proc->thread stage 4: rework the VFS and DEVICE subsystems to take thread
[dragonfly.git] / sys / net / sl / if_sl.c
CommitLineData
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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 $
dadab5e9 35 * $DragonFly: src/sys/net/sl/if_sl.c,v 1.4 2003/06/25 03:56:02 dillon Exp $
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36 */
37
38/*
39 * Serial Line interface
40 *
41 * Rick Adams
42 * Center for Seismic Studies
43 * 1300 N 17th Street, Suite 1450
44 * Arlington, Virginia 22209
45 * (703)276-7900
46 * rick@seismo.ARPA
47 * seismo!rick
48 *
49 * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris).
50 * N.B.: this belongs in netinet, not net, the way it stands now.
51 * Should have a link-layer type designation, but wouldn't be
52 * backwards-compatible.
53 *
54 * Converted to 4.3BSD Beta by Chris Torek.
55 * Other changes made at Berkeley, based in part on code by Kirk Smith.
56 * W. Jolitz added slip abort.
57 *
58 * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov).
59 * Added priority queuing for "interactive" traffic; hooks for TCP
60 * header compression; ICMP filtering (at 2400 baud, some cretin
61 * pinging you can use up all your bandwidth). Made low clist behavior
62 * more robust and slightly less likely to hang serial line.
63 * Sped up a bunch of things.
64 *
65 * Note that splimp() is used throughout to block both (tty) input
66 * interrupts and network activity; thus, splimp must be >= spltty.
67 */
68
69#include "sl.h"
70
71#include "opt_inet.h"
72#if !defined(KLD_MODULE)
73#include "opt_slip.h"
74#endif
75#include <sys/param.h>
76#include <sys/systm.h>
77#include <sys/proc.h>
78#include <sys/malloc.h>
79#include <sys/mbuf.h>
80#include <sys/dkstat.h>
81#include <sys/socket.h>
82#include <sys/sockio.h>
83#include <sys/fcntl.h>
84#include <sys/signalvar.h>
85#include <sys/tty.h>
86#include <sys/clist.h>
87#include <sys/kernel.h>
88#include <sys/conf.h>
89
90#include <net/if.h>
91#include <net/if_types.h>
92#include <net/netisr.h>
93
94#if INET
95#include <netinet/in.h>
96#include <netinet/in_systm.h>
97#include <netinet/in_var.h>
98#include <netinet/ip.h>
99#else
100#error "Huh? Slip without inet?"
101#endif
102
103#include <net/slcompress.h>
104#include <net/if_slvar.h>
105#include <net/slip.h>
106
107#include <net/bpf.h>
108
109#ifdef __i386__
110#include <i386/isa/intr_machdep.h>
111#endif
112
113static void slattach __P((void *));
114PSEUDO_SET(slattach, if_sl);
115
116/*
117 * SLRMAX is a hard limit on input packet size. To simplify the code
118 * and improve performance, we require that packets fit in an mbuf
119 * cluster, and if we get a compressed packet, there's enough extra
120 * room to expand the header into a max length tcp/ip header (128
121 * bytes). So, SLRMAX can be at most
122 * MCLBYTES - 128
123 *
124 * SLMTU is the default transmit MTU. The transmit MTU should be kept
125 * small enough so that interactive use doesn't suffer, but large
126 * enough to provide good performance. 552 is a good choice for SLMTU
127 * because it is high enough to not fragment TCP packets being routed
128 * through this host. Packet fragmentation is bad with SLIP because
129 * fragment headers aren't compressed. The previous assumptions about
130 * the best MTU value don't really hold when using modern modems with
131 * BTLZ data compression because the modem buffers play a much larger
132 * role in interactive performance than the MTU. The MTU can be changed
133 * at any time to suit the specific environment with ifconfig(8), and
134 * its maximum value is defined as SLTMAX. SLTMAX must not be so large
135 * that it would overflow the stack if BPF is configured (XXX; if_ppp.c
136 * handles this better).
137 *
138 * SLIP_HIWAT is the amount of data that will be queued 'downstream'
139 * of us (i.e., in clists waiting to be picked up by the tty output
140 * interrupt). If we queue a lot of data downstream, it's immune to
141 * our t.o.s. queuing.
142 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed
143 * telnet/ftp will see a 1 sec wait, independent of the mtu (the
144 * wait is dependent on the ftp window size but that's typically
145 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize
146 * the cost (in idle time on the wire) of the tty driver running
147 * off the end of its clists & having to call back slstart for a
148 * new packet. For a tty interface with any buffering at all, this
149 * cost will be zero. Even with a totally brain dead interface (like
150 * the one on a typical workstation), the cost will be <= 1 character
151 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose
152 * at most 1% while maintaining good interactive response.
153 */
154#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN)
155#define SLRMAX (MCLBYTES - BUFOFFSET)
156#define SLBUFSIZE (SLRMAX + BUFOFFSET)
157#ifndef SLMTU
158#define SLMTU 552 /* default MTU */
159#endif
160#define SLTMAX 1500 /* maximum MTU */
161#define SLIP_HIWAT roundup(50,CBSIZE)
162#define CLISTRESERVE 1024 /* Can't let clists get too low */
163
164/*
165 * SLIP ABORT ESCAPE MECHANISM:
166 * (inspired by HAYES modem escape arrangement)
167 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape }
168 * within window time signals a "soft" exit from slip mode by remote end
169 * if the IFF_DEBUG flag is on.
170 */
171#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/
172#define ABT_IDLE 1 /* in seconds - idle before an escape */
173#define ABT_COUNT 3 /* count of escapes for abort */
174#define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */
175
176static struct sl_softc sl_softc[NSL];
177
178#define FRAME_END 0xc0 /* Frame End */
179#define FRAME_ESCAPE 0xdb /* Frame Esc */
180#define TRANS_FRAME_END 0xdc /* transposed frame end */
181#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */
182
183static int slinit __P((struct sl_softc *));
184static struct mbuf *sl_btom __P((struct sl_softc *, int));
185static timeout_t sl_keepalive;
186static timeout_t sl_outfill;
187static int slclose __P((struct tty *,int));
188static int slinput __P((int, struct tty *));
189static int slioctl __P((struct ifnet *, u_long, caddr_t));
41c20dac 190static int sltioctl __P((struct tty *, u_long, caddr_t, int, struct thread *));
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191static int slopen __P((dev_t, struct tty *));
192static int sloutput __P((struct ifnet *,
193 struct mbuf *, struct sockaddr *, struct rtentry *));
194static int slstart __P((struct tty *));
195
196static struct linesw slipdisc = {
197 slopen, slclose, l_noread, l_nowrite,
198 sltioctl, slinput, slstart, ttymodem,
199 FRAME_END
200};
201
202/*
203 * Called from boot code to establish sl interfaces.
204 */
205static void
206slattach(dummy)
207 void *dummy;
208{
209 register struct sl_softc *sc;
210 register int i = 0;
211
212 linesw[SLIPDISC] = slipdisc;
213
214 for (sc = sl_softc; i < NSL; sc++) {
215 sc->sc_if.if_name = "sl";
216 sc->sc_if.if_unit = i++;
217 sc->sc_if.if_mtu = SLMTU;
218 sc->sc_if.if_flags =
219#ifdef SLIP_IFF_OPTS
220 SLIP_IFF_OPTS;
221#else
222 IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST;
223#endif
224 sc->sc_if.if_type = IFT_SLIP;
225 sc->sc_if.if_ioctl = slioctl;
226 sc->sc_if.if_output = sloutput;
227 sc->sc_if.if_snd.ifq_maxlen = 50;
228 sc->sc_fastq.ifq_maxlen = 32;
229 sc->sc_if.if_linkmib = sc;
230 sc->sc_if.if_linkmiblen = sizeof *sc;
231 if_attach(&sc->sc_if);
232 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
233 }
234}
235
236static int
237slinit(sc)
238 register struct sl_softc *sc;
239{
240 register caddr_t p;
241
242#ifdef __i386__
243 int s;
244
245 s = splhigh();
246 tty_imask |= net_imask;
247 net_imask = tty_imask;
248 update_intr_masks();
249 splx(s);
250 if (bootverbose)
251 printf("new imasks: bio %x, tty %x, net %x\n",
252 bio_imask, tty_imask, net_imask);
253#endif
254 if (sc->sc_ep == (u_char *) 0) {
255 MCLALLOC(p, M_WAIT);
256 if (p)
257 sc->sc_ep = (u_char *)p + SLBUFSIZE;
258 else {
259 printf("sl%ld: can't allocate buffer\n",
260 (long)(sc - sl_softc));
261 return (0);
262 }
263 }
264 sc->sc_buf = sc->sc_ep - SLRMAX;
265 sc->sc_mp = sc->sc_buf;
266 sl_compress_init(&sc->sc_comp, -1);
267 return (1);
268}
269
270/*
271 * Line specific open routine.
272 * Attach the given tty to the first available sl unit.
273 */
274/* ARGSUSED */
275static int
41c20dac 276slopen(dev_t dev, struct tty *tp)
984263bc 277{
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278 struct sl_softc *sc;
279 int nsl;
984263bc 280 int s, error;
dadab5e9 281 struct thread *td = curthread; /* XXX */
984263bc 282
dadab5e9 283 error = suser(td);
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284 if (error)
285 return (error);
286
287 if (tp->t_line == SLIPDISC)
288 return (0);
289
290 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++)
291 if (sc->sc_ttyp == NULL && !(sc->sc_flags & SC_STATIC)) {
292 if (slinit(sc) == 0)
293 return (ENOBUFS);
294 tp->t_sc = (caddr_t)sc;
295 sc->sc_ttyp = tp;
296 sc->sc_if.if_baudrate = tp->t_ospeed;
297 ttyflush(tp, FREAD | FWRITE);
298
299 tp->t_line = SLIPDISC;
300 /*
301 * We don't use t_canq or t_rawq, so reduce their
302 * cblock resources to 0. Reserve enough cblocks
303 * for t_outq to guarantee that we can fit a full
304 * packet if the SLIP_HIWAT check allows slstart()
305 * to loop. Use the same value for the cblock
306 * limit since the reserved blocks should always
307 * be enough. Reserving cblocks probably makes
308 * the CLISTRESERVE check unnecessary and wasteful.
309 */
310 clist_alloc_cblocks(&tp->t_canq, 0, 0);
311 clist_alloc_cblocks(&tp->t_outq,
312 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1,
313 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1);
314 clist_alloc_cblocks(&tp->t_rawq, 0, 0);
315
316 s = splnet();
317 if_up(&sc->sc_if);
318 splx(s);
319 return (0);
320 }
321 return (ENXIO);
322}
323
324/*
325 * Line specific close routine.
326 * Detach the tty from the sl unit.
327 */
328static int
329slclose(tp,flag)
330 struct tty *tp;
331 int flag;
332{
333 register struct sl_softc *sc;
334 int s;
335
336 ttyflush(tp, FREAD | FWRITE);
337 /*
338 * XXX the placement of the following spl is misleading. tty
339 * interrupts must be blocked across line discipline switches
340 * and throughout closes to avoid races.
341 */
342 s = splimp(); /* actually, max(spltty, splnet) */
343 clist_free_cblocks(&tp->t_outq);
344 tp->t_line = 0;
345 sc = (struct sl_softc *)tp->t_sc;
346 if (sc != NULL) {
347 if (sc->sc_outfill) {
348 sc->sc_outfill = 0;
349 untimeout(sl_outfill, sc, sc->sc_ofhandle);
350 }
351 if (sc->sc_keepalive) {
352 sc->sc_keepalive = 0;
353 untimeout(sl_keepalive, sc, sc->sc_kahandle);
354 }
355 if_down(&sc->sc_if);
356 sc->sc_flags &= SC_STATIC;
357 sc->sc_ttyp = NULL;
358 tp->t_sc = NULL;
359 MCLFREE((caddr_t)(sc->sc_ep - SLBUFSIZE));
360 sc->sc_ep = 0;
361 sc->sc_mp = 0;
362 sc->sc_buf = 0;
363 }
364 splx(s);
365 return 0;
366}
367
368/*
369 * Line specific (tty) ioctl routine.
370 * Provide a way to get the sl unit number.
371 */
372/* ARGSUSED */
373static int
41c20dac 374sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct thread *p)
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375{
376 struct sl_softc *sc = (struct sl_softc *)tp->t_sc, *nc, *tmpnc;
377 int s, nsl;
378
379 s = splimp();
380 switch (cmd) {
381 case SLIOCGUNIT:
382 *(int *)data = sc->sc_if.if_unit;
383 break;
384
385 case SLIOCSUNIT:
386 if (sc->sc_if.if_unit != *(u_int *)data) {
387 for (nsl = NSL, nc = sl_softc; --nsl >= 0; nc++) {
388 if ( nc->sc_if.if_unit == *(u_int *)data
389 && nc->sc_ttyp == NULL
390 ) {
391 tmpnc = malloc(sizeof *tmpnc, M_TEMP,
392 M_NOWAIT);
393 if (tmpnc == NULL) {
394 splx(s);
395 return (ENOMEM);
396 }
397 *tmpnc = *nc;
398 *nc = *sc;
399 nc->sc_if = tmpnc->sc_if;
400 tmpnc->sc_if = sc->sc_if;
401 *sc = *tmpnc;
402 free(tmpnc, M_TEMP);
403 if (sc->sc_if.if_flags & IFF_UP) {
404 if_down(&sc->sc_if);
405 if (!(nc->sc_if.if_flags & IFF_UP))
406 if_up(&nc->sc_if);
407 } else if (nc->sc_if.if_flags & IFF_UP)
408 if_down(&nc->sc_if);
409 sc->sc_flags &= ~SC_STATIC;
410 sc->sc_flags |= (nc->sc_flags & SC_STATIC);
411 tp->t_sc = sc = nc;
412 clist_alloc_cblocks(&tp->t_outq,
413 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1,
414 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1);
415 sl_compress_init(&sc->sc_comp, -1);
416 goto slfound;
417 }
418 }
419 splx(s);
420 return (ENXIO);
421 }
422 slfound:
423 sc->sc_flags |= SC_STATIC;
424 break;
425
426 case SLIOCSKEEPAL:
427 sc->sc_keepalive = *(u_int *)data * hz;
428 if (sc->sc_keepalive) {
429 sc->sc_flags |= SC_KEEPALIVE;
430 sc->sc_kahandle = timeout(sl_keepalive, sc,
431 sc->sc_keepalive);
432 } else {
433 if ((sc->sc_flags & SC_KEEPALIVE) != 0) {
434 untimeout(sl_keepalive, sc, sc->sc_kahandle);
435 sc->sc_flags &= ~SC_KEEPALIVE;
436 }
437 }
438 break;
439
440 case SLIOCGKEEPAL:
441 *(int *)data = sc->sc_keepalive / hz;
442 break;
443
444 case SLIOCSOUTFILL:
445 sc->sc_outfill = *(u_int *)data * hz;
446 if (sc->sc_outfill) {
447 sc->sc_flags |= SC_OUTWAIT;
448 sc->sc_ofhandle = timeout(sl_outfill, sc,
449 sc->sc_outfill);
450 } else {
451 if ((sc->sc_flags & SC_OUTWAIT) != 0) {
452 untimeout(sl_outfill, sc, sc->sc_ofhandle);
453 sc->sc_flags &= ~SC_OUTWAIT;
454 }
455 }
456 break;
457
458 case SLIOCGOUTFILL:
459 *(int *)data = sc->sc_outfill / hz;
460 break;
461
462 default:
463 splx(s);
464 return (ENOIOCTL);
465 }
466 splx(s);
467 return (0);
468}
469
470/*
471 * Queue a packet. Start transmission if not active.
472 * Compression happens in slstart; if we do it here, IP TOS
473 * will cause us to not compress "background" packets, because
474 * ordering gets trashed. It can be done for all packets in slstart.
475 */
476static int
477sloutput(ifp, m, dst, rtp)
478 struct ifnet *ifp;
479 register struct mbuf *m;
480 struct sockaddr *dst;
481 struct rtentry *rtp;
482{
483 register struct sl_softc *sc = &sl_softc[ifp->if_unit];
484 register struct ip *ip;
485 register struct ifqueue *ifq;
486 int s;
487
488 /*
489 * `Cannot happen' (see slioctl). Someday we will extend
490 * the line protocol to support other address families.
491 */
492 if (dst->sa_family != AF_INET) {
493 printf("sl%d: af%d not supported\n", sc->sc_if.if_unit,
494 dst->sa_family);
495 m_freem(m);
496 sc->sc_if.if_noproto++;
497 return (EAFNOSUPPORT);
498 }
499
500 if (sc->sc_ttyp == NULL || !(ifp->if_flags & IFF_UP)) {
501 m_freem(m);
502 return (ENETDOWN);
503 }
504 if ((sc->sc_ttyp->t_state & TS_CONNECTED) == 0) {
505 m_freem(m);
506 return (EHOSTUNREACH);
507 }
508 ifq = &sc->sc_if.if_snd;
509 ip = mtod(m, struct ip *);
510 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
511 m_freem(m);
512 return (ENETRESET); /* XXX ? */
513 }
514 if (ip->ip_tos & IPTOS_LOWDELAY)
515 ifq = &sc->sc_fastq;
516 s = splimp();
517 if (IF_QFULL(ifq)) {
518 IF_DROP(ifq);
519 m_freem(m);
520 splx(s);
521 sc->sc_if.if_oerrors++;
522 return (ENOBUFS);
523 }
524 IF_ENQUEUE(ifq, m);
525 if (sc->sc_ttyp->t_outq.c_cc == 0)
526 slstart(sc->sc_ttyp);
527 splx(s);
528 return (0);
529}
530
531/*
532 * Start output on interface. Get another datagram
533 * to send from the interface queue and map it to
534 * the interface before starting output.
535 */
536static int
537slstart(tp)
538 register struct tty *tp;
539{
540 register struct sl_softc *sc = (struct sl_softc *)tp->t_sc;
541 register struct mbuf *m;
542 register u_char *cp;
543 register struct ip *ip;
544 int s;
545 u_char bpfbuf[SLTMAX + SLIP_HDRLEN];
546 register int len = 0;
547
548 for (;;) {
549 /*
550 * Call output process whether or not there is more in the
551 * output queue. We are being called in lieu of ttstart
552 * and must do what it would.
553 */
554 (*tp->t_oproc)(tp);
555
556 if (tp->t_outq.c_cc != 0) {
557 if (sc != NULL)
558 sc->sc_flags &= ~SC_OUTWAIT;
559 if (tp->t_outq.c_cc > SLIP_HIWAT)
560 return 0;
561 }
562
563 /*
564 * This happens briefly when the line shuts down.
565 */
566 if (sc == NULL)
567 return 0;
568
569 /*
570 * Get a packet and send it to the interface.
571 */
572 s = splimp();
573 IF_DEQUEUE(&sc->sc_fastq, m);
574 if (m)
575 sc->sc_if.if_omcasts++; /* XXX */
576 else
577 IF_DEQUEUE(&sc->sc_if.if_snd, m);
578 splx(s);
579 if (m == NULL)
580 return 0;
581
582 /*
583 * We do the header compression here rather than in sloutput
584 * because the packets will be out of order if we are using TOS
585 * queueing, and the connection id compression will get
586 * munged when this happens.
587 */
588 if (sc->sc_if.if_bpf) {
589 /*
590 * We need to save the TCP/IP header before it's
591 * compressed. To avoid complicated code, we just
592 * copy the entire packet into a stack buffer (since
593 * this is a serial line, packets should be short
594 * and/or the copy should be negligible cost compared
595 * to the packet transmission time).
596 */
597 register struct mbuf *m1 = m;
598 register u_char *cp = bpfbuf + SLIP_HDRLEN;
599
600 len = 0;
601 do {
602 register int mlen = m1->m_len;
603
604 bcopy(mtod(m1, caddr_t), cp, mlen);
605 cp += mlen;
606 len += mlen;
607 } while ((m1 = m1->m_next) != NULL);
608 }
609 ip = mtod(m, struct ip *);
610 if (ip->ip_v == IPVERSION && ip->ip_p == IPPROTO_TCP) {
611 if (sc->sc_if.if_flags & SC_COMPRESS)
612 *mtod(m, u_char *) |= sl_compress_tcp(m, ip,
613 &sc->sc_comp, 1);
614 }
615 if (sc->sc_if.if_bpf) {
616 /*
617 * Put the SLIP pseudo-"link header" in place. The
618 * compressed header is now at the beginning of the
619 * mbuf.
620 */
621 bpfbuf[SLX_DIR] = SLIPDIR_OUT;
622 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN);
623 bpf_tap(&sc->sc_if, bpfbuf, len + SLIP_HDRLEN);
624 }
625
626 /*
627 * If system is getting low on clists, just flush our
628 * output queue (if the stuff was important, it'll get
629 * retransmitted). Note that SLTMAX is used instead of
630 * the current if_mtu setting because connections that
631 * have already been established still use the original
632 * (possibly larger) mss.
633 */
634 if (cfreecount < CLISTRESERVE + SLTMAX) {
635 m_freem(m);
636 sc->sc_if.if_collisions++;
637 continue;
638 }
639
640 sc->sc_flags &= ~SC_OUTWAIT;
641 /*
642 * The extra FRAME_END will start up a new packet, and thus
643 * will flush any accumulated garbage. We do this whenever
644 * the line may have been idle for some time.
645 */
646 if (tp->t_outq.c_cc == 0) {
647 ++sc->sc_if.if_obytes;
648 (void) putc(FRAME_END, &tp->t_outq);
649 }
650
651 while (m) {
652 register u_char *ep;
653
654 cp = mtod(m, u_char *); ep = cp + m->m_len;
655 while (cp < ep) {
656 /*
657 * Find out how many bytes in the string we can
658 * handle without doing something special.
659 */
660 register u_char *bp = cp;
661
662 while (cp < ep) {
663 switch (*cp++) {
664 case FRAME_ESCAPE:
665 case FRAME_END:
666 --cp;
667 goto out;
668 }
669 }
670 out:
671 if (cp > bp) {
672 /*
673 * Put n characters at once
674 * into the tty output queue.
675 */
676 if (b_to_q((char *)bp, cp - bp,
677 &tp->t_outq))
678 break;
679 sc->sc_if.if_obytes += cp - bp;
680 }
681 /*
682 * If there are characters left in the mbuf,
683 * the first one must be special..
684 * Put it out in a different form.
685 */
686 if (cp < ep) {
687 if (putc(FRAME_ESCAPE, &tp->t_outq))
688 break;
689 if (putc(*cp++ == FRAME_ESCAPE ?
690 TRANS_FRAME_ESCAPE : TRANS_FRAME_END,
691 &tp->t_outq)) {
692 (void) unputc(&tp->t_outq);
693 break;
694 }
695 sc->sc_if.if_obytes += 2;
696 }
697 }
698 m = m_free(m);
699 }
700
701 if (putc(FRAME_END, &tp->t_outq)) {
702 /*
703 * Not enough room. Remove a char to make room
704 * and end the packet normally.
705 * If you get many collisions (more than one or two
706 * a day) you probably do not have enough clists
707 * and you should increase "nclist" in param.c.
708 */
709 (void) unputc(&tp->t_outq);
710 (void) putc(FRAME_END, &tp->t_outq);
711 sc->sc_if.if_collisions++;
712 } else {
713 ++sc->sc_if.if_obytes;
714 sc->sc_if.if_opackets++;
715 }
716 }
717 return 0;
718}
719
720/*
721 * Copy data buffer to mbuf chain; add ifnet pointer.
722 */
723static struct mbuf *
724sl_btom(sc, len)
725 register struct sl_softc *sc;
726 register int len;
727{
728 register struct mbuf *m;
729
730 MGETHDR(m, M_DONTWAIT, MT_DATA);
731 if (m == NULL)
732 return (NULL);
733
734 /*
735 * If we have more than MHLEN bytes, it's cheaper to
736 * queue the cluster we just filled & allocate a new one
737 * for the input buffer. Otherwise, fill the mbuf we
738 * allocated above. Note that code in the input routine
739 * guarantees that packet will fit in a cluster.
740 */
741 if (len >= MHLEN) {
742 MCLGET(m, M_DONTWAIT);
743 if ((m->m_flags & M_EXT) == 0) {
744 /*
745 * we couldn't get a cluster - if memory's this
746 * low, it's time to start dropping packets.
747 */
748 (void) m_free(m);
749 return (NULL);
750 }
751 sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE;
752 m->m_data = (caddr_t)sc->sc_buf;
753 m->m_ext.ext_buf = (caddr_t)((intptr_t)sc->sc_buf &~ MCLOFSET);
754 } else
755 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len);
756
757 m->m_len = len;
758 m->m_pkthdr.len = len;
759 m->m_pkthdr.rcvif = &sc->sc_if;
760 return (m);
761}
762
763/*
764 * tty interface receiver interrupt.
765 */
766static int
767slinput(c, tp)
768 register int c;
769 register struct tty *tp;
770{
771 register struct sl_softc *sc;
772 register struct mbuf *m;
773 register int len;
774 int s;
775 u_char chdr[CHDR_LEN];
776
777 tk_nin++;
778 sc = (struct sl_softc *)tp->t_sc;
779 if (sc == NULL)
780 return 0;
781 if (c & TTY_ERRORMASK || (tp->t_state & TS_CONNECTED) == 0) {
782 sc->sc_flags |= SC_ERROR;
783 return 0;
784 }
785 c &= TTY_CHARMASK;
786
787 ++sc->sc_if.if_ibytes;
788
789 if (sc->sc_if.if_flags & IFF_DEBUG) {
790 if (c == ABT_ESC) {
791 /*
792 * If we have a previous abort, see whether
793 * this one is within the time limit.
794 */
795 if (sc->sc_abortcount &&
796 time_second >= sc->sc_starttime + ABT_WINDOW)
797 sc->sc_abortcount = 0;
798 /*
799 * If we see an abort after "idle" time, count it;
800 * record when the first abort escape arrived.
801 */
802 if (time_second >= sc->sc_lasttime + ABT_IDLE) {
803 if (++sc->sc_abortcount == 1)
804 sc->sc_starttime = time_second;
805 if (sc->sc_abortcount >= ABT_COUNT) {
806 slclose(tp,0);
807 return 0;
808 }
809 }
810 } else
811 sc->sc_abortcount = 0;
812 sc->sc_lasttime = time_second;
813 }
814
815 switch (c) {
816
817 case TRANS_FRAME_ESCAPE:
818 if (sc->sc_escape)
819 c = FRAME_ESCAPE;
820 break;
821
822 case TRANS_FRAME_END:
823 if (sc->sc_escape)
824 c = FRAME_END;
825 break;
826
827 case FRAME_ESCAPE:
828 sc->sc_escape = 1;
829 return 0;
830
831 case FRAME_END:
832 sc->sc_flags &= ~SC_KEEPALIVE;
833 if(sc->sc_flags & SC_ERROR) {
834 sc->sc_flags &= ~SC_ERROR;
835 goto newpack;
836 }
837 len = sc->sc_mp - sc->sc_buf;
838 if (len < 3)
839 /* less than min length packet - ignore */
840 goto newpack;
841
842 if (sc->sc_if.if_bpf) {
843 /*
844 * Save the compressed header, so we
845 * can tack it on later. Note that we
846 * will end up copying garbage in some
847 * cases but this is okay. We remember
848 * where the buffer started so we can
849 * compute the new header length.
850 */
851 bcopy(sc->sc_buf, chdr, CHDR_LEN);
852 }
853
854 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) {
855 if (c & 0x80)
856 c = TYPE_COMPRESSED_TCP;
857 else if (c == TYPE_UNCOMPRESSED_TCP)
858 *sc->sc_buf &= 0x4f; /* XXX */
859 /*
860 * We've got something that's not an IP packet.
861 * If compression is enabled, try to decompress it.
862 * Otherwise, if `auto-enable' compression is on and
863 * it's a reasonable packet, decompress it and then
864 * enable compression. Otherwise, drop it.
865 */
866 if (sc->sc_if.if_flags & SC_COMPRESS) {
867 len = sl_uncompress_tcp(&sc->sc_buf, len,
868 (u_int)c, &sc->sc_comp);
869 if (len <= 0)
870 goto error;
871 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
872 c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
873 len = sl_uncompress_tcp(&sc->sc_buf, len,
874 (u_int)c, &sc->sc_comp);
875 if (len <= 0)
876 goto error;
877 sc->sc_if.if_flags |= SC_COMPRESS;
878 } else
879 goto error;
880 }
881 if (sc->sc_if.if_bpf) {
882 /*
883 * Put the SLIP pseudo-"link header" in place.
884 * We couldn't do this any earlier since
885 * decompression probably moved the buffer
886 * pointer. Then, invoke BPF.
887 */
888 register u_char *hp = sc->sc_buf - SLIP_HDRLEN;
889
890 hp[SLX_DIR] = SLIPDIR_IN;
891 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN);
892 bpf_tap(&sc->sc_if, hp, len + SLIP_HDRLEN);
893 }
894 m = sl_btom(sc, len);
895 if (m == NULL)
896 goto error;
897
898 sc->sc_if.if_ipackets++;
899
900 if ((sc->sc_if.if_flags & IFF_UP) == 0) {
901 m_freem(m);
902 goto newpack;
903 }
904
905 s = splimp();
906 if (IF_QFULL(&ipintrq)) {
907 IF_DROP(&ipintrq);
908 sc->sc_if.if_ierrors++;
909 sc->sc_if.if_iqdrops++;
910 m_freem(m);
911 } else {
912 IF_ENQUEUE(&ipintrq, m);
913 schednetisr(NETISR_IP);
914 }
915 splx(s);
916 goto newpack;
917 }
918 if (sc->sc_mp < sc->sc_ep) {
919 *sc->sc_mp++ = c;
920 sc->sc_escape = 0;
921 return 0;
922 }
923
924 /* can't put lower; would miss an extra frame */
925 sc->sc_flags |= SC_ERROR;
926
927error:
928 sc->sc_if.if_ierrors++;
929newpack:
930 sc->sc_mp = sc->sc_buf = sc->sc_ep - SLRMAX;
931 sc->sc_escape = 0;
932 return 0;
933}
934
935/*
936 * Process an ioctl request.
937 */
938static int
939slioctl(ifp, cmd, data)
940 register struct ifnet *ifp;
941 u_long cmd;
942 caddr_t data;
943{
944 register struct ifaddr *ifa = (struct ifaddr *)data;
945 register struct ifreq *ifr = (struct ifreq *)data;
946 register int s, error = 0;
947
948 s = splimp();
949
950 switch (cmd) {
951
952 case SIOCSIFFLAGS:
953 /*
954 * if.c will set the interface up even if we
955 * don't want it to.
956 */
957 if (sl_softc[ifp->if_unit].sc_ttyp == NULL) {
958 ifp->if_flags &= ~IFF_UP;
959 }
960 break;
961 case SIOCSIFADDR:
962 /*
963 * This is "historical" - set the interface up when
964 * setting the address.
965 */
966 if (ifa->ifa_addr->sa_family == AF_INET) {
967 if (sl_softc[ifp->if_unit].sc_ttyp != NULL)
968 ifp->if_flags |= IFF_UP;
969 } else {
970 error = EAFNOSUPPORT;
971 }
972 break;
973
974 case SIOCSIFDSTADDR:
975 if (ifa->ifa_addr->sa_family != AF_INET)
976 error = EAFNOSUPPORT;
977 break;
978
979 case SIOCADDMULTI:
980 case SIOCDELMULTI:
981 break;
982
983 case SIOCSIFMTU:
984 /*
985 * Set the interface MTU.
986 */
987 if (ifr->ifr_mtu > SLTMAX)
988 error = EINVAL;
989 else {
990 struct tty *tp;
991
992 ifp->if_mtu = ifr->ifr_mtu;
993 tp = sl_softc[ifp->if_unit].sc_ttyp;
994 if (tp != NULL)
995 clist_alloc_cblocks(&tp->t_outq,
996 SLIP_HIWAT + 2 * ifp->if_mtu + 1,
997 SLIP_HIWAT + 2 * ifp->if_mtu + 1);
998 }
999 break;
1000
1001 default:
1002 error = EINVAL;
1003 }
1004 splx(s);
1005 return (error);
1006}
1007
1008static void
1009sl_keepalive(chan)
1010 void *chan;
1011{
1012 struct sl_softc *sc = chan;
1013
1014 if (sc->sc_keepalive) {
1015 if (sc->sc_flags & SC_KEEPALIVE)
1016 pgsignal (sc->sc_ttyp->t_pgrp, SIGURG, 1);
1017 else
1018 sc->sc_flags |= SC_KEEPALIVE;
1019 sc->sc_kahandle = timeout(sl_keepalive, sc, sc->sc_keepalive);
1020 } else {
1021 sc->sc_flags &= ~SC_KEEPALIVE;
1022 }
1023}
1024
1025static void
1026sl_outfill(chan)
1027 void *chan;
1028{
1029 struct sl_softc *sc = chan;
1030 register struct tty *tp = sc->sc_ttyp;
1031 int s;
1032
1033 if (sc->sc_outfill && tp != NULL) {
1034 if (sc->sc_flags & SC_OUTWAIT) {
1035 s = splimp ();
1036 ++sc->sc_if.if_obytes;
1037 (void) putc(FRAME_END, &tp->t_outq);
1038 (*tp->t_oproc)(tp);
1039 splx (s);
1040 } else
1041 sc->sc_flags |= SC_OUTWAIT;
1042 sc->sc_ofhandle = timeout(sl_outfill, sc, sc->sc_outfill);
1043 } else {
1044 sc->sc_flags &= ~SC_OUTWAIT;
1045 }
1046}