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.
6 * Version: @(#)slip.c 0.8.3 12/24/94
8 * Authors: Laurence Culhane, <loz@holmes.demon.co.uk>
9 * Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
12 * Alan Cox : Sanity checks and avoid tx overruns.
13 * Has a new sl->mtu field.
14 * 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.
19 * 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.
34 * ifconfig sl? up & down now works
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
49 * With MODULE-loading ``insmod'', user
50 * can issue parameter: slip_maxdev=1024
51 * (Or how much he/she wants.. Default
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
58 * Vitaly E. Lavrov : Sane behaviour on tty hangup.
59 * Alexey Kuznetsov : Cleanup interfaces to tty & netdevice
63 #define SL_CHECK_TRANSMIT
64 #include <linux/module.h>
65 #include <linux/moduleparam.h>
67 #include <asm/uaccess.h>
68 #include <linux/bitops.h>
69 #include <linux/sched.h>
70 #include <linux/string.h>
72 #include <linux/interrupt.h>
74 #include <linux/tty.h>
75 #include <linux/errno.h>
76 #include <linux/netdevice.h>
77 #include <linux/etherdevice.h>
78 #include <linux/skbuff.h>
79 #include <linux/rtnetlink.h>
80 #include <linux/if_arp.h>
81 #include <linux/if_slip.h>
82 #include <linux/compat.h>
83 #include <linux/delay.h>
84 #include <linux/init.h>
85 #include <linux/slab.h>
86 #include <linux/workqueue.h>
90 #include <linux/tcp.h>
91 #include <net/slhc_vj.h>
94 #define SLIP_VERSION "0.8.4-NET3.019-NEWTTY"
96 static struct net_device **slip_devs;
98 static int slip_maxdev = SL_NRUNIT;
99 module_param(slip_maxdev, int, 0);
100 MODULE_PARM_DESC(slip_maxdev, "Maximum number of slip devices");
102 static int slip_esc(unsigned char *p, unsigned char *d, int len);
103 static void slip_unesc(struct slip *sl, unsigned char c);
104 #ifdef CONFIG_SLIP_MODE_SLIP6
105 static int slip_esc6(unsigned char *p, unsigned char *d, int len);
106 static void slip_unesc6(struct slip *sl, unsigned char c);
108 #ifdef CONFIG_SLIP_SMART
109 static void sl_keepalive(unsigned long sls);
110 static void sl_outfill(unsigned long sls);
111 static int sl_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
114 /********************************
115 * Buffer administration routines:
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 *********************************/
126 Allocate channel buffers.
129 static int sl_alloc_bufs(struct slip *sl, int mtu)
135 #ifdef SL_INCLUDE_CSLIP
137 struct slcompress *slcomp = NULL;
141 * Allocate the SLIP frame buffers:
143 * rbuff Receive buffer.
144 * xbuff Transmit buffer.
145 * cbuff Temporary compression buffer.
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
156 rbuff = kmalloc(len + 4, GFP_KERNEL);
159 xbuff = kmalloc(len + 4, GFP_KERNEL);
162 #ifdef SL_INCLUDE_CSLIP
163 cbuff = kmalloc(len + 4, GFP_KERNEL);
166 slcomp = slhc_init(16, 16);
170 spin_lock_bh(&sl->lock);
171 if (sl->tty == NULL) {
172 spin_unlock_bh(&sl->lock);
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);
186 #ifdef CONFIG_SLIP_MODE_SLIP6
190 spin_unlock_bh(&sl->lock);
195 #ifdef SL_INCLUDE_CSLIP
204 /* Free a SLIP channel buffers. */
205 static void sl_free_bufs(struct slip *sl)
207 /* Free all SLIP frame buffers. */
208 kfree(xchg(&sl->rbuff, NULL));
209 kfree(xchg(&sl->xbuff, NULL));
210 #ifdef SL_INCLUDE_CSLIP
211 kfree(xchg(&sl->cbuff, NULL));
212 slhc_free(xchg(&sl->slcomp, NULL));
217 Reallocate slip channel buffers.
220 static int sl_realloc_bufs(struct slip *sl, int mtu)
223 struct net_device *dev = sl->dev;
224 unsigned char *xbuff, *rbuff;
225 #ifdef SL_INCLUDE_CSLIP
226 unsigned char *cbuff;
231 * allow for arrival of larger UDP packets, even if we say not to
232 * also fixes a bug in which SunOS sends 512-byte packets even with
238 xbuff = kmalloc(len + 4, GFP_ATOMIC);
239 rbuff = kmalloc(len + 4, GFP_ATOMIC);
240 #ifdef SL_INCLUDE_CSLIP
241 cbuff = kmalloc(len + 4, GFP_ATOMIC);
245 #ifdef SL_INCLUDE_CSLIP
246 if (xbuff == NULL || rbuff == NULL || cbuff == NULL) {
248 if (xbuff == NULL || rbuff == NULL) {
251 printk(KERN_WARNING "%s: unable to grow slip buffers, MTU change cancelled.\n",
257 spin_lock_bh(&sl->lock);
263 xbuff = xchg(&sl->xbuff, xbuff);
264 rbuff = xchg(&sl->rbuff, rbuff);
265 #ifdef SL_INCLUDE_CSLIP
266 cbuff = xchg(&sl->cbuff, cbuff);
269 if (sl->xleft <= len) {
270 memcpy(sl->xbuff, sl->xhead, sl->xleft);
273 dev->stats.tx_dropped++;
276 sl->xhead = sl->xbuff;
279 if (sl->rcount <= len) {
280 memcpy(sl->rbuff, rbuff, sl->rcount);
283 dev->stats.rx_over_errors++;
284 set_bit(SLF_ERROR, &sl->flags);
293 spin_unlock_bh(&sl->lock);
298 #ifdef SL_INCLUDE_CSLIP
305 /* Set the "sending" flag. This must be atomic hence the set_bit. */
306 static inline void sl_lock(struct slip *sl)
308 netif_stop_queue(sl->dev);
312 /* Clear the "sending" flag. This must be atomic, hence the ASM. */
313 static inline void sl_unlock(struct slip *sl)
315 netif_wake_queue(sl->dev);
318 /* Send one completely decapsulated IP datagram to the IP layer. */
319 static void sl_bump(struct slip *sl)
321 struct net_device *dev = sl->dev;
326 #ifdef SL_INCLUDE_CSLIP
327 if (sl->mode & (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) {
328 unsigned char c = sl->rbuff[0];
329 if (c & SL_TYPE_COMPRESSED_TCP) {
330 /* ignore compressed packets when CSLIP is off */
331 if (!(sl->mode & SL_MODE_CSLIP)) {
332 printk(KERN_WARNING "%s: compressed packet ignored\n", dev->name);
335 /* make sure we've reserved enough space for uncompress
337 if (count + 80 > sl->buffsize) {
338 dev->stats.rx_over_errors++;
341 count = slhc_uncompress(sl->slcomp, sl->rbuff, count);
344 } else if (c >= SL_TYPE_UNCOMPRESSED_TCP) {
345 if (!(sl->mode & SL_MODE_CSLIP)) {
346 /* turn on header compression */
347 sl->mode |= SL_MODE_CSLIP;
348 sl->mode &= ~SL_MODE_ADAPTIVE;
349 printk(KERN_INFO "%s: header compression turned on\n", dev->name);
351 sl->rbuff[0] &= 0x4f;
352 if (slhc_remember(sl->slcomp, sl->rbuff, count) <= 0)
356 #endif /* SL_INCLUDE_CSLIP */
358 dev->stats.rx_bytes += count;
360 skb = dev_alloc_skb(count);
362 printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", dev->name);
363 dev->stats.rx_dropped++;
367 memcpy(skb_put(skb, count), sl->rbuff, count);
368 skb_reset_mac_header(skb);
369 skb->protocol = htons(ETH_P_IP);
371 dev->stats.rx_packets++;
374 /* Encapsulate one IP datagram and stuff into a TTY queue. */
375 static void sl_encaps(struct slip *sl, unsigned char *icp, int len)
380 if (len > sl->mtu) { /* Sigh, shouldn't occur BUT ... */
381 printk(KERN_WARNING "%s: truncating oversized transmit packet!\n", sl->dev->name);
382 sl->dev->stats.tx_dropped++;
388 #ifdef SL_INCLUDE_CSLIP
389 if (sl->mode & SL_MODE_CSLIP)
390 len = slhc_compress(sl->slcomp, p, len, sl->cbuff, &p, 1);
392 #ifdef CONFIG_SLIP_MODE_SLIP6
393 if (sl->mode & SL_MODE_SLIP6)
394 count = slip_esc6(p, sl->xbuff, len);
397 count = slip_esc(p, sl->xbuff, len);
399 /* Order of next two lines is *very* important.
400 * When we are sending a little amount of data,
401 * the transfer may be completed inside the ops->write()
402 * routine, because it's running with interrupts enabled.
403 * In this case we *never* got WRITE_WAKEUP event,
404 * if we did not request it before write operation.
405 * 14 Oct 1994 Dmitry Gorodchanin.
407 set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
408 actual = sl->tty->ops->write(sl->tty, sl->xbuff, count);
409 #ifdef SL_CHECK_TRANSMIT
410 netif_trans_update(sl->dev);
412 sl->xleft = count - actual;
413 sl->xhead = sl->xbuff + actual;
414 #ifdef CONFIG_SLIP_SMART
416 clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */
420 /* Write out any remaining transmit buffer. Scheduled when tty is writable */
421 static void slip_transmit(struct work_struct *work)
423 struct slip *sl = container_of(work, struct slip, tx_work);
426 spin_lock_bh(&sl->lock);
427 /* First make sure we're connected. */
428 if (!sl->tty || sl->magic != SLIP_MAGIC || !netif_running(sl->dev)) {
429 spin_unlock_bh(&sl->lock);
433 if (sl->xleft <= 0) {
434 /* Now serial buffer is almost free & we can start
435 * transmission of another packet */
436 sl->dev->stats.tx_packets++;
437 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
438 spin_unlock_bh(&sl->lock);
443 actual = sl->tty->ops->write(sl->tty, sl->xhead, sl->xleft);
446 spin_unlock_bh(&sl->lock);
450 * Called by the driver when there's room for more data.
451 * Schedule the transmit.
453 static void slip_write_wakeup(struct tty_struct *tty)
458 sl = rcu_dereference(tty->disc_data);
462 schedule_work(&sl->tx_work);
467 static void sl_tx_timeout(struct net_device *dev)
469 struct slip *sl = netdev_priv(dev);
471 spin_lock(&sl->lock);
473 if (netif_queue_stopped(dev)) {
474 if (!netif_running(dev))
477 /* May be we must check transmitter timeout here ?
478 * 14 Oct 1994 Dmitry Gorodchanin.
480 #ifdef SL_CHECK_TRANSMIT
481 if (time_before(jiffies, dev_trans_start(dev) + 20 * HZ)) {
482 /* 20 sec timeout not reached */
485 printk(KERN_WARNING "%s: transmit timed out, %s?\n",
487 (tty_chars_in_buffer(sl->tty) || sl->xleft) ?
488 "bad line quality" : "driver error");
490 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
495 spin_unlock(&sl->lock);
499 /* Encapsulate an IP datagram and kick it into a TTY queue. */
501 sl_xmit(struct sk_buff *skb, struct net_device *dev)
503 struct slip *sl = netdev_priv(dev);
505 spin_lock(&sl->lock);
506 if (!netif_running(dev)) {
507 spin_unlock(&sl->lock);
508 printk(KERN_WARNING "%s: xmit call when iface is down\n", dev->name);
512 if (sl->tty == NULL) {
513 spin_unlock(&sl->lock);
519 dev->stats.tx_bytes += skb->len;
520 sl_encaps(sl, skb->data, skb->len);
521 spin_unlock(&sl->lock);
528 /******************************************
529 * Routines looking at netdevice side.
530 ******************************************/
532 /* Netdevice UP -> DOWN routine */
535 sl_close(struct net_device *dev)
537 struct slip *sl = netdev_priv(dev);
539 spin_lock_bh(&sl->lock);
541 /* TTY discipline is running. */
542 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
543 netif_stop_queue(dev);
546 spin_unlock_bh(&sl->lock);
551 /* Netdevice DOWN -> UP routine */
553 static int sl_open(struct net_device *dev)
555 struct slip *sl = netdev_priv(dev);
560 sl->flags &= (1 << SLF_INUSE);
561 netif_start_queue(dev);
565 /* Netdevice change MTU request */
567 static int sl_change_mtu(struct net_device *dev, int new_mtu)
569 struct slip *sl = netdev_priv(dev);
571 if (new_mtu < 68 || new_mtu > 65534)
574 if (new_mtu != dev->mtu)
575 return sl_realloc_bufs(sl, new_mtu);
579 /* Netdevice get statistics request */
581 static struct rtnl_link_stats64 *
582 sl_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
584 struct net_device_stats *devstats = &dev->stats;
585 #ifdef SL_INCLUDE_CSLIP
586 struct slip *sl = netdev_priv(dev);
587 struct slcompress *comp = sl->slcomp;
589 stats->rx_packets = devstats->rx_packets;
590 stats->tx_packets = devstats->tx_packets;
591 stats->rx_bytes = devstats->rx_bytes;
592 stats->tx_bytes = devstats->tx_bytes;
593 stats->rx_dropped = devstats->rx_dropped;
594 stats->tx_dropped = devstats->tx_dropped;
595 stats->tx_errors = devstats->tx_errors;
596 stats->rx_errors = devstats->rx_errors;
597 stats->rx_over_errors = devstats->rx_over_errors;
599 #ifdef SL_INCLUDE_CSLIP
601 /* Generic compressed statistics */
602 stats->rx_compressed = comp->sls_i_compressed;
603 stats->tx_compressed = comp->sls_o_compressed;
605 /* Are we really still needs this? */
606 stats->rx_fifo_errors += comp->sls_i_compressed;
607 stats->rx_dropped += comp->sls_i_tossed;
608 stats->tx_fifo_errors += comp->sls_o_compressed;
609 stats->collisions += comp->sls_o_misses;
615 /* Netdevice register callback */
617 static int sl_init(struct net_device *dev)
619 struct slip *sl = netdev_priv(dev);
622 * Finish setting up the DEVICE info.
626 dev->type = ARPHRD_SLIP + sl->mode;
627 #ifdef SL_CHECK_TRANSMIT
628 dev->watchdog_timeo = 20*HZ;
634 static void sl_uninit(struct net_device *dev)
636 struct slip *sl = netdev_priv(dev);
641 /* Hook the destructor so we can free slip devices at the right point in time */
642 static void sl_free_netdev(struct net_device *dev)
644 int i = dev->base_addr;
649 static const struct net_device_ops sl_netdev_ops = {
651 .ndo_uninit = sl_uninit,
653 .ndo_stop = sl_close,
654 .ndo_start_xmit = sl_xmit,
655 .ndo_get_stats64 = sl_get_stats64,
656 .ndo_change_mtu = sl_change_mtu,
657 .ndo_tx_timeout = sl_tx_timeout,
658 #ifdef CONFIG_SLIP_SMART
659 .ndo_do_ioctl = sl_ioctl,
664 static void sl_setup(struct net_device *dev)
666 dev->netdev_ops = &sl_netdev_ops;
667 dev->destructor = sl_free_netdev;
669 dev->hard_header_len = 0;
671 dev->tx_queue_len = 10;
673 /* New-style flags. */
674 dev->flags = IFF_NOARP|IFF_POINTOPOINT|IFF_MULTICAST;
677 /******************************************
678 Routines looking at TTY side.
679 ******************************************/
683 * Handle the 'receiver data ready' interrupt.
684 * This function is called by the 'tty_io' module in the kernel when
685 * a block of SLIP data has been received, which can now be decapsulated
686 * and sent on to some IP layer for further processing. This will not
687 * be re-entered while running but other ldisc functions may be called
691 static void slip_receive_buf(struct tty_struct *tty, const unsigned char *cp,
694 struct slip *sl = tty->disc_data;
696 if (!sl || sl->magic != SLIP_MAGIC || !netif_running(sl->dev))
699 /* Read the characters out of the buffer */
702 if (!test_and_set_bit(SLF_ERROR, &sl->flags))
703 sl->dev->stats.rx_errors++;
707 #ifdef CONFIG_SLIP_MODE_SLIP6
708 if (sl->mode & SL_MODE_SLIP6)
709 slip_unesc6(sl, *cp++);
712 slip_unesc(sl, *cp++);
716 /************************************
717 * slip_open helper routines.
718 ************************************/
720 /* Collect hanged up channels */
721 static void sl_sync(void)
724 struct net_device *dev;
727 for (i = 0; i < slip_maxdev; i++) {
732 sl = netdev_priv(dev);
733 if (sl->tty || sl->leased)
735 if (dev->flags & IFF_UP)
741 /* Find a free SLIP channel, and link in this `tty' line. */
742 static struct slip *sl_alloc(dev_t line)
746 struct net_device *dev = NULL;
749 for (i = 0; i < slip_maxdev; i++) {
754 /* Sorry, too many, all slots in use */
755 if (i >= slip_maxdev)
758 sprintf(name, "sl%d", i);
759 dev = alloc_netdev(sizeof(*sl), name, NET_NAME_UNKNOWN, sl_setup);
764 sl = netdev_priv(dev);
766 /* Initialize channel control data */
767 sl->magic = SLIP_MAGIC;
769 spin_lock_init(&sl->lock);
770 INIT_WORK(&sl->tx_work, slip_transmit);
771 sl->mode = SL_MODE_DEFAULT;
772 #ifdef CONFIG_SLIP_SMART
773 /* initialize timer_list struct */
774 init_timer(&sl->keepalive_timer);
775 sl->keepalive_timer.data = (unsigned long)sl;
776 sl->keepalive_timer.function = sl_keepalive;
777 init_timer(&sl->outfill_timer);
778 sl->outfill_timer.data = (unsigned long)sl;
779 sl->outfill_timer.function = sl_outfill;
786 * Open the high-level part of the SLIP channel.
787 * This function is called by the TTY module when the
788 * SLIP line discipline is called for. Because we are
789 * sure the tty line exists, we only have to link it to
790 * a free SLIP channel...
792 * Called in process context serialized from other ldisc calls.
795 static int slip_open(struct tty_struct *tty)
800 if (!capable(CAP_NET_ADMIN))
803 if (tty->ops->write == NULL)
806 /* RTnetlink lock is misused here to serialize concurrent
807 opens of slip channels. There are better ways, but it is
812 /* Collect hanged up channels. */
818 /* First make sure we're not already connected. */
819 if (sl && sl->magic == SLIP_MAGIC)
822 /* OK. Find a free SLIP channel to use. */
824 sl = sl_alloc(tty_devnum(tty));
830 sl->pid = current->pid;
832 if (!test_bit(SLF_INUSE, &sl->flags)) {
833 /* Perform the low-level SLIP initialization. */
834 err = sl_alloc_bufs(sl, SL_MTU);
838 set_bit(SLF_INUSE, &sl->flags);
840 err = register_netdevice(sl->dev);
845 #ifdef CONFIG_SLIP_SMART
847 sl->keepalive_timer.expires = jiffies + sl->keepalive * HZ;
848 add_timer(&sl->keepalive_timer);
851 sl->outfill_timer.expires = jiffies + sl->outfill * HZ;
852 add_timer(&sl->outfill_timer);
856 /* Done. We have linked the TTY line to a channel. */
858 tty->receive_room = 65536; /* We don't flow control */
860 /* TTY layer expects 0 on success */
868 tty->disc_data = NULL;
869 clear_bit(SLF_INUSE, &sl->flags);
870 /* do not call free_netdev before rtnl_unlock */
872 sl_free_netdev(sl->dev);
878 /* Count references from TTY module */
883 * Close down a SLIP channel.
884 * This means flushing out any pending queues, and then returning. This
885 * call is serialized against other ldisc functions.
887 * We also use this method fo a hangup event
890 static void slip_close(struct tty_struct *tty)
892 struct slip *sl = tty->disc_data;
894 /* First make sure we're connected. */
895 if (!sl || sl->magic != SLIP_MAGIC || sl->tty != tty)
898 spin_lock_bh(&sl->lock);
899 rcu_assign_pointer(tty->disc_data, NULL);
901 spin_unlock_bh(&sl->lock);
904 flush_work(&sl->tx_work);
906 /* VSV = very important to remove timers */
907 #ifdef CONFIG_SLIP_SMART
908 del_timer_sync(&sl->keepalive_timer);
909 del_timer_sync(&sl->outfill_timer);
911 /* Flush network side */
912 unregister_netdev(sl->dev);
913 /* This will complete via sl_free_netdev */
916 static int slip_hangup(struct tty_struct *tty)
921 /************************************************************************
922 * STANDARD SLIP ENCAPSULATION *
923 ************************************************************************/
925 static int slip_esc(unsigned char *s, unsigned char *d, int len)
927 unsigned char *ptr = d;
931 * Send an initial END character to flush out any
932 * data that may have accumulated in the receiver
939 * For each byte in the packet, send the appropriate
940 * character sequence, according to the SLIP protocol.
962 static void slip_unesc(struct slip *sl, unsigned char s)
967 #ifdef CONFIG_SLIP_SMART
968 /* drop keeptest bit = VSV */
969 if (test_bit(SLF_KEEPTEST, &sl->flags))
970 clear_bit(SLF_KEEPTEST, &sl->flags);
973 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
976 clear_bit(SLF_ESCAPE, &sl->flags);
981 set_bit(SLF_ESCAPE, &sl->flags);
984 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
988 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags))
992 if (!test_bit(SLF_ERROR, &sl->flags)) {
993 if (sl->rcount < sl->buffsize) {
994 sl->rbuff[sl->rcount++] = s;
997 sl->dev->stats.rx_over_errors++;
998 set_bit(SLF_ERROR, &sl->flags);
1003 #ifdef CONFIG_SLIP_MODE_SLIP6
1004 /************************************************************************
1005 * 6 BIT SLIP ENCAPSULATION *
1006 ************************************************************************/
1008 static int slip_esc6(unsigned char *s, unsigned char *d, int len)
1010 unsigned char *ptr = d;
1013 unsigned short v = 0;
1017 * Send an initial END character to flush out any
1018 * data that may have accumulated in the receiver
1019 * due to line noise.
1025 * Encode the packet into printable ascii characters
1028 for (i = 0; i < len; ++i) {
1029 v = (v << 8) | s[i];
1033 c = 0x30 + ((v >> bits) & 0x3F);
1038 c = 0x30 + ((v << (6 - bits)) & 0x3F);
1045 static void slip_unesc6(struct slip *sl, unsigned char s)
1050 #ifdef CONFIG_SLIP_SMART
1051 /* drop keeptest bit = VSV */
1052 if (test_bit(SLF_KEEPTEST, &sl->flags))
1053 clear_bit(SLF_KEEPTEST, &sl->flags);
1056 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
1062 } else if (s >= 0x30 && s < 0x70) {
1063 sl->xdata = (sl->xdata << 6) | ((s - 0x30) & 0x3F);
1065 if (sl->xbits >= 8) {
1067 c = (unsigned char)(sl->xdata >> sl->xbits);
1068 if (!test_bit(SLF_ERROR, &sl->flags)) {
1069 if (sl->rcount < sl->buffsize) {
1070 sl->rbuff[sl->rcount++] = c;
1073 sl->dev->stats.rx_over_errors++;
1074 set_bit(SLF_ERROR, &sl->flags);
1079 #endif /* CONFIG_SLIP_MODE_SLIP6 */
1081 /* Perform I/O control on an active SLIP channel. */
1082 static int slip_ioctl(struct tty_struct *tty, struct file *file,
1083 unsigned int cmd, unsigned long arg)
1085 struct slip *sl = tty->disc_data;
1087 int __user *p = (int __user *)arg;
1089 /* First make sure we're connected. */
1090 if (!sl || sl->magic != SLIP_MAGIC)
1095 tmp = strlen(sl->dev->name) + 1;
1096 if (copy_to_user((void __user *)arg, sl->dev->name, tmp))
1101 if (put_user(sl->mode, p))
1106 if (get_user(tmp, p))
1108 #ifndef SL_INCLUDE_CSLIP
1109 if (tmp & (SL_MODE_CSLIP|SL_MODE_ADAPTIVE))
1112 if ((tmp & (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) ==
1113 (SL_MODE_ADAPTIVE | SL_MODE_CSLIP))
1114 /* return -EINVAL; */
1115 tmp &= ~SL_MODE_ADAPTIVE;
1117 #ifndef CONFIG_SLIP_MODE_SLIP6
1118 if (tmp & SL_MODE_SLIP6)
1122 sl->dev->type = ARPHRD_SLIP + sl->mode;
1128 #ifdef CONFIG_SLIP_SMART
1129 /* VSV changes start here */
1130 case SIOCSKEEPALIVE:
1131 if (get_user(tmp, p))
1133 if (tmp > 255) /* max for unchar */
1136 spin_lock_bh(&sl->lock);
1138 spin_unlock_bh(&sl->lock);
1141 sl->keepalive = (u8)tmp;
1142 if (sl->keepalive != 0) {
1143 mod_timer(&sl->keepalive_timer,
1144 jiffies + sl->keepalive * HZ);
1145 set_bit(SLF_KEEPTEST, &sl->flags);
1147 del_timer(&sl->keepalive_timer);
1148 spin_unlock_bh(&sl->lock);
1151 case SIOCGKEEPALIVE:
1152 if (put_user(sl->keepalive, p))
1157 if (get_user(tmp, p))
1159 if (tmp > 255) /* max for unchar */
1161 spin_lock_bh(&sl->lock);
1163 spin_unlock_bh(&sl->lock);
1166 sl->outfill = (u8)tmp;
1167 if (sl->outfill != 0) {
1168 mod_timer(&sl->outfill_timer,
1169 jiffies + sl->outfill * HZ);
1170 set_bit(SLF_OUTWAIT, &sl->flags);
1172 del_timer(&sl->outfill_timer);
1173 spin_unlock_bh(&sl->lock);
1177 if (put_user(sl->outfill, p))
1180 /* VSV changes end */
1183 return tty_mode_ioctl(tty, file, cmd, arg);
1187 #ifdef CONFIG_COMPAT
1188 static long slip_compat_ioctl(struct tty_struct *tty, struct file *file,
1189 unsigned int cmd, unsigned long arg)
1196 case SIOCSKEEPALIVE:
1197 case SIOCGKEEPALIVE:
1200 return slip_ioctl(tty, file, cmd,
1201 (unsigned long)compat_ptr(arg));
1204 return -ENOIOCTLCMD;
1208 /* VSV changes start here */
1209 #ifdef CONFIG_SLIP_SMART
1210 /* function do_ioctl called from net/core/dev.c
1211 to allow get/set outfill/keepalive parameter
1214 static int sl_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
1216 struct slip *sl = netdev_priv(dev);
1217 unsigned long *p = (unsigned long *)&rq->ifr_ifru;
1219 if (sl == NULL) /* Allocation failed ?? */
1222 spin_lock_bh(&sl->lock);
1225 spin_unlock_bh(&sl->lock);
1230 case SIOCSKEEPALIVE:
1231 /* max for unchar */
1232 if ((unsigned)*p > 255) {
1233 spin_unlock_bh(&sl->lock);
1236 sl->keepalive = (u8)*p;
1237 if (sl->keepalive != 0) {
1238 sl->keepalive_timer.expires =
1239 jiffies + sl->keepalive * HZ;
1240 mod_timer(&sl->keepalive_timer,
1241 jiffies + sl->keepalive * HZ);
1242 set_bit(SLF_KEEPTEST, &sl->flags);
1244 del_timer(&sl->keepalive_timer);
1247 case SIOCGKEEPALIVE:
1252 if ((unsigned)*p > 255) { /* max for unchar */
1253 spin_unlock_bh(&sl->lock);
1256 sl->outfill = (u8)*p;
1257 if (sl->outfill != 0) {
1258 mod_timer(&sl->outfill_timer,
1259 jiffies + sl->outfill * HZ);
1260 set_bit(SLF_OUTWAIT, &sl->flags);
1262 del_timer(&sl->outfill_timer);
1270 /* Resolve race condition, when ioctl'ing hanged up
1271 and opened by another process device.
1273 if (sl->tty != current->signal->tty &&
1274 sl->pid != current->pid) {
1275 spin_unlock_bh(&sl->lock);
1286 spin_unlock_bh(&sl->lock);
1290 /* VSV changes end */
1292 static struct tty_ldisc_ops sl_ldisc = {
1293 .owner = THIS_MODULE,
1294 .magic = TTY_LDISC_MAGIC,
1297 .close = slip_close,
1298 .hangup = slip_hangup,
1299 .ioctl = slip_ioctl,
1300 #ifdef CONFIG_COMPAT
1301 .compat_ioctl = slip_compat_ioctl,
1303 .receive_buf = slip_receive_buf,
1304 .write_wakeup = slip_write_wakeup,
1307 static int __init slip_init(void)
1311 if (slip_maxdev < 4)
1312 slip_maxdev = 4; /* Sanity */
1314 printk(KERN_INFO "SLIP: version %s (dynamic channels, max=%d)"
1315 #ifdef CONFIG_SLIP_MODE_SLIP6
1316 " (6 bit encapsulation enabled)"
1319 SLIP_VERSION, slip_maxdev);
1320 #if defined(SL_INCLUDE_CSLIP)
1321 printk(KERN_INFO "CSLIP: code copyright 1989 Regents of the University of California.\n");
1323 #ifdef CONFIG_SLIP_SMART
1324 printk(KERN_INFO "SLIP linefill/keepalive option.\n");
1327 slip_devs = kzalloc(sizeof(struct net_device *)*slip_maxdev,
1332 /* Fill in our line protocol discipline, and register it */
1333 status = tty_register_ldisc(N_SLIP, &sl_ldisc);
1335 printk(KERN_ERR "SLIP: can't register line discipline (err = %d)\n", status);
1341 static void __exit slip_exit(void)
1344 struct net_device *dev;
1346 unsigned long timeout = jiffies + HZ;
1349 if (slip_devs == NULL)
1352 /* First of all: check for active disciplines and hangup them.
1356 msleep_interruptible(100);
1359 for (i = 0; i < slip_maxdev; i++) {
1363 sl = netdev_priv(dev);
1364 spin_lock_bh(&sl->lock);
1367 tty_hangup(sl->tty);
1369 spin_unlock_bh(&sl->lock);
1371 } while (busy && time_before(jiffies, timeout));
1373 /* FIXME: hangup is async so we should wait when doing this second
1376 for (i = 0; i < slip_maxdev; i++) {
1380 slip_devs[i] = NULL;
1382 sl = netdev_priv(dev);
1384 printk(KERN_ERR "%s: tty discipline still running\n",
1386 /* Intentionally leak the control block. */
1387 dev->destructor = NULL;
1390 unregister_netdev(dev);
1396 i = tty_unregister_ldisc(N_SLIP);
1398 printk(KERN_ERR "SLIP: can't unregister line discipline (err = %d)\n", i);
1401 module_init(slip_init);
1402 module_exit(slip_exit);
1404 #ifdef CONFIG_SLIP_SMART
1406 * This is start of the code for multislip style line checking
1407 * added by Stanislav Voronyi. All changes before marked VSV
1410 static void sl_outfill(unsigned long sls)
1412 struct slip *sl = (struct slip *)sls;
1414 spin_lock(&sl->lock);
1416 if (sl->tty == NULL)
1420 if (test_bit(SLF_OUTWAIT, &sl->flags)) {
1421 /* no packets were transmitted, do outfill */
1422 #ifdef CONFIG_SLIP_MODE_SLIP6
1423 unsigned char s = (sl->mode & SL_MODE_SLIP6)?0x70:END;
1425 unsigned char s = END;
1427 /* put END into tty queue. Is it right ??? */
1428 if (!netif_queue_stopped(sl->dev)) {
1429 /* if device busy no outfill */
1430 sl->tty->ops->write(sl->tty, &s, 1);
1433 set_bit(SLF_OUTWAIT, &sl->flags);
1435 mod_timer(&sl->outfill_timer, jiffies+sl->outfill*HZ);
1438 spin_unlock(&sl->lock);
1441 static void sl_keepalive(unsigned long sls)
1443 struct slip *sl = (struct slip *)sls;
1445 spin_lock(&sl->lock);
1447 if (sl->tty == NULL)
1450 if (sl->keepalive) {
1451 if (test_bit(SLF_KEEPTEST, &sl->flags)) {
1452 /* keepalive still high :(, we must hangup */
1454 /* outfill timer must be deleted too */
1455 (void)del_timer(&sl->outfill_timer);
1456 printk(KERN_DEBUG "%s: no packets received during keepalive timeout, hangup.\n", sl->dev->name);
1457 /* this must hangup tty & close slip */
1458 tty_hangup(sl->tty);
1459 /* I think we need not something else */
1462 set_bit(SLF_KEEPTEST, &sl->flags);
1464 mod_timer(&sl->keepalive_timer, jiffies+sl->keepalive*HZ);
1467 spin_unlock(&sl->lock);
1471 MODULE_LICENSE("GPL");
1472 MODULE_ALIAS_LDISC(N_SLIP);