if_sl.c revision 1.41
1/* $NetBSD: if_sl.c,v 1.41 1996/07/10 18:15:25 cgd Exp $ */ 2 3/* 4 * Copyright (c) 1987, 1989, 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)if_sl.c 8.6 (Berkeley) 2/1/94 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#if __NetBSD__ 86#include <sys/systm.h> 87#endif 88 89#include <machine/cpu.h> 90 91#include <net/if.h> 92#include <net/if_types.h> 93#include <net/netisr.h> 94#include <net/route.h> 95 96#if INET 97#include <netinet/in.h> 98#include <netinet/in_systm.h> 99#include <netinet/in_var.h> 100#include <netinet/ip.h> 101#else 102Huh? Slip without inet? 103#endif 104 105#include <net/slcompress.h> 106#include <net/if_slvar.h> 107#include <net/slip.h> 108 109#if NBPFILTER > 0 110#include <sys/time.h> 111#include <net/bpf.h> 112#endif 113 114/* 115 * SLMAX is a hard limit on input packet size. To simplify the code 116 * and improve performance, we require that packets fit in an mbuf 117 * cluster, and if we get a compressed packet, there's enough extra 118 * room to expand the header into a max length tcp/ip header (128 119 * bytes). So, SLMAX can be at most 120 * MCLBYTES - 128 121 * 122 * SLMTU is a hard limit on output packet size. To insure good 123 * interactive response, SLMTU wants to be the smallest size that 124 * amortizes the header cost. (Remember that even with 125 * type-of-service queuing, we have to wait for any in-progress 126 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 127 * cps, where cps is the line speed in characters per second. 128 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 129 * average compressed header size is 6-8 bytes so any MTU > 90 130 * bytes will give us 90% of the line bandwidth. A 100ms wait is 131 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 132 * will send 256 byte segments (to allow for 40 byte headers), the 133 * typical packet size on the wire will be around 260 bytes). In 134 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 135 * leave the interface MTU relatively high (so we don't IP fragment 136 * when acting as a gateway to someone using a stupid MTU). 137 * 138 * Similar considerations apply to SLIP_HIWAT: It's the amount of 139 * data that will be queued 'downstream' of us (i.e., in clists 140 * waiting to be picked up by the tty output interrupt). If we 141 * queue a lot of data downstream, it's immune to our t.o.s. queuing. 142 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 143 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 144 * wait is dependent on the ftp window size but that's typically 145 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 146 * the cost (in idle time on the wire) of the tty driver running 147 * off the end of its clists & having to call back slstart for a 148 * new packet. For a tty interface with any buffering at all, this 149 * cost will be zero. Even with a totally brain dead interface (like 150 * the one on a typical workstation), the cost will be <= 1 character 151 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 152 * at most 1% while maintaining good interactive response. 153 */ 154#if NBPFILTER > 0 155#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 156#else 157#define BUFOFFSET (128+sizeof(struct ifnet **)) 158#endif 159#define SLMAX (MCLBYTES - BUFOFFSET) 160#define SLBUFSIZE (SLMAX + BUFOFFSET) 161#ifndef SLMTU 162#define SLMTU 296 163#endif 164#if (SLMTU < 3) 165Huh? SLMTU way too small. 166#endif 167#define SLIP_HIWAT roundup(50,CBSIZE) 168#ifndef NetBSD /* XXX - cgd */ 169#define CLISTRESERVE 1024 /* Can't let clists get too low */ 170#endif /* !NetBSD */ 171 172/* 173 * SLIP ABORT ESCAPE MECHANISM: 174 * (inspired by HAYES modem escape arrangement) 175 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 176 * within window time signals a "soft" exit from slip mode by remote end 177 * if the IFF_DEBUG flag is on. 178 */ 179#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 180#define ABT_IDLE 1 /* in seconds - idle before an escape */ 181#define ABT_COUNT 3 /* count of escapes for abort */ 182#define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 183 184struct sl_softc sl_softc[NSL]; 185 186#define FRAME_END 0xc0 /* Frame End */ 187#define FRAME_ESCAPE 0xdb /* Frame Esc */ 188#define TRANS_FRAME_END 0xdc /* transposed frame end */ 189#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 190 191static int slinit __P((struct sl_softc *)); 192static struct mbuf *sl_btom __P((struct sl_softc *, int)); 193 194/* 195 * Called from boot code to establish sl interfaces. 196 */ 197void 198slattach() 199{ 200 register struct sl_softc *sc; 201 register int i = 0; 202 203 for (sc = sl_softc; i < NSL; sc++) { 204 sc->sc_unit = i; /* XXX */ 205 sprintf(sc->sc_if.if_xname, "sl%d", i++); 206 sc->sc_if.if_softc = sc; 207 sc->sc_if.if_mtu = SLMTU; 208 sc->sc_if.if_flags = 209 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 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%ld: 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, -1); 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#ifdef NetBSD 259 int s; 260#endif 261 262 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 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#ifdef NetBSD 277 /* 278 * make sure tty output queue is large enough 279 * to hold a full-sized packet (including frame 280 * end, and a possible extra frame end). full-sized 281 * packet occupies a max of 2*SLMTU bytes (because 282 * of possible escapes), and add two on for frame 283 * ends. 284 */ 285 s = spltty(); 286 if (tp->t_outq.c_cn < 2*SLMTU+2) { 287 sc->sc_oldbufsize = tp->t_outq.c_cn; 288 sc->sc_oldbufquot = tp->t_outq.c_cq != 0; 289 290 clfree(&tp->t_outq); 291 error = clalloc(&tp->t_outq, 3*SLMTU, 0); 292 if (error) { 293 splx(s); 294 return(error); 295 } 296 } else 297 sc->sc_oldbufsize = sc->sc_oldbufquot = 0; 298 splx(s); 299#endif /* NetBSD */ 300 return (0); 301 } 302 return (ENXIO); 303} 304 305/* 306 * Line specific close routine. 307 * Detach the tty from the sl unit. 308 */ 309void 310slclose(tp) 311 struct tty *tp; 312{ 313 register struct sl_softc *sc; 314 int s; 315 316 ttywflush(tp); 317 s = splimp(); /* actually, max(spltty, splsoftnet) */ 318 tp->t_line = 0; 319 sc = (struct sl_softc *)tp->t_sc; 320 if (sc != NULL) { 321 if_down(&sc->sc_if); 322 sc->sc_ttyp = NULL; 323 tp->t_sc = NULL; 324 MCLFREE((caddr_t)(sc->sc_ep - SLBUFSIZE)); 325 sc->sc_ep = 0; 326 sc->sc_mp = 0; 327 sc->sc_buf = 0; 328 } 329#ifdef NetBSD 330 /* if necessary, install a new outq buffer of the appropriate size */ 331 if (sc->sc_oldbufsize != 0) { 332 clfree(&tp->t_outq); 333 clalloc(&tp->t_outq, sc->sc_oldbufsize, sc->sc_oldbufquot); 334 } 335#endif 336 splx(s); 337} 338 339/* 340 * Line specific (tty) ioctl routine. 341 * Provide a way to get the sl unit number. 342 */ 343/* ARGSUSED */ 344int 345sltioctl(tp, cmd, data, flag) 346 struct tty *tp; 347 u_long cmd; 348 caddr_t data; 349 int flag; 350{ 351 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 352 353 switch (cmd) { 354 case SLIOCGUNIT: 355 *(int *)data = sc->sc_unit; /* XXX */ 356 break; 357 358 default: 359 return (-1); 360 } 361 return (0); 362} 363 364/* 365 * Queue a packet. Start transmission if not active. 366 * Compression happens in slstart; if we do it here, IP TOS 367 * will cause us to not compress "background" packets, because 368 * ordering gets trashed. It can be done for all packets in slstart. 369 */ 370int 371sloutput(ifp, m, dst, rtp) 372 struct ifnet *ifp; 373 register struct mbuf *m; 374 struct sockaddr *dst; 375 struct rtentry *rtp; 376{ 377 register struct sl_softc *sc = ifp->if_softc; 378 register struct ip *ip; 379 register struct ifqueue *ifq; 380 int s; 381 382 /* 383 * `Cannot happen' (see slioctl). Someday we will extend 384 * the line protocol to support other address families. 385 */ 386 if (dst->sa_family != AF_INET) { 387 printf("%s: af%d not supported\n", sc->sc_if.if_xname, 388 dst->sa_family); 389 m_freem(m); 390 sc->sc_if.if_noproto++; 391 return (EAFNOSUPPORT); 392 } 393 394 if (sc->sc_ttyp == NULL) { 395 m_freem(m); 396 return (ENETDOWN); /* sort of */ 397 } 398 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 399 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 400 m_freem(m); 401 return (EHOSTUNREACH); 402 } 403 ifq = &sc->sc_if.if_snd; 404 ip = mtod(m, struct ip *); 405 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 406 m_freem(m); 407 return (ENETRESET); /* XXX ? */ 408 } 409 if (ip->ip_tos & IPTOS_LOWDELAY) 410 ifq = &sc->sc_fastq; 411 s = splimp(); 412 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) { 413 struct timeval tv; 414 415 /* if output's been stalled for too long, and restart */ 416 timersub(&time, &sc->sc_if.if_lastchange, &tv); 417 if (tv.tv_sec > 0) { 418 sc->sc_otimeout++; 419 slstart(sc->sc_ttyp); 420 } 421 } 422 if (IF_QFULL(ifq)) { 423 IF_DROP(ifq); 424 m_freem(m); 425 splx(s); 426 sc->sc_if.if_oerrors++; 427 return (ENOBUFS); 428 } 429 IF_ENQUEUE(ifq, m); 430 sc->sc_if.if_lastchange = time; 431 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) 432 slstart(sc->sc_ttyp); 433 splx(s); 434 return (0); 435} 436 437/* 438 * Start output on interface. Get another datagram 439 * to send from the interface queue and map it to 440 * the interface before starting output. 441 */ 442void 443slstart(tp) 444 register struct tty *tp; 445{ 446 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 447 register struct mbuf *m; 448 register u_char *cp; 449 register struct ip *ip; 450 int s; 451 struct mbuf *m2; 452#if NBPFILTER > 0 453 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 454 register int len = 0; 455#endif 456#ifndef NetBSD /* XXX - cgd */ 457 extern int cfreecount; 458#endif 459 460 for (;;) { 461 /* 462 * If there is more in the output queue, just send it now. 463 * We are being called in lieu of ttstart and must do what 464 * it would. 465 */ 466 if (tp->t_outq.c_cc != 0) { 467 (*tp->t_oproc)(tp); 468 if (tp->t_outq.c_cc > SLIP_HIWAT) 469 return; 470 } 471 /* 472 * This happens briefly when the line shuts down. 473 */ 474 if (sc == NULL) 475 return; 476 477#ifdef NetBSD /* XXX - cgd */ 478 /* 479 * Do not remove the packet from the IP queue if it 480 * doesn't look like the packet will fit into the 481 * current serial output queue, with a packet full of 482 * escapes this could be as bad as SLMTU*2+2. 483 */ 484 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*SLMTU+2) 485 return; 486#endif /* NetBSD */ 487 488 /* 489 * Get a packet and send it to the interface. 490 */ 491 s = splimp(); 492 IF_DEQUEUE(&sc->sc_fastq, m); 493 if (m) 494 sc->sc_if.if_omcasts++; /* XXX */ 495 else 496 IF_DEQUEUE(&sc->sc_if.if_snd, m); 497 splx(s); 498 if (m == NULL) 499 return; 500 501 /* 502 * We do the header compression here rather than in sloutput 503 * because the packets will be out of order if we are using TOS 504 * queueing, and the connection id compression will get 505 * munged when this happens. 506 */ 507#if NBPFILTER > 0 508 if (sc->sc_bpf) { 509 /* 510 * We need to save the TCP/IP header before it's 511 * compressed. To avoid complicated code, we just 512 * copy the entire packet into a stack buffer (since 513 * this is a serial line, packets should be short 514 * and/or the copy should be negligible cost compared 515 * to the packet transmission time). 516 */ 517 register struct mbuf *m1 = m; 518 register u_char *cp = bpfbuf + SLIP_HDRLEN; 519 520 len = 0; 521 do { 522 register int mlen = m1->m_len; 523 524 bcopy(mtod(m1, caddr_t), cp, mlen); 525 cp += mlen; 526 len += mlen; 527 } while ((m1 = m1->m_next) != NULL); 528 } 529#endif 530 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 531 if (sc->sc_if.if_flags & SC_COMPRESS) 532 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 533 &sc->sc_comp, 1); 534 } 535#if NBPFILTER > 0 536 if (sc->sc_bpf) { 537 /* 538 * Put the SLIP pseudo-"link header" in place. The 539 * compressed header is now at the beginning of the 540 * mbuf. 541 */ 542 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 543 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 544 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 545 } 546#endif 547 sc->sc_if.if_lastchange = time; 548 549#ifndef __NetBSD__ /* XXX - cgd */ 550 /* 551 * If system is getting low on clists, just flush our 552 * output queue (if the stuff was important, it'll get 553 * retransmitted). 554 */ 555 if (cfreecount < CLISTRESERVE + SLMTU) { 556 m_freem(m); 557 sc->sc_if.if_collisions++; 558 continue; 559 } 560#endif /* !__NetBSD__ */ 561 /* 562 * The extra FRAME_END will start up a new packet, and thus 563 * will flush any accumulated garbage. We do this whenever 564 * the line may have been idle for some time. 565 */ 566 if (tp->t_outq.c_cc == 0) { 567 ++sc->sc_if.if_obytes; 568 (void) putc(FRAME_END, &tp->t_outq); 569 } 570 571 while (m) { 572 register u_char *ep; 573 574 cp = mtod(m, u_char *); ep = cp + m->m_len; 575 while (cp < ep) { 576 /* 577 * Find out how many bytes in the string we can 578 * handle without doing something special. 579 */ 580 register u_char *bp = cp; 581 582 while (cp < ep) { 583 switch (*cp++) { 584 case FRAME_ESCAPE: 585 case FRAME_END: 586 --cp; 587 goto out; 588 } 589 } 590 out: 591 if (cp > bp) { 592 /* 593 * Put n characters at once 594 * into the tty output queue. 595 */ 596#ifdef __NetBSD__ /* XXX - cgd */ 597 if (b_to_q((u_char *)bp, cp - bp, 598#else 599 if (b_to_q((char *)bp, cp - bp, 600#endif 601 &tp->t_outq)) 602 break; 603 sc->sc_if.if_obytes += cp - bp; 604 } 605 /* 606 * If there are characters left in the mbuf, 607 * the first one must be special.. 608 * Put it out in a different form. 609 */ 610 if (cp < ep) { 611 if (putc(FRAME_ESCAPE, &tp->t_outq)) 612 break; 613 if (putc(*cp++ == FRAME_ESCAPE ? 614 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 615 &tp->t_outq)) { 616 (void) unputc(&tp->t_outq); 617 break; 618 } 619 sc->sc_if.if_obytes += 2; 620 } 621 } 622 MFREE(m, m2); 623 m = m2; 624 } 625 626 if (putc(FRAME_END, &tp->t_outq)) { 627 /* 628 * Not enough room. Remove a char to make room 629 * and end the packet normally. 630 * If you get many collisions (more than one or two 631 * a day) you probably do not have enough clists 632 * and you should increase "nclist" in param.c. 633 */ 634 (void) unputc(&tp->t_outq); 635 (void) putc(FRAME_END, &tp->t_outq); 636 sc->sc_if.if_collisions++; 637 } else { 638 ++sc->sc_if.if_obytes; 639 sc->sc_if.if_opackets++; 640 } 641 } 642} 643 644/* 645 * Copy data buffer to mbuf chain; add ifnet pointer. 646 */ 647static struct mbuf * 648sl_btom(sc, len) 649 register struct sl_softc *sc; 650 register int len; 651{ 652 register struct mbuf *m; 653 654 MGETHDR(m, M_DONTWAIT, MT_DATA); 655 if (m == NULL) 656 return (NULL); 657 658 /* 659 * If we have more than MHLEN bytes, it's cheaper to 660 * queue the cluster we just filled & allocate a new one 661 * for the input buffer. Otherwise, fill the mbuf we 662 * allocated above. Note that code in the input routine 663 * guarantees that packet will fit in a cluster. 664 */ 665 if (len >= MHLEN) { 666 MCLGET(m, M_DONTWAIT); 667 if ((m->m_flags & M_EXT) == 0) { 668 /* 669 * we couldn't get a cluster - if memory's this 670 * low, it's time to start dropping packets. 671 */ 672 (void) m_free(m); 673 return (NULL); 674 } 675 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 676 m->m_data = (caddr_t)sc->sc_buf; 677 m->m_ext.ext_buf = (caddr_t)((long)sc->sc_buf &~ MCLOFSET); 678 } else 679 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 680 681 m->m_len = len; 682 m->m_pkthdr.len = len; 683 m->m_pkthdr.rcvif = &sc->sc_if; 684 return (m); 685} 686 687/* 688 * tty interface receiver interrupt. 689 */ 690void 691slinput(c, tp) 692 register int c; 693 register struct tty *tp; 694{ 695 register struct sl_softc *sc; 696 register struct mbuf *m; 697 register int len; 698 int s; 699#if NBPFILTER > 0 700 u_char chdr[CHDR_LEN]; 701#endif 702 703 tk_nin++; 704 sc = (struct sl_softc *)tp->t_sc; 705 if (sc == NULL) 706 return; 707 if (c & TTY_ERRORMASK || ((tp->t_state & TS_CARR_ON) == 0 && 708 (tp->t_cflag & CLOCAL) == 0)) { 709 sc->sc_flags |= SC_ERROR; 710 return; 711 } 712 c &= TTY_CHARMASK; 713 714 ++sc->sc_if.if_ibytes; 715 716 if (sc->sc_if.if_flags & IFF_DEBUG) { 717 if (c == ABT_ESC) { 718 /* 719 * If we have a previous abort, see whether 720 * this one is within the time limit. 721 */ 722 if (sc->sc_abortcount && 723 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 724 sc->sc_abortcount = 0; 725 /* 726 * If we see an abort after "idle" time, count it; 727 * record when the first abort escape arrived. 728 */ 729 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 730 if (++sc->sc_abortcount == 1) 731 sc->sc_starttime = time.tv_sec; 732 if (sc->sc_abortcount >= ABT_COUNT) { 733 slclose(tp); 734 return; 735 } 736 } 737 } else 738 sc->sc_abortcount = 0; 739 sc->sc_lasttime = time.tv_sec; 740 } 741 742 switch (c) { 743 744 case TRANS_FRAME_ESCAPE: 745 if (sc->sc_escape) 746 c = FRAME_ESCAPE; 747 break; 748 749 case TRANS_FRAME_END: 750 if (sc->sc_escape) 751 c = FRAME_END; 752 break; 753 754 case FRAME_ESCAPE: 755 sc->sc_escape = 1; 756 return; 757 758 case FRAME_END: 759 if(sc->sc_flags & SC_ERROR) { 760 sc->sc_flags &= ~SC_ERROR; 761 goto newpack; 762 } 763 len = sc->sc_mp - sc->sc_buf; 764 if (len < 3) 765 /* less than min length packet - ignore */ 766 goto newpack; 767 768#if NBPFILTER > 0 769 if (sc->sc_bpf) { 770 /* 771 * Save the compressed header, so we 772 * can tack it on later. Note that we 773 * will end up copying garbage in some 774 * cases but this is okay. We remember 775 * where the buffer started so we can 776 * compute the new header length. 777 */ 778 bcopy(sc->sc_buf, chdr, CHDR_LEN); 779 } 780#endif 781 782 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 783 if (c & 0x80) 784 c = TYPE_COMPRESSED_TCP; 785 else if (c == TYPE_UNCOMPRESSED_TCP) 786 *sc->sc_buf &= 0x4f; /* XXX */ 787 /* 788 * We've got something that's not an IP packet. 789 * If compression is enabled, try to decompress it. 790 * Otherwise, if `auto-enable' compression is on and 791 * it's a reasonable packet, decompress it and then 792 * enable compression. Otherwise, drop it. 793 */ 794 if (sc->sc_if.if_flags & SC_COMPRESS) { 795 len = sl_uncompress_tcp(&sc->sc_buf, len, 796 (u_int)c, &sc->sc_comp); 797 if (len <= 0) 798 goto error; 799 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 800 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 801 len = sl_uncompress_tcp(&sc->sc_buf, len, 802 (u_int)c, &sc->sc_comp); 803 if (len <= 0) 804 goto error; 805 sc->sc_if.if_flags |= SC_COMPRESS; 806 } else 807 goto error; 808 } 809#if NBPFILTER > 0 810 if (sc->sc_bpf) { 811 /* 812 * Put the SLIP pseudo-"link header" in place. 813 * We couldn't do this any earlier since 814 * decompression probably moved the buffer 815 * pointer. Then, invoke BPF. 816 */ 817 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 818 819 hp[SLX_DIR] = SLIPDIR_IN; 820 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 821 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 822 } 823#endif 824 m = sl_btom(sc, len); 825 if (m == NULL) 826 goto error; 827 828 sc->sc_if.if_ipackets++; 829 sc->sc_if.if_lastchange = time; 830 s = splimp(); 831 if (IF_QFULL(&ipintrq)) { 832 IF_DROP(&ipintrq); 833 sc->sc_if.if_ierrors++; 834 sc->sc_if.if_iqdrops++; 835 m_freem(m); 836 } else { 837 IF_ENQUEUE(&ipintrq, m); 838 schednetisr(NETISR_IP); 839 } 840 splx(s); 841 goto newpack; 842 } 843 if (sc->sc_mp < sc->sc_ep) { 844 *sc->sc_mp++ = c; 845 sc->sc_escape = 0; 846 return; 847 } 848 849 /* can't put lower; would miss an extra frame */ 850 sc->sc_flags |= SC_ERROR; 851 852error: 853 sc->sc_if.if_ierrors++; 854newpack: 855 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 856 sc->sc_escape = 0; 857} 858 859/* 860 * Process an ioctl request. 861 */ 862int 863slioctl(ifp, cmd, data) 864 register struct ifnet *ifp; 865 u_long cmd; 866 caddr_t data; 867{ 868 register struct ifaddr *ifa = (struct ifaddr *)data; 869 register struct ifreq *ifr; 870 register int s = splimp(), error = 0; 871 872 switch (cmd) { 873 874 case SIOCSIFADDR: 875 if (ifa->ifa_addr->sa_family == AF_INET) 876 ifp->if_flags |= IFF_UP; 877 else 878 error = EAFNOSUPPORT; 879 break; 880 881 case SIOCSIFDSTADDR: 882 if (ifa->ifa_addr->sa_family != AF_INET) 883 error = EAFNOSUPPORT; 884 break; 885 886 case SIOCADDMULTI: 887 case SIOCDELMULTI: 888 ifr = (struct ifreq *)data; 889 if (ifr == 0) { 890 error = EAFNOSUPPORT; /* XXX */ 891 break; 892 } 893 switch (ifr->ifr_addr.sa_family) { 894 895#ifdef INET 896 case AF_INET: 897 break; 898#endif 899 900 default: 901 error = EAFNOSUPPORT; 902 break; 903 } 904 break; 905 906 default: 907 error = EINVAL; 908 } 909 splx(s); 910 return (error); 911} 912#endif 913