if_sl.c revision 1.53
1/* $NetBSD: if_sl.c,v 1.53 1998/10/06 18:38:08 kleink 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 104#error 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) 167#error 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 int s; 263 264 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 265 return (error); 266 267 if (tp->t_line == SLIPDISC) 268 return (0); 269 270 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 271 if (sc->sc_ttyp == NULL) { 272 if (slinit(sc) == 0) 273 return (ENOBUFS); 274 tp->t_sc = (caddr_t)sc; 275 sc->sc_ttyp = tp; 276 sc->sc_if.if_baudrate = tp->t_ospeed; 277 s = spltty(); 278 tp->t_state |= TS_ISOPEN | TS_XCLUDE; 279 splx(s); 280 ttyflush(tp, FREAD | FWRITE); 281#ifdef __NetBSD__ 282 /* 283 * make sure tty output queue is large enough 284 * to hold a full-sized packet (including frame 285 * end, and a possible extra frame end). full-sized 286 * packet occupies a max of 2*SLMTU bytes (because 287 * of possible escapes), and add two on for frame 288 * ends. 289 */ 290 s = spltty(); 291 if (tp->t_outq.c_cn < 2*SLMTU+2) { 292 sc->sc_oldbufsize = tp->t_outq.c_cn; 293 sc->sc_oldbufquot = tp->t_outq.c_cq != 0; 294 295 clfree(&tp->t_outq); 296 error = clalloc(&tp->t_outq, 3*SLMTU, 0); 297 if (error) { 298 splx(s); 299 return(error); 300 } 301 } else 302 sc->sc_oldbufsize = sc->sc_oldbufquot = 0; 303 splx(s); 304#endif /* __NetBSD__ */ 305 return (0); 306 } 307 return (ENXIO); 308} 309 310/* 311 * Line specific close routine. 312 * Detach the tty from the sl unit. 313 */ 314void 315slclose(tp) 316 struct tty *tp; 317{ 318 register struct sl_softc *sc; 319 int s; 320 321 ttywflush(tp); 322 s = splimp(); /* actually, max(spltty, splsoftnet) */ 323 tp->t_line = 0; 324 tp->t_state = 0; 325 sc = (struct sl_softc *)tp->t_sc; 326 if (sc != NULL) { 327 if_down(&sc->sc_if); 328 sc->sc_ttyp = NULL; 329 tp->t_sc = NULL; 330 free((caddr_t)(sc->sc_ep - SLBUFSIZE), M_MBUF); 331 sc->sc_ep = 0; 332 sc->sc_mp = 0; 333 sc->sc_buf = 0; 334 } 335#ifdef __NetBSD__ 336 /* if necessary, install a new outq buffer of the appropriate size */ 337 if (sc->sc_oldbufsize != 0) { 338 clfree(&tp->t_outq); 339 clalloc(&tp->t_outq, sc->sc_oldbufsize, sc->sc_oldbufquot); 340 } 341#endif 342 splx(s); 343} 344 345/* 346 * Line specific (tty) ioctl routine. 347 * Provide a way to get the sl unit number. 348 */ 349/* ARGSUSED */ 350int 351sltioctl(tp, cmd, data, flag) 352 struct tty *tp; 353 u_long cmd; 354 caddr_t data; 355 int flag; 356{ 357 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 358 359 switch (cmd) { 360 case SLIOCGUNIT: 361 *(int *)data = sc->sc_unit; /* XXX */ 362 break; 363 364 default: 365 return (-1); 366 } 367 return (0); 368} 369 370/* 371 * Queue a packet. Start transmission if not active. 372 * Compression happens in slstart; if we do it here, IP TOS 373 * will cause us to not compress "background" packets, because 374 * ordering gets trashed. It can be done for all packets in slstart. 375 */ 376int 377sloutput(ifp, m, dst, rtp) 378 struct ifnet *ifp; 379 register struct mbuf *m; 380 struct sockaddr *dst; 381 struct rtentry *rtp; 382{ 383 register struct sl_softc *sc = ifp->if_softc; 384 register struct ip *ip; 385 register struct ifqueue *ifq; 386 int s; 387 388 /* 389 * `Cannot happen' (see slioctl). Someday we will extend 390 * the line protocol to support other address families. 391 */ 392 if (dst->sa_family != AF_INET) { 393 printf("%s: af%d not supported\n", sc->sc_if.if_xname, 394 dst->sa_family); 395 m_freem(m); 396 sc->sc_if.if_noproto++; 397 return (EAFNOSUPPORT); 398 } 399 400 if (sc->sc_ttyp == NULL) { 401 m_freem(m); 402 return (ENETDOWN); /* sort of */ 403 } 404 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 405 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 406 m_freem(m); 407 printf("%s: no carrier and not local\n", sc->sc_if.if_xname); 408 return (EHOSTUNREACH); 409 } 410 ifq = &sc->sc_if.if_snd; 411 ip = mtod(m, struct ip *); 412 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 413 m_freem(m); 414 return (ENETRESET); /* XXX ? */ 415 } 416 if (ip->ip_tos & IPTOS_LOWDELAY) 417 ifq = &sc->sc_fastq; 418 s = splimp(); 419 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) { 420 struct timeval tv; 421 422 /* if output's been stalled for too long, and restart */ 423 timersub(&time, &sc->sc_if.if_lastchange, &tv); 424 if (tv.tv_sec > 0) { 425 sc->sc_otimeout++; 426 slstart(sc->sc_ttyp); 427 } 428 } 429 if (IF_QFULL(ifq)) { 430 IF_DROP(ifq); 431 m_freem(m); 432 splx(s); 433 sc->sc_if.if_oerrors++; 434 return (ENOBUFS); 435 } 436 IF_ENQUEUE(ifq, m); 437 sc->sc_if.if_lastchange = time; 438 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) 439 slstart(sc->sc_ttyp); 440 splx(s); 441 return (0); 442} 443 444/* 445 * Start output on interface. Get another datagram 446 * to send from the interface queue and map it to 447 * the interface before starting output. 448 */ 449void 450slstart(tp) 451 register struct tty *tp; 452{ 453 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 454 register struct mbuf *m; 455 register u_char *cp; 456 register struct ip *ip; 457 int s; 458 struct mbuf *m2; 459#if NBPFILTER > 0 460 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 461 register int len = 0; 462#endif 463#ifndef __NetBSD__ /* XXX - cgd */ 464 extern int cfreecount; 465#endif 466 467 for (;;) { 468 /* 469 * If there is more in the output queue, just send it now. 470 * We are being called in lieu of ttstart and must do what 471 * it would. 472 */ 473 if (tp->t_outq.c_cc != 0) { 474 (*tp->t_oproc)(tp); 475 if (tp->t_outq.c_cc > SLIP_HIWAT) 476 return; 477 } 478 /* 479 * This happens briefly when the line shuts down. 480 */ 481 if (sc == NULL) 482 return; 483 484#ifdef __NetBSD__ /* XXX - cgd */ 485 /* 486 * Do not remove the packet from the IP queue if it 487 * doesn't look like the packet will fit into the 488 * current serial output queue, with a packet full of 489 * escapes this could be as bad as SLMTU*2+2. 490 */ 491 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*SLMTU+2) 492 return; 493#endif /* __NetBSD__ */ 494 495 /* 496 * Get a packet and send it to the interface. 497 */ 498 s = splimp(); 499 IF_DEQUEUE(&sc->sc_fastq, m); 500 if (m) 501 sc->sc_if.if_omcasts++; /* XXX */ 502 else 503 IF_DEQUEUE(&sc->sc_if.if_snd, m); 504 splx(s); 505 if (m == NULL) 506 return; 507 508 /* 509 * We do the header compression here rather than in sloutput 510 * because the packets will be out of order if we are using TOS 511 * queueing, and the connection id compression will get 512 * munged when this happens. 513 */ 514#if NBPFILTER > 0 515 if (sc->sc_bpf) { 516 /* 517 * We need to save the TCP/IP header before it's 518 * compressed. To avoid complicated code, we just 519 * copy the entire packet into a stack buffer (since 520 * this is a serial line, packets should be short 521 * and/or the copy should be negligible cost compared 522 * to the packet transmission time). 523 */ 524 register struct mbuf *m1 = m; 525 register u_char *cp = bpfbuf + SLIP_HDRLEN; 526 527 len = 0; 528 do { 529 register int mlen = m1->m_len; 530 531 bcopy(mtod(m1, caddr_t), cp, mlen); 532 cp += mlen; 533 len += mlen; 534 } while ((m1 = m1->m_next) != NULL); 535 } 536#endif 537 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 538 if (sc->sc_if.if_flags & SC_COMPRESS) 539 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 540 &sc->sc_comp, 1); 541 } 542#if NBPFILTER > 0 543 if (sc->sc_bpf) { 544 /* 545 * Put the SLIP pseudo-"link header" in place. The 546 * compressed header is now at the beginning of the 547 * mbuf. 548 */ 549 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 550 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 551 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 552 } 553#endif 554 sc->sc_if.if_lastchange = time; 555 556#ifndef __NetBSD__ /* XXX - cgd */ 557 /* 558 * If system is getting low on clists, just flush our 559 * output queue (if the stuff was important, it'll get 560 * retransmitted). 561 */ 562 if (cfreecount < CLISTRESERVE + SLMTU) { 563 m_freem(m); 564 sc->sc_if.if_collisions++; 565 continue; 566 } 567#endif /* !__NetBSD__ */ 568 /* 569 * The extra FRAME_END will start up a new packet, and thus 570 * will flush any accumulated garbage. We do this whenever 571 * the line may have been idle for some time. 572 */ 573 if (tp->t_outq.c_cc == 0) { 574 ++sc->sc_if.if_obytes; 575 (void) putc(FRAME_END, &tp->t_outq); 576 } 577 578 while (m) { 579 register u_char *ep; 580 581 cp = mtod(m, u_char *); ep = cp + m->m_len; 582 while (cp < ep) { 583 /* 584 * Find out how many bytes in the string we can 585 * handle without doing something special. 586 */ 587 register u_char *bp = cp; 588 589 while (cp < ep) { 590 switch (*cp++) { 591 case FRAME_ESCAPE: 592 case FRAME_END: 593 --cp; 594 goto out; 595 } 596 } 597 out: 598 if (cp > bp) { 599 /* 600 * Put n characters at once 601 * into the tty output queue. 602 */ 603#ifdef __NetBSD__ /* XXX - cgd */ 604 if (b_to_q((u_char *)bp, cp - bp, 605#else 606 if (b_to_q((char *)bp, cp - bp, 607#endif 608 &tp->t_outq)) 609 break; 610 sc->sc_if.if_obytes += cp - bp; 611 } 612 /* 613 * If there are characters left in the mbuf, 614 * the first one must be special.. 615 * Put it out in a different form. 616 */ 617 if (cp < ep) { 618 if (putc(FRAME_ESCAPE, &tp->t_outq)) 619 break; 620 if (putc(*cp++ == FRAME_ESCAPE ? 621 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 622 &tp->t_outq)) { 623 (void) unputc(&tp->t_outq); 624 break; 625 } 626 sc->sc_if.if_obytes += 2; 627 } 628 } 629 MFREE(m, m2); 630 m = m2; 631 } 632 633 if (putc(FRAME_END, &tp->t_outq)) { 634 /* 635 * Not enough room. Remove a char to make room 636 * and end the packet normally. 637 * If you get many collisions (more than one or two 638 * a day) you probably do not have enough clists 639 * and you should increase "nclist" in param.c. 640 */ 641 (void) unputc(&tp->t_outq); 642 (void) putc(FRAME_END, &tp->t_outq); 643 sc->sc_if.if_collisions++; 644 } else { 645 ++sc->sc_if.if_obytes; 646 sc->sc_if.if_opackets++; 647 } 648 } 649} 650 651/* 652 * Copy data buffer to mbuf chain; add ifnet pointer. 653 */ 654static struct mbuf * 655sl_btom(sc, len) 656 register struct sl_softc *sc; 657 register int len; 658{ 659 register struct mbuf *m; 660 register u_char *p; 661 662 MGETHDR(m, M_DONTWAIT, MT_DATA); 663 if (m == NULL) 664 return (NULL); 665 666 /* 667 * If we have more than MHLEN bytes, it's cheaper to 668 * queue the cluster we just filled & allocate a new one 669 * for the input buffer. Otherwise, fill the mbuf we 670 * allocated above. Note that code in the input routine 671 * guarantees that packet will fit in a cluster. 672 */ 673 if (len >= MHLEN) { 674 /* 675 * XXX this is that evil trick I mentioned... 676 */ 677 p = sc->sc_xxx; 678 sc->sc_xxx = (u_char *)malloc(MCLBYTES, M_MBUF, M_NOWAIT); 679 if (sc->sc_xxx == NULL) { 680 /* 681 * We couldn't allocate a new buffer - if 682 * memory's this low, it's time to start 683 * dropping packets. 684 */ 685 (void) m_free(m); 686 return (NULL); 687 } 688 sc->sc_ep = sc->sc_xxx + SLBUFSIZE; 689 MEXTADD(m, p, MCLBYTES, M_MBUF, NULL, NULL); 690 m->m_data = (caddr_t)sc->sc_buf; 691 } else 692 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 693 694 m->m_len = len; 695 m->m_pkthdr.len = len; 696 m->m_pkthdr.rcvif = &sc->sc_if; 697 return (m); 698} 699 700/* 701 * tty interface receiver interrupt. 702 */ 703void 704slinput(c, tp) 705 register int c; 706 register struct tty *tp; 707{ 708 register struct sl_softc *sc; 709 register struct mbuf *m; 710 register int len; 711 int s; 712#if NBPFILTER > 0 713 u_char chdr[CHDR_LEN]; 714#endif 715 716 tk_nin++; 717 sc = (struct sl_softc *)tp->t_sc; 718 if (sc == NULL) 719 return; 720 if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 && 721 (tp->t_cflag & CLOCAL) == 0)) { 722 sc->sc_flags |= SC_ERROR; 723 return; 724 } 725 c &= TTY_CHARMASK; 726 727 ++sc->sc_if.if_ibytes; 728 729 if (sc->sc_if.if_flags & IFF_DEBUG) { 730 if (c == ABT_ESC) { 731 /* 732 * If we have a previous abort, see whether 733 * this one is within the time limit. 734 */ 735 if (sc->sc_abortcount && 736 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 737 sc->sc_abortcount = 0; 738 /* 739 * If we see an abort after "idle" time, count it; 740 * record when the first abort escape arrived. 741 */ 742 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 743 if (++sc->sc_abortcount == 1) 744 sc->sc_starttime = time.tv_sec; 745 if (sc->sc_abortcount >= ABT_COUNT) { 746 slclose(tp); 747 return; 748 } 749 } 750 } else 751 sc->sc_abortcount = 0; 752 sc->sc_lasttime = time.tv_sec; 753 } 754 755 switch (c) { 756 757 case TRANS_FRAME_ESCAPE: 758 if (sc->sc_escape) 759 c = FRAME_ESCAPE; 760 break; 761 762 case TRANS_FRAME_END: 763 if (sc->sc_escape) 764 c = FRAME_END; 765 break; 766 767 case FRAME_ESCAPE: 768 sc->sc_escape = 1; 769 return; 770 771 case FRAME_END: 772 if(sc->sc_flags & SC_ERROR) { 773 sc->sc_flags &= ~SC_ERROR; 774 goto newpack; 775 } 776 len = sc->sc_mp - sc->sc_buf; 777 if (len < 3) 778 /* less than min length packet - ignore */ 779 goto newpack; 780 781#if NBPFILTER > 0 782 if (sc->sc_bpf) { 783 /* 784 * Save the compressed header, so we 785 * can tack it on later. Note that we 786 * will end up copying garbage in some 787 * cases but this is okay. We remember 788 * where the buffer started so we can 789 * compute the new header length. 790 */ 791 bcopy(sc->sc_buf, chdr, CHDR_LEN); 792 } 793#endif 794 795 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 796 if (c & 0x80) 797 c = TYPE_COMPRESSED_TCP; 798 else if (c == TYPE_UNCOMPRESSED_TCP) 799 *sc->sc_buf &= 0x4f; /* XXX */ 800 /* 801 * We've got something that's not an IP packet. 802 * If compression is enabled, try to decompress it. 803 * Otherwise, if `auto-enable' compression is on and 804 * it's a reasonable packet, decompress it and then 805 * enable compression. Otherwise, drop it. 806 */ 807 if (sc->sc_if.if_flags & SC_COMPRESS) { 808 len = sl_uncompress_tcp(&sc->sc_buf, len, 809 (u_int)c, &sc->sc_comp); 810 if (len <= 0) 811 goto error; 812 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 813 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 814 len = sl_uncompress_tcp(&sc->sc_buf, len, 815 (u_int)c, &sc->sc_comp); 816 if (len <= 0) 817 goto error; 818 sc->sc_if.if_flags |= SC_COMPRESS; 819 } else 820 goto error; 821 } 822#if NBPFILTER > 0 823 if (sc->sc_bpf) { 824 /* 825 * Put the SLIP pseudo-"link header" in place. 826 * We couldn't do this any earlier since 827 * decompression probably moved the buffer 828 * pointer. Then, invoke BPF. 829 */ 830 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 831 832 hp[SLX_DIR] = SLIPDIR_IN; 833 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 834 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 835 } 836#endif 837 m = sl_btom(sc, len); 838 if (m == NULL) 839 goto error; 840 841 sc->sc_if.if_ipackets++; 842 sc->sc_if.if_lastchange = time; 843 s = splimp(); 844 if (IF_QFULL(&ipintrq)) { 845 IF_DROP(&ipintrq); 846 sc->sc_if.if_ierrors++; 847 sc->sc_if.if_iqdrops++; 848 m_freem(m); 849 } else { 850 IF_ENQUEUE(&ipintrq, m); 851 schednetisr(NETISR_IP); 852 } 853 splx(s); 854 goto newpack; 855 } 856 if (sc->sc_mp < sc->sc_ep) { 857 *sc->sc_mp++ = c; 858 sc->sc_escape = 0; 859 return; 860 } 861 862 /* can't put lower; would miss an extra frame */ 863 sc->sc_flags |= SC_ERROR; 864 865error: 866 sc->sc_if.if_ierrors++; 867newpack: 868 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 869 sc->sc_escape = 0; 870} 871 872/* 873 * Process an ioctl request. 874 */ 875int 876slioctl(ifp, cmd, data) 877 register struct ifnet *ifp; 878 u_long cmd; 879 caddr_t data; 880{ 881 register struct ifaddr *ifa = (struct ifaddr *)data; 882 register struct ifreq *ifr; 883 register int s = splimp(), error = 0; 884 885 switch (cmd) { 886 887 case SIOCSIFADDR: 888 if (ifa->ifa_addr->sa_family == AF_INET) 889 ifp->if_flags |= IFF_UP; 890 else 891 error = EAFNOSUPPORT; 892 break; 893 894 case SIOCSIFDSTADDR: 895 if (ifa->ifa_addr->sa_family != AF_INET) 896 error = EAFNOSUPPORT; 897 break; 898 899 case SIOCADDMULTI: 900 case SIOCDELMULTI: 901 ifr = (struct ifreq *)data; 902 if (ifr == 0) { 903 error = EAFNOSUPPORT; /* XXX */ 904 break; 905 } 906 switch (ifr->ifr_addr.sa_family) { 907 908#ifdef INET 909 case AF_INET: 910 break; 911#endif 912 913 default: 914 error = EAFNOSUPPORT; 915 break; 916 } 917 break; 918 919 default: 920 error = EINVAL; 921 } 922 splx(s); 923 return (error); 924} 925#endif 926