1 /* $NetBSD: if_sl.c,v 1.35 1995/03/21 13:34:02 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1989, 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)if_sl.c 8.6 (Berkeley) 2/1/94 36 */ 37 38 /* 39 * Serial Line interface 40 * 41 * Rick Adams 42 * Center for Seismic Studies 43 * 1300 N 17th Street, Suite 1450 44 * Arlington, Virginia 22209 45 * (703)276-7900 46 * rick@seismo.ARPA 47 * seismo!rick 48 * 49 * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris). 50 * N.B.: this belongs in netinet, not net, the way it stands now. 51 * Should have a link-layer type designation, but wouldn't be 52 * backwards-compatible. 53 * 54 * Converted to 4.3BSD Beta by Chris Torek. 55 * Other changes made at Berkeley, based in part on code by Kirk Smith. 56 * W. Jolitz added slip abort. 57 * 58 * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov). 59 * Added priority queuing for "interactive" traffic; hooks for TCP 60 * header compression; ICMP filtering (at 2400 baud, some cretin 61 * pinging you can use up all your bandwidth). Made low clist behavior 62 * more robust and slightly less likely to hang serial line. 63 * Sped up a bunch of things. 64 * 65 * Note that splimp() is used throughout to block both (tty) input 66 * interrupts and network activity; thus, splimp must be >= spltty. 67 */ 68 69 #include "sl.h" 70 #if NSL > 0 71 72 #include "bpfilter.h" 73 74 #include <sys/param.h> 75 #include <sys/proc.h> 76 #include <sys/mbuf.h> 77 #include <sys/buf.h> 78 #include <sys/dkstat.h> 79 #include <sys/socket.h> 80 #include <sys/ioctl.h> 81 #include <sys/file.h> 82 #include <sys/tty.h> 83 #include <sys/kernel.h> 84 #include <sys/conf.h> 85 86 #include <machine/cpu.h> 87 88 #include <net/if.h> 89 #include <net/if_types.h> 90 #include <net/netisr.h> 91 #include <net/route.h> 92 93 #if INET 94 #include <netinet/in.h> 95 #include <netinet/in_systm.h> 96 #include <netinet/in_var.h> 97 #include <netinet/ip.h> 98 #else 99 Huh? Slip without inet? 100 #endif 101 102 #include <net/slcompress.h> 103 #include <net/if_slvar.h> 104 #include <net/slip.h> 105 106 #if NBPFILTER > 0 107 #include <sys/time.h> 108 #include <net/bpf.h> 109 #endif 110 111 /* 112 * SLMAX is a hard limit on input packet size. To simplify the code 113 * and improve performance, we require that packets fit in an mbuf 114 * cluster, and if we get a compressed packet, there's enough extra 115 * room to expand the header into a max length tcp/ip header (128 116 * bytes). So, SLMAX can be at most 117 * MCLBYTES - 128 118 * 119 * SLMTU is a hard limit on output packet size. To insure good 120 * interactive response, SLMTU wants to be the smallest size that 121 * amortizes the header cost. (Remember that even with 122 * type-of-service queuing, we have to wait for any in-progress 123 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 124 * cps, where cps is the line speed in characters per second. 125 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 126 * average compressed header size is 6-8 bytes so any MTU > 90 127 * bytes will give us 90% of the line bandwidth. A 100ms wait is 128 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 129 * will send 256 byte segments (to allow for 40 byte headers), the 130 * typical packet size on the wire will be around 260 bytes). In 131 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 132 * leave the interface MTU relatively high (so we don't IP fragment 133 * when acting as a gateway to someone using a stupid MTU). 134 * 135 * Similar considerations apply to SLIP_HIWAT: It's the amount of 136 * data that will be queued 'downstream' of us (i.e., in clists 137 * waiting to be picked up by the tty output interrupt). If we 138 * queue a lot of data downstream, it's immune to our t.o.s. queuing. 139 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 140 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 141 * wait is dependent on the ftp window size but that's typically 142 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 143 * the cost (in idle time on the wire) of the tty driver running 144 * off the end of its clists & having to call back slstart for a 145 * new packet. For a tty interface with any buffering at all, this 146 * cost will be zero. Even with a totally brain dead interface (like 147 * the one on a typical workstation), the cost will be <= 1 character 148 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 149 * at most 1% while maintaining good interactive response. 150 */ 151 #if NBPFILTER > 0 152 #define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 153 #else 154 #define BUFOFFSET (128+sizeof(struct ifnet **)) 155 #endif 156 #define SLMAX (MCLBYTES - BUFOFFSET) 157 #define SLBUFSIZE (SLMAX + BUFOFFSET) 158 #ifndef SLMTU 159 #define SLMTU 296 160 #endif 161 #if (SLMTU < 3) 162 Huh? SLMTU way too small. 163 #endif 164 #define SLIP_HIWAT roundup(50,CBSIZE) 165 #ifndef NetBSD /* XXX - cgd */ 166 #define CLISTRESERVE 1024 /* Can't let clists get too low */ 167 #endif /* !NetBSD */ 168 169 /* 170 * SLIP ABORT ESCAPE MECHANISM: 171 * (inspired by HAYES modem escape arrangement) 172 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 173 * within window time signals a "soft" exit from slip mode by remote end 174 * if the IFF_DEBUG flag is on. 175 */ 176 #define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 177 #define ABT_IDLE 1 /* in seconds - idle before an escape */ 178 #define ABT_COUNT 3 /* count of escapes for abort */ 179 #define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 180 181 struct sl_softc sl_softc[NSL]; 182 183 #define FRAME_END 0xc0 /* Frame End */ 184 #define FRAME_ESCAPE 0xdb /* Frame Esc */ 185 #define TRANS_FRAME_END 0xdc /* transposed frame end */ 186 #define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 187 188 static int slinit __P((struct sl_softc *)); 189 static struct mbuf *sl_btom __P((struct sl_softc *, int)); 190 191 /* 192 * Called from boot code to establish sl interfaces. 193 */ 194 void 195 slattach() 196 { 197 register struct sl_softc *sc; 198 register int i = 0; 199 200 for (sc = sl_softc; i < NSL; sc++) { 201 sc->sc_if.if_name = "sl"; 202 sc->sc_if.if_next = NULL; 203 sc->sc_if.if_unit = i++; 204 sc->sc_if.if_mtu = SLMTU; 205 sc->sc_if.if_flags = 206 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 207 sc->sc_if.if_type = IFT_SLIP; 208 sc->sc_if.if_ioctl = slioctl; 209 sc->sc_if.if_output = sloutput; 210 sc->sc_if.if_snd.ifq_maxlen = 50; 211 sc->sc_fastq.ifq_maxlen = 32; 212 if_attach(&sc->sc_if); 213 #if NBPFILTER > 0 214 bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 215 #endif 216 } 217 } 218 219 static int 220 slinit(sc) 221 register struct sl_softc *sc; 222 { 223 register caddr_t p; 224 225 if (sc->sc_ep == (u_char *) 0) { 226 MCLALLOC(p, M_WAIT); 227 if (p) 228 sc->sc_ep = (u_char *)p + SLBUFSIZE; 229 else { 230 printf("sl%d: can't allocate buffer\n", sc - sl_softc); 231 sc->sc_if.if_flags &= ~IFF_UP; 232 return (0); 233 } 234 } 235 sc->sc_buf = sc->sc_ep - SLMAX; 236 sc->sc_mp = sc->sc_buf; 237 sl_compress_init(&sc->sc_comp, -1); 238 return (1); 239 } 240 241 /* 242 * Line specific open routine. 243 * Attach the given tty to the first available sl unit. 244 */ 245 /* ARGSUSED */ 246 int 247 slopen(dev, tp) 248 dev_t dev; 249 register struct tty *tp; 250 { 251 struct proc *p = curproc; /* XXX */ 252 register struct sl_softc *sc; 253 register int nsl; 254 int error; 255 #ifdef NetBSD 256 int s; 257 #endif 258 259 if (error = suser(p->p_ucred, &p->p_acflag)) 260 return (error); 261 262 if (tp->t_line == SLIPDISC) 263 return (0); 264 265 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 266 if (sc->sc_ttyp == NULL) { 267 if (slinit(sc) == 0) 268 return (ENOBUFS); 269 tp->t_sc = (caddr_t)sc; 270 sc->sc_ttyp = tp; 271 sc->sc_if.if_baudrate = tp->t_ospeed; 272 ttyflush(tp, FREAD | FWRITE); 273 #ifdef NetBSD 274 /* 275 * make sure tty output queue is large enough 276 * to hold a full-sized packet (including frame 277 * end, and a possible extra frame end). full-sized 278 * packet occupies a max of 2*SLMTU bytes (because 279 * of possible escapes), and add two on for frame 280 * ends. 281 */ 282 s = spltty(); 283 if (tp->t_outq.c_cn < 2*SLMTU+2) { 284 sc->sc_oldbufsize = tp->t_outq.c_cn; 285 sc->sc_oldbufquot = tp->t_outq.c_cq != 0; 286 287 clfree(&tp->t_outq); 288 error = clalloc(&tp->t_outq, 3*SLMTU, 0); 289 if (error) { 290 splx(s); 291 return(error); 292 } 293 } else 294 sc->sc_oldbufsize = sc->sc_oldbufquot = 0; 295 splx(s); 296 #endif /* NetBSD */ 297 return (0); 298 } 299 return (ENXIO); 300 } 301 302 /* 303 * Line specific close routine. 304 * Detach the tty from the sl unit. 305 */ 306 void 307 slclose(tp) 308 struct tty *tp; 309 { 310 register struct sl_softc *sc; 311 int s; 312 313 ttywflush(tp); 314 s = splimp(); /* actually, max(spltty, splnet) */ 315 tp->t_line = 0; 316 sc = (struct sl_softc *)tp->t_sc; 317 if (sc != NULL) { 318 if_down(&sc->sc_if); 319 sc->sc_ttyp = NULL; 320 tp->t_sc = NULL; 321 MCLFREE((caddr_t)(sc->sc_ep - SLBUFSIZE)); 322 sc->sc_ep = 0; 323 sc->sc_mp = 0; 324 sc->sc_buf = 0; 325 } 326 #ifdef NetBSD 327 /* if necessary, install a new outq buffer of the appropriate size */ 328 if (sc->sc_oldbufsize != 0) { 329 clfree(&tp->t_outq); 330 clalloc(&tp->t_outq, sc->sc_oldbufsize, sc->sc_oldbufquot); 331 } 332 #endif 333 splx(s); 334 } 335 336 /* 337 * Line specific (tty) ioctl routine. 338 * Provide a way to get the sl unit number. 339 */ 340 /* ARGSUSED */ 341 int 342 sltioctl(tp, cmd, data, flag) 343 struct tty *tp; 344 u_long cmd; 345 caddr_t data; 346 int flag; 347 { 348 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 349 350 switch (cmd) { 351 case SLIOCGUNIT: 352 *(int *)data = sc->sc_if.if_unit; 353 break; 354 355 default: 356 return (-1); 357 } 358 return (0); 359 } 360 361 /* 362 * Queue a packet. Start transmission if not active. 363 * Compression happens in slstart; if we do it here, IP TOS 364 * will cause us to not compress "background" packets, because 365 * ordering gets trashed. It can be done for all packets in slstart. 366 */ 367 int 368 sloutput(ifp, m, dst, rtp) 369 struct ifnet *ifp; 370 register struct mbuf *m; 371 struct sockaddr *dst; 372 struct rtentry *rtp; 373 { 374 register struct sl_softc *sc = &sl_softc[ifp->if_unit]; 375 register struct ip *ip; 376 register struct ifqueue *ifq; 377 int s; 378 379 /* 380 * `Cannot happen' (see slioctl). Someday we will extend 381 * the line protocol to support other address families. 382 */ 383 if (dst->sa_family != AF_INET) { 384 printf("sl%d: af%d not supported\n", sc->sc_if.if_unit, 385 dst->sa_family); 386 m_freem(m); 387 sc->sc_if.if_noproto++; 388 return (EAFNOSUPPORT); 389 } 390 391 if (sc->sc_ttyp == NULL) { 392 m_freem(m); 393 return (ENETDOWN); /* sort of */ 394 } 395 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 396 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 397 m_freem(m); 398 return (EHOSTUNREACH); 399 } 400 ifq = &sc->sc_if.if_snd; 401 ip = mtod(m, struct ip *); 402 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 403 m_freem(m); 404 return (ENETRESET); /* XXX ? */ 405 } 406 if (ip->ip_tos & IPTOS_LOWDELAY) 407 ifq = &sc->sc_fastq; 408 s = splimp(); 409 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) { 410 struct timeval tv; 411 412 /* if output's been stalled for too long, and restart */ 413 timersub(&time, &sc->sc_if.if_lastchange, &tv); 414 if (tv.tv_sec > 0) { 415 sc->sc_otimeout++; 416 slstart(sc->sc_ttyp); 417 } 418 } 419 if (IF_QFULL(ifq)) { 420 IF_DROP(ifq); 421 m_freem(m); 422 splx(s); 423 sc->sc_if.if_oerrors++; 424 return (ENOBUFS); 425 } 426 IF_ENQUEUE(ifq, m); 427 sc->sc_if.if_lastchange = time; 428 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) 429 slstart(sc->sc_ttyp); 430 splx(s); 431 return (0); 432 } 433 434 /* 435 * Start output on interface. Get another datagram 436 * to send from the interface queue and map it to 437 * the interface before starting output. 438 */ 439 void 440 slstart(tp) 441 register struct tty *tp; 442 { 443 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 444 register struct mbuf *m; 445 register u_char *cp; 446 register struct ip *ip; 447 int s; 448 struct mbuf *m2; 449 #if NBPFILTER > 0 450 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 451 register int len; 452 #endif 453 #ifndef NetBSD /* XXX - cgd */ 454 extern int cfreecount; 455 #endif 456 457 for (;;) { 458 /* 459 * If there is more in the output queue, just send it now. 460 * We are being called in lieu of ttstart and must do what 461 * it would. 462 */ 463 if (tp->t_outq.c_cc != 0) { 464 (*tp->t_oproc)(tp); 465 if (tp->t_outq.c_cc > SLIP_HIWAT) 466 return; 467 } 468 /* 469 * This happens briefly when the line shuts down. 470 */ 471 if (sc == NULL) 472 return; 473 474 #ifdef NetBSD /* XXX - cgd */ 475 /* 476 * Do not remove the packet from the IP queue if it 477 * doesn't look like the packet will fit into the 478 * current serial output queue, with a packet full of 479 * escapes this could be as bad as SLMTU*2+2. 480 */ 481 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*SLMTU+2) 482 return; 483 #endif /* NetBSD */ 484 485 /* 486 * Get a packet and send it to the interface. 487 */ 488 s = splimp(); 489 IF_DEQUEUE(&sc->sc_fastq, m); 490 if (m) 491 sc->sc_if.if_omcasts++; /* XXX */ 492 else 493 IF_DEQUEUE(&sc->sc_if.if_snd, m); 494 splx(s); 495 if (m == NULL) 496 return; 497 498 /* 499 * We do the header compression here rather than in sloutput 500 * because the packets will be out of order if we are using TOS 501 * queueing, and the connection id compression will get 502 * munged when this happens. 503 */ 504 #if NBPFILTER > 0 505 if (sc->sc_bpf) { 506 /* 507 * We need to save the TCP/IP header before it's 508 * compressed. To avoid complicated code, we just 509 * copy the entire packet into a stack buffer (since 510 * this is a serial line, packets should be short 511 * and/or the copy should be negligible cost compared 512 * to the packet transmission time). 513 */ 514 register struct mbuf *m1 = m; 515 register u_char *cp = bpfbuf + SLIP_HDRLEN; 516 517 len = 0; 518 do { 519 register int mlen = m1->m_len; 520 521 bcopy(mtod(m1, caddr_t), cp, mlen); 522 cp += mlen; 523 len += mlen; 524 } while (m1 = m1->m_next); 525 } 526 #endif 527 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 528 if (sc->sc_if.if_flags & SC_COMPRESS) 529 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 530 &sc->sc_comp, 1); 531 } 532 #if NBPFILTER > 0 533 if (sc->sc_bpf) { 534 /* 535 * Put the SLIP pseudo-"link header" in place. The 536 * compressed header is now at the beginning of the 537 * mbuf. 538 */ 539 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 540 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 541 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 542 } 543 #endif 544 sc->sc_if.if_lastchange = time; 545 546 #ifndef NetBSD /* XXX - cgd */ 547 /* 548 * If system is getting low on clists, just flush our 549 * output queue (if the stuff was important, it'll get 550 * retransmitted). 551 */ 552 if (cfreecount < CLISTRESERVE + SLMTU) { 553 m_freem(m); 554 sc->sc_if.if_collisions++; 555 continue; 556 } 557 #endif /* !NetBSD */ 558 /* 559 * The extra FRAME_END will start up a new packet, and thus 560 * will flush any accumulated garbage. We do this whenever 561 * the line may have been idle for some time. 562 */ 563 if (tp->t_outq.c_cc == 0) { 564 ++sc->sc_if.if_obytes; 565 (void) putc(FRAME_END, &tp->t_outq); 566 } 567 568 while (m) { 569 register u_char *ep; 570 571 cp = mtod(m, u_char *); ep = cp + m->m_len; 572 while (cp < ep) { 573 /* 574 * Find out how many bytes in the string we can 575 * handle without doing something special. 576 */ 577 register u_char *bp = cp; 578 579 while (cp < ep) { 580 switch (*cp++) { 581 case FRAME_ESCAPE: 582 case FRAME_END: 583 --cp; 584 goto out; 585 } 586 } 587 out: 588 if (cp > bp) { 589 /* 590 * Put n characters at once 591 * into the tty output queue. 592 */ 593 #ifdef NetBSD /* XXX - cgd */ 594 if (b_to_q((u_char *)bp, cp - bp, 595 #else 596 if (b_to_q((char *)bp, cp - bp, 597 #endif 598 &tp->t_outq)) 599 break; 600 sc->sc_if.if_obytes += cp - bp; 601 } 602 /* 603 * If there are characters left in the mbuf, 604 * the first one must be special.. 605 * Put it out in a different form. 606 */ 607 if (cp < ep) { 608 if (putc(FRAME_ESCAPE, &tp->t_outq)) 609 break; 610 if (putc(*cp++ == FRAME_ESCAPE ? 611 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 612 &tp->t_outq)) { 613 (void) unputc(&tp->t_outq); 614 break; 615 } 616 sc->sc_if.if_obytes += 2; 617 } 618 } 619 MFREE(m, m2); 620 m = m2; 621 } 622 623 if (putc(FRAME_END, &tp->t_outq)) { 624 /* 625 * Not enough room. Remove a char to make room 626 * and end the packet normally. 627 * If you get many collisions (more than one or two 628 * a day) you probably do not have enough clists 629 * and you should increase "nclist" in param.c. 630 */ 631 (void) unputc(&tp->t_outq); 632 (void) putc(FRAME_END, &tp->t_outq); 633 sc->sc_if.if_collisions++; 634 } else { 635 ++sc->sc_if.if_obytes; 636 sc->sc_if.if_opackets++; 637 } 638 } 639 } 640 641 /* 642 * Copy data buffer to mbuf chain; add ifnet pointer. 643 */ 644 static struct mbuf * 645 sl_btom(sc, len) 646 register struct sl_softc *sc; 647 register int len; 648 { 649 register struct mbuf *m; 650 651 MGETHDR(m, M_DONTWAIT, MT_DATA); 652 if (m == NULL) 653 return (NULL); 654 655 /* 656 * If we have more than MHLEN bytes, it's cheaper to 657 * queue the cluster we just filled & allocate a new one 658 * for the input buffer. Otherwise, fill the mbuf we 659 * allocated above. Note that code in the input routine 660 * guarantees that packet will fit in a cluster. 661 */ 662 if (len >= MHLEN) { 663 MCLGET(m, M_DONTWAIT); 664 if ((m->m_flags & M_EXT) == 0) { 665 /* 666 * we couldn't get a cluster - if memory's this 667 * low, it's time to start dropping packets. 668 */ 669 (void) m_free(m); 670 return (NULL); 671 } 672 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 673 m->m_data = (caddr_t)sc->sc_buf; 674 m->m_ext.ext_buf = (caddr_t)((long)sc->sc_buf &~ MCLOFSET); 675 } else 676 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 677 678 m->m_len = len; 679 m->m_pkthdr.len = len; 680 m->m_pkthdr.rcvif = &sc->sc_if; 681 return (m); 682 } 683 684 /* 685 * tty interface receiver interrupt. 686 */ 687 void 688 slinput(c, tp) 689 register int c; 690 register struct tty *tp; 691 { 692 register struct sl_softc *sc; 693 register struct mbuf *m; 694 register int len; 695 int s; 696 #if NBPFILTER > 0 697 u_char chdr[CHDR_LEN]; 698 #endif 699 700 tk_nin++; 701 sc = (struct sl_softc *)tp->t_sc; 702 if (sc == NULL) 703 return; 704 if (c & TTY_ERRORMASK || ((tp->t_state & TS_CARR_ON) == 0 && 705 (tp->t_cflag & CLOCAL) == 0)) { 706 sc->sc_flags |= SC_ERROR; 707 return; 708 } 709 c &= TTY_CHARMASK; 710 711 ++sc->sc_if.if_ibytes; 712 713 if (sc->sc_if.if_flags & IFF_DEBUG) { 714 if (c == ABT_ESC) { 715 /* 716 * If we have a previous abort, see whether 717 * this one is within the time limit. 718 */ 719 if (sc->sc_abortcount && 720 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 721 sc->sc_abortcount = 0; 722 /* 723 * If we see an abort after "idle" time, count it; 724 * record when the first abort escape arrived. 725 */ 726 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 727 if (++sc->sc_abortcount == 1) 728 sc->sc_starttime = time.tv_sec; 729 if (sc->sc_abortcount >= ABT_COUNT) { 730 slclose(tp); 731 return; 732 } 733 } 734 } else 735 sc->sc_abortcount = 0; 736 sc->sc_lasttime = time.tv_sec; 737 } 738 739 switch (c) { 740 741 case TRANS_FRAME_ESCAPE: 742 if (sc->sc_escape) 743 c = FRAME_ESCAPE; 744 break; 745 746 case TRANS_FRAME_END: 747 if (sc->sc_escape) 748 c = FRAME_END; 749 break; 750 751 case FRAME_ESCAPE: 752 sc->sc_escape = 1; 753 return; 754 755 case FRAME_END: 756 if(sc->sc_flags & SC_ERROR) { 757 sc->sc_flags &= ~SC_ERROR; 758 goto newpack; 759 } 760 len = sc->sc_mp - sc->sc_buf; 761 if (len < 3) 762 /* less than min length packet - ignore */ 763 goto newpack; 764 765 #if NBPFILTER > 0 766 if (sc->sc_bpf) { 767 /* 768 * Save the compressed header, so we 769 * can tack it on later. Note that we 770 * will end up copying garbage in some 771 * cases but this is okay. We remember 772 * where the buffer started so we can 773 * compute the new header length. 774 */ 775 bcopy(sc->sc_buf, chdr, CHDR_LEN); 776 } 777 #endif 778 779 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 780 if (c & 0x80) 781 c = TYPE_COMPRESSED_TCP; 782 else if (c == TYPE_UNCOMPRESSED_TCP) 783 *sc->sc_buf &= 0x4f; /* XXX */ 784 /* 785 * We've got something that's not an IP packet. 786 * If compression is enabled, try to decompress it. 787 * Otherwise, if `auto-enable' compression is on and 788 * it's a reasonable packet, decompress it and then 789 * enable compression. Otherwise, drop it. 790 */ 791 if (sc->sc_if.if_flags & SC_COMPRESS) { 792 len = sl_uncompress_tcp(&sc->sc_buf, len, 793 (u_int)c, &sc->sc_comp); 794 if (len <= 0) 795 goto error; 796 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 797 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 798 len = sl_uncompress_tcp(&sc->sc_buf, len, 799 (u_int)c, &sc->sc_comp); 800 if (len <= 0) 801 goto error; 802 sc->sc_if.if_flags |= SC_COMPRESS; 803 } else 804 goto error; 805 } 806 #if NBPFILTER > 0 807 if (sc->sc_bpf) { 808 /* 809 * Put the SLIP pseudo-"link header" in place. 810 * We couldn't do this any earlier since 811 * decompression probably moved the buffer 812 * pointer. Then, invoke BPF. 813 */ 814 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 815 816 hp[SLX_DIR] = SLIPDIR_IN; 817 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 818 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 819 } 820 #endif 821 m = sl_btom(sc, len); 822 if (m == NULL) 823 goto error; 824 825 sc->sc_if.if_ipackets++; 826 sc->sc_if.if_lastchange = time; 827 s = splimp(); 828 if (IF_QFULL(&ipintrq)) { 829 IF_DROP(&ipintrq); 830 sc->sc_if.if_ierrors++; 831 sc->sc_if.if_iqdrops++; 832 m_freem(m); 833 } else { 834 IF_ENQUEUE(&ipintrq, m); 835 schednetisr(NETISR_IP); 836 } 837 splx(s); 838 goto newpack; 839 } 840 if (sc->sc_mp < sc->sc_ep) { 841 *sc->sc_mp++ = c; 842 sc->sc_escape = 0; 843 return; 844 } 845 846 /* can't put lower; would miss an extra frame */ 847 sc->sc_flags |= SC_ERROR; 848 849 error: 850 sc->sc_if.if_ierrors++; 851 newpack: 852 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 853 sc->sc_escape = 0; 854 } 855 856 /* 857 * Process an ioctl request. 858 */ 859 int 860 slioctl(ifp, cmd, data) 861 register struct ifnet *ifp; 862 u_long cmd; 863 caddr_t data; 864 { 865 register struct ifaddr *ifa = (struct ifaddr *)data; 866 register struct ifreq *ifr; 867 register int s = splimp(), error = 0; 868 869 switch (cmd) { 870 871 case SIOCSIFADDR: 872 if (ifa->ifa_addr->sa_family == AF_INET) 873 ifp->if_flags |= IFF_UP; 874 else 875 error = EAFNOSUPPORT; 876 break; 877 878 case SIOCSIFDSTADDR: 879 if (ifa->ifa_addr->sa_family != AF_INET) 880 error = EAFNOSUPPORT; 881 break; 882 883 case SIOCADDMULTI: 884 case SIOCDELMULTI: 885 ifr = (struct ifreq *)data; 886 if (ifr == 0) { 887 error = EAFNOSUPPORT; /* XXX */ 888 break; 889 } 890 switch (ifr->ifr_addr.sa_family) { 891 892 #ifdef INET 893 case AF_INET: 894 break; 895 #endif 896 897 default: 898 error = EAFNOSUPPORT; 899 break; 900 } 901 break; 902 903 default: 904 error = EINVAL; 905 } 906 splx(s); 907 return (error); 908 } 909 #endif 910