#include <u.h>#include <libc.h>#include <auth.h> int	eof;		/* send an eof if true */int	crtonl;		/* convert all received \r to \n */int	returns;	/* strip \r on reception */char	*note = "die: yankee dog";char	*ruser;		/* for BSD authentication */char *key; void	rex(int, char*, char*);void	tcpexec(int, char*, char*);int	call(char *, char*, char*, char**);char	*buildargs(char*[]);int	send(int);void	error(char*, char*);void	sshexec(char*, char*); voidusage(void){	fprint(2, "usage: %s [-e] [-T] [-r] [-k keypattern] [-l user] net!host command...\n", argv0);	exits("usage");} static intcatch(void *, char *s){	return strstr(s, "alarm") != nil;} voidmain(int argc, char *argv[]){	char *host, *addr, *args;	int fd; 	key = "";	eof = 1;	crtonl = 0;	returns = 1;	ARGBEGIN{	case 'T':		crtonl = 1;		break;	case 'r':		returns = 0;		break;	case 'e':		eof = 0;		break;	case 'k':		key = EARGF(usage());		break;	case 'l':		ruser = EARGF(usage());		break;	default:		usage();	}ARGEND 	if(argc < 2)		usage();	host = argv[0];	args = buildargs(&argv[1]);	atnotify(catch, 1); 	/* try rexexec p9any then dial again with p9sk2 */	fd = call(0, host, "rexexec", &addr);	if(fd >= 0)		rex(fd, args, "p9any");	close(fd);	fd = call(0, host, "rexexec", &addr);	if(fd >= 0)		rex(fd, args, "p9sk2");	close(fd); 	/* if there's an ssh port, try that */	fd = call("tcp", host, "ssh", &addr);	if(fd >= 0){		close(fd);		sshexec(host, args);		/* falls through if no ssh */	} 	/* specific attempts */	fd = call("tcp", host, "shell", &addr);	if(fd >= 0)		tcpexec(fd, addr, args); 	error("can't dial", host);	exits(0);} intcall(char *net, char *host, char *service, char **na){	*na = netmkaddr(host, net, service);	return dial(*na, 0, 0, 0);} voidrex(int fd, char *cmd, char *proto){	char buf[4096];	int kid, n, oalarm;	AuthInfo *ai; 	oalarm = alarm(2 * 60 * 1000);		/* don't hang forever */	ai = auth_proxy(fd, auth_getkey, "proto=%s role=client %s", proto, key);	alarm(oalarm);	if(ai == nil){		if(strcmp(proto, "p9any") == 0)			return;		error("auth_proxy", nil);	}	write(fd, cmd, strlen(cmd)+1); 	kid = send(fd);	while((n=read(fd, buf, sizeof buf))>0)		if(write(1, buf, n)!=n)			error("write error", 0);	sleep(250);	postnote(PNPROC, kid, note);/**/	exits(0);} voidtcpexec(int fd, char *addr, char *cmd){	char *cp, *ep, *u, *ru, buf[4096];	int kid, n; 	/*	 *  do the ucb authentication and send command	 */	u = getuser();	ru = ruser;	if(ru == nil)		ru = u;	if(write(fd, "", 1)<0 || write(fd, u, strlen(u)+1)<0	|| write(fd, ru, strlen(ru)+1)<0 || write(fd, cmd, strlen(cmd)+1)<0){		close(fd);		error("can't authenticate to", addr);	} 	/*	 *  get authentication reply	 */	if(read(fd, buf, 1) != 1){		close(fd);		error("can't authenticate to", addr);	}	if(buf[0] != 0){		while(read(fd, buf, 1) == 1){			write(2, buf, 1);			if(buf[0] == '\n')				break;		}		close(fd);		error("rejected by", addr);	} 	kid = send(fd);	while((n=read(fd, buf, sizeof buf))>0){		if(crtonl) {			/* convert cr's to nl's */			for (cp = buf; cp < buf + n; cp++)				if (*cp == '\r')					*cp = '\n';		}		else if(!returns){			/* convert cr's to null's */			cp = buf;			ep = buf + n;			while(cp < ep && (cp = memchr(cp, '\r', ep-cp))){				memmove(cp, cp+1, ep-cp-1);				ep--;				n--;			}		}		if(write(1, buf, n)!=n)			error("write error", 0);	}	sleep(250);	postnote(PNPROC, kid, note);/**/	exits(0);} voidsshexec(char *host, char *cmd){	char *argv[10];	int n; 	n = 0;	argv[n++] = "ssh";	argv[n++] = "-iCm";	if(!returns)		argv[n++] = "-r";	if(ruser){		argv[n++] = "-l";		argv[n++] = ruser;	}	argv[n++] = host;	argv[n++] = cmd;	argv[n] = 0;	exec("/bin/ssh", argv);} intsend(int fd){	char buf[4096];	int n;	int kid;	switch(kid = fork()){	case -1:		error("fork error", 0);	case 0:		break;	default:		return kid;	}	while((n=read(0, buf, sizeof buf))>0)		if(write(fd, buf, n)!=n)			exits("write error");	if(eof)		write(fd, buf, 0); 	exits(0);	return 0;			/* to keep compiler happy */} voiderror(char *s, char *z){	if(z == 0)		fprint(2, "%s: %s: %r\n", argv0, s);	else		fprint(2, "%s: %s %s: %r\n", argv0, s, z);	exits(s);} char *buildargs(char *argv[]){	char *args;	int m, n; 	args = malloc(1);	args[0] = '\0';	n = 0;	while(*argv){		m = strlen(*argv) + 1;		args = realloc(args, n+m +1);		if(args == 0)			error("malloc fail", 0);		args[n] = ' ';	/* smashes old null */		strcpy(args+n+1, *argv);		n += m;		argv++;	}	return args;}