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![Shirish Pargaonkar](/assets/img/avatar_default.png)
Set security descriptor using path name instead of a file handle. We can't be sure that the file handle has adequate permission to set a security descriptor (to modify DACL). Function set_cifs_acl_by_fid() has been removed since we can't be sure how a file was opened for writing, a valid request can fail if the file was not opened with two above mentioned permissions. We could have opted to add on WRITE_DAC and WRITE_OWNER permissions to file opens and then use that file handle but adding addtional permissions such as WRITE_DAC and WRITE_OWNER could cause an any open to fail. And it was incorrect to look for read file handle to set a security descriptor anyway. Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
1116 lines
29 KiB
C
1116 lines
29 KiB
C
/*
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* fs/cifs/cifsacl.c
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*
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* Copyright (C) International Business Machines Corp., 2007,2008
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* Author(s): Steve French (sfrench@us.ibm.com)
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*
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* Contains the routines for mapping CIFS/NTFS ACLs
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*
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* This library is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published
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* by the Free Software Foundation; either version 2.1 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/keyctl.h>
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#include <linux/key-type.h>
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#include <keys/user-type.h>
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#include "cifspdu.h"
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#include "cifsglob.h"
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#include "cifsacl.h"
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#include "cifsproto.h"
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#include "cifs_debug.h"
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/* security id for everyone/world system group */
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static const struct cifs_sid sid_everyone = {
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1, 1, {0, 0, 0, 0, 0, 1}, {0} };
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/* security id for Authenticated Users system group */
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static const struct cifs_sid sid_authusers = {
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1, 1, {0, 0, 0, 0, 0, 5}, {__constant_cpu_to_le32(11)} };
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/* group users */
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static const struct cifs_sid sid_user = {1, 2 , {0, 0, 0, 0, 0, 5}, {} };
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const struct cred *root_cred;
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static void
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shrink_idmap_tree(struct rb_root *root, int nr_to_scan, int *nr_rem,
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int *nr_del)
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{
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struct rb_node *node;
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struct rb_node *tmp;
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struct cifs_sid_id *psidid;
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node = rb_first(root);
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while (node) {
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tmp = node;
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node = rb_next(tmp);
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psidid = rb_entry(tmp, struct cifs_sid_id, rbnode);
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if (nr_to_scan == 0 || *nr_del == nr_to_scan)
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++(*nr_rem);
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else {
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if (time_after(jiffies, psidid->time + SID_MAP_EXPIRE)
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&& psidid->refcount == 0) {
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rb_erase(tmp, root);
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++(*nr_del);
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} else
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++(*nr_rem);
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}
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}
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}
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/*
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* Run idmap cache shrinker.
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*/
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static int
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cifs_idmap_shrinker(struct shrinker *shrink, struct shrink_control *sc)
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{
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int nr_to_scan = sc->nr_to_scan;
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int nr_del = 0;
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int nr_rem = 0;
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struct rb_root *root;
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root = &uidtree;
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spin_lock(&siduidlock);
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shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
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spin_unlock(&siduidlock);
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root = &gidtree;
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spin_lock(&sidgidlock);
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shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
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spin_unlock(&sidgidlock);
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return nr_rem;
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}
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static struct shrinker cifs_shrinker = {
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.shrink = cifs_idmap_shrinker,
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.seeks = DEFAULT_SEEKS,
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};
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static int
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cifs_idmap_key_instantiate(struct key *key, const void *data, size_t datalen)
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{
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char *payload;
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payload = kmalloc(datalen, GFP_KERNEL);
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if (!payload)
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return -ENOMEM;
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memcpy(payload, data, datalen);
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key->payload.data = payload;
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return 0;
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}
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static inline void
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cifs_idmap_key_destroy(struct key *key)
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{
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kfree(key->payload.data);
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}
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struct key_type cifs_idmap_key_type = {
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.name = "cifs.idmap",
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.instantiate = cifs_idmap_key_instantiate,
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.destroy = cifs_idmap_key_destroy,
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.describe = user_describe,
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.match = user_match,
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};
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static void
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sid_to_str(struct cifs_sid *sidptr, char *sidstr)
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{
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int i;
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unsigned long saval;
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char *strptr;
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strptr = sidstr;
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sprintf(strptr, "%s", "S");
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strptr = sidstr + strlen(sidstr);
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sprintf(strptr, "-%d", sidptr->revision);
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strptr = sidstr + strlen(sidstr);
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for (i = 0; i < 6; ++i) {
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if (sidptr->authority[i]) {
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sprintf(strptr, "-%d", sidptr->authority[i]);
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strptr = sidstr + strlen(sidstr);
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}
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}
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for (i = 0; i < sidptr->num_subauth; ++i) {
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saval = le32_to_cpu(sidptr->sub_auth[i]);
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sprintf(strptr, "-%ld", saval);
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strptr = sidstr + strlen(sidstr);
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}
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}
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static void
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id_rb_insert(struct rb_root *root, struct cifs_sid *sidptr,
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struct cifs_sid_id **psidid, char *typestr)
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{
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int rc;
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char *strptr;
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struct rb_node *node = root->rb_node;
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struct rb_node *parent = NULL;
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struct rb_node **linkto = &(root->rb_node);
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struct cifs_sid_id *lsidid;
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while (node) {
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lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
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parent = node;
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rc = compare_sids(sidptr, &((lsidid)->sid));
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if (rc > 0) {
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linkto = &(node->rb_left);
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node = node->rb_left;
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} else if (rc < 0) {
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linkto = &(node->rb_right);
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node = node->rb_right;
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}
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}
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memcpy(&(*psidid)->sid, sidptr, sizeof(struct cifs_sid));
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(*psidid)->time = jiffies - (SID_MAP_RETRY + 1);
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(*psidid)->refcount = 0;
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sprintf((*psidid)->sidstr, "%s", typestr);
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strptr = (*psidid)->sidstr + strlen((*psidid)->sidstr);
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sid_to_str(&(*psidid)->sid, strptr);
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clear_bit(SID_ID_PENDING, &(*psidid)->state);
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clear_bit(SID_ID_MAPPED, &(*psidid)->state);
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rb_link_node(&(*psidid)->rbnode, parent, linkto);
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rb_insert_color(&(*psidid)->rbnode, root);
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}
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static struct cifs_sid_id *
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id_rb_search(struct rb_root *root, struct cifs_sid *sidptr)
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{
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int rc;
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struct rb_node *node = root->rb_node;
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struct cifs_sid_id *lsidid;
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while (node) {
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lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
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rc = compare_sids(sidptr, &((lsidid)->sid));
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if (rc > 0) {
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node = node->rb_left;
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} else if (rc < 0) {
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node = node->rb_right;
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} else /* node found */
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return lsidid;
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}
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return NULL;
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}
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static int
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sidid_pending_wait(void *unused)
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{
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schedule();
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return signal_pending(current) ? -ERESTARTSYS : 0;
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}
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static int
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sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
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struct cifs_fattr *fattr, uint sidtype)
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{
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int rc;
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unsigned long cid;
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struct key *idkey;
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const struct cred *saved_cred;
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struct cifs_sid_id *psidid, *npsidid;
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struct rb_root *cidtree;
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spinlock_t *cidlock;
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if (sidtype == SIDOWNER) {
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cid = cifs_sb->mnt_uid; /* default uid, in case upcall fails */
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cidlock = &siduidlock;
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cidtree = &uidtree;
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} else if (sidtype == SIDGROUP) {
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cid = cifs_sb->mnt_gid; /* default gid, in case upcall fails */
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cidlock = &sidgidlock;
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cidtree = &gidtree;
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} else
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return -ENOENT;
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spin_lock(cidlock);
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psidid = id_rb_search(cidtree, psid);
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if (!psidid) { /* node does not exist, allocate one & attempt adding */
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spin_unlock(cidlock);
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npsidid = kzalloc(sizeof(struct cifs_sid_id), GFP_KERNEL);
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if (!npsidid)
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return -ENOMEM;
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npsidid->sidstr = kmalloc(SIDLEN, GFP_KERNEL);
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if (!npsidid->sidstr) {
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kfree(npsidid);
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return -ENOMEM;
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}
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spin_lock(cidlock);
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psidid = id_rb_search(cidtree, psid);
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if (psidid) { /* node happened to get inserted meanwhile */
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++psidid->refcount;
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spin_unlock(cidlock);
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kfree(npsidid->sidstr);
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kfree(npsidid);
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} else {
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psidid = npsidid;
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id_rb_insert(cidtree, psid, &psidid,
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sidtype == SIDOWNER ? "os:" : "gs:");
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++psidid->refcount;
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spin_unlock(cidlock);
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}
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} else {
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++psidid->refcount;
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spin_unlock(cidlock);
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}
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/*
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* If we are here, it is safe to access psidid and its fields
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* since a reference was taken earlier while holding the spinlock.
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* A reference on the node is put without holding the spinlock
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* and it is OK to do so in this case, shrinker will not erase
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* this node until all references are put and we do not access
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* any fields of the node after a reference is put .
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*/
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if (test_bit(SID_ID_MAPPED, &psidid->state)) {
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cid = psidid->id;
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psidid->time = jiffies; /* update ts for accessing */
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goto sid_to_id_out;
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}
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if (time_after(psidid->time + SID_MAP_RETRY, jiffies))
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goto sid_to_id_out;
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if (!test_and_set_bit(SID_ID_PENDING, &psidid->state)) {
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saved_cred = override_creds(root_cred);
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idkey = request_key(&cifs_idmap_key_type, psidid->sidstr, "");
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if (IS_ERR(idkey))
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cFYI(1, "%s: Can't map SID to an id", __func__);
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else {
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cid = *(unsigned long *)idkey->payload.value;
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psidid->id = cid;
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set_bit(SID_ID_MAPPED, &psidid->state);
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key_put(idkey);
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kfree(psidid->sidstr);
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}
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revert_creds(saved_cred);
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psidid->time = jiffies; /* update ts for accessing */
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clear_bit(SID_ID_PENDING, &psidid->state);
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wake_up_bit(&psidid->state, SID_ID_PENDING);
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} else {
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rc = wait_on_bit(&psidid->state, SID_ID_PENDING,
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sidid_pending_wait, TASK_INTERRUPTIBLE);
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if (rc) {
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cFYI(1, "%s: sidid_pending_wait interrupted %d",
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__func__, rc);
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--psidid->refcount; /* decremented without spinlock */
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return rc;
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}
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if (test_bit(SID_ID_MAPPED, &psidid->state))
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cid = psidid->id;
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}
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sid_to_id_out:
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--psidid->refcount; /* decremented without spinlock */
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if (sidtype == SIDOWNER)
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fattr->cf_uid = cid;
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else
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fattr->cf_gid = cid;
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return 0;
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}
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int
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init_cifs_idmap(void)
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{
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struct cred *cred;
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struct key *keyring;
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int ret;
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cFYI(1, "Registering the %s key type\n", cifs_idmap_key_type.name);
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/* create an override credential set with a special thread keyring in
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* which requests are cached
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*
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* this is used to prevent malicious redirections from being installed
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* with add_key().
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*/
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cred = prepare_kernel_cred(NULL);
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if (!cred)
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return -ENOMEM;
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keyring = key_alloc(&key_type_keyring, ".cifs_idmap", 0, 0, cred,
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(KEY_POS_ALL & ~KEY_POS_SETATTR) |
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KEY_USR_VIEW | KEY_USR_READ,
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KEY_ALLOC_NOT_IN_QUOTA);
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if (IS_ERR(keyring)) {
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ret = PTR_ERR(keyring);
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goto failed_put_cred;
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}
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ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
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if (ret < 0)
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goto failed_put_key;
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ret = register_key_type(&cifs_idmap_key_type);
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if (ret < 0)
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goto failed_put_key;
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/* instruct request_key() to use this special keyring as a cache for
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* the results it looks up */
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cred->thread_keyring = keyring;
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cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
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root_cred = cred;
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spin_lock_init(&siduidlock);
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uidtree = RB_ROOT;
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spin_lock_init(&sidgidlock);
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gidtree = RB_ROOT;
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register_shrinker(&cifs_shrinker);
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cFYI(1, "cifs idmap keyring: %d\n", key_serial(keyring));
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return 0;
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failed_put_key:
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key_put(keyring);
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failed_put_cred:
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put_cred(cred);
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return ret;
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}
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void
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exit_cifs_idmap(void)
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{
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key_revoke(root_cred->thread_keyring);
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unregister_key_type(&cifs_idmap_key_type);
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put_cred(root_cred);
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unregister_shrinker(&cifs_shrinker);
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cFYI(1, "Unregistered %s key type\n", cifs_idmap_key_type.name);
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}
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void
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cifs_destroy_idmaptrees(void)
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{
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struct rb_root *root;
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struct rb_node *node;
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root = &uidtree;
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spin_lock(&siduidlock);
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while ((node = rb_first(root)))
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rb_erase(node, root);
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spin_unlock(&siduidlock);
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root = &gidtree;
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spin_lock(&sidgidlock);
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while ((node = rb_first(root)))
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rb_erase(node, root);
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spin_unlock(&sidgidlock);
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}
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|
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/* if the two SIDs (roughly equivalent to a UUID for a user or group) are
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the same returns 1, if they do not match returns 0 */
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int compare_sids(const struct cifs_sid *ctsid, const struct cifs_sid *cwsid)
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{
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int i;
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int num_subauth, num_sat, num_saw;
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if ((!ctsid) || (!cwsid))
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return 1;
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|
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/* compare the revision */
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if (ctsid->revision != cwsid->revision) {
|
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if (ctsid->revision > cwsid->revision)
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return 1;
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else
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return -1;
|
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}
|
|
|
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/* compare all of the six auth values */
|
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for (i = 0; i < 6; ++i) {
|
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if (ctsid->authority[i] != cwsid->authority[i]) {
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if (ctsid->authority[i] > cwsid->authority[i])
|
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return 1;
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else
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return -1;
|
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}
|
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}
|
|
|
|
/* compare all of the subauth values if any */
|
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num_sat = ctsid->num_subauth;
|
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num_saw = cwsid->num_subauth;
|
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num_subauth = num_sat < num_saw ? num_sat : num_saw;
|
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if (num_subauth) {
|
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for (i = 0; i < num_subauth; ++i) {
|
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if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) {
|
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if (le32_to_cpu(ctsid->sub_auth[i]) >
|
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le32_to_cpu(cwsid->sub_auth[i]))
|
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return 1;
|
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else
|
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return -1;
|
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}
|
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}
|
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}
|
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|
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return 0; /* sids compare/match */
|
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}
|
|
|
|
|
|
/* copy ntsd, owner sid, and group sid from a security descriptor to another */
|
|
static void copy_sec_desc(const struct cifs_ntsd *pntsd,
|
|
struct cifs_ntsd *pnntsd, __u32 sidsoffset)
|
|
{
|
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int i;
|
|
|
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struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
|
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struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr;
|
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|
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/* copy security descriptor control portion */
|
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pnntsd->revision = pntsd->revision;
|
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pnntsd->type = pntsd->type;
|
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pnntsd->dacloffset = cpu_to_le32(sizeof(struct cifs_ntsd));
|
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pnntsd->sacloffset = 0;
|
|
pnntsd->osidoffset = cpu_to_le32(sidsoffset);
|
|
pnntsd->gsidoffset = cpu_to_le32(sidsoffset + sizeof(struct cifs_sid));
|
|
|
|
/* copy owner sid */
|
|
owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
|
|
le32_to_cpu(pntsd->osidoffset));
|
|
nowner_sid_ptr = (struct cifs_sid *)((char *)pnntsd + sidsoffset);
|
|
|
|
nowner_sid_ptr->revision = owner_sid_ptr->revision;
|
|
nowner_sid_ptr->num_subauth = owner_sid_ptr->num_subauth;
|
|
for (i = 0; i < 6; i++)
|
|
nowner_sid_ptr->authority[i] = owner_sid_ptr->authority[i];
|
|
for (i = 0; i < 5; i++)
|
|
nowner_sid_ptr->sub_auth[i] = owner_sid_ptr->sub_auth[i];
|
|
|
|
/* copy group sid */
|
|
group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
|
|
le32_to_cpu(pntsd->gsidoffset));
|
|
ngroup_sid_ptr = (struct cifs_sid *)((char *)pnntsd + sidsoffset +
|
|
sizeof(struct cifs_sid));
|
|
|
|
ngroup_sid_ptr->revision = group_sid_ptr->revision;
|
|
ngroup_sid_ptr->num_subauth = group_sid_ptr->num_subauth;
|
|
for (i = 0; i < 6; i++)
|
|
ngroup_sid_ptr->authority[i] = group_sid_ptr->authority[i];
|
|
for (i = 0; i < 5; i++)
|
|
ngroup_sid_ptr->sub_auth[i] = group_sid_ptr->sub_auth[i];
|
|
|
|
return;
|
|
}
|
|
|
|
|
|
/*
|
|
change posix mode to reflect permissions
|
|
pmode is the existing mode (we only want to overwrite part of this
|
|
bits to set can be: S_IRWXU, S_IRWXG or S_IRWXO ie 00700 or 00070 or 00007
|
|
*/
|
|
static void access_flags_to_mode(__le32 ace_flags, int type, umode_t *pmode,
|
|
umode_t *pbits_to_set)
|
|
{
|
|
__u32 flags = le32_to_cpu(ace_flags);
|
|
/* the order of ACEs is important. The canonical order is to begin with
|
|
DENY entries followed by ALLOW, otherwise an allow entry could be
|
|
encountered first, making the subsequent deny entry like "dead code"
|
|
which would be superflous since Windows stops when a match is made
|
|
for the operation you are trying to perform for your user */
|
|
|
|
/* For deny ACEs we change the mask so that subsequent allow access
|
|
control entries do not turn on the bits we are denying */
|
|
if (type == ACCESS_DENIED) {
|
|
if (flags & GENERIC_ALL)
|
|
*pbits_to_set &= ~S_IRWXUGO;
|
|
|
|
if ((flags & GENERIC_WRITE) ||
|
|
((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS))
|
|
*pbits_to_set &= ~S_IWUGO;
|
|
if ((flags & GENERIC_READ) ||
|
|
((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS))
|
|
*pbits_to_set &= ~S_IRUGO;
|
|
if ((flags & GENERIC_EXECUTE) ||
|
|
((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS))
|
|
*pbits_to_set &= ~S_IXUGO;
|
|
return;
|
|
} else if (type != ACCESS_ALLOWED) {
|
|
cERROR(1, "unknown access control type %d", type);
|
|
return;
|
|
}
|
|
/* else ACCESS_ALLOWED type */
|
|
|
|
if (flags & GENERIC_ALL) {
|
|
*pmode |= (S_IRWXUGO & (*pbits_to_set));
|
|
cFYI(DBG2, "all perms");
|
|
return;
|
|
}
|
|
if ((flags & GENERIC_WRITE) ||
|
|
((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS))
|
|
*pmode |= (S_IWUGO & (*pbits_to_set));
|
|
if ((flags & GENERIC_READ) ||
|
|
((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS))
|
|
*pmode |= (S_IRUGO & (*pbits_to_set));
|
|
if ((flags & GENERIC_EXECUTE) ||
|
|
((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS))
|
|
*pmode |= (S_IXUGO & (*pbits_to_set));
|
|
|
|
cFYI(DBG2, "access flags 0x%x mode now 0x%x", flags, *pmode);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
Generate access flags to reflect permissions mode is the existing mode.
|
|
This function is called for every ACE in the DACL whose SID matches
|
|
with either owner or group or everyone.
|
|
*/
|
|
|
|
static void mode_to_access_flags(umode_t mode, umode_t bits_to_use,
|
|
__u32 *pace_flags)
|
|
{
|
|
/* reset access mask */
|
|
*pace_flags = 0x0;
|
|
|
|
/* bits to use are either S_IRWXU or S_IRWXG or S_IRWXO */
|
|
mode &= bits_to_use;
|
|
|
|
/* check for R/W/X UGO since we do not know whose flags
|
|
is this but we have cleared all the bits sans RWX for
|
|
either user or group or other as per bits_to_use */
|
|
if (mode & S_IRUGO)
|
|
*pace_flags |= SET_FILE_READ_RIGHTS;
|
|
if (mode & S_IWUGO)
|
|
*pace_flags |= SET_FILE_WRITE_RIGHTS;
|
|
if (mode & S_IXUGO)
|
|
*pace_flags |= SET_FILE_EXEC_RIGHTS;
|
|
|
|
cFYI(DBG2, "mode: 0x%x, access flags now 0x%x", mode, *pace_flags);
|
|
return;
|
|
}
|
|
|
|
static __u16 fill_ace_for_sid(struct cifs_ace *pntace,
|
|
const struct cifs_sid *psid, __u64 nmode, umode_t bits)
|
|
{
|
|
int i;
|
|
__u16 size = 0;
|
|
__u32 access_req = 0;
|
|
|
|
pntace->type = ACCESS_ALLOWED;
|
|
pntace->flags = 0x0;
|
|
mode_to_access_flags(nmode, bits, &access_req);
|
|
if (!access_req)
|
|
access_req = SET_MINIMUM_RIGHTS;
|
|
pntace->access_req = cpu_to_le32(access_req);
|
|
|
|
pntace->sid.revision = psid->revision;
|
|
pntace->sid.num_subauth = psid->num_subauth;
|
|
for (i = 0; i < 6; i++)
|
|
pntace->sid.authority[i] = psid->authority[i];
|
|
for (i = 0; i < psid->num_subauth; i++)
|
|
pntace->sid.sub_auth[i] = psid->sub_auth[i];
|
|
|
|
size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth * 4);
|
|
pntace->size = cpu_to_le16(size);
|
|
|
|
return size;
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_CIFS_DEBUG2
|
|
static void dump_ace(struct cifs_ace *pace, char *end_of_acl)
|
|
{
|
|
int num_subauth;
|
|
|
|
/* validate that we do not go past end of acl */
|
|
|
|
if (le16_to_cpu(pace->size) < 16) {
|
|
cERROR(1, "ACE too small %d", le16_to_cpu(pace->size));
|
|
return;
|
|
}
|
|
|
|
if (end_of_acl < (char *)pace + le16_to_cpu(pace->size)) {
|
|
cERROR(1, "ACL too small to parse ACE");
|
|
return;
|
|
}
|
|
|
|
num_subauth = pace->sid.num_subauth;
|
|
if (num_subauth) {
|
|
int i;
|
|
cFYI(1, "ACE revision %d num_auth %d type %d flags %d size %d",
|
|
pace->sid.revision, pace->sid.num_subauth, pace->type,
|
|
pace->flags, le16_to_cpu(pace->size));
|
|
for (i = 0; i < num_subauth; ++i) {
|
|
cFYI(1, "ACE sub_auth[%d]: 0x%x", i,
|
|
le32_to_cpu(pace->sid.sub_auth[i]));
|
|
}
|
|
|
|
/* BB add length check to make sure that we do not have huge
|
|
num auths and therefore go off the end */
|
|
}
|
|
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
|
|
static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
|
|
struct cifs_sid *pownersid, struct cifs_sid *pgrpsid,
|
|
struct cifs_fattr *fattr)
|
|
{
|
|
int i;
|
|
int num_aces = 0;
|
|
int acl_size;
|
|
char *acl_base;
|
|
struct cifs_ace **ppace;
|
|
|
|
/* BB need to add parm so we can store the SID BB */
|
|
|
|
if (!pdacl) {
|
|
/* no DACL in the security descriptor, set
|
|
all the permissions for user/group/other */
|
|
fattr->cf_mode |= S_IRWXUGO;
|
|
return;
|
|
}
|
|
|
|
/* validate that we do not go past end of acl */
|
|
if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
|
|
cERROR(1, "ACL too small to parse DACL");
|
|
return;
|
|
}
|
|
|
|
cFYI(DBG2, "DACL revision %d size %d num aces %d",
|
|
le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size),
|
|
le32_to_cpu(pdacl->num_aces));
|
|
|
|
/* reset rwx permissions for user/group/other.
|
|
Also, if num_aces is 0 i.e. DACL has no ACEs,
|
|
user/group/other have no permissions */
|
|
fattr->cf_mode &= ~(S_IRWXUGO);
|
|
|
|
acl_base = (char *)pdacl;
|
|
acl_size = sizeof(struct cifs_acl);
|
|
|
|
num_aces = le32_to_cpu(pdacl->num_aces);
|
|
if (num_aces > 0) {
|
|
umode_t user_mask = S_IRWXU;
|
|
umode_t group_mask = S_IRWXG;
|
|
umode_t other_mask = S_IRWXU | S_IRWXG | S_IRWXO;
|
|
|
|
ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
|
|
GFP_KERNEL);
|
|
if (!ppace) {
|
|
cERROR(1, "DACL memory allocation error");
|
|
return;
|
|
}
|
|
|
|
for (i = 0; i < num_aces; ++i) {
|
|
ppace[i] = (struct cifs_ace *) (acl_base + acl_size);
|
|
#ifdef CONFIG_CIFS_DEBUG2
|
|
dump_ace(ppace[i], end_of_acl);
|
|
#endif
|
|
if (compare_sids(&(ppace[i]->sid), pownersid) == 0)
|
|
access_flags_to_mode(ppace[i]->access_req,
|
|
ppace[i]->type,
|
|
&fattr->cf_mode,
|
|
&user_mask);
|
|
if (compare_sids(&(ppace[i]->sid), pgrpsid) == 0)
|
|
access_flags_to_mode(ppace[i]->access_req,
|
|
ppace[i]->type,
|
|
&fattr->cf_mode,
|
|
&group_mask);
|
|
if (compare_sids(&(ppace[i]->sid), &sid_everyone) == 0)
|
|
access_flags_to_mode(ppace[i]->access_req,
|
|
ppace[i]->type,
|
|
&fattr->cf_mode,
|
|
&other_mask);
|
|
if (compare_sids(&(ppace[i]->sid), &sid_authusers) == 0)
|
|
access_flags_to_mode(ppace[i]->access_req,
|
|
ppace[i]->type,
|
|
&fattr->cf_mode,
|
|
&other_mask);
|
|
|
|
|
|
/* memcpy((void *)(&(cifscred->aces[i])),
|
|
(void *)ppace[i],
|
|
sizeof(struct cifs_ace)); */
|
|
|
|
acl_base = (char *)ppace[i];
|
|
acl_size = le16_to_cpu(ppace[i]->size);
|
|
}
|
|
|
|
kfree(ppace);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
|
|
static int set_chmod_dacl(struct cifs_acl *pndacl, struct cifs_sid *pownersid,
|
|
struct cifs_sid *pgrpsid, __u64 nmode)
|
|
{
|
|
u16 size = 0;
|
|
struct cifs_acl *pnndacl;
|
|
|
|
pnndacl = (struct cifs_acl *)((char *)pndacl + sizeof(struct cifs_acl));
|
|
|
|
size += fill_ace_for_sid((struct cifs_ace *) ((char *)pnndacl + size),
|
|
pownersid, nmode, S_IRWXU);
|
|
size += fill_ace_for_sid((struct cifs_ace *)((char *)pnndacl + size),
|
|
pgrpsid, nmode, S_IRWXG);
|
|
size += fill_ace_for_sid((struct cifs_ace *)((char *)pnndacl + size),
|
|
&sid_everyone, nmode, S_IRWXO);
|
|
|
|
pndacl->size = cpu_to_le16(size + sizeof(struct cifs_acl));
|
|
pndacl->num_aces = cpu_to_le32(3);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
|
|
{
|
|
/* BB need to add parm so we can store the SID BB */
|
|
|
|
/* validate that we do not go past end of ACL - sid must be at least 8
|
|
bytes long (assuming no sub-auths - e.g. the null SID */
|
|
if (end_of_acl < (char *)psid + 8) {
|
|
cERROR(1, "ACL too small to parse SID %p", psid);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (psid->num_subauth) {
|
|
#ifdef CONFIG_CIFS_DEBUG2
|
|
int i;
|
|
cFYI(1, "SID revision %d num_auth %d",
|
|
psid->revision, psid->num_subauth);
|
|
|
|
for (i = 0; i < psid->num_subauth; i++) {
|
|
cFYI(1, "SID sub_auth[%d]: 0x%x ", i,
|
|
le32_to_cpu(psid->sub_auth[i]));
|
|
}
|
|
|
|
/* BB add length check to make sure that we do not have huge
|
|
num auths and therefore go off the end */
|
|
cFYI(1, "RID 0x%x",
|
|
le32_to_cpu(psid->sub_auth[psid->num_subauth-1]));
|
|
#endif
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Convert CIFS ACL to POSIX form */
|
|
static int parse_sec_desc(struct cifs_sb_info *cifs_sb,
|
|
struct cifs_ntsd *pntsd, int acl_len, struct cifs_fattr *fattr)
|
|
{
|
|
int rc = 0;
|
|
struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
|
|
struct cifs_acl *dacl_ptr; /* no need for SACL ptr */
|
|
char *end_of_acl = ((char *)pntsd) + acl_len;
|
|
__u32 dacloffset;
|
|
|
|
if (pntsd == NULL)
|
|
return -EIO;
|
|
|
|
owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
|
|
le32_to_cpu(pntsd->osidoffset));
|
|
group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
|
|
le32_to_cpu(pntsd->gsidoffset));
|
|
dacloffset = le32_to_cpu(pntsd->dacloffset);
|
|
dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset);
|
|
cFYI(DBG2, "revision %d type 0x%x ooffset 0x%x goffset 0x%x "
|
|
"sacloffset 0x%x dacloffset 0x%x",
|
|
pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset),
|
|
le32_to_cpu(pntsd->gsidoffset),
|
|
le32_to_cpu(pntsd->sacloffset), dacloffset);
|
|
/* cifs_dump_mem("owner_sid: ", owner_sid_ptr, 64); */
|
|
rc = parse_sid(owner_sid_ptr, end_of_acl);
|
|
if (rc) {
|
|
cFYI(1, "%s: Error %d parsing Owner SID", __func__, rc);
|
|
return rc;
|
|
}
|
|
rc = sid_to_id(cifs_sb, owner_sid_ptr, fattr, SIDOWNER);
|
|
if (rc) {
|
|
cFYI(1, "%s: Error %d mapping Owner SID to uid", __func__, rc);
|
|
return rc;
|
|
}
|
|
|
|
rc = parse_sid(group_sid_ptr, end_of_acl);
|
|
if (rc) {
|
|
cFYI(1, "%s: Error %d mapping Owner SID to gid", __func__, rc);
|
|
return rc;
|
|
}
|
|
rc = sid_to_id(cifs_sb, group_sid_ptr, fattr, SIDGROUP);
|
|
if (rc) {
|
|
cFYI(1, "%s: Error %d mapping Group SID to gid", __func__, rc);
|
|
return rc;
|
|
}
|
|
|
|
if (dacloffset)
|
|
parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr,
|
|
group_sid_ptr, fattr);
|
|
else
|
|
cFYI(1, "no ACL"); /* BB grant all or default perms? */
|
|
|
|
/* cifscred->uid = owner_sid_ptr->rid;
|
|
cifscred->gid = group_sid_ptr->rid;
|
|
memcpy((void *)(&(cifscred->osid)), (void *)owner_sid_ptr,
|
|
sizeof(struct cifs_sid));
|
|
memcpy((void *)(&(cifscred->gsid)), (void *)group_sid_ptr,
|
|
sizeof(struct cifs_sid)); */
|
|
|
|
return rc;
|
|
}
|
|
|
|
|
|
/* Convert permission bits from mode to equivalent CIFS ACL */
|
|
static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
|
|
struct inode *inode, __u64 nmode)
|
|
{
|
|
int rc = 0;
|
|
__u32 dacloffset;
|
|
__u32 ndacloffset;
|
|
__u32 sidsoffset;
|
|
struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
|
|
struct cifs_acl *dacl_ptr = NULL; /* no need for SACL ptr */
|
|
struct cifs_acl *ndacl_ptr = NULL; /* no need for SACL ptr */
|
|
|
|
if ((inode == NULL) || (pntsd == NULL) || (pnntsd == NULL))
|
|
return -EIO;
|
|
|
|
owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
|
|
le32_to_cpu(pntsd->osidoffset));
|
|
group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
|
|
le32_to_cpu(pntsd->gsidoffset));
|
|
|
|
dacloffset = le32_to_cpu(pntsd->dacloffset);
|
|
dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset);
|
|
|
|
ndacloffset = sizeof(struct cifs_ntsd);
|
|
ndacl_ptr = (struct cifs_acl *)((char *)pnntsd + ndacloffset);
|
|
ndacl_ptr->revision = dacl_ptr->revision;
|
|
ndacl_ptr->size = 0;
|
|
ndacl_ptr->num_aces = 0;
|
|
|
|
rc = set_chmod_dacl(ndacl_ptr, owner_sid_ptr, group_sid_ptr, nmode);
|
|
|
|
sidsoffset = ndacloffset + le16_to_cpu(ndacl_ptr->size);
|
|
|
|
/* copy security descriptor control portion and owner and group sid */
|
|
copy_sec_desc(pntsd, pnntsd, sidsoffset);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
|
|
__u16 fid, u32 *pacllen)
|
|
{
|
|
struct cifs_ntsd *pntsd = NULL;
|
|
int xid, rc;
|
|
struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
|
|
|
|
if (IS_ERR(tlink))
|
|
return ERR_CAST(tlink);
|
|
|
|
xid = GetXid();
|
|
rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen);
|
|
FreeXid(xid);
|
|
|
|
cifs_put_tlink(tlink);
|
|
|
|
cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen);
|
|
if (rc)
|
|
return ERR_PTR(rc);
|
|
return pntsd;
|
|
}
|
|
|
|
static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
|
|
const char *path, u32 *pacllen)
|
|
{
|
|
struct cifs_ntsd *pntsd = NULL;
|
|
int oplock = 0;
|
|
int xid, rc;
|
|
__u16 fid;
|
|
struct cifs_tcon *tcon;
|
|
struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
|
|
|
|
if (IS_ERR(tlink))
|
|
return ERR_CAST(tlink);
|
|
|
|
tcon = tlink_tcon(tlink);
|
|
xid = GetXid();
|
|
|
|
rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, READ_CONTROL, 0,
|
|
&fid, &oplock, NULL, cifs_sb->local_nls,
|
|
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
|
|
if (!rc) {
|
|
rc = CIFSSMBGetCIFSACL(xid, tcon, fid, &pntsd, pacllen);
|
|
CIFSSMBClose(xid, tcon, fid);
|
|
}
|
|
|
|
cifs_put_tlink(tlink);
|
|
FreeXid(xid);
|
|
|
|
cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen);
|
|
if (rc)
|
|
return ERR_PTR(rc);
|
|
return pntsd;
|
|
}
|
|
|
|
/* Retrieve an ACL from the server */
|
|
struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
|
|
struct inode *inode, const char *path,
|
|
u32 *pacllen)
|
|
{
|
|
struct cifs_ntsd *pntsd = NULL;
|
|
struct cifsFileInfo *open_file = NULL;
|
|
|
|
if (inode)
|
|
open_file = find_readable_file(CIFS_I(inode), true);
|
|
if (!open_file)
|
|
return get_cifs_acl_by_path(cifs_sb, path, pacllen);
|
|
|
|
pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->netfid, pacllen);
|
|
cifsFileInfo_put(open_file);
|
|
return pntsd;
|
|
}
|
|
|
|
static int set_cifs_acl_by_path(struct cifs_sb_info *cifs_sb, const char *path,
|
|
struct cifs_ntsd *pnntsd, u32 acllen)
|
|
{
|
|
int oplock = 0;
|
|
int xid, rc;
|
|
__u16 fid;
|
|
struct cifs_tcon *tcon;
|
|
struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
|
|
|
|
if (IS_ERR(tlink))
|
|
return PTR_ERR(tlink);
|
|
|
|
tcon = tlink_tcon(tlink);
|
|
xid = GetXid();
|
|
|
|
rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, WRITE_DAC, 0,
|
|
&fid, &oplock, NULL, cifs_sb->local_nls,
|
|
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
|
|
if (rc) {
|
|
cERROR(1, "Unable to open file to set ACL");
|
|
goto out;
|
|
}
|
|
|
|
rc = CIFSSMBSetCIFSACL(xid, tcon, fid, pnntsd, acllen);
|
|
cFYI(DBG2, "SetCIFSACL rc = %d", rc);
|
|
|
|
CIFSSMBClose(xid, tcon, fid);
|
|
out:
|
|
FreeXid(xid);
|
|
cifs_put_tlink(tlink);
|
|
return rc;
|
|
}
|
|
|
|
/* Set an ACL on the server */
|
|
int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
|
|
struct inode *inode, const char *path)
|
|
{
|
|
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
|
|
|
|
cFYI(DBG2, "set ACL for %s from mode 0x%x", path, inode->i_mode);
|
|
|
|
return set_cifs_acl_by_path(cifs_sb, path, pnntsd, acllen);
|
|
}
|
|
|
|
/* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
|
|
int
|
|
cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
|
|
struct inode *inode, const char *path, const __u16 *pfid)
|
|
{
|
|
struct cifs_ntsd *pntsd = NULL;
|
|
u32 acllen = 0;
|
|
int rc = 0;
|
|
|
|
cFYI(DBG2, "converting ACL to mode for %s", path);
|
|
|
|
if (pfid)
|
|
pntsd = get_cifs_acl_by_fid(cifs_sb, *pfid, &acllen);
|
|
else
|
|
pntsd = get_cifs_acl(cifs_sb, inode, path, &acllen);
|
|
|
|
/* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
|
|
if (IS_ERR(pntsd)) {
|
|
rc = PTR_ERR(pntsd);
|
|
cERROR(1, "%s: error %d getting sec desc", __func__, rc);
|
|
} else {
|
|
rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr);
|
|
kfree(pntsd);
|
|
if (rc)
|
|
cERROR(1, "parse sec desc failed rc = %d", rc);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/* Convert mode bits to an ACL so we can update the ACL on the server */
|
|
int mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode)
|
|
{
|
|
int rc = 0;
|
|
__u32 secdesclen = 0;
|
|
struct cifs_ntsd *pntsd = NULL; /* acl obtained from server */
|
|
struct cifs_ntsd *pnntsd = NULL; /* modified acl to be sent to server */
|
|
|
|
cFYI(DBG2, "set ACL from mode for %s", path);
|
|
|
|
/* Get the security descriptor */
|
|
pntsd = get_cifs_acl(CIFS_SB(inode->i_sb), inode, path, &secdesclen);
|
|
|
|
/* Add three ACEs for owner, group, everyone getting rid of
|
|
other ACEs as chmod disables ACEs and set the security descriptor */
|
|
|
|
if (IS_ERR(pntsd)) {
|
|
rc = PTR_ERR(pntsd);
|
|
cERROR(1, "%s: error %d getting sec desc", __func__, rc);
|
|
} else {
|
|
/* allocate memory for the smb header,
|
|
set security descriptor request security descriptor
|
|
parameters, and secuirty descriptor itself */
|
|
|
|
secdesclen = secdesclen < DEFSECDESCLEN ?
|
|
DEFSECDESCLEN : secdesclen;
|
|
pnntsd = kmalloc(secdesclen, GFP_KERNEL);
|
|
if (!pnntsd) {
|
|
cERROR(1, "Unable to allocate security descriptor");
|
|
kfree(pntsd);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
rc = build_sec_desc(pntsd, pnntsd, inode, nmode);
|
|
|
|
cFYI(DBG2, "build_sec_desc rc: %d", rc);
|
|
|
|
if (!rc) {
|
|
/* Set the security descriptor */
|
|
rc = set_cifs_acl(pnntsd, secdesclen, inode, path);
|
|
cFYI(DBG2, "set_cifs_acl rc: %d", rc);
|
|
}
|
|
|
|
kfree(pnntsd);
|
|
kfree(pntsd);
|
|
}
|
|
|
|
return rc;
|
|
}
|