cifsacl.c 35.4 KB
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/*
 *   fs/cifs/cifsacl.c
 *
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 *   Copyright (C) International Business Machines  Corp., 2007,2008
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 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   Contains the routines for mapping CIFS/NTFS ACLs
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/string.h>
#include <linux/keyctl.h>
#include <linux/key-type.h>
#include <keys/user-type.h>
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#include "cifspdu.h"
#include "cifsglob.h"
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#include "cifsacl.h"
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#include "cifsproto.h"
#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 = {
	1, 1, {0, 0, 0, 0, 0, 1}, {0} };
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/* security id for Authenticated Users system group */
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 */
S
Steve French 已提交
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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;

static void
shrink_idmap_tree(struct rb_root *root, int nr_to_scan, int *nr_rem,
			int *nr_del)
{
	struct rb_node *node;
	struct rb_node *tmp;
	struct cifs_sid_id *psidid;

	node = rb_first(root);
	while (node) {
		tmp = node;
		node = rb_next(tmp);
		psidid = rb_entry(tmp, struct cifs_sid_id, rbnode);
		if (nr_to_scan == 0 || *nr_del == nr_to_scan)
			++(*nr_rem);
		else {
			if (time_after(jiffies, psidid->time + SID_MAP_EXPIRE)
						&& psidid->refcount == 0) {
				rb_erase(tmp, root);
				++(*nr_del);
			} else
				++(*nr_rem);
		}
	}
}
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/*
 * Run idmap cache shrinker.
 */
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;
	int nr_rem = 0;
	struct rb_root *root;

	root = &uidtree;
	spin_lock(&siduidlock);
	shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
	spin_unlock(&siduidlock);

	root = &gidtree;
	spin_lock(&sidgidlock);
	shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
	spin_unlock(&sidgidlock);

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	root = &siduidtree;
	spin_lock(&uidsidlock);
	shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
	spin_unlock(&uidsidlock);

	root = &sidgidtree;
	spin_lock(&gidsidlock);
	shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
	spin_unlock(&gidsidlock);

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	return nr_rem;
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}

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static void
sid_rb_insert(struct rb_root *root, unsigned long cid,
		struct cifs_sid_id **psidid, char *typestr)
{
	char *strptr;
	struct rb_node *node = root->rb_node;
	struct rb_node *parent = NULL;
	struct rb_node **linkto = &(root->rb_node);
	struct cifs_sid_id *lsidid;

	while (node) {
		lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
		parent = node;
		if (cid > lsidid->id) {
			linkto = &(node->rb_left);
			node = node->rb_left;
		}
		if (cid < lsidid->id) {
			linkto = &(node->rb_right);
			node = node->rb_right;
		}
	}

	(*psidid)->id = cid;
	(*psidid)->time = jiffies - (SID_MAP_RETRY + 1);
	(*psidid)->refcount = 0;

	sprintf((*psidid)->sidstr, "%s", typestr);
	strptr = (*psidid)->sidstr + strlen((*psidid)->sidstr);
	sprintf(strptr, "%ld", cid);

	clear_bit(SID_ID_PENDING, &(*psidid)->state);
	clear_bit(SID_ID_MAPPED, &(*psidid)->state);

	rb_link_node(&(*psidid)->rbnode, parent, linkto);
	rb_insert_color(&(*psidid)->rbnode, root);
}

static struct cifs_sid_id *
sid_rb_search(struct rb_root *root, unsigned long cid)
{
	struct rb_node *node = root->rb_node;
	struct cifs_sid_id *lsidid;

	while (node) {
		lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
		if (cid > lsidid->id)
			node = node->rb_left;
		else if (cid < lsidid->id)
			node = node->rb_right;
		else /* node found */
			return lsidid;
	}

	return NULL;
}

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static struct shrinker cifs_shrinker = {
	.shrink = cifs_idmap_shrinker,
	.seeks = DEFAULT_SEEKS,
};

static int
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cifs_idmap_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
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{
	char *payload;

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	payload = kmalloc(prep->datalen, GFP_KERNEL);
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	if (!payload)
		return -ENOMEM;

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	memcpy(payload, prep->data, prep->datalen);
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	key->payload.data = payload;
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	key->datalen = prep->datalen;
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	return 0;
}

static inline void
cifs_idmap_key_destroy(struct key *key)
{
	kfree(key->payload.data);
}

struct key_type cifs_idmap_key_type = {
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	.name        = "cifs.idmap",
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	.instantiate = cifs_idmap_key_instantiate,
	.destroy     = cifs_idmap_key_destroy,
	.describe    = user_describe,
	.match       = user_match,
};

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static void
sid_to_str(struct cifs_sid *sidptr, char *sidstr)
{
	int i;
	unsigned long saval;
	char *strptr;

	strptr = sidstr;

	sprintf(strptr, "%s", "S");
	strptr = sidstr + strlen(sidstr);

	sprintf(strptr, "-%d", sidptr->revision);
	strptr = sidstr + strlen(sidstr);

	for (i = 0; i < 6; ++i) {
		if (sidptr->authority[i]) {
			sprintf(strptr, "-%d", sidptr->authority[i]);
			strptr = sidstr + strlen(sidstr);
		}
	}

	for (i = 0; i < sidptr->num_subauth; ++i) {
		saval = le32_to_cpu(sidptr->sub_auth[i]);
		sprintf(strptr, "-%ld", saval);
		strptr = sidstr + strlen(sidstr);
	}
}

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static void
cifs_copy_sid(struct cifs_sid *dst, const struct cifs_sid *src)
{
	memcpy(dst, src, sizeof(*dst));
	dst->num_subauth = min_t(u8, src->num_subauth, NUM_SUBAUTHS);
}

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static void
id_rb_insert(struct rb_root *root, struct cifs_sid *sidptr,
		struct cifs_sid_id **psidid, char *typestr)
{
	int rc;
	char *strptr;
	struct rb_node *node = root->rb_node;
	struct rb_node *parent = NULL;
	struct rb_node **linkto = &(root->rb_node);
	struct cifs_sid_id *lsidid;

	while (node) {
		lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
		parent = node;
		rc = compare_sids(sidptr, &((lsidid)->sid));
		if (rc > 0) {
			linkto = &(node->rb_left);
			node = node->rb_left;
		} else if (rc < 0) {
			linkto = &(node->rb_right);
			node = node->rb_right;
		}
	}

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	cifs_copy_sid(&(*psidid)->sid, sidptr);
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	(*psidid)->time = jiffies - (SID_MAP_RETRY + 1);
	(*psidid)->refcount = 0;

	sprintf((*psidid)->sidstr, "%s", typestr);
	strptr = (*psidid)->sidstr + strlen((*psidid)->sidstr);
	sid_to_str(&(*psidid)->sid, strptr);

	clear_bit(SID_ID_PENDING, &(*psidid)->state);
	clear_bit(SID_ID_MAPPED, &(*psidid)->state);

	rb_link_node(&(*psidid)->rbnode, parent, linkto);
	rb_insert_color(&(*psidid)->rbnode, root);
}

static struct cifs_sid_id *
id_rb_search(struct rb_root *root, struct cifs_sid *sidptr)
{
	int rc;
	struct rb_node *node = root->rb_node;
	struct cifs_sid_id *lsidid;

	while (node) {
		lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
		rc = compare_sids(sidptr, &((lsidid)->sid));
		if (rc > 0) {
			node = node->rb_left;
		} else if (rc < 0) {
			node = node->rb_right;
		} else /* node found */
			return lsidid;
	}

	return NULL;
}

static int
sidid_pending_wait(void *unused)
{
	schedule();
	return signal_pending(current) ? -ERESTARTSYS : 0;
}

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static int
id_to_sid(unsigned long cid, uint sidtype, struct cifs_sid *ssid)
{
	int rc = 0;
	struct key *sidkey;
	const struct cred *saved_cred;
	struct cifs_sid *lsid;
	struct cifs_sid_id *psidid, *npsidid;
	struct rb_root *cidtree;
	spinlock_t *cidlock;

	if (sidtype == SIDOWNER) {
		cidlock = &siduidlock;
		cidtree = &uidtree;
	} else if (sidtype == SIDGROUP) {
		cidlock = &sidgidlock;
		cidtree = &gidtree;
	} else
		return -EINVAL;

	spin_lock(cidlock);
	psidid = sid_rb_search(cidtree, cid);

	if (!psidid) { /* node does not exist, allocate one & attempt adding */
		spin_unlock(cidlock);
		npsidid = kzalloc(sizeof(struct cifs_sid_id), GFP_KERNEL);
		if (!npsidid)
			return -ENOMEM;

		npsidid->sidstr = kmalloc(SIDLEN, GFP_KERNEL);
		if (!npsidid->sidstr) {
			kfree(npsidid);
			return -ENOMEM;
		}

		spin_lock(cidlock);
		psidid = sid_rb_search(cidtree, cid);
		if (psidid) { /* node happened to get inserted meanwhile */
			++psidid->refcount;
			spin_unlock(cidlock);
			kfree(npsidid->sidstr);
			kfree(npsidid);
		} else {
			psidid = npsidid;
			sid_rb_insert(cidtree, cid, &psidid,
					sidtype == SIDOWNER ? "oi:" : "gi:");
			++psidid->refcount;
			spin_unlock(cidlock);
		}
	} else {
		++psidid->refcount;
		spin_unlock(cidlock);
	}

	/*
	 * If we are here, it is safe to access psidid and its fields
	 * since a reference was taken earlier while holding the spinlock.
	 * A reference on the node is put without holding the spinlock
	 * and it is OK to do so in this case, shrinker will not erase
	 * this node until all references are put and we do not access
	 * any fields of the node after a reference is put .
	 */
	if (test_bit(SID_ID_MAPPED, &psidid->state)) {
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		cifs_copy_sid(ssid, &psidid->sid);
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		psidid->time = jiffies; /* update ts for accessing */
		goto id_sid_out;
	}

	if (time_after(psidid->time + SID_MAP_RETRY, jiffies)) {
		rc = -EINVAL;
		goto id_sid_out;
	}

	if (!test_and_set_bit(SID_ID_PENDING, &psidid->state)) {
		saved_cred = override_creds(root_cred);
		sidkey = request_key(&cifs_idmap_key_type, psidid->sidstr, "");
		if (IS_ERR(sidkey)) {
			rc = -EINVAL;
			cFYI(1, "%s: Can't map and id to a SID", __func__);
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		} else if (sidkey->datalen < sizeof(struct cifs_sid)) {
			rc = -EIO;
			cFYI(1, "%s: Downcall contained malformed key "
				"(datalen=%hu)", __func__, sidkey->datalen);
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		} else {
			lsid = (struct cifs_sid *)sidkey->payload.data;
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			cifs_copy_sid(&psidid->sid, lsid);
			cifs_copy_sid(ssid, &psidid->sid);
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			set_bit(SID_ID_MAPPED, &psidid->state);
			key_put(sidkey);
			kfree(psidid->sidstr);
		}
		psidid->time = jiffies; /* update ts for accessing */
		revert_creds(saved_cred);
		clear_bit(SID_ID_PENDING, &psidid->state);
		wake_up_bit(&psidid->state, SID_ID_PENDING);
	} else {
		rc = wait_on_bit(&psidid->state, SID_ID_PENDING,
				sidid_pending_wait, TASK_INTERRUPTIBLE);
		if (rc) {
			cFYI(1, "%s: sidid_pending_wait interrupted %d",
					__func__, rc);
			--psidid->refcount;
			return rc;
		}
		if (test_bit(SID_ID_MAPPED, &psidid->state))
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			cifs_copy_sid(ssid, &psidid->sid);
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		else
			rc = -EINVAL;
	}
id_sid_out:
	--psidid->refcount;
	return rc;
}

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static int
sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
		struct cifs_fattr *fattr, uint sidtype)
{
	int rc;
	unsigned long cid;
	struct key *idkey;
	const struct cred *saved_cred;
	struct cifs_sid_id *psidid, *npsidid;
	struct rb_root *cidtree;
	spinlock_t *cidlock;

	if (sidtype == SIDOWNER) {
		cid = cifs_sb->mnt_uid; /* default uid, in case upcall fails */
		cidlock = &siduidlock;
		cidtree = &uidtree;
	} else if (sidtype == SIDGROUP) {
		cid = cifs_sb->mnt_gid; /* default gid, in case upcall fails */
		cidlock = &sidgidlock;
		cidtree = &gidtree;
	} else
		return -ENOENT;

	spin_lock(cidlock);
	psidid = id_rb_search(cidtree, psid);

	if (!psidid) { /* node does not exist, allocate one & attempt adding */
		spin_unlock(cidlock);
		npsidid = kzalloc(sizeof(struct cifs_sid_id), GFP_KERNEL);
		if (!npsidid)
			return -ENOMEM;

		npsidid->sidstr = kmalloc(SIDLEN, GFP_KERNEL);
		if (!npsidid->sidstr) {
			kfree(npsidid);
			return -ENOMEM;
		}

		spin_lock(cidlock);
		psidid = id_rb_search(cidtree, psid);
		if (psidid) { /* node happened to get inserted meanwhile */
			++psidid->refcount;
			spin_unlock(cidlock);
			kfree(npsidid->sidstr);
			kfree(npsidid);
		} else {
			psidid = npsidid;
			id_rb_insert(cidtree, psid, &psidid,
					sidtype == SIDOWNER ? "os:" : "gs:");
			++psidid->refcount;
			spin_unlock(cidlock);
		}
	} else {
		++psidid->refcount;
		spin_unlock(cidlock);
	}

	/*
	 * If we are here, it is safe to access psidid and its fields
	 * since a reference was taken earlier while holding the spinlock.
	 * A reference on the node is put without holding the spinlock
	 * and it is OK to do so in this case, shrinker will not erase
	 * this node until all references are put and we do not access
	 * any fields of the node after a reference is put .
	 */
	if (test_bit(SID_ID_MAPPED, &psidid->state)) {
		cid = psidid->id;
		psidid->time = jiffies; /* update ts for accessing */
		goto sid_to_id_out;
	}

	if (time_after(psidid->time + SID_MAP_RETRY, jiffies))
		goto sid_to_id_out;

	if (!test_and_set_bit(SID_ID_PENDING, &psidid->state)) {
		saved_cred = override_creds(root_cred);
		idkey = request_key(&cifs_idmap_key_type, psidid->sidstr, "");
		if (IS_ERR(idkey))
			cFYI(1, "%s: Can't map SID to an id", __func__);
		else {
			cid = *(unsigned long *)idkey->payload.value;
			psidid->id = cid;
			set_bit(SID_ID_MAPPED, &psidid->state);
			key_put(idkey);
			kfree(psidid->sidstr);
		}
		revert_creds(saved_cred);
		psidid->time = jiffies; /* update ts for accessing */
		clear_bit(SID_ID_PENDING, &psidid->state);
		wake_up_bit(&psidid->state, SID_ID_PENDING);
	} else {
		rc = wait_on_bit(&psidid->state, SID_ID_PENDING,
				sidid_pending_wait, TASK_INTERRUPTIBLE);
		if (rc) {
			cFYI(1, "%s: sidid_pending_wait interrupted %d",
					__func__, rc);
			--psidid->refcount; /* decremented without spinlock */
			return rc;
		}
		if (test_bit(SID_ID_MAPPED, &psidid->state))
			cid = psidid->id;
	}

sid_to_id_out:
	--psidid->refcount; /* decremented without spinlock */
	if (sidtype == SIDOWNER)
		fattr->cf_uid = cid;
	else
		fattr->cf_gid = cid;

	return 0;
}

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int
init_cifs_idmap(void)
{
	struct cred *cred;
	struct key *keyring;
	int ret;

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	cFYI(1, "Registering the %s key type", cifs_idmap_key_type.name);
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	/* create an override credential set with a special thread keyring in
	 * which requests are cached
	 *
	 * this is used to prevent malicious redirections from being installed
	 * with add_key().
	 */
	cred = prepare_kernel_cred(NULL);
	if (!cred)
		return -ENOMEM;

	keyring = key_alloc(&key_type_keyring, ".cifs_idmap", 0, 0, cred,
			    (KEY_POS_ALL & ~KEY_POS_SETATTR) |
			    KEY_USR_VIEW | KEY_USR_READ,
			    KEY_ALLOC_NOT_IN_QUOTA);
	if (IS_ERR(keyring)) {
		ret = PTR_ERR(keyring);
		goto failed_put_cred;
	}

	ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
	if (ret < 0)
		goto failed_put_key;

	ret = register_key_type(&cifs_idmap_key_type);
	if (ret < 0)
		goto failed_put_key;

	/* instruct request_key() to use this special keyring as a cache for
	 * the results it looks up */
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	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
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	cred->thread_keyring = keyring;
	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
	root_cred = cred;

	spin_lock_init(&siduidlock);
	uidtree = RB_ROOT;
	spin_lock_init(&sidgidlock);
	gidtree = RB_ROOT;

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	spin_lock_init(&uidsidlock);
	siduidtree = RB_ROOT;
	spin_lock_init(&gidsidlock);
	sidgidtree = RB_ROOT;
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	register_shrinker(&cifs_shrinker);

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	cFYI(1, "cifs idmap keyring: %d", key_serial(keyring));
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	return 0;

failed_put_key:
	key_put(keyring);
failed_put_cred:
	put_cred(cred);
	return ret;
}

void
exit_cifs_idmap(void)
{
	key_revoke(root_cred->thread_keyring);
	unregister_key_type(&cifs_idmap_key_type);
	put_cred(root_cred);
	unregister_shrinker(&cifs_shrinker);
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	cFYI(1, "Unregistered %s key type", cifs_idmap_key_type.name);
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}

void
cifs_destroy_idmaptrees(void)
{
	struct rb_root *root;
	struct rb_node *node;

	root = &uidtree;
	spin_lock(&siduidlock);
	while ((node = rb_first(root)))
		rb_erase(node, root);
	spin_unlock(&siduidlock);

	root = &gidtree;
	spin_lock(&sidgidlock);
	while ((node = rb_first(root)))
		rb_erase(node, root);
	spin_unlock(&sidgidlock);
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	root = &siduidtree;
	spin_lock(&uidsidlock);
	while ((node = rb_first(root)))
		rb_erase(node, root);
	spin_unlock(&uidsidlock);

	root = &sidgidtree;
	spin_lock(&gidsidlock);
	while ((node = rb_first(root)))
		rb_erase(node, root);
	spin_unlock(&gidsidlock);
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}
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/* if the two SIDs (roughly equivalent to a UUID for a user or group) are
   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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{
	int i;
	int num_subauth, num_sat, num_saw;

	if ((!ctsid) || (!cwsid))
641
		return 1;
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	/* compare the revision */
644 645 646 647 648 649
	if (ctsid->revision != cwsid->revision) {
		if (ctsid->revision > cwsid->revision)
			return 1;
		else
			return -1;
	}
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650 651 652

	/* compare all of the six auth values */
	for (i = 0; i < 6; ++i) {
653 654 655 656 657 658
		if (ctsid->authority[i] != cwsid->authority[i]) {
			if (ctsid->authority[i] > cwsid->authority[i])
				return 1;
			else
				return -1;
		}
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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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663
	num_saw = cwsid->num_subauth;
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664 665 666
	num_subauth = num_sat < num_saw ? num_sat : num_saw;
	if (num_subauth) {
		for (i = 0; i < num_subauth; ++i) {
667
			if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) {
668 669
				if (le32_to_cpu(ctsid->sub_auth[i]) >
					le32_to_cpu(cwsid->sub_auth[i]))
670 671 672 673
					return 1;
				else
					return -1;
			}
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		}
	}

677
	return 0; /* sids compare/match */
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}

680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699

/* 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)
{
	struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
	struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr;

	/* copy security descriptor control portion */
	pnntsd->revision = pntsd->revision;
	pnntsd->type = pntsd->type;
	pnntsd->dacloffset = cpu_to_le32(sizeof(struct cifs_ntsd));
	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);
700
	cifs_copy_sid(nowner_sid_ptr, owner_sid_ptr);
701 702 703 704 705 706

	/* 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));
707
	cifs_copy_sid(ngroup_sid_ptr, group_sid_ptr);
708 709 710 711 712

	return;
}


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/*
   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
*/
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static void access_flags_to_mode(__le32 ace_flags, int type, umode_t *pmode,
719
				 umode_t *pbits_to_set)
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720
{
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721
	__u32 flags = le32_to_cpu(ace_flags);
722
	/* the order of ACEs is important.  The canonical order is to begin with
723
	   DENY entries followed by ALLOW, otherwise an allow entry could be
724
	   encountered first, making the subsequent deny entry like "dead code"
725
	   which would be superflous since Windows stops when a match is made
726 727 728 729 730
	   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) {
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731
		if (flags & GENERIC_ALL)
732
			*pbits_to_set &= ~S_IRWXUGO;
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733

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734 735
		if ((flags & GENERIC_WRITE) ||
			((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS))
736
			*pbits_to_set &= ~S_IWUGO;
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		if ((flags & GENERIC_READ) ||
			((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS))
739
			*pbits_to_set &= ~S_IRUGO;
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		if ((flags & GENERIC_EXECUTE) ||
			((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS))
742 743 744
			*pbits_to_set &= ~S_IXUGO;
		return;
	} else if (type != ACCESS_ALLOWED) {
745
		cERROR(1, "unknown access control type %d", type);
746 747 748
		return;
	}
	/* else ACCESS_ALLOWED type */
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	if (flags & GENERIC_ALL) {
751
		*pmode |= (S_IRWXUGO & (*pbits_to_set));
752
		cFYI(DBG2, "all perms");
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753 754
		return;
	}
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	if ((flags & GENERIC_WRITE) ||
			((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS))
757
		*pmode |= (S_IWUGO & (*pbits_to_set));
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	if ((flags & GENERIC_READ) ||
			((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS))
760
		*pmode |= (S_IRUGO & (*pbits_to_set));
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	if ((flags & GENERIC_EXECUTE) ||
			((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS))
763
		*pmode |= (S_IXUGO & (*pbits_to_set));
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764

765
	cFYI(DBG2, "access flags 0x%x mode now 0x%x", flags, *pmode);
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766 767 768
	return;
}

769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793
/*
   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;

794
	cFYI(DBG2, "mode: 0x%x, access flags now 0x%x", mode, *pace_flags);
795 796 797
	return;
}

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static __u16 fill_ace_for_sid(struct cifs_ace *pntace,
799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821
			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);

822
	return size;
823 824
}

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826 827
#ifdef CONFIG_CIFS_DEBUG2
static void dump_ace(struct cifs_ace *pace, char *end_of_acl)
828 829 830 831
{
	int num_subauth;

	/* validate that we do not go past end of acl */
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833
	if (le16_to_cpu(pace->size) < 16) {
834
		cERROR(1, "ACE too small %d", le16_to_cpu(pace->size));
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835 836 837 838
		return;
	}

	if (end_of_acl < (char *)pace + le16_to_cpu(pace->size)) {
839
		cERROR(1, "ACL too small to parse ACE");
840
		return;
S
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841
	}
842

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843
	num_subauth = pace->sid.num_subauth;
844
	if (num_subauth) {
845
		int i;
846
		cFYI(1, "ACE revision %d num_auth %d type %d flags %d size %d",
S
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847
			pace->sid.revision, pace->sid.num_subauth, pace->type,
848
			pace->flags, le16_to_cpu(pace->size));
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849
		for (i = 0; i < num_subauth; ++i) {
850 851
			cFYI(1, "ACE sub_auth[%d]: 0x%x", i,
				le32_to_cpu(pace->sid.sub_auth[i]));
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852 853 854 855 856 857 858 859
		}

		/* BB add length check to make sure that we do not have huge
			num auths and therefore go off the end */
	}

	return;
}
860
#endif
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861

862

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863
static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
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864
		       struct cifs_sid *pownersid, struct cifs_sid *pgrpsid,
865
		       struct cifs_fattr *fattr)
866 867 868 869 870 871 872 873 874
{
	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 */

875 876 877
	if (!pdacl) {
		/* no DACL in the security descriptor, set
		   all the permissions for user/group/other */
878
		fattr->cf_mode |= S_IRWXUGO;
879 880 881
		return;
	}

882
	/* validate that we do not go past end of acl */
883
	if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
884
		cERROR(1, "ACL too small to parse DACL");
885 886 887
		return;
	}

888
	cFYI(DBG2, "DACL revision %d size %d num aces %d",
889
		le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size),
890
		le32_to_cpu(pdacl->num_aces));
891

892 893 894
	/* 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 */
895
	fattr->cf_mode &= ~(S_IRWXUGO);
896

897 898 899
	acl_base = (char *)pdacl;
	acl_size = sizeof(struct cifs_acl);

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	num_aces = le32_to_cpu(pdacl->num_aces);
901
	if (num_aces > 0) {
902 903
		umode_t user_mask = S_IRWXU;
		umode_t group_mask = S_IRWXG;
904
		umode_t other_mask = S_IRWXU | S_IRWXG | S_IRWXO;
905

906 907
		if (num_aces > ULONG_MAX / sizeof(struct cifs_ace *))
			return;
908 909
		ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
				GFP_KERNEL);
910 911 912 913
		if (!ppace) {
			cERROR(1, "DACL memory allocation error");
			return;
		}
914 915

		for (i = 0; i < num_aces; ++i) {
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			ppace[i] = (struct cifs_ace *) (acl_base + acl_size);
917 918 919
#ifdef CONFIG_CIFS_DEBUG2
			dump_ace(ppace[i], end_of_acl);
#endif
920
			if (compare_sids(&(ppace[i]->sid), pownersid) == 0)
921
				access_flags_to_mode(ppace[i]->access_req,
922
						     ppace[i]->type,
923
						     &fattr->cf_mode,
924
						     &user_mask);
925
			if (compare_sids(&(ppace[i]->sid), pgrpsid) == 0)
926
				access_flags_to_mode(ppace[i]->access_req,
927
						     ppace[i]->type,
928
						     &fattr->cf_mode,
929
						     &group_mask);
930
			if (compare_sids(&(ppace[i]->sid), &sid_everyone) == 0)
931
				access_flags_to_mode(ppace[i]->access_req,
932
						     ppace[i]->type,
933
						     &fattr->cf_mode,
934
						     &other_mask);
935
			if (compare_sids(&(ppace[i]->sid), &sid_authusers) == 0)
936 937 938 939 940
				access_flags_to_mode(ppace[i]->access_req,
						     ppace[i]->type,
						     &fattr->cf_mode,
						     &other_mask);

941

S
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942
/*			memcpy((void *)(&(cifscred->aces[i])),
S
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943 944
				(void *)ppace[i],
				sizeof(struct cifs_ace)); */
945

S
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946 947
			acl_base = (char *)ppace[i];
			acl_size = le16_to_cpu(ppace[i]->size);
948 949 950 951 952 953 954 955
		}

		kfree(ppace);
	}

	return;
}

956

957 958 959
static int set_chmod_dacl(struct cifs_acl *pndacl, struct cifs_sid *pownersid,
			struct cifs_sid *pgrpsid, __u64 nmode)
{
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960
	u16 size = 0;
961 962 963 964 965 966 967 968 969 970 971 972
	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));
973
	pndacl->num_aces = cpu_to_le32(3);
974

975
	return 0;
976 977 978
}


979 980 981 982
static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
{
	/* BB need to add parm so we can store the SID BB */

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983 984 985
	/* 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) {
986
		cERROR(1, "ACL too small to parse SID %p", psid);
987 988
		return -EINVAL;
	}
989

990
	if (psid->num_subauth) {
991
#ifdef CONFIG_CIFS_DEBUG2
992
		int i;
993 994
		cFYI(1, "SID revision %d num_auth %d",
			psid->revision, psid->num_subauth);
995

996
		for (i = 0; i < psid->num_subauth; i++) {
997 998
			cFYI(1, "SID sub_auth[%d]: 0x%x ", i,
				le32_to_cpu(psid->sub_auth[i]));
999 1000
		}

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1001
		/* BB add length check to make sure that we do not have huge
1002
			num auths and therefore go off the end */
1003 1004
		cFYI(1, "RID 0x%x",
			le32_to_cpu(psid->sub_auth[psid->num_subauth-1]));
1005
#endif
1006 1007
	}

1008 1009 1010
	return 0;
}

1011

1012
/* Convert CIFS ACL to POSIX form */
1013 1014
static int parse_sec_desc(struct cifs_sb_info *cifs_sb,
		struct cifs_ntsd *pntsd, int acl_len, struct cifs_fattr *fattr)
1015
{
1016
	int rc = 0;
1017 1018 1019
	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;
1020
	__u32 dacloffset;
1021

1022
	if (pntsd == NULL)
S
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1023 1024
		return -EIO;

1025
	owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
1026
				le32_to_cpu(pntsd->osidoffset));
1027
	group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
1028
				le32_to_cpu(pntsd->gsidoffset));
1029
	dacloffset = le32_to_cpu(pntsd->dacloffset);
1030
	dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset);
1031
	cFYI(DBG2, "revision %d type 0x%x ooffset 0x%x goffset 0x%x "
1032
		 "sacloffset 0x%x dacloffset 0x%x",
1033 1034
		 pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset),
		 le32_to_cpu(pntsd->gsidoffset),
1035
		 le32_to_cpu(pntsd->sacloffset), dacloffset);
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1036
/*	cifs_dump_mem("owner_sid: ", owner_sid_ptr, 64); */
1037
	rc = parse_sid(owner_sid_ptr, end_of_acl);
1038 1039 1040 1041 1042 1043 1044
	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);
1045
		return rc;
1046
	}
1047 1048

	rc = parse_sid(group_sid_ptr, end_of_acl);
1049 1050
	if (rc) {
		cFYI(1, "%s: Error %d mapping Owner SID to gid", __func__, rc);
1051
		return rc;
1052 1053 1054 1055 1056 1057
	}
	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;
	}
1058

1059 1060
	if (dacloffset)
		parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr,
1061
			   group_sid_ptr, fattr);
1062
	else
1063
		cFYI(1, "no ACL"); /* BB grant all or default perms? */
1064

1065
	return rc;
1066
}
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1068 1069
/* Convert permission bits from mode to equivalent CIFS ACL */
static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
1070
	__u32 secdesclen, __u64 nmode, uid_t uid, gid_t gid, int *aclflag)
1071 1072 1073 1074 1075 1076
{
	int rc = 0;
	__u32 dacloffset;
	__u32 ndacloffset;
	__u32 sidsoffset;
	struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
1077
	struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr;
1078 1079 1080
	struct cifs_acl *dacl_ptr = NULL;  /* no need for SACL ptr */
	struct cifs_acl *ndacl_ptr = NULL; /* no need for SACL ptr */

1081 1082
	if (nmode != NO_CHANGE_64) { /* chmod */
		owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
1083
				le32_to_cpu(pntsd->osidoffset));
1084
		group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
1085
				le32_to_cpu(pntsd->gsidoffset));
1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
		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 sec desc control portion & owner and group sids */
		copy_sec_desc(pntsd, pnntsd, sidsoffset);
		*aclflag = CIFS_ACL_DACL;
	} else {
		memcpy(pnntsd, pntsd, secdesclen);
		if (uid != NO_CHANGE_32) { /* chown */
			owner_sid_ptr = (struct cifs_sid *)((char *)pnntsd +
					le32_to_cpu(pnntsd->osidoffset));
			nowner_sid_ptr = kmalloc(sizeof(struct cifs_sid),
								GFP_KERNEL);
			if (!nowner_sid_ptr)
				return -ENOMEM;
			rc = id_to_sid(uid, SIDOWNER, nowner_sid_ptr);
			if (rc) {
				cFYI(1, "%s: Mapping error %d for owner id %d",
						__func__, rc, uid);
				kfree(nowner_sid_ptr);
				return rc;
			}
1116
			cifs_copy_sid(owner_sid_ptr, nowner_sid_ptr);
1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133
			kfree(nowner_sid_ptr);
			*aclflag = CIFS_ACL_OWNER;
		}
		if (gid != NO_CHANGE_32) { /* chgrp */
			group_sid_ptr = (struct cifs_sid *)((char *)pnntsd +
					le32_to_cpu(pnntsd->gsidoffset));
			ngroup_sid_ptr = kmalloc(sizeof(struct cifs_sid),
								GFP_KERNEL);
			if (!ngroup_sid_ptr)
				return -ENOMEM;
			rc = id_to_sid(gid, SIDGROUP, ngroup_sid_ptr);
			if (rc) {
				cFYI(1, "%s: Mapping error %d for group id %d",
						__func__, rc, gid);
				kfree(ngroup_sid_ptr);
				return rc;
			}
1134
			cifs_copy_sid(group_sid_ptr, ngroup_sid_ptr);
1135 1136 1137 1138
			kfree(ngroup_sid_ptr);
			*aclflag = CIFS_ACL_GROUP;
		}
	}
1139

1140
	return rc;
1141 1142
}

1143 1144
static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
		__u16 fid, u32 *pacllen)
S
Steve French 已提交
1145 1146
{
	struct cifs_ntsd *pntsd = NULL;
1147 1148
	unsigned int xid;
	int rc;
1149 1150 1151
	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink))
1152
		return ERR_CAST(tlink);
S
Steve French 已提交
1153

1154
	xid = get_xid();
1155
	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen);
1156
	free_xid(xid);
S
Steve French 已提交
1157

1158
	cifs_put_tlink(tlink);
S
Steve French 已提交
1159

1160 1161 1162
	cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen);
	if (rc)
		return ERR_PTR(rc);
1163 1164
	return pntsd;
}
1165

1166 1167 1168 1169 1170
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;
1171 1172
	unsigned int xid;
	int rc, create_options = 0;
1173
	__u16 fid;
1174
	struct cifs_tcon *tcon;
1175 1176 1177
	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink))
1178
		return ERR_CAST(tlink);
S
Steve French 已提交
1179

1180
	tcon = tlink_tcon(tlink);
1181
	xid = get_xid();
1182

1183 1184 1185 1186 1187 1188
	if (backup_cred(cifs_sb))
		create_options |= CREATE_OPEN_BACKUP_INTENT;

	rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, READ_CONTROL,
			create_options, &fid, &oplock, NULL, cifs_sb->local_nls,
			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
1189 1190 1191
	if (!rc) {
		rc = CIFSSMBGetCIFSACL(xid, tcon, fid, &pntsd, pacllen);
		CIFSSMBClose(xid, tcon, fid);
S
Steve French 已提交
1192 1193
	}

1194
	cifs_put_tlink(tlink);
1195
	free_xid(xid);
1196 1197 1198 1199

	cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen);
	if (rc)
		return ERR_PTR(rc);
1200 1201 1202
	return pntsd;
}

1203
/* Retrieve an ACL from the server */
1204
struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
1205 1206 1207 1208 1209 1210 1211
				      struct inode *inode, const char *path,
				      u32 *pacllen)
{
	struct cifs_ntsd *pntsd = NULL;
	struct cifsFileInfo *open_file = NULL;

	if (inode)
1212
		open_file = find_readable_file(CIFS_I(inode), true);
1213 1214 1215
	if (!open_file)
		return get_cifs_acl_by_path(cifs_sb, path, pacllen);

1216
	pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->fid.netfid, pacllen);
1217
	cifsFileInfo_put(open_file);
1218 1219 1220
	return pntsd;
}

1221 1222 1223
 /* Set an ACL on the server */
int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
			struct inode *inode, const char *path, int aclflag)
1224 1225
{
	int oplock = 0;
1226 1227
	unsigned int xid;
	int rc, access_flags, create_options = 0;
1228
	__u16 fid;
1229
	struct cifs_tcon *tcon;
1230
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
1231
	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
1232

1233 1234 1235 1236
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);

	tcon = tlink_tcon(tlink);
1237
	xid = get_xid();
1238

1239 1240 1241
	if (backup_cred(cifs_sb))
		create_options |= CREATE_OPEN_BACKUP_INTENT;

1242 1243 1244 1245 1246 1247 1248 1249
	if (aclflag == CIFS_ACL_OWNER || aclflag == CIFS_ACL_GROUP)
		access_flags = WRITE_OWNER;
	else
		access_flags = WRITE_DAC;

	rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, access_flags,
			create_options, &fid, &oplock, NULL, cifs_sb->local_nls,
			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
1250
	if (rc) {
1251
		cERROR(1, "Unable to open file to set ACL");
1252
		goto out;
1253 1254
	}

1255
	rc = CIFSSMBSetCIFSACL(xid, tcon, fid, pnntsd, acllen, aclflag);
1256
	cFYI(DBG2, "SetCIFSACL rc = %d", rc);
1257

1258 1259
	CIFSSMBClose(xid, tcon, fid);
out:
1260
	free_xid(xid);
1261
	cifs_put_tlink(tlink);
1262 1263
	return rc;
}
1264

1265
/* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
1266
int
1267 1268
cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
		  struct inode *inode, const char *path, const __u16 *pfid)
1269 1270 1271 1272 1273
{
	struct cifs_ntsd *pntsd = NULL;
	u32 acllen = 0;
	int rc = 0;

1274
	cFYI(DBG2, "converting ACL to mode for %s", path);
1275 1276 1277 1278 1279

	if (pfid)
		pntsd = get_cifs_acl_by_fid(cifs_sb, *pfid, &acllen);
	else
		pntsd = get_cifs_acl(cifs_sb, inode, path, &acllen);
1280 1281

	/* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
1282 1283 1284 1285
	if (IS_ERR(pntsd)) {
		rc = PTR_ERR(pntsd);
		cERROR(1, "%s: error %d getting sec desc", __func__, rc);
	} else {
1286
		rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr);
1287 1288 1289 1290
		kfree(pntsd);
		if (rc)
			cERROR(1, "parse sec desc failed rc = %d", rc);
	}
1291

1292
	return rc;
S
Steve French 已提交
1293
}
1294

1295
/* Convert mode bits to an ACL so we can update the ACL on the server */
1296 1297 1298
int
id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode,
			uid_t uid, gid_t gid)
1299 1300
{
	int rc = 0;
1301
	int aclflag = CIFS_ACL_DACL; /* default flag to set */
1302
	__u32 secdesclen = 0;
1303 1304
	struct cifs_ntsd *pntsd = NULL; /* acl obtained from server */
	struct cifs_ntsd *pnntsd = NULL; /* modified acl to be sent to server */
1305

1306
	cFYI(DBG2, "set ACL from mode for %s", path);
1307 1308

	/* Get the security descriptor */
1309
	pntsd = get_cifs_acl(CIFS_SB(inode->i_sb), inode, path, &secdesclen);
1310 1311 1312
	if (IS_ERR(pntsd)) {
		rc = PTR_ERR(pntsd);
		cERROR(1, "%s: error %d getting sec desc", __func__, rc);
J
Jeff Layton 已提交
1313 1314
		goto out;
	}
1315

J
Jeff Layton 已提交
1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328
	/*
	 * Add three ACEs for owner, group, everyone getting rid of other ACEs
	 * as chmod disables ACEs and set the security descriptor. Allocate
	 * memory for the smb header, set security descriptor request security
	 * descriptor parameters, and secuirty descriptor itself
	 */
	secdesclen = max_t(u32, secdesclen, DEFSECDESCLEN);
	pnntsd = kmalloc(secdesclen, GFP_KERNEL);
	if (!pnntsd) {
		cERROR(1, "Unable to allocate security descriptor");
		kfree(pntsd);
		return -ENOMEM;
	}
1329

J
Jeff Layton 已提交
1330 1331
	rc = build_sec_desc(pntsd, pnntsd, secdesclen, nmode, uid, gid,
				&aclflag);
1332

J
Jeff Layton 已提交
1333
	cFYI(DBG2, "build_sec_desc rc: %d", rc);
1334

J
Jeff Layton 已提交
1335 1336 1337 1338
	if (!rc) {
		/* Set the security descriptor */
		rc = set_cifs_acl(pnntsd, secdesclen, inode, path, aclflag);
		cFYI(DBG2, "set_cifs_acl rc: %d", rc);
1339 1340
	}

J
Jeff Layton 已提交
1341 1342 1343
	kfree(pnntsd);
	kfree(pntsd);
out:
1344
	return rc;
1345
}