404 lines
9.6 KiB
C
404 lines
9.6 KiB
C
/*
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software donated to Berkeley by
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* Jan-Simon Pendry.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)umap_subr.c 8.6 (Berkeley) 1/26/94
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*
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* $Id: umap_subr.c,v 1.2 1994/05/25 09:09:07 rgrimes Exp $
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <sys/vnode.h>
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#include <sys/mount.h>
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#include <sys/namei.h>
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#include <sys/malloc.h>
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#include <miscfs/umapfs/umap.h>
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#define LOG2_SIZEVNODE 7 /* log2(sizeof struct vnode) */
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#define NUMAPNODECACHE 16
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#define UMAP_NHASH(vp) ((((u_long) vp)>>LOG2_SIZEVNODE) & (NUMAPNODECACHE-1))
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/*
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* Null layer cache:
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* Each cache entry holds a reference to the target vnode
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* along with a pointer to the alias vnode. When an
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* entry is added the target vnode is VREF'd. When the
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* alias is removed the target vnode is vrele'd.
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*/
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/*
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* Cache head
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*/
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struct umap_node_cache {
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struct umap_node *ac_forw;
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struct umap_node *ac_back;
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};
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static struct umap_node_cache umap_node_cache[NUMAPNODECACHE];
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/*
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* Initialise cache headers
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*/
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int
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umapfs_init()
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{
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struct umap_node_cache *ac;
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#ifdef UMAPFS_DIAGNOSTIC
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printf("umapfs_init\n"); /* printed during system boot */
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#endif
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for (ac = umap_node_cache; ac < umap_node_cache + NUMAPNODECACHE; ac++)
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ac->ac_forw = ac->ac_back = (struct umap_node *) ac;
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return (0);
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}
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/*
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* Compute hash list for given target vnode
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*/
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static struct umap_node_cache *
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umap_node_hash(targetvp)
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struct vnode *targetvp;
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{
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return (&umap_node_cache[UMAP_NHASH(targetvp)]);
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}
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/*
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* umap_findid is called by various routines in umap_vnodeops.c to
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* find a user or group id in a map.
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*/
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static u_long
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umap_findid(id, map, nentries)
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u_long id;
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u_long map[][2];
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int nentries;
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{
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int i;
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/* Find uid entry in map */
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i = 0;
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while ((i<nentries) && ((map[i][0]) != id))
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i++;
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if (i < nentries)
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return (map[i][1]);
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else
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return (-1);
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}
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/*
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* umap_reverse_findid is called by umap_getattr() in umap_vnodeops.c to
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* find a user or group id in a map, in reverse.
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*/
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u_long
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umap_reverse_findid(id, map, nentries)
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u_long id;
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u_long map[][2];
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int nentries;
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{
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int i;
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/* Find uid entry in map */
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i = 0;
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while ((i<nentries) && ((map[i][1]) != id))
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i++;
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if (i < nentries)
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return (map[i][0]);
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else
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return (-1);
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}
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/*
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* Return alias for target vnode if already exists, else 0.
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*/
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static struct vnode *
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umap_node_find(mp, targetvp)
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struct mount *mp;
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struct vnode *targetvp;
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{
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struct umap_node_cache *hd;
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struct umap_node *a;
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struct vnode *vp;
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#ifdef UMAPFS_DIAGNOSTIC
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printf("umap_node_find(mp = %x, target = %x)\n", mp, targetvp);
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#endif
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/*
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* Find hash base, and then search the (two-way) linked
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* list looking for a umap_node structure which is referencing
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* the target vnode. If found, the increment the umap_node
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* reference count (but NOT the target vnode's VREF counter).
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*/
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hd = umap_node_hash(targetvp);
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loop:
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for (a = hd->ac_forw; a != (struct umap_node *) hd; a = a->umap_forw) {
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if (a->umap_lowervp == targetvp &&
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a->umap_vnode->v_mount == mp) {
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vp = UMAPTOV(a);
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/*
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* We need vget for the VXLOCK
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* stuff, but we don't want to lock
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* the lower node.
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*/
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if (vget(vp, 0)) {
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#ifdef UMAPFS_DIAGNOSTIC
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printf ("umap_node_find: vget failed.\n");
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#endif
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goto loop;
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}
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return (vp);
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}
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}
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#ifdef UMAPFS_DIAGNOSTIC
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printf("umap_node_find(%x, %x): NOT found\n", mp, targetvp);
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#endif
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return (0);
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}
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/*
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* Make a new umap_node node.
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* Vp is the alias vnode, lofsvp is the target vnode.
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* Maintain a reference to (targetvp).
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*/
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static int
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umap_node_alloc(mp, lowervp, vpp)
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struct mount *mp;
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struct vnode *lowervp;
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struct vnode **vpp;
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{
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struct umap_node_cache *hd;
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struct umap_node *xp;
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struct vnode *othervp, *vp;
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int error;
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error = getnewvnode(VT_UMAP, mp, umap_vnodeop_p, vpp);
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if (error)
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return (error);
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vp = *vpp;
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MALLOC(xp, struct umap_node *, sizeof(struct umap_node),
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M_TEMP, M_WAITOK);
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vp->v_type = lowervp->v_type;
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xp->umap_vnode = vp;
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vp->v_data = xp;
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xp->umap_lowervp = lowervp;
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/*
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* Before we insert our new node onto the hash chains,
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* check to see if someone else has beaten us to it.
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* (We could have slept in MALLOC.)
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*/
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othervp = umap_node_find(lowervp);
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if (othervp) {
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FREE(xp, M_TEMP);
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vp->v_type = VBAD; /* node is discarded */
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vp->v_usecount = 0; /* XXX */
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*vpp = othervp;
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return (0);
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}
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VREF(lowervp); /* Extra VREF will be vrele'd in umap_node_create */
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hd = umap_node_hash(lowervp);
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insque(xp, hd);
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return (0);
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}
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/*
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* Try to find an existing umap_node vnode refering
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* to it, otherwise make a new umap_node vnode which
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* contains a reference to the target vnode.
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*/
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int
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umap_node_create(mp, targetvp, newvpp)
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struct mount *mp;
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struct vnode *targetvp;
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struct vnode **newvpp;
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{
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struct vnode *aliasvp;
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aliasvp = umap_node_find(mp, targetvp);
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if (aliasvp) {
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/*
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* Take another reference to the alias vnode
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*/
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#ifdef UMAPFS_DIAGNOSTIC
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vprint("umap_node_create: exists", ap->umap_vnode);
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#endif
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/* VREF(aliasvp); */
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} else {
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int error;
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/*
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* Get new vnode.
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*/
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#ifdef UMAPFS_DIAGNOSTIC
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printf("umap_node_create: create new alias vnode\n");
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#endif
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/*
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* Make new vnode reference the umap_node.
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*/
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error = umap_node_alloc(mp, targetvp, &aliasvp);
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if (error)
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return (error);
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/*
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* aliasvp is already VREF'd by getnewvnode()
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*/
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}
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vrele(targetvp);
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#ifdef UMAPFS_DIAGNOSTIC
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vprint("umap_node_create: alias", aliasvp);
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vprint("umap_node_create: target", targetvp);
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#endif
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*newvpp = aliasvp;
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return (0);
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}
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#ifdef UMAPFS_DIAGNOSTIC
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int umap_checkvp_barrier = 1;
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struct vnode *
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umap_checkvp(vp, fil, lno)
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struct vnode *vp;
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char *fil;
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int lno;
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{
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struct umap_node *a = VTOUMAP(vp);
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#if 0
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/*
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* Can't do this check because vop_reclaim runs
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* with funny vop vector.
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*/
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if (vp->v_op != umap_vnodeop_p) {
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printf ("umap_checkvp: on non-umap-node\n");
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while (umap_checkvp_barrier) /*WAIT*/ ;
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panic("umap_checkvp");
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}
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#endif
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if (a->umap_lowervp == NULL) {
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/* Should never happen */
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int i; u_long *p;
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printf("vp = %x, ZERO ptr\n", vp);
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for (p = (u_long *) a, i = 0; i < 8; i++)
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printf(" %x", p[i]);
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printf("\n");
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/* wait for debugger */
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while (umap_checkvp_barrier) /*WAIT*/ ;
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panic("umap_checkvp");
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}
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if (a->umap_lowervp->v_usecount < 1) {
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int i; u_long *p;
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printf("vp = %x, unref'ed lowervp\n", vp);
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for (p = (u_long *) a, i = 0; i < 8; i++)
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printf(" %x", p[i]);
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printf("\n");
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/* wait for debugger */
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while (umap_checkvp_barrier) /*WAIT*/ ;
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panic ("umap with unref'ed lowervp");
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}
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#if 0
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printf("umap %x/%d -> %x/%d [%s, %d]\n",
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a->umap_vnode, a->umap_vnode->v_usecount,
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a->umap_lowervp, a->umap_lowervp->v_usecount,
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fil, lno);
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#endif
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return (a->umap_lowervp);
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}
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#endif
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/* umap_mapids maps all of the ids in a credential, both user and group. */
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void
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umap_mapids(v_mount, credp)
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struct mount *v_mount;
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struct ucred *credp;
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{
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int i, unentries, gnentries;
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u_long *groupmap, *usermap;
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uid_t uid;
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gid_t gid;
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unentries = MOUNTTOUMAPMOUNT(v_mount)->info_nentries;
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usermap = &(MOUNTTOUMAPMOUNT(v_mount)->info_mapdata[0][0]);
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gnentries = MOUNTTOUMAPMOUNT(v_mount)->info_gnentries;
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groupmap = &(MOUNTTOUMAPMOUNT(v_mount)->info_gmapdata[0][0]);
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/* Find uid entry in map */
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uid = (uid_t) umap_findid(credp->cr_uid, usermap, unentries);
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if (uid != -1)
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credp->cr_uid = uid;
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else
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credp->cr_uid = (uid_t) NOBODY;
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#ifdef notdef
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/* cr_gid is the same as cr_groups[0] in 4BSD */
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/* Find gid entry in map */
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gid = (gid_t) umap_findid(credp->cr_gid, groupmap, gnentries);
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if (gid != -1)
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credp->cr_gid = gid;
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else
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credp->cr_gid = NULLGROUP;
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#endif
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/* Now we must map each of the set of groups in the cr_groups
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structure. */
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i = 0;
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while (credp->cr_groups[i] != 0) {
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gid = (gid_t) umap_findid(credp->cr_groups[i],
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groupmap, gnentries);
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if (gid != -1)
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credp->cr_groups[i++] = gid;
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else
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credp->cr_groups[i++] = NULLGROUP;
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}
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}
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