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Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * Things to sort out: | |
4 | * | |
5 | * o tbusy handling | |
6 | * o allow users to set the parameters | |
7 | * o sync/async switching ? | |
8 | * | |
9 | * Note: This does _not_ implement CCITT X.25 asynchronous framing | |
10 | * recommendations. Its primarily for testing purposes. If you wanted | |
11 | * to do CCITT then in theory all you need is to nick the HDLC async | |
12 | * checksum routines from ppp.c | |
13 | * Changes: | |
14 | * | |
15 | * 2000-10-29 Henner Eisen lapb_data_indication() return status. | |
16 | */ | |
17 | ||
23efcb73 JP |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
1da177e4 LT |
20 | #include <linux/module.h> |
21 | ||
f34d7a5b | 22 | #include <linux/uaccess.h> |
1da177e4 LT |
23 | #include <linux/bitops.h> |
24 | #include <linux/string.h> | |
25 | #include <linux/mm.h> | |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/in.h> | |
28 | #include <linux/tty.h> | |
29 | #include <linux/errno.h> | |
30 | #include <linux/netdevice.h> | |
31 | #include <linux/etherdevice.h> | |
32 | #include <linux/skbuff.h> | |
33 | #include <linux/if_arp.h> | |
1da177e4 LT |
34 | #include <linux/lapb.h> |
35 | #include <linux/init.h> | |
3e3cda96 | 36 | #include <linux/rtnetlink.h> |
5a0e3ad6 | 37 | #include <linux/slab.h> |
7eeeacf0 | 38 | #include <net/x25device.h> |
1da177e4 LT |
39 | #include "x25_asy.h" |
40 | ||
1da177e4 LT |
41 | static struct net_device **x25_asy_devs; |
42 | static int x25_asy_maxdev = SL_NRUNIT; | |
43 | ||
44 | module_param(x25_asy_maxdev, int, 0); | |
45 | MODULE_LICENSE("GPL"); | |
46 | ||
47 | static int x25_asy_esc(unsigned char *p, unsigned char *d, int len); | |
48 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char c); | |
49 | static void x25_asy_setup(struct net_device *dev); | |
50 | ||
51 | /* Find a free X.25 channel, and link in this `tty' line. */ | |
52 | static struct x25_asy *x25_asy_alloc(void) | |
53 | { | |
54 | struct net_device *dev = NULL; | |
55 | struct x25_asy *sl; | |
56 | int i; | |
57 | ||
58 | if (x25_asy_devs == NULL) | |
59 | return NULL; /* Master array missing ! */ | |
60 | ||
61 | for (i = 0; i < x25_asy_maxdev; i++) { | |
62 | dev = x25_asy_devs[i]; | |
63 | ||
64 | /* Not allocated ? */ | |
65 | if (dev == NULL) | |
66 | break; | |
67 | ||
8f15ea42 | 68 | sl = netdev_priv(dev); |
1da177e4 LT |
69 | /* Not in use ? */ |
70 | if (!test_and_set_bit(SLF_INUSE, &sl->flags)) | |
71 | return sl; | |
72 | } | |
73 | ||
74 | ||
75 | /* Sorry, too many, all slots in use */ | |
76 | if (i >= x25_asy_maxdev) | |
77 | return NULL; | |
78 | ||
79 | /* If no channels are available, allocate one */ | |
80 | if (!dev) { | |
81 | char name[IFNAMSIZ]; | |
82 | sprintf(name, "x25asy%d", i); | |
83 | ||
c835a677 TG |
84 | dev = alloc_netdev(sizeof(struct x25_asy), name, |
85 | NET_NAME_UNKNOWN, x25_asy_setup); | |
1da177e4 LT |
86 | if (!dev) |
87 | return NULL; | |
88 | ||
89 | /* Initialize channel control data */ | |
8f15ea42 | 90 | sl = netdev_priv(dev); |
1da177e4 LT |
91 | dev->base_addr = i; |
92 | ||
93 | /* register device so that it can be ifconfig'ed */ | |
94 | if (register_netdev(dev) == 0) { | |
95 | /* (Re-)Set the INUSE bit. Very Important! */ | |
96 | set_bit(SLF_INUSE, &sl->flags); | |
97 | x25_asy_devs[i] = dev; | |
98 | return sl; | |
99 | } else { | |
23efcb73 | 100 | pr_warn("%s(): register_netdev() failure\n", __func__); |
1da177e4 LT |
101 | free_netdev(dev); |
102 | } | |
103 | } | |
104 | return NULL; | |
105 | } | |
106 | ||
107 | ||
108 | /* Free an X.25 channel. */ | |
109 | static void x25_asy_free(struct x25_asy *sl) | |
110 | { | |
111 | /* Free all X.25 frame buffers. */ | |
6a5d3621 | 112 | kfree(sl->rbuff); |
1da177e4 | 113 | sl->rbuff = NULL; |
6a5d3621 | 114 | kfree(sl->xbuff); |
1da177e4 LT |
115 | sl->xbuff = NULL; |
116 | ||
f34d7a5b | 117 | if (!test_and_clear_bit(SLF_INUSE, &sl->flags)) |
23efcb73 | 118 | netdev_err(sl->dev, "x25_asy_free for already free unit\n"); |
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; |
a28d0e87 | 125 | int len; |
1da177e4 | 126 | |
a28d0e87 | 127 | len = 2 * newmtu; |
5cbded58 RD |
128 | xbuff = kmalloc(len + 4, GFP_ATOMIC); |
129 | rbuff = kmalloc(len + 4, GFP_ATOMIC); | |
1da177e4 | 130 | |
f34d7a5b | 131 | if (xbuff == NULL || rbuff == NULL) { |
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; | |
6a8eba3b | 144 | dev->stats.tx_dropped++; |
1da177e4 LT |
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; | |
6a8eba3b | 155 | dev->stats.rx_over_errors++; |
1da177e4 LT |
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 | ||
ac973074 | 186 | /* Send an LAPB frame to the LAPB module to process. */ |
1da177e4 LT |
187 | |
188 | static void x25_asy_bump(struct x25_asy *sl) | |
189 | { | |
6a8eba3b | 190 | struct net_device *dev = sl->dev; |
1da177e4 LT |
191 | struct sk_buff *skb; |
192 | int count; | |
193 | int err; | |
194 | ||
195 | count = sl->rcount; | |
6a8eba3b | 196 | dev->stats.rx_bytes += count; |
f34d7a5b | 197 | |
ac973074 | 198 | skb = dev_alloc_skb(count); |
f34d7a5b | 199 | if (skb == NULL) { |
23efcb73 | 200 | netdev_warn(sl->dev, "memory squeeze, dropping packet\n"); |
6a8eba3b | 201 | dev->stats.rx_dropped++; |
1da177e4 LT |
202 | return; |
203 | } | |
59ae1d12 | 204 | skb_put_data(skb, sl->rbuff, count); |
1da177e4 | 205 | skb->protocol = x25_type_trans(skb, sl->dev); |
f34d7a5b AC |
206 | err = lapb_data_received(skb->dev, skb); |
207 | if (err != LAPB_OK) { | |
1da177e4 | 208 | kfree_skb(skb); |
f34d7a5b AC |
209 | printk(KERN_DEBUG "x25_asy: data received err - %d\n", err); |
210 | } else { | |
6a8eba3b | 211 | dev->stats.rx_packets++; |
1da177e4 LT |
212 | } |
213 | } | |
214 | ||
215 | /* Encapsulate one IP datagram and stuff into a TTY queue. */ | |
216 | static void x25_asy_encaps(struct x25_asy *sl, unsigned char *icp, int len) | |
217 | { | |
218 | unsigned char *p; | |
219 | int actual, count, mtu = sl->dev->mtu; | |
220 | ||
f34d7a5b AC |
221 | if (len > mtu) { |
222 | /* Sigh, shouldn't occur BUT ... */ | |
1da177e4 | 223 | len = mtu; |
f34d7a5b AC |
224 | printk(KERN_DEBUG "%s: truncating oversized transmit packet!\n", |
225 | sl->dev->name); | |
6a8eba3b | 226 | sl->dev->stats.tx_dropped++; |
1da177e4 LT |
227 | x25_asy_unlock(sl); |
228 | return; | |
229 | } | |
230 | ||
231 | p = icp; | |
c2fd03a0 | 232 | count = x25_asy_esc(p, sl->xbuff, len); |
1da177e4 LT |
233 | |
234 | /* Order of next two lines is *very* important. | |
235 | * When we are sending a little amount of data, | |
236 | * the transfer may be completed inside driver.write() | |
237 | * routine, because it's running with interrupts enabled. | |
238 | * In this case we *never* got WRITE_WAKEUP event, | |
239 | * if we did not request it before write operation. | |
240 | * 14 Oct 1994 Dmitry Gorodchanin. | |
241 | */ | |
8a1ec21e | 242 | set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
f34d7a5b | 243 | actual = sl->tty->ops->write(sl->tty, sl->xbuff, count); |
1da177e4 LT |
244 | sl->xleft = count - actual; |
245 | sl->xhead = sl->xbuff + actual; | |
246 | /* VSV */ | |
247 | clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */ | |
248 | } | |
249 | ||
250 | /* | |
251 | * Called by the driver when there's room for more data. If we have | |
252 | * more packets to send, we send them here. | |
253 | */ | |
254 | static void x25_asy_write_wakeup(struct tty_struct *tty) | |
255 | { | |
256 | int actual; | |
d2b88814 | 257 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
258 | |
259 | /* First make sure we're connected. */ | |
260 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) | |
261 | return; | |
262 | ||
f34d7a5b | 263 | if (sl->xleft <= 0) { |
1da177e4 LT |
264 | /* Now serial buffer is almost free & we can start |
265 | * transmission of another packet */ | |
6a8eba3b | 266 | sl->dev->stats.tx_packets++; |
8a1ec21e | 267 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
1da177e4 LT |
268 | x25_asy_unlock(sl); |
269 | return; | |
270 | } | |
271 | ||
f34d7a5b | 272 | actual = tty->ops->write(tty, sl->xhead, sl->xleft); |
1da177e4 LT |
273 | sl->xleft -= actual; |
274 | sl->xhead += actual; | |
275 | } | |
276 | ||
277 | static void x25_asy_timeout(struct net_device *dev) | |
278 | { | |
8f15ea42 | 279 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
280 | |
281 | spin_lock(&sl->lock); | |
282 | if (netif_queue_stopped(dev)) { | |
283 | /* May be we must check transmitter timeout here ? | |
284 | * 14 Oct 1994 Dmitry Gorodchanin. | |
285 | */ | |
23efcb73 JP |
286 | netdev_warn(dev, "transmit timed out, %s?\n", |
287 | (tty_chars_in_buffer(sl->tty) || sl->xleft) ? | |
288 | "bad line quality" : "driver error"); | |
1da177e4 | 289 | sl->xleft = 0; |
8a1ec21e | 290 | clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
1da177e4 LT |
291 | x25_asy_unlock(sl); |
292 | } | |
293 | spin_unlock(&sl->lock); | |
294 | } | |
295 | ||
296 | /* Encapsulate an IP datagram and kick it into a TTY queue. */ | |
297 | ||
d71a6749 SH |
298 | static netdev_tx_t x25_asy_xmit(struct sk_buff *skb, |
299 | struct net_device *dev) | |
1da177e4 | 300 | { |
8f15ea42 | 301 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
302 | int err; |
303 | ||
304 | if (!netif_running(sl->dev)) { | |
23efcb73 | 305 | netdev_err(dev, "xmit call when iface is down\n"); |
1da177e4 | 306 | kfree_skb(skb); |
6ed10654 | 307 | return NETDEV_TX_OK; |
1da177e4 | 308 | } |
f34d7a5b AC |
309 | |
310 | switch (skb->data[0]) { | |
7eeeacf0 | 311 | case X25_IFACE_DATA: |
f34d7a5b | 312 | break; |
7eeeacf0 | 313 | case X25_IFACE_CONNECT: /* Connection request .. do nothing */ |
f34d7a5b AC |
314 | err = lapb_connect_request(dev); |
315 | if (err != LAPB_OK) | |
23efcb73 JP |
316 | netdev_err(dev, "lapb_connect_request error: %d\n", |
317 | err); | |
f34d7a5b | 318 | kfree_skb(skb); |
6ed10654 | 319 | return NETDEV_TX_OK; |
7eeeacf0 | 320 | case X25_IFACE_DISCONNECT: /* do nothing - hang up ?? */ |
f34d7a5b AC |
321 | err = lapb_disconnect_request(dev); |
322 | if (err != LAPB_OK) | |
23efcb73 JP |
323 | netdev_err(dev, "lapb_disconnect_request error: %d\n", |
324 | err); | |
a3e2ecba | 325 | /* fall through */ |
f34d7a5b AC |
326 | default: |
327 | kfree_skb(skb); | |
6ed10654 | 328 | return NETDEV_TX_OK; |
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) { | |
23efcb73 | 344 | netdev_err(dev, "lapb_data_request error: %d\n", err); |
1da177e4 | 345 | kfree_skb(skb); |
6ed10654 | 346 | return NETDEV_TX_OK; |
1da177e4 | 347 | } |
6ed10654 | 348 | return NETDEV_TX_OK; |
1da177e4 LT |
349 | } |
350 | ||
351 | ||
352 | /* | |
353 | * LAPB interface boilerplate | |
354 | */ | |
355 | ||
356 | /* | |
ac973074 XH |
357 | * Called when I frame data arrive. We add a pseudo header for upper |
358 | * layers and pass it to upper layers. | |
1da177e4 | 359 | */ |
f34d7a5b | 360 | |
1da177e4 LT |
361 | static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb) |
362 | { | |
ac973074 XH |
363 | if (skb_cow(skb, 1)) { |
364 | kfree_skb(skb); | |
365 | return NET_RX_DROP; | |
366 | } | |
367 | skb_push(skb, 1); | |
368 | skb->data[0] = X25_IFACE_DATA; | |
369 | ||
370 | skb->protocol = x25_type_trans(skb, dev); | |
371 | ||
1da177e4 LT |
372 | return netif_rx(skb); |
373 | } | |
374 | ||
375 | /* | |
376 | * Data has emerged from the LAPB protocol machine. We don't handle | |
377 | * busy cases too well. Its tricky to see how to do this nicely - | |
378 | * perhaps lapb should allow us to bounce this ? | |
379 | */ | |
f34d7a5b | 380 | |
1da177e4 LT |
381 | static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb) |
382 | { | |
8f15ea42 | 383 | struct x25_asy *sl = netdev_priv(dev); |
f34d7a5b | 384 | |
1da177e4 | 385 | spin_lock(&sl->lock); |
f34d7a5b | 386 | if (netif_queue_stopped(sl->dev) || sl->tty == NULL) { |
1da177e4 | 387 | spin_unlock(&sl->lock); |
23efcb73 | 388 | netdev_err(dev, "tbusy drop\n"); |
1da177e4 LT |
389 | kfree_skb(skb); |
390 | return; | |
391 | } | |
392 | /* We were not busy, so we are now... :-) */ | |
f34d7a5b | 393 | if (skb != NULL) { |
1da177e4 | 394 | x25_asy_lock(sl); |
6a8eba3b | 395 | dev->stats.tx_bytes += skb->len; |
1da177e4 LT |
396 | x25_asy_encaps(sl, skb->data, skb->len); |
397 | dev_kfree_skb(skb); | |
398 | } | |
399 | spin_unlock(&sl->lock); | |
400 | } | |
401 | ||
402 | /* | |
403 | * LAPB connection establish/down information. | |
404 | */ | |
f34d7a5b | 405 | |
1da177e4 LT |
406 | static void x25_asy_connected(struct net_device *dev, int reason) |
407 | { | |
8f15ea42 | 408 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
409 | struct sk_buff *skb; |
410 | unsigned char *ptr; | |
411 | ||
f34d7a5b AC |
412 | skb = dev_alloc_skb(1); |
413 | if (skb == NULL) { | |
23efcb73 | 414 | netdev_err(dev, "out of memory\n"); |
1da177e4 LT |
415 | return; |
416 | } | |
417 | ||
418 | ptr = skb_put(skb, 1); | |
7eeeacf0 | 419 | *ptr = X25_IFACE_CONNECT; |
1da177e4 LT |
420 | |
421 | skb->protocol = x25_type_trans(skb, sl->dev); | |
422 | netif_rx(skb); | |
1da177e4 LT |
423 | } |
424 | ||
425 | static void x25_asy_disconnected(struct net_device *dev, int reason) | |
426 | { | |
8f15ea42 | 427 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
428 | struct sk_buff *skb; |
429 | unsigned char *ptr; | |
430 | ||
f34d7a5b AC |
431 | skb = dev_alloc_skb(1); |
432 | if (skb == NULL) { | |
23efcb73 | 433 | netdev_err(dev, "out of memory\n"); |
1da177e4 LT |
434 | return; |
435 | } | |
436 | ||
437 | ptr = skb_put(skb, 1); | |
7eeeacf0 | 438 | *ptr = X25_IFACE_DISCONNECT; |
1da177e4 LT |
439 | |
440 | skb->protocol = x25_type_trans(skb, sl->dev); | |
441 | netif_rx(skb); | |
1da177e4 LT |
442 | } |
443 | ||
d97a077a | 444 | static const struct lapb_register_struct x25_asy_callbacks = { |
1da177e4 LT |
445 | .connect_confirmation = x25_asy_connected, |
446 | .connect_indication = x25_asy_connected, | |
447 | .disconnect_confirmation = x25_asy_disconnected, | |
448 | .disconnect_indication = x25_asy_disconnected, | |
449 | .data_indication = x25_asy_data_indication, | |
450 | .data_transmit = x25_asy_data_transmit, | |
1da177e4 LT |
451 | }; |
452 | ||
453 | ||
454 | /* Open the low-level part of the X.25 channel. Easy! */ | |
455 | static int x25_asy_open(struct net_device *dev) | |
456 | { | |
8f15ea42 | 457 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
458 | unsigned long len; |
459 | int err; | |
460 | ||
461 | if (sl->tty == NULL) | |
462 | return -ENODEV; | |
463 | ||
464 | /* | |
465 | * Allocate the X.25 frame buffers: | |
466 | * | |
467 | * rbuff Receive buffer. | |
468 | * xbuff Transmit buffer. | |
469 | */ | |
470 | ||
471 | len = dev->mtu * 2; | |
472 | ||
5cbded58 | 473 | sl->rbuff = kmalloc(len + 4, GFP_KERNEL); |
f34d7a5b | 474 | if (sl->rbuff == NULL) |
1da177e4 | 475 | goto norbuff; |
5cbded58 | 476 | sl->xbuff = kmalloc(len + 4, GFP_KERNEL); |
f34d7a5b | 477 | if (sl->xbuff == NULL) |
1da177e4 | 478 | goto noxbuff; |
1da177e4 LT |
479 | |
480 | sl->buffsize = len; | |
481 | sl->rcount = 0; | |
482 | sl->xleft = 0; | |
483 | sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */ | |
484 | ||
485 | netif_start_queue(dev); | |
f34d7a5b | 486 | |
1da177e4 LT |
487 | /* |
488 | * Now attach LAPB | |
489 | */ | |
f34d7a5b AC |
490 | err = lapb_register(dev, &x25_asy_callbacks); |
491 | if (err == LAPB_OK) | |
1da177e4 LT |
492 | return 0; |
493 | ||
494 | /* Cleanup */ | |
495 | kfree(sl->xbuff); | |
d5c7c745 | 496 | sl->xbuff = NULL; |
1da177e4 LT |
497 | noxbuff: |
498 | kfree(sl->rbuff); | |
d5c7c745 | 499 | sl->rbuff = NULL; |
1da177e4 LT |
500 | norbuff: |
501 | return -ENOMEM; | |
502 | } | |
503 | ||
504 | ||
505 | /* Close the low-level part of the X.25 channel. Easy! */ | |
506 | static int x25_asy_close(struct net_device *dev) | |
507 | { | |
8f15ea42 | 508 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
509 | |
510 | spin_lock(&sl->lock); | |
f34d7a5b | 511 | if (sl->tty) |
8a1ec21e | 512 | clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
1da177e4 LT |
513 | |
514 | netif_stop_queue(dev); | |
515 | sl->rcount = 0; | |
516 | sl->xleft = 0; | |
1da177e4 LT |
517 | spin_unlock(&sl->lock); |
518 | return 0; | |
519 | } | |
520 | ||
1da177e4 LT |
521 | /* |
522 | * Handle the 'receiver data ready' interrupt. | |
523 | * This function is called by the 'tty_io' module in the kernel when | |
524 | * a block of X.25 data has been received, which can now be decapsulated | |
525 | * and sent on to some IP layer for further processing. | |
526 | */ | |
f34d7a5b AC |
527 | |
528 | static void x25_asy_receive_buf(struct tty_struct *tty, | |
529 | const unsigned char *cp, char *fp, int count) | |
1da177e4 | 530 | { |
d2b88814 | 531 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
532 | |
533 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) | |
534 | return; | |
535 | ||
536 | ||
537 | /* Read the characters out of the buffer */ | |
538 | while (count--) { | |
539 | if (fp && *fp++) { | |
f34d7a5b | 540 | if (!test_and_set_bit(SLF_ERROR, &sl->flags)) |
6a8eba3b | 541 | sl->dev->stats.rx_errors++; |
1da177e4 LT |
542 | cp++; |
543 | continue; | |
544 | } | |
545 | x25_asy_unesc(sl, *cp++); | |
546 | } | |
547 | } | |
548 | ||
549 | /* | |
550 | * Open the high-level part of the X.25 channel. | |
551 | * This function is called by the TTY module when the | |
552 | * X.25 line discipline is called for. Because we are | |
553 | * sure the tty line exists, we only have to link it to | |
554 | * a free X.25 channel... | |
555 | */ | |
556 | ||
557 | static int x25_asy_open_tty(struct tty_struct *tty) | |
558 | { | |
ee9159dd | 559 | struct x25_asy *sl; |
1da177e4 LT |
560 | int err; |
561 | ||
f34d7a5b AC |
562 | if (tty->ops->write == NULL) |
563 | return -EOPNOTSUPP; | |
564 | ||
1da177e4 | 565 | /* OK. Find a free X.25 channel to use. */ |
f34d7a5b AC |
566 | sl = x25_asy_alloc(); |
567 | if (sl == NULL) | |
1da177e4 | 568 | return -ENFILE; |
1da177e4 LT |
569 | |
570 | sl->tty = tty; | |
571 | tty->disc_data = sl; | |
33f0f88f | 572 | tty->receive_room = 65536; |
f34d7a5b | 573 | tty_driver_flush_buffer(tty); |
11b0cc3a | 574 | tty_ldisc_flush(tty); |
1da177e4 LT |
575 | |
576 | /* Restore default settings */ | |
577 | sl->dev->type = ARPHRD_X25; | |
f34d7a5b | 578 | |
1da177e4 | 579 | /* Perform the low-level X.25 async init */ |
f34d7a5b | 580 | err = x25_asy_open(sl->dev); |
3b780bed DM |
581 | if (err) { |
582 | x25_asy_free(sl); | |
1da177e4 | 583 | return err; |
3b780bed | 584 | } |
1da177e4 | 585 | /* Done. We have linked the TTY line to a channel. */ |
6a20bd45 | 586 | return 0; |
1da177e4 LT |
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 | { | |
d2b88814 | 598 | struct x25_asy *sl = tty->disc_data; |
03fe5f3e | 599 | int err; |
1da177e4 LT |
600 | |
601 | /* First make sure we're connected. */ | |
602 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
603 | return; | |
604 | ||
3e3cda96 | 605 | rtnl_lock(); |
1da177e4 | 606 | if (sl->dev->flags & IFF_UP) |
f34d7a5b | 607 | dev_close(sl->dev); |
3e3cda96 | 608 | rtnl_unlock(); |
1da177e4 | 609 | |
03fe5f3e JS |
610 | err = lapb_unregister(sl->dev); |
611 | if (err != LAPB_OK) | |
8e6a4817 JS |
612 | pr_err("%s: lapb_unregister error: %d\n", |
613 | __func__, err); | |
03fe5f3e | 614 | |
1da177e4 LT |
615 | tty->disc_data = NULL; |
616 | sl->tty = NULL; | |
617 | x25_asy_free(sl); | |
618 | } | |
619 | ||
1da177e4 LT |
620 | /************************************************************************ |
621 | * STANDARD X.25 ENCAPSULATION * | |
622 | ************************************************************************/ | |
623 | ||
7b3dfa11 | 624 | static int x25_asy_esc(unsigned char *s, unsigned char *d, int len) |
1da177e4 LT |
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; | |
807540ba | 658 | return ptr - d; |
1da177e4 LT |
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: | |
8e95a202 | 666 | if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && |
ac973074 | 667 | sl->rcount >= 2) |
f34d7a5b AC |
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 | } | |
6a8eba3b | 686 | sl->dev->stats.rx_over_errors++; |
1da177e4 LT |
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 | { | |
d2b88814 | 696 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
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 | { | |
8f15ea42 | 717 | struct x25_asy *sl = netdev_priv(dev); |
f34d7a5b | 718 | if (sl->tty == NULL) |
1da177e4 LT |
719 | return -ENODEV; |
720 | return 0; | |
721 | } | |
722 | ||
48f26ad5 SH |
723 | static const struct net_device_ops x25_asy_netdev_ops = { |
724 | .ndo_open = x25_asy_open_dev, | |
725 | .ndo_stop = x25_asy_close, | |
726 | .ndo_start_xmit = x25_asy_xmit, | |
727 | .ndo_tx_timeout = x25_asy_timeout, | |
728 | .ndo_change_mtu = x25_asy_change_mtu, | |
729 | }; | |
730 | ||
1da177e4 LT |
731 | /* Initialise the X.25 driver. Called by the device init code */ |
732 | static void x25_asy_setup(struct net_device *dev) | |
733 | { | |
8f15ea42 | 734 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
735 | |
736 | sl->magic = X25_ASY_MAGIC; | |
737 | sl->dev = dev; | |
738 | spin_lock_init(&sl->lock); | |
739 | set_bit(SLF_INUSE, &sl->flags); | |
740 | ||
741 | /* | |
f34d7a5b | 742 | * Finish setting up the DEVICE info. |
1da177e4 | 743 | */ |
f34d7a5b | 744 | |
1da177e4 | 745 | dev->mtu = SL_MTU; |
8b6b4135 JW |
746 | dev->min_mtu = 0; |
747 | dev->max_mtu = 65534; | |
48f26ad5 | 748 | dev->netdev_ops = &x25_asy_netdev_ops; |
1da177e4 | 749 | dev->watchdog_timeo = HZ*20; |
1da177e4 LT |
750 | dev->hard_header_len = 0; |
751 | dev->addr_len = 0; | |
752 | dev->type = ARPHRD_X25; | |
753 | dev->tx_queue_len = 10; | |
754 | ||
755 | /* New-style flags. */ | |
756 | dev->flags = IFF_NOARP; | |
757 | } | |
758 | ||
a352def2 | 759 | static struct tty_ldisc_ops x25_ldisc = { |
1da177e4 LT |
760 | .owner = THIS_MODULE, |
761 | .magic = TTY_LDISC_MAGIC, | |
762 | .name = "X.25", | |
763 | .open = x25_asy_open_tty, | |
764 | .close = x25_asy_close_tty, | |
765 | .ioctl = x25_asy_ioctl, | |
766 | .receive_buf = x25_asy_receive_buf, | |
1da177e4 LT |
767 | .write_wakeup = x25_asy_write_wakeup, |
768 | }; | |
769 | ||
770 | static int __init init_x25_asy(void) | |
771 | { | |
772 | if (x25_asy_maxdev < 4) | |
773 | x25_asy_maxdev = 4; /* Sanity */ | |
774 | ||
23efcb73 JP |
775 | pr_info("X.25 async: version 0.00 ALPHA (dynamic channels, max=%d)\n", |
776 | x25_asy_maxdev); | |
1da177e4 | 777 | |
f34d7a5b AC |
778 | x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device *), |
779 | GFP_KERNEL); | |
e404decb | 780 | if (!x25_asy_devs) |
1da177e4 | 781 | return -ENOMEM; |
1da177e4 LT |
782 | |
783 | return tty_register_ldisc(N_X25, &x25_ldisc); | |
784 | } | |
785 | ||
786 | ||
787 | static void __exit exit_x25_asy(void) | |
788 | { | |
789 | struct net_device *dev; | |
790 | int i; | |
791 | ||
792 | for (i = 0; i < x25_asy_maxdev; i++) { | |
793 | dev = x25_asy_devs[i]; | |
794 | if (dev) { | |
8f15ea42 | 795 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
796 | |
797 | spin_lock_bh(&sl->lock); | |
f34d7a5b | 798 | if (sl->tty) |
1da177e4 LT |
799 | tty_hangup(sl->tty); |
800 | ||
801 | spin_unlock_bh(&sl->lock); | |
802 | /* | |
803 | * VSV = if dev->start==0, then device | |
804 | * unregistered while close proc. | |
805 | */ | |
806 | unregister_netdev(dev); | |
807 | free_netdev(dev); | |
808 | } | |
809 | } | |
810 | ||
811 | kfree(x25_asy_devs); | |
64ccd715 | 812 | tty_unregister_ldisc(N_X25); |
1da177e4 LT |
813 | } |
814 | ||
815 | module_init(init_x25_asy); | |
816 | module_exit(exit_x25_asy); |