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 * from: @(#)if_sl.c 8.6 (Berkeley) 2/1/94 34 * $Id: if_sl.c,v 1.28 1994/05/13 06:02:53 mycroft Exp $ 35 */ 36 37 /* 38 * Serial Line interface 39 * 40 * Rick Adams 41 * Center for Seismic Studies 42 * 1300 N 17th Street, Suite 1450 43 * Arlington, Virginia 22209 44 * (703)276-7900 45 * rick@seismo.ARPA 46 * seismo!rick 47 * 48 * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris). 49 * N.B.: this belongs in netinet, not net, the way it stands now. 50 * Should have a link-layer type designation, but wouldn't be 51 * backwards-compatible. 52 * 53 * Converted to 4.3BSD Beta by Chris Torek. 54 * Other changes made at Berkeley, based in part on code by Kirk Smith. 55 * W. Jolitz added slip abort. 56 * 57 * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov). 58 * Added priority queuing for "interactive" traffic; hooks for TCP 59 * header compression; ICMP filtering (at 2400 baud, some cretin 60 * pinging you can use up all your bandwidth). Made low clist behavior 61 * more robust and slightly less likely to hang serial line. 62 * Sped up a bunch of things. 63 * 64 * Note that splimp() is used throughout to block both (tty) input 65 * interrupts and network activity; thus, splimp must be >= spltty. 66 */ 67 68 #include "sl.h" 69 #if NSL > 0 70 71 #include "bpfilter.h" 72 73 #include <sys/param.h> 74 #include <sys/proc.h> 75 #include <sys/mbuf.h> 76 #include <sys/buf.h> 77 #include <sys/dkstat.h> 78 #include <sys/socket.h> 79 #include <sys/ioctl.h> 80 #include <sys/file.h> 81 #include <sys/tty.h> 82 #include <sys/kernel.h> 83 #include <sys/conf.h> 84 85 #include <machine/cpu.h> 86 87 #include <net/if.h> 88 #include <net/if_types.h> 89 #include <net/netisr.h> 90 #include <net/route.h> 91 92 #if INET 93 #include <netinet/in.h> 94 #include <netinet/in_systm.h> 95 #include <netinet/in_var.h> 96 #include <netinet/ip.h> 97 #else 98 Huh? Slip without inet? 99 #endif 100 101 #include <net/slcompress.h> 102 #include <net/if_slvar.h> 103 #include <net/slip.h> 104 105 #if NBPFILTER > 0 106 #include <sys/time.h> 107 #include <net/bpf.h> 108 #endif 109 110 /* 111 * SLMAX is a hard limit on input packet size. To simplify the code 112 * and improve performance, we require that packets fit in an mbuf 113 * cluster, and if we get a compressed packet, there's enough extra 114 * room to expand the header into a max length tcp/ip header (128 115 * bytes). So, SLMAX can be at most 116 * MCLBYTES - 128 117 * 118 * SLMTU is a hard limit on output packet size. To insure good 119 * interactive response, SLMTU wants to be the smallest size that 120 * amortizes the header cost. (Remember that even with 121 * type-of-service queuing, we have to wait for any in-progress 122 * packet to finish. I.e., we wait, on the average, 1/2 * mtu / 123 * cps, where cps is the line speed in characters per second. 124 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The 125 * average compressed header size is 6-8 bytes so any MTU > 90 126 * bytes will give us 90% of the line bandwidth. A 100ms wait is 127 * tolerable (500ms is not), so want an MTU around 296. (Since TCP 128 * will send 256 byte segments (to allow for 40 byte headers), the 129 * typical packet size on the wire will be around 260 bytes). In 130 * 4.3tahoe+ systems, we can set an MTU in a route so we do that & 131 * leave the interface MTU relatively high (so we don't IP fragment 132 * when acting as a gateway to someone using a stupid MTU). 133 * 134 * Similar considerations apply to SLIP_HIWAT: It's the amount of 135 * data that will be queued 'downstream' of us (i.e., in clists 136 * waiting to be picked up by the tty output interrupt). If we 137 * queue a lot of data downstream, it's immune to 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 #if NBPFILTER > 0 151 #define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) 152 #else 153 #define BUFOFFSET (128+sizeof(struct ifnet **)) 154 #endif 155 #define SLMAX (MCLBYTES - BUFOFFSET) 156 #define SLBUFSIZE (SLMAX + BUFOFFSET) 157 #ifndef SLMTU 158 #define SLMTU 296 159 #endif 160 #if (SLMTU < 3) 161 Huh? SLMTU way too small. 162 #endif 163 #define SLIP_HIWAT roundup(50,CBSIZE) 164 #ifndef __NetBSD__ /* XXX - cgd */ 165 #define CLISTRESERVE 1024 /* Can't let clists get too low */ 166 #endif /* !__NetBSD__ */ 167 168 /* 169 * SLIP ABORT ESCAPE MECHANISM: 170 * (inspired by HAYES modem escape arrangement) 171 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } 172 * within window time signals a "soft" exit from slip mode by remote end 173 * if the IFF_DEBUG flag is on. 174 */ 175 #define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ 176 #define ABT_IDLE 1 /* in seconds - idle before an escape */ 177 #define ABT_COUNT 3 /* count of escapes for abort */ 178 #define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ 179 180 struct sl_softc sl_softc[NSL]; 181 182 #define FRAME_END 0xc0 /* Frame End */ 183 #define FRAME_ESCAPE 0xdb /* Frame Esc */ 184 #define TRANS_FRAME_END 0xdc /* transposed frame end */ 185 #define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ 186 187 extern struct timeval time; 188 189 static int slinit __P((struct sl_softc *)); 190 static struct mbuf *sl_btom __P((struct sl_softc *, int)); 191 192 /* 193 * Called from boot code to establish sl interfaces. 194 */ 195 void 196 slattach() 197 { 198 register struct sl_softc *sc; 199 register int i = 0; 200 201 for (sc = sl_softc; i < NSL; sc++) { 202 sc->sc_if.if_name = "sl"; 203 sc->sc_if.if_next = NULL; 204 sc->sc_if.if_unit = i++; 205 sc->sc_if.if_mtu = SLMTU; 206 sc->sc_if.if_flags = 207 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; 208 sc->sc_if.if_type = IFT_SLIP; 209 sc->sc_if.if_ioctl = slioctl; 210 sc->sc_if.if_output = sloutput; 211 sc->sc_if.if_snd.ifq_maxlen = 50; 212 sc->sc_fastq.ifq_maxlen = 32; 213 if_attach(&sc->sc_if); 214 #if NBPFILTER > 0 215 bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, SLIP_HDRLEN); 216 #endif 217 } 218 } 219 220 static int 221 slinit(sc) 222 register struct sl_softc *sc; 223 { 224 register caddr_t p; 225 226 if (sc->sc_ep == (u_char *) 0) { 227 MCLALLOC(p, M_WAIT); 228 if (p) 229 sc->sc_ep = (u_char *)p + SLBUFSIZE; 230 else { 231 printf("sl%d: can't allocate buffer\n", sc - sl_softc); 232 sc->sc_if.if_flags &= ~IFF_UP; 233 return (0); 234 } 235 } 236 sc->sc_buf = sc->sc_ep - SLMAX; 237 sc->sc_mp = sc->sc_buf; 238 sl_compress_init(&sc->sc_comp, -1); 239 return (1); 240 } 241 242 /* 243 * Line specific open routine. 244 * Attach the given tty to the first available sl unit. 245 */ 246 /* ARGSUSED */ 247 int 248 slopen(dev, tp) 249 dev_t dev; 250 register struct tty *tp; 251 { 252 struct proc *p = curproc; /* XXX */ 253 register struct sl_softc *sc; 254 register int nsl; 255 int error; 256 #ifdef __NetBSD__ 257 int s; 258 #endif 259 260 if (error = suser(p->p_ucred, &p->p_acflag)) 261 return (error); 262 263 if (tp->t_line == SLIPDISC) 264 return (0); 265 266 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) 267 if (sc->sc_ttyp == NULL) { 268 if (slinit(sc) == 0) 269 return (ENOBUFS); 270 tp->t_sc = (caddr_t)sc; 271 sc->sc_ttyp = tp; 272 sc->sc_if.if_baudrate = tp->t_ospeed; 273 ttyflush(tp, FREAD | FWRITE); 274 #ifdef __NetBSD__ 275 /* 276 * make sure tty output queue is large enough 277 * to hold a full-sized packet (including frame 278 * end, and a possible extra frame end). full-sized 279 * packet occupies a max of 2*SLMTU bytes (because 280 * of possible escapes), and add two on for frame 281 * ends. 282 */ 283 s = spltty(); 284 if (tp->t_outq.c_cn < 2*SLMTU+2) { 285 sc->sc_oldbufsize = tp->t_outq.c_cn; 286 sc->sc_oldbufquot = tp->t_outq.c_cq != 0; 287 288 clfree(&tp->t_outq); 289 error = clalloc(&tp->t_outq, 3*SLMTU, 0); 290 if (error) { 291 splx(s); 292 return(error); 293 } 294 } else 295 sc->sc_oldbufsize = sc->sc_oldbufquot = 0; 296 splx(s); 297 #endif /* __NetBSD__ */ 298 return (0); 299 } 300 return (ENXIO); 301 } 302 303 /* 304 * Line specific close routine. 305 * Detach the tty from the sl unit. 306 */ 307 void 308 slclose(tp) 309 struct tty *tp; 310 { 311 register struct sl_softc *sc; 312 int s; 313 314 ttywflush(tp); 315 s = splimp(); /* actually, max(spltty, splnet) */ 316 tp->t_line = 0; 317 sc = (struct sl_softc *)tp->t_sc; 318 if (sc != NULL) { 319 if_down(&sc->sc_if); 320 sc->sc_ttyp = NULL; 321 tp->t_sc = NULL; 322 MCLFREE((caddr_t)(sc->sc_ep - SLBUFSIZE)); 323 sc->sc_ep = 0; 324 sc->sc_mp = 0; 325 sc->sc_buf = 0; 326 } 327 #ifdef __NetBSD__ 328 /* if necessary, install a new outq buffer of the appropriate size */ 329 if (sc->sc_oldbufsize != 0) { 330 clfree(&tp->t_outq); 331 clalloc(&tp->t_outq, sc->sc_oldbufsize, sc->sc_oldbufquot); 332 } 333 #endif 334 splx(s); 335 } 336 337 /* 338 * Line specific (tty) ioctl routine. 339 * Provide a way to get the sl unit number. 340 */ 341 /* ARGSUSED */ 342 int 343 sltioctl(tp, cmd, data, flag) 344 struct tty *tp; 345 int cmd; 346 caddr_t data; 347 int flag; 348 { 349 struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 350 351 switch (cmd) { 352 case SLIOCGUNIT: 353 *(int *)data = sc->sc_if.if_unit; 354 break; 355 356 default: 357 return (-1); 358 } 359 return (0); 360 } 361 362 /* 363 * Queue a packet. Start transmission if not active. 364 * Compression happens in slstart; if we do it here, IP TOS 365 * will cause us to not compress "background" packets, because 366 * ordering gets trashed. It can be done for all packets in slstart. 367 */ 368 int 369 sloutput(ifp, m, dst, rtp) 370 struct ifnet *ifp; 371 register struct mbuf *m; 372 struct sockaddr *dst; 373 struct rtentry *rtp; 374 { 375 register struct sl_softc *sc = &sl_softc[ifp->if_unit]; 376 register struct ip *ip; 377 register struct ifqueue *ifq; 378 int s; 379 380 /* 381 * `Cannot happen' (see slioctl). Someday we will extend 382 * the line protocol to support other address families. 383 */ 384 if (dst->sa_family != AF_INET) { 385 printf("sl%d: af%d not supported\n", sc->sc_if.if_unit, 386 dst->sa_family); 387 m_freem(m); 388 sc->sc_if.if_noproto++; 389 return (EAFNOSUPPORT); 390 } 391 392 if (sc->sc_ttyp == NULL) { 393 m_freem(m); 394 return (ENETDOWN); /* sort of */ 395 } 396 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 && 397 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) { 398 m_freem(m); 399 return (EHOSTUNREACH); 400 } 401 ifq = &sc->sc_if.if_snd; 402 ip = mtod(m, struct ip *); 403 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { 404 m_freem(m); 405 return (ENETRESET); /* XXX ? */ 406 } 407 if (ip->ip_tos & IPTOS_LOWDELAY) 408 ifq = &sc->sc_fastq; 409 s = splimp(); 410 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) { 411 struct timeval tv = time; 412 413 /* if output's been stalled for too long, and restart */ 414 timevalsub(&tv, &sc->sc_if.if_lastchange); 415 if (tv.tv_sec > 0) { 416 sc->sc_otimeout++; 417 slstart(sc->sc_ttyp); 418 } 419 } 420 if (IF_QFULL(ifq)) { 421 IF_DROP(ifq); 422 m_freem(m); 423 splx(s); 424 sc->sc_if.if_oerrors++; 425 return (ENOBUFS); 426 } 427 IF_ENQUEUE(ifq, m); 428 sc->sc_if.if_lastchange = time; 429 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) 430 slstart(sc->sc_ttyp); 431 splx(s); 432 return (0); 433 } 434 435 /* 436 * Start output on interface. Get another datagram 437 * to send from the interface queue and map it to 438 * the interface before starting output. 439 */ 440 void 441 slstart(tp) 442 register struct tty *tp; 443 { 444 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; 445 register struct mbuf *m; 446 register u_char *cp; 447 register struct ip *ip; 448 int s; 449 struct mbuf *m2; 450 #if NBPFILTER > 0 451 u_char bpfbuf[SLMTU + SLIP_HDRLEN]; 452 register int len; 453 #endif 454 #ifndef __NetBSD__ /* XXX - cgd */ 455 extern int cfreecount; 456 #endif 457 458 for (;;) { 459 /* 460 * If there is more in the output queue, just send it now. 461 * We are being called in lieu of ttstart and must do what 462 * it would. 463 */ 464 if (tp->t_outq.c_cc != 0) { 465 (*tp->t_oproc)(tp); 466 if (tp->t_outq.c_cc > SLIP_HIWAT) 467 return; 468 } 469 /* 470 * This happens briefly when the line shuts down. 471 */ 472 if (sc == NULL) 473 return; 474 475 #ifdef __NetBSD__ /* XXX - cgd */ 476 /* 477 * Do not remove the packet from the IP queue if it 478 * doesn't look like the packet will fit into the 479 * current serial output queue, with a packet full of 480 * escapes this could be as bad as SLMTU*2+2. 481 */ 482 if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*SLMTU+2) 483 return; 484 #endif /* __NetBSD__ */ 485 486 /* 487 * Get a packet and send it to the interface. 488 */ 489 s = splimp(); 490 IF_DEQUEUE(&sc->sc_fastq, m); 491 if (m) 492 sc->sc_if.if_omcasts++; /* XXX */ 493 else 494 IF_DEQUEUE(&sc->sc_if.if_snd, m); 495 splx(s); 496 if (m == NULL) 497 return; 498 499 /* 500 * We do the header compression here rather than in sloutput 501 * because the packets will be out of order if we are using TOS 502 * queueing, and the connection id compression will get 503 * munged when this happens. 504 */ 505 #if NBPFILTER > 0 506 if (sc->sc_bpf) { 507 /* 508 * We need to save the TCP/IP header before it's 509 * compressed. To avoid complicated code, we just 510 * copy the entire packet into a stack buffer (since 511 * this is a serial line, packets should be short 512 * and/or the copy should be negligible cost compared 513 * to the packet transmission time). 514 */ 515 register struct mbuf *m1 = m; 516 register u_char *cp = bpfbuf + SLIP_HDRLEN; 517 518 len = 0; 519 do { 520 register int mlen = m1->m_len; 521 522 bcopy(mtod(m1, caddr_t), cp, mlen); 523 cp += mlen; 524 len += mlen; 525 } while (m1 = m1->m_next); 526 } 527 #endif 528 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) { 529 if (sc->sc_if.if_flags & SC_COMPRESS) 530 *mtod(m, u_char *) |= sl_compress_tcp(m, ip, 531 &sc->sc_comp, 1); 532 } 533 #if NBPFILTER > 0 534 if (sc->sc_bpf) { 535 /* 536 * Put the SLIP pseudo-"link header" in place. The 537 * compressed header is now at the beginning of the 538 * mbuf. 539 */ 540 bpfbuf[SLX_DIR] = SLIPDIR_OUT; 541 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); 542 bpf_tap(sc->sc_bpf, bpfbuf, len + SLIP_HDRLEN); 543 } 544 #endif 545 sc->sc_if.if_lastchange = time; 546 547 #ifndef __NetBSD__ /* XXX - cgd */ 548 /* 549 * If system is getting low on clists, just flush our 550 * output queue (if the stuff was important, it'll get 551 * retransmitted). 552 */ 553 if (cfreecount < CLISTRESERVE + SLMTU) { 554 m_freem(m); 555 sc->sc_if.if_collisions++; 556 continue; 557 } 558 #endif /* !__NetBSD__ */ 559 /* 560 * The extra FRAME_END will start up a new packet, and thus 561 * will flush any accumulated garbage. We do this whenever 562 * the line may have been idle for some time. 563 */ 564 if (tp->t_outq.c_cc == 0) { 565 ++sc->sc_if.if_obytes; 566 (void) putc(FRAME_END, &tp->t_outq); 567 } 568 569 while (m) { 570 register u_char *ep; 571 572 cp = mtod(m, u_char *); ep = cp + m->m_len; 573 while (cp < ep) { 574 /* 575 * Find out how many bytes in the string we can 576 * handle without doing something special. 577 */ 578 register u_char *bp = cp; 579 580 while (cp < ep) { 581 switch (*cp++) { 582 case FRAME_ESCAPE: 583 case FRAME_END: 584 --cp; 585 goto out; 586 } 587 } 588 out: 589 if (cp > bp) { 590 /* 591 * Put n characters at once 592 * into the tty output queue. 593 */ 594 #ifdef __NetBSD__ /* XXX - cgd */ 595 if (b_to_q((u_char *)bp, cp - bp, 596 #else 597 if (b_to_q((char *)bp, cp - bp, 598 #endif 599 &tp->t_outq)) 600 break; 601 sc->sc_if.if_obytes += cp - bp; 602 } 603 /* 604 * If there are characters left in the mbuf, 605 * the first one must be special.. 606 * Put it out in a different form. 607 */ 608 if (cp < ep) { 609 if (putc(FRAME_ESCAPE, &tp->t_outq)) 610 break; 611 if (putc(*cp++ == FRAME_ESCAPE ? 612 TRANS_FRAME_ESCAPE : TRANS_FRAME_END, 613 &tp->t_outq)) { 614 (void) unputc(&tp->t_outq); 615 break; 616 } 617 sc->sc_if.if_obytes += 2; 618 } 619 } 620 MFREE(m, m2); 621 m = m2; 622 } 623 624 if (putc(FRAME_END, &tp->t_outq)) { 625 /* 626 * Not enough room. Remove a char to make room 627 * and end the packet normally. 628 * If you get many collisions (more than one or two 629 * a day) you probably do not have enough clists 630 * and you should increase "nclist" in param.c. 631 */ 632 (void) unputc(&tp->t_outq); 633 (void) putc(FRAME_END, &tp->t_outq); 634 sc->sc_if.if_collisions++; 635 } else { 636 ++sc->sc_if.if_obytes; 637 sc->sc_if.if_opackets++; 638 } 639 } 640 } 641 642 /* 643 * Copy data buffer to mbuf chain; add ifnet pointer. 644 */ 645 static struct mbuf * 646 sl_btom(sc, len) 647 register struct sl_softc *sc; 648 register int len; 649 { 650 register struct mbuf *m; 651 652 MGETHDR(m, M_DONTWAIT, MT_DATA); 653 if (m == NULL) 654 return (NULL); 655 656 /* 657 * If we have more than MHLEN bytes, it's cheaper to 658 * queue the cluster we just filled & allocate a new one 659 * for the input buffer. Otherwise, fill the mbuf we 660 * allocated above. Note that code in the input routine 661 * guarantees that packet will fit in a cluster. 662 */ 663 if (len >= MHLEN) { 664 MCLGET(m, M_DONTWAIT); 665 if ((m->m_flags & M_EXT) == 0) { 666 /* 667 * we couldn't get a cluster - if memory's this 668 * low, it's time to start dropping packets. 669 */ 670 (void) m_free(m); 671 return (NULL); 672 } 673 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; 674 m->m_data = (caddr_t)sc->sc_buf; 675 m->m_ext.ext_buf = (caddr_t)((int)sc->sc_buf &~ MCLOFSET); 676 } else 677 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); 678 679 m->m_len = len; 680 m->m_pkthdr.len = len; 681 m->m_pkthdr.rcvif = &sc->sc_if; 682 return (m); 683 } 684 685 /* 686 * tty interface receiver interrupt. 687 */ 688 void 689 slinput(c, tp) 690 register int c; 691 register struct tty *tp; 692 { 693 register struct sl_softc *sc; 694 register struct mbuf *m; 695 register int len; 696 int s; 697 #if NBPFILTER > 0 698 u_char chdr[CHDR_LEN]; 699 #endif 700 701 tk_nin++; 702 sc = (struct sl_softc *)tp->t_sc; 703 if (sc == NULL) 704 return; 705 if (c & TTY_ERRORMASK || ((tp->t_state & TS_CARR_ON) == 0 && 706 (tp->t_cflag & CLOCAL) == 0)) { 707 sc->sc_flags |= SC_ERROR; 708 return; 709 } 710 c &= TTY_CHARMASK; 711 712 ++sc->sc_if.if_ibytes; 713 714 if (sc->sc_if.if_flags & IFF_DEBUG) { 715 if (c == ABT_ESC) { 716 /* 717 * If we have a previous abort, see whether 718 * this one is within the time limit. 719 */ 720 if (sc->sc_abortcount && 721 time.tv_sec >= sc->sc_starttime + ABT_WINDOW) 722 sc->sc_abortcount = 0; 723 /* 724 * If we see an abort after "idle" time, count it; 725 * record when the first abort escape arrived. 726 */ 727 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) { 728 if (++sc->sc_abortcount == 1) 729 sc->sc_starttime = time.tv_sec; 730 if (sc->sc_abortcount >= ABT_COUNT) { 731 slclose(tp); 732 return; 733 } 734 } 735 } else 736 sc->sc_abortcount = 0; 737 sc->sc_lasttime = time.tv_sec; 738 } 739 740 switch (c) { 741 742 case TRANS_FRAME_ESCAPE: 743 if (sc->sc_escape) 744 c = FRAME_ESCAPE; 745 break; 746 747 case TRANS_FRAME_END: 748 if (sc->sc_escape) 749 c = FRAME_END; 750 break; 751 752 case FRAME_ESCAPE: 753 sc->sc_escape = 1; 754 return; 755 756 case FRAME_END: 757 if(sc->sc_flags & SC_ERROR) { 758 sc->sc_flags &= ~SC_ERROR; 759 goto newpack; 760 } 761 len = sc->sc_mp - sc->sc_buf; 762 if (len < 3) 763 /* less than min length packet - ignore */ 764 goto newpack; 765 766 #if NBPFILTER > 0 767 if (sc->sc_bpf) { 768 /* 769 * Save the compressed header, so we 770 * can tack it on later. Note that we 771 * will end up copying garbage in some 772 * cases but this is okay. We remember 773 * where the buffer started so we can 774 * compute the new header length. 775 */ 776 bcopy(sc->sc_buf, chdr, CHDR_LEN); 777 } 778 #endif 779 780 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { 781 if (c & 0x80) 782 c = TYPE_COMPRESSED_TCP; 783 else if (c == TYPE_UNCOMPRESSED_TCP) 784 *sc->sc_buf &= 0x4f; /* XXX */ 785 /* 786 * We've got something that's not an IP packet. 787 * If compression is enabled, try to decompress it. 788 * Otherwise, if `auto-enable' compression is on and 789 * it's a reasonable packet, decompress it and then 790 * enable compression. Otherwise, drop it. 791 */ 792 if (sc->sc_if.if_flags & SC_COMPRESS) { 793 len = sl_uncompress_tcp(&sc->sc_buf, len, 794 (u_int)c, &sc->sc_comp); 795 if (len <= 0) 796 goto error; 797 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && 798 c == TYPE_UNCOMPRESSED_TCP && len >= 40) { 799 len = sl_uncompress_tcp(&sc->sc_buf, len, 800 (u_int)c, &sc->sc_comp); 801 if (len <= 0) 802 goto error; 803 sc->sc_if.if_flags |= SC_COMPRESS; 804 } else 805 goto error; 806 } 807 #if NBPFILTER > 0 808 if (sc->sc_bpf) { 809 /* 810 * Put the SLIP pseudo-"link header" in place. 811 * We couldn't do this any earlier since 812 * decompression probably moved the buffer 813 * pointer. Then, invoke BPF. 814 */ 815 register u_char *hp = sc->sc_buf - SLIP_HDRLEN; 816 817 hp[SLX_DIR] = SLIPDIR_IN; 818 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); 819 bpf_tap(sc->sc_bpf, hp, len + SLIP_HDRLEN); 820 } 821 #endif 822 m = sl_btom(sc, len); 823 if (m == NULL) 824 goto error; 825 826 sc->sc_if.if_ipackets++; 827 sc->sc_if.if_lastchange = time; 828 s = splimp(); 829 if (IF_QFULL(&ipintrq)) { 830 IF_DROP(&ipintrq); 831 sc->sc_if.if_ierrors++; 832 sc->sc_if.if_iqdrops++; 833 m_freem(m); 834 } else { 835 IF_ENQUEUE(&ipintrq, m); 836 schednetisr(NETISR_IP); 837 } 838 splx(s); 839 goto newpack; 840 } 841 if (sc->sc_mp < sc->sc_ep) { 842 *sc->sc_mp++ = c; 843 sc->sc_escape = 0; 844 return; 845 } 846 847 /* can't put lower; would miss an extra frame */ 848 sc->sc_flags |= SC_ERROR; 849 850 error: 851 sc->sc_if.if_ierrors++; 852 newpack: 853 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX; 854 sc->sc_escape = 0; 855 } 856 857 /* 858 * Process an ioctl request. 859 */ 860 int 861 slioctl(ifp, cmd, data) 862 register struct ifnet *ifp; 863 int cmd; 864 caddr_t data; 865 { 866 register struct ifaddr *ifa = (struct ifaddr *)data; 867 register struct ifreq *ifr; 868 register int s = splimp(), error = 0; 869 870 switch (cmd) { 871 872 case SIOCSIFADDR: 873 if (ifa->ifa_addr->sa_family == AF_INET) 874 ifp->if_flags |= IFF_UP; 875 else 876 error = EAFNOSUPPORT; 877 break; 878 879 case SIOCSIFDSTADDR: 880 if (ifa->ifa_addr->sa_family != AF_INET) 881 error = EAFNOSUPPORT; 882 break; 883 884 case SIOCADDMULTI: 885 case SIOCDELMULTI: 886 ifr = (struct ifreq *)data; 887 if (ifr == 0) { 888 error = EAFNOSUPPORT; /* XXX */ 889 break; 890 } 891 switch (ifr->ifr_addr.sa_family) { 892 893 #ifdef INET 894 case AF_INET: 895 break; 896 #endif 897 898 default: 899 error = EAFNOSUPPORT; 900 break; 901 } 902 break; 903 904 default: 905 error = EINVAL; 906 } 907 splx(s); 908 return (error); 909 } 910 #endif 911