// aoe.c: the ATA over Ethernet virtual EtherDrive (R) blade
#include "config.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <netinet/in.h>
#include "dat.h"
#include "fns.h"

// dummy for testing
int
qcget(uchar *p, int len)
{
	memset(p, 0xff, len);
	return len;
}

int
qcset(uchar *p, int len)
{
	return len;
}

void
aoead(int fd)			// advertise the virtual blade
{
	int len;
	uchar buf[2000];
	Conf *p;

	p = (Conf *)buf;
	memset(p, 0, sizeof *p);
	memset(p->h.dst, 0xff, 6);
	memmove(p->h.src, mac, 6);
	p->h.type = htons(0x88a2);
	p->h.flags = Resp;
	p->h.maj = htons(shelf);
	p->h.min = slot;
	p->h.cmd = Config;
	p->bufcnt = htons(Bufcount);
	p->firmware = htons(FWV);
	p->vercmd = 0x10 | Qread;
	len = qcget(p->data, 1024);
	p->len = htons(len);
	if (write(fd, buf, len) == -1)
		perror("write aoe id");
}

int
isbcast(uchar *ea)		// replace with assembler routine
{
	uchar *b = (uchar *)"\377\377\377\377\377\377";

	return memcmp(ea, b, 6) == 0;
}

long long
getlba(uchar *p)
{
	vlong v;
	int i;

	v = 0;
	for (i = 0; i < 6; i++)
		v |= (vlong)(*p++) << i * 8;
	return v;
}

int
aoeata(Ata *p)	// do ATA reqeust
{
	Ataregs r;
	int len = 60;

	if (p->sectors && (p->aflag & Write) == 0)
		len = sizeof (Ata);
	r.lba = getlba(p->lba);
	r.sectors = p->sectors;
	r.feature = p->err;
	r.cmd = p->cmd;
	atacmd(&r, p->data);
	p->sectors = r.sectors;
	p->err = r.err;
	p->cmd = r.status;
	return len;
}

int
confcmd(Conf *p)	// process conf request
{
	uchar buf[1024];
	int len = 0, len2;

	switch (p->vercmd & 0xf) {
	case Qread:
		len = qcget(p->data, 1024);
		p->len = htons(len);
		break;
	case Qtest:
		len = qcget(buf, 1024);
		if (len != ntohs(p->len))
			return 0;
		if (memcmp(buf, p->data, len) != 0)
			return 0;
		memmove(p->data, buf, len);
		break;
	case Qprefix:
		len = qcget(buf, 1024);
		len2 = ntohs(p->len);
		if (len2 > len)
			return 0;
		if (memcmp(buf, p->data, len2) != 0)
			return 0;
		memmove(p->data, buf, len);
		p->len = htons(len);
		break;
	case Qset:
		if (qcget(buf, 1024) > 0) {
			p->h.flags |= Error;
			p->h.error = ConfigErr;
			break;
		}
		len = 1024;
		// fall thru
	case Qfset:
		len = ntohs(p->len);
		qcset(p->data, len);
		break;
	default:
		p->h.flags |= BadArg;
	}
	p->bufcnt = htons(Bufcount);
	p->firmware = htons(FWV);
	p->vercmd |= 0x10;
	return len;
}

void
doaoe(Aoehdr *p)
{
	int len;

	switch (p->cmd) {
	case ATAcmd:
		len = aoeata((Ata*)p);
		break;
	case Config:
		if ((len = confcmd((Conf *)p)) == 0)
			return;
		break;
	default:
		p->error = BadCmd;
		len = 1024;
		break;
	}
	memmove(p->dst, p->src, 6);
	memmove(p->src, mac, 6);
	p->maj = htons(shelf);
	p->min = slot;
	p->flags |= Resp;
	if (write(sfd, p, len) == -1) {
		perror("write to network");
		exit(1);
	}
}

void
aoe(void)
{
	Aoehdr *p;
	uchar buf[1400];
	int n, sh;

	aoead(sfd);

	for (;;) {
		n = read(sfd, buf, sizeof buf);
		if (n < 0) {
			perror("read network");
			exit(1);
		}
		if (n < 60)
			continue;
		p = (Aoehdr *)buf;
		if (ntohs(p->type) != 0x88a2)
			continue;
		if (p->flags & Resp)
			continue;
		sh = ntohs(p->maj);
		if (sh != shelf && sh != (ushort)~0)
			continue;
		if (p->min != slot && p->min != (uchar)~0)
			continue;
		doaoe(p);
	}
}

void
usage(void)
{
	fprintf(stderr, "usage: %s <shelf> <slot> <ethn> <device>\n", 
		progname);
	exit(1);
}

int
main(int argc, char **argv)
{
	setbuf(stdin, NULL);
	progname = *argv;
	if (argc != 5)
		usage();
	bfd = open(argv[4], O_RDWR);
	if (bfd == -1) {
		perror("open");
		exit(1);
	}
	shelf = atoi(argv[1]);
	slot = atoi(argv[2]);
	size = getsize(bfd);
	size /= 512;
	sfd = dial(argv[3]);
	getea(sfd, argv[3], mac);
	printf("pid %ld: e%d.%d, %lld sectors\n",
		(long) getpid(), shelf, slot, size);
	fflush(stdout);
	aoe();
	return 0;
}