[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_generic_cred(struct auth_cred *acred, int flags, gfp_t gfp)
{
	return rpcauth_lookup_credcache(&generic_auth, acred, flags, gfp);
}
EXPORT_SYMBOL_GPL(rpc_lookup_generic_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, GFP_KERNEL);
}

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

	gcred = kmalloc(sizeof(*gcred), gfp);
	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
c065d229 WAA	41	struct rpc_cred *
	42	rpc_lookup_generic_cred(struct auth_cred *acred, int flags, gfp_t gfp)
	43	{
	44	return rpcauth_lookup_credcache(&generic_auth, acred, flags, gfp);
	45	}
	46	EXPORT_SYMBOL_GPL(rpc_lookup_generic_cred);
	47
bd956080 N	48	struct rpc_cred *rpc_lookup_cred_nonblock(void)
	49	{
	50	return rpcauth_lookupcred(&generic_auth, RPCAUTH_LOOKUP_RCU);
	51	}
	52	EXPORT_SYMBOL_GPL(rpc_lookup_cred_nonblock);
	53
7c67db3a TM	54	/*
	55	* Public call interface for looking up machine creds.
	56	*/
68c97153	57	struct rpc_cred rpc_lookup_machine_cred(const char service_name)
7c67db3a TM	58	{
7c67db3a TM	59	struct auth_cred acred = {
b4528762 TM	60	.uid = RPC_MACHINE_CRED_USERID,
b4528762 TM	61	.gid = RPC_MACHINE_CRED_GROUPID,
68c97153	62	.principal = service_name,
7c67db3a TM	63	.machine_cred = 1,
	64	};
	65
68c97153 TM	66	dprintk("RPC: looking up machine cred for service %s\n",
68c97153 TM	67	service_name);
7c67db3a TM	68	return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
	69	}
	70	EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);
	71
8572b8e2 TM	72	static struct rpc_cred generic_bind_cred(struct rpc_task task,
8572b8e2 TM	73	struct rpc_cred *cred, int lookupflags)
5c691044 TM	74	{
	75	struct rpc_auth *auth = task->tk_client->cl_auth;
	76	struct auth_cred *acred = &container_of(cred, struct generic_cred, gc_base)->acred;
5c691044	77
8572b8e2	78	return auth->au_ops->lookup_cred(auth, acred, lookupflags);
5c691044 TM	79	}
5c691044 TM	80
9a559efd TM	81	/*
	82	* Lookup generic creds for current process
	83	*/
	84	static struct rpc_cred *
	85	generic_lookup_cred(struct rpc_auth auth, struct auth_cred acred, int flags)
	86	{
3c6e0bc8	87	return rpcauth_lookup_credcache(&generic_auth, acred, flags, GFP_KERNEL);
9a559efd TM	88	}
	89
	90	static struct rpc_cred *
3c6e0bc8	91	generic_create_cred(struct rpc_auth auth, struct auth_cred acred, int flags, gfp_t gfp)
9a559efd TM	92	{
	93	struct generic_cred *gcred;
	94
3c6e0bc8	95	gcred = kmalloc(sizeof(*gcred), gfp);
9a559efd TM	96	if (gcred == NULL)
	97	return ERR_PTR(-ENOMEM);
	98
	99	rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
	100	gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
	101
	102	gcred->acred.uid = acred->uid;
	103	gcred->acred.gid = acred->gid;
	104	gcred->acred.group_info = acred->group_info;
4de6caa2	105	gcred->acred.ac_flags = 0;
9a559efd TM	106	if (gcred->acred.group_info != NULL)
9a559efd TM	107	get_group_info(gcred->acred.group_info);
7c67db3a	108	gcred->acred.machine_cred = acred->machine_cred;
875ad3f8	109	gcred->acred.principal = acred->principal;
9a559efd	110
7c67db3a TM	111	dprintk("RPC: allocated %s cred %p for uid %d gid %d\n",
7c67db3a TM	112	gcred->acred.machine_cred ? "machine" : "generic",
cdba321e EB	113	gcred,
	114	from_kuid(&init_user_ns, acred->uid),
	115	from_kgid(&init_user_ns, acred->gid));
9a559efd TM	116	return &gcred->gc_base;
	117	}
	118
	119	static void
	120	generic_free_cred(struct rpc_cred *cred)
	121	{
	122	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
	123
	124	dprintk("RPC: generic_free_cred %p\n", gcred);
	125	if (gcred->acred.group_info != NULL)
	126	put_group_info(gcred->acred.group_info);
	127	kfree(gcred);
	128	}
	129
	130	static void
	131	generic_free_cred_callback(struct rcu_head *head)
	132	{
	133	struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
	134	generic_free_cred(cred);
	135	}
	136
	137	static void
	138	generic_destroy_cred(struct rpc_cred *cred)
	139	{
	140	call_rcu(&cred->cr_rcu, generic_free_cred_callback);
	141	}
	142
875ad3f8 TM	143	static int
	144	machine_cred_match(struct auth_cred acred, struct generic_cred gcred, int flags)
	145	{
	146	if (!gcred->acred.machine_cred \|\|
	147	gcred->acred.principal != acred->principal \|\|
0b4d51b0 EB	148	!uid_eq(gcred->acred.uid, acred->uid) \|\|
0b4d51b0 EB	149	!gid_eq(gcred->acred.gid, acred->gid))
875ad3f8 TM	150	return 0;
	151	return 1;
	152	}
	153
9a559efd TM	154	/*
	155	* Match credentials against current process creds.
	156	*/
	157	static int
	158	generic_match(struct auth_cred acred, struct rpc_cred cred, int flags)
	159	{
	160	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
23918b03	161	int i;
9a559efd	162
875ad3f8 TM	163	if (acred->machine_cred)
	164	return machine_cred_match(acred, gcred, flags);
	165
0b4d51b0 EB	166	if (!uid_eq(gcred->acred.uid, acred->uid) \|\|
0b4d51b0 EB	167	!gid_eq(gcred->acred.gid, acred->gid) \|\|
875ad3f8	168	gcred->acred.machine_cred != 0)
23918b03 TM	169	goto out_nomatch;
	170
	171	/* Optimisation in the case where pointers are identical... */
	172	if (gcred->acred.group_info == acred->group_info)
	173	goto out_match;
	174
	175	/* Slow path... */
	176	if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
	177	goto out_nomatch;
	178	for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
ae2975bc EB	179	if (!gid_eq(GROUP_AT(gcred->acred.group_info, i),
ae2975bc EB	180	GROUP_AT(acred->group_info, i)))
23918b03 TM	181	goto out_nomatch;
	182	}
	183	out_match:
9a559efd	184	return 1;
23918b03 TM	185	out_nomatch:
23918b03 TM	186	return 0;
9a559efd TM	187	}
9a559efd TM	188
5d8d9a4d	189	int __init rpc_init_generic_auth(void)
9a559efd	190	{
5d8d9a4d	191	return rpcauth_init_credcache(&generic_auth);
9a559efd TM	192	}
9a559efd TM	193
c135e84a	194	void rpc_destroy_generic_auth(void)
9a559efd	195	{
5d8d9a4d	196	rpcauth_destroy_credcache(&generic_auth);
9a559efd TM	197	}
9a559efd TM	198
4de6caa2 AA	199	/*
	200	* Test the the current time (now) against the underlying credential key expiry
	201	* minus a timeout and setup notification.
	202	*
	203	* The normal case:
	204	* If 'now' is before the key expiry minus RPC_KEY_EXPIRE_TIMEO, set
	205	* the RPC_CRED_NOTIFY_TIMEOUT flag to setup the underlying credential
	206	* rpc_credops crmatch routine to notify this generic cred when it's key
	207	* expiration is within RPC_KEY_EXPIRE_TIMEO, and return 0.
	208	*
	209	* The error case:
	210	* If the underlying cred lookup fails, return -EACCES.
	211	*
	212	* The 'almost' error case:
	213	* If 'now' is within key expiry minus RPC_KEY_EXPIRE_TIMEO, but not within
	214	* key expiry minus RPC_KEY_EXPIRE_FAIL, set the RPC_CRED_EXPIRE_SOON bit
	215	* on the acred ac_flags and return 0.
	216	*/
	217	static int
	218	generic_key_timeout(struct rpc_auth auth, struct rpc_cred cred)
	219	{
	220	struct auth_cred *acred = &container_of(cred, struct generic_cred,
	221	gc_base)->acred;
	222	struct rpc_cred *tcred;
	223	int ret = 0;
	224
	225
	226	/* Fast track for non crkey_timeout (no key) underlying credentials */
	227	if (test_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags))
	228	return 0;
	229
	230	/* Fast track for the normal case */
	231	if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags))
	232	return 0;
	233
	234	/* lookup_cred either returns a valid referenced rpc_cred, or PTR_ERR */
	235	tcred = auth->au_ops->lookup_cred(auth, acred, 0);
	236	if (IS_ERR(tcred))
	237	return -EACCES;
	238
	239	if (!tcred->cr_ops->crkey_timeout) {
	240	set_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags);
	241	ret = 0;
	242	goto out_put;
	243	}
	244
	245	/* Test for the almost error case */
	246	ret = tcred->cr_ops->crkey_timeout(tcred);
	247	if (ret != 0) {
	248	set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
	249	ret = 0;
	250	} else {
	251	/* In case underlying cred key has been reset */
	252	if (test_and_clear_bit(RPC_CRED_KEY_EXPIRE_SOON,
	253	&acred->ac_flags))
	254	dprintk("RPC: UID %d Credential key reset\n",
13429305	255	from_kuid(&init_user_ns, tcred->cr_uid));
4de6caa2 AA	256	/* set up fasttrack for the normal case */
	257	set_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
	258	}
	259
	260	out_put:
	261	put_rpccred(tcred);
	262	return ret;
	263	}
	264
9a559efd TM	265	static const struct rpc_authops generic_auth_ops = {
9a559efd TM	266	.owner = THIS_MODULE,
9a559efd	267	.au_name = "Generic",
9a559efd TM	268	.lookup_cred = generic_lookup_cred,
9a559efd TM	269	.crcreate = generic_create_cred,
4de6caa2	270	.key_timeout = generic_key_timeout,
9a559efd TM	271	};
	272
	273	static struct rpc_auth generic_auth = {
	274	.au_ops = &generic_auth_ops,
	275	.au_count = ATOMIC_INIT(0),
9a559efd TM	276	};
9a559efd TM	277
4de6caa2 AA	278	static bool generic_key_to_expire(struct rpc_cred *cred)
	279	{
	280	struct auth_cred *acred = &container_of(cred, struct generic_cred,
	281	gc_base)->acred;
	282	bool ret;
	283
	284	get_rpccred(cred);
	285	ret = test_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
	286	put_rpccred(cred);
	287
	288	return ret;
	289	}
	290
9a559efd TM	291	static const struct rpc_credops generic_credops = {
	292	.cr_name = "Generic cred",
	293	.crdestroy = generic_destroy_cred,
5c691044	294	.crbind = generic_bind_cred,
9a559efd	295	.crmatch = generic_match,
4de6caa2	296	.crkey_to_expire = generic_key_to_expire,
9a559efd	297	};