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 1.9 2003/09/15 23:38:14 hsu 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 sc->sc_if.if_name = "sl"; 216 sc->sc_if.if_unit = i++; 217 sc->sc_if.if_mtu = SLMTU; 218 sc->sc_if.if_flags = 219 #ifdef SLIP_IFF_OPTS 220 SLIP_IFF_OPTS; 221 #else 222 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 223 #endif 224 sc->sc_if.if_type = IFT_SLIP; 225 sc->sc_if.if_ioctl = slioctl; 226 sc->sc_if.if_output = sloutput; 227 sc->sc_if.if_snd.ifq_maxlen = 50; 228 sc->sc_fastq.ifq_maxlen = 32; 229 sc->sc_if.if_linkmib = sc; 230 sc->sc_if.if_linkmiblen = sizeof *sc; 231 if_attach(&sc->sc_if); 232 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 233 } 234 } 235 236 static int 237 slinit(sc) 238 struct sl_softc *sc; 239 { 240 caddr_t p; 241 242 #ifdef __i386__ 243 int s; 244 245 s = splhigh(); 246 tty_imask |= net_imask; 247 net_imask = tty_imask; 248 update_intr_masks(); 249 splx(s); 250 if (bootverbose) 251 printf("new imasks: bio %x, tty %x, net %x\n", 252 bio_imask, tty_imask, net_imask); 253 #endif 254 if (sc->sc_ep == (u_char *) 0) { 255 MCLALLOC(p, M_WAIT); 256 if (p) 257 sc->sc_ep = (u_char *)p + SLBUFSIZE; 258 else { 259 printf("sl%ld: can't allocate buffer\n", 260 (long)(sc - sl_softc)); 261 return (0); 262 } 263 } 264 sc->sc_buf = sc->sc_ep - SLRMAX; 265 sc->sc_mp = sc->sc_buf; 266 sl_compress_init(&sc->sc_comp, -1); 267 return (1); 268 } 269 270 /* 271 * Line specific open routine. 272 * Attach the given tty to the first available sl unit. 273 */ 274 /* ARGSUSED */ 275 static int 276 slopen(dev_t dev, struct tty *tp) 277 { 278 struct sl_softc *sc; 279 int nsl; 280 int s, error; 281 struct thread *td = curthread; /* XXX */ 282 283 error = suser(td); 284 if (error) 285 return (error); 286 287 if (tp->t_line == SLIPDISC) 288 return (0); 289 290 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 291 if (sc->sc_ttyp == NULL && !(sc->sc_flags & SC_STATIC)) { 292 if (slinit(sc) == 0) 293 return (ENOBUFS); 294 tp->t_sc = (caddr_t)sc; 295 sc->sc_ttyp = tp; 296 sc->sc_if.if_baudrate = tp->t_ospeed; 297 ttyflush(tp, FREAD | FWRITE); 298 299 tp->t_line = SLIPDISC; 300 /* 301 * We don't use t_canq or t_rawq, so reduce their 302 * cblock resources to 0. Reserve enough cblocks 303 * for t_outq to guarantee that we can fit a full 304 * packet if the SLIP_HIWAT check allows slstart() 305 * to loop. Use the same value for the cblock 306 * limit since the reserved blocks should always 307 * be enough. Reserving cblocks probably makes 308 * the CLISTRESERVE check unnecessary and wasteful. 309 */ 310 clist_alloc_cblocks(&tp->t_canq, 0, 0); 311 clist_alloc_cblocks(&tp->t_outq, 312 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, 313 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); 314 clist_alloc_cblocks(&tp->t_rawq, 0, 0); 315 316 s = splnet(); 317 if_up(&sc->sc_if); 318 splx(s); 319 return (0); 320 } 321 return (ENXIO); 322 } 323 324 /* 325 * Line specific close routine. 326 * Detach the tty from the sl unit. 327 */ 328 static int 329 slclose(tp,flag) 330 struct tty *tp; 331 int flag; 332 { 333 struct sl_softc *sc; 334 int s; 335 336 ttyflush(tp, FREAD | FWRITE); 337 /* 338 * XXX the placement of the following spl is misleading. tty 339 * interrupts must be blocked across line discipline switches 340 * and throughout closes to avoid races. 341 */ 342 s = splimp(); /* actually, max(spltty, splnet) */ 343 clist_free_cblocks(&tp->t_outq); 344 tp->t_line = 0; 345 sc = (struct sl_softc *)tp->t_sc; 346 if (sc != NULL) { 347 if (sc->sc_outfill) { 348 sc->sc_outfill = 0; 349 untimeout(sl_outfill, sc, sc->sc_ofhandle); 350 } 351 if (sc->sc_keepalive) { 352 sc->sc_keepalive = 0; 353 untimeout(sl_keepalive, sc, sc->sc_kahandle); 354 } 355 if_down(&sc->sc_if); 356 sc->sc_flags &= SC_STATIC; 357 sc->sc_ttyp = NULL; 358 tp->t_sc = NULL; 359 m_mclfree((caddr_t)(sc->sc_ep - SLBUFSIZE)); 360 sc->sc_ep = 0; 361 sc->sc_mp = 0; 362 sc->sc_buf = 0; 363 } 364 splx(s); 365 return 0; 366 } 367 368 /* 369 * Line specific (tty) ioctl routine. 370 * Provide a way to get the sl unit number. 371 */ 372 /* ARGSUSED */ 373 static int 374 sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct thread *p) 375 { 376 struct sl_softc *sc = (struct sl_softc *)tp->t_sc, *nc, *tmpnc; 377 int s, nsl; 378 379 s = splimp(); 380 switch (cmd) { 381 case SLIOCGUNIT: 382 *(int *)data = sc->sc_if.if_unit; 383 break; 384 385 case SLIOCSUNIT: 386 if (sc->sc_if.if_unit != *(u_int *)data) { 387 for (nsl = NSL, nc = sl_softc; --nsl >= 0; nc++) { 388 if ( nc->sc_if.if_unit == *(u_int *)data 389 && nc->sc_ttyp == NULL 390 ) { 391 tmpnc = malloc(sizeof *tmpnc, M_TEMP, 392 M_NOWAIT); 393 if (tmpnc == NULL) { 394 splx(s); 395 return (ENOMEM); 396 } 397 *tmpnc = *nc; 398 *nc = *sc; 399 nc->sc_if = tmpnc->sc_if; 400 tmpnc->sc_if = sc->sc_if; 401 *sc = *tmpnc; 402 free(tmpnc, M_TEMP); 403 if (sc->sc_if.if_flags & IFF_UP) { 404 if_down(&sc->sc_if); 405 if (!(nc->sc_if.if_flags & IFF_UP)) 406 if_up(&nc->sc_if); 407 } else if (nc->sc_if.if_flags & IFF_UP) 408 if_down(&nc->sc_if); 409 sc->sc_flags &= ~SC_STATIC; 410 sc->sc_flags |= (nc->sc_flags & SC_STATIC); 411 tp->t_sc = sc = nc; 412 clist_alloc_cblocks(&tp->t_outq, 413 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, 414 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); 415 sl_compress_init(&sc->sc_comp, -1); 416 goto slfound; 417 } 418 } 419 splx(s); 420 return (ENXIO); 421 } 422 slfound: 423 sc->sc_flags |= SC_STATIC; 424 break; 425 426 case SLIOCSKEEPAL: 427 sc->sc_keepalive = *(u_int *)data * hz; 428 if (sc->sc_keepalive) { 429 sc->sc_flags |= SC_KEEPALIVE; 430 sc->sc_kahandle = timeout(sl_keepalive, sc, 431 sc->sc_keepalive); 432 } else { 433 if ((sc->sc_flags & SC_KEEPALIVE) != 0) { 434 untimeout(sl_keepalive, sc, sc->sc_kahandle); 435 sc->sc_flags &= ~SC_KEEPALIVE; 436 } 437 } 438 break; 439 440 case SLIOCGKEEPAL: 441 *(int *)data = sc->sc_keepalive / hz; 442 break; 443 444 case SLIOCSOUTFILL: 445 sc->sc_outfill = *(u_int *)data * hz; 446 if (sc->sc_outfill) { 447 sc->sc_flags |= SC_OUTWAIT; 448 sc->sc_ofhandle = timeout(sl_outfill, sc, 449 sc->sc_outfill); 450 } else { 451 if ((sc->sc_flags & SC_OUTWAIT) != 0) { 452 untimeout(sl_outfill, sc, sc->sc_ofhandle); 453 sc->sc_flags &= ~SC_OUTWAIT; 454 } 455 } 456 break; 457 458 case SLIOCGOUTFILL: 459 *(int *)data = sc->sc_outfill / hz; 460 break; 461 462 default: 463 splx(s); 464 return (ENOIOCTL); 465 } 466 splx(s); 467 return (0); 468 } 469 470 /* 471 * Queue a packet. Start transmission if not active. 472 * Compression happens in slstart; if we do it here, IP TOS 473 * will cause us to not compress "background" packets, because 474 * ordering gets trashed. It can be done for all packets in slstart. 475 */ 476 static int 477 sloutput(ifp, m, dst, rtp) 478 struct ifnet *ifp; 479 struct mbuf *m; 480 struct sockaddr *dst; 481 struct rtentry *rtp; 482 { 483 struct sl_softc *sc = &sl_softc[ifp->if_unit]; 484 struct ip *ip; 485 struct ifqueue *ifq; 486 int s; 487 488 /* 489 * `Cannot happen' (see slioctl). Someday we will extend 490 * the line protocol to support other address families. 491 */ 492 if (dst->sa_family != AF_INET) { 493 printf("sl%d: af%d not supported\n", sc->sc_if.if_unit, 494 dst->sa_family); 495 m_freem(m); 496 sc->sc_if.if_noproto++; 497 return (EAFNOSUPPORT); 498 } 499 500 if (sc->sc_ttyp == NULL || !(ifp->if_flags & IFF_UP)) { 501 m_freem(m); 502 return (ENETDOWN); 503 } 504 if ((sc->sc_ttyp->t_state & TS_CONNECTED) == 0) { 505 m_freem(m); 506 return (EHOSTUNREACH); 507 } 508 ifq = &sc->sc_if.if_snd; 509 ip = mtod(m, struct ip *); 510 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 511 m_freem(m); 512 return (ENETRESET); /* XXX ? */ 513 } 514 if (ip->ip_tos & IPTOS_LOWDELAY) 515 ifq = &sc->sc_fastq; 516 s = splimp(); 517 if (IF_QFULL(ifq)) { 518 IF_DROP(ifq); 519 m_freem(m); 520 splx(s); 521 sc->sc_if.if_oerrors++; 522 return (ENOBUFS); 523 } 524 IF_ENQUEUE(ifq, m); 525 if (sc->sc_ttyp->t_outq.c_cc == 0) 526 slstart(sc->sc_ttyp); 527 splx(s); 528 return (0); 529 } 530 531 /* 532 * Start output on interface. Get another datagram 533 * to send from the interface queue and map it to 534 * the interface before starting output. 535 */ 536 static int 537 slstart(tp) 538 struct tty *tp; 539 { 540 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 541 struct mbuf *m; 542 u_char *cp; 543 struct ip *ip; 544 int s; 545 u_char bpfbuf[SLTMAX + SLIP_HDRLEN]; 546 int len = 0; 547 548 for (;;) { 549 /* 550 * Call output process whether or not there is more in the 551 * output queue. We are being called in lieu of ttstart 552 * and must do what it would. 553 */ 554 (*tp->t_oproc)(tp); 555 556 if (tp->t_outq.c_cc != 0) { 557 if (sc != NULL) 558 sc->sc_flags &= ~SC_OUTWAIT; 559 if (tp->t_outq.c_cc > SLIP_HIWAT) 560 return 0; 561 } 562 563 /* 564 * This happens briefly when the line shuts down. 565 */ 566 if (sc == NULL) 567 return 0; 568 569 /* 570 * Get a packet and send it to the interface. 571 */ 572 s = splimp(); 573 IF_DEQUEUE(&sc->sc_fastq, m); 574 if (m) 575 sc->sc_if.if_omcasts++; /* XXX */ 576 else 577 IF_DEQUEUE(&sc->sc_if.if_snd, m); 578 splx(s); 579 if (m == NULL) 580 return 0; 581 582 /* 583 * We do the header compression here rather than in sloutput 584 * because the packets will be out of order if we are using TOS 585 * queueing, and the connection id compression will get 586 * munged when this happens. 587 */ 588 if (sc->sc_if.if_bpf) { 589 /* 590 * We need to save the TCP/IP header before it's 591 * compressed. To avoid complicated code, we just 592 * copy the entire packet into a stack buffer (since 593 * this is a serial line, packets should be short 594 * and/or the copy should be negligible cost compared 595 * to the packet transmission time). 596 */ 597 struct mbuf *m1 = m; 598 u_char *cp = bpfbuf + SLIP_HDRLEN; 599 600 len = 0; 601 do { 602 int mlen = m1->m_len; 603 604 bcopy(mtod(m1, caddr_t), cp, mlen); 605 cp += mlen; 606 len += mlen; 607 } while ((m1 = m1->m_next) != NULL); 608 } 609 ip = mtod(m, struct ip *); 610 if (ip->ip_v == IPVERSION && ip->ip_p == IPPROTO_TCP) { 611 if (sc->sc_if.if_flags & SC_COMPRESS) 612 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 613 &sc->sc_comp, 1); 614 } 615 if (sc->sc_if.if_bpf) { 616 /* 617 * Put the SLIP pseudo-"link header" in place. The 618 * compressed header is now at the beginning of the 619 * mbuf. 620 */ 621 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 622 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 623 bpf_tap(&sc->sc_if, bpfbuf, len + SLIP_HDRLEN); 624 } 625 626 /* 627 * If system is getting low on clists, just flush our 628 * output queue (if the stuff was important, it'll get 629 * retransmitted). Note that SLTMAX is used instead of 630 * the current if_mtu setting because connections that 631 * have already been established still use the original 632 * (possibly larger) mss. 633 */ 634 if (cfreecount < CLISTRESERVE + SLTMAX) { 635 m_freem(m); 636 sc->sc_if.if_collisions++; 637 continue; 638 } 639 640 sc->sc_flags &= ~SC_OUTWAIT; 641 /* 642 * The extra FRAME_END will start up a new packet, and thus 643 * will flush any accumulated garbage. We do this whenever 644 * the line may have been idle for some time. 645 */ 646 if (tp->t_outq.c_cc == 0) { 647 ++sc->sc_if.if_obytes; 648 (void) putc(FRAME_END, &tp->t_outq); 649 } 650 651 while (m) { 652 u_char *ep; 653 654 cp = mtod(m, u_char *); ep = cp + m->m_len; 655 while (cp < ep) { 656 /* 657 * Find out how many bytes in the string we can 658 * handle without doing something special. 659 */ 660 u_char *bp = cp; 661 662 while (cp < ep) { 663 switch (*cp++) { 664 case FRAME_ESCAPE: 665 case FRAME_END: 666 --cp; 667 goto out; 668 } 669 } 670 out: 671 if (cp > bp) { 672 /* 673 * Put n characters at once 674 * into the tty output queue. 675 */ 676 if (b_to_q((char *)bp, cp - bp, 677 &tp->t_outq)) 678 break; 679 sc->sc_if.if_obytes += cp - bp; 680 } 681 /* 682 * If there are characters left in the mbuf, 683 * the first one must be special.. 684 * Put it out in a different form. 685 */ 686 if (cp < ep) { 687 if (putc(FRAME_ESCAPE, &tp->t_outq)) 688 break; 689 if (putc(*cp++ == FRAME_ESCAPE ? 690 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 691 &tp->t_outq)) { 692 (void) unputc(&tp->t_outq); 693 break; 694 } 695 sc->sc_if.if_obytes += 2; 696 } 697 } 698 m = m_free(m); 699 } 700 701 if (putc(FRAME_END, &tp->t_outq)) { 702 /* 703 * Not enough room. Remove a char to make room 704 * and end the packet normally. 705 * If you get many collisions (more than one or two 706 * a day) you probably do not have enough clists 707 * and you should increase "nclist" in param.c. 708 */ 709 (void) unputc(&tp->t_outq); 710 (void) putc(FRAME_END, &tp->t_outq); 711 sc->sc_if.if_collisions++; 712 } else { 713 ++sc->sc_if.if_obytes; 714 sc->sc_if.if_opackets++; 715 } 716 } 717 return 0; 718 } 719 720 /* 721 * Copy data buffer to mbuf chain; add ifnet pointer. 722 */ 723 static struct mbuf * 724 sl_btom(sc, len) 725 struct sl_softc *sc; 726 int len; 727 { 728 struct mbuf *m; 729 730 MGETHDR(m, M_DONTWAIT, MT_DATA); 731 if (m == NULL) 732 return (NULL); 733 734 /* 735 * If we have more than MHLEN bytes, it's cheaper to 736 * queue the cluster we just filled & allocate a new one 737 * for the input buffer. Otherwise, fill the mbuf we 738 * allocated above. Note that code in the input routine 739 * guarantees that packet will fit in a cluster. 740 */ 741 if (len >= MHLEN) { 742 MCLGET(m, M_DONTWAIT); 743 if ((m->m_flags & M_EXT) == 0) { 744 /* 745 * we couldn't get a cluster - if memory's this 746 * low, it's time to start dropping packets. 747 */ 748 (void) m_free(m); 749 return (NULL); 750 } 751 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 752 m->m_data = (caddr_t)sc->sc_buf; 753 m->m_ext.ext_buf = (caddr_t)((intptr_t)sc->sc_buf &~ MCLOFSET); 754 } else 755 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 756 757 m->m_len = len; 758 m->m_pkthdr.len = len; 759 m->m_pkthdr.rcvif = &sc->sc_if; 760 return (m); 761 } 762 763 /* 764 * tty interface receiver interrupt. 765 */ 766 static int 767 slinput(c, tp) 768 int c; 769 struct tty *tp; 770 { 771 struct sl_softc *sc; 772 struct mbuf *m; 773 int len; 774 u_char chdr[CHDR_LEN]; 775 776 tk_nin++; 777 sc = (struct sl_softc *)tp->t_sc; 778 if (sc == NULL) 779 return 0; 780 if (c & TTY_ERRORMASK || (tp->t_state & TS_CONNECTED) == 0) { 781 sc->sc_flags |= SC_ERROR; 782 return 0; 783 } 784 c &= TTY_CHARMASK; 785 786 ++sc->sc_if.if_ibytes; 787 788 if (sc->sc_if.if_flags & IFF_DEBUG) { 789 if (c == ABT_ESC) { 790 /* 791 * If we have a previous abort, see whether 792 * this one is within the time limit. 793 */ 794 if (sc->sc_abortcount && 795 time_second >= sc->sc_starttime + ABT_WINDOW) 796 sc->sc_abortcount = 0; 797 /* 798 * If we see an abort after "idle" time, count it; 799 * record when the first abort escape arrived. 800 */ 801 if (time_second >= sc->sc_lasttime + ABT_IDLE) { 802 if (++sc->sc_abortcount == 1) 803 sc->sc_starttime = time_second; 804 if (sc->sc_abortcount >= ABT_COUNT) { 805 slclose(tp,0); 806 return 0; 807 } 808 } 809 } else 810 sc->sc_abortcount = 0; 811 sc->sc_lasttime = time_second; 812 } 813 814 switch (c) { 815 816 case TRANS_FRAME_ESCAPE: 817 if (sc->sc_escape) 818 c = FRAME_ESCAPE; 819 break; 820 821 case TRANS_FRAME_END: 822 if (sc->sc_escape) 823 c = FRAME_END; 824 break; 825 826 case FRAME_ESCAPE: 827 sc->sc_escape = 1; 828 return 0; 829 830 case FRAME_END: 831 sc->sc_flags &= ~SC_KEEPALIVE; 832 if(sc->sc_flags & SC_ERROR) { 833 sc->sc_flags &= ~SC_ERROR; 834 goto newpack; 835 } 836 len = sc->sc_mp - sc->sc_buf; 837 if (len < 3) 838 /* less than min length packet - ignore */ 839 goto newpack; 840 841 if (sc->sc_if.if_bpf) { 842 /* 843 * Save the compressed header, so we 844 * can tack it on later. Note that we 845 * will end up copying garbage in some 846 * cases but this is okay. We remember 847 * where the buffer started so we can 848 * compute the new header length. 849 */ 850 bcopy(sc->sc_buf, chdr, CHDR_LEN); 851 } 852 853 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 854 if (c & 0x80) 855 c = TYPE_COMPRESSED_TCP; 856 else if (c == TYPE_UNCOMPRESSED_TCP) 857 *sc->sc_buf &= 0x4f; /* XXX */ 858 /* 859 * We've got something that's not an IP packet. 860 * If compression is enabled, try to decompress it. 861 * Otherwise, if `auto-enable' compression is on and 862 * it's a reasonable packet, decompress it and then 863 * enable compression. Otherwise, drop it. 864 */ 865 if (sc->sc_if.if_flags & SC_COMPRESS) { 866 len = sl_uncompress_tcp(&sc->sc_buf, len, 867 (u_int)c, &sc->sc_comp); 868 if (len <= 0) 869 goto error; 870 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 871 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 872 len = sl_uncompress_tcp(&sc->sc_buf, len, 873 (u_int)c, &sc->sc_comp); 874 if (len <= 0) 875 goto error; 876 sc->sc_if.if_flags |= SC_COMPRESS; 877 } else 878 goto error; 879 } 880 if (sc->sc_if.if_bpf) { 881 /* 882 * Put the SLIP pseudo-"link header" in place. 883 * We couldn't do this any earlier since 884 * decompression probably moved the buffer 885 * pointer. Then, invoke BPF. 886 */ 887 u_char *hp = sc->sc_buf - SLIP_HDRLEN; 888 889 hp[SLX_DIR] = SLIPDIR_IN; 890 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 891 bpf_tap(&sc->sc_if, hp, len + SLIP_HDRLEN); 892 } 893 m = sl_btom(sc, len); 894 if (m == NULL) 895 goto error; 896 897 sc->sc_if.if_ipackets++; 898 899 if ((sc->sc_if.if_flags & IFF_UP) == 0) { 900 m_freem(m); 901 goto newpack; 902 } 903 904 if (netisr_queue(NETISR_IP, m)) { 905 sc->sc_if.if_ierrors++; 906 sc->sc_if.if_iqdrops++; 907 } 908 909 goto newpack; 910 } 911 if (sc->sc_mp < sc->sc_ep) { 912 *sc->sc_mp++ = c; 913 sc->sc_escape = 0; 914 return 0; 915 } 916 917 /* can't put lower; would miss an extra frame */ 918 sc->sc_flags |= SC_ERROR; 919 920 error: 921 sc->sc_if.if_ierrors++; 922 newpack: 923 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLRMAX; 924 sc->sc_escape = 0; 925 return 0; 926 } 927 928 /* 929 * Process an ioctl request. 930 */ 931 static int 932 slioctl(ifp, cmd, data) 933 struct ifnet *ifp; 934 u_long cmd; 935 caddr_t data; 936 { 937 struct ifaddr *ifa = (struct ifaddr *)data; 938 struct ifreq *ifr = (struct ifreq *)data; 939 int s, error = 0; 940 941 s = splimp(); 942 943 switch (cmd) { 944 945 case SIOCSIFFLAGS: 946 /* 947 * if.c will set the interface up even if we 948 * don't want it to. 949 */ 950 if (sl_softc[ifp->if_unit].sc_ttyp == NULL) { 951 ifp->if_flags &= ~IFF_UP; 952 } 953 break; 954 case SIOCSIFADDR: 955 /* 956 * This is "historical" - set the interface up when 957 * setting the address. 958 */ 959 if (ifa->ifa_addr->sa_family == AF_INET) { 960 if (sl_softc[ifp->if_unit].sc_ttyp != NULL) 961 ifp->if_flags |= IFF_UP; 962 } else { 963 error = EAFNOSUPPORT; 964 } 965 break; 966 967 case SIOCSIFDSTADDR: 968 if (ifa->ifa_addr->sa_family != AF_INET) 969 error = EAFNOSUPPORT; 970 break; 971 972 case SIOCADDMULTI: 973 case SIOCDELMULTI: 974 break; 975 976 case SIOCSIFMTU: 977 /* 978 * Set the interface MTU. 979 */ 980 if (ifr->ifr_mtu > SLTMAX) 981 error = EINVAL; 982 else { 983 struct tty *tp; 984 985 ifp->if_mtu = ifr->ifr_mtu; 986 tp = sl_softc[ifp->if_unit].sc_ttyp; 987 if (tp != NULL) 988 clist_alloc_cblocks(&tp->t_outq, 989 SLIP_HIWAT + 2 * ifp->if_mtu + 1, 990 SLIP_HIWAT + 2 * ifp->if_mtu + 1); 991 } 992 break; 993 994 default: 995 error = EINVAL; 996 } 997 splx(s); 998 return (error); 999 } 1000 1001 static void 1002 sl_keepalive(chan) 1003 void *chan; 1004 { 1005 struct sl_softc *sc = chan; 1006 1007 if (sc->sc_keepalive) { 1008 if (sc->sc_flags & SC_KEEPALIVE) 1009 pgsignal (sc->sc_ttyp->t_pgrp, SIGURG, 1); 1010 else 1011 sc->sc_flags |= SC_KEEPALIVE; 1012 sc->sc_kahandle = timeout(sl_keepalive, sc, sc->sc_keepalive); 1013 } else { 1014 sc->sc_flags &= ~SC_KEEPALIVE; 1015 } 1016 } 1017 1018 static void 1019 sl_outfill(chan) 1020 void *chan; 1021 { 1022 struct sl_softc *sc = chan; 1023 struct tty *tp = sc->sc_ttyp; 1024 int s; 1025 1026 if (sc->sc_outfill && tp != NULL) { 1027 if (sc->sc_flags & SC_OUTWAIT) { 1028 s = splimp (); 1029 ++sc->sc_if.if_obytes; 1030 (void) putc(FRAME_END, &tp->t_outq); 1031 (*tp->t_oproc)(tp); 1032 splx (s); 1033 } else 1034 sc->sc_flags |= SC_OUTWAIT; 1035 sc->sc_ofhandle = timeout(sl_outfill, sc, sc->sc_outfill); 1036 } else { 1037 sc->sc_flags &= ~SC_OUTWAIT; 1038 } 1039 } 1040