1 /* 2 * Copyright (c) 1987, 1989, 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)if_sl.c 8.6 (Berkeley) 2/1/94 34 * $FreeBSD: src/sys/net/if_sl.c,v 1.84.2.2 2002/02/13 00:43:10 dillon Exp $ 35 * $DragonFly: src/sys/net/sl/if_sl.c,v 1.10 2004/01/06 03:17:26 dillon Exp $ 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 "use_sl.h" 70 71 #include "opt_inet.h" 72 #if !defined(KLD_MODULE) 73 #include "opt_slip.h" 74 #endif 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/proc.h> 78 #include <sys/malloc.h> 79 #include <sys/mbuf.h> 80 #include <sys/dkstat.h> 81 #include <sys/socket.h> 82 #include <sys/sockio.h> 83 #include <sys/fcntl.h> 84 #include <sys/signalvar.h> 85 #include <sys/tty.h> 86 #include <sys/clist.h> 87 #include <sys/kernel.h> 88 #include <sys/conf.h> 89 90 #include <net/if.h> 91 #include <net/if_types.h> 92 #include <net/netisr.h> 93 94 #if INET 95 #include <netinet/in.h> 96 #include <netinet/in_systm.h> 97 #include <netinet/in_var.h> 98 #include <netinet/ip.h> 99 #else 100 #error "Huh? Slip without inet?" 101 #endif 102 103 #include <net/slcompress.h> 104 #include "if_slvar.h" 105 #include <net/slip.h> 106 107 #include <net/bpf.h> 108 109 #ifdef __i386__ 110 #include <i386/isa/intr_machdep.h> 111 #endif 112 113 static void slattach (void *); 114 PSEUDO_SET(slattach, if_sl); 115 116 /* 117 * SLRMAX 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, SLRMAX can be at most 122 * MCLBYTES - 128 123 * 124 * SLMTU is the default transmit MTU. The transmit MTU should be kept 125 * small enough so that interactive use doesn't suffer, but large 126 * enough to provide good performance. 552 is a good choice for SLMTU 127 * because it is high enough to not fragment TCP packets being routed 128 * through this host. Packet fragmentation is bad with SLIP because 129 * fragment headers aren't compressed. The previous assumptions about 130 * the best MTU value don't really hold when using modern modems with 131 * BTLZ data compression because the modem buffers play a much larger 132 * role in interactive performance than the MTU. The MTU can be changed 133 * at any time to suit the specific environment with ifconfig(8), and 134 * its maximum value is defined as SLTMAX. SLTMAX must not be so large 135 * that it would overflow the stack if BPF is configured (XXX; if_ppp.c 136 * handles this better). 137 * 138 * SLIP_HIWAT is the amount of data that will be queued 'downstream' 139 * of us (i.e., in clists waiting to be picked up by the tty output 140 * interrupt). If we queue a lot of data downstream, it's immune to 141 * our t.o.s. queuing. 142 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 143 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 144 * wait is dependent on the ftp window size but that's typically 145 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 146 * the cost (in idle time on the wire) of the tty driver running 147 * off the end of its clists & having to call back slstart for a 148 * new packet. For a tty interface with any buffering at all, this 149 * cost will be zero. Even with a totally brain dead interface (like 150 * the one on a typical workstation), the cost will be <= 1 character 151 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 152 * at most 1% while maintaining good interactive response. 153 */ 154 #define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 155 #define SLRMAX (MCLBYTES - BUFOFFSET) 156 #define SLBUFSIZE (SLRMAX + BUFOFFSET) 157 #ifndef SLMTU 158 #define SLMTU 552 /* default MTU */ 159 #endif 160 #define SLTMAX 1500 /* maximum MTU */ 161 #define SLIP_HIWAT roundup(50,CBSIZE) 162 #define CLISTRESERVE 1024 /* Can't let clists get too low */ 163 164 /* 165 * SLIP ABORT ESCAPE MECHANISM: 166 * (inspired by HAYES modem escape arrangement) 167 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 168 * within window time signals a "soft" exit from slip mode by remote end 169 * if the IFF_DEBUG flag is on. 170 */ 171 #define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 172 #define ABT_IDLE 1 /* in seconds - idle before an escape */ 173 #define ABT_COUNT 3 /* count of escapes for abort */ 174 #define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 175 176 static struct sl_softc sl_softc[NSL]; 177 178 #define FRAME_END 0xc0 /* Frame End */ 179 #define FRAME_ESCAPE 0xdb /* Frame Esc */ 180 #define TRANS_FRAME_END 0xdc /* transposed frame end */ 181 #define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 182 183 static int slinit (struct sl_softc *); 184 static struct mbuf *sl_btom (struct sl_softc *, int); 185 static timeout_t sl_keepalive; 186 static timeout_t sl_outfill; 187 static int slclose (struct tty *,int); 188 static int slinput (int, struct tty *); 189 static int slioctl (struct ifnet *, u_long, caddr_t); 190 static int sltioctl (struct tty *, u_long, caddr_t, int, struct thread *); 191 static int slopen (dev_t, struct tty *); 192 static int sloutput (struct ifnet *, 193 struct mbuf *, struct sockaddr *, struct rtentry *); 194 static int slstart (struct tty *); 195 196 static struct linesw slipdisc = { 197 slopen, slclose, l_noread, l_nowrite, 198 sltioctl, slinput, slstart, ttymodem, 199 FRAME_END 200 }; 201 202 /* 203 * Called from boot code to establish sl interfaces. 204 */ 205 static void 206 slattach(dummy) 207 void *dummy; 208 { 209 struct sl_softc *sc; 210 int i = 0; 211 212 linesw[SLIPDISC] = slipdisc; 213 214 for (sc = sl_softc; i < NSL; sc++) { 215 if_initname(&(sc->sc_if), "sl", i++); 216 sc->sc_if.if_mtu = SLMTU; 217 sc->sc_if.if_flags = 218 #ifdef SLIP_IFF_OPTS 219 SLIP_IFF_OPTS; 220 #else 221 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 222 #endif 223 sc->sc_if.if_type = IFT_SLIP; 224 sc->sc_if.if_ioctl = slioctl; 225 sc->sc_if.if_output = sloutput; 226 sc->sc_if.if_snd.ifq_maxlen = 50; 227 sc->sc_fastq.ifq_maxlen = 32; 228 sc->sc_if.if_linkmib = sc; 229 sc->sc_if.if_linkmiblen = sizeof *sc; 230 if_attach(&sc->sc_if); 231 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 232 } 233 } 234 235 static int 236 slinit(sc) 237 struct sl_softc *sc; 238 { 239 caddr_t p; 240 241 #ifdef __i386__ 242 int s; 243 244 s = splhigh(); 245 tty_imask |= net_imask; 246 net_imask = tty_imask; 247 update_intr_masks(); 248 splx(s); 249 if (bootverbose) 250 printf("new imasks: bio %x, tty %x, net %x\n", 251 bio_imask, tty_imask, net_imask); 252 #endif 253 if (sc->sc_ep == (u_char *) 0) { 254 MCLALLOC(p, M_WAIT); 255 if (p) 256 sc->sc_ep = (u_char *)p + SLBUFSIZE; 257 else { 258 printf("sl%ld: can't allocate buffer\n", 259 (long)(sc - sl_softc)); 260 return (0); 261 } 262 } 263 sc->sc_buf = sc->sc_ep - SLRMAX; 264 sc->sc_mp = sc->sc_buf; 265 sl_compress_init(&sc->sc_comp, -1); 266 return (1); 267 } 268 269 /* 270 * Line specific open routine. 271 * Attach the given tty to the first available sl unit. 272 */ 273 /* ARGSUSED */ 274 static int 275 slopen(dev_t dev, struct tty *tp) 276 { 277 struct sl_softc *sc; 278 int nsl; 279 int s, error; 280 struct thread *td = curthread; /* XXX */ 281 282 error = suser(td); 283 if (error) 284 return (error); 285 286 if (tp->t_line == SLIPDISC) 287 return (0); 288 289 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 290 if (sc->sc_ttyp == NULL && !(sc->sc_flags & SC_STATIC)) { 291 if (slinit(sc) == 0) 292 return (ENOBUFS); 293 tp->t_sc = (caddr_t)sc; 294 sc->sc_ttyp = tp; 295 sc->sc_if.if_baudrate = tp->t_ospeed; 296 ttyflush(tp, FREAD | FWRITE); 297 298 tp->t_line = SLIPDISC; 299 /* 300 * We don't use t_canq or t_rawq, so reduce their 301 * cblock resources to 0. Reserve enough cblocks 302 * for t_outq to guarantee that we can fit a full 303 * packet if the SLIP_HIWAT check allows slstart() 304 * to loop. Use the same value for the cblock 305 * limit since the reserved blocks should always 306 * be enough. Reserving cblocks probably makes 307 * the CLISTRESERVE check unnecessary and wasteful. 308 */ 309 clist_alloc_cblocks(&tp->t_canq, 0, 0); 310 clist_alloc_cblocks(&tp->t_outq, 311 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, 312 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); 313 clist_alloc_cblocks(&tp->t_rawq, 0, 0); 314 315 s = splnet(); 316 if_up(&sc->sc_if); 317 splx(s); 318 return (0); 319 } 320 return (ENXIO); 321 } 322 323 /* 324 * Line specific close routine. 325 * Detach the tty from the sl unit. 326 */ 327 static int 328 slclose(tp,flag) 329 struct tty *tp; 330 int flag; 331 { 332 struct sl_softc *sc; 333 int s; 334 335 ttyflush(tp, FREAD | FWRITE); 336 /* 337 * XXX the placement of the following spl is misleading. tty 338 * interrupts must be blocked across line discipline switches 339 * and throughout closes to avoid races. 340 */ 341 s = splimp(); /* actually, max(spltty, splnet) */ 342 clist_free_cblocks(&tp->t_outq); 343 tp->t_line = 0; 344 sc = (struct sl_softc *)tp->t_sc; 345 if (sc != NULL) { 346 if (sc->sc_outfill) { 347 sc->sc_outfill = 0; 348 untimeout(sl_outfill, sc, sc->sc_ofhandle); 349 } 350 if (sc->sc_keepalive) { 351 sc->sc_keepalive = 0; 352 untimeout(sl_keepalive, sc, sc->sc_kahandle); 353 } 354 if_down(&sc->sc_if); 355 sc->sc_flags &= SC_STATIC; 356 sc->sc_ttyp = NULL; 357 tp->t_sc = NULL; 358 m_mclfree((caddr_t)(sc->sc_ep - SLBUFSIZE)); 359 sc->sc_ep = 0; 360 sc->sc_mp = 0; 361 sc->sc_buf = 0; 362 } 363 splx(s); 364 return 0; 365 } 366 367 /* 368 * Line specific (tty) ioctl routine. 369 * Provide a way to get the sl unit number. 370 */ 371 /* ARGSUSED */ 372 static int 373 sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct thread *p) 374 { 375 struct sl_softc *sc = (struct sl_softc *)tp->t_sc, *nc, *tmpnc; 376 int s, nsl; 377 378 s = splimp(); 379 switch (cmd) { 380 case SLIOCGUNIT: 381 *(int *)data = sc->sc_if.if_dunit; 382 break; 383 384 case SLIOCSUNIT: 385 if (sc->sc_if.if_dunit != *(u_int *)data) { 386 for (nsl = NSL, nc = sl_softc; --nsl >= 0; nc++) { 387 if ( nc->sc_if.if_dunit == *(u_int *)data 388 && nc->sc_ttyp == NULL 389 ) { 390 tmpnc = malloc(sizeof *tmpnc, M_TEMP, 391 M_NOWAIT); 392 if (tmpnc == NULL) { 393 splx(s); 394 return (ENOMEM); 395 } 396 *tmpnc = *nc; 397 *nc = *sc; 398 nc->sc_if = tmpnc->sc_if; 399 tmpnc->sc_if = sc->sc_if; 400 *sc = *tmpnc; 401 free(tmpnc, M_TEMP); 402 if (sc->sc_if.if_flags & IFF_UP) { 403 if_down(&sc->sc_if); 404 if (!(nc->sc_if.if_flags & IFF_UP)) 405 if_up(&nc->sc_if); 406 } else if (nc->sc_if.if_flags & IFF_UP) 407 if_down(&nc->sc_if); 408 sc->sc_flags &= ~SC_STATIC; 409 sc->sc_flags |= (nc->sc_flags & SC_STATIC); 410 tp->t_sc = sc = nc; 411 clist_alloc_cblocks(&tp->t_outq, 412 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, 413 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); 414 sl_compress_init(&sc->sc_comp, -1); 415 goto slfound; 416 } 417 } 418 splx(s); 419 return (ENXIO); 420 } 421 slfound: 422 sc->sc_flags |= SC_STATIC; 423 break; 424 425 case SLIOCSKEEPAL: 426 sc->sc_keepalive = *(u_int *)data * hz; 427 if (sc->sc_keepalive) { 428 sc->sc_flags |= SC_KEEPALIVE; 429 sc->sc_kahandle = timeout(sl_keepalive, sc, 430 sc->sc_keepalive); 431 } else { 432 if ((sc->sc_flags & SC_KEEPALIVE) != 0) { 433 untimeout(sl_keepalive, sc, sc->sc_kahandle); 434 sc->sc_flags &= ~SC_KEEPALIVE; 435 } 436 } 437 break; 438 439 case SLIOCGKEEPAL: 440 *(int *)data = sc->sc_keepalive / hz; 441 break; 442 443 case SLIOCSOUTFILL: 444 sc->sc_outfill = *(u_int *)data * hz; 445 if (sc->sc_outfill) { 446 sc->sc_flags |= SC_OUTWAIT; 447 sc->sc_ofhandle = timeout(sl_outfill, sc, 448 sc->sc_outfill); 449 } else { 450 if ((sc->sc_flags & SC_OUTWAIT) != 0) { 451 untimeout(sl_outfill, sc, sc->sc_ofhandle); 452 sc->sc_flags &= ~SC_OUTWAIT; 453 } 454 } 455 break; 456 457 case SLIOCGOUTFILL: 458 *(int *)data = sc->sc_outfill / hz; 459 break; 460 461 default: 462 splx(s); 463 return (ENOIOCTL); 464 } 465 splx(s); 466 return (0); 467 } 468 469 /* 470 * Queue a packet. Start transmission if not active. 471 * Compression happens in slstart; if we do it here, IP TOS 472 * will cause us to not compress "background" packets, because 473 * ordering gets trashed. It can be done for all packets in slstart. 474 */ 475 static int 476 sloutput(ifp, m, dst, rtp) 477 struct ifnet *ifp; 478 struct mbuf *m; 479 struct sockaddr *dst; 480 struct rtentry *rtp; 481 { 482 struct sl_softc *sc = &sl_softc[ifp->if_dunit]; 483 struct ip *ip; 484 struct ifqueue *ifq; 485 int s; 486 487 /* 488 * `Cannot happen' (see slioctl). Someday we will extend 489 * the line protocol to support other address families. 490 */ 491 if (dst->sa_family != AF_INET) { 492 printf("%s: af%d not supported\n", sc->sc_if.if_xname, 493 dst->sa_family); 494 m_freem(m); 495 sc->sc_if.if_noproto++; 496 return (EAFNOSUPPORT); 497 } 498 499 if (sc->sc_ttyp == NULL || !(ifp->if_flags & IFF_UP)) { 500 m_freem(m); 501 return (ENETDOWN); 502 } 503 if ((sc->sc_ttyp->t_state & TS_CONNECTED) == 0) { 504 m_freem(m); 505 return (EHOSTUNREACH); 506 } 507 ifq = &sc->sc_if.if_snd; 508 ip = mtod(m, struct ip *); 509 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 510 m_freem(m); 511 return (ENETRESET); /* XXX ? */ 512 } 513 if (ip->ip_tos & IPTOS_LOWDELAY) 514 ifq = &sc->sc_fastq; 515 s = splimp(); 516 if (IF_QFULL(ifq)) { 517 IF_DROP(ifq); 518 m_freem(m); 519 splx(s); 520 sc->sc_if.if_oerrors++; 521 return (ENOBUFS); 522 } 523 IF_ENQUEUE(ifq, m); 524 if (sc->sc_ttyp->t_outq.c_cc == 0) 525 slstart(sc->sc_ttyp); 526 splx(s); 527 return (0); 528 } 529 530 /* 531 * Start output on interface. Get another datagram 532 * to send from the interface queue and map it to 533 * the interface before starting output. 534 */ 535 static int 536 slstart(tp) 537 struct tty *tp; 538 { 539 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 540 struct mbuf *m; 541 u_char *cp; 542 struct ip *ip; 543 int s; 544 u_char bpfbuf[SLTMAX + SLIP_HDRLEN]; 545 int len = 0; 546 547 for (;;) { 548 /* 549 * Call output process whether or not there is more in the 550 * output queue. We are being called in lieu of ttstart 551 * and must do what it would. 552 */ 553 (*tp->t_oproc)(tp); 554 555 if (tp->t_outq.c_cc != 0) { 556 if (sc != NULL) 557 sc->sc_flags &= ~SC_OUTWAIT; 558 if (tp->t_outq.c_cc > SLIP_HIWAT) 559 return 0; 560 } 561 562 /* 563 * This happens briefly when the line shuts down. 564 */ 565 if (sc == NULL) 566 return 0; 567 568 /* 569 * Get a packet and send it to the interface. 570 */ 571 s = splimp(); 572 IF_DEQUEUE(&sc->sc_fastq, m); 573 if (m) 574 sc->sc_if.if_omcasts++; /* XXX */ 575 else 576 IF_DEQUEUE(&sc->sc_if.if_snd, m); 577 splx(s); 578 if (m == NULL) 579 return 0; 580 581 /* 582 * We do the header compression here rather than in sloutput 583 * because the packets will be out of order if we are using TOS 584 * queueing, and the connection id compression will get 585 * munged when this happens. 586 */ 587 if (sc->sc_if.if_bpf) { 588 /* 589 * We need to save the TCP/IP header before it's 590 * compressed. To avoid complicated code, we just 591 * copy the entire packet into a stack buffer (since 592 * this is a serial line, packets should be short 593 * and/or the copy should be negligible cost compared 594 * to the packet transmission time). 595 */ 596 struct mbuf *m1 = m; 597 u_char *cp = bpfbuf + SLIP_HDRLEN; 598 599 len = 0; 600 do { 601 int mlen = m1->m_len; 602 603 bcopy(mtod(m1, caddr_t), cp, mlen); 604 cp += mlen; 605 len += mlen; 606 } while ((m1 = m1->m_next) != NULL); 607 } 608 ip = mtod(m, struct ip *); 609 if (ip->ip_v == IPVERSION && ip->ip_p == IPPROTO_TCP) { 610 if (sc->sc_if.if_flags & SC_COMPRESS) 611 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 612 &sc->sc_comp, 1); 613 } 614 if (sc->sc_if.if_bpf) { 615 /* 616 * Put the SLIP pseudo-"link header" in place. The 617 * compressed header is now at the beginning of the 618 * mbuf. 619 */ 620 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 621 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 622 bpf_tap(&sc->sc_if, bpfbuf, len + SLIP_HDRLEN); 623 } 624 625 /* 626 * If system is getting low on clists, just flush our 627 * output queue (if the stuff was important, it'll get 628 * retransmitted). Note that SLTMAX is used instead of 629 * the current if_mtu setting because connections that 630 * have already been established still use the original 631 * (possibly larger) mss. 632 */ 633 if (cfreecount < CLISTRESERVE + SLTMAX) { 634 m_freem(m); 635 sc->sc_if.if_collisions++; 636 continue; 637 } 638 639 sc->sc_flags &= ~SC_OUTWAIT; 640 /* 641 * The extra FRAME_END will start up a new packet, and thus 642 * will flush any accumulated garbage. We do this whenever 643 * the line may have been idle for some time. 644 */ 645 if (tp->t_outq.c_cc == 0) { 646 ++sc->sc_if.if_obytes; 647 (void) putc(FRAME_END, &tp->t_outq); 648 } 649 650 while (m) { 651 u_char *ep; 652 653 cp = mtod(m, u_char *); ep = cp + m->m_len; 654 while (cp < ep) { 655 /* 656 * Find out how many bytes in the string we can 657 * handle without doing something special. 658 */ 659 u_char *bp = cp; 660 661 while (cp < ep) { 662 switch (*cp++) { 663 case FRAME_ESCAPE: 664 case FRAME_END: 665 --cp; 666 goto out; 667 } 668 } 669 out: 670 if (cp > bp) { 671 /* 672 * Put n characters at once 673 * into the tty output queue. 674 */ 675 if (b_to_q((char *)bp, cp - bp, 676 &tp->t_outq)) 677 break; 678 sc->sc_if.if_obytes += cp - bp; 679 } 680 /* 681 * If there are characters left in the mbuf, 682 * the first one must be special.. 683 * Put it out in a different form. 684 */ 685 if (cp < ep) { 686 if (putc(FRAME_ESCAPE, &tp->t_outq)) 687 break; 688 if (putc(*cp++ == FRAME_ESCAPE ? 689 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 690 &tp->t_outq)) { 691 (void) unputc(&tp->t_outq); 692 break; 693 } 694 sc->sc_if.if_obytes += 2; 695 } 696 } 697 m = m_free(m); 698 } 699 700 if (putc(FRAME_END, &tp->t_outq)) { 701 /* 702 * Not enough room. Remove a char to make room 703 * and end the packet normally. 704 * If you get many collisions (more than one or two 705 * a day) you probably do not have enough clists 706 * and you should increase "nclist" in param.c. 707 */ 708 (void) unputc(&tp->t_outq); 709 (void) putc(FRAME_END, &tp->t_outq); 710 sc->sc_if.if_collisions++; 711 } else { 712 ++sc->sc_if.if_obytes; 713 sc->sc_if.if_opackets++; 714 } 715 } 716 return 0; 717 } 718 719 /* 720 * Copy data buffer to mbuf chain; add ifnet pointer. 721 */ 722 static struct mbuf * 723 sl_btom(sc, len) 724 struct sl_softc *sc; 725 int len; 726 { 727 struct mbuf *m; 728 729 MGETHDR(m, M_DONTWAIT, MT_DATA); 730 if (m == NULL) 731 return (NULL); 732 733 /* 734 * If we have more than MHLEN bytes, it's cheaper to 735 * queue the cluster we just filled & allocate a new one 736 * for the input buffer. Otherwise, fill the mbuf we 737 * allocated above. Note that code in the input routine 738 * guarantees that packet will fit in a cluster. 739 */ 740 if (len >= MHLEN) { 741 MCLGET(m, M_DONTWAIT); 742 if ((m->m_flags & M_EXT) == 0) { 743 /* 744 * we couldn't get a cluster - if memory's this 745 * low, it's time to start dropping packets. 746 */ 747 (void) m_free(m); 748 return (NULL); 749 } 750 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 751 m->m_data = (caddr_t)sc->sc_buf; 752 m->m_ext.ext_buf = (caddr_t)((intptr_t)sc->sc_buf &~ MCLOFSET); 753 } else 754 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 755 756 m->m_len = len; 757 m->m_pkthdr.len = len; 758 m->m_pkthdr.rcvif = &sc->sc_if; 759 return (m); 760 } 761 762 /* 763 * tty interface receiver interrupt. 764 */ 765 static int 766 slinput(c, tp) 767 int c; 768 struct tty *tp; 769 { 770 struct sl_softc *sc; 771 struct mbuf *m; 772 int len; 773 u_char chdr[CHDR_LEN]; 774 775 tk_nin++; 776 sc = (struct sl_softc *)tp->t_sc; 777 if (sc == NULL) 778 return 0; 779 if (c & TTY_ERRORMASK || (tp->t_state & TS_CONNECTED) == 0) { 780 sc->sc_flags |= SC_ERROR; 781 return 0; 782 } 783 c &= TTY_CHARMASK; 784 785 ++sc->sc_if.if_ibytes; 786 787 if (sc->sc_if.if_flags & IFF_DEBUG) { 788 if (c == ABT_ESC) { 789 /* 790 * If we have a previous abort, see whether 791 * this one is within the time limit. 792 */ 793 if (sc->sc_abortcount && 794 time_second >= sc->sc_starttime + ABT_WINDOW) 795 sc->sc_abortcount = 0; 796 /* 797 * If we see an abort after "idle" time, count it; 798 * record when the first abort escape arrived. 799 */ 800 if (time_second >= sc->sc_lasttime + ABT_IDLE) { 801 if (++sc->sc_abortcount == 1) 802 sc->sc_starttime = time_second; 803 if (sc->sc_abortcount >= ABT_COUNT) { 804 slclose(tp,0); 805 return 0; 806 } 807 } 808 } else 809 sc->sc_abortcount = 0; 810 sc->sc_lasttime = time_second; 811 } 812 813 switch (c) { 814 815 case TRANS_FRAME_ESCAPE: 816 if (sc->sc_escape) 817 c = FRAME_ESCAPE; 818 break; 819 820 case TRANS_FRAME_END: 821 if (sc->sc_escape) 822 c = FRAME_END; 823 break; 824 825 case FRAME_ESCAPE: 826 sc->sc_escape = 1; 827 return 0; 828 829 case FRAME_END: 830 sc->sc_flags &= ~SC_KEEPALIVE; 831 if(sc->sc_flags & SC_ERROR) { 832 sc->sc_flags &= ~SC_ERROR; 833 goto newpack; 834 } 835 len = sc->sc_mp - sc->sc_buf; 836 if (len < 3) 837 /* less than min length packet - ignore */ 838 goto newpack; 839 840 if (sc->sc_if.if_bpf) { 841 /* 842 * Save the compressed header, so we 843 * can tack it on later. Note that we 844 * will end up copying garbage in some 845 * cases but this is okay. We remember 846 * where the buffer started so we can 847 * compute the new header length. 848 */ 849 bcopy(sc->sc_buf, chdr, CHDR_LEN); 850 } 851 852 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 853 if (c & 0x80) 854 c = TYPE_COMPRESSED_TCP; 855 else if (c == TYPE_UNCOMPRESSED_TCP) 856 *sc->sc_buf &= 0x4f; /* XXX */ 857 /* 858 * We've got something that's not an IP packet. 859 * If compression is enabled, try to decompress it. 860 * Otherwise, if `auto-enable' compression is on and 861 * it's a reasonable packet, decompress it and then 862 * enable compression. Otherwise, drop it. 863 */ 864 if (sc->sc_if.if_flags & SC_COMPRESS) { 865 len = sl_uncompress_tcp(&sc->sc_buf, len, 866 (u_int)c, &sc->sc_comp); 867 if (len <= 0) 868 goto error; 869 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 870 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 871 len = sl_uncompress_tcp(&sc->sc_buf, len, 872 (u_int)c, &sc->sc_comp); 873 if (len <= 0) 874 goto error; 875 sc->sc_if.if_flags |= SC_COMPRESS; 876 } else 877 goto error; 878 } 879 if (sc->sc_if.if_bpf) { 880 /* 881 * Put the SLIP pseudo-"link header" in place. 882 * We couldn't do this any earlier since 883 * decompression probably moved the buffer 884 * pointer. Then, invoke BPF. 885 */ 886 u_char *hp = sc->sc_buf - SLIP_HDRLEN; 887 888 hp[SLX_DIR] = SLIPDIR_IN; 889 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 890 bpf_tap(&sc->sc_if, hp, len + SLIP_HDRLEN); 891 } 892 m = sl_btom(sc, len); 893 if (m == NULL) 894 goto error; 895 896 sc->sc_if.if_ipackets++; 897 898 if ((sc->sc_if.if_flags & IFF_UP) == 0) { 899 m_freem(m); 900 goto newpack; 901 } 902 903 if (netisr_queue(NETISR_IP, m)) { 904 sc->sc_if.if_ierrors++; 905 sc->sc_if.if_iqdrops++; 906 } 907 908 goto newpack; 909 } 910 if (sc->sc_mp < sc->sc_ep) { 911 *sc->sc_mp++ = c; 912 sc->sc_escape = 0; 913 return 0; 914 } 915 916 /* can't put lower; would miss an extra frame */ 917 sc->sc_flags |= SC_ERROR; 918 919 error: 920 sc->sc_if.if_ierrors++; 921 newpack: 922 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLRMAX; 923 sc->sc_escape = 0; 924 return 0; 925 } 926 927 /* 928 * Process an ioctl request. 929 */ 930 static int 931 slioctl(ifp, cmd, data) 932 struct ifnet *ifp; 933 u_long cmd; 934 caddr_t data; 935 { 936 struct ifaddr *ifa = (struct ifaddr *)data; 937 struct ifreq *ifr = (struct ifreq *)data; 938 int s, error = 0; 939 940 s = splimp(); 941 942 switch (cmd) { 943 944 case SIOCSIFFLAGS: 945 /* 946 * if.c will set the interface up even if we 947 * don't want it to. 948 */ 949 if (sl_softc[ifp->if_dunit].sc_ttyp == NULL) { 950 ifp->if_flags &= ~IFF_UP; 951 } 952 break; 953 case SIOCSIFADDR: 954 /* 955 * This is "historical" - set the interface up when 956 * setting the address. 957 */ 958 if (ifa->ifa_addr->sa_family == AF_INET) { 959 if (sl_softc[ifp->if_dunit].sc_ttyp != NULL) 960 ifp->if_flags |= IFF_UP; 961 } else { 962 error = EAFNOSUPPORT; 963 } 964 break; 965 966 case SIOCSIFDSTADDR: 967 if (ifa->ifa_addr->sa_family != AF_INET) 968 error = EAFNOSUPPORT; 969 break; 970 971 case SIOCADDMULTI: 972 case SIOCDELMULTI: 973 break; 974 975 case SIOCSIFMTU: 976 /* 977 * Set the interface MTU. 978 */ 979 if (ifr->ifr_mtu > SLTMAX) 980 error = EINVAL; 981 else { 982 struct tty *tp; 983 984 ifp->if_mtu = ifr->ifr_mtu; 985 tp = sl_softc[ifp->if_dunit].sc_ttyp; 986 if (tp != NULL) 987 clist_alloc_cblocks(&tp->t_outq, 988 SLIP_HIWAT + 2 * ifp->if_mtu + 1, 989 SLIP_HIWAT + 2 * ifp->if_mtu + 1); 990 } 991 break; 992 993 default: 994 error = EINVAL; 995 } 996 splx(s); 997 return (error); 998 } 999 1000 static void 1001 sl_keepalive(chan) 1002 void *chan; 1003 { 1004 struct sl_softc *sc = chan; 1005 1006 if (sc->sc_keepalive) { 1007 if (sc->sc_flags & SC_KEEPALIVE) 1008 pgsignal (sc->sc_ttyp->t_pgrp, SIGURG, 1); 1009 else 1010 sc->sc_flags |= SC_KEEPALIVE; 1011 sc->sc_kahandle = timeout(sl_keepalive, sc, sc->sc_keepalive); 1012 } else { 1013 sc->sc_flags &= ~SC_KEEPALIVE; 1014 } 1015 } 1016 1017 static void 1018 sl_outfill(chan) 1019 void *chan; 1020 { 1021 struct sl_softc *sc = chan; 1022 struct tty *tp = sc->sc_ttyp; 1023 int s; 1024 1025 if (sc->sc_outfill && tp != NULL) { 1026 if (sc->sc_flags & SC_OUTWAIT) { 1027 s = splimp (); 1028 ++sc->sc_if.if_obytes; 1029 (void) putc(FRAME_END, &tp->t_outq); 1030 (*tp->t_oproc)(tp); 1031 splx (s); 1032 } else 1033 sc->sc_flags |= SC_OUTWAIT; 1034 sc->sc_ofhandle = timeout(sl_outfill, sc, sc->sc_outfill); 1035 } else { 1036 sc->sc_flags &= ~SC_OUTWAIT; 1037 } 1038 } 1039