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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 | ||
8fdcabea | 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 | |
8fdcabea | 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 | ||
0290bd29 | 277 | static void x25_asy_timeout(struct net_device *dev, unsigned int txqueue) |
1da177e4 | 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 | 309 | |
c79f428d XH |
310 | /* There should be a pseudo header of 1 byte added by upper layers. |
311 | * Check to make sure it is there before reading it. | |
312 | */ | |
313 | if (skb->len < 1) { | |
314 | kfree_skb(skb); | |
315 | return NETDEV_TX_OK; | |
316 | } | |
317 | ||
f34d7a5b | 318 | switch (skb->data[0]) { |
7eeeacf0 | 319 | case X25_IFACE_DATA: |
f34d7a5b | 320 | break; |
7eeeacf0 | 321 | case X25_IFACE_CONNECT: /* Connection request .. do nothing */ |
f34d7a5b AC |
322 | err = lapb_connect_request(dev); |
323 | if (err != LAPB_OK) | |
23efcb73 JP |
324 | netdev_err(dev, "lapb_connect_request error: %d\n", |
325 | err); | |
f34d7a5b | 326 | kfree_skb(skb); |
6ed10654 | 327 | return NETDEV_TX_OK; |
7eeeacf0 | 328 | case X25_IFACE_DISCONNECT: /* do nothing - hang up ?? */ |
f34d7a5b AC |
329 | err = lapb_disconnect_request(dev); |
330 | if (err != LAPB_OK) | |
23efcb73 JP |
331 | netdev_err(dev, "lapb_disconnect_request error: %d\n", |
332 | err); | |
df561f66 | 333 | fallthrough; |
f34d7a5b AC |
334 | default: |
335 | kfree_skb(skb); | |
6ed10654 | 336 | return NETDEV_TX_OK; |
1da177e4 | 337 | } |
f34d7a5b | 338 | skb_pull(skb, 1); /* Remove control byte */ |
1da177e4 LT |
339 | /* |
340 | * If we are busy already- too bad. We ought to be able | |
341 | * to queue things at this point, to allow for a little | |
342 | * frame buffer. Oh well... | |
343 | * ----------------------------------------------------- | |
344 | * I hate queues in X.25 driver. May be it's efficient, | |
345 | * but for me latency is more important. ;) | |
346 | * So, no queues ! | |
347 | * 14 Oct 1994 Dmitry Gorodchanin. | |
348 | */ | |
f34d7a5b AC |
349 | |
350 | err = lapb_data_request(dev, skb); | |
351 | if (err != LAPB_OK) { | |
23efcb73 | 352 | netdev_err(dev, "lapb_data_request error: %d\n", err); |
1da177e4 | 353 | kfree_skb(skb); |
6ed10654 | 354 | return NETDEV_TX_OK; |
1da177e4 | 355 | } |
6ed10654 | 356 | return NETDEV_TX_OK; |
1da177e4 LT |
357 | } |
358 | ||
359 | ||
360 | /* | |
361 | * LAPB interface boilerplate | |
362 | */ | |
363 | ||
364 | /* | |
8fdcabea XH |
365 | * Called when I frame data arrive. We add a pseudo header for upper |
366 | * layers and pass it to upper layers. | |
1da177e4 | 367 | */ |
f34d7a5b | 368 | |
1da177e4 LT |
369 | static int x25_asy_data_indication(struct net_device *dev, struct sk_buff *skb) |
370 | { | |
8fdcabea XH |
371 | if (skb_cow(skb, 1)) { |
372 | kfree_skb(skb); | |
373 | return NET_RX_DROP; | |
374 | } | |
375 | skb_push(skb, 1); | |
376 | skb->data[0] = X25_IFACE_DATA; | |
377 | ||
378 | skb->protocol = x25_type_trans(skb, dev); | |
379 | ||
1da177e4 LT |
380 | return netif_rx(skb); |
381 | } | |
382 | ||
383 | /* | |
384 | * Data has emerged from the LAPB protocol machine. We don't handle | |
385 | * busy cases too well. Its tricky to see how to do this nicely - | |
386 | * perhaps lapb should allow us to bounce this ? | |
387 | */ | |
f34d7a5b | 388 | |
1da177e4 LT |
389 | static void x25_asy_data_transmit(struct net_device *dev, struct sk_buff *skb) |
390 | { | |
8f15ea42 | 391 | struct x25_asy *sl = netdev_priv(dev); |
f34d7a5b | 392 | |
1da177e4 | 393 | spin_lock(&sl->lock); |
f34d7a5b | 394 | if (netif_queue_stopped(sl->dev) || sl->tty == NULL) { |
1da177e4 | 395 | spin_unlock(&sl->lock); |
23efcb73 | 396 | netdev_err(dev, "tbusy drop\n"); |
1da177e4 LT |
397 | kfree_skb(skb); |
398 | return; | |
399 | } | |
400 | /* We were not busy, so we are now... :-) */ | |
f34d7a5b | 401 | if (skb != NULL) { |
1da177e4 | 402 | x25_asy_lock(sl); |
6a8eba3b | 403 | dev->stats.tx_bytes += skb->len; |
1da177e4 LT |
404 | x25_asy_encaps(sl, skb->data, skb->len); |
405 | dev_kfree_skb(skb); | |
406 | } | |
407 | spin_unlock(&sl->lock); | |
408 | } | |
409 | ||
410 | /* | |
411 | * LAPB connection establish/down information. | |
412 | */ | |
f34d7a5b | 413 | |
1da177e4 LT |
414 | static void x25_asy_connected(struct net_device *dev, int reason) |
415 | { | |
8f15ea42 | 416 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
417 | struct sk_buff *skb; |
418 | unsigned char *ptr; | |
419 | ||
f34d7a5b AC |
420 | skb = dev_alloc_skb(1); |
421 | if (skb == NULL) { | |
23efcb73 | 422 | netdev_err(dev, "out of memory\n"); |
1da177e4 LT |
423 | return; |
424 | } | |
425 | ||
426 | ptr = skb_put(skb, 1); | |
7eeeacf0 | 427 | *ptr = X25_IFACE_CONNECT; |
1da177e4 LT |
428 | |
429 | skb->protocol = x25_type_trans(skb, sl->dev); | |
430 | netif_rx(skb); | |
1da177e4 LT |
431 | } |
432 | ||
433 | static void x25_asy_disconnected(struct net_device *dev, int reason) | |
434 | { | |
8f15ea42 | 435 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
436 | struct sk_buff *skb; |
437 | unsigned char *ptr; | |
438 | ||
f34d7a5b AC |
439 | skb = dev_alloc_skb(1); |
440 | if (skb == NULL) { | |
23efcb73 | 441 | netdev_err(dev, "out of memory\n"); |
1da177e4 LT |
442 | return; |
443 | } | |
444 | ||
445 | ptr = skb_put(skb, 1); | |
7eeeacf0 | 446 | *ptr = X25_IFACE_DISCONNECT; |
1da177e4 LT |
447 | |
448 | skb->protocol = x25_type_trans(skb, sl->dev); | |
449 | netif_rx(skb); | |
1da177e4 LT |
450 | } |
451 | ||
d97a077a | 452 | static const struct lapb_register_struct x25_asy_callbacks = { |
1da177e4 LT |
453 | .connect_confirmation = x25_asy_connected, |
454 | .connect_indication = x25_asy_connected, | |
455 | .disconnect_confirmation = x25_asy_disconnected, | |
456 | .disconnect_indication = x25_asy_disconnected, | |
457 | .data_indication = x25_asy_data_indication, | |
458 | .data_transmit = x25_asy_data_transmit, | |
1da177e4 LT |
459 | }; |
460 | ||
461 | ||
462 | /* Open the low-level part of the X.25 channel. Easy! */ | |
463 | static int x25_asy_open(struct net_device *dev) | |
464 | { | |
8f15ea42 | 465 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
466 | unsigned long len; |
467 | int err; | |
468 | ||
469 | if (sl->tty == NULL) | |
470 | return -ENODEV; | |
471 | ||
472 | /* | |
473 | * Allocate the X.25 frame buffers: | |
474 | * | |
475 | * rbuff Receive buffer. | |
476 | * xbuff Transmit buffer. | |
477 | */ | |
478 | ||
479 | len = dev->mtu * 2; | |
480 | ||
5cbded58 | 481 | sl->rbuff = kmalloc(len + 4, GFP_KERNEL); |
f34d7a5b | 482 | if (sl->rbuff == NULL) |
1da177e4 | 483 | goto norbuff; |
5cbded58 | 484 | sl->xbuff = kmalloc(len + 4, GFP_KERNEL); |
f34d7a5b | 485 | if (sl->xbuff == NULL) |
1da177e4 | 486 | goto noxbuff; |
1da177e4 LT |
487 | |
488 | sl->buffsize = len; | |
489 | sl->rcount = 0; | |
490 | sl->xleft = 0; | |
491 | sl->flags &= (1 << SLF_INUSE); /* Clear ESCAPE & ERROR flags */ | |
492 | ||
493 | netif_start_queue(dev); | |
f34d7a5b | 494 | |
1da177e4 LT |
495 | /* |
496 | * Now attach LAPB | |
497 | */ | |
f34d7a5b AC |
498 | err = lapb_register(dev, &x25_asy_callbacks); |
499 | if (err == LAPB_OK) | |
1da177e4 LT |
500 | return 0; |
501 | ||
502 | /* Cleanup */ | |
503 | kfree(sl->xbuff); | |
d5c7c745 | 504 | sl->xbuff = NULL; |
1da177e4 LT |
505 | noxbuff: |
506 | kfree(sl->rbuff); | |
d5c7c745 | 507 | sl->rbuff = NULL; |
1da177e4 LT |
508 | norbuff: |
509 | return -ENOMEM; | |
510 | } | |
511 | ||
512 | ||
513 | /* Close the low-level part of the X.25 channel. Easy! */ | |
514 | static int x25_asy_close(struct net_device *dev) | |
515 | { | |
8f15ea42 | 516 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
517 | |
518 | spin_lock(&sl->lock); | |
f34d7a5b | 519 | if (sl->tty) |
8a1ec21e | 520 | clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); |
1da177e4 LT |
521 | |
522 | netif_stop_queue(dev); | |
523 | sl->rcount = 0; | |
524 | sl->xleft = 0; | |
1da177e4 LT |
525 | spin_unlock(&sl->lock); |
526 | return 0; | |
527 | } | |
528 | ||
1da177e4 LT |
529 | /* |
530 | * Handle the 'receiver data ready' interrupt. | |
531 | * This function is called by the 'tty_io' module in the kernel when | |
532 | * a block of X.25 data has been received, which can now be decapsulated | |
533 | * and sent on to some IP layer for further processing. | |
534 | */ | |
f34d7a5b AC |
535 | |
536 | static void x25_asy_receive_buf(struct tty_struct *tty, | |
537 | const unsigned char *cp, char *fp, int count) | |
1da177e4 | 538 | { |
d2b88814 | 539 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
540 | |
541 | if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) | |
542 | return; | |
543 | ||
544 | ||
545 | /* Read the characters out of the buffer */ | |
546 | while (count--) { | |
547 | if (fp && *fp++) { | |
f34d7a5b | 548 | if (!test_and_set_bit(SLF_ERROR, &sl->flags)) |
6a8eba3b | 549 | sl->dev->stats.rx_errors++; |
1da177e4 LT |
550 | cp++; |
551 | continue; | |
552 | } | |
553 | x25_asy_unesc(sl, *cp++); | |
554 | } | |
555 | } | |
556 | ||
557 | /* | |
558 | * Open the high-level part of the X.25 channel. | |
559 | * This function is called by the TTY module when the | |
560 | * X.25 line discipline is called for. Because we are | |
561 | * sure the tty line exists, we only have to link it to | |
562 | * a free X.25 channel... | |
563 | */ | |
564 | ||
565 | static int x25_asy_open_tty(struct tty_struct *tty) | |
566 | { | |
ee9159dd | 567 | struct x25_asy *sl; |
1da177e4 LT |
568 | int err; |
569 | ||
f34d7a5b AC |
570 | if (tty->ops->write == NULL) |
571 | return -EOPNOTSUPP; | |
572 | ||
1da177e4 | 573 | /* OK. Find a free X.25 channel to use. */ |
f34d7a5b AC |
574 | sl = x25_asy_alloc(); |
575 | if (sl == NULL) | |
1da177e4 | 576 | return -ENFILE; |
1da177e4 LT |
577 | |
578 | sl->tty = tty; | |
579 | tty->disc_data = sl; | |
33f0f88f | 580 | tty->receive_room = 65536; |
f34d7a5b | 581 | tty_driver_flush_buffer(tty); |
11b0cc3a | 582 | tty_ldisc_flush(tty); |
1da177e4 LT |
583 | |
584 | /* Restore default settings */ | |
585 | sl->dev->type = ARPHRD_X25; | |
f34d7a5b | 586 | |
1da177e4 | 587 | /* Perform the low-level X.25 async init */ |
f34d7a5b | 588 | err = x25_asy_open(sl->dev); |
3b780bed DM |
589 | if (err) { |
590 | x25_asy_free(sl); | |
1da177e4 | 591 | return err; |
3b780bed | 592 | } |
1da177e4 | 593 | /* Done. We have linked the TTY line to a channel. */ |
6a20bd45 | 594 | return 0; |
1da177e4 LT |
595 | } |
596 | ||
597 | ||
598 | /* | |
599 | * Close down an X.25 channel. | |
600 | * This means flushing out any pending queues, and then restoring the | |
601 | * TTY line discipline to what it was before it got hooked to X.25 | |
602 | * (which usually is TTY again). | |
603 | */ | |
604 | static void x25_asy_close_tty(struct tty_struct *tty) | |
605 | { | |
d2b88814 | 606 | struct x25_asy *sl = tty->disc_data; |
03fe5f3e | 607 | int err; |
1da177e4 LT |
608 | |
609 | /* First make sure we're connected. */ | |
610 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
611 | return; | |
612 | ||
3e3cda96 | 613 | rtnl_lock(); |
1da177e4 | 614 | if (sl->dev->flags & IFF_UP) |
f34d7a5b | 615 | dev_close(sl->dev); |
3e3cda96 | 616 | rtnl_unlock(); |
1da177e4 | 617 | |
03fe5f3e JS |
618 | err = lapb_unregister(sl->dev); |
619 | if (err != LAPB_OK) | |
8e6a4817 JS |
620 | pr_err("%s: lapb_unregister error: %d\n", |
621 | __func__, err); | |
03fe5f3e | 622 | |
1da177e4 LT |
623 | tty->disc_data = NULL; |
624 | sl->tty = NULL; | |
625 | x25_asy_free(sl); | |
626 | } | |
627 | ||
1da177e4 LT |
628 | /************************************************************************ |
629 | * STANDARD X.25 ENCAPSULATION * | |
630 | ************************************************************************/ | |
631 | ||
7b3dfa11 | 632 | static int x25_asy_esc(unsigned char *s, unsigned char *d, int len) |
1da177e4 LT |
633 | { |
634 | unsigned char *ptr = d; | |
635 | unsigned char c; | |
636 | ||
637 | /* | |
638 | * Send an initial END character to flush out any | |
639 | * data that may have accumulated in the receiver | |
640 | * due to line noise. | |
641 | */ | |
642 | ||
643 | *ptr++ = X25_END; /* Send 10111110 bit seq */ | |
644 | ||
645 | /* | |
646 | * For each byte in the packet, send the appropriate | |
647 | * character sequence, according to the X.25 protocol. | |
648 | */ | |
649 | ||
f34d7a5b AC |
650 | while (len-- > 0) { |
651 | switch (c = *s++) { | |
652 | case X25_END: | |
653 | *ptr++ = X25_ESC; | |
654 | *ptr++ = X25_ESCAPE(X25_END); | |
655 | break; | |
656 | case X25_ESC: | |
657 | *ptr++ = X25_ESC; | |
658 | *ptr++ = X25_ESCAPE(X25_ESC); | |
659 | break; | |
660 | default: | |
661 | *ptr++ = c; | |
662 | break; | |
1da177e4 LT |
663 | } |
664 | } | |
665 | *ptr++ = X25_END; | |
807540ba | 666 | return ptr - d; |
1da177e4 LT |
667 | } |
668 | ||
669 | static void x25_asy_unesc(struct x25_asy *sl, unsigned char s) | |
670 | { | |
671 | ||
f34d7a5b AC |
672 | switch (s) { |
673 | case X25_END: | |
8e95a202 | 674 | if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && |
8fdcabea | 675 | sl->rcount >= 2) |
f34d7a5b AC |
676 | x25_asy_bump(sl); |
677 | clear_bit(SLF_ESCAPE, &sl->flags); | |
678 | sl->rcount = 0; | |
679 | return; | |
680 | case X25_ESC: | |
681 | set_bit(SLF_ESCAPE, &sl->flags); | |
682 | return; | |
683 | case X25_ESCAPE(X25_ESC): | |
684 | case X25_ESCAPE(X25_END): | |
685 | if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) | |
686 | s = X25_UNESCAPE(s); | |
687 | break; | |
688 | } | |
689 | if (!test_bit(SLF_ERROR, &sl->flags)) { | |
690 | if (sl->rcount < sl->buffsize) { | |
1da177e4 LT |
691 | sl->rbuff[sl->rcount++] = s; |
692 | return; | |
693 | } | |
6a8eba3b | 694 | sl->dev->stats.rx_over_errors++; |
1da177e4 LT |
695 | set_bit(SLF_ERROR, &sl->flags); |
696 | } | |
697 | } | |
698 | ||
699 | ||
700 | /* Perform I/O control on an active X.25 channel. */ | |
701 | static int x25_asy_ioctl(struct tty_struct *tty, struct file *file, | |
702 | unsigned int cmd, unsigned long arg) | |
703 | { | |
d2b88814 | 704 | struct x25_asy *sl = tty->disc_data; |
1da177e4 LT |
705 | |
706 | /* First make sure we're connected. */ | |
707 | if (!sl || sl->magic != X25_ASY_MAGIC) | |
708 | return -EINVAL; | |
709 | ||
f34d7a5b | 710 | switch (cmd) { |
1da177e4 LT |
711 | case SIOCGIFNAME: |
712 | if (copy_to_user((void __user *)arg, sl->dev->name, | |
713 | strlen(sl->dev->name) + 1)) | |
714 | return -EFAULT; | |
715 | return 0; | |
716 | case SIOCSIFHWADDR: | |
717 | return -EINVAL; | |
1da177e4 | 718 | default: |
d0127539 | 719 | return tty_mode_ioctl(tty, file, cmd, arg); |
1da177e4 LT |
720 | } |
721 | } | |
722 | ||
723 | static int x25_asy_open_dev(struct net_device *dev) | |
724 | { | |
8f15ea42 | 725 | struct x25_asy *sl = netdev_priv(dev); |
f34d7a5b | 726 | if (sl->tty == NULL) |
1da177e4 LT |
727 | return -ENODEV; |
728 | return 0; | |
729 | } | |
730 | ||
48f26ad5 SH |
731 | static 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 | ||
1da177e4 LT |
739 | /* Initialise the X.25 driver. Called by the device init code */ |
740 | static void x25_asy_setup(struct net_device *dev) | |
741 | { | |
8f15ea42 | 742 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
743 | |
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 | /* | |
f34d7a5b | 750 | * Finish setting up the DEVICE info. |
1da177e4 | 751 | */ |
f34d7a5b | 752 | |
1da177e4 | 753 | dev->mtu = SL_MTU; |
8b6b4135 JW |
754 | dev->min_mtu = 0; |
755 | dev->max_mtu = 65534; | |
48f26ad5 | 756 | dev->netdev_ops = &x25_asy_netdev_ops; |
1da177e4 | 757 | dev->watchdog_timeo = HZ*20; |
1da177e4 LT |
758 | dev->hard_header_len = 0; |
759 | dev->addr_len = 0; | |
760 | dev->type = ARPHRD_X25; | |
761 | dev->tx_queue_len = 10; | |
762 | ||
c79f428d XH |
763 | /* When transmitting data: |
764 | * first this driver removes a pseudo header of 1 byte, | |
765 | * then the lapb module prepends an LAPB header of at most 3 bytes. | |
766 | */ | |
767 | dev->needed_headroom = 3 - 1; | |
768 | ||
1da177e4 LT |
769 | /* New-style flags. */ |
770 | dev->flags = IFF_NOARP; | |
771 | } | |
772 | ||
a352def2 | 773 | static struct tty_ldisc_ops x25_ldisc = { |
1da177e4 LT |
774 | .owner = THIS_MODULE, |
775 | .magic = TTY_LDISC_MAGIC, | |
776 | .name = "X.25", | |
777 | .open = x25_asy_open_tty, | |
778 | .close = x25_asy_close_tty, | |
779 | .ioctl = x25_asy_ioctl, | |
780 | .receive_buf = x25_asy_receive_buf, | |
1da177e4 LT |
781 | .write_wakeup = x25_asy_write_wakeup, |
782 | }; | |
783 | ||
784 | static int __init init_x25_asy(void) | |
785 | { | |
786 | if (x25_asy_maxdev < 4) | |
787 | x25_asy_maxdev = 4; /* Sanity */ | |
788 | ||
23efcb73 JP |
789 | pr_info("X.25 async: version 0.00 ALPHA (dynamic channels, max=%d)\n", |
790 | x25_asy_maxdev); | |
1da177e4 | 791 | |
f34d7a5b AC |
792 | x25_asy_devs = kcalloc(x25_asy_maxdev, sizeof(struct net_device *), |
793 | GFP_KERNEL); | |
e404decb | 794 | if (!x25_asy_devs) |
1da177e4 | 795 | return -ENOMEM; |
1da177e4 LT |
796 | |
797 | return tty_register_ldisc(N_X25, &x25_ldisc); | |
798 | } | |
799 | ||
800 | ||
801 | static void __exit exit_x25_asy(void) | |
802 | { | |
803 | struct net_device *dev; | |
804 | int i; | |
805 | ||
806 | for (i = 0; i < x25_asy_maxdev; i++) { | |
807 | dev = x25_asy_devs[i]; | |
808 | if (dev) { | |
8f15ea42 | 809 | struct x25_asy *sl = netdev_priv(dev); |
1da177e4 LT |
810 | |
811 | spin_lock_bh(&sl->lock); | |
f34d7a5b | 812 | if (sl->tty) |
1da177e4 LT |
813 | tty_hangup(sl->tty); |
814 | ||
815 | spin_unlock_bh(&sl->lock); | |
816 | /* | |
817 | * VSV = if dev->start==0, then device | |
818 | * unregistered while close proc. | |
819 | */ | |
820 | unregister_netdev(dev); | |
821 | free_netdev(dev); | |
822 | } | |
823 | } | |
824 | ||
825 | kfree(x25_asy_devs); | |
64ccd715 | 826 | tty_unregister_ldisc(N_X25); |
1da177e4 LT |
827 | } |
828 | ||
829 | module_init(init_x25_asy); | |
830 | module_exit(exit_x25_asy); |