xref: /csrg-svn/sys/vax/if/if_en.c (revision 6503)
1 /*	if_en.c	4.54	82/04/10	*/
2 
3 #include "en.h"
4 #include "imp.h"
5 
6 /*
7  * Xerox prototype (3 Mb) Ethernet interface driver.
8  */
9 
10 #include "../h/param.h"
11 #include "../h/systm.h"
12 #include "../h/mbuf.h"
13 #include "../h/pte.h"
14 #include "../h/buf.h"
15 #include "../h/protosw.h"
16 #include "../h/socket.h"
17 #include "../h/ubareg.h"
18 #include "../h/ubavar.h"
19 #include "../h/enreg.h"
20 #include "../h/cpu.h"
21 #include "../h/mtpr.h"
22 #include "../h/vmmac.h"
23 #include "../net/in.h"
24 #include "../net/in_systm.h"
25 #include "../net/if.h"
26 #include "../net/if_en.h"
27 #include "../net/if_uba.h"
28 #include "../net/ip.h"
29 #include "../net/ip_var.h"
30 #include "../net/pup.h"
31 #include "../net/route.h"
32 #include <errno.h>
33 
34 #define	ENMTU	(1024+512)
35 
36 int	enprobe(), enattach(), enrint(), enxint(), encollide();
37 struct	uba_device *eninfo[NEN];
38 u_short enstd[] = { 0 };
39 struct	uba_driver endriver =
40 	{ enprobe, 0, enattach, 0, enstd, "en", eninfo };
41 #define	ENUNIT(x)	minor(x)
42 
43 int	eninit(),enoutput(),enreset();
44 
45 /*
46  * Ethernet software status per interface.
47  *
48  * Each interface is referenced by a network interface structure,
49  * es_if, which the routing code uses to locate the interface.
50  * This structure contains the output queue for the interface, its address, ...
51  * We also have, for each interface, a UBA interface structure, which
52  * contains information about the UNIBUS resources held by the interface:
53  * map registers, buffered data paths, etc.  Information is cached in this
54  * structure for use by the if_uba.c routines in running the interface
55  * efficiently.
56  */
57 struct	en_softc {
58 	struct	ifnet es_if;		/* network-visible interface */
59 	struct	ifuba es_ifuba;		/* UNIBUS resources */
60 	short	es_delay;		/* current output delay */
61 	short	es_mask;		/* mask for current output delay */
62 	short	es_lastx;		/* host last transmitted to */
63 	short	es_oactive;		/* is output active? */
64 	short	es_olen;		/* length of last output */
65 } en_softc[NEN];
66 
67 /*
68  * Do output DMA to determine interface presence and
69  * interrupt vector.  DMA is too short to disturb other hosts.
70  */
71 enprobe(reg)
72 	caddr_t reg;
73 {
74 	register int br, cvec;		/* r11, r10 value-result */
75 	register struct endevice *addr = (struct endevice *)reg;
76 
77 COUNT(ENPROBE);
78 #ifdef lint
79 	br = 0; cvec = br; br = cvec;
80 	enrint(0); enxint(0); encollide(0);
81 #endif
82 	addr->en_istat = 0;
83 	addr->en_owc = -1;
84 	addr->en_oba = 0;
85 	addr->en_ostat = EN_IEN|EN_GO;
86 	DELAY(100000);
87 	addr->en_ostat = 0;
88 	return (1);
89 }
90 
91 /*
92  * Interface exists: make available by filling in network interface
93  * record.  System will initialize the interface when it is ready
94  * to accept packets.
95  */
96 enattach(ui)
97 	struct uba_device *ui;
98 {
99 	register struct en_softc *es = &en_softc[ui->ui_unit];
100 	register struct sockaddr_in *sin;
101 COUNT(ENATTACH);
102 
103 	es->es_if.if_unit = ui->ui_unit;
104 	es->es_if.if_name = "en";
105 	es->es_if.if_mtu = ENMTU;
106 	es->es_if.if_net = ui->ui_flags & 0xff;
107 	es->es_if.if_host[0] =
108 	 (~(((struct endevice *)eninfo[ui->ui_unit]->ui_addr)->en_addr)) & 0xff;
109 	sin = (struct sockaddr_in *)&es->es_if.if_addr;
110 	sin->sin_family = AF_INET;
111 	sin->sin_addr = if_makeaddr(es->es_if.if_net, es->es_if.if_host[0]);
112 	sin = (struct sockaddr_in *)&es->es_if.if_broadaddr;
113 	sin->sin_family = AF_INET;
114 	sin->sin_addr = if_makeaddr(es->es_if.if_net, 0);
115 	es->es_if.if_flags = IFF_BROADCAST;
116 	es->es_if.if_init = eninit;
117 	es->es_if.if_output = enoutput;
118 	es->es_if.if_ubareset = enreset;
119 	es->es_ifuba.ifu_flags = UBA_NEEDBDP | UBA_NEED16;
120 	if_attach(&es->es_if);
121 #if NIMP == 0
122 	/* here's one for you john baby.... */
123 	enlhinit((ui->ui_flags &~ 0xff) | 0x0a);
124 #endif
125 }
126 
127 /*
128  * Reset of interface after UNIBUS reset.
129  * If interface is on specified uba, reset its state.
130  */
131 enreset(unit, uban)
132 	int unit, uban;
133 {
134 	register struct uba_device *ui;
135 COUNT(ENRESET);
136 
137 	if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0 ||
138 	    ui->ui_ubanum != uban)
139 		return;
140 	printf(" en%d", unit);
141 	eninit(unit);
142 }
143 
144 /*
145  * Initialization of interface; clear recorded pending
146  * operations, and reinitialize UNIBUS usage.
147  */
148 eninit(unit)
149 	int unit;
150 {
151 	register struct en_softc *es = &en_softc[unit];
152 	register struct uba_device *ui = eninfo[unit];
153 	register struct endevice *addr;
154 	int s;
155 
156 	if (if_ubainit(&es->es_ifuba, ui->ui_ubanum,
157 	    sizeof (struct en_header), (int)btoc(ENMTU)) == 0) {
158 		printf("en%d: can't initialize\n", unit);
159 		es->es_if.if_flags &= ~IFF_UP;
160 		return;
161 	}
162 	addr = (struct endevice *)ui->ui_addr;
163 	addr->en_istat = addr->en_ostat = 0;
164 
165 	/*
166 	 * Hang a receive and start any
167 	 * pending writes by faking a transmit complete.
168 	 */
169 	s = splimp();
170 	addr->en_iba = es->es_ifuba.ifu_r.ifrw_info;
171 	addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1;
172 	addr->en_istat = EN_IEN|EN_GO;
173 	es->es_oactive = 1;
174 	es->es_if.if_flags |= IFF_UP;
175 	enxint(unit);
176 	splx(s);
177 	if_rtinit(&es->es_if, RTF_DIRECT|RTF_UP);
178 }
179 
180 int	enalldelay = 0;
181 int	enlastdel = 25;
182 int	enlastmask = (~0) << 5;
183 
184 /*
185  * Start or restart output on interface.
186  * If interface is already active, then this is a retransmit
187  * after a collision, and just restuff registers and delay.
188  * If interface is not already active, get another datagram
189  * to send off of the interface queue, and map it to the interface
190  * before starting the output.
191  */
192 enstart(dev)
193 	dev_t dev;
194 {
195         int unit = ENUNIT(dev);
196 	struct uba_device *ui = eninfo[unit];
197 	register struct en_softc *es = &en_softc[unit];
198 	register struct endevice *addr;
199 	struct mbuf *m;
200 	int dest;
201 COUNT(ENSTART);
202 
203 	if (es->es_oactive)
204 		goto restart;
205 
206 	/*
207 	 * Not already active: dequeue another request
208 	 * and map it to the UNIBUS.  If no more requests,
209 	 * just return.
210 	 */
211 	IF_DEQUEUE(&es->es_if.if_snd, m);
212 	if (m == 0) {
213 		es->es_oactive = 0;
214 		return;
215 	}
216 	dest = mtod(m, struct en_header *)->en_dhost;
217 	es->es_olen = if_wubaput(&es->es_ifuba, m);
218 
219 	/*
220 	 * Ethernet cannot take back-to-back packets (no
221 	 * buffering in interface.  To help avoid overrunning
222 	 * receivers, enforce a small delay (about 1ms) in interface:
223 	 *	* between all packets when enalldelay
224 	 *	* whenever last packet was broadcast
225 	 *	* whenever this packet is to same host as last packet
226 	 */
227 	if (enalldelay || es->es_lastx == 0 || es->es_lastx == dest) {
228 		es->es_delay = enlastdel;
229 		es->es_mask = enlastmask;
230 	}
231 	es->es_lastx = dest;
232 
233 restart:
234 	/*
235 	 * Have request mapped to UNIBUS for transmission.
236 	 * Purge any stale data from this BDP, and start the otput.
237 	 */
238 	if (es->es_ifuba.ifu_flags & UBA_NEEDBDP)
239 		UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_w.ifrw_bdp);
240 	addr = (struct endevice *)ui->ui_addr;
241 	addr->en_oba = (int)es->es_ifuba.ifu_w.ifrw_info;
242 	addr->en_odelay = es->es_delay;
243 	addr->en_owc = -((es->es_olen + 1) >> 1);
244 	addr->en_ostat = EN_IEN|EN_GO;
245 	es->es_oactive = 1;
246 }
247 
248 /*
249  * Ethernet interface transmitter interrupt.
250  * Start another output if more data to send.
251  */
252 enxint(unit)
253 	int unit;
254 {
255 	register struct uba_device *ui = eninfo[unit];
256 	register struct en_softc *es = &en_softc[unit];
257 	register struct endevice *addr = (struct endevice *)ui->ui_addr;
258 COUNT(ENXINT);
259 
260 	if (es->es_oactive == 0)
261 		return;
262 	if (es->es_mask && (addr->en_ostat&EN_OERROR)) {
263 		es->es_if.if_oerrors++;
264 		if (es->es_if.if_oerrors % 100 == 0)
265 			printf("en%d: += 100 output errors\n", unit);
266 		endocoll(unit);
267 		return;
268 	}
269 	es->es_if.if_opackets++;
270 	es->es_oactive = 0;
271 	es->es_delay = 0;
272 	es->es_mask = ~0;
273 	if (es->es_ifuba.ifu_xtofree) {
274 		m_freem(es->es_ifuba.ifu_xtofree);
275 		es->es_ifuba.ifu_xtofree = 0;
276 	}
277 	if (es->es_if.if_snd.ifq_head == 0) {
278 		es->es_lastx = 256;		/* putatively illegal */
279 		return;
280 	}
281 	enstart(unit);
282 }
283 
284 /*
285  * Collision on ethernet interface.  Do exponential
286  * backoff, and retransmit.  If have backed off all
287  * the way print warning diagnostic, and drop packet.
288  */
289 encollide(unit)
290 	int unit;
291 {
292 	struct en_softc *es = &en_softc[unit];
293 COUNT(ENCOLLIDE);
294 
295 	es->es_if.if_collisions++;
296 	if (es->es_oactive == 0)
297 		return;
298 	endocoll(unit);
299 }
300 
301 endocoll(unit)
302 	int unit;
303 {
304 	register struct en_softc *es = &en_softc[unit];
305 
306 	/*
307 	 * Es_mask is a 16 bit number with n low zero bits, with
308 	 * n the number of backoffs.  When es_mask is 0 we have
309 	 * backed off 16 times, and give up.
310 	 */
311 	if (es->es_mask == 0) {
312 		printf("en%d: send error\n", unit);
313 		enxint(unit);
314 		return;
315 	}
316 	/*
317 	 * Another backoff.  Restart with delay based on n low bits
318 	 * of the interval timer.
319 	 */
320 	es->es_mask <<= 1;
321 	es->es_delay = mfpr(ICR) &~ es->es_mask;
322 	enstart(unit);
323 }
324 
325 struct	sockaddr_pup pupsrc = { AF_PUP };
326 struct	sockaddr_pup pupdst = { AF_PUP };
327 struct	sockproto pupproto = { PF_PUP };
328 /*
329  * Ethernet interface receiver interrupt.
330  * If input error just drop packet.
331  * Otherwise purge input buffered data path and examine
332  * packet to determine type.  If can't determine length
333  * from type, then have to drop packet.  Othewise decapsulate
334  * packet based on type and pass to type specific higher-level
335  * input routine.
336  */
337 enrint(unit)
338 	int unit;
339 {
340 	register struct en_softc *es = &en_softc[unit];
341 	struct endevice *addr = (struct endevice *)eninfo[unit]->ui_addr;
342 	register struct en_header *en;
343     	struct mbuf *m;
344 	int len, plen; short resid;
345 	register struct ifqueue *inq;
346 	int off;
347 COUNT(ENRINT);
348 
349 	es->es_if.if_ipackets++;
350 
351 	/*
352 	 * Purge BDP; drop if input error indicated.
353 	 */
354 	if (es->es_ifuba.ifu_flags & UBA_NEEDBDP)
355 		UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_r.ifrw_bdp);
356 	if (addr->en_istat&EN_IERROR) {
357 		es->es_if.if_ierrors++;
358 		if (es->es_if.if_ierrors % 100 == 0)
359 			printf("en%d: += 100 input errors\n", unit);
360 		goto setup;
361 	}
362 
363 	/*
364 	 * Calculate input data length.
365 	 * Get pointer to ethernet header (in input buffer).
366 	 * Deal with trailer protocol: if type is PUP trailer
367 	 * get true type from first 16-bit word past data.
368 	 * Remember that type was trailer by setting off.
369 	 */
370 	resid = addr->en_iwc;
371 	if (resid)
372 		resid |= 0176000;
373 	len = (((sizeof (struct en_header) + ENMTU) >> 1) + resid) << 1;
374 	len -= sizeof (struct en_header);
375 	if (len >= ENMTU)
376 		goto setup;			/* sanity */
377 	en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr);
378 #define	endataaddr(en, off, type)	((type)(((caddr_t)((en)+1)+(off))))
379 	if (en->en_type >= ENPUP_TRAIL &&
380 	    en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) {
381 		off = (en->en_type - ENPUP_TRAIL) * 512;
382 		if (off >= ENMTU)
383 			goto setup;		/* sanity */
384 		en->en_type = *endataaddr(en, off, u_short *);
385 		resid = *(endataaddr(en, off+2, u_short *));
386 		if (off + resid > len)
387 			goto setup;		/* sanity */
388 		len = off + resid;
389 	} else
390 		off = 0;
391 	if (len == 0)
392 		goto setup;
393 	/*
394 	 * Pull packet off interface.  Off is nonzero if packet
395 	 * has trailing header; if_rubaget will then force this header
396 	 * information to be at the front, but we still have to drop
397 	 * the type and length which are at the front of any trailer data.
398 	 */
399 	m = if_rubaget(&es->es_ifuba, len, off);
400 	if (m == 0)
401 		goto setup;
402 	if (off) {
403 		m->m_off += 2 * sizeof (u_short);
404 		m->m_len -= 2 * sizeof (u_short);
405 	}
406 	switch (en->en_type) {
407 
408 #ifdef INET
409 	case ENPUP_IPTYPE:
410 		schednetisr(NETISR_IP);
411 		inq = &ipintrq;
412 		break;
413 #endif
414 #ifdef PUP
415 	case ENPUP_PUPTYPE: {
416 		struct pup_header *pup = mtod(m, struct pup_header *);
417 
418 		pupproto.sp_protocol = pup->pup_type;
419 		pupdst.spup_addr = pup->pup_dport;
420 		pupsrc.spup_addr = pup->pup_sport;
421 		raw_input(m, &pupproto, (struct sockaddr *)&pupdst,
422 		  (struct sockaddr *)&pupsrc);
423 		goto setup;
424 	}
425 #endif
426 	default:
427 		m_freem(m);
428 		goto setup;
429 	}
430 
431 	if (IF_QFULL(inq)) {
432 		IF_DROP(inq);
433 		m_freem(m);
434 	} else
435 		IF_ENQUEUE(inq, m);
436 
437 setup:
438 	/*
439 	 * Reset for next packet.
440 	 */
441 	addr->en_iba = es->es_ifuba.ifu_r.ifrw_info;
442 	addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1;
443 	addr->en_istat = EN_IEN|EN_GO;
444 }
445 
446 /*
447  * Ethernet output routine.
448  * Encapsulate a packet of type family for the local net.
449  * Use trailer local net encapsulation if enough data in first
450  * packet leaves a multiple of 512 bytes of data in remainder.
451  */
452 enoutput(ifp, m0, dst)
453 	struct ifnet *ifp;
454 	struct mbuf *m0;
455 	struct sockaddr *dst;
456 {
457 	int type, dest, s, error;
458 	register struct mbuf *m = m0;
459 	register struct en_header *en;
460 	register int off;
461 
462 COUNT(ENOUTPUT);
463 	switch (dst->sa_family) {
464 
465 #ifdef INET
466 	case AF_INET:
467 		dest = ((struct sockaddr_in *)dst)->sin_addr.s_addr;
468 		if (dest & 0x00ffff00) {
469 			error = EPERM;		/* ??? */
470 			goto bad;
471 		}
472 		dest = (dest >> 24) & 0xff;
473 		off = ntohs((u_short)mtod(m, struct ip *)->ip_len) - m->m_len;
474 		if (off > 0 && (off & 0x1ff) == 0 &&
475 		    m->m_off >= MMINOFF + 2 * sizeof (u_short)) {
476 			type = ENPUP_TRAIL + (off>>9);
477 			m->m_off -= 2 * sizeof (u_short);
478 			m->m_len += 2 * sizeof (u_short);
479 			*mtod(m, u_short *) = ENPUP_IPTYPE;
480 			*(mtod(m, u_short *) + 1) = m->m_len;
481 			goto gottrailertype;
482 		}
483 		type = ENPUP_IPTYPE;
484 		off = 0;
485 		goto gottype;
486 #endif
487 #ifdef PUP
488 	case AF_PUP:
489 		dest = ((struct sockaddr_pup *)dst)->spup_addr.pp_host;
490 		type = ENPUP_PUPTYPE;
491 		off = 0;
492 		goto gottype;
493 #endif
494 
495 	default:
496 		printf("en%d: can't handle af%d\n", ifp->if_unit,
497 			dst->sa_family);
498 		error = EAFNOSUPPORT;
499 		goto bad;
500 	}
501 
502 gottrailertype:
503 	/*
504 	 * Packet to be sent as trailer: move first packet
505 	 * (control information) to end of chain.
506 	 */
507 	while (m->m_next)
508 		m = m->m_next;
509 	m->m_next = m0;
510 	m = m0->m_next;
511 	m0->m_next = 0;
512 	m0 = m;
513 
514 gottype:
515 	/*
516 	 * Add local net header.  If no space in first mbuf,
517 	 * allocate another.
518 	 */
519 	if (m->m_off > MMAXOFF ||
520 	    MMINOFF + sizeof (struct en_header) > m->m_off) {
521 		m = m_get(M_DONTWAIT);
522 		if (m == 0) {
523 			error = ENOBUFS;
524 			goto bad;
525 		}
526 		m->m_next = m0;
527 		m->m_off = MMINOFF;
528 		m->m_len = sizeof (struct en_header);
529 	} else {
530 		m->m_off -= sizeof (struct en_header);
531 		m->m_len += sizeof (struct en_header);
532 	}
533 	en = mtod(m, struct en_header *);
534 	en->en_shost = ifp->if_host[0];
535 	en->en_dhost = dest;
536 	en->en_type = type;
537 
538 	/*
539 	 * Queue message on interface, and start output if interface
540 	 * not yet active.
541 	 */
542 	s = splimp();
543 	if (IF_QFULL(&ifp->if_snd)) {
544 		IF_DROP(&ifp->if_snd);
545 		error = ENOBUFS;
546 		goto qfull;
547 	}
548 	IF_ENQUEUE(&ifp->if_snd, m);
549 	if (en_softc[ifp->if_unit].es_oactive == 0)
550 		enstart(ifp->if_unit);
551 	splx(s);
552 	return (0);
553 qfull:
554 	m0 = m;
555 	splx(s);
556 bad:
557 	m_freem(m0);
558 	return (error);
559 }
560 
561 #if NIMP == 0 && NEN > 0
562 /*
563  * Logical host interface driver.
564  * Allows host to appear as an ARPAnet
565  * logical host.  Must also have routing
566  * table entry set up to forward packets
567  * to appropriate gateway on localnet.
568  */
569 
570 struct	ifnet enlhif;
571 int	enlhoutput();
572 
573 /*
574  * Called by localnet interface to allow logical
575  * host interface to "attach".  Nothing should ever
576  * be sent locally to this interface, it's purpose
577  * is simply to establish the host's arpanet address.
578  */
579 enlhinit(addr)
580 	int addr;
581 {
582 	register struct ifnet *ifp = &enlhif;
583 	register struct sockaddr_in *sin;
584 
585 COUNT(ENLHINIT);
586 	ifp->if_name = "lh";
587 	ifp->if_mtu = ENMTU;
588 	sin = (struct sockaddr_in *)&ifp->if_addr;
589 	sin->sin_family = AF_INET;
590 	sin->sin_addr.s_addr = addr;
591 	ifp->if_net = sin->sin_addr.s_net;
592 	ifp->if_flags = IFF_UP;
593 	ifp->if_output = enlhoutput;	/* should never be used */
594 	if_attach(ifp);
595 }
596 
597 enlhoutput(ifp, m0, dst)
598 	struct ifnet *ifp;
599 	struct mbuf *m0;
600 	struct sockaddr *dst;
601 {
602 COUNT(ENLHOUTPUT);
603 	ifp->if_oerrors++;
604 	m_freem(m0);
605 	return (0);
606 }
607 #endif
608