#include	"dat.h"#include	"fns.h"#include	"error.h" typedef struct Srv Srv;struct Srv{	Ref;	int	fd;	/* fd for opened /srv or /srv/X, or -1 */	int	sfd;	/* fd for created /srv entry or -1 */	uvlong	path;	Srv	*next;}; static QLock	srv9lk;static Srv	*srv9;static Srv	*srvroot; static char*srvname(Chan *c){	char *p; 	p = strrchr(c->name->s, '/');	if(p == nil)		return "";	return p+1;} static Srv*srvget(uvlong path){	Srv *sv; 	qlock(&srv9lk);	for(sv = srv9; sv != nil; sv = sv->next)		if(sv->path == path){			incref(sv);			qunlock(&srv9lk);			return sv;		}	sv = smalloc(sizeof(*sv));	sv->path = path;	sv->fd = -1;	sv->sfd = -1;	sv->ref = 1;	sv->next = srv9;	srv9 = sv;	qunlock(&srv9lk);	return sv;} static voidsrvput(Srv *sv){	Srv **l;	int fd, sfd; 	if(sv != nil && decref(sv) == 0){		qlock(&srv9lk);		for(l = &srv9; *l != nil; l = &(*l)->next)			if(*l == sv){				*l = sv->next;				break;			}		qunlock(&srv9lk);		fd = sv->fd;		sfd = sv->sfd;		free(sv);		if(sfd >= 0){			osenter();			close(sfd);			osleave();		}		if(fd >= 0){			osenter();			close(fd);			osleave();		}	}} static voidsrv9init(void){	Srv *sv; 	sv = mallocz(sizeof(*srvroot), 1);	sv->path = 0;	sv->fd = -1;	sv->ref = 1;	/* subsequently never reaches zero */	srvroot = srv9 = sv;} static Chan*srv9attach(char *spec){	Chan *c; 	if(*spec)		error(Ebadspec);	c = devattach(L'₪', spec);	if(c != nil){		incref(srvroot);		c->aux = srvroot;	}	return c;} static Walkqid*srv9walk(Chan *c, Chan *nc, char **name, int nname){	int j, alloc;	Walkqid *wq;	char *n;	Dir *d; 	if(nname > 0)		isdir(c); 	alloc = 0;	wq = smalloc(sizeof(Walkqid)+(nname-1)*sizeof(Qid));	if(waserror()){		if(alloc)			cclose(wq->clone);		free(wq);		return nil;	}	if(nc == nil){		nc = devclone(c);		nc->type = 0;	/* device doesn't know about this channel yet */		alloc = 1;	}	wq->clone = nc; 	for(j=0; j<nname; j++){		if(!(nc->qid.type&QTDIR)){			if(j==0)				error(Enotdir);			break;		}		n = name[j];		if(strcmp(n, ".") != 0 && strcmp(n, "..") != 0){			snprint(up->genbuf, sizeof(up->genbuf), "/srv/%s", n);			d = dirstat(up->genbuf);			if(d == nil){				if(j == 0)					error(Enonexist);				kstrcpy(up->env->errstr, Enonexist, ERRMAX);				break;			}			nc->qid = d->qid;			free(d);		}		wq->qid[wq->nqid++] = nc->qid;	}	poperror();	if(wq->nqid < nname){		if(alloc)			cclose(wq->clone);		wq->clone = nil;	}else{		/* attach cloned channel to device */		wq->clone->type = c->type;		if(wq->clone != c)			nc->aux = srvget(nc->qid.path);	}	return wq;} static intsrv9stat(Chan *c, uchar *db, int n){	Srv *sv;	Dir d; 	if(c->qid.type & QTDIR){		devdir(c, c->qid, "#₪", 0, eve, 0775, &d);		n = convD2M(&d, db, n);		if(n == 0)			error(Eshortstat);		return n;	}	sv = c->aux;	if(sv->fd >= 0){		osenter();		n = fstat(sv->fd, db, n);		osleave();	}else{		osenter();		n = stat(srvname(c), db, n);		osleave();	}	return n;} static Chan*srv9open(Chan *c, int omode){	Srv *sv;	char *args[10];	int fd[2], i, ifd, is9p;	Dir *d; 	sv = c->aux;	if(c->qid.type == QTDIR){		osenter();		sv->fd = open("/srv", omode);		osleave();		if(sv->fd < 0)			oserror();		c->mode = omode;		c->flag |= COPEN;		c->offset = 0;		return c;	} 	if(omode&OTRUNC || openmode(omode) != ORDWR)		error(Eperm);	if(sv->fd < 0){		snprint(up->genbuf, sizeof(up->genbuf), "/srv/%s", srvname(c)); 		/* check permission */		osenter();		ifd = open(up->genbuf, omode);		osleave();		if(ifd < 0)			oserror();		osenter();		d = dirfstat(ifd);		is9p = d != nil && d->qid.type & QTMOUNT;		free(d);		osleave(); 		if(is9p){			close(ifd); 			/* spawn exportfs */			args[0] = "exportfs";			args[1] = "-S";			args[2] = up->genbuf;			args[3] = nil;			if(pipe(fd) < 0)				oserror();			/* TO DO: without RFMEM there's a copy made of each page touched by any kproc until the exec */			switch(rfork(RFPROC|RFNOWAIT|RFREND|RFFDG|RFNAMEG|RFENVG)){	/* no sharing except NOTEG */			case -1:				oserrstr(up->genbuf, sizeof(up->genbuf));				close(fd[0]);				close(fd[1]);				error(up->genbuf);			case 0:				for(i=3; i<MAXNFD; i++)					if(i != fd[1])						close(i);				dup(fd[1], 0);				if(fd[0] != 0)					close(fd[0]);				dup(0, 1);				exec("/bin/exportfs", args);				exits("exportfs failed");			default:				sv->fd = fd[0];				close(fd[1]);				break;			}		}else			sv->fd = ifd;	} 	c->mode = ORDWR;	c->offset = 0;	c->flag |= COPEN;	return c;} static voidsrv9close(Chan *c){	srvput(c->aux);} static longsrv9read(Chan *c, void *va, long n, vlong off){	Srv *sv; 	sv = c->aux;	osenter();	n = pread(sv->fd, va, n, off);	osleave();	if(n < 0)		oserror();	return n;} static longsrv9write(Chan *c, void *va, long n, vlong off){	Srv *sv; 	sv = c->aux;	osenter();	n = pwrite(sv->fd, va, n, off);	osleave();	if(n == 0)		error(Ehungup);	if(n < 0)		oserror();	return n;} static voidsrv9create(Chan *c, char *name, int omode, ulong perm){	Srv *sv;	int sfd, fd[2];	vlong path;	Dir *d; 	if(openmode(omode) != ORDWR)		error(Eperm); 	if(pipe(fd) < 0)		oserror();	if(waserror()){		close(fd[0]);		close(fd[1]);		nexterror();	} 	snprint(up->genbuf, sizeof(up->genbuf), "/srv/%s", name);	osenter();	sfd = create(up->genbuf, OWRITE|ORCLOSE, perm);	osleave();	if(sfd < 0)		oserror();	if(waserror()){		close(sfd);		nexterror();	}	osenter();	if(fprint(sfd, "%d", fd[1]) < 0){		osleave();		oserror();	}	d = dirfstat(sfd);	osleave();	if(d != nil){		path = d->qid.path;		free(d);	}else		oserror(); 	poperror();	poperror();	close(fd[1]); 	if(waserror()){		close(sfd);		close(fd[0]);		nexterror();	}	sv = srvget(path);	sv->fd = fd[0];	sv->sfd = sfd;	poperror(); 	srvput((Srv*)c->aux);	c->qid.type = QTFILE;	c->qid.path = path;	c->aux = sv;	c->flag |= COPEN;	c->mode = ORDWR;	c->offset = 0;} Dev srv9devtab = {	L'₪',	"srv9", 	srv9init,		srv9attach,	srv9walk,	srv9stat,	srv9open,	srv9create,	/* TO DO */	srv9close,	srv9read,	devbread,	srv9write,	devbwrite,	devremove,	/* TO DO */	devwstat,	/* TO DO */};