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 1.31 2006/12/22 23:44:57 swildner 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 66 #include "use_sl.h" 67 68 #include "opt_inet.h" 69 #if !defined(KLD_MODULE) 70 #include "opt_slip.h" 71 #endif 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/proc.h> 75 #include <sys/malloc.h> 76 #include <sys/mbuf.h> 77 #include <sys/dkstat.h> 78 #include <sys/socket.h> 79 #include <sys/sockio.h> 80 #include <sys/fcntl.h> 81 #include <sys/signalvar.h> 82 #include <sys/tty.h> 83 #include <sys/clist.h> 84 #include <sys/kernel.h> 85 #include <sys/conf.h> 86 #include <sys/thread2.h> 87 88 #include <net/if.h> 89 #include <net/if_types.h> 90 #include <net/ifq_var.h> 91 #include <net/netisr.h> 92 93 #if INET 94 #include <netinet/in.h> 95 #include <netinet/in_systm.h> 96 #include <netinet/in_var.h> 97 #include <netinet/ip.h> 98 #else 99 #error "Huh? Slip without inet?" 100 #endif 101 102 #include <net/slcompress.h> 103 #include "if_slvar.h" 104 #include <net/slip.h> 105 106 #include <net/bpf.h> 107 108 static void slattach (void *); 109 PSEUDO_SET(slattach, if_sl); 110 111 /* 112 * SLRMAX is a hard limit on input packet size. To simplify the code 113 * and improve performance, we require that packets fit in an mbuf 114 * cluster, and if we get a compressed packet, there's enough extra 115 * room to expand the header into a max length tcp/ip header (128 116 * bytes). So, SLRMAX can be at most 117 * MCLBYTES - 128 118 * 119 * SLMTU is the default transmit MTU. The transmit MTU should be kept 120 * small enough so that interactive use doesn't suffer, but large 121 * enough to provide good performance. 552 is a good choice for SLMTU 122 * because it is high enough to not fragment TCP packets being routed 123 * through this host. Packet fragmentation is bad with SLIP because 124 * fragment headers aren't compressed. The previous assumptions about 125 * the best MTU value don't really hold when using modern modems with 126 * BTLZ data compression because the modem buffers play a much larger 127 * role in interactive performance than the MTU. The MTU can be changed 128 * at any time to suit the specific environment with ifconfig(8), and 129 * its maximum value is defined as SLTMAX. SLTMAX must not be so large 130 * that it would overflow the stack if BPF is configured (XXX; if_ppp.c 131 * handles this better). 132 * 133 * SLIP_HIWAT is the amount of data that will be queued 'downstream' 134 * of us (i.e., in clists waiting to be picked up by the tty output 135 * interrupt). If we queue a lot of data downstream, it's immune to 136 * our t.o.s. queuing. 137 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 138 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 139 * wait is dependent on the ftp window size but that's typically 140 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 141 * the cost (in idle time on the wire) of the tty driver running 142 * off the end of its clists & having to call back slstart for a 143 * new packet. For a tty interface with any buffering at all, this 144 * cost will be zero. Even with a totally brain dead interface (like 145 * the one on a typical workstation), the cost will be <= 1 character 146 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 147 * at most 1% while maintaining good interactive response. 148 */ 149 #define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 150 #define SLRMAX (MCLBYTES - BUFOFFSET) 151 #define SLBUFSIZE (SLRMAX + BUFOFFSET) 152 #ifndef SLMTU 153 #define SLMTU 552 /* default MTU */ 154 #endif 155 #define SLTMAX 1500 /* maximum MTU */ 156 #define SLIP_HIWAT roundup(50,CBSIZE) 157 #define CLISTRESERVE 1024 /* Can't let clists get too low */ 158 159 /* 160 * SLIP ABORT ESCAPE MECHANISM: 161 * (inspired by HAYES modem escape arrangement) 162 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 163 * within window time signals a "soft" exit from slip mode by remote end 164 * if the IFF_DEBUG flag is on. 165 */ 166 #define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 167 #define ABT_IDLE 1 /* in seconds - idle before an escape */ 168 #define ABT_COUNT 3 /* count of escapes for abort */ 169 #define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 170 171 static struct sl_softc sl_softc[NSL]; 172 173 #define FRAME_END 0xc0 /* Frame End */ 174 #define FRAME_ESCAPE 0xdb /* Frame Esc */ 175 #define TRANS_FRAME_END 0xdc /* transposed frame end */ 176 #define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 177 178 static int slinit (struct sl_softc *); 179 static struct mbuf *sl_btom (struct sl_softc *, int); 180 static timeout_t sl_keepalive; 181 static timeout_t sl_outfill; 182 static int slclose (struct tty *,int); 183 static int slinput (int, struct tty *); 184 static int slioctl (struct ifnet *, u_long, caddr_t, struct ucred *); 185 static int sltioctl (struct tty *, u_long, caddr_t, int, struct ucred *); 186 static int slopen (cdev_t, struct tty *); 187 static int sloutput (struct ifnet *, 188 struct mbuf *, struct sockaddr *, struct rtentry *); 189 static int slstart (struct tty *); 190 191 static struct linesw slipdisc = { 192 slopen, slclose, l_noread, l_nowrite, 193 sltioctl, slinput, slstart, ttymodem, 194 FRAME_END 195 }; 196 197 /* 198 * Called from boot code to establish sl interfaces. 199 */ 200 static void 201 slattach(void *dummy) 202 { 203 struct sl_softc *sc; 204 int i = 0; 205 206 linesw[SLIPDISC] = slipdisc; 207 208 for (sc = sl_softc; i < NSL; sc++) { 209 if_initname(&(sc->sc_if), "sl", i++); 210 sc->sc_if.if_mtu = SLMTU; 211 sc->sc_if.if_flags = 212 #ifdef SLIP_IFF_OPTS 213 SLIP_IFF_OPTS; 214 #else 215 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 216 #endif 217 sc->sc_if.if_type = IFT_SLIP; 218 sc->sc_if.if_ioctl = slioctl; 219 sc->sc_if.if_output = sloutput; 220 ifq_set_maxlen(&sc->sc_if.if_snd, 50); 221 ifq_set_ready(&sc->sc_if.if_snd); 222 sc->sc_fastq.ifq_maxlen = 32; 223 sc->sc_if.if_linkmib = sc; 224 sc->sc_if.if_linkmiblen = sizeof *sc; 225 callout_init(&sc->sc_oftimeout); 226 callout_init(&sc->sc_katimeout); 227 if_attach(&sc->sc_if, NULL); 228 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 229 } 230 } 231 232 static int 233 slinit(struct sl_softc *sc) 234 { 235 if (sc->sc_ep == NULL) 236 sc->sc_ep = kmalloc(SLBUFSIZE, M_DEVBUF, M_WAITOK); 237 sc->sc_buf = sc->sc_ep + SLBUFSIZE - SLRMAX; 238 sc->sc_mp = sc->sc_buf; 239 sl_compress_init(&sc->sc_comp, -1); 240 return (1); 241 } 242 243 /* 244 * Line specific open routine. 245 * Attach the given tty to the first available sl unit. 246 */ 247 /* ARGSUSED */ 248 static int 249 slopen(cdev_t dev, struct tty *tp) 250 { 251 struct sl_softc *sc; 252 int nsl; 253 int error; 254 struct thread *td = curthread; /* XXX */ 255 256 error = suser(td); 257 if (error) 258 return (error); 259 260 if (tp->t_line == SLIPDISC) 261 return (0); 262 263 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 264 if (sc->sc_ttyp == NULL && !(sc->sc_flags & SC_STATIC)) { 265 if (slinit(sc) == 0) 266 return (ENOBUFS); 267 tp->t_sc = (caddr_t)sc; 268 sc->sc_ttyp = tp; 269 sc->sc_if.if_baudrate = tp->t_ospeed; 270 ttyflush(tp, FREAD | FWRITE); 271 272 tp->t_line = SLIPDISC; 273 /* 274 * We don't use t_canq or t_rawq, so reduce their 275 * cblock resources to 0. Reserve enough cblocks 276 * for t_outq to guarantee that we can fit a full 277 * packet if the SLIP_HIWAT check allows slstart() 278 * to loop. Use the same value for the cblock 279 * limit since the reserved blocks should always 280 * be enough. Reserving cblocks probably makes 281 * the CLISTRESERVE check unnecessary and wasteful. 282 */ 283 clist_alloc_cblocks(&tp->t_canq, 0, 0); 284 clist_alloc_cblocks(&tp->t_outq, 285 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, 286 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); 287 clist_alloc_cblocks(&tp->t_rawq, 0, 0); 288 289 crit_enter(); 290 if_up(&sc->sc_if); 291 crit_exit(); 292 return (0); 293 } 294 return (ENXIO); 295 } 296 297 /* 298 * Line specific close routine. 299 * Detach the tty from the sl unit. 300 */ 301 static int 302 slclose(struct tty *tp, int flag) 303 { 304 struct sl_softc *sc; 305 306 ttyflush(tp, FREAD | FWRITE); 307 crit_enter(); 308 309 clist_free_cblocks(&tp->t_outq); 310 tp->t_line = 0; 311 sc = (struct sl_softc *)tp->t_sc; 312 if (sc != NULL) { 313 if (sc->sc_outfill) { 314 sc->sc_outfill = 0; 315 callout_stop(&sc->sc_oftimeout); 316 } 317 if (sc->sc_keepalive) { 318 sc->sc_keepalive = 0; 319 callout_stop(&sc->sc_katimeout); 320 } 321 if_down(&sc->sc_if); 322 sc->sc_flags &= SC_STATIC; 323 sc->sc_ttyp = NULL; 324 tp->t_sc = NULL; 325 if (sc->sc_ep) { 326 kfree(sc->sc_ep, M_DEVBUF); 327 sc->sc_ep = NULL; 328 } 329 sc->sc_mp = 0; 330 sc->sc_buf = 0; 331 } 332 crit_exit(); 333 return 0; 334 } 335 336 /* 337 * Line specific (tty) ioctl routine. 338 * Provide a way to get the sl unit number. 339 */ 340 /* ARGSUSED */ 341 static int 342 sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct ucred *cred) 343 { 344 struct sl_softc *sc = (struct sl_softc *)tp->t_sc, *nc, *tmpnc; 345 int nsl; 346 347 crit_enter(); 348 349 switch (cmd) { 350 case SLIOCGUNIT: 351 *(int *)data = sc->sc_if.if_dunit; 352 break; 353 354 case SLIOCSUNIT: 355 if (sc->sc_if.if_dunit != *(u_int *)data) { 356 for (nsl = NSL, nc = sl_softc; --nsl >= 0; nc++) { 357 if ( nc->sc_if.if_dunit == *(u_int *)data 358 && nc->sc_ttyp == NULL 359 ) { 360 tmpnc = kmalloc(sizeof *tmpnc, M_TEMP, 361 M_WAITOK); 362 *tmpnc = *nc; 363 *nc = *sc; 364 nc->sc_if = tmpnc->sc_if; 365 tmpnc->sc_if = sc->sc_if; 366 *sc = *tmpnc; 367 kfree(tmpnc, M_TEMP); 368 if (sc->sc_if.if_flags & IFF_UP) { 369 if_down(&sc->sc_if); 370 if (!(nc->sc_if.if_flags & IFF_UP)) 371 if_up(&nc->sc_if); 372 } else if (nc->sc_if.if_flags & IFF_UP) 373 if_down(&nc->sc_if); 374 sc->sc_flags &= ~SC_STATIC; 375 sc->sc_flags |= (nc->sc_flags & SC_STATIC); 376 tp->t_sc = sc = nc; 377 clist_alloc_cblocks(&tp->t_outq, 378 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, 379 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); 380 sl_compress_init(&sc->sc_comp, -1); 381 goto slfound; 382 } 383 } 384 crit_exit(); 385 return (ENXIO); 386 } 387 slfound: 388 sc->sc_flags |= SC_STATIC; 389 break; 390 391 case SLIOCSKEEPAL: 392 sc->sc_keepalive = *(u_int *)data * hz; 393 if (sc->sc_keepalive) { 394 sc->sc_flags |= SC_KEEPALIVE; 395 callout_reset(&sc->sc_katimeout, sc->sc_keepalive, 396 sl_keepalive, sc); 397 } else { 398 if ((sc->sc_flags & SC_KEEPALIVE) != 0) { 399 callout_stop(&sc->sc_katimeout); 400 sc->sc_flags &= ~SC_KEEPALIVE; 401 } 402 } 403 break; 404 405 case SLIOCGKEEPAL: 406 *(int *)data = sc->sc_keepalive / hz; 407 break; 408 409 case SLIOCSOUTFILL: 410 sc->sc_outfill = *(u_int *)data * hz; 411 if (sc->sc_outfill) { 412 sc->sc_flags |= SC_OUTWAIT; 413 callout_reset(&sc->sc_oftimeout, sc->sc_outfill, 414 sl_outfill, sc); 415 } else { 416 if ((sc->sc_flags & SC_OUTWAIT) != 0) { 417 callout_stop(&sc->sc_oftimeout); 418 sc->sc_flags &= ~SC_OUTWAIT; 419 } 420 } 421 break; 422 423 case SLIOCGOUTFILL: 424 *(int *)data = sc->sc_outfill / hz; 425 break; 426 427 default: 428 crit_exit(); 429 return (ENOIOCTL); 430 } 431 crit_exit(); 432 return (0); 433 } 434 435 /* 436 * Queue a packet. Start transmission if not active. 437 * Compression happens in slstart; if we do it here, IP TOS 438 * will cause us to not compress "background" packets, because 439 * ordering gets trashed. It can be done for all packets in slstart. 440 */ 441 static int 442 sloutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 443 struct rtentry *rtp) 444 { 445 struct sl_softc *sc = &sl_softc[ifp->if_dunit]; 446 struct ip *ip; 447 int error; 448 struct altq_pktattr pktattr; 449 450 ifq_classify(&ifp->if_snd, m, dst->sa_family, &pktattr); 451 452 /* 453 * `Cannot happen' (see slioctl). Someday we will extend 454 * the line protocol to support other address families. 455 */ 456 if (dst->sa_family != AF_INET) { 457 kprintf("%s: af%d not supported\n", sc->sc_if.if_xname, 458 dst->sa_family); 459 m_freem(m); 460 sc->sc_if.if_noproto++; 461 return (EAFNOSUPPORT); 462 } 463 464 if (sc->sc_ttyp == NULL || !(ifp->if_flags & IFF_UP)) { 465 m_freem(m); 466 return (ENETDOWN); 467 } 468 if ((sc->sc_ttyp->t_state & TS_CONNECTED) == 0) { 469 m_freem(m); 470 return (EHOSTUNREACH); 471 } 472 ip = mtod(m, struct ip *); 473 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 474 m_freem(m); 475 return (ENETRESET); /* XXX ? */ 476 } 477 478 crit_enter(); 479 480 if ((ip->ip_tos & IPTOS_LOWDELAY) && !ifq_is_enabled(&sc->sc_if.if_snd)) { 481 if (IF_QFULL(&sc->sc_fastq)) { 482 IF_DROP(&sc->sc_fastq); 483 m_freem(m); 484 error = ENOBUFS; 485 } else { 486 IF_ENQUEUE(&sc->sc_fastq, m); 487 error = 0; 488 } 489 } else { 490 error = ifq_enqueue(&sc->sc_if.if_snd, m, &pktattr); 491 } 492 if (error) { 493 sc->sc_if.if_oerrors++; 494 crit_exit(); 495 return (error); 496 } 497 if (sc->sc_ttyp->t_outq.c_cc == 0) 498 slstart(sc->sc_ttyp); 499 crit_exit(); 500 return (0); 501 } 502 503 /* 504 * Start output on interface. Get another datagram 505 * to send from the interface queue and map it to 506 * the interface before starting output. 507 */ 508 static int 509 slstart(struct tty *tp) 510 { 511 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 512 struct mbuf *m; 513 u_char *cp; 514 struct ip *ip; 515 u_char bpfbuf[SLTMAX + SLIP_HDRLEN]; 516 int len = 0; 517 518 for (;;) { 519 /* 520 * Call output process whether or not there is more in the 521 * output queue. We are being called in lieu of ttstart 522 * and must do what it would. 523 */ 524 (*tp->t_oproc)(tp); 525 526 if (tp->t_outq.c_cc != 0) { 527 if (sc != NULL) 528 sc->sc_flags &= ~SC_OUTWAIT; 529 if (tp->t_outq.c_cc > SLIP_HIWAT) 530 return 0; 531 } 532 533 /* 534 * This happens briefly when the line shuts down. 535 */ 536 if (sc == NULL) 537 return 0; 538 539 /* 540 * Get a packet and send it to the interface. 541 */ 542 crit_enter(); 543 IF_DEQUEUE(&sc->sc_fastq, m); 544 if (m) 545 sc->sc_if.if_omcasts++; /* XXX */ 546 else 547 m = ifq_dequeue(&sc->sc_if.if_snd, NULL); 548 crit_exit(); 549 if (m == NULL) 550 return 0; 551 552 /* 553 * We do the header compression here rather than in sloutput 554 * because the packets will be out of order if we are using TOS 555 * queueing, and the connection id compression will get 556 * munged when this happens. 557 */ 558 if (sc->sc_if.if_bpf) { 559 /* 560 * We need to save the TCP/IP header before it's 561 * compressed. To avoid complicated code, we just 562 * copy the entire packet into a stack buffer (since 563 * this is a serial line, packets should be short 564 * and/or the copy should be negligible cost compared 565 * to the packet transmission time). 566 */ 567 struct mbuf *m1 = m; 568 u_char *cp = bpfbuf + SLIP_HDRLEN; 569 570 len = 0; 571 do { 572 int mlen = m1->m_len; 573 574 bcopy(mtod(m1, caddr_t), cp, mlen); 575 cp += mlen; 576 len += mlen; 577 } while ((m1 = m1->m_next) != NULL); 578 } 579 ip = mtod(m, struct ip *); 580 if (ip->ip_v == IPVERSION && ip->ip_p == IPPROTO_TCP) { 581 if (sc->sc_if.if_flags & SC_COMPRESS) 582 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 583 &sc->sc_comp, 1); 584 } 585 if (sc->sc_if.if_bpf) { 586 /* 587 * Put the SLIP pseudo-"link header" in place. The 588 * compressed header is now at the beginning of the 589 * mbuf. 590 */ 591 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 592 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 593 bpf_tap(sc->sc_if.if_bpf, bpfbuf, len + SLIP_HDRLEN); 594 } 595 596 /* 597 * If system is getting low on clists, just flush our 598 * output queue (if the stuff was important, it'll get 599 * retransmitted). Note that SLTMAX is used instead of 600 * the current if_mtu setting because connections that 601 * have already been established still use the original 602 * (possibly larger) mss. 603 */ 604 if (cfreecount < CLISTRESERVE + SLTMAX) { 605 m_freem(m); 606 sc->sc_if.if_collisions++; 607 continue; 608 } 609 610 sc->sc_flags &= ~SC_OUTWAIT; 611 /* 612 * The extra FRAME_END will start up a new packet, and thus 613 * will flush any accumulated garbage. We do this whenever 614 * the line may have been idle for some time. 615 */ 616 if (tp->t_outq.c_cc == 0) { 617 ++sc->sc_if.if_obytes; 618 clist_putc(FRAME_END, &tp->t_outq); 619 } 620 621 while (m) { 622 u_char *ep; 623 624 cp = mtod(m, u_char *); ep = cp + m->m_len; 625 while (cp < ep) { 626 /* 627 * Find out how many bytes in the string we can 628 * handle without doing something special. 629 */ 630 u_char *bp = cp; 631 632 while (cp < ep) { 633 switch (*cp++) { 634 case FRAME_ESCAPE: 635 case FRAME_END: 636 --cp; 637 goto out; 638 } 639 } 640 out: 641 if (cp > bp) { 642 /* 643 * Put n characters at once 644 * into the tty output queue. 645 */ 646 if (b_to_q((char *)bp, cp - bp, 647 &tp->t_outq)) 648 break; 649 sc->sc_if.if_obytes += cp - bp; 650 } 651 /* 652 * If there are characters left in the mbuf, 653 * the first one must be special.. 654 * Put it out in a different form. 655 */ 656 if (cp < ep) { 657 if (clist_putc(FRAME_ESCAPE, &tp->t_outq)) 658 break; 659 if (clist_putc(*cp++ == FRAME_ESCAPE ? 660 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 661 &tp->t_outq)) { 662 clist_unputc(&tp->t_outq); 663 break; 664 } 665 sc->sc_if.if_obytes += 2; 666 } 667 } 668 m = m_free(m); 669 } 670 671 if (clist_putc(FRAME_END, &tp->t_outq)) { 672 /* 673 * Not enough room. Remove a char to make room 674 * and end the packet normally. 675 * If you get many collisions (more than one or two 676 * a day) you probably do not have enough clists 677 * and you should increase "nclist" in param.c. 678 */ 679 clist_unputc(&tp->t_outq); 680 clist_putc(FRAME_END, &tp->t_outq); 681 sc->sc_if.if_collisions++; 682 } else { 683 ++sc->sc_if.if_obytes; 684 sc->sc_if.if_opackets++; 685 } 686 } 687 return 0; 688 } 689 690 /* 691 * Copy data buffer to mbuf chain; add ifnet pointer. 692 */ 693 static struct mbuf * 694 sl_btom(struct sl_softc *sc, int len) 695 { 696 struct mbuf *m; 697 698 if (len >= MCLBYTES) 699 return (NULL); 700 701 MGETHDR(m, MB_DONTWAIT, MT_DATA); 702 if (m == NULL) 703 return (NULL); 704 705 /* 706 * If we have more than MHLEN bytes, it's cheaper to 707 * queue the cluster we just filled & allocate a new one 708 * for the input buffer. Otherwise, fill the mbuf we 709 * allocated above. Note that code in the input routine 710 * guarantees that packet will fit in a cluster. 711 */ 712 if (len >= MHLEN) { 713 MCLGET(m, MB_DONTWAIT); 714 if ((m->m_flags & M_EXT) == 0) { 715 /* 716 * we couldn't get a cluster - if memory's this 717 * low, it's time to start dropping packets. 718 */ 719 m_free(m); 720 return (NULL); 721 } 722 } 723 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 724 m->m_len = len; 725 m->m_pkthdr.len = len; 726 m->m_pkthdr.rcvif = &sc->sc_if; 727 return (m); 728 } 729 730 /* 731 * tty interface receiver interrupt. 732 */ 733 static int 734 slinput(int c, struct tty *tp) 735 { 736 struct sl_softc *sc; 737 struct mbuf *m; 738 int len; 739 u_char chdr[CHDR_LEN]; 740 741 tk_nin++; 742 sc = (struct sl_softc *)tp->t_sc; 743 if (sc == NULL) 744 return 0; 745 if (c & TTY_ERRORMASK || (tp->t_state & TS_CONNECTED) == 0) { 746 sc->sc_flags |= SC_ERROR; 747 return 0; 748 } 749 c &= TTY_CHARMASK; 750 751 ++sc->sc_if.if_ibytes; 752 753 if (sc->sc_if.if_flags & IFF_DEBUG) { 754 if (c == ABT_ESC) { 755 /* 756 * If we have a previous abort, see whether 757 * this one is within the time limit. 758 */ 759 if (sc->sc_abortcount && 760 time_second >= sc->sc_starttime + ABT_WINDOW) 761 sc->sc_abortcount = 0; 762 /* 763 * If we see an abort after "idle" time, count it; 764 * record when the first abort escape arrived. 765 */ 766 if (time_second >= sc->sc_lasttime + ABT_IDLE) { 767 if (++sc->sc_abortcount == 1) 768 sc->sc_starttime = time_second; 769 if (sc->sc_abortcount >= ABT_COUNT) { 770 slclose(tp,0); 771 return 0; 772 } 773 } 774 } else 775 sc->sc_abortcount = 0; 776 sc->sc_lasttime = time_second; 777 } 778 779 switch (c) { 780 781 case TRANS_FRAME_ESCAPE: 782 if (sc->sc_escape) 783 c = FRAME_ESCAPE; 784 break; 785 786 case TRANS_FRAME_END: 787 if (sc->sc_escape) 788 c = FRAME_END; 789 break; 790 791 case FRAME_ESCAPE: 792 sc->sc_escape = 1; 793 return 0; 794 795 case FRAME_END: 796 sc->sc_flags &= ~SC_KEEPALIVE; 797 if(sc->sc_flags & SC_ERROR) { 798 sc->sc_flags &= ~SC_ERROR; 799 goto newpack; 800 } 801 len = sc->sc_mp - sc->sc_buf; 802 if (len < 3) 803 /* less than min length packet - ignore */ 804 goto newpack; 805 806 if (sc->sc_if.if_bpf) { 807 /* 808 * Save the compressed header, so we 809 * can tack it on later. Note that we 810 * will end up copying garbage in some 811 * cases but this is okay. We remember 812 * where the buffer started so we can 813 * compute the new header length. 814 */ 815 bcopy(sc->sc_buf, chdr, CHDR_LEN); 816 } 817 818 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 819 if (c & 0x80) 820 c = TYPE_COMPRESSED_TCP; 821 else if (c == TYPE_UNCOMPRESSED_TCP) 822 *sc->sc_buf &= 0x4f; /* XXX */ 823 /* 824 * We've got something that's not an IP packet. 825 * If compression is enabled, try to decompress it. 826 * Otherwise, if `auto-enable' compression is on and 827 * it's a reasonable packet, decompress it and then 828 * enable compression. Otherwise, drop it. 829 */ 830 if (sc->sc_if.if_flags & SC_COMPRESS) { 831 len = sl_uncompress_tcp(&sc->sc_buf, len, 832 (u_int)c, &sc->sc_comp); 833 if (len <= 0) 834 goto error; 835 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 836 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 837 len = sl_uncompress_tcp(&sc->sc_buf, len, 838 (u_int)c, &sc->sc_comp); 839 if (len <= 0) 840 goto error; 841 sc->sc_if.if_flags |= SC_COMPRESS; 842 } else 843 goto error; 844 } 845 if (sc->sc_if.if_bpf) { 846 /* 847 * Put the SLIP pseudo-"link header" in place. 848 * We couldn't do this any earlier since 849 * decompression probably moved the buffer 850 * pointer. Then, invoke BPF. 851 */ 852 u_char *hp = sc->sc_buf - SLIP_HDRLEN; 853 854 hp[SLX_DIR] = SLIPDIR_IN; 855 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 856 bpf_tap(sc->sc_if.if_bpf, hp, len + SLIP_HDRLEN); 857 } 858 m = sl_btom(sc, len); 859 if (m == NULL) 860 goto error; 861 862 sc->sc_if.if_ipackets++; 863 864 if ((sc->sc_if.if_flags & IFF_UP) == 0) { 865 m_freem(m); 866 goto newpack; 867 } 868 869 if (netisr_queue(NETISR_IP, m)) { 870 sc->sc_if.if_ierrors++; 871 sc->sc_if.if_iqdrops++; 872 } 873 874 goto newpack; 875 } 876 if (sc->sc_mp < sc->sc_ep + SLBUFSIZE) { 877 *sc->sc_mp++ = c; 878 sc->sc_escape = 0; 879 return 0; 880 } 881 882 /* can't put lower; would miss an extra frame */ 883 sc->sc_flags |= SC_ERROR; 884 885 error: 886 sc->sc_if.if_ierrors++; 887 newpack: 888 sc->sc_mp = sc->sc_buf = sc->sc_ep + SLBUFSIZE - SLRMAX; 889 sc->sc_escape = 0; 890 return 0; 891 } 892 893 /* 894 * Process an ioctl request. 895 */ 896 static int 897 slioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 898 { 899 struct ifaddr *ifa = (struct ifaddr *)data; 900 struct ifreq *ifr = (struct ifreq *)data; 901 int error = 0; 902 903 crit_enter(); 904 905 switch (cmd) { 906 907 case SIOCSIFFLAGS: 908 /* 909 * if.c will set the interface up even if we 910 * don't want it to. 911 */ 912 if (sl_softc[ifp->if_dunit].sc_ttyp == NULL) { 913 ifp->if_flags &= ~IFF_UP; 914 } 915 break; 916 case SIOCSIFADDR: 917 /* 918 * This is "historical" - set the interface up when 919 * setting the address. 920 */ 921 if (ifa->ifa_addr->sa_family == AF_INET) { 922 if (sl_softc[ifp->if_dunit].sc_ttyp != NULL) 923 ifp->if_flags |= IFF_UP; 924 } else { 925 error = EAFNOSUPPORT; 926 } 927 break; 928 929 case SIOCSIFDSTADDR: 930 if (ifa->ifa_addr->sa_family != AF_INET) 931 error = EAFNOSUPPORT; 932 break; 933 934 case SIOCADDMULTI: 935 case SIOCDELMULTI: 936 break; 937 938 case SIOCSIFMTU: 939 /* 940 * Set the interface MTU. 941 */ 942 if (ifr->ifr_mtu > SLTMAX) 943 error = EINVAL; 944 else { 945 struct tty *tp; 946 947 ifp->if_mtu = ifr->ifr_mtu; 948 tp = sl_softc[ifp->if_dunit].sc_ttyp; 949 if (tp != NULL) 950 clist_alloc_cblocks(&tp->t_outq, 951 SLIP_HIWAT + 2 * ifp->if_mtu + 1, 952 SLIP_HIWAT + 2 * ifp->if_mtu + 1); 953 } 954 break; 955 956 default: 957 error = EINVAL; 958 } 959 960 crit_exit(); 961 return (error); 962 } 963 964 static void 965 sl_keepalive(void *chan) 966 { 967 struct sl_softc *sc = chan; 968 969 if (sc->sc_keepalive) { 970 if (sc->sc_flags & SC_KEEPALIVE) 971 pgsignal (sc->sc_ttyp->t_pgrp, SIGURG, 1); 972 else 973 sc->sc_flags |= SC_KEEPALIVE; 974 callout_reset(&sc->sc_katimeout, sc->sc_keepalive, 975 sl_keepalive, sc); 976 } else { 977 sc->sc_flags &= ~SC_KEEPALIVE; 978 } 979 } 980 981 static void 982 sl_outfill(void *chan) 983 { 984 struct sl_softc *sc = chan; 985 struct tty *tp = sc->sc_ttyp; 986 987 if (sc->sc_outfill && tp != NULL) { 988 if (sc->sc_flags & SC_OUTWAIT) { 989 crit_enter(); 990 ++sc->sc_if.if_obytes; 991 clist_putc(FRAME_END, &tp->t_outq); 992 (*tp->t_oproc)(tp); 993 crit_exit(); 994 } else 995 sc->sc_flags |= SC_OUTWAIT; 996 callout_reset(&sc->sc_oftimeout, sc->sc_outfill, 997 sl_outfill, sc); 998 } else { 999 sc->sc_flags &= ~SC_OUTWAIT; 1000 } 1001 } 1002