20060303a

1 files changed, 403 insertions, 0 deletions

diff --git a/emu/Plan9/devsrv9.c b/emu/Plan9/devsrv9.c
new file mode 100644
index 00000000..74c97588
--- /dev/null
+++ b/emu/Plan9/devsrv9.c
@@ -0,0 +1,403 @@
+#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 void
+oserr(void)
+{
+	up->genbuf[0] = 0;
+	oserrstr(up->genbuf, sizeof(up->genbuf));
+	error(up->genbuf);
+}
+
+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 void
+srvput(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 void
+srv9init(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 int
+srv9stat(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)
+			oserr();
+		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)
+			oserr();
+		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] = "-dS";
+			args[2] = up->genbuf;
+			args[3] = nil;
+			if(pipe(fd) < 0)
+				oserr();
+			/* 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 void
+srv9close(Chan *c)
+{
+	srvput(c->aux);
+}
+
+static long
+srv9read(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)
+		oserr();
+	return n;
+}
+
+static long
+srv9write(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)
+		oserr();
+	return n;
+}
+
+static void
+srv9create(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)
+		oserr();
+	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)
+		oserr();
+	if(waserror()){
+		close(sfd);
+		nexterror();
+	}
+	osenter();
+	if(fprint(sfd, "%d", fd[1]) < 0){
+		osleave();
+		oserr();
+	}
+	d = dirfstat(sfd);
+	osleave();
+	if(d != nil){
+		path = d->qid.path;
+		free(d);
+	}else
+		oserr();
+
+	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 */
+};