1 files changed, 397 insertions, 0 deletions
diff --git a/sys/fs/umapfs/umap_subr.c b/sys/fs/umapfs/umap_subr.c
new file mode 100644
index 0000000..6f1f077
--- /dev/null
+++ b/sys/fs/umapfs/umap_subr.c
@@ -0,0 +1,397 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)umap_subr.c	8.6 (Berkeley) 1/26/94
+ *
+ * $Id: lofs_subr.c, v 1.11 1992/05/30 10:05:43 jsp Exp jsp $
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <miscfs/umapfs/umap.h>
+
+#define LOG2_SIZEVNODE 7		/* log2(sizeof struct vnode) */
+#define	NUMAPNODECACHE 16
+#define	UMAP_NHASH(vp) ((((u_long) vp)>>LOG2_SIZEVNODE) & (NUMAPNODECACHE-1))
+
+/*
+ * Null layer cache:
+ * Each cache entry holds a reference to the target vnode
+ * along with a pointer to the alias vnode.  When an
+ * entry is added the target vnode is VREF'd.  When the
+ * alias is removed the target vnode is vrele'd.
+ */
+
+/*
+ * Cache head
+ */
+struct umap_node_cache {
+	struct umap_node	*ac_forw;
+	struct umap_node	*ac_back;
+};
+
+static struct umap_node_cache umap_node_cache[NUMAPNODECACHE];
+
+/*
+ * Initialise cache headers
+ */
+umapfs_init()
+{
+	struct umap_node_cache *ac;
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umapfs_init\n");		/* printed during system boot */
+#endif
+
+	for (ac = umap_node_cache; ac < umap_node_cache + NUMAPNODECACHE; ac++)
+		ac->ac_forw = ac->ac_back = (struct umap_node *) ac;
+}
+
+/*
+ * Compute hash list for given target vnode
+ */
+static struct umap_node_cache *
+umap_node_hash(targetvp)
+	struct vnode *targetvp;
+{
+
+	return (&umap_node_cache[UMAP_NHASH(targetvp)]);
+}
+
+/*
+ * umap_findid is called by various routines in umap_vnodeops.c to
+ * find a user or group id in a map.
+ */
+static u_long
+umap_findid(id, map, nentries)
+	u_long id;
+	u_long map[][2];
+	int nentries;
+{
+	int i;
+
+	/* Find uid entry in map */
+	i = 0;
+	while ((i<nentries) && ((map[i][0]) != id))
+		i++;
+
+	if (i < nentries)
+		return (map[i][1]);
+	else
+		return (-1);
+
+}
+
+/*
+ * umap_reverse_findid is called by umap_getattr() in umap_vnodeops.c to
+ * find a user or group id in a map, in reverse.
+ */
+u_long
+umap_reverse_findid(id, map, nentries)
+	u_long id;
+	u_long map[][2];
+	int nentries;
+{
+	int i;
+
+	/* Find uid entry in map */
+	i = 0;
+	while ((i<nentries) && ((map[i][1]) != id))
+		i++;
+
+	if (i < nentries)
+		return (map[i][0]);
+	else
+		return (-1);
+
+}
+
+/*
+ * Return alias for target vnode if already exists, else 0.
+ */
+static struct vnode *
+umap_node_find(mp, targetvp)
+	struct mount *mp;
+	struct vnode *targetvp;
+{
+	struct umap_node_cache *hd;
+	struct umap_node *a;
+	struct vnode *vp;
+
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umap_node_find(mp = %x, target = %x)\n", mp, targetvp);
+#endif
+
+	/*
+	 * Find hash base, and then search the (two-way) linked
+	 * list looking for a umap_node structure which is referencing
+	 * the target vnode.  If found, the increment the umap_node
+	 * reference count (but NOT the target vnode's VREF counter).
+	 */
+	hd = umap_node_hash(targetvp);
+
+ loop:
+	for (a = hd->ac_forw; a != (struct umap_node *) hd; a = a->umap_forw) {
+		if (a->umap_lowervp == targetvp &&
+		    a->umap_vnode->v_mount == mp) {
+			vp = UMAPTOV(a);
+			/*
+			 * We need vget for the VXLOCK
+			 * stuff, but we don't want to lock
+			 * the lower node.
+			 */
+			if (vget(vp, 0)) {
+#ifdef UMAPFS_DIAGNOSTIC
+				printf ("umap_node_find: vget failed.\n");
+#endif
+				goto loop;
+			}
+			return (vp);
+		}
+	}
+
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umap_node_find(%x, %x): NOT found\n", mp, targetvp);
+#endif
+
+	return (0);
+}
+
+/*
+ * Make a new umap_node node.
+ * Vp is the alias vnode, lofsvp is the target vnode.
+ * Maintain a reference to (targetvp).
+ */
+static int
+umap_node_alloc(mp, lowervp, vpp)
+	struct mount *mp;
+	struct vnode *lowervp;
+	struct vnode **vpp;
+{
+	struct umap_node_cache *hd;
+	struct umap_node *xp;
+	struct vnode *othervp, *vp;
+	int error;
+
+	if (error = getnewvnode(VT_UMAP, mp, umap_vnodeop_p, vpp))
+		return (error);
+	vp = *vpp;
+
+	MALLOC(xp, struct umap_node *, sizeof(struct umap_node),
+	    M_TEMP, M_WAITOK);
+	vp->v_type = lowervp->v_type;
+	xp->umap_vnode = vp;
+	vp->v_data = xp;
+	xp->umap_lowervp = lowervp;
+	/*
+	 * Before we insert our new node onto the hash chains,
+	 * check to see if someone else has beaten us to it.
+	 * (We could have slept in MALLOC.)
+	 */
+	if (othervp = umap_node_find(lowervp)) {
+		FREE(xp, M_TEMP);
+		vp->v_type = VBAD;	/* node is discarded */
+		vp->v_usecount = 0;	/* XXX */
+		*vpp = othervp;
+		return (0);
+	}
+	VREF(lowervp);   /* Extra VREF will be vrele'd in umap_node_create */
+	hd = umap_node_hash(lowervp);
+	insque(xp, hd);
+	return (0);
+}
+
+
+/*
+ * Try to find an existing umap_node vnode refering
+ * to it, otherwise make a new umap_node vnode which
+ * contains a reference to the target vnode.
+ */
+int
+umap_node_create(mp, targetvp, newvpp)
+	struct mount *mp;
+	struct vnode *targetvp;
+	struct vnode **newvpp;
+{
+	struct vnode *aliasvp;
+
+	if (aliasvp = umap_node_find(mp, targetvp)) {
+		/*
+		 * Take another reference to the alias vnode
+		 */
+#ifdef UMAPFS_DIAGNOSTIC
+		vprint("umap_node_create: exists", ap->umap_vnode);
+#endif
+		/* VREF(aliasvp); */
+	} else {
+		int error;
+
+		/*
+		 * Get new vnode.
+		 */
+#ifdef UMAPFS_DIAGNOSTIC
+		printf("umap_node_create: create new alias vnode\n");
+#endif
+		/*
+		 * Make new vnode reference the umap_node.
+		 */
+		if (error = umap_node_alloc(mp, targetvp, &aliasvp))
+			return (error);
+
+		/*
+		 * aliasvp is already VREF'd by getnewvnode()
+		 */
+	}
+
+	vrele(targetvp);
+
+#ifdef UMAPFS_DIAGNOSTIC
+	vprint("umap_node_create: alias", aliasvp);
+	vprint("umap_node_create: target", targetvp);
+#endif
+
+	*newvpp = aliasvp;
+	return (0);
+}
+
+#ifdef UMAPFS_DIAGNOSTIC
+int umap_checkvp_barrier = 1;
+struct vnode *
+umap_checkvp(vp, fil, lno)
+	struct vnode *vp;
+	char *fil;
+	int lno;
+{
+	struct umap_node *a = VTOUMAP(vp);
+#if 0
+	/*
+	 * Can't do this check because vop_reclaim runs
+	 * with funny vop vector.
+	 */
+	if (vp->v_op != umap_vnodeop_p) {
+		printf ("umap_checkvp: on non-umap-node\n");
+		while (umap_checkvp_barrier) /*WAIT*/ ;
+		panic("umap_checkvp");
+	}
+#endif
+	if (a->umap_lowervp == NULL) {
+		/* Should never happen */
+		int i; u_long *p;
+		printf("vp = %x, ZERO ptr\n", vp);
+		for (p = (u_long *) a, i = 0; i < 8; i++)
+			printf(" %x", p[i]);
+		printf("\n");
+		/* wait for debugger */
+		while (umap_checkvp_barrier) /*WAIT*/ ;
+		panic("umap_checkvp");
+	}
+	if (a->umap_lowervp->v_usecount < 1) {
+		int i; u_long *p;
+		printf("vp = %x, unref'ed lowervp\n", vp);
+		for (p = (u_long *) a, i = 0; i < 8; i++)
+			printf(" %x", p[i]);
+		printf("\n");
+		/* wait for debugger */
+		while (umap_checkvp_barrier) /*WAIT*/ ;
+		panic ("umap with unref'ed lowervp");
+	}
+#if 0
+	printf("umap %x/%d -> %x/%d [%s, %d]\n",
+	        a->umap_vnode, a->umap_vnode->v_usecount,
+		a->umap_lowervp, a->umap_lowervp->v_usecount,
+		fil, lno);
+#endif
+	return (a->umap_lowervp);
+}
+#endif
+
+/* umap_mapids maps all of the ids in a credential, both user and group. */
+
+void
+umap_mapids(v_mount, credp)
+	struct mount *v_mount;
+	struct ucred *credp;
+{
+	int i, unentries, gnentries;
+	u_long *groupmap, *usermap;
+	uid_t uid;
+	gid_t gid;
+
+	unentries =  MOUNTTOUMAPMOUNT(v_mount)->info_nentries;
+	usermap =  &(MOUNTTOUMAPMOUNT(v_mount)->info_mapdata[0][0]);
+	gnentries =  MOUNTTOUMAPMOUNT(v_mount)->info_gnentries;
+	groupmap =  &(MOUNTTOUMAPMOUNT(v_mount)->info_gmapdata[0][0]);
+
+	/* Find uid entry in map */
+
+	uid = (uid_t) umap_findid(credp->cr_uid, usermap, unentries);
+
+	if (uid != -1)
+		credp->cr_uid = uid;
+	else
+		credp->cr_uid = (uid_t) NOBODY;
+
+#ifdef notdef
+	/* cr_gid is the same as cr_groups[0] in 4BSD */
+
+	/* Find gid entry in map */
+
+	gid = (gid_t) umap_findid(credp->cr_gid, groupmap, gnentries);
+
+	if (gid != -1)
+		credp->cr_gid = gid;
+	else
+		credp->cr_gid = NULLGROUP;
+#endif
+
+	/* Now we must map each of the set of groups in the cr_groups 
+		structure. */
+
+	i = 0;
+	while (credp->cr_groups[i] != 0) {
+		gid = (gid_t) umap_findid(credp->cr_groups[i],
+					groupmap, gnentries);
+
+		if (gid != -1)
+			credp->cr_groups[i++] = gid;
+		else
+			credp->cr_groups[i++] = NULLGROUP;
+	}
+}