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