xref: /freebsd/sys/dev/ppbus/if_plip.c (revision 0640d357f29fb1c0daaaffadd0416c5981413afd)
1 /*-
2  * Copyright (c) 1997 Poul-Henning Kamp
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  *	From Id: lpt.c,v 1.55.2.1 1996/11/12 09:08:38 phk Exp
27  *	$Id: if_plip.c,v 1.4 1998/10/07 14:42:24 des Exp $
28  */
29 
30 /*
31  * Parallel port TCP/IP interfaces added.  I looked at the driver from
32  * MACH but this is a complete rewrite, and btw. incompatible, and it
33  * should perform better too.  I have never run the MACH driver though.
34  *
35  * This driver sends two bytes (0x08, 0x00) in front of each packet,
36  * to allow us to distinguish another format later.
37  *
38  * Now added an Linux/Crynwr compatibility mode which is enabled using
39  * IF_LINK0 - Tim Wilkinson.
40  *
41  * TODO:
42  *    Make HDLC/PPP mode, use IF_LLC1 to enable.
43  *
44  * Connect the two computers using a Laplink parallel cable to use this
45  * feature:
46  *
47  *      +----------------------------------------+
48  * 	|A-name	A-End	B-End	Descr.	Port/Bit |
49  *      +----------------------------------------+
50  *	|DATA0	2	15	Data	0/0x01   |
51  *	|-ERROR	15	2	   	1/0x08   |
52  *      +----------------------------------------+
53  *	|DATA1	3	13	Data	0/0x02	 |
54  *	|+SLCT	13	3	   	1/0x10   |
55  *      +----------------------------------------+
56  *	|DATA2	4	12	Data	0/0x04   |
57  *	|+PE	12	4	   	1/0x20   |
58  *      +----------------------------------------+
59  *	|DATA3	5	10	Strobe	0/0x08   |
60  *	|-ACK	10	5	   	1/0x40   |
61  *      +----------------------------------------+
62  *	|DATA4	6	11	Data	0/0x10   |
63  *	|BUSY	11	6	   	1/~0x80  |
64  *      +----------------------------------------+
65  *	|GND	18-25	18-25	GND	-        |
66  *      +----------------------------------------+
67  *
68  * Expect transfer-rates up to 75 kbyte/sec.
69  *
70  * If GCC could correctly grok
71  *	register int port asm("edx")
72  * the code would be cleaner
73  *
74  * Poul-Henning Kamp <phk@freebsd.org>
75  */
76 
77 /*
78  * Update for ppbus, PLIP support only - Nicolas Souchu
79  */
80 
81 #include <sys/param.h>
82 #include <sys/systm.h>
83 #include <sys/mbuf.h>
84 #include <sys/socket.h>
85 #include <sys/sockio.h>
86 #include <sys/kernel.h>
87 #include <sys/malloc.h>
88 
89 #include <net/if.h>
90 #include <net/if_types.h>
91 #include <net/netisr.h>
92 
93 #include <netinet/in.h>
94 #include <netinet/in_var.h>
95 
96 #include "bpfilter.h"
97 #if NBPFILTER > 0
98 #include <net/bpf.h>
99 #endif
100 
101 #include <dev/ppbus/ppbconf.h>
102 #include <dev/ppbus/nlpt.h>
103 
104 #ifndef LPMTU			/* MTU for the lp# interfaces */
105 #define	LPMTU	1500
106 #endif
107 
108 #ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
109 #define	LPMAXSPIN1	8000   /* Spinning for remote intr to happen */
110 #endif
111 
112 #ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
113 #define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
114 #endif
115 
116 #ifndef LPMAXERRS		/* Max errors before !RUNNING */
117 #define	LPMAXERRS	100
118 #endif
119 
120 #define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
121 #define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
122 #define MLPIPHDRLEN	CLPIPHDRLEN
123 
124 #define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
125 #define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
126 #if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
127 #define MLPIPHDRLEN	LPIPHDRLEN
128 #endif
129 
130 #define	LPIPTBLSIZE	256	/* Size of octet translation table */
131 
132 #define DEBUG
133 
134 #ifndef DEBUG
135 #define lprintf (void)
136 #else
137 #define lprintf		if (lptflag) printf
138 static int volatile lptflag = 1;
139 #endif
140 
141 struct lpt_softc {
142 	unsigned short lp_unit;
143 
144 	struct ppb_device lp_dev;
145 
146 	struct  ifnet	sc_if;
147 	u_char		*sc_ifbuf;
148 	int		sc_iferrs;
149 };
150 
151 static int	nlp = 0;
152 #define MAXPLIP	8			/* XXX not much better! */
153 static struct lpt_softc *lpdata[MAXPLIP];
154 
155 
156 /* Tables for the lp# interface */
157 static u_char *txmith;
158 #define txmitl (txmith+(1*LPIPTBLSIZE))
159 #define trecvh (txmith+(2*LPIPTBLSIZE))
160 #define trecvl (txmith+(3*LPIPTBLSIZE))
161 
162 static u_char *ctxmith;
163 #define ctxmitl (ctxmith+(1*LPIPTBLSIZE))
164 #define ctrecvh (ctxmith+(2*LPIPTBLSIZE))
165 #define ctrecvl (ctxmith+(3*LPIPTBLSIZE))
166 
167 /* Functions for the lp# interface */
168 static struct ppb_device	*lpprobe(struct ppb_data *);
169 static int			lpattach(struct ppb_device *);
170 
171 static int lpinittables(void);
172 static int lpioctl(struct ifnet *, u_long, caddr_t);
173 static int lpoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
174 	struct rtentry *);
175 static void lpintr(int);
176 
177 /*
178  * Make ourselves visible as a ppbus driver
179  */
180 
181 static struct ppb_driver lpdriver = {
182     lpprobe, lpattach, "lp"
183 };
184 DATA_SET(ppbdriver_set, lpdriver);
185 
186 
187 /*
188  * lpprobe()
189  */
190 static struct ppb_device *
191 lpprobe(struct ppb_data *ppb)
192 {
193 	struct lpt_softc *lp;
194 
195 	/* if we haven't interrupts, the probe fails */
196 	if (!ppb->ppb_link->id_irq)
197 		return (0);
198 
199 	lp = (struct lpt_softc *) malloc(sizeof(struct lpt_softc),
200 							M_TEMP, M_NOWAIT);
201 	if (!lp) {
202 		printf("lp: cannot malloc!\n");
203 		return (0);
204 	}
205 	bzero(lp, sizeof(struct lpt_softc));
206 
207 	lpdata[nlp] = lp;
208 
209 	/*
210 	 * lp dependent initialisation.
211 	 */
212 	lp->lp_unit = nlp;
213 
214 	if (bootverbose)
215 		printf("plip: irq %d\n", ppb->ppb_link->id_irq);
216 
217 	/*
218 	 * ppbus dependent initialisation.
219 	 */
220 	lp->lp_dev.id_unit = lp->lp_unit;
221 	lp->lp_dev.name = lpdriver.name;
222 	lp->lp_dev.ppb = ppb;
223 	lp->lp_dev.intr = lpintr;
224 
225 	/* Ok, go to next device on next probe */
226 	nlp ++;
227 
228 	return (&lp->lp_dev);
229 }
230 
231 static int
232 lpattach (struct ppb_device *dev)
233 {
234 	int unit = dev->id_unit;
235 	struct lpt_softc *sc = lpdata[unit];
236 	struct ifnet *ifp = &sc->sc_if;
237 
238 	/*
239 	 * Report ourselves
240 	 */
241 	printf("plip%d: <PLIP network interface> on ppbus %d\n",
242 	       dev->id_unit, dev->ppb->ppb_link->adapter_unit);
243 
244 	ifp->if_softc = sc;
245 	ifp->if_name = "lp";
246 	ifp->if_unit = unit;
247 	ifp->if_mtu = LPMTU;
248 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
249 	ifp->if_ioctl = lpioctl;
250 	ifp->if_output = lpoutput;
251 	ifp->if_type = IFT_PARA;
252 	ifp->if_hdrlen = 0;
253 	ifp->if_addrlen = 0;
254 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
255 	if_attach(ifp);
256 
257 #if NBPFILTER > 0
258 	bpfattach(ifp, DLT_NULL, LPIPHDRLEN);
259 #endif
260 
261 	return (1);
262 }
263 /*
264  * Build the translation tables for the LPIP (BSD unix) protocol.
265  * We don't want to calculate these nasties in our tight loop, so we
266  * precalculate them when we initialize.
267  */
268 static int
269 lpinittables (void)
270 {
271     int i;
272 
273     if (!txmith)
274 	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
275 
276     if (!txmith)
277 	return 1;
278 
279     if (!ctxmith)
280 	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
281 
282     if (!ctxmith)
283 	return 1;
284 
285     for (i=0; i < LPIPTBLSIZE; i++) {
286 	ctxmith[i] = (i & 0xF0) >> 4;
287 	ctxmitl[i] = 0x10 | (i & 0x0F);
288 	ctrecvh[i] = (i & 0x78) << 1;
289 	ctrecvl[i] = (i & 0x78) >> 3;
290     }
291 
292     for (i=0; i < LPIPTBLSIZE; i++) {
293 	txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
294 	txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
295 	trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
296 	trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
297     }
298 
299     return 0;
300 }
301 
302 /*
303  * Process an ioctl request.
304  */
305 
306 static int
307 lpioctl (struct ifnet *ifp, u_long cmd, caddr_t data)
308 {
309     struct lpt_softc *sc = lpdata[ifp->if_unit];
310     struct ifaddr *ifa = (struct ifaddr *)data;
311     struct ifreq *ifr = (struct ifreq *)data;
312     u_char *ptr;
313     int error;
314 
315     switch (cmd) {
316 
317     case SIOCSIFDSTADDR:
318     case SIOCAIFADDR:
319     case SIOCSIFADDR:
320 	if (ifa->ifa_addr->sa_family != AF_INET)
321 	    return EAFNOSUPPORT;
322 
323 	ifp->if_flags |= IFF_UP;
324 	/* FALLTHROUGH */
325     case SIOCSIFFLAGS:
326 	if ((!(ifp->if_flags & IFF_UP)) && (ifp->if_flags & IFF_RUNNING)) {
327 
328 	    ppb_wctr(&sc->lp_dev, 0x00);
329 	    ifp->if_flags &= ~IFF_RUNNING;
330 
331 	    /* IFF_UP is not set, try to release the bus anyway */
332 	    ppb_release_bus(&sc->lp_dev);
333 	    break;
334 	}
335 	if (((ifp->if_flags & IFF_UP)) && (!(ifp->if_flags & IFF_RUNNING))) {
336 
337 	    /*
338 	     * Try to allocate the ppbus as soon as possible
339 	     * With ppbus allocation, interrupts are enabled
340 	     * Now IFF_UP means that we own the bus
341 	     *
342 	     * XXX
343 	     * Should the request be interruptible?
344 	     */
345 	    if ((error = ppb_request_bus(&sc->lp_dev, PPB_WAIT|PPB_INTR)))
346 		return (error);
347 
348 	    if (lpinittables()) {
349 		ppb_release_bus(&sc->lp_dev);
350 		return ENOBUFS;
351 	    }
352 
353 	    sc->sc_ifbuf = malloc(sc->sc_if.if_mtu + MLPIPHDRLEN,
354 				  M_DEVBUF, M_WAITOK);
355 	    if (!sc->sc_ifbuf) {
356 		ppb_release_bus(&sc->lp_dev);
357 		return ENOBUFS;
358 	    }
359 
360 	    ppb_wctr(&sc->lp_dev, LPC_ENA);
361 	    ifp->if_flags |= IFF_RUNNING;
362 	}
363 	break;
364 
365     case SIOCSIFMTU:
366 	ptr = sc->sc_ifbuf;
367 	sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
368 	if (!sc->sc_ifbuf) {
369 	    sc->sc_ifbuf = ptr;
370 	    return ENOBUFS;
371 	}
372 	if (ptr)
373 	    free(ptr,M_DEVBUF);
374 	sc->sc_if.if_mtu = ifr->ifr_mtu;
375 	break;
376 
377     case SIOCGIFMTU:
378 	ifr->ifr_mtu = sc->sc_if.if_mtu;
379 	break;
380 
381     case SIOCADDMULTI:
382     case SIOCDELMULTI:
383 	if (ifr == 0) {
384 	    return EAFNOSUPPORT;		/* XXX */
385 	}
386 	switch (ifr->ifr_addr.sa_family) {
387 
388 	case AF_INET:
389 	    break;
390 
391 	default:
392 	    return EAFNOSUPPORT;
393 	}
394 	break;
395 
396     case SIOCGIFMEDIA:
397 	/*
398 	 * No ifmedia support at this stage; maybe use it
399 	 * in future for eg. protocol selection.
400 	 */
401 	return EINVAL;
402 
403     default:
404 	lprintf("LP:ioctl(0x%lx)\n", cmd);
405 	return EINVAL;
406     }
407     return 0;
408 }
409 
410 static __inline int
411 clpoutbyte (u_char byte, int spin, struct ppb_device *dev)
412 {
413 	ppb_wdtr(dev, ctxmitl[byte]);
414 	while (ppb_rstr(dev) & CLPIP_SHAKE)
415 		if (--spin == 0) {
416 			return 1;
417 		}
418 	ppb_wdtr(dev, ctxmith[byte]);
419 	while (!(ppb_rstr(dev) & CLPIP_SHAKE))
420 		if (--spin == 0) {
421 			return 1;
422 		}
423 	return 0;
424 }
425 
426 static __inline int
427 clpinbyte (int spin, struct ppb_device *dev)
428 {
429 	int c, cl;
430 
431 	while((ppb_rstr(dev) & CLPIP_SHAKE))
432 	    if(!--spin) {
433 		return -1;
434 	    }
435 	cl = ppb_rstr(dev);
436 	ppb_wdtr(dev, 0x10);
437 
438 	while(!(ppb_rstr(dev) & CLPIP_SHAKE))
439 	    if(!--spin) {
440 		return -1;
441 	    }
442 	c = ppb_rstr(dev);
443 	ppb_wdtr(dev, 0x00);
444 
445 	return (ctrecvl[cl] | ctrecvh[c]);
446 }
447 
448 static void
449 lpintr (int unit)
450 {
451 	struct   lpt_softc *sc = lpdata[unit];
452 	int len, s, j;
453 	u_char *bp;
454 	u_char c, cl;
455 	struct mbuf *top;
456 
457 	s = splhigh();
458 
459 	if (sc->sc_if.if_flags & IFF_LINK0) {
460 
461 	    /* Ack. the request */
462 	    ppb_wdtr(&sc->lp_dev, 0x01);
463 
464 	    /* Get the packet length */
465 	    j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
466 	    if (j == -1)
467 		goto err;
468 	    len = j;
469 	    j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
470 	    if (j == -1)
471 		goto err;
472 	    len = len + (j << 8);
473 	    if (len > sc->sc_if.if_mtu + MLPIPHDRLEN)
474 		goto err;
475 
476 	    bp  = sc->sc_ifbuf;
477 
478 	    while (len--) {
479 	        j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
480 	        if (j == -1) {
481 		    goto err;
482 	        }
483 	        *bp++ = j;
484 	    }
485 	    /* Get and ignore checksum */
486 	    j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
487 	    if (j == -1) {
488 	        goto err;
489 	    }
490 
491 	    len = bp - sc->sc_ifbuf;
492 	    if (len <= CLPIPHDRLEN)
493 	        goto err;
494 
495 	    sc->sc_iferrs = 0;
496 
497 	    if (IF_QFULL(&ipintrq)) {
498 	        lprintf("DROP");
499 	        IF_DROP(&ipintrq);
500 		goto done;
501 	    }
502 	    len -= CLPIPHDRLEN;
503 	    sc->sc_if.if_ipackets++;
504 	    sc->sc_if.if_ibytes += len;
505 	    top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, &sc->sc_if, 0);
506 	    if (top) {
507 	        IF_ENQUEUE(&ipintrq, top);
508 	        schednetisr(NETISR_IP);
509 	    }
510 	    goto done;
511 	}
512 	while ((ppb_rstr(&sc->lp_dev) & LPIP_SHAKE)) {
513 	    len = sc->sc_if.if_mtu + LPIPHDRLEN;
514 	    bp  = sc->sc_ifbuf;
515 	    while (len--) {
516 
517 		cl = ppb_rstr(&sc->lp_dev);
518 		ppb_wdtr(&sc->lp_dev, 8);
519 
520 		j = LPMAXSPIN2;
521 		while((ppb_rstr(&sc->lp_dev) & LPIP_SHAKE))
522 		    if(!--j) goto err;
523 
524 		c = ppb_rstr(&sc->lp_dev);
525 		ppb_wdtr(&sc->lp_dev, 0);
526 
527 		*bp++= trecvh[cl] | trecvl[c];
528 
529 		j = LPMAXSPIN2;
530 		while (!((cl=ppb_rstr(&sc->lp_dev)) & LPIP_SHAKE)) {
531 		    if (cl != c &&
532 			(((cl = ppb_rstr(&sc->lp_dev)) ^ 0xb8) & 0xf8) ==
533 			  (c & 0xf8))
534 			goto end;
535 		    if (!--j) goto err;
536 		}
537 	    }
538 
539 	end:
540 	    len = bp - sc->sc_ifbuf;
541 	    if (len <= LPIPHDRLEN)
542 		goto err;
543 
544 	    sc->sc_iferrs = 0;
545 
546 	    if (IF_QFULL(&ipintrq)) {
547 		lprintf("DROP");
548 		IF_DROP(&ipintrq);
549 		goto done;
550 	    }
551 #if NBPFILTER > 0
552 	    if (sc->sc_if.if_bpf) {
553 		bpf_tap(&sc->sc_if, sc->sc_ifbuf, len);
554 	    }
555 #endif
556 	    len -= LPIPHDRLEN;
557 	    sc->sc_if.if_ipackets++;
558 	    sc->sc_if.if_ibytes += len;
559 	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
560 	    if (top) {
561 		    IF_ENQUEUE(&ipintrq, top);
562 		    schednetisr(NETISR_IP);
563 	    }
564 	}
565 	goto done;
566 
567     err:
568 	ppb_wdtr(&sc->lp_dev, 0);
569 	lprintf("R");
570 	sc->sc_if.if_ierrors++;
571 	sc->sc_iferrs++;
572 
573 	/*
574 	 * We are not able to send receive anything for now,
575 	 * so stop wasting our time
576 	 */
577 	if (sc->sc_iferrs > LPMAXERRS) {
578 	    printf("lp%d: Too many errors, Going off-line.\n", unit);
579 	    ppb_wctr(&sc->lp_dev, 0x00);
580 	    sc->sc_if.if_flags &= ~IFF_RUNNING;
581 	    sc->sc_iferrs=0;
582 	}
583 
584     done:
585 	splx(s);
586 	return;
587 }
588 
589 static __inline int
590 lpoutbyte (u_char byte, int spin, struct ppb_device *dev)
591 {
592     ppb_wdtr(dev, txmith[byte]);
593     while (!(ppb_rstr(dev) & LPIP_SHAKE))
594 	if (--spin == 0)
595 		return 1;
596     ppb_wdtr(dev, txmitl[byte]);
597     while (ppb_rstr(dev) & LPIP_SHAKE)
598 	if (--spin == 0)
599 		return 1;
600     return 0;
601 }
602 
603 static int
604 lpoutput (struct ifnet *ifp, struct mbuf *m,
605 	  struct sockaddr *dst, struct rtentry *rt)
606 {
607     struct lpt_softc *sc = lpdata[ifp->if_unit];
608     int s, err;
609     struct mbuf *mm;
610     u_char *cp = "\0\0";
611     u_char chksum = 0;
612     int count = 0;
613     int i;
614     int spin;
615 
616     /* We need a sensible value if we abort */
617     cp++;
618     ifp->if_flags |= IFF_RUNNING;
619 
620     err = 1;			/* assume we're aborting because of an error */
621 
622     s = splhigh();
623 
624     /* Suspend (on laptops) or receive-errors might have taken us offline */
625     ppb_wctr(&sc->lp_dev, LPC_ENA);
626 
627     if (ifp->if_flags & IFF_LINK0) {
628 
629 	if (!(ppb_rstr(&sc->lp_dev) & CLPIP_SHAKE)) {
630 	    lprintf("&");
631 	    lpintr(ifp->if_unit);
632 	}
633 
634 	/* Alert other end to pending packet */
635 	spin = LPMAXSPIN1;
636 	ppb_wdtr(&sc->lp_dev, 0x08);
637 	while ((ppb_rstr(&sc->lp_dev) & 0x08) == 0)
638 		if (--spin == 0) {
639 			goto nend;
640 		}
641 
642 	/* Calculate length of packet, then send that */
643 
644 	count += 14;		/* Ethernet header len */
645 
646 	mm = m;
647 	for (mm = m; mm; mm = mm->m_next) {
648 		count += mm->m_len;
649 	}
650 	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, &sc->lp_dev))
651 		goto nend;
652 	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, &sc->lp_dev))
653 		goto nend;
654 
655 	/* Send dummy ethernet header */
656 	for (i = 0; i < 12; i++) {
657 		if (clpoutbyte(i, LPMAXSPIN1, &sc->lp_dev))
658 			goto nend;
659 		chksum += i;
660 	}
661 
662 	if (clpoutbyte(0x08, LPMAXSPIN1, &sc->lp_dev))
663 		goto nend;
664 	if (clpoutbyte(0x00, LPMAXSPIN1, &sc->lp_dev))
665 		goto nend;
666 	chksum += 0x08 + 0x00;		/* Add into checksum */
667 
668 	mm = m;
669 	do {
670 		cp = mtod(mm, u_char *);
671 		while (mm->m_len--) {
672 			chksum += *cp;
673 			if (clpoutbyte(*cp++, LPMAXSPIN2, &sc->lp_dev))
674 				goto nend;
675 		}
676 	} while ((mm = mm->m_next));
677 
678 	/* Send checksum */
679 	if (clpoutbyte(chksum, LPMAXSPIN2, &sc->lp_dev))
680 		goto nend;
681 
682 	/* Go quiescent */
683 	ppb_wdtr(&sc->lp_dev, 0);
684 
685 	err = 0;			/* No errors */
686 
687 	nend:
688 	if (err)  {				/* if we didn't timeout... */
689 		ifp->if_oerrors++;
690 		lprintf("X");
691 	} else {
692 		ifp->if_opackets++;
693 		ifp->if_obytes += m->m_pkthdr.len;
694 	}
695 
696 	m_freem(m);
697 
698 	if (!(ppb_rstr(&sc->lp_dev) & CLPIP_SHAKE)) {
699 		lprintf("^");
700 		lpintr(ifp->if_unit);
701 	}
702 	(void) splx(s);
703 	return 0;
704     }
705 
706     if (ppb_rstr(&sc->lp_dev) & LPIP_SHAKE) {
707         lprintf("&");
708         lpintr(ifp->if_unit);
709     }
710 
711     if (lpoutbyte(0x08, LPMAXSPIN1, &sc->lp_dev))
712         goto end;
713     if (lpoutbyte(0x00, LPMAXSPIN2, &sc->lp_dev))
714         goto end;
715 
716     mm = m;
717     do {
718         cp = mtod(mm,u_char *);
719         while (mm->m_len--)
720 	    if (lpoutbyte(*cp++, LPMAXSPIN2, &sc->lp_dev))
721 	        goto end;
722     } while ((mm = mm->m_next));
723 
724     err = 0;				/* no errors were encountered */
725 
726     end:
727     --cp;
728     ppb_wdtr(&sc->lp_dev, txmitl[*cp] ^ 0x17);
729 
730     if (err)  {				/* if we didn't timeout... */
731 	ifp->if_oerrors++;
732         lprintf("X");
733     } else {
734 	ifp->if_opackets++;
735 	ifp->if_obytes += m->m_pkthdr.len;
736 #if NBPFILTER > 0
737 	if (ifp->if_bpf) {
738 	    /*
739 	     * We need to prepend the packet type as
740 	     * a two byte field.  Cons up a dummy header
741 	     * to pacify bpf.  This is safe because bpf
742 	     * will only read from the mbuf (i.e., it won't
743 	     * try to free it or keep a pointer to it).
744 	     */
745 	    struct mbuf m0;
746 	    u_short hdr = 0x800;
747 
748 	    m0.m_next = m;
749 	    m0.m_len = 2;
750 	    m0.m_data = (char *)&hdr;
751 
752 	    bpf_mtap(ifp, &m0);
753 	}
754 #endif
755     }
756 
757     m_freem(m);
758 
759     if (ppb_rstr(&sc->lp_dev) & LPIP_SHAKE) {
760 	lprintf("^");
761 	lpintr(ifp->if_unit);
762     }
763 
764     (void) splx(s);
765     return 0;
766 }
767