1 /*
2 * slcan.c - serial line CAN interface driver (using tty line discipline)
3 *
4 * This file is derived from linux/drivers/net/slip/slip.c
5 *
6 * slip.c Authors : Laurence Culhane <loz@holmes.demon.co.uk>
7 * Fred N. van Kempen <waltje@uwalt.nl.mugnet.org>
8 * slcan.c Author : Oliver Hartkopp <socketcan@hartkopp.net>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 59 Temple Place, Suite 330, Boston, MA 02111-1307. You can also get it
23 * at http://www.gnu.org/licenses/gpl.html
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
36 * DAMAGE.
37 *
38 */
39
40 #include <linux/module.h>
41 #include <linux/moduleparam.h>
42
43 #include <linux/uaccess.h>
44 #include <linux/bitops.h>
45 #include <linux/string.h>
46 #include <linux/tty.h>
47 #include <linux/errno.h>
48 #include <linux/netdevice.h>
49 #include <linux/skbuff.h>
50 #include <linux/rtnetlink.h>
51 #include <linux/if_arp.h>
52 #include <linux/if_ether.h>
53 #include <linux/sched.h>
54 #include <linux/delay.h>
55 #include <linux/init.h>
56 #include <linux/kernel.h>
57 #include <linux/can.h>
58
59 static __initdata const char banner[] =
60 KERN_INFO "slcan: serial line CAN interface driver\n";
61
62 MODULE_ALIAS_LDISC(N_SLCAN);
63 MODULE_DESCRIPTION("serial line CAN interface");
64 MODULE_LICENSE("GPL");
65 MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
66
67 #define SLCAN_MAGIC 0x53CA
68
69 static int maxdev = 10; /* MAX number of SLCAN channels;
70 This can be overridden with
71 insmod slcan.ko maxdev=nnn */
72 module_param(maxdev, int, 0);
73 MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces");
74
75 /* maximum rx buffer len: extended CAN frame with timestamp */
76 #define SLC_MTU (sizeof("T1111222281122334455667788EA5F\r")+1)
77
78 struct slcan {
79 int magic;
80
81 /* Various fields. */
82 struct tty_struct *tty; /* ptr to TTY structure */
83 struct net_device *dev; /* easy for intr handling */
84 spinlock_t lock;
85
86 /* These are pointers to the malloc()ed frame buffers. */
87 unsigned char rbuff[SLC_MTU]; /* receiver buffer */
88 int rcount; /* received chars counter */
89 unsigned char xbuff[SLC_MTU]; /* transmitter buffer */
90 unsigned char *xhead; /* pointer to next XMIT byte */
91 int xleft; /* bytes left in XMIT queue */
92
93 unsigned long flags; /* Flag values/ mode etc */
94 #define SLF_INUSE 0 /* Channel in use */
95 #define SLF_ERROR 1 /* Parity, etc. error */
96 };
97
98 static struct net_device **slcan_devs;
99
100 /************************************************************************
101 * SLCAN ENCAPSULATION FORMAT *
102 ************************************************************************/
103
104 /*
105 * A CAN frame has a can_id (11 bit standard frame format OR 29 bit extended
106 * frame format) a data length code (can_dlc) which can be from 0 to 8
107 * and up to <can_dlc> data bytes as payload.
108 * Additionally a CAN frame may become a remote transmission frame if the
109 * RTR-bit is set. This causes another ECU to send a CAN frame with the
110 * given can_id.
111 *
112 * The SLCAN ASCII representation of these different frame types is:
113 * <type> <id> <dlc> <data>*
114 *
115 * Extended frames (29 bit) are defined by capital characters in the type.
116 * RTR frames are defined as 'r' types - normal frames have 't' type:
117 * t => 11 bit data frame
118 * r => 11 bit RTR frame
119 * T => 29 bit data frame
120 * R => 29 bit RTR frame
121 *
122 * The <id> is 3 (standard) or 8 (extended) bytes in ASCII Hex (base64).
123 * The <dlc> is a one byte ASCII number ('0' - '8')
124 * The <data> section has at much ASCII Hex bytes as defined by the <dlc>
125 *
126 * Examples:
127 *
128 * t1230 : can_id 0x123, can_dlc 0, no data
129 * t4563112233 : can_id 0x456, can_dlc 3, data 0x11 0x22 0x33
130 * T12ABCDEF2AA55 : extended can_id 0x12ABCDEF, can_dlc 2, data 0xAA 0x55
131 * r1230 : can_id 0x123, can_dlc 0, no data, remote transmission request
132 *
133 */
134
135 /************************************************************************
136 * STANDARD SLCAN DECAPSULATION *
137 ************************************************************************/
138
139 /* Send one completely decapsulated can_frame to the network layer */
slc_bump(struct slcan * sl)140 static void slc_bump(struct slcan *sl)
141 {
142 struct sk_buff *skb;
143 struct can_frame cf;
144 int i, dlc_pos, tmp;
145 unsigned long ultmp;
146 char cmd = sl->rbuff[0];
147
148 if ((cmd != 't') && (cmd != 'T') && (cmd != 'r') && (cmd != 'R'))
149 return;
150
151 if (cmd & 0x20) /* tiny chars 'r' 't' => standard frame format */
152 dlc_pos = 4; /* dlc position tiiid */
153 else
154 dlc_pos = 9; /* dlc position Tiiiiiiiid */
155
156 if (!((sl->rbuff[dlc_pos] >= '0') && (sl->rbuff[dlc_pos] < '9')))
157 return;
158
159 cf.can_dlc = sl->rbuff[dlc_pos] - '0'; /* get can_dlc from ASCII val */
160
161 sl->rbuff[dlc_pos] = 0; /* terminate can_id string */
162
163 if (strict_strtoul(sl->rbuff+1, 16, &ultmp))
164 return;
165
166 cf.can_id = ultmp;
167
168 if (!(cmd & 0x20)) /* NO tiny chars => extended frame format */
169 cf.can_id |= CAN_EFF_FLAG;
170
171 if ((cmd | 0x20) == 'r') /* RTR frame */
172 cf.can_id |= CAN_RTR_FLAG;
173
174 *(u64 *) (&cf.data) = 0; /* clear payload */
175
176 for (i = 0, dlc_pos++; i < cf.can_dlc; i++) {
177 tmp = hex_to_bin(sl->rbuff[dlc_pos++]);
178 if (tmp < 0)
179 return;
180 cf.data[i] = (tmp << 4);
181 tmp = hex_to_bin(sl->rbuff[dlc_pos++]);
182 if (tmp < 0)
183 return;
184 cf.data[i] |= tmp;
185 }
186
187 skb = dev_alloc_skb(sizeof(struct can_frame));
188 if (!skb)
189 return;
190
191 skb->dev = sl->dev;
192 skb->protocol = htons(ETH_P_CAN);
193 skb->pkt_type = PACKET_BROADCAST;
194 skb->ip_summed = CHECKSUM_UNNECESSARY;
195 memcpy(skb_put(skb, sizeof(struct can_frame)),
196 &cf, sizeof(struct can_frame));
197 netif_rx_ni(skb);
198
199 sl->dev->stats.rx_packets++;
200 sl->dev->stats.rx_bytes += cf.can_dlc;
201 }
202
203 /* parse tty input stream */
slcan_unesc(struct slcan * sl,unsigned char s)204 static void slcan_unesc(struct slcan *sl, unsigned char s)
205 {
206
207 if ((s == '\r') || (s == '\a')) { /* CR or BEL ends the pdu */
208 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
209 (sl->rcount > 4)) {
210 slc_bump(sl);
211 }
212 sl->rcount = 0;
213 } else {
214 if (!test_bit(SLF_ERROR, &sl->flags)) {
215 if (sl->rcount < SLC_MTU) {
216 sl->rbuff[sl->rcount++] = s;
217 return;
218 } else {
219 sl->dev->stats.rx_over_errors++;
220 set_bit(SLF_ERROR, &sl->flags);
221 }
222 }
223 }
224 }
225
226 /************************************************************************
227 * STANDARD SLCAN ENCAPSULATION *
228 ************************************************************************/
229
230 /* Encapsulate one can_frame and stuff into a TTY queue. */
slc_encaps(struct slcan * sl,struct can_frame * cf)231 static void slc_encaps(struct slcan *sl, struct can_frame *cf)
232 {
233 int actual, idx, i;
234 char cmd;
235
236 if (cf->can_id & CAN_RTR_FLAG)
237 cmd = 'R'; /* becomes 'r' in standard frame format */
238 else
239 cmd = 'T'; /* becomes 't' in standard frame format */
240
241 if (cf->can_id & CAN_EFF_FLAG)
242 sprintf(sl->xbuff, "%c%08X%d", cmd,
243 cf->can_id & CAN_EFF_MASK, cf->can_dlc);
244 else
245 sprintf(sl->xbuff, "%c%03X%d", cmd | 0x20,
246 cf->can_id & CAN_SFF_MASK, cf->can_dlc);
247
248 idx = strlen(sl->xbuff);
249
250 for (i = 0; i < cf->can_dlc; i++)
251 sprintf(&sl->xbuff[idx + 2*i], "%02X", cf->data[i]);
252
253 strcat(sl->xbuff, "\r"); /* add terminating character */
254
255 /* Order of next two lines is *very* important.
256 * When we are sending a little amount of data,
257 * the transfer may be completed inside the ops->write()
258 * routine, because it's running with interrupts enabled.
259 * In this case we *never* got WRITE_WAKEUP event,
260 * if we did not request it before write operation.
261 * 14 Oct 1994 Dmitry Gorodchanin.
262 */
263 set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
264 actual = sl->tty->ops->write(sl->tty, sl->xbuff, strlen(sl->xbuff));
265 sl->xleft = strlen(sl->xbuff) - actual;
266 sl->xhead = sl->xbuff + actual;
267 sl->dev->stats.tx_bytes += cf->can_dlc;
268 }
269
270 /*
271 * Called by the driver when there's room for more data. If we have
272 * more packets to send, we send them here.
273 */
slcan_write_wakeup(struct tty_struct * tty)274 static void slcan_write_wakeup(struct tty_struct *tty)
275 {
276 int actual;
277 struct slcan *sl = (struct slcan *) tty->disc_data;
278
279 /* First make sure we're connected. */
280 if (!sl || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev))
281 return;
282
283 if (sl->xleft <= 0) {
284 /* Now serial buffer is almost free & we can start
285 * transmission of another packet */
286 sl->dev->stats.tx_packets++;
287 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
288 netif_wake_queue(sl->dev);
289 return;
290 }
291
292 actual = tty->ops->write(tty, sl->xhead, sl->xleft);
293 sl->xleft -= actual;
294 sl->xhead += actual;
295 }
296
297 /* Send a can_frame to a TTY queue. */
slc_xmit(struct sk_buff * skb,struct net_device * dev)298 static netdev_tx_t slc_xmit(struct sk_buff *skb, struct net_device *dev)
299 {
300 struct slcan *sl = netdev_priv(dev);
301
302 if (skb->len != sizeof(struct can_frame))
303 goto out;
304
305 spin_lock(&sl->lock);
306 if (!netif_running(dev)) {
307 spin_unlock(&sl->lock);
308 printk(KERN_WARNING "%s: xmit: iface is down\n", dev->name);
309 goto out;
310 }
311 if (sl->tty == NULL) {
312 spin_unlock(&sl->lock);
313 goto out;
314 }
315
316 netif_stop_queue(sl->dev);
317 slc_encaps(sl, (struct can_frame *) skb->data); /* encaps & send */
318 spin_unlock(&sl->lock);
319
320 out:
321 kfree_skb(skb);
322 return NETDEV_TX_OK;
323 }
324
325
326 /******************************************
327 * Routines looking at netdevice side.
328 ******************************************/
329
330 /* Netdevice UP -> DOWN routine */
slc_close(struct net_device * dev)331 static int slc_close(struct net_device *dev)
332 {
333 struct slcan *sl = netdev_priv(dev);
334
335 spin_lock_bh(&sl->lock);
336 if (sl->tty) {
337 /* TTY discipline is running. */
338 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
339 }
340 netif_stop_queue(dev);
341 sl->rcount = 0;
342 sl->xleft = 0;
343 spin_unlock_bh(&sl->lock);
344
345 return 0;
346 }
347
348 /* Netdevice DOWN -> UP routine */
slc_open(struct net_device * dev)349 static int slc_open(struct net_device *dev)
350 {
351 struct slcan *sl = netdev_priv(dev);
352
353 if (sl->tty == NULL)
354 return -ENODEV;
355
356 sl->flags &= (1 << SLF_INUSE);
357 netif_start_queue(dev);
358 return 0;
359 }
360
361 /* Hook the destructor so we can free slcan devs at the right point in time */
slc_free_netdev(struct net_device * dev)362 static void slc_free_netdev(struct net_device *dev)
363 {
364 int i = dev->base_addr;
365 free_netdev(dev);
366 slcan_devs[i] = NULL;
367 }
368
369 static const struct net_device_ops slc_netdev_ops = {
370 .ndo_open = slc_open,
371 .ndo_stop = slc_close,
372 .ndo_start_xmit = slc_xmit,
373 };
374
slc_setup(struct net_device * dev)375 static void slc_setup(struct net_device *dev)
376 {
377 dev->netdev_ops = &slc_netdev_ops;
378 dev->destructor = slc_free_netdev;
379
380 dev->hard_header_len = 0;
381 dev->addr_len = 0;
382 dev->tx_queue_len = 10;
383
384 dev->mtu = sizeof(struct can_frame);
385 dev->type = ARPHRD_CAN;
386
387 /* New-style flags. */
388 dev->flags = IFF_NOARP;
389 dev->features = NETIF_F_HW_CSUM;
390 }
391
392 /******************************************
393 Routines looking at TTY side.
394 ******************************************/
395
396 /*
397 * Handle the 'receiver data ready' interrupt.
398 * This function is called by the 'tty_io' module in the kernel when
399 * a block of SLCAN data has been received, which can now be decapsulated
400 * and sent on to some IP layer for further processing. This will not
401 * be re-entered while running but other ldisc functions may be called
402 * in parallel
403 */
404
slcan_receive_buf(struct tty_struct * tty,const unsigned char * cp,char * fp,int count)405 static void slcan_receive_buf(struct tty_struct *tty,
406 const unsigned char *cp, char *fp, int count)
407 {
408 struct slcan *sl = (struct slcan *) tty->disc_data;
409
410 if (!sl || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev))
411 return;
412
413 /* Read the characters out of the buffer */
414 while (count--) {
415 if (fp && *fp++) {
416 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
417 sl->dev->stats.rx_errors++;
418 cp++;
419 continue;
420 }
421 slcan_unesc(sl, *cp++);
422 }
423 }
424
425 /************************************
426 * slcan_open helper routines.
427 ************************************/
428
429 /* Collect hanged up channels */
slc_sync(void)430 static void slc_sync(void)
431 {
432 int i;
433 struct net_device *dev;
434 struct slcan *sl;
435
436 for (i = 0; i < maxdev; i++) {
437 dev = slcan_devs[i];
438 if (dev == NULL)
439 break;
440
441 sl = netdev_priv(dev);
442 if (sl->tty)
443 continue;
444 if (dev->flags & IFF_UP)
445 dev_close(dev);
446 }
447 }
448
449 /* Find a free SLCAN channel, and link in this `tty' line. */
slc_alloc(dev_t line)450 static struct slcan *slc_alloc(dev_t line)
451 {
452 int i;
453 char name[IFNAMSIZ];
454 struct net_device *dev = NULL;
455 struct slcan *sl;
456
457 for (i = 0; i < maxdev; i++) {
458 dev = slcan_devs[i];
459 if (dev == NULL)
460 break;
461
462 }
463
464 /* Sorry, too many, all slots in use */
465 if (i >= maxdev)
466 return NULL;
467
468 sprintf(name, "slcan%d", i);
469 dev = alloc_netdev(sizeof(*sl), name, slc_setup);
470 if (!dev)
471 return NULL;
472
473 dev->base_addr = i;
474 sl = netdev_priv(dev);
475
476 /* Initialize channel control data */
477 sl->magic = SLCAN_MAGIC;
478 sl->dev = dev;
479 spin_lock_init(&sl->lock);
480 slcan_devs[i] = dev;
481
482 return sl;
483 }
484
485 /*
486 * Open the high-level part of the SLCAN channel.
487 * This function is called by the TTY module when the
488 * SLCAN line discipline is called for. Because we are
489 * sure the tty line exists, we only have to link it to
490 * a free SLCAN channel...
491 *
492 * Called in process context serialized from other ldisc calls.
493 */
494
slcan_open(struct tty_struct * tty)495 static int slcan_open(struct tty_struct *tty)
496 {
497 struct slcan *sl;
498 int err;
499
500 if (!capable(CAP_NET_ADMIN))
501 return -EPERM;
502
503 if (tty->ops->write == NULL)
504 return -EOPNOTSUPP;
505
506 /* RTnetlink lock is misused here to serialize concurrent
507 opens of slcan channels. There are better ways, but it is
508 the simplest one.
509 */
510 rtnl_lock();
511
512 /* Collect hanged up channels. */
513 slc_sync();
514
515 sl = tty->disc_data;
516
517 err = -EEXIST;
518 /* First make sure we're not already connected. */
519 if (sl && sl->magic == SLCAN_MAGIC)
520 goto err_exit;
521
522 /* OK. Find a free SLCAN channel to use. */
523 err = -ENFILE;
524 sl = slc_alloc(tty_devnum(tty));
525 if (sl == NULL)
526 goto err_exit;
527
528 sl->tty = tty;
529 tty->disc_data = sl;
530
531 if (!test_bit(SLF_INUSE, &sl->flags)) {
532 /* Perform the low-level SLCAN initialization. */
533 sl->rcount = 0;
534 sl->xleft = 0;
535
536 set_bit(SLF_INUSE, &sl->flags);
537
538 err = register_netdevice(sl->dev);
539 if (err)
540 goto err_free_chan;
541 }
542
543 /* Done. We have linked the TTY line to a channel. */
544 rtnl_unlock();
545 tty->receive_room = 65536; /* We don't flow control */
546
547 /* TTY layer expects 0 on success */
548 return 0;
549
550 err_free_chan:
551 sl->tty = NULL;
552 tty->disc_data = NULL;
553 clear_bit(SLF_INUSE, &sl->flags);
554
555 err_exit:
556 rtnl_unlock();
557
558 /* Count references from TTY module */
559 return err;
560 }
561
562 /*
563 * Close down a SLCAN channel.
564 * This means flushing out any pending queues, and then returning. This
565 * call is serialized against other ldisc functions.
566 *
567 * We also use this method for a hangup event.
568 */
569
slcan_close(struct tty_struct * tty)570 static void slcan_close(struct tty_struct *tty)
571 {
572 struct slcan *sl = (struct slcan *) tty->disc_data;
573
574 /* First make sure we're connected. */
575 if (!sl || sl->magic != SLCAN_MAGIC || sl->tty != tty)
576 return;
577
578 tty->disc_data = NULL;
579 sl->tty = NULL;
580
581 /* Flush network side */
582 unregister_netdev(sl->dev);
583 /* This will complete via sl_free_netdev */
584 }
585
slcan_hangup(struct tty_struct * tty)586 static int slcan_hangup(struct tty_struct *tty)
587 {
588 slcan_close(tty);
589 return 0;
590 }
591
592 /* Perform I/O control on an active SLCAN channel. */
slcan_ioctl(struct tty_struct * tty,struct file * file,unsigned int cmd,unsigned long arg)593 static int slcan_ioctl(struct tty_struct *tty, struct file *file,
594 unsigned int cmd, unsigned long arg)
595 {
596 struct slcan *sl = (struct slcan *) tty->disc_data;
597 unsigned int tmp;
598
599 /* First make sure we're connected. */
600 if (!sl || sl->magic != SLCAN_MAGIC)
601 return -EINVAL;
602
603 switch (cmd) {
604 case SIOCGIFNAME:
605 tmp = strlen(sl->dev->name) + 1;
606 if (copy_to_user((void __user *)arg, sl->dev->name, tmp))
607 return -EFAULT;
608 return 0;
609
610 case SIOCSIFHWADDR:
611 return -EINVAL;
612
613 default:
614 return tty_mode_ioctl(tty, file, cmd, arg);
615 }
616 }
617
618 static struct tty_ldisc_ops slc_ldisc = {
619 .owner = THIS_MODULE,
620 .magic = TTY_LDISC_MAGIC,
621 .name = "slcan",
622 .open = slcan_open,
623 .close = slcan_close,
624 .hangup = slcan_hangup,
625 .ioctl = slcan_ioctl,
626 .receive_buf = slcan_receive_buf,
627 .write_wakeup = slcan_write_wakeup,
628 };
629
slcan_init(void)630 static int __init slcan_init(void)
631 {
632 int status;
633
634 if (maxdev < 4)
635 maxdev = 4; /* Sanity */
636
637 printk(banner);
638 printk(KERN_INFO "slcan: %d dynamic interface channels.\n", maxdev);
639
640 slcan_devs = kzalloc(sizeof(struct net_device *)*maxdev, GFP_KERNEL);
641 if (!slcan_devs)
642 return -ENOMEM;
643
644 /* Fill in our line protocol discipline, and register it */
645 status = tty_register_ldisc(N_SLCAN, &slc_ldisc);
646 if (status) {
647 printk(KERN_ERR "slcan: can't register line discipline\n");
648 kfree(slcan_devs);
649 }
650 return status;
651 }
652
slcan_exit(void)653 static void __exit slcan_exit(void)
654 {
655 int i;
656 struct net_device *dev;
657 struct slcan *sl;
658 unsigned long timeout = jiffies + HZ;
659 int busy = 0;
660
661 if (slcan_devs == NULL)
662 return;
663
664 /* First of all: check for active disciplines and hangup them.
665 */
666 do {
667 if (busy)
668 msleep_interruptible(100);
669
670 busy = 0;
671 for (i = 0; i < maxdev; i++) {
672 dev = slcan_devs[i];
673 if (!dev)
674 continue;
675 sl = netdev_priv(dev);
676 spin_lock_bh(&sl->lock);
677 if (sl->tty) {
678 busy++;
679 tty_hangup(sl->tty);
680 }
681 spin_unlock_bh(&sl->lock);
682 }
683 } while (busy && time_before(jiffies, timeout));
684
685 /* FIXME: hangup is async so we should wait when doing this second
686 phase */
687
688 for (i = 0; i < maxdev; i++) {
689 dev = slcan_devs[i];
690 if (!dev)
691 continue;
692 slcan_devs[i] = NULL;
693
694 sl = netdev_priv(dev);
695 if (sl->tty) {
696 printk(KERN_ERR "%s: tty discipline still running\n",
697 dev->name);
698 /* Intentionally leak the control block. */
699 dev->destructor = NULL;
700 }
701
702 unregister_netdev(dev);
703 }
704
705 kfree(slcan_devs);
706 slcan_devs = NULL;
707
708 i = tty_unregister_ldisc(N_SLCAN);
709 if (i)
710 printk(KERN_ERR "slcan: can't unregister ldisc (err %d)\n", i);
711 }
712
713 module_init(slcan_init);
714 module_exit(slcan_exit);
715