[mirror_ubuntu-artful-kernel.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);
}

static int
generic_hash_cred(struct auth_cred *acred, unsigned int hashbits)
{
	return hash_64(from_kgid(&init_user_ns, acred->gid) |
		((u64)from_kuid(&init_user_ns, acred->uid) <<
			(sizeof(gid_t) * 8)), hashbits);
}

/*
 * 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(gcred->acred.group_info->gid[i],
				acred->group_info->gid[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 (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
		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;

	/* 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);
	}

	put_rpccred(tcred);
	return ret;
}

static const struct rpc_authops generic_auth_ops = {
	.owner = THIS_MODULE,
	.au_name = "Generic",
	.hash_cred = generic_hash_cred,
	.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
18028c96 FS	81	static int
	82	generic_hash_cred(struct auth_cred *acred, unsigned int hashbits)
	83	{
	84	return hash_64(from_kgid(&init_user_ns, acred->gid) \|
	85	((u64)from_kuid(&init_user_ns, acred->uid) <<
	86	(sizeof(gid_t) * 8)), hashbits);
	87	}
	88
9a559efd TM	89	/*
	90	* Lookup generic creds for current process
	91	*/
	92	static struct rpc_cred *
	93	generic_lookup_cred(struct rpc_auth auth, struct auth_cred acred, int flags)
	94	{
3c6e0bc8	95	return rpcauth_lookup_credcache(&generic_auth, acred, flags, GFP_KERNEL);
9a559efd TM	96	}
	97
	98	static struct rpc_cred *
3c6e0bc8	99	generic_create_cred(struct rpc_auth auth, struct auth_cred acred, int flags, gfp_t gfp)
9a559efd TM	100	{
	101	struct generic_cred *gcred;
	102
3c6e0bc8	103	gcred = kmalloc(sizeof(*gcred), gfp);
9a559efd TM	104	if (gcred == NULL)
	105	return ERR_PTR(-ENOMEM);
	106
	107	rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
	108	gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
	109
	110	gcred->acred.uid = acred->uid;
	111	gcred->acred.gid = acred->gid;
	112	gcred->acred.group_info = acred->group_info;
4de6caa2	113	gcred->acred.ac_flags = 0;
9a559efd TM	114	if (gcred->acred.group_info != NULL)
9a559efd TM	115	get_group_info(gcred->acred.group_info);
7c67db3a	116	gcred->acred.machine_cred = acred->machine_cred;
875ad3f8	117	gcred->acred.principal = acred->principal;
9a559efd	118
7c67db3a TM	119	dprintk("RPC: allocated %s cred %p for uid %d gid %d\n",
7c67db3a TM	120	gcred->acred.machine_cred ? "machine" : "generic",
cdba321e EB	121	gcred,
	122	from_kuid(&init_user_ns, acred->uid),
	123	from_kgid(&init_user_ns, acred->gid));
9a559efd TM	124	return &gcred->gc_base;
	125	}
	126
	127	static void
	128	generic_free_cred(struct rpc_cred *cred)
	129	{
	130	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
	131
	132	dprintk("RPC: generic_free_cred %p\n", gcred);
	133	if (gcred->acred.group_info != NULL)
	134	put_group_info(gcred->acred.group_info);
	135	kfree(gcred);
	136	}
	137
	138	static void
	139	generic_free_cred_callback(struct rcu_head *head)
	140	{
	141	struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
	142	generic_free_cred(cred);
	143	}
	144
	145	static void
	146	generic_destroy_cred(struct rpc_cred *cred)
	147	{
	148	call_rcu(&cred->cr_rcu, generic_free_cred_callback);
	149	}
	150
875ad3f8 TM	151	static int
	152	machine_cred_match(struct auth_cred acred, struct generic_cred gcred, int flags)
	153	{
	154	if (!gcred->acred.machine_cred \|\|
	155	gcred->acred.principal != acred->principal \|\|
0b4d51b0 EB	156	!uid_eq(gcred->acred.uid, acred->uid) \|\|
0b4d51b0 EB	157	!gid_eq(gcred->acred.gid, acred->gid))
875ad3f8 TM	158	return 0;
	159	return 1;
	160	}
	161
9a559efd TM	162	/*
	163	* Match credentials against current process creds.
	164	*/
	165	static int
	166	generic_match(struct auth_cred acred, struct rpc_cred cred, int flags)
	167	{
	168	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
23918b03	169	int i;
9a559efd	170
875ad3f8 TM	171	if (acred->machine_cred)
	172	return machine_cred_match(acred, gcred, flags);
	173
0b4d51b0 EB	174	if (!uid_eq(gcred->acred.uid, acred->uid) \|\|
0b4d51b0 EB	175	!gid_eq(gcred->acred.gid, acred->gid) \|\|
875ad3f8	176	gcred->acred.machine_cred != 0)
23918b03 TM	177	goto out_nomatch;
	178
	179	/* Optimisation in the case where pointers are identical... */
	180	if (gcred->acred.group_info == acred->group_info)
	181	goto out_match;
	182
	183	/* Slow path... */
	184	if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
	185	goto out_nomatch;
	186	for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
81243eac AD	187	if (!gid_eq(gcred->acred.group_info->gid[i],
81243eac AD	188	acred->group_info->gid[i]))
23918b03 TM	189	goto out_nomatch;
	190	}
	191	out_match:
9a559efd	192	return 1;
23918b03 TM	193	out_nomatch:
23918b03 TM	194	return 0;
9a559efd TM	195	}
9a559efd TM	196
5d8d9a4d	197	int __init rpc_init_generic_auth(void)
9a559efd	198	{
5d8d9a4d	199	return rpcauth_init_credcache(&generic_auth);
9a559efd TM	200	}
9a559efd TM	201
c135e84a	202	void rpc_destroy_generic_auth(void)
9a559efd	203	{
5d8d9a4d	204	rpcauth_destroy_credcache(&generic_auth);
9a559efd TM	205	}
9a559efd TM	206
4de6caa2 AA	207	/*
	208	* Test the the current time (now) against the underlying credential key expiry
	209	* minus a timeout and setup notification.
	210	*
	211	* The normal case:
	212	* If 'now' is before the key expiry minus RPC_KEY_EXPIRE_TIMEO, set
	213	* the RPC_CRED_NOTIFY_TIMEOUT flag to setup the underlying credential
	214	* rpc_credops crmatch routine to notify this generic cred when it's key
	215	* expiration is within RPC_KEY_EXPIRE_TIMEO, and return 0.
	216	*
	217	* The error case:
	218	* If the underlying cred lookup fails, return -EACCES.
	219	*
	220	* The 'almost' error case:
	221	* If 'now' is within key expiry minus RPC_KEY_EXPIRE_TIMEO, but not within
	222	* key expiry minus RPC_KEY_EXPIRE_FAIL, set the RPC_CRED_EXPIRE_SOON bit
	223	* on the acred ac_flags and return 0.
	224	*/
	225	static int
	226	generic_key_timeout(struct rpc_auth auth, struct rpc_cred cred)
	227	{
	228	struct auth_cred *acred = &container_of(cred, struct generic_cred,
	229	gc_base)->acred;
	230	struct rpc_cred *tcred;
	231	int ret = 0;
	232
	233
	234	/* Fast track for non crkey_timeout (no key) underlying credentials */
ce52914e	235	if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
4de6caa2 AA	236	return 0;
	237
	238	/* Fast track for the normal case */
	239	if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags))
	240	return 0;
	241
	242	/* lookup_cred either returns a valid referenced rpc_cred, or PTR_ERR */
	243	tcred = auth->au_ops->lookup_cred(auth, acred, 0);
	244	if (IS_ERR(tcred))
	245	return -EACCES;
	246
4de6caa2 AA	247	/* Test for the almost error case */
	248	ret = tcred->cr_ops->crkey_timeout(tcred);
	249	if (ret != 0) {
	250	set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
	251	ret = 0;
	252	} else {
	253	/* In case underlying cred key has been reset */
	254	if (test_and_clear_bit(RPC_CRED_KEY_EXPIRE_SOON,
	255	&acred->ac_flags))
	256	dprintk("RPC: UID %d Credential key reset\n",
13429305	257	from_kuid(&init_user_ns, tcred->cr_uid));
4de6caa2 AA	258	/* set up fasttrack for the normal case */
	259	set_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
	260	}
	261
4de6caa2 AA	262	put_rpccred(tcred);
	263	return ret;
	264	}
	265
9a559efd TM	266	static const struct rpc_authops generic_auth_ops = {
9a559efd TM	267	.owner = THIS_MODULE,
9a559efd	268	.au_name = "Generic",
18028c96	269	.hash_cred = generic_hash_cred,
9a559efd TM	270	.lookup_cred = generic_lookup_cred,
9a559efd TM	271	.crcreate = generic_create_cred,
4de6caa2	272	.key_timeout = generic_key_timeout,
9a559efd TM	273	};
	274
	275	static struct rpc_auth generic_auth = {
	276	.au_ops = &generic_auth_ops,
	277	.au_count = ATOMIC_INIT(0),
9a559efd TM	278	};
9a559efd TM	279
4de6caa2 AA	280	static bool generic_key_to_expire(struct rpc_cred *cred)
	281	{
	282	struct auth_cred *acred = &container_of(cred, struct generic_cred,
	283	gc_base)->acred;
	284	bool ret;
	285
	286	get_rpccred(cred);
	287	ret = test_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
	288	put_rpccred(cred);
	289
	290	return ret;
	291	}
	292
9a559efd TM	293	static const struct rpc_credops generic_credops = {
	294	.cr_name = "Generic cred",
	295	.crdestroy = generic_destroy_cred,
5c691044	296	.crbind = generic_bind_cred,
9a559efd	297	.crmatch = generic_match,
4de6caa2	298	.crkey_to_expire = generic_key_to_expire,
9a559efd	299	};