1 /* $NetBSD: if_sl.c,v 1.55 1999/03/27 22:48:36 dbj 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 */ 185 186 struct 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 */ 192 193 static int slinit __P((struct sl_softc *)); 194 static struct mbuf *sl_btom __P((struct sl_softc *, int)); 195 196 /* 197 * Called from boot code to establish sl interfaces. 198 */ 199 void 200 slattach() 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 } 223 224 static int 225 slinit(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 */ 253 int 254 slopen(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*SLMAX 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*SLMAX+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, 2*SLMAX+2, 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 */ 314 void 315 slclose(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 */ 350 int 351 sltioctl(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 */ 376 int 377 sloutput(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 */ 449 void 450 slstart(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; 461 register int len = 0; 462 #endif 463 #ifndef __NetBSD__ /* XXX - cgd */ 464 extern int cfreecount; 465 #endif 466 #if NBPFILTER > 0 467 MALLOC(bpfbuf, u_char *, SLMAX + SLIP_HDRLEN, M_DEVBUF, M_NOWAIT); 468 #endif 469 470 for (;;) { 471 /* 472 * If there is more in the output queue, just send it now. 473 * We are being called in lieu of ttstart and must do what 474 * it would. 475 */ 476 if (tp->t_outq.c_cc != 0) { 477 (*tp->t_oproc)(tp); 478 if (tp->t_outq.c_cc > SLIP_HIWAT) { 479 #if NBPFILTER > 0 480 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 481 #endif 482 return; 483 } 484 } 485 /* 486 * This happens briefly when the line shuts down. 487 */ 488 if (sc == NULL) { 489 #if NBPFILTER > 0 490 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 491 #endif 492 return; 493 } 494 495 #ifdef __NetBSD__ /* XXX - cgd */ 496 /* 497 * Do not remove the packet from the IP queue if it 498 * doesn't look like the packet will fit into the 499 * current serial output queue, with a packet full of 500 * escapes this could be as bad as MTU*2+2. 501 */ 502 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*sc->sc_if.if_mtu+2) { 503 #if NBPFILTER > 0 504 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 505 #endif 506 return; 507 } 508 #endif /* __NetBSD__ */ 509 510 /* 511 * Get a packet and send it to the interface. 512 */ 513 s = splimp(); 514 IF_DEQUEUE(&sc->sc_fastq, m); 515 if (m) 516 sc->sc_if.if_omcasts++; /* XXX */ 517 else 518 IF_DEQUEUE(&sc->sc_if.if_snd, m); 519 splx(s); 520 if (m == NULL) { 521 #if NBPFILTER > 0 522 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 523 #endif 524 return; 525 } 526 527 /* 528 * We do the header compression here rather than in sloutput 529 * because the packets will be out of order if we are using TOS 530 * queueing, and the connection id compression will get 531 * munged when this happens. 532 */ 533 #if NBPFILTER > 0 534 if (sc->sc_bpf && bpfbuf != NULL) { 535 /* 536 * We need to save the TCP/IP header before it's 537 * compressed. To avoid complicated code, we just 538 * copy the entire packet into a stack buffer (since 539 * this is a serial line, packets should be short 540 * and/or the copy should be negligible cost compared 541 * to the packet transmission time). 542 */ 543 register struct mbuf *m1 = m; 544 register u_char *cp = bpfbuf + SLIP_HDRLEN; 545 546 len = 0; 547 do { 548 register int mlen = m1->m_len; 549 550 bcopy(mtod(m1, caddr_t), cp, mlen); 551 cp += mlen; 552 len += mlen; 553 } while ((m1 = m1->m_next) != NULL); 554 } 555 #endif 556 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 557 if (sc->sc_if.if_flags & SC_COMPRESS) 558 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 559 &sc->sc_comp, 1); 560 } 561 #if NBPFILTER > 0 562 if (sc->sc_bpf && bpfbuf != NULL) { 563 /* 564 * Put the SLIP pseudo-"link header" in place. The 565 * compressed header is now at the beginning of the 566 * mbuf. 567 */ 568 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 569 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 570 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 571 } 572 #endif 573 sc->sc_if.if_lastchange = time; 574 575 #ifndef __NetBSD__ /* XXX - cgd */ 576 /* 577 * If system is getting low on clists, just flush our 578 * output queue (if the stuff was important, it'll get 579 * retransmitted). 580 */ 581 if (cfreecount < CLISTRESERVE + SLMTU) { 582 m_freem(m); 583 sc->sc_if.if_collisions++; 584 continue; 585 } 586 #endif /* !__NetBSD__ */ 587 /* 588 * The extra FRAME_END will start up a new packet, and thus 589 * will flush any accumulated garbage. We do this whenever 590 * the line may have been idle for some time. 591 */ 592 if (tp->t_outq.c_cc == 0) { 593 ++sc->sc_if.if_obytes; 594 (void) putc(FRAME_END, &tp->t_outq); 595 } 596 597 while (m) { 598 register u_char *ep; 599 600 cp = mtod(m, u_char *); ep = cp + m->m_len; 601 while (cp < ep) { 602 /* 603 * Find out how many bytes in the string we can 604 * handle without doing something special. 605 */ 606 register u_char *bp = cp; 607 608 while (cp < ep) { 609 switch (*cp++) { 610 case FRAME_ESCAPE: 611 case FRAME_END: 612 --cp; 613 goto out; 614 } 615 } 616 out: 617 if (cp > bp) { 618 /* 619 * Put n characters at once 620 * into the tty output queue. 621 */ 622 #ifdef __NetBSD__ /* XXX - cgd */ 623 if (b_to_q((u_char *)bp, cp - bp, 624 #else 625 if (b_to_q((char *)bp, cp - bp, 626 #endif 627 &tp->t_outq)) 628 break; 629 sc->sc_if.if_obytes += cp - bp; 630 } 631 /* 632 * If there are characters left in the mbuf, 633 * the first one must be special.. 634 * Put it out in a different form. 635 */ 636 if (cp < ep) { 637 if (putc(FRAME_ESCAPE, &tp->t_outq)) 638 break; 639 if (putc(*cp++ == FRAME_ESCAPE ? 640 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 641 &tp->t_outq)) { 642 (void) unputc(&tp->t_outq); 643 break; 644 } 645 sc->sc_if.if_obytes += 2; 646 } 647 } 648 MFREE(m, m2); 649 m = m2; 650 } 651 652 if (putc(FRAME_END, &tp->t_outq)) { 653 /* 654 * Not enough room. Remove a char to make room 655 * and end the packet normally. 656 * If you get many collisions (more than one or two 657 * a day) you probably do not have enough clists 658 * and you should increase "nclist" in param.c. 659 */ 660 (void) unputc(&tp->t_outq); 661 (void) putc(FRAME_END, &tp->t_outq); 662 sc->sc_if.if_collisions++; 663 } else { 664 ++sc->sc_if.if_obytes; 665 sc->sc_if.if_opackets++; 666 } 667 } 668 } 669 670 /* 671 * Copy data buffer to mbuf chain; add ifnet pointer. 672 */ 673 static struct mbuf * 674 sl_btom(sc, len) 675 register struct sl_softc *sc; 676 register int len; 677 { 678 register struct mbuf *m; 679 register u_char *p; 680 681 MGETHDR(m, M_DONTWAIT, MT_DATA); 682 if (m == NULL) 683 return (NULL); 684 685 /* 686 * If we have more than MHLEN bytes, it's cheaper to 687 * queue the cluster we just filled & allocate a new one 688 * for the input buffer. Otherwise, fill the mbuf we 689 * allocated above. Note that code in the input routine 690 * guarantees that packet will fit in a cluster. 691 */ 692 if (len >= MHLEN) { 693 /* 694 * XXX this is that evil trick I mentioned... 695 */ 696 p = sc->sc_xxx; 697 sc->sc_xxx = (u_char *)malloc(MCLBYTES, M_MBUF, M_NOWAIT); 698 if (sc->sc_xxx == NULL) { 699 /* 700 * We couldn't allocate a new buffer - if 701 * memory's this low, it's time to start 702 * dropping packets. 703 */ 704 (void) m_free(m); 705 return (NULL); 706 } 707 sc->sc_ep = sc->sc_xxx + SLBUFSIZE; 708 MEXTADD(m, p, MCLBYTES, M_MBUF, NULL, NULL); 709 m->m_data = (caddr_t)sc->sc_buf; 710 } else 711 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 712 713 m->m_len = len; 714 m->m_pkthdr.len = len; 715 m->m_pkthdr.rcvif = &sc->sc_if; 716 return (m); 717 } 718 719 /* 720 * tty interface receiver interrupt. 721 */ 722 void 723 slinput(c, tp) 724 register int c; 725 register struct tty *tp; 726 { 727 register struct sl_softc *sc; 728 register struct mbuf *m; 729 register int len; 730 int s; 731 #if NBPFILTER > 0 732 u_char chdr[CHDR_LEN]; 733 #endif 734 735 tk_nin++; 736 sc = (struct sl_softc *)tp->t_sc; 737 if (sc == NULL) 738 return; 739 if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 && 740 (tp->t_cflag & CLOCAL) == 0)) { 741 sc->sc_flags |= SC_ERROR; 742 return; 743 } 744 c &= TTY_CHARMASK; 745 746 ++sc->sc_if.if_ibytes; 747 748 if (sc->sc_if.if_flags & IFF_DEBUG) { 749 if (c == ABT_ESC) { 750 /* 751 * If we have a previous abort, see whether 752 * this one is within the time limit. 753 */ 754 if (sc->sc_abortcount && 755 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 756 sc->sc_abortcount = 0; 757 /* 758 * If we see an abort after "idle" time, count it; 759 * record when the first abort escape arrived. 760 */ 761 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 762 if (++sc->sc_abortcount == 1) 763 sc->sc_starttime = time.tv_sec; 764 if (sc->sc_abortcount >= ABT_COUNT) { 765 slclose(tp); 766 return; 767 } 768 } 769 } else 770 sc->sc_abortcount = 0; 771 sc->sc_lasttime = time.tv_sec; 772 } 773 774 switch (c) { 775 776 case TRANS_FRAME_ESCAPE: 777 if (sc->sc_escape) 778 c = FRAME_ESCAPE; 779 break; 780 781 case TRANS_FRAME_END: 782 if (sc->sc_escape) 783 c = FRAME_END; 784 break; 785 786 case FRAME_ESCAPE: 787 sc->sc_escape = 1; 788 return; 789 790 case FRAME_END: 791 if(sc->sc_flags & SC_ERROR) { 792 sc->sc_flags &= ~SC_ERROR; 793 goto newpack; 794 } 795 len = sc->sc_mp - sc->sc_buf; 796 if (len < 3) 797 /* less than min length packet - ignore */ 798 goto newpack; 799 800 #if NBPFILTER > 0 801 if (sc->sc_bpf) { 802 /* 803 * Save the compressed header, so we 804 * can tack it on later. Note that we 805 * will end up copying garbage in some 806 * cases but this is okay. We remember 807 * where the buffer started so we can 808 * compute the new header length. 809 */ 810 bcopy(sc->sc_buf, chdr, CHDR_LEN); 811 } 812 #endif 813 814 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 815 if (c & 0x80) 816 c = TYPE_COMPRESSED_TCP; 817 else if (c == TYPE_UNCOMPRESSED_TCP) 818 *sc->sc_buf &= 0x4f; /* XXX */ 819 /* 820 * We've got something that's not an IP packet. 821 * If compression is enabled, try to decompress it. 822 * Otherwise, if `auto-enable' compression is on and 823 * it's a reasonable packet, decompress it and then 824 * enable compression. Otherwise, drop it. 825 */ 826 if (sc->sc_if.if_flags & SC_COMPRESS) { 827 len = sl_uncompress_tcp(&sc->sc_buf, len, 828 (u_int)c, &sc->sc_comp); 829 if (len <= 0) 830 goto error; 831 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 832 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 833 len = sl_uncompress_tcp(&sc->sc_buf, len, 834 (u_int)c, &sc->sc_comp); 835 if (len <= 0) 836 goto error; 837 sc->sc_if.if_flags |= SC_COMPRESS; 838 } else 839 goto error; 840 } 841 #if NBPFILTER > 0 842 if (sc->sc_bpf) { 843 /* 844 * Put the SLIP pseudo-"link header" in place. 845 * We couldn't do this any earlier since 846 * decompression probably moved the buffer 847 * pointer. Then, invoke BPF. 848 */ 849 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 850 851 hp[SLX_DIR] = SLIPDIR_IN; 852 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 853 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 854 } 855 #endif 856 m = sl_btom(sc, len); 857 if (m == NULL) 858 goto error; 859 860 sc->sc_if.if_ipackets++; 861 sc->sc_if.if_lastchange = time; 862 s = splimp(); 863 if (IF_QFULL(&ipintrq)) { 864 IF_DROP(&ipintrq); 865 sc->sc_if.if_ierrors++; 866 sc->sc_if.if_iqdrops++; 867 m_freem(m); 868 } else { 869 IF_ENQUEUE(&ipintrq, m); 870 schednetisr(NETISR_IP); 871 } 872 splx(s); 873 goto newpack; 874 } 875 if (sc->sc_mp < sc->sc_ep) { 876 *sc->sc_mp++ = c; 877 sc->sc_escape = 0; 878 return; 879 } 880 881 /* can't put lower; would miss an extra frame */ 882 sc->sc_flags |= SC_ERROR; 883 884 error: 885 sc->sc_if.if_ierrors++; 886 newpack: 887 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 888 sc->sc_escape = 0; 889 } 890 891 /* 892 * Process an ioctl request. 893 */ 894 int 895 slioctl(ifp, cmd, data) 896 register struct ifnet *ifp; 897 u_long cmd; 898 caddr_t data; 899 { 900 register struct ifaddr *ifa = (struct ifaddr *)data; 901 register struct ifreq *ifr = (struct ifreq *)data; 902 register int s = splimp(), error = 0; 903 register struct sl_softc *sc = ifp->if_softc; 904 905 switch (cmd) { 906 907 case SIOCSIFADDR: 908 if (ifa->ifa_addr->sa_family == AF_INET) 909 ifp->if_flags |= IFF_UP; 910 else 911 error = EAFNOSUPPORT; 912 break; 913 914 case SIOCSIFDSTADDR: 915 if (ifa->ifa_addr->sa_family != AF_INET) 916 error = EAFNOSUPPORT; 917 break; 918 919 case SIOCSIFMTU: 920 if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) { 921 error = EINVAL; 922 break; 923 } 924 sc->sc_if.if_mtu = ifr->ifr_mtu; 925 break; 926 927 case SIOCGIFMTU: 928 ifr->ifr_mtu = sc->sc_if.if_mtu; 929 break; 930 931 case SIOCADDMULTI: 932 case SIOCDELMULTI: 933 if (ifr == 0) { 934 error = EAFNOSUPPORT; /* XXX */ 935 break; 936 } 937 switch (ifr->ifr_addr.sa_family) { 938 939 #ifdef INET 940 case AF_INET: 941 break; 942 #endif 943 944 default: 945 error = EAFNOSUPPORT; 946 break; 947 } 948 break; 949 950 default: 951 error = EINVAL; 952 } 953 splx(s); 954 return (error); 955 } 956 #endif 957