xref: /freebsd/sys/dev/ppbus/if_plip.c (revision 6e8394b8baa7d5d9153ab90de6824bcd19b3b4e1)
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 1.11 1999/02/14 11:59:59 nsouch 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 
103 #include "opt_plip.h"
104 
105 #ifndef LPMTU			/* MTU for the lp# interfaces */
106 #define	LPMTU	1500
107 #endif
108 
109 #ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
110 #define	LPMAXSPIN1	8000   /* Spinning for remote intr to happen */
111 #endif
112 
113 #ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
114 #define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
115 #endif
116 
117 #ifndef LPMAXERRS		/* Max errors before !RUNNING */
118 #define	LPMAXERRS	100
119 #endif
120 
121 #define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
122 #define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
123 #define MLPIPHDRLEN	CLPIPHDRLEN
124 
125 #define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
126 #define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
127 #if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
128 #define MLPIPHDRLEN	LPIPHDRLEN
129 #endif
130 
131 #define	LPIPTBLSIZE	256	/* Size of octet translation table */
132 
133 #define lprintf		if (lptflag) printf
134 
135 #ifdef PLIP_DEBUG
136 static int volatile lptflag = 1;
137 #else
138 static int volatile lptflag = 0;
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 		printf("plip: not an interrupt driven port, failed.\n");
198 		return (0);
199 	}
200 
201 	lp = (struct lpt_softc *) malloc(sizeof(struct lpt_softc),
202 							M_TEMP, M_NOWAIT);
203 	if (!lp) {
204 		printf("lp: cannot malloc!\n");
205 		return (0);
206 	}
207 	bzero(lp, sizeof(struct lpt_softc));
208 
209 	lpdata[nlp] = lp;
210 
211 	/*
212 	 * lp dependent initialisation.
213 	 */
214 	lp->lp_unit = nlp;
215 
216 	if (bootverbose)
217 		printf("plip: irq %d\n", ppb->ppb_link->id_irq);
218 
219 	/*
220 	 * ppbus dependent initialisation.
221 	 */
222 	lp->lp_dev.id_unit = lp->lp_unit;
223 	lp->lp_dev.name = lpdriver.name;
224 	lp->lp_dev.ppb = ppb;
225 	lp->lp_dev.intr = lpintr;
226 
227 	/* Ok, go to next device on next probe */
228 	nlp ++;
229 
230 	return (&lp->lp_dev);
231 }
232 
233 static int
234 lpattach (struct ppb_device *dev)
235 {
236 	int unit = dev->id_unit;
237 	struct lpt_softc *sc = lpdata[unit];
238 	struct ifnet *ifp = &sc->sc_if;
239 
240 	/*
241 	 * Report ourselves
242 	 */
243 	printf("plip%d: <PLIP network interface> on ppbus %d\n",
244 	       dev->id_unit, dev->ppb->ppb_link->adapter_unit);
245 
246 	ifp->if_softc = sc;
247 	ifp->if_name = "lp";
248 	ifp->if_unit = unit;
249 	ifp->if_mtu = LPMTU;
250 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
251 	ifp->if_ioctl = lpioctl;
252 	ifp->if_output = lpoutput;
253 	ifp->if_type = IFT_PARA;
254 	ifp->if_hdrlen = 0;
255 	ifp->if_addrlen = 0;
256 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
257 	if_attach(ifp);
258 
259 #if NBPFILTER > 0
260 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
261 #endif
262 
263 	return (1);
264 }
265 /*
266  * Build the translation tables for the LPIP (BSD unix) protocol.
267  * We don't want to calculate these nasties in our tight loop, so we
268  * precalculate them when we initialize.
269  */
270 static int
271 lpinittables (void)
272 {
273     int i;
274 
275     if (!txmith)
276 	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
277 
278     if (!txmith)
279 	return 1;
280 
281     if (!ctxmith)
282 	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
283 
284     if (!ctxmith)
285 	return 1;
286 
287     for (i=0; i < LPIPTBLSIZE; i++) {
288 	ctxmith[i] = (i & 0xF0) >> 4;
289 	ctxmitl[i] = 0x10 | (i & 0x0F);
290 	ctrecvh[i] = (i & 0x78) << 1;
291 	ctrecvl[i] = (i & 0x78) >> 3;
292     }
293 
294     for (i=0; i < LPIPTBLSIZE; i++) {
295 	txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
296 	txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
297 	trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
298 	trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
299     }
300 
301     return 0;
302 }
303 
304 /*
305  * Process an ioctl request.
306  */
307 
308 static int
309 lpioctl (struct ifnet *ifp, u_long cmd, caddr_t data)
310 {
311     struct lpt_softc *sc = lpdata[ifp->if_unit];
312     struct ifaddr *ifa = (struct ifaddr *)data;
313     struct ifreq *ifr = (struct ifreq *)data;
314     u_char *ptr;
315     int error;
316 
317     switch (cmd) {
318 
319     case SIOCSIFDSTADDR:
320     case SIOCAIFADDR:
321     case SIOCSIFADDR:
322 	if (ifa->ifa_addr->sa_family != AF_INET)
323 	    return EAFNOSUPPORT;
324 
325 	ifp->if_flags |= IFF_UP;
326 	/* FALLTHROUGH */
327     case SIOCSIFFLAGS:
328 	if ((!(ifp->if_flags & IFF_UP)) && (ifp->if_flags & IFF_RUNNING)) {
329 
330 	    ppb_wctr(&sc->lp_dev, 0x00);
331 	    ifp->if_flags &= ~IFF_RUNNING;
332 
333 	    /* IFF_UP is not set, try to release the bus anyway */
334 	    ppb_release_bus(&sc->lp_dev);
335 	    break;
336 	}
337 	if (((ifp->if_flags & IFF_UP)) && (!(ifp->if_flags & IFF_RUNNING))) {
338 
339 	    /* XXX
340 	     * Should the request be interruptible?
341 	     */
342 	    if ((error = ppb_request_bus(&sc->lp_dev, PPB_WAIT|PPB_INTR)))
343 		return (error);
344 
345 	    /* Now IFF_UP means that we own the bus */
346 
347 	    ppb_set_mode(&sc->lp_dev, PPB_COMPATIBLE);
348 
349 	    if (lpinittables()) {
350 		ppb_release_bus(&sc->lp_dev);
351 		return ENOBUFS;
352 	    }
353 
354 	    sc->sc_ifbuf = malloc(sc->sc_if.if_mtu + MLPIPHDRLEN,
355 				  M_DEVBUF, M_WAITOK);
356 	    if (!sc->sc_ifbuf) {
357 		ppb_release_bus(&sc->lp_dev);
358 		return ENOBUFS;
359 	    }
360 
361 	    ppb_wctr(&sc->lp_dev, IRQENABLE);
362 	    ifp->if_flags |= IFF_RUNNING;
363 	}
364 	break;
365 
366     case SIOCSIFMTU:
367 	ptr = sc->sc_ifbuf;
368 	sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
369 	if (!sc->sc_ifbuf) {
370 	    sc->sc_ifbuf = ptr;
371 	    return ENOBUFS;
372 	}
373 	if (ptr)
374 	    free(ptr,M_DEVBUF);
375 	sc->sc_if.if_mtu = ifr->ifr_mtu;
376 	break;
377 
378     case SIOCGIFMTU:
379 	ifr->ifr_mtu = sc->sc_if.if_mtu;
380 	break;
381 
382     case SIOCADDMULTI:
383     case SIOCDELMULTI:
384 	if (ifr == 0) {
385 	    return EAFNOSUPPORT;		/* XXX */
386 	}
387 	switch (ifr->ifr_addr.sa_family) {
388 
389 	case AF_INET:
390 	    break;
391 
392 	default:
393 	    return EAFNOSUPPORT;
394 	}
395 	break;
396 
397     case SIOCGIFMEDIA:
398 	/*
399 	 * No ifmedia support at this stage; maybe use it
400 	 * in future for eg. protocol selection.
401 	 */
402 	return EINVAL;
403 
404     default:
405 	lprintf("LP:ioctl(0x%lx)\n", cmd);
406 	return EINVAL;
407     }
408     return 0;
409 }
410 
411 static __inline int
412 clpoutbyte (u_char byte, int spin, struct ppb_device *dev)
413 {
414 	ppb_wdtr(dev, ctxmitl[byte]);
415 	while (ppb_rstr(dev) & CLPIP_SHAKE)
416 		if (--spin == 0) {
417 			return 1;
418 		}
419 	ppb_wdtr(dev, ctxmith[byte]);
420 	while (!(ppb_rstr(dev) & CLPIP_SHAKE))
421 		if (--spin == 0) {
422 			return 1;
423 		}
424 	return 0;
425 }
426 
427 static __inline int
428 clpinbyte (int spin, struct ppb_device *dev)
429 {
430 	u_char c, cl;
431 
432 	while((ppb_rstr(dev) & CLPIP_SHAKE))
433 	    if(!--spin) {
434 		return -1;
435 	    }
436 	cl = ppb_rstr(dev);
437 	ppb_wdtr(dev, 0x10);
438 
439 	while(!(ppb_rstr(dev) & CLPIP_SHAKE))
440 	    if(!--spin) {
441 		return -1;
442 	    }
443 	c = ppb_rstr(dev);
444 	ppb_wdtr(dev, 0x00);
445 
446 	return (ctrecvl[cl] | ctrecvh[c]);
447 }
448 
449 #if NBPFILTER > 0
450 static void
451 lptap(struct ifnet *ifp, struct mbuf *m)
452 {
453 	/*
454 	 * Send a packet through bpf. We need to prepend the address family
455 	 * as a four byte field. Cons up a dummy header to pacify bpf. This
456 	 * is safe because bpf will only read from the mbuf (i.e., it won't
457 	 * try to free it or keep a pointer to it).
458 	 */
459 	u_int32_t af = AF_INET;
460 	struct mbuf m0;
461 
462 	m0.m_next = m;
463 	m0.m_len = sizeof(u_int32_t);
464 	m0.m_data = (char *)&af;
465 	bpf_mtap(ifp, &m0);
466 }
467 #endif
468 
469 static void
470 lpintr (int unit)
471 {
472 	struct   lpt_softc *sc = lpdata[unit];
473 	int len, s, j;
474 	u_char *bp;
475 	u_char c, cl;
476 	struct mbuf *top;
477 
478 	s = splhigh();
479 
480 	if (sc->sc_if.if_flags & IFF_LINK0) {
481 
482 	    /* Ack. the request */
483 	    ppb_wdtr(&sc->lp_dev, 0x01);
484 
485 	    /* Get the packet length */
486 	    j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
487 	    if (j == -1)
488 		goto err;
489 	    len = j;
490 	    j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
491 	    if (j == -1)
492 		goto err;
493 	    len = len + (j << 8);
494 	    if (len > sc->sc_if.if_mtu + MLPIPHDRLEN)
495 		goto err;
496 
497 	    bp  = sc->sc_ifbuf;
498 
499 	    while (len--) {
500 	        j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
501 	        if (j == -1) {
502 		    goto err;
503 	        }
504 	        *bp++ = j;
505 	    }
506 	    /* Get and ignore checksum */
507 	    j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
508 	    if (j == -1) {
509 	        goto err;
510 	    }
511 
512 	    len = bp - sc->sc_ifbuf;
513 	    if (len <= CLPIPHDRLEN)
514 	        goto err;
515 
516 	    sc->sc_iferrs = 0;
517 
518 	    if (IF_QFULL(&ipintrq)) {
519 	        lprintf("DROP");
520 	        IF_DROP(&ipintrq);
521 		goto done;
522 	    }
523 	    len -= CLPIPHDRLEN;
524 	    sc->sc_if.if_ipackets++;
525 	    sc->sc_if.if_ibytes += len;
526 	    top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, &sc->sc_if, 0);
527 	    if (top) {
528 #if NBPFILTER > 0
529 		if (sc->sc_if.if_bpf)
530 		    lptap(&sc->sc_if, top);
531 #endif
532 	        IF_ENQUEUE(&ipintrq, top);
533 	        schednetisr(NETISR_IP);
534 	    }
535 	    goto done;
536 	}
537 	while ((ppb_rstr(&sc->lp_dev) & LPIP_SHAKE)) {
538 	    len = sc->sc_if.if_mtu + LPIPHDRLEN;
539 	    bp  = sc->sc_ifbuf;
540 	    while (len--) {
541 
542 		cl = ppb_rstr(&sc->lp_dev);
543 		ppb_wdtr(&sc->lp_dev, 8);
544 
545 		j = LPMAXSPIN2;
546 		while((ppb_rstr(&sc->lp_dev) & LPIP_SHAKE))
547 		    if(!--j) goto err;
548 
549 		c = ppb_rstr(&sc->lp_dev);
550 		ppb_wdtr(&sc->lp_dev, 0);
551 
552 		*bp++= trecvh[cl] | trecvl[c];
553 
554 		j = LPMAXSPIN2;
555 		while (!((cl=ppb_rstr(&sc->lp_dev)) & LPIP_SHAKE)) {
556 		    if (cl != c &&
557 			(((cl = ppb_rstr(&sc->lp_dev)) ^ 0xb8) & 0xf8) ==
558 			  (c & 0xf8))
559 			goto end;
560 		    if (!--j) goto err;
561 		}
562 	    }
563 
564 	end:
565 	    len = bp - sc->sc_ifbuf;
566 	    if (len <= LPIPHDRLEN)
567 		goto err;
568 
569 	    sc->sc_iferrs = 0;
570 
571 	    if (IF_QFULL(&ipintrq)) {
572 		lprintf("DROP");
573 		IF_DROP(&ipintrq);
574 		goto done;
575 	    }
576 	    len -= LPIPHDRLEN;
577 	    sc->sc_if.if_ipackets++;
578 	    sc->sc_if.if_ibytes += len;
579 	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
580 	    if (top) {
581 #if NBPFILTER > 0
582 		if (sc->sc_if.if_bpf)
583 		    lptap(&sc->sc_if, top);
584 #endif
585 		IF_ENQUEUE(&ipintrq, top);
586 		schednetisr(NETISR_IP);
587 	    }
588 	}
589 	goto done;
590 
591     err:
592 	ppb_wdtr(&sc->lp_dev, 0);
593 	lprintf("R");
594 	sc->sc_if.if_ierrors++;
595 	sc->sc_iferrs++;
596 
597 	/*
598 	 * We are not able to send receive anything for now,
599 	 * so stop wasting our time
600 	 */
601 	if (sc->sc_iferrs > LPMAXERRS) {
602 	    printf("lp%d: Too many errors, Going off-line.\n", unit);
603 	    ppb_wctr(&sc->lp_dev, 0x00);
604 	    sc->sc_if.if_flags &= ~IFF_RUNNING;
605 	    sc->sc_iferrs=0;
606 	}
607 
608     done:
609 	splx(s);
610 	return;
611 }
612 
613 static __inline int
614 lpoutbyte (u_char byte, int spin, struct ppb_device *dev)
615 {
616     ppb_wdtr(dev, txmith[byte]);
617     while (!(ppb_rstr(dev) & LPIP_SHAKE))
618 	if (--spin == 0)
619 		return 1;
620     ppb_wdtr(dev, txmitl[byte]);
621     while (ppb_rstr(dev) & LPIP_SHAKE)
622 	if (--spin == 0)
623 		return 1;
624     return 0;
625 }
626 
627 static int
628 lpoutput (struct ifnet *ifp, struct mbuf *m,
629 	  struct sockaddr *dst, struct rtentry *rt)
630 {
631     struct lpt_softc *sc = lpdata[ifp->if_unit];
632     int s, err;
633     struct mbuf *mm;
634     u_char *cp = "\0\0";
635     u_char chksum = 0;
636     int count = 0;
637     int i, len, spin;
638 
639     /* We need a sensible value if we abort */
640     cp++;
641     ifp->if_flags |= IFF_RUNNING;
642 
643     err = 1;			/* assume we're aborting because of an error */
644 
645     s = splhigh();
646 
647     /* Suspend (on laptops) or receive-errors might have taken us offline */
648     ppb_wctr(&sc->lp_dev, IRQENABLE);
649 
650     if (ifp->if_flags & IFF_LINK0) {
651 
652 	if (!(ppb_rstr(&sc->lp_dev) & CLPIP_SHAKE)) {
653 	    lprintf("&");
654 	    lpintr(ifp->if_unit);
655 	}
656 
657 	/* Alert other end to pending packet */
658 	spin = LPMAXSPIN1;
659 	ppb_wdtr(&sc->lp_dev, 0x08);
660 	while ((ppb_rstr(&sc->lp_dev) & 0x08) == 0)
661 		if (--spin == 0) {
662 			goto nend;
663 		}
664 
665 	/* Calculate length of packet, then send that */
666 
667 	count += 14;		/* Ethernet header len */
668 
669 	mm = m;
670 	for (mm = m; mm; mm = mm->m_next) {
671 		count += mm->m_len;
672 	}
673 	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, &sc->lp_dev))
674 		goto nend;
675 	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, &sc->lp_dev))
676 		goto nend;
677 
678 	/* Send dummy ethernet header */
679 	for (i = 0; i < 12; i++) {
680 		if (clpoutbyte(i, LPMAXSPIN1, &sc->lp_dev))
681 			goto nend;
682 		chksum += i;
683 	}
684 
685 	if (clpoutbyte(0x08, LPMAXSPIN1, &sc->lp_dev))
686 		goto nend;
687 	if (clpoutbyte(0x00, LPMAXSPIN1, &sc->lp_dev))
688 		goto nend;
689 	chksum += 0x08 + 0x00;		/* Add into checksum */
690 
691 	mm = m;
692 	do {
693 		cp = mtod(mm, u_char *);
694 		len = mm->m_len;
695 		while (len--) {
696 			chksum += *cp;
697 			if (clpoutbyte(*cp++, LPMAXSPIN2, &sc->lp_dev))
698 				goto nend;
699 		}
700 	} while ((mm = mm->m_next));
701 
702 	/* Send checksum */
703 	if (clpoutbyte(chksum, LPMAXSPIN2, &sc->lp_dev))
704 		goto nend;
705 
706 	/* Go quiescent */
707 	ppb_wdtr(&sc->lp_dev, 0);
708 
709 	err = 0;			/* No errors */
710 
711 	nend:
712 	if (err)  {				/* if we didn't timeout... */
713 		ifp->if_oerrors++;
714 		lprintf("X");
715 	} else {
716 		ifp->if_opackets++;
717 		ifp->if_obytes += m->m_pkthdr.len;
718 #if NBPFILTER > 0
719 		if (ifp->if_bpf)
720 		    lptap(ifp, m);
721 #endif
722 	}
723 
724 	m_freem(m);
725 
726 	if (!(ppb_rstr(&sc->lp_dev) & CLPIP_SHAKE)) {
727 		lprintf("^");
728 		lpintr(ifp->if_unit);
729 	}
730 	(void) splx(s);
731 	return 0;
732     }
733 
734     if (ppb_rstr(&sc->lp_dev) & LPIP_SHAKE) {
735         lprintf("&");
736         lpintr(ifp->if_unit);
737     }
738 
739     if (lpoutbyte(0x08, LPMAXSPIN1, &sc->lp_dev))
740         goto end;
741     if (lpoutbyte(0x00, LPMAXSPIN2, &sc->lp_dev))
742         goto end;
743 
744     mm = m;
745     do {
746         cp = mtod(mm,u_char *);
747 	len = mm->m_len;
748         while (len--)
749 	    if (lpoutbyte(*cp++, LPMAXSPIN2, &sc->lp_dev))
750 	        goto end;
751     } while ((mm = mm->m_next));
752 
753     err = 0;				/* no errors were encountered */
754 
755     end:
756     --cp;
757     ppb_wdtr(&sc->lp_dev, txmitl[*cp] ^ 0x17);
758 
759     if (err)  {				/* if we didn't timeout... */
760 	ifp->if_oerrors++;
761         lprintf("X");
762     } else {
763 	ifp->if_opackets++;
764 	ifp->if_obytes += m->m_pkthdr.len;
765 #if NBPFILTER > 0
766 	if (ifp->if_bpf)
767 	    lptap(ifp, m);
768 #endif
769     }
770 
771     m_freem(m);
772 
773     if (ppb_rstr(&sc->lp_dev) & LPIP_SHAKE) {
774 	lprintf("^");
775 	lpintr(ifp->if_unit);
776     }
777 
778     (void) splx(s);
779     return 0;
780 }
781