[net-next-2.6.git] / net / sunrpc / auth_unix.c

/*
 * linux/net/sunrpc/auth_unix.c
 *
 * UNIX-style authentication; no AUTH_SHORT support
 *
 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

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

#define NFS_NGROUPS	16

struct unx_cred {
	struct rpc_cred		uc_base;
	gid_t			uc_gid;
	gid_t			uc_gids[NFS_NGROUPS];
};
#define uc_uid			uc_base.cr_uid

#define UNX_WRITESLACK		(21 + (UNX_MAXNODENAME >> 2))

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_AUTH
#endif

static struct rpc_auth		unix_auth;
static const struct rpc_credops	unix_credops;

static struct rpc_auth *
unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
{
	dprintk("RPC:       creating UNIX authenticator for client %p\n",
			clnt);
	atomic_inc(&unix_auth.au_count);
	return &unix_auth;
}

static void
unx_destroy(struct rpc_auth *auth)
{
	dprintk("RPC:       destroying UNIX authenticator %p\n", auth);
	rpcauth_clear_credcache(auth->au_credcache);
}

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

static struct rpc_cred *
unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
{
	struct unx_cred	*cred;
	unsigned int groups = 0;
	unsigned int i;

	dprintk("RPC:       allocating UNIX cred for uid %d gid %d\n",
			acred->uid, acred->gid);

	if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
		return ERR_PTR(-ENOMEM);

	rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
	cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;

	if (acred->group_info != NULL)
		groups = acred->group_info->ngroups;
	if (groups > NFS_NGROUPS)
		groups = NFS_NGROUPS;

	cred->uc_gid = acred->gid;
	for (i = 0; i < groups; i++)
		cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
	if (i < NFS_NGROUPS)
		cred->uc_gids[i] = NOGROUP;

	return &cred->uc_base;
}

static void
unx_free_cred(struct unx_cred *unx_cred)
{
	dprintk("RPC:       unx_free_cred %p\n", unx_cred);
	kfree(unx_cred);
}

static void
unx_free_cred_callback(struct rcu_head *head)
{
	struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
	unx_free_cred(unx_cred);
}

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

/*
 * Match credentials against current process creds.
 * The root_override argument takes care of cases where the caller may
 * request root creds (e.g. for NFS swapping).
 */
static int
unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
{
	struct unx_cred	*cred = container_of(rcred, struct unx_cred, uc_base);
	unsigned int groups = 0;
	unsigned int i;


	if (cred->uc_uid != acred->uid || cred->uc_gid != acred->gid)
		return 0;

	if (acred->group_info != NULL)
		groups = acred->group_info->ngroups;
	if (groups > NFS_NGROUPS)
		groups = NFS_NGROUPS;
	for (i = 0; i < groups ; i++)
		if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
			return 0;
	return 1;
}

/*
 * Marshal credentials.
 * Maybe we should keep a cached credential for performance reasons.
 */
static __be32 *
unx_marshal(struct rpc_task *task, __be32 *p)
{
	struct rpc_clnt	*clnt = task->tk_client;
	struct unx_cred	*cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
	__be32		*base, *hold;
	int		i;

	*p++ = htonl(RPC_AUTH_UNIX);
	base = p++;
	*p++ = htonl(jiffies/HZ);

	/*
	 * Copy the UTS nodename captured when the client was created.
	 */
	p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);

	*p++ = htonl((u32) cred->uc_uid);
	*p++ = htonl((u32) cred->uc_gid);
	hold = p++;
	for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
		*p++ = htonl((u32) cred->uc_gids[i]);
	*hold = htonl(p - hold - 1);		/* gid array length */
	*base = htonl((p - base - 1) << 2);	/* cred length */

	*p++ = htonl(RPC_AUTH_NULL);
	*p++ = htonl(0);

	return p;
}

/*
 * Refresh credentials. This is a no-op for AUTH_UNIX
 */
static int
unx_refresh(struct rpc_task *task)
{
	set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
	return 0;
}

static __be32 *
unx_validate(struct rpc_task *task, __be32 *p)
{
	rpc_authflavor_t	flavor;
	u32			size;

	flavor = ntohl(*p++);
	if (flavor != RPC_AUTH_NULL &&
	    flavor != RPC_AUTH_UNIX &&
	    flavor != RPC_AUTH_SHORT) {
		printk("RPC: bad verf flavor: %u\n", flavor);
		return NULL;
	}

	size = ntohl(*p++);
	if (size > RPC_MAX_AUTH_SIZE) {
		printk("RPC: giant verf size: %u\n", size);
		return NULL;
	}
	task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
	p += (size >> 2);

	return p;
}

int __init rpc_init_authunix(void)
{
	return rpcauth_init_credcache(&unix_auth);
}

void rpc_destroy_authunix(void)
{
	rpcauth_destroy_credcache(&unix_auth);
}

const struct rpc_authops authunix_ops = {
	.owner		= THIS_MODULE,
	.au_flavor	= RPC_AUTH_UNIX,
	.au_name	= "UNIX",
	.create		= unx_create,
	.destroy	= unx_destroy,
	.lookup_cred	= unx_lookup_cred,
	.crcreate	= unx_create_cred,
};

static
struct rpc_auth		unix_auth = {
	.au_cslack	= UNX_WRITESLACK,
	.au_rslack	= 2,			/* assume AUTH_NULL verf */
	.au_ops		= &authunix_ops,
	.au_flavor	= RPC_AUTH_UNIX,
	.au_count	= ATOMIC_INIT(0),
};

static
const struct rpc_credops unix_credops = {
	.cr_name	= "AUTH_UNIX",
	.crdestroy	= unx_destroy_cred,
	.crbind		= rpcauth_generic_bind_cred,
	.crmatch	= unx_match,
	.crmarshal	= unx_marshal,
	.crrefresh	= unx_refresh,
	.crvalidate	= unx_validate,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/net/sunrpc/auth_unix.c
	3	*
	4	* UNIX-style authentication; no AUTH_SHORT support
	5	*
	6	* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
	7	*/
	8
5a0e3ad6	9	#include <linux/slab.h>
1da177e4 LT	10	#include <linux/types.h>
	11	#include <linux/sched.h>
	12	#include <linux/module.h>
1da177e4 LT	13	#include <linux/sunrpc/clnt.h>
	14	#include <linux/sunrpc/auth.h>
	15
	16	#define NFS_NGROUPS 16
	17
	18	struct unx_cred {
	19	struct rpc_cred uc_base;
	20	gid_t uc_gid;
	21	gid_t uc_gids[NFS_NGROUPS];
	22	};
	23	#define uc_uid uc_base.cr_uid
1da177e4	24
1da177e4 LT	25	#define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2))
	26
	27	#ifdef RPC_DEBUG
	28	# define RPCDBG_FACILITY RPCDBG_AUTH
	29	#endif
	30
	31	static struct rpc_auth unix_auth;
f1c0a861	32	static const struct rpc_credops unix_credops;
1da177e4 LT	33
	34	static struct rpc_auth *
	35	unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
	36	{
46121cf7 CL	37	dprintk("RPC: creating UNIX authenticator for client %p\n",
46121cf7 CL	38	clnt);
f5c2187c	39	atomic_inc(&unix_auth.au_count);
1da177e4 LT	40	return &unix_auth;
	41	}
	42
	43	static void
	44	unx_destroy(struct rpc_auth *auth)
	45	{
46121cf7	46	dprintk("RPC: destroying UNIX authenticator %p\n", auth);
3ab9bb72	47	rpcauth_clear_credcache(auth->au_credcache);
1da177e4 LT	48	}
	49
	50	/*
	51	* Lookup AUTH_UNIX creds for current process
	52	*/
	53	static struct rpc_cred *
	54	unx_lookup_cred(struct rpc_auth auth, struct auth_cred acred, int flags)
	55	{
	56	return rpcauth_lookup_credcache(auth, acred, flags);
	57	}
	58
	59	static struct rpc_cred *
	60	unx_create_cred(struct rpc_auth auth, struct auth_cred acred, int flags)
	61	{
	62	struct unx_cred *cred;
af093835 TM	63	unsigned int groups = 0;
af093835 TM	64	unsigned int i;
1da177e4	65
46121cf7 CL	66	dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
46121cf7 CL	67	acred->uid, acred->gid);
1da177e4	68
0f38b873	69	if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
1da177e4 LT	70	return ERR_PTR(-ENOMEM);
1da177e4 LT	71
5fe4755e	72	rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
fc432dd9	73	cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
af093835 TM	74
	75	if (acred->group_info != NULL)
	76	groups = acred->group_info->ngroups;
	77	if (groups > NFS_NGROUPS)
	78	groups = NFS_NGROUPS;
	79
	80	cred->uc_gid = acred->gid;
	81	for (i = 0; i < groups; i++)
	82	cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
	83	if (i < NFS_NGROUPS)
	84	cred->uc_gids[i] = NOGROUP;
1da177e4	85
696e38df	86	return &cred->uc_base;
1da177e4 LT	87	}
	88
	89	static void
31be5bf1	90	unx_free_cred(struct unx_cred *unx_cred)
1da177e4	91	{
31be5bf1 TM	92	dprintk("RPC: unx_free_cred %p\n", unx_cred);
	93	kfree(unx_cred);
	94	}
696e38df	95
31be5bf1 TM	96	static void
	97	unx_free_cred_callback(struct rcu_head *head)
	98	{
	99	struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
	100	unx_free_cred(unx_cred);
	101	}
	102
	103	static void
	104	unx_destroy_cred(struct rpc_cred *cred)
	105	{
	106	call_rcu(&cred->cr_rcu, unx_free_cred_callback);
1da177e4 LT	107	}
	108
	109	/*
	110	* Match credentials against current process creds.
	111	* The root_override argument takes care of cases where the caller may
	112	* request root creds (e.g. for NFS swapping).
	113	*/
	114	static int
8a317760	115	unx_match(struct auth_cred acred, struct rpc_cred rcred, int flags)
1da177e4	116	{
696e38df	117	struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
af093835 TM	118	unsigned int groups = 0;
af093835 TM	119	unsigned int i;
1da177e4	120
1da177e4	121
af093835 TM	122	if (cred->uc_uid != acred->uid \|\| cred->uc_gid != acred->gid)
af093835 TM	123	return 0;
1da177e4	124
af093835	125	if (acred->group_info != NULL)
1da177e4	126	groups = acred->group_info->ngroups;
af093835 TM	127	if (groups > NFS_NGROUPS)
	128	groups = NFS_NGROUPS;
	129	for (i = 0; i < groups ; i++)
	130	if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
	131	return 0;
	132	return 1;
1da177e4 LT	133	}
	134
	135	/*
	136	* Marshal credentials.
	137	* Maybe we should keep a cached credential for performance reasons.
	138	*/
d8ed029d AD	139	static __be32 *
d8ed029d AD	140	unx_marshal(struct rpc_task task, __be32 p)
1da177e4 LT	141	{
1da177e4 LT	142	struct rpc_clnt *clnt = task->tk_client;
a17c2153	143	struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
d8ed029d	144	__be32 base, hold;
1da177e4 LT	145	int i;
	146
	147	*p++ = htonl(RPC_AUTH_UNIX);
	148	base = p++;
	149	*p++ = htonl(jiffies/HZ);
	150
	151	/*
	152	* Copy the UTS nodename captured when the client was created.
	153	*/
	154	p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
	155
	156	*p++ = htonl((u32) cred->uc_uid);
	157	*p++ = htonl((u32) cred->uc_gid);
	158	hold = p++;
	159	for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
	160	*p++ = htonl((u32) cred->uc_gids[i]);
	161	hold = htonl(p - hold - 1); / gid array length */
	162	base = htonl((p - base - 1) << 2); / cred length */
	163
	164	*p++ = htonl(RPC_AUTH_NULL);
	165	*p++ = htonl(0);
	166
	167	return p;
	168	}
	169
	170	/*
	171	* Refresh credentials. This is a no-op for AUTH_UNIX
	172	*/
	173	static int
	174	unx_refresh(struct rpc_task *task)
	175	{
a17c2153	176	set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
1da177e4 LT	177	return 0;
	178	}
	179
d8ed029d AD	180	static __be32 *
d8ed029d AD	181	unx_validate(struct rpc_task task, __be32 p)
1da177e4 LT	182	{
	183	rpc_authflavor_t flavor;
	184	u32 size;
	185
	186	flavor = ntohl(*p++);
	187	if (flavor != RPC_AUTH_NULL &&
	188	flavor != RPC_AUTH_UNIX &&
	189	flavor != RPC_AUTH_SHORT) {
	190	printk("RPC: bad verf flavor: %u\n", flavor);
	191	return NULL;
	192	}
	193
	194	size = ntohl(*p++);
	195	if (size > RPC_MAX_AUTH_SIZE) {
	196	printk("RPC: giant verf size: %u\n", size);
	197	return NULL;
	198	}
a17c2153	199	task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
1da177e4 LT	200	p += (size >> 2);
	201
	202	return p;
	203	}
	204
5d8d9a4d	205	int __init rpc_init_authunix(void)
9499b434	206	{
5d8d9a4d TM	207	return rpcauth_init_credcache(&unix_auth);
	208	}
	209
	210	void rpc_destroy_authunix(void)
	211	{
	212	rpcauth_destroy_credcache(&unix_auth);
9499b434 TM	213	}
9499b434 TM	214
f1c0a861	215	const struct rpc_authops authunix_ops = {
1da177e4 LT	216	.owner = THIS_MODULE,
1da177e4 LT	217	.au_flavor = RPC_AUTH_UNIX,
1da177e4	218	.au_name = "UNIX",
1da177e4 LT	219	.create = unx_create,
	220	.destroy = unx_destroy,
	221	.lookup_cred = unx_lookup_cred,
	222	.crcreate = unx_create_cred,
	223	};
	224
1da177e4 LT	225	static
	226	struct rpc_auth unix_auth = {
	227	.au_cslack = UNX_WRITESLACK,
	228	.au_rslack = 2, /* assume AUTH_NULL verf */
	229	.au_ops = &authunix_ops,
81039f1f	230	.au_flavor = RPC_AUTH_UNIX,
1da177e4	231	.au_count = ATOMIC_INIT(0),
1da177e4 LT	232	};
	233
	234	static
f1c0a861	235	const struct rpc_credops unix_credops = {
1da177e4 LT	236	.cr_name = "AUTH_UNIX",
1da177e4 LT	237	.crdestroy = unx_destroy_cred,
5c691044	238	.crbind = rpcauth_generic_bind_cred,
1da177e4 LT	239	.crmatch = unx_match,
	240	.crmarshal = unx_marshal,
	241	.crrefresh = unx_refresh,
	242	.crvalidate = unx_validate,
	243	};