if_sl.c revision 1.17
1/* 2 * Copyright (c) 1987, 1989 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from: if_sl.c,v 1.11 84/10/04 12:54:47 rick Exp 34 * from: @(#)if_sl.c 7.22 (Berkeley) 4/20/91 35 * if_sl.c,v 1.8 1993/05/22 11:42:11 cgd Exp 36 */ 37 38/* 39 * Serial Line interface 40 * 41 * Rick Adams 42 * Center for Seismic Studies 43 * 1300 N 17th Street, Suite 1450 44 * Arlington, Virginia 22209 45 * (703)276-7900 46 * rick@seismo.ARPA 47 * seismo!rick 48 * 49 * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris). 50 * N.B.: this belongs in netinet, not net, the way it stands now. 51 * Should have a link-layer type designation, but wouldn't be 52 * backwards-compatible. 53 * 54 * Converted to 4.3BSD Beta by Chris Torek. 55 * Other changes made at Berkeley, based in part on code by Kirk Smith. 56 * W. Jolitz added slip abort. 57 * 58 * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov). 59 * Added priority queuing for "interactive" traffic; hooks for TCP 60 * header compression; ICMP filtering (at 2400 baud, some cretin 61 * pinging you can use up all your bandwidth). Made low clist behavior 62 * more robust and slightly less likely to hang serial line. 63 * Sped up a bunch of things. 64 * 65 * Note that splimp() is used throughout to block both (tty) input 66 * interrupts and network activity; thus, splimp must be >= spltty. 67 */ 68 69#include "sl.h" 70#if NSL > 0 71 72#include "param.h" 73#include "proc.h" 74#include "mbuf.h" 75#include "buf.h" 76#include "dkstat.h" 77#include "socket.h" 78#include "ioctl.h" 79#include "file.h" 80#include "tty.h" 81#include "kernel.h" 82#include "conf.h" 83 84#include "if.h" 85#include "if_types.h" 86#include "netisr.h" 87#include "route.h" 88#if INET 89#include "netinet/in.h" 90#include "netinet/in_systm.h" 91#include "netinet/in_var.h" 92#include "netinet/ip.h" 93#else 94Huh? Slip without inet? 95#endif 96 97#include "machine/mtpr.h" 98 99#include "slcompress.h" 100#include "if_slvar.h" 101#include "slip.h" 102 103#include "bpfilter.h" 104#if NBPFILTER > 0 105#include <sys/time.h> 106#include <net/bpf.h> 107#endif 108 109/* 110 * SLMAX is a hard limit on input packet size. To simplify the code 111 * and improve performance, we require that packets fit in an mbuf 112 * cluster, and if we get a compressed packet, there's enough extra 113 * room to expand the header into a max length tcp/ip header (128 114 * bytes). So, SLMAX can be at most 115 * MCLBYTES - 128 116 * 117 * SLMTU is a hard limit on output packet size. To insure good 118 * interactive response, SLMTU wants to be the smallest size that 119 * amortizes the header cost. (Remember that even with 120 * type-of-service queuing, we have to wait for any in-progress 121 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 122 * cps, where cps is the line speed in characters per second. 123 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 124 * average compressed header size is 6-8 bytes so any MTU > 90 125 * bytes will give us 90% of the line bandwidth. A 100ms wait is 126 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 127 * will send 256 byte segments (to allow for 40 byte headers), the 128 * typical packet size on the wire will be around 260 bytes). In 129 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 130 * leave the interface MTU relatively high (so we don't IP fragment 131 * when acting as a gateway to someone using a stupid MTU). 132 * 133 * Similar considerations apply to SLIP_HIWAT: It's the amount of 134 * data that will be queued 'downstream' of us (i.e., in clists 135 * waiting to be picked up by the tty output interrupt). If we 136 * queue a lot of data downstream, it's immune to our t.o.s. queuing. 137 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 138 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 139 * wait is dependent on the ftp window size but that's typically 140 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 141 * the cost (in idle time on the wire) of the tty driver running 142 * off the end of its clists & having to call back slstart for a 143 * new packet. For a tty interface with any buffering at all, this 144 * cost will be zero. Even with a totally brain dead interface (like 145 * the one on a typical workstation), the cost will be <= 1 character 146 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 147 * at most 1% while maintaining good interactive response. 148 */ 149#if NBPFILTER > 0 150#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 151#else 152#define BUFOFFSET (128+sizeof(struct ifnet **)) 153#endif 154#define SLMAX (MCLBYTES - BUFOFFSET) 155#define SLBUFSIZE (SLMAX + BUFOFFSET) 156#define SLMTU 296 /* try 1006 later */ 157#define SLIP_HIWAT roundup(50,CBSIZE) 158 159/* 160 * SLIP ABORT ESCAPE MECHANISM: 161 * (inspired by HAYES modem escape arrangement) 162 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 163 * signals a "soft" exit from slip mode by usermode process 164 */ 165 166#ifdef ABT_ESC 167#undef ABT_ESC 168#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 169#define ABT_WAIT 1 /* in seconds - idle before an escape & after */ 170#define ABT_RECYCLE (5*2+2) /* in seconds - time window processing abort */ 171#define ABT_SOFT 3 /* count of escapes */ 172#endif /* ABT_ESC */ 173 174/* 175 * The following disgusting hack gets around the problem that IP TOS 176 * can't be set yet. We want to put "interactive" traffic on a high 177 * priority queue. To decide if traffic is interactive, we check that 178 * a) it is TCP and b) one of its ports is telnet, rlogin or ftp control. 179 */ 180static u_short interactive_ports[8] = { 181 0, 513, 0, 0, 182 0, 21, 0, 23, 183}; 184#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p)) 185 186struct sl_softc sl_softc[NSL]; 187 188#define FRAME_END 0xc0 /* Frame End */ 189#define FRAME_ESCAPE 0xdb /* Frame Esc */ 190#define TRANS_FRAME_END 0xdc /* transposed frame end */ 191#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 192 193 194int sloutput(), slioctl(), ttrstrt(); 195void slstart(); 196extern struct timeval time; 197 198/* 199 * Called from boot code to establish sl interfaces. 200 */ 201slattach() 202{ 203 register struct sl_softc *sc; 204 register int i = 0; 205 206 for (sc = sl_softc; i < NSL; sc++) { 207 sc->sc_if.if_name = "sl"; 208 sc->sc_if.if_unit = i++; 209 sc->sc_if.if_mtu = SLMTU; 210 sc->sc_if.if_flags = IFF_POINTOPOINT; 211 sc->sc_if.if_type = IFT_SLIP; 212 sc->sc_if.if_ioctl = slioctl; 213 sc->sc_if.if_output = sloutput; 214 sc->sc_if.if_snd.ifq_maxlen = 50; 215 sc->sc_fastq.ifq_maxlen = 32; 216 if_attach(&sc->sc_if); 217#if NBPFILTER > 0 218 bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, 219 SLIP_HDRLEN); 220#endif 221 } 222} 223 224static int 225slinit(sc) 226 register struct sl_softc *sc; 227{ 228 register caddr_t p; 229 230 if (sc->sc_ep == (u_char *) 0) { 231 MCLALLOC(p, M_WAIT); 232 if (p) 233 sc->sc_ep = (u_char *)p + SLBUFSIZE; 234 else { 235 printf("sl%d: can't allocate buffer\n", sc - sl_softc); 236 sc->sc_if.if_flags &= ~IFF_UP; 237 return (0); 238 } 239 } 240 sc->sc_buf = sc->sc_ep - SLMAX; 241 sc->sc_mp = sc->sc_buf; 242 sl_compress_init(&sc->sc_comp); 243 return (1); 244} 245 246/* 247 * Line specific open routine. 248 * Attach the given tty to the first available sl unit. 249 */ 250/* ARGSUSED */ 251int 252slopen(dev_t dev, struct tty *tp) 253{ 254 struct proc *p = curproc; /* XXX */ 255 register struct sl_softc *sc; 256 register int nsl; 257 int error; 258 259 if (error = suser(p->p_ucred, &p->p_acflag)) 260 return (error); 261 262 if (tp->t_line == SLIPDISC) 263 return (0); 264 265 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 266 if (sc->sc_ttyp == NULL) { 267 if (slinit(sc) == 0) 268 return (ENOBUFS); 269 tp->t_sc = (caddr_t)sc; 270 sc->sc_ttyp = tp; 271 sc->sc_if.if_baudrate = tp->t_ospeed; 272 ttyflush(tp, FREAD | FWRITE); 273 return (0); 274 } 275 return (ENXIO); 276} 277 278/* 279 * Line specific close routine. 280 * Detach the tty from the sl unit. 281 * Mimics part of ttyclose(). 282 */ 283void 284slclose(tp, flag) 285 struct tty *tp; 286 int flag; 287{ 288 register struct sl_softc *sc; 289 int s; 290 291 ttywflush(tp); 292 s = splimp(); /* actually, max(spltty, splnet) */ 293 tp->t_line = 0; 294 sc = (struct sl_softc *)tp->t_sc; 295 if (sc != NULL) { 296 if_down(&sc->sc_if); 297 sc->sc_ttyp = NULL; 298 tp->t_sc = NULL; 299 MCLFREE((caddr_t)(sc->sc_ep - SLBUFSIZE)); 300 sc->sc_ep = 0; 301 sc->sc_mp = 0; 302 sc->sc_buf = 0; 303 } 304 splx(s); 305} 306 307/* 308 * Line specific (tty) ioctl routine. 309 * Provide a way to get the sl unit number. 310 */ 311/* ARGSUSED */ 312sltioctl(tp, cmd, data, flag) 313 struct tty *tp; 314 caddr_t data; 315{ 316 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 317 struct proc *p = curproc; /* XXX */ 318 int error; 319 int s; 320 321 switch (cmd) { 322 case SLIOCGUNIT: 323 *(int *)data = sc->sc_if.if_unit; 324 break; 325 326 case SLIOCGFLAGS: 327 *(int *)data = sc->sc_flags; 328 break; 329 330 case SLIOCSFLAGS: 331 if (error = suser(p->p_ucred, &p->p_acflag)) 332 return (error); 333#define SC_MASK 0xffff 334 s = splimp(); 335 sc->sc_flags = 336 (sc->sc_flags &~ SC_MASK) | ((*(int *)data) & SC_MASK); 337 splx(s); 338 break; 339 340 default: 341 return (-1); 342 } 343 return (0); 344} 345 346/* 347 * Queue a packet. Start transmission if not active. 348 */ 349sloutput(ifp, m, dst) 350 struct ifnet *ifp; 351 register struct mbuf *m; 352 struct sockaddr *dst; 353{ 354 register struct sl_softc *sc = &sl_softc[ifp->if_unit]; 355 register struct ip *ip; 356 register struct ifqueue *ifq; 357 int s; 358 359 /* 360 * `Cannot happen' (see slioctl). Someday we will extend 361 * the line protocol to support other address families. 362 */ 363 if (dst->sa_family != AF_INET) { 364 printf("sl%d: af%d not supported\n", sc->sc_if.if_unit, 365 dst->sa_family); 366 m_freem(m); 367 return (EAFNOSUPPORT); 368 } 369 370 if (sc->sc_ttyp == NULL) { 371 m_freem(m); 372 return (ENETDOWN); /* sort of */ 373 } 374 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 375 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 376 m_freem(m); 377 return (EHOSTUNREACH); 378 } 379 ifq = &sc->sc_if.if_snd; 380 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 381 u_short srcport = ntohs(((short *)ip)[ip->ip_hl << 1]); 382 u_short dstport = ntohs(((short *)ip)[(ip->ip_hl << 1) + 1]); 383 384 if (INTERACTIVE(srcport) || INTERACTIVE(dstport)) { 385 ifq = &sc->sc_fastq; 386 } 387 388 } else if (sc->sc_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 389 m_freem(m); 390 return (0); 391 } 392 s = splimp(); 393 if (IF_QFULL(ifq)) { 394 IF_DROP(ifq); 395 m_freem(m); 396 splx(s); 397 sc->sc_if.if_oerrors++; 398 return (ENOBUFS); 399 } 400 IF_ENQUEUE(ifq, m); 401 sc->sc_if.if_lastchange = time; 402 if (sc->sc_ttyp->t_outq.c_cc == 0) 403 slstart(sc->sc_ttyp); 404 else 405 (*sc->sc_ttyp->t_oproc)(sc->sc_ttyp); /* XXX */ 406 splx(s); 407 return (0); 408} 409 410/* 411 * Start output on interface. Get another datagram 412 * to send from the interface queue and map it to 413 * the interface before starting output. 414 */ 415void 416slstart(tp) 417 register struct tty *tp; 418{ 419 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 420 register struct mbuf *m; 421 register u_char *cp; 422 register struct ip *ip; 423 int s; 424 struct mbuf *m2; 425#if NBPFILTER > 0 426 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 427 register int len; 428#endif 429 430 for (;;) { 431 /* 432 * If there is more in the output queue, just send it now. 433 * We are being called in lieu of ttstart and must do what 434 * it would. 435 */ 436 if (tp->t_outq.c_cc != 0) { 437 (*tp->t_oproc)(tp); 438 if (tp->t_outq.c_cc > SLIP_HIWAT) 439 return; 440 } 441 /* 442 * This happens briefly when the line shuts down. 443 */ 444 if (sc == NULL) 445 return; 446 447 /* 448 * Do not remove the packet from the IP queue if it 449 * doesn't look like the packet will fit into the 450 * current COM output queue, with a packet full of 451 * escapes this could be as bad as SLMTU*2. The size 452 * of the ring buffer must be at least SLMTU*2 to 453 * avoid deadlock. 454 */ 455 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2 * SLMTU) 456 return; 457 458 /* 459 * Get a packet and send it to the interface. 460 */ 461 s = splimp(); 462 IF_DEQUEUE(&sc->sc_fastq, m); 463 if (m == NULL) 464 IF_DEQUEUE(&sc->sc_if.if_snd, m); 465 splx(s); 466 if (m == NULL) 467 return; 468 /* 469 * We do the header compression here rather than in sl_output 470 * because the packets will be out of order if we are using TOS 471 * queueing, and the connection id compression will get messed 472 * up when this happens. 473 */ 474#if NBPFILTER > 0 475 if (sc->sc_bpf) { 476 /* 477 * We need to save the TCP/IP header before it's compressed. 478 * To avoid complicated code, we just copy the entire packet 479 * into a stack buffer (since this is a serial line, packets 480 * should be short and/or the copy should be negligible cost 481 * compared to the packet transmission time). 482 */ 483 register struct mbuf *m1 = m; 484 register u_char *cp = bpfbuf + SLIP_HDRLEN; 485 len = 0; 486 do { 487 register int mlen = m1->m_len; 488 489 bcopy(mtod(m1, caddr_t), cp, mlen); 490 cp += mlen; 491 len += mlen; 492 } while (m1 = m1->m_next); 493 } 494#endif 495 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 496 if (sc->sc_flags & SC_COMPRESS) 497 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, &sc->sc_comp, 1); 498 } 499#if NBPFILTER > 0 500 if (sc->sc_bpf) { 501 /* 502 * Put the SLIP pseudo-"link header" in place. The compressed 503 * header is now at the beginning of the mbuf. 504 */ 505 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 506 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 507 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 508 } 509#endif 510 511 sc->sc_if.if_lastchange = time; 512 513 /* 514 * The extra FRAME_END will start up a new packet, and thus 515 * will flush any accumulated garbage. We do this whenever 516 * the line may have been idle for some time. 517 */ 518 if (tp->t_outq.c_cc == 0) { 519 ++sc->sc_bytessent; 520 (void) putc(FRAME_END, &tp->t_outq); 521 } 522 523 while (m) { 524 register u_char *ep; 525 526 cp = mtod(m, u_char *); ep = cp + m->m_len; 527 while (cp < ep) { 528 /* 529 * Find out how many bytes in the string we can 530 * handle without doing something special. 531 */ 532 register u_char *bp = cp; 533 534 while (cp < ep) { 535 switch (*cp++) { 536 case FRAME_ESCAPE: 537 case FRAME_END: 538 --cp; 539 goto out; 540 } 541 } 542 out: 543 if (cp > bp) { 544 /* 545 * Put n characters at once 546 * into the tty output queue. 547 */ 548 if (b_to_q((u_char *)bp, cp - bp, &tp->t_outq)) 549 break; 550 sc->sc_bytessent += cp - bp; 551 } 552 /* 553 * If there are characters left in the mbuf, 554 * the first one must be special.. 555 * Put it out in a different form. 556 */ 557 if (cp < ep) { 558 if (putc(FRAME_ESCAPE, &tp->t_outq)) 559 break; 560 if (putc(*cp++ == FRAME_ESCAPE ? 561 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 562 &tp->t_outq)) { 563 (void) unputc(&tp->t_outq); 564 break; 565 } 566 sc->sc_bytessent += 2; 567 } 568 } 569 MFREE(m, m2); 570 m = m2; 571 } 572 573 if (putc(FRAME_END, &tp->t_outq)) { 574 /* 575 * Not enough room. Remove a char to make room 576 * and end the packet normally. 577 * If you get many collisions (more than one or two 578 * a day) you probably do not have enough clists 579 * and you should increase "nclist" in param.c. 580 */ 581 (void) unputc(&tp->t_outq); 582 (void) putc(FRAME_END, &tp->t_outq); 583 sc->sc_if.if_collisions++; 584 } else { 585 ++sc->sc_bytessent; 586 sc->sc_if.if_opackets++; 587 } 588 sc->sc_if.if_obytes = sc->sc_bytessent; 589 } 590} 591 592/* 593 * Copy data buffer to mbuf chain; add ifnet pointer. 594 */ 595static struct mbuf * 596sl_btom(sc, len) 597 register struct sl_softc *sc; 598 register int len; 599{ 600 register struct mbuf *m; 601 602 MGETHDR(m, M_DONTWAIT, MT_DATA); 603 if (m == NULL) 604 return (NULL); 605 606 /* 607 * If we have more than MHLEN bytes, it's cheaper to 608 * queue the cluster we just filled & allocate a new one 609 * for the input buffer. Otherwise, fill the mbuf we 610 * allocated above. Note that code in the input routine 611 * guarantees that packet will fit in a cluster. 612 */ 613 if (len >= MHLEN) { 614 MCLGET(m, M_DONTWAIT); 615 if ((m->m_flags & M_EXT) == 0) { 616 /* 617 * we couldn't get a cluster - if memory's this 618 * low, it's time to start dropping packets. 619 */ 620 (void) m_free(m); 621 return (NULL); 622 } 623 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 624 m->m_data = (caddr_t)sc->sc_buf; 625 m->m_ext.ext_buf = (caddr_t)((int)sc->sc_buf &~ MCLOFSET); 626 } else 627 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 628 629 m->m_len = len; 630 m->m_pkthdr.len = len; 631 m->m_pkthdr.rcvif = &sc->sc_if; 632 return (m); 633} 634 635/* 636 * tty interface receiver interrupt. 637 */ 638void 639slinput(c, tp) 640 register int c; 641 register struct tty *tp; 642{ 643 register struct sl_softc *sc; 644 register struct mbuf *m; 645 register int len; 646 int s; 647#if NBPFILTER > 0 648 u_char chdr[CHDR_LEN]; 649#endif 650 tk_nin++; 651 sc = (struct sl_softc *)tp->t_sc; 652 if (sc == NULL) 653 return; 654 if (c & TTY_ERRORMASK || ((tp->t_state & TS_CARR_ON) == 0 && 655 (tp->t_cflag & CLOCAL) == 0)) { 656 sc->sc_flags |= SC_ERROR; 657 return; 658 } 659 660 ++sc->sc_bytesrcvd; 661 ++sc->sc_if.if_ibytes; 662 663#ifdef ABT_ESC 664 if (sc->sc_flags & SC_ABORT) { 665 /* if we see an abort after "idle" time, count it */ 666 if (c == ABT_ESC && time.tv_sec >= sc->sc_lasttime + ABT_WAIT) { 667 sc->sc_abortcount++; 668 /* record when the first abort escape arrived */ 669 if (sc->sc_abortcount == 1) 670 sc->sc_starttime = time.tv_sec; 671 } 672 /* 673 * if we have an abort, see that we have not run out of time, 674 * or that we have an "idle" time after the complete escape 675 * sequence 676 */ 677 if (sc->sc_abortcount) { 678 if (time.tv_sec >= sc->sc_starttime + ABT_RECYCLE) 679 sc->sc_abortcount = 0; 680 if (sc->sc_abortcount >= ABT_SOFT && 681 time.tv_sec >= sc->sc_lasttime + ABT_WAIT) { 682 slclose(tp); 683 return; 684 } 685 } 686 sc->sc_lasttime = time.tv_sec; 687 } 688#endif 689 690 switch (c) { 691 692 case TRANS_FRAME_ESCAPE: 693 if (sc->sc_escape) 694 c = FRAME_ESCAPE; 695 break; 696 697 case TRANS_FRAME_END: 698 if (sc->sc_escape) 699 c = FRAME_END; 700 break; 701 702 case FRAME_ESCAPE: 703 sc->sc_escape = 1; 704 return; 705 706 case FRAME_END: 707 if(sc->sc_flags & SC_ERROR) { 708 sc->sc_flags &= ~SC_ERROR; 709 goto newpack; 710 } 711 len = sc->sc_mp - sc->sc_buf; 712 713 if (len < 3) 714 /* less than min length packet - ignore */ 715 goto newpack; 716 717#if NBPFILTER > 0 718 if (sc->sc_bpf) 719 /* 720 * Save the compressed header, so we can 721 * tack it on later. Note that we just 722 * we will end up copying garbage in some 723 * cases but this is okay. We remember 724 * where the buffer started so we can 725 * compute the new header length. 726 */ 727 bcopy(sc->sc_buf, chdr, CHDR_LEN); 728#endif 729 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 730 if (c & 0x80) 731 c = TYPE_COMPRESSED_TCP; 732 else if (c == TYPE_UNCOMPRESSED_TCP) 733 *sc->sc_buf &= 0x4f; /* XXX */ 734 /* 735 * We've got something that's not an IP packet. 736 * If compression is enabled, try to decompress it. 737 * Otherwise, if `auto-enable' compression is on and 738 * it's a reasonable packet, decompress it and then 739 * enable compression. Otherwise, drop it. 740 */ 741 if (sc->sc_flags & SC_COMPRESS) { 742 len = sl_uncompress_tcp(&sc->sc_buf, len, 743 (u_int)c, &sc->sc_comp); 744 if (len <= 0) 745 goto error; 746 } else if ((sc->sc_flags & SC_AUTOCOMP) && 747 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 748 len = sl_uncompress_tcp(&sc->sc_buf, len, 749 (u_int)c, &sc->sc_comp); 750 if (len <= 0) 751 goto error; 752 sc->sc_flags |= SC_COMPRESS; 753 } else 754 goto error; 755 } 756#if NBPFILTER > 0 757 if (sc->sc_bpf) { 758 /* 759 * Put the SLIP pseudo-"link header" in place. 760 * We couldn't do this any earlier since 761 * decompression probably moved the buffer 762 * pointer. Then, invoke BPF. 763 */ 764 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 765 766 hp[SLX_DIR] = SLIPDIR_IN; 767 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 768 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 769 } 770#endif 771 m = sl_btom(sc, len); 772 if (m == NULL) 773 goto error; 774 775 sc->sc_if.if_ipackets++; 776 sc->sc_if.if_lastchange = time; 777 s = splimp(); 778 if (IF_QFULL(&ipintrq)) { 779 IF_DROP(&ipintrq); 780 sc->sc_if.if_ierrors++; 781 sc->sc_if.if_iqdrops++; 782 m_freem(m); 783 } else { 784 IF_ENQUEUE(&ipintrq, m); 785 schednetisr(NETISR_IP); 786 } 787 splx(s); 788 goto newpack; 789 } 790 if (sc->sc_mp < sc->sc_ep) { 791 *sc->sc_mp++ = c; 792 sc->sc_escape = 0; 793 return; 794 } 795 sc->sc_flags |= SC_ERROR; 796error: 797 sc->sc_if.if_ierrors++; 798newpack: 799 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 800 sc->sc_escape = 0; 801} 802 803/* 804 * Process an ioctl request. 805 */ 806slioctl(ifp, cmd, data) 807 register struct ifnet *ifp; 808 int cmd; 809 caddr_t data; 810{ 811 register struct ifaddr *ifa = (struct ifaddr *)data; 812 int s = splimp(), error = 0; 813 814 switch (cmd) { 815 816 case SIOCSIFADDR: 817 if (ifa->ifa_addr->sa_family == AF_INET) 818 ifp->if_flags |= IFF_UP; 819 else 820 error = EAFNOSUPPORT; 821 break; 822 823 case SIOCSIFDSTADDR: 824 if (ifa->ifa_addr->sa_family != AF_INET) 825 error = EAFNOSUPPORT; 826 break; 827 828 default: 829 error = EINVAL; 830 } 831 splx(s); 832 return (error); 833} 834#endif 835