/* $OpenBSD: umap_subr.c,v 1.14 2002/06/14 21:35:00 todd Exp $ */ /* $NetBSD: umap_subr.c,v 1.8 1996/03/05 02:35:39 thorpej Exp $ */ /* * 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. * * from: Id: lofs_subr.c, v 1.11 1992/05/30 10:05:43 jsp Exp * @(#)umap_subr.c 8.6 (Berkeley) 1/26/94 */ #include #include #include #include #include #include #include #include #include #include #include #define LOG2_SIZEVNODE 7 /* log2(sizeof struct vnode) */ #define NUMAPNODECACHE 16 /* * 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. */ #define UMAP_NHASH(vp) \ (&umap_node_hashtbl[(((u_long)vp)>>LOG2_SIZEVNODE) & umap_node_hash]) LIST_HEAD(umap_node_hashhead, umap_node) *umap_node_hashtbl; u_long umap_node_hash; static id_t umap_findid(id_t, id_map_t, int); static struct vnode *umap_node_find(struct mount *, struct vnode *); static int umap_node_alloc(struct mount *, struct vnode *, struct vnode **); /* * Initialise cache headers */ int umapfs_init(struct vfsconf *vfsp) { #ifdef UMAPFS_DIAGNOSTIC printf("umapfs_init\n"); /* printed during system boot */ #endif umap_node_hashtbl = hashinit(NUMAPNODECACHE, M_CACHE, M_WAITOK, &umap_node_hash); return (0); } /* * umap_findid is called by various routines in umap_vnodeops.c to * find a user or group id in a map. */ static id_t umap_findid(id, map, nentries) id_t id; id_map_t map; int nentries; { int i; /* Find {g,u}id entry in map */ i = 0; while ((ilh_first; a != 0; a = a->umap_hash.le_next) { 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, p)) { #ifdef UMAPFS_DIAGNOSTIC printf ("umap_node_find: vget failed.\n"); #endif goto loop; } return (vp); } } #ifdef UMAPFS_DIAGNOSTIC printf("umap_node_find(%p, %p): NOT found\n", mp, targetvp); #endif return (0); } /* * Make a new umap_node node. * Vp is the alias vnode, lowervp is the target vnode. * Maintain a reference to lowervp. */ static int umap_node_alloc(mp, lowervp, vpp) struct mount *mp; struct vnode *lowervp; struct vnode **vpp; { struct umap_node_hashhead *hd; struct umap_node *xp; struct vnode *vp, *nvp; int error; struct proc *p = curproc; extern int (**dead_vnodeop_p)(void *); if ((error = getnewvnode(VT_UMAP, mp, umap_vnodeop_p, &vp)) != 0) return (error); vp->v_type = lowervp->v_type; MALLOC(xp, struct umap_node *, sizeof(struct umap_node), M_TEMP, M_WAITOK); if (vp->v_type == VBLK || vp->v_type == VCHR) { MALLOC(vp->v_specinfo, struct specinfo *, sizeof(struct specinfo), M_VNODE, M_WAITOK); vp->v_rdev = lowervp->v_rdev; } vp->v_data = xp; xp->umap_vnode = vp; 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 ((nvp = umap_node_find(mp, lowervp)) != NULL) { *vpp = nvp; /* free the substructures we've allocated. */ FREE(xp, M_TEMP); if (vp->v_type == VBLK || vp->v_type == VCHR) FREE(vp->v_specinfo, M_VNODE); vp->v_type = VBAD; /* node is discarded */ vp->v_op = dead_vnodeop_p; /* so ops will still work */ vrele(vp); /* get rid of it. */ return (0); } /* * XXX if it's a device node, it needs to be checkalias()ed. * however, for locking reasons, that's just not possible. * so we have to do most of the dirty work inline. Note that * this is a limited case; we know that there's going to be * an alias, and we know that that alias will be a "real" * device node, i.e. not tagged VT_NON. */ if (vp->v_type == VBLK || vp->v_type == VCHR) { struct vnode *cvp, **cvpp; cvpp = &speclisth[SPECHASH(vp->v_rdev)]; loop: for (cvp = *cvpp; cvp; cvp = cvp->v_specnext) { if (vp->v_rdev != cvp->v_rdev || vp->v_type != cvp->v_type) continue; /* * Alias, but not in use, so flush it out. */ if (cvp->v_usecount == 0) { vgone(cvp); goto loop; } if (vget(cvp, 0, p)) /* can't lock; will die! */ goto loop; break; } vp->v_hashchain = cvpp; vp->v_specnext = *cvpp; vp->v_specmountpoint = NULL; *cvpp = vp; #ifdef DIAGNOSTIC if (cvp == NULLVP) panic("umap_node_alloc: no alias for device"); #endif vp->v_flag |= VALIASED; cvp->v_flag |= VALIASED; vrele(cvp); } /* XXX end of transmogrified checkalias() */ *vpp = vp; VREF(lowervp); /* Extra VREF will be vrele'd in umap_node_create */ hd = UMAP_NHASH(lowervp); LIST_INSERT_HEAD(hd, xp, umap_hash); return (0); } /* * Try to find an existing umap_node vnode referring * 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)) != NULL) { /* * Take another reference to the alias vnode */ #ifdef UMAPFS_DIAGNOSTIC vprint("umap_node_create: exists", aliasvp); #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)) != 0) 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); #ifdef notyet /* * 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 = %p, ZERO ptr\n", vp); for (p = (u_long *) a, i = 0; i < 8; i++) printf(" %lx", 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 = %p, unref'ed lowervp\n", vp); for (p = (u_long *) a, i = 0; i < 8; i++) printf(" %lx", p[i]); printf("\n"); /* wait for debugger */ while (umap_checkvp_barrier) /*WAIT*/ ; panic ("umap with unref'ed lowervp"); } #ifdef notyet printf("umap %p/%d -> %p/%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; uid_t uid; gid_t gid; id_map_t usermap, groupmap; if (credp == NOCRED) return; unentries = MOUNTTOUMAPMOUNT(v_mount)->info_unentries; usermap = MOUNTTOUMAPMOUNT(v_mount)->info_umapdata; gnentries = MOUNTTOUMAPMOUNT(v_mount)->info_gnentries; groupmap = MOUNTTOUMAPMOUNT(v_mount)->info_gmapdata; /* 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; #if 1 /* cr_gid is the same as cr_groups[0] in 4BSD, but not in NetBSD */ /* 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. */ for ( i = 0 ; credp->cr_groups[i] != 0 ; i++ ) { 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; } }