[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/hash.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;
}
EXPORT_SYMBOL_GPL(rpcauth_register);

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;
}
EXPORT_SYMBOL_GPL(rpcauth_unregister);

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;

	if ((ops = auth_flavors[flavor]) == NULL)
		request_module("rpc-auth-%u", flavor);
	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;
}
EXPORT_SYMBOL_GPL(rpcauth_create);

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;
}
EXPORT_SYMBOL_GPL(rpcauth_init_credcache);

/*
 * 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);
	}
}
EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);


#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)

/*
 * 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;
	unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;

	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;
		/* Enforce a 5 second garbage collection moratorium */
		if (time_in_range(cred->cr_expire, expired, jiffies) &&
		    test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 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;
	unsigned int nr;

	nr = hash_long(acred->uid, RPC_CREDCACHE_HASHBITS);

	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;
}
EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);

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_GPL(rpcauth_init_cred);

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

static void
rpcauth_bind_root_cred(struct rpc_task *task)
{
	struct rpc_auth *auth = task->tk_client->cl_auth;
	struct auth_cred acred = {
		.uid = 0,
		.gid = 0,
	};
	struct rpc_cred *ret;

	dprintk("RPC: %5u looking up %s cred\n",
		task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
	ret = auth->au_ops->lookup_cred(auth, &acred, 0);
	if (!IS_ERR(ret))
		task->tk_msg.rpc_cred = ret;
	else
		task->tk_status = PTR_ERR(ret);
}

static void
rpcauth_bind_new_cred(struct rpc_task *task)
{
	struct rpc_auth *auth = task->tk_client->cl_auth;
	struct rpc_cred *ret;

	dprintk("RPC: %5u looking up %s cred\n",
		task->tk_pid, auth->au_ops->au_name);
	ret = rpcauth_lookupcred(auth, 0);
	if (!IS_ERR(ret))
		task->tk_msg.rpc_cred = ret;
	else
		task->tk_status = PTR_ERR(ret);
}

void
rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
{
	if (cred != NULL)
		cred->cr_ops->crbind(task, cred);
	else if (flags & RPC_TASK_ROOTCREDS)
		rpcauth_bind_root_cred(task);
	else
		rpcauth_bind_new_cred(task);
}

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);
}
EXPORT_SYMBOL_GPL(put_rpccred);

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();
	rpc_init_generic_auth();
	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>
25337fdc	14	#include <linux/hash.h>
1da177e4 LT	15	#include <linux/sunrpc/clnt.h>
	16	#include <linux/spinlock.h>
	17
	18	#ifdef RPC_DEBUG
	19	# define RPCDBG_FACILITY RPCDBG_AUTH
	20	#endif
	21
fc1b356f	22	static DEFINE_SPINLOCK(rpc_authflavor_lock);
f1c0a861	23	static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
1da177e4 LT	24	&authnull_ops, /* AUTH_NULL */
	25	&authunix_ops, /* AUTH_UNIX */
	26	NULL, /* others can be loadable modules */
	27	};
	28
e092bdcd	29	static LIST_HEAD(cred_unused);
f5c2187c	30	static unsigned long number_cred_unused;
e092bdcd	31
1da177e4 LT	32	static u32
	33	pseudoflavor_to_flavor(u32 flavor) {
	34	if (flavor >= RPC_AUTH_MAXFLAVOR)
	35	return RPC_AUTH_GSS;
	36	return flavor;
	37	}
	38
	39	int
f1c0a861	40	rpcauth_register(const struct rpc_authops *ops)
1da177e4 LT	41	{
1da177e4 LT	42	rpc_authflavor_t flavor;
fc1b356f	43	int ret = -EPERM;
1da177e4 LT	44
	45	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
	46	return -EINVAL;
fc1b356f TM	47	spin_lock(&rpc_authflavor_lock);
	48	if (auth_flavors[flavor] == NULL) {
	49	auth_flavors[flavor] = ops;
	50	ret = 0;
	51	}
	52	spin_unlock(&rpc_authflavor_lock);
	53	return ret;
1da177e4	54	}
e8914c65	55	EXPORT_SYMBOL_GPL(rpcauth_register);
1da177e4 LT	56
1da177e4 LT	57	int
f1c0a861	58	rpcauth_unregister(const struct rpc_authops *ops)
1da177e4 LT	59	{
1da177e4 LT	60	rpc_authflavor_t flavor;
fc1b356f	61	int ret = -EPERM;
1da177e4 LT	62
	63	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
	64	return -EINVAL;
fc1b356f TM	65	spin_lock(&rpc_authflavor_lock);
	66	if (auth_flavors[flavor] == ops) {
	67	auth_flavors[flavor] = NULL;
	68	ret = 0;
	69	}
	70	spin_unlock(&rpc_authflavor_lock);
	71	return ret;
1da177e4	72	}
e8914c65	73	EXPORT_SYMBOL_GPL(rpcauth_unregister);
1da177e4 LT	74
	75	struct rpc_auth *
	76	rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
	77	{
	78	struct rpc_auth *auth;
f1c0a861	79	const struct rpc_authops *ops;
1da177e4 LT	80	u32 flavor = pseudoflavor_to_flavor(pseudoflavor);
1da177e4 LT	81
f344f6df OK	82	auth = ERR_PTR(-EINVAL);
	83	if (flavor >= RPC_AUTH_MAXFLAVOR)
	84	goto out;
	85
f344f6df OK	86	if ((ops = auth_flavors[flavor]) == NULL)
f344f6df OK	87	request_module("rpc-auth-%u", flavor);
fc1b356f TM	88	spin_lock(&rpc_authflavor_lock);
	89	ops = auth_flavors[flavor];
	90	if (ops == NULL \|\| !try_module_get(ops->owner)) {
	91	spin_unlock(&rpc_authflavor_lock);
f344f6df	92	goto out;
fc1b356f TM	93	}
fc1b356f TM	94	spin_unlock(&rpc_authflavor_lock);
1da177e4	95	auth = ops->create(clnt, pseudoflavor);
fc1b356f	96	module_put(ops->owner);
6a19275a BF	97	if (IS_ERR(auth))
6a19275a BF	98	return auth;
1da177e4	99	if (clnt->cl_auth)
de7a8ce3	100	rpcauth_release(clnt->cl_auth);
1da177e4	101	clnt->cl_auth = auth;
f344f6df OK	102
f344f6df OK	103	out:
1da177e4 LT	104	return auth;
1da177e4 LT	105	}
e8914c65	106	EXPORT_SYMBOL_GPL(rpcauth_create);
1da177e4 LT	107
1da177e4 LT	108	void
de7a8ce3	109	rpcauth_release(struct rpc_auth *auth)
1da177e4 LT	110	{
	111	if (!atomic_dec_and_test(&auth->au_count))
	112	return;
	113	auth->au_ops->destroy(auth);
	114	}
	115
	116	static DEFINE_SPINLOCK(rpc_credcache_lock);
	117
31be5bf1 TM	118	static void
	119	rpcauth_unhash_cred_locked(struct rpc_cred *cred)
	120	{
	121	hlist_del_rcu(&cred->cr_hash);
	122	smp_mb__before_clear_bit();
	123	clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	124	}
	125
9499b434 TM	126	static void
	127	rpcauth_unhash_cred(struct rpc_cred *cred)
	128	{
	129	spinlock_t *cache_lock;
	130
	131	cache_lock = &cred->cr_auth->au_credcache->lock;
	132	spin_lock(cache_lock);
	133	if (atomic_read(&cred->cr_count) == 0)
	134	rpcauth_unhash_cred_locked(cred);
	135	spin_unlock(cache_lock);
	136	}
	137
1da177e4 LT	138	/*
	139	* Initialize RPC credential cache
	140	*/
	141	int
f5c2187c	142	rpcauth_init_credcache(struct rpc_auth *auth)
1da177e4 LT	143	{
	144	struct rpc_cred_cache *new;
	145	int i;
	146
8b3a7005	147	new = kmalloc(sizeof(*new), GFP_KERNEL);
1da177e4 LT	148	if (!new)
	149	return -ENOMEM;
	150	for (i = 0; i < RPC_CREDCACHE_NR; i++)
	151	INIT_HLIST_HEAD(&new->hashtable[i]);
9499b434	152	spin_lock_init(&new->lock);
1da177e4 LT	153	auth->au_credcache = new;
	154	return 0;
	155	}
e8914c65	156	EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
1da177e4 LT	157
	158	/*
	159	* Destroy a list of credentials
	160	*/
	161	static inline
e092bdcd	162	void rpcauth_destroy_credlist(struct list_head *head)
1da177e4 LT	163	{
	164	struct rpc_cred *cred;
	165
e092bdcd TM	166	while (!list_empty(head)) {
	167	cred = list_entry(head->next, struct rpc_cred, cr_lru);
	168	list_del_init(&cred->cr_lru);
1da177e4 LT	169	put_rpccred(cred);
	170	}
	171	}
	172
	173	/*
	174	* Clear the RPC credential cache, and delete those credentials
	175	* that are not referenced.
	176	*/
	177	void
3ab9bb72	178	rpcauth_clear_credcache(struct rpc_cred_cache *cache)
1da177e4	179	{
e092bdcd TM	180	LIST_HEAD(free);
e092bdcd TM	181	struct hlist_head *head;
1da177e4 LT	182	struct rpc_cred *cred;
	183	int i;
	184
	185	spin_lock(&rpc_credcache_lock);
9499b434	186	spin_lock(&cache->lock);
1da177e4	187	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
e092bdcd TM	188	head = &cache->hashtable[i];
	189	while (!hlist_empty(head)) {
	190	cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
	191	get_rpccred(cred);
f5c2187c TM	192	if (!list_empty(&cred->cr_lru)) {
	193	list_del(&cred->cr_lru);
	194	number_cred_unused--;
	195	}
	196	list_add_tail(&cred->cr_lru, &free);
31be5bf1	197	rpcauth_unhash_cred_locked(cred);
1da177e4 LT	198	}
1da177e4 LT	199	}
9499b434	200	spin_unlock(&cache->lock);
1da177e4 LT	201	spin_unlock(&rpc_credcache_lock);
	202	rpcauth_destroy_credlist(&free);
	203	}
	204
3ab9bb72 TM	205	/*
	206	* Destroy the RPC credential cache
	207	*/
	208	void
	209	rpcauth_destroy_credcache(struct rpc_auth *auth)
	210	{
	211	struct rpc_cred_cache *cache = auth->au_credcache;
	212
	213	if (cache) {
	214	auth->au_credcache = NULL;
	215	rpcauth_clear_credcache(cache);
	216	kfree(cache);
	217	}
	218	}
e8914c65	219	EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
3ab9bb72	220
d2b83141 TM	221
	222	#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
	223
e092bdcd TM	224	/*
	225	* Remove stale credentials. Avoid sleeping inside the loop.
	226	*/
f5c2187c TM	227	static int
f5c2187c TM	228	rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
1da177e4	229	{
9499b434	230	spinlock_t *cache_lock;
e092bdcd	231	struct rpc_cred *cred;
d2b83141	232	unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
e092bdcd TM	233
	234	while (!list_empty(&cred_unused)) {
	235	cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
e092bdcd	236	list_del_init(&cred->cr_lru);
f5c2187c	237	number_cred_unused--;
e092bdcd TM	238	if (atomic_read(&cred->cr_count) != 0)
e092bdcd TM	239	continue;
d2b83141 TM	240	/* Enforce a 5 second garbage collection moratorium */
	241	if (time_in_range(cred->cr_expire, expired, jiffies) &&
	242	test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0)
	243	continue;
9499b434 TM	244	cache_lock = &cred->cr_auth->au_credcache->lock;
	245	spin_lock(cache_lock);
	246	if (atomic_read(&cred->cr_count) == 0) {
	247	get_rpccred(cred);
	248	list_add_tail(&cred->cr_lru, free);
	249	rpcauth_unhash_cred_locked(cred);
f5c2187c	250	nr_to_scan--;
9499b434 TM	251	}
9499b434 TM	252	spin_unlock(cache_lock);
f5c2187c TM	253	if (nr_to_scan == 0)
f5c2187c TM	254	break;
1da177e4	255	}
f5c2187c	256	return nr_to_scan;
1da177e4 LT	257	}
	258
	259	/*
f5c2187c	260	* Run memory cache shrinker.
1da177e4	261	*/
f5c2187c TM	262	static int
f5c2187c TM	263	rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
1da177e4	264	{
f5c2187c TM	265	LIST_HEAD(free);
	266	int res;
	267
	268	if (list_empty(&cred_unused))
	269	return 0;
31be5bf1	270	spin_lock(&rpc_credcache_lock);
f5c2187c TM	271	nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
f5c2187c TM	272	res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
31be5bf1	273	spin_unlock(&rpc_credcache_lock);
f5c2187c TM	274	rpcauth_destroy_credlist(&free);
f5c2187c TM	275	return res;
1da177e4 LT	276	}
	277
	278	/*
	279	* Look up a process' credentials in the authentication cache
	280	*/
	281	struct rpc_cred *
	282	rpcauth_lookup_credcache(struct rpc_auth auth, struct auth_cred acred,
8a317760	283	int flags)
1da177e4	284	{
e092bdcd	285	LIST_HEAD(free);
1da177e4	286	struct rpc_cred_cache *cache = auth->au_credcache;
e092bdcd	287	struct hlist_node *pos;
31be5bf1 TM	288	struct rpc_cred *cred = NULL,
31be5bf1 TM	289	entry, new;
25337fdc TM	290	unsigned int nr;
	291
	292	nr = hash_long(acred->uid, RPC_CREDCACHE_HASHBITS);
1da177e4	293
31be5bf1 TM	294	rcu_read_lock();
31be5bf1 TM	295	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
e092bdcd TM	296	if (!entry->cr_ops->crmatch(acred, entry, flags))
e092bdcd TM	297	continue;
9499b434	298	spin_lock(&cache->lock);
31be5bf1	299	if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
9499b434	300	spin_unlock(&cache->lock);
31be5bf1 TM	301	continue;
31be5bf1 TM	302	}
e092bdcd	303	cred = get_rpccred(entry);
9499b434	304	spin_unlock(&cache->lock);
e092bdcd	305	break;
1da177e4	306	}
31be5bf1 TM	307	rcu_read_unlock();
31be5bf1 TM	308
9499b434	309	if (cred != NULL)
31be5bf1	310	goto found;
1da177e4	311
31be5bf1 TM	312	new = auth->au_ops->crcreate(auth, acred, flags);
	313	if (IS_ERR(new)) {
	314	cred = new;
	315	goto out;
	316	}
1da177e4	317
9499b434	318	spin_lock(&cache->lock);
31be5bf1 TM	319	hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
	320	if (!entry->cr_ops->crmatch(acred, entry, flags))
	321	continue;
	322	cred = get_rpccred(entry);
	323	break;
	324	}
	325	if (cred == NULL) {
5fe4755e	326	cred = new;
31be5bf1 TM	327	set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	328	hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
	329	} else
	330	list_add_tail(&new->cr_lru, &free);
9499b434	331	spin_unlock(&cache->lock);
31be5bf1 TM	332	found:
31be5bf1 TM	333	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)
fba3bad4 TM	334	&& cred->cr_ops->cr_init != NULL
	335	&& !(flags & RPCAUTH_LOOKUP_NEW)) {
	336	int res = cred->cr_ops->cr_init(auth, cred);
	337	if (res < 0) {
	338	put_rpccred(cred);
	339	cred = ERR_PTR(res);
	340	}
1da177e4	341	}
31be5bf1 TM	342	rpcauth_destroy_credlist(&free);
	343	out:
	344	return cred;
1da177e4	345	}
e8914c65	346	EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
1da177e4 LT	347
1da177e4 LT	348	struct rpc_cred *
8a317760	349	rpcauth_lookupcred(struct rpc_auth *auth, int flags)
1da177e4 LT	350	{
	351	struct auth_cred acred = {
	352	.uid = current->fsuid,
	353	.gid = current->fsgid,
	354	.group_info = current->group_info,
	355	};
	356	struct rpc_cred *ret;
	357
46121cf7	358	dprintk("RPC: looking up %s cred\n",
1da177e4 LT	359	auth->au_ops->au_name);
1da177e4 LT	360	get_group_info(acred.group_info);
8a317760	361	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
1da177e4 LT	362	put_group_info(acred.group_info);
	363	return ret;
	364	}
	365
5fe4755e TM	366	void
	367	rpcauth_init_cred(struct rpc_cred cred, const struct auth_cred acred,
	368	struct rpc_auth auth, const struct rpc_credops ops)
	369	{
	370	INIT_HLIST_NODE(&cred->cr_hash);
e092bdcd	371	INIT_LIST_HEAD(&cred->cr_lru);
5fe4755e TM	372	atomic_set(&cred->cr_count, 1);
	373	cred->cr_auth = auth;
	374	cred->cr_ops = ops;
	375	cred->cr_expire = jiffies;
	376	#ifdef RPC_DEBUG
	377	cred->cr_magic = RPCAUTH_CRED_MAGIC;
	378	#endif
	379	cred->cr_uid = acred->uid;
	380	}
e8914c65	381	EXPORT_SYMBOL_GPL(rpcauth_init_cred);
5fe4755e	382
5c691044	383	void
4ccda2cd TM	384	rpcauth_generic_bind_cred(struct rpc_task task, struct rpc_cred cred)
	385	{
	386	task->tk_msg.rpc_cred = get_rpccred(cred);
	387	dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
	388	cred->cr_auth->au_ops->au_name, cred);
	389	}
5c691044	390	EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
4ccda2cd TM	391
4ccda2cd TM	392	static void
af093835	393	rpcauth_bind_root_cred(struct rpc_task *task)
1da177e4	394	{
1be27f36	395	struct rpc_auth *auth = task->tk_client->cl_auth;
1da177e4	396	struct auth_cred acred = {
af093835 TM	397	.uid = 0,
af093835 TM	398	.gid = 0,
1da177e4 LT	399	};
	400	struct rpc_cred *ret;
	401
46121cf7	402	dprintk("RPC: %5u looking up %s cred\n",
1be27f36	403	task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
af093835 TM	404	ret = auth->au_ops->lookup_cred(auth, &acred, 0);
	405	if (!IS_ERR(ret))
	406	task->tk_msg.rpc_cred = ret;
	407	else
	408	task->tk_status = PTR_ERR(ret);
	409	}
	410
4ccda2cd TM	411	static void
4ccda2cd TM	412	rpcauth_bind_new_cred(struct rpc_task *task)
af093835 TM	413	{
	414	struct rpc_auth *auth = task->tk_client->cl_auth;
	415	struct rpc_cred *ret;
	416
	417	dprintk("RPC: %5u looking up %s cred\n",
	418	task->tk_pid, auth->au_ops->au_name);
	419	ret = rpcauth_lookupcred(auth, 0);
1da177e4 LT	420	if (!IS_ERR(ret))
	421	task->tk_msg.rpc_cred = ret;
	422	else
	423	task->tk_status = PTR_ERR(ret);
1da177e4 LT	424	}
	425
	426	void
4ccda2cd	427	rpcauth_bindcred(struct rpc_task task, struct rpc_cred cred, int flags)
1da177e4	428	{
4ccda2cd	429	if (cred != NULL)
5c691044	430	cred->cr_ops->crbind(task, cred);
4ccda2cd TM	431	else if (flags & RPC_TASK_ROOTCREDS)
	432	rpcauth_bind_root_cred(task);
	433	else
	434	rpcauth_bind_new_cred(task);
1da177e4 LT	435	}
	436
	437	void
	438	put_rpccred(struct rpc_cred *cred)
	439	{
e092bdcd	440	/* Fast path for unhashed credentials */
31be5bf1	441	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
e092bdcd TM	442	goto need_lock;
e092bdcd TM	443
1da177e4 LT	444	if (!atomic_dec_and_test(&cred->cr_count))
1da177e4 LT	445	return;
e092bdcd	446	goto out_destroy;
e092bdcd TM	447	need_lock:
	448	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
	449	return;
f5c2187c TM	450	if (!list_empty(&cred->cr_lru)) {
f5c2187c TM	451	number_cred_unused--;
e092bdcd	452	list_del_init(&cred->cr_lru);
f5c2187c	453	}
e092bdcd	454	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
9499b434	455	rpcauth_unhash_cred(cred);
31be5bf1	456	else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
e092bdcd TM	457	cred->cr_expire = jiffies;
e092bdcd TM	458	list_add_tail(&cred->cr_lru, &cred_unused);
f5c2187c	459	number_cred_unused++;
e092bdcd TM	460	spin_unlock(&rpc_credcache_lock);
	461	return;
	462	}
	463	spin_unlock(&rpc_credcache_lock);
	464	out_destroy:
1da177e4 LT	465	cred->cr_ops->crdestroy(cred);
1da177e4 LT	466	}
e8914c65	467	EXPORT_SYMBOL_GPL(put_rpccred);
1da177e4 LT	468
	469	void
	470	rpcauth_unbindcred(struct rpc_task *task)
	471	{
1da177e4 LT	472	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	473
46121cf7	474	dprintk("RPC: %5u releasing %s cred %p\n",
1be27f36	475	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
1da177e4 LT	476
	477	put_rpccred(cred);
	478	task->tk_msg.rpc_cred = NULL;
	479	}
	480
d8ed029d AD	481	__be32 *
d8ed029d AD	482	rpcauth_marshcred(struct rpc_task task, __be32 p)
1da177e4	483	{
1da177e4 LT	484	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	485
46121cf7	486	dprintk("RPC: %5u marshaling %s cred %p\n",
1be27f36	487	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	488
1da177e4 LT	489	return cred->cr_ops->crmarshal(task, p);
	490	}
	491
d8ed029d AD	492	__be32 *
d8ed029d AD	493	rpcauth_checkverf(struct rpc_task task, __be32 p)
1da177e4	494	{
1da177e4 LT	495	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	496
46121cf7	497	dprintk("RPC: %5u validating %s cred %p\n",
1be27f36	498	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	499
1da177e4 LT	500	return cred->cr_ops->crvalidate(task, p);
	501	}
	502
	503	int
	504	rpcauth_wrap_req(struct rpc_task task, kxdrproc_t encode, void rqstp,
d8ed029d	505	__be32 data, void obj)
1da177e4 LT	506	{
	507	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	508
46121cf7	509	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
1da177e4 LT	510	task->tk_pid, cred->cr_ops->cr_name, cred);
	511	if (cred->cr_ops->crwrap_req)
	512	return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
	513	/* By default, we encode the arguments normally. */
be879c4e	514	return rpc_call_xdrproc(encode, rqstp, data, obj);
1da177e4 LT	515	}
	516
	517	int
	518	rpcauth_unwrap_resp(struct rpc_task task, kxdrproc_t decode, void rqstp,
d8ed029d	519	__be32 data, void obj)
1da177e4 LT	520	{
	521	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	522
46121cf7	523	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
1da177e4 LT	524	task->tk_pid, cred->cr_ops->cr_name, cred);
	525	if (cred->cr_ops->crunwrap_resp)
	526	return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
	527	data, obj);
	528	/* By default, we decode the arguments normally. */
be879c4e	529	return rpc_call_xdrproc(decode, rqstp, data, obj);
1da177e4 LT	530	}
	531
	532	int
	533	rpcauth_refreshcred(struct rpc_task *task)
	534	{
1da177e4 LT	535	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	536	int err;
	537
46121cf7	538	dprintk("RPC: %5u refreshing %s cred %p\n",
1be27f36	539	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	540
1da177e4 LT	541	err = cred->cr_ops->crrefresh(task);
	542	if (err < 0)
	543	task->tk_status = err;
	544	return err;
	545	}
	546
	547	void
	548	rpcauth_invalcred(struct rpc_task *task)
	549	{
fc432dd9 TM	550	struct rpc_cred *cred = task->tk_msg.rpc_cred;
fc432dd9 TM	551
46121cf7	552	dprintk("RPC: %5u invalidating %s cred %p\n",
1be27f36	553	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
fc432dd9 TM	554	if (cred)
fc432dd9 TM	555	clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1da177e4 LT	556	}
	557
	558	int
	559	rpcauth_uptodatecred(struct rpc_task *task)
	560	{
fc432dd9 TM	561	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	562
	563	return cred == NULL \|\|
	564	test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
1da177e4	565	}
f5c2187c	566
8e1f936b RR	567	static struct shrinker rpc_cred_shrinker = {
	568	.shrink = rpcauth_cache_shrinker,
	569	.seeks = DEFAULT_SEEKS,
	570	};
f5c2187c TM	571
	572	void __init rpcauth_init_module(void)
	573	{
	574	rpc_init_authunix();
9a559efd	575	rpc_init_generic_auth();
8e1f936b	576	register_shrinker(&rpc_cred_shrinker);
f5c2187c TM	577	}
	578
	579	void __exit rpcauth_remove_module(void)
	580	{
8e1f936b	581	unregister_shrinker(&rpc_cred_shrinker);
f5c2187c	582	}