/* * exportfs - Export a plan 9 name space across a network */#include <u.h>#include <libc.h>#include <auth.h>#include <fcall.h>#define Extern#include "exportfs.h" void (*fcalls[])(Fsrpc*) ={	[Tnop]		Xnop,	[Tsession]	Xsession,	[Tflush]	Xflush,	[Tattach]	Xattach,	[Tclone]	Xclone,	[Twalk]		Xwalk,	[Topen]		slave,	[Tcreate]	Xcreate,	[Tclunk]	Xclunk,	[Tread]		slave,	[Twrite]	slave,	[Tremove]	Xremove,	[Tstat]		Xstat,	[Twstat]	Xwstat,	[Tclwalk]	Xclwalk,}; int nonone; voidusage(void){	fprint(2, "usage: %s [-as] [-c ctlfile]\n", argv0);	fatal("usage");} voidmain(int argc, char **argv){	char buf[128];	Fsrpc *r;	int n, srv;	char *dbfile;	char *ctlfile;	char user[NAMELEN]; 	dbfile = "/tmp/exportdb";	ctlfile = 0;	srv = 0; 	ARGBEGIN{	case 'a':		if(srvauth(0, user) < 0)			fatal("srvauth");		if(newns(user, 0) < 0)			fatal("newns");		putenv("service", "exportfs");		break; 	case 'c':		ctlfile = ARGF();		break; 	case 'd':		dbg++;		break; 	case 'f':		dbfile = ARGF();		break; 	case 's':		srv++;		break; 	default:		usage();	}ARGEND	USED(argc, argv); 	if(dbg) {		n = create(dbfile, OWRITE|OTRUNC, 0666);		dup(n, 2);		close(n);	} 	DEBUG(2, "exportfs: started\n"); 	rfork(RFNOTEG); 	Workq = malloc(sizeof(Fsrpc)*Nr_workbufs);	fhash = malloc(sizeof(Fid*)*FHASHSIZE); 	if(Workq == 0 || fhash == 0)		fatal("no initial memory"); 	memset(Workq, 0, sizeof(Fsrpc)*Nr_workbufs); 	fmtinstall('F', fcallconv); 	/*	 * Get tree to serve from network connection,	 * check we can get there and ack the connection 	 */	if(srv) {		chdir("/");		DEBUG(2, "invoked as server for /");	}	else {		buf[0] = 0;		n = read(0, buf, sizeof(buf));		if(n < 0) {			errstr(buf);			fprint(0, "read(0): %s", buf);			DEBUG(2, "read(0): %s", buf);			exits(buf);		}		buf[n] = 0;		if(chdir(buf) < 0) {			char ebuf[128];			errstr(ebuf);			fprint(0, "chdir(%d:\"%s\"): %s", n, buf, ebuf);			DEBUG(2, "chdir(%d:\"%s\"): %s", n, buf, ebuf);			exits(ebuf);		}	} 	/*	 * take ownership of the network connection and	 * push the fcall line discipline	 */	if(ctlfile)		pushfcall(ctlfile); 	DEBUG(2, "initing root\n");	initroot(); 	DEBUG(2, "exportfs: %s\n", buf); 	if(srv == 0 && write(0, "OK", 2) != 2)		fatal("open ack write"); 	/*	 * Start serving file requests from the network	 */	for(;;) {		r = getsbuf();		if(r == 0)			fatal("Out of service buffers"); 		do			n = read9p(0, r->buf, sizeof(r->buf));		while(n == 0); 		if(n < 0)			fatal("server read");  		if(convM2S(r->buf, &r->work, n) == 0)			fatal("format error"); 		DEBUG(2, "%F\n", &r->work, &r->work);		(fcalls[r->work.type])(r);	}} voidreply(Fcall *r, Fcall *t, char *err){	char data[MAXFDATA+MAXMSG];	int n; 	t->tag = r->tag;	t->fid = r->fid;	if(err) {		t->type = Rerror;		strncpy(t->ename, err, ERRLEN);	}	else 		t->type = r->type + 1; 	DEBUG(2, "\t%F\n", t); 	n = convS2M(t, data);	if(write9p(0, data, n)!=n)		fatal("mount write");} Fid *getfid(int nr){	Fid *f; 	for(f = fidhash(nr); f; f = f->next)		if(f->nr == nr)			return f; 	return 0;} intfreefid(int nr){	Fid *f, **l;	char buf[128]; 	l = &fidhash(nr);	for(f = *l; f; f = f->next) {		if(f->nr == nr) {			if(f->mpend)				f->mpend->busy = 0;			if(f->mid) {				sprint(buf, "/mnt/exportfs/%d", f->mid);				unmount(0, buf);				psmap[f->mid] = 0;			}			*l = f->next;			f->next = fidfree;			fidfree = f;			return 1;		}		l = &f->next;	} 	return 0;	} Fid *newfid(int nr){	Fid *new, **l;	int i; 	l = &fidhash(nr);	for(new = *l; new; new = new->next)		if(new->nr == nr)			return 0; 	if(fidfree == 0) {		fidfree = malloc(sizeof(Fid) * Fidchunk);		if(fidfree == 0)			fatal("out of memory"); 		for(i = 0; i < Fidchunk-1; i++)			fidfree[i].next = &fidfree[i+1]; 		fidfree[Fidchunk-1].next = 0;	} 	new = fidfree;	fidfree = new->next; 	memset(new, 0, sizeof(Fid));	new->next = *l;	*l = new;	new->nr = nr;	new->fid = -1;	new->mpend = 0;	new->mid = 0; 	return new;	} Fsrpc *getsbuf(void){	static int ap;	int look;	Fsrpc *wb; 	for(look = 0; look < Nr_workbufs; look++) {		if(++ap == Nr_workbufs)			ap = 0;		if(Workq[ap].busy == 0)			break;	} 	if(look == Nr_workbufs)		fatal("No more work buffers"); 	wb = &Workq[ap];	wb->pid = 0;	wb->canint = 0;	wb->flushtag = NOTAG;	wb->busy = 1; 	return wb;} char *strcatalloc(char *p, char *n){	char *v; 	v = realloc(p, strlen(p)+strlen(n)+1);	if(v == 0)		fatal("no memory");	strcat(v, n);	return v;} File *file(File *parent, char *name){	Dir dir;	char buf[128];	File *f, *new; 	DEBUG(2, "\tfile: 0x%x %s name %s\n", parent, parent->name, name); 	for(f = parent->child; f; f = f->childlist)		if(strcmp(name, f->name) == 0)			return f; 	makepath(buf, parent, name);	if(dirstat(buf, &dir) < 0)		return 0;		new = malloc(sizeof(File));	if(new == 0)		fatal("no memory"); 	memset(new, 0, sizeof(File));	strcpy(new->name, name);	new->qid.vers = dir.qid.vers;	new->qid.path = (dir.qid.path&CHDIR)|++qid; 	new->parent = parent;	new->childlist = parent->child;	parent->child = new; 	return new;} voidinitroot(void){	Dir dir; 	root = malloc(sizeof(File));	if(root == 0)		fatal("no memory"); 	memset(root, 0, sizeof(File));	strcpy(root->name, ".");	if(dirstat(root->name, &dir) < 0)		fatal("root stat"); 	root->qid.vers = dir.qid.vers;	root->qid.path = (dir.qid.path&CHDIR)|++qid; 	psmpt = malloc(sizeof(File));	if(psmpt == 0)		fatal("no memory"); 	memset(psmpt, 0, sizeof(File));	strcpy(psmpt->name, "/");	if(dirstat(psmpt->name, &dir) < 0)		return; 	psmpt->qid.vers = dir.qid.vers;	psmpt->qid.path = (dir.qid.path&CHDIR)|++qid; 	psmpt = file(psmpt, "mnt");	if(psmpt == 0)		return;	psmpt = file(psmpt, "exportfs");} voidmakepath(char *s, File *p, char *name){	int i;	char *c, *seg[256]; 	seg[0] = name;	for(i = 1; i < 100 && p; i++, p = p->parent)		seg[i] = p->name; 	while(i--) {		for(c = seg[i]; *c; c++)			*s++ = *c;		*s++ = '/';	}	while(s[-1] == '/')		s--;	*s = '\0';} voidfatal(char *s){	char buf[128];	Proc *m; 	sprint(buf, "exportfs: %r: %s", s); 	/* Clear away the slave children */	for(m = Proclist; m; m = m->next)		postnote(PNPROC, m->pid, "kill"); 	DEBUG(2, "%s\n", buf);	exits(buf);} char pushmsg[] = "push fcall"; voidpushfcall(char *ctl){	int cfd;	Dir dir; 	if(dirfstat(0, &dir) < 0){		fprint(2, "dirfstat(0) failed: %r\n");		return;	}	memmove(dir.uid, getuser(), NAMELEN);	if(dirfwstat(1, &dir) < 0){		fprint(2, "dirfwstat(1) failed: %r\n");		return;	}	cfd = open(ctl, ORDWR);	if(cfd < 0){		fprint(2, "open(%s0) failed: %r\n", ctl);		return;	}	if(write(cfd, pushmsg, strlen(pushmsg)) < 0){		fprint(2, "%s failed: %r\n", pushmsg);		return;	}	close(cfd);}