1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 1987, 1989, 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)if_sl.c 8.6 (Berkeley) 2/1/94 32 * $FreeBSD: src/sys/net/if_sl.c,v 1.84.2.2 2002/02/13 00:43:10 dillon Exp $ 33 */ 34 35 /* 36 * Serial Line interface 37 * 38 * Rick Adams 39 * Center for Seismic Studies 40 * 1300 N 17th Street, Suite 1450 41 * Arlington, Virginia 22209 42 * (703)276-7900 43 * rick@seismo.ARPA 44 * seismo!rick 45 * 46 * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris). 47 * N.B.: this belongs in netinet, not net, the way it stands now. 48 * Should have a link-layer type designation, but wouldn't be 49 * backwards-compatible. 50 * 51 * Converted to 4.3BSD Beta by Chris Torek. 52 * Other changes made at Berkeley, based in part on code by Kirk Smith. 53 * W. Jolitz added slip abort. 54 * 55 * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov). 56 * Added priority queuing for "interactive" traffic; hooks for TCP 57 * header compression; ICMP filtering (at 2400 baud, some cretin 58 * pinging you can use up all your bandwidth). Made low clist behavior 59 * more robust and slightly less likely to hang serial line. 60 * Sped up a bunch of things. 61 */ 62 63 #include "use_sl.h" 64 #include "opt_inet.h" 65 66 #include <sys/param.h> 67 #include <sys/systm.h> 68 #include <sys/proc.h> 69 #include <sys/caps.h> 70 #include <sys/malloc.h> 71 #include <sys/mbuf.h> 72 #include <sys/dkstat.h> 73 #include <sys/socket.h> 74 #include <sys/sockio.h> 75 #include <sys/fcntl.h> 76 #include <sys/signalvar.h> 77 #include <sys/tty.h> 78 #include <sys/kernel.h> 79 #include <sys/sysctl.h> 80 #include <sys/conf.h> 81 82 #include <net/if.h> 83 #include <net/if_types.h> 84 #include <net/ifq_var.h> 85 #include <net/netisr.h> 86 87 #if INET 88 #include <netinet/in.h> 89 #include <netinet/in_systm.h> 90 #include <netinet/in_var.h> 91 #include <netinet/ip.h> 92 #else 93 #error "Huh? Slip without inet?" 94 #endif 95 96 #include <net/slcompress.h> 97 #include "if_slvar.h" 98 #include <net/slip.h> 99 100 #include <net/bpf.h> 101 102 static void slattach (void *); 103 PSEUDO_SET(slattach, if_sl); 104 105 /* Set to 0xC002 for broadcast instead of p-to-p */ 106 static int sliffopts = IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 107 SYSCTL_INT(_net, OID_AUTO, sliffopts, CTLFLAG_RW, 108 &sliffopts, 0, ""); 109 TUNABLE_INT("net.sliffopts", &sliffopts); 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 50 157 #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 = sliffopts; 212 sc->sc_if.if_type = IFT_SLIP; 213 sc->sc_if.if_ioctl = slioctl; 214 sc->sc_if.if_output = sloutput; 215 ifq_set_maxlen(&sc->sc_if.if_snd, 50); 216 ifq_set_ready(&sc->sc_if.if_snd); 217 sc->sc_fastq.ifq_maxlen = 32; 218 sc->sc_if.if_linkmib = sc; 219 sc->sc_if.if_linkmiblen = sizeof *sc; 220 callout_init_mp(&sc->sc_oftimeout); 221 callout_init_mp(&sc->sc_katimeout); 222 if_attach(&sc->sc_if, NULL); 223 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 224 } 225 } 226 227 static int 228 slinit(struct sl_softc *sc) 229 { 230 if (sc->sc_ep == NULL) 231 sc->sc_ep = kmalloc(SLBUFSIZE, M_DEVBUF, M_WAITOK); 232 sc->sc_buf = sc->sc_ep + SLBUFSIZE - SLRMAX; 233 sc->sc_mp = sc->sc_buf; 234 sl_compress_init(&sc->sc_comp, -1); 235 236 return (1); 237 } 238 239 /* 240 * Line specific open routine. 241 * Attach the given tty to the first available sl unit. 242 */ 243 /* ARGSUSED */ 244 static int 245 slopen(cdev_t dev, struct tty *tp) 246 { 247 struct sl_softc *sc; 248 int nsl; 249 int error; 250 251 error = caps_priv_check_self(SYSCAP_RESTRICTEDROOT); 252 if (error) 253 return (error); 254 255 lwkt_gettoken(&tty_token); 256 if (tp->t_line == SLIPDISC) { 257 lwkt_reltoken(&tty_token); 258 return (0); 259 } 260 261 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) { 262 if (sc->sc_ttyp == NULL && !(sc->sc_flags & SC_STATIC)) { 263 if (slinit(sc) == 0) { 264 lwkt_reltoken(&tty_token); 265 return (ENOBUFS); 266 } 267 tp->t_slsc = (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); 284 clist_alloc_cblocks(&tp->t_outq, 285 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); 286 clist_alloc_cblocks(&tp->t_rawq, 0); 287 288 if_up(&sc->sc_if); 289 lwkt_reltoken(&tty_token); 290 return (0); 291 } 292 } 293 lwkt_reltoken(&tty_token); 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 lwkt_gettoken(&tty_token); 308 lwkt_gettoken(&tp->t_token); 309 ttyflush(tp, FREAD | FWRITE); 310 311 clist_free_cblocks(&tp->t_outq); 312 tp->t_line = 0; 313 sc = (struct sl_softc *)tp->t_slsc; 314 if (sc != NULL) { 315 if (sc->sc_outfill) { 316 sc->sc_outfill = 0; 317 callout_stop(&sc->sc_oftimeout); 318 } 319 if (sc->sc_keepalive) { 320 sc->sc_keepalive = 0; 321 callout_stop(&sc->sc_katimeout); 322 } 323 if_down(&sc->sc_if); 324 sc->sc_flags &= SC_STATIC; 325 sc->sc_ttyp = NULL; 326 tp->t_slsc = NULL; 327 if (sc->sc_ep) { 328 kfree(sc->sc_ep, M_DEVBUF); 329 sc->sc_ep = NULL; 330 } 331 sc->sc_mp = 0; 332 sc->sc_buf = 0; 333 } 334 lwkt_reltoken(&tp->t_token); 335 lwkt_reltoken(&tty_token); 336 337 return 0; 338 } 339 340 /* 341 * Line specific (tty) ioctl routine. 342 * Provide a way to get the sl unit number. 343 */ 344 /* ARGSUSED */ 345 static int 346 sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct ucred *cred) 347 { 348 struct sl_softc *sc = (struct sl_softc *)tp->t_slsc, *nc, *tmpnc; 349 int nsl; 350 351 lwkt_gettoken(&tty_token); 352 lwkt_gettoken(&tp->t_token); 353 354 switch (cmd) { 355 case SLIOCGUNIT: 356 *(int *)data = sc->sc_if.if_dunit; 357 break; 358 359 case SLIOCSUNIT: 360 if (sc->sc_if.if_dunit != *(u_int *)data) { 361 for (nsl = NSL, nc = sl_softc; --nsl >= 0; nc++) { 362 if ( nc->sc_if.if_dunit == *(u_int *)data 363 && nc->sc_ttyp == NULL 364 ) { 365 tmpnc = kmalloc(sizeof *tmpnc, M_TEMP, 366 M_WAITOK); 367 *tmpnc = *nc; 368 *nc = *sc; 369 nc->sc_if = tmpnc->sc_if; 370 tmpnc->sc_if = sc->sc_if; 371 *sc = *tmpnc; 372 kfree(tmpnc, M_TEMP); 373 if (sc->sc_if.if_flags & IFF_UP) { 374 if_down(&sc->sc_if); 375 if (!(nc->sc_if.if_flags & IFF_UP)) 376 if_up(&nc->sc_if); 377 } else if (nc->sc_if.if_flags & IFF_UP) 378 if_down(&nc->sc_if); 379 sc->sc_flags &= ~SC_STATIC; 380 sc->sc_flags |= (nc->sc_flags & SC_STATIC); 381 tp->t_slsc = sc = nc; 382 clist_alloc_cblocks(&tp->t_outq, 383 SLIP_HIWAT + 384 2 * sc->sc_if.if_mtu + 1); 385 sl_compress_init(&sc->sc_comp, -1); 386 goto slfound; 387 } 388 } 389 lwkt_reltoken(&tp->t_token); 390 lwkt_reltoken(&tty_token); 391 return (ENXIO); 392 } 393 slfound: 394 sc->sc_flags |= SC_STATIC; 395 break; 396 397 case SLIOCSKEEPAL: 398 sc->sc_keepalive = *(u_int *)data * hz; 399 if (sc->sc_keepalive) { 400 sc->sc_flags |= SC_KEEPALIVE; 401 callout_reset(&sc->sc_katimeout, sc->sc_keepalive, 402 sl_keepalive, sc); 403 } else { 404 if ((sc->sc_flags & SC_KEEPALIVE) != 0) { 405 callout_stop(&sc->sc_katimeout); 406 sc->sc_flags &= ~SC_KEEPALIVE; 407 } 408 } 409 break; 410 411 case SLIOCGKEEPAL: 412 *(int *)data = sc->sc_keepalive / hz; 413 break; 414 415 case SLIOCSOUTFILL: 416 sc->sc_outfill = *(u_int *)data * hz; 417 if (sc->sc_outfill) { 418 sc->sc_flags |= SC_OUTWAIT; 419 callout_reset(&sc->sc_oftimeout, sc->sc_outfill, 420 sl_outfill, sc); 421 } else { 422 if ((sc->sc_flags & SC_OUTWAIT) != 0) { 423 callout_stop(&sc->sc_oftimeout); 424 sc->sc_flags &= ~SC_OUTWAIT; 425 } 426 } 427 break; 428 429 case SLIOCGOUTFILL: 430 *(int *)data = sc->sc_outfill / hz; 431 break; 432 433 default: 434 lwkt_reltoken(&tp->t_token); 435 lwkt_reltoken(&tty_token); 436 return (ENOIOCTL); 437 } 438 lwkt_reltoken(&tp->t_token); 439 lwkt_reltoken(&tty_token); 440 441 return (0); 442 } 443 444 /* 445 * Queue a packet. Start transmission if not active. 446 * Compression happens in slstart; if we do it here, IP TOS 447 * will cause us to not compress "background" packets, because 448 * ordering gets trashed. It can be done for all packets in slstart. 449 */ 450 static int 451 sloutput_serialized(struct ifnet *ifp, struct ifaltq_subque *ifsq, 452 struct mbuf *m, struct sockaddr *dst, struct rtentry *rtp) 453 { 454 struct sl_softc *sc = &sl_softc[ifp->if_dunit]; 455 struct ip *ip; 456 int error; 457 struct altq_pktattr pktattr; 458 459 ifq_classify(&ifp->if_snd, m, dst->sa_family, &pktattr); 460 461 /* 462 * `Cannot happen' (see slioctl). Someday we will extend 463 * the line protocol to support other address families. 464 */ 465 if (dst->sa_family != AF_INET) { 466 kprintf("%s: af%d not supported\n", sc->sc_if.if_xname, 467 dst->sa_family); 468 m_freem(m); 469 IFNET_STAT_INC(&sc->sc_if, noproto, 1); 470 return (EAFNOSUPPORT); 471 } 472 473 if (sc->sc_ttyp == NULL || !(ifp->if_flags & IFF_UP)) { 474 m_freem(m); 475 return (ENETDOWN); 476 } 477 if ((sc->sc_ttyp->t_state & TS_CONNECTED) == 0) { 478 m_freem(m); 479 return (EHOSTUNREACH); 480 } 481 ip = mtod(m, struct ip *); 482 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 483 m_freem(m); 484 return (ENETRESET); /* XXX ? */ 485 } 486 487 if ((ip->ip_tos & IPTOS_LOWDELAY) && 488 !ifq_is_enabled(&sc->sc_if.if_snd)) { 489 if (IF_QFULL(&sc->sc_fastq)) { 490 IF_DROP(&sc->sc_fastq); 491 m_freem(m); 492 error = ENOBUFS; 493 } else { 494 IF_ENQUEUE(&sc->sc_fastq, m); 495 error = 0; 496 } 497 } else { 498 error = ifsq_enqueue(ifsq, m, &pktattr); 499 } 500 if (error) { 501 IFNET_STAT_INC(&sc->sc_if, oqdrops, 1); 502 return (error); 503 } 504 if (sc->sc_ttyp->t_outq.c_cc == 0) 505 slstart(sc->sc_ttyp); 506 return (0); 507 } 508 509 static int 510 sloutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 511 struct rtentry *rtp) 512 { 513 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd); 514 int error; 515 516 ifsq_serialize_hw(ifsq); 517 error = sloutput_serialized(ifp, ifsq, m, dst, rtp); 518 ifsq_deserialize_hw(ifsq); 519 520 return error; 521 } 522 523 /* 524 * Start output on interface. Get another datagram 525 * to send from the interface queue and map it to 526 * the interface before starting output. 527 */ 528 static int 529 slstart(struct tty *tp) 530 { 531 struct sl_softc *sc = (struct sl_softc *)tp->t_slsc; 532 struct ifaltq_subque *ifsq = ifq_get_subq_default(&sc->sc_if.if_snd); 533 struct mbuf *m; 534 u_char *cp; 535 struct ip *ip; 536 u_char bpfbuf[SLTMAX + SLIP_HDRLEN]; 537 int len = 0; 538 539 lwkt_gettoken(&tp->t_token); 540 for (;;) { 541 /* 542 * Call output process whether or not there is more in the 543 * output queue. We are being called in lieu of ttstart 544 * and must do what it would. 545 */ 546 (*tp->t_oproc)(tp); 547 548 if (tp->t_outq.c_cc != 0) { 549 if (sc != NULL) 550 sc->sc_flags &= ~SC_OUTWAIT; 551 if (tp->t_outq.c_cc > SLIP_HIWAT) { 552 lwkt_reltoken(&tp->t_token); 553 return 0; 554 } 555 } 556 557 /* 558 * This happens briefly when the line shuts down. 559 */ 560 if (sc == NULL) { 561 lwkt_reltoken(&tp->t_token); 562 return 0; 563 } 564 565 /* 566 * Get a packet and send it to the interface. 567 */ 568 IF_DEQUEUE(&sc->sc_fastq, m); 569 if (m) 570 IFNET_STAT_INC(&sc->sc_if, omcasts, 1); /* XXX */ 571 else 572 m = ifsq_dequeue(ifsq); 573 if (m == NULL) { 574 lwkt_reltoken(&tp->t_token); 575 return 0; 576 } 577 578 /* 579 * We do the header compression here rather than in sloutput 580 * because the packets will be out of order if we are using TOS 581 * queueing, and the connection id compression will get 582 * munged when this happens. 583 */ 584 if (sc->sc_if.if_bpf) { 585 /* 586 * We need to save the TCP/IP header before it's 587 * compressed. To avoid complicated code, we just 588 * copy the entire packet into a stack buffer (since 589 * this is a serial line, packets should be short 590 * and/or the copy should be negligible cost compared 591 * to the packet transmission time). 592 */ 593 struct mbuf *m1 = m; 594 u_char *cp = bpfbuf + SLIP_HDRLEN; 595 596 len = 0; 597 do { 598 int mlen = m1->m_len; 599 600 bcopy(mtod(m1, caddr_t), cp, mlen); 601 cp += mlen; 602 len += mlen; 603 } while ((m1 = m1->m_next) != NULL); 604 } 605 ip = mtod(m, struct ip *); 606 if (ip->ip_v == IPVERSION && ip->ip_p == IPPROTO_TCP) { 607 if (sc->sc_if.if_flags & SC_COMPRESS) 608 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 609 &sc->sc_comp, 1); 610 } 611 if (sc->sc_if.if_bpf) { 612 bpf_gettoken(); 613 614 if (sc->sc_if.if_bpf) { 615 /* 616 * Put the SLIP pseudo-"link header" in place. 617 * The compressed header is now at the 618 * beginning of the mbuf. 619 */ 620 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 621 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], 622 CHDR_LEN); 623 bpf_tap(sc->sc_if.if_bpf, bpfbuf, 624 len + SLIP_HDRLEN); 625 } 626 627 bpf_reltoken(); 628 } 629 630 sc->sc_flags &= ~SC_OUTWAIT; 631 632 /* 633 * The extra FRAME_END will start up a new packet, and thus 634 * will flush any accumulated garbage. We do this whenever 635 * the line may have been idle for some time. 636 */ 637 if (tp->t_outq.c_cc == 0) { 638 IFNET_STAT_INC(&sc->sc_if, obytes, 1); 639 clist_putc(FRAME_END, &tp->t_outq); 640 } 641 642 while (m) { 643 u_char *ep; 644 645 cp = mtod(m, u_char *); ep = cp + m->m_len; 646 while (cp < ep) { 647 /* 648 * Find out how many bytes in the string we can 649 * handle without doing something special. 650 */ 651 u_char *bp = cp; 652 653 while (cp < ep) { 654 switch (*cp++) { 655 case FRAME_ESCAPE: 656 case FRAME_END: 657 --cp; 658 goto out; 659 } 660 } 661 out: 662 if (cp > bp) { 663 /* 664 * Put n characters at once 665 * into the tty output queue. 666 */ 667 if (clist_btoq((char *)bp, cp - bp, 668 &tp->t_outq)) { 669 break; 670 } 671 IFNET_STAT_INC(&sc->sc_if, obytes, 672 cp - bp); 673 } 674 /* 675 * If there are characters left in the mbuf, 676 * the first one must be special.. 677 * Put it out in a different form. 678 */ 679 if (cp < ep) { 680 if (clist_putc(FRAME_ESCAPE, &tp->t_outq)) 681 break; 682 if (clist_putc(*cp++ == FRAME_ESCAPE ? 683 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 684 &tp->t_outq)) { 685 clist_unputc(&tp->t_outq); 686 break; 687 } 688 IFNET_STAT_INC(&sc->sc_if, obytes, 2); 689 } 690 } 691 m = m_free(m); 692 } 693 694 if (clist_putc(FRAME_END, &tp->t_outq)) { 695 /* 696 * Not enough room. Remove a char to make room 697 * and end the packet normally. 698 * If you get many collisions (more than one or two 699 * a day) you probably do not have enough clists 700 * and you should increase "nclist" in param.c. 701 */ 702 clist_unputc(&tp->t_outq); 703 clist_putc(FRAME_END, &tp->t_outq); 704 IFNET_STAT_INC(&sc->sc_if, collisions, 1); 705 } else { 706 IFNET_STAT_INC(&sc->sc_if, obytes, 1); 707 IFNET_STAT_INC(&sc->sc_if, opackets, 1); 708 } 709 } 710 lwkt_reltoken(&tp->t_token); 711 712 return 0; 713 } 714 715 /* 716 * Copy data buffer to mbuf chain; add ifnet pointer. 717 */ 718 static struct mbuf * 719 sl_btom(struct sl_softc *sc, int len) 720 { 721 struct mbuf *m; 722 723 if (len >= MCLBYTES) 724 return (NULL); 725 726 MGETHDR(m, M_NOWAIT, MT_DATA); 727 if (m == NULL) 728 return (NULL); 729 730 /* 731 * If we have more than MHLEN bytes, it's cheaper to 732 * queue the cluster we just filled & allocate a new one 733 * for the input buffer. Otherwise, fill the mbuf we 734 * allocated above. Note that code in the input routine 735 * guarantees that packet will fit in a cluster. 736 */ 737 if (len >= MHLEN) { 738 MCLGET(m, M_NOWAIT); 739 if ((m->m_flags & M_EXT) == 0) { 740 /* 741 * we couldn't get a cluster - if memory's this 742 * low, it's time to start dropping packets. 743 */ 744 m_free(m); 745 return (NULL); 746 } 747 } 748 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 749 m->m_len = len; 750 m->m_pkthdr.len = len; 751 m->m_pkthdr.rcvif = &sc->sc_if; 752 return (m); 753 } 754 755 /* 756 * tty interface receiver interrupt. 757 */ 758 static int 759 slinput(int c, struct tty *tp) 760 { 761 struct sl_softc *sc; 762 struct mbuf *m; 763 int len; 764 u_char chdr[CHDR_LEN]; 765 766 #if 0 767 kprintf(" %02x", (unsigned char)c); 768 if ((unsigned char)c == 0xC0) 769 kprintf("\n"); 770 #endif 771 772 lwkt_gettoken(&tp->t_token); 773 tk_nin++; 774 sc = (struct sl_softc *)tp->t_slsc; 775 if (sc == NULL) { 776 lwkt_reltoken(&tp->t_token); 777 #if 0 778 kprintf("X"); 779 #endif 780 return 0; 781 } 782 if (c & TTY_ERRORMASK || (tp->t_state & TS_CONNECTED) == 0) { 783 sc->sc_flags |= SC_ERROR; 784 lwkt_reltoken(&tp->t_token); 785 #if 0 786 kprintf("Y"); 787 #endif 788 return 0; 789 } 790 c &= TTY_CHARMASK; 791 792 IFNET_STAT_INC(&sc->sc_if, ibytes, 1); 793 794 if (sc->sc_if.if_flags & IFF_DEBUG) { 795 if (c == ABT_ESC) { 796 /* 797 * If we have a previous abort, see whether 798 * this one is within the time limit. 799 */ 800 if (sc->sc_abortcount && 801 time_uptime >= sc->sc_starttime + ABT_WINDOW) 802 sc->sc_abortcount = 0; 803 /* 804 * If we see an abort after "idle" time, count it; 805 * record when the first abort escape arrived. 806 */ 807 if (time_uptime >= sc->sc_lasttime + ABT_IDLE) { 808 if (++sc->sc_abortcount == 1) 809 sc->sc_starttime = time_uptime; 810 if (sc->sc_abortcount >= ABT_COUNT) { 811 slclose(tp,0); 812 lwkt_reltoken(&tp->t_token); 813 return 0; 814 } 815 } 816 } else 817 sc->sc_abortcount = 0; 818 sc->sc_lasttime = time_uptime; 819 } 820 821 switch (c) { 822 823 case TRANS_FRAME_ESCAPE: 824 if (sc->sc_escape) 825 c = FRAME_ESCAPE; 826 break; 827 828 case TRANS_FRAME_END: 829 if (sc->sc_escape) 830 c = FRAME_END; 831 break; 832 833 case FRAME_ESCAPE: 834 sc->sc_escape = 1; 835 lwkt_reltoken(&tp->t_token); 836 return 0; 837 838 case FRAME_END: 839 sc->sc_flags &= ~SC_KEEPALIVE; 840 if(sc->sc_flags & SC_ERROR) { 841 sc->sc_flags &= ~SC_ERROR; 842 goto newpack; 843 } 844 len = sc->sc_mp - sc->sc_buf; 845 if (len < 3) 846 /* less than min length packet - ignore */ 847 goto newpack; 848 849 if (sc->sc_if.if_bpf) { 850 /* 851 * Save the compressed header, so we 852 * can tack it on later. Note that we 853 * will end up copying garbage in some 854 * cases but this is okay. We remember 855 * where the buffer started so we can 856 * compute the new header length. 857 */ 858 bcopy(sc->sc_buf, chdr, CHDR_LEN); 859 } 860 861 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 862 if (c & 0x80) 863 c = TYPE_COMPRESSED_TCP; 864 else if (c == TYPE_UNCOMPRESSED_TCP) 865 *sc->sc_buf &= 0x4f; /* XXX */ 866 /* 867 * We've got something that's not an IP packet. 868 * If compression is enabled, try to decompress it. 869 * Otherwise, if `auto-enable' compression is on and 870 * it's a reasonable packet, decompress it and then 871 * enable compression. Otherwise, drop it. 872 */ 873 if (sc->sc_if.if_flags & SC_COMPRESS) { 874 len = sl_uncompress_tcp(&sc->sc_buf, len, 875 (u_int)c, &sc->sc_comp); 876 if (len <= 0) 877 goto error; 878 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 879 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 880 len = sl_uncompress_tcp(&sc->sc_buf, len, 881 (u_int)c, &sc->sc_comp); 882 if (len <= 0) 883 goto error; 884 sc->sc_if.if_flags |= SC_COMPRESS; 885 } else 886 goto error; 887 } 888 if (sc->sc_if.if_bpf) { 889 bpf_gettoken(); 890 891 if (sc->sc_if.if_bpf) { 892 /* 893 * Put the SLIP pseudo-"link header" in place. 894 * We couldn't do this any earlier since 895 * decompression probably moved the buffer 896 * pointer. Then, invoke BPF. 897 */ 898 u_char *hp = sc->sc_buf - SLIP_HDRLEN; 899 900 hp[SLX_DIR] = SLIPDIR_IN; 901 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 902 bpf_tap(sc->sc_if.if_bpf, hp, 903 len + SLIP_HDRLEN); 904 } 905 906 bpf_reltoken(); 907 } 908 m = sl_btom(sc, len); 909 if (m == NULL) 910 goto error; 911 912 IFNET_STAT_INC(&sc->sc_if, ipackets, 1); 913 914 if ((sc->sc_if.if_flags & IFF_UP) == 0) { 915 m_freem(m); 916 goto newpack; 917 } 918 919 if (netisr_queue(NETISR_IP, m)) { 920 IFNET_STAT_INC(&sc->sc_if, ierrors, 1); 921 IFNET_STAT_INC(&sc->sc_if, iqdrops, 1); 922 } 923 924 goto newpack; 925 } 926 if (sc->sc_mp < sc->sc_ep + SLBUFSIZE) { 927 *sc->sc_mp++ = c; 928 sc->sc_escape = 0; 929 lwkt_reltoken(&tp->t_token); 930 return 0; 931 } 932 933 /* can't put lower; would miss an extra frame */ 934 sc->sc_flags |= SC_ERROR; 935 936 error: 937 IFNET_STAT_INC(&sc->sc_if, ierrors, 1); 938 newpack: 939 sc->sc_mp = sc->sc_buf = sc->sc_ep + SLBUFSIZE - SLRMAX; 940 sc->sc_escape = 0; 941 lwkt_reltoken(&tp->t_token); 942 943 return 0; 944 } 945 946 /* 947 * Process an ioctl request. 948 */ 949 static int 950 slioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 951 { 952 struct ifaddr *ifa = (struct ifaddr *)data; 953 struct ifreq *ifr = (struct ifreq *)data; 954 int error = 0; 955 956 switch (cmd) { 957 958 case SIOCSIFFLAGS: 959 /* 960 * if.c will set the interface up even if we 961 * don't want it to. 962 */ 963 if (sl_softc[ifp->if_dunit].sc_ttyp == NULL) { 964 ifp->if_flags &= ~IFF_UP; 965 } 966 break; 967 case SIOCSIFADDR: 968 /* 969 * This is "historical" - set the interface up when 970 * setting the address. 971 */ 972 if (ifa->ifa_addr->sa_family == AF_INET) { 973 if (sl_softc[ifp->if_dunit].sc_ttyp != NULL) 974 ifp->if_flags |= IFF_UP; 975 } else { 976 error = EAFNOSUPPORT; 977 } 978 break; 979 980 case SIOCSIFDSTADDR: 981 if (ifa->ifa_addr->sa_family != AF_INET) 982 error = EAFNOSUPPORT; 983 break; 984 985 case SIOCADDMULTI: 986 case SIOCDELMULTI: 987 break; 988 989 case SIOCSIFMTU: 990 /* 991 * Set the interface MTU. 992 */ 993 if (ifr->ifr_mtu > SLTMAX) 994 error = EINVAL; 995 else { 996 struct tty *tp; 997 998 ifp->if_mtu = ifr->ifr_mtu; 999 tp = sl_softc[ifp->if_dunit].sc_ttyp; 1000 if (tp != NULL) 1001 clist_alloc_cblocks(&tp->t_outq, 1002 SLIP_HIWAT + 2 * ifp->if_mtu + 1); 1003 } 1004 break; 1005 1006 default: 1007 error = EINVAL; 1008 } 1009 return (error); 1010 } 1011 1012 static void 1013 sl_keepalive(void *chan) 1014 { 1015 struct sl_softc *sc = chan; 1016 struct tty *tp = sc->sc_ttyp; 1017 struct pgrp *pg; 1018 1019 lwkt_gettoken(&tp->t_token); 1020 if (sc->sc_keepalive) { 1021 if (sc->sc_flags & SC_KEEPALIVE) { 1022 pg = sc->sc_ttyp->t_pgrp; 1023 if (pg) { 1024 pgref(pg); 1025 pgsignal (pg, SIGURG, 1); 1026 pgrel(pg); 1027 } 1028 } else { 1029 sc->sc_flags |= SC_KEEPALIVE; 1030 } 1031 callout_reset(&sc->sc_katimeout, sc->sc_keepalive, 1032 sl_keepalive, sc); 1033 } else { 1034 sc->sc_flags &= ~SC_KEEPALIVE; 1035 } 1036 lwkt_reltoken(&tp->t_token); 1037 } 1038 1039 static void 1040 sl_outfill(void *chan) 1041 { 1042 struct sl_softc *sc = chan; 1043 struct tty *tp = sc->sc_ttyp; 1044 1045 lwkt_gettoken(&tp->t_token); 1046 1047 if (sc->sc_outfill && tp != NULL) { 1048 if (sc->sc_flags & SC_OUTWAIT) { 1049 IFNET_STAT_INC(&sc->sc_if, obytes, 1); 1050 clist_putc(FRAME_END, &tp->t_outq); 1051 (*tp->t_oproc)(tp); 1052 } else 1053 sc->sc_flags |= SC_OUTWAIT; 1054 callout_reset(&sc->sc_oftimeout, sc->sc_outfill, 1055 sl_outfill, sc); 1056 } else { 1057 sc->sc_flags &= ~SC_OUTWAIT; 1058 } 1059 lwkt_reltoken(&tp->t_token); 1060 } 1061 1062 MODULE_VERSION(if_sl, 1); 1063