if_sl.c revision 1.71
1/* $NetBSD: if_sl.c,v 1.71 2001/01/15 16:33:31 thorpej 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 66#include "sl.h" 67#if NSL > 0 68 69#include "opt_inet.h" 70#include "bpfilter.h" 71 72#include <sys/param.h> 73#include <sys/proc.h> 74#include <sys/malloc.h> 75#include <sys/mbuf.h> 76#include <sys/buf.h> 77#include <sys/dkstat.h> 78#include <sys/socket.h> 79#include <sys/ioctl.h> 80#include <sys/file.h> 81#include <sys/conf.h> 82#include <sys/tty.h> 83#include <sys/kernel.h> 84#if __NetBSD__ 85#include <sys/systm.h> 86#endif 87 88#include <machine/cpu.h> 89#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS 90#include <machine/intr.h> 91#endif 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#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 157#define SLMAX (MCLBYTES - BUFOFFSET) 158#define SLBUFSIZE (SLMAX + BUFOFFSET) 159#ifndef SLMTU 160#define SLMTU 296 161#endif 162#if (SLMTU < 3) 163#error SLMTU way too small. 164#endif 165#define SLIP_HIWAT roundup(50,CBSIZE) 166#ifndef __NetBSD__ /* XXX - cgd */ 167#define CLISTRESERVE 1024 /* Can't let clists get too low */ 168#endif /* !__NetBSD__ */ 169 170/* 171 * SLIP ABORT ESCAPE MECHANISM: 172 * (inspired by HAYES modem escape arrangement) 173 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 174 * within window time signals a "soft" exit from slip mode by remote end 175 * if the IFF_DEBUG flag is on. 176 */ 177#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 178#define ABT_IDLE 1 /* in seconds - idle before an escape */ 179#define ABT_COUNT 3 /* count of escapes for abort */ 180#define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 181 182struct sl_softc sl_softc[NSL]; 183 184#define FRAME_END 0xc0 /* Frame End */ 185#define FRAME_ESCAPE 0xdb /* Frame Esc */ 186#define TRANS_FRAME_END 0xdc /* transposed frame end */ 187#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 188 189#ifndef __HAVE_GENERIC_SOFT_INTERRUPTS 190void slnetisr(void); 191#endif 192void slintr(void *); 193 194static int slinit __P((struct sl_softc *)); 195static struct mbuf *sl_btom __P((struct sl_softc *, int)); 196 197/* 198 * Called from boot code to establish sl interfaces. 199 */ 200void 201slattach() 202{ 203 struct sl_softc *sc; 204 int i = 0; 205 206 for (sc = sl_softc; i < NSL; sc++) { 207 sc->sc_unit = i; /* XXX */ 208 sprintf(sc->sc_if.if_xname, "sl%d", i++); 209 sc->sc_if.if_softc = sc; 210 sc->sc_if.if_mtu = SLMTU; 211 sc->sc_if.if_flags = 212 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 213 sc->sc_if.if_type = IFT_SLIP; 214 sc->sc_if.if_ioctl = slioctl; 215 sc->sc_if.if_output = sloutput; 216 sc->sc_if.if_dlt = DLT_SLIP; 217 sc->sc_fastq.ifq_maxlen = 32; 218 IFQ_SET_READY(&sc->sc_if.if_snd); 219 if_attach(&sc->sc_if); 220#if NBPFILTER > 0 221 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 222#endif 223 } 224} 225 226static int 227slinit(sc) 228 struct sl_softc *sc; 229{ 230 231 if (sc->sc_mbuf == NULL) { 232 MGETHDR(sc->sc_mbuf, M_WAIT, MT_DATA); 233 MCLGET(sc->sc_mbuf, M_WAIT); 234 } 235 sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 236 sc->sc_mbuf->m_ext.ext_size; 237 sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 238 BUFOFFSET; 239 240 sl_compress_init(&sc->sc_comp); 241 242 return (1); 243} 244 245/* 246 * Line specific open routine. 247 * Attach the given tty to the first available sl unit. 248 */ 249/* ARGSUSED */ 250int 251slopen(dev, tp) 252 dev_t dev; 253 struct tty *tp; 254{ 255 struct proc *p = curproc; /* XXX */ 256 struct sl_softc *sc; 257 int nsl; 258 int error; 259 int s; 260 261 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 262 return (error); 263 264 if (tp->t_linesw && (tp->t_linesw->l_no == SLIPDISC)) 265 return (0); 266 267 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 268 if (sc->sc_ttyp == NULL) { 269#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS 270 sc->sc_si = softintr_establish(IPL_SOFTNET, 271 slintr, sc); 272 if (sc->sc_si == NULL) 273 return (ENOMEM); 274#endif 275 if (slinit(sc) == 0) { 276#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS 277 softintr_disestablish(sc->sc_si); 278#endif 279 return (ENOBUFS); 280 } 281 tp->t_sc = (caddr_t)sc; 282 sc->sc_ttyp = tp; 283 sc->sc_if.if_baudrate = tp->t_ospeed; 284 s = spltty(); 285 tp->t_state |= TS_ISOPEN | TS_XCLUDE; 286 splx(s); 287 ttyflush(tp, FREAD | FWRITE); 288#ifdef __NetBSD__ 289 /* 290 * make sure tty output queue is large enough 291 * to hold a full-sized packet (including frame 292 * end, and a possible extra frame end). full-sized 293 * packet occupies a max of 2*SLMAX bytes (because 294 * of possible escapes), and add two on for frame 295 * ends. 296 */ 297 s = spltty(); 298 if (tp->t_outq.c_cn < 2*SLMAX+2) { 299 sc->sc_oldbufsize = tp->t_outq.c_cn; 300 sc->sc_oldbufquot = tp->t_outq.c_cq != 0; 301 302 clfree(&tp->t_outq); 303 error = clalloc(&tp->t_outq, 2*SLMAX+2, 0); 304 if (error) { 305 splx(s); 306#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS 307 softintr_disestablish(sc->sc_si); 308#endif 309 return(error); 310 } 311 } else 312 sc->sc_oldbufsize = sc->sc_oldbufquot = 0; 313 splx(s); 314#endif /* __NetBSD__ */ 315 return (0); 316 } 317 return (ENXIO); 318} 319 320/* 321 * Line specific close routine. 322 * Detach the tty from the sl unit. 323 */ 324void 325slclose(tp) 326 struct tty *tp; 327{ 328 struct sl_softc *sc; 329 int s; 330 331 ttywflush(tp); 332 sc = tp->t_sc; 333 334 if (sc != NULL) { 335#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS 336 softintr_disestablish(sc->sc_si); 337#endif 338 s = splnet(); 339 if_down(&sc->sc_if); 340 IF_PURGE(&sc->sc_fastq); 341 splx(s); 342 343 s = spltty(); 344 tp->t_linesw = linesw[0]; /* default line disc. */ 345 tp->t_state = 0; 346 347 sc->sc_ttyp = NULL; 348 tp->t_sc = NULL; 349 350 m_freem(sc->sc_mbuf); 351 sc->sc_mbuf = NULL; 352 sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL; 353 IF_PURGE(&sc->sc_inq); 354 355 /* 356 * If necessary, install a new outq buffer of the 357 * appropriate size. 358 */ 359 if (sc->sc_oldbufsize != 0) { 360 clfree(&tp->t_outq); 361 clalloc(&tp->t_outq, sc->sc_oldbufsize, 362 sc->sc_oldbufquot); 363 } 364 splx(s); 365 } 366} 367 368/* 369 * Line specific (tty) ioctl routine. 370 * Provide a way to get the sl unit number. 371 */ 372/* ARGSUSED */ 373int 374sltioctl(tp, cmd, data, flag) 375 struct tty *tp; 376 u_long cmd; 377 caddr_t data; 378 int flag; 379{ 380 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 381 382 switch (cmd) { 383 case SLIOCGUNIT: 384 *(int *)data = sc->sc_unit; /* XXX */ 385 break; 386 387 default: 388 return (-1); 389 } 390 return (0); 391} 392 393/* 394 * Queue a packet. Start transmission if not active. 395 * Compression happens in slintr(); if we do it here, IP TOS 396 * will cause us to not compress "background" packets, because 397 * ordering gets trashed. It can be done for all packets in slintr(). 398 */ 399int 400sloutput(ifp, m, dst, rtp) 401 struct ifnet *ifp; 402 struct mbuf *m; 403 struct sockaddr *dst; 404 struct rtentry *rtp; 405{ 406 struct sl_softc *sc = ifp->if_softc; 407 struct ip *ip; 408 int s, error; 409 ALTQ_DECL(struct altq_pktattr pktattr;) 410 411 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr); 412 413 /* 414 * `Cannot happen' (see slioctl). Someday we will extend 415 * the line protocol to support other address families. 416 */ 417 if (dst->sa_family != AF_INET) { 418 printf("%s: af%d not supported\n", sc->sc_if.if_xname, 419 dst->sa_family); 420 m_freem(m); 421 sc->sc_if.if_noproto++; 422 return (EAFNOSUPPORT); 423 } 424 425 if (sc->sc_ttyp == NULL) { 426 m_freem(m); 427 return (ENETDOWN); /* sort of */ 428 } 429 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 430 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 431 m_freem(m); 432 printf("%s: no carrier and not local\n", sc->sc_if.if_xname); 433 return (EHOSTUNREACH); 434 } 435 ip = mtod(m, struct ip *); 436 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 437 m_freem(m); 438 return (ENETRESET); /* XXX ? */ 439 } 440 441 s = spltty(); 442 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) { 443 struct timeval tv; 444 445 /* if output's been stalled for too long, and restart */ 446 timersub(&time, &sc->sc_if.if_lastchange, &tv); 447 if (tv.tv_sec > 0) { 448 sc->sc_otimeout++; 449 slstart(sc->sc_ttyp); 450 } 451 } 452 splx(s); 453 454 s = splnet(); 455 if ((ip->ip_tos & IPTOS_LOWDELAY) != 0 456#ifdef ALTQ 457 && ALTQ_IS_ENABLED(&ifp->if_snd) == 0 458#endif 459 ) { 460 if (IF_QFULL(&sc->sc_fastq)) { 461 IF_DROP(&sc->sc_fastq); 462 m_freem(m); 463 error = ENOBUFS; 464 } else { 465 IF_ENQUEUE(&sc->sc_fastq, m); 466 error = 0; 467 } 468 } else 469 IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error); 470 if (error) { 471 splx(s); 472 ifp->if_oerrors++; 473 return (error); 474 } 475 sc->sc_if.if_lastchange = time; 476 splx(s); 477 478 s = spltty(); 479 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) 480 slstart(sc->sc_ttyp); 481 splx(s); 482 483 return (0); 484} 485 486/* 487 * Start output on interface. Get another datagram 488 * to send from the interface queue and map it to 489 * the interface before starting output. 490 */ 491void 492slstart(tp) 493 struct tty *tp; 494{ 495 struct sl_softc *sc = tp->t_sc; 496 497 /* 498 * If there is more in the output queue, just send it now. 499 * We are being called in lieu of ttstart and must do what 500 * it would. 501 */ 502 if (tp->t_outq.c_cc != 0) { 503 (*tp->t_oproc)(tp); 504 if (tp->t_outq.c_cc > SLIP_HIWAT) 505 return; 506 } 507 508 /* 509 * This happens briefly when the line shuts down. 510 */ 511 if (sc == NULL) 512 return; 513#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS 514 softintr_schedule(sc->sc_si); 515#else 516 { 517 int s = splimp(); 518 schednetisr(NETISR_SLIP); 519 splx(s); 520 } 521#endif 522} 523 524/* 525 * Copy data buffer to mbuf chain; add ifnet pointer. 526 */ 527static struct mbuf * 528sl_btom(sc, len) 529 struct sl_softc *sc; 530 int len; 531{ 532 struct mbuf *m; 533 534 MGETHDR(m, M_DONTWAIT, MT_DATA); 535 if (m == NULL) 536 return (NULL); 537 538 /* 539 * Allocate a new input buffer and swap. 540 */ 541 m = sc->sc_mbuf; 542 MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA); 543 if (sc->sc_mbuf == NULL) { 544 sc->sc_mbuf = m; 545 return (NULL); 546 } 547 MCLGET(sc->sc_mbuf, M_DONTWAIT); 548 if ((sc->sc_mbuf->m_flags & M_EXT) == 0) { 549 m_freem(sc->sc_mbuf); 550 sc->sc_mbuf = m; 551 return (NULL); 552 } 553 sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 554 sc->sc_mbuf->m_ext.ext_size; 555 556 m->m_data = sc->sc_pktstart; 557 558 m->m_pkthdr.len = m->m_len = len; 559 m->m_pkthdr.rcvif = &sc->sc_if; 560 return (m); 561} 562 563/* 564 * tty interface receiver interrupt. 565 */ 566void 567slinput(c, tp) 568 int c; 569 struct tty *tp; 570{ 571 struct sl_softc *sc; 572 struct mbuf *m; 573 int len; 574 575 tk_nin++; 576 sc = (struct sl_softc *)tp->t_sc; 577 if (sc == NULL) 578 return; 579 if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 && 580 (tp->t_cflag & CLOCAL) == 0)) { 581 sc->sc_flags |= SC_ERROR; 582 return; 583 } 584 c &= TTY_CHARMASK; 585 586 ++sc->sc_if.if_ibytes; 587 588 if (sc->sc_if.if_flags & IFF_DEBUG) { 589 if (c == ABT_ESC) { 590 /* 591 * If we have a previous abort, see whether 592 * this one is within the time limit. 593 */ 594 if (sc->sc_abortcount && 595 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 596 sc->sc_abortcount = 0; 597 /* 598 * If we see an abort after "idle" time, count it; 599 * record when the first abort escape arrived. 600 */ 601 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 602 if (++sc->sc_abortcount == 1) 603 sc->sc_starttime = time.tv_sec; 604 if (sc->sc_abortcount >= ABT_COUNT) { 605 slclose(tp); 606 return; 607 } 608 } 609 } else 610 sc->sc_abortcount = 0; 611 sc->sc_lasttime = time.tv_sec; 612 } 613 614 switch (c) { 615 616 case TRANS_FRAME_ESCAPE: 617 if (sc->sc_escape) 618 c = FRAME_ESCAPE; 619 break; 620 621 case TRANS_FRAME_END: 622 if (sc->sc_escape) 623 c = FRAME_END; 624 break; 625 626 case FRAME_ESCAPE: 627 sc->sc_escape = 1; 628 return; 629 630 case FRAME_END: 631 if(sc->sc_flags & SC_ERROR) { 632 sc->sc_flags &= ~SC_ERROR; 633 goto newpack; 634 } 635 len = sc->sc_mp - sc->sc_pktstart; 636 if (len < 3) 637 /* less than min length packet - ignore */ 638 goto newpack; 639 640 m = sl_btom(sc, len); 641 if (m == NULL) 642 goto error; 643 644 IF_ENQUEUE(&sc->sc_inq, m); 645#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS 646 softintr_schedule(sc->sc_si); 647#else 648 { 649 int s = splimp(); 650 schednetisr(NETISR_SLIP); 651 splx(s); 652 } 653#endif 654 goto newpack; 655 } 656 if (sc->sc_mp < sc->sc_ep) { 657 *sc->sc_mp++ = c; 658 sc->sc_escape = 0; 659 return; 660 } 661 662 /* can't put lower; would miss an extra frame */ 663 sc->sc_flags |= SC_ERROR; 664 665error: 666 sc->sc_if.if_ierrors++; 667newpack: 668 sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 669 BUFOFFSET; 670 sc->sc_escape = 0; 671} 672 673#ifndef __HAVE_GENERIC_SOFT_INTERRUPTS 674void 675slnetisr(void) 676{ 677 struct sl_softc *sc; 678 int i; 679 680 for (i = 0; i < NSL; i++) { 681 sc = &sl_softc[i]; 682 if (sc->sc_ttyp == NULL) 683 continue; 684 slintr(sc); 685 } 686} 687#endif 688 689void 690slintr(void *arg) 691{ 692 struct sl_softc *sc = arg; 693 struct tty *tp = sc->sc_ttyp; 694 struct mbuf *m; 695 int s, len; 696 u_char *pktstart, c; 697#if NBPFILTER > 0 698 u_char chdr[CHDR_LEN]; 699#endif 700 701 KASSERT(tp != NULL); 702 703 /* 704 * Output processing loop. 705 */ 706 for (;;) { 707 struct ip *ip; 708 struct mbuf *m2; 709#if NBPFILTER > 0 710 struct mbuf *bpf_m; 711#endif 712 713 /* 714 * Do not remove the packet from the queue if it 715 * doesn't look like it will fit into the current 716 * serial output queue. With a packet full of 717 * escapes, this could be as bad as MTU*2+2. 718 */ 719 s = spltty(); 720 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 721 2*sc->sc_if.if_mtu+2) { 722 splx(s); 723 break; 724 } 725 splx(s); 726 727 /* 728 * Get a packet and send it to the interface. 729 */ 730 s = splnet(); 731 IF_DEQUEUE(&sc->sc_fastq, m); 732 if (m) 733 sc->sc_if.if_omcasts++; /* XXX */ 734 else 735 IFQ_DEQUEUE(&sc->sc_if.if_snd, m); 736 splx(s); 737 738 if (m == NULL) 739 break; 740 741 /* 742 * We do the header compression here rather than in 743 * sloutput() because the packets will be out of order 744 * if we are using TOS queueing, and the connection 745 * ID compression will get munged when this happens. 746 */ 747#if NBPFILTER > 0 748 if (sc->sc_if.if_bpf) { 749 /* 750 * We need to save the TCP/IP header before 751 * it's compressed. To avoid complicated 752 * code, we just make a deep copy of the 753 * entire packet (since this is a serial 754 * line, packets should be short and/or the 755 * copy should be negligible cost compared 756 * to the packet transmission time). 757 */ 758 bpf_m = m_dup(m, 0, M_COPYALL, M_DONTWAIT); 759 } else 760 bpf_m = NULL; 761#endif 762 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 763 if (sc->sc_if.if_flags & SC_COMPRESS) 764 *mtod(m, u_char *) |= 765 sl_compress_tcp(m, ip, 766 &sc->sc_comp, 1); 767 } 768#if NBPFILTER > 0 769 if (sc->sc_if.if_bpf && bpf_m != NULL) { 770 /* 771 * Put the SLIP pseudo-"link header" in 772 * place. The compressed header is now 773 * at the beginning of the mbuf. 774 */ 775 struct mbuf n; 776 u_char *hp; 777 778 n.m_next = bpf_m; 779 n.m_data = n.m_dat; 780 n.m_len = SLIP_HDRLEN; 781 782 hp = mtod(&n, u_char *); 783 784 hp[SLX_DIR] = SLIPDIR_OUT; 785 memcpy(&hp[SLX_CHDR], mtod(m, caddr_t), 786 CHDR_LEN); 787 788 s = splnet(); 789 bpf_mtap(sc->sc_if.if_bpf, &n); 790 splx(s); 791 m_freem(bpf_m); 792 } 793#endif 794 sc->sc_if.if_lastchange = time; 795 796 s = spltty(); 797 798 /* 799 * The extra FRAME_END will start up a new packet, 800 * and thus will flush any accumulated garbage. We 801 * do this whenever the line may have been idle for 802 * some time. 803 */ 804 if (tp->t_outq.c_cc == 0) { 805 sc->sc_if.if_obytes++; 806 (void) putc(FRAME_END, &tp->t_outq); 807 } 808 809 while (m) { 810 u_char *bp, *cp, *ep; 811 812 bp = cp = mtod(m, u_char *); 813 ep = cp + m->m_len; 814 while (cp < ep) { 815 /* 816 * Find out how many bytes in the 817 * string we can handle without 818 * doing something special. 819 */ 820 while (cp < ep) { 821 switch (*cp++) { 822 case FRAME_ESCAPE: 823 case FRAME_END: 824 cp--; 825 goto out; 826 } 827 } 828 out: 829 if (cp > bp) { 830 /* 831 * Put N characters at once 832 * into the tty output queue. 833 */ 834 if (b_to_q(bp, cp - bp, 835 &tp->t_outq)) 836 break; 837 sc->sc_if.if_obytes += cp - bp; 838 } 839 /* 840 * If there are characters left in 841 * the mbuf, the first one must be 842 * special.. Put it out in a different 843 * form. 844 */ 845 if (cp < ep) { 846 if (putc(FRAME_ESCAPE, 847 &tp->t_outq)) 848 break; 849 if (putc(*cp++ == FRAME_ESCAPE ? 850 TRANS_FRAME_ESCAPE : 851 TRANS_FRAME_END, 852 &tp->t_outq)) { 853 (void) 854 unputc(&tp->t_outq); 855 break; 856 } 857 sc->sc_if.if_obytes += 2; 858 } 859 } 860 MFREE(m, m2); 861 m = m2; 862 } 863 864 if (putc(FRAME_END, &tp->t_outq)) { 865 /* 866 * Not enough room. Remove a char to make 867 * room and end the packet normally. If 868 * you get many collisions (more than one 869 * or two a day), you probably do not have 870 * enough clists and you should increase 871 * "nclist" in param.c 872 */ 873 (void) unputc(&tp->t_outq); 874 (void) putc(FRAME_END, &tp->t_outq); 875 sc->sc_if.if_collisions++; 876 } else { 877 sc->sc_if.if_obytes++; 878 sc->sc_if.if_opackets++; 879 } 880 881 /* 882 * We now have characters in the output queue, 883 * kick the serial port. 884 */ 885 (*tp->t_oproc)(tp); 886 splx(s); 887 } 888 889 /* 890 * Input processing loop. 891 */ 892 for (;;) { 893 s = spltty(); 894 IF_DEQUEUE(&sc->sc_inq, m); 895 splx(s); 896 if (m == NULL) 897 break; 898 pktstart = mtod(m, u_char *); 899 len = m->m_pkthdr.len; 900#if NBPFILTER > 0 901 if (sc->sc_if.if_bpf) { 902 /* 903 * Save the compressed header, so we 904 * can tack it on later. Note that we 905 * will end up copying garbage in some 906 * cases but this is okay. We remember 907 * where the buffer started so we can 908 * compute the new header length. 909 */ 910 memcpy(chdr, pktstart, CHDR_LEN); 911 } 912#endif /* NBPFILTER > 0 */ 913 if ((c = (*pktstart & 0xf0)) != (IPVERSION << 4)) { 914 if (c & 0x80) 915 c = TYPE_COMPRESSED_TCP; 916 else if (c == TYPE_UNCOMPRESSED_TCP) 917 *pktstart &= 0x4f; /* XXX */ 918 /* 919 * We've got something that's not an IP 920 * packet. If compression is enabled, 921 * try to decompress it. Otherwise, if 922 * `auto-enable' compression is on and 923 * it's a reasonable packet, decompress 924 * it and then enable compression. 925 * Otherwise, drop it. 926 */ 927 if (sc->sc_if.if_flags & SC_COMPRESS) { 928 len = sl_uncompress_tcp(&pktstart, len, 929 (u_int)c, &sc->sc_comp); 930 if (len <= 0) { 931 m_freem(m); 932 continue; 933 } 934 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 935 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 936 len = sl_uncompress_tcp(&pktstart, len, 937 (u_int)c, &sc->sc_comp); 938 if (len <= 0) { 939 m_freem(m); 940 continue; 941 } 942 sc->sc_if.if_flags |= SC_COMPRESS; 943 } else { 944 m_freem(m); 945 continue; 946 } 947 } 948 m->m_data = (caddr_t) pktstart; 949 m->m_pkthdr.len = m->m_len = len; 950#if NBPFILTER > 0 951 if (sc->sc_if.if_bpf) { 952 /* 953 * Put the SLIP pseudo-"link header" in place. 954 * Note this M_PREPEND() should bever fail, 955 * since we know we always have enough space 956 * in the input buffer. 957 */ 958 u_char *hp; 959 960 M_PREPEND(m, SLIP_HDRLEN, M_DONTWAIT); 961 if (m == NULL) 962 continue; 963 964 hp = mtod(m, u_char *); 965 hp[SLX_DIR] = SLIPDIR_IN; 966 memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN); 967 968 s = splnet(); 969 bpf_mtap(sc->sc_if.if_bpf, m); 970 splx(s); 971 972 m_adj(m, SLIP_HDRLEN); 973 } 974#endif /* NBPFILTER > 0 */ 975 /* 976 * If the packet will fit into a single 977 * header mbuf, copy it into one, to save 978 * memory. 979 */ 980 if (m->m_pkthdr.len < MHLEN) { 981 struct mbuf *n; 982 983 MGETHDR(n, M_DONTWAIT, MT_DATA); 984 M_COPY_PKTHDR(n, m); 985 memcpy(mtod(n, caddr_t), mtod(m, caddr_t), 986 m->m_pkthdr.len); 987 n->m_len = m->m_len; 988 m_freem(m); 989 m = n; 990 } 991 992 sc->sc_if.if_ipackets++; 993 sc->sc_if.if_lastchange = time; 994 995 s = splimp(); 996 if (IF_QFULL(&ipintrq)) { 997 IF_DROP(&ipintrq); 998 sc->sc_if.if_ierrors++; 999 sc->sc_if.if_iqdrops++; 1000 m_freem(m); 1001 } else { 1002 IF_ENQUEUE(&ipintrq, m); 1003 schednetisr(NETISR_IP); 1004 } 1005 splx(s); 1006 } 1007} 1008 1009/* 1010 * Process an ioctl request. 1011 */ 1012int 1013slioctl(ifp, cmd, data) 1014 struct ifnet *ifp; 1015 u_long cmd; 1016 caddr_t data; 1017{ 1018 struct ifaddr *ifa = (struct ifaddr *)data; 1019 struct ifreq *ifr = (struct ifreq *)data; 1020 int s = splnet(), error = 0; 1021 struct sl_softc *sc = ifp->if_softc; 1022 1023 switch (cmd) { 1024 1025 case SIOCSIFADDR: 1026 if (ifa->ifa_addr->sa_family == AF_INET) 1027 ifp->if_flags |= IFF_UP; 1028 else 1029 error = EAFNOSUPPORT; 1030 break; 1031 1032 case SIOCSIFDSTADDR: 1033 if (ifa->ifa_addr->sa_family != AF_INET) 1034 error = EAFNOSUPPORT; 1035 break; 1036 1037 case SIOCSIFMTU: 1038 if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) { 1039 error = EINVAL; 1040 break; 1041 } 1042 sc->sc_if.if_mtu = ifr->ifr_mtu; 1043 break; 1044 1045 case SIOCGIFMTU: 1046 ifr->ifr_mtu = sc->sc_if.if_mtu; 1047 break; 1048 1049 case SIOCADDMULTI: 1050 case SIOCDELMULTI: 1051 if (ifr == 0) { 1052 error = EAFNOSUPPORT; /* XXX */ 1053 break; 1054 } 1055 switch (ifr->ifr_addr.sa_family) { 1056 1057#ifdef INET 1058 case AF_INET: 1059 break; 1060#endif 1061 1062 default: 1063 error = EAFNOSUPPORT; 1064 break; 1065 } 1066 break; 1067 1068 default: 1069 error = EINVAL; 1070 } 1071 splx(s); 1072 return (error); 1073} 1074#endif 1075