if_sl.c revision 1.51
1/* $NetBSD: if_sl.c,v 1.51 1998/07/06 13:51:32 jtk 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 8.9 (Berkeley) 1/9/95 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 "opt_inet.h" 73#include "bpfilter.h" 74 75#include <sys/param.h> 76#include <sys/proc.h> 77#include <sys/malloc.h> 78#include <sys/mbuf.h> 79#include <sys/buf.h> 80#include <sys/dkstat.h> 81#include <sys/socket.h> 82#include <sys/ioctl.h> 83#include <sys/file.h> 84#include <sys/tty.h> 85#include <sys/kernel.h> 86#include <sys/conf.h> 87#if __NetBSD__ 88#include <sys/systm.h> 89#endif 90 91#include <machine/cpu.h> 92 93#include <net/if.h> 94#include <net/if_types.h> 95#include <net/netisr.h> 96#include <net/route.h> 97 98#ifdef INET 99#include <netinet/in.h> 100#include <netinet/in_systm.h> 101#include <netinet/in_var.h> 102#include <netinet/ip.h> 103#else 104Huh? Slip without inet? 105#endif 106 107#include <net/slcompress.h> 108#include <net/if_slvar.h> 109#include <net/slip.h> 110 111#if NBPFILTER > 0 112#include <sys/time.h> 113#include <net/bpf.h> 114#endif 115 116/* 117 * SLMAX is a hard limit on input packet size. To simplify the code 118 * and improve performance, we require that packets fit in an mbuf 119 * cluster, and if we get a compressed packet, there's enough extra 120 * room to expand the header into a max length tcp/ip header (128 121 * bytes). So, SLMAX can be at most 122 * MCLBYTES - 128 123 * 124 * SLMTU is a hard limit on output packet size. To insure good 125 * interactive response, SLMTU wants to be the smallest size that 126 * amortizes the header cost. (Remember that even with 127 * type-of-service queuing, we have to wait for any in-progress 128 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 129 * cps, where cps is the line speed in characters per second. 130 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 131 * average compressed header size is 6-8 bytes so any MTU > 90 132 * bytes will give us 90% of the line bandwidth. A 100ms wait is 133 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 134 * will send 256 byte segments (to allow for 40 byte headers), the 135 * typical packet size on the wire will be around 260 bytes). In 136 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 137 * leave the interface MTU relatively high (so we don't IP fragment 138 * when acting as a gateway to someone using a stupid MTU). 139 * 140 * Similar considerations apply to SLIP_HIWAT: It's the amount of 141 * data that will be queued 'downstream' of us (i.e., in clists 142 * waiting to be picked up by the tty output interrupt). If we 143 * queue a lot of data downstream, it's immune to our t.o.s. queuing. 144 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 145 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 146 * wait is dependent on the ftp window size but that's typically 147 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 148 * the cost (in idle time on the wire) of the tty driver running 149 * off the end of its clists & having to call back slstart for a 150 * new packet. For a tty interface with any buffering at all, this 151 * cost will be zero. Even with a totally brain dead interface (like 152 * the one on a typical workstation), the cost will be <= 1 character 153 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 154 * at most 1% while maintaining good interactive response. 155 */ 156#if NBPFILTER > 0 157#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 158#else 159#define BUFOFFSET (128+sizeof(struct ifnet **)) 160#endif 161#define SLMAX (MCLBYTES - BUFOFFSET) 162#define SLBUFSIZE (SLMAX + BUFOFFSET) 163#ifndef SLMTU 164#define SLMTU 296 165#endif 166#if (SLMTU < 3) 167Huh? SLMTU way too small. 168#endif 169#define SLIP_HIWAT roundup(50,CBSIZE) 170#ifndef NetBSD /* XXX - cgd */ 171#define CLISTRESERVE 1024 /* Can't let clists get too low */ 172#endif /* !NetBSD */ 173 174/* 175 * SLIP ABORT ESCAPE MECHANISM: 176 * (inspired by HAYES modem escape arrangement) 177 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 178 * within window time signals a "soft" exit from slip mode by remote end 179 * if the IFF_DEBUG flag is on. 180 */ 181#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 182#define ABT_IDLE 1 /* in seconds - idle before an escape */ 183#define ABT_COUNT 3 /* count of escapes for abort */ 184#define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 185 186struct sl_softc sl_softc[NSL]; 187 188#define FRAME_END 0xc0 /* Frame End */ 189#define FRAME_ESCAPE 0xdb /* Frame Esc */ 190#define TRANS_FRAME_END 0xdc /* transposed frame end */ 191#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 192 193static int slinit __P((struct sl_softc *)); 194static struct mbuf *sl_btom __P((struct sl_softc *, int)); 195 196/* 197 * Called from boot code to establish sl interfaces. 198 */ 199void 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_unit = i; /* XXX */ 207 sprintf(sc->sc_if.if_xname, "sl%d", i++); 208 sc->sc_if.if_softc = sc; 209 sc->sc_if.if_mtu = SLMTU; 210 sc->sc_if.if_flags = 211 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 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, SLIP_HDRLEN); 220#endif 221 } 222} 223 224static int 225slinit(sc) 226 register struct sl_softc *sc; 227{ 228 229 if (sc->sc_ep == NULL) { 230 /* 231 * XXX the trick this is used for is evil... 232 */ 233 sc->sc_xxx = (u_char *)malloc(MCLBYTES, M_MBUF, M_WAITOK); 234 if (sc->sc_xxx) 235 sc->sc_ep = sc->sc_xxx + SLBUFSIZE; 236 else { 237 printf("sl%d: can't allocate buffer\n", sc->sc_unit); 238 sc->sc_if.if_flags &= ~IFF_UP; 239 return (0); 240 } 241 } 242 sc->sc_buf = sc->sc_ep - SLMAX; 243 sc->sc_mp = sc->sc_buf; 244 sl_compress_init(&sc->sc_comp); 245 return (1); 246} 247 248/* 249 * Line specific open routine. 250 * Attach the given tty to the first available sl unit. 251 */ 252/* ARGSUSED */ 253int 254slopen(dev, tp) 255 dev_t dev; 256 register struct tty *tp; 257{ 258 struct proc *p = curproc; /* XXX */ 259 register struct sl_softc *sc; 260 register int nsl; 261 int error; 262#ifdef NetBSD 263 int s; 264#endif 265 266 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 267 return (error); 268 269 if (tp->t_line == SLIPDISC) 270 return (0); 271 272 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 273 if (sc->sc_ttyp == NULL) { 274 if (slinit(sc) == 0) 275 return (ENOBUFS); 276 tp->t_sc = (caddr_t)sc; 277 sc->sc_ttyp = tp; 278 sc->sc_if.if_baudrate = tp->t_ospeed; 279 s = spltty(); 280 tp->t_state |= TS_ISOPEN | TS_XCLUDE; 281 splx(s); 282 ttyflush(tp, FREAD | FWRITE); 283#ifdef NetBSD 284 /* 285 * make sure tty output queue is large enough 286 * to hold a full-sized packet (including frame 287 * end, and a possible extra frame end). full-sized 288 * packet occupies a max of 2*SLMTU bytes (because 289 * of possible escapes), and add two on for frame 290 * ends. 291 */ 292 s = spltty(); 293 if (tp->t_outq.c_cn < 2*SLMTU+2) { 294 sc->sc_oldbufsize = tp->t_outq.c_cn; 295 sc->sc_oldbufquot = tp->t_outq.c_cq != 0; 296 297 clfree(&tp->t_outq); 298 error = clalloc(&tp->t_outq, 3*SLMTU, 0); 299 if (error) { 300 splx(s); 301 return(error); 302 } 303 } else 304 sc->sc_oldbufsize = sc->sc_oldbufquot = 0; 305 splx(s); 306#endif /* NetBSD */ 307 return (0); 308 } 309 return (ENXIO); 310} 311 312/* 313 * Line specific close routine. 314 * Detach the tty from the sl unit. 315 */ 316void 317slclose(tp) 318 struct tty *tp; 319{ 320 register struct sl_softc *sc; 321 int s; 322 323 ttywflush(tp); 324 s = splimp(); /* actually, max(spltty, splsoftnet) */ 325 tp->t_line = 0; 326 tp->t_state = 0; 327 sc = (struct sl_softc *)tp->t_sc; 328 if (sc != NULL) { 329 if_down(&sc->sc_if); 330 sc->sc_ttyp = NULL; 331 tp->t_sc = NULL; 332 free((caddr_t)(sc->sc_ep - SLBUFSIZE), M_MBUF); 333 sc->sc_ep = 0; 334 sc->sc_mp = 0; 335 sc->sc_buf = 0; 336 } 337#ifdef NetBSD 338 /* if necessary, install a new outq buffer of the appropriate size */ 339 if (sc->sc_oldbufsize != 0) { 340 clfree(&tp->t_outq); 341 clalloc(&tp->t_outq, sc->sc_oldbufsize, sc->sc_oldbufquot); 342 } 343#endif 344 splx(s); 345} 346 347/* 348 * Line specific (tty) ioctl routine. 349 * Provide a way to get the sl unit number. 350 */ 351/* ARGSUSED */ 352int 353sltioctl(tp, cmd, data, flag) 354 struct tty *tp; 355 u_long cmd; 356 caddr_t data; 357 int flag; 358{ 359 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 360 361 switch (cmd) { 362 case SLIOCGUNIT: 363 *(int *)data = sc->sc_unit; /* XXX */ 364 break; 365 366 default: 367 return (-1); 368 } 369 return (0); 370} 371 372/* 373 * Queue a packet. Start transmission if not active. 374 * Compression happens in slstart; if we do it here, IP TOS 375 * will cause us to not compress "background" packets, because 376 * ordering gets trashed. It can be done for all packets in slstart. 377 */ 378int 379sloutput(ifp, m, dst, rtp) 380 struct ifnet *ifp; 381 register struct mbuf *m; 382 struct sockaddr *dst; 383 struct rtentry *rtp; 384{ 385 register struct sl_softc *sc = ifp->if_softc; 386 register struct ip *ip; 387 register struct ifqueue *ifq; 388 int s; 389 390 /* 391 * `Cannot happen' (see slioctl). Someday we will extend 392 * the line protocol to support other address families. 393 */ 394 if (dst->sa_family != AF_INET) { 395 printf("%s: af%d not supported\n", sc->sc_if.if_xname, 396 dst->sa_family); 397 m_freem(m); 398 sc->sc_if.if_noproto++; 399 return (EAFNOSUPPORT); 400 } 401 402 if (sc->sc_ttyp == NULL) { 403 m_freem(m); 404 return (ENETDOWN); /* sort of */ 405 } 406 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 407 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 408 m_freem(m); 409 printf("%s: no carrier and not local\n", sc->sc_if.if_xname); 410 return (EHOSTUNREACH); 411 } 412 ifq = &sc->sc_if.if_snd; 413 ip = mtod(m, struct ip *); 414 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 415 m_freem(m); 416 return (ENETRESET); /* XXX ? */ 417 } 418 if (ip->ip_tos & IPTOS_LOWDELAY) 419 ifq = &sc->sc_fastq; 420 s = splimp(); 421 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) { 422 struct timeval tv; 423 424 /* if output's been stalled for too long, and restart */ 425 timersub(&time, &sc->sc_if.if_lastchange, &tv); 426 if (tv.tv_sec > 0) { 427 sc->sc_otimeout++; 428 slstart(sc->sc_ttyp); 429 } 430 } 431 if (IF_QFULL(ifq)) { 432 IF_DROP(ifq); 433 m_freem(m); 434 splx(s); 435 sc->sc_if.if_oerrors++; 436 return (ENOBUFS); 437 } 438 IF_ENQUEUE(ifq, m); 439 sc->sc_if.if_lastchange = time; 440 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) 441 slstart(sc->sc_ttyp); 442 splx(s); 443 return (0); 444} 445 446/* 447 * Start output on interface. Get another datagram 448 * to send from the interface queue and map it to 449 * the interface before starting output. 450 */ 451void 452slstart(tp) 453 register struct tty *tp; 454{ 455 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 456 register struct mbuf *m; 457 register u_char *cp; 458 register struct ip *ip; 459 int s; 460 struct mbuf *m2; 461#if NBPFILTER > 0 462 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 463 register int len = 0; 464#endif 465#ifndef NetBSD /* XXX - cgd */ 466 extern int cfreecount; 467#endif 468 469 for (;;) { 470 /* 471 * If there is more in the output queue, just send it now. 472 * We are being called in lieu of ttstart and must do what 473 * it would. 474 */ 475 if (tp->t_outq.c_cc != 0) { 476 (*tp->t_oproc)(tp); 477 if (tp->t_outq.c_cc > SLIP_HIWAT) 478 return; 479 } 480 /* 481 * This happens briefly when the line shuts down. 482 */ 483 if (sc == NULL) 484 return; 485 486#ifdef NetBSD /* XXX - cgd */ 487 /* 488 * Do not remove the packet from the IP queue if it 489 * doesn't look like the packet will fit into the 490 * current serial output queue, with a packet full of 491 * escapes this could be as bad as SLMTU*2+2. 492 */ 493 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*SLMTU+2) 494 return; 495#endif /* NetBSD */ 496 497 /* 498 * Get a packet and send it to the interface. 499 */ 500 s = splimp(); 501 IF_DEQUEUE(&sc->sc_fastq, m); 502 if (m) 503 sc->sc_if.if_omcasts++; /* XXX */ 504 else 505 IF_DEQUEUE(&sc->sc_if.if_snd, m); 506 splx(s); 507 if (m == NULL) 508 return; 509 510 /* 511 * We do the header compression here rather than in sloutput 512 * because the packets will be out of order if we are using TOS 513 * queueing, and the connection id compression will get 514 * munged when this happens. 515 */ 516#if NBPFILTER > 0 517 if (sc->sc_bpf) { 518 /* 519 * We need to save the TCP/IP header before it's 520 * compressed. To avoid complicated code, we just 521 * copy the entire packet into a stack buffer (since 522 * this is a serial line, packets should be short 523 * and/or the copy should be negligible cost compared 524 * to the packet transmission time). 525 */ 526 register struct mbuf *m1 = m; 527 register u_char *cp = bpfbuf + SLIP_HDRLEN; 528 529 len = 0; 530 do { 531 register int mlen = m1->m_len; 532 533 bcopy(mtod(m1, caddr_t), cp, mlen); 534 cp += mlen; 535 len += mlen; 536 } while ((m1 = m1->m_next) != NULL); 537 } 538#endif 539 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 540 if (sc->sc_if.if_flags & SC_COMPRESS) 541 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 542 &sc->sc_comp, 1); 543 } 544#if NBPFILTER > 0 545 if (sc->sc_bpf) { 546 /* 547 * Put the SLIP pseudo-"link header" in place. The 548 * compressed header is now at the beginning of the 549 * mbuf. 550 */ 551 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 552 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 553 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 554 } 555#endif 556 sc->sc_if.if_lastchange = time; 557 558#ifndef __NetBSD__ /* XXX - cgd */ 559 /* 560 * If system is getting low on clists, just flush our 561 * output queue (if the stuff was important, it'll get 562 * retransmitted). 563 */ 564 if (cfreecount < CLISTRESERVE + SLMTU) { 565 m_freem(m); 566 sc->sc_if.if_collisions++; 567 continue; 568 } 569#endif /* !__NetBSD__ */ 570 /* 571 * The extra FRAME_END will start up a new packet, and thus 572 * will flush any accumulated garbage. We do this whenever 573 * the line may have been idle for some time. 574 */ 575 if (tp->t_outq.c_cc == 0) { 576 ++sc->sc_if.if_obytes; 577 (void) putc(FRAME_END, &tp->t_outq); 578 } 579 580 while (m) { 581 register u_char *ep; 582 583 cp = mtod(m, u_char *); ep = cp + m->m_len; 584 while (cp < ep) { 585 /* 586 * Find out how many bytes in the string we can 587 * handle without doing something special. 588 */ 589 register u_char *bp = cp; 590 591 while (cp < ep) { 592 switch (*cp++) { 593 case FRAME_ESCAPE: 594 case FRAME_END: 595 --cp; 596 goto out; 597 } 598 } 599 out: 600 if (cp > bp) { 601 /* 602 * Put n characters at once 603 * into the tty output queue. 604 */ 605#ifdef __NetBSD__ /* XXX - cgd */ 606 if (b_to_q((u_char *)bp, cp - bp, 607#else 608 if (b_to_q((char *)bp, cp - bp, 609#endif 610 &tp->t_outq)) 611 break; 612 sc->sc_if.if_obytes += cp - bp; 613 } 614 /* 615 * If there are characters left in the mbuf, 616 * the first one must be special.. 617 * Put it out in a different form. 618 */ 619 if (cp < ep) { 620 if (putc(FRAME_ESCAPE, &tp->t_outq)) 621 break; 622 if (putc(*cp++ == FRAME_ESCAPE ? 623 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 624 &tp->t_outq)) { 625 (void) unputc(&tp->t_outq); 626 break; 627 } 628 sc->sc_if.if_obytes += 2; 629 } 630 } 631 MFREE(m, m2); 632 m = m2; 633 } 634 635 if (putc(FRAME_END, &tp->t_outq)) { 636 /* 637 * Not enough room. Remove a char to make room 638 * and end the packet normally. 639 * If you get many collisions (more than one or two 640 * a day) you probably do not have enough clists 641 * and you should increase "nclist" in param.c. 642 */ 643 (void) unputc(&tp->t_outq); 644 (void) putc(FRAME_END, &tp->t_outq); 645 sc->sc_if.if_collisions++; 646 } else { 647 ++sc->sc_if.if_obytes; 648 sc->sc_if.if_opackets++; 649 } 650 } 651} 652 653/* 654 * Copy data buffer to mbuf chain; add ifnet pointer. 655 */ 656static struct mbuf * 657sl_btom(sc, len) 658 register struct sl_softc *sc; 659 register int len; 660{ 661 register struct mbuf *m; 662 register u_char *p; 663 664 MGETHDR(m, M_DONTWAIT, MT_DATA); 665 if (m == NULL) 666 return (NULL); 667 668 /* 669 * If we have more than MHLEN bytes, it's cheaper to 670 * queue the cluster we just filled & allocate a new one 671 * for the input buffer. Otherwise, fill the mbuf we 672 * allocated above. Note that code in the input routine 673 * guarantees that packet will fit in a cluster. 674 */ 675 if (len >= MHLEN) { 676 /* 677 * XXX this is that evil trick I mentioned... 678 */ 679 p = sc->sc_xxx; 680 sc->sc_xxx = (u_char *)malloc(MCLBYTES, M_MBUF, M_NOWAIT); 681 if (sc->sc_xxx == NULL) { 682 /* 683 * We couldn't allocate a new buffer - if 684 * memory's this low, it's time to start 685 * dropping packets. 686 */ 687 (void) m_free(m); 688 return (NULL); 689 } 690 sc->sc_ep = sc->sc_xxx + SLBUFSIZE; 691 MEXTADD(m, p, MCLBYTES, M_MBUF, NULL, NULL); 692 m->m_data = (caddr_t)sc->sc_buf; 693 } else 694 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 695 696 m->m_len = len; 697 m->m_pkthdr.len = len; 698 m->m_pkthdr.rcvif = &sc->sc_if; 699 return (m); 700} 701 702/* 703 * tty interface receiver interrupt. 704 */ 705void 706slinput(c, tp) 707 register int c; 708 register struct tty *tp; 709{ 710 register struct sl_softc *sc; 711 register struct mbuf *m; 712 register int len; 713 int s; 714#if NBPFILTER > 0 715 u_char chdr[CHDR_LEN]; 716#endif 717 718 tk_nin++; 719 sc = (struct sl_softc *)tp->t_sc; 720 if (sc == NULL) 721 return; 722 if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 && 723 (tp->t_cflag & CLOCAL) == 0)) { 724 sc->sc_flags |= SC_ERROR; 725 return; 726 } 727 c &= TTY_CHARMASK; 728 729 ++sc->sc_if.if_ibytes; 730 731 if (sc->sc_if.if_flags & IFF_DEBUG) { 732 if (c == ABT_ESC) { 733 /* 734 * If we have a previous abort, see whether 735 * this one is within the time limit. 736 */ 737 if (sc->sc_abortcount && 738 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 739 sc->sc_abortcount = 0; 740 /* 741 * If we see an abort after "idle" time, count it; 742 * record when the first abort escape arrived. 743 */ 744 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 745 if (++sc->sc_abortcount == 1) 746 sc->sc_starttime = time.tv_sec; 747 if (sc->sc_abortcount >= ABT_COUNT) { 748 slclose(tp); 749 return; 750 } 751 } 752 } else 753 sc->sc_abortcount = 0; 754 sc->sc_lasttime = time.tv_sec; 755 } 756 757 switch (c) { 758 759 case TRANS_FRAME_ESCAPE: 760 if (sc->sc_escape) 761 c = FRAME_ESCAPE; 762 break; 763 764 case TRANS_FRAME_END: 765 if (sc->sc_escape) 766 c = FRAME_END; 767 break; 768 769 case FRAME_ESCAPE: 770 sc->sc_escape = 1; 771 return; 772 773 case FRAME_END: 774 if(sc->sc_flags & SC_ERROR) { 775 sc->sc_flags &= ~SC_ERROR; 776 goto newpack; 777 } 778 len = sc->sc_mp - sc->sc_buf; 779 if (len < 3) 780 /* less than min length packet - ignore */ 781 goto newpack; 782 783#if NBPFILTER > 0 784 if (sc->sc_bpf) { 785 /* 786 * Save the compressed header, so we 787 * can tack it on later. Note that we 788 * will end up copying garbage in some 789 * cases but this is okay. We remember 790 * where the buffer started so we can 791 * compute the new header length. 792 */ 793 bcopy(sc->sc_buf, chdr, CHDR_LEN); 794 } 795#endif 796 797 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 798 if (c & 0x80) 799 c = TYPE_COMPRESSED_TCP; 800 else if (c == TYPE_UNCOMPRESSED_TCP) 801 *sc->sc_buf &= 0x4f; /* XXX */ 802 /* 803 * We've got something that's not an IP packet. 804 * If compression is enabled, try to decompress it. 805 * Otherwise, if `auto-enable' compression is on and 806 * it's a reasonable packet, decompress it and then 807 * enable compression. Otherwise, drop it. 808 */ 809 if (sc->sc_if.if_flags & SC_COMPRESS) { 810 len = sl_uncompress_tcp(&sc->sc_buf, len, 811 (u_int)c, &sc->sc_comp); 812 if (len <= 0) 813 goto error; 814 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 815 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 816 len = sl_uncompress_tcp(&sc->sc_buf, len, 817 (u_int)c, &sc->sc_comp); 818 if (len <= 0) 819 goto error; 820 sc->sc_if.if_flags |= SC_COMPRESS; 821 } else 822 goto error; 823 } 824#if NBPFILTER > 0 825 if (sc->sc_bpf) { 826 /* 827 * Put the SLIP pseudo-"link header" in place. 828 * We couldn't do this any earlier since 829 * decompression probably moved the buffer 830 * pointer. Then, invoke BPF. 831 */ 832 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 833 834 hp[SLX_DIR] = SLIPDIR_IN; 835 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 836 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 837 } 838#endif 839 m = sl_btom(sc, len); 840 if (m == NULL) 841 goto error; 842 843 sc->sc_if.if_ipackets++; 844 sc->sc_if.if_lastchange = time; 845 s = splimp(); 846 if (IF_QFULL(&ipintrq)) { 847 IF_DROP(&ipintrq); 848 sc->sc_if.if_ierrors++; 849 sc->sc_if.if_iqdrops++; 850 m_freem(m); 851 } else { 852 IF_ENQUEUE(&ipintrq, m); 853 schednetisr(NETISR_IP); 854 } 855 splx(s); 856 goto newpack; 857 } 858 if (sc->sc_mp < sc->sc_ep) { 859 *sc->sc_mp++ = c; 860 sc->sc_escape = 0; 861 return; 862 } 863 864 /* can't put lower; would miss an extra frame */ 865 sc->sc_flags |= SC_ERROR; 866 867error: 868 sc->sc_if.if_ierrors++; 869newpack: 870 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 871 sc->sc_escape = 0; 872} 873 874/* 875 * Process an ioctl request. 876 */ 877int 878slioctl(ifp, cmd, data) 879 register struct ifnet *ifp; 880 u_long cmd; 881 caddr_t data; 882{ 883 register struct ifaddr *ifa = (struct ifaddr *)data; 884 register struct ifreq *ifr; 885 register int s = splimp(), error = 0; 886 887 switch (cmd) { 888 889 case SIOCSIFADDR: 890 if (ifa->ifa_addr->sa_family == AF_INET) 891 ifp->if_flags |= IFF_UP; 892 else 893 error = EAFNOSUPPORT; 894 break; 895 896 case SIOCSIFDSTADDR: 897 if (ifa->ifa_addr->sa_family != AF_INET) 898 error = EAFNOSUPPORT; 899 break; 900 901 case SIOCADDMULTI: 902 case SIOCDELMULTI: 903 ifr = (struct ifreq *)data; 904 if (ifr == 0) { 905 error = EAFNOSUPPORT; /* XXX */ 906 break; 907 } 908 switch (ifr->ifr_addr.sa_family) { 909 910#ifdef INET 911 case AF_INET: 912 break; 913#endif 914 915 default: 916 error = EAFNOSUPPORT; 917 break; 918 } 919 break; 920 921 default: 922 error = EINVAL; 923 } 924 splx(s); 925 return (error); 926} 927#endif 928