net/sunrpc/auth.c - kernel/msm - Gitiles

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

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

 int
 rpcauth_register(struct rpc_authops *ops)
 {
 	rpc_authflavor_t flavor;

 	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 		return -EINVAL;
 	if (auth_flavors[flavor] != NULL)
 		return -EPERM;		/* what else? */
 	auth_flavors[flavor] = ops;
 	return 0;
 }

 int
 rpcauth_unregister(struct rpc_authops *ops)
 {
 	rpc_authflavor_t flavor;

 	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 		return -EINVAL;
 	if (auth_flavors[flavor] != ops)
 		return -EPERM;		/* what else? */
 	auth_flavors[flavor] = NULL;
 	return 0;
 }

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

 	if (flavor >= RPC_AUTH_MAXFLAVOR || !(ops = auth_flavors[flavor]))
 		return ERR_PTR(-EINVAL);
 	auth = ops->create(clnt, pseudoflavor);
 	if (IS_ERR(auth))
 		return auth;
 	if (clnt->cl_auth)
 		rpcauth_destroy(clnt->cl_auth);
 	clnt->cl_auth = auth;
 	return auth;
 }

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

 static DEFINE_SPINLOCK(rpc_credcache_lock);

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

 	new = (struct rpc_cred_cache *)kmalloc(sizeof(*new), GFP_KERNEL);
 	if (!new)
 		return -ENOMEM;
 	for (i = 0; i < RPC_CREDCACHE_NR; i++)
 		INIT_HLIST_HEAD(&new->hashtable[i]);
 	new->expire = expire;
 	new->nextgc = jiffies + (expire >> 1);
 	auth->au_credcache = new;
 	return 0;
 }

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

 	while (!hlist_empty(head)) {
 		cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
 		hlist_del_init(&cred->cr_hash);
 		put_rpccred(cred);
 	}
 }

 /*
  * Clear the RPC credential cache, and delete those credentials
  * that are not referenced.
  */
 void
 rpcauth_free_credcache(struct rpc_auth *auth)
 {
 	struct rpc_cred_cache *cache = auth->au_credcache;
 	HLIST_HEAD(free);
 	struct hlist_node *pos, *next;
 	struct rpc_cred	*cred;
 	int		i;

 	spin_lock(&rpc_credcache_lock);
 	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
 		hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
 			cred = hlist_entry(pos, struct rpc_cred, cr_hash);
 			__hlist_del(&cred->cr_hash);
 			hlist_add_head(&cred->cr_hash, &free);
 		}
 	}
 	spin_unlock(&rpc_credcache_lock);
 	rpcauth_destroy_credlist(&free);
 }

 static void
 rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist_head *free)
 {
 	if (atomic_read(&cred->cr_count) != 1)
 	       return;
 	if (time_after(jiffies, cred->cr_expire + auth->au_credcache->expire))
 		cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 	if (!(cred->cr_flags & RPCAUTH_CRED_UPTODATE)) {
 		__hlist_del(&cred->cr_hash);
 		hlist_add_head(&cred->cr_hash, free);
 	}
 }

 /*
  * Remove stale credentials. Avoid sleeping inside the loop.
  */
 static void
 rpcauth_gc_credcache(struct rpc_auth *auth, struct hlist_head *free)
 {
 	struct rpc_cred_cache *cache = auth->au_credcache;
 	struct hlist_node *pos, *next;
 	struct rpc_cred	*cred;
 	int		i;

 	dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth);
 	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
 		hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
 			cred = hlist_entry(pos, struct rpc_cred, cr_hash);
 			rpcauth_prune_expired(auth, cred, free);
 		}
 	}
 	cache->nextgc = jiffies + cache->expire;
 }

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

 	if (!(taskflags & RPC_TASK_ROOTCREDS))
 		nr = acred->uid & RPC_CREDCACHE_MASK;
 retry:
 	spin_lock(&rpc_credcache_lock);
 	if (time_before(cache->nextgc, jiffies))
 		rpcauth_gc_credcache(auth, &free);
 	hlist_for_each_safe(pos, next, &cache->hashtable[nr]) {
 		struct rpc_cred *entry;
 	       	entry = hlist_entry(pos, struct rpc_cred, cr_hash);
 		if (entry->cr_ops->crmatch(acred, entry, taskflags)) {
 			hlist_del(&entry->cr_hash);
 			cred = entry;
 			break;
 		}
 		rpcauth_prune_expired(auth, entry, &free);
 	}
 	if (new) {
 		if (cred)
 			hlist_add_head(&new->cr_hash, &free);
 		else
 			cred = new;
 	}
 	if (cred) {
 		hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
 		get_rpccred(cred);
 	}
 	spin_unlock(&rpc_credcache_lock);

 	rpcauth_destroy_credlist(&free);

 	if (!cred) {
 		new = auth->au_ops->crcreate(auth, acred, taskflags);
 		if (!IS_ERR(new)) {
 #ifdef RPC_DEBUG
 			new->cr_magic = RPCAUTH_CRED_MAGIC;
 #endif
 			goto retry;
 		} else
 			cred = new;
 	}

 	return (struct rpc_cred *) cred;
 }

 struct rpc_cred *
 rpcauth_lookupcred(struct rpc_auth *auth, int taskflags)
 {
 	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, taskflags);
 	put_group_info(acred.group_info);
 	return ret;
 }

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

 	dprintk("RPC: %4d looking up %s cred\n",
 		task->tk_pid, task->tk_auth->au_ops->au_name);
 	get_group_info(acred.group_info);
 	ret = auth->au_ops->lookup_cred(auth, &acred, task->tk_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)
 {
 	dprintk("RPC: %4d holding %s cred %p\n",
 		task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
 	if (task->tk_msg.rpc_cred)
 		get_rpccred(task->tk_msg.rpc_cred);
 }

 void
 put_rpccred(struct rpc_cred *cred)
 {
 	cred->cr_expire = jiffies;
 	if (!atomic_dec_and_test(&cred->cr_count))
 		return;
 	cred->cr_ops->crdestroy(cred);
 }

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

 	dprintk("RPC: %4d releasing %s cred %p\n",
 		task->tk_pid, task->tk_auth->au_ops->au_name, cred);

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

 u32 *
 rpcauth_marshcred(struct rpc_task *task, u32 *p)
 {
 	struct rpc_cred	*cred = task->tk_msg.rpc_cred;

 	dprintk("RPC: %4d marshaling %s cred %p\n",
 		task->tk_pid, task->tk_auth->au_ops->au_name, cred);

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

 u32 *
 rpcauth_checkverf(struct rpc_task *task, u32 *p)
 {
 	struct rpc_cred	*cred = task->tk_msg.rpc_cred;

 	dprintk("RPC: %4d validating %s cred %p\n",
 		task->tk_pid, task->tk_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,
 		u32 *data, void *obj)
 {
 	struct rpc_cred *cred = task->tk_msg.rpc_cred;

 	dprintk("RPC: %4d 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,
 		u32 *data, void *obj)
 {
 	struct rpc_cred *cred = task->tk_msg.rpc_cred;

 	dprintk("RPC: %4d 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: %4d refreshing %s cred %p\n",
 		task->tk_pid, task->tk_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)
 {
 	dprintk("RPC: %4d invalidating %s cred %p\n",
 		task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
 	spin_lock(&rpc_credcache_lock);
 	if (task->tk_msg.rpc_cred)
 		task->tk_msg.rpc_cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 	spin_unlock(&rpc_credcache_lock);
 }

 int
 rpcauth_uptodatecred(struct rpc_task *task)
 {
 	return !(task->tk_msg.rpc_cred) ||
 		(task->tk_msg.rpc_cred->cr_flags & RPCAUTH_CRED_UPTODATE);
 }
	/*
	* 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 struct rpc_authops * auth_flavors[RPC_AUTH_MAXFLAVOR] = {
	&authnull_ops, /* AUTH_NULL */
	&authunix_ops, /* AUTH_UNIX */
	NULL, /* others can be loadable modules */
	};

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

	int
	rpcauth_register(struct rpc_authops *ops)
	{
	rpc_authflavor_t flavor;

	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
	return -EINVAL;
	if (auth_flavors[flavor] != NULL)
	return -EPERM; /* what else? */
	auth_flavors[flavor] = ops;
	return 0;
	}

	int
	rpcauth_unregister(struct rpc_authops *ops)
	{
	rpc_authflavor_t flavor;

	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
	return -EINVAL;
	if (auth_flavors[flavor] != ops)
	return -EPERM; /* what else? */
	auth_flavors[flavor] = NULL;
	return 0;
	}

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

	if (flavor >= RPC_AUTH_MAXFLAVOR \|\| !(ops = auth_flavors[flavor]))
	return ERR_PTR(-EINVAL);
	auth = ops->create(clnt, pseudoflavor);
	if (IS_ERR(auth))
	return auth;
	if (clnt->cl_auth)
	rpcauth_destroy(clnt->cl_auth);
	clnt->cl_auth = auth;
	return auth;
	}

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

	static DEFINE_SPINLOCK(rpc_credcache_lock);

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

	new = (struct rpc_cred_cache )kmalloc(sizeof(new), GFP_KERNEL);
	if (!new)
	return -ENOMEM;
	for (i = 0; i < RPC_CREDCACHE_NR; i++)
	INIT_HLIST_HEAD(&new->hashtable[i]);
	new->expire = expire;
	new->nextgc = jiffies + (expire >> 1);
	auth->au_credcache = new;
	return 0;
	}

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

	while (!hlist_empty(head)) {
	cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
	hlist_del_init(&cred->cr_hash);
	put_rpccred(cred);
	}
	}

	/*
	* Clear the RPC credential cache, and delete those credentials
	* that are not referenced.
	*/
	void
	rpcauth_free_credcache(struct rpc_auth *auth)
	{
	struct rpc_cred_cache *cache = auth->au_credcache;
	HLIST_HEAD(free);
	struct hlist_node pos, next;
	struct rpc_cred *cred;
	int i;

	spin_lock(&rpc_credcache_lock);
	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
	hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
	cred = hlist_entry(pos, struct rpc_cred, cr_hash);
	__hlist_del(&cred->cr_hash);
	hlist_add_head(&cred->cr_hash, &free);
	}
	}
	spin_unlock(&rpc_credcache_lock);
	rpcauth_destroy_credlist(&free);
	}

	static void
	rpcauth_prune_expired(struct rpc_auth auth, struct rpc_cred cred, struct hlist_head *free)
	{
	if (atomic_read(&cred->cr_count) != 1)
	return;
	if (time_after(jiffies, cred->cr_expire + auth->au_credcache->expire))
	cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
	if (!(cred->cr_flags & RPCAUTH_CRED_UPTODATE)) {
	__hlist_del(&cred->cr_hash);
	hlist_add_head(&cred->cr_hash, free);
	}
	}

	/*
	* Remove stale credentials. Avoid sleeping inside the loop.
	*/
	static void
	rpcauth_gc_credcache(struct rpc_auth auth, struct hlist_head free)
	{
	struct rpc_cred_cache *cache = auth->au_credcache;
	struct hlist_node pos, next;
	struct rpc_cred *cred;
	int i;

	dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth);
	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
	hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
	cred = hlist_entry(pos, struct rpc_cred, cr_hash);
	rpcauth_prune_expired(auth, cred, free);
	}
	}
	cache->nextgc = jiffies + cache->expire;
	}

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

	if (!(taskflags & RPC_TASK_ROOTCREDS))
	nr = acred->uid & RPC_CREDCACHE_MASK;
	retry:
	spin_lock(&rpc_credcache_lock);
	if (time_before(cache->nextgc, jiffies))
	rpcauth_gc_credcache(auth, &free);
	hlist_for_each_safe(pos, next, &cache->hashtable[nr]) {
	struct rpc_cred *entry;
	entry = hlist_entry(pos, struct rpc_cred, cr_hash);
	if (entry->cr_ops->crmatch(acred, entry, taskflags)) {
	hlist_del(&entry->cr_hash);
	cred = entry;
	break;
	}
	rpcauth_prune_expired(auth, entry, &free);
	}
	if (new) {
	if (cred)
	hlist_add_head(&new->cr_hash, &free);
	else
	cred = new;
	}
	if (cred) {
	hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
	get_rpccred(cred);
	}
	spin_unlock(&rpc_credcache_lock);

	rpcauth_destroy_credlist(&free);

	if (!cred) {
	new = auth->au_ops->crcreate(auth, acred, taskflags);
	if (!IS_ERR(new)) {
	#ifdef RPC_DEBUG
	new->cr_magic = RPCAUTH_CRED_MAGIC;
	#endif
	goto retry;
	} else
	cred = new;
	}

	return (struct rpc_cred *) cred;
	}

	struct rpc_cred *
	rpcauth_lookupcred(struct rpc_auth *auth, int taskflags)
	{
	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, taskflags);
	put_group_info(acred.group_info);
	return ret;
	}

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

	dprintk("RPC: %4d looking up %s cred\n",
	task->tk_pid, task->tk_auth->au_ops->au_name);
	get_group_info(acred.group_info);
	ret = auth->au_ops->lookup_cred(auth, &acred, task->tk_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)
	{
	dprintk("RPC: %4d holding %s cred %p\n",
	task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
	if (task->tk_msg.rpc_cred)
	get_rpccred(task->tk_msg.rpc_cred);
	}

	void
	put_rpccred(struct rpc_cred *cred)
	{
	cred->cr_expire = jiffies;
	if (!atomic_dec_and_test(&cred->cr_count))
	return;
	cred->cr_ops->crdestroy(cred);
	}

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

	dprintk("RPC: %4d releasing %s cred %p\n",
	task->tk_pid, task->tk_auth->au_ops->au_name, cred);

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

	u32 *
	rpcauth_marshcred(struct rpc_task task, u32 p)
	{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %4d marshaling %s cred %p\n",
	task->tk_pid, task->tk_auth->au_ops->au_name, cred);

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

	u32 *
	rpcauth_checkverf(struct rpc_task task, u32 p)
	{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %4d validating %s cred %p\n",
	task->tk_pid, task->tk_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,
	u32 data, void obj)
	{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %4d 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,
	u32 data, void obj)
	{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %4d 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: %4d refreshing %s cred %p\n",
	task->tk_pid, task->tk_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)
	{
	dprintk("RPC: %4d invalidating %s cred %p\n",
	task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
	spin_lock(&rpc_credcache_lock);
	if (task->tk_msg.rpc_cred)
	task->tk_msg.rpc_cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
	spin_unlock(&rpc_credcache_lock);
	}

	int
	rpcauth_uptodatecred(struct rpc_task *task)
	{
	return !(task->tk_msg.rpc_cred) \|\|
	(task->tk_msg.rpc_cred->cr_flags & RPCAUTH_CRED_UPTODATE);
	}