if_sl.c revision 1.5
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 * @(#)if_sl.c 7.22 (Berkeley) 4/20/91 34 */ 35 36/* 37 * Serial Line interface 38 * 39 * Rick Adams 40 * Center for Seismic Studies 41 * 1300 N 17th Street, Suite 1450 42 * Arlington, Virginia 22209 43 * (703)276-7900 44 * rick@seismo.ARPA 45 * seismo!rick 46 * 47 * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris). 48 * N.B.: this belongs in netinet, not net, the way it stands now. 49 * Should have a link-layer type designation, but wouldn't be 50 * backwards-compatible. 51 * 52 * Converted to 4.3BSD Beta by Chris Torek. 53 * Other changes made at Berkeley, based in part on code by Kirk Smith. 54 * W. Jolitz added slip abort. 55 * 56 * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov). 57 * Added priority queuing for "interactive" traffic; hooks for TCP 58 * header compression; ICMP filtering (at 2400 baud, some cretin 59 * pinging you can use up all your bandwidth). Made low clist behavior 60 * more robust and slightly less likely to hang serial line. 61 * Sped up a bunch of things. 62 * 63 * Note that splimp() is used throughout to block both (tty) input 64 * interrupts and network activity; thus, splimp must be >= spltty. 65 */ 66 67/* $Header: /usr/local/opengrok/home/cvs-mirror/mirrors/netbsd/src/sys/net/if_sl.c,v 1.5 1993/04/09 20:42:06 cgd Exp $ */ 68/* from if_sl.c,v 1.11 84/10/04 12:54:47 rick Exp */ 69 70#include "sl.h" 71#if NSL > 0 72 73#include "param.h" 74#include "proc.h" 75#include "mbuf.h" 76#include "buf.h" 77#include "dkstat.h" 78#include "socket.h" 79#include "ioctl.h" 80#include "file.h" 81#include "tty.h" 82#include "kernel.h" 83#include "conf.h" 84 85#include "if.h" 86#include "if_types.h" 87#include "netisr.h" 88#include "route.h" 89#if INET 90#include "netinet/in.h" 91#include "netinet/in_systm.h" 92#include "netinet/in_var.h" 93#include "netinet/ip.h" 94#else 95Huh? Slip without inet? 96#endif 97 98#include "machine/mtpr.h" 99 100#include "slcompress.h" 101#include "if_slvar.h" 102#include "slip.h" 103 104#include "bpfilter.h" 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 /* try 1006 later */ 158#define SLIP_HIWAT roundup(50,CBSIZE) 159 160/* 161 * SLIP ABORT ESCAPE MECHANISM: 162 * (inspired by HAYES modem escape arrangement) 163 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 164 * signals a "soft" exit from slip mode by usermode process 165 */ 166 167#ifdef ABT_ESC 168#undef ABT_ESC 169#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 170#define ABT_WAIT 1 /* in seconds - idle before an escape & after */ 171#define ABT_RECYCLE (5*2+2) /* in seconds - time window processing abort */ 172#define ABT_SOFT 3 /* count of escapes */ 173#endif /* ABT_ESC */ 174 175/* 176 * The following disgusting hack gets around the problem that IP TOS 177 * can't be set yet. We want to put "interactive" traffic on a high 178 * priority queue. To decide if traffic is interactive, we check that 179 * a) it is TCP and b) one of its ports is telnet, rlogin or ftp control. 180 */ 181static u_short interactive_ports[8] = { 182 0, 513, 0, 0, 183 0, 21, 0, 23, 184}; 185#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p)) 186 187struct sl_softc sl_softc[NSL]; 188 189#define FRAME_END 0xc0 /* Frame End */ 190#define FRAME_ESCAPE 0xdb /* Frame Esc */ 191#define TRANS_FRAME_END 0xdc /* transposed frame end */ 192#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 193 194#define t_sc T_LINEP 195 196int sloutput(), slioctl(), ttrstrt(); 197extern struct timeval time; 198 199/* 200 * Called from boot code to establish sl interfaces. 201 */ 202slattach() 203{ 204 register struct sl_softc *sc; 205 register int i = 0; 206 207 for (sc = sl_softc; i < NSL; sc++) { 208 sc->sc_if.if_name = "sl"; 209 sc->sc_if.if_unit = i++; 210 sc->sc_if.if_mtu = SLMTU; 211 sc->sc_if.if_flags = IFF_POINTOPOINT; 212 sc->sc_if.if_type = IFT_SLIP; 213 sc->sc_if.if_ioctl = slioctl; 214 sc->sc_if.if_output = sloutput; 215 sc->sc_if.if_snd.ifq_maxlen = 50; 216 sc->sc_fastq.ifq_maxlen = 32; 217 if_attach(&sc->sc_if); 218#if NBPFILTER > 0 219 bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, 220 SLIP_HDRLEN); 221#endif 222 } 223} 224 225static int 226slinit(sc) 227 register struct sl_softc *sc; 228{ 229 register caddr_t p; 230 231 if (sc->sc_ep == (u_char *) 0) { 232 MCLALLOC(p, M_WAIT); 233 if (p) 234 sc->sc_ep = (u_char *)p + SLBUFSIZE; 235 else { 236 printf("sl%d: can't allocate buffer\n", sc - sl_softc); 237 sc->sc_if.if_flags &= ~IFF_UP; 238 return (0); 239 } 240 } 241 sc->sc_buf = sc->sc_ep - SLMAX; 242 sc->sc_mp = sc->sc_buf; 243 sl_compress_init(&sc->sc_comp); 244 return (1); 245} 246 247/* 248 * Line specific open routine. 249 * Attach the given tty to the first available sl unit. 250 */ 251/* ARGSUSED */ 252slopen(dev, tp) 253 dev_t dev; 254 register struct tty *tp; 255{ 256 struct proc *p = curproc; /* XXX */ 257 register struct sl_softc *sc; 258 register int nsl; 259 int error; 260 261 if (error = suser(p->p_ucred, &p->p_acflag)) 262 return (error); 263 264 if (tp->t_line == SLIPDISC) 265 return (0); 266 267 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 268 if (sc->sc_ttyp == NULL) { 269 if (slinit(sc) == 0) 270 return (ENOBUFS); 271 tp->t_sc = (caddr_t)sc; 272 sc->sc_ttyp = tp; 273 sc->sc_if.if_baudrate = tp->t_ospeed; 274 ttyflush(tp, FREAD | FWRITE); 275 return (0); 276 } 277 return (ENXIO); 278} 279 280/* 281 * Line specific close routine. 282 * Detach the tty from the sl unit. 283 * Mimics part of ttyclose(). 284 */ 285slclose(tp) 286 struct tty *tp; 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 int s; 318 319 switch (cmd) { 320 case SLIOCGUNIT: 321 *(int *)data = sc->sc_if.if_unit; 322 break; 323 324 case SLIOCGFLAGS: 325 *(int *)data = sc->sc_flags; 326 break; 327 328 case SLIOCSFLAGS: 329#define SC_MASK 0xffff 330 s = splimp(); 331 sc->sc_flags = 332 (sc->sc_flags &~ SC_MASK) | ((*(int *)data) & SC_MASK); 333 splx(s); 334 break; 335 336 default: 337 return (-1); 338 } 339 return (0); 340} 341 342/* 343 * Queue a packet. Start transmission if not active. 344 */ 345sloutput(ifp, m, dst) 346 struct ifnet *ifp; 347 register struct mbuf *m; 348 struct sockaddr *dst; 349{ 350 register struct sl_softc *sc = &sl_softc[ifp->if_unit]; 351 register struct ip *ip; 352 register struct ifqueue *ifq; 353 int s; 354 355 /* 356 * `Cannot happen' (see slioctl). Someday we will extend 357 * the line protocol to support other address families. 358 */ 359 if (dst->sa_family != AF_INET) { 360 printf("sl%d: af%d not supported\n", sc->sc_if.if_unit, 361 dst->sa_family); 362 m_freem(m); 363 return (EAFNOSUPPORT); 364 } 365 366 if (sc->sc_ttyp == NULL) { 367 m_freem(m); 368 return (ENETDOWN); /* sort of */ 369 } 370 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0) { 371 m_freem(m); 372 return (EHOSTUNREACH); 373 } 374 ifq = &sc->sc_if.if_snd; 375 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 376 u_short srcport = ntohs(((short *)ip)[ip->ip_hl << 1]); 377 u_short dstport = ntohs(((short *)ip)[(ip->ip_hl << 1) + 1]); 378 379 if (INTERACTIVE(srcport) || INTERACTIVE(dstport)) { 380 ifq = &sc->sc_fastq; 381 } 382 383 } else if (sc->sc_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 384 m_freem(m); 385 return (0); 386 } 387 s = splimp(); 388 if (IF_QFULL(ifq)) { 389 IF_DROP(ifq); 390 m_freem(m); 391 splx(s); 392 sc->sc_if.if_oerrors++; 393 return (ENOBUFS); 394 } 395 IF_ENQUEUE(ifq, m); 396 sc->sc_if.if_lastchange = time; 397 if (RB_LEN(&sc->sc_ttyp->t_out) == 0) 398 slstart(sc->sc_ttyp); 399 splx(s); 400 return (0); 401} 402 403/* 404 * Start output on interface. Get another datagram 405 * to send from the interface queue and map it to 406 * the interface before starting output. 407 */ 408slstart(tp) 409 register struct tty *tp; 410{ 411 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 412 register struct mbuf *m; 413 register u_char *cp; 414 register struct ip *ip; 415 int s; 416 struct mbuf *m2; 417#if NBPFILTER > 0 418 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 419 register int len; 420#endif 421 422 for (;;) { 423 /* 424 * If there is more in the output queue, just send it now. 425 * We are being called in lieu of ttstart and must do what 426 * it would. 427 */ 428 if (RB_LEN(&tp->t_out) != 0) { 429 (*tp->t_oproc)(tp); 430 if (RB_LEN(&tp->t_out) > SLIP_HIWAT) 431 return; 432 } 433 /* 434 * This happens briefly when the line shuts down. 435 */ 436 if (sc == NULL) 437 return; 438 439 /* 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 COM output queue, with a packet full of 443 * escapes this could be as bad as SLMTU*2. The value 444 * of RBSZ in tty.h also has to be upped to be at least 445 * SLMTU*2. 446 */ 447 if (RBSZ - RB_LEN(&tp->t_out) < 2 * SLMTU + 2) 448 return; 449 450 /* 451 * Get a packet and send it to the interface. 452 */ 453 s = splimp(); 454 IF_DEQUEUE(&sc->sc_fastq, m); 455 if (m == NULL) 456 IF_DEQUEUE(&sc->sc_if.if_snd, m); 457 splx(s); 458 if (m == NULL) 459 return; 460 /* 461 * We do the header compression here rather than in sl_output 462 * because the packets will be out of order if we are using TOS 463 * queueing, and the connection id compression will get messed 464 * up when this happens. 465 */ 466#if NBPFILTER > 0 467 if (sc->sc_bpf) { 468 /* 469 * We need to save the TCP/IP header before it's compressed. 470 * To avoid complicated code, we just copy the entire packet 471 * into a stack buffer (since this is a serial line, packets 472 * should be short and/or the copy should be negligible cost 473 * compared to the packet transmission time). 474 */ 475 register struct mbuf *m1 = m; 476 register u_char *cp = bpfbuf + SLIP_HDRLEN; 477 len = 0; 478 do { 479 register int mlen = m1->m_len; 480 481 bcopy(mtod(m1, caddr_t), cp, mlen); 482 cp += mlen; 483 len += mlen; 484 } while (m1 = m1->m_next); 485 } 486#endif 487 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 488 if (sc->sc_flags & SC_COMPRESS) 489 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, &sc->sc_comp, 1); 490 } 491#if NBPFILTER > 0 492 if (sc->sc_bpf) { 493 /* 494 * Put the SLIP pseudo-"link header" in place. The compressed 495 * header is now at the beginning of the mbuf. 496 */ 497 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 498 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 499 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 500 } 501#endif 502 503 sc->sc_if.if_lastchange = time; 504 505 /* 506 * The extra FRAME_END will start up a new packet, and thus 507 * will flush any accumulated garbage. We do this whenever 508 * the line may have been idle for some time. 509 */ 510 if (RB_LEN(&tp->t_out) == 0) { 511 ++sc->sc_bytessent; 512 (void) putc(FRAME_END, &tp->t_out); 513 } 514 515 while (m) { 516 register u_char *ep; 517 518 cp = mtod(m, u_char *); ep = cp + m->m_len; 519 while (cp < ep) { 520 /* 521 * Find out how many bytes in the string we can 522 * handle without doing something special. 523 */ 524 register u_char *bp = cp; 525 526 while (cp < ep) { 527 switch (*cp++) { 528 case FRAME_ESCAPE: 529 case FRAME_END: 530 --cp; 531 goto out; 532 } 533 } 534 out: 535 if (cp > bp) { 536 /* 537 * Put the non-special bytes 538 * into the tty output queue. 539 */ 540 sc->sc_bytessent += rb_write( 541 &tp->t_out, 542 (char *) bp, 543 cp - bp); 544 } 545 /* 546 * If there are characters left in the mbuf, 547 * the first one must be special.. 548 * Put it out in a different form. 549 */ 550 if (cp < ep) { 551 if (putc(FRAME_ESCAPE, &tp->t_out)) 552 break; 553 if (putc(*cp++ == FRAME_ESCAPE ? 554 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 555 &tp->t_out)) { 556 (void) unputc(&tp->t_out); 557 break; 558 } 559 sc->sc_bytessent += 2; 560 } 561 } 562 MFREE(m, m2); 563 m = m2; 564 } 565 566 if (putc(FRAME_END, &tp->t_out)) { 567 /* 568 * Not enough room. Remove a char to make room 569 * and end the packet normally. 570 * If you get many collisions (more than one or two 571 * a day) you probably do not have enough clists 572 * and you should increase "nclist" in param.c. 573 */ 574 (void) unputc(&tp->t_out); 575 (void) putc(FRAME_END, &tp->t_out); 576 sc->sc_if.if_collisions++; 577 } else { 578 ++sc->sc_bytessent; 579 sc->sc_if.if_opackets++; 580 } 581 sc->sc_if.if_obytes = sc->sc_bytessent; 582 } 583} 584 585/* 586 * Copy data buffer to mbuf chain; add ifnet pointer. 587 */ 588static struct mbuf * 589sl_btom(sc, len) 590 register struct sl_softc *sc; 591 register int len; 592{ 593 register struct mbuf *m; 594 595 MGETHDR(m, M_DONTWAIT, MT_DATA); 596 if (m == NULL) 597 return (NULL); 598 599 /* 600 * If we have more than MHLEN bytes, it's cheaper to 601 * queue the cluster we just filled & allocate a new one 602 * for the input buffer. Otherwise, fill the mbuf we 603 * allocated above. Note that code in the input routine 604 * guarantees that packet will fit in a cluster. 605 */ 606 if (len >= MHLEN) { 607 MCLGET(m, M_DONTWAIT); 608 if ((m->m_flags & M_EXT) == 0) { 609 /* 610 * we couldn't get a cluster - if memory's this 611 * low, it's time to start dropping packets. 612 */ 613 (void) m_free(m); 614 return (NULL); 615 } 616 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 617 m->m_data = (caddr_t)sc->sc_buf; 618 m->m_ext.ext_buf = (caddr_t)((int)sc->sc_buf &~ MCLOFSET); 619 } else 620 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 621 622 m->m_len = len; 623 m->m_pkthdr.len = len; 624 m->m_pkthdr.rcvif = &sc->sc_if; 625 return (m); 626} 627 628/* 629 * tty interface receiver interrupt. 630 */ 631slinput(c, tp) 632 register int c; 633 register struct tty *tp; 634{ 635 register struct sl_softc *sc; 636 register struct mbuf *m; 637 register int len; 638 int s; 639#if NBPFILTER > 0 640 u_char chdr[CHDR_LEN]; 641#endif 642 tk_nin++; 643 sc = (struct sl_softc *)tp->t_sc; 644 if (sc == NULL) 645 return; 646 if (c & TTY_ERRORMASK|| !(tp->t_state&TS_CARR_ON)) { 647 sc->sc_flags |= SC_ERROR; 648 return; 649 } 650 651 ++sc->sc_bytesrcvd; 652 ++sc->sc_if.if_ibytes; 653 654#ifdef ABT_ESC 655 if (sc->sc_flags & SC_ABORT) { 656 /* if we see an abort after "idle" time, count it */ 657 if (c == ABT_ESC && time.tv_sec >= sc->sc_lasttime + ABT_WAIT) { 658 sc->sc_abortcount++; 659 /* record when the first abort escape arrived */ 660 if (sc->sc_abortcount == 1) 661 sc->sc_starttime = time.tv_sec; 662 } 663 /* 664 * if we have an abort, see that we have not run out of time, 665 * or that we have an "idle" time after the complete escape 666 * sequence 667 */ 668 if (sc->sc_abortcount) { 669 if (time.tv_sec >= sc->sc_starttime + ABT_RECYCLE) 670 sc->sc_abortcount = 0; 671 if (sc->sc_abortcount >= ABT_SOFT && 672 time.tv_sec >= sc->sc_lasttime + ABT_WAIT) { 673 slclose(tp); 674 return; 675 } 676 } 677 sc->sc_lasttime = time.tv_sec; 678 } 679#endif 680 681 switch (c) { 682 683 case TRANS_FRAME_ESCAPE: 684 if (sc->sc_escape) 685 c = FRAME_ESCAPE; 686 break; 687 688 case TRANS_FRAME_END: 689 if (sc->sc_escape) 690 c = FRAME_END; 691 break; 692 693 case FRAME_ESCAPE: 694 sc->sc_escape = 1; 695 return; 696 697 case FRAME_END: 698 if(sc->sc_flags & SC_ERROR) { 699 sc->sc_flags &= ~SC_ERROR; 700 goto newpack; 701 } 702 len = sc->sc_mp - sc->sc_buf; 703 704 if (len < 3) 705 /* less than min length packet - ignore */ 706 goto newpack; 707 708#if NBPFILTER > 0 709 if (sc->sc_bpf) 710 /* 711 * Save the compressed header, so we can 712 * tack it on later. Note that we just 713 * we will end up copying garbage in some 714 * cases but this is okay. We remember 715 * where the buffer started so we can 716 * compute the new header length. 717 */ 718 bcopy(sc->sc_buf, chdr, CHDR_LEN); 719#endif 720 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 721 if (c & 0x80) 722 c = TYPE_COMPRESSED_TCP; 723 else if (c == TYPE_UNCOMPRESSED_TCP) 724 *sc->sc_buf &= 0x4f; /* XXX */ 725 /* 726 * We've got something that's not an IP packet. 727 * If compression is enabled, try to decompress it. 728 * Otherwise, if `auto-enable' compression is on and 729 * it's a reasonable packet, decompress it and then 730 * enable compression. Otherwise, drop it. 731 */ 732 if (sc->sc_flags & SC_COMPRESS) { 733 len = sl_uncompress_tcp(&sc->sc_buf, len, 734 (u_int)c, &sc->sc_comp); 735 if (len <= 0) 736 goto error; 737 } else if ((sc->sc_flags & SC_AUTOCOMP) && 738 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 739 len = sl_uncompress_tcp(&sc->sc_buf, len, 740 (u_int)c, &sc->sc_comp); 741 if (len <= 0) 742 goto error; 743 sc->sc_flags |= SC_COMPRESS; 744 } else 745 goto error; 746 } 747#if NBPFILTER > 0 748 if (sc->sc_bpf) { 749 /* 750 * Put the SLIP pseudo-"link header" in place. 751 * We couldn't do this any earlier since 752 * decompression probably moved the buffer 753 * pointer. Then, invoke BPF. 754 */ 755 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 756 757 hp[SLX_DIR] = SLIPDIR_IN; 758 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 759 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 760 } 761#endif 762 m = sl_btom(sc, len); 763 if (m == NULL) 764 goto error; 765 766 sc->sc_if.if_ipackets++; 767 sc->sc_if.if_lastchange = time; 768 s = splimp(); 769 if (IF_QFULL(&ipintrq)) { 770 IF_DROP(&ipintrq); 771 sc->sc_if.if_ierrors++; 772 sc->sc_if.if_iqdrops++; 773 m_freem(m); 774 } else { 775 IF_ENQUEUE(&ipintrq, m); 776 schednetisr(NETISR_IP); 777 } 778 splx(s); 779 goto newpack; 780 } 781 if (sc->sc_mp < sc->sc_ep) { 782 *sc->sc_mp++ = c; 783 sc->sc_escape = 0; 784 return; 785 } 786 sc->sc_flags |= SC_ERROR; 787error: 788 sc->sc_if.if_ierrors++; 789newpack: 790 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 791 sc->sc_escape = 0; 792} 793 794/* 795 * Process an ioctl request. 796 */ 797slioctl(ifp, cmd, data) 798 register struct ifnet *ifp; 799 int cmd; 800 caddr_t data; 801{ 802 register struct ifaddr *ifa = (struct ifaddr *)data; 803 int s = splimp(), error = 0; 804 805 switch (cmd) { 806 807 case SIOCSIFADDR: 808 if (ifa->ifa_addr->sa_family == AF_INET) 809 ifp->if_flags |= IFF_UP; 810 else 811 error = EAFNOSUPPORT; 812 break; 813 814 case SIOCSIFDSTADDR: 815 if (ifa->ifa_addr->sa_family != AF_INET) 816 error = EAFNOSUPPORT; 817 break; 818 819 default: 820 error = EINVAL; 821 } 822 splx(s); 823 return (error); 824} 825#endif 826