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NetBSD/sys/miscfs/umapfs/umap_vnops.c

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/* $NetBSD: umap_vnops.c,v 1.53 2011/07/11 08:27:39 hannken 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
* the UCLA Ficus project.
*
* 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. 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_vnops.c 8.6 (Berkeley) 5/22/95
*/
/*
* Umap Layer
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: umap_vnops.c,v 1.53 2011/07/11 08:27:39 hannken Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/buf.h>
#include <sys/kauth.h>
#include <miscfs/umapfs/umap.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/genfs/layer_extern.h>
/*
* Note: If the LAYERFS_MBYPASSDEBUG flag is set, it is possible
* that the debug printing will bomb out, because kauth routines
* do not handle NOCRED or FSCRED like other credentials and end
* up dereferencing an inappropriate pointer.
*
* That should be fixed in kauth rather than here.
*/
int umap_lookup(void *);
int umap_getattr(void *);
int umap_print(void *);
int umap_rename(void *);
/*
* Global vfs data structures
*/
/*
* XXX - strategy, bwrite are hand coded currently. They should
* go away with a merged buffer/block cache.
*
*/
int (**umap_vnodeop_p)(void *);
const struct vnodeopv_entry_desc umap_vnodeop_entries[] = {
{ &vop_default_desc, umap_bypass },
{ &vop_lookup_desc, umap_lookup },
{ &vop_getattr_desc, umap_getattr },
{ &vop_print_desc, umap_print },
{ &vop_rename_desc, umap_rename },
{ &vop_fsync_desc, layer_fsync },
{ &vop_inactive_desc, layer_inactive },
{ &vop_reclaim_desc, layer_reclaim },
{ &vop_open_desc, layer_open },
{ &vop_setattr_desc, layer_setattr },
{ &vop_access_desc, layer_access },
{ &vop_remove_desc, layer_remove },
{ &vop_revoke_desc, layer_revoke },
{ &vop_rmdir_desc, layer_rmdir },
{ &vop_bmap_desc, layer_bmap },
{ &vop_getpages_desc, layer_getpages },
{ &vop_putpages_desc, layer_putpages },
{ NULL, NULL }
};
const struct vnodeopv_desc umapfs_vnodeop_opv_desc =
{ &umap_vnodeop_p, umap_vnodeop_entries };
/*
* This is the 08-June-1999 bypass routine.
* See layer_vnops.c:layer_bypass for more details.
*/
int
umap_bypass(void *v)
{
struct vop_generic_args /* {
struct vnodeop_desc *a_desc;
<other random data follows, presumably>
} */ *ap = v;
int (**our_vnodeop_p)(void *);
kauth_cred_t *credpp = NULL, credp = 0;
kauth_cred_t savecredp = 0, savecompcredp = 0;
kauth_cred_t compcredp = 0;
struct vnode **this_vp_p;
int error;
struct vnode *old_vps[VDESC_MAX_VPS], *vp0;
struct vnode **vps_p[VDESC_MAX_VPS];
struct vnode ***vppp;
struct vnodeop_desc *descp = ap->a_desc;
int reles, i, flags;
struct componentname **compnamepp = 0;
#ifdef DIAGNOSTIC
/*
* We require at least one vp.
*/
if (descp->vdesc_vp_offsets == NULL ||
descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
panic("%s: no vp's in map.\n", __func__);
#endif
vps_p[0] =
VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[0], ap);
vp0 = *vps_p[0];
flags = MOUNTTOUMAPMOUNT(vp0->v_mount)->umapm_flags;
our_vnodeop_p = vp0->v_op;
if (flags & LAYERFS_MBYPASSDEBUG)
printf("%s: %s\n", __func__, descp->vdesc_name);
/*
* Map the vnodes going in.
* Later, we'll invoke the operation based on
* the first mapped vnode's operation vector.
*/
reles = descp->vdesc_flags;
for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
break; /* bail out at end of list */
vps_p[i] = this_vp_p =
VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[i],
ap);
/*
* We're not guaranteed that any but the first vnode
* are of our type. Check for and don't map any
* that aren't. (We must always map first vp or vclean fails.)
*/
if (i && (*this_vp_p == NULL ||
(*this_vp_p)->v_op != our_vnodeop_p)) {
old_vps[i] = NULL;
} else {
old_vps[i] = *this_vp_p;
*(vps_p[i]) = UMAPVPTOLOWERVP(*this_vp_p);
/*
* XXX - Several operations have the side effect
* of vrele'ing their vp's. We must account for
* that. (This should go away in the future.)
*/
if (reles & VDESC_VP0_WILLRELE)
vref(*this_vp_p);
}
}
/*
* Fix the credentials. (That's the purpose of this layer.)
*/
if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
credpp = VOPARG_OFFSETTO(kauth_cred_t*,
descp->vdesc_cred_offset, ap);
/* Save old values */
savecredp = *credpp;
if (savecredp != NOCRED && savecredp != FSCRED)
*credpp = kauth_cred_dup(savecredp);
credp = *credpp;
if ((flags & LAYERFS_MBYPASSDEBUG) &&
kauth_cred_geteuid(credp) != 0)
printf("umap_bypass: user was %d, group %d\n",
kauth_cred_geteuid(credp), kauth_cred_getegid(credp));
/* Map all ids in the credential structure. */
umap_mapids(vp0->v_mount, credp);
if ((flags & LAYERFS_MBYPASSDEBUG) &&
kauth_cred_geteuid(credp) != 0)
printf("umap_bypass: user now %d, group %d\n",
kauth_cred_geteuid(credp), kauth_cred_getegid(credp));
}
/* BSD often keeps a credential in the componentname structure
* for speed. If there is one, it better get mapped, too.
*/
if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
compnamepp = VOPARG_OFFSETTO(struct componentname**,
descp->vdesc_componentname_offset, ap);
savecompcredp = (*compnamepp)->cn_cred;
if (savecompcredp != NOCRED && savecompcredp != FSCRED)
(*compnamepp)->cn_cred = kauth_cred_dup(savecompcredp);
compcredp = (*compnamepp)->cn_cred;
if ((flags & LAYERFS_MBYPASSDEBUG) &&
kauth_cred_geteuid(compcredp) != 0)
printf("umap_bypass: component credit user was %d, group %d\n",
kauth_cred_geteuid(compcredp), kauth_cred_getegid(compcredp));
/* Map all ids in the credential structure. */
umap_mapids(vp0->v_mount, compcredp);
if ((flags & LAYERFS_MBYPASSDEBUG) &&
kauth_cred_geteuid(compcredp) != 0)
printf("umap_bypass: component credit user now %d, group %d\n",
kauth_cred_geteuid(compcredp), kauth_cred_getegid(compcredp));
}
/*
* Call the operation on the lower layer
* with the modified argument structure.
*/
error = VCALL(*vps_p[0], descp->vdesc_offset, ap);
/*
* Maintain the illusion of call-by-value
* by restoring vnodes in the argument structure
* to their original value.
*/
reles = descp->vdesc_flags;
for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
break; /* bail out at end of list */
if (old_vps[i]) {
*(vps_p[i]) = old_vps[i];
if (reles & VDESC_VP0_WILLRELE)
vrele(*(vps_p[i]));
}
}
/*
* Map the possible out-going vpp
* (Assumes that the lower layer always returns
* a VREF'ed vpp unless it gets an error.)
*/
if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET && !error) {
vppp = VOPARG_OFFSETTO(struct vnode***,
descp->vdesc_vpp_offset, ap);
/*
* Only vop_lookup, vop_create, vop_makedir, vop_bmap,
* vop_mknod, and vop_symlink return vpp's. vop_bmap
* doesn't call bypass as the lower vpp is fine (we're just
* going to do i/o on it). vop_lookup doesn't call bypass
* as a lookup on "." would generate a locking error.
* So all the calls which get us here have a locked vpp. :-)
*/
error = layer_node_create(old_vps[0]->v_mount, **vppp, *vppp);
if (error) {
vput(**vppp);
**vppp = NULL;
}
}
/*
* Free duplicate cred structure and restore old one.
*/
if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
if ((flags & LAYERFS_MBYPASSDEBUG) && credp &&
kauth_cred_geteuid(credp) != 0)
printf("umap_bypass: returning-user was %d\n",
kauth_cred_geteuid(credp));
if (savecredp != NOCRED && savecredp != FSCRED && credpp) {
kauth_cred_free(credp);
*credpp = savecredp;
if ((flags & LAYERFS_MBYPASSDEBUG) && credpp &&
kauth_cred_geteuid(*credpp) != 0)
printf("umap_bypass: returning-user now %d\n\n",
kauth_cred_geteuid(savecredp));
}
}
if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
if ((flags & LAYERFS_MBYPASSDEBUG) && compcredp &&
kauth_cred_geteuid(compcredp) != 0)
printf("umap_bypass: returning-component-user was %d\n",
kauth_cred_geteuid(compcredp));
if (savecompcredp != NOCRED && savecompcredp != FSCRED) {
kauth_cred_free(compcredp);
(*compnamepp)->cn_cred = savecompcredp;
if ((flags & LAYERFS_MBYPASSDEBUG) && savecompcredp &&
kauth_cred_geteuid(savecompcredp) != 0)
printf("umap_bypass: returning-component-user now %d\n",
kauth_cred_geteuid(savecompcredp));
}
}
return (error);
}
/*
* This is based on the 08-June-1999 bypass routine.
* See layer_vnops.c:layer_bypass for more details.
*/
int
umap_lookup(void *v)
{
struct vop_lookup_args /* {
struct vnodeop_desc *a_desc;
struct vnode * a_dvp;
struct vnode ** a_vpp;
struct componentname * a_cnp;
} */ *ap = v;
struct componentname *cnp = ap->a_cnp;
kauth_cred_t savecompcredp = NULL;
kauth_cred_t compcredp = NULL;
struct vnode *dvp, *vp, *ldvp;
struct mount *mp;
int error;
int flags, cnf = cnp->cn_flags;
dvp = ap->a_dvp;
mp = dvp->v_mount;
if ((cnf & ISLASTCN) && (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
(cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME))
return (EROFS);
flags = MOUNTTOUMAPMOUNT(mp)->umapm_flags;
ldvp = UMAPVPTOLOWERVP(dvp);
if (flags & LAYERFS_MBYPASSDEBUG)
printf("umap_lookup\n");
/*
* Fix the credentials. (That's the purpose of this layer.)
*
* BSD often keeps a credential in the componentname structure
* for speed. If there is one, it better get mapped, too.
*/
if ((savecompcredp = cnp->cn_cred)) {
compcredp = kauth_cred_dup(savecompcredp);
cnp->cn_cred = compcredp;
if ((flags & LAYERFS_MBYPASSDEBUG) &&
kauth_cred_geteuid(compcredp) != 0)
printf("umap_lookup: component credit user was %d, group %d\n",
kauth_cred_geteuid(compcredp), kauth_cred_getegid(compcredp));
/* Map all ids in the credential structure. */
umap_mapids(mp, compcredp);
}
if ((flags & LAYERFS_MBYPASSDEBUG) && compcredp &&
kauth_cred_geteuid(compcredp) != 0)
printf("umap_lookup: component credit user now %d, group %d\n",
kauth_cred_geteuid(compcredp), kauth_cred_getegid(compcredp));
ap->a_dvp = ldvp;
error = VCALL(ldvp, ap->a_desc->vdesc_offset, ap);
vp = *ap->a_vpp;
*ap->a_vpp = NULL;
if (error == EJUSTRETURN && (cnf & ISLASTCN) &&
(dvp->v_mount->mnt_flag & MNT_RDONLY) &&
(cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME))
error = EROFS;
/* Do locking fixup as appropriate. See layer_lookup() for info */
if (ldvp == vp) {
*ap->a_vpp = dvp;
vref(dvp);
vrele(vp);
} else if (vp != NULL) {
error = layer_node_create(mp, vp, ap->a_vpp);
if (error) {
vput(vp);
}
}
/*
* Free duplicate cred structure and restore old one.
*/
if ((flags & LAYERFS_MBYPASSDEBUG) && compcredp &&
kauth_cred_geteuid(compcredp) != 0)
printf("umap_lookup: returning-component-user was %d\n",
kauth_cred_geteuid(compcredp));
if (savecompcredp != NOCRED && savecompcredp != FSCRED) {
if (compcredp)
kauth_cred_free(compcredp);
cnp->cn_cred = savecompcredp;
if ((flags & LAYERFS_MBYPASSDEBUG) && savecompcredp &&
kauth_cred_geteuid(savecompcredp) != 0)
printf("umap_lookup: returning-component-user now %d\n",
kauth_cred_geteuid(savecompcredp));
}
return (error);
}
/*
* We handle getattr to change the fsid.
*/
int
umap_getattr(void *v)
{
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
kauth_cred_t a_cred;
struct lwp *a_l;
} */ *ap = v;
uid_t uid;
gid_t gid;
int error, tmpid, nentries, gnentries, flags;
u_long (*mapdata)[2];
u_long (*gmapdata)[2];
struct vnode **vp1p;
const struct vnodeop_desc *descp = ap->a_desc;
if ((error = umap_bypass(ap)) != 0)
return (error);
/* Requires that arguments be restored. */
ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
flags = MOUNTTOUMAPMOUNT(ap->a_vp->v_mount)->umapm_flags;
/*
* Umap needs to map the uid and gid returned by a stat
* into the proper values for this site. This involves
* finding the returned uid in the mapping information,
* translating it into the uid on the other end,
* and filling in the proper field in the vattr
* structure pointed to by ap->a_vap. The group
* is easier, since currently all groups will be
* translate to the NULLGROUP.
*/
/* Find entry in map */
uid = ap->a_vap->va_uid;
gid = ap->a_vap->va_gid;
if ((flags & LAYERFS_MBYPASSDEBUG))
printf("umap_getattr: mapped uid = %d, mapped gid = %d\n", uid,
gid);
vp1p = VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[0], ap);
nentries = MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_nentries;
mapdata = (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_mapdata);
gnentries = MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gnentries;
gmapdata = (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gmapdata);
/* Reverse map the uid for the vnode. Since it's a reverse
map, we can't use umap_mapids() to do it. */
tmpid = umap_reverse_findid(uid, mapdata, nentries);
if (tmpid != -1) {
ap->a_vap->va_uid = (uid_t) tmpid;
if ((flags & LAYERFS_MBYPASSDEBUG))
printf("umap_getattr: original uid = %d\n", uid);
} else
ap->a_vap->va_uid = (uid_t) NOBODY;
/* Reverse map the gid for the vnode. */
tmpid = umap_reverse_findid(gid, gmapdata, gnentries);
if (tmpid != -1) {
ap->a_vap->va_gid = (gid_t) tmpid;
if ((flags & LAYERFS_MBYPASSDEBUG))
printf("umap_getattr: original gid = %d\n", gid);
} else
ap->a_vap->va_gid = (gid_t) NULLGROUP;
return (0);
}
int
umap_print(void *v)
{
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
printf("\ttag VT_UMAPFS, vp=%p, lowervp=%p\n", vp,
UMAPVPTOLOWERVP(vp));
return (0);
}
int
umap_rename(void *v)
{
struct vop_rename_args /* {
struct vnode *a_fdvp;
struct vnode *a_fvp;
struct componentname *a_fcnp;
struct vnode *a_tdvp;
struct vnode *a_tvp;
struct componentname *a_tcnp;
} */ *ap = v;
int error, flags;
struct componentname *compnamep;
kauth_cred_t compcredp, savecompcredp;
struct vnode *vp;
struct vnode *tvp;
/*
* Rename is irregular, having two componentname structures.
* We need to map the cre in the second structure,
* and then bypass takes care of the rest.
*/
vp = ap->a_fdvp;
flags = MOUNTTOUMAPMOUNT(vp->v_mount)->umapm_flags;
compnamep = ap->a_tcnp;
compcredp = compnamep->cn_cred;
savecompcredp = compcredp;
compcredp = compnamep->cn_cred = kauth_cred_dup(savecompcredp);
if ((flags & LAYERFS_MBYPASSDEBUG) &&
kauth_cred_geteuid(compcredp) != 0)
printf("umap_rename: rename component credit user was %d, group %d\n",
kauth_cred_geteuid(compcredp), kauth_cred_getegid(compcredp));
/* Map all ids in the credential structure. */
umap_mapids(vp->v_mount, compcredp);
if ((flags & LAYERFS_MBYPASSDEBUG) &&
kauth_cred_geteuid(compcredp) != 0)
printf("umap_rename: rename component credit user now %d, group %d\n",
kauth_cred_geteuid(compcredp), kauth_cred_getegid(compcredp));
tvp = ap->a_tvp;
if (tvp) {
if (tvp->v_mount != vp->v_mount)
tvp = NULL;
else
vref(tvp);
}
error = umap_bypass(ap);
if (tvp) {
if (error == 0)
VTOLAYER(tvp)->layer_flags |= LAYERFS_REMOVED;
vrele(tvp);
}
/* Restore the additional mapped componentname cred structure. */
kauth_cred_free(compcredp);
compnamep->cn_cred = savecompcredp;
return error;
}
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