[GitHub/moto-9609/android_kernel_motorola_exynos9610.git] / net / sunrpc / auth.c

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

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

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_AUTH
#endif

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

static LIST_HEAD(cred_unused);
static unsigned long number_cred_unused;

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

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

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

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

out:
	return auth;
}
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);

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

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

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

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

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

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

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

	if (cred != NULL)
		goto found;

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

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

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);

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

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

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

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

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

void __exit rpcauth_remove_module(void)
{
	unregister_shrinker(&rpc_cred_shrinker);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/net/sunrpc/auth.c
	3	*
	4	* Generic RPC client authentication API.
	5	*
	6	* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
	7	*/
	8
	9	#include <linux/types.h>
	10	#include <linux/sched.h>
	11	#include <linux/module.h>
	12	#include <linux/slab.h>
	13	#include <linux/errno.h>
1da177e4 LT	14	#include <linux/sunrpc/clnt.h>
	15	#include <linux/spinlock.h>
	16
	17	#ifdef RPC_DEBUG
	18	# define RPCDBG_FACILITY RPCDBG_AUTH
	19	#endif
	20
fc1b356f	21	static DEFINE_SPINLOCK(rpc_authflavor_lock);
f1c0a861	22	static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
1da177e4 LT	23	&authnull_ops, /* AUTH_NULL */
	24	&authunix_ops, /* AUTH_UNIX */
	25	NULL, /* others can be loadable modules */
	26	};
	27
e092bdcd	28	static LIST_HEAD(cred_unused);
f5c2187c	29	static unsigned long number_cred_unused;
e092bdcd	30
1da177e4 LT	31	static u32
	32	pseudoflavor_to_flavor(u32 flavor) {
	33	if (flavor >= RPC_AUTH_MAXFLAVOR)
	34	return RPC_AUTH_GSS;
	35	return flavor;
	36	}
	37
	38	int
f1c0a861	39	rpcauth_register(const struct rpc_authops *ops)
1da177e4 LT	40	{
1da177e4 LT	41	rpc_authflavor_t flavor;
fc1b356f	42	int ret = -EPERM;
1da177e4 LT	43
	44	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
	45	return -EINVAL;
fc1b356f TM	46	spin_lock(&rpc_authflavor_lock);
	47	if (auth_flavors[flavor] == NULL) {
	48	auth_flavors[flavor] = ops;
	49	ret = 0;
	50	}
	51	spin_unlock(&rpc_authflavor_lock);
	52	return ret;
1da177e4	53	}
e8914c65	54	EXPORT_SYMBOL_GPL(rpcauth_register);
1da177e4 LT	55
1da177e4 LT	56	int
f1c0a861	57	rpcauth_unregister(const struct rpc_authops *ops)
1da177e4 LT	58	{
1da177e4 LT	59	rpc_authflavor_t flavor;
fc1b356f	60	int ret = -EPERM;
1da177e4 LT	61
	62	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
	63	return -EINVAL;
fc1b356f TM	64	spin_lock(&rpc_authflavor_lock);
	65	if (auth_flavors[flavor] == ops) {
	66	auth_flavors[flavor] = NULL;
	67	ret = 0;
	68	}
	69	spin_unlock(&rpc_authflavor_lock);
	70	return ret;
1da177e4	71	}
e8914c65	72	EXPORT_SYMBOL_GPL(rpcauth_unregister);
1da177e4 LT	73
	74	struct rpc_auth *
	75	rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
	76	{
	77	struct rpc_auth *auth;
f1c0a861	78	const struct rpc_authops *ops;
1da177e4 LT	79	u32 flavor = pseudoflavor_to_flavor(pseudoflavor);
1da177e4 LT	80
f344f6df OK	81	auth = ERR_PTR(-EINVAL);
	82	if (flavor >= RPC_AUTH_MAXFLAVOR)
	83	goto out;
	84
f344f6df OK	85	#ifdef CONFIG_KMOD
	86	if ((ops = auth_flavors[flavor]) == NULL)
	87	request_module("rpc-auth-%u", flavor);
	88	#endif
fc1b356f TM	89	spin_lock(&rpc_authflavor_lock);
	90	ops = auth_flavors[flavor];
	91	if (ops == NULL \|\| !try_module_get(ops->owner)) {
	92	spin_unlock(&rpc_authflavor_lock);
f344f6df	93	goto out;
fc1b356f TM	94	}
fc1b356f TM	95	spin_unlock(&rpc_authflavor_lock);
1da177e4	96	auth = ops->create(clnt, pseudoflavor);
fc1b356f	97	module_put(ops->owner);
6a19275a BF	98	if (IS_ERR(auth))
6a19275a BF	99	return auth;
1da177e4	100	if (clnt->cl_auth)
de7a8ce3	101	rpcauth_release(clnt->cl_auth);
1da177e4	102	clnt->cl_auth = auth;
f344f6df OK	103
f344f6df OK	104	out:
1da177e4 LT	105	return auth;
1da177e4 LT	106	}
e8914c65	107	EXPORT_SYMBOL_GPL(rpcauth_create);
1da177e4 LT	108
1da177e4 LT	109	void
de7a8ce3	110	rpcauth_release(struct rpc_auth *auth)
1da177e4 LT	111	{
	112	if (!atomic_dec_and_test(&auth->au_count))
	113	return;
	114	auth->au_ops->destroy(auth);
	115	}
	116
	117	static DEFINE_SPINLOCK(rpc_credcache_lock);
	118
31be5bf1 TM	119	static void
	120	rpcauth_unhash_cred_locked(struct rpc_cred *cred)
	121	{
	122	hlist_del_rcu(&cred->cr_hash);
	123	smp_mb__before_clear_bit();
	124	clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	125	}
	126
9499b434 TM	127	static void
	128	rpcauth_unhash_cred(struct rpc_cred *cred)
	129	{
	130	spinlock_t *cache_lock;
	131
	132	cache_lock = &cred->cr_auth->au_credcache->lock;
	133	spin_lock(cache_lock);
	134	if (atomic_read(&cred->cr_count) == 0)
	135	rpcauth_unhash_cred_locked(cred);
	136	spin_unlock(cache_lock);
	137	}
	138
1da177e4 LT	139	/*
	140	* Initialize RPC credential cache
	141	*/
	142	int
f5c2187c	143	rpcauth_init_credcache(struct rpc_auth *auth)
1da177e4 LT	144	{
	145	struct rpc_cred_cache *new;
	146	int i;
	147
8b3a7005	148	new = kmalloc(sizeof(*new), GFP_KERNEL);
1da177e4 LT	149	if (!new)
	150	return -ENOMEM;
	151	for (i = 0; i < RPC_CREDCACHE_NR; i++)
	152	INIT_HLIST_HEAD(&new->hashtable[i]);
9499b434	153	spin_lock_init(&new->lock);
1da177e4 LT	154	auth->au_credcache = new;
	155	return 0;
	156	}
e8914c65	157	EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
1da177e4 LT	158
	159	/*
	160	* Destroy a list of credentials
	161	*/
	162	static inline
e092bdcd	163	void rpcauth_destroy_credlist(struct list_head *head)
1da177e4 LT	164	{
	165	struct rpc_cred *cred;
	166
e092bdcd TM	167	while (!list_empty(head)) {
	168	cred = list_entry(head->next, struct rpc_cred, cr_lru);
	169	list_del_init(&cred->cr_lru);
1da177e4 LT	170	put_rpccred(cred);
	171	}
	172	}
	173
	174	/*
	175	* Clear the RPC credential cache, and delete those credentials
	176	* that are not referenced.
	177	*/
	178	void
3ab9bb72	179	rpcauth_clear_credcache(struct rpc_cred_cache *cache)
1da177e4	180	{
e092bdcd TM	181	LIST_HEAD(free);
e092bdcd TM	182	struct hlist_head *head;
1da177e4 LT	183	struct rpc_cred *cred;
	184	int i;
	185
	186	spin_lock(&rpc_credcache_lock);
9499b434	187	spin_lock(&cache->lock);
1da177e4	188	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
e092bdcd TM	189	head = &cache->hashtable[i];
	190	while (!hlist_empty(head)) {
	191	cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
	192	get_rpccred(cred);
f5c2187c TM	193	if (!list_empty(&cred->cr_lru)) {
	194	list_del(&cred->cr_lru);
	195	number_cred_unused--;
	196	}
	197	list_add_tail(&cred->cr_lru, &free);
31be5bf1	198	rpcauth_unhash_cred_locked(cred);
1da177e4 LT	199	}
1da177e4 LT	200	}
9499b434	201	spin_unlock(&cache->lock);
1da177e4 LT	202	spin_unlock(&rpc_credcache_lock);
	203	rpcauth_destroy_credlist(&free);
	204	}
	205
3ab9bb72 TM	206	/*
	207	* Destroy the RPC credential cache
	208	*/
	209	void
	210	rpcauth_destroy_credcache(struct rpc_auth *auth)
	211	{
	212	struct rpc_cred_cache *cache = auth->au_credcache;
	213
	214	if (cache) {
	215	auth->au_credcache = NULL;
	216	rpcauth_clear_credcache(cache);
	217	kfree(cache);
	218	}
	219	}
e8914c65	220	EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
3ab9bb72	221
e092bdcd TM	222	/*
	223	* Remove stale credentials. Avoid sleeping inside the loop.
	224	*/
f5c2187c TM	225	static int
f5c2187c TM	226	rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
1da177e4	227	{
9499b434	228	spinlock_t *cache_lock;
e092bdcd TM	229	struct rpc_cred *cred;
	230
	231	while (!list_empty(&cred_unused)) {
	232	cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
e092bdcd	233	list_del_init(&cred->cr_lru);
f5c2187c	234	number_cred_unused--;
e092bdcd TM	235	if (atomic_read(&cred->cr_count) != 0)
e092bdcd TM	236	continue;
9499b434 TM	237	cache_lock = &cred->cr_auth->au_credcache->lock;
	238	spin_lock(cache_lock);
	239	if (atomic_read(&cred->cr_count) == 0) {
	240	get_rpccred(cred);
	241	list_add_tail(&cred->cr_lru, free);
	242	rpcauth_unhash_cred_locked(cred);
f5c2187c	243	nr_to_scan--;
9499b434 TM	244	}
9499b434 TM	245	spin_unlock(cache_lock);
f5c2187c TM	246	if (nr_to_scan == 0)
f5c2187c TM	247	break;
1da177e4	248	}
f5c2187c	249	return nr_to_scan;
1da177e4 LT	250	}
	251
	252	/*
f5c2187c	253	* Run memory cache shrinker.
1da177e4	254	*/
f5c2187c TM	255	static int
f5c2187c TM	256	rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
1da177e4	257	{
f5c2187c TM	258	LIST_HEAD(free);
	259	int res;
	260
	261	if (list_empty(&cred_unused))
	262	return 0;
31be5bf1	263	spin_lock(&rpc_credcache_lock);
f5c2187c TM	264	nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
f5c2187c TM	265	res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
31be5bf1	266	spin_unlock(&rpc_credcache_lock);
f5c2187c TM	267	rpcauth_destroy_credlist(&free);
f5c2187c TM	268	return res;
1da177e4 LT	269	}
	270
	271	/*
	272	* Look up a process' credentials in the authentication cache
	273	*/
	274	struct rpc_cred *
	275	rpcauth_lookup_credcache(struct rpc_auth auth, struct auth_cred acred,
8a317760	276	int flags)
1da177e4	277	{
e092bdcd	278	LIST_HEAD(free);
1da177e4	279	struct rpc_cred_cache *cache = auth->au_credcache;
e092bdcd	280	struct hlist_node *pos;
31be5bf1 TM	281	struct rpc_cred *cred = NULL,
31be5bf1 TM	282	entry, new;
1da177e4 LT	283	int nr = 0;
1da177e4 LT	284
8a317760	285	if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
1da177e4	286	nr = acred->uid & RPC_CREDCACHE_MASK;
31be5bf1 TM	287
	288	rcu_read_lock();
	289	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
e092bdcd TM	290	if (!entry->cr_ops->crmatch(acred, entry, flags))
e092bdcd TM	291	continue;
9499b434	292	spin_lock(&cache->lock);
31be5bf1	293	if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
9499b434	294	spin_unlock(&cache->lock);
31be5bf1 TM	295	continue;
31be5bf1 TM	296	}
e092bdcd	297	cred = get_rpccred(entry);
9499b434	298	spin_unlock(&cache->lock);
e092bdcd	299	break;
1da177e4	300	}
31be5bf1 TM	301	rcu_read_unlock();
31be5bf1 TM	302
9499b434	303	if (cred != NULL)
31be5bf1	304	goto found;
1da177e4	305
31be5bf1 TM	306	new = auth->au_ops->crcreate(auth, acred, flags);
	307	if (IS_ERR(new)) {
	308	cred = new;
	309	goto out;
	310	}
1da177e4	311
9499b434	312	spin_lock(&cache->lock);
31be5bf1 TM	313	hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
	314	if (!entry->cr_ops->crmatch(acred, entry, flags))
	315	continue;
	316	cred = get_rpccred(entry);
	317	break;
	318	}
	319	if (cred == NULL) {
5fe4755e	320	cred = new;
31be5bf1 TM	321	set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	322	hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
	323	} else
	324	list_add_tail(&new->cr_lru, &free);
9499b434	325	spin_unlock(&cache->lock);
31be5bf1 TM	326	found:
31be5bf1 TM	327	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)
fba3bad4 TM	328	&& cred->cr_ops->cr_init != NULL
	329	&& !(flags & RPCAUTH_LOOKUP_NEW)) {
	330	int res = cred->cr_ops->cr_init(auth, cred);
	331	if (res < 0) {
	332	put_rpccred(cred);
	333	cred = ERR_PTR(res);
	334	}
1da177e4	335	}
31be5bf1 TM	336	rpcauth_destroy_credlist(&free);
	337	out:
	338	return cred;
1da177e4	339	}
e8914c65	340	EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
1da177e4 LT	341
1da177e4 LT	342	struct rpc_cred *
8a317760	343	rpcauth_lookupcred(struct rpc_auth *auth, int flags)
1da177e4 LT	344	{
	345	struct auth_cred acred = {
	346	.uid = current->fsuid,
	347	.gid = current->fsgid,
	348	.group_info = current->group_info,
	349	};
	350	struct rpc_cred *ret;
	351
46121cf7	352	dprintk("RPC: looking up %s cred\n",
1da177e4 LT	353	auth->au_ops->au_name);
1da177e4 LT	354	get_group_info(acred.group_info);
8a317760	355	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
1da177e4 LT	356	put_group_info(acred.group_info);
	357	return ret;
	358	}
e8914c65	359	EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
1da177e4	360
5fe4755e TM	361	void
	362	rpcauth_init_cred(struct rpc_cred cred, const struct auth_cred acred,
	363	struct rpc_auth auth, const struct rpc_credops ops)
	364	{
	365	INIT_HLIST_NODE(&cred->cr_hash);
e092bdcd	366	INIT_LIST_HEAD(&cred->cr_lru);
5fe4755e TM	367	atomic_set(&cred->cr_count, 1);
	368	cred->cr_auth = auth;
	369	cred->cr_ops = ops;
	370	cred->cr_expire = jiffies;
	371	#ifdef RPC_DEBUG
	372	cred->cr_magic = RPCAUTH_CRED_MAGIC;
	373	#endif
	374	cred->cr_uid = acred->uid;
	375	}
e8914c65	376	EXPORT_SYMBOL_GPL(rpcauth_init_cred);
5fe4755e	377
1da177e4 LT	378	struct rpc_cred *
	379	rpcauth_bindcred(struct rpc_task *task)
	380	{
1be27f36	381	struct rpc_auth *auth = task->tk_client->cl_auth;
1da177e4 LT	382	struct auth_cred acred = {
	383	.uid = current->fsuid,
	384	.gid = current->fsgid,
	385	.group_info = current->group_info,
	386	};
	387	struct rpc_cred *ret;
50859259	388	sigset_t oldset;
8a317760	389	int flags = 0;
1da177e4	390
46121cf7	391	dprintk("RPC: %5u looking up %s cred\n",
1be27f36	392	task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
1da177e4	393	get_group_info(acred.group_info);
8a317760 TM	394	if (task->tk_flags & RPC_TASK_ROOTCREDS)
8a317760 TM	395	flags \|= RPCAUTH_LOOKUP_ROOTCREDS;
50859259	396	rpc_clnt_sigmask(task->tk_client, &oldset);
8a317760	397	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
50859259	398	rpc_clnt_sigunmask(task->tk_client, &oldset);
1da177e4 LT	399	if (!IS_ERR(ret))
	400	task->tk_msg.rpc_cred = ret;
	401	else
	402	task->tk_status = PTR_ERR(ret);
	403	put_group_info(acred.group_info);
	404	return ret;
	405	}
	406
	407	void
	408	rpcauth_holdcred(struct rpc_task *task)
	409	{
1be27f36 TM	410	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	411	if (cred != NULL) {
	412	get_rpccred(cred);
	413	dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
	414	cred->cr_auth->au_ops->au_name, cred);
	415	}
1da177e4 LT	416	}
	417
	418	void
	419	put_rpccred(struct rpc_cred *cred)
	420	{
e092bdcd	421	/* Fast path for unhashed credentials */
31be5bf1	422	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
e092bdcd TM	423	goto need_lock;
e092bdcd TM	424
1da177e4 LT	425	if (!atomic_dec_and_test(&cred->cr_count))
1da177e4 LT	426	return;
e092bdcd	427	goto out_destroy;
e092bdcd TM	428	need_lock:
	429	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
	430	return;
f5c2187c TM	431	if (!list_empty(&cred->cr_lru)) {
f5c2187c TM	432	number_cred_unused--;
e092bdcd	433	list_del_init(&cred->cr_lru);
f5c2187c	434	}
e092bdcd	435	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
9499b434	436	rpcauth_unhash_cred(cred);
31be5bf1	437	else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
e092bdcd TM	438	cred->cr_expire = jiffies;
e092bdcd TM	439	list_add_tail(&cred->cr_lru, &cred_unused);
f5c2187c	440	number_cred_unused++;
e092bdcd TM	441	spin_unlock(&rpc_credcache_lock);
	442	return;
	443	}
	444	spin_unlock(&rpc_credcache_lock);
	445	out_destroy:
1da177e4 LT	446	cred->cr_ops->crdestroy(cred);
1da177e4 LT	447	}
e8914c65	448	EXPORT_SYMBOL_GPL(put_rpccred);
1da177e4 LT	449
	450	void
	451	rpcauth_unbindcred(struct rpc_task *task)
	452	{
1da177e4 LT	453	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	454
46121cf7	455	dprintk("RPC: %5u releasing %s cred %p\n",
1be27f36	456	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
1da177e4 LT	457
	458	put_rpccred(cred);
	459	task->tk_msg.rpc_cred = NULL;
	460	}
	461
d8ed029d AD	462	__be32 *
d8ed029d AD	463	rpcauth_marshcred(struct rpc_task task, __be32 p)
1da177e4	464	{
1da177e4 LT	465	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	466
46121cf7	467	dprintk("RPC: %5u marshaling %s cred %p\n",
1be27f36	468	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	469
1da177e4 LT	470	return cred->cr_ops->crmarshal(task, p);
	471	}
	472
d8ed029d AD	473	__be32 *
d8ed029d AD	474	rpcauth_checkverf(struct rpc_task task, __be32 p)
1da177e4	475	{
1da177e4 LT	476	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	477
46121cf7	478	dprintk("RPC: %5u validating %s cred %p\n",
1be27f36	479	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	480
1da177e4 LT	481	return cred->cr_ops->crvalidate(task, p);
	482	}
	483
	484	int
	485	rpcauth_wrap_req(struct rpc_task task, kxdrproc_t encode, void rqstp,
d8ed029d	486	__be32 data, void obj)
1da177e4 LT	487	{
	488	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	489
46121cf7	490	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
1da177e4 LT	491	task->tk_pid, cred->cr_ops->cr_name, cred);
	492	if (cred->cr_ops->crwrap_req)
	493	return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
	494	/* By default, we encode the arguments normally. */
be879c4e	495	return rpc_call_xdrproc(encode, rqstp, data, obj);
1da177e4 LT	496	}
	497
	498	int
	499	rpcauth_unwrap_resp(struct rpc_task task, kxdrproc_t decode, void rqstp,
d8ed029d	500	__be32 data, void obj)
1da177e4 LT	501	{
	502	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	503
46121cf7	504	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
1da177e4 LT	505	task->tk_pid, cred->cr_ops->cr_name, cred);
	506	if (cred->cr_ops->crunwrap_resp)
	507	return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
	508	data, obj);
	509	/* By default, we decode the arguments normally. */
be879c4e	510	return rpc_call_xdrproc(decode, rqstp, data, obj);
1da177e4 LT	511	}
	512
	513	int
	514	rpcauth_refreshcred(struct rpc_task *task)
	515	{
1da177e4 LT	516	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	517	int err;
	518
46121cf7	519	dprintk("RPC: %5u refreshing %s cred %p\n",
1be27f36	520	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	521
1da177e4 LT	522	err = cred->cr_ops->crrefresh(task);
	523	if (err < 0)
	524	task->tk_status = err;
	525	return err;
	526	}
	527
	528	void
	529	rpcauth_invalcred(struct rpc_task *task)
	530	{
fc432dd9 TM	531	struct rpc_cred *cred = task->tk_msg.rpc_cred;
fc432dd9 TM	532
46121cf7	533	dprintk("RPC: %5u invalidating %s cred %p\n",
1be27f36	534	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
fc432dd9 TM	535	if (cred)
fc432dd9 TM	536	clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1da177e4 LT	537	}
	538
	539	int
	540	rpcauth_uptodatecred(struct rpc_task *task)
	541	{
fc432dd9 TM	542	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	543
	544	return cred == NULL \|\|
	545	test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
1da177e4	546	}
f5c2187c	547
8e1f936b RR	548	static struct shrinker rpc_cred_shrinker = {
	549	.shrink = rpcauth_cache_shrinker,
	550	.seeks = DEFAULT_SEEKS,
	551	};
f5c2187c TM	552
	553	void __init rpcauth_init_module(void)
	554	{
	555	rpc_init_authunix();
8e1f936b	556	register_shrinker(&rpc_cred_shrinker);
f5c2187c TM	557	}
	558
	559	void __exit rpcauth_remove_module(void)
	560	{
8e1f936b	561	unregister_shrinker(&rpc_cred_shrinker);
f5c2187c	562	}