[deliverable/linux.git] / net / sunrpc / auth_generic.c

/*
 * Generic RPC credential
 *
 * Copyright (C) 2008, Trond Myklebust <Trond.Myklebust@netapp.com>
 */

#include <linux/err.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/debug.h>
#include <linux/sunrpc/sched.h>

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_AUTH
#endif

#define RPC_MACHINE_CRED_USERID		GLOBAL_ROOT_UID
#define RPC_MACHINE_CRED_GROUPID	GLOBAL_ROOT_GID

struct generic_cred {
	struct rpc_cred gc_base;
	struct auth_cred acred;
};

static struct rpc_auth generic_auth;
static const struct rpc_credops generic_credops;

/*
 * Public call interface
 */
struct rpc_cred *rpc_lookup_cred(void)
{
	return rpcauth_lookupcred(&generic_auth, 0);
}
EXPORT_SYMBOL_GPL(rpc_lookup_cred);

/*
 * Public call interface for looking up machine creds.
 */
struct rpc_cred *rpc_lookup_machine_cred(const char *service_name)
{
	struct auth_cred acred = {
		.uid = RPC_MACHINE_CRED_USERID,
		.gid = RPC_MACHINE_CRED_GROUPID,
		.principal = service_name,
		.machine_cred = 1,
	};

	dprintk("RPC:       looking up machine cred for service %s\n",
			service_name);
	return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
}
EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);

static struct rpc_cred *generic_bind_cred(struct rpc_task *task,
		struct rpc_cred *cred, int lookupflags)
{
	struct rpc_auth *auth = task->tk_client->cl_auth;
	struct auth_cred *acred = &container_of(cred, struct generic_cred, gc_base)->acred;

	return auth->au_ops->lookup_cred(auth, acred, lookupflags);
}

/*
 * Lookup generic creds for current process
 */
static struct rpc_cred *
generic_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
{
	return rpcauth_lookup_credcache(&generic_auth, acred, flags);
}

static struct rpc_cred *
generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
{
	struct generic_cred *gcred;

	gcred = kmalloc(sizeof(*gcred), GFP_KERNEL);
	if (gcred == NULL)
		return ERR_PTR(-ENOMEM);

	rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
	gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;

	gcred->acred.uid = acred->uid;
	gcred->acred.gid = acred->gid;
	gcred->acred.group_info = acred->group_info;
	gcred->acred.ac_flags = 0;
	if (gcred->acred.group_info != NULL)
		get_group_info(gcred->acred.group_info);
	gcred->acred.machine_cred = acred->machine_cred;
	gcred->acred.principal = acred->principal;

	dprintk("RPC:       allocated %s cred %p for uid %d gid %d\n",
			gcred->acred.machine_cred ? "machine" : "generic",
			gcred,
			from_kuid(&init_user_ns, acred->uid),
			from_kgid(&init_user_ns, acred->gid));
	return &gcred->gc_base;
}

static void
generic_free_cred(struct rpc_cred *cred)
{
	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);

	dprintk("RPC:       generic_free_cred %p\n", gcred);
	if (gcred->acred.group_info != NULL)
		put_group_info(gcred->acred.group_info);
	kfree(gcred);
}

static void
generic_free_cred_callback(struct rcu_head *head)
{
	struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
	generic_free_cred(cred);
}

static void
generic_destroy_cred(struct rpc_cred *cred)
{
	call_rcu(&cred->cr_rcu, generic_free_cred_callback);
}

static int
machine_cred_match(struct auth_cred *acred, struct generic_cred *gcred, int flags)
{
	if (!gcred->acred.machine_cred ||
	    gcred->acred.principal != acred->principal ||
	    !uid_eq(gcred->acred.uid, acred->uid) ||
	    !gid_eq(gcred->acred.gid, acred->gid))
		return 0;
	return 1;
}

/*
 * Match credentials against current process creds.
 */
static int
generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
{
	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
	int i;

	if (acred->machine_cred)
		return machine_cred_match(acred, gcred, flags);

	if (!uid_eq(gcred->acred.uid, acred->uid) ||
	    !gid_eq(gcred->acred.gid, acred->gid) ||
	    gcred->acred.machine_cred != 0)
		goto out_nomatch;

	/* Optimisation in the case where pointers are identical... */
	if (gcred->acred.group_info == acred->group_info)
		goto out_match;

	/* Slow path... */
	if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
		goto out_nomatch;
	for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
		if (!gid_eq(GROUP_AT(gcred->acred.group_info, i),
				GROUP_AT(acred->group_info, i)))
			goto out_nomatch;
	}
out_match:
	return 1;
out_nomatch:
	return 0;
}

int __init rpc_init_generic_auth(void)
{
	return rpcauth_init_credcache(&generic_auth);
}

void rpc_destroy_generic_auth(void)
{
	rpcauth_destroy_credcache(&generic_auth);
}

/*
 * Test the the current time (now) against the underlying credential key expiry
 * minus a timeout and setup notification.
 *
 * The normal case:
 * If 'now' is before the key expiry minus RPC_KEY_EXPIRE_TIMEO, set
 * the RPC_CRED_NOTIFY_TIMEOUT flag to setup the underlying credential
 * rpc_credops crmatch routine to notify this generic cred when it's key
 * expiration is within RPC_KEY_EXPIRE_TIMEO, and return 0.
 *
 * The error case:
 * If the underlying cred lookup fails, return -EACCES.
 *
 * The 'almost' error case:
 * If 'now' is within key expiry minus RPC_KEY_EXPIRE_TIMEO, but not within
 * key expiry minus RPC_KEY_EXPIRE_FAIL, set the RPC_CRED_EXPIRE_SOON bit
 * on the acred ac_flags and return 0.
 */
static int
generic_key_timeout(struct rpc_auth *auth, struct rpc_cred *cred)
{
	struct auth_cred *acred = &container_of(cred, struct generic_cred,
						gc_base)->acred;
	struct rpc_cred *tcred;
	int ret = 0;


	/* Fast track for non crkey_timeout (no key) underlying credentials */
	if (test_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags))
		return 0;

	/* Fast track for the normal case */
	if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags))
		return 0;

	/* lookup_cred either returns a valid referenced rpc_cred, or PTR_ERR */
	tcred = auth->au_ops->lookup_cred(auth, acred, 0);
	if (IS_ERR(tcred))
		return -EACCES;

	if (!tcred->cr_ops->crkey_timeout) {
		set_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags);
		ret = 0;
		goto out_put;
	}

	/* Test for the almost error case */
	ret = tcred->cr_ops->crkey_timeout(tcred);
	if (ret != 0) {
		set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
		ret = 0;
	} else {
		/* In case underlying cred key has been reset */
		if (test_and_clear_bit(RPC_CRED_KEY_EXPIRE_SOON,
					&acred->ac_flags))
			dprintk("RPC:        UID %d Credential key reset\n",
				from_kuid(&init_user_ns, tcred->cr_uid));
		/* set up fasttrack for the normal case */
		set_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
	}

out_put:
	put_rpccred(tcred);
	return ret;
}

static const struct rpc_authops generic_auth_ops = {
	.owner = THIS_MODULE,
	.au_name = "Generic",
	.lookup_cred = generic_lookup_cred,
	.crcreate = generic_create_cred,
	.key_timeout = generic_key_timeout,
};

static struct rpc_auth generic_auth = {
	.au_ops = &generic_auth_ops,
	.au_count = ATOMIC_INIT(0),
};

static bool generic_key_to_expire(struct rpc_cred *cred)
{
	struct auth_cred *acred = &container_of(cred, struct generic_cred,
						gc_base)->acred;
	bool ret;

	get_rpccred(cred);
	ret = test_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
	put_rpccred(cred);

	return ret;
}

static const struct rpc_credops generic_credops = {
	.cr_name = "Generic cred",
	.crdestroy = generic_destroy_cred,
	.crbind = generic_bind_cred,
	.crmatch = generic_match,
	.crkey_to_expire = generic_key_to_expire,
};
Commit	Line	Data
9a559efd TM	1	/*
	2	* Generic RPC credential
	3	*
	4	* Copyright (C) 2008, Trond Myklebust <Trond.Myklebust@netapp.com>
	5	*/
	6
	7	#include <linux/err.h>
5a0e3ad6	8	#include <linux/slab.h>
9a559efd TM	9	#include <linux/types.h>
	10	#include <linux/module.h>
	11	#include <linux/sched.h>
	12	#include <linux/sunrpc/auth.h>
	13	#include <linux/sunrpc/clnt.h>
	14	#include <linux/sunrpc/debug.h>
	15	#include <linux/sunrpc/sched.h>
	16
	17	#ifdef RPC_DEBUG
	18	# define RPCDBG_FACILITY RPCDBG_AUTH
	19	#endif
	20
bf37f794 EB	21	#define RPC_MACHINE_CRED_USERID GLOBAL_ROOT_UID
bf37f794 EB	22	#define RPC_MACHINE_CRED_GROUPID GLOBAL_ROOT_GID
7c67db3a	23
9a559efd TM	24	struct generic_cred {
	25	struct rpc_cred gc_base;
	26	struct auth_cred acred;
	27	};
	28
	29	static struct rpc_auth generic_auth;
9a559efd TM	30	static const struct rpc_credops generic_credops;
	31
	32	/*
	33	* Public call interface
	34	*/
	35	struct rpc_cred *rpc_lookup_cred(void)
	36	{
	37	return rpcauth_lookupcred(&generic_auth, 0);
	38	}
	39	EXPORT_SYMBOL_GPL(rpc_lookup_cred);
	40
7c67db3a TM	41	/*
	42	* Public call interface for looking up machine creds.
	43	*/
68c97153	44	struct rpc_cred rpc_lookup_machine_cred(const char service_name)
7c67db3a TM	45	{
7c67db3a TM	46	struct auth_cred acred = {
b4528762 TM	47	.uid = RPC_MACHINE_CRED_USERID,
b4528762 TM	48	.gid = RPC_MACHINE_CRED_GROUPID,
68c97153	49	.principal = service_name,
7c67db3a TM	50	.machine_cred = 1,
	51	};
	52
68c97153 TM	53	dprintk("RPC: looking up machine cred for service %s\n",
68c97153 TM	54	service_name);
7c67db3a TM	55	return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
	56	}
	57	EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);
	58
8572b8e2 TM	59	static struct rpc_cred generic_bind_cred(struct rpc_task task,
8572b8e2 TM	60	struct rpc_cred *cred, int lookupflags)
5c691044 TM	61	{
	62	struct rpc_auth *auth = task->tk_client->cl_auth;
	63	struct auth_cred *acred = &container_of(cred, struct generic_cred, gc_base)->acred;
5c691044	64
8572b8e2	65	return auth->au_ops->lookup_cred(auth, acred, lookupflags);
5c691044 TM	66	}
5c691044 TM	67
9a559efd TM	68	/*
	69	* Lookup generic creds for current process
	70	*/
	71	static struct rpc_cred *
	72	generic_lookup_cred(struct rpc_auth auth, struct auth_cred acred, int flags)
	73	{
	74	return rpcauth_lookup_credcache(&generic_auth, acred, flags);
	75	}
	76
	77	static struct rpc_cred *
	78	generic_create_cred(struct rpc_auth auth, struct auth_cred acred, int flags)
	79	{
	80	struct generic_cred *gcred;
	81
	82	gcred = kmalloc(sizeof(*gcred), GFP_KERNEL);
	83	if (gcred == NULL)
	84	return ERR_PTR(-ENOMEM);
	85
	86	rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
	87	gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
	88
	89	gcred->acred.uid = acred->uid;
	90	gcred->acred.gid = acred->gid;
	91	gcred->acred.group_info = acred->group_info;
4de6caa2	92	gcred->acred.ac_flags = 0;
9a559efd TM	93	if (gcred->acred.group_info != NULL)
9a559efd TM	94	get_group_info(gcred->acred.group_info);
7c67db3a	95	gcred->acred.machine_cred = acred->machine_cred;
875ad3f8	96	gcred->acred.principal = acred->principal;
9a559efd	97
7c67db3a TM	98	dprintk("RPC: allocated %s cred %p for uid %d gid %d\n",
7c67db3a TM	99	gcred->acred.machine_cred ? "machine" : "generic",
cdba321e EB	100	gcred,
	101	from_kuid(&init_user_ns, acred->uid),
	102	from_kgid(&init_user_ns, acred->gid));
9a559efd TM	103	return &gcred->gc_base;
	104	}
	105
	106	static void
	107	generic_free_cred(struct rpc_cred *cred)
	108	{
	109	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
	110
	111	dprintk("RPC: generic_free_cred %p\n", gcred);
	112	if (gcred->acred.group_info != NULL)
	113	put_group_info(gcred->acred.group_info);
	114	kfree(gcred);
	115	}
	116
	117	static void
	118	generic_free_cred_callback(struct rcu_head *head)
	119	{
	120	struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
	121	generic_free_cred(cred);
	122	}
	123
	124	static void
	125	generic_destroy_cred(struct rpc_cred *cred)
	126	{
	127	call_rcu(&cred->cr_rcu, generic_free_cred_callback);
	128	}
	129
875ad3f8 TM	130	static int
	131	machine_cred_match(struct auth_cred acred, struct generic_cred gcred, int flags)
	132	{
	133	if (!gcred->acred.machine_cred \|\|
	134	gcred->acred.principal != acred->principal \|\|
0b4d51b0 EB	135	!uid_eq(gcred->acred.uid, acred->uid) \|\|
0b4d51b0 EB	136	!gid_eq(gcred->acred.gid, acred->gid))
875ad3f8 TM	137	return 0;
	138	return 1;
	139	}
	140
9a559efd TM	141	/*
	142	* Match credentials against current process creds.
	143	*/
	144	static int
	145	generic_match(struct auth_cred acred, struct rpc_cred cred, int flags)
	146	{
	147	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
23918b03	148	int i;
9a559efd	149
875ad3f8 TM	150	if (acred->machine_cred)
	151	return machine_cred_match(acred, gcred, flags);
	152
0b4d51b0 EB	153	if (!uid_eq(gcred->acred.uid, acred->uid) \|\|
0b4d51b0 EB	154	!gid_eq(gcred->acred.gid, acred->gid) \|\|
875ad3f8	155	gcred->acred.machine_cred != 0)
23918b03 TM	156	goto out_nomatch;
	157
	158	/* Optimisation in the case where pointers are identical... */
	159	if (gcred->acred.group_info == acred->group_info)
	160	goto out_match;
	161
	162	/* Slow path... */
	163	if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
	164	goto out_nomatch;
	165	for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
ae2975bc EB	166	if (!gid_eq(GROUP_AT(gcred->acred.group_info, i),
ae2975bc EB	167	GROUP_AT(acred->group_info, i)))
23918b03 TM	168	goto out_nomatch;
	169	}
	170	out_match:
9a559efd	171	return 1;
23918b03 TM	172	out_nomatch:
23918b03 TM	173	return 0;
9a559efd TM	174	}
9a559efd TM	175
5d8d9a4d	176	int __init rpc_init_generic_auth(void)
9a559efd	177	{
5d8d9a4d	178	return rpcauth_init_credcache(&generic_auth);
9a559efd TM	179	}
9a559efd TM	180
c135e84a	181	void rpc_destroy_generic_auth(void)
9a559efd	182	{
5d8d9a4d	183	rpcauth_destroy_credcache(&generic_auth);
9a559efd TM	184	}
9a559efd TM	185
4de6caa2 AA	186	/*
	187	* Test the the current time (now) against the underlying credential key expiry
	188	* minus a timeout and setup notification.
	189	*
	190	* The normal case:
	191	* If 'now' is before the key expiry minus RPC_KEY_EXPIRE_TIMEO, set
	192	* the RPC_CRED_NOTIFY_TIMEOUT flag to setup the underlying credential
	193	* rpc_credops crmatch routine to notify this generic cred when it's key
	194	* expiration is within RPC_KEY_EXPIRE_TIMEO, and return 0.
	195	*
	196	* The error case:
	197	* If the underlying cred lookup fails, return -EACCES.
	198	*
	199	* The 'almost' error case:
	200	* If 'now' is within key expiry minus RPC_KEY_EXPIRE_TIMEO, but not within
	201	* key expiry minus RPC_KEY_EXPIRE_FAIL, set the RPC_CRED_EXPIRE_SOON bit
	202	* on the acred ac_flags and return 0.
	203	*/
	204	static int
	205	generic_key_timeout(struct rpc_auth auth, struct rpc_cred cred)
	206	{
	207	struct auth_cred *acred = &container_of(cred, struct generic_cred,
	208	gc_base)->acred;
	209	struct rpc_cred *tcred;
	210	int ret = 0;
	211
	212
	213	/* Fast track for non crkey_timeout (no key) underlying credentials */
	214	if (test_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags))
	215	return 0;
	216
	217	/* Fast track for the normal case */
	218	if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags))
	219	return 0;
	220
	221	/* lookup_cred either returns a valid referenced rpc_cred, or PTR_ERR */
	222	tcred = auth->au_ops->lookup_cred(auth, acred, 0);
	223	if (IS_ERR(tcred))
	224	return -EACCES;
	225
	226	if (!tcred->cr_ops->crkey_timeout) {
	227	set_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags);
	228	ret = 0;
	229	goto out_put;
	230	}
	231
	232	/* Test for the almost error case */
	233	ret = tcred->cr_ops->crkey_timeout(tcred);
	234	if (ret != 0) {
	235	set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
	236	ret = 0;
	237	} else {
	238	/* In case underlying cred key has been reset */
	239	if (test_and_clear_bit(RPC_CRED_KEY_EXPIRE_SOON,
	240	&acred->ac_flags))
	241	dprintk("RPC: UID %d Credential key reset\n",
13429305	242	from_kuid(&init_user_ns, tcred->cr_uid));
4de6caa2 AA	243	/* set up fasttrack for the normal case */
	244	set_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
	245	}
	246
	247	out_put:
	248	put_rpccred(tcred);
	249	return ret;
	250	}
	251
9a559efd TM	252	static const struct rpc_authops generic_auth_ops = {
9a559efd TM	253	.owner = THIS_MODULE,
9a559efd	254	.au_name = "Generic",
9a559efd TM	255	.lookup_cred = generic_lookup_cred,
9a559efd TM	256	.crcreate = generic_create_cred,
4de6caa2	257	.key_timeout = generic_key_timeout,
9a559efd TM	258	};
	259
	260	static struct rpc_auth generic_auth = {
	261	.au_ops = &generic_auth_ops,
	262	.au_count = ATOMIC_INIT(0),
9a559efd TM	263	};
9a559efd TM	264
4de6caa2 AA	265	static bool generic_key_to_expire(struct rpc_cred *cred)
	266	{
	267	struct auth_cred *acred = &container_of(cred, struct generic_cred,
	268	gc_base)->acred;
	269	bool ret;
	270
	271	get_rpccred(cred);
	272	ret = test_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
	273	put_rpccred(cred);
	274
	275	return ret;
	276	}
	277
9a559efd TM	278	static const struct rpc_credops generic_credops = {
	279	.cr_name = "Generic cred",
	280	.crdestroy = generic_destroy_cred,
5c691044	281	.crbind = generic_bind_cred,
9a559efd	282	.crmatch = generic_match,
4de6caa2	283	.crkey_to_expire = generic_key_to_expire,
9a559efd	284	};