cifsacl.c 35.6 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 */
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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);

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	for (i = 0; i < NUM_AUTHS; ++i) {
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		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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/*
 * if the two SIDs (roughly equivalent to a UUID for a user or group) are
 * the same returns zero, if they do not match returns non-zero.
 */
static int
compare_sids(const struct cifs_sid *ctsid, const struct cifs_sid *cwsid)
{
	int i;
	int num_subauth, num_sat, num_saw;

	if ((!ctsid) || (!cwsid))
		return 1;

	/* compare the revision */
	if (ctsid->revision != cwsid->revision) {
		if (ctsid->revision > cwsid->revision)
			return 1;
		else
			return -1;
	}

	/* compare all of the six auth values */
	for (i = 0; i < NUM_AUTHS; ++i) {
		if (ctsid->authority[i] != cwsid->authority[i]) {
			if (ctsid->authority[i] > cwsid->authority[i])
				return 1;
			else
				return -1;
		}
	}

	/* compare all of the subauth values if any */
	num_sat = ctsid->num_subauth;
	num_saw = cwsid->num_subauth;
	num_subauth = num_sat < num_saw ? num_sat : num_saw;
	if (num_subauth) {
		for (i = 0; i < num_subauth; ++i) {
			if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) {
				if (le32_to_cpu(ctsid->sub_auth[i]) >
					le32_to_cpu(cwsid->sub_auth[i]))
					return 1;
				else
					return -1;
			}
		}
	}

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

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static void
cifs_copy_sid(struct cifs_sid *dst, const struct cifs_sid *src)
{
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	int i;

	dst->revision = src->revision;
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	dst->num_subauth = min_t(u8, src->num_subauth, NUM_SUBAUTHS);
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	for (i = 0; i < NUM_AUTHS; ++i)
		dst->authority[i] = src->authority[i];
	for (i = 0; i < dst->num_subauth; ++i)
		dst->sub_auth[i] = src->sub_auth[i];
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}

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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 < CIFS_SID_BASE_SIZE) {
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			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;
636 637
	register_shrinker(&cifs_shrinker);

638
	cFYI(1, "cifs idmap keyring: %d", key_serial(keyring));
639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654
	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);
655
	cFYI(1, "Unregistered %s key type", cifs_idmap_key_type.name);
656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674
}

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);
675 676 677 678 679 680 681 682 683 684 685 686

	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);
687
}
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689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707
/* 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);
708
	cifs_copy_sid(nowner_sid_ptr, owner_sid_ptr);
709 710 711 712 713 714

	/* 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));
715
	cifs_copy_sid(ngroup_sid_ptr, group_sid_ptr);
716 717 718 719 720

	return;
}


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721 722 723 724 725
/*
   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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726
static void access_flags_to_mode(__le32 ace_flags, int type, umode_t *pmode,
727
				 umode_t *pbits_to_set)
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728
{
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729
	__u32 flags = le32_to_cpu(ace_flags);
730
	/* the order of ACEs is important.  The canonical order is to begin with
731
	   DENY entries followed by ALLOW, otherwise an allow entry could be
732
	   encountered first, making the subsequent deny entry like "dead code"
733
	   which would be superflous since Windows stops when a match is made
734 735 736 737 738
	   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) {
S
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739
		if (flags & GENERIC_ALL)
740
			*pbits_to_set &= ~S_IRWXUGO;
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741

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742 743
		if ((flags & GENERIC_WRITE) ||
			((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS))
744
			*pbits_to_set &= ~S_IWUGO;
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745 746
		if ((flags & GENERIC_READ) ||
			((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS))
747
			*pbits_to_set &= ~S_IRUGO;
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748 749
		if ((flags & GENERIC_EXECUTE) ||
			((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS))
750 751 752
			*pbits_to_set &= ~S_IXUGO;
		return;
	} else if (type != ACCESS_ALLOWED) {
753
		cERROR(1, "unknown access control type %d", type);
754 755 756
		return;
	}
	/* else ACCESS_ALLOWED type */
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758
	if (flags & GENERIC_ALL) {
759
		*pmode |= (S_IRWXUGO & (*pbits_to_set));
760
		cFYI(DBG2, "all perms");
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761 762
		return;
	}
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763 764
	if ((flags & GENERIC_WRITE) ||
			((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS))
765
		*pmode |= (S_IWUGO & (*pbits_to_set));
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766 767
	if ((flags & GENERIC_READ) ||
			((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS))
768
		*pmode |= (S_IRUGO & (*pbits_to_set));
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769 770
	if ((flags & GENERIC_EXECUTE) ||
			((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS))
771
		*pmode |= (S_IXUGO & (*pbits_to_set));
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773
	cFYI(DBG2, "access flags 0x%x mode now 0x%x", flags, *pmode);
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774 775 776
	return;
}

777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801
/*
   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;

802
	cFYI(DBG2, "mode: 0x%x, access flags now 0x%x", mode, *pace_flags);
803 804 805
	return;
}

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806
static __u16 fill_ace_for_sid(struct cifs_ace *pntace,
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;
822
	for (i = 0; i < NUM_AUTHS; i++)
823 824 825 826 827 828 829
		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);

830
	return size;
831 832
}

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833

834 835
#ifdef CONFIG_CIFS_DEBUG2
static void dump_ace(struct cifs_ace *pace, char *end_of_acl)
836 837 838 839
{
	int num_subauth;

	/* validate that we do not go past end of acl */
S
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840

S
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841
	if (le16_to_cpu(pace->size) < 16) {
842
		cERROR(1, "ACE too small %d", le16_to_cpu(pace->size));
S
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843 844 845 846
		return;
	}

	if (end_of_acl < (char *)pace + le16_to_cpu(pace->size)) {
847
		cERROR(1, "ACL too small to parse ACE");
848
		return;
S
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849
	}
850

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851
	num_subauth = pace->sid.num_subauth;
852
	if (num_subauth) {
853
		int i;
854
		cFYI(1, "ACE revision %d num_auth %d type %d flags %d size %d",
S
Steve French 已提交
855
			pace->sid.revision, pace->sid.num_subauth, pace->type,
856
			pace->flags, le16_to_cpu(pace->size));
S
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857
		for (i = 0; i < num_subauth; ++i) {
858 859
			cFYI(1, "ACE sub_auth[%d]: 0x%x", i,
				le32_to_cpu(pace->sid.sub_auth[i]));
S
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860 861 862 863 864 865 866 867
		}

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

	return;
}
868
#endif
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869

870

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871
static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
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872
		       struct cifs_sid *pownersid, struct cifs_sid *pgrpsid,
873
		       struct cifs_fattr *fattr)
874 875 876 877 878 879 880 881 882
{
	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 */

883 884 885
	if (!pdacl) {
		/* no DACL in the security descriptor, set
		   all the permissions for user/group/other */
886
		fattr->cf_mode |= S_IRWXUGO;
887 888 889
		return;
	}

890
	/* validate that we do not go past end of acl */
891
	if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
892
		cERROR(1, "ACL too small to parse DACL");
893 894 895
		return;
	}

896
	cFYI(DBG2, "DACL revision %d size %d num aces %d",
897
		le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size),
898
		le32_to_cpu(pdacl->num_aces));
899

900 901 902
	/* 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 */
903
	fattr->cf_mode &= ~(S_IRWXUGO);
904

905 906 907
	acl_base = (char *)pdacl;
	acl_size = sizeof(struct cifs_acl);

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908
	num_aces = le32_to_cpu(pdacl->num_aces);
909
	if (num_aces > 0) {
910 911
		umode_t user_mask = S_IRWXU;
		umode_t group_mask = S_IRWXG;
912
		umode_t other_mask = S_IRWXU | S_IRWXG | S_IRWXO;
913

914 915
		if (num_aces > ULONG_MAX / sizeof(struct cifs_ace *))
			return;
916 917
		ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
				GFP_KERNEL);
918 919 920 921
		if (!ppace) {
			cERROR(1, "DACL memory allocation error");
			return;
		}
922 923

		for (i = 0; i < num_aces; ++i) {
S
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924
			ppace[i] = (struct cifs_ace *) (acl_base + acl_size);
925 926 927
#ifdef CONFIG_CIFS_DEBUG2
			dump_ace(ppace[i], end_of_acl);
#endif
928
			if (compare_sids(&(ppace[i]->sid), pownersid) == 0)
929
				access_flags_to_mode(ppace[i]->access_req,
930
						     ppace[i]->type,
931
						     &fattr->cf_mode,
932
						     &user_mask);
933
			if (compare_sids(&(ppace[i]->sid), pgrpsid) == 0)
934
				access_flags_to_mode(ppace[i]->access_req,
935
						     ppace[i]->type,
936
						     &fattr->cf_mode,
937
						     &group_mask);
938
			if (compare_sids(&(ppace[i]->sid), &sid_everyone) == 0)
939
				access_flags_to_mode(ppace[i]->access_req,
940
						     ppace[i]->type,
941
						     &fattr->cf_mode,
942
						     &other_mask);
943
			if (compare_sids(&(ppace[i]->sid), &sid_authusers) == 0)
944 945 946 947 948
				access_flags_to_mode(ppace[i]->access_req,
						     ppace[i]->type,
						     &fattr->cf_mode,
						     &other_mask);

949

S
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950
/*			memcpy((void *)(&(cifscred->aces[i])),
S
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951 952
				(void *)ppace[i],
				sizeof(struct cifs_ace)); */
953

S
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954 955
			acl_base = (char *)ppace[i];
			acl_size = le16_to_cpu(ppace[i]->size);
956 957 958 959 960 961 962 963
		}

		kfree(ppace);
	}

	return;
}

964

965 966 967
static int set_chmod_dacl(struct cifs_acl *pndacl, struct cifs_sid *pownersid,
			struct cifs_sid *pgrpsid, __u64 nmode)
{
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968
	u16 size = 0;
969 970 971 972 973 974 975 976 977 978 979 980
	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));
981
	pndacl->num_aces = cpu_to_le32(3);
982

983
	return 0;
984 985 986
}


987 988 989 990
static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
{
	/* BB need to add parm so we can store the SID BB */

S
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991 992 993
	/* 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) {
994
		cERROR(1, "ACL too small to parse SID %p", psid);
995 996
		return -EINVAL;
	}
997

998
#ifdef CONFIG_CIFS_DEBUG2
999
	if (psid->num_subauth) {
1000
		int i;
1001 1002
		cFYI(1, "SID revision %d num_auth %d",
			psid->revision, psid->num_subauth);
1003

1004
		for (i = 0; i < psid->num_subauth; i++) {
1005 1006
			cFYI(1, "SID sub_auth[%d]: 0x%x ", i,
				le32_to_cpu(psid->sub_auth[i]));
1007 1008
		}

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Steve French 已提交
1009
		/* BB add length check to make sure that we do not have huge
1010
			num auths and therefore go off the end */
1011 1012
		cFYI(1, "RID 0x%x",
			le32_to_cpu(psid->sub_auth[psid->num_subauth-1]));
1013
	}
1014
#endif
1015

1016 1017 1018
	return 0;
}

1019

1020
/* Convert CIFS ACL to POSIX form */
1021 1022
static int parse_sec_desc(struct cifs_sb_info *cifs_sb,
		struct cifs_ntsd *pntsd, int acl_len, struct cifs_fattr *fattr)
1023
{
1024
	int rc = 0;
1025 1026 1027
	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;
1028
	__u32 dacloffset;
1029

1030
	if (pntsd == NULL)
S
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1031 1032
		return -EIO;

1033
	owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
1034
				le32_to_cpu(pntsd->osidoffset));
1035
	group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
1036
				le32_to_cpu(pntsd->gsidoffset));
1037
	dacloffset = le32_to_cpu(pntsd->dacloffset);
1038
	dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset);
1039
	cFYI(DBG2, "revision %d type 0x%x ooffset 0x%x goffset 0x%x "
1040
		 "sacloffset 0x%x dacloffset 0x%x",
1041 1042
		 pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset),
		 le32_to_cpu(pntsd->gsidoffset),
1043
		 le32_to_cpu(pntsd->sacloffset), dacloffset);
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1044
/*	cifs_dump_mem("owner_sid: ", owner_sid_ptr, 64); */
1045
	rc = parse_sid(owner_sid_ptr, end_of_acl);
1046 1047 1048 1049 1050 1051 1052
	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);
1053
		return rc;
1054
	}
1055 1056

	rc = parse_sid(group_sid_ptr, end_of_acl);
1057 1058
	if (rc) {
		cFYI(1, "%s: Error %d mapping Owner SID to gid", __func__, rc);
1059
		return rc;
1060 1061 1062 1063 1064 1065
	}
	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;
	}
1066

1067 1068
	if (dacloffset)
		parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr,
1069
			   group_sid_ptr, fattr);
1070
	else
1071
		cFYI(1, "no ACL"); /* BB grant all or default perms? */
1072

1073
	return rc;
1074
}
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1075

1076 1077
/* Convert permission bits from mode to equivalent CIFS ACL */
static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
1078
	__u32 secdesclen, __u64 nmode, uid_t uid, gid_t gid, int *aclflag)
1079 1080 1081 1082 1083 1084
{
	int rc = 0;
	__u32 dacloffset;
	__u32 ndacloffset;
	__u32 sidsoffset;
	struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
1085
	struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr;
1086 1087 1088
	struct cifs_acl *dacl_ptr = NULL;  /* no need for SACL ptr */
	struct cifs_acl *ndacl_ptr = NULL; /* no need for SACL ptr */

1089 1090
	if (nmode != NO_CHANGE_64) { /* chmod */
		owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
1091
				le32_to_cpu(pntsd->osidoffset));
1092
		group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
1093
				le32_to_cpu(pntsd->gsidoffset));
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123
		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;
			}
1124
			cifs_copy_sid(owner_sid_ptr, nowner_sid_ptr);
1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141
			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;
			}
1142
			cifs_copy_sid(group_sid_ptr, ngroup_sid_ptr);
1143 1144 1145 1146
			kfree(ngroup_sid_ptr);
			*aclflag = CIFS_ACL_GROUP;
		}
	}
1147

1148
	return rc;
1149 1150
}

1151 1152
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
1153 1154
{
	struct cifs_ntsd *pntsd = NULL;
1155 1156
	unsigned int xid;
	int rc;
1157 1158 1159
	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink))
1160
		return ERR_CAST(tlink);
S
Steve French 已提交
1161

1162
	xid = get_xid();
1163
	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen);
1164
	free_xid(xid);
S
Steve French 已提交
1165

1166
	cifs_put_tlink(tlink);
S
Steve French 已提交
1167

1168 1169 1170
	cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen);
	if (rc)
		return ERR_PTR(rc);
1171 1172
	return pntsd;
}
1173

1174 1175 1176 1177 1178
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;
1179 1180
	unsigned int xid;
	int rc, create_options = 0;
1181
	__u16 fid;
1182
	struct cifs_tcon *tcon;
1183 1184 1185
	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink))
1186
		return ERR_CAST(tlink);
S
Steve French 已提交
1187

1188
	tcon = tlink_tcon(tlink);
1189
	xid = get_xid();
1190

1191 1192 1193 1194 1195 1196
	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);
1197 1198 1199
	if (!rc) {
		rc = CIFSSMBGetCIFSACL(xid, tcon, fid, &pntsd, pacllen);
		CIFSSMBClose(xid, tcon, fid);
S
Steve French 已提交
1200 1201
	}

1202
	cifs_put_tlink(tlink);
1203
	free_xid(xid);
1204 1205 1206 1207

	cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen);
	if (rc)
		return ERR_PTR(rc);
1208 1209 1210
	return pntsd;
}

1211
/* Retrieve an ACL from the server */
1212
struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
1213 1214 1215 1216 1217 1218 1219
				      struct inode *inode, const char *path,
				      u32 *pacllen)
{
	struct cifs_ntsd *pntsd = NULL;
	struct cifsFileInfo *open_file = NULL;

	if (inode)
1220
		open_file = find_readable_file(CIFS_I(inode), true);
1221 1222 1223
	if (!open_file)
		return get_cifs_acl_by_path(cifs_sb, path, pacllen);

1224
	pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->fid.netfid, pacllen);
1225
	cifsFileInfo_put(open_file);
1226 1227 1228
	return pntsd;
}

1229 1230 1231
 /* Set an ACL on the server */
int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
			struct inode *inode, const char *path, int aclflag)
1232 1233
{
	int oplock = 0;
1234 1235
	unsigned int xid;
	int rc, access_flags, create_options = 0;
1236
	__u16 fid;
1237
	struct cifs_tcon *tcon;
1238
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
1239
	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
1240

1241 1242 1243 1244
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);

	tcon = tlink_tcon(tlink);
1245
	xid = get_xid();
1246

1247 1248 1249
	if (backup_cred(cifs_sb))
		create_options |= CREATE_OPEN_BACKUP_INTENT;

1250 1251 1252 1253 1254 1255 1256 1257
	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);
1258
	if (rc) {
1259
		cERROR(1, "Unable to open file to set ACL");
1260
		goto out;
1261 1262
	}

1263
	rc = CIFSSMBSetCIFSACL(xid, tcon, fid, pnntsd, acllen, aclflag);
1264
	cFYI(DBG2, "SetCIFSACL rc = %d", rc);
1265

1266 1267
	CIFSSMBClose(xid, tcon, fid);
out:
1268
	free_xid(xid);
1269
	cifs_put_tlink(tlink);
1270 1271
	return rc;
}
1272

1273
/* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
1274
int
1275 1276
cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
		  struct inode *inode, const char *path, const __u16 *pfid)
1277 1278 1279 1280 1281
{
	struct cifs_ntsd *pntsd = NULL;
	u32 acllen = 0;
	int rc = 0;

1282
	cFYI(DBG2, "converting ACL to mode for %s", path);
1283 1284 1285 1286 1287

	if (pfid)
		pntsd = get_cifs_acl_by_fid(cifs_sb, *pfid, &acllen);
	else
		pntsd = get_cifs_acl(cifs_sb, inode, path, &acllen);
1288 1289

	/* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
1290 1291 1292 1293
	if (IS_ERR(pntsd)) {
		rc = PTR_ERR(pntsd);
		cERROR(1, "%s: error %d getting sec desc", __func__, rc);
	} else {
1294
		rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr);
1295 1296 1297 1298
		kfree(pntsd);
		if (rc)
			cERROR(1, "parse sec desc failed rc = %d", rc);
	}
1299

1300
	return rc;
S
Steve French 已提交
1301
}
1302

1303
/* Convert mode bits to an ACL so we can update the ACL on the server */
1304 1305 1306
int
id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode,
			uid_t uid, gid_t gid)
1307 1308
{
	int rc = 0;
1309
	int aclflag = CIFS_ACL_DACL; /* default flag to set */
1310
	__u32 secdesclen = 0;
1311 1312
	struct cifs_ntsd *pntsd = NULL; /* acl obtained from server */
	struct cifs_ntsd *pnntsd = NULL; /* modified acl to be sent to server */
1313

1314
	cFYI(DBG2, "set ACL from mode for %s", path);
1315 1316

	/* Get the security descriptor */
1317
	pntsd = get_cifs_acl(CIFS_SB(inode->i_sb), inode, path, &secdesclen);
1318 1319 1320
	if (IS_ERR(pntsd)) {
		rc = PTR_ERR(pntsd);
		cERROR(1, "%s: error %d getting sec desc", __func__, rc);
J
Jeff Layton 已提交
1321 1322
		goto out;
	}
1323

J
Jeff Layton 已提交
1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336
	/*
	 * 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;
	}
1337

J
Jeff Layton 已提交
1338 1339
	rc = build_sec_desc(pntsd, pnntsd, secdesclen, nmode, uid, gid,
				&aclflag);
1340

J
Jeff Layton 已提交
1341
	cFYI(DBG2, "build_sec_desc rc: %d", rc);
1342

J
Jeff Layton 已提交
1343 1344 1345 1346
	if (!rc) {
		/* Set the security descriptor */
		rc = set_cifs_acl(pnntsd, secdesclen, inode, path, aclflag);
		cFYI(DBG2, "set_cifs_acl rc: %d", rc);
1347 1348
	}

J
Jeff Layton 已提交
1349 1350 1351
	kfree(pnntsd);
	kfree(pntsd);
out:
1352
	return rc;
1353
}