[linux-2.6-block.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>

#if IS_ENABLED(CONFIG_SUNRPC_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);

struct rpc_cred *rpc_lookup_cred_nonblock(void)
{
	return rpcauth_lookupcred(&generic_auth, RPCAUTH_LOOKUP_RCU);
}
EXPORT_SYMBOL_GPL(rpc_lookup_cred_nonblock);

/*
 * 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
f895b252	17	#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
9a559efd TM	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
bd956080 N	41	struct rpc_cred *rpc_lookup_cred_nonblock(void)
	42	{
	43	return rpcauth_lookupcred(&generic_auth, RPCAUTH_LOOKUP_RCU);
	44	}
	45	EXPORT_SYMBOL_GPL(rpc_lookup_cred_nonblock);
	46
7c67db3a TM	47	/*
	48	* Public call interface for looking up machine creds.
	49	*/
68c97153	50	struct rpc_cred rpc_lookup_machine_cred(const char service_name)
7c67db3a TM	51	{
7c67db3a TM	52	struct auth_cred acred = {
b4528762 TM	53	.uid = RPC_MACHINE_CRED_USERID,
b4528762 TM	54	.gid = RPC_MACHINE_CRED_GROUPID,
68c97153	55	.principal = service_name,
7c67db3a TM	56	.machine_cred = 1,
	57	};
	58
68c97153 TM	59	dprintk("RPC: looking up machine cred for service %s\n",
68c97153 TM	60	service_name);
7c67db3a TM	61	return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
	62	}
	63	EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);
	64
8572b8e2 TM	65	static struct rpc_cred generic_bind_cred(struct rpc_task task,
8572b8e2 TM	66	struct rpc_cred *cred, int lookupflags)
5c691044 TM	67	{
	68	struct rpc_auth *auth = task->tk_client->cl_auth;
	69	struct auth_cred *acred = &container_of(cred, struct generic_cred, gc_base)->acred;
5c691044	70
8572b8e2	71	return auth->au_ops->lookup_cred(auth, acred, lookupflags);
5c691044 TM	72	}
5c691044 TM	73
9a559efd TM	74	/*
	75	* Lookup generic creds for current process
	76	*/
	77	static struct rpc_cred *
	78	generic_lookup_cred(struct rpc_auth auth, struct auth_cred acred, int flags)
	79	{
	80	return rpcauth_lookup_credcache(&generic_auth, acred, flags);
	81	}
	82
	83	static struct rpc_cred *
	84	generic_create_cred(struct rpc_auth auth, struct auth_cred acred, int flags)
	85	{
	86	struct generic_cred *gcred;
	87
	88	gcred = kmalloc(sizeof(*gcred), GFP_KERNEL);
	89	if (gcred == NULL)
	90	return ERR_PTR(-ENOMEM);
	91
	92	rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
	93	gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
	94
	95	gcred->acred.uid = acred->uid;
	96	gcred->acred.gid = acred->gid;
	97	gcred->acred.group_info = acred->group_info;
4de6caa2	98	gcred->acred.ac_flags = 0;
9a559efd TM	99	if (gcred->acred.group_info != NULL)
9a559efd TM	100	get_group_info(gcred->acred.group_info);
7c67db3a	101	gcred->acred.machine_cred = acred->machine_cred;
875ad3f8	102	gcred->acred.principal = acred->principal;
9a559efd	103
7c67db3a TM	104	dprintk("RPC: allocated %s cred %p for uid %d gid %d\n",
7c67db3a TM	105	gcred->acred.machine_cred ? "machine" : "generic",
cdba321e EB	106	gcred,
	107	from_kuid(&init_user_ns, acred->uid),
	108	from_kgid(&init_user_ns, acred->gid));
9a559efd TM	109	return &gcred->gc_base;
	110	}
	111
	112	static void
	113	generic_free_cred(struct rpc_cred *cred)
	114	{
	115	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
	116
	117	dprintk("RPC: generic_free_cred %p\n", gcred);
	118	if (gcred->acred.group_info != NULL)
	119	put_group_info(gcred->acred.group_info);
	120	kfree(gcred);
	121	}
	122
	123	static void
	124	generic_free_cred_callback(struct rcu_head *head)
	125	{
	126	struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
	127	generic_free_cred(cred);
	128	}
	129
	130	static void
	131	generic_destroy_cred(struct rpc_cred *cred)
	132	{
	133	call_rcu(&cred->cr_rcu, generic_free_cred_callback);
	134	}
	135
875ad3f8 TM	136	static int
	137	machine_cred_match(struct auth_cred acred, struct generic_cred gcred, int flags)
	138	{
	139	if (!gcred->acred.machine_cred \|\|
	140	gcred->acred.principal != acred->principal \|\|
0b4d51b0 EB	141	!uid_eq(gcred->acred.uid, acred->uid) \|\|
0b4d51b0 EB	142	!gid_eq(gcred->acred.gid, acred->gid))
875ad3f8 TM	143	return 0;
	144	return 1;
	145	}
	146
9a559efd TM	147	/*
	148	* Match credentials against current process creds.
	149	*/
	150	static int
	151	generic_match(struct auth_cred acred, struct rpc_cred cred, int flags)
	152	{
	153	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
23918b03	154	int i;
9a559efd	155
875ad3f8 TM	156	if (acred->machine_cred)
	157	return machine_cred_match(acred, gcred, flags);
	158
0b4d51b0 EB	159	if (!uid_eq(gcred->acred.uid, acred->uid) \|\|
0b4d51b0 EB	160	!gid_eq(gcred->acred.gid, acred->gid) \|\|
875ad3f8	161	gcred->acred.machine_cred != 0)
23918b03 TM	162	goto out_nomatch;
	163
	164	/* Optimisation in the case where pointers are identical... */
	165	if (gcred->acred.group_info == acred->group_info)
	166	goto out_match;
	167
	168	/* Slow path... */
	169	if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
	170	goto out_nomatch;
	171	for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
ae2975bc EB	172	if (!gid_eq(GROUP_AT(gcred->acred.group_info, i),
ae2975bc EB	173	GROUP_AT(acred->group_info, i)))
23918b03 TM	174	goto out_nomatch;
	175	}
	176	out_match:
9a559efd	177	return 1;
23918b03 TM	178	out_nomatch:
23918b03 TM	179	return 0;
9a559efd TM	180	}
9a559efd TM	181
5d8d9a4d	182	int __init rpc_init_generic_auth(void)
9a559efd	183	{
5d8d9a4d	184	return rpcauth_init_credcache(&generic_auth);
9a559efd TM	185	}
9a559efd TM	186
c135e84a	187	void rpc_destroy_generic_auth(void)
9a559efd	188	{
5d8d9a4d	189	rpcauth_destroy_credcache(&generic_auth);
9a559efd TM	190	}
9a559efd TM	191
4de6caa2 AA	192	/*
	193	* Test the the current time (now) against the underlying credential key expiry
	194	* minus a timeout and setup notification.
	195	*
	196	* The normal case:
	197	* If 'now' is before the key expiry minus RPC_KEY_EXPIRE_TIMEO, set
	198	* the RPC_CRED_NOTIFY_TIMEOUT flag to setup the underlying credential
	199	* rpc_credops crmatch routine to notify this generic cred when it's key
	200	* expiration is within RPC_KEY_EXPIRE_TIMEO, and return 0.
	201	*
	202	* The error case:
	203	* If the underlying cred lookup fails, return -EACCES.
	204	*
	205	* The 'almost' error case:
	206	* If 'now' is within key expiry minus RPC_KEY_EXPIRE_TIMEO, but not within
	207	* key expiry minus RPC_KEY_EXPIRE_FAIL, set the RPC_CRED_EXPIRE_SOON bit
	208	* on the acred ac_flags and return 0.
	209	*/
	210	static int
	211	generic_key_timeout(struct rpc_auth auth, struct rpc_cred cred)
	212	{
	213	struct auth_cred *acred = &container_of(cred, struct generic_cred,
	214	gc_base)->acred;
	215	struct rpc_cred *tcred;
	216	int ret = 0;
	217
	218
	219	/* Fast track for non crkey_timeout (no key) underlying credentials */
	220	if (test_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags))
	221	return 0;
	222
	223	/* Fast track for the normal case */
	224	if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags))
	225	return 0;
	226
	227	/* lookup_cred either returns a valid referenced rpc_cred, or PTR_ERR */
	228	tcred = auth->au_ops->lookup_cred(auth, acred, 0);
	229	if (IS_ERR(tcred))
	230	return -EACCES;
	231
	232	if (!tcred->cr_ops->crkey_timeout) {
	233	set_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags);
	234	ret = 0;
	235	goto out_put;
	236	}
	237
	238	/* Test for the almost error case */
	239	ret = tcred->cr_ops->crkey_timeout(tcred);
	240	if (ret != 0) {
	241	set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
	242	ret = 0;
	243	} else {
	244	/* In case underlying cred key has been reset */
	245	if (test_and_clear_bit(RPC_CRED_KEY_EXPIRE_SOON,
	246	&acred->ac_flags))
	247	dprintk("RPC: UID %d Credential key reset\n",
13429305	248	from_kuid(&init_user_ns, tcred->cr_uid));
4de6caa2 AA	249	/* set up fasttrack for the normal case */
	250	set_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
	251	}
	252
	253	out_put:
	254	put_rpccred(tcred);
	255	return ret;
	256	}
	257
9a559efd TM	258	static const struct rpc_authops generic_auth_ops = {
9a559efd TM	259	.owner = THIS_MODULE,
9a559efd	260	.au_name = "Generic",
9a559efd TM	261	.lookup_cred = generic_lookup_cred,
9a559efd TM	262	.crcreate = generic_create_cred,
4de6caa2	263	.key_timeout = generic_key_timeout,
9a559efd TM	264	};
	265
	266	static struct rpc_auth generic_auth = {
	267	.au_ops = &generic_auth_ops,
	268	.au_count = ATOMIC_INIT(0),
9a559efd TM	269	};
9a559efd TM	270
4de6caa2 AA	271	static bool generic_key_to_expire(struct rpc_cred *cred)
	272	{
	273	struct auth_cred *acred = &container_of(cred, struct generic_cred,
	274	gc_base)->acred;
	275	bool ret;
	276
	277	get_rpccred(cred);
	278	ret = test_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
	279	put_rpccred(cred);
	280
	281	return ret;
	282	}
	283
9a559efd TM	284	static const struct rpc_credops generic_credops = {
	285	.cr_name = "Generic cred",
	286	.crdestroy = generic_destroy_cred,
5c691044	287	.crbind = generic_bind_cred,
9a559efd	288	.crmatch = generic_match,
4de6caa2	289	.crkey_to_expire = generic_key_to_expire,
9a559efd	290	};