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

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

		/* Enforce a 60 second garbage collection moratorium */
		if (time_in_range_open(cred->cr_expire, expired, jiffies) &&
		    test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
			continue;

		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;
	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)
		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);
	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 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,
};

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;
eac0d18d	231	struct rpc_cred cred, next;
d2b83141	232	unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
e092bdcd	233
eac0d18d TM	234	list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
	235
	236	/* Enforce a 60 second garbage collection moratorium */
64672d55	237	if (time_in_range_open(cred->cr_expire, expired, jiffies) &&
eac0d18d TM	238	test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
	239	continue;
	240
e092bdcd	241	list_del_init(&cred->cr_lru);
f5c2187c	242	number_cred_unused--;
e092bdcd TM	243	if (atomic_read(&cred->cr_count) != 0)
e092bdcd TM	244	continue;
eac0d18d	245
9499b434 TM	246	cache_lock = &cred->cr_auth->au_credcache->lock;
	247	spin_lock(cache_lock);
	248	if (atomic_read(&cred->cr_count) == 0) {
	249	get_rpccred(cred);
	250	list_add_tail(&cred->cr_lru, free);
	251	rpcauth_unhash_cred_locked(cred);
f5c2187c	252	nr_to_scan--;
9499b434 TM	253	}
9499b434 TM	254	spin_unlock(cache_lock);
f5c2187c TM	255	if (nr_to_scan == 0)
f5c2187c TM	256	break;
1da177e4	257	}
f5c2187c	258	return nr_to_scan;
1da177e4 LT	259	}
	260
	261	/*
f5c2187c	262	* Run memory cache shrinker.
1da177e4	263	*/
f5c2187c TM	264	static int
f5c2187c TM	265	rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
1da177e4	266	{
f5c2187c TM	267	LIST_HEAD(free);
	268	int res;
	269
	270	if (list_empty(&cred_unused))
	271	return 0;
31be5bf1	272	spin_lock(&rpc_credcache_lock);
f5c2187c TM	273	nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
f5c2187c TM	274	res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
31be5bf1	275	spin_unlock(&rpc_credcache_lock);
f5c2187c TM	276	rpcauth_destroy_credlist(&free);
f5c2187c TM	277	return res;
1da177e4 LT	278	}
	279
	280	/*
	281	* Look up a process' credentials in the authentication cache
	282	*/
	283	struct rpc_cred *
	284	rpcauth_lookup_credcache(struct rpc_auth auth, struct auth_cred acred,
8a317760	285	int flags)
1da177e4	286	{
e092bdcd	287	LIST_HEAD(free);
1da177e4	288	struct rpc_cred_cache *cache = auth->au_credcache;
e092bdcd	289	struct hlist_node *pos;
31be5bf1 TM	290	struct rpc_cred *cred = NULL,
31be5bf1 TM	291	entry, new;
25337fdc TM	292	unsigned int nr;
	293
	294	nr = hash_long(acred->uid, RPC_CREDCACHE_HASHBITS);
1da177e4	295
31be5bf1 TM	296	rcu_read_lock();
31be5bf1 TM	297	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
e092bdcd TM	298	if (!entry->cr_ops->crmatch(acred, entry, flags))
e092bdcd TM	299	continue;
9499b434	300	spin_lock(&cache->lock);
31be5bf1	301	if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
9499b434	302	spin_unlock(&cache->lock);
31be5bf1 TM	303	continue;
31be5bf1 TM	304	}
e092bdcd	305	cred = get_rpccred(entry);
9499b434	306	spin_unlock(&cache->lock);
e092bdcd	307	break;
1da177e4	308	}
31be5bf1 TM	309	rcu_read_unlock();
31be5bf1 TM	310
9499b434	311	if (cred != NULL)
31be5bf1	312	goto found;
1da177e4	313
31be5bf1 TM	314	new = auth->au_ops->crcreate(auth, acred, flags);
	315	if (IS_ERR(new)) {
	316	cred = new;
	317	goto out;
	318	}
1da177e4	319
9499b434	320	spin_lock(&cache->lock);
31be5bf1 TM	321	hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
	322	if (!entry->cr_ops->crmatch(acred, entry, flags))
	323	continue;
	324	cred = get_rpccred(entry);
	325	break;
	326	}
	327	if (cred == NULL) {
5fe4755e	328	cred = new;
31be5bf1 TM	329	set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	330	hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
	331	} else
	332	list_add_tail(&new->cr_lru, &free);
9499b434	333	spin_unlock(&cache->lock);
31be5bf1	334	found:
f64f9e71 JP	335	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
	336	cred->cr_ops->cr_init != NULL &&
	337	!(flags & RPCAUTH_LOOKUP_NEW)) {
fba3bad4 TM	338	int res = cred->cr_ops->cr_init(auth, cred);
	339	if (res < 0) {
	340	put_rpccred(cred);
	341	cred = ERR_PTR(res);
	342	}
1da177e4	343	}
31be5bf1 TM	344	rpcauth_destroy_credlist(&free);
	345	out:
	346	return cred;
1da177e4	347	}
e8914c65	348	EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
1da177e4 LT	349
1da177e4 LT	350	struct rpc_cred *
8a317760	351	rpcauth_lookupcred(struct rpc_auth *auth, int flags)
1da177e4	352	{
86a264ab	353	struct auth_cred acred;
1da177e4	354	struct rpc_cred *ret;
86a264ab	355	const struct cred *cred = current_cred();
1da177e4	356
46121cf7	357	dprintk("RPC: looking up %s cred\n",
1da177e4	358	auth->au_ops->au_name);
86a264ab DH	359
	360	memset(&acred, 0, sizeof(acred));
	361	acred.uid = cred->fsuid;
	362	acred.gid = cred->fsgid;
	363	acred.group_info = get_group_info(((struct cred *)cred)->group_info);
	364
8a317760	365	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
1da177e4 LT	366	put_group_info(acred.group_info);
	367	return ret;
	368	}
	369
5fe4755e TM	370	void
	371	rpcauth_init_cred(struct rpc_cred cred, const struct auth_cred acred,
	372	struct rpc_auth auth, const struct rpc_credops ops)
	373	{
	374	INIT_HLIST_NODE(&cred->cr_hash);
e092bdcd	375	INIT_LIST_HEAD(&cred->cr_lru);
5fe4755e TM	376	atomic_set(&cred->cr_count, 1);
	377	cred->cr_auth = auth;
	378	cred->cr_ops = ops;
	379	cred->cr_expire = jiffies;
	380	#ifdef RPC_DEBUG
	381	cred->cr_magic = RPCAUTH_CRED_MAGIC;
	382	#endif
	383	cred->cr_uid = acred->uid;
	384	}
e8914c65	385	EXPORT_SYMBOL_GPL(rpcauth_init_cred);
5fe4755e	386
5c691044	387	void
5d351754	388	rpcauth_generic_bind_cred(struct rpc_task task, struct rpc_cred cred, int lookupflags)
4ccda2cd TM	389	{
	390	task->tk_msg.rpc_cred = get_rpccred(cred);
	391	dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
	392	cred->cr_auth->au_ops->au_name, cred);
	393	}
5c691044	394	EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
4ccda2cd TM	395
4ccda2cd TM	396	static void
5d351754	397	rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
1da177e4	398	{
1be27f36	399	struct rpc_auth *auth = task->tk_client->cl_auth;
1da177e4	400	struct auth_cred acred = {
af093835 TM	401	.uid = 0,
af093835 TM	402	.gid = 0,
1da177e4 LT	403	};
	404	struct rpc_cred *ret;
	405
46121cf7	406	dprintk("RPC: %5u looking up %s cred\n",
1be27f36	407	task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
5d351754	408	ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
af093835 TM	409	if (!IS_ERR(ret))
	410	task->tk_msg.rpc_cred = ret;
	411	else
	412	task->tk_status = PTR_ERR(ret);
	413	}
	414
4ccda2cd	415	static void
5d351754	416	rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
af093835 TM	417	{
	418	struct rpc_auth *auth = task->tk_client->cl_auth;
	419	struct rpc_cred *ret;
	420
	421	dprintk("RPC: %5u looking up %s cred\n",
	422	task->tk_pid, auth->au_ops->au_name);
5d351754	423	ret = rpcauth_lookupcred(auth, lookupflags);
1da177e4 LT	424	if (!IS_ERR(ret))
	425	task->tk_msg.rpc_cred = ret;
	426	else
	427	task->tk_status = PTR_ERR(ret);
1da177e4 LT	428	}
	429
	430	void
4ccda2cd	431	rpcauth_bindcred(struct rpc_task task, struct rpc_cred cred, int flags)
1da177e4	432	{
5d351754 TM	433	int lookupflags = 0;
	434
	435	if (flags & RPC_TASK_ASYNC)
	436	lookupflags \|= RPCAUTH_LOOKUP_NEW;
4ccda2cd	437	if (cred != NULL)
5d351754	438	cred->cr_ops->crbind(task, cred, lookupflags);
4ccda2cd	439	else if (flags & RPC_TASK_ROOTCREDS)
5d351754	440	rpcauth_bind_root_cred(task, lookupflags);
4ccda2cd	441	else
5d351754	442	rpcauth_bind_new_cred(task, lookupflags);
1da177e4 LT	443	}
	444
	445	void
	446	put_rpccred(struct rpc_cred *cred)
	447	{
e092bdcd	448	/* Fast path for unhashed credentials */
31be5bf1	449	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
e092bdcd TM	450	goto need_lock;
e092bdcd TM	451
1da177e4 LT	452	if (!atomic_dec_and_test(&cred->cr_count))
1da177e4 LT	453	return;
e092bdcd	454	goto out_destroy;
e092bdcd TM	455	need_lock:
	456	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
	457	return;
f5c2187c TM	458	if (!list_empty(&cred->cr_lru)) {
f5c2187c TM	459	number_cred_unused--;
e092bdcd	460	list_del_init(&cred->cr_lru);
f5c2187c	461	}
e092bdcd	462	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
9499b434	463	rpcauth_unhash_cred(cred);
5f707eb4	464	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
e092bdcd TM	465	cred->cr_expire = jiffies;
e092bdcd TM	466	list_add_tail(&cred->cr_lru, &cred_unused);
f5c2187c	467	number_cred_unused++;
e092bdcd TM	468	spin_unlock(&rpc_credcache_lock);
	469	return;
	470	}
	471	spin_unlock(&rpc_credcache_lock);
	472	out_destroy:
1da177e4 LT	473	cred->cr_ops->crdestroy(cred);
1da177e4 LT	474	}
e8914c65	475	EXPORT_SYMBOL_GPL(put_rpccred);
1da177e4 LT	476
	477	void
	478	rpcauth_unbindcred(struct rpc_task *task)
	479	{
1da177e4 LT	480	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	481
46121cf7	482	dprintk("RPC: %5u releasing %s cred %p\n",
1be27f36	483	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
1da177e4 LT	484
	485	put_rpccred(cred);
	486	task->tk_msg.rpc_cred = NULL;
	487	}
	488
d8ed029d AD	489	__be32 *
d8ed029d AD	490	rpcauth_marshcred(struct rpc_task task, __be32 p)
1da177e4	491	{
1da177e4 LT	492	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	493
46121cf7	494	dprintk("RPC: %5u marshaling %s cred %p\n",
1be27f36	495	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	496
1da177e4 LT	497	return cred->cr_ops->crmarshal(task, p);
	498	}
	499
d8ed029d AD	500	__be32 *
d8ed029d AD	501	rpcauth_checkverf(struct rpc_task task, __be32 p)
1da177e4	502	{
1da177e4 LT	503	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	504
46121cf7	505	dprintk("RPC: %5u validating %s cred %p\n",
1be27f36	506	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	507
1da177e4 LT	508	return cred->cr_ops->crvalidate(task, p);
	509	}
	510
	511	int
	512	rpcauth_wrap_req(struct rpc_task task, kxdrproc_t encode, void rqstp,
d8ed029d	513	__be32 data, void obj)
1da177e4 LT	514	{
	515	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	516
46121cf7	517	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
1da177e4 LT	518	task->tk_pid, cred->cr_ops->cr_name, cred);
	519	if (cred->cr_ops->crwrap_req)
	520	return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
	521	/* By default, we encode the arguments normally. */
88a9fe8c	522	return encode(rqstp, data, obj);
1da177e4 LT	523	}
	524
	525	int
	526	rpcauth_unwrap_resp(struct rpc_task task, kxdrproc_t decode, void rqstp,
d8ed029d	527	__be32 data, void obj)
1da177e4 LT	528	{
	529	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	530
46121cf7	531	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
1da177e4 LT	532	task->tk_pid, cred->cr_ops->cr_name, cred);
	533	if (cred->cr_ops->crunwrap_resp)
	534	return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
	535	data, obj);
	536	/* By default, we decode the arguments normally. */
88a9fe8c	537	return decode(rqstp, data, obj);
1da177e4 LT	538	}
	539
	540	int
	541	rpcauth_refreshcred(struct rpc_task *task)
	542	{
1da177e4 LT	543	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	544	int err;
	545
46121cf7	546	dprintk("RPC: %5u refreshing %s cred %p\n",
1be27f36	547	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	548
1da177e4 LT	549	err = cred->cr_ops->crrefresh(task);
	550	if (err < 0)
	551	task->tk_status = err;
	552	return err;
	553	}
	554
	555	void
	556	rpcauth_invalcred(struct rpc_task *task)
	557	{
fc432dd9 TM	558	struct rpc_cred *cred = task->tk_msg.rpc_cred;
fc432dd9 TM	559
46121cf7	560	dprintk("RPC: %5u invalidating %s cred %p\n",
1be27f36	561	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
fc432dd9 TM	562	if (cred)
fc432dd9 TM	563	clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1da177e4 LT	564	}
	565
	566	int
	567	rpcauth_uptodatecred(struct rpc_task *task)
	568	{
fc432dd9 TM	569	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	570
	571	return cred == NULL \|\|
	572	test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
1da177e4	573	}
f5c2187c	574
8e1f936b RR	575	static struct shrinker rpc_cred_shrinker = {
	576	.shrink = rpcauth_cache_shrinker,
	577	.seeks = DEFAULT_SEEKS,
	578	};
f5c2187c TM	579
	580	void __init rpcauth_init_module(void)
	581	{
	582	rpc_init_authunix();
9a559efd	583	rpc_init_generic_auth();
8e1f936b	584	register_shrinker(&rpc_cred_shrinker);
f5c2187c TM	585	}
	586
	587	void __exit rpcauth_remove_module(void)
	588	{
8e1f936b	589	unregister_shrinker(&rpc_cred_shrinker);
f5c2187c	590	}