blob: 86cbb9ea2f269ee2532078dea529eebdb8cc0a9f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * slip.c This module implements the SLIP protocol for kernel-based
3 * devices like TTY. It interfaces between a raw TTY, and the
4 * kernel's INET protocol layers.
5 *
6 * Version: @(#)slip.c 0.8.3 12/24/94
7 *
8 * Authors: Laurence Culhane, <loz@holmes.demon.co.uk>
9 * Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
10 *
11 * Fixes:
12 * Alan Cox : Sanity checks and avoid tx overruns.
13 * Has a new sl->mtu field.
Alan Cox9ce6cf22007-11-19 15:03:38 +000014 * Alan Cox : Found cause of overrun. ifconfig sl0
15 * mtu upwards. Driver now spots this
16 * and grows/shrinks its buffers(hack!).
17 * Memory leak if you run out of memory
18 * setting up a slip driver fixed.
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * Matt Dillon : Printable slip (borrowed from NET2E)
20 * Pauline Middelink : Slip driver fixes.
21 * Alan Cox : Honours the old SL_COMPRESSED flag
22 * Alan Cox : KISS AX.25 and AXUI IP support
23 * Michael Riepe : Automatic CSLIP recognition added
24 * Charles Hedrick : CSLIP header length problem fix.
25 * Alan Cox : Corrected non-IP cases of the above.
26 * Alan Cox : Now uses hardware type as per FvK.
27 * Alan Cox : Default to 192.168.0.0 (RFC 1597)
28 * A.N.Kuznetsov : dev_tint() recursion fix.
29 * Dmitry Gorodchanin : SLIP memory leaks
30 * Dmitry Gorodchanin : Code cleanup. Reduce tty driver
31 * buffering from 4096 to 256 bytes.
32 * Improving SLIP response time.
33 * CONFIG_SLIP_MODE_SLIP6.
Alan Cox9ce6cf22007-11-19 15:03:38 +000034 * ifconfig sl? up & down now works
35 * correctly.
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 * Modularization.
37 * Alan Cox : Oops - fix AX.25 buffer lengths
38 * Dmitry Gorodchanin : Even more cleanups. Preserve CSLIP
39 * statistics. Include CSLIP code only
40 * if it really needed.
41 * Alan Cox : Free slhc buffers in the right place.
42 * Alan Cox : Allow for digipeated IP over AX.25
43 * Matti Aarnio : Dynamic SLIP devices, with ideas taken
44 * from Jim Freeman's <jfree@caldera.com>
45 * dynamic PPP devices. We do NOT kfree()
46 * device entries, just reg./unreg. them
47 * as they are needed. We kfree() them
48 * at module cleanup.
Alan Cox9ce6cf22007-11-19 15:03:38 +000049 * With MODULE-loading ``insmod'', user
50 * can issue parameter: slip_maxdev=1024
51 * (Or how much he/she wants.. Default
52 * is 256)
53 * Stanislav Voronyi : Slip line checking, with ideas taken
54 * from multislip BSDI driver which was
55 * written by Igor Chechik, RELCOM Corp.
56 * Only algorithms have been ported to
57 * Linux SLIP driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 * Vitaly E. Lavrov : Sane behaviour on tty hangup.
Alan Cox9ce6cf22007-11-19 15:03:38 +000059 * Alexey Kuznetsov : Cleanup interfaces to tty & netdevice
60 * modules.
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 */
62
63#define SL_CHECK_TRANSMIT
Linus Torvalds1da177e2005-04-16 15:20:36 -070064#include <linux/module.h>
65#include <linux/moduleparam.h>
66
67#include <asm/system.h>
68#include <asm/uaccess.h>
69#include <linux/bitops.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040070#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070071#include <linux/string.h>
72#include <linux/mm.h>
73#include <linux/interrupt.h>
74#include <linux/in.h>
75#include <linux/tty.h>
76#include <linux/errno.h>
77#include <linux/netdevice.h>
78#include <linux/etherdevice.h>
79#include <linux/skbuff.h>
80#include <linux/rtnetlink.h>
81#include <linux/if_arp.h>
82#include <linux/if_slip.h>
Arnd Bergmann9646e7c2009-11-06 22:51:16 -080083#include <linux/compat.h>
David S. Miller12dc2fd2005-06-28 16:27:32 -070084#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070085#include <linux/init.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090086#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070087#include "slip.h"
88#ifdef CONFIG_INET
89#include <linux/ip.h>
90#include <linux/tcp.h>
91#include <net/slhc_vj.h>
92#endif
93
94#define SLIP_VERSION "0.8.4-NET3.019-NEWTTY"
95
96static struct net_device **slip_devs;
97
98static int slip_maxdev = SL_NRUNIT;
99module_param(slip_maxdev, int, 0);
100MODULE_PARM_DESC(slip_maxdev, "Maximum number of slip devices");
101
102static int slip_esc(unsigned char *p, unsigned char *d, int len);
103static void slip_unesc(struct slip *sl, unsigned char c);
104#ifdef CONFIG_SLIP_MODE_SLIP6
105static int slip_esc6(unsigned char *p, unsigned char *d, int len);
106static void slip_unesc6(struct slip *sl, unsigned char c);
107#endif
108#ifdef CONFIG_SLIP_SMART
109static void sl_keepalive(unsigned long sls);
110static void sl_outfill(unsigned long sls);
Alan Cox9ce6cf22007-11-19 15:03:38 +0000111static int sl_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112#endif
113
114/********************************
115* Buffer administration routines:
116* sl_alloc_bufs()
117* sl_free_bufs()
118* sl_realloc_bufs()
119*
120* NOTE: sl_realloc_bufs != sl_free_bufs + sl_alloc_bufs, because
121* sl_realloc_bufs provides strong atomicity and reallocation
122* on actively running device.
123*********************************/
124
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400125/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 Allocate channel buffers.
127 */
128
Alan Cox9ce6cf22007-11-19 15:03:38 +0000129static int sl_alloc_bufs(struct slip *sl, int mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130{
131 int err = -ENOBUFS;
132 unsigned long len;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000133 char *rbuff = NULL;
134 char *xbuff = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135#ifdef SL_INCLUDE_CSLIP
Alan Cox9ce6cf22007-11-19 15:03:38 +0000136 char *cbuff = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 struct slcompress *slcomp = NULL;
138#endif
139
140 /*
141 * Allocate the SLIP frame buffers:
142 *
143 * rbuff Receive buffer.
144 * xbuff Transmit buffer.
145 * cbuff Temporary compression buffer.
146 */
147 len = mtu * 2;
148
149 /*
150 * allow for arrival of larger UDP packets, even if we say not to
151 * also fixes a bug in which SunOS sends 512-byte packets even with
152 * an MSS of 128
153 */
154 if (len < 576 * 2)
155 len = 576 * 2;
156 rbuff = kmalloc(len + 4, GFP_KERNEL);
157 if (rbuff == NULL)
158 goto err_exit;
159 xbuff = kmalloc(len + 4, GFP_KERNEL);
160 if (xbuff == NULL)
161 goto err_exit;
162#ifdef SL_INCLUDE_CSLIP
163 cbuff = kmalloc(len + 4, GFP_KERNEL);
164 if (cbuff == NULL)
165 goto err_exit;
166 slcomp = slhc_init(16, 16);
167 if (slcomp == NULL)
168 goto err_exit;
169#endif
170 spin_lock_bh(&sl->lock);
171 if (sl->tty == NULL) {
172 spin_unlock_bh(&sl->lock);
173 err = -ENODEV;
174 goto err_exit;
175 }
176 sl->mtu = mtu;
177 sl->buffsize = len;
178 sl->rcount = 0;
179 sl->xleft = 0;
180 rbuff = xchg(&sl->rbuff, rbuff);
181 xbuff = xchg(&sl->xbuff, xbuff);
182#ifdef SL_INCLUDE_CSLIP
183 cbuff = xchg(&sl->cbuff, cbuff);
184 slcomp = xchg(&sl->slcomp, slcomp);
185#ifdef CONFIG_SLIP_MODE_SLIP6
186 sl->xdata = 0;
187 sl->xbits = 0;
188#endif
189#endif
190 spin_unlock_bh(&sl->lock);
191 err = 0;
192
193 /* Cleanup */
194err_exit:
195#ifdef SL_INCLUDE_CSLIP
Jesper Juhl158a0e42005-04-24 18:59:30 -0700196 kfree(cbuff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 if (slcomp)
198 slhc_free(slcomp);
199#endif
Jesper Juhl158a0e42005-04-24 18:59:30 -0700200 kfree(xbuff);
201 kfree(rbuff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 return err;
203}
204
205/* Free a SLIP channel buffers. */
Alan Cox9ce6cf22007-11-19 15:03:38 +0000206static void sl_free_bufs(struct slip *sl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 /* Free all SLIP frame buffers. */
Jesper Juhl9b200b02005-06-23 21:06:56 -0700209 kfree(xchg(&sl->rbuff, NULL));
210 kfree(xchg(&sl->xbuff, NULL));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211#ifdef SL_INCLUDE_CSLIP
Jesper Juhl9b200b02005-06-23 21:06:56 -0700212 kfree(xchg(&sl->cbuff, NULL));
213 slhc_free(xchg(&sl->slcomp, NULL));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214#endif
215}
216
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400217/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 Reallocate slip channel buffers.
219 */
220
221static int sl_realloc_bufs(struct slip *sl, int mtu)
222{
223 int err = 0;
224 struct net_device *dev = sl->dev;
225 unsigned char *xbuff, *rbuff;
226#ifdef SL_INCLUDE_CSLIP
227 unsigned char *cbuff;
228#endif
229 int len = mtu * 2;
230
231/*
232 * allow for arrival of larger UDP packets, even if we say not to
233 * also fixes a bug in which SunOS sends 512-byte packets even with
234 * an MSS of 128
235 */
236 if (len < 576 * 2)
237 len = 576 * 2;
238
Robert P. J. Day5cbded52006-12-13 00:35:56 -0800239 xbuff = kmalloc(len + 4, GFP_ATOMIC);
240 rbuff = kmalloc(len + 4, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241#ifdef SL_INCLUDE_CSLIP
Robert P. J. Day5cbded52006-12-13 00:35:56 -0800242 cbuff = kmalloc(len + 4, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243#endif
244
245
246#ifdef SL_INCLUDE_CSLIP
247 if (xbuff == NULL || rbuff == NULL || cbuff == NULL) {
248#else
249 if (xbuff == NULL || rbuff == NULL) {
250#endif
251 if (mtu >= sl->mtu) {
252 printk(KERN_WARNING "%s: unable to grow slip buffers, MTU change cancelled.\n",
253 dev->name);
254 err = -ENOBUFS;
255 }
256 goto done;
257 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 spin_lock_bh(&sl->lock);
259
260 err = -ENODEV;
261 if (sl->tty == NULL)
262 goto done_on_bh;
263
264 xbuff = xchg(&sl->xbuff, xbuff);
265 rbuff = xchg(&sl->rbuff, rbuff);
266#ifdef SL_INCLUDE_CSLIP
267 cbuff = xchg(&sl->cbuff, cbuff);
268#endif
269 if (sl->xleft) {
270 if (sl->xleft <= len) {
271 memcpy(sl->xbuff, sl->xhead, sl->xleft);
272 } else {
273 sl->xleft = 0;
Tobias Klauser034de002010-08-26 22:12:08 +0000274 dev->stats.tx_dropped++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 }
276 }
277 sl->xhead = sl->xbuff;
278
279 if (sl->rcount) {
280 if (sl->rcount <= len) {
281 memcpy(sl->rbuff, rbuff, sl->rcount);
282 } else {
283 sl->rcount = 0;
Tobias Klauser034de002010-08-26 22:12:08 +0000284 dev->stats.rx_over_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 set_bit(SLF_ERROR, &sl->flags);
286 }
287 }
288 sl->mtu = mtu;
289 dev->mtu = mtu;
290 sl->buffsize = len;
291 err = 0;
292
293done_on_bh:
294 spin_unlock_bh(&sl->lock);
295
296done:
Jesper Juhl158a0e42005-04-24 18:59:30 -0700297 kfree(xbuff);
298 kfree(rbuff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299#ifdef SL_INCLUDE_CSLIP
Jesper Juhl158a0e42005-04-24 18:59:30 -0700300 kfree(cbuff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301#endif
302 return err;
303}
304
305
306/* Set the "sending" flag. This must be atomic hence the set_bit. */
Alan Cox9ce6cf22007-11-19 15:03:38 +0000307static inline void sl_lock(struct slip *sl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308{
309 netif_stop_queue(sl->dev);
310}
311
312
313/* Clear the "sending" flag. This must be atomic, hence the ASM. */
Alan Cox9ce6cf22007-11-19 15:03:38 +0000314static inline void sl_unlock(struct slip *sl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315{
316 netif_wake_queue(sl->dev);
317}
318
319/* Send one completely decapsulated IP datagram to the IP layer. */
Alan Cox9ce6cf22007-11-19 15:03:38 +0000320static void sl_bump(struct slip *sl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321{
Tobias Klauser034de002010-08-26 22:12:08 +0000322 struct net_device *dev = sl->dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 struct sk_buff *skb;
324 int count;
325
326 count = sl->rcount;
327#ifdef SL_INCLUDE_CSLIP
328 if (sl->mode & (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) {
Alan Cox9ce6cf22007-11-19 15:03:38 +0000329 unsigned char c = sl->rbuff[0];
330 if (c & SL_TYPE_COMPRESSED_TCP) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 /* ignore compressed packets when CSLIP is off */
332 if (!(sl->mode & SL_MODE_CSLIP)) {
Tobias Klauser034de002010-08-26 22:12:08 +0000333 printk(KERN_WARNING "%s: compressed packet ignored\n", dev->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 return;
335 }
Alan Cox9ce6cf22007-11-19 15:03:38 +0000336 /* make sure we've reserved enough space for uncompress
337 to use */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 if (count + 80 > sl->buffsize) {
Tobias Klauser034de002010-08-26 22:12:08 +0000339 dev->stats.rx_over_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 return;
341 }
342 count = slhc_uncompress(sl->slcomp, sl->rbuff, count);
Alan Cox9ce6cf22007-11-19 15:03:38 +0000343 if (count <= 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 } else if (c >= SL_TYPE_UNCOMPRESSED_TCP) {
346 if (!(sl->mode & SL_MODE_CSLIP)) {
347 /* turn on header compression */
348 sl->mode |= SL_MODE_CSLIP;
349 sl->mode &= ~SL_MODE_ADAPTIVE;
Tobias Klauser034de002010-08-26 22:12:08 +0000350 printk(KERN_INFO "%s: header compression turned on\n", dev->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 }
352 sl->rbuff[0] &= 0x4f;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000353 if (slhc_remember(sl->slcomp, sl->rbuff, count) <= 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 }
356 }
357#endif /* SL_INCLUDE_CSLIP */
358
Tobias Klauser034de002010-08-26 22:12:08 +0000359 dev->stats.rx_bytes += count;
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400360
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 skb = dev_alloc_skb(count);
Alan Cox9ce6cf22007-11-19 15:03:38 +0000362 if (skb == NULL) {
Tobias Klauser034de002010-08-26 22:12:08 +0000363 printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", dev->name);
364 dev->stats.rx_dropped++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 return;
366 }
Tobias Klauser034de002010-08-26 22:12:08 +0000367 skb->dev = dev;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000368 memcpy(skb_put(skb, count), sl->rbuff, count);
Arnaldo Carvalho de Melo98e399f2007-03-19 15:33:04 -0700369 skb_reset_mac_header(skb);
Alan Cox9ce6cf22007-11-19 15:03:38 +0000370 skb->protocol = htons(ETH_P_IP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 netif_rx(skb);
Tobias Klauser034de002010-08-26 22:12:08 +0000372 dev->stats.rx_packets++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373}
374
375/* Encapsulate one IP datagram and stuff into a TTY queue. */
Alan Cox9ce6cf22007-11-19 15:03:38 +0000376static void sl_encaps(struct slip *sl, unsigned char *icp, int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377{
378 unsigned char *p;
379 int actual, count;
380
381 if (len > sl->mtu) { /* Sigh, shouldn't occur BUT ... */
382 printk(KERN_WARNING "%s: truncating oversized transmit packet!\n", sl->dev->name);
Tobias Klauser034de002010-08-26 22:12:08 +0000383 sl->dev->stats.tx_dropped++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 sl_unlock(sl);
385 return;
386 }
387
388 p = icp;
389#ifdef SL_INCLUDE_CSLIP
Alan Cox9ce6cf22007-11-19 15:03:38 +0000390 if (sl->mode & SL_MODE_CSLIP)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 len = slhc_compress(sl->slcomp, p, len, sl->cbuff, &p, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392#endif
393#ifdef CONFIG_SLIP_MODE_SLIP6
Alan Cox9ce6cf22007-11-19 15:03:38 +0000394 if (sl->mode & SL_MODE_SLIP6)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 count = slip_esc6(p, (unsigned char *) sl->xbuff, len);
396 else
397#endif
398 count = slip_esc(p, (unsigned char *) sl->xbuff, len);
399
400 /* Order of next two lines is *very* important.
401 * When we are sending a little amount of data,
Alan Coxf34d7a52008-04-30 00:54:13 -0700402 * the transfer may be completed inside the ops->write()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 * routine, because it's running with interrupts enabled.
404 * In this case we *never* got WRITE_WAKEUP event,
405 * if we did not request it before write operation.
406 * 14 Oct 1994 Dmitry Gorodchanin.
407 */
Alan Cox8a1ec212008-12-05 22:31:52 -0800408 set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
Alan Coxf34d7a52008-04-30 00:54:13 -0700409 actual = sl->tty->ops->write(sl->tty, sl->xbuff, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410#ifdef SL_CHECK_TRANSMIT
411 sl->dev->trans_start = jiffies;
412#endif
413 sl->xleft = count - actual;
414 sl->xhead = sl->xbuff + actual;
415#ifdef CONFIG_SLIP_SMART
416 /* VSV */
417 clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */
418#endif
419}
420
421/*
422 * Called by the driver when there's room for more data. If we have
423 * more packets to send, we send them here.
424 */
425static void slip_write_wakeup(struct tty_struct *tty)
426{
427 int actual;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000428 struct slip *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
430 /* First make sure we're connected. */
Alan Cox9ce6cf22007-11-19 15:03:38 +0000431 if (!sl || sl->magic != SLIP_MAGIC || !netif_running(sl->dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 return;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000433
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 if (sl->xleft <= 0) {
435 /* Now serial buffer is almost free & we can start
436 * transmission of another packet */
Tobias Klauser034de002010-08-26 22:12:08 +0000437 sl->dev->stats.tx_packets++;
Alan Cox8a1ec212008-12-05 22:31:52 -0800438 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 sl_unlock(sl);
440 return;
441 }
442
Alan Coxf34d7a52008-04-30 00:54:13 -0700443 actual = tty->ops->write(tty, sl->xhead, sl->xleft);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 sl->xleft -= actual;
445 sl->xhead += actual;
446}
447
448static void sl_tx_timeout(struct net_device *dev)
449{
450 struct slip *sl = netdev_priv(dev);
451
452 spin_lock(&sl->lock);
453
454 if (netif_queue_stopped(dev)) {
455 if (!netif_running(dev))
456 goto out;
457
458 /* May be we must check transmitter timeout here ?
459 * 14 Oct 1994 Dmitry Gorodchanin.
460 */
461#ifdef SL_CHECK_TRANSMIT
Eric Dumazet1ae5dc32010-05-10 05:01:31 -0700462 if (time_before(jiffies, dev_trans_start(dev) + 20 * HZ)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 /* 20 sec timeout not reached */
464 goto out;
465 }
Alan Cox9ce6cf22007-11-19 15:03:38 +0000466 printk(KERN_WARNING "%s: transmit timed out, %s?\n",
467 dev->name,
Alan Coxf34d7a52008-04-30 00:54:13 -0700468 (tty_chars_in_buffer(sl->tty) || sl->xleft) ?
Alan Cox9ce6cf22007-11-19 15:03:38 +0000469 "bad line quality" : "driver error");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 sl->xleft = 0;
Alan Cox8a1ec212008-12-05 22:31:52 -0800471 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 sl_unlock(sl);
473#endif
474 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475out:
476 spin_unlock(&sl->lock);
477}
478
479
480/* Encapsulate an IP datagram and kick it into a TTY queue. */
Stephen Hemminger424efe92009-08-31 19:50:51 +0000481static netdev_tx_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482sl_xmit(struct sk_buff *skb, struct net_device *dev)
483{
484 struct slip *sl = netdev_priv(dev);
485
486 spin_lock(&sl->lock);
Alan Cox9ce6cf22007-11-19 15:03:38 +0000487 if (!netif_running(dev)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 spin_unlock(&sl->lock);
489 printk(KERN_WARNING "%s: xmit call when iface is down\n", dev->name);
490 dev_kfree_skb(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000491 return NETDEV_TX_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 }
493 if (sl->tty == NULL) {
494 spin_unlock(&sl->lock);
495 dev_kfree_skb(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000496 return NETDEV_TX_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 }
498
499 sl_lock(sl);
Tobias Klauser034de002010-08-26 22:12:08 +0000500 dev->stats.tx_bytes += skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 sl_encaps(sl, skb->data, skb->len);
502 spin_unlock(&sl->lock);
503
504 dev_kfree_skb(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000505 return NETDEV_TX_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506}
507
508
509/******************************************
510 * Routines looking at netdevice side.
511 ******************************************/
512
513/* Netdevice UP -> DOWN routine */
514
515static int
516sl_close(struct net_device *dev)
517{
518 struct slip *sl = netdev_priv(dev);
519
520 spin_lock_bh(&sl->lock);
Alan Cox8a1ec212008-12-05 22:31:52 -0800521 if (sl->tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 /* TTY discipline is running. */
Alan Cox8a1ec212008-12-05 22:31:52 -0800523 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 netif_stop_queue(dev);
525 sl->rcount = 0;
526 sl->xleft = 0;
527 spin_unlock_bh(&sl->lock);
528
529 return 0;
530}
531
532/* Netdevice DOWN -> UP routine */
533
534static int sl_open(struct net_device *dev)
535{
536 struct slip *sl = netdev_priv(dev);
537
Alan Cox9ce6cf22007-11-19 15:03:38 +0000538 if (sl->tty == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 return -ENODEV;
540
541 sl->flags &= (1 << SLF_INUSE);
542 netif_start_queue(dev);
543 return 0;
544}
545
546/* Netdevice change MTU request */
547
548static int sl_change_mtu(struct net_device *dev, int new_mtu)
549{
550 struct slip *sl = netdev_priv(dev);
551
552 if (new_mtu < 68 || new_mtu > 65534)
553 return -EINVAL;
554
555 if (new_mtu != dev->mtu)
556 return sl_realloc_bufs(sl, new_mtu);
557 return 0;
558}
559
560/* Netdevice get statistics request */
561
Tobias Klauser034de002010-08-26 22:12:08 +0000562static struct rtnl_link_stats64 *
563sl_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564{
Tobias Klauser034de002010-08-26 22:12:08 +0000565 struct net_device_stats *devstats = &dev->stats;
Eric Dumazet6f0bee12010-08-18 03:13:08 +0000566 unsigned long c_rx_dropped = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567#ifdef SL_INCLUDE_CSLIP
Eric Dumazet6f0bee12010-08-18 03:13:08 +0000568 unsigned long c_rx_fifo_errors = 0;
569 unsigned long c_tx_fifo_errors = 0;
570 unsigned long c_collisions = 0;
Tobias Klauser034de002010-08-26 22:12:08 +0000571 struct slip *sl = netdev_priv(dev);
Eric Dumazet6f0bee12010-08-18 03:13:08 +0000572 struct slcompress *comp = sl->slcomp;
573
574 if (comp) {
575 c_rx_fifo_errors = comp->sls_i_compressed;
576 c_rx_dropped = comp->sls_i_tossed;
577 c_tx_fifo_errors = comp->sls_o_compressed;
578 c_collisions = comp->sls_o_misses;
579 }
580 stats->rx_fifo_errors = sl->rx_compressed + c_rx_fifo_errors;
581 stats->tx_fifo_errors = sl->tx_compressed + c_tx_fifo_errors;
582 stats->collisions = sl->tx_misses + c_collisions;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583#endif
Tobias Klauser034de002010-08-26 22:12:08 +0000584 stats->rx_packets = devstats->rx_packets;
585 stats->tx_packets = devstats->tx_packets;
586 stats->rx_bytes = devstats->rx_bytes;
587 stats->tx_bytes = devstats->tx_bytes;
588 stats->rx_dropped = devstats->rx_dropped + c_rx_dropped;
589 stats->tx_dropped = devstats->tx_dropped;
590 stats->tx_errors = devstats->tx_errors;
591 stats->rx_errors = devstats->rx_errors;
592 stats->rx_over_errors = devstats->rx_over_errors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593
Eric Dumazet6f0bee12010-08-18 03:13:08 +0000594 return stats;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595}
596
597/* Netdevice register callback */
598
599static int sl_init(struct net_device *dev)
600{
601 struct slip *sl = netdev_priv(dev);
602
603 /*
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400604 * Finish setting up the DEVICE info.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 */
606
607 dev->mtu = sl->mtu;
608 dev->type = ARPHRD_SLIP + sl->mode;
609#ifdef SL_CHECK_TRANSMIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 dev->watchdog_timeo = 20*HZ;
611#endif
612 return 0;
613}
614
615
616static void sl_uninit(struct net_device *dev)
617{
618 struct slip *sl = netdev_priv(dev);
619
620 sl_free_bufs(sl);
621}
622
Alan Cox5342b772009-09-19 13:13:17 -0700623/* Hook the destructor so we can free slip devices at the right point in time */
624static void sl_free_netdev(struct net_device *dev)
625{
626 int i = dev->base_addr;
627 free_netdev(dev);
628 slip_devs[i] = NULL;
629}
630
Stephen Hemmingerb1da6832009-01-07 18:09:36 -0800631static const struct net_device_ops sl_netdev_ops = {
632 .ndo_init = sl_init,
633 .ndo_uninit = sl_uninit,
634 .ndo_open = sl_open,
635 .ndo_stop = sl_close,
636 .ndo_start_xmit = sl_xmit,
Tobias Klauser034de002010-08-26 22:12:08 +0000637 .ndo_get_stats64 = sl_get_stats64,
Stephen Hemmingerb1da6832009-01-07 18:09:36 -0800638 .ndo_change_mtu = sl_change_mtu,
639 .ndo_tx_timeout = sl_tx_timeout,
640#ifdef CONFIG_SLIP_SMART
641 .ndo_do_ioctl = sl_ioctl,
642#endif
643};
644
645
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646static void sl_setup(struct net_device *dev)
647{
Stephen Hemmingerb1da6832009-01-07 18:09:36 -0800648 dev->netdev_ops = &sl_netdev_ops;
Alan Cox5342b772009-09-19 13:13:17 -0700649 dev->destructor = sl_free_netdev;
Stephen Hemmingerb1da6832009-01-07 18:09:36 -0800650
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 dev->hard_header_len = 0;
652 dev->addr_len = 0;
653 dev->tx_queue_len = 10;
654
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 /* New-style flags. */
656 dev->flags = IFF_NOARP|IFF_POINTOPOINT|IFF_MULTICAST;
657}
658
659/******************************************
660 Routines looking at TTY side.
661 ******************************************/
662
663
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664/*
665 * Handle the 'receiver data ready' interrupt.
666 * This function is called by the 'tty_io' module in the kernel when
667 * a block of SLIP data has been received, which can now be decapsulated
668 * and sent on to some IP layer for further processing. This will not
669 * be re-entered while running but other ldisc functions may be called
670 * in parallel
671 */
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400672
Alan Cox9ce6cf22007-11-19 15:03:38 +0000673static void slip_receive_buf(struct tty_struct *tty, const unsigned char *cp,
674 char *fp, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675{
Alan Cox9ce6cf22007-11-19 15:03:38 +0000676 struct slip *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677
Alan Cox9ce6cf22007-11-19 15:03:38 +0000678 if (!sl || sl->magic != SLIP_MAGIC || !netif_running(sl->dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 return;
680
681 /* Read the characters out of the buffer */
682 while (count--) {
683 if (fp && *fp++) {
Alan Cox9ce6cf22007-11-19 15:03:38 +0000684 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
Tobias Klauser034de002010-08-26 22:12:08 +0000685 sl->dev->stats.rx_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 cp++;
687 continue;
688 }
689#ifdef CONFIG_SLIP_MODE_SLIP6
690 if (sl->mode & SL_MODE_SLIP6)
691 slip_unesc6(sl, *cp++);
692 else
693#endif
694 slip_unesc(sl, *cp++);
695 }
696}
697
698/************************************
699 * slip_open helper routines.
700 ************************************/
701
702/* Collect hanged up channels */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703static void sl_sync(void)
704{
705 int i;
706 struct net_device *dev;
707 struct slip *sl;
708
709 for (i = 0; i < slip_maxdev; i++) {
Alan Cox9ce6cf22007-11-19 15:03:38 +0000710 dev = slip_devs[i];
711 if (dev == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 break;
713
714 sl = netdev_priv(dev);
715 if (sl->tty || sl->leased)
716 continue;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000717 if (dev->flags & IFF_UP)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 dev_close(dev);
719 }
720}
721
722
723/* Find a free SLIP channel, and link in this `tty' line. */
Alan Cox9ce6cf22007-11-19 15:03:38 +0000724static struct slip *sl_alloc(dev_t line)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725{
726 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 struct net_device *dev = NULL;
728 struct slip *sl;
729
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400730 if (slip_devs == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 return NULL; /* Master array missing ! */
732
733 for (i = 0; i < slip_maxdev; i++) {
734 dev = slip_devs[i];
735 if (dev == NULL)
736 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 /* Sorry, too many, all slots in use */
739 if (i >= slip_maxdev)
740 return NULL;
741
742 if (dev) {
743 sl = netdev_priv(dev);
744 if (test_bit(SLF_INUSE, &sl->flags)) {
745 unregister_netdevice(dev);
746 dev = NULL;
747 slip_devs[i] = NULL;
748 }
749 }
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400750
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 if (!dev) {
752 char name[IFNAMSIZ];
753 sprintf(name, "sl%d", i);
754
755 dev = alloc_netdev(sizeof(*sl), name, sl_setup);
756 if (!dev)
757 return NULL;
758 dev->base_addr = i;
759 }
760
761 sl = netdev_priv(dev);
762
763 /* Initialize channel control data */
764 sl->magic = SLIP_MAGIC;
765 sl->dev = dev;
766 spin_lock_init(&sl->lock);
767 sl->mode = SL_MODE_DEFAULT;
768#ifdef CONFIG_SLIP_SMART
Alan Cox9ce6cf22007-11-19 15:03:38 +0000769 /* initialize timer_list struct */
770 init_timer(&sl->keepalive_timer);
771 sl->keepalive_timer.data = (unsigned long)sl;
772 sl->keepalive_timer.function = sl_keepalive;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 init_timer(&sl->outfill_timer);
Alan Cox9ce6cf22007-11-19 15:03:38 +0000774 sl->outfill_timer.data = (unsigned long)sl;
775 sl->outfill_timer.function = sl_outfill;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776#endif
777 slip_devs[i] = dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 return sl;
779}
780
781/*
782 * Open the high-level part of the SLIP channel.
783 * This function is called by the TTY module when the
784 * SLIP line discipline is called for. Because we are
785 * sure the tty line exists, we only have to link it to
786 * a free SLIP channel...
787 *
788 * Called in process context serialized from other ldisc calls.
789 */
790
791static int slip_open(struct tty_struct *tty)
792{
793 struct slip *sl;
794 int err;
795
Alan Cox9ce6cf22007-11-19 15:03:38 +0000796 if (!capable(CAP_NET_ADMIN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 return -EPERM;
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400798
Alan Coxf34d7a52008-04-30 00:54:13 -0700799 if (tty->ops->write == NULL)
800 return -EOPNOTSUPP;
801
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 /* RTnetlink lock is misused here to serialize concurrent
803 opens of slip channels. There are better ways, but it is
804 the simplest one.
805 */
806 rtnl_lock();
807
808 /* Collect hanged up channels. */
809 sl_sync();
810
Alan Cox9ce6cf22007-11-19 15:03:38 +0000811 sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812
813 err = -EEXIST;
814 /* First make sure we're not already connected. */
815 if (sl && sl->magic == SLIP_MAGIC)
816 goto err_exit;
817
818 /* OK. Find a free SLIP channel to use. */
819 err = -ENFILE;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000820 sl = sl_alloc(tty_devnum(tty));
821 if (sl == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822 goto err_exit;
823
824 sl->tty = tty;
825 tty->disc_data = sl;
826 sl->line = tty_devnum(tty);
827 sl->pid = current->pid;
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400828
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 if (!test_bit(SLF_INUSE, &sl->flags)) {
830 /* Perform the low-level SLIP initialization. */
Alan Cox9ce6cf22007-11-19 15:03:38 +0000831 err = sl_alloc_bufs(sl, SL_MTU);
832 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 goto err_free_chan;
834
835 set_bit(SLF_INUSE, &sl->flags);
836
Alan Cox9ce6cf22007-11-19 15:03:38 +0000837 err = register_netdevice(sl->dev);
838 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 goto err_free_bufs;
840 }
841
842#ifdef CONFIG_SLIP_SMART
843 if (sl->keepalive) {
Alan Cox9ce6cf22007-11-19 15:03:38 +0000844 sl->keepalive_timer.expires = jiffies + sl->keepalive * HZ;
845 add_timer(&sl->keepalive_timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 }
847 if (sl->outfill) {
Alan Cox9ce6cf22007-11-19 15:03:38 +0000848 sl->outfill_timer.expires = jiffies + sl->outfill * HZ;
849 add_timer(&sl->outfill_timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 }
851#endif
852
853 /* Done. We have linked the TTY line to a channel. */
854 rtnl_unlock();
Alan Cox33f0f882006-01-09 20:54:13 -0800855 tty->receive_room = 65536; /* We don't flow control */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 return sl->dev->base_addr;
857
858err_free_bufs:
859 sl_free_bufs(sl);
860
861err_free_chan:
862 sl->tty = NULL;
863 tty->disc_data = NULL;
864 clear_bit(SLF_INUSE, &sl->flags);
865
866err_exit:
867 rtnl_unlock();
868
869 /* Count references from TTY module */
870 return err;
871}
872
873/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 * Close down a SLIP channel.
875 * This means flushing out any pending queues, and then returning. This
876 * call is serialized against other ldisc functions.
Alan Cox5342b772009-09-19 13:13:17 -0700877 *
878 * We also use this method fo a hangup event
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 */
Alan Cox5342b772009-09-19 13:13:17 -0700880
Alan Cox9ce6cf22007-11-19 15:03:38 +0000881static void slip_close(struct tty_struct *tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882{
Alan Cox9ce6cf22007-11-19 15:03:38 +0000883 struct slip *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884
885 /* First make sure we're connected. */
886 if (!sl || sl->magic != SLIP_MAGIC || sl->tty != tty)
887 return;
888
889 tty->disc_data = NULL;
890 sl->tty = NULL;
891 if (!sl->leased)
892 sl->line = 0;
893
894 /* VSV = very important to remove timers */
895#ifdef CONFIG_SLIP_SMART
896 del_timer_sync(&sl->keepalive_timer);
897 del_timer_sync(&sl->outfill_timer);
898#endif
Alan Cox5342b772009-09-19 13:13:17 -0700899 /* Flush network side */
900 unregister_netdev(sl->dev);
901 /* This will complete via sl_free_netdev */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902}
903
Alan Cox5342b772009-09-19 13:13:17 -0700904static int slip_hangup(struct tty_struct *tty)
905{
906 slip_close(tty);
907 return 0;
908}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909 /************************************************************************
910 * STANDARD SLIP ENCAPSULATION *
911 ************************************************************************/
912
Alan Cox9ce6cf22007-11-19 15:03:38 +0000913static int slip_esc(unsigned char *s, unsigned char *d, int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914{
915 unsigned char *ptr = d;
916 unsigned char c;
917
918 /*
919 * Send an initial END character to flush out any
920 * data that may have accumulated in the receiver
921 * due to line noise.
922 */
923
924 *ptr++ = END;
925
926 /*
927 * For each byte in the packet, send the appropriate
928 * character sequence, according to the SLIP protocol.
929 */
930
931 while (len-- > 0) {
Alan Cox9ce6cf22007-11-19 15:03:38 +0000932 switch (c = *s++) {
933 case END:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 *ptr++ = ESC;
935 *ptr++ = ESC_END;
936 break;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000937 case ESC:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 *ptr++ = ESC;
939 *ptr++ = ESC_ESC;
940 break;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000941 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942 *ptr++ = c;
943 break;
944 }
945 }
946 *ptr++ = END;
Eric Dumazet807540b2010-09-23 05:40:09 +0000947 return ptr - d;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948}
949
950static void slip_unesc(struct slip *sl, unsigned char s)
951{
952
Alan Cox9ce6cf22007-11-19 15:03:38 +0000953 switch (s) {
954 case END:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955#ifdef CONFIG_SLIP_SMART
956 /* drop keeptest bit = VSV */
957 if (test_bit(SLF_KEEPTEST, &sl->flags))
958 clear_bit(SLF_KEEPTEST, &sl->flags);
959#endif
960
Joe Perches8e95a202009-12-03 07:58:21 +0000961 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
962 (sl->rcount > 2))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 sl_bump(sl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 clear_bit(SLF_ESCAPE, &sl->flags);
965 sl->rcount = 0;
966 return;
967
Alan Cox9ce6cf22007-11-19 15:03:38 +0000968 case ESC:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 set_bit(SLF_ESCAPE, &sl->flags);
970 return;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000971 case ESC_ESC:
972 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973 s = ESC;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 break;
Alan Cox9ce6cf22007-11-19 15:03:38 +0000975 case ESC_END:
976 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 s = END;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 break;
979 }
980 if (!test_bit(SLF_ERROR, &sl->flags)) {
981 if (sl->rcount < sl->buffsize) {
982 sl->rbuff[sl->rcount++] = s;
983 return;
984 }
Tobias Klauser034de002010-08-26 22:12:08 +0000985 sl->dev->stats.rx_over_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 set_bit(SLF_ERROR, &sl->flags);
987 }
988}
989
990
991#ifdef CONFIG_SLIP_MODE_SLIP6
992/************************************************************************
993 * 6 BIT SLIP ENCAPSULATION *
994 ************************************************************************/
995
Alan Cox9ce6cf22007-11-19 15:03:38 +0000996static int slip_esc6(unsigned char *s, unsigned char *d, int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997{
998 unsigned char *ptr = d;
999 unsigned char c;
1000 int i;
1001 unsigned short v = 0;
1002 short bits = 0;
1003
1004 /*
1005 * Send an initial END character to flush out any
1006 * data that may have accumulated in the receiver
1007 * due to line noise.
1008 */
1009
1010 *ptr++ = 0x70;
1011
1012 /*
1013 * Encode the packet into printable ascii characters
1014 */
1015
1016 for (i = 0; i < len; ++i) {
1017 v = (v << 8) | s[i];
1018 bits += 8;
1019 while (bits >= 6) {
1020 bits -= 6;
1021 c = 0x30 + ((v >> bits) & 0x3F);
1022 *ptr++ = c;
1023 }
1024 }
1025 if (bits) {
1026 c = 0x30 + ((v << (6 - bits)) & 0x3F);
1027 *ptr++ = c;
1028 }
1029 *ptr++ = 0x70;
1030 return ptr - d;
1031}
1032
Alan Cox9ce6cf22007-11-19 15:03:38 +00001033static void slip_unesc6(struct slip *sl, unsigned char s)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034{
1035 unsigned char c;
1036
1037 if (s == 0x70) {
1038#ifdef CONFIG_SLIP_SMART
1039 /* drop keeptest bit = VSV */
1040 if (test_bit(SLF_KEEPTEST, &sl->flags))
1041 clear_bit(SLF_KEEPTEST, &sl->flags);
1042#endif
1043
Joe Perches8e95a202009-12-03 07:58:21 +00001044 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
1045 (sl->rcount > 2))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 sl_bump(sl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 sl->rcount = 0;
1048 sl->xbits = 0;
1049 sl->xdata = 0;
Alan Cox9ce6cf22007-11-19 15:03:38 +00001050 } else if (s >= 0x30 && s < 0x70) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051 sl->xdata = (sl->xdata << 6) | ((s - 0x30) & 0x3F);
1052 sl->xbits += 6;
1053 if (sl->xbits >= 8) {
1054 sl->xbits -= 8;
1055 c = (unsigned char)(sl->xdata >> sl->xbits);
1056 if (!test_bit(SLF_ERROR, &sl->flags)) {
1057 if (sl->rcount < sl->buffsize) {
1058 sl->rbuff[sl->rcount++] = c;
1059 return;
1060 }
Tobias Klauser034de002010-08-26 22:12:08 +00001061 sl->dev->stats.rx_over_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 set_bit(SLF_ERROR, &sl->flags);
1063 }
1064 }
Alan Cox9ce6cf22007-11-19 15:03:38 +00001065 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066}
1067#endif /* CONFIG_SLIP_MODE_SLIP6 */
1068
1069/* Perform I/O control on an active SLIP channel. */
Alan Cox9ce6cf22007-11-19 15:03:38 +00001070static int slip_ioctl(struct tty_struct *tty, struct file *file,
1071 unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072{
Alan Cox9ce6cf22007-11-19 15:03:38 +00001073 struct slip *sl = tty->disc_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074 unsigned int tmp;
1075 int __user *p = (int __user *)arg;
1076
1077 /* First make sure we're connected. */
Alan Cox9ce6cf22007-11-19 15:03:38 +00001078 if (!sl || sl->magic != SLIP_MAGIC)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080
Alan Cox9ce6cf22007-11-19 15:03:38 +00001081 switch (cmd) {
1082 case SIOCGIFNAME:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083 tmp = strlen(sl->dev->name) + 1;
1084 if (copy_to_user((void __user *)arg, sl->dev->name, tmp))
1085 return -EFAULT;
1086 return 0;
1087
1088 case SIOCGIFENCAP:
1089 if (put_user(sl->mode, p))
1090 return -EFAULT;
1091 return 0;
1092
1093 case SIOCSIFENCAP:
1094 if (get_user(tmp, p))
1095 return -EFAULT;
1096#ifndef SL_INCLUDE_CSLIP
Alan Cox9ce6cf22007-11-19 15:03:38 +00001097 if (tmp & (SL_MODE_CSLIP|SL_MODE_ADAPTIVE))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099#else
1100 if ((tmp & (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) ==
Alan Cox9ce6cf22007-11-19 15:03:38 +00001101 (SL_MODE_ADAPTIVE | SL_MODE_CSLIP))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 /* return -EINVAL; */
1103 tmp &= ~SL_MODE_ADAPTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104#endif
1105#ifndef CONFIG_SLIP_MODE_SLIP6
Alan Cox9ce6cf22007-11-19 15:03:38 +00001106 if (tmp & SL_MODE_SLIP6)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108#endif
1109 sl->mode = tmp;
Alan Cox9ce6cf22007-11-19 15:03:38 +00001110 sl->dev->type = ARPHRD_SLIP + sl->mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 return 0;
1112
Alan Cox9ce6cf22007-11-19 15:03:38 +00001113 case SIOCSIFHWADDR:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114 return -EINVAL;
1115
1116#ifdef CONFIG_SLIP_SMART
1117 /* VSV changes start here */
Alan Cox9ce6cf22007-11-19 15:03:38 +00001118 case SIOCSKEEPALIVE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 if (get_user(tmp, p))
1120 return -EFAULT;
Alan Cox9ce6cf22007-11-19 15:03:38 +00001121 if (tmp > 255) /* max for unchar */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 return -EINVAL;
1123
1124 spin_lock_bh(&sl->lock);
1125 if (!sl->tty) {
1126 spin_unlock_bh(&sl->lock);
1127 return -ENODEV;
1128 }
Alan Cox9ce6cf22007-11-19 15:03:38 +00001129 sl->keepalive = (u8)tmp;
1130 if (sl->keepalive != 0) {
1131 mod_timer(&sl->keepalive_timer,
1132 jiffies + sl->keepalive * HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133 set_bit(SLF_KEEPTEST, &sl->flags);
Alan Cox9ce6cf22007-11-19 15:03:38 +00001134 } else
1135 del_timer(&sl->keepalive_timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 spin_unlock_bh(&sl->lock);
1137 return 0;
1138
Alan Cox9ce6cf22007-11-19 15:03:38 +00001139 case SIOCGKEEPALIVE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 if (put_user(sl->keepalive, p))
1141 return -EFAULT;
1142 return 0;
1143
Alan Cox9ce6cf22007-11-19 15:03:38 +00001144 case SIOCSOUTFILL:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 if (get_user(tmp, p))
1146 return -EFAULT;
Alan Cox9ce6cf22007-11-19 15:03:38 +00001147 if (tmp > 255) /* max for unchar */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148 return -EINVAL;
1149 spin_lock_bh(&sl->lock);
1150 if (!sl->tty) {
1151 spin_unlock_bh(&sl->lock);
1152 return -ENODEV;
1153 }
Alan Cox9ce6cf22007-11-19 15:03:38 +00001154 sl->outfill = (u8)tmp;
1155 if (sl->outfill != 0) {
1156 mod_timer(&sl->outfill_timer,
1157 jiffies + sl->outfill * HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 set_bit(SLF_OUTWAIT, &sl->flags);
Alan Cox9ce6cf22007-11-19 15:03:38 +00001159 } else
1160 del_timer(&sl->outfill_timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 spin_unlock_bh(&sl->lock);
Alan Cox9ce6cf22007-11-19 15:03:38 +00001162 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163
Alan Cox9ce6cf22007-11-19 15:03:38 +00001164 case SIOCGOUTFILL:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165 if (put_user(sl->outfill, p))
1166 return -EFAULT;
1167 return 0;
1168 /* VSV changes end */
1169#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 default:
Alan Coxd0127532007-11-07 01:27:34 -08001171 return tty_mode_ioctl(tty, file, cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 }
1173}
1174
Arnd Bergmann9646e7c2009-11-06 22:51:16 -08001175#ifdef CONFIG_COMPAT
1176static long slip_compat_ioctl(struct tty_struct *tty, struct file *file,
1177 unsigned int cmd, unsigned long arg)
1178{
1179 switch (cmd) {
1180 case SIOCGIFNAME:
1181 case SIOCGIFENCAP:
1182 case SIOCSIFENCAP:
1183 case SIOCSIFHWADDR:
1184 case SIOCSKEEPALIVE:
1185 case SIOCGKEEPALIVE:
1186 case SIOCSOUTFILL:
1187 case SIOCGOUTFILL:
1188 return slip_ioctl(tty, file, cmd,
1189 (unsigned long)compat_ptr(arg));
1190 }
1191
1192 return -ENOIOCTLCMD;
1193}
1194#endif
1195
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196/* VSV changes start here */
1197#ifdef CONFIG_SLIP_SMART
1198/* function do_ioctl called from net/core/dev.c
1199 to allow get/set outfill/keepalive parameter
1200 by ifconfig */
1201
Alan Cox9ce6cf22007-11-19 15:03:38 +00001202static int sl_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203{
1204 struct slip *sl = netdev_priv(dev);
1205 unsigned long *p = (unsigned long *)&rq->ifr_ifru;
1206
1207 if (sl == NULL) /* Allocation failed ?? */
1208 return -ENODEV;
1209
1210 spin_lock_bh(&sl->lock);
1211
1212 if (!sl->tty) {
1213 spin_unlock_bh(&sl->lock);
1214 return -ENODEV;
1215 }
1216
Alan Cox9ce6cf22007-11-19 15:03:38 +00001217 switch (cmd) {
1218 case SIOCSKEEPALIVE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219 /* max for unchar */
Alan Cox9ce6cf22007-11-19 15:03:38 +00001220 if ((unsigned)*p > 255) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221 spin_unlock_bh(&sl->lock);
1222 return -EINVAL;
1223 }
Alan Cox9ce6cf22007-11-19 15:03:38 +00001224 sl->keepalive = (u8)*p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 if (sl->keepalive != 0) {
Alan Cox9ce6cf22007-11-19 15:03:38 +00001226 sl->keepalive_timer.expires =
1227 jiffies + sl->keepalive * HZ;
1228 mod_timer(&sl->keepalive_timer,
1229 jiffies + sl->keepalive * HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 set_bit(SLF_KEEPTEST, &sl->flags);
Alan Cox9ce6cf22007-11-19 15:03:38 +00001231 } else
1232 del_timer(&sl->keepalive_timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 break;
1234
Alan Cox9ce6cf22007-11-19 15:03:38 +00001235 case SIOCGKEEPALIVE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 *p = sl->keepalive;
1237 break;
1238
Alan Cox9ce6cf22007-11-19 15:03:38 +00001239 case SIOCSOUTFILL:
1240 if ((unsigned)*p > 255) { /* max for unchar */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241 spin_unlock_bh(&sl->lock);
1242 return -EINVAL;
1243 }
Alan Cox9ce6cf22007-11-19 15:03:38 +00001244 sl->outfill = (u8)*p;
1245 if (sl->outfill != 0) {
1246 mod_timer(&sl->outfill_timer,
1247 jiffies + sl->outfill * HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248 set_bit(SLF_OUTWAIT, &sl->flags);
Alan Cox9ce6cf22007-11-19 15:03:38 +00001249 } else
1250 del_timer(&sl->outfill_timer);
1251 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252
Alan Cox9ce6cf22007-11-19 15:03:38 +00001253 case SIOCGOUTFILL:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 *p = sl->outfill;
1255 break;
1256
Alan Cox9ce6cf22007-11-19 15:03:38 +00001257 case SIOCSLEASE:
Jeff Garzik6aa20a22006-09-13 13:24:59 -04001258 /* Resolve race condition, when ioctl'ing hanged up
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259 and opened by another process device.
1260 */
Alan Cox9ce6cf22007-11-19 15:03:38 +00001261 if (sl->tty != current->signal->tty &&
1262 sl->pid != current->pid) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 spin_unlock_bh(&sl->lock);
1264 return -EPERM;
1265 }
1266 sl->leased = 0;
Alan Cox9ce6cf22007-11-19 15:03:38 +00001267 if (*p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268 sl->leased = 1;
Alan Cox9ce6cf22007-11-19 15:03:38 +00001269 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270
Alan Cox9ce6cf22007-11-19 15:03:38 +00001271 case SIOCGLEASE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 *p = sl->leased;
Joe Perchesee289b62010-05-17 22:47:34 -07001273 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 spin_unlock_bh(&sl->lock);
1275 return 0;
1276}
1277#endif
1278/* VSV changes end */
1279
Alan Coxa352def2008-07-16 21:53:12 +01001280static struct tty_ldisc_ops sl_ldisc = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 .owner = THIS_MODULE,
1282 .magic = TTY_LDISC_MAGIC,
1283 .name = "slip",
1284 .open = slip_open,
1285 .close = slip_close,
Alan Cox5342b772009-09-19 13:13:17 -07001286 .hangup = slip_hangup,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287 .ioctl = slip_ioctl,
Arnd Bergmann9646e7c2009-11-06 22:51:16 -08001288#ifdef CONFIG_COMPAT
1289 .compat_ioctl = slip_compat_ioctl,
1290#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291 .receive_buf = slip_receive_buf,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 .write_wakeup = slip_write_wakeup,
1293};
1294
1295static int __init slip_init(void)
1296{
1297 int status;
1298
1299 if (slip_maxdev < 4)
1300 slip_maxdev = 4; /* Sanity */
1301
1302 printk(KERN_INFO "SLIP: version %s (dynamic channels, max=%d)"
1303#ifdef CONFIG_SLIP_MODE_SLIP6
1304 " (6 bit encapsulation enabled)"
1305#endif
1306 ".\n",
Alan Cox9ce6cf22007-11-19 15:03:38 +00001307 SLIP_VERSION, slip_maxdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308#if defined(SL_INCLUDE_CSLIP)
1309 printk(KERN_INFO "CSLIP: code copyright 1989 Regents of the University of California.\n");
1310#endif
1311#ifdef CONFIG_SLIP_SMART
1312 printk(KERN_INFO "SLIP linefill/keepalive option.\n");
1313#endif
1314
Alan Cox9ce6cf22007-11-19 15:03:38 +00001315 slip_devs = kzalloc(sizeof(struct net_device *)*slip_maxdev,
1316 GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 if (!slip_devs) {
Alan Cox9ce6cf22007-11-19 15:03:38 +00001318 printk(KERN_ERR "SLIP: Can't allocate slip devices array.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319 return -ENOMEM;
1320 }
1321
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322 /* Fill in our line protocol discipline, and register it */
Alan Cox9ce6cf22007-11-19 15:03:38 +00001323 status = tty_register_ldisc(N_SLIP, &sl_ldisc);
1324 if (status != 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 printk(KERN_ERR "SLIP: can't register line discipline (err = %d)\n", status);
1326 kfree(slip_devs);
1327 }
1328 return status;
1329}
1330
1331static void __exit slip_exit(void)
1332{
1333 int i;
1334 struct net_device *dev;
1335 struct slip *sl;
1336 unsigned long timeout = jiffies + HZ;
1337 int busy = 0;
1338
Jeff Garzik6aa20a22006-09-13 13:24:59 -04001339 if (slip_devs == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340 return;
1341
1342 /* First of all: check for active disciplines and hangup them.
1343 */
1344 do {
Nishanth Aravamudana9fc2512005-05-01 23:34:57 -07001345 if (busy)
1346 msleep_interruptible(100);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347
1348 busy = 0;
1349 for (i = 0; i < slip_maxdev; i++) {
1350 dev = slip_devs[i];
1351 if (!dev)
1352 continue;
1353 sl = netdev_priv(dev);
1354 spin_lock_bh(&sl->lock);
1355 if (sl->tty) {
1356 busy++;
1357 tty_hangup(sl->tty);
1358 }
1359 spin_unlock_bh(&sl->lock);
1360 }
1361 } while (busy && time_before(jiffies, timeout));
1362
Alan Cox5342b772009-09-19 13:13:17 -07001363 /* FIXME: hangup is async so we should wait when doing this second
1364 phase */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365
1366 for (i = 0; i < slip_maxdev; i++) {
1367 dev = slip_devs[i];
1368 if (!dev)
1369 continue;
1370 slip_devs[i] = NULL;
1371
1372 sl = netdev_priv(dev);
1373 if (sl->tty) {
1374 printk(KERN_ERR "%s: tty discipline still running\n",
1375 dev->name);
1376 /* Intentionally leak the control block. */
1377 dev->destructor = NULL;
Jeff Garzik6aa20a22006-09-13 13:24:59 -04001378 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379
1380 unregister_netdev(dev);
1381 }
1382
1383 kfree(slip_devs);
1384 slip_devs = NULL;
1385
Alan Cox9ce6cf22007-11-19 15:03:38 +00001386 i = tty_unregister_ldisc(N_SLIP);
1387 if (i != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388 printk(KERN_ERR "SLIP: can't unregister line discipline (err = %d)\n", i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389}
1390
1391module_init(slip_init);
1392module_exit(slip_exit);
1393
1394#ifdef CONFIG_SLIP_SMART
1395/*
1396 * This is start of the code for multislip style line checking
1397 * added by Stanislav Voronyi. All changes before marked VSV
1398 */
1399
1400static void sl_outfill(unsigned long sls)
1401{
Alan Cox9ce6cf22007-11-19 15:03:38 +00001402 struct slip *sl = (struct slip *)sls;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403
1404 spin_lock(&sl->lock);
1405
1406 if (sl->tty == NULL)
1407 goto out;
1408
Alan Cox9ce6cf22007-11-19 15:03:38 +00001409 if (sl->outfill) {
1410 if (test_bit(SLF_OUTWAIT, &sl->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411 /* no packets were transmitted, do outfill */
1412#ifdef CONFIG_SLIP_MODE_SLIP6
1413 unsigned char s = (sl->mode & SL_MODE_SLIP6)?0x70:END;
1414#else
1415 unsigned char s = END;
1416#endif
1417 /* put END into tty queue. Is it right ??? */
Alan Cox9ce6cf22007-11-19 15:03:38 +00001418 if (!netif_queue_stopped(sl->dev)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419 /* if device busy no outfill */
Alan Coxf34d7a52008-04-30 00:54:13 -07001420 sl->tty->ops->write(sl->tty, &s, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421 }
Alan Cox9ce6cf22007-11-19 15:03:38 +00001422 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001423 set_bit(SLF_OUTWAIT, &sl->flags);
1424
1425 mod_timer(&sl->outfill_timer, jiffies+sl->outfill*HZ);
1426 }
1427out:
1428 spin_unlock(&sl->lock);
1429}
1430
1431static void sl_keepalive(unsigned long sls)
1432{
Alan Cox9ce6cf22007-11-19 15:03:38 +00001433 struct slip *sl = (struct slip *)sls;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434
1435 spin_lock(&sl->lock);
1436
1437 if (sl->tty == NULL)
1438 goto out;
1439
Alan Cox9ce6cf22007-11-19 15:03:38 +00001440 if (sl->keepalive) {
1441 if (test_bit(SLF_KEEPTEST, &sl->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442 /* keepalive still high :(, we must hangup */
Alan Cox9ce6cf22007-11-19 15:03:38 +00001443 if (sl->outfill)
1444 /* outfill timer must be deleted too */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445 (void)del_timer(&sl->outfill_timer);
1446 printk(KERN_DEBUG "%s: no packets received during keepalive timeout, hangup.\n", sl->dev->name);
Alan Cox9ce6cf22007-11-19 15:03:38 +00001447 /* this must hangup tty & close slip */
1448 tty_hangup(sl->tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 /* I think we need not something else */
1450 goto out;
Alan Cox9ce6cf22007-11-19 15:03:38 +00001451 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001452 set_bit(SLF_KEEPTEST, &sl->flags);
1453
1454 mod_timer(&sl->keepalive_timer, jiffies+sl->keepalive*HZ);
1455 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456out:
1457 spin_unlock(&sl->lock);
1458}
1459
1460#endif
1461MODULE_LICENSE("GPL");
1462MODULE_ALIAS_LDISC(N_SLIP);