[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 int
rpcauth_unhash_cred(struct rpc_cred *cred)
{
	spinlock_t *cache_lock;
	int ret;

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

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

	list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {

		if (nr_to_scan-- == 0)
			break;
		/*
		 * Enforce a 60 second garbage collection moratorium
		 * Note that the cred_unused list must be time-ordered.
		 */
		if (time_in_range(cred->cr_expire, expired, jiffies) &&
		    test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
			return 0;

		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);
		}
		spin_unlock(cache_lock);
	}
	return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
}

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

	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
		return (nr_to_scan == 0) ? 0 : -1;
	if (list_empty(&cred_unused))
		return 0;
	spin_lock(&rpc_credcache_lock);
	res = rpcauth_prune_expired(&free, nr_to_scan);
	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;
	struct rpc_cred *ret;
	const struct cred *cred = current_cred();

	dprintk("RPC:       looking up %s cred\n",
		auth->au_ops->au_name);

	memset(&acred, 0, sizeof(acred));
	acred.uid = cred->fsuid;
	acred.gid = cred->fsgid;
	acred.group_info = get_group_info(((struct cred *)cred)->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, int lookupflags)
{
	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, int lookupflags)
{
	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, lookupflags);
	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, int lookupflags)
{
	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, lookupflags);
	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)
{
	int lookupflags = 0;

	if (flags & RPC_TASK_ASYNC)
		lookupflags |= RPCAUTH_LOOKUP_NEW;
	if (cred != NULL)
		cred->cr_ops->crbind(task, cred, lookupflags);
	else if (flags & RPC_TASK_ROOTCREDS)
		rpcauth_bind_root_cred(task, lookupflags);
	else
		rpcauth_bind_new_cred(task, lookupflags);
}

void
put_rpccred(struct rpc_cred *cred)
{
	/* Fast path for unhashed credentials */
	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
		if (atomic_dec_and_test(&cred->cr_count))
			cred->cr_ops->crdestroy(cred);
		return;
	}

	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_HASHED, &cred->cr_flags) != 0) {
		if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
			cred->cr_expire = jiffies;
			list_add_tail(&cred->cr_lru, &cred_unused);
			number_cred_unused++;
			goto out_nodestroy;
		}
		if (!rpcauth_unhash_cred(cred)) {
			/* We were hashed and someone looked us up... */
			goto out_nodestroy;
		}
	}
	spin_unlock(&rpc_credcache_lock);
	cred->cr_ops->crdestroy(cred);
	return;
out_nodestroy:
	spin_unlock(&rpc_credcache_lock);
}
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 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 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,
};

int __init rpcauth_init_module(void)
{
	int err;

	err = rpc_init_authunix();
	if (err < 0)
		goto out1;
	err = rpc_init_generic_auth();
	if (err < 0)
		goto out2;
	register_shrinker(&rpc_cred_shrinker);
	return 0;
out2:
	rpc_destroy_authunix();
out1:
	return err;
}

void __exit rpcauth_remove_module(void)
{
	rpc_destroy_authunix();
	rpc_destroy_generic_auth();
	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
f0380f3d	126	static int
9499b434 TM	127	rpcauth_unhash_cred(struct rpc_cred *cred)
	128	{
	129	spinlock_t *cache_lock;
f0380f3d	130	int ret;
9499b434 TM	131
	132	cache_lock = &cred->cr_auth->au_credcache->lock;
	133	spin_lock(cache_lock);
f0380f3d TM	134	ret = atomic_read(&cred->cr_count) == 0;
f0380f3d TM	135	if (ret)
9499b434 TM	136	rpcauth_unhash_cred_locked(cred);
9499b434 TM	137	spin_unlock(cache_lock);
f0380f3d	138	return ret;
9499b434 TM	139	}
9499b434 TM	140
1da177e4 LT	141	/*
	142	* Initialize RPC credential cache
	143	*/
	144	int
f5c2187c	145	rpcauth_init_credcache(struct rpc_auth *auth)
1da177e4 LT	146	{
	147	struct rpc_cred_cache *new;
	148	int i;
	149
8b3a7005	150	new = kmalloc(sizeof(*new), GFP_KERNEL);
1da177e4 LT	151	if (!new)
	152	return -ENOMEM;
	153	for (i = 0; i < RPC_CREDCACHE_NR; i++)
	154	INIT_HLIST_HEAD(&new->hashtable[i]);
9499b434	155	spin_lock_init(&new->lock);
1da177e4 LT	156	auth->au_credcache = new;
	157	return 0;
	158	}
e8914c65	159	EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
1da177e4 LT	160
	161	/*
	162	* Destroy a list of credentials
	163	*/
	164	static inline
e092bdcd	165	void rpcauth_destroy_credlist(struct list_head *head)
1da177e4 LT	166	{
	167	struct rpc_cred *cred;
	168
e092bdcd TM	169	while (!list_empty(head)) {
	170	cred = list_entry(head->next, struct rpc_cred, cr_lru);
	171	list_del_init(&cred->cr_lru);
1da177e4 LT	172	put_rpccred(cred);
	173	}
	174	}
	175
	176	/*
	177	* Clear the RPC credential cache, and delete those credentials
	178	* that are not referenced.
	179	*/
	180	void
3ab9bb72	181	rpcauth_clear_credcache(struct rpc_cred_cache *cache)
1da177e4	182	{
e092bdcd TM	183	LIST_HEAD(free);
e092bdcd TM	184	struct hlist_head *head;
1da177e4 LT	185	struct rpc_cred *cred;
	186	int i;
	187
	188	spin_lock(&rpc_credcache_lock);
9499b434	189	spin_lock(&cache->lock);
1da177e4	190	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
e092bdcd TM	191	head = &cache->hashtable[i];
	192	while (!hlist_empty(head)) {
	193	cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
	194	get_rpccred(cred);
f5c2187c TM	195	if (!list_empty(&cred->cr_lru)) {
	196	list_del(&cred->cr_lru);
	197	number_cred_unused--;
	198	}
	199	list_add_tail(&cred->cr_lru, &free);
31be5bf1	200	rpcauth_unhash_cred_locked(cred);
1da177e4 LT	201	}
1da177e4 LT	202	}
9499b434	203	spin_unlock(&cache->lock);
1da177e4 LT	204	spin_unlock(&rpc_credcache_lock);
	205	rpcauth_destroy_credlist(&free);
	206	}
	207
3ab9bb72 TM	208	/*
	209	* Destroy the RPC credential cache
	210	*/
	211	void
	212	rpcauth_destroy_credcache(struct rpc_auth *auth)
	213	{
	214	struct rpc_cred_cache *cache = auth->au_credcache;
	215
	216	if (cache) {
	217	auth->au_credcache = NULL;
	218	rpcauth_clear_credcache(cache);
	219	kfree(cache);
	220	}
	221	}
e8914c65	222	EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
3ab9bb72	223
d2b83141 TM	224
	225	#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
	226
e092bdcd TM	227	/*
	228	* Remove stale credentials. Avoid sleeping inside the loop.
	229	*/
f5c2187c TM	230	static int
f5c2187c TM	231	rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
1da177e4	232	{
9499b434	233	spinlock_t *cache_lock;
eac0d18d	234	struct rpc_cred cred, next;
d2b83141	235	unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
e092bdcd	236
eac0d18d TM	237	list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
eac0d18d TM	238
20673406 TM	239	if (nr_to_scan-- == 0)
20673406 TM	240	break;
93a05e65 TM	241	/*
	242	* Enforce a 60 second garbage collection moratorium
	243	* Note that the cred_unused list must be time-ordered.
	244	*/
3d7b0894	245	if (time_in_range(cred->cr_expire, expired, jiffies) &&
eac0d18d	246	test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
93a05e65	247	return 0;
eac0d18d	248
e092bdcd	249	list_del_init(&cred->cr_lru);
f5c2187c	250	number_cred_unused--;
e092bdcd TM	251	if (atomic_read(&cred->cr_count) != 0)
e092bdcd TM	252	continue;
eac0d18d	253
9499b434 TM	254	cache_lock = &cred->cr_auth->au_credcache->lock;
	255	spin_lock(cache_lock);
	256	if (atomic_read(&cred->cr_count) == 0) {
	257	get_rpccred(cred);
	258	list_add_tail(&cred->cr_lru, free);
	259	rpcauth_unhash_cred_locked(cred);
	260	}
	261	spin_unlock(cache_lock);
1da177e4	262	}
93a05e65	263	return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
1da177e4 LT	264	}
	265
	266	/*
f5c2187c	267	* Run memory cache shrinker.
1da177e4	268	*/
f5c2187c TM	269	static int
f5c2187c TM	270	rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
1da177e4	271	{
f5c2187c TM	272	LIST_HEAD(free);
	273	int res;
	274
d300a41e TM	275	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
d300a41e TM	276	return (nr_to_scan == 0) ? 0 : -1;
f5c2187c TM	277	if (list_empty(&cred_unused))
f5c2187c TM	278	return 0;
31be5bf1	279	spin_lock(&rpc_credcache_lock);
93a05e65	280	res = rpcauth_prune_expired(&free, nr_to_scan);
31be5bf1	281	spin_unlock(&rpc_credcache_lock);
f5c2187c TM	282	rpcauth_destroy_credlist(&free);
f5c2187c TM	283	return res;
1da177e4 LT	284	}
	285
	286	/*
	287	* Look up a process' credentials in the authentication cache
	288	*/
	289	struct rpc_cred *
	290	rpcauth_lookup_credcache(struct rpc_auth auth, struct auth_cred acred,
8a317760	291	int flags)
1da177e4	292	{
e092bdcd	293	LIST_HEAD(free);
1da177e4	294	struct rpc_cred_cache *cache = auth->au_credcache;
e092bdcd	295	struct hlist_node *pos;
31be5bf1 TM	296	struct rpc_cred *cred = NULL,
31be5bf1 TM	297	entry, new;
25337fdc TM	298	unsigned int nr;
	299
	300	nr = hash_long(acred->uid, RPC_CREDCACHE_HASHBITS);
1da177e4	301
31be5bf1 TM	302	rcu_read_lock();
31be5bf1 TM	303	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
e092bdcd TM	304	if (!entry->cr_ops->crmatch(acred, entry, flags))
e092bdcd TM	305	continue;
9499b434	306	spin_lock(&cache->lock);
31be5bf1	307	if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
9499b434	308	spin_unlock(&cache->lock);
31be5bf1 TM	309	continue;
31be5bf1 TM	310	}
e092bdcd	311	cred = get_rpccred(entry);
9499b434	312	spin_unlock(&cache->lock);
e092bdcd	313	break;
1da177e4	314	}
31be5bf1 TM	315	rcu_read_unlock();
31be5bf1 TM	316
9499b434	317	if (cred != NULL)
31be5bf1	318	goto found;
1da177e4	319
31be5bf1 TM	320	new = auth->au_ops->crcreate(auth, acred, flags);
	321	if (IS_ERR(new)) {
	322	cred = new;
	323	goto out;
	324	}
1da177e4	325
9499b434	326	spin_lock(&cache->lock);
31be5bf1 TM	327	hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
	328	if (!entry->cr_ops->crmatch(acred, entry, flags))
	329	continue;
	330	cred = get_rpccred(entry);
	331	break;
	332	}
	333	if (cred == NULL) {
5fe4755e	334	cred = new;
31be5bf1 TM	335	set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	336	hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
	337	} else
	338	list_add_tail(&new->cr_lru, &free);
9499b434	339	spin_unlock(&cache->lock);
31be5bf1	340	found:
f64f9e71 JP	341	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
	342	cred->cr_ops->cr_init != NULL &&
	343	!(flags & RPCAUTH_LOOKUP_NEW)) {
fba3bad4 TM	344	int res = cred->cr_ops->cr_init(auth, cred);
	345	if (res < 0) {
	346	put_rpccred(cred);
	347	cred = ERR_PTR(res);
	348	}
1da177e4	349	}
31be5bf1 TM	350	rpcauth_destroy_credlist(&free);
	351	out:
	352	return cred;
1da177e4	353	}
e8914c65	354	EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
1da177e4 LT	355
1da177e4 LT	356	struct rpc_cred *
8a317760	357	rpcauth_lookupcred(struct rpc_auth *auth, int flags)
1da177e4	358	{
86a264ab	359	struct auth_cred acred;
1da177e4	360	struct rpc_cred *ret;
86a264ab	361	const struct cred *cred = current_cred();
1da177e4	362
46121cf7	363	dprintk("RPC: looking up %s cred\n",
1da177e4	364	auth->au_ops->au_name);
86a264ab DH	365
	366	memset(&acred, 0, sizeof(acred));
	367	acred.uid = cred->fsuid;
	368	acred.gid = cred->fsgid;
	369	acred.group_info = get_group_info(((struct cred *)cred)->group_info);
	370
8a317760	371	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
1da177e4 LT	372	put_group_info(acred.group_info);
	373	return ret;
	374	}
	375
5fe4755e TM	376	void
	377	rpcauth_init_cred(struct rpc_cred cred, const struct auth_cred acred,
	378	struct rpc_auth auth, const struct rpc_credops ops)
	379	{
	380	INIT_HLIST_NODE(&cred->cr_hash);
e092bdcd	381	INIT_LIST_HEAD(&cred->cr_lru);
5fe4755e TM	382	atomic_set(&cred->cr_count, 1);
	383	cred->cr_auth = auth;
	384	cred->cr_ops = ops;
	385	cred->cr_expire = jiffies;
	386	#ifdef RPC_DEBUG
	387	cred->cr_magic = RPCAUTH_CRED_MAGIC;
	388	#endif
	389	cred->cr_uid = acred->uid;
	390	}
e8914c65	391	EXPORT_SYMBOL_GPL(rpcauth_init_cred);
5fe4755e	392
5c691044	393	void
5d351754	394	rpcauth_generic_bind_cred(struct rpc_task task, struct rpc_cred cred, int lookupflags)
4ccda2cd TM	395	{
	396	task->tk_msg.rpc_cred = get_rpccred(cred);
	397	dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
	398	cred->cr_auth->au_ops->au_name, cred);
	399	}
5c691044	400	EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
4ccda2cd TM	401
4ccda2cd TM	402	static void
5d351754	403	rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
1da177e4	404	{
1be27f36	405	struct rpc_auth *auth = task->tk_client->cl_auth;
1da177e4	406	struct auth_cred acred = {
af093835 TM	407	.uid = 0,
af093835 TM	408	.gid = 0,
1da177e4 LT	409	};
	410	struct rpc_cred *ret;
	411
46121cf7	412	dprintk("RPC: %5u looking up %s cred\n",
1be27f36	413	task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
5d351754	414	ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
af093835 TM	415	if (!IS_ERR(ret))
	416	task->tk_msg.rpc_cred = ret;
	417	else
	418	task->tk_status = PTR_ERR(ret);
	419	}
	420
4ccda2cd	421	static void
5d351754	422	rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
af093835 TM	423	{
	424	struct rpc_auth *auth = task->tk_client->cl_auth;
	425	struct rpc_cred *ret;
	426
	427	dprintk("RPC: %5u looking up %s cred\n",
	428	task->tk_pid, auth->au_ops->au_name);
5d351754	429	ret = rpcauth_lookupcred(auth, lookupflags);
1da177e4 LT	430	if (!IS_ERR(ret))
	431	task->tk_msg.rpc_cred = ret;
	432	else
	433	task->tk_status = PTR_ERR(ret);
1da177e4 LT	434	}
	435
	436	void
4ccda2cd	437	rpcauth_bindcred(struct rpc_task task, struct rpc_cred cred, int flags)
1da177e4	438	{
5d351754 TM	439	int lookupflags = 0;
	440
	441	if (flags & RPC_TASK_ASYNC)
	442	lookupflags \|= RPCAUTH_LOOKUP_NEW;
4ccda2cd	443	if (cred != NULL)
5d351754	444	cred->cr_ops->crbind(task, cred, lookupflags);
4ccda2cd	445	else if (flags & RPC_TASK_ROOTCREDS)
5d351754	446	rpcauth_bind_root_cred(task, lookupflags);
4ccda2cd	447	else
5d351754	448	rpcauth_bind_new_cred(task, lookupflags);
1da177e4 LT	449	}
	450
	451	void
	452	put_rpccred(struct rpc_cred *cred)
	453	{
e092bdcd	454	/* Fast path for unhashed credentials */
f0380f3d TM	455	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
	456	if (atomic_dec_and_test(&cred->cr_count))
	457	cred->cr_ops->crdestroy(cred);
1da177e4	458	return;
f0380f3d TM	459	}
f0380f3d TM	460
e092bdcd TM	461	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
e092bdcd TM	462	return;
f5c2187c TM	463	if (!list_empty(&cred->cr_lru)) {
f5c2187c TM	464	number_cred_unused--;
e092bdcd	465	list_del_init(&cred->cr_lru);
f5c2187c	466	}
5f707eb4	467	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
f0380f3d TM	468	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
	469	cred->cr_expire = jiffies;
	470	list_add_tail(&cred->cr_lru, &cred_unused);
	471	number_cred_unused++;
	472	goto out_nodestroy;
	473	}
	474	if (!rpcauth_unhash_cred(cred)) {
	475	/* We were hashed and someone looked us up... */
	476	goto out_nodestroy;
	477	}
e092bdcd TM	478	}
e092bdcd TM	479	spin_unlock(&rpc_credcache_lock);
1da177e4	480	cred->cr_ops->crdestroy(cred);
f0380f3d TM	481	return;
	482	out_nodestroy:
	483	spin_unlock(&rpc_credcache_lock);
1da177e4	484	}
e8914c65	485	EXPORT_SYMBOL_GPL(put_rpccred);
1da177e4 LT	486
	487	void
	488	rpcauth_unbindcred(struct rpc_task *task)
	489	{
1da177e4 LT	490	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	491
46121cf7	492	dprintk("RPC: %5u releasing %s cred %p\n",
1be27f36	493	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
1da177e4 LT	494
	495	put_rpccred(cred);
	496	task->tk_msg.rpc_cred = NULL;
	497	}
	498
d8ed029d AD	499	__be32 *
d8ed029d AD	500	rpcauth_marshcred(struct rpc_task task, __be32 p)
1da177e4	501	{
1da177e4 LT	502	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	503
46121cf7	504	dprintk("RPC: %5u marshaling %s cred %p\n",
1be27f36	505	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	506
1da177e4 LT	507	return cred->cr_ops->crmarshal(task, p);
	508	}
	509
d8ed029d AD	510	__be32 *
d8ed029d AD	511	rpcauth_checkverf(struct rpc_task task, __be32 p)
1da177e4	512	{
1da177e4 LT	513	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	514
46121cf7	515	dprintk("RPC: %5u validating %s cred %p\n",
1be27f36	516	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	517
1da177e4 LT	518	return cred->cr_ops->crvalidate(task, p);
	519	}
	520
	521	int
	522	rpcauth_wrap_req(struct rpc_task task, kxdrproc_t encode, void rqstp,
d8ed029d	523	__be32 data, void obj)
1da177e4 LT	524	{
	525	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	526
46121cf7	527	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
1da177e4 LT	528	task->tk_pid, cred->cr_ops->cr_name, cred);
	529	if (cred->cr_ops->crwrap_req)
	530	return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
	531	/* By default, we encode the arguments normally. */
88a9fe8c	532	return encode(rqstp, data, obj);
1da177e4 LT	533	}
	534
	535	int
	536	rpcauth_unwrap_resp(struct rpc_task task, kxdrproc_t decode, void rqstp,
d8ed029d	537	__be32 data, void obj)
1da177e4 LT	538	{
	539	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	540
46121cf7	541	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
1da177e4 LT	542	task->tk_pid, cred->cr_ops->cr_name, cred);
	543	if (cred->cr_ops->crunwrap_resp)
	544	return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
	545	data, obj);
	546	/* By default, we decode the arguments normally. */
88a9fe8c	547	return decode(rqstp, data, obj);
1da177e4 LT	548	}
	549
	550	int
	551	rpcauth_refreshcred(struct rpc_task *task)
	552	{
1da177e4 LT	553	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	554	int err;
	555
46121cf7	556	dprintk("RPC: %5u refreshing %s cred %p\n",
1be27f36	557	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	558
1da177e4 LT	559	err = cred->cr_ops->crrefresh(task);
	560	if (err < 0)
	561	task->tk_status = err;
	562	return err;
	563	}
	564
	565	void
	566	rpcauth_invalcred(struct rpc_task *task)
	567	{
fc432dd9 TM	568	struct rpc_cred *cred = task->tk_msg.rpc_cred;
fc432dd9 TM	569
46121cf7	570	dprintk("RPC: %5u invalidating %s cred %p\n",
1be27f36	571	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
fc432dd9 TM	572	if (cred)
fc432dd9 TM	573	clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1da177e4 LT	574	}
	575
	576	int
	577	rpcauth_uptodatecred(struct rpc_task *task)
	578	{
fc432dd9 TM	579	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	580
	581	return cred == NULL \|\|
	582	test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
1da177e4	583	}
f5c2187c	584
8e1f936b RR	585	static struct shrinker rpc_cred_shrinker = {
	586	.shrink = rpcauth_cache_shrinker,
	587	.seeks = DEFAULT_SEEKS,
	588	};
f5c2187c	589
5d8d9a4d	590	int __init rpcauth_init_module(void)
f5c2187c	591	{
5d8d9a4d TM	592	int err;
	593
	594	err = rpc_init_authunix();
	595	if (err < 0)
	596	goto out1;
	597	err = rpc_init_generic_auth();
	598	if (err < 0)
	599	goto out2;
8e1f936b	600	register_shrinker(&rpc_cred_shrinker);
5d8d9a4d TM	601	return 0;
	602	out2:
	603	rpc_destroy_authunix();
	604	out1:
	605	return err;
f5c2187c TM	606	}
	607
	608	void __exit rpcauth_remove_module(void)
	609	{
5d8d9a4d TM	610	rpc_destroy_authunix();
5d8d9a4d TM	611	rpc_destroy_generic_auth();
8e1f936b	612	unregister_shrinker(&rpc_cred_shrinker);
f5c2187c	613	}