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 1.32 2008/05/14 11:59:23 sephe 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/priv.h> 76 #include <sys/malloc.h> 77 #include <sys/mbuf.h> 78 #include <sys/dkstat.h> 79 #include <sys/socket.h> 80 #include <sys/sockio.h> 81 #include <sys/fcntl.h> 82 #include <sys/signalvar.h> 83 #include <sys/tty.h> 84 #include <sys/clist.h> 85 #include <sys/kernel.h> 86 #include <sys/conf.h> 87 #include <sys/thread2.h> 88 89 #include <net/if.h> 90 #include <net/if_types.h> 91 #include <net/ifq_var.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 static void slattach (void *); 110 PSEUDO_SET(slattach, if_sl); 111 112 /* 113 * SLRMAX is a hard limit on input packet size. To simplify the code 114 * and improve performance, we require that packets fit in an mbuf 115 * cluster, and if we get a compressed packet, there's enough extra 116 * room to expand the header into a max length tcp/ip header (128 117 * bytes). So, SLRMAX can be at most 118 * MCLBYTES - 128 119 * 120 * SLMTU is the default transmit MTU. The transmit MTU should be kept 121 * small enough so that interactive use doesn't suffer, but large 122 * enough to provide good performance. 552 is a good choice for SLMTU 123 * because it is high enough to not fragment TCP packets being routed 124 * through this host. Packet fragmentation is bad with SLIP because 125 * fragment headers aren't compressed. The previous assumptions about 126 * the best MTU value don't really hold when using modern modems with 127 * BTLZ data compression because the modem buffers play a much larger 128 * role in interactive performance than the MTU. The MTU can be changed 129 * at any time to suit the specific environment with ifconfig(8), and 130 * its maximum value is defined as SLTMAX. SLTMAX must not be so large 131 * that it would overflow the stack if BPF is configured (XXX; if_ppp.c 132 * handles this better). 133 * 134 * SLIP_HIWAT is the amount of data that will be queued 'downstream' 135 * of us (i.e., in clists waiting to be picked up by the tty output 136 * interrupt). If we queue a lot of data downstream, it's immune to 137 * our t.o.s. queuing. 138 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed 139 * telnet/ftp will see a 1 sec wait, independent of the mtu (the 140 * wait is dependent on the ftp window size but that's typically 141 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize 142 * the cost (in idle time on the wire) of the tty driver running 143 * off the end of its clists & having to call back slstart for a 144 * new packet. For a tty interface with any buffering at all, this 145 * cost will be zero. Even with a totally brain dead interface (like 146 * the one on a typical workstation), the cost will be <= 1 character 147 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose 148 * at most 1% while maintaining good interactive response. 149 */ 150 #define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 151 #define SLRMAX (MCLBYTES - BUFOFFSET) 152 #define SLBUFSIZE (SLRMAX + BUFOFFSET) 153 #ifndef SLMTU 154 #define SLMTU 552 /* default MTU */ 155 #endif 156 #define SLTMAX 1500 /* maximum MTU */ 157 #define SLIP_HIWAT roundup(50,CBSIZE) 158 #define CLISTRESERVE 1024 /* Can't let clists get too low */ 159 160 /* 161 * SLIP ABORT ESCAPE MECHANISM: 162 * (inspired by HAYES modem escape arrangement) 163 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 164 * within window time signals a "soft" exit from slip mode by remote end 165 * if the IFF_DEBUG flag is on. 166 */ 167 #define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 168 #define ABT_IDLE 1 /* in seconds - idle before an escape */ 169 #define ABT_COUNT 3 /* count of escapes for abort */ 170 #define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 171 172 static struct sl_softc sl_softc[NSL]; 173 174 #define FRAME_END 0xc0 /* Frame End */ 175 #define FRAME_ESCAPE 0xdb /* Frame Esc */ 176 #define TRANS_FRAME_END 0xdc /* transposed frame end */ 177 #define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 178 179 static int slinit (struct sl_softc *); 180 static struct mbuf *sl_btom (struct sl_softc *, int); 181 static timeout_t sl_keepalive; 182 static timeout_t sl_outfill; 183 static int slclose (struct tty *,int); 184 static int slinput (int, struct tty *); 185 static int slioctl (struct ifnet *, u_long, caddr_t, struct ucred *); 186 static int sltioctl (struct tty *, u_long, caddr_t, int, struct ucred *); 187 static int slopen (cdev_t, struct tty *); 188 static int sloutput (struct ifnet *, 189 struct mbuf *, struct sockaddr *, struct rtentry *); 190 static int slstart (struct tty *); 191 192 static struct linesw slipdisc = { 193 slopen, slclose, l_noread, l_nowrite, 194 sltioctl, slinput, slstart, ttymodem, 195 FRAME_END 196 }; 197 198 /* 199 * Called from boot code to establish sl interfaces. 200 */ 201 static void 202 slattach(void *dummy) 203 { 204 struct sl_softc *sc; 205 int i = 0; 206 207 linesw[SLIPDISC] = slipdisc; 208 209 for (sc = sl_softc; i < NSL; sc++) { 210 if_initname(&(sc->sc_if), "sl", i++); 211 sc->sc_if.if_mtu = SLMTU; 212 sc->sc_if.if_flags = 213 #ifdef SLIP_IFF_OPTS 214 SLIP_IFF_OPTS; 215 #else 216 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 217 #endif 218 sc->sc_if.if_type = IFT_SLIP; 219 sc->sc_if.if_ioctl = slioctl; 220 sc->sc_if.if_output = sloutput; 221 ifq_set_maxlen(&sc->sc_if.if_snd, 50); 222 ifq_set_ready(&sc->sc_if.if_snd); 223 sc->sc_fastq.ifq_maxlen = 32; 224 sc->sc_if.if_linkmib = sc; 225 sc->sc_if.if_linkmiblen = sizeof *sc; 226 callout_init(&sc->sc_oftimeout); 227 callout_init(&sc->sc_katimeout); 228 if_attach(&sc->sc_if, NULL); 229 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 230 } 231 } 232 233 static int 234 slinit(struct sl_softc *sc) 235 { 236 if (sc->sc_ep == NULL) 237 sc->sc_ep = kmalloc(SLBUFSIZE, M_DEVBUF, M_WAITOK); 238 sc->sc_buf = sc->sc_ep + SLBUFSIZE - SLRMAX; 239 sc->sc_mp = sc->sc_buf; 240 sl_compress_init(&sc->sc_comp, -1); 241 return (1); 242 } 243 244 /* 245 * Line specific open routine. 246 * Attach the given tty to the first available sl unit. 247 */ 248 /* ARGSUSED */ 249 static int 250 slopen(cdev_t dev, struct tty *tp) 251 { 252 struct sl_softc *sc; 253 int nsl; 254 int error; 255 struct thread *td = curthread; /* XXX */ 256 257 error = priv_check(td, PRIV_ROOT); 258 if (error) 259 return (error); 260 261 if (tp->t_line == SLIPDISC) 262 return (0); 263 264 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 265 if (sc->sc_ttyp == NULL && !(sc->sc_flags & SC_STATIC)) { 266 if (slinit(sc) == 0) 267 return (ENOBUFS); 268 tp->t_sc = (caddr_t)sc; 269 sc->sc_ttyp = tp; 270 sc->sc_if.if_baudrate = tp->t_ospeed; 271 ttyflush(tp, FREAD | FWRITE); 272 273 tp->t_line = SLIPDISC; 274 /* 275 * We don't use t_canq or t_rawq, so reduce their 276 * cblock resources to 0. Reserve enough cblocks 277 * for t_outq to guarantee that we can fit a full 278 * packet if the SLIP_HIWAT check allows slstart() 279 * to loop. Use the same value for the cblock 280 * limit since the reserved blocks should always 281 * be enough. Reserving cblocks probably makes 282 * the CLISTRESERVE check unnecessary and wasteful. 283 */ 284 clist_alloc_cblocks(&tp->t_canq, 0, 0); 285 clist_alloc_cblocks(&tp->t_outq, 286 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, 287 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); 288 clist_alloc_cblocks(&tp->t_rawq, 0, 0); 289 290 crit_enter(); 291 if_up(&sc->sc_if); 292 crit_exit(); 293 return (0); 294 } 295 return (ENXIO); 296 } 297 298 /* 299 * Line specific close routine. 300 * Detach the tty from the sl unit. 301 */ 302 static int 303 slclose(struct tty *tp, int flag) 304 { 305 struct sl_softc *sc; 306 307 ttyflush(tp, FREAD | FWRITE); 308 crit_enter(); 309 310 clist_free_cblocks(&tp->t_outq); 311 tp->t_line = 0; 312 sc = (struct sl_softc *)tp->t_sc; 313 if (sc != NULL) { 314 if (sc->sc_outfill) { 315 sc->sc_outfill = 0; 316 callout_stop(&sc->sc_oftimeout); 317 } 318 if (sc->sc_keepalive) { 319 sc->sc_keepalive = 0; 320 callout_stop(&sc->sc_katimeout); 321 } 322 if_down(&sc->sc_if); 323 sc->sc_flags &= SC_STATIC; 324 sc->sc_ttyp = NULL; 325 tp->t_sc = NULL; 326 if (sc->sc_ep) { 327 kfree(sc->sc_ep, M_DEVBUF); 328 sc->sc_ep = NULL; 329 } 330 sc->sc_mp = 0; 331 sc->sc_buf = 0; 332 } 333 crit_exit(); 334 return 0; 335 } 336 337 /* 338 * Line specific (tty) ioctl routine. 339 * Provide a way to get the sl unit number. 340 */ 341 /* ARGSUSED */ 342 static int 343 sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct ucred *cred) 344 { 345 struct sl_softc *sc = (struct sl_softc *)tp->t_sc, *nc, *tmpnc; 346 int nsl; 347 348 crit_enter(); 349 350 switch (cmd) { 351 case SLIOCGUNIT: 352 *(int *)data = sc->sc_if.if_dunit; 353 break; 354 355 case SLIOCSUNIT: 356 if (sc->sc_if.if_dunit != *(u_int *)data) { 357 for (nsl = NSL, nc = sl_softc; --nsl >= 0; nc++) { 358 if ( nc->sc_if.if_dunit == *(u_int *)data 359 && nc->sc_ttyp == NULL 360 ) { 361 tmpnc = kmalloc(sizeof *tmpnc, M_TEMP, 362 M_WAITOK); 363 *tmpnc = *nc; 364 *nc = *sc; 365 nc->sc_if = tmpnc->sc_if; 366 tmpnc->sc_if = sc->sc_if; 367 *sc = *tmpnc; 368 kfree(tmpnc, M_TEMP); 369 if (sc->sc_if.if_flags & IFF_UP) { 370 if_down(&sc->sc_if); 371 if (!(nc->sc_if.if_flags & IFF_UP)) 372 if_up(&nc->sc_if); 373 } else if (nc->sc_if.if_flags & IFF_UP) 374 if_down(&nc->sc_if); 375 sc->sc_flags &= ~SC_STATIC; 376 sc->sc_flags |= (nc->sc_flags & SC_STATIC); 377 tp->t_sc = sc = nc; 378 clist_alloc_cblocks(&tp->t_outq, 379 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, 380 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); 381 sl_compress_init(&sc->sc_comp, -1); 382 goto slfound; 383 } 384 } 385 crit_exit(); 386 return (ENXIO); 387 } 388 slfound: 389 sc->sc_flags |= SC_STATIC; 390 break; 391 392 case SLIOCSKEEPAL: 393 sc->sc_keepalive = *(u_int *)data * hz; 394 if (sc->sc_keepalive) { 395 sc->sc_flags |= SC_KEEPALIVE; 396 callout_reset(&sc->sc_katimeout, sc->sc_keepalive, 397 sl_keepalive, sc); 398 } else { 399 if ((sc->sc_flags & SC_KEEPALIVE) != 0) { 400 callout_stop(&sc->sc_katimeout); 401 sc->sc_flags &= ~SC_KEEPALIVE; 402 } 403 } 404 break; 405 406 case SLIOCGKEEPAL: 407 *(int *)data = sc->sc_keepalive / hz; 408 break; 409 410 case SLIOCSOUTFILL: 411 sc->sc_outfill = *(u_int *)data * hz; 412 if (sc->sc_outfill) { 413 sc->sc_flags |= SC_OUTWAIT; 414 callout_reset(&sc->sc_oftimeout, sc->sc_outfill, 415 sl_outfill, sc); 416 } else { 417 if ((sc->sc_flags & SC_OUTWAIT) != 0) { 418 callout_stop(&sc->sc_oftimeout); 419 sc->sc_flags &= ~SC_OUTWAIT; 420 } 421 } 422 break; 423 424 case SLIOCGOUTFILL: 425 *(int *)data = sc->sc_outfill / hz; 426 break; 427 428 default: 429 crit_exit(); 430 return (ENOIOCTL); 431 } 432 crit_exit(); 433 return (0); 434 } 435 436 /* 437 * Queue a packet. Start transmission if not active. 438 * Compression happens in slstart; if we do it here, IP TOS 439 * will cause us to not compress "background" packets, because 440 * ordering gets trashed. It can be done for all packets in slstart. 441 */ 442 static int 443 sloutput_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 444 struct rtentry *rtp) 445 { 446 struct sl_softc *sc = &sl_softc[ifp->if_dunit]; 447 struct ip *ip; 448 int error; 449 struct altq_pktattr pktattr; 450 451 ifq_classify(&ifp->if_snd, m, dst->sa_family, &pktattr); 452 453 /* 454 * `Cannot happen' (see slioctl). Someday we will extend 455 * the line protocol to support other address families. 456 */ 457 if (dst->sa_family != AF_INET) { 458 kprintf("%s: af%d not supported\n", sc->sc_if.if_xname, 459 dst->sa_family); 460 m_freem(m); 461 sc->sc_if.if_noproto++; 462 return (EAFNOSUPPORT); 463 } 464 465 if (sc->sc_ttyp == NULL || !(ifp->if_flags & IFF_UP)) { 466 m_freem(m); 467 return (ENETDOWN); 468 } 469 if ((sc->sc_ttyp->t_state & TS_CONNECTED) == 0) { 470 m_freem(m); 471 return (EHOSTUNREACH); 472 } 473 ip = mtod(m, struct ip *); 474 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 475 m_freem(m); 476 return (ENETRESET); /* XXX ? */ 477 } 478 479 crit_enter(); 480 481 if ((ip->ip_tos & IPTOS_LOWDELAY) && !ifq_is_enabled(&sc->sc_if.if_snd)) { 482 if (IF_QFULL(&sc->sc_fastq)) { 483 IF_DROP(&sc->sc_fastq); 484 m_freem(m); 485 error = ENOBUFS; 486 } else { 487 IF_ENQUEUE(&sc->sc_fastq, m); 488 error = 0; 489 } 490 } else { 491 error = ifq_enqueue(&sc->sc_if.if_snd, m, &pktattr); 492 } 493 if (error) { 494 sc->sc_if.if_oerrors++; 495 crit_exit(); 496 return (error); 497 } 498 if (sc->sc_ttyp->t_outq.c_cc == 0) 499 slstart(sc->sc_ttyp); 500 crit_exit(); 501 return (0); 502 } 503 504 static int 505 sloutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 506 struct rtentry *rtp) 507 { 508 int error; 509 510 lwkt_serialize_enter(ifp->if_serializer); 511 error = sloutput_serialized(ifp, m, dst, rtp); 512 lwkt_serialize_exit(ifp->if_serializer); 513 514 return error; 515 } 516 517 /* 518 * Start output on interface. Get another datagram 519 * to send from the interface queue and map it to 520 * the interface before starting output. 521 */ 522 static int 523 slstart(struct tty *tp) 524 { 525 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 526 struct mbuf *m; 527 u_char *cp; 528 struct ip *ip; 529 u_char bpfbuf[SLTMAX + SLIP_HDRLEN]; 530 int len = 0; 531 532 for (;;) { 533 /* 534 * Call output process whether or not there is more in the 535 * output queue. We are being called in lieu of ttstart 536 * and must do what it would. 537 */ 538 (*tp->t_oproc)(tp); 539 540 if (tp->t_outq.c_cc != 0) { 541 if (sc != NULL) 542 sc->sc_flags &= ~SC_OUTWAIT; 543 if (tp->t_outq.c_cc > SLIP_HIWAT) 544 return 0; 545 } 546 547 /* 548 * This happens briefly when the line shuts down. 549 */ 550 if (sc == NULL) 551 return 0; 552 553 /* 554 * Get a packet and send it to the interface. 555 */ 556 crit_enter(); 557 IF_DEQUEUE(&sc->sc_fastq, m); 558 if (m) 559 sc->sc_if.if_omcasts++; /* XXX */ 560 else 561 m = ifq_dequeue(&sc->sc_if.if_snd, NULL); 562 crit_exit(); 563 if (m == NULL) 564 return 0; 565 566 /* 567 * We do the header compression here rather than in sloutput 568 * because the packets will be out of order if we are using TOS 569 * queueing, and the connection id compression will get 570 * munged when this happens. 571 */ 572 if (sc->sc_if.if_bpf) { 573 /* 574 * We need to save the TCP/IP header before it's 575 * compressed. To avoid complicated code, we just 576 * copy the entire packet into a stack buffer (since 577 * this is a serial line, packets should be short 578 * and/or the copy should be negligible cost compared 579 * to the packet transmission time). 580 */ 581 struct mbuf *m1 = m; 582 u_char *cp = bpfbuf + SLIP_HDRLEN; 583 584 len = 0; 585 do { 586 int mlen = m1->m_len; 587 588 bcopy(mtod(m1, caddr_t), cp, mlen); 589 cp += mlen; 590 len += mlen; 591 } while ((m1 = m1->m_next) != NULL); 592 } 593 ip = mtod(m, struct ip *); 594 if (ip->ip_v == IPVERSION && ip->ip_p == IPPROTO_TCP) { 595 if (sc->sc_if.if_flags & SC_COMPRESS) 596 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 597 &sc->sc_comp, 1); 598 } 599 if (sc->sc_if.if_bpf) { 600 /* 601 * Put the SLIP pseudo-"link header" in place. The 602 * compressed header is now at the beginning of the 603 * mbuf. 604 */ 605 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 606 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 607 bpf_tap(sc->sc_if.if_bpf, bpfbuf, len + SLIP_HDRLEN); 608 } 609 610 /* 611 * If system is getting low on clists, just flush our 612 * output queue (if the stuff was important, it'll get 613 * retransmitted). Note that SLTMAX is used instead of 614 * the current if_mtu setting because connections that 615 * have already been established still use the original 616 * (possibly larger) mss. 617 */ 618 if (cfreecount < CLISTRESERVE + SLTMAX) { 619 m_freem(m); 620 sc->sc_if.if_collisions++; 621 continue; 622 } 623 624 sc->sc_flags &= ~SC_OUTWAIT; 625 /* 626 * The extra FRAME_END will start up a new packet, and thus 627 * will flush any accumulated garbage. We do this whenever 628 * the line may have been idle for some time. 629 */ 630 if (tp->t_outq.c_cc == 0) { 631 ++sc->sc_if.if_obytes; 632 clist_putc(FRAME_END, &tp->t_outq); 633 } 634 635 while (m) { 636 u_char *ep; 637 638 cp = mtod(m, u_char *); ep = cp + m->m_len; 639 while (cp < ep) { 640 /* 641 * Find out how many bytes in the string we can 642 * handle without doing something special. 643 */ 644 u_char *bp = cp; 645 646 while (cp < ep) { 647 switch (*cp++) { 648 case FRAME_ESCAPE: 649 case FRAME_END: 650 --cp; 651 goto out; 652 } 653 } 654 out: 655 if (cp > bp) { 656 /* 657 * Put n characters at once 658 * into the tty output queue. 659 */ 660 if (b_to_q((char *)bp, cp - bp, 661 &tp->t_outq)) 662 break; 663 sc->sc_if.if_obytes += cp - bp; 664 } 665 /* 666 * If there are characters left in the mbuf, 667 * the first one must be special.. 668 * Put it out in a different form. 669 */ 670 if (cp < ep) { 671 if (clist_putc(FRAME_ESCAPE, &tp->t_outq)) 672 break; 673 if (clist_putc(*cp++ == FRAME_ESCAPE ? 674 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 675 &tp->t_outq)) { 676 clist_unputc(&tp->t_outq); 677 break; 678 } 679 sc->sc_if.if_obytes += 2; 680 } 681 } 682 m = m_free(m); 683 } 684 685 if (clist_putc(FRAME_END, &tp->t_outq)) { 686 /* 687 * Not enough room. Remove a char to make room 688 * and end the packet normally. 689 * If you get many collisions (more than one or two 690 * a day) you probably do not have enough clists 691 * and you should increase "nclist" in param.c. 692 */ 693 clist_unputc(&tp->t_outq); 694 clist_putc(FRAME_END, &tp->t_outq); 695 sc->sc_if.if_collisions++; 696 } else { 697 ++sc->sc_if.if_obytes; 698 sc->sc_if.if_opackets++; 699 } 700 } 701 return 0; 702 } 703 704 /* 705 * Copy data buffer to mbuf chain; add ifnet pointer. 706 */ 707 static struct mbuf * 708 sl_btom(struct sl_softc *sc, int len) 709 { 710 struct mbuf *m; 711 712 if (len >= MCLBYTES) 713 return (NULL); 714 715 MGETHDR(m, MB_DONTWAIT, MT_DATA); 716 if (m == NULL) 717 return (NULL); 718 719 /* 720 * If we have more than MHLEN bytes, it's cheaper to 721 * queue the cluster we just filled & allocate a new one 722 * for the input buffer. Otherwise, fill the mbuf we 723 * allocated above. Note that code in the input routine 724 * guarantees that packet will fit in a cluster. 725 */ 726 if (len >= MHLEN) { 727 MCLGET(m, MB_DONTWAIT); 728 if ((m->m_flags & M_EXT) == 0) { 729 /* 730 * we couldn't get a cluster - if memory's this 731 * low, it's time to start dropping packets. 732 */ 733 m_free(m); 734 return (NULL); 735 } 736 } 737 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 738 m->m_len = len; 739 m->m_pkthdr.len = len; 740 m->m_pkthdr.rcvif = &sc->sc_if; 741 return (m); 742 } 743 744 /* 745 * tty interface receiver interrupt. 746 */ 747 static int 748 slinput(int c, struct tty *tp) 749 { 750 struct sl_softc *sc; 751 struct mbuf *m; 752 int len; 753 u_char chdr[CHDR_LEN]; 754 755 tk_nin++; 756 sc = (struct sl_softc *)tp->t_sc; 757 if (sc == NULL) 758 return 0; 759 if (c & TTY_ERRORMASK || (tp->t_state & TS_CONNECTED) == 0) { 760 sc->sc_flags |= SC_ERROR; 761 return 0; 762 } 763 c &= TTY_CHARMASK; 764 765 ++sc->sc_if.if_ibytes; 766 767 if (sc->sc_if.if_flags & IFF_DEBUG) { 768 if (c == ABT_ESC) { 769 /* 770 * If we have a previous abort, see whether 771 * this one is within the time limit. 772 */ 773 if (sc->sc_abortcount && 774 time_second >= sc->sc_starttime + ABT_WINDOW) 775 sc->sc_abortcount = 0; 776 /* 777 * If we see an abort after "idle" time, count it; 778 * record when the first abort escape arrived. 779 */ 780 if (time_second >= sc->sc_lasttime + ABT_IDLE) { 781 if (++sc->sc_abortcount == 1) 782 sc->sc_starttime = time_second; 783 if (sc->sc_abortcount >= ABT_COUNT) { 784 slclose(tp,0); 785 return 0; 786 } 787 } 788 } else 789 sc->sc_abortcount = 0; 790 sc->sc_lasttime = time_second; 791 } 792 793 switch (c) { 794 795 case TRANS_FRAME_ESCAPE: 796 if (sc->sc_escape) 797 c = FRAME_ESCAPE; 798 break; 799 800 case TRANS_FRAME_END: 801 if (sc->sc_escape) 802 c = FRAME_END; 803 break; 804 805 case FRAME_ESCAPE: 806 sc->sc_escape = 1; 807 return 0; 808 809 case FRAME_END: 810 sc->sc_flags &= ~SC_KEEPALIVE; 811 if(sc->sc_flags & SC_ERROR) { 812 sc->sc_flags &= ~SC_ERROR; 813 goto newpack; 814 } 815 len = sc->sc_mp - sc->sc_buf; 816 if (len < 3) 817 /* less than min length packet - ignore */ 818 goto newpack; 819 820 if (sc->sc_if.if_bpf) { 821 /* 822 * Save the compressed header, so we 823 * can tack it on later. Note that we 824 * will end up copying garbage in some 825 * cases but this is okay. We remember 826 * where the buffer started so we can 827 * compute the new header length. 828 */ 829 bcopy(sc->sc_buf, chdr, CHDR_LEN); 830 } 831 832 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 833 if (c & 0x80) 834 c = TYPE_COMPRESSED_TCP; 835 else if (c == TYPE_UNCOMPRESSED_TCP) 836 *sc->sc_buf &= 0x4f; /* XXX */ 837 /* 838 * We've got something that's not an IP packet. 839 * If compression is enabled, try to decompress it. 840 * Otherwise, if `auto-enable' compression is on and 841 * it's a reasonable packet, decompress it and then 842 * enable compression. Otherwise, drop it. 843 */ 844 if (sc->sc_if.if_flags & SC_COMPRESS) { 845 len = sl_uncompress_tcp(&sc->sc_buf, len, 846 (u_int)c, &sc->sc_comp); 847 if (len <= 0) 848 goto error; 849 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 850 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 851 len = sl_uncompress_tcp(&sc->sc_buf, len, 852 (u_int)c, &sc->sc_comp); 853 if (len <= 0) 854 goto error; 855 sc->sc_if.if_flags |= SC_COMPRESS; 856 } else 857 goto error; 858 } 859 if (sc->sc_if.if_bpf) { 860 /* 861 * Put the SLIP pseudo-"link header" in place. 862 * We couldn't do this any earlier since 863 * decompression probably moved the buffer 864 * pointer. Then, invoke BPF. 865 */ 866 u_char *hp = sc->sc_buf - SLIP_HDRLEN; 867 868 hp[SLX_DIR] = SLIPDIR_IN; 869 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 870 bpf_tap(sc->sc_if.if_bpf, hp, len + SLIP_HDRLEN); 871 } 872 m = sl_btom(sc, len); 873 if (m == NULL) 874 goto error; 875 876 sc->sc_if.if_ipackets++; 877 878 if ((sc->sc_if.if_flags & IFF_UP) == 0) { 879 m_freem(m); 880 goto newpack; 881 } 882 883 if (netisr_queue(NETISR_IP, m)) { 884 sc->sc_if.if_ierrors++; 885 sc->sc_if.if_iqdrops++; 886 } 887 888 goto newpack; 889 } 890 if (sc->sc_mp < sc->sc_ep + SLBUFSIZE) { 891 *sc->sc_mp++ = c; 892 sc->sc_escape = 0; 893 return 0; 894 } 895 896 /* can't put lower; would miss an extra frame */ 897 sc->sc_flags |= SC_ERROR; 898 899 error: 900 sc->sc_if.if_ierrors++; 901 newpack: 902 sc->sc_mp = sc->sc_buf = sc->sc_ep + SLBUFSIZE - SLRMAX; 903 sc->sc_escape = 0; 904 return 0; 905 } 906 907 /* 908 * Process an ioctl request. 909 */ 910 static int 911 slioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 912 { 913 struct ifaddr *ifa = (struct ifaddr *)data; 914 struct ifreq *ifr = (struct ifreq *)data; 915 int error = 0; 916 917 crit_enter(); 918 919 switch (cmd) { 920 921 case SIOCSIFFLAGS: 922 /* 923 * if.c will set the interface up even if we 924 * don't want it to. 925 */ 926 if (sl_softc[ifp->if_dunit].sc_ttyp == NULL) { 927 ifp->if_flags &= ~IFF_UP; 928 } 929 break; 930 case SIOCSIFADDR: 931 /* 932 * This is "historical" - set the interface up when 933 * setting the address. 934 */ 935 if (ifa->ifa_addr->sa_family == AF_INET) { 936 if (sl_softc[ifp->if_dunit].sc_ttyp != NULL) 937 ifp->if_flags |= IFF_UP; 938 } else { 939 error = EAFNOSUPPORT; 940 } 941 break; 942 943 case SIOCSIFDSTADDR: 944 if (ifa->ifa_addr->sa_family != AF_INET) 945 error = EAFNOSUPPORT; 946 break; 947 948 case SIOCADDMULTI: 949 case SIOCDELMULTI: 950 break; 951 952 case SIOCSIFMTU: 953 /* 954 * Set the interface MTU. 955 */ 956 if (ifr->ifr_mtu > SLTMAX) 957 error = EINVAL; 958 else { 959 struct tty *tp; 960 961 ifp->if_mtu = ifr->ifr_mtu; 962 tp = sl_softc[ifp->if_dunit].sc_ttyp; 963 if (tp != NULL) 964 clist_alloc_cblocks(&tp->t_outq, 965 SLIP_HIWAT + 2 * ifp->if_mtu + 1, 966 SLIP_HIWAT + 2 * ifp->if_mtu + 1); 967 } 968 break; 969 970 default: 971 error = EINVAL; 972 } 973 974 crit_exit(); 975 return (error); 976 } 977 978 static void 979 sl_keepalive(void *chan) 980 { 981 struct sl_softc *sc = chan; 982 983 if (sc->sc_keepalive) { 984 if (sc->sc_flags & SC_KEEPALIVE) 985 pgsignal (sc->sc_ttyp->t_pgrp, SIGURG, 1); 986 else 987 sc->sc_flags |= SC_KEEPALIVE; 988 callout_reset(&sc->sc_katimeout, sc->sc_keepalive, 989 sl_keepalive, sc); 990 } else { 991 sc->sc_flags &= ~SC_KEEPALIVE; 992 } 993 } 994 995 static void 996 sl_outfill(void *chan) 997 { 998 struct sl_softc *sc = chan; 999 struct tty *tp = sc->sc_ttyp; 1000 1001 if (sc->sc_outfill && tp != NULL) { 1002 if (sc->sc_flags & SC_OUTWAIT) { 1003 crit_enter(); 1004 ++sc->sc_if.if_obytes; 1005 clist_putc(FRAME_END, &tp->t_outq); 1006 (*tp->t_oproc)(tp); 1007 crit_exit(); 1008 } else 1009 sc->sc_flags |= SC_OUTWAIT; 1010 callout_reset(&sc->sc_oftimeout, sc->sc_outfill, 1011 sl_outfill, sc); 1012 } else { 1013 sc->sc_flags &= ~SC_OUTWAIT; 1014 } 1015 } 1016