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e3b3d0f5 | 1 | // SPDX-License-Identifier: GPL-1.0+ |
1da177e4 LT |
2 | /* generic HDLC line discipline for Linux |
3 | * | |
4 | * Written by Paul Fulghum paulkf@microgate.com | |
5 | * for Microgate Corporation | |
6 | * | |
7 | * Microgate and SyncLink are registered trademarks of Microgate Corporation | |
8 | * | |
9 | * Adapted from ppp.c, written by Michael Callahan <callahan@maths.ox.ac.uk>, | |
10 | * Al Longyear <longyear@netcom.com>, | |
11 | * Paul Mackerras <Paul.Mackerras@cs.anu.edu.au> | |
12 | * | |
13 | * Original release 01/11/99 | |
1da177e4 | 14 | * |
1da177e4 LT |
15 | * This module implements the tty line discipline N_HDLC for use with |
16 | * tty device drivers that support bit-synchronous HDLC communications. | |
17 | * | |
18 | * All HDLC data is frame oriented which means: | |
19 | * | |
20 | * 1. tty write calls represent one complete transmit frame of data | |
21 | * The device driver should accept the complete frame or none of | |
22 | * the frame (busy) in the write method. Each write call should have | |
23 | * a byte count in the range of 2-65535 bytes (2 is min HDLC frame | |
24 | * with 1 addr byte and 1 ctrl byte). The max byte count of 65535 | |
25 | * should include any crc bytes required. For example, when using | |
26 | * CCITT CRC32, 4 crc bytes are required, so the maximum size frame | |
27 | * the application may transmit is limited to 65531 bytes. For CCITT | |
28 | * CRC16, the maximum application frame size would be 65533. | |
29 | * | |
30 | * | |
31 | * 2. receive callbacks from the device driver represents | |
32 | * one received frame. The device driver should bypass | |
33 | * the tty flip buffer and call the line discipline receive | |
34 | * callback directly to avoid fragmenting or concatenating | |
35 | * multiple frames into a single receive callback. | |
36 | * | |
37 | * The HDLC line discipline queues the receive frames in separate | |
38 | * buffers so complete receive frames can be returned by the | |
39 | * tty read calls. | |
40 | * | |
41 | * 3. tty read calls returns an entire frame of data or nothing. | |
42 | * | |
43 | * 4. all send and receive data is considered raw. No processing | |
44 | * or translation is performed by the line discipline, regardless | |
45 | * of the tty flags | |
46 | * | |
47 | * 5. When line discipline is queried for the amount of receive | |
48 | * data available (FIOC), 0 is returned if no data available, | |
49 | * otherwise the count of the next available frame is returned. | |
50 | * (instead of the sum of all received frame counts). | |
51 | * | |
52 | * These conventions allow the standard tty programming interface | |
53 | * to be used for synchronous HDLC applications when used with | |
54 | * this line discipline (or another line discipline that is frame | |
55 | * oriented such as N_PPP). | |
56 | * | |
57 | * The SyncLink driver (synclink.c) implements both asynchronous | |
58 | * (using standard line discipline N_TTY) and synchronous HDLC | |
59 | * (using N_HDLC) communications, with the latter using the above | |
60 | * conventions. | |
61 | * | |
62 | * This implementation is very basic and does not maintain | |
63 | * any statistics. The main point is to enforce the raw data | |
64 | * and frame orientation of HDLC communications. | |
65 | * | |
66 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED | |
67 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
68 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
69 | * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, | |
70 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
71 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | |
72 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
73 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
74 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
75 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | |
76 | * OF THE POSSIBILITY OF SUCH DAMAGE. | |
77 | */ | |
78 | ||
79 | #define HDLC_MAGIC 0x239e | |
1da177e4 | 80 | |
1da177e4 LT |
81 | #include <linux/module.h> |
82 | #include <linux/init.h> | |
83 | #include <linux/kernel.h> | |
84 | #include <linux/sched.h> | |
85 | #include <linux/types.h> | |
86 | #include <linux/fcntl.h> | |
87 | #include <linux/interrupt.h> | |
88 | #include <linux/ptrace.h> | |
89 | ||
90 | #undef VERSION | |
91 | #define VERSION(major,minor,patch) (((((major)<<8)+(minor))<<8)+(patch)) | |
92 | ||
93 | #include <linux/poll.h> | |
94 | #include <linux/in.h> | |
95 | #include <linux/ioctl.h> | |
96 | #include <linux/slab.h> | |
97 | #include <linux/tty.h> | |
98 | #include <linux/errno.h> | |
99 | #include <linux/string.h> /* used in new tty drivers */ | |
100 | #include <linux/signal.h> /* used in new tty drivers */ | |
101 | #include <linux/if.h> | |
102 | #include <linux/bitops.h> | |
103 | ||
1da177e4 | 104 | #include <asm/termios.h> |
7c0f6ba6 | 105 | #include <linux/uaccess.h> |
1da177e4 LT |
106 | |
107 | /* | |
108 | * Buffers for individual HDLC frames | |
109 | */ | |
110 | #define MAX_HDLC_FRAME_SIZE 65535 | |
111 | #define DEFAULT_RX_BUF_COUNT 10 | |
112 | #define MAX_RX_BUF_COUNT 60 | |
be10eb75 | 113 | #define DEFAULT_TX_BUF_COUNT 3 |
1da177e4 LT |
114 | |
115 | struct n_hdlc_buf { | |
82f2341c | 116 | struct list_head list_item; |
1da177e4 LT |
117 | int count; |
118 | char buf[1]; | |
119 | }; | |
120 | ||
121 | #define N_HDLC_BUF_SIZE (sizeof(struct n_hdlc_buf) + maxframe) | |
122 | ||
123 | struct n_hdlc_buf_list { | |
82f2341c | 124 | struct list_head list; |
1da177e4 LT |
125 | int count; |
126 | spinlock_t spinlock; | |
127 | }; | |
128 | ||
129 | /** | |
130 | * struct n_hdlc - per device instance data structure | |
131 | * @magic - magic value for structure | |
132 | * @flags - miscellaneous control flags | |
133 | * @tty - ptr to TTY structure | |
134 | * @backup_tty - TTY to use if tty gets closed | |
135 | * @tbusy - reentrancy flag for tx wakeup code | |
136 | * @woke_up - FIXME: describe this field | |
1da177e4 LT |
137 | * @tx_buf_list - list of pending transmit frame buffers |
138 | * @rx_buf_list - list of received frame buffers | |
139 | * @tx_free_buf_list - list unused transmit frame buffers | |
140 | * @rx_free_buf_list - list unused received frame buffers | |
141 | */ | |
142 | struct n_hdlc { | |
143 | int magic; | |
144 | __u32 flags; | |
145 | struct tty_struct *tty; | |
146 | struct tty_struct *backup_tty; | |
147 | int tbusy; | |
148 | int woke_up; | |
1da177e4 LT |
149 | struct n_hdlc_buf_list tx_buf_list; |
150 | struct n_hdlc_buf_list rx_buf_list; | |
151 | struct n_hdlc_buf_list tx_free_buf_list; | |
152 | struct n_hdlc_buf_list rx_free_buf_list; | |
153 | }; | |
154 | ||
155 | /* | |
156 | * HDLC buffer list manipulation functions | |
157 | */ | |
82f2341c AP |
158 | static void n_hdlc_buf_return(struct n_hdlc_buf_list *buf_list, |
159 | struct n_hdlc_buf *buf); | |
1da177e4 LT |
160 | static void n_hdlc_buf_put(struct n_hdlc_buf_list *list, |
161 | struct n_hdlc_buf *buf); | |
162 | static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *list); | |
163 | ||
164 | /* Local functions */ | |
165 | ||
166 | static struct n_hdlc *n_hdlc_alloc (void); | |
167 | ||
168 | /* debug level can be set by insmod for debugging purposes */ | |
169 | #define DEBUG_LEVEL_INFO 1 | |
170 | static int debuglevel; | |
171 | ||
172 | /* max frame size for memory allocations */ | |
173 | static int maxframe = 4096; | |
174 | ||
175 | /* TTY callbacks */ | |
176 | ||
177 | static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file, | |
178 | __u8 __user *buf, size_t nr); | |
179 | static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file, | |
180 | const unsigned char *buf, size_t nr); | |
181 | static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file, | |
182 | unsigned int cmd, unsigned long arg); | |
afc9a42b | 183 | static __poll_t n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp, |
1da177e4 LT |
184 | poll_table *wait); |
185 | static int n_hdlc_tty_open(struct tty_struct *tty); | |
186 | static void n_hdlc_tty_close(struct tty_struct *tty); | |
55db4c64 LT |
187 | static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *cp, |
188 | char *fp, int count); | |
1da177e4 LT |
189 | static void n_hdlc_tty_wakeup(struct tty_struct *tty); |
190 | ||
191 | #define bset(p,b) ((p)[(b) >> 5] |= (1 << ((b) & 0x1f))) | |
192 | ||
193 | #define tty2n_hdlc(tty) ((struct n_hdlc *) ((tty)->disc_data)) | |
194 | #define n_hdlc2tty(n_hdlc) ((n_hdlc)->tty) | |
195 | ||
be10eb75 PF |
196 | static void flush_rx_queue(struct tty_struct *tty) |
197 | { | |
198 | struct n_hdlc *n_hdlc = tty2n_hdlc(tty); | |
199 | struct n_hdlc_buf *buf; | |
200 | ||
201 | while ((buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list))) | |
202 | n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, buf); | |
203 | } | |
204 | ||
205 | static void flush_tx_queue(struct tty_struct *tty) | |
206 | { | |
207 | struct n_hdlc *n_hdlc = tty2n_hdlc(tty); | |
208 | struct n_hdlc_buf *buf; | |
be10eb75 PF |
209 | |
210 | while ((buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list))) | |
211 | n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, buf); | |
be10eb75 PF |
212 | } |
213 | ||
a352def2 | 214 | static struct tty_ldisc_ops n_hdlc_ldisc = { |
1da177e4 LT |
215 | .owner = THIS_MODULE, |
216 | .magic = TTY_LDISC_MAGIC, | |
217 | .name = "hdlc", | |
218 | .open = n_hdlc_tty_open, | |
219 | .close = n_hdlc_tty_close, | |
220 | .read = n_hdlc_tty_read, | |
221 | .write = n_hdlc_tty_write, | |
222 | .ioctl = n_hdlc_tty_ioctl, | |
223 | .poll = n_hdlc_tty_poll, | |
224 | .receive_buf = n_hdlc_tty_receive, | |
1da177e4 | 225 | .write_wakeup = n_hdlc_tty_wakeup, |
be10eb75 | 226 | .flush_buffer = flush_rx_queue, |
1da177e4 LT |
227 | }; |
228 | ||
229 | /** | |
230 | * n_hdlc_release - release an n_hdlc per device line discipline info structure | |
231 | * @n_hdlc - per device line discipline info structure | |
232 | */ | |
233 | static void n_hdlc_release(struct n_hdlc *n_hdlc) | |
234 | { | |
235 | struct tty_struct *tty = n_hdlc2tty (n_hdlc); | |
236 | struct n_hdlc_buf *buf; | |
237 | ||
238 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
239 | printk("%s(%d)n_hdlc_release() called\n",__FILE__,__LINE__); | |
240 | ||
241 | /* Ensure that the n_hdlcd process is not hanging on select()/poll() */ | |
242 | wake_up_interruptible (&tty->read_wait); | |
243 | wake_up_interruptible (&tty->write_wait); | |
244 | ||
827afdf0 | 245 | if (tty->disc_data == n_hdlc) |
1da177e4 LT |
246 | tty->disc_data = NULL; /* Break the tty->n_hdlc link */ |
247 | ||
248 | /* Release transmit and receive buffers */ | |
249 | for(;;) { | |
250 | buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list); | |
251 | if (buf) { | |
252 | kfree(buf); | |
253 | } else | |
254 | break; | |
255 | } | |
256 | for(;;) { | |
257 | buf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list); | |
258 | if (buf) { | |
259 | kfree(buf); | |
260 | } else | |
261 | break; | |
262 | } | |
263 | for(;;) { | |
264 | buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list); | |
265 | if (buf) { | |
266 | kfree(buf); | |
267 | } else | |
268 | break; | |
269 | } | |
270 | for(;;) { | |
271 | buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list); | |
272 | if (buf) { | |
273 | kfree(buf); | |
274 | } else | |
275 | break; | |
276 | } | |
1da177e4 LT |
277 | kfree(n_hdlc); |
278 | ||
279 | } /* end of n_hdlc_release() */ | |
280 | ||
281 | /** | |
282 | * n_hdlc_tty_close - line discipline close | |
283 | * @tty - pointer to tty info structure | |
284 | * | |
285 | * Called when the line discipline is changed to something | |
286 | * else, the tty is closed, or the tty detects a hangup. | |
287 | */ | |
288 | static void n_hdlc_tty_close(struct tty_struct *tty) | |
289 | { | |
290 | struct n_hdlc *n_hdlc = tty2n_hdlc (tty); | |
291 | ||
292 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
293 | printk("%s(%d)n_hdlc_tty_close() called\n",__FILE__,__LINE__); | |
294 | ||
295 | if (n_hdlc != NULL) { | |
296 | if (n_hdlc->magic != HDLC_MAGIC) { | |
297 | printk (KERN_WARNING"n_hdlc: trying to close unopened tty!\n"); | |
298 | return; | |
299 | } | |
300 | #if defined(TTY_NO_WRITE_SPLIT) | |
301 | clear_bit(TTY_NO_WRITE_SPLIT,&tty->flags); | |
302 | #endif | |
303 | tty->disc_data = NULL; | |
304 | if (tty == n_hdlc->backup_tty) | |
305 | n_hdlc->backup_tty = NULL; | |
306 | if (tty != n_hdlc->tty) | |
307 | return; | |
308 | if (n_hdlc->backup_tty) { | |
309 | n_hdlc->tty = n_hdlc->backup_tty; | |
310 | } else { | |
311 | n_hdlc_release (n_hdlc); | |
312 | } | |
313 | } | |
314 | ||
315 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
316 | printk("%s(%d)n_hdlc_tty_close() success\n",__FILE__,__LINE__); | |
317 | ||
318 | } /* end of n_hdlc_tty_close() */ | |
319 | ||
320 | /** | |
321 | * n_hdlc_tty_open - called when line discipline changed to n_hdlc | |
322 | * @tty - pointer to tty info structure | |
323 | * | |
324 | * Returns 0 if success, otherwise error code | |
325 | */ | |
326 | static int n_hdlc_tty_open (struct tty_struct *tty) | |
327 | { | |
328 | struct n_hdlc *n_hdlc = tty2n_hdlc (tty); | |
329 | ||
330 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
331 | printk("%s(%d)n_hdlc_tty_open() called (device=%s)\n", | |
332 | __FILE__,__LINE__, | |
333 | tty->name); | |
334 | ||
335 | /* There should not be an existing table for this slot. */ | |
336 | if (n_hdlc) { | |
337 | printk (KERN_ERR"n_hdlc_tty_open:tty already associated!\n" ); | |
338 | return -EEXIST; | |
339 | } | |
340 | ||
341 | n_hdlc = n_hdlc_alloc(); | |
342 | if (!n_hdlc) { | |
343 | printk (KERN_ERR "n_hdlc_alloc failed\n"); | |
344 | return -ENFILE; | |
345 | } | |
346 | ||
347 | tty->disc_data = n_hdlc; | |
348 | n_hdlc->tty = tty; | |
33f0f88f | 349 | tty->receive_room = 65536; |
1da177e4 LT |
350 | |
351 | #if defined(TTY_NO_WRITE_SPLIT) | |
352 | /* change tty_io write() to not split large writes into 8K chunks */ | |
353 | set_bit(TTY_NO_WRITE_SPLIT,&tty->flags); | |
354 | #endif | |
355 | ||
be10eb75 | 356 | /* flush receive data from driver */ |
f34d7a5b | 357 | tty_driver_flush_buffer(tty); |
1da177e4 LT |
358 | |
359 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
360 | printk("%s(%d)n_hdlc_tty_open() success\n",__FILE__,__LINE__); | |
361 | ||
362 | return 0; | |
363 | ||
364 | } /* end of n_tty_hdlc_open() */ | |
365 | ||
366 | /** | |
367 | * n_hdlc_send_frames - send frames on pending send buffer list | |
368 | * @n_hdlc - pointer to ldisc instance data | |
369 | * @tty - pointer to tty instance data | |
370 | * | |
371 | * Send frames on pending send buffer list until the driver does not accept a | |
372 | * frame (busy) this function is called after adding a frame to the send buffer | |
373 | * list and by the tty wakeup callback. | |
374 | */ | |
375 | static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty) | |
376 | { | |
377 | register int actual; | |
378 | unsigned long flags; | |
379 | struct n_hdlc_buf *tbuf; | |
380 | ||
381 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
382 | printk("%s(%d)n_hdlc_send_frames() called\n",__FILE__,__LINE__); | |
383 | check_again: | |
384 | ||
385 | spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags); | |
386 | if (n_hdlc->tbusy) { | |
387 | n_hdlc->woke_up = 1; | |
388 | spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags); | |
389 | return; | |
390 | } | |
391 | n_hdlc->tbusy = 1; | |
392 | n_hdlc->woke_up = 0; | |
393 | spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags); | |
394 | ||
82f2341c | 395 | tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list); |
1da177e4 LT |
396 | while (tbuf) { |
397 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
398 | printk("%s(%d)sending frame %p, count=%d\n", | |
399 | __FILE__,__LINE__,tbuf,tbuf->count); | |
400 | ||
401 | /* Send the next block of data to device */ | |
7962fce9 | 402 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
f34d7a5b | 403 | actual = tty->ops->write(tty, tbuf->buf, tbuf->count); |
b0fed314 JS |
404 | |
405 | /* rollback was possible and has been done */ | |
406 | if (actual == -ERESTARTSYS) { | |
82f2341c | 407 | n_hdlc_buf_return(&n_hdlc->tx_buf_list, tbuf); |
b0fed314 JS |
408 | break; |
409 | } | |
1da177e4 LT |
410 | /* if transmit error, throw frame away by */ |
411 | /* pretending it was accepted by driver */ | |
412 | if (actual < 0) | |
413 | actual = tbuf->count; | |
414 | ||
415 | if (actual == tbuf->count) { | |
416 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
417 | printk("%s(%d)frame %p completed\n", | |
418 | __FILE__,__LINE__,tbuf); | |
419 | ||
420 | /* free current transmit buffer */ | |
421 | n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, tbuf); | |
82f2341c | 422 | |
1da177e4 LT |
423 | /* wait up sleeping writers */ |
424 | wake_up_interruptible(&tty->write_wait); | |
425 | ||
426 | /* get next pending transmit buffer */ | |
427 | tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list); | |
428 | } else { | |
429 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
430 | printk("%s(%d)frame %p pending\n", | |
431 | __FILE__,__LINE__,tbuf); | |
82f2341c AP |
432 | |
433 | /* | |
434 | * the buffer was not accepted by driver, | |
435 | * return it back into tx queue | |
436 | */ | |
437 | n_hdlc_buf_return(&n_hdlc->tx_buf_list, tbuf); | |
1da177e4 LT |
438 | break; |
439 | } | |
440 | } | |
441 | ||
442 | if (!tbuf) | |
7962fce9 | 443 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
1da177e4 LT |
444 | |
445 | /* Clear the re-entry flag */ | |
446 | spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags); | |
447 | n_hdlc->tbusy = 0; | |
448 | spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags); | |
449 | ||
450 | if (n_hdlc->woke_up) | |
451 | goto check_again; | |
452 | ||
453 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
454 | printk("%s(%d)n_hdlc_send_frames() exit\n",__FILE__,__LINE__); | |
455 | ||
456 | } /* end of n_hdlc_send_frames() */ | |
457 | ||
458 | /** | |
459 | * n_hdlc_tty_wakeup - Callback for transmit wakeup | |
460 | * @tty - pointer to associated tty instance data | |
461 | * | |
462 | * Called when low level device driver can accept more send data. | |
463 | */ | |
464 | static void n_hdlc_tty_wakeup(struct tty_struct *tty) | |
465 | { | |
466 | struct n_hdlc *n_hdlc = tty2n_hdlc(tty); | |
467 | ||
468 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
469 | printk("%s(%d)n_hdlc_tty_wakeup() called\n",__FILE__,__LINE__); | |
470 | ||
471 | if (!n_hdlc) | |
472 | return; | |
473 | ||
474 | if (tty != n_hdlc->tty) { | |
7962fce9 | 475 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
1da177e4 LT |
476 | return; |
477 | } | |
478 | ||
479 | n_hdlc_send_frames (n_hdlc, tty); | |
480 | ||
481 | } /* end of n_hdlc_tty_wakeup() */ | |
482 | ||
1da177e4 LT |
483 | /** |
484 | * n_hdlc_tty_receive - Called by tty driver when receive data is available | |
485 | * @tty - pointer to tty instance data | |
486 | * @data - pointer to received data | |
487 | * @flags - pointer to flags for data | |
488 | * @count - count of received data in bytes | |
489 | * | |
490 | * Called by tty low level driver when receive data is available. Data is | |
491 | * interpreted as one HDLC frame. | |
492 | */ | |
55db4c64 LT |
493 | static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data, |
494 | char *flags, int count) | |
1da177e4 LT |
495 | { |
496 | register struct n_hdlc *n_hdlc = tty2n_hdlc (tty); | |
497 | register struct n_hdlc_buf *buf; | |
498 | ||
499 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
500 | printk("%s(%d)n_hdlc_tty_receive() called count=%d\n", | |
501 | __FILE__,__LINE__, count); | |
502 | ||
503 | /* This can happen if stuff comes in on the backup tty */ | |
a01e035e | 504 | if (!n_hdlc || tty != n_hdlc->tty) |
55db4c64 | 505 | return; |
1da177e4 LT |
506 | |
507 | /* verify line is using HDLC discipline */ | |
508 | if (n_hdlc->magic != HDLC_MAGIC) { | |
509 | printk("%s(%d) line not using HDLC discipline\n", | |
510 | __FILE__,__LINE__); | |
55db4c64 | 511 | return; |
1da177e4 LT |
512 | } |
513 | ||
514 | if ( count>maxframe ) { | |
515 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
516 | printk("%s(%d) rx count>maxframesize, data discarded\n", | |
517 | __FILE__,__LINE__); | |
55db4c64 | 518 | return; |
1da177e4 LT |
519 | } |
520 | ||
521 | /* get a free HDLC buffer */ | |
522 | buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list); | |
523 | if (!buf) { | |
524 | /* no buffers in free list, attempt to allocate another rx buffer */ | |
525 | /* unless the maximum count has been reached */ | |
526 | if (n_hdlc->rx_buf_list.count < MAX_RX_BUF_COUNT) | |
527 | buf = kmalloc(N_HDLC_BUF_SIZE, GFP_ATOMIC); | |
528 | } | |
529 | ||
530 | if (!buf) { | |
531 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
532 | printk("%s(%d) no more rx buffers, data discarded\n", | |
533 | __FILE__,__LINE__); | |
55db4c64 | 534 | return; |
1da177e4 LT |
535 | } |
536 | ||
537 | /* copy received data to HDLC buffer */ | |
538 | memcpy(buf->buf,data,count); | |
539 | buf->count=count; | |
540 | ||
541 | /* add HDLC buffer to list of received frames */ | |
542 | n_hdlc_buf_put(&n_hdlc->rx_buf_list, buf); | |
543 | ||
544 | /* wake up any blocked reads and perform async signalling */ | |
545 | wake_up_interruptible (&tty->read_wait); | |
546 | if (n_hdlc->tty->fasync != NULL) | |
547 | kill_fasync (&n_hdlc->tty->fasync, SIGIO, POLL_IN); | |
548 | ||
549 | } /* end of n_hdlc_tty_receive() */ | |
550 | ||
551 | /** | |
4a4efbde | 552 | * n_hdlc_tty_read - Called to retrieve one frame of data (if available) |
1da177e4 LT |
553 | * @tty - pointer to tty instance data |
554 | * @file - pointer to open file object | |
555 | * @buf - pointer to returned data buffer | |
556 | * @nr - size of returned data buffer | |
557 | * | |
558 | * Returns the number of bytes returned or error code. | |
559 | */ | |
560 | static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file, | |
561 | __u8 __user *buf, size_t nr) | |
562 | { | |
563 | struct n_hdlc *n_hdlc = tty2n_hdlc(tty); | |
1035b63d | 564 | int ret = 0; |
1da177e4 | 565 | struct n_hdlc_buf *rbuf; |
1035b63d | 566 | DECLARE_WAITQUEUE(wait, current); |
1da177e4 LT |
567 | |
568 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
569 | printk("%s(%d)n_hdlc_tty_read() called\n",__FILE__,__LINE__); | |
570 | ||
571 | /* Validate the pointers */ | |
572 | if (!n_hdlc) | |
573 | return -EIO; | |
574 | ||
575 | /* verify user access to buffer */ | |
96d4f267 | 576 | if (!access_ok(buf, nr)) { |
1da177e4 LT |
577 | printk(KERN_WARNING "%s(%d) n_hdlc_tty_read() can't verify user " |
578 | "buffer\n", __FILE__, __LINE__); | |
579 | return -EFAULT; | |
580 | } | |
581 | ||
1035b63d | 582 | add_wait_queue(&tty->read_wait, &wait); |
04f378b1 | 583 | |
1da177e4 | 584 | for (;;) { |
0f40fbbc | 585 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { |
1035b63d PF |
586 | ret = -EIO; |
587 | break; | |
04f378b1 | 588 | } |
1035b63d PF |
589 | if (tty_hung_up_p(file)) |
590 | break; | |
1da177e4 | 591 | |
1035b63d | 592 | set_current_state(TASK_INTERRUPTIBLE); |
1da177e4 LT |
593 | |
594 | rbuf = n_hdlc_buf_get(&n_hdlc->rx_buf_list); | |
1035b63d PF |
595 | if (rbuf) { |
596 | if (rbuf->count > nr) { | |
597 | /* too large for caller's buffer */ | |
598 | ret = -EOVERFLOW; | |
599 | } else { | |
fc01d8c6 | 600 | __set_current_state(TASK_RUNNING); |
1035b63d PF |
601 | if (copy_to_user(buf, rbuf->buf, rbuf->count)) |
602 | ret = -EFAULT; | |
603 | else | |
604 | ret = rbuf->count; | |
605 | } | |
606 | ||
607 | if (n_hdlc->rx_free_buf_list.count > | |
608 | DEFAULT_RX_BUF_COUNT) | |
609 | kfree(rbuf); | |
610 | else | |
611 | n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, rbuf); | |
1da177e4 | 612 | break; |
1035b63d | 613 | } |
1da177e4 LT |
614 | |
615 | /* no data */ | |
c96cf923 | 616 | if (tty_io_nonblock(tty, file)) { |
1035b63d PF |
617 | ret = -EAGAIN; |
618 | break; | |
04f378b1 | 619 | } |
1035b63d PF |
620 | |
621 | schedule(); | |
622 | ||
04f378b1 | 623 | if (signal_pending(current)) { |
1035b63d PF |
624 | ret = -EINTR; |
625 | break; | |
04f378b1 | 626 | } |
1da177e4 | 627 | } |
1035b63d PF |
628 | |
629 | remove_wait_queue(&tty->read_wait, &wait); | |
630 | __set_current_state(TASK_RUNNING); | |
631 | ||
1da177e4 LT |
632 | return ret; |
633 | ||
634 | } /* end of n_hdlc_tty_read() */ | |
635 | ||
636 | /** | |
637 | * n_hdlc_tty_write - write a single frame of data to device | |
638 | * @tty - pointer to associated tty device instance data | |
639 | * @file - pointer to file object data | |
640 | * @data - pointer to transmit data (one frame) | |
641 | * @count - size of transmit frame in bytes | |
642 | * | |
643 | * Returns the number of bytes written (or error code). | |
644 | */ | |
645 | static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file, | |
646 | const unsigned char *data, size_t count) | |
647 | { | |
648 | struct n_hdlc *n_hdlc = tty2n_hdlc (tty); | |
649 | int error = 0; | |
650 | DECLARE_WAITQUEUE(wait, current); | |
651 | struct n_hdlc_buf *tbuf; | |
652 | ||
653 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
5b5e0928 | 654 | printk("%s(%d)n_hdlc_tty_write() called count=%zd\n", |
1da177e4 LT |
655 | __FILE__,__LINE__,count); |
656 | ||
657 | /* Verify pointers */ | |
658 | if (!n_hdlc) | |
659 | return -EIO; | |
660 | ||
661 | if (n_hdlc->magic != HDLC_MAGIC) | |
662 | return -EIO; | |
663 | ||
664 | /* verify frame size */ | |
665 | if (count > maxframe ) { | |
666 | if (debuglevel & DEBUG_LEVEL_INFO) | |
667 | printk (KERN_WARNING | |
668 | "n_hdlc_tty_write: truncating user packet " | |
669 | "from %lu to %d\n", (unsigned long) count, | |
670 | maxframe ); | |
671 | count = maxframe; | |
672 | } | |
673 | ||
674 | add_wait_queue(&tty->write_wait, &wait); | |
1035b63d PF |
675 | |
676 | for (;;) { | |
677 | set_current_state(TASK_INTERRUPTIBLE); | |
1da177e4 | 678 | |
1035b63d PF |
679 | tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list); |
680 | if (tbuf) | |
681 | break; | |
682 | ||
c96cf923 | 683 | if (tty_io_nonblock(tty, file)) { |
c72f527c PF |
684 | error = -EAGAIN; |
685 | break; | |
686 | } | |
1da177e4 LT |
687 | schedule(); |
688 | ||
689 | n_hdlc = tty2n_hdlc (tty); | |
690 | if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC || | |
691 | tty != n_hdlc->tty) { | |
692 | printk("n_hdlc_tty_write: %p invalid after wait!\n", n_hdlc); | |
693 | error = -EIO; | |
694 | break; | |
695 | } | |
696 | ||
697 | if (signal_pending(current)) { | |
698 | error = -EINTR; | |
699 | break; | |
700 | } | |
701 | } | |
702 | ||
1035b63d | 703 | __set_current_state(TASK_RUNNING); |
1da177e4 LT |
704 | remove_wait_queue(&tty->write_wait, &wait); |
705 | ||
706 | if (!error) { | |
707 | /* Retrieve the user's buffer */ | |
708 | memcpy(tbuf->buf, data, count); | |
709 | ||
710 | /* Send the data */ | |
711 | tbuf->count = error = count; | |
712 | n_hdlc_buf_put(&n_hdlc->tx_buf_list,tbuf); | |
713 | n_hdlc_send_frames(n_hdlc,tty); | |
714 | } | |
1035b63d | 715 | |
1da177e4 LT |
716 | return error; |
717 | ||
718 | } /* end of n_hdlc_tty_write() */ | |
719 | ||
720 | /** | |
721 | * n_hdlc_tty_ioctl - process IOCTL system call for the tty device. | |
722 | * @tty - pointer to tty instance data | |
723 | * @file - pointer to open file object for device | |
724 | * @cmd - IOCTL command code | |
725 | * @arg - argument for IOCTL call (cmd dependent) | |
726 | * | |
727 | * Returns command dependent result. | |
728 | */ | |
729 | static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file, | |
730 | unsigned int cmd, unsigned long arg) | |
731 | { | |
732 | struct n_hdlc *n_hdlc = tty2n_hdlc (tty); | |
733 | int error = 0; | |
734 | int count; | |
735 | unsigned long flags; | |
82f2341c AP |
736 | struct n_hdlc_buf *buf = NULL; |
737 | ||
1da177e4 LT |
738 | if (debuglevel >= DEBUG_LEVEL_INFO) |
739 | printk("%s(%d)n_hdlc_tty_ioctl() called %d\n", | |
740 | __FILE__,__LINE__,cmd); | |
741 | ||
742 | /* Verify the status of the device */ | |
743 | if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC) | |
744 | return -EBADF; | |
745 | ||
746 | switch (cmd) { | |
747 | case FIONREAD: | |
748 | /* report count of read data available */ | |
749 | /* in next available frame (if any) */ | |
750 | spin_lock_irqsave(&n_hdlc->rx_buf_list.spinlock,flags); | |
82f2341c AP |
751 | buf = list_first_entry_or_null(&n_hdlc->rx_buf_list.list, |
752 | struct n_hdlc_buf, list_item); | |
753 | if (buf) | |
754 | count = buf->count; | |
1da177e4 LT |
755 | else |
756 | count = 0; | |
757 | spin_unlock_irqrestore(&n_hdlc->rx_buf_list.spinlock,flags); | |
758 | error = put_user(count, (int __user *)arg); | |
759 | break; | |
760 | ||
761 | case TIOCOUTQ: | |
762 | /* get the pending tx byte count in the driver */ | |
f34d7a5b | 763 | count = tty_chars_in_buffer(tty); |
1da177e4 LT |
764 | /* add size of next output frame in queue */ |
765 | spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock,flags); | |
82f2341c AP |
766 | buf = list_first_entry_or_null(&n_hdlc->tx_buf_list.list, |
767 | struct n_hdlc_buf, list_item); | |
768 | if (buf) | |
769 | count += buf->count; | |
1da177e4 LT |
770 | spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock,flags); |
771 | error = put_user(count, (int __user *)arg); | |
772 | break; | |
773 | ||
be10eb75 PF |
774 | case TCFLSH: |
775 | switch (arg) { | |
776 | case TCIOFLUSH: | |
777 | case TCOFLUSH: | |
778 | flush_tx_queue(tty); | |
779 | } | |
361bf8a9 | 780 | /* fall through - to default */ |
be10eb75 | 781 | |
1da177e4 | 782 | default: |
47afa7a5 | 783 | error = n_tty_ioctl_helper(tty, file, cmd, arg); |
1da177e4 LT |
784 | break; |
785 | } | |
786 | return error; | |
787 | ||
788 | } /* end of n_hdlc_tty_ioctl() */ | |
789 | ||
790 | /** | |
791 | * n_hdlc_tty_poll - TTY callback for poll system call | |
792 | * @tty - pointer to tty instance data | |
793 | * @filp - pointer to open file object for device | |
794 | * @poll_table - wait queue for operations | |
795 | * | |
796 | * Determine which operations (read/write) will not block and return info | |
797 | * to caller. | |
798 | * Returns a bit mask containing info on which ops will not block. | |
799 | */ | |
afc9a42b | 800 | static __poll_t n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp, |
1da177e4 LT |
801 | poll_table *wait) |
802 | { | |
803 | struct n_hdlc *n_hdlc = tty2n_hdlc (tty); | |
afc9a42b | 804 | __poll_t mask = 0; |
1da177e4 LT |
805 | |
806 | if (debuglevel >= DEBUG_LEVEL_INFO) | |
807 | printk("%s(%d)n_hdlc_tty_poll() called\n",__FILE__,__LINE__); | |
808 | ||
809 | if (n_hdlc && n_hdlc->magic == HDLC_MAGIC && tty == n_hdlc->tty) { | |
810 | /* queue current process into any wait queue that */ | |
811 | /* may awaken in the future (read and write) */ | |
812 | ||
813 | poll_wait(filp, &tty->read_wait, wait); | |
814 | poll_wait(filp, &tty->write_wait, wait); | |
815 | ||
816 | /* set bits for operations that won't block */ | |
82f2341c | 817 | if (!list_empty(&n_hdlc->rx_buf_list.list)) |
a9a08845 | 818 | mask |= EPOLLIN | EPOLLRDNORM; /* readable */ |
0f40fbbc | 819 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) |
a9a08845 | 820 | mask |= EPOLLHUP; |
9c1729db | 821 | if (tty_hung_up_p(filp)) |
a9a08845 | 822 | mask |= EPOLLHUP; |
9c1729db | 823 | if (!tty_is_writelocked(tty) && |
82f2341c | 824 | !list_empty(&n_hdlc->tx_free_buf_list.list)) |
a9a08845 | 825 | mask |= EPOLLOUT | EPOLLWRNORM; /* writable */ |
1da177e4 LT |
826 | } |
827 | return mask; | |
828 | } /* end of n_hdlc_tty_poll() */ | |
829 | ||
830 | /** | |
831 | * n_hdlc_alloc - allocate an n_hdlc instance data structure | |
832 | * | |
833 | * Returns a pointer to newly created structure if success, otherwise %NULL | |
834 | */ | |
835 | static struct n_hdlc *n_hdlc_alloc(void) | |
836 | { | |
837 | struct n_hdlc_buf *buf; | |
838 | int i; | |
8e25f8ce | 839 | struct n_hdlc *n_hdlc = kzalloc(sizeof(*n_hdlc), GFP_KERNEL); |
1da177e4 LT |
840 | |
841 | if (!n_hdlc) | |
842 | return NULL; | |
843 | ||
e9b736d8 JS |
844 | spin_lock_init(&n_hdlc->rx_free_buf_list.spinlock); |
845 | spin_lock_init(&n_hdlc->tx_free_buf_list.spinlock); | |
846 | spin_lock_init(&n_hdlc->rx_buf_list.spinlock); | |
847 | spin_lock_init(&n_hdlc->tx_buf_list.spinlock); | |
82f2341c AP |
848 | |
849 | INIT_LIST_HEAD(&n_hdlc->rx_free_buf_list.list); | |
850 | INIT_LIST_HEAD(&n_hdlc->tx_free_buf_list.list); | |
851 | INIT_LIST_HEAD(&n_hdlc->rx_buf_list.list); | |
852 | INIT_LIST_HEAD(&n_hdlc->tx_buf_list.list); | |
853 | ||
1da177e4 LT |
854 | /* allocate free rx buffer list */ |
855 | for(i=0;i<DEFAULT_RX_BUF_COUNT;i++) { | |
856 | buf = kmalloc(N_HDLC_BUF_SIZE, GFP_KERNEL); | |
857 | if (buf) | |
858 | n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,buf); | |
859 | else if (debuglevel >= DEBUG_LEVEL_INFO) | |
860 | printk("%s(%d)n_hdlc_alloc(), kalloc() failed for rx buffer %d\n",__FILE__,__LINE__, i); | |
861 | } | |
862 | ||
863 | /* allocate free tx buffer list */ | |
864 | for(i=0;i<DEFAULT_TX_BUF_COUNT;i++) { | |
865 | buf = kmalloc(N_HDLC_BUF_SIZE, GFP_KERNEL); | |
866 | if (buf) | |
867 | n_hdlc_buf_put(&n_hdlc->tx_free_buf_list,buf); | |
868 | else if (debuglevel >= DEBUG_LEVEL_INFO) | |
869 | printk("%s(%d)n_hdlc_alloc(), kalloc() failed for tx buffer %d\n",__FILE__,__LINE__, i); | |
870 | } | |
871 | ||
872 | /* Initialize the control block */ | |
873 | n_hdlc->magic = HDLC_MAGIC; | |
874 | n_hdlc->flags = 0; | |
875 | ||
876 | return n_hdlc; | |
877 | ||
878 | } /* end of n_hdlc_alloc() */ | |
879 | ||
82f2341c AP |
880 | /** |
881 | * n_hdlc_buf_return - put the HDLC buffer after the head of the specified list | |
882 | * @buf_list - pointer to the buffer list | |
883 | * @buf - pointer to the buffer | |
884 | */ | |
885 | static void n_hdlc_buf_return(struct n_hdlc_buf_list *buf_list, | |
886 | struct n_hdlc_buf *buf) | |
887 | { | |
888 | unsigned long flags; | |
889 | ||
890 | spin_lock_irqsave(&buf_list->spinlock, flags); | |
891 | ||
892 | list_add(&buf->list_item, &buf_list->list); | |
893 | buf_list->count++; | |
894 | ||
895 | spin_unlock_irqrestore(&buf_list->spinlock, flags); | |
896 | } | |
897 | ||
1da177e4 LT |
898 | /** |
899 | * n_hdlc_buf_put - add specified HDLC buffer to tail of specified list | |
82f2341c | 900 | * @buf_list - pointer to buffer list |
1da177e4 LT |
901 | * @buf - pointer to buffer |
902 | */ | |
82f2341c | 903 | static void n_hdlc_buf_put(struct n_hdlc_buf_list *buf_list, |
1da177e4 LT |
904 | struct n_hdlc_buf *buf) |
905 | { | |
906 | unsigned long flags; | |
82f2341c AP |
907 | |
908 | spin_lock_irqsave(&buf_list->spinlock, flags); | |
909 | ||
910 | list_add_tail(&buf->list_item, &buf_list->list); | |
911 | buf_list->count++; | |
912 | ||
913 | spin_unlock_irqrestore(&buf_list->spinlock, flags); | |
1da177e4 LT |
914 | } /* end of n_hdlc_buf_put() */ |
915 | ||
916 | /** | |
917 | * n_hdlc_buf_get - remove and return an HDLC buffer from list | |
82f2341c | 918 | * @buf_list - pointer to HDLC buffer list |
1da177e4 LT |
919 | * |
920 | * Remove and return an HDLC buffer from the head of the specified HDLC buffer | |
921 | * list. | |
922 | * Returns a pointer to HDLC buffer if available, otherwise %NULL. | |
923 | */ | |
82f2341c | 924 | static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *buf_list) |
1da177e4 LT |
925 | { |
926 | unsigned long flags; | |
927 | struct n_hdlc_buf *buf; | |
82f2341c AP |
928 | |
929 | spin_lock_irqsave(&buf_list->spinlock, flags); | |
930 | ||
931 | buf = list_first_entry_or_null(&buf_list->list, | |
932 | struct n_hdlc_buf, list_item); | |
1da177e4 | 933 | if (buf) { |
82f2341c AP |
934 | list_del(&buf->list_item); |
935 | buf_list->count--; | |
1da177e4 | 936 | } |
82f2341c AP |
937 | |
938 | spin_unlock_irqrestore(&buf_list->spinlock, flags); | |
1da177e4 | 939 | return buf; |
1da177e4 LT |
940 | } /* end of n_hdlc_buf_get() */ |
941 | ||
06324664 | 942 | static const char hdlc_banner[] __initconst = |
be10eb75 | 943 | KERN_INFO "HDLC line discipline maxframe=%u\n"; |
06324664 | 944 | static const char hdlc_register_ok[] __initconst = |
1da177e4 | 945 | KERN_INFO "N_HDLC line discipline registered.\n"; |
06324664 | 946 | static const char hdlc_register_fail[] __initconst = |
1da177e4 | 947 | KERN_ERR "error registering line discipline: %d\n"; |
1da177e4 LT |
948 | |
949 | static int __init n_hdlc_init(void) | |
950 | { | |
951 | int status; | |
952 | ||
953 | /* range check maxframe arg */ | |
954 | if (maxframe < 4096) | |
955 | maxframe = 4096; | |
956 | else if (maxframe > 65535) | |
957 | maxframe = 65535; | |
958 | ||
959 | printk(hdlc_banner, maxframe); | |
960 | ||
961 | status = tty_register_ldisc(N_HDLC, &n_hdlc_ldisc); | |
962 | if (!status) | |
963 | printk(hdlc_register_ok); | |
964 | else | |
965 | printk(hdlc_register_fail, status); | |
966 | ||
1da177e4 LT |
967 | return status; |
968 | ||
969 | } /* end of init_module() */ | |
970 | ||
47a7e5e9 RD |
971 | #ifdef CONFIG_SPARC |
972 | #undef __exitdata | |
973 | #define __exitdata | |
974 | #endif | |
975 | ||
06324664 | 976 | static const char hdlc_unregister_ok[] __exitdata = |
1da177e4 | 977 | KERN_INFO "N_HDLC: line discipline unregistered\n"; |
06324664 | 978 | static const char hdlc_unregister_fail[] __exitdata = |
1da177e4 LT |
979 | KERN_ERR "N_HDLC: can't unregister line discipline (err = %d)\n"; |
980 | ||
981 | static void __exit n_hdlc_exit(void) | |
982 | { | |
983 | /* Release tty registration of line discipline */ | |
64ccd715 | 984 | int status = tty_unregister_ldisc(N_HDLC); |
1da177e4 LT |
985 | |
986 | if (status) | |
987 | printk(hdlc_unregister_fail, status); | |
988 | else | |
989 | printk(hdlc_unregister_ok); | |
990 | } | |
991 | ||
992 | module_init(n_hdlc_init); | |
993 | module_exit(n_hdlc_exit); | |
994 | ||
995 | MODULE_LICENSE("GPL"); | |
996 | MODULE_AUTHOR("Paul Fulghum paulkf@microgate.com"); | |
997 | module_param(debuglevel, int, 0); | |
998 | module_param(maxframe, int, 0); | |
999 | MODULE_ALIAS_LDISC(N_HDLC); |