// 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 <sys/stat.h>
#include <fcntl.h>
#include <netinet/in.h>
#include "dat.h"
#include "fns.h"

enum {
	Nmasks= 32,
	Alen= 6,
};

uchar masks[Nmasks*Alen];
int nmasks;
char config[Nconfig];
int nconfig = 0;
int maxscnt = 2;
char *ifname;

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

	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->scnt = maxscnt = (getmtu(sfd, ifname) - sizeof (Ata)) / 512;
	p->firmware = htons(FWV);
	p->vercmd = 0x10 | Qread;
	memcpy(p->data, config, nconfig);
	p->len = htons(nconfig);
	if (nmasks == 0)
	if (putpkt(fd, buf, sizeof *p - sizeof p->data + nconfig) == -1) {
		perror("putpkt aoe id");
		return;
	}
	for (i=0; i<nmasks; i++) {
		memcpy(p->h.dst, &masks[i*Alen], Alen);
		if (putpkt(fd, buf, sizeof *p - sizeof p->data + nconfig) == -1)
			perror("putpkt 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, int pktlen)	// do ATA reqeust
{
	Ataregs r;
	int len = 60;
	int n;

	r.lba = getlba(p->lba);
	r.sectors = p->sectors;
	r.feature = p->err;
	r.cmd = p->cmd;
	if (atacmd(&r, (uchar *)(p+1), maxscnt*512, pktlen - sizeof(*p)) < 0) {
		p->h.flags |= Error;
		p->h.error = BadArg;
		return len;
	}
	if (!(p->aflag & Write))
	if ((n = p->sectors)) {
		n -= r.sectors;
		len = sizeof (Ata) + (n*512);
	}
	p->sectors = r.sectors;
	p->err = r.err;
	p->cmd = r.status;
	return len;
}

#define QCMD(x) ((x)->vercmd & 0xf)

// yes, this makes unnecessary copies.

int
confcmd(Conf *p, int payload)	// process conf request
{
	int len;

	len = ntohs(p->len);
	if (QCMD(p) != Qread)
	if (len > Nconfig || len > payload)
		return 0;	// if you can't play nice ...
	switch (QCMD(p)) {
	case Qtest:
		if (len != nconfig)
			return 0;
		// fall thru
	case Qprefix:
		if (len > nconfig)
			return 0;
		if (memcmp(config, p->data, len))
			return 0;
		// fall thru
	case Qread:
		break;
	case Qset:
		if (nconfig)
		if (nconfig != len || memcmp(config, p->data, len)) {
			p->h.flags |= Error;
			p->h.error = ConfigErr;
			break;
		}
		// fall thru
	case Qfset:
		nconfig = len;
		memcpy(config, p->data, nconfig);
		break;
	default:
		p->h.flags |= Error;
		p->h.error = BadArg;
	}
	memmove(p->data, config, nconfig);
	p->len = htons(nconfig);
	p->bufcnt = htons(Bufcount);
	p->scnt = maxscnt = (getmtu(sfd, ifname) - sizeof (Ata)) / 512;
	p->firmware = htons(FWV);
	p->vercmd = 0x10 | QCMD(p);	// aoe v.1
	return nconfig + sizeof *p - sizeof p->data;
}

void
doaoe(Aoehdr *p, int n)
{
	int len;
	enum {	// config query header size
		CHDR_SIZ = sizeof(Conf) - sizeof(((Conf *)0)->data),
	};

	switch (p->cmd) {
	case ATAcmd:
		if (n < sizeof(Ata))
			return;
		len = aoeata((Ata*)p, n);
		break;
	case Config:
		if (n < CHDR_SIZ)
			return;
		len = confcmd((Conf *)p, n - CHDR_SIZ);
		if (len == 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 (putpkt(sfd, (uchar *) p, len) == -1) {
		perror("write to network");
		exit(1);
	}
}

void
aoe(void)
{
	Aoehdr *p;
	uchar *buf;
	int n, sh;
	enum { bufsz = 1<<16, };

	buf = malloc(bufsz);
	aoead(sfd);

	for (;;) {
		n = getpkt(sfd, buf, bufsz);
		if (n < 0) {
			perror("read network");
			exit(1);
		}
		if (n < sizeof(Aoehdr))
			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;
		if (nmasks && !maskok(p->src))
			continue;
		doaoe(p, n);
	}
	free(buf);
}

void
usage(void)
{
	fprintf(stderr, "usage: %s [ -m mac[,mac...] ] shelf slot netif filename\n", 
		progname);
	exit(1);
}

/* parseether from plan 9 */
int
parseether(uchar *to, char *from)
{
	char nip[4];
	char *p;
	int i;

	p = from;
	for(i = 0; i < 6; i++){
		if(*p == 0)
			return -1;
		nip[0] = *p++;
		if(*p == 0)
			return -1;
		nip[1] = *p++;
		nip[2] = 0;
		to[i] = strtoul(nip, 0, 16);
		if(*p == ':')
			p++;
	}
	return 0;
}

void
setmask(char *ml)
{
	char *p;
	int n;

	for (; ml; ml=p) {
		p = strchr(ml, ',');
		if (p)
			*p++ = '\0';
		n = parseether(&masks[nmasks*Alen], ml);
		if (n < 0)
			fprintf(stderr, "ignoring mask %s, parseether failure\n", ml);
		else
			nmasks++;
	}
}

int
maskok(uchar *ea)
{
	int i, ok = 0;

	for (i=0; !ok && i<nmasks; i++)
		ok = memcmp(ea, &masks[i*Alen], Alen) == 0;
	return ok;
}

int
main(int argc, char **argv)
{
	int ch, omode = O_RDONLY;
	struct stat s;

	setbuf(stdin, NULL);
	atainit();
	progname = *argv;
	while ((ch = getopt(argc, argv, "m:")) != -1) {
		switch (ch) {
		case 'm':
			setmask(optarg);
			break;
		case '?':
		default:
			usage();
		}
	}
	argc -= optind;
	argv += optind;
	if (argc != 4)
		usage();
	if (stat(argv[3], &s) < 0) {
		perror("stat");
		exit(1);
	}
	if (s.st_mode & (S_IWUSR|S_IWGRP|S_IWOTH))
		omode = O_RDWR;
	bfd = open(argv[3], omode);
	if (bfd == -1) {
		perror("open");
		exit(1);
	}
	shelf = atoi(argv[0]);
	slot = atoi(argv[1]);
	size = getsize(bfd);
	size /= 512;
	ifname = argv[2];
	sfd = dial(ifname);
	getea(sfd, ifname, mac);
	printf("pid %ld: e%d.%d, %lld sectors %s\n",
		(long) getpid(), shelf, slot, size,
		omode == O_RDWR ? "O_RDWR" : "O_RDONLY");
	fflush(stdout);
	aoe();
	return 0;
}