FreeBSD/Linux Kernel Cross Reference
sys/net/if_sl.c
1 /* $NetBSD: if_sl.c,v 1.90 2004/12/06 02:59:23 christos Exp $ */
2
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 8.9 (Berkeley) 1/9/95
32 */
33
34 /*
35 * Serial Line interface
36 *
37 * Rick Adams
38 * Center for Seismic Studies
39 * 1300 N 17th Street, Suite 1450
40 * Arlington, Virginia 22209
41 * (703)276-7900
42 * rick@seismo.ARPA
43 * seismo!rick
44 *
45 * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris).
46 * N.B.: this belongs in netinet, not net, the way it stands now.
47 * Should have a link-layer type designation, but wouldn't be
48 * backwards-compatible.
49 *
50 * Converted to 4.3BSD Beta by Chris Torek.
51 * Other changes made at Berkeley, based in part on code by Kirk Smith.
52 * W. Jolitz added slip abort.
53 *
54 * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov).
55 * Added priority queuing for "interactive" traffic; hooks for TCP
56 * header compression; ICMP filtering (at 2400 baud, some cretin
57 * pinging you can use up all your bandwidth). Made low clist behavior
58 * more robust and slightly less likely to hang serial line.
59 * Sped up a bunch of things.
60 */
61
62 #include <sys/cdefs.h>
63 __KERNEL_RCSID(0, "$NetBSD: if_sl.c,v 1.90 2004/12/06 02:59:23 christos Exp $");
64
65 #include "opt_inet.h"
66 #include "bpfilter.h"
67
68 #include <sys/param.h>
69 #include <sys/proc.h>
70 #include <sys/malloc.h>
71 #include <sys/mbuf.h>
72 #include <sys/buf.h>
73 #include <sys/dkstat.h>
74 #include <sys/socket.h>
75 #include <sys/ioctl.h>
76 #include <sys/file.h>
77 #include <sys/conf.h>
78 #include <sys/tty.h>
79 #include <sys/kernel.h>
80 #if __NetBSD__
81 #include <sys/systm.h>
82 #endif
83
84 #include <machine/cpu.h>
85 #include <machine/intr.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 #ifdef INET
93 #include <netinet/in.h>
94 #include <netinet/in_systm.h>
95 #include <netinet/in_var.h>
96 #include <netinet/ip.h>
97 #endif
98
99 #include <net/slcompress.h>
100 #include <net/if_slvar.h>
101 #include <net/slip.h>
102
103 #if NBPFILTER > 0
104 #include <sys/time.h>
105 #include <net/bpf.h>
106 #endif
107
108 /*
109 * SLMAX is a hard limit on input packet size. To simplify the code
110 * and improve performance, we require that packets fit in an mbuf
111 * cluster, and if we get a compressed packet, there's enough extra
112 * room to expand the header into a max length tcp/ip header (128
113 * bytes). So, SLMAX can be at most
114 * MCLBYTES - 128
115 *
116 * SLMTU is a hard limit on output packet size. To insure good
117 * interactive response, SLMTU wants to be the smallest size that
118 * amortizes the header cost. (Remember that even with
119 * type-of-service queuing, we have to wait for any in-progress
120 * packet to finish. I.e., we wait, on the average, 1/2 * mtu /
121 * cps, where cps is the line speed in characters per second.
122 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The
123 * average compressed header size is 6-8 bytes so any MTU > 90
124 * bytes will give us 90% of the line bandwidth. A 100ms wait is
125 * tolerable (500ms is not), so want an MTU around 296. (Since TCP
126 * will send 256 byte segments (to allow for 40 byte headers), the
127 * typical packet size on the wire will be around 260 bytes). In
128 * 4.3tahoe+ systems, we can set an MTU in a route so we do that &
129 * leave the interface MTU relatively high (so we don't IP fragment
130 * when acting as a gateway to someone using a stupid MTU).
131 *
132 * Similar considerations apply to SLIP_HIWAT: It's the amount of
133 * data that will be queued 'downstream' of us (i.e., in clists
134 * waiting to be picked up by the tty output interrupt). If we
135 * queue a lot of data downstream, it's immune to our t.o.s. queuing.
136 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed
137 * telnet/ftp will see a 1 sec wait, independent of the mtu (the
138 * wait is dependent on the ftp window size but that's typically
139 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize
140 * the cost (in idle time on the wire) of the tty driver running
141 * off the end of its clists & having to call back slstart for a
142 * new packet. For a tty interface with any buffering at all, this
143 * cost will be zero. Even with a totally brain dead interface (like
144 * the one on a typical workstation), the cost will be <= 1 character
145 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose
146 * at most 1% while maintaining good interactive response.
147 */
148 #define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN)
149 #define SLMAX (MCLBYTES - BUFOFFSET)
150 #define SLBUFSIZE (SLMAX + BUFOFFSET)
151 #ifndef SLMTU
152 #define SLMTU 296
153 #endif
154 #if (SLMTU < 3)
155 #error SLMTU way too small.
156 #endif
157 #define SLIP_HIWAT roundup(50,CBSIZE)
158 #ifndef __NetBSD__ /* XXX - cgd */
159 #define CLISTRESERVE 1024 /* Can't let clists get too low */
160 #endif /* !__NetBSD__ */
161
162 /*
163 * SLIP ABORT ESCAPE MECHANISM:
164 * (inspired by HAYES modem escape arrangement)
165 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape }
166 * within window time signals a "soft" exit from slip mode by remote end
167 * if the IFF_DEBUG flag is on.
168 */
169 #define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/
170 #define ABT_IDLE 1 /* in seconds - idle before an escape */
171 #define ABT_COUNT 3 /* count of escapes for abort */
172 #define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */
173
174 static int sl_clone_create(struct if_clone *, int);
175 static int sl_clone_destroy(struct ifnet *);
176
177 static LIST_HEAD(, sl_softc) sl_softc_list;
178
179 struct if_clone sl_cloner =
180 IF_CLONE_INITIALIZER("sl", sl_clone_create, sl_clone_destroy);
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 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
188 void slnetisr(void);
189 #endif
190 void slintr(void *);
191
192 static int slinit __P((struct sl_softc *));
193 static struct mbuf *sl_btom __P((struct sl_softc *, int));
194
195 void
196 slattach(void)
197 {
198 LIST_INIT(&sl_softc_list);
199 if_clone_attach(&sl_cloner);
200 }
201
202 static int
203 sl_clone_create(struct if_clone *ifc, int unit)
204 {
205 struct sl_softc *sc;
206
207 MALLOC(sc, struct sl_softc *, sizeof(*sc), M_DEVBUF, M_WAIT|M_ZERO);
208 sc->sc_unit = unit;
209 (void)snprintf(sc->sc_if.if_xname, sizeof(sc->sc_if.if_xname),
210 "%s%d", ifc->ifc_name, unit);
211 sc->sc_if.if_softc = sc;
212 sc->sc_if.if_mtu = SLMTU;
213 sc->sc_if.if_flags = IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST;
214 sc->sc_if.if_type = IFT_SLIP;
215 sc->sc_if.if_ioctl = slioctl;
216 sc->sc_if.if_output = sloutput;
217 sc->sc_if.if_dlt = DLT_SLIP;
218 sc->sc_fastq.ifq_maxlen = 32;
219 IFQ_SET_READY(&sc->sc_if.if_snd);
220 if_attach(&sc->sc_if);
221 if_alloc_sadl(&sc->sc_if);
222 #if NBPFILTER > 0
223 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
224 #endif
225 LIST_INSERT_HEAD(&sl_softc_list, sc, sc_iflist);
226 return 0;
227 }
228
229 static int
230 sl_clone_destroy(struct ifnet *ifp)
231 {
232 struct sl_softc *sc = (struct sl_softc *)ifp->if_softc;
233
234 if (sc->sc_ttyp != NULL)
235 return EBUSY; /* Not removing it */
236
237 LIST_REMOVE(sc, sc_iflist);
238
239 #if NBPFILTER > 0
240 bpfdetach(ifp);
241 #endif
242 if_detach(ifp);
243
244 FREE(sc, M_DEVBUF);
245 return 0;
246 }
247
248 static int
249 slinit(sc)
250 struct sl_softc *sc;
251 {
252
253 if (sc->sc_mbuf == NULL) {
254 sc->sc_mbuf = m_gethdr(M_WAIT, MT_DATA);
255 m_clget(sc->sc_mbuf, M_WAIT);
256 }
257 sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
258 sc->sc_mbuf->m_ext.ext_size;
259 sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
260 BUFOFFSET;
261
262 #ifdef INET
263 sl_compress_init(&sc->sc_comp);
264 #endif
265
266 return (1);
267 }
268
269 /*
270 * Line specific open routine.
271 * Attach the given tty to the first available sl unit.
272 */
273 /* ARGSUSED */
274 int
275 slopen(dev, tp)
276 dev_t dev;
277 struct tty *tp;
278 {
279 struct proc *p = curproc; /* XXX */
280 struct sl_softc *sc;
281 int error;
282 int s;
283
284 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
285 return (error);
286
287 if (tp->t_linesw->l_no == SLIPDISC)
288 return (0);
289
290 LIST_FOREACH(sc, &sl_softc_list, sc_iflist)
291 if (sc->sc_ttyp == NULL) {
292 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
293 sc->sc_si = softintr_establish(IPL_SOFTNET,
294 slintr, sc);
295 if (sc->sc_si == NULL)
296 return (ENOMEM);
297 #endif
298 if (slinit(sc) == 0) {
299 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
300 softintr_disestablish(sc->sc_si);
301 #endif
302 return (ENOBUFS);
303 }
304 tp->t_sc = (caddr_t)sc;
305 sc->sc_ttyp = tp;
306 sc->sc_if.if_baudrate = tp->t_ospeed;
307 s = spltty();
308 tp->t_state |= TS_ISOPEN | TS_XCLUDE;
309 splx(s);
310 ttyflush(tp, FREAD | FWRITE);
311 #ifdef __NetBSD__
312 /*
313 * make sure tty output queue is large enough
314 * to hold a full-sized packet (including frame
315 * end, and a possible extra frame end). full-sized
316 * packet occupies a max of 2*SLMAX bytes (because
317 * of possible escapes), and add two on for frame
318 * ends.
319 */
320 s = spltty();
321 if (tp->t_outq.c_cn < 2*SLMAX+2) {
322 sc->sc_oldbufsize = tp->t_outq.c_cn;
323 sc->sc_oldbufquot = tp->t_outq.c_cq != 0;
324
325 clfree(&tp->t_outq);
326 error = clalloc(&tp->t_outq, 2*SLMAX+2, 0);
327 if (error) {
328 splx(s);
329 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
330 softintr_disestablish(sc->sc_si);
331 #endif
332 /*
333 * clalloc() might return -1 which
334 * is no good, so we need to return
335 * something else.
336 */
337 return (ENOMEM); /* XXX ?! */
338 }
339 } else
340 sc->sc_oldbufsize = sc->sc_oldbufquot = 0;
341 splx(s);
342 #endif /* __NetBSD__ */
343 return (0);
344 }
345 return (ENXIO);
346 }
347
348 /*
349 * Line specific close routine.
350 * Detach the tty from the sl unit.
351 */
352 void
353 slclose(tp)
354 struct tty *tp;
355 {
356 struct sl_softc *sc;
357 int s;
358
359 ttywflush(tp);
360 sc = tp->t_sc;
361
362 if (sc != NULL) {
363 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
364 softintr_disestablish(sc->sc_si);
365 #endif
366 s = splnet();
367 if_down(&sc->sc_if);
368 IF_PURGE(&sc->sc_fastq);
369 splx(s);
370
371 s = spltty();
372 tp->t_linesw = linesw[0]; /* default line disc. */
373 tp->t_state = 0;
374
375 sc->sc_ttyp = NULL;
376 tp->t_sc = NULL;
377
378 m_freem(sc->sc_mbuf);
379 sc->sc_mbuf = NULL;
380 sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL;
381 IF_PURGE(&sc->sc_inq);
382
383 /*
384 * If necessary, install a new outq buffer of the
385 * appropriate size.
386 */
387 if (sc->sc_oldbufsize != 0) {
388 clfree(&tp->t_outq);
389 clalloc(&tp->t_outq, sc->sc_oldbufsize,
390 sc->sc_oldbufquot);
391 }
392 splx(s);
393 }
394 }
395
396 /*
397 * Line specific (tty) ioctl routine.
398 * Provide a way to get the sl unit number.
399 */
400 /* ARGSUSED */
401 int
402 sltioctl(tp, cmd, data, flag)
403 struct tty *tp;
404 u_long cmd;
405 caddr_t data;
406 int flag;
407 {
408 struct sl_softc *sc = (struct sl_softc *)tp->t_sc;
409
410 switch (cmd) {
411 case SLIOCGUNIT:
412 *(int *)data = sc->sc_unit; /* XXX */
413 break;
414
415 default:
416 return (EPASSTHROUGH);
417 }
418 return (0);
419 }
420
421 /*
422 * Queue a packet. Start transmission if not active.
423 * Compression happens in slintr(); if we do it here, IP TOS
424 * will cause us to not compress "background" packets, because
425 * ordering gets trashed. It can be done for all packets in slintr().
426 */
427 int
428 sloutput(ifp, m, dst, rtp)
429 struct ifnet *ifp;
430 struct mbuf *m;
431 struct sockaddr *dst;
432 struct rtentry *rtp;
433 {
434 struct sl_softc *sc = ifp->if_softc;
435 struct ip *ip;
436 int s, error;
437 ALTQ_DECL(struct altq_pktattr pktattr;)
438
439 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
440
441 /*
442 * `Cannot happen' (see slioctl). Someday we will extend
443 * the line protocol to support other address families.
444 */
445 if (dst->sa_family != AF_INET) {
446 printf("%s: af%d not supported\n", sc->sc_if.if_xname,
447 dst->sa_family);
448 m_freem(m);
449 sc->sc_if.if_noproto++;
450 return (EAFNOSUPPORT);
451 }
452
453 if (sc->sc_ttyp == NULL) {
454 m_freem(m);
455 return (ENETDOWN); /* sort of */
456 }
457 if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 &&
458 (sc->sc_ttyp->t_cflag & CLOCAL) == 0) {
459 m_freem(m);
460 printf("%s: no carrier and not local\n", sc->sc_if.if_xname);
461 return (EHOSTUNREACH);
462 }
463 ip = mtod(m, struct ip *);
464 #ifdef INET
465 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
466 m_freem(m);
467 return (ENETRESET); /* XXX ? */
468 }
469 #endif
470
471 s = spltty();
472 if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) {
473 struct timeval tv;
474
475 /* if output's been stalled for too long, and restart */
476 timersub(&time, &sc->sc_lastpacket, &tv);
477 if (tv.tv_sec > 0) {
478 sc->sc_otimeout++;
479 slstart(sc->sc_ttyp);
480 }
481 }
482 splx(s);
483
484 s = splnet();
485 #ifdef INET
486 if ((ip->ip_tos & IPTOS_LOWDELAY) != 0
487 #ifdef ALTQ
488 && ALTQ_IS_ENABLED(&ifp->if_snd) == 0
489 #endif
490 ) {
491 if (IF_QFULL(&sc->sc_fastq)) {
492 IF_DROP(&sc->sc_fastq);
493 m_freem(m);
494 error = ENOBUFS;
495 } else {
496 IF_ENQUEUE(&sc->sc_fastq, m);
497 error = 0;
498 }
499 } else
500 #endif
501 IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
502 if (error) {
503 splx(s);
504 ifp->if_oerrors++;
505 return (error);
506 }
507 sc->sc_lastpacket = time;
508 splx(s);
509
510 s = spltty();
511 if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0)
512 slstart(sc->sc_ttyp);
513 splx(s);
514
515 return (0);
516 }
517
518 /*
519 * Start output on interface. Get another datagram
520 * to send from the interface queue and map it to
521 * the interface before starting output.
522 */
523 void
524 slstart(tp)
525 struct tty *tp;
526 {
527 struct sl_softc *sc = tp->t_sc;
528
529 /*
530 * If there is more in the output queue, just send it now.
531 * We are being called in lieu of ttstart and must do what
532 * it would.
533 */
534 if (tp->t_outq.c_cc != 0) {
535 (*tp->t_oproc)(tp);
536 if (tp->t_outq.c_cc > SLIP_HIWAT)
537 return;
538 }
539
540 /*
541 * This happens briefly when the line shuts down.
542 */
543 if (sc == NULL)
544 return;
545 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
546 softintr_schedule(sc->sc_si);
547 #else
548 {
549 int s = splhigh();
550 schednetisr(NETISR_SLIP);
551 splx(s);
552 }
553 #endif
554 }
555
556 /*
557 * Copy data buffer to mbuf chain; add ifnet pointer.
558 */
559 static struct mbuf *
560 sl_btom(sc, len)
561 struct sl_softc *sc;
562 int len;
563 {
564 struct mbuf *m;
565
566 /*
567 * Allocate a new input buffer and swap.
568 */
569 m = sc->sc_mbuf;
570 MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA);
571 if (sc->sc_mbuf == NULL) {
572 sc->sc_mbuf = m;
573 return (NULL);
574 }
575 MCLGET(sc->sc_mbuf, M_DONTWAIT);
576 if ((sc->sc_mbuf->m_flags & M_EXT) == 0) {
577 m_freem(sc->sc_mbuf);
578 sc->sc_mbuf = m;
579 return (NULL);
580 }
581 sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
582 sc->sc_mbuf->m_ext.ext_size;
583
584 m->m_data = sc->sc_pktstart;
585
586 m->m_pkthdr.len = m->m_len = len;
587 m->m_pkthdr.rcvif = &sc->sc_if;
588 return (m);
589 }
590
591 /*
592 * tty interface receiver interrupt.
593 */
594 void
595 slinput(c, tp)
596 int c;
597 struct tty *tp;
598 {
599 struct sl_softc *sc;
600 struct mbuf *m;
601 int len;
602
603 tk_nin++;
604 sc = (struct sl_softc *)tp->t_sc;
605 if (sc == NULL)
606 return;
607 if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 &&
608 (tp->t_cflag & CLOCAL) == 0)) {
609 sc->sc_flags |= SC_ERROR;
610 return;
611 }
612 c &= TTY_CHARMASK;
613
614 ++sc->sc_if.if_ibytes;
615
616 if (sc->sc_if.if_flags & IFF_DEBUG) {
617 if (c == ABT_ESC) {
618 /*
619 * If we have a previous abort, see whether
620 * this one is within the time limit.
621 */
622 if (sc->sc_abortcount &&
623 time.tv_sec >= sc->sc_starttime + ABT_WINDOW)
624 sc->sc_abortcount = 0;
625 /*
626 * If we see an abort after "idle" time, count it;
627 * record when the first abort escape arrived.
628 */
629 if (time.tv_sec >= sc->sc_lasttime + ABT_IDLE) {
630 if (++sc->sc_abortcount == 1)
631 sc->sc_starttime = time.tv_sec;
632 if (sc->sc_abortcount >= ABT_COUNT) {
633 slclose(tp);
634 return;
635 }
636 }
637 } else
638 sc->sc_abortcount = 0;
639 sc->sc_lasttime = time.tv_sec;
640 }
641
642 switch (c) {
643
644 case TRANS_FRAME_ESCAPE:
645 if (sc->sc_escape)
646 c = FRAME_ESCAPE;
647 break;
648
649 case TRANS_FRAME_END:
650 if (sc->sc_escape)
651 c = FRAME_END;
652 break;
653
654 case FRAME_ESCAPE:
655 sc->sc_escape = 1;
656 return;
657
658 case FRAME_END:
659 if(sc->sc_flags & SC_ERROR) {
660 sc->sc_flags &= ~SC_ERROR;
661 goto newpack;
662 }
663 len = sc->sc_mp - sc->sc_pktstart;
664 if (len < 3)
665 /* less than min length packet - ignore */
666 goto newpack;
667
668 m = sl_btom(sc, len);
669 if (m == NULL)
670 goto error;
671
672 IF_ENQUEUE(&sc->sc_inq, m);
673 #ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
674 softintr_schedule(sc->sc_si);
675 #else
676 {
677 int s = splhigh();
678 schednetisr(NETISR_SLIP);
679 splx(s);
680 }
681 #endif
682 goto newpack;
683 }
684 if (sc->sc_mp < sc->sc_ep) {
685 *sc->sc_mp++ = c;
686 sc->sc_escape = 0;
687 return;
688 }
689
690 /* can't put lower; would miss an extra frame */
691 sc->sc_flags |= SC_ERROR;
692
693 error:
694 sc->sc_if.if_ierrors++;
695 newpack:
696 sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
697 BUFOFFSET;
698 sc->sc_escape = 0;
699 }
700
701 #ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
702 void
703 slnetisr(void)
704 {
705 struct sl_softc *sc;
706
707 LIST_FOREACH(sc, &sl_softc_list, sc_iflist) {
708 if (sc->sc_ttyp == NULL)
709 continue;
710 slintr(sc);
711 }
712 }
713 #endif
714
715 void
716 slintr(void *arg)
717 {
718 struct sl_softc *sc = arg;
719 struct tty *tp = sc->sc_ttyp;
720 struct mbuf *m;
721 int s, len;
722 u_char *pktstart;
723 #ifdef INET
724 u_char c;
725 #endif
726 #if NBPFILTER > 0
727 u_char chdr[CHDR_LEN];
728 #endif
729
730 KASSERT(tp != NULL);
731
732 /*
733 * Output processing loop.
734 */
735 for (;;) {
736 #ifdef INET
737 struct ip *ip;
738 #endif
739 struct mbuf *m2;
740 #if NBPFILTER > 0
741 struct mbuf *bpf_m;
742 #endif
743
744 /*
745 * Do not remove the packet from the queue if it
746 * doesn't look like it will fit into the current
747 * serial output queue. With a packet full of
748 * escapes, this could be as bad as MTU*2+2.
749 */
750 s = spltty();
751 if (tp->t_outq.c_cn - tp->t_outq.c_cc <
752 2*sc->sc_if.if_mtu+2) {
753 splx(s);
754 break;
755 }
756 splx(s);
757
758 /*
759 * Get a packet and send it to the interface.
760 */
761 s = splnet();
762 IF_DEQUEUE(&sc->sc_fastq, m);
763 if (m)
764 sc->sc_if.if_omcasts++; /* XXX */
765 else
766 IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
767 splx(s);
768
769 if (m == NULL)
770 break;
771
772 /*
773 * We do the header compression here rather than in
774 * sloutput() because the packets will be out of order
775 * if we are using TOS queueing, and the connection
776 * ID compression will get munged when this happens.
777 */
778 #if NBPFILTER > 0
779 if (sc->sc_if.if_bpf) {
780 /*
781 * We need to save the TCP/IP header before
782 * it's compressed. To avoid complicated
783 * code, we just make a deep copy of the
784 * entire packet (since this is a serial
785 * line, packets should be short and/or the
786 * copy should be negligible cost compared
787 * to the packet transmission time).
788 */
789 bpf_m = m_dup(m, 0, M_COPYALL, M_DONTWAIT);
790 } else
791 bpf_m = NULL;
792 #endif
793 #ifdef INET
794 if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) {
795 if (sc->sc_if.if_flags & SC_COMPRESS)
796 *mtod(m, u_char *) |=
797 sl_compress_tcp(m, ip,
798 &sc->sc_comp, 1);
799 }
800 #endif
801 #if NBPFILTER > 0
802 if (sc->sc_if.if_bpf && bpf_m != NULL)
803 bpf_mtap_sl_out(sc->sc_if.if_bpf, mtod(m, u_char *),
804 bpf_m);
805 #endif
806 sc->sc_lastpacket = time;
807
808 s = spltty();
809
810 /*
811 * The extra FRAME_END will start up a new packet,
812 * and thus will flush any accumulated garbage. We
813 * do this whenever the line may have been idle for
814 * some time.
815 */
816 if (tp->t_outq.c_cc == 0) {
817 sc->sc_if.if_obytes++;
818 (void) putc(FRAME_END, &tp->t_outq);
819 }
820
821 while (m) {
822 u_char *bp, *cp, *ep;
823
824 bp = cp = mtod(m, u_char *);
825 ep = cp + m->m_len;
826 while (cp < ep) {
827 /*
828 * Find out how many bytes in the
829 * string we can handle without
830 * doing something special.
831 */
832 while (cp < ep) {
833 switch (*cp++) {
834 case FRAME_ESCAPE:
835 case FRAME_END:
836 cp--;
837 goto out;
838 }
839 }
840 out:
841 if (cp > bp) {
842 /*
843 * Put N characters at once
844 * into the tty output queue.
845 */
846 if (b_to_q(bp, cp - bp,
847 &tp->t_outq))
848 break;
849 sc->sc_if.if_obytes += cp - bp;
850 }
851 /*
852 * If there are characters left in
853 * the mbuf, the first one must be
854 * special.. Put it out in a different
855 * form.
856 */
857 if (cp < ep) {
858 if (putc(FRAME_ESCAPE,
859 &tp->t_outq))
860 break;
861 if (putc(*cp++ == FRAME_ESCAPE ?
862 TRANS_FRAME_ESCAPE :
863 TRANS_FRAME_END,
864 &tp->t_outq)) {
865 (void)
866 unputc(&tp->t_outq);
867 break;
868 }
869 sc->sc_if.if_obytes += 2;
870 }
871 bp = cp;
872 }
873 MFREE(m, m2);
874 m = m2;
875 }
876
877 if (putc(FRAME_END, &tp->t_outq)) {
878 /*
879 * Not enough room. Remove a char to make
880 * room and end the packet normally. If
881 * you get many collisions (more than one
882 * or two a day), you probably do not have
883 * enough clists and you should increase
884 * "nclist" in param.c
885 */
886 (void) unputc(&tp->t_outq);
887 (void) putc(FRAME_END, &tp->t_outq);
888 sc->sc_if.if_collisions++;
889 } else {
890 sc->sc_if.if_obytes++;
891 sc->sc_if.if_opackets++;
892 }
893
894 /*
895 * We now have characters in the output queue,
896 * kick the serial port.
897 */
898 (*tp->t_oproc)(tp);
899 splx(s);
900 }
901
902 /*
903 * Input processing loop.
904 */
905 for (;;) {
906 s = spltty();
907 IF_DEQUEUE(&sc->sc_inq, m);
908 splx(s);
909 if (m == NULL)
910 break;
911 pktstart = mtod(m, u_char *);
912 len = m->m_pkthdr.len;
913 #if NBPFILTER > 0
914 if (sc->sc_if.if_bpf) {
915 /*
916 * Save the compressed header, so we
917 * can tack it on later. Note that we
918 * will end up copying garbage in some
919 * cases but this is okay. We remember
920 * where the buffer started so we can
921 * compute the new header length.
922 */
923 memcpy(chdr, pktstart, CHDR_LEN);
924 }
925 #endif /* NBPFILTER > 0 */
926 #ifdef INET
927 if ((c = (*pktstart & 0xf0)) != (IPVERSION << 4)) {
928 if (c & 0x80)
929 c = TYPE_COMPRESSED_TCP;
930 else if (c == TYPE_UNCOMPRESSED_TCP)
931 *pktstart &= 0x4f; /* XXX */
932 /*
933 * We've got something that's not an IP
934 * packet. If compression is enabled,
935 * try to decompress it. Otherwise, if
936 * `auto-enable' compression is on and
937 * it's a reasonable packet, decompress
938 * it and then enable compression.
939 * Otherwise, drop it.
940 */
941 if (sc->sc_if.if_flags & SC_COMPRESS) {
942 len = sl_uncompress_tcp(&pktstart, len,
943 (u_int)c, &sc->sc_comp);
944 if (len <= 0) {
945 m_freem(m);
946 continue;
947 }
948 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
949 c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
950 len = sl_uncompress_tcp(&pktstart, len,
951 (u_int)c, &sc->sc_comp);
952 if (len <= 0) {
953 m_freem(m);
954 continue;
955 }
956 sc->sc_if.if_flags |= SC_COMPRESS;
957 } else {
958 m_freem(m);
959 continue;
960 }
961 }
962 #endif
963 m->m_data = (caddr_t) pktstart;
964 m->m_pkthdr.len = m->m_len = len;
965 #if NBPFILTER > 0
966 if (sc->sc_if.if_bpf) {
967 bpf_mtap_sl_in(sc->sc_if.if_bpf, chdr, &m);
968 if (m == NULL)
969 continue;
970 }
971 #endif /* NBPFILTER > 0 */
972 /*
973 * If the packet will fit into a single
974 * header mbuf, copy it into one, to save
975 * memory.
976 */
977 if (m->m_pkthdr.len < MHLEN) {
978 struct mbuf *n;
979
980 MGETHDR(n, M_DONTWAIT, MT_DATA);
981 M_COPY_PKTHDR(n, m);
982 memcpy(mtod(n, caddr_t), mtod(m, caddr_t),
983 m->m_pkthdr.len);
984 n->m_len = m->m_len;
985 m_freem(m);
986 m = n;
987 }
988
989 sc->sc_if.if_ipackets++;
990 sc->sc_lastpacket = time;
991
992 #ifdef INET
993 s = splnet();
994 if (IF_QFULL(&ipintrq)) {
995 IF_DROP(&ipintrq);
996 sc->sc_if.if_ierrors++;
997 sc->sc_if.if_iqdrops++;
998 m_freem(m);
999 } else {
1000 IF_ENQUEUE(&ipintrq, m);
1001 schednetisr(NETISR_IP);
1002 }
1003 splx(s);
1004 #endif
1005 }
1006 }
1007
1008 /*
1009 * Process an ioctl request.
1010 */
1011 int
1012 slioctl(ifp, cmd, data)
1013 struct ifnet *ifp;
1014 u_long cmd;
1015 caddr_t data;
1016 {
1017 struct ifaddr *ifa = (struct ifaddr *)data;
1018 struct ifreq *ifr = (struct ifreq *)data;
1019 int s = splnet(), error = 0;
1020 struct sl_softc *sc = ifp->if_softc;
1021
1022 switch (cmd) {
1023
1024 case SIOCSIFADDR:
1025 if (ifa->ifa_addr->sa_family == AF_INET)
1026 ifp->if_flags |= IFF_UP;
1027 else
1028 error = EAFNOSUPPORT;
1029 break;
1030
1031 case SIOCSIFDSTADDR:
1032 if (ifa->ifa_addr->sa_family != AF_INET)
1033 error = EAFNOSUPPORT;
1034 break;
1035
1036 case SIOCSIFMTU:
1037 if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) {
1038 error = EINVAL;
1039 break;
1040 }
1041 sc->sc_if.if_mtu = ifr->ifr_mtu;
1042 break;
1043
1044 case SIOCGIFMTU:
1045 ifr->ifr_mtu = sc->sc_if.if_mtu;
1046 break;
1047
1048 case SIOCADDMULTI:
1049 case SIOCDELMULTI:
1050 if (ifr == 0) {
1051 error = EAFNOSUPPORT; /* XXX */
1052 break;
1053 }
1054 switch (ifr->ifr_addr.sa_family) {
1055
1056 #ifdef INET
1057 case AF_INET:
1058 break;
1059 #endif
1060
1061 default:
1062 error = EAFNOSUPPORT;
1063 break;
1064 }
1065 break;
1066
1067 default:
1068 error = EINVAL;
1069 }
1070 splx(s);
1071 return (error);
1072 }
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