if_sl.c revision 1.57
1/* $NetBSD: if_sl.c,v 1.57 2000/03/30 09:45:36 augustss 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#if __NetBSD__ 87#include <sys/systm.h> 88#endif 89 90#include <machine/cpu.h> 91 92#include <net/if.h> 93#include <net/if_types.h> 94#include <net/netisr.h> 95#include <net/route.h> 96 97#ifdef INET 98#include <netinet/in.h> 99#include <netinet/in_systm.h> 100#include <netinet/in_var.h> 101#include <netinet/ip.h> 102#else 103#error Slip without inet? 104#endif 105 106#include <net/slcompress.h> 107#include <net/if_slvar.h> 108#include <net/slip.h> 109 110#if NBPFILTER > 0 111#include <sys/time.h> 112#include <net/bpf.h> 113#endif 114 115/* 116 * SLMAX is a hard limit on input packet size. To simplify the code 117 * and improve performance, we require that packets fit in an mbuf 118 * cluster, and if we get a compressed packet, there's enough extra 119 * room to expand the header into a max length tcp/ip header (128 120 * bytes). So, SLMAX can be at most 121 * MCLBYTES - 128 122 * 123 * SLMTU is a hard limit on output packet size. To insure good 124 * interactive response, SLMTU wants to be the smallest size that 125 * amortizes the header cost. (Remember that even with 126 * type-of-service queuing, we have to wait for any in-progress 127 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 128 * cps, where cps is the line speed in characters per second. 129 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 130 * average compressed header size is 6-8 bytes so any MTU > 90 131 * bytes will give us 90% of the line bandwidth. A 100ms wait is 132 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 133 * will send 256 byte segments (to allow for 40 byte headers), the 134 * typical packet size on the wire will be around 260 bytes). In 135 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 136 * leave the interface MTU relatively high (so we don't IP fragment 137 * when acting as a gateway to someone using a stupid MTU). 138 * 139 * Similar considerations apply to SLIP_HIWAT: It's the amount of 140 * data that will be queued 'downstream' of us (i.e., in clists 141 * waiting to be picked up by the tty output interrupt). If we 142 * queue a lot of data downstream, it's immune to our t.o.s. queuing. 143 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 144 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 145 * wait is dependent on the ftp window size but that's typically 146 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 147 * the cost (in idle time on the wire) of the tty driver running 148 * off the end of its clists & having to call back slstart for a 149 * new packet. For a tty interface with any buffering at all, this 150 * cost will be zero. Even with a totally brain dead interface (like 151 * the one on a typical workstation), the cost will be <= 1 character 152 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 153 * at most 1% while maintaining good interactive response. 154 */ 155#if NBPFILTER > 0 156#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 157#else 158#define BUFOFFSET (128+sizeof(struct ifnet **)) 159#endif 160#define SLMAX (MCLBYTES - BUFOFFSET) 161#define SLBUFSIZE (SLMAX + BUFOFFSET) 162#ifndef SLMTU 163#define SLMTU 296 164#endif 165#if (SLMTU < 3) 166#error SLMTU way too small. 167#endif 168#define SLIP_HIWAT roundup(50,CBSIZE) 169#ifndef __NetBSD__ /* XXX - cgd */ 170#define CLISTRESERVE 1024 /* Can't let clists get too low */ 171#endif /* !__NetBSD__ */ 172 173/* 174 * SLIP ABORT ESCAPE MECHANISM: 175 * (inspired by HAYES modem escape arrangement) 176 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 177 * within window time signals a "soft" exit from slip mode by remote end 178 * if the IFF_DEBUG flag is on. 179 */ 180#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 181#define ABT_IDLE 1 /* in seconds - idle before an escape */ 182#define ABT_COUNT 3 /* count of escapes for abort */ 183#define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 184 185struct sl_softc sl_softc[NSL]; 186 187#define FRAME_END 0xc0 /* Frame End */ 188#define FRAME_ESCAPE 0xdb /* Frame Esc */ 189#define TRANS_FRAME_END 0xdc /* transposed frame end */ 190#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 191 192static int slinit __P((struct sl_softc *)); 193static struct mbuf *sl_btom __P((struct sl_softc *, int)); 194 195/* 196 * Called from boot code to establish sl interfaces. 197 */ 198void 199slattach() 200{ 201 struct sl_softc *sc; 202 int i = 0; 203 204 for (sc = sl_softc; i < NSL; sc++) { 205 sc->sc_unit = i; /* XXX */ 206 sprintf(sc->sc_if.if_xname, "sl%d", i++); 207 sc->sc_if.if_softc = sc; 208 sc->sc_if.if_mtu = SLMTU; 209 sc->sc_if.if_flags = 210 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 211 sc->sc_if.if_type = IFT_SLIP; 212 sc->sc_if.if_ioctl = slioctl; 213 sc->sc_if.if_output = sloutput; 214 sc->sc_if.if_snd.ifq_maxlen = 50; 215 sc->sc_fastq.ifq_maxlen = 32; 216 if_attach(&sc->sc_if); 217#if NBPFILTER > 0 218 bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 219#endif 220 } 221} 222 223static int 224slinit(sc) 225 struct sl_softc *sc; 226{ 227 228 if (sc->sc_ep == NULL) { 229 /* 230 * XXX the trick this is used for is evil... 231 */ 232 sc->sc_xxx = (u_char *)malloc(MCLBYTES, M_MBUF, M_WAITOK); 233 if (sc->sc_xxx) 234 sc->sc_ep = sc->sc_xxx + SLBUFSIZE; 235 else { 236 printf("sl%d: can't allocate buffer\n", sc->sc_unit); 237 sc->sc_if.if_flags &= ~IFF_UP; 238 return (0); 239 } 240 } 241 sc->sc_buf = sc->sc_ep - SLMAX; 242 sc->sc_mp = sc->sc_buf; 243 sl_compress_init(&sc->sc_comp); 244 return (1); 245} 246 247/* 248 * Line specific open routine. 249 * Attach the given tty to the first available sl unit. 250 */ 251/* ARGSUSED */ 252int 253slopen(dev, tp) 254 dev_t dev; 255 struct tty *tp; 256{ 257 struct proc *p = curproc; /* XXX */ 258 struct sl_softc *sc; 259 int nsl; 260 int error; 261 int s; 262 263 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 264 return (error); 265 266 if (tp->t_line == SLIPDISC) 267 return (0); 268 269 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 270 if (sc->sc_ttyp == NULL) { 271 if (slinit(sc) == 0) 272 return (ENOBUFS); 273 tp->t_sc = (caddr_t)sc; 274 sc->sc_ttyp = tp; 275 sc->sc_if.if_baudrate = tp->t_ospeed; 276 s = spltty(); 277 tp->t_state |= TS_ISOPEN | TS_XCLUDE; 278 splx(s); 279 ttyflush(tp, FREAD | FWRITE); 280#ifdef __NetBSD__ 281 /* 282 * make sure tty output queue is large enough 283 * to hold a full-sized packet (including frame 284 * end, and a possible extra frame end). full-sized 285 * packet occupies a max of 2*SLMAX bytes (because 286 * of possible escapes), and add two on for frame 287 * ends. 288 */ 289 s = spltty(); 290 if (tp->t_outq.c_cn < 2*SLMAX+2) { 291 sc->sc_oldbufsize = tp->t_outq.c_cn; 292 sc->sc_oldbufquot = tp->t_outq.c_cq != 0; 293 294 clfree(&tp->t_outq); 295 error = clalloc(&tp->t_outq, 2*SLMAX+2, 0); 296 if (error) { 297 splx(s); 298 return(error); 299 } 300 } else 301 sc->sc_oldbufsize = sc->sc_oldbufquot = 0; 302 splx(s); 303#endif /* __NetBSD__ */ 304 return (0); 305 } 306 return (ENXIO); 307} 308 309/* 310 * Line specific close routine. 311 * Detach the tty from the sl unit. 312 */ 313void 314slclose(tp) 315 struct tty *tp; 316{ 317 struct sl_softc *sc; 318 int s; 319 320 ttywflush(tp); 321 s = splimp(); /* actually, max(spltty, splsoftnet) */ 322 tp->t_line = 0; 323 tp->t_state = 0; 324 sc = (struct sl_softc *)tp->t_sc; 325 if (sc != NULL) { 326 if_down(&sc->sc_if); 327 sc->sc_ttyp = NULL; 328 tp->t_sc = NULL; 329 free((caddr_t)(sc->sc_ep - SLBUFSIZE), M_MBUF); 330 sc->sc_ep = 0; 331 sc->sc_mp = 0; 332 sc->sc_buf = 0; 333 } 334#ifdef __NetBSD__ 335 /* if necessary, install a new outq buffer of the appropriate size */ 336 if (sc->sc_oldbufsize != 0) { 337 clfree(&tp->t_outq); 338 clalloc(&tp->t_outq, sc->sc_oldbufsize, sc->sc_oldbufquot); 339 } 340#endif 341 splx(s); 342} 343 344/* 345 * Line specific (tty) ioctl routine. 346 * Provide a way to get the sl unit number. 347 */ 348/* ARGSUSED */ 349int 350sltioctl(tp, cmd, data, flag) 351 struct tty *tp; 352 u_long cmd; 353 caddr_t data; 354 int flag; 355{ 356 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 357 358 switch (cmd) { 359 case SLIOCGUNIT: 360 *(int *)data = sc->sc_unit; /* XXX */ 361 break; 362 363 default: 364 return (-1); 365 } 366 return (0); 367} 368 369/* 370 * Queue a packet. Start transmission if not active. 371 * Compression happens in slstart; if we do it here, IP TOS 372 * will cause us to not compress "background" packets, because 373 * ordering gets trashed. It can be done for all packets in slstart. 374 */ 375int 376sloutput(ifp, m, dst, rtp) 377 struct ifnet *ifp; 378 struct mbuf *m; 379 struct sockaddr *dst; 380 struct rtentry *rtp; 381{ 382 struct sl_softc *sc = ifp->if_softc; 383 struct ip *ip; 384 struct ifqueue *ifq; 385 int s; 386 387 /* 388 * `Cannot happen' (see slioctl). Someday we will extend 389 * the line protocol to support other address families. 390 */ 391 if (dst->sa_family != AF_INET) { 392 printf("%s: af%d not supported\n", sc->sc_if.if_xname, 393 dst->sa_family); 394 m_freem(m); 395 sc->sc_if.if_noproto++; 396 return (EAFNOSUPPORT); 397 } 398 399 if (sc->sc_ttyp == NULL) { 400 m_freem(m); 401 return (ENETDOWN); /* sort of */ 402 } 403 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 404 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 405 m_freem(m); 406 printf("%s: no carrier and not local\n", sc->sc_if.if_xname); 407 return (EHOSTUNREACH); 408 } 409 ifq = &sc->sc_if.if_snd; 410 ip = mtod(m, struct ip *); 411 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 412 m_freem(m); 413 return (ENETRESET); /* XXX ? */ 414 } 415 if (ip->ip_tos & IPTOS_LOWDELAY) 416 ifq = &sc->sc_fastq; 417 s = splimp(); 418 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) { 419 struct timeval tv; 420 421 /* if output's been stalled for too long, and restart */ 422 timersub(&time, &sc->sc_if.if_lastchange, &tv); 423 if (tv.tv_sec > 0) { 424 sc->sc_otimeout++; 425 slstart(sc->sc_ttyp); 426 } 427 } 428 if (IF_QFULL(ifq)) { 429 IF_DROP(ifq); 430 m_freem(m); 431 splx(s); 432 sc->sc_if.if_oerrors++; 433 return (ENOBUFS); 434 } 435 IF_ENQUEUE(ifq, m); 436 sc->sc_if.if_lastchange = time; 437 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) 438 slstart(sc->sc_ttyp); 439 splx(s); 440 return (0); 441} 442 443/* 444 * Start output on interface. Get another datagram 445 * to send from the interface queue and map it to 446 * the interface before starting output. 447 */ 448void 449slstart(tp) 450 struct tty *tp; 451{ 452 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 453 struct mbuf *m; 454 u_char *cp; 455 struct ip *ip; 456 int s; 457 struct mbuf *m2; 458#if NBPFILTER > 0 459 u_char *bpfbuf; 460 int len = 0; 461#endif 462#ifndef __NetBSD__ /* XXX - cgd */ 463 extern int cfreecount; 464#endif 465#if NBPFILTER > 0 466 MALLOC(bpfbuf, u_char *, SLMAX + SLIP_HDRLEN, M_DEVBUF, M_NOWAIT); 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#if NBPFILTER > 0 479 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 480#endif 481 return; 482 } 483 } 484 /* 485 * This happens briefly when the line shuts down. 486 */ 487 if (sc == NULL) { 488#if NBPFILTER > 0 489 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 490#endif 491 return; 492 } 493 494#ifdef __NetBSD__ /* XXX - cgd */ 495 /* 496 * Do not remove the packet from the IP queue if it 497 * doesn't look like the packet will fit into the 498 * current serial output queue, with a packet full of 499 * escapes this could be as bad as MTU*2+2. 500 */ 501 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*sc->sc_if.if_mtu+2) { 502#if NBPFILTER > 0 503 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 504#endif 505 return; 506 } 507#endif /* __NetBSD__ */ 508 509 /* 510 * Get a packet and send it to the interface. 511 */ 512 s = splimp(); 513 IF_DEQUEUE(&sc->sc_fastq, m); 514 if (m) 515 sc->sc_if.if_omcasts++; /* XXX */ 516 else 517 IF_DEQUEUE(&sc->sc_if.if_snd, m); 518 splx(s); 519 if (m == NULL) { 520#if NBPFILTER > 0 521 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 522#endif 523 return; 524 } 525 526 /* 527 * We do the header compression here rather than in sloutput 528 * because the packets will be out of order if we are using TOS 529 * queueing, and the connection id compression will get 530 * munged when this happens. 531 */ 532#if NBPFILTER > 0 533 if (sc->sc_bpf && bpfbuf != NULL) { 534 /* 535 * We need to save the TCP/IP header before it's 536 * compressed. To avoid complicated code, we just 537 * copy the entire packet into a stack buffer (since 538 * this is a serial line, packets should be short 539 * and/or the copy should be negligible cost compared 540 * to the packet transmission time). 541 */ 542 struct mbuf *m1 = m; 543 u_char *cp = bpfbuf + SLIP_HDRLEN; 544 545 len = 0; 546 do { 547 int mlen = m1->m_len; 548 549 bcopy(mtod(m1, caddr_t), cp, mlen); 550 cp += mlen; 551 len += mlen; 552 } while ((m1 = m1->m_next) != NULL); 553 } 554#endif 555 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 556 if (sc->sc_if.if_flags & SC_COMPRESS) 557 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 558 &sc->sc_comp, 1); 559 } 560#if NBPFILTER > 0 561 if (sc->sc_bpf && bpfbuf != NULL) { 562 /* 563 * Put the SLIP pseudo-"link header" in place. The 564 * compressed header is now at the beginning of the 565 * mbuf. 566 */ 567 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 568 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 569 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 570 } 571#endif 572 sc->sc_if.if_lastchange = time; 573 574#ifndef __NetBSD__ /* XXX - cgd */ 575 /* 576 * If system is getting low on clists, just flush our 577 * output queue (if the stuff was important, it'll get 578 * retransmitted). 579 */ 580 if (cfreecount < CLISTRESERVE + SLMTU) { 581 m_freem(m); 582 sc->sc_if.if_collisions++; 583 continue; 584 } 585#endif /* !__NetBSD__ */ 586 /* 587 * The extra FRAME_END will start up a new packet, and thus 588 * will flush any accumulated garbage. We do this whenever 589 * the line may have been idle for some time. 590 */ 591 if (tp->t_outq.c_cc == 0) { 592 ++sc->sc_if.if_obytes; 593 (void) putc(FRAME_END, &tp->t_outq); 594 } 595 596 while (m) { 597 u_char *ep; 598 599 cp = mtod(m, u_char *); ep = cp + m->m_len; 600 while (cp < ep) { 601 /* 602 * Find out how many bytes in the string we can 603 * handle without doing something special. 604 */ 605 u_char *bp = cp; 606 607 while (cp < ep) { 608 switch (*cp++) { 609 case FRAME_ESCAPE: 610 case FRAME_END: 611 --cp; 612 goto out; 613 } 614 } 615 out: 616 if (cp > bp) { 617 /* 618 * Put n characters at once 619 * into the tty output queue. 620 */ 621#ifdef __NetBSD__ /* XXX - cgd */ 622 if (b_to_q((u_char *)bp, cp - bp, 623#else 624 if (b_to_q((char *)bp, cp - bp, 625#endif 626 &tp->t_outq)) 627 break; 628 sc->sc_if.if_obytes += cp - bp; 629 } 630 /* 631 * If there are characters left in the mbuf, 632 * the first one must be special.. 633 * Put it out in a different form. 634 */ 635 if (cp < ep) { 636 if (putc(FRAME_ESCAPE, &tp->t_outq)) 637 break; 638 if (putc(*cp++ == FRAME_ESCAPE ? 639 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 640 &tp->t_outq)) { 641 (void) unputc(&tp->t_outq); 642 break; 643 } 644 sc->sc_if.if_obytes += 2; 645 } 646 } 647 MFREE(m, m2); 648 m = m2; 649 } 650 651 if (putc(FRAME_END, &tp->t_outq)) { 652 /* 653 * Not enough room. Remove a char to make room 654 * and end the packet normally. 655 * If you get many collisions (more than one or two 656 * a day) you probably do not have enough clists 657 * and you should increase "nclist" in param.c. 658 */ 659 (void) unputc(&tp->t_outq); 660 (void) putc(FRAME_END, &tp->t_outq); 661 sc->sc_if.if_collisions++; 662 } else { 663 ++sc->sc_if.if_obytes; 664 sc->sc_if.if_opackets++; 665 } 666 } 667} 668 669/* 670 * Copy data buffer to mbuf chain; add ifnet pointer. 671 */ 672static struct mbuf * 673sl_btom(sc, len) 674 struct sl_softc *sc; 675 int len; 676{ 677 struct mbuf *m; 678 u_char *p; 679 680 MGETHDR(m, M_DONTWAIT, MT_DATA); 681 if (m == NULL) 682 return (NULL); 683 684 /* 685 * If we have more than MHLEN bytes, it's cheaper to 686 * queue the cluster we just filled & allocate a new one 687 * for the input buffer. Otherwise, fill the mbuf we 688 * allocated above. Note that code in the input routine 689 * guarantees that packet will fit in a cluster. 690 */ 691 if (len >= MHLEN) { 692 /* 693 * XXX this is that evil trick I mentioned... 694 */ 695 p = sc->sc_xxx; 696 sc->sc_xxx = (u_char *)malloc(MCLBYTES, M_MBUF, M_NOWAIT); 697 if (sc->sc_xxx == NULL) { 698 /* 699 * We couldn't allocate a new buffer - if 700 * memory's this low, it's time to start 701 * dropping packets. 702 */ 703 (void) m_free(m); 704 return (NULL); 705 } 706 sc->sc_ep = sc->sc_xxx + SLBUFSIZE; 707 MEXTADD(m, p, MCLBYTES, M_MBUF, NULL, NULL); 708 m->m_data = (caddr_t)sc->sc_buf; 709 } else 710 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 711 712 m->m_len = len; 713 m->m_pkthdr.len = len; 714 m->m_pkthdr.rcvif = &sc->sc_if; 715 return (m); 716} 717 718/* 719 * tty interface receiver interrupt. 720 */ 721void 722slinput(c, tp) 723 int c; 724 struct tty *tp; 725{ 726 struct sl_softc *sc; 727 struct mbuf *m; 728 int len; 729 int s; 730#if NBPFILTER > 0 731 u_char chdr[CHDR_LEN]; 732#endif 733 734 tk_nin++; 735 sc = (struct sl_softc *)tp->t_sc; 736 if (sc == NULL) 737 return; 738 if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 && 739 (tp->t_cflag & CLOCAL) == 0)) { 740 sc->sc_flags |= SC_ERROR; 741 return; 742 } 743 c &= TTY_CHARMASK; 744 745 ++sc->sc_if.if_ibytes; 746 747 if (sc->sc_if.if_flags & IFF_DEBUG) { 748 if (c == ABT_ESC) { 749 /* 750 * If we have a previous abort, see whether 751 * this one is within the time limit. 752 */ 753 if (sc->sc_abortcount && 754 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 755 sc->sc_abortcount = 0; 756 /* 757 * If we see an abort after "idle" time, count it; 758 * record when the first abort escape arrived. 759 */ 760 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 761 if (++sc->sc_abortcount == 1) 762 sc->sc_starttime = time.tv_sec; 763 if (sc->sc_abortcount >= ABT_COUNT) { 764 slclose(tp); 765 return; 766 } 767 } 768 } else 769 sc->sc_abortcount = 0; 770 sc->sc_lasttime = time.tv_sec; 771 } 772 773 switch (c) { 774 775 case TRANS_FRAME_ESCAPE: 776 if (sc->sc_escape) 777 c = FRAME_ESCAPE; 778 break; 779 780 case TRANS_FRAME_END: 781 if (sc->sc_escape) 782 c = FRAME_END; 783 break; 784 785 case FRAME_ESCAPE: 786 sc->sc_escape = 1; 787 return; 788 789 case FRAME_END: 790 if(sc->sc_flags & SC_ERROR) { 791 sc->sc_flags &= ~SC_ERROR; 792 goto newpack; 793 } 794 len = sc->sc_mp - sc->sc_buf; 795 if (len < 3) 796 /* less than min length packet - ignore */ 797 goto newpack; 798 799#if NBPFILTER > 0 800 if (sc->sc_bpf) { 801 /* 802 * Save the compressed header, so we 803 * can tack it on later. Note that we 804 * will end up copying garbage in some 805 * cases but this is okay. We remember 806 * where the buffer started so we can 807 * compute the new header length. 808 */ 809 bcopy(sc->sc_buf, chdr, CHDR_LEN); 810 } 811#endif 812 813 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 814 if (c & 0x80) 815 c = TYPE_COMPRESSED_TCP; 816 else if (c == TYPE_UNCOMPRESSED_TCP) 817 *sc->sc_buf &= 0x4f; /* XXX */ 818 /* 819 * We've got something that's not an IP packet. 820 * If compression is enabled, try to decompress it. 821 * Otherwise, if `auto-enable' compression is on and 822 * it's a reasonable packet, decompress it and then 823 * enable compression. Otherwise, drop it. 824 */ 825 if (sc->sc_if.if_flags & SC_COMPRESS) { 826 len = sl_uncompress_tcp(&sc->sc_buf, len, 827 (u_int)c, &sc->sc_comp); 828 if (len <= 0) 829 goto error; 830 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 831 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 832 len = sl_uncompress_tcp(&sc->sc_buf, len, 833 (u_int)c, &sc->sc_comp); 834 if (len <= 0) 835 goto error; 836 sc->sc_if.if_flags |= SC_COMPRESS; 837 } else 838 goto error; 839 } 840#if NBPFILTER > 0 841 if (sc->sc_bpf) { 842 /* 843 * Put the SLIP pseudo-"link header" in place. 844 * We couldn't do this any earlier since 845 * decompression probably moved the buffer 846 * pointer. Then, invoke BPF. 847 */ 848 u_char *hp = sc->sc_buf - SLIP_HDRLEN; 849 850 hp[SLX_DIR] = SLIPDIR_IN; 851 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 852 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 853 } 854#endif 855 m = sl_btom(sc, len); 856 if (m == NULL) 857 goto error; 858 859 sc->sc_if.if_ipackets++; 860 sc->sc_if.if_lastchange = time; 861 s = splimp(); 862 if (IF_QFULL(&ipintrq)) { 863 IF_DROP(&ipintrq); 864 sc->sc_if.if_ierrors++; 865 sc->sc_if.if_iqdrops++; 866 m_freem(m); 867 } else { 868 IF_ENQUEUE(&ipintrq, m); 869 schednetisr(NETISR_IP); 870 } 871 splx(s); 872 goto newpack; 873 } 874 if (sc->sc_mp < sc->sc_ep) { 875 *sc->sc_mp++ = c; 876 sc->sc_escape = 0; 877 return; 878 } 879 880 /* can't put lower; would miss an extra frame */ 881 sc->sc_flags |= SC_ERROR; 882 883error: 884 sc->sc_if.if_ierrors++; 885newpack: 886 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 887 sc->sc_escape = 0; 888} 889 890/* 891 * Process an ioctl request. 892 */ 893int 894slioctl(ifp, cmd, data) 895 struct ifnet *ifp; 896 u_long cmd; 897 caddr_t data; 898{ 899 struct ifaddr *ifa = (struct ifaddr *)data; 900 struct ifreq *ifr = (struct ifreq *)data; 901 int s = splimp(), error = 0; 902 struct sl_softc *sc = ifp->if_softc; 903 904 switch (cmd) { 905 906 case SIOCSIFADDR: 907 if (ifa->ifa_addr->sa_family == AF_INET) 908 ifp->if_flags |= IFF_UP; 909 else 910 error = EAFNOSUPPORT; 911 break; 912 913 case SIOCSIFDSTADDR: 914 if (ifa->ifa_addr->sa_family != AF_INET) 915 error = EAFNOSUPPORT; 916 break; 917 918 case SIOCSIFMTU: 919 if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) { 920 error = EINVAL; 921 break; 922 } 923 sc->sc_if.if_mtu = ifr->ifr_mtu; 924 break; 925 926 case SIOCGIFMTU: 927 ifr->ifr_mtu = sc->sc_if.if_mtu; 928 break; 929 930 case SIOCADDMULTI: 931 case SIOCDELMULTI: 932 if (ifr == 0) { 933 error = EAFNOSUPPORT; /* XXX */ 934 break; 935 } 936 switch (ifr->ifr_addr.sa_family) { 937 938#ifdef INET 939 case AF_INET: 940 break; 941#endif 942 943 default: 944 error = EAFNOSUPPORT; 945 break; 946 } 947 break; 948 949 default: 950 error = EINVAL; 951 } 952 splx(s); 953 return (error); 954} 955#endif 956