1 /* 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. 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 35 * correctly. 36 * 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. 49 * 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. 58 * Vitaly E. Lavrov : Sane behaviour on tty hangup. 59 * Alexey Kuznetsov : Cleanup interfaces to tty & netdevice 60 * modules. 61 */ 62 63 #define SL_CHECK_TRANSMIT 64 #include <linux/module.h> 65 #include <linux/moduleparam.h> 66 67 #include <linux/uaccess.h> 68 #include <linux/bitops.h> 69 #include <linux/sched.h> 70 #include <linux/string.h> 71 #include <linux/mm.h> 72 #include <linux/interrupt.h> 73 #include <linux/in.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> 87 #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 96 static struct net_device **slip_devs; 97 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"); 101 102 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); 107 #endif 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); 112 #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 *********************************/ 124 125 /* 126 Allocate channel buffers. 127 */ 128 129 static int sl_alloc_bufs(struct slip *sl, int mtu) 130 { 131 int err = -ENOBUFS; 132 unsigned long len; 133 char *rbuff = NULL; 134 char *xbuff = NULL; 135 #ifdef SL_INCLUDE_CSLIP 136 char *cbuff = NULL; 137 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 (IS_ERR(slcomp)) 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 #endif 186 #ifdef CONFIG_SLIP_MODE_SLIP6 187 sl->xdata = 0; 188 sl->xbits = 0; 189 #endif 190 spin_unlock_bh(&sl->lock); 191 err = 0; 192 193 /* Cleanup */ 194 err_exit: 195 #ifdef SL_INCLUDE_CSLIP 196 kfree(cbuff); 197 slhc_free(slcomp); 198 #endif 199 kfree(xbuff); 200 kfree(rbuff); 201 return err; 202 } 203 204 /* Free a SLIP channel buffers. */ 205 static void sl_free_bufs(struct slip *sl) 206 { 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)); 213 #endif 214 } 215 216 /* 217 Reallocate slip channel buffers. 218 */ 219 220 static int sl_realloc_bufs(struct slip *sl, int mtu) 221 { 222 int err = 0; 223 struct net_device *dev = sl->dev; 224 unsigned char *xbuff, *rbuff; 225 #ifdef SL_INCLUDE_CSLIP 226 unsigned char *cbuff; 227 #endif 228 int len = mtu * 2; 229 230 /* 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 233 * an MSS of 128 234 */ 235 if (len < 576 * 2) 236 len = 576 * 2; 237 238 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); 242 #endif 243 244 245 #ifdef SL_INCLUDE_CSLIP 246 if (xbuff == NULL || rbuff == NULL || cbuff == NULL) { 247 #else 248 if (xbuff == NULL || rbuff == NULL) { 249 #endif 250 if (mtu > sl->mtu) { 251 printk(KERN_WARNING "%s: unable to grow slip buffers, MTU change cancelled.\n", 252 dev->name); 253 err = -ENOBUFS; 254 } 255 goto done; 256 } 257 spin_lock_bh(&sl->lock); 258 259 err = -ENODEV; 260 if (sl->tty == NULL) 261 goto done_on_bh; 262 263 xbuff = xchg(&sl->xbuff, xbuff); 264 rbuff = xchg(&sl->rbuff, rbuff); 265 #ifdef SL_INCLUDE_CSLIP 266 cbuff = xchg(&sl->cbuff, cbuff); 267 #endif 268 if (sl->xleft) { 269 if (sl->xleft <= len) { 270 memcpy(sl->xbuff, sl->xhead, sl->xleft); 271 } else { 272 sl->xleft = 0; 273 dev->stats.tx_dropped++; 274 } 275 } 276 sl->xhead = sl->xbuff; 277 278 if (sl->rcount) { 279 if (sl->rcount <= len) { 280 memcpy(sl->rbuff, rbuff, sl->rcount); 281 } else { 282 sl->rcount = 0; 283 dev->stats.rx_over_errors++; 284 set_bit(SLF_ERROR, &sl->flags); 285 } 286 } 287 sl->mtu = mtu; 288 dev->mtu = mtu; 289 sl->buffsize = len; 290 err = 0; 291 292 done_on_bh: 293 spin_unlock_bh(&sl->lock); 294 295 done: 296 kfree(xbuff); 297 kfree(rbuff); 298 #ifdef SL_INCLUDE_CSLIP 299 kfree(cbuff); 300 #endif 301 return err; 302 } 303 304 305 /* Set the "sending" flag. This must be atomic hence the set_bit. */ 306 static inline void sl_lock(struct slip *sl) 307 { 308 netif_stop_queue(sl->dev); 309 } 310 311 312 /* Clear the "sending" flag. This must be atomic, hence the ASM. */ 313 static inline void sl_unlock(struct slip *sl) 314 { 315 netif_wake_queue(sl->dev); 316 } 317 318 /* Send one completely decapsulated IP datagram to the IP layer. */ 319 static void sl_bump(struct slip *sl) 320 { 321 struct net_device *dev = sl->dev; 322 struct sk_buff *skb; 323 int count; 324 325 count = sl->rcount; 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); 333 return; 334 } 335 /* make sure we've reserved enough space for uncompress 336 to use */ 337 if (count + 80 > sl->buffsize) { 338 dev->stats.rx_over_errors++; 339 return; 340 } 341 count = slhc_uncompress(sl->slcomp, sl->rbuff, count); 342 if (count <= 0) 343 return; 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); 350 } 351 sl->rbuff[0] &= 0x4f; 352 if (slhc_remember(sl->slcomp, sl->rbuff, count) <= 0) 353 return; 354 } 355 } 356 #endif /* SL_INCLUDE_CSLIP */ 357 358 dev->stats.rx_bytes += count; 359 360 skb = dev_alloc_skb(count); 361 if (skb == NULL) { 362 printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", dev->name); 363 dev->stats.rx_dropped++; 364 return; 365 } 366 skb->dev = dev; 367 memcpy(skb_put(skb, count), sl->rbuff, count); 368 skb_reset_mac_header(skb); 369 skb->protocol = htons(ETH_P_IP); 370 netif_rx_ni(skb); 371 dev->stats.rx_packets++; 372 } 373 374 /* Encapsulate one IP datagram and stuff into a TTY queue. */ 375 static void sl_encaps(struct slip *sl, unsigned char *icp, int len) 376 { 377 unsigned char *p; 378 int actual, count; 379 380 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++; 383 sl_unlock(sl); 384 return; 385 } 386 387 p = icp; 388 #ifdef SL_INCLUDE_CSLIP 389 if (sl->mode & SL_MODE_CSLIP) 390 len = slhc_compress(sl->slcomp, p, len, sl->cbuff, &p, 1); 391 #endif 392 #ifdef CONFIG_SLIP_MODE_SLIP6 393 if (sl->mode & SL_MODE_SLIP6) 394 count = slip_esc6(p, sl->xbuff, len); 395 else 396 #endif 397 count = slip_esc(p, sl->xbuff, len); 398 399 /* 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. 406 */ 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); 411 #endif 412 sl->xleft = count - actual; 413 sl->xhead = sl->xbuff + actual; 414 #ifdef CONFIG_SLIP_SMART 415 /* VSV */ 416 clear_bit(SLF_OUTWAIT, &sl->flags); /* reset outfill flag */ 417 #endif 418 } 419 420 /* Write out any remaining transmit buffer. Scheduled when tty is writable */ 421 static void slip_transmit(struct work_struct *work) 422 { 423 struct slip *sl = container_of(work, struct slip, tx_work); 424 int actual; 425 426 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); 430 return; 431 } 432 433 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); 439 sl_unlock(sl); 440 return; 441 } 442 443 actual = sl->tty->ops->write(sl->tty, sl->xhead, sl->xleft); 444 sl->xleft -= actual; 445 sl->xhead += actual; 446 spin_unlock_bh(&sl->lock); 447 } 448 449 /* 450 * Called by the driver when there's room for more data. 451 * Schedule the transmit. 452 */ 453 static void slip_write_wakeup(struct tty_struct *tty) 454 { 455 struct slip *sl = tty->disc_data; 456 457 schedule_work(&sl->tx_work); 458 } 459 460 static void sl_tx_timeout(struct net_device *dev) 461 { 462 struct slip *sl = netdev_priv(dev); 463 464 spin_lock(&sl->lock); 465 466 if (netif_queue_stopped(dev)) { 467 if (!netif_running(dev)) 468 goto out; 469 470 /* May be we must check transmitter timeout here ? 471 * 14 Oct 1994 Dmitry Gorodchanin. 472 */ 473 #ifdef SL_CHECK_TRANSMIT 474 if (time_before(jiffies, dev_trans_start(dev) + 20 * HZ)) { 475 /* 20 sec timeout not reached */ 476 goto out; 477 } 478 printk(KERN_WARNING "%s: transmit timed out, %s?\n", 479 dev->name, 480 (tty_chars_in_buffer(sl->tty) || sl->xleft) ? 481 "bad line quality" : "driver error"); 482 sl->xleft = 0; 483 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); 484 sl_unlock(sl); 485 #endif 486 } 487 out: 488 spin_unlock(&sl->lock); 489 } 490 491 492 /* Encapsulate an IP datagram and kick it into a TTY queue. */ 493 static netdev_tx_t 494 sl_xmit(struct sk_buff *skb, struct net_device *dev) 495 { 496 struct slip *sl = netdev_priv(dev); 497 498 spin_lock(&sl->lock); 499 if (!netif_running(dev)) { 500 spin_unlock(&sl->lock); 501 printk(KERN_WARNING "%s: xmit call when iface is down\n", dev->name); 502 dev_kfree_skb(skb); 503 return NETDEV_TX_OK; 504 } 505 if (sl->tty == NULL) { 506 spin_unlock(&sl->lock); 507 dev_kfree_skb(skb); 508 return NETDEV_TX_OK; 509 } 510 511 sl_lock(sl); 512 dev->stats.tx_bytes += skb->len; 513 sl_encaps(sl, skb->data, skb->len); 514 spin_unlock(&sl->lock); 515 516 dev_kfree_skb(skb); 517 return NETDEV_TX_OK; 518 } 519 520 521 /****************************************** 522 * Routines looking at netdevice side. 523 ******************************************/ 524 525 /* Netdevice UP -> DOWN routine */ 526 527 static int 528 sl_close(struct net_device *dev) 529 { 530 struct slip *sl = netdev_priv(dev); 531 532 spin_lock_bh(&sl->lock); 533 if (sl->tty) 534 /* TTY discipline is running. */ 535 clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); 536 netif_stop_queue(dev); 537 sl->rcount = 0; 538 sl->xleft = 0; 539 spin_unlock_bh(&sl->lock); 540 541 return 0; 542 } 543 544 /* Netdevice DOWN -> UP routine */ 545 546 static int sl_open(struct net_device *dev) 547 { 548 struct slip *sl = netdev_priv(dev); 549 550 if (sl->tty == NULL) 551 return -ENODEV; 552 553 sl->flags &= (1 << SLF_INUSE); 554 netif_start_queue(dev); 555 return 0; 556 } 557 558 /* Netdevice change MTU request */ 559 560 static int sl_change_mtu(struct net_device *dev, int new_mtu) 561 { 562 struct slip *sl = netdev_priv(dev); 563 564 return sl_realloc_bufs(sl, new_mtu); 565 } 566 567 /* Netdevice get statistics request */ 568 569 static struct rtnl_link_stats64 * 570 sl_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) 571 { 572 struct net_device_stats *devstats = &dev->stats; 573 #ifdef SL_INCLUDE_CSLIP 574 struct slip *sl = netdev_priv(dev); 575 struct slcompress *comp = sl->slcomp; 576 #endif 577 stats->rx_packets = devstats->rx_packets; 578 stats->tx_packets = devstats->tx_packets; 579 stats->rx_bytes = devstats->rx_bytes; 580 stats->tx_bytes = devstats->tx_bytes; 581 stats->rx_dropped = devstats->rx_dropped; 582 stats->tx_dropped = devstats->tx_dropped; 583 stats->tx_errors = devstats->tx_errors; 584 stats->rx_errors = devstats->rx_errors; 585 stats->rx_over_errors = devstats->rx_over_errors; 586 587 #ifdef SL_INCLUDE_CSLIP 588 if (comp) { 589 /* Generic compressed statistics */ 590 stats->rx_compressed = comp->sls_i_compressed; 591 stats->tx_compressed = comp->sls_o_compressed; 592 593 /* Are we really still needs this? */ 594 stats->rx_fifo_errors += comp->sls_i_compressed; 595 stats->rx_dropped += comp->sls_i_tossed; 596 stats->tx_fifo_errors += comp->sls_o_compressed; 597 stats->collisions += comp->sls_o_misses; 598 } 599 #endif 600 return stats; 601 } 602 603 /* Netdevice register callback */ 604 605 static int sl_init(struct net_device *dev) 606 { 607 struct slip *sl = netdev_priv(dev); 608 609 /* 610 * Finish setting up the DEVICE info. 611 */ 612 613 dev->mtu = sl->mtu; 614 dev->type = ARPHRD_SLIP + sl->mode; 615 #ifdef SL_CHECK_TRANSMIT 616 dev->watchdog_timeo = 20*HZ; 617 #endif 618 return 0; 619 } 620 621 622 static void sl_uninit(struct net_device *dev) 623 { 624 struct slip *sl = netdev_priv(dev); 625 626 sl_free_bufs(sl); 627 } 628 629 /* Hook the destructor so we can free slip devices at the right point in time */ 630 static void sl_free_netdev(struct net_device *dev) 631 { 632 int i = dev->base_addr; 633 free_netdev(dev); 634 slip_devs[i] = NULL; 635 } 636 637 static const struct net_device_ops sl_netdev_ops = { 638 .ndo_init = sl_init, 639 .ndo_uninit = sl_uninit, 640 .ndo_open = sl_open, 641 .ndo_stop = sl_close, 642 .ndo_start_xmit = sl_xmit, 643 .ndo_get_stats64 = sl_get_stats64, 644 .ndo_change_mtu = sl_change_mtu, 645 .ndo_tx_timeout = sl_tx_timeout, 646 #ifdef CONFIG_SLIP_SMART 647 .ndo_do_ioctl = sl_ioctl, 648 #endif 649 }; 650 651 652 static void sl_setup(struct net_device *dev) 653 { 654 dev->netdev_ops = &sl_netdev_ops; 655 dev->destructor = sl_free_netdev; 656 657 dev->hard_header_len = 0; 658 dev->addr_len = 0; 659 dev->tx_queue_len = 10; 660 661 /* MTU range: 68 - 65534 */ 662 dev->min_mtu = 68; 663 dev->max_mtu = 65534; 664 665 /* New-style flags. */ 666 dev->flags = IFF_NOARP|IFF_POINTOPOINT|IFF_MULTICAST; 667 } 668 669 /****************************************** 670 Routines looking at TTY side. 671 ******************************************/ 672 673 674 /* 675 * Handle the 'receiver data ready' interrupt. 676 * This function is called by the 'tty_io' module in the kernel when 677 * a block of SLIP data has been received, which can now be decapsulated 678 * and sent on to some IP layer for further processing. This will not 679 * be re-entered while running but other ldisc functions may be called 680 * in parallel 681 */ 682 683 static void slip_receive_buf(struct tty_struct *tty, const unsigned char *cp, 684 char *fp, int count) 685 { 686 struct slip *sl = tty->disc_data; 687 688 if (!sl || sl->magic != SLIP_MAGIC || !netif_running(sl->dev)) 689 return; 690 691 /* Read the characters out of the buffer */ 692 while (count--) { 693 if (fp && *fp++) { 694 if (!test_and_set_bit(SLF_ERROR, &sl->flags)) 695 sl->dev->stats.rx_errors++; 696 cp++; 697 continue; 698 } 699 #ifdef CONFIG_SLIP_MODE_SLIP6 700 if (sl->mode & SL_MODE_SLIP6) 701 slip_unesc6(sl, *cp++); 702 else 703 #endif 704 slip_unesc(sl, *cp++); 705 } 706 } 707 708 /************************************ 709 * slip_open helper routines. 710 ************************************/ 711 712 /* Collect hanged up channels */ 713 static void sl_sync(void) 714 { 715 int i; 716 struct net_device *dev; 717 struct slip *sl; 718 719 for (i = 0; i < slip_maxdev; i++) { 720 dev = slip_devs[i]; 721 if (dev == NULL) 722 break; 723 724 sl = netdev_priv(dev); 725 if (sl->tty || sl->leased) 726 continue; 727 if (dev->flags & IFF_UP) 728 dev_close(dev); 729 } 730 } 731 732 733 /* Find a free SLIP channel, and link in this `tty' line. */ 734 static struct slip *sl_alloc(dev_t line) 735 { 736 int i; 737 char name[IFNAMSIZ]; 738 struct net_device *dev = NULL; 739 struct slip *sl; 740 741 for (i = 0; i < slip_maxdev; i++) { 742 dev = slip_devs[i]; 743 if (dev == NULL) 744 break; 745 } 746 /* Sorry, too many, all slots in use */ 747 if (i >= slip_maxdev) 748 return NULL; 749 750 sprintf(name, "sl%d", i); 751 dev = alloc_netdev(sizeof(*sl), name, NET_NAME_UNKNOWN, sl_setup); 752 if (!dev) 753 return NULL; 754 755 dev->base_addr = i; 756 sl = netdev_priv(dev); 757 758 /* Initialize channel control data */ 759 sl->magic = SLIP_MAGIC; 760 sl->dev = dev; 761 spin_lock_init(&sl->lock); 762 INIT_WORK(&sl->tx_work, slip_transmit); 763 sl->mode = SL_MODE_DEFAULT; 764 #ifdef CONFIG_SLIP_SMART 765 /* initialize timer_list struct */ 766 init_timer(&sl->keepalive_timer); 767 sl->keepalive_timer.data = (unsigned long)sl; 768 sl->keepalive_timer.function = sl_keepalive; 769 init_timer(&sl->outfill_timer); 770 sl->outfill_timer.data = (unsigned long)sl; 771 sl->outfill_timer.function = sl_outfill; 772 #endif 773 slip_devs[i] = dev; 774 return sl; 775 } 776 777 /* 778 * Open the high-level part of the SLIP channel. 779 * This function is called by the TTY module when the 780 * SLIP line discipline is called for. Because we are 781 * sure the tty line exists, we only have to link it to 782 * a free SLIP channel... 783 * 784 * Called in process context serialized from other ldisc calls. 785 */ 786 787 static int slip_open(struct tty_struct *tty) 788 { 789 struct slip *sl; 790 int err; 791 792 if (!capable(CAP_NET_ADMIN)) 793 return -EPERM; 794 795 if (tty->ops->write == NULL) 796 return -EOPNOTSUPP; 797 798 /* RTnetlink lock is misused here to serialize concurrent 799 opens of slip channels. There are better ways, but it is 800 the simplest one. 801 */ 802 rtnl_lock(); 803 804 /* Collect hanged up channels. */ 805 sl_sync(); 806 807 sl = tty->disc_data; 808 809 err = -EEXIST; 810 /* First make sure we're not already connected. */ 811 if (sl && sl->magic == SLIP_MAGIC) 812 goto err_exit; 813 814 /* OK. Find a free SLIP channel to use. */ 815 err = -ENFILE; 816 sl = sl_alloc(tty_devnum(tty)); 817 if (sl == NULL) 818 goto err_exit; 819 820 sl->tty = tty; 821 tty->disc_data = sl; 822 sl->pid = current->pid; 823 824 if (!test_bit(SLF_INUSE, &sl->flags)) { 825 /* Perform the low-level SLIP initialization. */ 826 err = sl_alloc_bufs(sl, SL_MTU); 827 if (err) 828 goto err_free_chan; 829 830 set_bit(SLF_INUSE, &sl->flags); 831 832 err = register_netdevice(sl->dev); 833 if (err) 834 goto err_free_bufs; 835 } 836 837 #ifdef CONFIG_SLIP_SMART 838 if (sl->keepalive) { 839 sl->keepalive_timer.expires = jiffies + sl->keepalive * HZ; 840 add_timer(&sl->keepalive_timer); 841 } 842 if (sl->outfill) { 843 sl->outfill_timer.expires = jiffies + sl->outfill * HZ; 844 add_timer(&sl->outfill_timer); 845 } 846 #endif 847 848 /* Done. We have linked the TTY line to a channel. */ 849 rtnl_unlock(); 850 tty->receive_room = 65536; /* We don't flow control */ 851 852 /* TTY layer expects 0 on success */ 853 return 0; 854 855 err_free_bufs: 856 sl_free_bufs(sl); 857 858 err_free_chan: 859 sl->tty = NULL; 860 tty->disc_data = NULL; 861 clear_bit(SLF_INUSE, &sl->flags); 862 863 err_exit: 864 rtnl_unlock(); 865 866 /* Count references from TTY module */ 867 return err; 868 } 869 870 /* 871 * Close down a SLIP channel. 872 * This means flushing out any pending queues, and then returning. This 873 * call is serialized against other ldisc functions. 874 * 875 * We also use this method fo a hangup event 876 */ 877 878 static void slip_close(struct tty_struct *tty) 879 { 880 struct slip *sl = tty->disc_data; 881 882 /* First make sure we're connected. */ 883 if (!sl || sl->magic != SLIP_MAGIC || sl->tty != tty) 884 return; 885 886 spin_lock_bh(&sl->lock); 887 tty->disc_data = NULL; 888 sl->tty = NULL; 889 spin_unlock_bh(&sl->lock); 890 891 flush_work(&sl->tx_work); 892 893 /* VSV = very important to remove timers */ 894 #ifdef CONFIG_SLIP_SMART 895 del_timer_sync(&sl->keepalive_timer); 896 del_timer_sync(&sl->outfill_timer); 897 #endif 898 /* Flush network side */ 899 unregister_netdev(sl->dev); 900 /* This will complete via sl_free_netdev */ 901 } 902 903 static int slip_hangup(struct tty_struct *tty) 904 { 905 slip_close(tty); 906 return 0; 907 } 908 /************************************************************************ 909 * STANDARD SLIP ENCAPSULATION * 910 ************************************************************************/ 911 912 static int slip_esc(unsigned char *s, unsigned char *d, int len) 913 { 914 unsigned char *ptr = d; 915 unsigned char c; 916 917 /* 918 * Send an initial END character to flush out any 919 * data that may have accumulated in the receiver 920 * due to line noise. 921 */ 922 923 *ptr++ = END; 924 925 /* 926 * For each byte in the packet, send the appropriate 927 * character sequence, according to the SLIP protocol. 928 */ 929 930 while (len-- > 0) { 931 switch (c = *s++) { 932 case END: 933 *ptr++ = ESC; 934 *ptr++ = ESC_END; 935 break; 936 case ESC: 937 *ptr++ = ESC; 938 *ptr++ = ESC_ESC; 939 break; 940 default: 941 *ptr++ = c; 942 break; 943 } 944 } 945 *ptr++ = END; 946 return ptr - d; 947 } 948 949 static void slip_unesc(struct slip *sl, unsigned char s) 950 { 951 952 switch (s) { 953 case END: 954 #ifdef CONFIG_SLIP_SMART 955 /* drop keeptest bit = VSV */ 956 if (test_bit(SLF_KEEPTEST, &sl->flags)) 957 clear_bit(SLF_KEEPTEST, &sl->flags); 958 #endif 959 960 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && 961 (sl->rcount > 2)) 962 sl_bump(sl); 963 clear_bit(SLF_ESCAPE, &sl->flags); 964 sl->rcount = 0; 965 return; 966 967 case ESC: 968 set_bit(SLF_ESCAPE, &sl->flags); 969 return; 970 case ESC_ESC: 971 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) 972 s = ESC; 973 break; 974 case ESC_END: 975 if (test_and_clear_bit(SLF_ESCAPE, &sl->flags)) 976 s = END; 977 break; 978 } 979 if (!test_bit(SLF_ERROR, &sl->flags)) { 980 if (sl->rcount < sl->buffsize) { 981 sl->rbuff[sl->rcount++] = s; 982 return; 983 } 984 sl->dev->stats.rx_over_errors++; 985 set_bit(SLF_ERROR, &sl->flags); 986 } 987 } 988 989 990 #ifdef CONFIG_SLIP_MODE_SLIP6 991 /************************************************************************ 992 * 6 BIT SLIP ENCAPSULATION * 993 ************************************************************************/ 994 995 static int slip_esc6(unsigned char *s, unsigned char *d, int len) 996 { 997 unsigned char *ptr = d; 998 unsigned char c; 999 int i; 1000 unsigned short v = 0; 1001 short bits = 0; 1002 1003 /* 1004 * Send an initial END character to flush out any 1005 * data that may have accumulated in the receiver 1006 * due to line noise. 1007 */ 1008 1009 *ptr++ = 0x70; 1010 1011 /* 1012 * Encode the packet into printable ascii characters 1013 */ 1014 1015 for (i = 0; i < len; ++i) { 1016 v = (v << 8) | s[i]; 1017 bits += 8; 1018 while (bits >= 6) { 1019 bits -= 6; 1020 c = 0x30 + ((v >> bits) & 0x3F); 1021 *ptr++ = c; 1022 } 1023 } 1024 if (bits) { 1025 c = 0x30 + ((v << (6 - bits)) & 0x3F); 1026 *ptr++ = c; 1027 } 1028 *ptr++ = 0x70; 1029 return ptr - d; 1030 } 1031 1032 static void slip_unesc6(struct slip *sl, unsigned char s) 1033 { 1034 unsigned char c; 1035 1036 if (s == 0x70) { 1037 #ifdef CONFIG_SLIP_SMART 1038 /* drop keeptest bit = VSV */ 1039 if (test_bit(SLF_KEEPTEST, &sl->flags)) 1040 clear_bit(SLF_KEEPTEST, &sl->flags); 1041 #endif 1042 1043 if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && 1044 (sl->rcount > 2)) 1045 sl_bump(sl); 1046 sl->rcount = 0; 1047 sl->xbits = 0; 1048 sl->xdata = 0; 1049 } else if (s >= 0x30 && s < 0x70) { 1050 sl->xdata = (sl->xdata << 6) | ((s - 0x30) & 0x3F); 1051 sl->xbits += 6; 1052 if (sl->xbits >= 8) { 1053 sl->xbits -= 8; 1054 c = (unsigned char)(sl->xdata >> sl->xbits); 1055 if (!test_bit(SLF_ERROR, &sl->flags)) { 1056 if (sl->rcount < sl->buffsize) { 1057 sl->rbuff[sl->rcount++] = c; 1058 return; 1059 } 1060 sl->dev->stats.rx_over_errors++; 1061 set_bit(SLF_ERROR, &sl->flags); 1062 } 1063 } 1064 } 1065 } 1066 #endif /* CONFIG_SLIP_MODE_SLIP6 */ 1067 1068 /* Perform I/O control on an active SLIP channel. */ 1069 static int slip_ioctl(struct tty_struct *tty, struct file *file, 1070 unsigned int cmd, unsigned long arg) 1071 { 1072 struct slip *sl = tty->disc_data; 1073 unsigned int tmp; 1074 int __user *p = (int __user *)arg; 1075 1076 /* First make sure we're connected. */ 1077 if (!sl || sl->magic != SLIP_MAGIC) 1078 return -EINVAL; 1079 1080 switch (cmd) { 1081 case SIOCGIFNAME: 1082 tmp = strlen(sl->dev->name) + 1; 1083 if (copy_to_user((void __user *)arg, sl->dev->name, tmp)) 1084 return -EFAULT; 1085 return 0; 1086 1087 case SIOCGIFENCAP: 1088 if (put_user(sl->mode, p)) 1089 return -EFAULT; 1090 return 0; 1091 1092 case SIOCSIFENCAP: 1093 if (get_user(tmp, p)) 1094 return -EFAULT; 1095 #ifndef SL_INCLUDE_CSLIP 1096 if (tmp & (SL_MODE_CSLIP|SL_MODE_ADAPTIVE)) 1097 return -EINVAL; 1098 #else 1099 if ((tmp & (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) == 1100 (SL_MODE_ADAPTIVE | SL_MODE_CSLIP)) 1101 /* return -EINVAL; */ 1102 tmp &= ~SL_MODE_ADAPTIVE; 1103 #endif 1104 #ifndef CONFIG_SLIP_MODE_SLIP6 1105 if (tmp & SL_MODE_SLIP6) 1106 return -EINVAL; 1107 #endif 1108 sl->mode = tmp; 1109 sl->dev->type = ARPHRD_SLIP + sl->mode; 1110 return 0; 1111 1112 case SIOCSIFHWADDR: 1113 return -EINVAL; 1114 1115 #ifdef CONFIG_SLIP_SMART 1116 /* VSV changes start here */ 1117 case SIOCSKEEPALIVE: 1118 if (get_user(tmp, p)) 1119 return -EFAULT; 1120 if (tmp > 255) /* max for unchar */ 1121 return -EINVAL; 1122 1123 spin_lock_bh(&sl->lock); 1124 if (!sl->tty) { 1125 spin_unlock_bh(&sl->lock); 1126 return -ENODEV; 1127 } 1128 sl->keepalive = (u8)tmp; 1129 if (sl->keepalive != 0) { 1130 mod_timer(&sl->keepalive_timer, 1131 jiffies + sl->keepalive * HZ); 1132 set_bit(SLF_KEEPTEST, &sl->flags); 1133 } else 1134 del_timer(&sl->keepalive_timer); 1135 spin_unlock_bh(&sl->lock); 1136 return 0; 1137 1138 case SIOCGKEEPALIVE: 1139 if (put_user(sl->keepalive, p)) 1140 return -EFAULT; 1141 return 0; 1142 1143 case SIOCSOUTFILL: 1144 if (get_user(tmp, p)) 1145 return -EFAULT; 1146 if (tmp > 255) /* max for unchar */ 1147 return -EINVAL; 1148 spin_lock_bh(&sl->lock); 1149 if (!sl->tty) { 1150 spin_unlock_bh(&sl->lock); 1151 return -ENODEV; 1152 } 1153 sl->outfill = (u8)tmp; 1154 if (sl->outfill != 0) { 1155 mod_timer(&sl->outfill_timer, 1156 jiffies + sl->outfill * HZ); 1157 set_bit(SLF_OUTWAIT, &sl->flags); 1158 } else 1159 del_timer(&sl->outfill_timer); 1160 spin_unlock_bh(&sl->lock); 1161 return 0; 1162 1163 case SIOCGOUTFILL: 1164 if (put_user(sl->outfill, p)) 1165 return -EFAULT; 1166 return 0; 1167 /* VSV changes end */ 1168 #endif 1169 default: 1170 return tty_mode_ioctl(tty, file, cmd, arg); 1171 } 1172 } 1173 1174 #ifdef CONFIG_COMPAT 1175 static long slip_compat_ioctl(struct tty_struct *tty, struct file *file, 1176 unsigned int cmd, unsigned long arg) 1177 { 1178 switch (cmd) { 1179 case SIOCGIFNAME: 1180 case SIOCGIFENCAP: 1181 case SIOCSIFENCAP: 1182 case SIOCSIFHWADDR: 1183 case SIOCSKEEPALIVE: 1184 case SIOCGKEEPALIVE: 1185 case SIOCSOUTFILL: 1186 case SIOCGOUTFILL: 1187 return slip_ioctl(tty, file, cmd, 1188 (unsigned long)compat_ptr(arg)); 1189 } 1190 1191 return -ENOIOCTLCMD; 1192 } 1193 #endif 1194 1195 /* VSV changes start here */ 1196 #ifdef CONFIG_SLIP_SMART 1197 /* function do_ioctl called from net/core/dev.c 1198 to allow get/set outfill/keepalive parameter 1199 by ifconfig */ 1200 1201 static int sl_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) 1202 { 1203 struct slip *sl = netdev_priv(dev); 1204 unsigned long *p = (unsigned long *)&rq->ifr_ifru; 1205 1206 if (sl == NULL) /* Allocation failed ?? */ 1207 return -ENODEV; 1208 1209 spin_lock_bh(&sl->lock); 1210 1211 if (!sl->tty) { 1212 spin_unlock_bh(&sl->lock); 1213 return -ENODEV; 1214 } 1215 1216 switch (cmd) { 1217 case SIOCSKEEPALIVE: 1218 /* max for unchar */ 1219 if ((unsigned)*p > 255) { 1220 spin_unlock_bh(&sl->lock); 1221 return -EINVAL; 1222 } 1223 sl->keepalive = (u8)*p; 1224 if (sl->keepalive != 0) { 1225 sl->keepalive_timer.expires = 1226 jiffies + sl->keepalive * HZ; 1227 mod_timer(&sl->keepalive_timer, 1228 jiffies + sl->keepalive * HZ); 1229 set_bit(SLF_KEEPTEST, &sl->flags); 1230 } else 1231 del_timer(&sl->keepalive_timer); 1232 break; 1233 1234 case SIOCGKEEPALIVE: 1235 *p = sl->keepalive; 1236 break; 1237 1238 case SIOCSOUTFILL: 1239 if ((unsigned)*p > 255) { /* max for unchar */ 1240 spin_unlock_bh(&sl->lock); 1241 return -EINVAL; 1242 } 1243 sl->outfill = (u8)*p; 1244 if (sl->outfill != 0) { 1245 mod_timer(&sl->outfill_timer, 1246 jiffies + sl->outfill * HZ); 1247 set_bit(SLF_OUTWAIT, &sl->flags); 1248 } else 1249 del_timer(&sl->outfill_timer); 1250 break; 1251 1252 case SIOCGOUTFILL: 1253 *p = sl->outfill; 1254 break; 1255 1256 case SIOCSLEASE: 1257 /* Resolve race condition, when ioctl'ing hanged up 1258 and opened by another process device. 1259 */ 1260 if (sl->tty != current->signal->tty && 1261 sl->pid != current->pid) { 1262 spin_unlock_bh(&sl->lock); 1263 return -EPERM; 1264 } 1265 sl->leased = 0; 1266 if (*p) 1267 sl->leased = 1; 1268 break; 1269 1270 case SIOCGLEASE: 1271 *p = sl->leased; 1272 } 1273 spin_unlock_bh(&sl->lock); 1274 return 0; 1275 } 1276 #endif 1277 /* VSV changes end */ 1278 1279 static struct tty_ldisc_ops sl_ldisc = { 1280 .owner = THIS_MODULE, 1281 .magic = TTY_LDISC_MAGIC, 1282 .name = "slip", 1283 .open = slip_open, 1284 .close = slip_close, 1285 .hangup = slip_hangup, 1286 .ioctl = slip_ioctl, 1287 #ifdef CONFIG_COMPAT 1288 .compat_ioctl = slip_compat_ioctl, 1289 #endif 1290 .receive_buf = slip_receive_buf, 1291 .write_wakeup = slip_write_wakeup, 1292 }; 1293 1294 static int __init slip_init(void) 1295 { 1296 int status; 1297 1298 if (slip_maxdev < 4) 1299 slip_maxdev = 4; /* Sanity */ 1300 1301 printk(KERN_INFO "SLIP: version %s (dynamic channels, max=%d)" 1302 #ifdef CONFIG_SLIP_MODE_SLIP6 1303 " (6 bit encapsulation enabled)" 1304 #endif 1305 ".\n", 1306 SLIP_VERSION, slip_maxdev); 1307 #if defined(SL_INCLUDE_CSLIP) 1308 printk(KERN_INFO "CSLIP: code copyright 1989 Regents of the University of California.\n"); 1309 #endif 1310 #ifdef CONFIG_SLIP_SMART 1311 printk(KERN_INFO "SLIP linefill/keepalive option.\n"); 1312 #endif 1313 1314 slip_devs = kzalloc(sizeof(struct net_device *)*slip_maxdev, 1315 GFP_KERNEL); 1316 if (!slip_devs) 1317 return -ENOMEM; 1318 1319 /* Fill in our line protocol discipline, and register it */ 1320 status = tty_register_ldisc(N_SLIP, &sl_ldisc); 1321 if (status != 0) { 1322 printk(KERN_ERR "SLIP: can't register line discipline (err = %d)\n", status); 1323 kfree(slip_devs); 1324 } 1325 return status; 1326 } 1327 1328 static void __exit slip_exit(void) 1329 { 1330 int i; 1331 struct net_device *dev; 1332 struct slip *sl; 1333 unsigned long timeout = jiffies + HZ; 1334 int busy = 0; 1335 1336 if (slip_devs == NULL) 1337 return; 1338 1339 /* First of all: check for active disciplines and hangup them. 1340 */ 1341 do { 1342 if (busy) 1343 msleep_interruptible(100); 1344 1345 busy = 0; 1346 for (i = 0; i < slip_maxdev; i++) { 1347 dev = slip_devs[i]; 1348 if (!dev) 1349 continue; 1350 sl = netdev_priv(dev); 1351 spin_lock_bh(&sl->lock); 1352 if (sl->tty) { 1353 busy++; 1354 tty_hangup(sl->tty); 1355 } 1356 spin_unlock_bh(&sl->lock); 1357 } 1358 } while (busy && time_before(jiffies, timeout)); 1359 1360 /* FIXME: hangup is async so we should wait when doing this second 1361 phase */ 1362 1363 for (i = 0; i < slip_maxdev; i++) { 1364 dev = slip_devs[i]; 1365 if (!dev) 1366 continue; 1367 slip_devs[i] = NULL; 1368 1369 sl = netdev_priv(dev); 1370 if (sl->tty) { 1371 printk(KERN_ERR "%s: tty discipline still running\n", 1372 dev->name); 1373 /* Intentionally leak the control block. */ 1374 dev->destructor = NULL; 1375 } 1376 1377 unregister_netdev(dev); 1378 } 1379 1380 kfree(slip_devs); 1381 slip_devs = NULL; 1382 1383 i = tty_unregister_ldisc(N_SLIP); 1384 if (i != 0) 1385 printk(KERN_ERR "SLIP: can't unregister line discipline (err = %d)\n", i); 1386 } 1387 1388 module_init(slip_init); 1389 module_exit(slip_exit); 1390 1391 #ifdef CONFIG_SLIP_SMART 1392 /* 1393 * This is start of the code for multislip style line checking 1394 * added by Stanislav Voronyi. All changes before marked VSV 1395 */ 1396 1397 static void sl_outfill(unsigned long sls) 1398 { 1399 struct slip *sl = (struct slip *)sls; 1400 1401 spin_lock(&sl->lock); 1402 1403 if (sl->tty == NULL) 1404 goto out; 1405 1406 if (sl->outfill) { 1407 if (test_bit(SLF_OUTWAIT, &sl->flags)) { 1408 /* no packets were transmitted, do outfill */ 1409 #ifdef CONFIG_SLIP_MODE_SLIP6 1410 unsigned char s = (sl->mode & SL_MODE_SLIP6)?0x70:END; 1411 #else 1412 unsigned char s = END; 1413 #endif 1414 /* put END into tty queue. Is it right ??? */ 1415 if (!netif_queue_stopped(sl->dev)) { 1416 /* if device busy no outfill */ 1417 sl->tty->ops->write(sl->tty, &s, 1); 1418 } 1419 } else 1420 set_bit(SLF_OUTWAIT, &sl->flags); 1421 1422 mod_timer(&sl->outfill_timer, jiffies+sl->outfill*HZ); 1423 } 1424 out: 1425 spin_unlock(&sl->lock); 1426 } 1427 1428 static void sl_keepalive(unsigned long sls) 1429 { 1430 struct slip *sl = (struct slip *)sls; 1431 1432 spin_lock(&sl->lock); 1433 1434 if (sl->tty == NULL) 1435 goto out; 1436 1437 if (sl->keepalive) { 1438 if (test_bit(SLF_KEEPTEST, &sl->flags)) { 1439 /* keepalive still high :(, we must hangup */ 1440 if (sl->outfill) 1441 /* outfill timer must be deleted too */ 1442 (void)del_timer(&sl->outfill_timer); 1443 printk(KERN_DEBUG "%s: no packets received during keepalive timeout, hangup.\n", sl->dev->name); 1444 /* this must hangup tty & close slip */ 1445 tty_hangup(sl->tty); 1446 /* I think we need not something else */ 1447 goto out; 1448 } else 1449 set_bit(SLF_KEEPTEST, &sl->flags); 1450 1451 mod_timer(&sl->keepalive_timer, jiffies+sl->keepalive*HZ); 1452 } 1453 out: 1454 spin_unlock(&sl->lock); 1455 } 1456 1457 #endif 1458 MODULE_LICENSE("GPL"); 1459 MODULE_ALIAS_LDISC(N_SLIP); 1460