#include <vfs.h>
#include <kfs.h>
#include <slab.h>
#include <kmalloc.h>
#include <kref.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <error.h>
#include <cpio.h>
#include <pmap.h>
#include <smp.h>
#include <etherif.h>

static struct ether *etherxx[Maxether];

struct chan *etherattach(char *spec)
{
	ERRSTACK(2);
	uint32_t ctlrno;
	char *p;
	struct chan *chan;

	ctlrno = 0;
	/* 'spec' is the special, i.e. l0, l1, etc. */
	if (spec && *spec) {
		ctlrno = strtoul(spec, &p, 0);
		if ((ctlrno == 0 && p == spec) || *p || (ctlrno >= Maxether))
			error(Ebadarg);
	}
	if (etherxx[ctlrno] == 0)
		error(Enodev);

	chan = devattach('l', spec);
	if (waserror()) {
		chanfree(chan);
		nexterror();
	}
	chan->devno = ctlrno;
	if (etherxx[ctlrno]->attach)
		etherxx[ctlrno]->attach(etherxx[ctlrno]);

	return chan;
}

static struct walkqid *etherwalk(struct chan *chan, struct chan *nchan,
								 char **name, int nname)
{
	return netifwalk(&etherxx[chan->devno]->netif, chan, nchan, name, nname);
}

static long
etherstat(struct chan *chan, uint8_t * dp, long n)
{
	return netifstat(&etherxx[chan->devno]->netif, chan, dp, n);
}

static struct chan *etheropen(struct chan *chan, int omode)
{
	return netifopen(&etherxx[chan->devno]->netif, chan, omode);
}

static void
ethercreate(struct chan *u1, char *u2, int u3, int u4)
{
}

static void etherclose(struct chan *chan)
{
	netifclose(&etherxx[chan->devno]->netif, chan);
}

static long
etherread(struct chan *chan, void *buf, long n, int64_t off)
{
	struct ether *ether;
	uint32_t offset = off;

	ether = etherxx[chan->devno];
	if ((chan->qid.type & QTDIR) == 0 && ether->ifstat) {
		/*
		 * With some controllers it is necessary to reach
		 * into the chip to extract statistics.
		 */
		if (NETTYPE(chan->qid.path) == Nifstatqid)
			return ether->ifstat(ether, buf, n, offset);
		else if (NETTYPE(chan->qid.path) == Nstatqid)
			ether->ifstat(ether, buf, 0, offset);
	}

	return netifread(&ether->netif, chan, buf, n, offset);
}

static struct block *etherbread(struct chan *chan, long n, int64_t offset)
{
	return netifbread(&etherxx[chan->devno]->netif, chan, n, offset);
}

static long
etherwstat(struct chan *chan, uint8_t * dp, long n)
{
	return netifwstat(&etherxx[chan->devno]->netif, chan, dp, n);
}

#if 0
part of plan 9 packet dump infrastructure.wrap output packets back to input
	static void etherrtrace(Netfile * f, struct etherpkt *pkt, int len)
{
	int i, n;
	struct block *bp;

	if (qwindow(f->iq) <= 0)
		return;
	if (len > 58)
		n = 58;
	else
		n = len;
	bp = iallocb(64);
	if (bp == NULL)
		return;
	memmove(bp->wp, pkt->d, n);
	i = TK2MS(sys->ticks);
	bp->wp[58] = len >> 8;
	bp->wp[59] = len;
	bp->wp[60] = i >> 24;
	bp->wp[61] = i >> 16;
	bp->wp[62] = i >> 8;
	bp->wp[63] = i;
	bp->wp += 64;
	qpass(f->iq, bp);
}
#endif

struct block *etheriq(struct ether *ether, struct block *bp, int fromwire)
{
	struct etherpkt *pkt;
	uint16_t type;
	int len, multi, tome, fromme;
	struct netfile **ep, *f, **fp, *fx;
	struct block *xbp;

	ether->netif.inpackets++;

	pkt = (struct etherpkt *)bp->rp;
	len = BLEN(bp);
	type = (pkt->type[0] << 8) | pkt->type[1];
	fx = 0;
	ep = &ether->netif.f[Ntypes];

	multi = pkt->d[0] & 1;
	/* check for valid multicast addresses */
	if (multi && memcmp(pkt->d, ether->netif.bcast, sizeof(pkt->d)) != 0
		&& ether->netif.prom == 0) {
		if (!activemulti(&ether->netif, pkt->d, sizeof(pkt->d))) {
			if (fromwire) {
				freeb(bp);
				bp = 0;
			}
			return bp;
		}
	}

	/* is it for me? */
	tome = memcmp(pkt->d, ether->ea, sizeof(pkt->d)) == 0;
	fromme = memcmp(pkt->s, ether->ea, sizeof(pkt->s)) == 0;

	/*
	 * Multiplex the packet to all the connections which want it.
	 * If the packet is not to be used subsequently (fromwire != 0),
	 * attempt to simply pass it into one of the connections, thereby
	 * saving a copy of the data (usual case hopefully).
	 */
	for (fp = ether->netif.f; fp < ep; fp++) {
		if ((f = *fp))
			if (f->type == type || f->type < 0)
				if (tome || multi || f->prom || f->bridge & 2) {
					/* Don't want to hear bridged packets */
					if (f->bridge && !fromwire && !fromme)
						continue;
					if (!f->headersonly) {
						if (fromwire && fx == 0)
							fx = f;
						else if ((xbp = iallocb(len))) {
							memmove(xbp->wp, pkt, len);
							xbp->wp += len;
							if (qpass(f->iq, xbp) < 0)
								ether->netif.soverflows++;
						} else
							ether->netif.soverflows++;
					} else;	//etherrtrace(f, pkt, len);
				}
	}

	if (fx) {
		if (qpass(fx->iq, bp) < 0)
			ether->netif.soverflows++;
		return 0;
	}
	if (fromwire) {
		freeb(bp);
		return 0;
	}

	return bp;
}

static int
etheroq(struct ether *ether, struct block *bp)
{
	int len, loopback;
	struct etherpkt *pkt;
	int8_t irq_state = 0;

	ether->netif.outpackets++;

	/*
	 * Check if the packet has to be placed back onto the input queue,
	 * i.e. if it's a loopback or broadcast packet or the interface is
	 * in promiscuous mode.
	 * If it's a loopback packet indicate to etheriq that the data isn't
	 * needed and return, etheriq will pass-on or free the block.
	 * To enable bridging to work, only packets that were originated
	 * by this interface are fed back.
	 */
	pkt = (struct etherpkt *)bp->rp;
	len = BLEN(bp);
	loopback = memcmp(pkt->d, ether->ea, sizeof(pkt->d)) == 0;
	if (loopback || memcmp(pkt->d, ether->netif.bcast, sizeof(pkt->d)) == 0
		|| ether->netif.prom) {
		disable_irqsave(&irq_state);
		etheriq(ether, bp, 0);
		enable_irqsave(&irq_state);
	}

	if (!loopback) {
		qbwrite(ether->netif.oq, bp);
		if (ether->transmit != NULL)
			ether->transmit(ether);
	} else
		freeb(bp);

	return len;
}

static long
etherwrite(struct chan *chan, void *buf, long n, int64_t unused)
{
	ERRSTACK(2);
	struct ether *ether;
	struct block *bp;
	int nn, onoff;
	struct cmdbuf *cb;

	ether = etherxx[chan->devno];
	if (NETTYPE(chan->qid.path) != Ndataqid) {
		nn = netifwrite(&ether->netif, chan, buf, n);
		if (nn >= 0)
			return nn;
		cb = parsecmd(buf, n);
		if (cb->f[0] && strcmp(cb->f[0], "nonblocking") == 0) {
			if (cb->nf <= 1)
				onoff = 1;
			else
				onoff = atoi(cb->f[1]);
			qnoblock(ether->netif.oq, onoff);
			kfree(cb);
			return n;
		}
		kfree(cb);
		if (ether->ctl != NULL)
			return ether->ctl(ether, buf, n);

		error(Ebadctl);
	}

	if (n > ether->netif.mtu)
		error(Etoobig);
	if (n < ether->netif.minmtu)
		error(Etoosmall);

	bp = allocb(n);
	if (waserror()) {
		freeb(bp);
		nexterror();
	}
	memmove(bp->rp, buf, n);
	if ((ether->netif.f[NETID(chan->qid.path)]->bridge & 2) == 0)
		memmove(bp->rp + Eaddrlen, ether->ea, Eaddrlen);

	bp->wp += n;

	return etheroq(ether, bp);
}

static long
etherbwrite(struct chan *chan, struct block *bp, int64_t unused)
{
	ERRSTACK(1);
	struct ether *ether;
	long n;

	n = BLEN(bp);
	if (NETTYPE(chan->qid.path) != Ndataqid) {
		if (waserror()) {
			freeb(bp);
			nexterror();
		}
		n = etherwrite(chan, bp->rp, n, 0);
		freeb(bp);
		return n;
	}
	ether = etherxx[chan->devno];

	if (n > ether->netif.mtu) {
		freeb(bp);
		error(Etoobig);
	}
	if (n < ether->netif.minmtu) {
		freeb(bp);
		error(Etoosmall);
	}

	return etheroq(ether, bp);
}

static struct {
	char *type;
	int (*reset) (struct ether *);
} cards[Maxether + 1];

void addethercard(char *t, int (*r) (struct ether *))
{
	static int ncard;

	if (ncard == Maxether)
		panic("too many ether cards");
	cards[ncard].type = t;
	cards[ncard].reset = r;
	ncard++;
}

static struct ether *etherprobe(int cardno, int ctlrno)
{
	int i, j;
	struct ether *ether;
	char buf[128], name[32];

	ether = kzmalloc(sizeof(struct ether), 0);
	memset(ether, 0, sizeof(struct ether));
	ether->ctlrno = ctlrno;
	ether->netif.mbps = 10;
	ether->netif.minmtu = ETHERMINTU;
	ether->netif.mtu = ETHERMAXTU;
	ether->netif.maxmtu = ETHERMAXTU;
	qlock_init(&ether->netif.qlock);

	if (cardno >= Maxether || cards[cardno].type == NULL) {
		kfree(ether);
		return NULL;
	}
	if (cards[cardno].reset(ether) < 0) {
		kfree(ether);
		return NULL;
	}

	/*
	 * IRQ2 doesn't really exist, it's used to gang the interrupt
	 * controllers together. A device set to IRQ2 will appear on
	 * the second interrupt controller as IRQ9.
	 */
	if (ether->irq == 2)
		ether->irq = 9;
	snprintf(name, sizeof(name), "ether%d", ctlrno);

	/*
	 * If ether->irq is <0, it is a hack to indicate no interrupt
	 * used by ethersink.
	 */
	if (ether->irq >= 0)
		register_dev_irq(ether->irq, ether->interrupt, ether);

	i = snprintf(buf, sizeof(buf), "#l%d: %s: %dMbps port %#p irq %d tu %d",
				 ctlrno, cards[cardno].type, ether->netif.mbps, ether->port,
				 ether->irq, ether->netif.mtu);
#if 0
	if (ether->mem)
		i += sprint(buf + i, " addr %#p", ether->mem);

	if (ether->size)
		i += sprint(buf + i, " size 0x%luX", ether->size);
#endif
	i += snprintf(buf + i, sizeof(buf) - i,
				  ": %2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux", ether->ea[0],
				  ether->ea[1], ether->ea[2], ether->ea[3], ether->ea[4],
				  ether->ea[5]);
	snprintf(buf + i, sizeof(buf) - i, "\n");
	printd(buf);

	j = ether->netif.mbps;
	if (j > 1000)
		j *= 10;
	for (i = 0; j >= 100; i++)
		j /= 10;
	i = (128 << i) * 1024;
	netifinit(&ether->netif, name, Ntypes, i);
	if (ether->netif.oq == 0)
		ether->netif.oq = qopen(i, Qmsg, 0, 0);
	if (ether->netif.oq == 0)
		panic("etherreset %s", name);
	ether->netif.alen = Eaddrlen;
	memmove(ether->netif.addr, ether->ea, Eaddrlen);
	memset(ether->netif.bcast, 0xFF, Eaddrlen);

	return ether;
}

static
void etherreset(void)
{
	struct ether *ether;
	int cardno, ctlrno;

	cardno = ctlrno = 0;
	while (cards[cardno].type != NULL && ctlrno < Maxether) {
		if (etherxx[ctlrno] != NULL) {
			ctlrno++;
			continue;
		}
		if ((ether = etherprobe(cardno, ctlrno)) == NULL) {
			cardno++;
			continue;
		}
		etherxx[ctlrno] = ether;
		ctlrno++;
	}
}

static void ethershutdown(void)
{
	char name[32];
	int i;
	struct ether *ether;

	for (i = 0; i < Maxether; i++) {
		ether = etherxx[i];
		if (ether == NULL)
			continue;
		if (ether->shutdown == NULL) {
			printd("#l%d: no shutdown function\n", i);
			continue;
		}
		snprintf(name, sizeof(name), "ether%d", i);
		if (ether->irq >= 0) {
			//  intrdisable(ether->irq, ether->interrupt, ether, ether->tbdf, name);
		}
		(*ether->shutdown) (ether);
	}
}

#define ROLYPOLY 0xedb88320

/* really slow 32 bit crc for ethers */
uint32_t ethercrc(uint8_t * p, int len)
{
	int i, j;
	uint32_t crc, b;

	crc = 0xffffffff;
	for (i = 0; i < len; i++) {
		b = *p++;
		for (j = 0; j < 8; j++) {
			crc = (crc >> 1) ^ (((crc ^ b) & 1) ? ROLYPOLY : 0);
			b >>= 1;
		}
	}
	return crc;
}

struct dev etherdevtab = {
	'l',
	"ether",

	etherreset,
	devinit,
	ethershutdown,
	etherattach,
	etherwalk,
	etherstat,
	etheropen,
	ethercreate,
	etherclose,
	etherread,
	etherbread,
	etherwrite,
	etherbwrite,
	devremove,
	etherwstat,
	devpower,
	devconfig,
	devchaninfo,
};