if_sl.c revision 1.99
1/*	$NetBSD: if_sl.c,v 1.99 2006/07/08 18:32:53 tsutsui 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 1.99 2006/07/08 18:32:53 tsutsui 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 *, 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 proc *p = curproc;		/* XXX */
307	struct sl_softc *sc;
308	int error;
309	int s;
310
311	if ((error = kauth_authorize_generic(p->p_cred, KAUTH_GENERIC_ISSUSER,
312	    &p->p_acflag)) != 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, struct lwp *l)
433{
434	struct sl_softc *sc = (struct sl_softc *)tp->t_sc;
435
436	switch (cmd) {
437	case SLIOCGUNIT:
438		*(int *)data = sc->sc_unit;	/* XXX */
439		break;
440
441	default:
442		return EPASSTHROUGH;
443	}
444	return 0;
445}
446
447/*
448 * Queue a packet.  Start transmission if not active.
449 * Compression happens in slintr(); if we do it here, IP TOS
450 * will cause us to not compress "background" packets, because
451 * ordering gets trashed.  It can be done for all packets in slintr().
452 */
453static int
454sloutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
455    struct rtentry *rtp)
456{
457	struct sl_softc *sc = ifp->if_softc;
458	struct ip *ip;
459	struct ifqueue *ifq = NULL;
460	int s, error;
461	ALTQ_DECL(struct altq_pktattr pktattr;)
462
463	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
464
465	/*
466	 * `Cannot happen' (see slioctl).  Someday we will extend
467	 * the line protocol to support other address families.
468	 */
469	if (dst->sa_family != AF_INET) {
470		printf("%s: af%d not supported\n", sc->sc_if.if_xname,
471		    dst->sa_family);
472		m_freem(m);
473		sc->sc_if.if_noproto++;
474		return EAFNOSUPPORT;
475	}
476
477	if (sc->sc_ttyp == NULL) {
478		m_freem(m);
479		return ENETDOWN;	/* sort of */
480	}
481	if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 &&
482	    (sc->sc_ttyp->t_cflag & CLOCAL) == 0) {
483		m_freem(m);
484		printf("%s: no carrier and not local\n", sc->sc_if.if_xname);
485		return EHOSTUNREACH;
486	}
487	ip = mtod(m, struct ip *);
488#ifdef INET
489	if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
490		m_freem(m);
491		return ENETRESET;		/* XXX ? */
492	}
493#endif
494
495	s = spltty();
496	if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) {
497		struct bintime bt;
498
499		/* if output's been stalled for too long, and restart */
500		getbinuptime(&bt);
501		bintime_sub(&bt, &sc->sc_lastpacket);
502		if (bt.sec > 0) {
503			sc->sc_otimeout++;
504			slstart(sc->sc_ttyp);
505		}
506	}
507	splx(s);
508
509	s = splnet();
510#ifdef INET
511	if ((ip->ip_tos & IPTOS_LOWDELAY) != 0)
512		ifq = &sc->sc_fastq;
513#endif
514	if ((error = ifq_enqueue2(ifp, ifq, m ALTQ_COMMA
515	    ALTQ_DECL(&pktattr))) != 0) {
516		splx(s);
517		return error;
518	}
519	getbinuptime(&sc->sc_lastpacket);
520	splx(s);
521
522	s = spltty();
523	if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0)
524		slstart(sc->sc_ttyp);
525	splx(s);
526
527	return 0;
528}
529
530/*
531 * Start output on interface.  Get another datagram
532 * to send from the interface queue and map it to
533 * the interface before starting output.
534 */
535static int
536slstart(struct tty *tp)
537{
538	struct sl_softc *sc = tp->t_sc;
539
540	/*
541	 * If there is more in the output queue, just send it now.
542	 * We are being called in lieu of ttstart and must do what
543	 * it would.
544	 */
545	if (tp->t_outq.c_cc != 0) {
546		(*tp->t_oproc)(tp);
547		if (tp->t_outq.c_cc > SLIP_HIWAT)
548			return 0;
549	}
550
551	/*
552	 * This happens briefly when the line shuts down.
553	 */
554	if (sc == NULL)
555		return 0;
556#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
557	softintr_schedule(sc->sc_si);
558#else
559    {
560	int s = splhigh();
561	schednetisr(NETISR_SLIP);
562	splx(s);
563    }
564#endif
565	return 0;
566}
567
568/*
569 * Copy data buffer to mbuf chain; add ifnet pointer.
570 */
571static struct mbuf *
572sl_btom(struct sl_softc *sc, int len)
573{
574	struct mbuf *m;
575
576	/*
577	 * Allocate a new input buffer and swap.
578	 */
579	m = sc->sc_mbuf;
580	MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA);
581	if (sc->sc_mbuf == NULL) {
582		sc->sc_mbuf = m;
583		return NULL;
584	}
585	MCLGET(sc->sc_mbuf, M_DONTWAIT);
586	if ((sc->sc_mbuf->m_flags & M_EXT) == 0) {
587		m_freem(sc->sc_mbuf);
588		sc->sc_mbuf = m;
589		return NULL;
590	}
591	sc->sc_ep = (u_char *)sc->sc_mbuf->m_ext.ext_buf +
592	    sc->sc_mbuf->m_ext.ext_size;
593
594	m->m_data = sc->sc_pktstart;
595
596	m->m_pkthdr.len = m->m_len = len;
597	m->m_pkthdr.rcvif = &sc->sc_if;
598	return m;
599}
600
601/*
602 * tty interface receiver interrupt.
603 */
604static int
605slinput(int c, struct tty *tp)
606{
607	struct sl_softc *sc;
608	struct mbuf *m;
609	int len;
610
611	tk_nin++;
612	sc = (struct sl_softc *)tp->t_sc;
613	if (sc == NULL)
614		return 0;
615	if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 &&
616	    (tp->t_cflag & CLOCAL) == 0)) {
617		sc->sc_flags |= SC_ERROR;
618		return 0;
619	}
620	c &= TTY_CHARMASK;
621
622	++sc->sc_if.if_ibytes;
623
624	if (sc->sc_if.if_flags & IFF_DEBUG) {
625		if (c == ABT_ESC) {
626			/*
627			 * If we have a previous abort, see whether
628			 * this one is within the time limit.
629			 */
630			if (sc->sc_abortcount &&
631			    time_second >= sc->sc_starttime + ABT_WINDOW)
632				sc->sc_abortcount = 0;
633			/*
634			 * If we see an abort after "idle" time, count it;
635			 * record when the first abort escape arrived.
636			 */
637			if (time_second >= sc->sc_lasttime + ABT_IDLE) {
638				if (++sc->sc_abortcount == 1)
639					sc->sc_starttime = time_second;
640				if (sc->sc_abortcount >= ABT_COUNT) {
641					slclose(tp, 0);
642					return 0;
643				}
644			}
645		} else
646			sc->sc_abortcount = 0;
647		sc->sc_lasttime = time_second;
648	}
649
650	switch (c) {
651
652	case TRANS_FRAME_ESCAPE:
653		if (sc->sc_escape)
654			c = FRAME_ESCAPE;
655		break;
656
657	case TRANS_FRAME_END:
658		if (sc->sc_escape)
659			c = FRAME_END;
660		break;
661
662	case FRAME_ESCAPE:
663		sc->sc_escape = 1;
664		return 0;
665
666	case FRAME_END:
667		if (sc->sc_flags & SC_ERROR) {
668			sc->sc_flags &= ~SC_ERROR;
669			goto newpack;
670		}
671		len = sc->sc_mp - sc->sc_pktstart;
672		if (len < 3)
673			/* less than min length packet - ignore */
674			goto newpack;
675
676		m = sl_btom(sc, len);
677		if (m == NULL)
678			goto error;
679
680		IF_ENQUEUE(&sc->sc_inq, m);
681#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
682		softintr_schedule(sc->sc_si);
683#else
684	    {
685		int s = splhigh();
686		schednetisr(NETISR_SLIP);
687		splx(s);
688	    }
689#endif
690		goto newpack;
691	}
692	if (sc->sc_mp < sc->sc_ep) {
693		*sc->sc_mp++ = c;
694		sc->sc_escape = 0;
695		return 0;
696	}
697
698	/* can't put lower; would miss an extra frame */
699	sc->sc_flags |= SC_ERROR;
700
701error:
702	sc->sc_if.if_ierrors++;
703newpack:
704	sc->sc_mp = sc->sc_pktstart = (u_char *)sc->sc_mbuf->m_ext.ext_buf +
705	    BUFOFFSET;
706	sc->sc_escape = 0;
707
708	return 0;
709}
710
711#ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
712void
713slnetisr(void)
714{
715	struct sl_softc *sc;
716
717	LIST_FOREACH(sc, &sl_softc_list, sc_iflist) {
718		if (sc->sc_ttyp == NULL)
719			continue;
720		slintr(sc);
721	}
722}
723#endif
724
725static void
726slintr(void *arg)
727{
728	struct sl_softc *sc = arg;
729	struct tty *tp = sc->sc_ttyp;
730	struct mbuf *m;
731	int s, len;
732	u_char *pktstart;
733#ifdef INET
734	u_char c;
735#endif
736#if NBPFILTER > 0
737	u_char chdr[CHDR_LEN];
738#endif
739
740	KASSERT(tp != NULL);
741
742	/*
743	 * Output processing loop.
744	 */
745	for (;;) {
746#ifdef INET
747		struct ip *ip;
748#endif
749		struct mbuf *m2;
750#if NBPFILTER > 0
751		struct mbuf *bpf_m;
752#endif
753
754		/*
755		 * Do not remove the packet from the queue if it
756		 * doesn't look like it will fit into the current
757		 * serial output queue.  With a packet full of
758		 * escapes, this could be as bad as MTU*2+2.
759		 */
760		s = spltty();
761		if (tp->t_outq.c_cn - tp->t_outq.c_cc <
762		    2 * sc->sc_if.if_mtu + 2) {
763			splx(s);
764			break;
765		}
766		splx(s);
767
768		/*
769		 * Get a packet and send it to the interface.
770		 */
771		s = splnet();
772		IF_DEQUEUE(&sc->sc_fastq, m);
773		if (m)
774			sc->sc_if.if_omcasts++;	/* XXX */
775		else
776			IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
777		splx(s);
778
779		if (m == NULL)
780			break;
781
782		/*
783		 * We do the header compression here rather than in
784		 * sloutput() because the packets will be out of order
785		 * if we are using TOS queueing, and the connection
786		 * ID compression will get munged when this happens.
787		 */
788#if NBPFILTER > 0
789		if (sc->sc_if.if_bpf) {
790			/*
791			 * We need to save the TCP/IP header before
792			 * it's compressed.  To avoid complicated
793			 * code, we just make a deep copy of the
794			 * entire packet (since this is a serial
795			 * line, packets should be short and/or the
796			 * copy should be negligible cost compared
797			 * to the packet transmission time).
798			 */
799			bpf_m = m_dup(m, 0, M_COPYALL, M_DONTWAIT);
800		} else
801			bpf_m = NULL;
802#endif
803#ifdef INET
804		if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) {
805			if (sc->sc_if.if_flags & SC_COMPRESS)
806				*mtod(m, u_char *) |=
807				    sl_compress_tcp(m, ip, &sc->sc_comp, 1);
808		}
809#endif
810#if NBPFILTER > 0
811		if (sc->sc_if.if_bpf && bpf_m != NULL)
812			bpf_mtap_sl_out(sc->sc_if.if_bpf, mtod(m, u_char *),
813			    bpf_m);
814#endif
815		getbinuptime(&sc->sc_lastpacket);
816
817		s = spltty();
818
819		/*
820		 * The extra FRAME_END will start up a new packet,
821		 * and thus will flush any accumulated garbage.  We
822		 * do this whenever the line may have been idle for
823		 * some time.
824		 */
825		if (tp->t_outq.c_cc == 0) {
826			sc->sc_if.if_obytes++;
827			(void)putc(FRAME_END, &tp->t_outq);
828		}
829
830		while (m) {
831			u_char *bp, *cp, *ep;
832
833			bp = cp = mtod(m, u_char *);
834			ep = cp + m->m_len;
835			while (cp < ep) {
836				/*
837				 * Find out how many bytes in the
838				 * string we can handle without
839				 * doing something special.
840				 */
841				while (cp < ep) {
842					switch (*cp++) {
843					case FRAME_ESCAPE:
844					case FRAME_END:
845						cp--;
846						goto out;
847					}
848				}
849				out:
850				if (cp > bp) {
851					/*
852					 * Put N characters at once
853					 * into the tty output queue.
854					 */
855					if (b_to_q(bp, cp - bp, &tp->t_outq))
856						break;
857					sc->sc_if.if_obytes += cp - bp;
858				}
859				/*
860				 * If there are characters left in
861				 * the mbuf, the first one must be
862				 * special..  Put it out in a different
863				 * form.
864				 */
865				if (cp < ep) {
866					if (putc(FRAME_ESCAPE, &tp->t_outq))
867						break;
868					if (putc(*cp++ == FRAME_ESCAPE ?
869					    TRANS_FRAME_ESCAPE :
870					    TRANS_FRAME_END,
871					    &tp->t_outq)) {
872						(void)unputc(&tp->t_outq);
873						break;
874					}
875					sc->sc_if.if_obytes += 2;
876				}
877				bp = cp;
878			}
879			MFREE(m, m2);
880			m = m2;
881		}
882
883		if (putc(FRAME_END, &tp->t_outq)) {
884			/*
885			 * Not enough room.  Remove a char to make
886			 * room and end the packet normally.  If
887			 * you get many collisions (more than one
888			 * or two a day), you probably do not have
889			 * enough clists and you should increase
890			 * "nclist" in param.c
891			 */
892			(void)unputc(&tp->t_outq);
893			(void)putc(FRAME_END, &tp->t_outq);
894			sc->sc_if.if_collisions++;
895		} else {
896			sc->sc_if.if_obytes++;
897			sc->sc_if.if_opackets++;
898		}
899
900		/*
901		 * We now have characters in the output queue,
902		 * kick the serial port.
903		 */
904		(*tp->t_oproc)(tp);
905		splx(s);
906	}
907
908	/*
909	 * Input processing loop.
910	 */
911	for (;;) {
912		s = spltty();
913		IF_DEQUEUE(&sc->sc_inq, m);
914		splx(s);
915		if (m == NULL)
916			break;
917		pktstart = mtod(m, u_char *);
918		len = m->m_pkthdr.len;
919#if NBPFILTER > 0
920		if (sc->sc_if.if_bpf) {
921			/*
922			 * Save the compressed header, so we
923			 * can tack it on later.  Note that we
924			 * will end up copying garbage in some
925			 * cases but this is okay.  We remember
926			 * where the buffer started so we can
927			 * compute the new header length.
928			 */
929			memcpy(chdr, pktstart, CHDR_LEN);
930		}
931#endif /* NBPFILTER > 0 */
932#ifdef INET
933		if ((c = (*pktstart & 0xf0)) != (IPVERSION << 4)) {
934			if (c & 0x80)
935				c = TYPE_COMPRESSED_TCP;
936			else if (c == TYPE_UNCOMPRESSED_TCP)
937				*pktstart &= 0x4f; /* XXX */
938			/*
939			 * We've got something that's not an IP
940			 * packet.  If compression is enabled,
941			 * try to decompress it.  Otherwise, if
942			 * `auto-enable' compression is on and
943			 * it's a reasonable packet, decompress
944			 * it and then enable compression.
945			 * Otherwise, drop it.
946			 */
947			if (sc->sc_if.if_flags & SC_COMPRESS) {
948				len = sl_uncompress_tcp(&pktstart, len,
949				    (u_int)c, &sc->sc_comp);
950				if (len <= 0) {
951					m_freem(m);
952					continue;
953				}
954			} else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
955			    c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
956				len = sl_uncompress_tcp(&pktstart, len,
957				    (u_int)c, &sc->sc_comp);
958				if (len <= 0) {
959					m_freem(m);
960					continue;
961				}
962				sc->sc_if.if_flags |= SC_COMPRESS;
963			} else {
964				m_freem(m);
965				continue;
966			}
967		}
968#endif
969		m->m_data = (caddr_t) pktstart;
970		m->m_pkthdr.len = m->m_len = len;
971#if NBPFILTER > 0
972		if (sc->sc_if.if_bpf) {
973			bpf_mtap_sl_in(sc->sc_if.if_bpf, chdr, &m);
974			if (m == NULL)
975				continue;
976		}
977#endif /* NBPFILTER > 0 */
978		/*
979		 * If the packet will fit into a single
980		 * header mbuf, copy it into one, to save
981		 * memory.
982		 */
983		if (m->m_pkthdr.len < MHLEN) {
984			struct mbuf *n;
985			int pktlen;
986
987			MGETHDR(n, M_DONTWAIT, MT_DATA);
988			pktlen = m->m_pkthdr.len;
989			M_MOVE_PKTHDR(n, m);
990			memcpy(mtod(n, caddr_t), mtod(m, caddr_t), pktlen);
991			n->m_len = m->m_len;
992			m_freem(m);
993			m = n;
994		}
995
996		sc->sc_if.if_ipackets++;
997		getbinuptime(&sc->sc_lastpacket);
998
999#ifdef INET
1000		s = splnet();
1001		if (IF_QFULL(&ipintrq)) {
1002			IF_DROP(&ipintrq);
1003			sc->sc_if.if_ierrors++;
1004			sc->sc_if.if_iqdrops++;
1005			m_freem(m);
1006		} else {
1007			IF_ENQUEUE(&ipintrq, m);
1008			schednetisr(NETISR_IP);
1009		}
1010		splx(s);
1011#endif
1012	}
1013}
1014
1015/*
1016 * Process an ioctl request.
1017 */
1018static int
1019slioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1020{
1021	struct ifaddr *ifa = (struct ifaddr *)data;
1022	struct ifreq *ifr = (struct ifreq *)data;
1023	int s = splnet(), error = 0;
1024	struct sl_softc *sc = ifp->if_softc;
1025	struct ppp_stats *psp;
1026	struct ppp_comp_stats *pcp;
1027
1028	switch (cmd) {
1029
1030	case SIOCSIFADDR:
1031		if (ifa->ifa_addr->sa_family == AF_INET)
1032			ifp->if_flags |= IFF_UP;
1033		else
1034			error = EAFNOSUPPORT;
1035		break;
1036
1037	case SIOCSIFDSTADDR:
1038		if (ifa->ifa_addr->sa_family != AF_INET)
1039			error = EAFNOSUPPORT;
1040		break;
1041
1042	case SIOCSIFMTU:
1043		if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) {
1044		    error = EINVAL;
1045		    break;
1046		}
1047		sc->sc_if.if_mtu = ifr->ifr_mtu;
1048		break;
1049
1050	case SIOCGIFMTU:
1051		ifr->ifr_mtu = sc->sc_if.if_mtu;
1052		break;
1053
1054	case SIOCADDMULTI:
1055	case SIOCDELMULTI:
1056		if (ifr == 0) {
1057			error = EAFNOSUPPORT;		/* XXX */
1058			break;
1059		}
1060		switch (ifr->ifr_addr.sa_family) {
1061
1062#ifdef INET
1063		case AF_INET:
1064			break;
1065#endif
1066
1067		default:
1068			error = EAFNOSUPPORT;
1069			break;
1070		}
1071		break;
1072
1073	case SIOCGPPPSTATS:
1074		psp = &((struct ifpppstatsreq *) data)->stats;
1075		(void)memset(psp, 0, sizeof(*psp));
1076		psp->p.ppp_ibytes = sc->sc_if.if_ibytes;
1077		psp->p.ppp_ipackets = sc->sc_if.if_ipackets;
1078		psp->p.ppp_ierrors = sc->sc_if.if_ierrors;
1079		psp->p.ppp_obytes = sc->sc_if.if_obytes;
1080		psp->p.ppp_opackets = sc->sc_if.if_opackets;
1081		psp->p.ppp_oerrors = sc->sc_if.if_oerrors;
1082#ifdef INET
1083		psp->vj.vjs_packets = sc->sc_comp.sls_packets;
1084		psp->vj.vjs_compressed = sc->sc_comp.sls_compressed;
1085		psp->vj.vjs_searches = sc->sc_comp.sls_searches;
1086		psp->vj.vjs_misses = sc->sc_comp.sls_misses;
1087		psp->vj.vjs_uncompressedin = sc->sc_comp.sls_uncompressedin;
1088		psp->vj.vjs_compressedin = sc->sc_comp.sls_compressedin;
1089		psp->vj.vjs_errorin = sc->sc_comp.sls_errorin;
1090		psp->vj.vjs_tossed = sc->sc_comp.sls_tossed;
1091#endif
1092		break;
1093
1094	case SIOCGPPPCSTATS:
1095		pcp = &((struct ifpppcstatsreq *) data)->stats;
1096		(void)memset(pcp, 0, sizeof(*pcp));
1097		break;
1098
1099	default:
1100		error = EINVAL;
1101	}
1102	splx(s);
1103	return error;
1104}
1105