if_sl.c revision 1.21
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 <sys/param.h> 73#include <sys/proc.h> 74#include <sys/mbuf.h> 75#include <sys/buf.h> 76#include <sys/dkstat.h> 77#include <sys/socket.h> 78#include <sys/ioctl.h> 79#include <sys/file.h> 80#include <sys/tty.h> 81#include <sys/kernel.h> 82#include <sys/conf.h> 83 84#include <net/if.h> 85#include <net/if_types.h> 86#include <net/netisr.h> 87#include <net/route.h> 88 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/cpu.h> /* XXX */ 99#include <machine/mtpr.h> 100 101#include <net/slcompress.h> 102#include <net/if_slvar.h> 103#include <net/slip.h> 104 105#include "bpfilter.h" 106#if NBPFILTER > 0 107#include <sys/time.h> 108#include <net/bpf.h> 109#endif 110 111/* 112 * SLMAX is a hard limit on input packet size. To simplify the code 113 * and improve performance, we require that packets fit in an mbuf 114 * cluster, and if we get a compressed packet, there's enough extra 115 * room to expand the header into a max length tcp/ip header (128 116 * bytes). So, SLMAX can be at most 117 * MCLBYTES - 128 118 * 119 * SLMTU is a hard limit on output packet size. To insure good 120 * interactive response, SLMTU wants to be the smallest size that 121 * amortizes the header cost. (Remember that even with 122 * type-of-service queuing, we have to wait for any in-progress 123 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 124 * cps, where cps is the line speed in characters per second. 125 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 126 * average compressed header size is 6-8 bytes so any MTU > 90 127 * bytes will give us 90% of the line bandwidth. A 100ms wait is 128 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 129 * will send 256 byte segments (to allow for 40 byte headers), the 130 * typical packet size on the wire will be around 260 bytes). In 131 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 132 * leave the interface MTU relatively high (so we don't IP fragment 133 * when acting as a gateway to someone using a stupid MTU). 134 * 135 * Similar considerations apply to SLIP_HIWAT: It's the amount of 136 * data that will be queued 'downstream' of us (i.e., in clists 137 * waiting to be picked up by the tty output interrupt). If we 138 * queue a lot of data downstream, it's immune to our t.o.s. queuing. 139 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 140 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 141 * wait is dependent on the ftp window size but that's typically 142 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 143 * the cost (in idle time on the wire) of the tty driver running 144 * off the end of its clists & having to call back slstart for a 145 * new packet. For a tty interface with any buffering at all, this 146 * cost will be zero. Even with a totally brain dead interface (like 147 * the one on a typical workstation), the cost will be <= 1 character 148 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 149 * at most 1% while maintaining good interactive response. 150 */ 151#if NBPFILTER > 0 152#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 153#else 154#define BUFOFFSET (128+sizeof(struct ifnet **)) 155#endif 156#define SLMAX (MCLBYTES - BUFOFFSET) 157#define SLBUFSIZE (SLMAX + BUFOFFSET) 158#define SLMTU 296 /* try 1006 later */ 159#define SLIP_HIWAT roundup(50,CBSIZE) 160 161/* 162 * SLIP ABORT ESCAPE MECHANISM: 163 * (inspired by HAYES modem escape arrangement) 164 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 165 * signals a "soft" exit from slip mode by usermode process 166 */ 167 168#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 */ 172 173/* 174 * The following disgusting hack gets around the problem that IP TOS 175 * can't be set yet. We want to put "interactive" traffic on a high 176 * priority queue. To decide if traffic is interactive, we check that 177 * a) it is TCP and b) one of its ports is telnet, rlogin or ftp control. 178 */ 179static u_short interactive_ports[8] = { 180 0, 513, 0, 0, 181 0, 21, 0, 23, 182}; 183#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p)) 184 185struct sl_softc sl_softc[NSL]; 186 187#define FRAME_END 0xc0 /* Frame End */ 188#define FRAME_ESCAPE 0xdb /* Frame Esc */ 189#define TRANS_FRAME_END 0xdc /* transposed frame end */ 190#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 191 192 193int sloutput(), slioctl(), ttrstrt(); 194void slstart(); 195extern struct timeval time; 196 197/* 198 * Called from boot code to establish sl interfaces. 199 */ 200slattach() 201{ 202 register struct sl_softc *sc; 203 register int i = 0; 204 205 for (sc = sl_softc; i < NSL; sc++) { 206 sc->sc_if.if_name = "sl"; 207 sc->sc_if.if_unit = i++; 208 sc->sc_if.if_mtu = SLMTU; 209#ifdef MULTICAST 210 sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 211#else 212 sc->sc_if.if_flags = IFF_POINTOPOINT; 213#endif 214 sc->sc_if.if_type = IFT_SLIP; 215 sc->sc_if.if_ioctl = slioctl; 216 sc->sc_if.if_output = sloutput; 217 sc->sc_if.if_snd.ifq_maxlen = 50; 218 sc->sc_fastq.ifq_maxlen = 32; 219 if_attach(&sc->sc_if); 220#if NBPFILTER > 0 221 bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, 222 SLIP_HDRLEN); 223#endif 224 } 225} 226 227static int 228slinit(sc) 229 register struct sl_softc *sc; 230{ 231 register caddr_t p; 232 233 if (sc->sc_ep == (u_char *) 0) { 234 MCLALLOC(p, M_WAIT); 235 if (p) 236 sc->sc_ep = (u_char *)p + SLBUFSIZE; 237 else { 238 printf("sl%d: can't allocate buffer\n", sc - sl_softc); 239 sc->sc_if.if_flags &= ~IFF_UP; 240 return (0); 241 } 242 } 243 sc->sc_buf = sc->sc_ep - SLMAX; 244 sc->sc_mp = sc->sc_buf; 245 sl_compress_init(&sc->sc_comp); 246 return (1); 247} 248 249/* 250 * Line specific open routine. 251 * Attach the given tty to the first available sl unit. 252 */ 253/* ARGSUSED */ 254int 255slopen(dev_t dev, struct tty *tp) 256{ 257 struct proc *p = curproc; /* XXX */ 258 register struct sl_softc *sc; 259 register int nsl; 260 int error; 261 262 if (error = suser(p->p_ucred, &p->p_acflag)) 263 return (error); 264 265 if (tp->t_line == SLIPDISC) 266 return (0); 267 268 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 269 if (sc->sc_ttyp == NULL) { 270 if (slinit(sc) == 0) 271 return (ENOBUFS); 272 tp->t_sc = (caddr_t)sc; 273 sc->sc_ttyp = tp; 274 sc->sc_if.if_baudrate = tp->t_ospeed; 275 ttyflush(tp, FREAD | FWRITE); 276 return (0); 277 } 278 return (ENXIO); 279} 280 281/* 282 * Line specific close routine. 283 * Detach the tty from the sl unit. 284 * Mimics part of ttyclose(). 285 */ 286void 287slclose(tp, flag) 288 struct tty *tp; 289 int flag; 290{ 291 register struct sl_softc *sc; 292 int s; 293 294 ttywflush(tp); 295 s = splimp(); /* actually, max(spltty, splnet) */ 296 tp->t_line = 0; 297 sc = (struct sl_softc *)tp->t_sc; 298 if (sc != NULL) { 299 if_down(&sc->sc_if); 300 sc->sc_ttyp = NULL; 301 tp->t_sc = NULL; 302 MCLFREE((caddr_t)(sc->sc_ep - SLBUFSIZE)); 303 sc->sc_ep = 0; 304 sc->sc_mp = 0; 305 sc->sc_buf = 0; 306 } 307 splx(s); 308} 309 310/* 311 * Line specific (tty) ioctl routine. 312 * Provide a way to get the sl unit number. 313 */ 314/* ARGSUSED */ 315sltioctl(tp, cmd, data, flag) 316 struct tty *tp; 317 caddr_t data; 318{ 319 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 320 struct proc *p = curproc; /* XXX */ 321 int error; 322 int s; 323 324 switch (cmd) { 325 case SLIOCGUNIT: 326 *(int *)data = sc->sc_if.if_unit; 327 break; 328 329 default: 330 return (-1); 331 } 332 return (0); 333} 334 335/* 336 * Queue a packet. Start transmission if not active. 337 */ 338sloutput(ifp, m, dst) 339 struct ifnet *ifp; 340 register struct mbuf *m; 341 struct sockaddr *dst; 342{ 343 register struct sl_softc *sc = &sl_softc[ifp->if_unit]; 344 register struct ip *ip; 345 register struct ifqueue *ifq; 346 int s; 347 348 /* 349 * `Cannot happen' (see slioctl). Someday we will extend 350 * the line protocol to support other address families. 351 */ 352 if (dst->sa_family != AF_INET) { 353 printf("sl%d: af%d not supported\n", sc->sc_if.if_unit, 354 dst->sa_family); 355 m_freem(m); 356 return (EAFNOSUPPORT); 357 } 358 359 if (sc->sc_ttyp == NULL) { 360 m_freem(m); 361 return (ENETDOWN); /* sort of */ 362 } 363 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 364 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 365 m_freem(m); 366 return (EHOSTUNREACH); 367 } 368 ifq = &sc->sc_if.if_snd; 369 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 370 u_short srcport = ntohs(((short *)ip)[ip->ip_hl << 1]); 371 u_short dstport = ntohs(((short *)ip)[(ip->ip_hl << 1) + 1]); 372 373 if (INTERACTIVE(srcport) || INTERACTIVE(dstport)) { 374 ifq = &sc->sc_fastq; 375 } 376 377 } else if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 378 m_freem(m); 379 return (0); 380 } 381 s = splimp(); 382 if (IF_QFULL(ifq)) { 383 IF_DROP(ifq); 384 m_freem(m); 385 splx(s); 386 sc->sc_if.if_oerrors++; 387 return (ENOBUFS); 388 } 389 IF_ENQUEUE(ifq, m); 390 sc->sc_if.if_lastchange = time; 391 if (sc->sc_ttyp->t_outq.c_cc == 0) 392 slstart(sc->sc_ttyp); 393 else 394 (*sc->sc_ttyp->t_oproc)(sc->sc_ttyp); /* XXX */ 395 splx(s); 396 return (0); 397} 398 399/* 400 * Start output on interface. Get another datagram 401 * to send from the interface queue and map it to 402 * the interface before starting output. 403 */ 404void 405slstart(tp) 406 register struct tty *tp; 407{ 408 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 409 register struct mbuf *m; 410 register u_char *cp; 411 register struct ip *ip; 412 int s; 413 struct mbuf *m2; 414#if NBPFILTER > 0 415 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 416 register int len; 417#endif 418 419 for (;;) { 420 /* 421 * If there is more in the output queue, just send it now. 422 * We are being called in lieu of ttstart and must do what 423 * it would. 424 */ 425 if (tp->t_outq.c_cc != 0) { 426 (*tp->t_oproc)(tp); 427 if (tp->t_outq.c_cc > SLIP_HIWAT) 428 return; 429 } 430 /* 431 * This happens briefly when the line shuts down. 432 */ 433 if (sc == NULL) 434 return; 435 436 /* 437 * Do not remove the packet from the IP queue if it 438 * doesn't look like the packet will fit into the 439 * current COM output queue, with a packet full of 440 * escapes this could be as bad as SLMTU*2. The size 441 * of the ring buffer must be at least SLMTU*2 to 442 * avoid deadlock. 443 */ 444 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2 * SLMTU) 445 return; 446 447 /* 448 * Get a packet and send it to the interface. 449 */ 450 s = splimp(); 451 IF_DEQUEUE(&sc->sc_fastq, m); 452 if (m == NULL) 453 IF_DEQUEUE(&sc->sc_if.if_snd, m); 454 splx(s); 455 if (m == NULL) 456 return; 457 /* 458 * We do the header compression here rather than in sl_output 459 * because the packets will be out of order if we are using TOS 460 * queueing, and the connection id compression will get messed 461 * up when this happens. 462 */ 463#if NBPFILTER > 0 464 if (sc->sc_bpf) { 465 /* 466 * We need to save the TCP/IP header before it's compressed. 467 * To avoid complicated code, we just copy the entire packet 468 * into a stack buffer (since this is a serial line, packets 469 * should be short and/or the copy should be negligible cost 470 * compared to the packet transmission time). 471 */ 472 register struct mbuf *m1 = m; 473 register u_char *cp = bpfbuf + SLIP_HDRLEN; 474 len = 0; 475 do { 476 register int mlen = m1->m_len; 477 478 bcopy(mtod(m1, caddr_t), cp, mlen); 479 cp += mlen; 480 len += mlen; 481 } while (m1 = m1->m_next); 482 } 483#endif 484 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 485 if (sc->sc_if.if_flags & SC_COMPRESS) 486 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, &sc->sc_comp, 1); 487 } 488#if NBPFILTER > 0 489 if (sc->sc_bpf) { 490 /* 491 * Put the SLIP pseudo-"link header" in place. The compressed 492 * header is now at the beginning of the mbuf. 493 */ 494 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 495 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 496 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 497 } 498#endif 499 500 sc->sc_if.if_lastchange = time; 501 502 /* 503 * The extra FRAME_END will start up a new packet, and thus 504 * will flush any accumulated garbage. We do this whenever 505 * the line may have been idle for some time. 506 */ 507 if (tp->t_outq.c_cc == 0) { 508 ++sc->sc_bytessent; 509 (void) putc(FRAME_END, &tp->t_outq); 510 } 511 512 while (m) { 513 register u_char *ep; 514 515 cp = mtod(m, u_char *); ep = cp + m->m_len; 516 while (cp < ep) { 517 /* 518 * Find out how many bytes in the string we can 519 * handle without doing something special. 520 */ 521 register u_char *bp = cp; 522 523 while (cp < ep) { 524 switch (*cp++) { 525 case FRAME_ESCAPE: 526 case FRAME_END: 527 --cp; 528 goto out; 529 } 530 } 531 out: 532 if (cp > bp) { 533 /* 534 * Put n characters at once 535 * into the tty output queue. 536 */ 537 if (b_to_q((u_char *)bp, cp - bp, &tp->t_outq)) 538 break; 539 sc->sc_bytessent += cp - bp; 540 } 541 /* 542 * If there are characters left in the mbuf, 543 * the first one must be special.. 544 * Put it out in a different form. 545 */ 546 if (cp < ep) { 547 if (putc(FRAME_ESCAPE, &tp->t_outq)) 548 break; 549 if (putc(*cp++ == FRAME_ESCAPE ? 550 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 551 &tp->t_outq)) { 552 (void) unputc(&tp->t_outq); 553 break; 554 } 555 sc->sc_bytessent += 2; 556 } 557 } 558 MFREE(m, m2); 559 m = m2; 560 } 561 562 if (putc(FRAME_END, &tp->t_outq)) { 563 /* 564 * Not enough room. Remove a char to make room 565 * and end the packet normally. 566 * If you get many collisions (more than one or two 567 * a day) you probably do not have enough clists 568 * and you should increase "nclist" in param.c. 569 */ 570 (void) unputc(&tp->t_outq); 571 (void) putc(FRAME_END, &tp->t_outq); 572 sc->sc_if.if_collisions++; 573 } else { 574 ++sc->sc_bytessent; 575 sc->sc_if.if_opackets++; 576 } 577 sc->sc_if.if_obytes = sc->sc_bytessent; 578 } 579} 580 581/* 582 * Copy data buffer to mbuf chain; add ifnet pointer. 583 */ 584static struct mbuf * 585sl_btom(sc, len) 586 register struct sl_softc *sc; 587 register int len; 588{ 589 register struct mbuf *m; 590 591 MGETHDR(m, M_DONTWAIT, MT_DATA); 592 if (m == NULL) 593 return (NULL); 594 595 /* 596 * If we have more than MHLEN bytes, it's cheaper to 597 * queue the cluster we just filled & allocate a new one 598 * for the input buffer. Otherwise, fill the mbuf we 599 * allocated above. Note that code in the input routine 600 * guarantees that packet will fit in a cluster. 601 */ 602 if (len >= MHLEN) { 603 MCLGET(m, M_DONTWAIT); 604 if ((m->m_flags & M_EXT) == 0) { 605 /* 606 * we couldn't get a cluster - if memory's this 607 * low, it's time to start dropping packets. 608 */ 609 (void) m_free(m); 610 return (NULL); 611 } 612 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 613 m->m_data = (caddr_t)sc->sc_buf; 614 m->m_ext.ext_buf = (caddr_t)((int)sc->sc_buf &~ MCLOFSET); 615 } else 616 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 617 618 m->m_len = len; 619 m->m_pkthdr.len = len; 620 m->m_pkthdr.rcvif = &sc->sc_if; 621 return (m); 622} 623 624/* 625 * tty interface receiver interrupt. 626 */ 627void 628slinput(c, tp) 629 register int c; 630 register struct tty *tp; 631{ 632 register struct sl_softc *sc; 633 register struct mbuf *m; 634 register int len; 635 int s; 636#if NBPFILTER > 0 637 u_char chdr[CHDR_LEN]; 638#endif 639 tk_nin++; 640 sc = (struct sl_softc *)tp->t_sc; 641 if (sc == NULL) 642 return; 643 if (c & TTY_ERRORMASK || ((tp->t_state & TS_CARR_ON) == 0 && 644 (tp->t_cflag & CLOCAL) == 0)) { 645 sc->sc_flags |= SC_ERROR; 646 return; 647 } 648 649 ++sc->sc_bytesrcvd; 650 ++sc->sc_if.if_ibytes; 651 652 if (sc->sc_if.if_flags & IFF_DEBUG) { 653 /* if we see an abort after "idle" time, count it */ 654 if (c == ABT_ESC && time.tv_sec >= sc->sc_lasttime + ABT_WAIT) { 655 sc->sc_abortcount++; 656 /* record when the first abort escape arrived */ 657 if (sc->sc_abortcount == 1) 658 sc->sc_starttime = time.tv_sec; 659 } 660 /* 661 * if we have an abort, see that we have not run out of time, 662 * or that we have an "idle" time after the complete escape 663 * sequence 664 */ 665 if (sc->sc_abortcount) { 666 if (time.tv_sec >= sc->sc_starttime + ABT_RECYCLE) 667 sc->sc_abortcount = 0; 668 if (sc->sc_abortcount >= ABT_SOFT && 669 time.tv_sec >= sc->sc_lasttime + ABT_WAIT) { 670 slclose(tp); 671 return; 672 } 673 } 674 sc->sc_lasttime = time.tv_sec; 675 } 676 677 switch (c) { 678 679 case TRANS_FRAME_ESCAPE: 680 if (sc->sc_escape) 681 c = FRAME_ESCAPE; 682 break; 683 684 case TRANS_FRAME_END: 685 if (sc->sc_escape) 686 c = FRAME_END; 687 break; 688 689 case FRAME_ESCAPE: 690 sc->sc_escape = 1; 691 return; 692 693 case FRAME_END: 694 if(sc->sc_flags & SC_ERROR) { 695 sc->sc_flags &= ~SC_ERROR; 696 goto newpack; 697 } 698 len = sc->sc_mp - sc->sc_buf; 699 700 if (len < 3) 701 /* less than min length packet - ignore */ 702 goto newpack; 703 704#if NBPFILTER > 0 705 if (sc->sc_bpf) 706 /* 707 * Save the compressed header, so we can 708 * tack it on later. Note that we just 709 * we will end up copying garbage in some 710 * cases but this is okay. We remember 711 * where the buffer started so we can 712 * compute the new header length. 713 */ 714 bcopy(sc->sc_buf, chdr, CHDR_LEN); 715#endif 716 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 717 if (c & 0x80) 718 c = TYPE_COMPRESSED_TCP; 719 else if (c == TYPE_UNCOMPRESSED_TCP) 720 *sc->sc_buf &= 0x4f; /* XXX */ 721 /* 722 * We've got something that's not an IP packet. 723 * If compression is enabled, try to decompress it. 724 * Otherwise, if `auto-enable' compression is on and 725 * it's a reasonable packet, decompress it and then 726 * enable compression. Otherwise, drop it. 727 */ 728 if (sc->sc_if.if_flags & SC_COMPRESS) { 729 len = sl_uncompress_tcp(&sc->sc_buf, len, 730 (u_int)c, &sc->sc_comp); 731 if (len <= 0) 732 goto error; 733 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 734 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 735 len = sl_uncompress_tcp(&sc->sc_buf, len, 736 (u_int)c, &sc->sc_comp); 737 if (len <= 0) 738 goto error; 739 sc->sc_if.if_flags |= SC_COMPRESS; 740 } else 741 goto error; 742 } 743#if NBPFILTER > 0 744 if (sc->sc_bpf) { 745 /* 746 * Put the SLIP pseudo-"link header" in place. 747 * We couldn't do this any earlier since 748 * decompression probably moved the buffer 749 * pointer. Then, invoke BPF. 750 */ 751 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 752 753 hp[SLX_DIR] = SLIPDIR_IN; 754 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 755 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 756 } 757#endif 758 m = sl_btom(sc, len); 759 if (m == NULL) 760 goto error; 761 762 sc->sc_if.if_ipackets++; 763 sc->sc_if.if_lastchange = time; 764 s = splimp(); 765 if (IF_QFULL(&ipintrq)) { 766 IF_DROP(&ipintrq); 767 sc->sc_if.if_ierrors++; 768 sc->sc_if.if_iqdrops++; 769 m_freem(m); 770 } else { 771 IF_ENQUEUE(&ipintrq, m); 772 schednetisr(NETISR_IP); 773 } 774 splx(s); 775 goto newpack; 776 } 777 if (sc->sc_mp < sc->sc_ep) { 778 *sc->sc_mp++ = c; 779 sc->sc_escape = 0; 780 return; 781 } 782 sc->sc_flags |= SC_ERROR; 783error: 784 sc->sc_if.if_ierrors++; 785newpack: 786 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 787 sc->sc_escape = 0; 788} 789 790/* 791 * Process an ioctl request. 792 */ 793slioctl(ifp, cmd, data) 794 register struct ifnet *ifp; 795 int cmd; 796 caddr_t data; 797{ 798 register struct ifaddr *ifa = (struct ifaddr *)data; 799#ifdef MULTICAST 800 register struct ifreq *ifr; 801#endif 802 int s = splimp(), error = 0; 803 804 switch (cmd) { 805 806 case SIOCSIFADDR: 807 if (ifa->ifa_addr->sa_family == AF_INET) 808 ifp->if_flags |= IFF_UP; 809 else 810 error = EAFNOSUPPORT; 811 break; 812 813 case SIOCSIFDSTADDR: 814 if (ifa->ifa_addr->sa_family != AF_INET) 815 error = EAFNOSUPPORT; 816 break; 817 818#ifdef MULTICAST 819 case SIOCADDMULTI: 820 case SIOCDELMULTI: 821 ifr = (struct ifreq *)data; 822 if (ifr == 0) { 823 error = EAFNOSUPPORT; /* XXX */ 824 break; 825 } 826 switch (ifr->ifr_addr.sa_family) { 827 828#ifdef INET 829 case AF_INET: 830 break; 831#endif 832 default: 833 error = EAFNOSUPPORT; 834 break; 835 } 836 break; 837#endif 838 default: 839 error = EINVAL; 840 } 841 splx(s); 842 return (error); 843} 844#endif 845