/* * watchdog framework */#include	"u.h"#include	"../port/lib.h"#include	"mem.h"#include	"dat.h"#include	"fns.h"#include	"io.h"#include	"../port/error.h" enum {	Qdir,	Qwdctl,}; static Watchdog *wd;static Dirtab wddir[] = {	".",		{ Qdir, 0, QTDIR },	0,		0550,	"wdctl",	{ Qwdctl, 0 },		0,		0660,};  voidaddwatchdog(Watchdog *watchdog){	if(wd){		print("addwatchdog: watchdog already installed\n");		return;	}	wd = watchdog;	if(wd)		wd->disable();} static Chan*wdattach(char *spec){	return devattach('w', spec);} static Walkqid*wdwalk(Chan *c, Chan *nc, char **name, int nname){	return devwalk(c, nc, name, nname, wddir, nelem(wddir), devgen);} static intwdstat(Chan *c, uchar *dp, int n){	return devstat(c, dp, n, wddir, nelem(wddir), devgen);} static Chan*wdopen(Chan* c, int omode){	return devopen(c, omode, wddir, nelem(wddir), devgen);} static voidwdclose(Chan*){} static longwdread(Chan* c, void* a, long n, vlong off){	ulong offset = off;	char *p; 	switch((ulong)c->qid.path){	case Qdir:		return devdirread(c, a, n, wddir, nelem(wddir), devgen); 	case Qwdctl:		if(wd == nil || wd->stat == nil)			return 0; 		p = smalloc(READSTR);		if(waserror()){			free(p);			nexterror();		} 		wd->stat(p, p + READSTR);		n = readstr(offset, a, n, p);		free(p);		poperror();		return n; 	default:		error(Egreg);		break;	}	return 0;} static longwdwrite(Chan* c, void* a, long n, vlong off){	ulong offset = off;	char *p; 	switch((ulong)c->qid.path){	case Qdir:		error(Eperm); 	case Qwdctl:		if(wd == nil)			return n; 		if(offset || n >= READSTR)			error(Ebadarg); 		if((p = strchr(a, '\n')) != nil)			*p = 0; 		if(strncmp(a, "enable", n) == 0)			wd->enable();		else if(strncmp(a, "disable", n) == 0)			wd->disable();		else if(strncmp(a, "restart", n) == 0)			wd->restart();		else			error(Ebadarg);		return n; 	default:		error(Egreg);		break;	} 	return 0;} Dev wddevtab = {	'w',	"watchdog", 	devreset,	devinit,	devshutdown,	wdattach,	wdwalk,	wdstat,	wdopen,	devcreate,	wdclose,	wdread,	devbread,	wdwrite,	devbwrite,	devremove,	devwstat,	devpower,};