xref: /csrg-svn/sys/vax/if/if_en.c (revision 6575)
1 /*	if_en.c	4.58	82/04/20	*/
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 #ifdef ECHACK
89 	br = 0x16;
90 #endif
91 	return (1);
92 }
93 
94 /*
95  * Interface exists: make available by filling in network interface
96  * record.  System will initialize the interface when it is ready
97  * to accept packets.
98  */
99 enattach(ui)
100 	struct uba_device *ui;
101 {
102 	register struct en_softc *es = &en_softc[ui->ui_unit];
103 	register struct sockaddr_in *sin;
104 COUNT(ENATTACH);
105 
106 	es->es_if.if_unit = ui->ui_unit;
107 	es->es_if.if_name = "en";
108 	es->es_if.if_mtu = ENMTU;
109 	es->es_if.if_net = ui->ui_flags & 0xff;
110 	es->es_if.if_host[0] =
111 	 (~(((struct endevice *)eninfo[ui->ui_unit]->ui_addr)->en_addr)) & 0xff;
112 	sin = (struct sockaddr_in *)&es->es_if.if_addr;
113 	sin->sin_family = AF_INET;
114 	sin->sin_addr = if_makeaddr(es->es_if.if_net, es->es_if.if_host[0]);
115 	sin = (struct sockaddr_in *)&es->es_if.if_broadaddr;
116 	sin->sin_family = AF_INET;
117 	sin->sin_addr = if_makeaddr(es->es_if.if_net, 0);
118 	es->es_if.if_flags = IFF_BROADCAST;
119 	es->es_if.if_init = eninit;
120 	es->es_if.if_output = enoutput;
121 	es->es_if.if_ubareset = enreset;
122 	es->es_ifuba.ifu_flags = UBA_NEEDBDP | UBA_NEED16 | UBA_CANTWAIT;
123 	if_attach(&es->es_if);
124 #if NIMP == 0
125 	/* here's one for you john baby.... */
126 	enlhinit((ui->ui_flags &~ 0xff) | 0x0a);
127 #endif
128 }
129 
130 /*
131  * Reset of interface after UNIBUS reset.
132  * If interface is on specified uba, reset its state.
133  */
134 enreset(unit, uban)
135 	int unit, uban;
136 {
137 	register struct uba_device *ui;
138 COUNT(ENRESET);
139 
140 	if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0 ||
141 	    ui->ui_ubanum != uban)
142 		return;
143 	printf(" en%d", unit);
144 	eninit(unit);
145 }
146 
147 /*
148  * Initialization of interface; clear recorded pending
149  * operations, and reinitialize UNIBUS usage.
150  */
151 eninit(unit)
152 	int unit;
153 {
154 	register struct en_softc *es = &en_softc[unit];
155 	register struct uba_device *ui = eninfo[unit];
156 	register struct endevice *addr;
157 	int s;
158 
159 	if (if_ubainit(&es->es_ifuba, ui->ui_ubanum,
160 	    sizeof (struct en_header), (int)btoc(ENMTU)) == 0) {
161 		printf("en%d: can't initialize\n", unit);
162 		es->es_if.if_flags &= ~IFF_UP;
163 		return;
164 	}
165 	addr = (struct endevice *)ui->ui_addr;
166 	addr->en_istat = addr->en_ostat = 0;
167 
168 	/*
169 	 * Hang a receive and start any
170 	 * pending writes by faking a transmit complete.
171 	 */
172 	s = splimp();
173 	addr->en_iba = es->es_ifuba.ifu_r.ifrw_info;
174 	addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1;
175 	addr->en_istat = EN_IEN|EN_GO;
176 	es->es_oactive = 1;
177 	es->es_if.if_flags |= IFF_UP;
178 	enxint(unit);
179 	splx(s);
180 	if_rtinit(&es->es_if, RTF_DIRECT|RTF_UP);
181 }
182 
183 int	enalldelay = 0;
184 int	enlastdel = 25;
185 int	enlastmask = (~0) << 5;
186 
187 /*
188  * Start or restart output on interface.
189  * If interface is already active, then this is a retransmit
190  * after a collision, and just restuff registers and delay.
191  * If interface is not already active, get another datagram
192  * to send off of the interface queue, and map it to the interface
193  * before starting the output.
194  */
195 enstart(dev)
196 	dev_t dev;
197 {
198         int unit = ENUNIT(dev);
199 	struct uba_device *ui = eninfo[unit];
200 	register struct en_softc *es = &en_softc[unit];
201 	register struct endevice *addr;
202 	struct mbuf *m;
203 	int dest;
204 COUNT(ENSTART);
205 
206 	if (es->es_oactive)
207 		goto restart;
208 
209 	/*
210 	 * Not already active: dequeue another request
211 	 * and map it to the UNIBUS.  If no more requests,
212 	 * just return.
213 	 */
214 	IF_DEQUEUE(&es->es_if.if_snd, m);
215 	if (m == 0) {
216 		es->es_oactive = 0;
217 		return;
218 	}
219 	dest = mtod(m, struct en_header *)->en_dhost;
220 	es->es_olen = if_wubaput(&es->es_ifuba, m);
221 
222 	/*
223 	 * Ethernet cannot take back-to-back packets (no
224 	 * buffering in interface.  To help avoid overrunning
225 	 * receivers, enforce a small delay (about 1ms) in interface:
226 	 *	* between all packets when enalldelay
227 	 *	* whenever last packet was broadcast
228 	 *	* whenever this packet is to same host as last packet
229 	 */
230 	if (enalldelay || es->es_lastx == 0 || es->es_lastx == dest) {
231 		es->es_delay = enlastdel;
232 		es->es_mask = enlastmask;
233 	}
234 	es->es_lastx = dest;
235 
236 restart:
237 	/*
238 	 * Have request mapped to UNIBUS for transmission.
239 	 * Purge any stale data from this BDP, and start the otput.
240 	 */
241 	if (es->es_ifuba.ifu_flags & UBA_NEEDBDP)
242 		UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_w.ifrw_bdp);
243 	addr = (struct endevice *)ui->ui_addr;
244 	addr->en_oba = (int)es->es_ifuba.ifu_w.ifrw_info;
245 	addr->en_odelay = es->es_delay;
246 	addr->en_owc = -((es->es_olen + 1) >> 1);
247 	addr->en_ostat = EN_IEN|EN_GO;
248 	es->es_oactive = 1;
249 }
250 
251 /*
252  * Ethernet interface transmitter interrupt.
253  * Start another output if more data to send.
254  */
255 enxint(unit)
256 	int unit;
257 {
258 	register struct uba_device *ui = eninfo[unit];
259 	register struct en_softc *es = &en_softc[unit];
260 	register struct endevice *addr = (struct endevice *)ui->ui_addr;
261 COUNT(ENXINT);
262 
263 	if (es->es_oactive == 0)
264 		return;
265 	if (es->es_mask && (addr->en_ostat&EN_OERROR)) {
266 		es->es_if.if_oerrors++;
267 		if (es->es_if.if_oerrors % 100 == 0)
268 			printf("en%d: += 100 output errors\n", unit);
269 		endocoll(unit);
270 		return;
271 	}
272 	es->es_if.if_opackets++;
273 	es->es_oactive = 0;
274 	es->es_delay = 0;
275 	es->es_mask = ~0;
276 	if (es->es_ifuba.ifu_xtofree) {
277 		m_freem(es->es_ifuba.ifu_xtofree);
278 		es->es_ifuba.ifu_xtofree = 0;
279 	}
280 	if (es->es_if.if_snd.ifq_head == 0) {
281 		es->es_lastx = 256;		/* putatively illegal */
282 		return;
283 	}
284 	enstart(unit);
285 }
286 
287 /*
288  * Collision on ethernet interface.  Do exponential
289  * backoff, and retransmit.  If have backed off all
290  * the way print warning diagnostic, and drop packet.
291  */
292 encollide(unit)
293 	int unit;
294 {
295 	struct en_softc *es = &en_softc[unit];
296 COUNT(ENCOLLIDE);
297 
298 	es->es_if.if_collisions++;
299 	if (es->es_oactive == 0)
300 		return;
301 	endocoll(unit);
302 }
303 
304 endocoll(unit)
305 	int unit;
306 {
307 	register struct en_softc *es = &en_softc[unit];
308 
309 	/*
310 	 * Es_mask is a 16 bit number with n low zero bits, with
311 	 * n the number of backoffs.  When es_mask is 0 we have
312 	 * backed off 16 times, and give up.
313 	 */
314 	if (es->es_mask == 0) {
315 		printf("en%d: send error\n", unit);
316 		enxint(unit);
317 		return;
318 	}
319 	/*
320 	 * Another backoff.  Restart with delay based on n low bits
321 	 * of the interval timer.
322 	 */
323 	es->es_mask <<= 1;
324 	es->es_delay = mfpr(ICR) &~ es->es_mask;
325 	enstart(unit);
326 }
327 
328 struct	sockaddr_pup pupsrc = { AF_PUP };
329 struct	sockaddr_pup pupdst = { AF_PUP };
330 struct	sockproto pupproto = { PF_PUP };
331 /*
332  * Ethernet interface receiver interrupt.
333  * If input error just drop packet.
334  * Otherwise purge input buffered data path and examine
335  * packet to determine type.  If can't determine length
336  * from type, then have to drop packet.  Othewise decapsulate
337  * packet based on type and pass to type specific higher-level
338  * input routine.
339  */
340 enrint(unit)
341 	int unit;
342 {
343 	register struct en_softc *es = &en_softc[unit];
344 	struct endevice *addr = (struct endevice *)eninfo[unit]->ui_addr;
345 	register struct en_header *en;
346     	struct mbuf *m;
347 	int len, plen; short resid;
348 	register struct ifqueue *inq;
349 	int off;
350 COUNT(ENRINT);
351 
352 	es->es_if.if_ipackets++;
353 
354 	/*
355 	 * Purge BDP; drop if input error indicated.
356 	 */
357 	if (es->es_ifuba.ifu_flags & UBA_NEEDBDP)
358 		UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_r.ifrw_bdp);
359 	if (addr->en_istat&EN_IERROR) {
360 		es->es_if.if_ierrors++;
361 		if (es->es_if.if_ierrors % 100 == 0)
362 			printf("en%d: += 100 input errors\n", unit);
363 		goto setup;
364 	}
365 
366 	/*
367 	 * Calculate input data length.
368 	 * Get pointer to ethernet header (in input buffer).
369 	 * Deal with trailer protocol: if type is PUP trailer
370 	 * get true type from first 16-bit word past data.
371 	 * Remember that type was trailer by setting off.
372 	 */
373 	resid = addr->en_iwc;
374 	if (resid)
375 		resid |= 0176000;
376 	len = (((sizeof (struct en_header) + ENMTU) >> 1) + resid) << 1;
377 	len -= sizeof (struct en_header);
378 	if (len >= ENMTU)
379 		goto setup;			/* sanity */
380 	en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr);
381 #define	endataaddr(en, off, type)	((type)(((caddr_t)((en)+1)+(off))))
382 	if (en->en_type >= ENPUP_TRAIL &&
383 	    en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) {
384 		off = (en->en_type - ENPUP_TRAIL) * 512;
385 		if (off >= ENMTU)
386 			goto setup;		/* sanity */
387 		en->en_type = *endataaddr(en, off, u_short *);
388 		resid = *(endataaddr(en, off+2, u_short *));
389 		if (off + resid > len)
390 			goto setup;		/* sanity */
391 		len = off + resid;
392 	} else
393 		off = 0;
394 	if (len == 0)
395 		goto setup;
396 	/*
397 	 * Pull packet off interface.  Off is nonzero if packet
398 	 * has trailing header; if_rubaget will then force this header
399 	 * information to be at the front, but we still have to drop
400 	 * the type and length which are at the front of any trailer data.
401 	 */
402 	m = if_rubaget(&es->es_ifuba, len, off);
403 	if (m == 0)
404 		goto setup;
405 	if (off) {
406 		m->m_off += 2 * sizeof (u_short);
407 		m->m_len -= 2 * sizeof (u_short);
408 	}
409 	switch (en->en_type) {
410 
411 #ifdef INET
412 	case ENPUP_IPTYPE:
413 		schednetisr(NETISR_IP);
414 		inq = &ipintrq;
415 		break;
416 #endif
417 #ifdef PUP
418 	case ENPUP_PUPTYPE: {
419 		struct pup_header *pup = mtod(m, struct pup_header *);
420 
421 		pupproto.sp_protocol = pup->pup_type;
422 		pupdst.spup_addr = pup->pup_dport;
423 		pupsrc.spup_addr = pup->pup_sport;
424 		raw_input(m, &pupproto, (struct sockaddr *)&pupsrc,
425 		  (struct sockaddr *)&pupdst);
426 		goto setup;
427 	}
428 #endif
429 	default:
430 		m_freem(m);
431 		goto setup;
432 	}
433 
434 	if (IF_QFULL(inq)) {
435 		IF_DROP(inq);
436 		m_freem(m);
437 	} else
438 		IF_ENQUEUE(inq, m);
439 
440 setup:
441 	/*
442 	 * Reset for next packet.
443 	 */
444 	addr->en_iba = es->es_ifuba.ifu_r.ifrw_info;
445 	addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1;
446 	addr->en_istat = EN_IEN|EN_GO;
447 }
448 
449 /*
450  * Ethernet output routine.
451  * Encapsulate a packet of type family for the local net.
452  * Use trailer local net encapsulation if enough data in first
453  * packet leaves a multiple of 512 bytes of data in remainder.
454  */
455 enoutput(ifp, m0, dst)
456 	struct ifnet *ifp;
457 	struct mbuf *m0;
458 	struct sockaddr *dst;
459 {
460 	int type, dest, s, error;
461 	register struct mbuf *m = m0;
462 	register struct en_header *en;
463 	register int off;
464 
465 COUNT(ENOUTPUT);
466 	switch (dst->sa_family) {
467 
468 #ifdef INET
469 	case AF_INET:
470 		dest = ((struct sockaddr_in *)dst)->sin_addr.s_addr;
471 		if (dest & 0x00ffff00) {
472 			error = EPERM;		/* ??? */
473 			goto bad;
474 		}
475 		dest = (dest >> 24) & 0xff;
476 		off = ntohs((u_short)mtod(m, struct ip *)->ip_len) - m->m_len;
477 		if (off > 0 && (off & 0x1ff) == 0 &&
478 		    m->m_off >= MMINOFF + 2 * sizeof (u_short)) {
479 			type = ENPUP_TRAIL + (off>>9);
480 			m->m_off -= 2 * sizeof (u_short);
481 			m->m_len += 2 * sizeof (u_short);
482 			*mtod(m, u_short *) = ENPUP_IPTYPE;
483 			*(mtod(m, u_short *) + 1) = m->m_len;
484 			goto gottrailertype;
485 		}
486 		type = ENPUP_IPTYPE;
487 		off = 0;
488 		goto gottype;
489 #endif
490 #ifdef PUP
491 	case AF_PUP:
492 		dest = ((struct sockaddr_pup *)dst)->spup_addr.pp_host;
493 		type = ENPUP_PUPTYPE;
494 		off = 0;
495 		goto gottype;
496 #endif
497 
498 	default:
499 		printf("en%d: can't handle af%d\n", ifp->if_unit,
500 			dst->sa_family);
501 		error = EAFNOSUPPORT;
502 		goto bad;
503 	}
504 
505 gottrailertype:
506 	/*
507 	 * Packet to be sent as trailer: move first packet
508 	 * (control information) to end of chain.
509 	 */
510 	while (m->m_next)
511 		m = m->m_next;
512 	m->m_next = m0;
513 	m = m0->m_next;
514 	m0->m_next = 0;
515 	m0 = m;
516 
517 gottype:
518 	/*
519 	 * Add local net header.  If no space in first mbuf,
520 	 * allocate another.
521 	 */
522 	if (m->m_off > MMAXOFF ||
523 	    MMINOFF + sizeof (struct en_header) > m->m_off) {
524 		m = m_get(M_DONTWAIT);
525 		if (m == 0) {
526 			error = ENOBUFS;
527 			goto bad;
528 		}
529 		m->m_next = m0;
530 		m->m_off = MMINOFF;
531 		m->m_len = sizeof (struct en_header);
532 	} else {
533 		m->m_off -= sizeof (struct en_header);
534 		m->m_len += sizeof (struct en_header);
535 	}
536 	en = mtod(m, struct en_header *);
537 	en->en_shost = ifp->if_host[0];
538 	en->en_dhost = dest;
539 	en->en_type = type;
540 
541 	/*
542 	 * Queue message on interface, and start output if interface
543 	 * not yet active.
544 	 */
545 	s = splimp();
546 	if (IF_QFULL(&ifp->if_snd)) {
547 		IF_DROP(&ifp->if_snd);
548 		error = ENOBUFS;
549 		goto qfull;
550 	}
551 	IF_ENQUEUE(&ifp->if_snd, m);
552 	if (en_softc[ifp->if_unit].es_oactive == 0)
553 		enstart(ifp->if_unit);
554 	splx(s);
555 	return (0);
556 qfull:
557 	m0 = m;
558 	splx(s);
559 bad:
560 	m_freem(m0);
561 	return (error);
562 }
563 
564 #if NIMP == 0 && NEN > 0
565 /*
566  * Logical host interface driver.
567  * Allows host to appear as an ARPAnet
568  * logical host.  Must also have routing
569  * table entry set up to forward packets
570  * to appropriate gateway on localnet.
571  */
572 
573 struct	ifnet enlhif;
574 int	enlhoutput();
575 
576 /*
577  * Called by localnet interface to allow logical
578  * host interface to "attach".  Nothing should ever
579  * be sent locally to this interface, it's purpose
580  * is simply to establish the host's arpanet address.
581  */
582 enlhinit(addr)
583 	int addr;
584 {
585 	register struct ifnet *ifp = &enlhif;
586 	register struct sockaddr_in *sin;
587 
588 COUNT(ENLHINIT);
589 	ifp->if_name = "lh";
590 	ifp->if_mtu = ENMTU;
591 	sin = (struct sockaddr_in *)&ifp->if_addr;
592 	sin->sin_family = AF_INET;
593 	sin->sin_addr.s_addr = addr;
594 	ifp->if_net = sin->sin_addr.s_net;
595 	ifp->if_flags = IFF_UP;
596 	ifp->if_output = enlhoutput;	/* should never be used */
597 	if_attach(ifp);
598 }
599 
600 enlhoutput(ifp, m0, dst)
601 	struct ifnet *ifp;
602 	struct mbuf *m0;
603 	struct sockaddr *dst;
604 {
605 COUNT(ENLHOUTPUT);
606 	ifp->if_oerrors++;
607 	m_freem(m0);
608 	return (0);
609 }
610 #endif
611