if_sl.c revision 1.104
1/*	$NetBSD: if_sl.c,v 1.104 2007/02/17 22:34:09 dyoung 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 1.104 2007/02/17 22:34:09 dyoung 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#include <sys/kauth.h>
83#endif
84
85#include <machine/cpu.h>
86#include <machine/intr.h>
87
88#include <net/if.h>
89#include <net/if_types.h>
90#include <net/netisr.h>
91#include <net/route.h>
92
93#ifdef INET
94#include <netinet/in.h>
95#include <netinet/in_systm.h>
96#include <netinet/in_var.h>
97#include <netinet/ip.h>
98#endif
99
100#include <net/slcompress.h>
101#include <net/if_slvar.h>
102#include <net/slip.h>
103#include <net/ppp_defs.h>
104#include <net/if_ppp.h>
105
106#if NBPFILTER > 0
107#include <sys/time.h>
108#include <net/bpf.h>
109#endif
110
111/*
112 * SLMAX 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, SLMAX can be at most
117 *	MCLBYTES - 128
118 *
119 * SLMTU is a hard limit on output packet size.  To insure good
120 * interactive response, SLMTU wants to be the smallest size that
121 * amortizes the header cost.  (Remember that even with
122 * type-of-service queuing, we have to wait for any in-progress
123 * packet to finish.  I.e., we wait, on the average, 1/2 * mtu /
124 * cps, where cps is the line speed in characters per second.
125 * E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line.  The
126 * average compressed header size is 6-8 bytes so any MTU > 90
127 * bytes will give us 90% of the line bandwidth.  A 100ms wait is
128 * tolerable (500ms is not), so want an MTU around 296.  (Since TCP
129 * will send 256 byte segments (to allow for 40 byte headers), the
130 * typical packet size on the wire will be around 260 bytes).  In
131 * 4.3tahoe+ systems, we can set an MTU in a route so we do that &
132 * leave the interface MTU relatively high (so we don't IP fragment
133 * when acting as a gateway to someone using a stupid MTU).
134 *
135 * Similar considerations apply to SLIP_HIWAT:  It's the amount of
136 * data that will be queued 'downstream' of us (i.e., in clists
137 * waiting to be picked up by the tty output interrupt).  If we
138 * queue a lot of data downstream, it's immune to our t.o.s. queuing.
139 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed
140 * telnet/ftp will see a 1 sec wait, independent of the mtu (the
141 * wait is dependent on the ftp window size but that's typically
142 * 1k - 4k).  So, we want SLIP_HIWAT just big enough to amortize
143 * the cost (in idle time on the wire) of the tty driver running
144 * off the end of its clists & having to call back slstart for a
145 * new packet.  For a tty interface with any buffering at all, this
146 * cost will be zero.  Even with a totally brain dead interface (like
147 * the one on a typical workstation), the cost will be <= 1 character
148 * time.  So, setting SLIP_HIWAT to ~100 guarantees that we'll lose
149 * at most 1% while maintaining good interactive response.
150 */
151#define	BUFOFFSET	(128+sizeof(struct ifnet **)+SLIP_HDRLEN)
152#define	SLMAX		(MCLBYTES - BUFOFFSET)
153#define	SLBUFSIZE	(SLMAX + BUFOFFSET)
154#ifndef SLMTU
155#define	SLMTU		296
156#endif
157#if (SLMTU < 3)
158#error SLMTU way too small.
159#endif
160#define	SLIP_HIWAT	roundup(50,CBSIZE)
161#ifndef __NetBSD__					/* XXX - cgd */
162#define	CLISTRESERVE	1024	/* Can't let clists get too low */
163#endif	/* !__NetBSD__ */
164
165/*
166 * SLIP ABORT ESCAPE MECHANISM:
167 *	(inspired by HAYES modem escape arrangement)
168 *	1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape }
169 *	within window time signals a "soft" exit from slip mode by remote end
170 *	if the IFF_DEBUG flag is on.
171 */
172#define	ABT_ESC		'\033'	/* can't be t_intr - distant host must know it*/
173#define	ABT_IDLE	1	/* in seconds - idle before an escape */
174#define	ABT_COUNT	3	/* count of escapes for abort */
175#define	ABT_WINDOW	(ABT_COUNT*2+2)	/* in seconds - time to count */
176
177static int		sl_clone_create(struct if_clone *, int);
178static int		sl_clone_destroy(struct ifnet *);
179
180static LIST_HEAD(, sl_softc) sl_softc_list;
181
182struct if_clone sl_cloner =
183    IF_CLONE_INITIALIZER("sl", sl_clone_create, sl_clone_destroy);
184
185#define FRAME_END		0xc0		/* Frame End */
186#define FRAME_ESCAPE		0xdb		/* Frame Esc */
187#define TRANS_FRAME_END		0xdc		/* transposed frame end */
188#define TRANS_FRAME_ESCAPE	0xdd		/* transposed frame esc */
189
190#ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
191void	slnetisr(void);
192#endif
193static void	slintr(void *);
194
195static int	slinit(struct sl_softc *);
196static struct mbuf *sl_btom(struct sl_softc *, int);
197
198static int	slclose(struct tty *, int);
199static int	slinput(int, struct tty *);
200static int	slioctl(struct ifnet *, u_long, caddr_t);
201static int	slopen(dev_t, struct tty *);
202static int	sloutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
203			 struct rtentry *);
204static int	slstart(struct tty *);
205static int	sltioctl(struct tty *, u_long, caddr_t, int, struct lwp *);
206
207static struct linesw slip_disc = {
208	.l_name = "slip",
209	.l_open = slopen,
210	.l_close = slclose,
211	.l_read = ttyerrio,
212	.l_write = ttyerrio,
213	.l_ioctl = sltioctl,
214	.l_rint = slinput,
215	.l_start = slstart,
216	.l_modem = nullmodem,
217	.l_poll = ttyerrpoll
218};
219
220void	slattach(void);
221
222void
223slattach(void)
224{
225
226	if (ttyldisc_attach(&slip_disc) != 0)
227		panic("slattach");
228	LIST_INIT(&sl_softc_list);
229	if_clone_attach(&sl_cloner);
230}
231
232static int
233sl_clone_create(struct if_clone *ifc, int unit)
234{
235	struct sl_softc *sc;
236
237	MALLOC(sc, struct sl_softc *, sizeof(*sc), M_DEVBUF, M_WAIT|M_ZERO);
238	sc->sc_unit = unit;
239	(void)snprintf(sc->sc_if.if_xname, sizeof(sc->sc_if.if_xname),
240	    "%s%d", ifc->ifc_name, unit);
241	sc->sc_if.if_softc = sc;
242	sc->sc_if.if_mtu = SLMTU;
243	sc->sc_if.if_flags = IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST;
244	sc->sc_if.if_type = IFT_SLIP;
245	sc->sc_if.if_ioctl = slioctl;
246	sc->sc_if.if_output = sloutput;
247	sc->sc_if.if_dlt = DLT_SLIP;
248	sc->sc_fastq.ifq_maxlen = 32;
249	IFQ_SET_READY(&sc->sc_if.if_snd);
250	if_attach(&sc->sc_if);
251	if_alloc_sadl(&sc->sc_if);
252#if NBPFILTER > 0
253	bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
254#endif
255	LIST_INSERT_HEAD(&sl_softc_list, sc, sc_iflist);
256	return 0;
257}
258
259static int
260sl_clone_destroy(struct ifnet *ifp)
261{
262	struct sl_softc *sc = (struct sl_softc *)ifp->if_softc;
263
264	if (sc->sc_ttyp != NULL)
265		return EBUSY;	/* Not removing it */
266
267	LIST_REMOVE(sc, sc_iflist);
268
269#if NBPFILTER > 0
270	bpfdetach(ifp);
271#endif
272	if_detach(ifp);
273
274	FREE(sc, M_DEVBUF);
275	return 0;
276}
277
278static int
279slinit(struct sl_softc *sc)
280{
281
282	if (sc->sc_mbuf == NULL) {
283		sc->sc_mbuf = m_gethdr(M_WAIT, MT_DATA);
284		m_clget(sc->sc_mbuf, M_WAIT);
285	}
286	sc->sc_ep = (u_char *)sc->sc_mbuf->m_ext.ext_buf +
287	    sc->sc_mbuf->m_ext.ext_size;
288	sc->sc_mp = sc->sc_pktstart = (u_char *)sc->sc_mbuf->m_ext.ext_buf +
289	    BUFOFFSET;
290
291#ifdef INET
292	sl_compress_init(&sc->sc_comp);
293#endif
294
295	return 1;
296}
297
298/*
299 * Line specific open routine.
300 * Attach the given tty to the first available sl unit.
301 */
302/* ARGSUSED */
303static int
304slopen(dev_t dev, struct tty *tp)
305{
306	struct lwp *l = curlwp;		/* XXX */
307	struct sl_softc *sc;
308	int error;
309	int s;
310
311	if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER,
312	    NULL)) != 0)
313		return error;
314
315	if (tp->t_linesw == &slip_disc)
316		return 0;
317
318	LIST_FOREACH(sc, &sl_softc_list, sc_iflist)
319		if (sc->sc_ttyp == NULL) {
320#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
321			sc->sc_si = softintr_establish(IPL_SOFTNET,
322			    slintr, sc);
323			if (sc->sc_si == NULL)
324				return ENOMEM;
325#endif
326			if (slinit(sc) == 0) {
327#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
328				softintr_disestablish(sc->sc_si);
329#endif
330				return ENOBUFS;
331			}
332			tp->t_sc = (caddr_t)sc;
333			sc->sc_ttyp = tp;
334			sc->sc_if.if_baudrate = tp->t_ospeed;
335			s = spltty();
336			tp->t_state |= TS_ISOPEN | TS_XCLUDE;
337			splx(s);
338			ttyflush(tp, FREAD | FWRITE);
339#ifdef __NetBSD__
340			/*
341			 * make sure tty output queue is large enough
342			 * to hold a full-sized packet (including frame
343			 * end, and a possible extra frame end).  full-sized
344			 * packet occupies a max of 2*SLMAX bytes (because
345			 * of possible escapes), and add two on for frame
346			 * ends.
347			 */
348			s = spltty();
349			if (tp->t_outq.c_cn < 2 * SLMAX + 2) {
350				sc->sc_oldbufsize = tp->t_outq.c_cn;
351				sc->sc_oldbufquot = tp->t_outq.c_cq != 0;
352
353				clfree(&tp->t_outq);
354				error = clalloc(&tp->t_outq, 2 * SLMAX + 2, 0);
355				if (error) {
356					splx(s);
357#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
358					softintr_disestablish(sc->sc_si);
359#endif
360					/*
361					 * clalloc() might return -1 which
362					 * is no good, so we need to return
363					 * something else.
364					 */
365					return ENOMEM; /* XXX ?! */
366				}
367			} else
368				sc->sc_oldbufsize = sc->sc_oldbufquot = 0;
369			splx(s);
370#endif /* __NetBSD__ */
371			return 0;
372		}
373	return ENXIO;
374}
375
376/*
377 * Line specific close routine.
378 * Detach the tty from the sl unit.
379 */
380static int
381slclose(struct tty *tp, int flag)
382{
383	struct sl_softc *sc;
384	int s;
385
386	ttywflush(tp);
387	sc = tp->t_sc;
388
389	if (sc != NULL) {
390#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
391		softintr_disestablish(sc->sc_si);
392#endif
393		s = splnet();
394		if_down(&sc->sc_if);
395		IF_PURGE(&sc->sc_fastq);
396		splx(s);
397
398		s = spltty();
399		ttyldisc_release(tp->t_linesw);
400		tp->t_linesw = ttyldisc_default();
401		tp->t_state = 0;
402
403		sc->sc_ttyp = NULL;
404		tp->t_sc = NULL;
405
406		m_freem(sc->sc_mbuf);
407		sc->sc_mbuf = NULL;
408		sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL;
409		IF_PURGE(&sc->sc_inq);
410
411		/*
412		 * If necessary, install a new outq buffer of the
413		 * appropriate size.
414		 */
415		if (sc->sc_oldbufsize != 0) {
416			clfree(&tp->t_outq);
417			clalloc(&tp->t_outq, sc->sc_oldbufsize,
418			    sc->sc_oldbufquot);
419		}
420		splx(s);
421	}
422
423	return 0;
424}
425
426/*
427 * Line specific (tty) ioctl routine.
428 * Provide a way to get the sl unit number.
429 */
430/* ARGSUSED */
431static int
432sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag,
433    struct lwp *l)
434{
435	struct sl_softc *sc = (struct sl_softc *)tp->t_sc;
436
437	switch (cmd) {
438	case SLIOCGUNIT:
439		*(int *)data = sc->sc_unit;	/* XXX */
440		break;
441
442	default:
443		return EPASSTHROUGH;
444	}
445	return 0;
446}
447
448/*
449 * Queue a packet.  Start transmission if not active.
450 * Compression happens in slintr(); if we do it here, IP TOS
451 * will cause us to not compress "background" packets, because
452 * ordering gets trashed.  It can be done for all packets in slintr().
453 */
454static int
455sloutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
456    struct rtentry *rtp)
457{
458	struct sl_softc *sc = ifp->if_softc;
459	struct ip *ip;
460	struct ifqueue *ifq = NULL;
461	int s, error;
462	ALTQ_DECL(struct altq_pktattr pktattr;)
463
464	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
465
466	/*
467	 * `Cannot happen' (see slioctl).  Someday we will extend
468	 * the line protocol to support other address families.
469	 */
470	if (dst->sa_family != AF_INET) {
471		printf("%s: af%d not supported\n", sc->sc_if.if_xname,
472		    dst->sa_family);
473		m_freem(m);
474		sc->sc_if.if_noproto++;
475		return EAFNOSUPPORT;
476	}
477
478	if (sc->sc_ttyp == NULL) {
479		m_freem(m);
480		return ENETDOWN;	/* sort of */
481	}
482	if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 &&
483	    (sc->sc_ttyp->t_cflag & CLOCAL) == 0) {
484		m_freem(m);
485		printf("%s: no carrier and not local\n", sc->sc_if.if_xname);
486		return EHOSTUNREACH;
487	}
488	ip = mtod(m, struct ip *);
489#ifdef INET
490	if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
491		m_freem(m);
492		return ENETRESET;		/* XXX ? */
493	}
494#endif
495
496	s = spltty();
497	if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) {
498		struct bintime bt;
499
500		/* if output's been stalled for too long, and restart */
501		getbinuptime(&bt);
502		bintime_sub(&bt, &sc->sc_lastpacket);
503		if (bt.sec > 0) {
504			sc->sc_otimeout++;
505			slstart(sc->sc_ttyp);
506		}
507	}
508	splx(s);
509
510	s = splnet();
511#ifdef INET
512	if ((ip->ip_tos & IPTOS_LOWDELAY) != 0)
513		ifq = &sc->sc_fastq;
514#endif
515	if ((error = ifq_enqueue2(ifp, ifq, m ALTQ_COMMA
516	    ALTQ_DECL(&pktattr))) != 0) {
517		splx(s);
518		return error;
519	}
520	getbinuptime(&sc->sc_lastpacket);
521	splx(s);
522
523	s = spltty();
524	if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0)
525		slstart(sc->sc_ttyp);
526	splx(s);
527
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(struct tty *tp)
538{
539	struct sl_softc *sc = tp->t_sc;
540
541	/*
542	 * If there is more in the output queue, just send it now.
543	 * We are being called in lieu of ttstart and must do what
544	 * it would.
545	 */
546	if (tp->t_outq.c_cc != 0) {
547		(*tp->t_oproc)(tp);
548		if (tp->t_outq.c_cc > SLIP_HIWAT)
549			return 0;
550	}
551
552	/*
553	 * This happens briefly when the line shuts down.
554	 */
555	if (sc == NULL)
556		return 0;
557#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
558	softintr_schedule(sc->sc_si);
559#else
560    {
561	int s = splhigh();
562	schednetisr(NETISR_SLIP);
563	splx(s);
564    }
565#endif
566	return 0;
567}
568
569/*
570 * Copy data buffer to mbuf chain; add ifnet pointer.
571 */
572static struct mbuf *
573sl_btom(struct sl_softc *sc, int len)
574{
575	struct mbuf *m;
576
577	/*
578	 * Allocate a new input buffer and swap.
579	 */
580	m = sc->sc_mbuf;
581	MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA);
582	if (sc->sc_mbuf == NULL) {
583		sc->sc_mbuf = m;
584		return NULL;
585	}
586	MCLGET(sc->sc_mbuf, M_DONTWAIT);
587	if ((sc->sc_mbuf->m_flags & M_EXT) == 0) {
588		m_freem(sc->sc_mbuf);
589		sc->sc_mbuf = m;
590		return NULL;
591	}
592	sc->sc_ep = (u_char *)sc->sc_mbuf->m_ext.ext_buf +
593	    sc->sc_mbuf->m_ext.ext_size;
594
595	m->m_data = sc->sc_pktstart;
596
597	m->m_pkthdr.len = m->m_len = len;
598	m->m_pkthdr.rcvif = &sc->sc_if;
599	return m;
600}
601
602/*
603 * tty interface receiver interrupt.
604 */
605static int
606slinput(int c, struct tty *tp)
607{
608	struct sl_softc *sc;
609	struct mbuf *m;
610	int len;
611
612	tk_nin++;
613	sc = (struct sl_softc *)tp->t_sc;
614	if (sc == NULL)
615		return 0;
616	if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 &&
617	    (tp->t_cflag & CLOCAL) == 0)) {
618		sc->sc_flags |= SC_ERROR;
619		return 0;
620	}
621	c &= TTY_CHARMASK;
622
623	++sc->sc_if.if_ibytes;
624
625	if (sc->sc_if.if_flags & IFF_DEBUG) {
626		if (c == ABT_ESC) {
627			/*
628			 * If we have a previous abort, see whether
629			 * this one is within the time limit.
630			 */
631			if (sc->sc_abortcount &&
632			    time_second >= sc->sc_starttime + ABT_WINDOW)
633				sc->sc_abortcount = 0;
634			/*
635			 * If we see an abort after "idle" time, count it;
636			 * record when the first abort escape arrived.
637			 */
638			if (time_second >= sc->sc_lasttime + ABT_IDLE) {
639				if (++sc->sc_abortcount == 1)
640					sc->sc_starttime = time_second;
641				if (sc->sc_abortcount >= ABT_COUNT) {
642					slclose(tp, 0);
643					return 0;
644				}
645			}
646		} else
647			sc->sc_abortcount = 0;
648		sc->sc_lasttime = time_second;
649	}
650
651	switch (c) {
652
653	case TRANS_FRAME_ESCAPE:
654		if (sc->sc_escape)
655			c = FRAME_ESCAPE;
656		break;
657
658	case TRANS_FRAME_END:
659		if (sc->sc_escape)
660			c = FRAME_END;
661		break;
662
663	case FRAME_ESCAPE:
664		sc->sc_escape = 1;
665		return 0;
666
667	case FRAME_END:
668		if (sc->sc_flags & SC_ERROR) {
669			sc->sc_flags &= ~SC_ERROR;
670			goto newpack;
671		}
672		len = sc->sc_mp - sc->sc_pktstart;
673		if (len < 3)
674			/* less than min length packet - ignore */
675			goto newpack;
676
677		m = sl_btom(sc, len);
678		if (m == NULL)
679			goto error;
680
681		IF_ENQUEUE(&sc->sc_inq, m);
682#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
683		softintr_schedule(sc->sc_si);
684#else
685	    {
686		int s = splhigh();
687		schednetisr(NETISR_SLIP);
688		splx(s);
689	    }
690#endif
691		goto newpack;
692	}
693	if (sc->sc_mp < sc->sc_ep) {
694		*sc->sc_mp++ = c;
695		sc->sc_escape = 0;
696		return 0;
697	}
698
699	/* can't put lower; would miss an extra frame */
700	sc->sc_flags |= SC_ERROR;
701
702error:
703	sc->sc_if.if_ierrors++;
704newpack:
705	sc->sc_mp = sc->sc_pktstart = (u_char *)sc->sc_mbuf->m_ext.ext_buf +
706	    BUFOFFSET;
707	sc->sc_escape = 0;
708
709	return 0;
710}
711
712#ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
713void
714slnetisr(void)
715{
716	struct sl_softc *sc;
717
718	LIST_FOREACH(sc, &sl_softc_list, sc_iflist) {
719		if (sc->sc_ttyp == NULL)
720			continue;
721		slintr(sc);
722	}
723}
724#endif
725
726static void
727slintr(void *arg)
728{
729	struct sl_softc *sc = arg;
730	struct tty *tp = sc->sc_ttyp;
731	struct mbuf *m;
732	int s, len;
733	u_char *pktstart;
734#ifdef INET
735	u_char c;
736#endif
737#if NBPFILTER > 0
738	u_char chdr[CHDR_LEN];
739#endif
740
741	KASSERT(tp != NULL);
742
743	/*
744	 * Output processing loop.
745	 */
746	for (;;) {
747#ifdef INET
748		struct ip *ip;
749#endif
750		struct mbuf *m2;
751#if NBPFILTER > 0
752		struct mbuf *bpf_m;
753#endif
754
755		/*
756		 * Do not remove the packet from the queue if it
757		 * doesn't look like it will fit into the current
758		 * serial output queue.  With a packet full of
759		 * escapes, this could be as bad as MTU*2+2.
760		 */
761		s = spltty();
762		if (tp->t_outq.c_cn - tp->t_outq.c_cc <
763		    2 * sc->sc_if.if_mtu + 2) {
764			splx(s);
765			break;
766		}
767		splx(s);
768
769		/*
770		 * Get a packet and send it to the interface.
771		 */
772		s = splnet();
773		IF_DEQUEUE(&sc->sc_fastq, m);
774		if (m)
775			sc->sc_if.if_omcasts++;	/* XXX */
776		else
777			IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
778		splx(s);
779
780		if (m == NULL)
781			break;
782
783		/*
784		 * We do the header compression here rather than in
785		 * sloutput() because the packets will be out of order
786		 * if we are using TOS queueing, and the connection
787		 * ID compression will get munged when this happens.
788		 */
789#if NBPFILTER > 0
790		if (sc->sc_if.if_bpf) {
791			/*
792			 * We need to save the TCP/IP header before
793			 * it's compressed.  To avoid complicated
794			 * code, we just make a deep copy of the
795			 * entire packet (since this is a serial
796			 * line, packets should be short and/or the
797			 * copy should be negligible cost compared
798			 * to the packet transmission time).
799			 */
800			bpf_m = m_dup(m, 0, M_COPYALL, M_DONTWAIT);
801		} else
802			bpf_m = NULL;
803#endif
804#ifdef INET
805		if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) {
806			if (sc->sc_if.if_flags & SC_COMPRESS)
807				*mtod(m, u_char *) |=
808				    sl_compress_tcp(m, ip, &sc->sc_comp, 1);
809		}
810#endif
811#if NBPFILTER > 0
812		if (sc->sc_if.if_bpf && bpf_m != NULL)
813			bpf_mtap_sl_out(sc->sc_if.if_bpf, mtod(m, u_char *),
814			    bpf_m);
815#endif
816		getbinuptime(&sc->sc_lastpacket);
817
818		s = spltty();
819
820		/*
821		 * The extra FRAME_END will start up a new packet,
822		 * and thus will flush any accumulated garbage.  We
823		 * do this whenever the line may have been idle for
824		 * some time.
825		 */
826		if (tp->t_outq.c_cc == 0) {
827			sc->sc_if.if_obytes++;
828			(void)putc(FRAME_END, &tp->t_outq);
829		}
830
831		while (m) {
832			u_char *bp, *cp, *ep;
833
834			bp = cp = mtod(m, u_char *);
835			ep = cp + m->m_len;
836			while (cp < ep) {
837				/*
838				 * Find out how many bytes in the
839				 * string we can handle without
840				 * doing something special.
841				 */
842				while (cp < ep) {
843					switch (*cp++) {
844					case FRAME_ESCAPE:
845					case FRAME_END:
846						cp--;
847						goto out;
848					}
849				}
850				out:
851				if (cp > bp) {
852					/*
853					 * Put N characters at once
854					 * into the tty output queue.
855					 */
856					if (b_to_q(bp, cp - bp, &tp->t_outq))
857						break;
858					sc->sc_if.if_obytes += cp - bp;
859				}
860				/*
861				 * If there are characters left in
862				 * the mbuf, the first one must be
863				 * special..  Put it out in a different
864				 * form.
865				 */
866				if (cp < ep) {
867					if (putc(FRAME_ESCAPE, &tp->t_outq))
868						break;
869					if (putc(*cp++ == FRAME_ESCAPE ?
870					    TRANS_FRAME_ESCAPE :
871					    TRANS_FRAME_END,
872					    &tp->t_outq)) {
873						(void)unputc(&tp->t_outq);
874						break;
875					}
876					sc->sc_if.if_obytes += 2;
877				}
878				bp = cp;
879			}
880			MFREE(m, m2);
881			m = m2;
882		}
883
884		if (putc(FRAME_END, &tp->t_outq)) {
885			/*
886			 * Not enough room.  Remove a char to make
887			 * room and end the packet normally.  If
888			 * you get many collisions (more than one
889			 * or two a day), you probably do not have
890			 * enough clists and you should increase
891			 * "nclist" in param.c
892			 */
893			(void)unputc(&tp->t_outq);
894			(void)putc(FRAME_END, &tp->t_outq);
895			sc->sc_if.if_collisions++;
896		} else {
897			sc->sc_if.if_obytes++;
898			sc->sc_if.if_opackets++;
899		}
900
901		/*
902		 * We now have characters in the output queue,
903		 * kick the serial port.
904		 */
905		(*tp->t_oproc)(tp);
906		splx(s);
907	}
908
909	/*
910	 * Input processing loop.
911	 */
912	for (;;) {
913		s = spltty();
914		IF_DEQUEUE(&sc->sc_inq, m);
915		splx(s);
916		if (m == NULL)
917			break;
918		pktstart = mtod(m, u_char *);
919		len = m->m_pkthdr.len;
920#if NBPFILTER > 0
921		if (sc->sc_if.if_bpf) {
922			/*
923			 * Save the compressed header, so we
924			 * can tack it on later.  Note that we
925			 * will end up copying garbage in some
926			 * cases but this is okay.  We remember
927			 * where the buffer started so we can
928			 * compute the new header length.
929			 */
930			memcpy(chdr, pktstart, CHDR_LEN);
931		}
932#endif /* NBPFILTER > 0 */
933#ifdef INET
934		if ((c = (*pktstart & 0xf0)) != (IPVERSION << 4)) {
935			if (c & 0x80)
936				c = TYPE_COMPRESSED_TCP;
937			else if (c == TYPE_UNCOMPRESSED_TCP)
938				*pktstart &= 0x4f; /* XXX */
939			/*
940			 * We've got something that's not an IP
941			 * packet.  If compression is enabled,
942			 * try to decompress it.  Otherwise, if
943			 * `auto-enable' compression is on and
944			 * it's a reasonable packet, decompress
945			 * it and then enable compression.
946			 * Otherwise, drop it.
947			 */
948			if (sc->sc_if.if_flags & SC_COMPRESS) {
949				len = sl_uncompress_tcp(&pktstart, len,
950				    (u_int)c, &sc->sc_comp);
951				if (len <= 0) {
952					m_freem(m);
953					continue;
954				}
955			} else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
956			    c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
957				len = sl_uncompress_tcp(&pktstart, len,
958				    (u_int)c, &sc->sc_comp);
959				if (len <= 0) {
960					m_freem(m);
961					continue;
962				}
963				sc->sc_if.if_flags |= SC_COMPRESS;
964			} else {
965				m_freem(m);
966				continue;
967			}
968		}
969#endif
970		m->m_data = (caddr_t) pktstart;
971		m->m_pkthdr.len = m->m_len = len;
972#if NBPFILTER > 0
973		if (sc->sc_if.if_bpf) {
974			bpf_mtap_sl_in(sc->sc_if.if_bpf, chdr, &m);
975			if (m == NULL)
976				continue;
977		}
978#endif /* NBPFILTER > 0 */
979		/*
980		 * If the packet will fit into a single
981		 * header mbuf, copy it into one, to save
982		 * memory.
983		 */
984		if (m->m_pkthdr.len < MHLEN) {
985			struct mbuf *n;
986			int pktlen;
987
988			MGETHDR(n, M_DONTWAIT, MT_DATA);
989			pktlen = m->m_pkthdr.len;
990			M_MOVE_PKTHDR(n, m);
991			memcpy(mtod(n, caddr_t), mtod(m, caddr_t), pktlen);
992			n->m_len = m->m_len;
993			m_freem(m);
994			m = n;
995		}
996
997		sc->sc_if.if_ipackets++;
998		getbinuptime(&sc->sc_lastpacket);
999
1000#ifdef INET
1001		s = splnet();
1002		if (IF_QFULL(&ipintrq)) {
1003			IF_DROP(&ipintrq);
1004			sc->sc_if.if_ierrors++;
1005			sc->sc_if.if_iqdrops++;
1006			m_freem(m);
1007		} else {
1008			IF_ENQUEUE(&ipintrq, m);
1009			schednetisr(NETISR_IP);
1010		}
1011		splx(s);
1012#endif
1013	}
1014}
1015
1016/*
1017 * Process an ioctl request.
1018 */
1019static int
1020slioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1021{
1022	struct ifaddr *ifa = (struct ifaddr *)data;
1023	struct ifreq *ifr = (struct ifreq *)data;
1024	int s = splnet(), error = 0;
1025	struct sl_softc *sc = ifp->if_softc;
1026	struct ppp_stats *psp;
1027	struct ppp_comp_stats *pcp;
1028
1029	switch (cmd) {
1030
1031	case SIOCSIFADDR:
1032		if (ifa->ifa_addr->sa_family == AF_INET)
1033			ifp->if_flags |= IFF_UP;
1034		else
1035			error = EAFNOSUPPORT;
1036		break;
1037
1038	case SIOCSIFDSTADDR:
1039		if (ifa->ifa_addr->sa_family != AF_INET)
1040			error = EAFNOSUPPORT;
1041		break;
1042
1043	case SIOCSIFMTU:
1044		if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) {
1045		    error = EINVAL;
1046		    break;
1047		}
1048		sc->sc_if.if_mtu = ifr->ifr_mtu;
1049		break;
1050
1051	case SIOCGIFMTU:
1052		ifr->ifr_mtu = sc->sc_if.if_mtu;
1053		break;
1054
1055	case SIOCADDMULTI:
1056	case SIOCDELMULTI:
1057		if (ifr == 0) {
1058			error = EAFNOSUPPORT;		/* XXX */
1059			break;
1060		}
1061		switch (ifr->ifr_addr.sa_family) {
1062
1063#ifdef INET
1064		case AF_INET:
1065			break;
1066#endif
1067
1068		default:
1069			error = EAFNOSUPPORT;
1070			break;
1071		}
1072		break;
1073
1074	case SIOCGPPPSTATS:
1075		psp = &((struct ifpppstatsreq *) data)->stats;
1076		(void)memset(psp, 0, sizeof(*psp));
1077		psp->p.ppp_ibytes = sc->sc_if.if_ibytes;
1078		psp->p.ppp_ipackets = sc->sc_if.if_ipackets;
1079		psp->p.ppp_ierrors = sc->sc_if.if_ierrors;
1080		psp->p.ppp_obytes = sc->sc_if.if_obytes;
1081		psp->p.ppp_opackets = sc->sc_if.if_opackets;
1082		psp->p.ppp_oerrors = sc->sc_if.if_oerrors;
1083#ifdef INET
1084		psp->vj.vjs_packets = sc->sc_comp.sls_packets;
1085		psp->vj.vjs_compressed = sc->sc_comp.sls_compressed;
1086		psp->vj.vjs_searches = sc->sc_comp.sls_searches;
1087		psp->vj.vjs_misses = sc->sc_comp.sls_misses;
1088		psp->vj.vjs_uncompressedin = sc->sc_comp.sls_uncompressedin;
1089		psp->vj.vjs_compressedin = sc->sc_comp.sls_compressedin;
1090		psp->vj.vjs_errorin = sc->sc_comp.sls_errorin;
1091		psp->vj.vjs_tossed = sc->sc_comp.sls_tossed;
1092#endif
1093		break;
1094
1095	case SIOCGPPPCSTATS:
1096		pcp = &((struct ifpppcstatsreq *) data)->stats;
1097		(void)memset(pcp, 0, sizeof(*pcp));
1098		break;
1099
1100	default:
1101		error = EINVAL;
1102	}
1103	splx(s);
1104	return error;
1105}
1106