[linux-2.6-block.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>
#include <linux/smp_lock.h>

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_AUTH
#endif

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

static LIST_HEAD(cred_unused);
static unsigned long number_cred_unused;

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

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

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

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

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

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

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

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

out:
	return auth;
}

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

static DEFINE_SPINLOCK(rpc_credcache_lock);

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	if (cred != NULL)
		goto found;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	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. */
	lock_kernel();
	ret = encode(rqstp, data, obj);
	unlock_kernel();
	return ret;
}

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;
	int ret;

	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. */
	lock_kernel();
	ret = decode(rqstp, data, obj);
	unlock_kernel();
	return ret;
}

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>
1da177e4 LT	15	#include <linux/spinlock.h>
d8558f99	16	#include <linux/smp_lock.h>
1da177e4 LT	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 LT	54	}
	55
	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 LT	71	}
	72
	73	struct rpc_auth *
	74	rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
	75	{
	76	struct rpc_auth *auth;
f1c0a861	77	const struct rpc_authops *ops;
1da177e4 LT	78	u32 flavor = pseudoflavor_to_flavor(pseudoflavor);
1da177e4 LT	79
f344f6df OK	80	auth = ERR_PTR(-EINVAL);
	81	if (flavor >= RPC_AUTH_MAXFLAVOR)
	82	goto out;
	83
f344f6df OK	84	#ifdef CONFIG_KMOD
	85	if ((ops = auth_flavors[flavor]) == NULL)
	86	request_module("rpc-auth-%u", flavor);
	87	#endif
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;
	105	}
	106
	107	void
de7a8ce3	108	rpcauth_release(struct rpc_auth *auth)
1da177e4 LT	109	{
	110	if (!atomic_dec_and_test(&auth->au_count))
	111	return;
	112	auth->au_ops->destroy(auth);
	113	}
	114
	115	static DEFINE_SPINLOCK(rpc_credcache_lock);
	116
31be5bf1 TM	117	static void
	118	rpcauth_unhash_cred_locked(struct rpc_cred *cred)
	119	{
	120	hlist_del_rcu(&cred->cr_hash);
	121	smp_mb__before_clear_bit();
	122	clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	123	}
	124
9499b434 TM	125	static void
	126	rpcauth_unhash_cred(struct rpc_cred *cred)
	127	{
	128	spinlock_t *cache_lock;
	129
	130	cache_lock = &cred->cr_auth->au_credcache->lock;
	131	spin_lock(cache_lock);
	132	if (atomic_read(&cred->cr_count) == 0)
	133	rpcauth_unhash_cred_locked(cred);
	134	spin_unlock(cache_lock);
	135	}
	136
1da177e4 LT	137	/*
	138	* Initialize RPC credential cache
	139	*/
	140	int
f5c2187c	141	rpcauth_init_credcache(struct rpc_auth *auth)
1da177e4 LT	142	{
	143	struct rpc_cred_cache *new;
	144	int i;
	145
8b3a7005	146	new = kmalloc(sizeof(*new), GFP_KERNEL);
1da177e4 LT	147	if (!new)
	148	return -ENOMEM;
	149	for (i = 0; i < RPC_CREDCACHE_NR; i++)
	150	INIT_HLIST_HEAD(&new->hashtable[i]);
9499b434	151	spin_lock_init(&new->lock);
1da177e4 LT	152	auth->au_credcache = new;
	153	return 0;
	154	}
	155
	156	/*
	157	* Destroy a list of credentials
	158	*/
	159	static inline
e092bdcd	160	void rpcauth_destroy_credlist(struct list_head *head)
1da177e4 LT	161	{
	162	struct rpc_cred *cred;
	163
e092bdcd TM	164	while (!list_empty(head)) {
	165	cred = list_entry(head->next, struct rpc_cred, cr_lru);
	166	list_del_init(&cred->cr_lru);
1da177e4 LT	167	put_rpccred(cred);
	168	}
	169	}
	170
	171	/*
	172	* Clear the RPC credential cache, and delete those credentials
	173	* that are not referenced.
	174	*/
	175	void
3ab9bb72	176	rpcauth_clear_credcache(struct rpc_cred_cache *cache)
1da177e4	177	{
e092bdcd TM	178	LIST_HEAD(free);
e092bdcd TM	179	struct hlist_head *head;
1da177e4 LT	180	struct rpc_cred *cred;
	181	int i;
	182
	183	spin_lock(&rpc_credcache_lock);
9499b434	184	spin_lock(&cache->lock);
1da177e4	185	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
e092bdcd TM	186	head = &cache->hashtable[i];
	187	while (!hlist_empty(head)) {
	188	cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
	189	get_rpccred(cred);
f5c2187c TM	190	if (!list_empty(&cred->cr_lru)) {
	191	list_del(&cred->cr_lru);
	192	number_cred_unused--;
	193	}
	194	list_add_tail(&cred->cr_lru, &free);
31be5bf1	195	rpcauth_unhash_cred_locked(cred);
1da177e4 LT	196	}
1da177e4 LT	197	}
9499b434	198	spin_unlock(&cache->lock);
1da177e4 LT	199	spin_unlock(&rpc_credcache_lock);
	200	rpcauth_destroy_credlist(&free);
	201	}
	202
3ab9bb72 TM	203	/*
	204	* Destroy the RPC credential cache
	205	*/
	206	void
	207	rpcauth_destroy_credcache(struct rpc_auth *auth)
	208	{
	209	struct rpc_cred_cache *cache = auth->au_credcache;
	210
	211	if (cache) {
	212	auth->au_credcache = NULL;
	213	rpcauth_clear_credcache(cache);
	214	kfree(cache);
	215	}
	216	}
	217
e092bdcd TM	218	/*
	219	* Remove stale credentials. Avoid sleeping inside the loop.
	220	*/
f5c2187c TM	221	static int
f5c2187c TM	222	rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
1da177e4	223	{
9499b434	224	spinlock_t *cache_lock;
e092bdcd TM	225	struct rpc_cred *cred;
	226
	227	while (!list_empty(&cred_unused)) {
	228	cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
e092bdcd	229	list_del_init(&cred->cr_lru);
f5c2187c	230	number_cred_unused--;
e092bdcd TM	231	if (atomic_read(&cred->cr_count) != 0)
e092bdcd TM	232	continue;
9499b434 TM	233	cache_lock = &cred->cr_auth->au_credcache->lock;
	234	spin_lock(cache_lock);
	235	if (atomic_read(&cred->cr_count) == 0) {
	236	get_rpccred(cred);
	237	list_add_tail(&cred->cr_lru, free);
	238	rpcauth_unhash_cred_locked(cred);
f5c2187c	239	nr_to_scan--;
9499b434 TM	240	}
9499b434 TM	241	spin_unlock(cache_lock);
f5c2187c TM	242	if (nr_to_scan == 0)
f5c2187c TM	243	break;
1da177e4	244	}
f5c2187c	245	return nr_to_scan;
1da177e4 LT	246	}
	247
	248	/*
f5c2187c	249	* Run memory cache shrinker.
1da177e4	250	*/
f5c2187c TM	251	static int
f5c2187c TM	252	rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
1da177e4	253	{
f5c2187c TM	254	LIST_HEAD(free);
	255	int res;
	256
	257	if (list_empty(&cred_unused))
	258	return 0;
31be5bf1	259	spin_lock(&rpc_credcache_lock);
f5c2187c TM	260	nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
f5c2187c TM	261	res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
31be5bf1	262	spin_unlock(&rpc_credcache_lock);
f5c2187c TM	263	rpcauth_destroy_credlist(&free);
f5c2187c TM	264	return res;
1da177e4 LT	265	}
	266
	267	/*
	268	* Look up a process' credentials in the authentication cache
	269	*/
	270	struct rpc_cred *
	271	rpcauth_lookup_credcache(struct rpc_auth auth, struct auth_cred acred,
8a317760	272	int flags)
1da177e4	273	{
e092bdcd	274	LIST_HEAD(free);
1da177e4	275	struct rpc_cred_cache *cache = auth->au_credcache;
e092bdcd	276	struct hlist_node *pos;
31be5bf1 TM	277	struct rpc_cred *cred = NULL,
31be5bf1 TM	278	entry, new;
1da177e4 LT	279	int nr = 0;
1da177e4 LT	280
8a317760	281	if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
1da177e4	282	nr = acred->uid & RPC_CREDCACHE_MASK;
31be5bf1 TM	283
	284	rcu_read_lock();
	285	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
e092bdcd TM	286	if (!entry->cr_ops->crmatch(acred, entry, flags))
e092bdcd TM	287	continue;
9499b434	288	spin_lock(&cache->lock);
31be5bf1	289	if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
9499b434	290	spin_unlock(&cache->lock);
31be5bf1 TM	291	continue;
31be5bf1 TM	292	}
e092bdcd	293	cred = get_rpccred(entry);
9499b434	294	spin_unlock(&cache->lock);
e092bdcd	295	break;
1da177e4	296	}
31be5bf1 TM	297	rcu_read_unlock();
31be5bf1 TM	298
9499b434	299	if (cred != NULL)
31be5bf1	300	goto found;
1da177e4	301
31be5bf1 TM	302	new = auth->au_ops->crcreate(auth, acred, flags);
	303	if (IS_ERR(new)) {
	304	cred = new;
	305	goto out;
	306	}
1da177e4	307
9499b434	308	spin_lock(&cache->lock);
31be5bf1 TM	309	hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
	310	if (!entry->cr_ops->crmatch(acred, entry, flags))
	311	continue;
	312	cred = get_rpccred(entry);
	313	break;
	314	}
	315	if (cred == NULL) {
5fe4755e	316	cred = new;
31be5bf1 TM	317	set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
	318	hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
	319	} else
	320	list_add_tail(&new->cr_lru, &free);
9499b434	321	spin_unlock(&cache->lock);
31be5bf1 TM	322	found:
31be5bf1 TM	323	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)
fba3bad4 TM	324	&& cred->cr_ops->cr_init != NULL
	325	&& !(flags & RPCAUTH_LOOKUP_NEW)) {
	326	int res = cred->cr_ops->cr_init(auth, cred);
	327	if (res < 0) {
	328	put_rpccred(cred);
	329	cred = ERR_PTR(res);
	330	}
1da177e4	331	}
31be5bf1 TM	332	rpcauth_destroy_credlist(&free);
	333	out:
	334	return cred;
1da177e4 LT	335	}
	336
	337	struct rpc_cred *
8a317760	338	rpcauth_lookupcred(struct rpc_auth *auth, int flags)
1da177e4 LT	339	{
	340	struct auth_cred acred = {
	341	.uid = current->fsuid,
	342	.gid = current->fsgid,
	343	.group_info = current->group_info,
	344	};
	345	struct rpc_cred *ret;
	346
46121cf7	347	dprintk("RPC: looking up %s cred\n",
1da177e4 LT	348	auth->au_ops->au_name);
1da177e4 LT	349	get_group_info(acred.group_info);
8a317760	350	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
1da177e4 LT	351	put_group_info(acred.group_info);
	352	return ret;
	353	}
	354
5fe4755e TM	355	void
	356	rpcauth_init_cred(struct rpc_cred cred, const struct auth_cred acred,
	357	struct rpc_auth auth, const struct rpc_credops ops)
	358	{
	359	INIT_HLIST_NODE(&cred->cr_hash);
e092bdcd	360	INIT_LIST_HEAD(&cred->cr_lru);
5fe4755e TM	361	atomic_set(&cred->cr_count, 1);
	362	cred->cr_auth = auth;
	363	cred->cr_ops = ops;
	364	cred->cr_expire = jiffies;
	365	#ifdef RPC_DEBUG
	366	cred->cr_magic = RPCAUTH_CRED_MAGIC;
	367	#endif
	368	cred->cr_uid = acred->uid;
	369	}
	370	EXPORT_SYMBOL(rpcauth_init_cred);
	371
1da177e4 LT	372	struct rpc_cred *
	373	rpcauth_bindcred(struct rpc_task *task)
	374	{
1be27f36	375	struct rpc_auth *auth = task->tk_client->cl_auth;
1da177e4 LT	376	struct auth_cred acred = {
	377	.uid = current->fsuid,
	378	.gid = current->fsgid,
	379	.group_info = current->group_info,
	380	};
	381	struct rpc_cred *ret;
8a317760	382	int flags = 0;
1da177e4	383
46121cf7	384	dprintk("RPC: %5u looking up %s cred\n",
1be27f36	385	task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
1da177e4	386	get_group_info(acred.group_info);
8a317760 TM	387	if (task->tk_flags & RPC_TASK_ROOTCREDS)
	388	flags \|= RPCAUTH_LOOKUP_ROOTCREDS;
	389	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
1da177e4 LT	390	if (!IS_ERR(ret))
	391	task->tk_msg.rpc_cred = ret;
	392	else
	393	task->tk_status = PTR_ERR(ret);
	394	put_group_info(acred.group_info);
	395	return ret;
	396	}
	397
	398	void
	399	rpcauth_holdcred(struct rpc_task *task)
	400	{
1be27f36 TM	401	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	402	if (cred != NULL) {
	403	get_rpccred(cred);
	404	dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
	405	cred->cr_auth->au_ops->au_name, cred);
	406	}
1da177e4 LT	407	}
	408
	409	void
	410	put_rpccred(struct rpc_cred *cred)
	411	{
e092bdcd	412	/* Fast path for unhashed credentials */
31be5bf1	413	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
e092bdcd TM	414	goto need_lock;
e092bdcd TM	415
1da177e4 LT	416	if (!atomic_dec_and_test(&cred->cr_count))
1da177e4 LT	417	return;
e092bdcd	418	goto out_destroy;
e092bdcd TM	419	need_lock:
	420	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
	421	return;
f5c2187c TM	422	if (!list_empty(&cred->cr_lru)) {
f5c2187c TM	423	number_cred_unused--;
e092bdcd	424	list_del_init(&cred->cr_lru);
f5c2187c	425	}
e092bdcd	426	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
9499b434	427	rpcauth_unhash_cred(cred);
31be5bf1	428	else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
e092bdcd TM	429	cred->cr_expire = jiffies;
e092bdcd TM	430	list_add_tail(&cred->cr_lru, &cred_unused);
f5c2187c	431	number_cred_unused++;
e092bdcd TM	432	spin_unlock(&rpc_credcache_lock);
	433	return;
	434	}
	435	spin_unlock(&rpc_credcache_lock);
	436	out_destroy:
1da177e4 LT	437	cred->cr_ops->crdestroy(cred);
	438	}
	439
	440	void
	441	rpcauth_unbindcred(struct rpc_task *task)
	442	{
1da177e4 LT	443	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	444
46121cf7	445	dprintk("RPC: %5u releasing %s cred %p\n",
1be27f36	446	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
1da177e4 LT	447
	448	put_rpccred(cred);
	449	task->tk_msg.rpc_cred = NULL;
	450	}
	451
d8ed029d AD	452	__be32 *
d8ed029d AD	453	rpcauth_marshcred(struct rpc_task task, __be32 p)
1da177e4	454	{
1da177e4 LT	455	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	456
46121cf7	457	dprintk("RPC: %5u marshaling %s cred %p\n",
1be27f36	458	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	459
1da177e4 LT	460	return cred->cr_ops->crmarshal(task, p);
	461	}
	462
d8ed029d AD	463	__be32 *
d8ed029d AD	464	rpcauth_checkverf(struct rpc_task task, __be32 p)
1da177e4	465	{
1da177e4 LT	466	struct rpc_cred *cred = task->tk_msg.rpc_cred;
1da177e4 LT	467
46121cf7	468	dprintk("RPC: %5u validating %s cred %p\n",
1be27f36	469	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	470
1da177e4 LT	471	return cred->cr_ops->crvalidate(task, p);
	472	}
	473
	474	int
	475	rpcauth_wrap_req(struct rpc_task task, kxdrproc_t encode, void rqstp,
d8ed029d	476	__be32 data, void obj)
1da177e4 LT	477	{
1da177e4 LT	478	struct rpc_cred *cred = task->tk_msg.rpc_cred;
d8558f99	479	int ret;
1da177e4	480
46121cf7	481	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
1da177e4 LT	482	task->tk_pid, cred->cr_ops->cr_name, cred);
	483	if (cred->cr_ops->crwrap_req)
	484	return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
	485	/* By default, we encode the arguments normally. */
d8558f99 BF	486	lock_kernel();
	487	ret = encode(rqstp, data, obj);
	488	unlock_kernel();
	489	return ret;
1da177e4 LT	490	}
	491
	492	int
	493	rpcauth_unwrap_resp(struct rpc_task task, kxdrproc_t decode, void rqstp,
d8ed029d	494	__be32 data, void obj)
1da177e4 LT	495	{
1da177e4 LT	496	struct rpc_cred *cred = task->tk_msg.rpc_cred;
d8558f99	497	int ret;
1da177e4	498
46121cf7	499	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
1da177e4 LT	500	task->tk_pid, cred->cr_ops->cr_name, cred);
	501	if (cred->cr_ops->crunwrap_resp)
	502	return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
	503	data, obj);
	504	/* By default, we decode the arguments normally. */
d8558f99 BF	505	lock_kernel();
	506	ret = decode(rqstp, data, obj);
	507	unlock_kernel();
	508	return ret;
1da177e4 LT	509	}
	510
	511	int
	512	rpcauth_refreshcred(struct rpc_task *task)
	513	{
1da177e4 LT	514	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	515	int err;
	516
46121cf7	517	dprintk("RPC: %5u refreshing %s cred %p\n",
1be27f36	518	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
0bbacc40	519
1da177e4 LT	520	err = cred->cr_ops->crrefresh(task);
	521	if (err < 0)
	522	task->tk_status = err;
	523	return err;
	524	}
	525
	526	void
	527	rpcauth_invalcred(struct rpc_task *task)
	528	{
fc432dd9 TM	529	struct rpc_cred *cred = task->tk_msg.rpc_cred;
fc432dd9 TM	530
46121cf7	531	dprintk("RPC: %5u invalidating %s cred %p\n",
1be27f36	532	task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
fc432dd9 TM	533	if (cred)
fc432dd9 TM	534	clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1da177e4 LT	535	}
	536
	537	int
	538	rpcauth_uptodatecred(struct rpc_task *task)
	539	{
fc432dd9 TM	540	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	541
	542	return cred == NULL \|\|
	543	test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
1da177e4	544	}
f5c2187c	545
8e1f936b RR	546	static struct shrinker rpc_cred_shrinker = {
	547	.shrink = rpcauth_cache_shrinker,
	548	.seeks = DEFAULT_SEEKS,
	549	};
f5c2187c TM	550
	551	void __init rpcauth_init_module(void)
	552	{
	553	rpc_init_authunix();
8e1f936b	554	register_shrinker(&rpc_cred_shrinker);
f5c2187c TM	555	}
	556
	557	void __exit rpcauth_remove_module(void)
	558	{
8e1f936b	559	unregister_shrinker(&rpc_cred_shrinker);
f5c2187c	560	}