if_sl.c revision 1.66
1/* $NetBSD: if_sl.c,v 1.66 2001/01/10 23:29:42 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 * 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/conf.h> 85#include <sys/tty.h> 86#include <sys/kernel.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#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 189static int slinit __P((struct sl_softc *)); 190static struct mbuf *sl_btom __P((struct sl_softc *, int)); 191 192/* 193 * Called from boot code to establish sl interfaces. 194 */ 195void 196slattach() 197{ 198 struct sl_softc *sc; 199 int i = 0; 200 201 for (sc = sl_softc; i < NSL; sc++) { 202 sc->sc_unit = i; /* XXX */ 203 sprintf(sc->sc_if.if_xname, "sl%d", i++); 204 sc->sc_if.if_softc = sc; 205 sc->sc_if.if_mtu = SLMTU; 206 sc->sc_if.if_flags = 207 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 208 sc->sc_if.if_type = IFT_SLIP; 209 sc->sc_if.if_ioctl = slioctl; 210 sc->sc_if.if_output = sloutput; 211 sc->sc_if.if_dlt = DLT_SLIP; 212 sc->sc_fastq.ifq_maxlen = 32; 213 IFQ_SET_READY(&sc->sc_if.if_snd); 214 if_attach(&sc->sc_if); 215#if NBPFILTER > 0 216 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 217#endif 218 } 219} 220 221static int 222slinit(sc) 223 struct sl_softc *sc; 224{ 225 226 if (sc->sc_mbuf == NULL) { 227 MGETHDR(sc->sc_mbuf, M_WAIT, MT_DATA); 228 MCLGET(sc->sc_mbuf, M_WAIT); 229 } 230 sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 231 sc->sc_mbuf->m_ext.ext_size; 232 sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 233 BUFOFFSET; 234 235 sl_compress_init(&sc->sc_comp); 236 237 return (1); 238} 239 240/* 241 * Line specific open routine. 242 * Attach the given tty to the first available sl unit. 243 */ 244/* ARGSUSED */ 245int 246slopen(dev, tp) 247 dev_t dev; 248 struct tty *tp; 249{ 250 struct proc *p = curproc; /* XXX */ 251 struct sl_softc *sc; 252 int nsl; 253 int error; 254 int s; 255 256 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 257 return (error); 258 259 if (tp->t_linesw && (tp->t_linesw->l_no == SLIPDISC)) 260 return (0); 261 262 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 263 if (sc->sc_ttyp == NULL) { 264 if (slinit(sc) == 0) 265 return (ENOBUFS); 266 tp->t_sc = (caddr_t)sc; 267 sc->sc_ttyp = tp; 268 sc->sc_if.if_baudrate = tp->t_ospeed; 269 s = spltty(); 270 tp->t_state |= TS_ISOPEN | TS_XCLUDE; 271 splx(s); 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*SLMAX 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*SLMAX+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, 2*SLMAX+2, 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 */ 306void 307slclose(tp) 308 struct tty *tp; 309{ 310 struct sl_softc *sc; 311 int s; 312 313 ttywflush(tp); 314 s = splimp(); /* actually, max(spltty, splsoftnet) */ 315 tp->t_linesw = linesw[0]; /* default line discipline */ 316 tp->t_state = 0; 317 sc = (struct sl_softc *)tp->t_sc; 318 if (sc != NULL) { 319 if_down(&sc->sc_if); 320 sc->sc_ttyp = NULL; 321 tp->t_sc = NULL; 322 m_freem(sc->sc_mbuf); 323 sc->sc_mbuf = NULL; 324 sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL; 325 IF_PURGE(&sc->sc_fastq); 326 IF_PURGE(&sc->sc_inq); 327 } 328#ifdef __NetBSD__ 329 /* if necessary, install a new outq buffer of the appropriate size */ 330 if (sc->sc_oldbufsize != 0) { 331 clfree(&tp->t_outq); 332 clalloc(&tp->t_outq, sc->sc_oldbufsize, sc->sc_oldbufquot); 333 } 334#endif 335 splx(s); 336} 337 338/* 339 * Line specific (tty) ioctl routine. 340 * Provide a way to get the sl unit number. 341 */ 342/* ARGSUSED */ 343int 344sltioctl(tp, cmd, data, flag) 345 struct tty *tp; 346 u_long cmd; 347 caddr_t data; 348 int flag; 349{ 350 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 351 352 switch (cmd) { 353 case SLIOCGUNIT: 354 *(int *)data = sc->sc_unit; /* XXX */ 355 break; 356 357 default: 358 return (-1); 359 } 360 return (0); 361} 362 363/* 364 * Queue a packet. Start transmission if not active. 365 * Compression happens in slstart; if we do it here, IP TOS 366 * will cause us to not compress "background" packets, because 367 * ordering gets trashed. It can be done for all packets in slstart. 368 */ 369int 370sloutput(ifp, m, dst, rtp) 371 struct ifnet *ifp; 372 struct mbuf *m; 373 struct sockaddr *dst; 374 struct rtentry *rtp; 375{ 376 struct sl_softc *sc = ifp->if_softc; 377 struct ip *ip; 378 int s, error; 379 ALTQ_DECL(struct altq_pktattr pktattr;) 380 381 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr); 382 383 /* 384 * `Cannot happen' (see slioctl). Someday we will extend 385 * the line protocol to support other address families. 386 */ 387 if (dst->sa_family != AF_INET) { 388 printf("%s: af%d not supported\n", sc->sc_if.if_xname, 389 dst->sa_family); 390 m_freem(m); 391 sc->sc_if.if_noproto++; 392 return (EAFNOSUPPORT); 393 } 394 395 if (sc->sc_ttyp == NULL) { 396 m_freem(m); 397 return (ENETDOWN); /* sort of */ 398 } 399 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 400 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 401 m_freem(m); 402 printf("%s: no carrier and not local\n", sc->sc_if.if_xname); 403 return (EHOSTUNREACH); 404 } 405 ip = mtod(m, struct ip *); 406 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 407 m_freem(m); 408 return (ENETRESET); /* XXX ? */ 409 } 410 s = splimp(); 411 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) { 412 struct timeval tv; 413 414 /* if output's been stalled for too long, and restart */ 415 timersub(&time, &sc->sc_if.if_lastchange, &tv); 416 if (tv.tv_sec > 0) { 417 sc->sc_otimeout++; 418 slstart(sc->sc_ttyp); 419 } 420 } 421 if ((ip->ip_tos & IPTOS_LOWDELAY) != 0 422#ifdef ALTQ 423 && ALTQ_IS_ENABLED(&ifp->if_snd) == 0 424#endif 425 ) { 426 if (IF_QFULL(&sc->sc_fastq)) { 427 IF_DROP(&sc->sc_fastq); 428 m_freem(m); 429 error = ENOBUFS; 430 } else { 431 IF_ENQUEUE(&sc->sc_fastq, m); 432 error = 0; 433 } 434 } else 435 IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error); 436 if (error) { 437 splx(s); 438 ifp->if_oerrors++; 439 return (error); 440 } 441 sc->sc_if.if_lastchange = time; 442 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) 443 slstart(sc->sc_ttyp); 444 splx(s); 445 return (0); 446} 447 448/* 449 * Start output on interface. Get another datagram 450 * to send from the interface queue and map it to 451 * the interface before starting output. 452 */ 453void 454slstart(tp) 455 struct tty *tp; 456{ 457 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 458 struct mbuf *m; 459 u_char *cp; 460 struct ip *ip; 461 int s; 462 struct mbuf *m2; 463#if NBPFILTER > 0 464 u_char *bpfbuf; 465 int len = 0; 466#endif 467#ifndef __NetBSD__ /* XXX - cgd */ 468 extern int cfreecount; 469#endif 470#if NBPFILTER > 0 471 MALLOC(bpfbuf, u_char *, SLMAX + SLIP_HDRLEN, M_DEVBUF, M_NOWAIT); 472#endif 473 474 for (;;) { 475 /* 476 * If there is more in the output queue, just send it now. 477 * We are being called in lieu of ttstart and must do what 478 * it would. 479 */ 480 if (tp->t_outq.c_cc != 0) { 481 (*tp->t_oproc)(tp); 482 if (tp->t_outq.c_cc > SLIP_HIWAT) { 483#if NBPFILTER > 0 484 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 485#endif 486 return; 487 } 488 } 489 /* 490 * This happens briefly when the line shuts down. 491 */ 492 if (sc == NULL) { 493#if NBPFILTER > 0 494 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 495#endif 496 return; 497 } 498 499#ifdef __NetBSD__ /* XXX - cgd */ 500 /* 501 * Do not remove the packet from the IP queue if it 502 * doesn't look like the packet will fit into the 503 * current serial output queue, with a packet full of 504 * escapes this could be as bad as MTU*2+2. 505 */ 506 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*sc->sc_if.if_mtu+2) { 507#if NBPFILTER > 0 508 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 509#endif 510 return; 511 } 512#endif /* __NetBSD__ */ 513 514 /* 515 * Get a packet and send it to the interface. 516 */ 517 s = splimp(); 518 IF_DEQUEUE(&sc->sc_fastq, m); 519 if (m) 520 sc->sc_if.if_omcasts++; /* XXX */ 521 else 522 IFQ_DEQUEUE(&sc->sc_if.if_snd, m); 523 splx(s); 524 if (m == NULL) { 525#if NBPFILTER > 0 526 if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF); 527#endif 528 return; 529 } 530 531 /* 532 * We do the header compression here rather than in sloutput 533 * because the packets will be out of order if we are using TOS 534 * queueing, and the connection id compression will get 535 * munged when this happens. 536 */ 537#if NBPFILTER > 0 538 if (sc->sc_if.if_bpf && bpfbuf != NULL) { 539 /* 540 * We need to save the TCP/IP header before it's 541 * compressed. To avoid complicated code, we just 542 * copy the entire packet into a stack buffer (since 543 * this is a serial line, packets should be short 544 * and/or the copy should be negligible cost compared 545 * to the packet transmission time). 546 */ 547 struct mbuf *m1 = m; 548 u_char *cp = bpfbuf + SLIP_HDRLEN; 549 550 len = 0; 551 do { 552 int mlen = m1->m_len; 553 554 bcopy(mtod(m1, caddr_t), cp, mlen); 555 cp += mlen; 556 len += mlen; 557 } while ((m1 = m1->m_next) != NULL); 558 } 559#endif 560 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 561 if (sc->sc_if.if_flags & SC_COMPRESS) 562 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 563 &sc->sc_comp, 1); 564 } 565#if NBPFILTER > 0 566 if (sc->sc_if.if_bpf && bpfbuf != NULL) { 567 /* 568 * Put the SLIP pseudo-"link header" in place. The 569 * compressed header is now at the beginning of the 570 * mbuf. 571 */ 572 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 573 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 574 bpf_tap(sc->sc_if.if_bpf, bpfbuf, len + SLIP_HDRLEN); 575 } 576#endif 577 sc->sc_if.if_lastchange = time; 578 579#ifndef __NetBSD__ /* XXX - cgd */ 580 /* 581 * If system is getting low on clists, just flush our 582 * output queue (if the stuff was important, it'll get 583 * retransmitted). 584 */ 585 if (cfreecount < CLISTRESERVE + SLMTU) { 586 m_freem(m); 587 sc->sc_if.if_collisions++; 588 continue; 589 } 590#endif /* !__NetBSD__ */ 591 /* 592 * The extra FRAME_END will start up a new packet, and thus 593 * will flush any accumulated garbage. We do this whenever 594 * the line may have been idle for some time. 595 */ 596 if (tp->t_outq.c_cc == 0) { 597 ++sc->sc_if.if_obytes; 598 (void) putc(FRAME_END, &tp->t_outq); 599 } 600 601 while (m) { 602 u_char *ep; 603 604 cp = mtod(m, u_char *); ep = cp + m->m_len; 605 while (cp < ep) { 606 /* 607 * Find out how many bytes in the string we can 608 * handle without doing something special. 609 */ 610 u_char *bp = cp; 611 612 while (cp < ep) { 613 switch (*cp++) { 614 case FRAME_ESCAPE: 615 case FRAME_END: 616 --cp; 617 goto out; 618 } 619 } 620 out: 621 if (cp > bp) { 622 /* 623 * Put n characters at once 624 * into the tty output queue. 625 */ 626#ifdef __NetBSD__ /* XXX - cgd */ 627 if (b_to_q((u_char *)bp, cp - bp, 628#else 629 if (b_to_q((char *)bp, cp - bp, 630#endif 631 &tp->t_outq)) 632 break; 633 sc->sc_if.if_obytes += cp - bp; 634 } 635 /* 636 * If there are characters left in the mbuf, 637 * the first one must be special.. 638 * Put it out in a different form. 639 */ 640 if (cp < ep) { 641 if (putc(FRAME_ESCAPE, &tp->t_outq)) 642 break; 643 if (putc(*cp++ == FRAME_ESCAPE ? 644 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 645 &tp->t_outq)) { 646 (void) unputc(&tp->t_outq); 647 break; 648 } 649 sc->sc_if.if_obytes += 2; 650 } 651 } 652 MFREE(m, m2); 653 m = m2; 654 } 655 656 if (putc(FRAME_END, &tp->t_outq)) { 657 /* 658 * Not enough room. Remove a char to make room 659 * and end the packet normally. 660 * If you get many collisions (more than one or two 661 * a day) you probably do not have enough clists 662 * and you should increase "nclist" in param.c. 663 */ 664 (void) unputc(&tp->t_outq); 665 (void) putc(FRAME_END, &tp->t_outq); 666 sc->sc_if.if_collisions++; 667 } else { 668 ++sc->sc_if.if_obytes; 669 sc->sc_if.if_opackets++; 670 } 671 } 672} 673 674/* 675 * Copy data buffer to mbuf chain; add ifnet pointer. 676 */ 677static struct mbuf * 678sl_btom(sc, len) 679 struct sl_softc *sc; 680 int len; 681{ 682 struct mbuf *m; 683 684 MGETHDR(m, M_DONTWAIT, MT_DATA); 685 if (m == NULL) 686 return (NULL); 687 688 /* 689 * Allocate a new input buffer and swap. 690 */ 691 m = sc->sc_mbuf; 692 MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA); 693 if (sc->sc_mbuf == NULL) { 694 sc->sc_mbuf = m; 695 return (NULL); 696 } 697 MCLGET(sc->sc_mbuf, M_DONTWAIT); 698 if ((sc->sc_mbuf->m_flags & M_EXT) == 0) { 699 sc->sc_mbuf = m; 700 return (NULL); 701 } 702 sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 703 sc->sc_mbuf->m_ext.ext_size; 704 705 m->m_data = sc->sc_pktstart; 706 707 m->m_pkthdr.len = m->m_len = len; 708 m->m_pkthdr.rcvif = &sc->sc_if; 709 return (m); 710} 711 712/* 713 * tty interface receiver interrupt. 714 */ 715void 716slinput(c, tp) 717 int c; 718 struct tty *tp; 719{ 720 struct sl_softc *sc; 721 struct mbuf *m; 722 int len; 723 int s; 724 725 tk_nin++; 726 sc = (struct sl_softc *)tp->t_sc; 727 if (sc == NULL) 728 return; 729 if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 && 730 (tp->t_cflag & CLOCAL) == 0)) { 731 sc->sc_flags |= SC_ERROR; 732 return; 733 } 734 c &= TTY_CHARMASK; 735 736 ++sc->sc_if.if_ibytes; 737 738 if (sc->sc_if.if_flags & IFF_DEBUG) { 739 if (c == ABT_ESC) { 740 /* 741 * If we have a previous abort, see whether 742 * this one is within the time limit. 743 */ 744 if (sc->sc_abortcount && 745 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 746 sc->sc_abortcount = 0; 747 /* 748 * If we see an abort after "idle" time, count it; 749 * record when the first abort escape arrived. 750 */ 751 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 752 if (++sc->sc_abortcount == 1) 753 sc->sc_starttime = time.tv_sec; 754 if (sc->sc_abortcount >= ABT_COUNT) { 755 slclose(tp); 756 return; 757 } 758 } 759 } else 760 sc->sc_abortcount = 0; 761 sc->sc_lasttime = time.tv_sec; 762 } 763 764 switch (c) { 765 766 case TRANS_FRAME_ESCAPE: 767 if (sc->sc_escape) 768 c = FRAME_ESCAPE; 769 break; 770 771 case TRANS_FRAME_END: 772 if (sc->sc_escape) 773 c = FRAME_END; 774 break; 775 776 case FRAME_ESCAPE: 777 sc->sc_escape = 1; 778 return; 779 780 case FRAME_END: 781 if(sc->sc_flags & SC_ERROR) { 782 sc->sc_flags &= ~SC_ERROR; 783 goto newpack; 784 } 785 len = sc->sc_mp - sc->sc_pktstart; 786 if (len < 3) 787 /* less than min length packet - ignore */ 788 goto newpack; 789 790 m = sl_btom(sc, len); 791 if (m == NULL) 792 goto error; 793 794 IF_ENQUEUE(&sc->sc_inq, m); 795 s = splimp(); 796 schednetisr(NETISR_SLIP); 797 splx(s); 798 goto newpack; 799 } 800 if (sc->sc_mp < sc->sc_ep) { 801 *sc->sc_mp++ = c; 802 sc->sc_escape = 0; 803 return; 804 } 805 806 /* can't put lower; would miss an extra frame */ 807 sc->sc_flags |= SC_ERROR; 808 809error: 810 sc->sc_if.if_ierrors++; 811newpack: 812 sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf + 813 BUFOFFSET; 814 sc->sc_escape = 0; 815} 816 817void 818slintr(void) 819{ 820 struct sl_softc *sc; 821 struct mbuf *m; 822 int i, s, len; 823 u_char *pktstart, c; 824#if NBPFILTER > 0 825 u_char chdr[CHDR_LEN]; 826#endif 827 828 for (i = 0; i < NSL; i++) { 829 sc = &sl_softc[i]; 830 for (;;) { 831 s = spltty(); 832 IF_DEQUEUE(&sc->sc_inq, m); 833 splx(s); 834 if (m == NULL) 835 break; 836 pktstart = mtod(m, u_char *); 837 len = m->m_pkthdr.len; 838#if NBPFILTER > 0 839 if (sc->sc_if.if_bpf) { 840 /* 841 * Save the compressed header, so we 842 * can tack it on later. Note that we 843 * will end up copying garbage in some 844 * cases but this is okay. We remember 845 * where the buffer started so we can 846 * compute the new header length. 847 */ 848 memcpy(chdr, pktstart, CHDR_LEN); 849 } 850#endif /* NBPFILTER > 0 */ 851 if ((c = (*pktstart & 0xf0)) != (IPVERSION << 4)) { 852 if (c & 0x80) 853 c = TYPE_COMPRESSED_TCP; 854 else if (c == TYPE_UNCOMPRESSED_TCP) 855 *pktstart &= 0x4f; /* XXX */ 856 /* 857 * We've got something that's not an IP 858 * packet. If compression is enabled, 859 * try to decompress it. Otherwise, if 860 * `auto-enable' compression is on and 861 * it's a reasonable packet, decompress 862 * it and then enable compression. 863 * Otherwise, drop it. 864 */ 865 if (sc->sc_if.if_flags & SC_COMPRESS) { 866 len = sl_uncompress_tcp(&pktstart, len, 867 (u_int)c, &sc->sc_comp); 868 if (len <= 0) { 869 m_freem(m); 870 continue; 871 } 872 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 873 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 874 len = sl_uncompress_tcp(&pktstart, len, 875 (u_int)c, &sc->sc_comp); 876 if (len <= 0) { 877 m_freem(m); 878 continue; 879 } 880 sc->sc_if.if_flags |= SC_COMPRESS; 881 } else { 882 m_freem(m); 883 continue; 884 } 885 } 886 m->m_data = (caddr_t) pktstart; 887 m->m_pkthdr.len = m->m_len = len; 888#if NBPFILTER > 0 889 if (sc->sc_if.if_bpf) { 890 /* 891 * Put the SLIP pseudo-"link header" in place. 892 * Note this M_PREPEND() should bever fail, 893 * since we know we always have enough space 894 * in the input buffer. 895 */ 896 u_char *hp; 897 898 M_PREPEND(m, SLIP_HDRLEN, M_DONTWAIT); 899 if (m == NULL) 900 continue; 901 902 hp = mtod(m, u_char *); 903 hp[SLX_DIR] = SLIPDIR_IN; 904 memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN); 905 906 s = splnet(); 907 bpf_mtap(sc->sc_if.if_bpf, m); 908 splx(s); 909 910 m_adj(m, SLIP_HDRLEN); 911 } 912#endif /* NBPFILTER > 0 */ 913 /* 914 * If the packet will fit into a single 915 * header mbuf, copy it into one, to save 916 * memory. 917 */ 918 if (m->m_pkthdr.len < MHLEN) { 919 struct mbuf *n; 920 921 MGETHDR(n, M_DONTWAIT, MT_DATA); 922 M_COPY_PKTHDR(n, m); 923 memcpy(mtod(n, caddr_t), mtod(m, caddr_t), 924 m->m_pkthdr.len); 925 n->m_len = m->m_len; 926 m_freem(m); 927 m = n; 928 } 929 930 sc->sc_if.if_ipackets++; 931 sc->sc_if.if_lastchange = time; 932 933 s = splimp(); 934 if (IF_QFULL(&ipintrq)) { 935 IF_DROP(&ipintrq); 936 sc->sc_if.if_ierrors++; 937 sc->sc_if.if_iqdrops++; 938 m_freem(m); 939 } else { 940 IF_ENQUEUE(&ipintrq, m); 941 schednetisr(NETISR_IP); 942 } 943 splx(s); 944 } 945 } 946} 947 948/* 949 * Process an ioctl request. 950 */ 951int 952slioctl(ifp, cmd, data) 953 struct ifnet *ifp; 954 u_long cmd; 955 caddr_t data; 956{ 957 struct ifaddr *ifa = (struct ifaddr *)data; 958 struct ifreq *ifr = (struct ifreq *)data; 959 int s = splimp(), error = 0; 960 struct sl_softc *sc = ifp->if_softc; 961 962 switch (cmd) { 963 964 case SIOCSIFADDR: 965 if (ifa->ifa_addr->sa_family == AF_INET) 966 ifp->if_flags |= IFF_UP; 967 else 968 error = EAFNOSUPPORT; 969 break; 970 971 case SIOCSIFDSTADDR: 972 if (ifa->ifa_addr->sa_family != AF_INET) 973 error = EAFNOSUPPORT; 974 break; 975 976 case SIOCSIFMTU: 977 if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) { 978 error = EINVAL; 979 break; 980 } 981 sc->sc_if.if_mtu = ifr->ifr_mtu; 982 break; 983 984 case SIOCGIFMTU: 985 ifr->ifr_mtu = sc->sc_if.if_mtu; 986 break; 987 988 case SIOCADDMULTI: 989 case SIOCDELMULTI: 990 if (ifr == 0) { 991 error = EAFNOSUPPORT; /* XXX */ 992 break; 993 } 994 switch (ifr->ifr_addr.sa_family) { 995 996#ifdef INET 997 case AF_INET: 998 break; 999#endif 1000 1001 default: 1002 error = EAFNOSUPPORT; 1003 break; 1004 } 1005 break; 1006 1007 default: 1008 error = EINVAL; 1009 } 1010 splx(s); 1011 return (error); 1012} 1013#endif 1014