 default:
646 *ptr++ = c;
647 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 }
649 }
650 *ptr++ = X25_END;
651 return (ptr - d);
652}
653
654static void x25_asy_unesc(struct x25_asy *sl, unsigned char s)
655{
656
Alan Coxf34d7a52008-04-30 00:54:13 -0700657 switch (s) {
658 case X25_END:
Joe Perches8e95a202009-12-03 07:58:21 +0000659 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
660 sl->rcount > 2)
Alan Coxf34d7a52008-04-30 00:54:13 -0700661 x25_asy_bump(sl);
662 clear_bit(SLF_ESCAPE, &sl->flags);
663 sl->rcount = 0;
664 return;
665 case X25_ESC:
666 set_bit(SLF_ESCAPE, &sl->flags);
667 return;
668 case X25_ESCAPE(X25_ESC):
669 case X25_ESCAPE(X25_END):
670 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
671 s = X25_UNESCAPE(s);
672 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 }
Alan Coxf34d7a52008-04-30 00:54:13 -0700674 if (!test_bit(SLF_ERROR, &sl->flags)) {
675 if (sl->rcount < sl->buffsize) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 sl->rbuff[sl->rcount++] = s;
677 return;
678 }
Stephen Hemminger6a8eba32009-03-20 19:36:12 +0000679 sl->dev->stats.rx_over_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 set_bit(SLF_ERROR, &sl->flags);
681 }
682}
683
684
685/* Perform I/O control on an active X.25 channel. */
686static int x25_asy_ioctl(struct tty_struct *tty, struct file *file,
687 unsigned int cmd, unsigned long arg)
688{
Alan Coxd2b88812008-12-05 22:32:22 -0800689 struct x25_asy *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690
691 /* First make sure we're connected. */
692 if (!sl || sl->magic != X25_ASY_MAGIC)
693 return -EINVAL;
694
Alan Coxf34d7a52008-04-30 00:54:13 -0700695 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 case SIOCGIFNAME:
697 if (copy_to_user((void __user *)arg, sl->dev->name,
698 strlen(sl->dev->name) + 1))
699 return -EFAULT;
700 return 0;
701 case SIOCSIFHWADDR:
702 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 default:
Alan Coxd0127532007-11-07 01:27:34 -0800704 return tty_mode_ioctl(tty, file, cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 }
706}
707
Arnd Bergmann9646e7c2009-11-06 22:51:16 -0800708#ifdef CONFIG_COMPAT
709static long x25_asy_compat_ioctl(struct tty_struct *tty, struct file *file,
710 unsigned int cmd, unsigned long arg)
711{
712 switch (cmd) {
713 case SIOCGIFNAME:
714 case SIOCSIFHWADDR:
715 return x25_asy_ioctl(tty, file, cmd,
716 (unsigned long)compat_ptr(arg));
717 }
718
719 return -ENOIOCTLCMD;
720}
721#endif
722
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723static int x25_asy_open_dev(struct net_device *dev)
724{
Wang Chen8f15ea42008-11-12 23:38:36 -0800725 struct x25_asy *sl = netdev_priv(dev);
Alan Coxf34d7a52008-04-30 00:54:13 -0700726 if (sl->tty == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 return -ENODEV;
728 return 0;
729}
730
Stephen Hemminger48f26ad2009-03-20 19:36:13 +0000731static const struct net_device_ops x25_asy_netdev_ops = {
732 .ndo_open = x25_asy_open_dev,
733 .ndo_stop = x25_asy_close,
734 .ndo_start_xmit = x25_asy_xmit,
735 .ndo_tx_timeout = x25_asy_timeout,
736 .ndo_change_mtu = x25_asy_change_mtu,
737};
738
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739/* Initialise the X.25 driver. Called by the device init code */
740static void x25_asy_setup(struct net_device *dev)
741{
Wang Chen8f15ea42008-11-12 23:38:36 -0800742 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743
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 /*
Alan Coxf34d7a52008-04-30 00:54:13 -0700750 * Finish setting up the DEVICE info.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 */
Alan Coxf34d7a52008-04-30 00:54:13 -0700752
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 dev->mtu = SL_MTU;
Stephen Hemminger48f26ad2009-03-20 19:36:13 +0000754 dev->netdev_ops = &x25_asy_netdev_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 dev->watchdog_timeo = HZ*20;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 dev->hard_header_len = 0;
757 dev->addr_len = 0;
758 dev->type = ARPHRD_X25;
759 dev->tx_queue_len = 10;
760
761 /* New-style flags. */
762 dev->flags = IFF_NOARP;
763}
764
Alan Coxa352def2008-07-16 21:53:12 +0100765static struct tty_ldisc_ops x25_ldisc = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 .owner = THIS_MODULE,
767 .magic = TTY_LDISC_MAGIC,
768 .name = "X.25",
769 .open = x25_asy_open_tty,
770 .close = x25_asy_close_tty,
771 .ioctl = x25_asy_ioctl,
Arnd Bergmann9646e7c2009-11-06 22:51:16 -0800772#ifdef CONFIG_COMPAT
773 .compat_ioctl = x25_asy_compat_ioctl,
774#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 .receive_buf = x25_asy_receive_buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 .write_wakeup = x25_asy_write_wakeup,
777};
778
779static int __init init_x25_asy(void)
780{
781 if (x25_asy_maxdev < 4)
782 x25_asy_maxdev = 4; /* Sanity */
783
784 printk(KERN_INFO "X.25 async: version 0.00 ALPHA "
Alan Coxf34d7a52008-04-30 00:54:13 -0700785 "(dynamic channels, max=%d).\n", x25_asy_maxdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
Alan Coxf34d7a52008-04-30 00:54:13 -0700787 x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device *),
788 GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 if (!x25_asy_devs) {
790 printk(KERN_WARNING "X25 async: Can't allocate x25_asy_ctrls[] "
791 "array! Uaargh! (-> No X.25 available)\n");
792 return -ENOMEM;
793 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794
795 return tty_register_ldisc(N_X25, &x25_ldisc);
796}
797
798
799static void __exit exit_x25_asy(void)
800{
801 struct net_device *dev;
802 int i;
803
804 for (i = 0; i < x25_asy_maxdev; i++) {
805 dev = x25_asy_devs[i];
806 if (dev) {
Wang Chen8f15ea42008-11-12 23:38:36 -0800807 struct x25_asy *sl = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808
809 spin_lock_bh(&sl->lock);
Alan Coxf34d7a52008-04-30 00:54:13 -0700810 if (sl->tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 tty_hangup(sl->tty);
812
813 spin_unlock_bh(&sl->lock);
814 /*
815 * VSV = if dev->start==0, then device
816 * unregistered while close proc.
817 */
818 unregister_netdev(dev);
819 free_netdev(dev);
820 }
821 }
822
823 kfree(x25_asy_devs);
Alexey Dobriyan64ccd712005-06-23 00:10:33 -0700824 tty_unregister_ldisc(N_X25);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825}
826
827module_init(init_x25_asy);
828module_exit(exit_x25_asy);