if_sl.c revision 1.98
1/*	$NetBSD: if_sl.c,v 1.98 2006/06/07 22:33:43 kardel 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 1.98 2006/06/07 22:33:43 kardel 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	if (ttyldisc_attach(&slip_disc) != 0)
226		panic("slattach");
227	LIST_INIT(&sl_softc_list);
228	if_clone_attach(&sl_cloner);
229}
230
231static int
232sl_clone_create(struct if_clone *ifc, int unit)
233{
234	struct sl_softc *sc;
235
236	MALLOC(sc, struct sl_softc *, sizeof(*sc), M_DEVBUF, M_WAIT|M_ZERO);
237	sc->sc_unit = unit;
238	(void)snprintf(sc->sc_if.if_xname, sizeof(sc->sc_if.if_xname),
239	    "%s%d", ifc->ifc_name, unit);
240	sc->sc_if.if_softc = sc;
241	sc->sc_if.if_mtu = SLMTU;
242	sc->sc_if.if_flags = IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST;
243	sc->sc_if.if_type = IFT_SLIP;
244	sc->sc_if.if_ioctl = slioctl;
245	sc->sc_if.if_output = sloutput;
246	sc->sc_if.if_dlt = DLT_SLIP;
247	sc->sc_fastq.ifq_maxlen = 32;
248	IFQ_SET_READY(&sc->sc_if.if_snd);
249	if_attach(&sc->sc_if);
250	if_alloc_sadl(&sc->sc_if);
251#if NBPFILTER > 0
252	bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
253#endif
254	LIST_INSERT_HEAD(&sl_softc_list, sc, sc_iflist);
255	return 0;
256}
257
258static int
259sl_clone_destroy(struct ifnet *ifp)
260{
261	struct sl_softc *sc = (struct sl_softc *)ifp->if_softc;
262
263	if (sc->sc_ttyp != NULL)
264		return EBUSY;	/* Not removing it */
265
266	LIST_REMOVE(sc, sc_iflist);
267
268#if NBPFILTER > 0
269	bpfdetach(ifp);
270#endif
271	if_detach(ifp);
272
273	FREE(sc, M_DEVBUF);
274	return 0;
275}
276
277static int
278slinit(struct sl_softc *sc)
279{
280
281	if (sc->sc_mbuf == NULL) {
282		sc->sc_mbuf = m_gethdr(M_WAIT, MT_DATA);
283		m_clget(sc->sc_mbuf, M_WAIT);
284	}
285	sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
286	    sc->sc_mbuf->m_ext.ext_size;
287	sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
288	    BUFOFFSET;
289
290#ifdef INET
291	sl_compress_init(&sc->sc_comp);
292#endif
293
294	return (1);
295}
296
297/*
298 * Line specific open routine.
299 * Attach the given tty to the first available sl unit.
300 */
301/* ARGSUSED */
302static int
303slopen(dev_t dev, struct tty *tp)
304{
305	struct proc *p = curproc;		/* XXX */
306	struct sl_softc *sc;
307	int error;
308	int s;
309
310	if ((error = kauth_authorize_generic(p->p_cred, KAUTH_GENERIC_ISSUSER, &p->p_acflag)) != 0)
311		return (error);
312
313	if (tp->t_linesw == &slip_disc)
314		return (0);
315
316	LIST_FOREACH(sc, &sl_softc_list, sc_iflist)
317		if (sc->sc_ttyp == NULL) {
318#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
319			sc->sc_si = softintr_establish(IPL_SOFTNET,
320			    slintr, sc);
321			if (sc->sc_si == NULL)
322				return (ENOMEM);
323#endif
324			if (slinit(sc) == 0) {
325#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
326				softintr_disestablish(sc->sc_si);
327#endif
328				return (ENOBUFS);
329			}
330			tp->t_sc = (caddr_t)sc;
331			sc->sc_ttyp = tp;
332			sc->sc_if.if_baudrate = tp->t_ospeed;
333			s = spltty();
334			tp->t_state |= TS_ISOPEN | TS_XCLUDE;
335			splx(s);
336			ttyflush(tp, FREAD | FWRITE);
337#ifdef __NetBSD__
338			/*
339			 * make sure tty output queue is large enough
340			 * to hold a full-sized packet (including frame
341			 * end, and a possible extra frame end).  full-sized
342			 * packet occupies a max of 2*SLMAX bytes (because
343			 * of possible escapes), and add two on for frame
344			 * ends.
345			 */
346			s = spltty();
347			if (tp->t_outq.c_cn < 2*SLMAX+2) {
348				sc->sc_oldbufsize = tp->t_outq.c_cn;
349				sc->sc_oldbufquot = tp->t_outq.c_cq != 0;
350
351				clfree(&tp->t_outq);
352				error = clalloc(&tp->t_outq, 2*SLMAX+2, 0);
353				if (error) {
354					splx(s);
355#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
356					softintr_disestablish(sc->sc_si);
357#endif
358					/*
359					 * clalloc() might return -1 which
360					 * is no good, so we need to return
361					 * something else.
362					 */
363					return (ENOMEM); /* XXX ?! */
364				}
365			} else
366				sc->sc_oldbufsize = sc->sc_oldbufquot = 0;
367			splx(s);
368#endif /* __NetBSD__ */
369			return (0);
370		}
371	return (ENXIO);
372}
373
374/*
375 * Line specific close routine.
376 * Detach the tty from the sl unit.
377 */
378static int
379slclose(struct tty *tp, int flag)
380{
381	struct sl_softc *sc;
382	int s;
383
384	ttywflush(tp);
385	sc = tp->t_sc;
386
387	if (sc != NULL) {
388#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
389		softintr_disestablish(sc->sc_si);
390#endif
391		s = splnet();
392		if_down(&sc->sc_if);
393		IF_PURGE(&sc->sc_fastq);
394		splx(s);
395
396		s = spltty();
397		ttyldisc_release(tp->t_linesw);
398		tp->t_linesw = ttyldisc_default();
399		tp->t_state = 0;
400
401		sc->sc_ttyp = NULL;
402		tp->t_sc = NULL;
403
404		m_freem(sc->sc_mbuf);
405		sc->sc_mbuf = NULL;
406		sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL;
407		IF_PURGE(&sc->sc_inq);
408
409		/*
410		 * If necessary, install a new outq buffer of the
411		 * appropriate size.
412		 */
413		if (sc->sc_oldbufsize != 0) {
414			clfree(&tp->t_outq);
415			clalloc(&tp->t_outq, sc->sc_oldbufsize,
416			    sc->sc_oldbufquot);
417		}
418		splx(s);
419	}
420
421	return (0);
422}
423
424/*
425 * Line specific (tty) ioctl routine.
426 * Provide a way to get the sl unit number.
427 */
428/* ARGSUSED */
429static int
430sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct lwp *l)
431{
432	struct sl_softc *sc = (struct sl_softc *)tp->t_sc;
433
434	switch (cmd) {
435	case SLIOCGUNIT:
436		*(int *)data = sc->sc_unit;	/* XXX */
437		break;
438
439	default:
440		return (EPASSTHROUGH);
441	}
442	return (0);
443}
444
445/*
446 * Queue a packet.  Start transmission if not active.
447 * Compression happens in slintr(); if we do it here, IP TOS
448 * will cause us to not compress "background" packets, because
449 * ordering gets trashed.  It can be done for all packets in slintr().
450 */
451static int
452sloutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
453    struct rtentry *rtp)
454{
455	struct sl_softc *sc = ifp->if_softc;
456	struct ip *ip;
457	struct ifqueue *ifq = NULL;
458	int s, error;
459	ALTQ_DECL(struct altq_pktattr pktattr;)
460
461	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
462
463	/*
464	 * `Cannot happen' (see slioctl).  Someday we will extend
465	 * the line protocol to support other address families.
466	 */
467	if (dst->sa_family != AF_INET) {
468		printf("%s: af%d not supported\n", sc->sc_if.if_xname,
469		    dst->sa_family);
470		m_freem(m);
471		sc->sc_if.if_noproto++;
472		return (EAFNOSUPPORT);
473	}
474
475	if (sc->sc_ttyp == NULL) {
476		m_freem(m);
477		return (ENETDOWN);	/* sort of */
478	}
479	if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 &&
480	    (sc->sc_ttyp->t_cflag & CLOCAL) == 0) {
481		m_freem(m);
482		printf("%s: no carrier and not local\n", sc->sc_if.if_xname);
483		return (EHOSTUNREACH);
484	}
485	ip = mtod(m, struct ip *);
486#ifdef INET
487	if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
488		m_freem(m);
489		return (ENETRESET);		/* XXX ? */
490	}
491#endif
492
493	s = spltty();
494	if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) {
495		struct bintime bt;
496
497		/* if output's been stalled for too long, and restart */
498		getbinuptime(&bt);
499		bintime_sub(&bt, &sc->sc_lastpacket);
500		if (bt.sec > 0) {
501			sc->sc_otimeout++;
502			slstart(sc->sc_ttyp);
503		}
504	}
505	splx(s);
506
507	s = splnet();
508#ifdef INET
509	if ((ip->ip_tos & IPTOS_LOWDELAY) != 0)
510		ifq = &sc->sc_fastq;
511#endif
512	if ((error = ifq_enqueue2(ifp, ifq, m ALTQ_COMMA
513	    ALTQ_DECL(&pktattr))) != 0) {
514		splx(s);
515		return error;
516	}
517	getbinuptime(&sc->sc_lastpacket);
518	splx(s);
519
520	s = spltty();
521	if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0)
522		slstart(sc->sc_ttyp);
523	splx(s);
524
525	return (0);
526}
527
528/*
529 * Start output on interface.  Get another datagram
530 * to send from the interface queue and map it to
531 * the interface before starting output.
532 */
533static int
534slstart(struct tty *tp)
535{
536	struct sl_softc *sc = tp->t_sc;
537
538	/*
539	 * If there is more in the output queue, just send it now.
540	 * We are being called in lieu of ttstart and must do what
541	 * it would.
542	 */
543	if (tp->t_outq.c_cc != 0) {
544		(*tp->t_oproc)(tp);
545		if (tp->t_outq.c_cc > SLIP_HIWAT)
546			return (0);
547	}
548
549	/*
550	 * This happens briefly when the line shuts down.
551	 */
552	if (sc == NULL)
553		return (0);
554#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
555	softintr_schedule(sc->sc_si);
556#else
557    {
558	int s = splhigh();
559	schednetisr(NETISR_SLIP);
560	splx(s);
561    }
562#endif
563	return (0);
564}
565
566/*
567 * Copy data buffer to mbuf chain; add ifnet pointer.
568 */
569static struct mbuf *
570sl_btom(struct sl_softc *sc, int len)
571{
572	struct mbuf *m;
573
574	/*
575	 * Allocate a new input buffer and swap.
576	 */
577	m = sc->sc_mbuf;
578	MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA);
579	if (sc->sc_mbuf == NULL) {
580		sc->sc_mbuf = m;
581		return (NULL);
582	}
583	MCLGET(sc->sc_mbuf, M_DONTWAIT);
584	if ((sc->sc_mbuf->m_flags & M_EXT) == 0) {
585		m_freem(sc->sc_mbuf);
586		sc->sc_mbuf = m;
587		return (NULL);
588	}
589	sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
590	    sc->sc_mbuf->m_ext.ext_size;
591
592	m->m_data = sc->sc_pktstart;
593
594	m->m_pkthdr.len = m->m_len = len;
595	m->m_pkthdr.rcvif = &sc->sc_if;
596	return (m);
597}
598
599/*
600 * tty interface receiver interrupt.
601 */
602static int
603slinput(int c, struct tty *tp)
604{
605	struct sl_softc *sc;
606	struct mbuf *m;
607	int len;
608
609	tk_nin++;
610	sc = (struct sl_softc *)tp->t_sc;
611	if (sc == NULL)
612		return (0);
613	if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 &&
614	    (tp->t_cflag & CLOCAL) == 0)) {
615		sc->sc_flags |= SC_ERROR;
616		return (0);
617	}
618	c &= TTY_CHARMASK;
619
620	++sc->sc_if.if_ibytes;
621
622	if (sc->sc_if.if_flags & IFF_DEBUG) {
623		if (c == ABT_ESC) {
624			/*
625			 * If we have a previous abort, see whether
626			 * this one is within the time limit.
627			 */
628			if (sc->sc_abortcount &&
629			    time_second >= sc->sc_starttime + ABT_WINDOW)
630				sc->sc_abortcount = 0;
631			/*
632			 * If we see an abort after "idle" time, count it;
633			 * record when the first abort escape arrived.
634			 */
635			if (time_second >= sc->sc_lasttime + ABT_IDLE) {
636				if (++sc->sc_abortcount == 1)
637					sc->sc_starttime = time_second;
638				if (sc->sc_abortcount >= ABT_COUNT) {
639					slclose(tp, 0);
640					return (0);
641				}
642			}
643		} else
644			sc->sc_abortcount = 0;
645		sc->sc_lasttime = time_second;
646	}
647
648	switch (c) {
649
650	case TRANS_FRAME_ESCAPE:
651		if (sc->sc_escape)
652			c = FRAME_ESCAPE;
653		break;
654
655	case TRANS_FRAME_END:
656		if (sc->sc_escape)
657			c = FRAME_END;
658		break;
659
660	case FRAME_ESCAPE:
661		sc->sc_escape = 1;
662		return (0);
663
664	case FRAME_END:
665		if(sc->sc_flags & SC_ERROR) {
666			sc->sc_flags &= ~SC_ERROR;
667			goto newpack;
668		}
669		len = sc->sc_mp - sc->sc_pktstart;
670		if (len < 3)
671			/* less than min length packet - ignore */
672			goto newpack;
673
674		m = sl_btom(sc, len);
675		if (m == NULL)
676			goto error;
677
678		IF_ENQUEUE(&sc->sc_inq, m);
679#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
680		softintr_schedule(sc->sc_si);
681#else
682	    {
683		int s = splhigh();
684		schednetisr(NETISR_SLIP);
685		splx(s);
686	    }
687#endif
688		goto newpack;
689	}
690	if (sc->sc_mp < sc->sc_ep) {
691		*sc->sc_mp++ = c;
692		sc->sc_escape = 0;
693		return (0);
694	}
695
696	/* can't put lower; would miss an extra frame */
697	sc->sc_flags |= SC_ERROR;
698
699error:
700	sc->sc_if.if_ierrors++;
701newpack:
702	sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
703	    BUFOFFSET;
704	sc->sc_escape = 0;
705
706	return (0);
707}
708
709#ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
710void
711slnetisr(void)
712{
713	struct sl_softc *sc;
714
715	LIST_FOREACH(sc, &sl_softc_list, sc_iflist) {
716		if (sc->sc_ttyp == NULL)
717			continue;
718		slintr(sc);
719	}
720}
721#endif
722
723static void
724slintr(void *arg)
725{
726	struct sl_softc *sc = arg;
727	struct tty *tp = sc->sc_ttyp;
728	struct mbuf *m;
729	int s, len;
730	u_char *pktstart;
731#ifdef INET
732	u_char c;
733#endif
734#if NBPFILTER > 0
735	u_char chdr[CHDR_LEN];
736#endif
737
738	KASSERT(tp != NULL);
739
740	/*
741	 * Output processing loop.
742	 */
743	for (;;) {
744#ifdef INET
745		struct ip *ip;
746#endif
747		struct mbuf *m2;
748#if NBPFILTER > 0
749		struct mbuf *bpf_m;
750#endif
751
752		/*
753		 * Do not remove the packet from the queue if it
754		 * doesn't look like it will fit into the current
755		 * serial output queue.  With a packet full of
756		 * escapes, this could be as bad as MTU*2+2.
757		 */
758		s = spltty();
759		if (tp->t_outq.c_cn - tp->t_outq.c_cc <
760		    2*sc->sc_if.if_mtu+2) {
761			splx(s);
762			break;
763		}
764		splx(s);
765
766		/*
767		 * Get a packet and send it to the interface.
768		 */
769		s = splnet();
770		IF_DEQUEUE(&sc->sc_fastq, m);
771		if (m)
772			sc->sc_if.if_omcasts++;	/* XXX */
773		else
774			IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
775		splx(s);
776
777		if (m == NULL)
778			break;
779
780		/*
781		 * We do the header compression here rather than in
782		 * sloutput() because the packets will be out of order
783		 * if we are using TOS queueing, and the connection
784		 * ID compression will get munged when this happens.
785		 */
786#if NBPFILTER > 0
787		if (sc->sc_if.if_bpf) {
788			/*
789			 * We need to save the TCP/IP header before
790			 * it's compressed.  To avoid complicated
791			 * code, we just make a deep copy of the
792			 * entire packet (since this is a serial
793			 * line, packets should be short and/or the
794			 * copy should be negligible cost compared
795			 * to the packet transmission time).
796			 */
797			bpf_m = m_dup(m, 0, M_COPYALL, M_DONTWAIT);
798		} else
799			bpf_m = NULL;
800#endif
801#ifdef INET
802		if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) {
803			if (sc->sc_if.if_flags & SC_COMPRESS)
804				*mtod(m, u_char *) |=
805				    sl_compress_tcp(m, ip,
806				    &sc->sc_comp, 1);
807		}
808#endif
809#if NBPFILTER > 0
810		if (sc->sc_if.if_bpf && bpf_m != NULL)
811			bpf_mtap_sl_out(sc->sc_if.if_bpf, mtod(m, u_char *),
812			    bpf_m);
813#endif
814		getbinuptime(&sc->sc_lastpacket);
815
816		s = spltty();
817
818		/*
819		 * The extra FRAME_END will start up a new packet,
820		 * and thus will flush any accumulated garbage.  We
821		 * do this whenever the line may have been idle for
822		 * some time.
823		 */
824		if (tp->t_outq.c_cc == 0) {
825			sc->sc_if.if_obytes++;
826			(void) putc(FRAME_END, &tp->t_outq);
827		}
828
829		while (m) {
830			u_char *bp, *cp, *ep;
831
832			bp = cp = mtod(m, u_char *);
833			ep = cp + m->m_len;
834			while (cp < ep) {
835				/*
836				 * Find out how many bytes in the
837				 * string we can handle without
838				 * doing something special.
839				 */
840				while (cp < ep) {
841					switch (*cp++) {
842					case FRAME_ESCAPE:
843					case FRAME_END:
844						cp--;
845						goto out;
846					}
847				}
848				out:
849				if (cp > bp) {
850					/*
851					 * Put N characters at once
852					 * into the tty output queue.
853					 */
854					if (b_to_q(bp, cp - bp,
855					    &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,
867					    &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)
874						   unputc(&tp->t_outq);
875						break;
876					}
877					sc->sc_if.if_obytes += 2;
878				}
879				bp = cp;
880			}
881			MFREE(m, m2);
882			m = m2;
883		}
884
885		if (putc(FRAME_END, &tp->t_outq)) {
886			/*
887			 * Not enough room.  Remove a char to make
888			 * room and end the packet normally.  If
889			 * you get many collisions (more than one
890			 * or two a day), you probably do not have
891			 * enough clists and you should increase
892			 * "nclist" in param.c
893			 */
894			(void) unputc(&tp->t_outq);
895			(void) putc(FRAME_END, &tp->t_outq);
896			sc->sc_if.if_collisions++;
897		} else {
898			sc->sc_if.if_obytes++;
899			sc->sc_if.if_opackets++;
900		}
901
902		/*
903		 * We now have characters in the output queue,
904		 * kick the serial port.
905		 */
906		(*tp->t_oproc)(tp);
907		splx(s);
908	}
909
910	/*
911	 * Input processing loop.
912	 */
913	for (;;) {
914		s = spltty();
915		IF_DEQUEUE(&sc->sc_inq, m);
916		splx(s);
917		if (m == NULL)
918			break;
919		pktstart = mtod(m, u_char *);
920		len = m->m_pkthdr.len;
921#if NBPFILTER > 0
922		if (sc->sc_if.if_bpf) {
923			/*
924			 * Save the compressed header, so we
925			 * can tack it on later.  Note that we
926			 * will end up copying garbage in some
927			 * cases but this is okay.  We remember
928			 * where the buffer started so we can
929			 * compute the new header length.
930			 */
931			memcpy(chdr, pktstart, CHDR_LEN);
932		}
933#endif /* NBPFILTER > 0 */
934#ifdef INET
935		if ((c = (*pktstart & 0xf0)) != (IPVERSION << 4)) {
936			if (c & 0x80)
937				c = TYPE_COMPRESSED_TCP;
938			else if (c == TYPE_UNCOMPRESSED_TCP)
939				*pktstart &= 0x4f; /* XXX */
940			/*
941			 * We've got something that's not an IP
942			 * packet.  If compression is enabled,
943			 * try to decompress it.  Otherwise, if
944			 * `auto-enable' compression is on and
945			 * it's a reasonable packet, decompress
946			 * it and then enable compression.
947			 * Otherwise, drop it.
948			 */
949			if (sc->sc_if.if_flags & SC_COMPRESS) {
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			} else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
957			    c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
958				len = sl_uncompress_tcp(&pktstart, len,
959				    (u_int)c, &sc->sc_comp);
960				if (len <= 0) {
961					m_freem(m);
962					continue;
963				}
964				sc->sc_if.if_flags |= SC_COMPRESS;
965			} else {
966				m_freem(m);
967				continue;
968			}
969		}
970#endif
971		m->m_data = (caddr_t) pktstart;
972		m->m_pkthdr.len = m->m_len = len;
973#if NBPFILTER > 0
974		if (sc->sc_if.if_bpf) {
975			bpf_mtap_sl_in(sc->sc_if.if_bpf, chdr, &m);
976			if (m == NULL)
977				continue;
978		}
979#endif /* NBPFILTER > 0 */
980		/*
981		 * If the packet will fit into a single
982		 * header mbuf, copy it into one, to save
983		 * memory.
984		 */
985		if (m->m_pkthdr.len < MHLEN) {
986			struct mbuf *n;
987			int pktlen;
988
989			MGETHDR(n, M_DONTWAIT, MT_DATA);
990			pktlen = m->m_pkthdr.len;
991			M_MOVE_PKTHDR(n, m);
992			memcpy(mtod(n, caddr_t), mtod(m, caddr_t), pktlen);
993			n->m_len = m->m_len;
994			m_freem(m);
995			m = n;
996		}
997
998		sc->sc_if.if_ipackets++;
999		getbinuptime(&sc->sc_lastpacket);
1000
1001#ifdef INET
1002		s = splnet();
1003		if (IF_QFULL(&ipintrq)) {
1004			IF_DROP(&ipintrq);
1005			sc->sc_if.if_ierrors++;
1006			sc->sc_if.if_iqdrops++;
1007			m_freem(m);
1008		} else {
1009			IF_ENQUEUE(&ipintrq, m);
1010			schednetisr(NETISR_IP);
1011		}
1012		splx(s);
1013#endif
1014	}
1015}
1016
1017/*
1018 * Process an ioctl request.
1019 */
1020static int
1021slioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1022{
1023	struct ifaddr *ifa = (struct ifaddr *)data;
1024	struct ifreq *ifr = (struct ifreq *)data;
1025	int s = splnet(), error = 0;
1026	struct sl_softc *sc = ifp->if_softc;
1027	struct ppp_stats *psp;
1028	struct ppp_comp_stats *pcp;
1029
1030	switch (cmd) {
1031
1032	case SIOCSIFADDR:
1033		if (ifa->ifa_addr->sa_family == AF_INET)
1034			ifp->if_flags |= IFF_UP;
1035		else
1036			error = EAFNOSUPPORT;
1037		break;
1038
1039	case SIOCSIFDSTADDR:
1040		if (ifa->ifa_addr->sa_family != AF_INET)
1041			error = EAFNOSUPPORT;
1042		break;
1043
1044	case SIOCSIFMTU:
1045		if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) {
1046		    error = EINVAL;
1047		    break;
1048		}
1049		sc->sc_if.if_mtu = ifr->ifr_mtu;
1050		break;
1051
1052	case SIOCGIFMTU:
1053		ifr->ifr_mtu = sc->sc_if.if_mtu;
1054		break;
1055
1056	case SIOCADDMULTI:
1057	case SIOCDELMULTI:
1058		if (ifr == 0) {
1059			error = EAFNOSUPPORT;		/* XXX */
1060			break;
1061		}
1062		switch (ifr->ifr_addr.sa_family) {
1063
1064#ifdef INET
1065		case AF_INET:
1066			break;
1067#endif
1068
1069		default:
1070			error = EAFNOSUPPORT;
1071			break;
1072		}
1073		break;
1074
1075	case SIOCGPPPSTATS:
1076		psp = &((struct ifpppstatsreq *) data)->stats;
1077		(void)memset(psp, 0, sizeof(*psp));
1078		psp->p.ppp_ibytes = sc->sc_if.if_ibytes;
1079		psp->p.ppp_ipackets = sc->sc_if.if_ipackets;
1080		psp->p.ppp_ierrors = sc->sc_if.if_ierrors;
1081		psp->p.ppp_obytes = sc->sc_if.if_obytes;
1082		psp->p.ppp_opackets = sc->sc_if.if_opackets;
1083		psp->p.ppp_oerrors = sc->sc_if.if_oerrors;
1084#ifdef INET
1085		psp->vj.vjs_packets = sc->sc_comp.sls_packets;
1086		psp->vj.vjs_compressed = sc->sc_comp.sls_compressed;
1087		psp->vj.vjs_searches = sc->sc_comp.sls_searches;
1088		psp->vj.vjs_misses = sc->sc_comp.sls_misses;
1089		psp->vj.vjs_uncompressedin = sc->sc_comp.sls_uncompressedin;
1090		psp->vj.vjs_compressedin = sc->sc_comp.sls_compressedin;
1091		psp->vj.vjs_errorin = sc->sc_comp.sls_errorin;
1092		psp->vj.vjs_tossed = sc->sc_comp.sls_tossed;
1093#endif
1094		break;
1095
1096	case SIOCGPPPCSTATS:
1097		pcp = &((struct ifpppcstatsreq *) data)->stats;
1098		(void)memset(pcp, 0, sizeof(*pcp));
1099		break;
1100
1101	default:
1102		error = EINVAL;
1103	}
1104	splx(s);
1105	return (error);
1106}
1107