/*	execcmd - proc file system execution wrapper wrapper 	Copyright (C) 2010, IBM Corporation,  		Eric Van Hensbergen (bergevan@us.ibm.com) 	Description:		This provides a small wrapper the file system can use		to boot strap the application while maintaining expected		clone semantics. 	TODO:		* fork namespace after mounting mpipes		* support for ns configuration prior to exec */ #include <u.h>#include <libc.h>#include <fcall.h>#include <thread.h>#include <9p.h>#include <debug.h> static char defaultpath[] =	"/proc";static char *procpath, *mmount; char Estdios[] = "execcmd: couldn't open stdios";char Ebadctl[] = "execcmd: bad ctl command";char Ebadexec[] = "execcmd: bad exec command"; /* using parsecmd for later expansion */enum{	Cexec,}; Cmdtab ctltab[]={	Cexec,	"exec", 0,};	 /* FIXME: debugging... */enum{	STACK = (8 * 1024),};char *extpath = 0;static voidlsproc(void *arg){	Channel *pidc = arg;	// FIXME: procpath currently not used	char *path = procpath; 	if (extpath)		path = extpath; //	Channel *pidc = chancreate(sizeof(ulong), 0);//	char *path = arg; 	threadsetname("exec2fs-lsproc");	DPRINT(DFID, "lsproc (%p) (%s) (%s) (%s) (%s) pid=(%d): %r\n",	       pidc, "/bin/ls", "ls", "-l", path, getpid());	procexecl(pidc, "/bin/ls", "ls", path, nil); 	sendul(pidc, 0); 	threadexits(nil); } static voidusage(void){	fprint(2, "execcmd [-D] [-v debuglevel] [-s srvctl] [-L logdir]\n");	exits("usage");} voidthreadmain(int argc, char **argv){	int stdinfd;	int stdoutfd;	int stderrfd;	int ctlfd;	int ret;	char *ctlbuf = emalloc9p(255);	char *fname = emalloc9p(255);	Cmdbuf *cb;	Cmdtab *cmd;	char *srvctl = nil;	char *logfile;	char *logdir = nil;	char *x;		int pid = getpid(); 	procpath = defaultpath;	mmount = defaultpath; 	ARGBEGIN{	case 'D':		chatty9p++;		break;	case 'v':		x = ARGF();		if(x)			vflag = atol(x);		break;	case 's':		srvctl = ARGF();		break;	case 'm':	/* mntpt override */		procpath = ARGF();		break;	case 'M':	/* mntpt override */		mmount = ARGF();		break;	case 'L':		logdir = ARGF();		break;	default:		/* break */		usage();		exits("argument");	}ARGEND 	if(argc != 0){		DPRINT(DERR, "*ERROR*: number of argument mismatch\n");		usage();		exits("number of arguments");	} 	/* move the  log file generation outside the test directory */	if(vflag > 0) {		if(logdir)			logfile = smprint("%s/execcmd-%d.log", logdir, getpid());		else			logfile = smprint("execcmd-%d.log", getpid());		debugfd = create(logfile, OWRITE, 0666);		if(debugfd <= 2){			DPRINT(DERR, "*ERROR*: could not open log file (%s)\n", logfile);			exits("logfile");		} 		//sleep(100);		DPRINT(DEXC, "Main: logfile=%s\n", logfile);		free(logfile);	}  	DPRINT(DEXC, "Inside execution wrapper: logdir=%s vflag=%d debugfd=%d\n", logdir, vflag, debugfd);	DPRINT(DEXC, "\tsrvctl=%s\n", srvctl);	DPRINT(DEXC, "\tprocpath=%s\n", procpath);	DPRINT(DEXC, "\tmmount=%s\n", mmount); 	/* open our files */	ctlfd = open(srvctl, ORDWR|OCEXEC);	if(ctlfd < 0){		DPRINT(DERR, "*ERROR*: could not open server ctl (%s)\n", srvctl);		exits("srvctl");	}	remove(srvctl); 	DPRINT(DEXC, "After srv ctl open\n"); 	ret = read(ctlfd, ctlbuf, 255);	if(ret <= 0){		DPRINT(DERR, "*ERROR*: ctl read failed\n");		exits("ctl read");	}	ctlbuf[ret] = 0; 	DPRINT(DEXC, "got ret=(%d) ctlbuf=(%s) pid=(%d)\n", ret, ctlbuf, pid); 	/* need to open our bit */	snprint(fname, 255, "%s/%d/stdin", mmount, pid);	stdinfd = open(fname, OREAD);	DPRINT(DCUR, "stdin=(%s) stdinfd=(%d)\n", fname, stdinfd); 	snprint(fname, 255, "%s/%d/stdout", mmount, pid);	stdoutfd = open(fname, OWRITE);	DPRINT(DCUR, "stdout=(%s) stdoutfd=(%d)\n", fname, stdoutfd); 	snprint(fname, 255, "%s/%d/stderr", mmount, pid);	stderrfd = open(fname, OWRITE);	DPRINT(DCUR, "stderr=(%s) stderrfd=(%d)\n", fname, stderrfd); 	DPRINT(DEXC, "after opening stdio pipes\n"); 	if((stdinfd < 0)||(stdoutfd < 0)||(stderrfd < 0)) {		DPRINT(DERR, "*ERROR*: some sort of issue opening stdio pipes\n"); 		write(ctlfd, Estdios, strlen(Estdios));		exits("stdios");	} 	DPRINT(DEXC, "reporting partial success\n"); 	ret = write(ctlfd, "1", 1);	/* report partial sucess */	if(ret <= 0){		DPRINT(DERR, "*ERROR*: ctl write failed\n");		exits("ctl write");	}  	DPRINT(DEXC, "waiting for cmds\n");	while((ret = read(ctlfd, ctlbuf, 255)) > 0) {		DPRINT(DEXC, "received cmd \"%s\"\n", ctlbuf); 		cb = parsecmd(ctlbuf, ret);		cmd = lookupcmd(cb, ctltab, nelem(ctltab));		if(cmd == nil) {			DPRINT(DERR, "ERROR: bad ctl\n");			write(ctlfd, Ebadctl, strlen(Ebadctl));			continue;		} 		switch(cmd->index){		case Cexec:			if(cb->nf < 2) {				DPRINT(DERR, "ERROR: bad exec\n");				write(ctlfd, Ebadexec, strlen(Ebadexec));				continue;			}			DPRINT(DEXC, "exec, duping and going\n"); 			dup(stdinfd, 0);			dup(stdoutfd, 1);			dup(stderrfd, 2);			close(debugfd);			debugfd = 2;			free(fname);			free(ctlbuf); //exits(0);						/* go baby go */			exec(cb->f[1], &cb->f[1]); // FIXME: test this fail over... 			/* something happened report it */			DPRINT(DERR, "ERROR:  something happened with the exec\n");			ctlbuf = smprint("execcmd: exec: %r");			write(ctlfd, ctlbuf, ret); 			/* make sure that we will not try to free fname twice... */			fname = nil;			goto error;			break;		/* room for more commands later */		}			}error:	free(fname);	free(ctlbuf);	close(ctlfd);	close(stdinfd);	close(stdoutfd);	close(stderrfd);	exits("ctl abort");}