1 /* 2 * Copyright (c) 1987, 1989, 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)if_sl.c 8.6 (Berkeley) 02/01/94 8 */ 9 10 /* 11 * Serial Line interface 12 * 13 * Rick Adams 14 * Center for Seismic Studies 15 * 1300 N 17th Street, Suite 1450 16 * Arlington, Virginia 22209 17 * (703)276-7900 18 * rick@seismo.ARPA 19 * seismo!rick 20 * 21 * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris). 22 * N.B.: this belongs in netinet, not net, the way it stands now. 23 * Should have a link-layer type designation, but wouldn't be 24 * backwards-compatible. 25 * 26 * Converted to 4.3BSD Beta by Chris Torek. 27 * Other changes made at Berkeley, based in part on code by Kirk Smith. 28 * W. Jolitz added slip abort. 29 * 30 * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov). 31 * Added priority queuing for "interactive" traffic; hooks for TCP 32 * header compression; ICMP filtering (at 2400 baud, some cretin 33 * pinging you can use up all your bandwidth). Made low clist behavior 34 * more robust and slightly less likely to hang serial line. 35 * Sped up a bunch of things. 36 * 37 * Note that splimp() is used throughout to block both (tty) input 38 * interrupts and network activity; thus, splimp must be >= spltty. 39 */ 40 41 #include "sl.h" 42 #if NSL > 0 43 44 #include "bpfilter.h" 45 46 #include <sys/param.h> 47 #include <sys/proc.h> 48 #include <sys/mbuf.h> 49 #include <sys/buf.h> 50 #include <sys/dkstat.h> 51 #include <sys/socket.h> 52 #include <sys/ioctl.h> 53 #include <sys/file.h> 54 #include <sys/tty.h> 55 #include <sys/kernel.h> 56 #include <sys/conf.h> 57 58 #include <machine/cpu.h> 59 60 #include <net/if.h> 61 #include <net/if_types.h> 62 #include <net/netisr.h> 63 #include <net/route.h> 64 65 #if INET 66 #include <netinet/in.h> 67 #include <netinet/in_systm.h> 68 #include <netinet/in_var.h> 69 #include <netinet/ip.h> 70 #else 71 Huh? Slip without inet? 72 #endif 73 74 #include <net/slcompress.h> 75 #include <net/if_slvar.h> 76 #include <net/slip.h> 77 78 #if NBPFILTER > 0 79 #include <sys/time.h> 80 #include <net/bpf.h> 81 #endif 82 83 /* 84 * SLMAX is a hard limit on input packet size. To simplify the code 85 * and improve performance, we require that packets fit in an mbuf 86 * cluster, and if we get a compressed packet, there's enough extra 87 * room to expand the header into a max length tcp/ip header (128 88 * bytes). So, SLMAX can be at most 89 * MCLBYTES - 128 90 * 91 * SLMTU is a hard limit on output packet size. To insure good 92 * interactive response, SLMTU wants to be the smallest size that 93 * amortizes the header cost. (Remember that even with 94 * type-of-service queuing, we have to wait for any in-progress 95 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 96 * cps, where cps is the line speed in characters per second. 97 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 98 * average compressed header size is 6-8 bytes so any MTU > 90 99 * bytes will give us 90% of the line bandwidth. A 100ms wait is 100 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 101 * will send 256 byte segments (to allow for 40 byte headers), the 102 * typical packet size on the wire will be around 260 bytes). In 103 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 104 * leave the interface MTU relatively high (so we don't IP fragment 105 * when acting as a gateway to someone using a stupid MTU). 106 * 107 * Similar considerations apply to SLIP_HIWAT: It's the amount of 108 * data that will be queued 'downstream' of us (i.e., in clists 109 * waiting to be picked up by the tty output interrupt). If we 110 * queue a lot of data downstream, it's immune to our t.o.s. queuing. 111 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 112 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 113 * wait is dependent on the ftp window size but that's typically 114 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 115 * the cost (in idle time on the wire) of the tty driver running 116 * off the end of its clists & having to call back slstart for a 117 * new packet. For a tty interface with any buffering at all, this 118 * cost will be zero. Even with a totally brain dead interface (like 119 * the one on a typical workstation), the cost will be <= 1 character 120 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 121 * at most 1% while maintaining good interactive response. 122 */ 123 #if NBPFILTER > 0 124 #define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 125 #else 126 #define BUFOFFSET (128+sizeof(struct ifnet **)) 127 #endif 128 #define SLMAX (MCLBYTES - BUFOFFSET) 129 #define SLBUFSIZE (SLMAX + BUFOFFSET) 130 #define SLMTU 296 131 #define SLIP_HIWAT roundup(50,CBSIZE) 132 #define CLISTRESERVE 1024 /* Can't let clists get too low */ 133 134 /* 135 * SLIP ABORT ESCAPE MECHANISM: 136 * (inspired by HAYES modem escape arrangement) 137 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 138 * within window time signals a "soft" exit from slip mode by remote end 139 * if the IFF_DEBUG flag is on. 140 */ 141 #define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 142 #define ABT_IDLE 1 /* in seconds - idle before an escape */ 143 #define ABT_COUNT 3 /* count of escapes for abort */ 144 #define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 145 146 struct sl_softc sl_softc[NSL]; 147 148 #define FRAME_END 0xc0 /* Frame End */ 149 #define FRAME_ESCAPE 0xdb /* Frame Esc */ 150 #define TRANS_FRAME_END 0xdc /* transposed frame end */ 151 #define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 152 153 extern struct timeval time; 154 155 static int slinit __P((struct sl_softc *)); 156 static struct mbuf *sl_btom __P((struct sl_softc *, int)); 157 158 /* 159 * Called from boot code to establish sl interfaces. 160 */ 161 void 162 slattach() 163 { 164 register struct sl_softc *sc; 165 register int i = 0; 166 167 for (sc = sl_softc; i < NSL; sc++) { 168 sc->sc_if.if_name = "sl"; 169 sc->sc_if.if_next = NULL; 170 sc->sc_if.if_unit = i++; 171 sc->sc_if.if_mtu = SLMTU; 172 sc->sc_if.if_flags = 173 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 174 sc->sc_if.if_type = IFT_SLIP; 175 sc->sc_if.if_ioctl = slioctl; 176 sc->sc_if.if_output = sloutput; 177 sc->sc_if.if_snd.ifq_maxlen = 50; 178 sc->sc_fastq.ifq_maxlen = 32; 179 if_attach(&sc->sc_if); 180 #if NBPFILTER > 0 181 bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 182 #endif 183 } 184 } 185 186 static int 187 slinit(sc) 188 register struct sl_softc *sc; 189 { 190 register caddr_t p; 191 192 if (sc->sc_ep == (u_char *) 0) { 193 MCLALLOC(p, M_WAIT); 194 if (p) 195 sc->sc_ep = (u_char *)p + SLBUFSIZE; 196 else { 197 printf("sl%d: can't allocate buffer\n", sc - sl_softc); 198 sc->sc_if.if_flags &= ~IFF_UP; 199 return (0); 200 } 201 } 202 sc->sc_buf = sc->sc_ep - SLMAX; 203 sc->sc_mp = sc->sc_buf; 204 sl_compress_init(&sc->sc_comp); 205 return (1); 206 } 207 208 /* 209 * Line specific open routine. 210 * Attach the given tty to the first available sl unit. 211 */ 212 /* ARGSUSED */ 213 int 214 slopen(dev, tp) 215 dev_t dev; 216 register struct tty *tp; 217 { 218 struct proc *p = curproc; /* XXX */ 219 register struct sl_softc *sc; 220 register int nsl; 221 int error; 222 223 if (error = suser(p->p_ucred, &p->p_acflag)) 224 return (error); 225 226 if (tp->t_line == SLIPDISC) 227 return (0); 228 229 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 230 if (sc->sc_ttyp == NULL) { 231 if (slinit(sc) == 0) 232 return (ENOBUFS); 233 tp->t_sc = (caddr_t)sc; 234 sc->sc_ttyp = tp; 235 sc->sc_if.if_baudrate = tp->t_ospeed; 236 ttyflush(tp, FREAD | FWRITE); 237 return (0); 238 } 239 return (ENXIO); 240 } 241 242 /* 243 * Line specific close routine. 244 * Detach the tty from the sl unit. 245 */ 246 void 247 slclose(tp) 248 struct tty *tp; 249 { 250 register struct sl_softc *sc; 251 int s; 252 253 ttywflush(tp); 254 s = splimp(); /* actually, max(spltty, splnet) */ 255 tp->t_line = 0; 256 sc = (struct sl_softc *)tp->t_sc; 257 if (sc != NULL) { 258 if_down(&sc->sc_if); 259 sc->sc_ttyp = NULL; 260 tp->t_sc = NULL; 261 MCLFREE((caddr_t)(sc->sc_ep - SLBUFSIZE)); 262 sc->sc_ep = 0; 263 sc->sc_mp = 0; 264 sc->sc_buf = 0; 265 } 266 splx(s); 267 } 268 269 /* 270 * Line specific (tty) ioctl routine. 271 * Provide a way to get the sl unit number. 272 */ 273 /* ARGSUSED */ 274 int 275 sltioctl(tp, cmd, data, flag) 276 struct tty *tp; 277 int cmd; 278 caddr_t data; 279 int flag; 280 { 281 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 282 283 switch (cmd) { 284 case SLIOCGUNIT: 285 *(int *)data = sc->sc_if.if_unit; 286 break; 287 288 default: 289 return (-1); 290 } 291 return (0); 292 } 293 294 /* 295 * Queue a packet. Start transmission if not active. 296 * Compression happens in slstart; if we do it here, IP TOS 297 * will cause us to not compress "background" packets, because 298 * ordering gets trashed. It can be done for all packets in slstart. 299 */ 300 int 301 sloutput(ifp, m, dst, rtp) 302 struct ifnet *ifp; 303 register struct mbuf *m; 304 struct sockaddr *dst; 305 struct rtentry *rtp; 306 { 307 register struct sl_softc *sc = &sl_softc[ifp->if_unit]; 308 register struct ip *ip; 309 register struct ifqueue *ifq; 310 int s; 311 312 /* 313 * `Cannot happen' (see slioctl). Someday we will extend 314 * the line protocol to support other address families. 315 */ 316 if (dst->sa_family != AF_INET) { 317 printf("sl%d: af%d not supported\n", sc->sc_if.if_unit, 318 dst->sa_family); 319 m_freem(m); 320 sc->sc_if.if_noproto++; 321 return (EAFNOSUPPORT); 322 } 323 324 if (sc->sc_ttyp == NULL) { 325 m_freem(m); 326 return (ENETDOWN); /* sort of */ 327 } 328 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 329 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 330 m_freem(m); 331 return (EHOSTUNREACH); 332 } 333 ifq = &sc->sc_if.if_snd; 334 ip = mtod(m, struct ip *); 335 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 336 m_freem(m); 337 return (ENETRESET); /* XXX ? */ 338 } 339 if (ip->ip_tos & IPTOS_LOWDELAY) 340 ifq = &sc->sc_fastq; 341 s = splimp(); 342 if (IF_QFULL(ifq)) { 343 IF_DROP(ifq); 344 m_freem(m); 345 splx(s); 346 sc->sc_if.if_oerrors++; 347 return (ENOBUFS); 348 } 349 IF_ENQUEUE(ifq, m); 350 sc->sc_if.if_lastchange = time; 351 if (sc->sc_ttyp->t_outq.c_cc == 0) 352 slstart(sc->sc_ttyp); 353 splx(s); 354 return (0); 355 } 356 357 /* 358 * Start output on interface. Get another datagram 359 * to send from the interface queue and map it to 360 * the interface before starting output. 361 */ 362 void 363 slstart(tp) 364 register struct tty *tp; 365 { 366 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 367 register struct mbuf *m; 368 register u_char *cp; 369 register struct ip *ip; 370 int s; 371 struct mbuf *m2; 372 #if NBPFILTER > 0 373 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 374 register int len; 375 #endif 376 extern int cfreecount; 377 378 for (;;) { 379 /* 380 * If there is more in the output queue, just send it now. 381 * We are being called in lieu of ttstart and must do what 382 * it would. 383 */ 384 if (tp->t_outq.c_cc != 0) { 385 (*tp->t_oproc)(tp); 386 if (tp->t_outq.c_cc > SLIP_HIWAT) 387 return; 388 } 389 /* 390 * This happens briefly when the line shuts down. 391 */ 392 if (sc == NULL) 393 return; 394 395 /* 396 * Get a packet and send it to the interface. 397 */ 398 s = splimp(); 399 IF_DEQUEUE(&sc->sc_fastq, m); 400 if (m) 401 sc->sc_if.if_omcasts++; /* XXX */ 402 else 403 IF_DEQUEUE(&sc->sc_if.if_snd, m); 404 splx(s); 405 if (m == NULL) 406 return; 407 408 /* 409 * We do the header compression here rather than in sloutput 410 * because the packets will be out of order if we are using TOS 411 * queueing, and the connection id compression will get 412 * munged when this happens. 413 */ 414 #if NBPFILTER > 0 415 if (sc->sc_bpf) { 416 /* 417 * We need to save the TCP/IP header before it's 418 * compressed. To avoid complicated code, we just 419 * copy the entire packet into a stack buffer (since 420 * this is a serial line, packets should be short 421 * and/or the copy should be negligible cost compared 422 * to the packet transmission time). 423 */ 424 register struct mbuf *m1 = m; 425 register u_char *cp = bpfbuf + SLIP_HDRLEN; 426 427 len = 0; 428 do { 429 register int mlen = m1->m_len; 430 431 bcopy(mtod(m1, caddr_t), cp, mlen); 432 cp += mlen; 433 len += mlen; 434 } while (m1 = m1->m_next); 435 } 436 #endif 437 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 438 if (sc->sc_if.if_flags & SC_COMPRESS) 439 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 440 &sc->sc_comp, 1); 441 } 442 #if NBPFILTER > 0 443 if (sc->sc_bpf) { 444 /* 445 * Put the SLIP pseudo-"link header" in place. The 446 * compressed header is now at the beginning of the 447 * mbuf. 448 */ 449 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 450 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 451 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 452 } 453 #endif 454 sc->sc_if.if_lastchange = time; 455 456 /* 457 * If system is getting low on clists, just flush our 458 * output queue (if the stuff was important, it'll get 459 * retransmitted). 460 */ 461 if (cfreecount < CLISTRESERVE + SLMTU) { 462 m_freem(m); 463 sc->sc_if.if_collisions++; 464 continue; 465 } 466 /* 467 * The extra FRAME_END will start up a new packet, and thus 468 * will flush any accumulated garbage. We do this whenever 469 * the line may have been idle for some time. 470 */ 471 if (tp->t_outq.c_cc == 0) { 472 ++sc->sc_if.if_obytes; 473 (void) putc(FRAME_END, &tp->t_outq); 474 } 475 476 while (m) { 477 register u_char *ep; 478 479 cp = mtod(m, u_char *); ep = cp + m->m_len; 480 while (cp < ep) { 481 /* 482 * Find out how many bytes in the string we can 483 * handle without doing something special. 484 */ 485 register u_char *bp = cp; 486 487 while (cp < ep) { 488 switch (*cp++) { 489 case FRAME_ESCAPE: 490 case FRAME_END: 491 --cp; 492 goto out; 493 } 494 } 495 out: 496 if (cp > bp) { 497 /* 498 * Put n characters at once 499 * into the tty output queue. 500 */ 501 if (b_to_q((char *)bp, cp - bp, 502 &tp->t_outq)) 503 break; 504 sc->sc_if.if_obytes += cp - bp; 505 } 506 /* 507 * If there are characters left in the mbuf, 508 * the first one must be special.. 509 * Put it out in a different form. 510 */ 511 if (cp < ep) { 512 if (putc(FRAME_ESCAPE, &tp->t_outq)) 513 break; 514 if (putc(*cp++ == FRAME_ESCAPE ? 515 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 516 &tp->t_outq)) { 517 (void) unputc(&tp->t_outq); 518 break; 519 } 520 sc->sc_if.if_obytes += 2; 521 } 522 } 523 MFREE(m, m2); 524 m = m2; 525 } 526 527 if (putc(FRAME_END, &tp->t_outq)) { 528 /* 529 * Not enough room. Remove a char to make room 530 * and end the packet normally. 531 * If you get many collisions (more than one or two 532 * a day) you probably do not have enough clists 533 * and you should increase "nclist" in param.c. 534 */ 535 (void) unputc(&tp->t_outq); 536 (void) putc(FRAME_END, &tp->t_outq); 537 sc->sc_if.if_collisions++; 538 } else { 539 ++sc->sc_if.if_obytes; 540 sc->sc_if.if_opackets++; 541 } 542 } 543 } 544 545 /* 546 * Copy data buffer to mbuf chain; add ifnet pointer. 547 */ 548 static struct mbuf * 549 sl_btom(sc, len) 550 register struct sl_softc *sc; 551 register int len; 552 { 553 register struct mbuf *m; 554 555 MGETHDR(m, M_DONTWAIT, MT_DATA); 556 if (m == NULL) 557 return (NULL); 558 559 /* 560 * If we have more than MHLEN bytes, it's cheaper to 561 * queue the cluster we just filled & allocate a new one 562 * for the input buffer. Otherwise, fill the mbuf we 563 * allocated above. Note that code in the input routine 564 * guarantees that packet will fit in a cluster. 565 */ 566 if (len >= MHLEN) { 567 MCLGET(m, M_DONTWAIT); 568 if ((m->m_flags & M_EXT) == 0) { 569 /* 570 * we couldn't get a cluster - if memory's this 571 * low, it's time to start dropping packets. 572 */ 573 (void) m_free(m); 574 return (NULL); 575 } 576 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 577 m->m_data = (caddr_t)sc->sc_buf; 578 m->m_ext.ext_buf = (caddr_t)((int)sc->sc_buf &~ MCLOFSET); 579 } else 580 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 581 582 m->m_len = len; 583 m->m_pkthdr.len = len; 584 m->m_pkthdr.rcvif = &sc->sc_if; 585 return (m); 586 } 587 588 /* 589 * tty interface receiver interrupt. 590 */ 591 void 592 slinput(c, tp) 593 register int c; 594 register struct tty *tp; 595 { 596 register struct sl_softc *sc; 597 register struct mbuf *m; 598 register int len; 599 int s; 600 #if NBPFILTER > 0 601 u_char chdr[CHDR_LEN]; 602 #endif 603 604 tk_nin++; 605 sc = (struct sl_softc *)tp->t_sc; 606 if (sc == NULL) 607 return; 608 if (c & TTY_ERRORMASK || ((tp->t_state & TS_CARR_ON) == 0 && 609 (tp->t_cflag & CLOCAL) == 0)) { 610 sc->sc_flags |= SC_ERROR; 611 return; 612 } 613 c &= TTY_CHARMASK; 614 615 ++sc->sc_if.if_ibytes; 616 617 if (sc->sc_if.if_flags & IFF_DEBUG) { 618 if (c == ABT_ESC) { 619 /* 620 * If we have a previous abort, see whether 621 * this one is within the time limit. 622 */ 623 if (sc->sc_abortcount && 624 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 625 sc->sc_abortcount = 0; 626 /* 627 * If we see an abort after "idle" time, count it; 628 * record when the first abort escape arrived. 629 */ 630 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 631 if (++sc->sc_abortcount == 1) 632 sc->sc_starttime = time.tv_sec; 633 if (sc->sc_abortcount >= ABT_COUNT) { 634 slclose(tp); 635 return; 636 } 637 } 638 } else 639 sc->sc_abortcount = 0; 640 sc->sc_lasttime = time.tv_sec; 641 } 642 643 switch (c) { 644 645 case TRANS_FRAME_ESCAPE: 646 if (sc->sc_escape) 647 c = FRAME_ESCAPE; 648 break; 649 650 case TRANS_FRAME_END: 651 if (sc->sc_escape) 652 c = FRAME_END; 653 break; 654 655 case FRAME_ESCAPE: 656 sc->sc_escape = 1; 657 return; 658 659 case FRAME_END: 660 if(sc->sc_flags & SC_ERROR) { 661 sc->sc_flags &= ~SC_ERROR; 662 goto newpack; 663 } 664 len = sc->sc_mp - sc->sc_buf; 665 if (len < 3) 666 /* less than min length packet - ignore */ 667 goto newpack; 668 669 #if NBPFILTER > 0 670 if (sc->sc_bpf) { 671 /* 672 * Save the compressed header, so we 673 * can tack it on later. Note that we 674 * will end up copying garbage in some 675 * cases but this is okay. We remember 676 * where the buffer started so we can 677 * compute the new header length. 678 */ 679 bcopy(sc->sc_buf, chdr, CHDR_LEN); 680 } 681 #endif 682 683 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 684 if (c & 0x80) 685 c = TYPE_COMPRESSED_TCP; 686 else if (c == TYPE_UNCOMPRESSED_TCP) 687 *sc->sc_buf &= 0x4f; /* XXX */ 688 /* 689 * We've got something that's not an IP packet. 690 * If compression is enabled, try to decompress it. 691 * Otherwise, if `auto-enable' compression is on and 692 * it's a reasonable packet, decompress it and then 693 * enable compression. Otherwise, drop it. 694 */ 695 if (sc->sc_if.if_flags & SC_COMPRESS) { 696 len = sl_uncompress_tcp(&sc->sc_buf, len, 697 (u_int)c, &sc->sc_comp); 698 if (len <= 0) 699 goto error; 700 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 701 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 702 len = sl_uncompress_tcp(&sc->sc_buf, len, 703 (u_int)c, &sc->sc_comp); 704 if (len <= 0) 705 goto error; 706 sc->sc_if.if_flags |= SC_COMPRESS; 707 } else 708 goto error; 709 } 710 #if NBPFILTER > 0 711 if (sc->sc_bpf) { 712 /* 713 * Put the SLIP pseudo-"link header" in place. 714 * We couldn't do this any earlier since 715 * decompression probably moved the buffer 716 * pointer. Then, invoke BPF. 717 */ 718 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 719 720 hp[SLX_DIR] = SLIPDIR_IN; 721 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 722 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 723 } 724 #endif 725 m = sl_btom(sc, len); 726 if (m == NULL) 727 goto error; 728 729 sc->sc_if.if_ipackets++; 730 sc->sc_if.if_lastchange = time; 731 s = splimp(); 732 if (IF_QFULL(&ipintrq)) { 733 IF_DROP(&ipintrq); 734 sc->sc_if.if_ierrors++; 735 sc->sc_if.if_iqdrops++; 736 m_freem(m); 737 } else { 738 IF_ENQUEUE(&ipintrq, m); 739 schednetisr(NETISR_IP); 740 } 741 splx(s); 742 goto newpack; 743 } 744 if (sc->sc_mp < sc->sc_ep) { 745 *sc->sc_mp++ = c; 746 sc->sc_escape = 0; 747 return; 748 } 749 750 /* can't put lower; would miss an extra frame */ 751 sc->sc_flags |= SC_ERROR; 752 753 error: 754 sc->sc_if.if_ierrors++; 755 newpack: 756 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 757 sc->sc_escape = 0; 758 } 759 760 /* 761 * Process an ioctl request. 762 */ 763 int 764 slioctl(ifp, cmd, data) 765 register struct ifnet *ifp; 766 int cmd; 767 caddr_t data; 768 { 769 register struct ifaddr *ifa = (struct ifaddr *)data; 770 register struct ifreq *ifr; 771 register int s = splimp(), error = 0; 772 773 switch (cmd) { 774 775 case SIOCSIFADDR: 776 if (ifa->ifa_addr->sa_family == AF_INET) 777 ifp->if_flags |= IFF_UP; 778 else 779 error = EAFNOSUPPORT; 780 break; 781 782 case SIOCSIFDSTADDR: 783 if (ifa->ifa_addr->sa_family != AF_INET) 784 error = EAFNOSUPPORT; 785 break; 786 787 case SIOCADDMULTI: 788 case SIOCDELMULTI: 789 ifr = (struct ifreq *)data; 790 if (ifr == 0) { 791 error = EAFNOSUPPORT; /* XXX */ 792 break; 793 } 794 switch (ifr->ifr_addr.sa_family) { 795 796 #ifdef INET 797 case AF_INET: 798 break; 799 #endif 800 801 default: 802 error = EAFNOSUPPORT; 803 break; 804 } 805 break; 806 807 default: 808 error = EINVAL; 809 } 810 splx(s); 811 return (error); 812 } 813 #endif 814