wavelan.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

		return 0;
	}
	return -1;
}

/* set scanning interval */
static void
w_scanbs(void *a, uint secs)
{
	Ether *ether = a;
	Ctlr* ctlr = (Ctlr*) ether->ctlr;

	ctlr->scanticks = secs*(1000/MSperTick);
}

static void
w_intr(Ether *ether)
{
	int rc, txid;
	Ctlr* ctlr = (Ctlr*) ether->ctlr;

	if((ctlr->state & Power) == 0)
		return;

	if((ctlr->state & Attached) == 0){
		csr_ack(ctlr, 0xffff);
		csr_outs(ctlr, WR_IntEna, 0);
		return;
	}

	rc = csr_ins(ctlr, WR_EvSts);
	csr_ack(ctlr, ~WEvs);	// Not interested in them
	if(rc & WRXEv){
		w_rxdone(ether);
		csr_ack(ctlr, WRXEv);
	}
	if(rc & WTXEv){
		w_txdone(ctlr, rc);
		csr_ack(ctlr, WTXEv);
	}
	if(rc & WAllocEv){
		ctlr->nalloc++;
		txid = csr_ins(ctlr, WR_Alloc);
		csr_ack(ctlr, WAllocEv);
		if(txid == ctlr->txdid){
			if((rc & WTXEv) == 0)
				w_txdone(ctlr, rc);
		}
	}
	if(rc & WInfoEv){
		ctlr->ninfo++;
		w_info(ether, ctlr);
		csr_ack(ctlr, WInfoEv);
	}
	if(rc & WTxErrEv){
		w_txdone(ctlr, rc);
		csr_ack(ctlr, WTxErrEv);
	}
	if(rc & WIDropEv){
		ctlr->nidrop++;
		csr_ack(ctlr, WIDropEv);
	}
	w_txstart(ether);
}

// Watcher to ensure that the card still works properly and
// to request WStats updates once a minute.
// BUG: it runs much more often, see the comment below.

static void
w_timer(void* arg)
{
	Ether* ether = (Ether*) arg;
	Ctlr* ctlr = (Ctlr*)ether->ctlr;

	ctlr->timerproc = up;
	for(;;){
		tsleep(&up->sleep, return0, 0, MSperTick);
		ctlr = (Ctlr*)ether->ctlr;
		if(ctlr == 0)
			break;
		if((ctlr->state & (Attached|Power)) != (Attached|Power))
			continue;
		ctlr->ticks++;

		ilock(ctlr);

		// Seems that the card gets frames BUT does
		// not send the interrupt; this is a problem because
		// I suspect it runs out of receive buffers and
		// stops receiving until a transmit watchdog
		// reenables the card.
		// The problem is serious because it leads to
		// poor rtts.
		// This can be seen clearly by commenting out
		// the next if and doing a ping: it will stop
		// receiving (although the icmp replies are being
		// issued from the remote) after a few seconds.
		// Of course this `bug' could be because I'm reading
		// the card frames in the wrong way; due to the
		// lack of documentation I cannot know.

		if(csr_ins(ctlr, WR_EvSts)&WEvs){
			ctlr->tickintr++;
			w_intr(ether);
		}

		if((ctlr->ticks % 10) == 0) {
			if(ctlr->txtmout && --ctlr->txtmout == 0){
				ctlr->nwatchdogs++;
				w_txdone(ctlr, WTxErrEv);
				if(w_enable(ether)){
					DEBUG("wavelan: wdog enable failed\n");
				}
				w_txstart(ether);
			}
			if((ctlr->ticks % 120) == 0)
			if(ctlr->txbusy == 0)
				w_cmd(ctlr, WCmdEnquire, WTyp_Stats);
			if(ctlr->scanticks > 0)
			if((ctlr->ticks % ctlr->scanticks) == 0)
			if(ctlr->txbusy == 0)
				w_cmd(ctlr, WCmdEnquire, WTyp_Scan);
		}
		iunlock(ctlr);
	}
	pexit("terminated", 0);
}

void
w_multicast(void*, uchar*, int)
{
	// BUG: to be added.
}

void
w_attach(Ether* ether)
{
	Ctlr* ctlr;
	char name[64];
	int rc;

	if(ether->ctlr == 0)
		return;

	snprint(name, sizeof(name), "#l%dtimer", ether->ctlrno);
	ctlr = (Ctlr*) ether->ctlr;
	if((ctlr->state & Attached) == 0){
		ilock(ctlr);
		rc = w_enable(ether);
		iunlock(ctlr);
		if(rc == 0){
			ctlr->state |= Attached;
			kproc(name, w_timer, ether);
		} else
			print("#l%d: enable failed\n",ether->ctlrno);
	}
}

void
w_detach(Ether* ether)
{
	Ctlr* ctlr;
	char name[64];

	if(ether->ctlr == nil)
		return;

	snprint(name, sizeof(name), "#l%dtimer", ether->ctlrno);
	ctlr = (Ctlr*) ether->ctlr;
	if(ctlr->state & Attached){
		ilock(ctlr);
		w_intdis(ctlr);
		if(ctlr->timerproc){
			if(!postnote(ctlr->timerproc, 1, "kill", NExit))
				print("timerproc note not posted\n");
			print("w_detach, killing 0x%p\n", ctlr->timerproc);
		}
		ctlr->state &= ~Attached;
		iunlock(ctlr);
	}
	ether->ctlr = nil;
}

void
w_power(Ether* ether, int on)
{
	Ctlr *ctlr;

	ctlr = (Ctlr*) ether->ctlr;
	ilock(ctlr);
iprint("w_power %d\n", on);
	if(on){
		if((ctlr->state & Power) == 0){
			if (wavelanreset(ether, ctlr) < 0){
				iprint("w_power: reset failed\n");
				iunlock(ctlr);
				w_detach(ether);
				free(ctlr);
				return;
			}
			if(ctlr->state & Attached)
				w_enable(ether);
			ctlr->state |= Power;
		}
	}else{
		if(ctlr->state & Power){
			if(ctlr->state & Attached)
				w_intdis(ctlr);
			ctlr->state &= ~Power;
		}
	}
	iunlock(ctlr);
}

#define PRINTSTAT(fmt,val)	l += snprint(p+l, READSTR-l, (fmt), (val))
#define PRINTSTR(fmt)		l += snprint(p+l, READSTR-l, (fmt))

long
w_ifstat(Ether* ether, void* a, long n, ulong offset)
{
	Ctlr *ctlr = (Ctlr*) ether->ctlr;
	char *k, *p;
	int i, l, txid;

	ether->oerrs = ctlr->ntxerr;
	ether->crcs = ctlr->nrxfcserr;
	ether->frames = 0;
	ether->buffs = ctlr->nrxdropnobuf;
	ether->overflows = 0;

	//
	// Offset must be zero or there's a possibility the
	// new data won't match the previous read.
	//
	if(n == 0 || offset != 0)
		return 0;

	p = malloc(READSTR);
	l = 0;

	PRINTSTAT("Signal: %d\n", ctlr->signal-149);
	PRINTSTAT("Noise: %d\n", ctlr->noise-149);
	PRINTSTAT("SNR: %ud\n", ctlr->signal-ctlr->noise);
	PRINTSTAT("Interrupts: %lud\n", ctlr->nints);
	PRINTSTAT("Double Interrupts: %lud\n", ctlr->ndoubleint);
	PRINTSTAT("TxPackets: %lud\n", ctlr->ntx);
	PRINTSTAT("RxPackets: %lud\n", ctlr->nrx);
	PRINTSTAT("TxErrors: %lud\n", ctlr->ntxerr);
	PRINTSTAT("RxErrors: %lud\n", ctlr->nrxerr);
	PRINTSTAT("TxRequests: %lud\n", ctlr->ntxrq);
	PRINTSTAT("AllocEvs: %lud\n", ctlr->nalloc);
	PRINTSTAT("InfoEvs: %lud\n", ctlr->ninfo);
	PRINTSTAT("InfoDrop: %lud\n", ctlr->nidrop);
	PRINTSTAT("WatchDogs: %lud\n", ctlr->nwatchdogs);
	PRINTSTAT("Ticks: %ud\n", ctlr->ticks);
	PRINTSTAT("TickIntr: %ud\n", ctlr->tickintr);
	k = ((ctlr->state & Attached) ? "attached" : "not attached");
	PRINTSTAT("Card %s", k);
	k = ((ctlr->state & Power) ? "on" : "off");
	PRINTSTAT(", power %s", k);
	k = ((ctlr->txbusy)? ", txbusy" : "");
	PRINTSTAT("%s\n", k);

	if(ctlr->hascrypt){
		PRINTSTR("Keys: ");
		for (i = 0; i < WNKeys; i++){
			if(ctlr->keys.keys[i].len == 0)
				PRINTSTR("none ");
			else if(SEEKEYS == 0)
				PRINTSTR("set ");
			else
				PRINTSTAT("%s ", ctlr->keys.keys[i].dat);
		}
		PRINTSTR("\n");
	}

	// real card stats
	ilock(ctlr);
	PRINTSTR("\nCard stats: \n");
	PRINTSTAT("Status: %ux\n", csr_ins(ctlr, WR_Sts));
	PRINTSTAT("Event status: %ux\n", csr_ins(ctlr, WR_EvSts));
	i = ltv_ins(ctlr, WTyp_Ptype);
	PRINTSTAT("Port type: %d\n", i);
	PRINTSTAT("Transmit rate: %d\n", ltv_ins(ctlr, WTyp_TxRate));
	PRINTSTAT("Current Transmit rate: %d\n",
		ltv_ins(ctlr, WTyp_CurTxRate));
	PRINTSTAT("Channel: %d\n", ltv_ins(ctlr, WTyp_Chan));
	PRINTSTAT("AP density: %d\n", ltv_ins(ctlr, WTyp_ApDens));
	PRINTSTAT("Promiscuous mode: %d\n", ltv_ins(ctlr, WTyp_Prom));
	if(i == WPTypeAdHoc)
		PRINTSTAT("SSID name: %s\n", ltv_inname(ctlr, WTyp_NetName));
	else {
		Wltv ltv;
		PRINTSTAT("Current name: %s\n", ltv_inname(ctlr, WTyp_CurName));
		ltv.type = WTyp_BaseID;
		ltv.len = 4;
		if(w_inltv(ctlr, &ltv))
			print("#l%d: unable to read base station mac addr\n", ether->ctlrno);
		l += snprint(p+l, READSTR-l, "Base station: %2.2x%2.2x%2.2x%2.2x%2.2x%2.2x\n",
			ltv.addr[0], ltv.addr[1], ltv.addr[2], ltv.addr[3], ltv.addr[4], ltv.addr[5]);
	}
	PRINTSTAT("Net name: %s\n", ltv_inname(ctlr, WTyp_WantName));
	PRINTSTAT("Node name: %s\n", ltv_inname(ctlr, WTyp_NodeName));
	if(ltv_ins(ctlr, WTyp_HasCrypt) == 0)
		PRINTSTR("WEP: not supported\n");
	else {
		if(ltv_ins(ctlr, WTyp_Crypt) == 0)
			PRINTSTR("WEP: disabled\n");
		else{
			PRINTSTR("WEP: enabled\n");
			k = ((ctlr->xclear)? "excluded": "included");
			PRINTSTAT("Clear packets: %s\n", k);
			txid = ltv_ins(ctlr, WTyp_TxKey);
			PRINTSTAT("Transmit key id: %d\n", txid);
		}
	}
	iunlock(ctlr);

	PRINTSTAT("ntxuframes: %lud\n", ctlr->ntxuframes);
	PRINTSTAT("ntxmframes: %lud\n", ctlr->ntxmframes);
	PRINTSTAT("ntxfrags: %lud\n", ctlr->ntxfrags);
	PRINTSTAT("ntxubytes: %lud\n", ctlr->ntxubytes);
	PRINTSTAT("ntxmbytes: %lud\n", ctlr->ntxmbytes);
	PRINTSTAT("ntxdeferred: %lud\n", ctlr->ntxdeferred);
	PRINTSTAT("ntxsretries: %lud\n", ctlr->ntxsretries);
	PRINTSTAT("ntxmultiretries: %lud\n", ctlr->ntxmultiretries);
	PRINTSTAT("ntxretrylimit: %lud\n", ctlr->ntxretrylimit);
	PRINTSTAT("ntxdiscards: %lud\n", ctlr->ntxdiscards);
	PRINTSTAT("nrxuframes: %lud\n", ctlr->nrxuframes);
	PRINTSTAT("nrxmframes: %lud\n", ctlr->nrxmframes);
	PRINTSTAT("nrxfrags: %lud\n", ctlr->nrxfrags);
	PRINTSTAT("nrxubytes: %lud\n", ctlr->nrxubytes);
	PRINTSTAT("nrxmbytes: %lud\n", ctlr->nrxmbytes);
	PRINTSTAT("nrxfcserr: %lud\n", ctlr->nrxfcserr);
	PRINTSTAT("nrxdropnobuf: %lud\n", ctlr->nrxdropnobuf);
	PRINTSTAT("nrxdropnosa: %lud\n", ctlr->nrxdropnosa);
	PRINTSTAT("nrxcantdecrypt: %lud\n", ctlr->nrxcantdecrypt);
	PRINTSTAT("nrxmsgfrag: %lud\n", ctlr->nrxmsgfrag);
	PRINTSTAT("nrxmsgbadfrag: %lud\n", ctlr->nrxmsgbadfrag);
	USED(l);
	n = readstr(offset, a, n, p);
	free(p);
	return n;
}
#undef PRINTSTR
#undef PRINTSTAT

int
w_option(Ctlr* ctlr, char* buf, long n)
{
	char *p;
	int i, r;
	WKey *key;
	Cmdbuf *cb;

	r = 0;

	cb = parsecmd(buf, n);
	if(cb->nf < 2)
		r = -1;
	else if(cistrcmp(cb->f[0], "essid") == 0){
		if(cistrcmp(cb->f[1],"default") == 0)
			p = "";
		else
			p = cb->f[1];
		if(ctlr->ptype == WPTypeAdHoc){
			memset(ctlr->netname, 0, sizeof(ctlr->netname));
			strncpy(ctlr->netname, p, WNameLen);
		}
		else{
			memset(ctlr->wantname, 0, sizeof(ctlr->wantname));
			strncpy(ctlr->wantname, p, WNameLen);
		}
	}
	else if(cistrcmp(cb->f[0], "station") == 0){
		memset(ctlr->nodename, 0, sizeof(ctlr->nodename));
		strncpy(ctlr->nodename, cb->f[1], WNameLen);
	}
	else if(cistrcmp(cb->f[0], "channel") == 0){
		if((i = atoi(cb->f[1])) >= 1 && i <= 16)
			ctlr->chan = i;
		else
			r = -1;
	}
	else if(cistrcmp(cb->f[0], "mode") == 0){
		if(cistrcmp(cb->f[1], "managed") == 0)
			ctlr->ptype = WPTypeManaged;
		else if(cistrcmp(cb->f[1], "wds") == 0)
			ctlr->ptype = WPTypeWDS;
		else if(cistrcmp(cb->f[1], "adhoc") == 0)
			ctlr->ptype = WPTypeAdHoc;
		else if((i = atoi(cb->f[1])) >= 1 && i <= 3)
			ctlr->ptype = i;
		else
			r = -1;
	}
	else if(cistrcmp(cb->f[0], "ibss") == 0){
		if(cistrcmp(cb->f[1], "on") == 0)
			ctlr->createibss = 1;
		else
			ctlr->createibss = 0;
	}
	else if(cistrcmp(cb->f[0], "crypt") == 0){
		if(cistrcmp(cb->f[1], "off") == 0)
			ctlr->crypt = 0;
		else if(cistrcmp(cb->f[1], "on") == 0 && ctlr->hascrypt)
			ctlr->crypt = 1;
		else
			r = -1;
	}
	else if(cistrcmp(cb->f[0], "clear") == 0){
		if(cistrcmp(cb->f[1], "on") == 0)
			ctlr->xclear = 0;
		else if(cistrcmp(cb->f[1], "off") == 0 && ctlr->hascrypt)
			ctlr->xclear = 1;
		else
			r = -1;
	}
	else if(cistrncmp(cb->f[0], "key", 3) == 0){
		if((i = atoi(cb->f[0]+3)) >= 1 && i <= WNKeys){
			ctlr->txkey = i-1;
			key = &ctlr->keys.keys[ctlr->txkey];
			key->len = strlen(cb->f[1]);
			if(key->len > WKeyLen)
				key->len = WKeyLen;
			memset(key->dat, 0, sizeof(key->dat));
			memmove(key->dat, cb->f[1], key->len);
		}
		else
			r = -1;
	}
	else if(cistrcmp(cb->f[0], "txkey") == 0){
		if((i = atoi(cb->f[1])) >= 1 && i <= WNKeys)
			ctlr->txkey = i-1;
		else
			r = -1;
	}
	else if(cistrcmp(cb->f[0], "pm") == 0){
		if(cistrcmp(cb->f[1], "off") == 0)
			ctlr->pmena = 0;
		else if(cistrcmp(cb->f[1], "on") == 0){
			ctlr->pmena = 1;
			if(cb->nf == 3){
				i = atoi(cb->f[2]);
				// check range here? what are the units?
				ctlr->pmwait = i;
			}
		}
		else
			r = -1;
	}
	else
		r = -2;
	free(cb);

	return r;
}

long
w_ctl(Ether* ether, void* buf, long n)
{
	Ctlr *ctlr;

	if((ctlr = ether->ctlr) == nil)
		error(Enonexist);
	if((ctlr->state & Attached) == 0)
		error(Eshutdown);

	ilock(ctlr);
	if(w_option(ctlr, buf, n)){
		iunlock(ctlr);
		error(Ebadctl);
	}
	if(ctlr->txbusy)
		w_txdone(ctlr, WTxErrEv);
	w_enable(ether);
	w_txstart(ether);
	iunlock(ctlr);

	return n;
}

void
w_transmit(Ether* ether)
{
	Ctlr* ctlr = ether->ctlr;

	if(ctlr == 0)
		return;

	ilock(ctlr);
	ctlr->ntxrq++;
	w_txstart(ether);
	iunlock(ctlr);
}

void
w_promiscuous(void* arg, int on)
{
	Ether* ether = (Ether*)arg;
	Ctlr* ctlr = ether->ctlr;

	if(ctlr == nil)
		error("card not found");
	if((ctlr->state & Attached) == 0)
		error("card not attached");
	ilock(ctlr);
	ltv_outs(ctlr, WTyp_Prom, (on?1:0));
	iunlock(ctlr);
}

void
w_interrupt(Ureg* ,void* arg)
{
	Ether* ether = (Ether*) arg;
	Ctlr* ctlr = (Ctlr*) ether->ctlr;

	if(ctlr == 0)
		return;
	ilock(ctlr);
	ctlr->nints++;
	w_intr(ether);
	iunlock(ctlr);
}

int
wavelanreset(Ether* ether, Ctlr *ctlr)
{
	Wltv ltv;

	iprint("wavelanreset, iob 0x%ux\n", ctlr->iob);
	w_intdis(ctlr);
	if(w_cmd(ctlr,WCmdIni,0)){
		iprint("#l%d: init failed\n", ether->ctlrno);
		return -1;
	}
	w_intdis(ctlr);
	ltv_outs(ctlr, WTyp_Tick, 8);

	ctlr->chan = 0;
	ctlr->ptype = WDfltPType;
	ctlr->txkey = 0;
	ctlr->createibss = 0;
	ctlr->keys.len = sizeof(WKey)*WNKeys/2 + 1;
	ctlr->keys.type = WTyp_Keys;
	if(ctlr->hascrypt = ltv_ins(ctlr, WTyp_HasCrypt))
		ctlr->crypt = 1;
	*ctlr->netname = *ctlr->wantname = 0;
	strcpy(ctlr->nodename, "Plan 9 STA");

	ctlr->netname[WNameLen-1] = 0;
	ctlr->wantname[WNameLen-1] = 0;
	ctlr->nodename[WNameLen-1] =0;

	ltv.type = WTyp_Mac;
	ltv.len	= 4;
	if(w_inltv(ctlr, &ltv)){
		iprint("#l%d: unable to read mac addr\n",
			ether->ctlrno);
		return -1;
	}
	memmove(ether->ea, ltv.addr, Eaddrlen);

	if(ctlr->chan == 0)
		ctlr->chan = ltv_ins(ctlr, WTyp_Chan);
	ctlr->apdensity = WDfltApDens;
	ctlr->rtsthres = WDfltRtsThres;
	ctlr->txrate = WDfltTxRate;
	ctlr->maxlen = WMaxLen;
	ctlr->pmena = 0;
	ctlr->pmwait = 100;
	ctlr->signal = 1;
	ctlr->noise = 1;
	ctlr->state |= Power;

	// free old Ctlr struct if resetting after suspend
	if(ether->ctlr && ether->ctlr != ctlr)
		free(ether->ctlr);

	// link to ether
	ether->ctlr = ctlr;
	ether->mbps = 10;
	ether->attach = w_attach;
	ether->detach = w_detach;
	ether->interrupt = w_interrupt;
	ether->transmit = w_transmit;
	ether->ifstat = w_ifstat;
	ether->ctl = w_ctl;
	ether->power = w_power;
	ether->promiscuous = w_promiscuous;
	ether->multicast = w_multicast;
	ether->scanbs = w_scanbs;
	ether->arg = ether;

	DEBUG("#l%d: irq %lud port %lx type %s",
		ether->ctlrno, ether->intnum, ether->ports[0].port,	ether->type);
	DEBUG(" %2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux\n",
		ether->ea[0], ether->ea[1], ether->ea[2],
		ether->ea[3], ether->ea[4], ether->ea[5]);

	return 0;
}

char* wavenames[] = {
	"WaveLAN/IEEE",
	"TrueMobile 1150",
	"Instant Wireless ; Network PC CARD",
	"Instant Wireless Network PC Card",
	"Avaya Wireless PC Card",
	"AirLancer MC-11",
	nil,
};