[deliverable/linux.git] / net / sunrpc / auth.c

/*
 * linux/net/sunrpc/auth.c
 *
 * Generic RPC client authentication API.
 *
 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/sunrpc/clnt.h>
#include <linux/spinlock.h>

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_AUTH
#endif

static DEFINE_SPINLOCK(rpc_authflavor_lock);
static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
	&authnull_ops,		/* AUTH_NULL */
	&authunix_ops,		/* AUTH_UNIX */
	NULL,			/* others can be loadable modules */
};

static LIST_HEAD(cred_unused);
static unsigned long number_cred_unused;

static u32
pseudoflavor_to_flavor(u32 flavor) {
	if (flavor >= RPC_AUTH_MAXFLAVOR)
		return RPC_AUTH_GSS;
	return flavor;
}

int
rpcauth_register(const struct rpc_authops *ops)
{
	rpc_authflavor_t flavor;
	int ret = -EPERM;

	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
		return -EINVAL;
	spin_lock(&rpc_authflavor_lock);
	if (auth_flavors[flavor] == NULL) {
		auth_flavors[flavor] = ops;
		ret = 0;
	}
	spin_unlock(&rpc_authflavor_lock);
	return ret;
}

int
rpcauth_unregister(const struct rpc_authops *ops)
{
	rpc_authflavor_t flavor;
	int ret = -EPERM;

	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
		return -EINVAL;
	spin_lock(&rpc_authflavor_lock);
	if (auth_flavors[flavor] == ops) {
		auth_flavors[flavor] = NULL;
		ret = 0;
	}
	spin_unlock(&rpc_authflavor_lock);
	return ret;
}

struct rpc_auth *
rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
{
	struct rpc_auth		*auth;
	const struct rpc_authops *ops;
	u32			flavor = pseudoflavor_to_flavor(pseudoflavor);

	auth = ERR_PTR(-EINVAL);
	if (flavor >= RPC_AUTH_MAXFLAVOR)
		goto out;

#ifdef CONFIG_KMOD
	if ((ops = auth_flavors[flavor]) == NULL)
		request_module("rpc-auth-%u", flavor);
#endif
	spin_lock(&rpc_authflavor_lock);
	ops = auth_flavors[flavor];
	if (ops == NULL || !try_module_get(ops->owner)) {
		spin_unlock(&rpc_authflavor_lock);
		goto out;
	}
	spin_unlock(&rpc_authflavor_lock);
	auth = ops->create(clnt, pseudoflavor);
	module_put(ops->owner);
	if (IS_ERR(auth))
		return auth;
	if (clnt->cl_auth)
		rpcauth_release(clnt->cl_auth);
	clnt->cl_auth = auth;

out:
	return auth;
}

void
rpcauth_release(struct rpc_auth *auth)
{
	if (!atomic_dec_and_test(&auth->au_count))
		return;
	auth->au_ops->destroy(auth);
}

static DEFINE_SPINLOCK(rpc_credcache_lock);

static void
rpcauth_unhash_cred_locked(struct rpc_cred *cred)
{
	hlist_del_rcu(&cred->cr_hash);
	smp_mb__before_clear_bit();
	clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
}

static void
rpcauth_unhash_cred(struct rpc_cred *cred)
{
	spinlock_t *cache_lock;

	cache_lock = &cred->cr_auth->au_credcache->lock;
	spin_lock(cache_lock);
	if (atomic_read(&cred->cr_count) == 0)
		rpcauth_unhash_cred_locked(cred);
	spin_unlock(cache_lock);
}

/*
 * Initialize RPC credential cache
 */
int
rpcauth_init_credcache(struct rpc_auth *auth)
{
	struct rpc_cred_cache *new;
	int i;

	new = kmalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		return -ENOMEM;
	for (i = 0; i < RPC_CREDCACHE_NR; i++)
		INIT_HLIST_HEAD(&new->hashtable[i]);
	spin_lock_init(&new->lock);
	auth->au_credcache = new;
	return 0;
}

/*
 * Destroy a list of credentials
 */
static inline
void rpcauth_destroy_credlist(struct list_head *head)
{
	struct rpc_cred *cred;

	while (!list_empty(head)) {
		cred = list_entry(head->next, struct rpc_cred, cr_lru);
		list_del_init(&cred->cr_lru);
		put_rpccred(cred);
	}
}

/*
 * Clear the RPC credential cache, and delete those credentials
 * that are not referenced.
 */
void
rpcauth_clear_credcache(struct rpc_cred_cache *cache)
{
	LIST_HEAD(free);
	struct hlist_head *head;
	struct rpc_cred	*cred;
	int		i;

	spin_lock(&rpc_credcache_lock);
	spin_lock(&cache->lock);
	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
		head = &cache->hashtable[i];
		while (!hlist_empty(head)) {
			cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
			get_rpccred(cred);
			if (!list_empty(&cred->cr_lru)) {
				list_del(&cred->cr_lru);
				number_cred_unused--;
			}
			list_add_tail(&cred->cr_lru, &free);
			rpcauth_unhash_cred_locked(cred);
		}
	}
	spin_unlock(&cache->lock);
	spin_unlock(&rpc_credcache_lock);
	rpcauth_destroy_credlist(&free);
}

/*
 * Destroy the RPC credential cache
 */
void
rpcauth_destroy_credcache(struct rpc_auth *auth)
{
	struct rpc_cred_cache *cache = auth->au_credcache;

	if (cache) {
		auth->au_credcache = NULL;
		rpcauth_clear_credcache(cache);
		kfree(cache);
	}
}

/*
 * Remove stale credentials. Avoid sleeping inside the loop.
 */
static int
rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
{
	spinlock_t *cache_lock;
	struct rpc_cred *cred;

	while (!list_empty(&cred_unused)) {
		cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
		list_del_init(&cred->cr_lru);
		number_cred_unused--;
		if (atomic_read(&cred->cr_count) != 0)
			continue;
		cache_lock = &cred->cr_auth->au_credcache->lock;
		spin_lock(cache_lock);
		if (atomic_read(&cred->cr_count) == 0) {
			get_rpccred(cred);
			list_add_tail(&cred->cr_lru, free);
			rpcauth_unhash_cred_locked(cred);
			nr_to_scan--;
		}
		spin_unlock(cache_lock);
		if (nr_to_scan == 0)
			break;
	}
	return nr_to_scan;
}

/*
 * Run memory cache shrinker.
 */
static int
rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
{
	LIST_HEAD(free);
	int res;

	if (list_empty(&cred_unused))
		return 0;
	spin_lock(&rpc_credcache_lock);
	nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
	res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
	spin_unlock(&rpc_credcache_lock);
	rpcauth_destroy_credlist(&free);
	return res;
}

/*
 * Look up a process' credentials in the authentication cache
 */
struct rpc_cred *
rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
		int flags)
{
	LIST_HEAD(free);
	struct rpc_cred_cache *cache = auth->au_credcache;
	struct hlist_node *pos;
	struct rpc_cred	*cred = NULL,
			*entry, *new;
	int		nr = 0;

	if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
		nr = acred->uid & RPC_CREDCACHE_MASK;

	rcu_read_lock();
	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
		if (!entry->cr_ops->crmatch(acred, entry, flags))
			continue;
		spin_lock(&cache->lock);
		if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
			spin_unlock(&cache->lock);
			continue;
		}
		cred = get_rpccred(entry);
		spin_unlock(&cache->lock);
		break;
	}
	rcu_read_unlock();

	if (cred != NULL)
		goto found;

	new = auth->au_ops->crcreate(auth, acred, flags);
	if (IS_ERR(new)) {
		cred = new;
		goto out;
	}

	spin_lock(&cache->lock);
	hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
		if (!entry->cr_ops->crmatch(acred, entry, flags))
			continue;
		cred = get_rpccred(entry);
		break;
	}
	if (cred == NULL) {
		cred = new;
		set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
		hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
	} else
		list_add_tail(&new->cr_lru, &free);
	spin_unlock(&cache->lock);
found:
	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)
			&& cred->cr_ops->cr_init != NULL
			&& !(flags & RPCAUTH_LOOKUP_NEW)) {
		int res = cred->cr_ops->cr_init(auth, cred);
		if (res < 0) {
			put_rpccred(cred);
			cred = ERR_PTR(res);
		}
	}
	rpcauth_destroy_credlist(&free);
out:
	return cred;
}

struct rpc_cred *
rpcauth_lookupcred(struct rpc_auth *auth, int flags)
{
	struct auth_cred acred = {
		.uid = current->fsuid,
		.gid = current->fsgid,
		.group_info = current->group_info,
	};
	struct rpc_cred *ret;

	dprintk("RPC:       looking up %s cred\n",
		auth->au_ops->au_name);
	get_group_info(acred.group_info);
	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
	put_group_info(acred.group_info);
	return ret;
}

void
rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
		  struct rpc_auth *auth, const struct rpc_credops *ops)
{
	INIT_HLIST_NODE(&cred->cr_hash);
	INIT_LIST_HEAD(&cred->cr_lru);
	atomic_set(&cred->cr_count, 1);
	cred->cr_auth = auth;
	cred->cr_ops = ops;
	cred->cr_expire = jiffies;
#ifdef RPC_DEBUG
	cred->cr_magic = RPCAUTH_CRED_MAGIC;
#endif
	cred->cr_uid = acred->uid;
}
EXPORT_SYMBOL(rpcauth_init_cred);

struct rpc_cred *
rpcauth_bindcred(struct rpc_task *task)
{
	struct rpc_auth *auth = task->tk_client->cl_auth;
	struct auth_cred acred = {
		.uid = current->fsuid,
		.gid = current->fsgid,
		.group_info = current->group_info,
	};
	struct rpc_cred *ret;
	int flags = 0;

	dprintk("RPC: %5u looking up %s cred\n",
		task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
	get_group_info(acred.group_info);
	if (task->tk_flags & RPC_TASK_ROOTCREDS)
		flags |= RPCAUTH_LOOKUP_ROOTCREDS;
	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
	if (!IS_ERR(ret))
		task->tk_msg.rpc_cred = ret;
	else
		task->tk_status = PTR_ERR(ret);
	put_group_info(acred.group_info);
	return ret;
}

void
rpcauth_holdcred(struct rpc_task *task)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	if (cred != NULL) {
		get_rpccred(cred);
		dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
				cred->cr_auth->au_ops->au_name, cred);
	}
}

void
put_rpccred(struct rpc_cred *cred)
{
	/* Fast path for unhashed credentials */
	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
		goto need_lock;

	if (!atomic_dec_and_test(&cred->cr_count))
		return;
	goto out_destroy;
need_lock:
	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
		return;
	if (!list_empty(&cred->cr_lru)) {
		number_cred_unused--;
		list_del_init(&cred->cr_lru);
	}
	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
		rpcauth_unhash_cred(cred);
	else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
		cred->cr_expire = jiffies;
		list_add_tail(&cred->cr_lru, &cred_unused);
		number_cred_unused++;
		spin_unlock(&rpc_credcache_lock);
		return;
	}
	spin_unlock(&rpc_credcache_lock);
out_destroy:
	cred->cr_ops->crdestroy(cred);
}

void
rpcauth_unbindcred(struct rpc_task *task)
{
	struct rpc_cred	*cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %5u releasing %s cred %p\n",
		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);

	put_rpccred(cred);
	task->tk_msg.rpc_cred = NULL;
}

__be32 *
rpcauth_marshcred(struct rpc_task *task, __be32 *p)
{
	struct rpc_cred	*cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %5u marshaling %s cred %p\n",
		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);

	return cred->cr_ops->crmarshal(task, p);
}

__be32 *
rpcauth_checkverf(struct rpc_task *task, __be32 *p)
{
	struct rpc_cred	*cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %5u validating %s cred %p\n",
		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);

	return cred->cr_ops->crvalidate(task, p);
}

int
rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
		__be32 *data, void *obj)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
			task->tk_pid, cred->cr_ops->cr_name, cred);
	if (cred->cr_ops->crwrap_req)
		return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
	/* By default, we encode the arguments normally. */
	return rpc_call_xdrproc(encode, rqstp, data, obj);
}

int
rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
		__be32 *data, void *obj)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
			task->tk_pid, cred->cr_ops->cr_name, cred);
	if (cred->cr_ops->crunwrap_resp)
		return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
						   data, obj);
	/* By default, we decode the arguments normally. */
	return rpc_call_xdrproc(decode, rqstp, data, obj);
}

int
rpcauth_refreshcred(struct rpc_task *task)
{
	struct rpc_cred	*cred = task->tk_msg.rpc_cred;
	int err;

	dprintk("RPC: %5u refreshing %s cred %p\n",
		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);

	err = cred->cr_ops->crrefresh(task);
	if (err < 0)
		task->tk_status = err;
	return err;
}

void
rpcauth_invalcred(struct rpc_task *task)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %5u invalidating %s cred %p\n",
		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
	if (cred)
		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
}

int
rpcauth_uptodatecred(struct rpc_task *task)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	return cred == NULL ||
		test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
}

static struct shrinker rpc_cred_shrinker = {
	.shrink = rpcauth_cache_shrinker,
	.seeks = DEFAULT_SEEKS,
};

void __init rpcauth_init_module(void)
{
	rpc_init_authunix();
	register_shrinker(&rpc_cred_shrinker);
}

void __exit rpcauth_remove_module(void)
{
	unregister_shrinker(&rpc_cred_shrinker);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/net/sunrpc/auth.c
	3	*
	4	* Generic RPC client authentication API.
	5	*
	6	* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
	7	*/
	8
	9	#include <linux/types.h>
	10	#include <linux/sched.h>
	11	#include <linux/module.h>
	12	#include <linux/slab.h>
	13	#include <linux/errno.h>
1da177e4 LT	14	#include <linux/sunrpc/clnt.h>
	15	#include <linux/spinlock.h>
	16
	17	#ifdef RPC_DEBUG
	18	# define RPCDBG_FACILITY RPCDBG_AUTH
	19	#endif
	20
fc1b356f	21	static DEFINE_SPINLOCK(rpc_authflavor_lock);
f1c0a861	22	static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
1da177e4 LT	23	&authnull_ops, /* AUTH_NULL */
	24	&authunix_ops, /* AUTH_UNIX */
	25	NULL, /* others can be loadable modules */
	26	};
	27
e092bdcd	28	static LIST_HEAD(cred_unused);
f5c2187c	29	static unsigned long number_cred_unused;
e092bdcd	30
1da177e4 LT	31	static u32
	32	pseudoflavor_to_flavor(u32 flavor) {
	33	if (flavor >= RPC_AUTH_MAXFLAVOR)
	34	return RPC_AUTH_GSS;
	35	return flavor;
	36	}
	37
	38	int
f1c0a861	39	rpcauth_register(const struct rpc_authops *ops)
1da177e4 LT	40	{
1da177e4 LT	41	rpc_authflavor_t flavor;
fc1b356f	42	int ret = -EPERM;
1da177e4 LT	43
	44	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
	45	return -EINVAL;
fc1b356f TM	46	spin_lock(&rpc_authflavor_lock);
	47	if (auth_flavors[flavor] == NULL) {
	48	auth_flavors[flavor] = ops;
	49	ret = 0;
	50	}
	51	spin_unlock(&rpc_authflavor_lock);
	52	return ret;
1da177e4 LT	53	}
	54
	55	int
f1c0a861	56	rpcauth_unregister(const struct rpc_authops *ops)
1da177e4 LT	57	{
1da177e4 LT	58	rpc_authflavor_t flavor;
fc1b356f	59	int ret = -EPERM;
1da177e4 LT	60
	61	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
	62	return -EINVAL;
fc1b356f TM	63	spin_lock(&rpc_authflavor_lock);
	64	if (auth_flavors[flavor] == ops) {
	65	auth_flavors[flavor] = NULL;
	66	ret = 0;
	67	}
	68	spin_unlock(&rpc_authflavor_lock);
	69	return ret;
1da177e4 LT	70	}
	71
	72	struct rpc_auth *
	73	rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
	74	{
	75	struct rpc_auth *auth;
f1c0a861	76	const struct rpc_authops *ops;
1da177e4 LT	77	u32 flavor = pseudoflavor_to_flavor(pseudoflavor);
1da177e4 LT	78
f344f6df OK	79	auth = ERR_PTR(-EINVAL);
	80	if (flavor >= RPC_AUTH_MAXFLAVOR)
	81	goto out;
	82
f344f6df OK	83	#ifdef CONFIG_KMOD
	84	if ((ops = auth_flavors[flavor]) == NULL)
	85	request_module("rpc-auth-%u", flavor);
	86	#endif
fc1b356f TM	87	spin_lock(&rpc_authflavor_lock);
	88	ops = auth_flavors[flavor];
	89	if (ops == NULL \|\| !try_module_get(ops->owner)) {
	90	spin_unlock(&rpc_authflavor_lock);
f344f6df	91	goto out;
fc1b356f TM	92	}
fc1b356f TM	93	spin_unlock(&rpc_authflavor_lock);
1da177e4	94	auth = ops->create(clnt, pseudoflavor);
fc1b356f	95	module_put(ops->owner);
6a19275a BF	96	if (IS_ERR(auth))
6a19275a BF	97	return auth;
1da177e4	98	if (clnt->cl_auth)
de7a8ce3	99	rpcauth_release(clnt->cl_auth);
1da177e4	100	clnt->cl_auth = auth;
f344f6df OK	101
f344f6df OK	102	out:
1da177e4 LT	103	return auth;
	104	}
	105
	106	void
de7a8ce3	107	rpcauth_release(struct rpc_auth *auth)
1da177e4 LT	108	{
	109	if (!atomic_dec_and_test(&auth->au_count))
	110	return;
	111	auth->au_ops->destroy(auth);
	112	}
	113
	114	static DEFINE_SPINLOCK(rpc_credcache_lock);
	115
31be5bf1 TM	116	static void
	117	rpcauth_unhash_cred_locked(struct rpc_cred *cred)
	118	{
	119	hlist_del_rcu(&cred->cr_hash);
	120	smp_mb__before_clear_bit();
	121	clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	122	}
	123
9499b434 TM	124	static void
	125	rpcauth_unhash_cred(struct rpc_cred *cred)
	126	{
	127	spinlock_t *cache_lock;
	128
	129	cache_lock = &cred->cr_auth->au_credcache->lock;
	130	spin_lock(cache_lock);
	131	if (atomic_read(&cred->cr_count) == 0)
	132	rpcauth_unhash_cred_locked(cred);
	133	spin_unlock(cache_lock);
	134	}
	135
1da177e4 LT	136	/*
	137	* Initialize RPC credential cache
	138	*/
	139	int
f5c2187c	140	rpcauth_init_credcache(struct rpc_auth *auth)
1da177e4 LT	141	{
	142	struct rpc_cred_cache *new;
	143	int i;
	144
8b3a7005	145	new = kmalloc(sizeof(*new), GFP_KERNEL);
1da177e4 LT	146	if (!new)
	147	return -ENOMEM;
	148	for (i = 0; i < RPC_CREDCACHE_NR; i++)
	149	INIT_HLIST_HEAD(&new->hashtable[i]);
9499b434	150	spin_lock_init(&new->lock);
1da177e4 LT	151	auth->au_credcache = new;
	152	return 0;
	153	}
	154
	155	/*
	156	* Destroy a list of credentials
	157	*/
	158	static inline
e092bdcd	159	void rpcauth_destroy_credlist(struct list_head *head)
1da177e4 LT	160	{
	161	struct rpc_cred *cred;
	162
e092bdcd TM	163	while (!list_empty(head)) {
	164	cred = list_entry(head->next, struct rpc_cred, cr_lru);
	165	list_del_init(&cred->cr_lru);
1da177e4 LT	166	put_rpccred(cred);
	167	}
	168	}
	169
	170	/*
	171	* Clear the RPC credential cache, and delete those credentials
	172	* that are not referenced.
	173	*/
	174	void
3ab9bb72	175	rpcauth_clear_credcache(struct rpc_cred_cache *cache)
1da177e4	176	{
e092bdcd TM	177	LIST_HEAD(free);
e092bdcd TM	178	struct hlist_head *head;
1da177e4 LT	179	struct rpc_cred *cred;
	180	int i;
	181
	182	spin_lock(&rpc_credcache_lock);
9499b434	183	spin_lock(&cache->lock);
1da177e4	184	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
e092bdcd TM	185	head = &cache->hashtable[i];
	186	while (!hlist_empty(head)) {
	187	cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
	188	get_rpccred(cred);
f5c2187c TM	189	if (!list_empty(&cred->cr_lru)) {
	190	list_del(&cred->cr_lru);
	191	number_cred_unused--;
	192	}
	193	list_add_tail(&cred->cr_lru, &free);
31be5bf1	194	rpcauth_unhash_cred_locked(cred);
1da177e4 LT	195	}
1da177e4 LT	196	}
9499b434	197	spin_unlock(&cache->lock);
1da177e4 LT	198	spin_unlock(&rpc_credcache_lock);
	199	rpcauth_destroy_credlist(&free);
	200	}
	201
3ab9bb72 TM	202	/*
	203	* Destroy the RPC credential cache
	204	*/
	205	void
	206	rpcauth_destroy_credcache(struct rpc_auth *auth)
	207	{
	208	struct rpc_cred_cache *cache = auth->au_credcache;
	209
	210	if (cache) {
	211	auth->au_credcache = NULL;
	212	rpcauth_clear_credcache(cache);
	213	kfree(cache);
	214	}
	215	}
	216
e092bdcd TM	217	/*
	218	* Remove stale credentials. Avoid sleeping inside the loop.
	219	*/
f5c2187c TM	220	static int
f5c2187c TM	221	rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
1da177e4	222	{
9499b434	223	spinlock_t *cache_lock;
e092bdcd TM	224	struct rpc_cred *cred;
	225
	226	while (!list_empty(&cred_unused)) {
	227	cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
e092bdcd	228	list_del_init(&cred->cr_lru);
f5c2187c	229	number_cred_unused--;
e092bdcd TM	230	if (atomic_read(&cred->cr_count) != 0)
e092bdcd TM	231	continue;
9499b434 TM	232	cache_lock = &cred->cr_auth->au_credcache->lock;
	233	spin_lock(cache_lock);
	234	if (atomic_read(&cred->cr_count) == 0) {
	235	get_rpccred(cred);
	236	list_add_tail(&cred->cr_lru, free);
	237	rpcauth_unhash_cred_locked(cred);
f5c2187c	238	nr_to_scan--;
9499b434 TM	239	}
9499b434 TM	240	spin_unlock(cache_lock);
f5c2187c TM	241	if (nr_to_scan == 0)
f5c2187c TM	242	break;
1da177e4	243	}
f5c2187c	244	return nr_to_scan;
1da177e4 LT	245	}
	246
	247	/*
f5c2187c	248	* Run memory cache shrinker.
1da177e4	249	*/
f5c2187c TM	250	static int
f5c2187c TM	251	rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
1da177e4	252	{
f5c2187c TM	253	LIST_HEAD(free);
	254	int res;
	255
	256	if (list_empty(&cred_unused))
	257	return 0;
31be5bf1	258	spin_lock(&rpc_credcache_lock);
f5c2187c TM	259	nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
f5c2187c TM	260	res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
31be5bf1	261	spin_unlock(&rpc_credcache_lock);
f5c2187c TM	262	rpcauth_destroy_credlist(&free);
f5c2187c TM	263	return res;
1da177e4 LT	264	}
	265
	266	/*
	267	* Look up a process' credentials in the authentication cache
	268	*/
	269	struct rpc_cred *
	270	rpcauth_lookup_credcache(struct rpc_auth auth, struct auth_cred acred,
8a317760	271	int flags)
1da177e4	272	{
e092bdcd	273	LIST_HEAD(free);
1da177e4	274	struct rpc_cred_cache *cache = auth->au_credcache;
e092bdcd	275	struct hlist_node *pos;
31be5bf1 TM	276	struct rpc_cred *cred = NULL,
31be5bf1 TM	277	entry, new;
1da177e4 LT	278	int nr = 0;
1da177e4 LT	279
8a317760	280	if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
1da177e4	281	nr = acred->uid & RPC_CREDCACHE_MASK;
31be5bf1 TM	282
	283	rcu_read_lock();
	284	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
e092bdcd TM	285	if (!entry->cr_ops->crmatch(acred, entry, flags))
e092bdcd TM	286	continue;
9499b434	287	spin_lock(&cache->lock);
31be5bf1	288	if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
9499b434	289	spin_unlock(&cache->lock);
31be5bf1 TM	290	continue;
31be5bf1 TM	291	}
e092bdcd	292	cred = get_rpccred(entry);
9499b434	293	spin_unlock(&cache->lock);
e092bdcd	294	break;
1da177e4	295	}
31be5bf1 TM	296	rcu_read_unlock();
31be5bf1 TM	297
9499b434	298	if (cred != NULL)
31be5bf1	299	goto found;
1da177e4	300
31be5bf1 TM	301	new = auth->au_ops->crcreate(auth, acred, flags);
	302	if (IS_ERR(new)) {
	303	cred = new;
	304	goto out;
	305	}
1da177e4	306
9499b434	307	spin_lock(&cache->lock);
31be5bf1 TM	308	hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
	309	if (!entry->cr_ops->crmatch(acred, entry, flags))
	310	continue;
	311	cred = get_rpccred(entry);
	312	break;
	313	}
	314	if (cred == NULL) {
5fe4755e	315	cred = new;
31be5bf1 TM	316	set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	317	hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
	318	} else
	319	list_add_tail(&new->cr_lru, &free);
9499b434	320	spin_unlock(&cache->lock);
31be5bf1 TM	321	found:
31be5bf1 TM	322	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)
fba3bad4 TM	323	&& cred->cr_ops->cr_init != NULL
	324	&& !(flags & RPCAUTH_LOOKUP_NEW)) {
	325	int res = cred->cr_ops->cr_init(auth, cred);
	326	if (res < 0) {
	327	put_rpccred(cred);
	328	cred = ERR_PTR(res);
	329	}
1da177e4	330	}
31be5bf1 TM	331	rpcauth_destroy_credlist(&free);
	332	out:
	333	return cred;
1da177e4 LT	334	}
	335
	336	struct rpc_cred *
8a317760	337	rpcauth_lookupcred(struct rpc_auth *auth, int flags)
1da177e4 LT	338	{
	339	struct auth_cred acred = {
	340	.uid = current->fsuid,
	341	.gid = current->fsgid,
	342	.group_info = current->group_info,
	343	};
	344	struct rpc_cred *ret;
	345
46121cf7	346	dprintk("RPC: looking up %s cred\n",
1da177e4 LT	347	auth->au_ops->au_name);
1da177e4 LT	348	get_group_info(acred.group_info);
8a317760	349	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
1da177e4 LT	350	put_group_info(acred.group_info);
	351	return ret;
	352	}
	353
5fe4755e TM	354	void
	355	rpcauth_init_cred(struct rpc_cred cred, const struct auth_cred acred,
	356	struct rpc_auth auth, const struct rpc_credops ops)
	357	{
	358	INIT_HLIST_NODE(&cred->cr_hash);
e092bdcd	359	INIT_LIST_HEAD(&cred->cr_lru);
5fe4755e TM	360	atomic_set(&cred->cr_count, 1);
	361	cred->cr_auth = auth;
	362	cred->cr_ops = ops;
	363	cred->cr_expire = jiffies;
	364	#ifdef RPC_DEBUG
	365	cred->cr_magic = RPCAUTH_CRED_MAGIC;
	366	#endif
	367	cred->cr_uid = acred->uid;
	368	}
	369	EXPORT_SYMBOL(rpcauth_init_cred);
	370
1da177e4 LT	371	struct rpc_cred *
	372	rpcauth_bindcred(struct rpc_task *task)
	373	{
1be27f36	374	struct rpc_auth *auth = task->tk_client->cl_auth;
1da177e4 LT	375	struct auth_cred acred = {
	376	.uid = current->fsuid,
	377	.gid = current->fsgid,
	378	.group_info = current->group_info,
	379	};
	380	struct rpc_cred *ret;
8a317760	381	int flags = 0;
1da177e4	382
46121cf7	383	dprintk("RPC: %5u looking up %s cred\n",
1be27f36	384	task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
1da177e4	385	get_group_info(acred.group_info);
8a317760 TM	386	if (task->tk_flags & RPC_TASK_ROOTCREDS)
	387	flags \|= RPCAUTH_LOOKUP_ROOTCREDS;
	388	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
1da177e4 LT	389	if (!IS_ERR(ret))
	390	task->tk_msg.rpc_cred = ret;
	391	else
	392	task->tk_status = PTR_ERR(ret);
	393	put_group_info(acred.group_info);
	394	return ret;
	395	}
	396
	397	void
	398	rpcauth_holdcred(struct rpc_task *task)
	399	{
1be27f36 TM	400	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	401	if (cred != NULL) {
	402	get_rpccred(cred);
	403	dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
	404	cred->cr_auth->au_ops->au_name, cred);
	405	}
1da177e4 LT	406	}
	407
	408	void
	409	put_rpccred(struct rpc_cred *cred)
	410	{
e092bdcd	411	/* Fast path for unhashed credentials */
31be5bf1	412	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
e092bdcd TM	413	goto need_lock;
e092bdcd TM	414
1da177e4 LT	415	if (!atomic_dec_and_test(&cred->cr_count))
1da177e4 LT	416	return;
e092bdcd	417	goto out_destroy;
e092bdcd TM	418	need_lock:
	419	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
	420	return;
f5c2187c TM	421	if (!list_empty(&cred->cr_lru)) {
f5c2187c TM	422	number_cred_unused--;
e092bdcd	423	list_del_init(&cred->cr_lru);
f5c2187c	424	}
e092bdcd	425	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
9499b434	426	rpcauth_unhash_cred(cred);
31be5bf1	427	else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
e092bdcd TM	428	cred->cr_expire = jiffies;
e092bdcd TM	429	list_add_tail(&cred->cr_lru, &cred_unused);
f5c2187c	430	number_cred_unused++;
e092bdcd TM	431	spin_unlock(&rpc_credcache_lock);
	432	return;
	433	}
	434	spin_unlock(&rpc_credcache_lock);
	435	out_destroy:
1da177e4 LT	436	cred->cr_ops->crdestroy(cred);
	437	}
	438
	439	void
	440	rpcauth_unbindcred(struct rpc_task *task)
	441	{
1da177e4 LT	442	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	443
46121cf7	444	dprintk("RPC: %5u releasing %s cred %p\n",
1be27f36	445	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
1da177e4 LT	446
	447	put_rpccred(cred);
	448	task->tk_msg.rpc_cred = NULL;
	449	}
	450
d8ed029d AD	451	__be32 *
d8ed029d AD	452	rpcauth_marshcred(struct rpc_task task, __be32 p)
1da177e4	453	{
1da177e4 LT	454	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	455
46121cf7	456	dprintk("RPC: %5u marshaling %s cred %p\n",
1be27f36	457	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	458
1da177e4 LT	459	return cred->cr_ops->crmarshal(task, p);
	460	}
	461
d8ed029d AD	462	__be32 *
d8ed029d AD	463	rpcauth_checkverf(struct rpc_task task, __be32 p)
1da177e4	464	{
1da177e4 LT	465	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	466
46121cf7	467	dprintk("RPC: %5u validating %s cred %p\n",
1be27f36	468	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	469
1da177e4 LT	470	return cred->cr_ops->crvalidate(task, p);
	471	}
	472
	473	int
	474	rpcauth_wrap_req(struct rpc_task task, kxdrproc_t encode, void rqstp,
d8ed029d	475	__be32 data, void obj)
1da177e4 LT	476	{
	477	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	478
46121cf7	479	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
1da177e4 LT	480	task->tk_pid, cred->cr_ops->cr_name, cred);
	481	if (cred->cr_ops->crwrap_req)
	482	return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
	483	/* By default, we encode the arguments normally. */
be879c4e	484	return rpc_call_xdrproc(encode, rqstp, data, obj);
1da177e4 LT	485	}
	486
	487	int
	488	rpcauth_unwrap_resp(struct rpc_task task, kxdrproc_t decode, void rqstp,
d8ed029d	489	__be32 data, void obj)
1da177e4 LT	490	{
	491	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	492
46121cf7	493	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
1da177e4 LT	494	task->tk_pid, cred->cr_ops->cr_name, cred);
	495	if (cred->cr_ops->crunwrap_resp)
	496	return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
	497	data, obj);
	498	/* By default, we decode the arguments normally. */
be879c4e	499	return rpc_call_xdrproc(decode, rqstp, data, obj);
1da177e4 LT	500	}
	501
	502	int
	503	rpcauth_refreshcred(struct rpc_task *task)
	504	{
1da177e4 LT	505	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	506	int err;
	507
46121cf7	508	dprintk("RPC: %5u refreshing %s cred %p\n",
1be27f36	509	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	510
1da177e4 LT	511	err = cred->cr_ops->crrefresh(task);
	512	if (err < 0)
	513	task->tk_status = err;
	514	return err;
	515	}
	516
	517	void
	518	rpcauth_invalcred(struct rpc_task *task)
	519	{
fc432dd9 TM	520	struct rpc_cred *cred = task->tk_msg.rpc_cred;
fc432dd9 TM	521
46121cf7	522	dprintk("RPC: %5u invalidating %s cred %p\n",
1be27f36	523	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
fc432dd9 TM	524	if (cred)
fc432dd9 TM	525	clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1da177e4 LT	526	}
	527
	528	int
	529	rpcauth_uptodatecred(struct rpc_task *task)
	530	{
fc432dd9 TM	531	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	532
	533	return cred == NULL \|\|
	534	test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
1da177e4	535	}
f5c2187c	536
8e1f936b RR	537	static struct shrinker rpc_cred_shrinker = {
	538	.shrink = rpcauth_cache_shrinker,
	539	.seeks = DEFAULT_SEEKS,
	540	};
f5c2187c TM	541
	542	void __init rpcauth_init_module(void)
	543	{
	544	rpc_init_authunix();
8e1f936b	545	register_shrinker(&rpc_cred_shrinker);
f5c2187c TM	546	}
	547
	548	void __exit rpcauth_remove_module(void)
	549	{
8e1f936b	550	unregister_shrinker(&rpc_cred_shrinker);
f5c2187c	551	}