if_sl.c revision 1.22
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 * $Id: if_sl.c,v 1.22 1993/12/20 07:47:15 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 "bpfilter.h" 73 74#include <sys/param.h> 75#include <sys/proc.h> 76#include <sys/mbuf.h> 77#include <sys/buf.h> 78#include <sys/dkstat.h> 79#include <sys/socket.h> 80#include <sys/ioctl.h> 81#include <sys/file.h> 82#include <sys/tty.h> 83#include <sys/kernel.h> 84#include <sys/conf.h> 85 86#include <machine/cpu.h> 87 88#include <net/if.h> 89#include <net/if_types.h> 90#include <net/netisr.h> 91#include <net/route.h> 92 93#if INET 94#include <netinet/in.h> 95#include <netinet/in_systm.h> 96#include <netinet/in_var.h> 97#include <netinet/ip.h> 98#else 99Huh? Slip without inet? 100#endif 101 102#include <net/slcompress.h> 103#include <net/if_slvar.h> 104 105#if NBPFILTER > 0 106#include <sys/time.h> 107#include <net/bpf.h> 108#endif 109 110/* 111 * SLMAX is a hard limit on input packet size. To simplify the code 112 * and improve performance, we require that packets fit in an mbuf 113 * cluster, and if we get a compressed packet, there's enough extra 114 * room to expand the header into a max length tcp/ip header (128 115 * bytes). So, SLMAX can be at most 116 * MCLBYTES - 128 117 * 118 * SLMTU is a hard limit on output packet size. To insure good 119 * interactive response, SLMTU wants to be the smallest size that 120 * amortizes the header cost. (Remember that even with 121 * type-of-service queuing, we have to wait for any in-progress 122 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 123 * cps, where cps is the line speed in characters per second. 124 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 125 * average compressed header size is 6-8 bytes so any MTU > 90 126 * bytes will give us 90% of the line bandwidth. A 100ms wait is 127 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 128 * will send 256 byte segments (to allow for 40 byte headers), the 129 * typical packet size on the wire will be around 260 bytes). In 130 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 131 * leave the interface MTU relatively high (so we don't IP fragment 132 * when acting as a gateway to someone using a stupid MTU). 133 * 134 * Similar considerations apply to SLIP_HIWAT: It's the amount of 135 * data that will be queued 'downstream' of us (i.e., in clists 136 * waiting to be picked up by the tty output interrupt). If we 137 * queue a lot of data downstream, it's immune to our t.o.s. queuing. 138 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 139 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 140 * wait is dependent on the ftp window size but that's typically 141 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 142 * the cost (in idle time on the wire) of the tty driver running 143 * off the end of its clists & having to call back slstart for a 144 * new packet. For a tty interface with any buffering at all, this 145 * cost will be zero. Even with a totally brain dead interface (like 146 * the one on a typical workstation), the cost will be <= 1 character 147 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 148 * at most 1% while maintaining good interactive response. 149 */ 150#if NBPFILTER > 0 151#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 152#else 153#define BUFOFFSET (128+sizeof(struct ifnet **)) 154#endif 155#define SLMAX (MCLBYTES - BUFOFFSET) 156#define SLBUFSIZE (SLMAX + BUFOFFSET) 157#define SLMTU 296 158#define SLIP_HIWAT roundup(50,CBSIZE) 159#ifndef __NetBSD__ /* XXX - cgd */ 160#define CLISTRESERVE 1024 /* Can't let clists get too low */ 161#endif /* !__NetBSD__ */ 162 163/* 164 * SLIP ABORT ESCAPE MECHANISM: 165 * (inspired by HAYES modem escape arrangement) 166 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 167 * within window time signals a "soft" exit from slip mode by remote end 168 * if the IFF_DEBUG flag is on. 169 */ 170#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 171#define ABT_IDLE 1 /* in seconds - idle before an escape */ 172#define ABT_COUNT 3 /* count of escapes for abort */ 173#define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 174 175struct sl_softc sl_softc[NSL]; 176 177#define FRAME_END 0xc0 /* Frame End */ 178#define FRAME_ESCAPE 0xdb /* Frame Esc */ 179#define TRANS_FRAME_END 0xdc /* transposed frame end */ 180#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 181 182extern struct timeval time; 183 184static int slinit __P((struct sl_softc *)); 185static struct mbuf *sl_btom __P((struct sl_softc *, int)); 186 187/* 188 * Called from boot code to establish sl interfaces. 189 */ 190void 191slattach() 192{ 193 register struct sl_softc *sc; 194 register int i = 0; 195 196 for (sc = sl_softc; i < NSL; sc++) { 197 sc->sc_if.if_name = "sl"; 198 sc->sc_if.if_next = NULL; 199 sc->sc_if.if_unit = i++; 200 sc->sc_if.if_mtu = SLMTU; 201#ifdef __NetBSD__ /* XXX - cgd */ 202 sc->sc_if.if_flags = IFF_POINTOPOINT | SC_AUTOCOMP; 203#ifdef MULTICAST 204 sc->sc_if.if_flags |= IFF_MULTICAST; 205#endif 206#else 207 sc->sc_if.if_flags = 208 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 209#endif /* !__NetBSD__ */ 210 sc->sc_if.if_type = IFT_SLIP; 211 sc->sc_if.if_ioctl = slioctl; 212 sc->sc_if.if_output = sloutput; 213 sc->sc_if.if_snd.ifq_maxlen = 50; 214 sc->sc_fastq.ifq_maxlen = 32; 215 if_attach(&sc->sc_if); 216#if NBPFILTER > 0 217 bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 218#endif 219 } 220} 221 222static int 223slinit(sc) 224 register struct sl_softc *sc; 225{ 226 register caddr_t p; 227 228 if (sc->sc_ep == (u_char *) 0) { 229 MCLALLOC(p, M_WAIT); 230 if (p) 231 sc->sc_ep = (u_char *)p + SLBUFSIZE; 232 else { 233 printf("sl%d: can't allocate buffer\n", sc - sl_softc); 234 sc->sc_if.if_flags &= ~IFF_UP; 235 return (0); 236 } 237 } 238 sc->sc_buf = sc->sc_ep - SLMAX; 239 sc->sc_mp = sc->sc_buf; 240 sl_compress_init(&sc->sc_comp); 241 return (1); 242} 243 244/* 245 * Line specific open routine. 246 * Attach the given tty to the first available sl unit. 247 */ 248/* ARGSUSED */ 249int 250slopen(dev, tp) 251 dev_t dev; 252 register 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 */ 282void 283slclose(tp) 284 struct tty *tp; 285{ 286 register struct sl_softc *sc; 287 int s; 288 289 ttywflush(tp); 290 s = splimp(); /* actually, max(spltty, splnet) */ 291 tp->t_line = 0; 292 sc = (struct sl_softc *)tp->t_sc; 293 if (sc != NULL) { 294 if_down(&sc->sc_if); 295 sc->sc_ttyp = NULL; 296 tp->t_sc = NULL; 297 MCLFREE((caddr_t)(sc->sc_ep - SLBUFSIZE)); 298 sc->sc_ep = 0; 299 sc->sc_mp = 0; 300 sc->sc_buf = 0; 301 } 302 splx(s); 303} 304 305/* 306 * Line specific (tty) ioctl routine. 307 * Provide a way to get the sl unit number. 308 */ 309/* ARGSUSED */ 310int 311sltioctl(tp, cmd, data, flag) 312 struct tty *tp; 313 int cmd; 314 caddr_t data; 315 int flag; 316{ 317 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 318 int s; 319 320 switch (cmd) { 321 case SLIOCGUNIT: 322 *(int *)data = sc->sc_if.if_unit; 323 break; 324 325 default: 326 return (-1); 327 } 328 return (0); 329} 330 331/* 332 * Queue a packet. Start transmission if not active. 333 * Compression happens in slstart; if we do it here, IP TOS 334 * will cause us to not compress "background" packets, because 335 * ordering gets hosed. It can be done for all packets in slstart. 336 */ 337int 338sloutput(ifp, m, dst, rtp) 339 struct ifnet *ifp; 340 register struct mbuf *m; 341 struct sockaddr *dst; 342 struct rtentry *rtp; 343{ 344 register struct sl_softc *sc = &sl_softc[ifp->if_unit]; 345 register struct ip *ip; 346 register struct ifqueue *ifq; 347 int s; 348 349 /* 350 * `Cannot happen' (see slioctl). Someday we will extend 351 * the line protocol to support other address families. 352 */ 353 if (dst->sa_family != AF_INET) { 354 printf("sl%d: af%d not supported\n", sc->sc_if.if_unit, 355 dst->sa_family); 356 m_freem(m); 357 sc->sc_if.if_noproto++; 358 return (EAFNOSUPPORT); 359 } 360 361 if (sc->sc_ttyp == NULL) { 362 m_freem(m); 363 return (ENETDOWN); /* sort of */ 364 } 365 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 366 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 367 m_freem(m); 368 return (EHOSTUNREACH); 369 } 370 ifq = &sc->sc_if.if_snd; 371 ip = mtod(m, struct ip *); 372 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 373 m_freem(m); 374 return (ENETRESET); /* XXX ? */ 375 } 376 if (ip->ip_tos & IPTOS_LOWDELAY) 377 ifq = &sc->sc_fastq; 378 s = splimp(); 379 if (IF_QFULL(ifq)) { 380 IF_DROP(ifq); 381 m_freem(m); 382 splx(s); 383 sc->sc_if.if_oerrors++; 384 return (ENOBUFS); 385 } 386 IF_ENQUEUE(ifq, m); 387 sc->sc_if.if_lastchange = time; 388 if (sc->sc_ttyp->t_outq.c_cc == 0) 389 slstart(sc->sc_ttyp); 390#ifdef __NetBSD__ 391 else /* XXX - cgd */ 392 (*sc->sc_ttyp->t_oproc)(sc->sc_ttyp); 393#endif 394 splx(s); 395 return (0); 396} 397 398/* 399 * Start output on interface. Get another datagram 400 * to send from the interface queue and map it to 401 * the interface before starting output. 402 */ 403void 404slstart(tp) 405 register struct tty *tp; 406{ 407 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 408 register struct mbuf *m; 409 register u_char *cp; 410 register struct ip *ip; 411 int s; 412 struct mbuf *m2; 413#if NBPFILTER > 0 414 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 415 register int len; 416#endif 417#ifndef __NetBSD__ /* XXX - cgd */ 418 extern int cfreecount; 419#endif 420 421 for (;;) { 422 /* 423 * If there is more in the output queue, just send it now. 424 * We are being called in lieu of ttstart and must do what 425 * it would. 426 */ 427 if (tp->t_outq.c_cc != 0) { 428 (*tp->t_oproc)(tp); 429 if (tp->t_outq.c_cc > SLIP_HIWAT) 430 return; 431 } 432 /* 433 * This happens briefly when the line shuts down. 434 */ 435 if (sc == NULL) 436 return; 437 438#ifdef __NetBSD__ /* XXX - cgd */ 439 /* 440 * Do not remove the packet from the IP queue if it 441 * doesn't look like the packet will fit into the 442 * current serial output queue, with a packet full of 443 * escapes this could be as bad as SLMTU*2. The size 444 * of the ring buffer must be at least SLMTU*2 to 445 * avoid deadlock. 446 */ 447 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2 * SLMTU) 448 return; 449#endif /* __NetBSD__ */ 450 451 /* 452 * Get a packet and send it to the interface. 453 */ 454 s = splimp(); 455 IF_DEQUEUE(&sc->sc_fastq, m); 456 if (m) 457 sc->sc_if.if_omcasts++; /* XXX */ 458 else 459 IF_DEQUEUE(&sc->sc_if.if_snd, m); 460 splx(s); 461 if (m == NULL) 462 return; 463 464 /* 465 * We do the header compression here rather than in sloutput 466 * because the packets will be out of order if we are using TOS 467 * queueing, and the connection id compression will get 468 * munged when this happens. 469 */ 470#if NBPFILTER > 0 471 if (sc->sc_bpf) { 472 /* 473 * We need to save the TCP/IP header before it's 474 * compressed. To avoid complicated code, we just 475 * copy the entire packet into a stack buffer (since 476 * this is a serial line, packets should be short 477 * and/or the copy should be negligible cost compared 478 * to the packet transmission time). 479 */ 480 register struct mbuf *m1 = m; 481 register u_char *cp = bpfbuf + SLIP_HDRLEN; 482 483 len = 0; 484 do { 485 register int mlen = m1->m_len; 486 487 bcopy(mtod(m1, caddr_t), cp, mlen); 488 cp += mlen; 489 len += mlen; 490 } while (m1 = m1->m_next); 491 } 492#endif 493 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 494 if (sc->sc_if.if_flags & SC_COMPRESS) 495 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 496 &sc->sc_comp, 1); 497 } 498#if NBPFILTER > 0 499 if (sc->sc_bpf) { 500 /* 501 * Put the SLIP pseudo-"link header" in place. The 502 * compressed header is now at the beginning of the 503 * 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 sc->sc_if.if_lastchange = time; 511 512#ifndef __NetBSD__ /* XXX - cgd */ 513 /* 514 * If system is getting low on clists, just flush our 515 * output queue (if the stuff was important, it'll get 516 * retransmitted). 517 */ 518 if (cfreecount < CLISTRESERVE + SLMTU) { 519 m_freem(m); 520 sc->sc_if.if_collisions++; 521 continue; 522 } 523#endif /* !__NetBSD__ */ 524 /* 525 * The extra FRAME_END will start up a new packet, and thus 526 * will flush any accumulated garbage. We do this whenever 527 * the line may have been idle for some time. 528 */ 529 if (tp->t_outq.c_cc == 0) { 530 ++sc->sc_if.if_obytes; 531 (void) putc(FRAME_END, &tp->t_outq); 532 } 533 534 while (m) { 535 register u_char *ep; 536 537 cp = mtod(m, u_char *); ep = cp + m->m_len; 538 while (cp < ep) { 539 /* 540 * Find out how many bytes in the string we can 541 * handle without doing something special. 542 */ 543 register u_char *bp = cp; 544 545 while (cp < ep) { 546 switch (*cp++) { 547 case FRAME_ESCAPE: 548 case FRAME_END: 549 --cp; 550 goto out; 551 } 552 } 553 out: 554 if (cp > bp) { 555 /* 556 * Put n characters at once 557 * into the tty output queue. 558 */ 559#ifdef __NetBSD__ /* XXX - cgd */ 560 if (b_to_q((u_char *)bp, cp - bp, 561#else 562 if (b_to_q((char *)bp, cp - bp, 563#endif 564 &tp->t_outq)) 565 break; 566 sc->sc_if.if_obytes += cp - bp; 567 } 568 /* 569 * If there are characters left in the mbuf, 570 * the first one must be special.. 571 * Put it out in a different form. 572 */ 573 if (cp < ep) { 574 if (putc(FRAME_ESCAPE, &tp->t_outq)) 575 break; 576 if (putc(*cp++ == FRAME_ESCAPE ? 577 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 578 &tp->t_outq)) { 579 (void) unputc(&tp->t_outq); 580 break; 581 } 582 sc->sc_if.if_obytes += 2; 583 } 584 } 585 MFREE(m, m2); 586 m = m2; 587 } 588 589 if (putc(FRAME_END, &tp->t_outq)) { 590 /* 591 * Not enough room. Remove a char to make room 592 * and end the packet normally. 593 * If you get many collisions (more than one or two 594 * a day) you probably do not have enough clists 595 * and you should increase "nclist" in param.c. 596 */ 597 (void) unputc(&tp->t_outq); 598 (void) putc(FRAME_END, &tp->t_outq); 599 sc->sc_if.if_collisions++; 600 } else { 601 ++sc->sc_if.if_obytes; 602 sc->sc_if.if_opackets++; 603 } 604 } 605} 606 607/* 608 * Copy data buffer to mbuf chain; add ifnet pointer. 609 */ 610static struct mbuf * 611sl_btom(sc, len) 612 register struct sl_softc *sc; 613 register int len; 614{ 615 register struct mbuf *m; 616 617 MGETHDR(m, M_DONTWAIT, MT_DATA); 618 if (m == NULL) 619 return (NULL); 620 621 /* 622 * If we have more than MHLEN bytes, it's cheaper to 623 * queue the cluster we just filled & allocate a new one 624 * for the input buffer. Otherwise, fill the mbuf we 625 * allocated above. Note that code in the input routine 626 * guarantees that packet will fit in a cluster. 627 */ 628 if (len >= MHLEN) { 629 MCLGET(m, M_DONTWAIT); 630 if ((m->m_flags & M_EXT) == 0) { 631 /* 632 * we couldn't get a cluster - if memory's this 633 * low, it's time to start dropping packets. 634 */ 635 (void) m_free(m); 636 return (NULL); 637 } 638 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 639 m->m_data = (caddr_t)sc->sc_buf; 640 m->m_ext.ext_buf = (caddr_t)((int)sc->sc_buf &~ MCLOFSET); 641 } else 642 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 643 644 m->m_len = len; 645 m->m_pkthdr.len = len; 646 m->m_pkthdr.rcvif = &sc->sc_if; 647 return (m); 648} 649 650/* 651 * tty interface receiver interrupt. 652 */ 653void 654slinput(c, tp) 655 register int c; 656 register struct tty *tp; 657{ 658 register struct sl_softc *sc; 659 register struct mbuf *m; 660 register int len; 661 int s; 662#if NBPFILTER > 0 663 u_char chdr[CHDR_LEN]; 664#endif 665 666 tk_nin++; 667 sc = (struct sl_softc *)tp->t_sc; 668 if (sc == NULL) 669 return; 670 if (c & TTY_ERRORMASK || ((tp->t_state & TS_CARR_ON) == 0 && 671 (tp->t_cflag & CLOCAL) == 0)) { 672 sc->sc_flags |= SC_ERROR; 673 return; 674 } 675 c &= TTY_CHARMASK; 676 677 ++sc->sc_if.if_ibytes; 678 679 if (sc->sc_if.if_flags & IFF_DEBUG) { 680 if (c == ABT_ESC) { 681 /* 682 * If we have a previous abort, see whether 683 * this one is within the time limit. 684 */ 685 if (sc->sc_abortcount && 686 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 687 sc->sc_abortcount = 0; 688 /* 689 * If we see an abort after "idle" time, count it; 690 * record when the first abort escape arrived. 691 */ 692 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 693 if (++sc->sc_abortcount == 1) 694 sc->sc_starttime = time.tv_sec; 695 if (sc->sc_abortcount >= ABT_COUNT) { 696 slclose(tp); 697 return; 698 } 699 } 700 } else 701 sc->sc_abortcount = 0; 702 sc->sc_lasttime = time.tv_sec; 703 } 704 705 switch (c) { 706 707 case TRANS_FRAME_ESCAPE: 708 if (sc->sc_escape) 709 c = FRAME_ESCAPE; 710 break; 711 712 case TRANS_FRAME_END: 713 if (sc->sc_escape) 714 c = FRAME_END; 715 break; 716 717 case FRAME_ESCAPE: 718 sc->sc_escape = 1; 719 return; 720 721 case FRAME_END: 722 if(sc->sc_flags & SC_ERROR) { 723 sc->sc_flags &= ~SC_ERROR; 724 goto newpack; 725 } 726 len = sc->sc_mp - sc->sc_buf; 727 if (len < 3) 728 /* less than min length packet - ignore */ 729 goto newpack; 730 731#if NBPFILTER > 0 732 if (sc->sc_bpf) { 733 /* 734 * Save the compressed header, so we can 735 * tack it on later. Note that we just 736 * we will end up copying garbage in some 737 * cases but this is okay. We remember 738 * where the buffer started so we can 739 * compute the new header length. 740 */ 741 bcopy(sc->sc_buf, chdr, CHDR_LEN); 742 } 743#endif 744 745 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 746 if (c & 0x80) 747 c = TYPE_COMPRESSED_TCP; 748 else if (c == TYPE_UNCOMPRESSED_TCP) 749 *sc->sc_buf &= 0x4f; /* XXX */ 750 /* 751 * We've got something that's not an IP packet. 752 * If compression is enabled, try to decompress it. 753 * Otherwise, if `auto-enable' compression is on and 754 * it's a reasonable packet, decompress it and then 755 * enable compression. Otherwise, drop it. 756 */ 757 if (sc->sc_if.if_flags & SC_COMPRESS) { 758 len = sl_uncompress_tcp(&sc->sc_buf, len, 759 (u_int)c, &sc->sc_comp); 760 if (len <= 0) 761 goto error; 762 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 763 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 764 len = sl_uncompress_tcp(&sc->sc_buf, len, 765 (u_int)c, &sc->sc_comp); 766 if (len <= 0) 767 goto error; 768 sc->sc_if.if_flags |= SC_COMPRESS; 769 } else 770 goto error; 771 } 772#if NBPFILTER > 0 773 if (sc->sc_bpf) { 774 /* 775 * Put the SLIP pseudo-"link header" in place. 776 * We couldn't do this any earlier since 777 * decompression probably moved the buffer 778 * pointer. Then, invoke BPF. 779 */ 780 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 781 782 hp[SLX_DIR] = SLIPDIR_IN; 783 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 784 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 785 } 786#endif 787 m = sl_btom(sc, len); 788 if (m == NULL) 789 goto error; 790 791 sc->sc_if.if_ipackets++; 792 sc->sc_if.if_lastchange = time; 793 s = splimp(); 794 if (IF_QFULL(&ipintrq)) { 795 IF_DROP(&ipintrq); 796 sc->sc_if.if_ierrors++; 797 sc->sc_if.if_iqdrops++; 798 m_freem(m); 799 } else { 800 IF_ENQUEUE(&ipintrq, m); 801 schednetisr(NETISR_IP); 802 } 803 splx(s); 804 goto newpack; 805 } 806 if (sc->sc_mp < sc->sc_ep) { 807 *sc->sc_mp++ = c; 808 sc->sc_escape = 0; 809 return; 810 } 811 812 /* can't put lower; would miss an extra frame */ 813 sc->sc_flags |= SC_ERROR; 814 815error: 816 sc->sc_if.if_ierrors++; 817newpack: 818 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 819 sc->sc_escape = 0; 820} 821 822/* 823 * Process an ioctl request. 824 */ 825int 826slioctl(ifp, cmd, data) 827 register struct ifnet *ifp; 828 int cmd; 829 caddr_t data; 830{ 831 register struct ifaddr *ifa = (struct ifaddr *)data; 832#ifdef MULTICAST /* XXX - cgd - del ifdef */ 833 register struct ifreq *ifr; 834#endif 835 register int s = splimp(), error = 0; 836 837 switch (cmd) { 838 839 case SIOCSIFADDR: 840 if (ifa->ifa_addr->sa_family == AF_INET) 841 ifp->if_flags |= IFF_UP; 842 else 843 error = EAFNOSUPPORT; 844 break; 845 846 case SIOCSIFDSTADDR: 847 if (ifa->ifa_addr->sa_family != AF_INET) 848 error = EAFNOSUPPORT; 849 break; 850 851#ifdef MULTICAST /* XXX - cgd - del ifdef */ 852 case SIOCADDMULTI: 853 case SIOCDELMULTI: 854 ifr = (struct ifreq *)data; 855 if (ifr == 0) { 856 error = EAFNOSUPPORT; /* XXX */ 857 break; 858 } 859 switch (ifr->ifr_addr.sa_family) { 860 861#ifdef INET 862 case AF_INET: 863 break; 864#endif 865 866 default: 867 error = EAFNOSUPPORT; 868 break; 869 } 870 break; 871#endif 872 873 default: 874 error = EINVAL; 875 } 876 splx(s); 877 return (error); 878} 879#endif 880