if_sl.c revision 1.69
1/* $NetBSD: if_sl.c,v 1.69 2001/01/12 19:26:48 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 90#include <net/if.h> 91#include <net/if_types.h> 92#include <net/netisr.h> 93#include <net/route.h> 94 95#ifdef INET 96#include <netinet/in.h> 97#include <netinet/in_systm.h> 98#include <netinet/in_var.h> 99#include <netinet/ip.h> 100#else 101#error Slip without inet? 102#endif 103 104#include <net/slcompress.h> 105#include <net/if_slvar.h> 106#include <net/slip.h> 107 108#if NBPFILTER > 0 109#include <sys/time.h> 110#include <net/bpf.h> 111#endif 112 113/* 114 * SLMAX is a hard limit on input packet size. To simplify the code 115 * and improve performance, we require that packets fit in an mbuf 116 * cluster, and if we get a compressed packet, there's enough extra 117 * room to expand the header into a max length tcp/ip header (128 118 * bytes). So, SLMAX can be at most 119 * MCLBYTES - 128 120 * 121 * SLMTU is a hard limit on output packet size. To insure good 122 * interactive response, SLMTU wants to be the smallest size that 123 * amortizes the header cost. (Remember that even with 124 * type-of-service queuing, we have to wait for any in-progress 125 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 126 * cps, where cps is the line speed in characters per second. 127 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 128 * average compressed header size is 6-8 bytes so any MTU > 90 129 * bytes will give us 90% of the line bandwidth. A 100ms wait is 130 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 131 * will send 256 byte segments (to allow for 40 byte headers), the 132 * typical packet size on the wire will be around 260 bytes). In 133 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 134 * leave the interface MTU relatively high (so we don't IP fragment 135 * when acting as a gateway to someone using a stupid MTU). 136 * 137 * Similar considerations apply to SLIP_HIWAT: It's the amount of 138 * data that will be queued 'downstream' of us (i.e., in clists 139 * waiting to be picked up by the tty output interrupt). If we 140 * queue a lot of data downstream, it's immune to our t.o.s. queuing. 141 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 142 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 143 * wait is dependent on the ftp window size but that's typically 144 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 145 * the cost (in idle time on the wire) of the tty driver running 146 * off the end of its clists & having to call back slstart for a 147 * new packet. For a tty interface with any buffering at all, this 148 * cost will be zero. Even with a totally brain dead interface (like 149 * the one on a typical workstation), the cost will be <= 1 character 150 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 151 * at most 1% while maintaining good interactive response. 152 */ 153#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 154#define SLMAX (MCLBYTES - BUFOFFSET) 155#define SLBUFSIZE (SLMAX + BUFOFFSET) 156#ifndef SLMTU 157#define SLMTU 296 158#endif 159#if (SLMTU < 3) 160#error SLMTU way too small. 161#endif 162#define SLIP_HIWAT roundup(50,CBSIZE) 163#ifndef __NetBSD__ /* XXX - cgd */ 164#define CLISTRESERVE 1024 /* Can't let clists get too low */ 165#endif /* !__NetBSD__ */ 166 167/* 168 * SLIP ABORT ESCAPE MECHANISM: 169 * (inspired by HAYES modem escape arrangement) 170 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 171 * within window time signals a "soft" exit from slip mode by remote end 172 * if the IFF_DEBUG flag is on. 173 */ 174#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 175#define ABT_IDLE 1 /* in seconds - idle before an escape */ 176#define ABT_COUNT 3 /* count of escapes for abort */ 177#define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 178 179struct sl_softc sl_softc[NSL]; 180 181#define FRAME_END 0xc0 /* Frame End */ 182#define FRAME_ESCAPE 0xdb /* Frame Esc */ 183#define TRANS_FRAME_END 0xdc /* transposed frame end */ 184#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 185 186static int slinit __P((struct sl_softc *)); 187static struct mbuf *sl_btom __P((struct sl_softc *, int)); 188 189/* 190 * Called from boot code to establish sl interfaces. 191 */ 192void 193slattach() 194{ 195 struct sl_softc *sc; 196 int i = 0; 197 198 for (sc = sl_softc; i < NSL; sc++) { 199 sc->sc_unit = i; /* XXX */ 200 sprintf(sc->sc_if.if_xname, "sl%d", i++); 201 sc->sc_if.if_softc = sc; 202 sc->sc_if.if_mtu = SLMTU; 203 sc->sc_if.if_flags = 204 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 205 sc->sc_if.if_type = IFT_SLIP; 206 sc->sc_if.if_ioctl = slioctl; 207 sc->sc_if.if_output = sloutput; 208 sc->sc_if.if_dlt = DLT_SLIP; 209 sc->sc_fastq.ifq_maxlen = 32; 210 IFQ_SET_READY(&sc->sc_if.if_snd); 211 if_attach(&sc->sc_if); 212#if NBPFILTER > 0 213 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 214#endif 215 } 216} 217 218static int 219slinit(sc) 220 struct sl_softc *sc; 221{ 222 223 if (sc->sc_mbuf == NULL) { 224 MGETHDR(sc->sc_mbuf, M_WAIT, MT_DATA); 225 MCLGET(sc->sc_mbuf, M_WAIT); 226 } 227 sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 228 sc->sc_mbuf->m_ext.ext_size; 229 sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 230 BUFOFFSET; 231 232 sl_compress_init(&sc->sc_comp); 233 234 return (1); 235} 236 237/* 238 * Line specific open routine. 239 * Attach the given tty to the first available sl unit. 240 */ 241/* ARGSUSED */ 242int 243slopen(dev, tp) 244 dev_t dev; 245 struct tty *tp; 246{ 247 struct proc *p = curproc; /* XXX */ 248 struct sl_softc *sc; 249 int nsl; 250 int error; 251 int s; 252 253 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 254 return (error); 255 256 if (tp->t_linesw && (tp->t_linesw->l_no == SLIPDISC)) 257 return (0); 258 259 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 260 if (sc->sc_ttyp == NULL) { 261 if (slinit(sc) == 0) 262 return (ENOBUFS); 263 tp->t_sc = (caddr_t)sc; 264 sc->sc_ttyp = tp; 265 sc->sc_if.if_baudrate = tp->t_ospeed; 266 s = spltty(); 267 tp->t_state |= TS_ISOPEN | TS_XCLUDE; 268 splx(s); 269 ttyflush(tp, FREAD | FWRITE); 270#ifdef __NetBSD__ 271 /* 272 * make sure tty output queue is large enough 273 * to hold a full-sized packet (including frame 274 * end, and a possible extra frame end). full-sized 275 * packet occupies a max of 2*SLMAX bytes (because 276 * of possible escapes), and add two on for frame 277 * ends. 278 */ 279 s = spltty(); 280 if (tp->t_outq.c_cn < 2*SLMAX+2) { 281 sc->sc_oldbufsize = tp->t_outq.c_cn; 282 sc->sc_oldbufquot = tp->t_outq.c_cq != 0; 283 284 clfree(&tp->t_outq); 285 error = clalloc(&tp->t_outq, 2*SLMAX+2, 0); 286 if (error) { 287 splx(s); 288 return(error); 289 } 290 } else 291 sc->sc_oldbufsize = sc->sc_oldbufquot = 0; 292 splx(s); 293#endif /* __NetBSD__ */ 294 return (0); 295 } 296 return (ENXIO); 297} 298 299/* 300 * Line specific close routine. 301 * Detach the tty from the sl unit. 302 */ 303void 304slclose(tp) 305 struct tty *tp; 306{ 307 struct sl_softc *sc; 308 int s; 309 310 ttywflush(tp); 311 sc = tp->t_sc; 312 313 if (sc != NULL) { 314 s = splnet(); 315 if_down(&sc->sc_if); 316 IF_PURGE(&sc->sc_fastq); 317 splx(s); 318 319 s = spltty(); 320 tp->t_linesw = linesw[0]; /* default line disc. */ 321 tp->t_state = 0; 322 323 sc->sc_ttyp = NULL; 324 tp->t_sc = NULL; 325 326 m_freem(sc->sc_mbuf); 327 sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL; 328 IF_PURGE(&sc->sc_inq); 329 330 /* 331 * If necessary, install a new outq buffer of the 332 * appropriate size. 333 */ 334 if (sc->sc_oldbufsize != 0) { 335 clfree(&tp->t_outq); 336 clalloc(&tp->t_outq, sc->sc_oldbufsize, 337 sc->sc_oldbufquot); 338 } 339 splx(s); 340 } 341} 342 343/* 344 * Line specific (tty) ioctl routine. 345 * Provide a way to get the sl unit number. 346 */ 347/* ARGSUSED */ 348int 349sltioctl(tp, cmd, data, flag) 350 struct tty *tp; 351 u_long cmd; 352 caddr_t data; 353 int flag; 354{ 355 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 356 357 switch (cmd) { 358 case SLIOCGUNIT: 359 *(int *)data = sc->sc_unit; /* XXX */ 360 break; 361 362 default: 363 return (-1); 364 } 365 return (0); 366} 367 368/* 369 * Queue a packet. Start transmission if not active. 370 * Compression happens in slintr(); if we do it here, IP TOS 371 * will cause us to not compress "background" packets, because 372 * ordering gets trashed. It can be done for all packets in slintr(). 373 */ 374int 375sloutput(ifp, m, dst, rtp) 376 struct ifnet *ifp; 377 struct mbuf *m; 378 struct sockaddr *dst; 379 struct rtentry *rtp; 380{ 381 struct sl_softc *sc = ifp->if_softc; 382 struct ip *ip; 383 int s, error; 384 ALTQ_DECL(struct altq_pktattr pktattr;) 385 386 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr); 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 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 } 415 416 s = spltty(); 417 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) { 418 struct timeval tv; 419 420 /* if output's been stalled for too long, and restart */ 421 timersub(&time, &sc->sc_if.if_lastchange, &tv); 422 if (tv.tv_sec > 0) { 423 sc->sc_otimeout++; 424 slstart(sc->sc_ttyp); 425 } 426 } 427 splx(s); 428 429 s = splnet(); 430 if ((ip->ip_tos & IPTOS_LOWDELAY) != 0 431#ifdef ALTQ 432 && ALTQ_IS_ENABLED(&ifp->if_snd) == 0 433#endif 434 ) { 435 if (IF_QFULL(&sc->sc_fastq)) { 436 IF_DROP(&sc->sc_fastq); 437 m_freem(m); 438 error = ENOBUFS; 439 } else { 440 IF_ENQUEUE(&sc->sc_fastq, m); 441 error = 0; 442 } 443 } else 444 IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error); 445 if (error) { 446 splx(s); 447 ifp->if_oerrors++; 448 return (error); 449 } 450 sc->sc_if.if_lastchange = time; 451 splx(s); 452 453 s = spltty(); 454 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) 455 slstart(sc->sc_ttyp); 456 splx(s); 457 458 return (0); 459} 460 461/* 462 * Start output on interface. Get another datagram 463 * to send from the interface queue and map it to 464 * the interface before starting output. 465 */ 466void 467slstart(tp) 468 struct tty *tp; 469{ 470 int s; 471 472 /* 473 * If there is more in the output queue, just send it now. 474 * We are being called in lieu of ttstart and must do what 475 * it would. 476 */ 477 if (tp->t_outq.c_cc != 0) { 478 (*tp->t_oproc)(tp); 479 if (tp->t_outq.c_cc > SLIP_HIWAT) 480 return; 481 } 482 483 /* 484 * This happens briefly when the line shuts down. 485 */ 486 if (tp->t_sc == NULL) 487 return; 488 489 s = splimp(); 490 schednetisr(NETISR_SLIP); 491 splx(s); 492} 493 494/* 495 * Copy data buffer to mbuf chain; add ifnet pointer. 496 */ 497static struct mbuf * 498sl_btom(sc, len) 499 struct sl_softc *sc; 500 int len; 501{ 502 struct mbuf *m; 503 504 MGETHDR(m, M_DONTWAIT, MT_DATA); 505 if (m == NULL) 506 return (NULL); 507 508 /* 509 * Allocate a new input buffer and swap. 510 */ 511 m = sc->sc_mbuf; 512 MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA); 513 if (sc->sc_mbuf == NULL) { 514 sc->sc_mbuf = m; 515 return (NULL); 516 } 517 MCLGET(sc->sc_mbuf, M_DONTWAIT); 518 if ((sc->sc_mbuf->m_flags & M_EXT) == 0) { 519 m_freem(sc->sc_mbuf); 520 sc->sc_mbuf = m; 521 return (NULL); 522 } 523 sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 524 sc->sc_mbuf->m_ext.ext_size; 525 526 m->m_data = sc->sc_pktstart; 527 528 m->m_pkthdr.len = m->m_len = len; 529 m->m_pkthdr.rcvif = &sc->sc_if; 530 return (m); 531} 532 533/* 534 * tty interface receiver interrupt. 535 */ 536void 537slinput(c, tp) 538 int c; 539 struct tty *tp; 540{ 541 struct sl_softc *sc; 542 struct mbuf *m; 543 int len; 544 int s; 545 546 tk_nin++; 547 sc = (struct sl_softc *)tp->t_sc; 548 if (sc == NULL) 549 return; 550 if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 && 551 (tp->t_cflag & CLOCAL) == 0)) { 552 sc->sc_flags |= SC_ERROR; 553 return; 554 } 555 c &= TTY_CHARMASK; 556 557 ++sc->sc_if.if_ibytes; 558 559 if (sc->sc_if.if_flags & IFF_DEBUG) { 560 if (c == ABT_ESC) { 561 /* 562 * If we have a previous abort, see whether 563 * this one is within the time limit. 564 */ 565 if (sc->sc_abortcount && 566 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 567 sc->sc_abortcount = 0; 568 /* 569 * If we see an abort after "idle" time, count it; 570 * record when the first abort escape arrived. 571 */ 572 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 573 if (++sc->sc_abortcount == 1) 574 sc->sc_starttime = time.tv_sec; 575 if (sc->sc_abortcount >= ABT_COUNT) { 576 slclose(tp); 577 return; 578 } 579 } 580 } else 581 sc->sc_abortcount = 0; 582 sc->sc_lasttime = time.tv_sec; 583 } 584 585 switch (c) { 586 587 case TRANS_FRAME_ESCAPE: 588 if (sc->sc_escape) 589 c = FRAME_ESCAPE; 590 break; 591 592 case TRANS_FRAME_END: 593 if (sc->sc_escape) 594 c = FRAME_END; 595 break; 596 597 case FRAME_ESCAPE: 598 sc->sc_escape = 1; 599 return; 600 601 case FRAME_END: 602 if(sc->sc_flags & SC_ERROR) { 603 sc->sc_flags &= ~SC_ERROR; 604 goto newpack; 605 } 606 len = sc->sc_mp - sc->sc_pktstart; 607 if (len < 3) 608 /* less than min length packet - ignore */ 609 goto newpack; 610 611 m = sl_btom(sc, len); 612 if (m == NULL) 613 goto error; 614 615 IF_ENQUEUE(&sc->sc_inq, m); 616 s = splimp(); 617 schednetisr(NETISR_SLIP); 618 splx(s); 619 goto newpack; 620 } 621 if (sc->sc_mp < sc->sc_ep) { 622 *sc->sc_mp++ = c; 623 sc->sc_escape = 0; 624 return; 625 } 626 627 /* can't put lower; would miss an extra frame */ 628 sc->sc_flags |= SC_ERROR; 629 630error: 631 sc->sc_if.if_ierrors++; 632newpack: 633 sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 634 BUFOFFSET; 635 sc->sc_escape = 0; 636} 637 638void 639slintr(void) 640{ 641 struct sl_softc *sc; 642 struct tty *tp; 643 struct mbuf *m; 644 int i, s, len; 645 u_char *pktstart, c; 646#if NBPFILTER > 0 647 u_char chdr[CHDR_LEN]; 648#endif 649 650 for (i = 0; i < NSL; i++) { 651 sc = &sl_softc[i]; 652 tp = sc->sc_ttyp; 653 654 if (tp == NULL) 655 continue; 656 657 /* 658 * Output processing loop. 659 */ 660 for (;;) { 661 struct ip *ip; 662 struct mbuf *m2; 663#if NBPFILTER > 0 664 struct mbuf *bpf_m; 665#endif 666 667 /* 668 * Do not remove the packet from the queue if it 669 * doesn't look like it will fit into the current 670 * serial output queue. With a packet full of 671 * escapes, this could be as bad as MTU*2+2. 672 */ 673 s = spltty(); 674 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 675 2*sc->sc_if.if_mtu+2) { 676 splx(s); 677 break; 678 } 679 splx(s); 680 681 /* 682 * Get a packet and send it to the interface. 683 */ 684 s = splnet(); 685 IF_DEQUEUE(&sc->sc_fastq, m); 686 if (m) 687 sc->sc_if.if_omcasts++; /* XXX */ 688 else 689 IFQ_DEQUEUE(&sc->sc_if.if_snd, m); 690 splx(s); 691 692 if (m == NULL) 693 break; 694 695 /* 696 * We do the header compression here rather than in 697 * sloutput() because the packets will be out of order 698 * if we are using TOS queueing, and the connection 699 * ID compression will get munged when this happens. 700 */ 701#if NBPFILTER > 0 702 if (sc->sc_if.if_bpf) { 703 /* 704 * We need to save the TCP/IP header before 705 * it's compressed. To avoid complicated 706 * code, we just make a deep copy of the 707 * entire packet (since this is a serial 708 * line, packets should be short and/or the 709 * copy should be negligible cost compared 710 * to the packet transmission time). 711 */ 712 bpf_m = m_dup(m, 0, M_COPYALL, M_DONTWAIT); 713 } else 714 bpf_m = NULL; 715#endif 716 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 717 if (sc->sc_if.if_flags & SC_COMPRESS) 718 *mtod(m, u_char *) |= 719 sl_compress_tcp(m, ip, 720 &sc->sc_comp, 1); 721 } 722#if NBPFILTER > 0 723 if (sc->sc_if.if_bpf && bpf_m != NULL) { 724 /* 725 * Put the SLIP pseudo-"link header" in 726 * place. The compressed header is now 727 * at the beginning of the mbuf. 728 */ 729 struct mbuf n; 730 u_char *hp; 731 732 n.m_next = bpf_m; 733 n.m_data = n.m_dat; 734 n.m_len = SLIP_HDRLEN; 735 736 hp = mtod(&n, u_char *); 737 738 hp[SLX_DIR] = SLIPDIR_OUT; 739 memcpy(&hp[SLX_CHDR], mtod(m, caddr_t), 740 CHDR_LEN); 741 742 s = splnet(); 743 bpf_mtap(sc->sc_if.if_bpf, &n); 744 splx(s); 745 m_freem(bpf_m); 746 } 747#endif 748 sc->sc_if.if_lastchange = time; 749 750 s = spltty(); 751 752 /* 753 * The extra FRAME_END will start up a new packet, 754 * and thus will flush any accumulated garbage. We 755 * do this whenever the line may have been idle for 756 * some time. 757 */ 758 if (tp->t_outq.c_cc == 0) { 759 sc->sc_if.if_obytes++; 760 (void) putc(FRAME_END, &tp->t_outq); 761 } 762 763 while (m) { 764 u_char *bp, *cp, *ep; 765 766 bp = cp = mtod(m, u_char *); 767 ep = cp + m->m_len; 768 while (cp < ep) { 769 /* 770 * Find out how many bytes in the 771 * string we can handle without 772 * doing something special. 773 */ 774 while (cp < ep) { 775 switch (*cp++) { 776 case FRAME_ESCAPE: 777 case FRAME_END: 778 cp--; 779 goto out; 780 } 781 } 782 out: 783 if (cp > bp) { 784 /* 785 * Put N characters at once 786 * into the tty output queue. 787 */ 788 if (b_to_q(bp, cp - bp, 789 &tp->t_outq)) 790 break; 791 sc->sc_if.if_obytes += cp - bp; 792 } 793 /* 794 * If there are characters left in 795 * the mbuf, the first one must be 796 * special.. Put it out in a different 797 * form. 798 */ 799 if (cp < ep) { 800 if (putc(FRAME_ESCAPE, 801 &tp->t_outq)) 802 break; 803 if (putc(*cp++ == FRAME_ESCAPE ? 804 TRANS_FRAME_ESCAPE : 805 TRANS_FRAME_END, 806 &tp->t_outq)) { 807 (void) 808 unputc(&tp->t_outq); 809 break; 810 } 811 sc->sc_if.if_obytes += 2; 812 } 813 } 814 MFREE(m, m2); 815 m = m2; 816 } 817 818 if (putc(FRAME_END, &tp->t_outq)) { 819 /* 820 * Not enough room. Remove a char to make 821 * room and end the packet normally. If 822 * you get many collisions (more than one 823 * or two a day), you probably do not have 824 * enough clists and you should increase 825 * "nclist" in param.c 826 */ 827 (void) unputc(&tp->t_outq); 828 (void) putc(FRAME_END, &tp->t_outq); 829 sc->sc_if.if_collisions++; 830 } else { 831 sc->sc_if.if_obytes++; 832 sc->sc_if.if_opackets++; 833 } 834 835 /* 836 * We now have characters in the output queue, 837 * kick the serial port. 838 */ 839 (*tp->t_oproc)(tp); 840 splx(s); 841 } 842 843 /* 844 * Input processing loop. 845 */ 846 for (;;) { 847 s = spltty(); 848 IF_DEQUEUE(&sc->sc_inq, m); 849 splx(s); 850 if (m == NULL) 851 break; 852 pktstart = mtod(m, u_char *); 853 len = m->m_pkthdr.len; 854#if NBPFILTER > 0 855 if (sc->sc_if.if_bpf) { 856 /* 857 * Save the compressed header, so we 858 * can tack it on later. Note that we 859 * will end up copying garbage in some 860 * cases but this is okay. We remember 861 * where the buffer started so we can 862 * compute the new header length. 863 */ 864 memcpy(chdr, pktstart, CHDR_LEN); 865 } 866#endif /* NBPFILTER > 0 */ 867 if ((c = (*pktstart & 0xf0)) != (IPVERSION << 4)) { 868 if (c & 0x80) 869 c = TYPE_COMPRESSED_TCP; 870 else if (c == TYPE_UNCOMPRESSED_TCP) 871 *pktstart &= 0x4f; /* XXX */ 872 /* 873 * We've got something that's not an IP 874 * packet. If compression is enabled, 875 * try to decompress it. Otherwise, if 876 * `auto-enable' compression is on and 877 * it's a reasonable packet, decompress 878 * it and then enable compression. 879 * Otherwise, drop it. 880 */ 881 if (sc->sc_if.if_flags & SC_COMPRESS) { 882 len = sl_uncompress_tcp(&pktstart, len, 883 (u_int)c, &sc->sc_comp); 884 if (len <= 0) { 885 m_freem(m); 886 continue; 887 } 888 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 889 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 890 len = sl_uncompress_tcp(&pktstart, len, 891 (u_int)c, &sc->sc_comp); 892 if (len <= 0) { 893 m_freem(m); 894 continue; 895 } 896 sc->sc_if.if_flags |= SC_COMPRESS; 897 } else { 898 m_freem(m); 899 continue; 900 } 901 } 902 m->m_data = (caddr_t) pktstart; 903 m->m_pkthdr.len = m->m_len = len; 904#if NBPFILTER > 0 905 if (sc->sc_if.if_bpf) { 906 /* 907 * Put the SLIP pseudo-"link header" in place. 908 * Note this M_PREPEND() should bever fail, 909 * since we know we always have enough space 910 * in the input buffer. 911 */ 912 u_char *hp; 913 914 M_PREPEND(m, SLIP_HDRLEN, M_DONTWAIT); 915 if (m == NULL) 916 continue; 917 918 hp = mtod(m, u_char *); 919 hp[SLX_DIR] = SLIPDIR_IN; 920 memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN); 921 922 s = splnet(); 923 bpf_mtap(sc->sc_if.if_bpf, m); 924 splx(s); 925 926 m_adj(m, SLIP_HDRLEN); 927 } 928#endif /* NBPFILTER > 0 */ 929 /* 930 * If the packet will fit into a single 931 * header mbuf, copy it into one, to save 932 * memory. 933 */ 934 if (m->m_pkthdr.len < MHLEN) { 935 struct mbuf *n; 936 937 MGETHDR(n, M_DONTWAIT, MT_DATA); 938 M_COPY_PKTHDR(n, m); 939 memcpy(mtod(n, caddr_t), mtod(m, caddr_t), 940 m->m_pkthdr.len); 941 n->m_len = m->m_len; 942 m_freem(m); 943 m = n; 944 } 945 946 sc->sc_if.if_ipackets++; 947 sc->sc_if.if_lastchange = time; 948 949 s = splimp(); 950 if (IF_QFULL(&ipintrq)) { 951 IF_DROP(&ipintrq); 952 sc->sc_if.if_ierrors++; 953 sc->sc_if.if_iqdrops++; 954 m_freem(m); 955 } else { 956 IF_ENQUEUE(&ipintrq, m); 957 schednetisr(NETISR_IP); 958 } 959 splx(s); 960 } 961 } 962} 963 964/* 965 * Process an ioctl request. 966 */ 967int 968slioctl(ifp, cmd, data) 969 struct ifnet *ifp; 970 u_long cmd; 971 caddr_t data; 972{ 973 struct ifaddr *ifa = (struct ifaddr *)data; 974 struct ifreq *ifr = (struct ifreq *)data; 975 int s = splnet(), error = 0; 976 struct sl_softc *sc = ifp->if_softc; 977 978 switch (cmd) { 979 980 case SIOCSIFADDR: 981 if (ifa->ifa_addr->sa_family == AF_INET) 982 ifp->if_flags |= IFF_UP; 983 else 984 error = EAFNOSUPPORT; 985 break; 986 987 case SIOCSIFDSTADDR: 988 if (ifa->ifa_addr->sa_family != AF_INET) 989 error = EAFNOSUPPORT; 990 break; 991 992 case SIOCSIFMTU: 993 if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) { 994 error = EINVAL; 995 break; 996 } 997 sc->sc_if.if_mtu = ifr->ifr_mtu; 998 break; 999 1000 case SIOCGIFMTU: 1001 ifr->ifr_mtu = sc->sc_if.if_mtu; 1002 break; 1003 1004 case SIOCADDMULTI: 1005 case SIOCDELMULTI: 1006 if (ifr == 0) { 1007 error = EAFNOSUPPORT; /* XXX */ 1008 break; 1009 } 1010 switch (ifr->ifr_addr.sa_family) { 1011 1012#ifdef INET 1013 case AF_INET: 1014 break; 1015#endif 1016 1017 default: 1018 error = EAFNOSUPPORT; 1019 break; 1020 } 1021 break; 1022 1023 default: 1024 error = EINVAL; 1025 } 1026 splx(s); 1027 return (error); 1028} 1029#endif 1030