harvey/sys/src/cmd/cec/cec.c

/*
 * Copyright © Coraid, Inc. 2006, 2007.  All Rights Reserved.
 * ethernet console for Coraid storage products.
 *  simple command line version.
 */
#include <u.h>
#include <libc.h>
#include <ip.h>	/* really! */
#include <ctype.h>
#include "cec.h"

enum {
	Tinita = 0,
	Tinitb,
	Tinitc,
	Tdata,
	Tack,
	Tdiscover,
	Toffer,
	Treset,

	HDRSIZ = 18,
	Eaddrlen = 6,
};

typedef struct Shelf Shelf;

struct Shelf {
	uchar	ea[Eaddrlen];
	int	shelfno;
	char	*str;
};

void 	conn(int);
void	exits0(char *);
void 	gettingkilled(int);
int 	pickone(void);
void 	probe(void);
void	sethdr(Pkt *, int);
int	shelfidx(void);

extern int errno;
extern int fd;			/* set in netopen */

Shelf	tab[1000];
int	ntab;
uchar	contag;
int	shelf = -1;
Shelf	*connp;
char 	esc = '';

void
usage(void)
{
	fprint(2, "usage: cec [-d] [-e esc] [-s shelf] interface\n");
	exits0("usage");
}

void
catch(void*, char *note)
{
	if(strcmp(note, "alarm") == 0)
		noted(NCONT);
	noted(NDFLT);
}

void
main(int argc, char **argv)
{
	int r, n;

	ARGBEGIN{
	case 'd':
		debug++;
		break;
	case 's':
		shelf = atoi(EARGF(usage()));
		break;
	case 'e':
		esc = toupper(*(EARGF(usage()))) - 'A' + 1;
		if(esc <= 0 || esc >= ' ')
			usage();
		break;
	default:
		usage();
	}ARGEND
	if(debug)
		fprint(2, "debug is on\n");
	if(argc != 1)
		usage();

	fmtinstall('E', eipfmt);
	r = netopen(*argv);
	if(r == -1){
		fprint(2, "cec: can't netopen %s\n", *argv);
		exits0("open");
	}
	notify(catch);
	probe();
	for(;;){
		n = 0;
		if(shelf == -1)
			n = pickone();
		rawon();
		conn(n);
		rawoff();
		if(shelf != -1)
			exits0("shelf not found");
	}
}

void
timewait(int ms)  /* arrange for a sig_alarm signal after `ms' milliseconds */
{
	alarm(ms);
}

int
didtimeout(void)
{
	char buf[ERRMAX];

	rerrstr(buf, sizeof buf);
	if(strcmp(buf, "interrupted") == 0){
		werrstr(buf, 0);
		return 1;
	}
	return 0;
}

ushort
htons(ushort h)
{
	ushort n;
	uchar *p;

	p = (uchar*)&n;
	p[0] = h >> 8;
	p[1] = h;
	return n;
}

ushort
ntohs(int h)
{
	ushort n;
	uchar *p;

	n = h;
	p = (uchar*)&n;
	return p[0] << 8 | p[1];
}

void
probe(void)
{
	int n;
	char *sh, *other;
	uchar buf[1500];
	Pkt q;
	Shelf *p;

	ntab = 0;
	memset(buf, 0xff, Eaddrlen);
	memset(q.dst, 0xff, Eaddrlen);
	memset(q.src, 0, Eaddrlen);
	q.etype = htons(Etype);
	q.type = Tdiscover;
	q.len = 0;
	q.conn = 0;
	q.seq = 0;
	netsend(&q, 60);
//	fprint(2, "Probing for shelves ... ");
	timewait(Iowait);
	while((n = netget(&q, sizeof q)) >= 0) {
		if((n <= 0 && didtimeout()) || ntab == nelem(tab))
			break;
		if(n < 60 || q.len == 0 || q.type != Toffer)
			continue;
		q.data[q.len] = 0;
		sh = strtok((char *)q.data, " \t");
		if(sh == nil)
			continue;
		if(shelf != -1 && atoi(sh) != shelf)
			continue;
		other = strtok(nil, "\x1");
		p = tab + ntab++;
		memcpy(p->ea, q.src, Eaddrlen);
		p->shelfno = atoi(sh);
		p->str = other? strdup(other): "";
		if(shelf != -1) {
			fprint(2, "shelf %d found.\n", shelf);
			break;
		}
	}
	alarm(0);
	if(ntab == 0) {
		fprint(2, "none found.\n");
		exits0("none found");
	}
//	fprint(2, "done.\n");
}

void
showtable(void)
{
	int i;

	for(i = 0; i < ntab; i++)
		print("%2d   %5d %E %s\n", i,
			tab[i].shelfno, tab[i].ea, tab[i].str);
}

int
pickone(void)
{
	char buf[80];
	int n, i;

	for(;;){
		showtable();
		print("[#qp]: ");
		switch(n = read(0, buf, sizeof buf)){
		case 1:
			if(buf[0] == '\n')
				continue;
			/* fall through */
		case 2:
			if(buf[0] == 'p'){
				probe();
				break;
			}
			if(buf[0] == 'q')
			/* fall through */
		case 0:
		case -1:
				exits0(0);
		}
		if(isdigit(buf[0])){
			buf[n] = 0;
			i = atoi(buf);
			if(i >= 0 && i < ntab)
				break;
		}
	}
	return i;
}

void
sethdr(Pkt *pp, int type)
{
	memmove(pp->dst, connp->ea, Eaddrlen);
	memset(pp->src, 0, Eaddrlen);
	pp->etype = htons(Etype);
	pp->type = type;
	pp->len = 0;
	pp->conn = contag;
}

void
ethclose(void)
{
	static Pkt msg;

	sethdr(&msg, Treset);
	timewait(Iowait);
	netsend(&msg, 60);
	alarm(0);
	connp = 0;
}

int
ethopen(void)
{
	Pkt tpk, rpk;
	int i, n;

	contag = (getpid() >> 8) ^ (getpid() & 0xff);
	sethdr(&tpk, Tinita);
	sethdr(&rpk, 0);
	for(i = 0; i < 3 && rpk.type != Tinitb; i++){
		netsend(&tpk, 60);
		timewait(Iowait);
		n = netget(&rpk, 1000);
		alarm(0);
		if(n < 0)
			return -1;
	}
	if(rpk.type != Tinitb)
		return -1;
	sethdr(&tpk, Tinitc);
	netsend(&tpk, 60);
	return 0;
}

char
escape(void)
{
	char buf[64];

	for(;;){
		fprint(2, ">>> ");
		buf[0] = '.';
		rawoff();
		read(0, buf, sizeof buf-1);
		rawon();
		switch(buf[0]){
		case 'i':
		case 'q':
		case '.':
			return buf[0];
		}
		fprint(2, "	(q)uit, (i)nterrupt, (.)continue\n");
	}
}

/*
 * this is a bit too agressive.  it really needs to replace only \n\r with \n.
 */
static uchar crbuf[1514];

void
nocrwrite(int fd, uchar *buf, int n)
{
	int i, j, c;

	j = 0;
	for(i = 0; i < n; i++){
		if((c = buf[i]) == '\r')
			continue;
		crbuf[j++] = c;
	}
	write(fd, crbuf, j);
}

int
doloop(void)
{
	int unacked, retries, set[2];
	uchar c, tseq, rseq;
	uchar ea[Eaddrlen];
	Mux * m;
	Pkt tpk, spk;

	memmove(ea, connp->ea, Eaddrlen);
	retries = 0;
	unacked = 0;
	tseq = 0;
	rseq = -1;
	set[0] = 0;
	set[1] = fd;
top:
	if ((m = mux(set)) == 0)
		exits0("mux: %r");
	for (; ; )
		switch (muxread(m, &spk)) {
		case -1:
			if (unacked == 0)
				break;
			if (retries-- == 0) {
				fprint(2, "Connection timed out\n");
				muxfree(m);
				return 0;
			}
			netsend(&tpk, HDRSIZ + unacked);
			break;
		case 0:
			c = spk.data[0];
			if (c == esc) {
				muxfree(m);
				switch (escape()) {
				case 'q':
					tpk.len = 0;
					tpk.type = Treset;
					netsend(&tpk, 60);
					return 0;
				case '.':
					goto top;
				case 'i':
					if ((m = mux(set)) == 0)
						exits0("mux: %r");
					break;
				}
			}
			sethdr(&tpk, Tdata);
			memcpy(tpk.data, spk.data, spk.len);
			tpk.len = spk.len;
			tpk.seq = ++tseq;
			unacked = spk.len;
			retries = 2;
			netsend(&tpk, HDRSIZ + spk.len);
			break;
		default:
			if (memcmp(spk.src, ea, Eaddrlen) != 0 ||
			    ntohs(spk.etype) != Etype)
				continue;
			if (spk.type == Toffer) {
				muxfree(m);
				return 1;
			}
			if (spk.conn != contag)
				continue;
			switch (spk.type) {
			case Tdata:
				if (spk.seq == rseq)
					break;
				nocrwrite(1, spk.data, spk.len);
				if (0)
					write(1, spk.data, spk.len);
				memmove(spk.dst, spk.src, Eaddrlen);
				memset(spk.src, 0, Eaddrlen);
				spk.type = Tack;
				spk.len = 0;
				rseq = spk.seq;
				netsend(&spk, 60);
				break;
			case Tack:
				if (spk.seq == tseq)
					unacked = 0;
				break;
			case Treset:
				muxfree(m);
				return 1;
			}
		}
}

void
conn(int n)
{
	do {
		if(connp)
			ethclose();
		connp = &tab[n];
		if(ethopen() < 0){
			fprint(2, "connection failed.\n");
			return;
		}
	} while(doloop());
}

void
exits0(char *s)
{
	if(connp != nil)
		ethclose();
	rawoff();
	exits(s);
}