[GitHub/moto-9609/android_kernel_motorola_exynos9610.git] / net / sunrpc / auth_unix.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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>
#include <linux/user_namespace.h>

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

#if IS_ENABLED(CONFIG_SUNRPC_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_auth_create_args *args, struct rpc_clnt *clnt)
{
	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);
}

static int
unx_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 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, GFP_NOFS);
}

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

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

	if (!(cred = kmalloc(sizeof(*cred), gfp)))
		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 > UNX_NGROUPS)
		groups = UNX_NGROUPS;

	cred->uc_gid = acred->gid;
	for (i = 0; i < groups; i++)
		cred->uc_gids[i] = acred->group_info->gid[i];
	if (i < UNX_NGROUPS)
		cred->uc_gids[i] = INVALID_GID;

	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 (!uid_eq(cred->uc_uid, acred->uid) || !gid_eq(cred->uc_gid, acred->gid))
		return 0;

	if (acred->group_info != NULL)
		groups = acred->group_info->ngroups;
	if (groups > UNX_NGROUPS)
		groups = UNX_NGROUPS;
	for (i = 0; i < groups ; i++)
		if (!gid_eq(cred->uc_gids[i], acred->group_info->gid[i]))
			return 0;
	if (groups < UNX_NGROUPS && gid_valid(cred->uc_gids[groups]))
		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) from_kuid(&init_user_ns, cred->uc_uid));
	*p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid));
	hold = p++;
	for (i = 0; i < UNX_NGROUPS && gid_valid(cred->uc_gids[i]); i++)
		*p++ = htonl((u32) from_kgid(&init_user_ns, 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 ERR_PTR(-EIO);
	}

	size = ntohl(*p++);
	if (size > RPC_MAX_AUTH_SIZE) {
		printk("RPC: giant verf size: %u\n", size);
		return ERR_PTR(-EIO);
	}
	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,
	.hash_cred	= unx_hash_cred,
	.lookup_cred	= unx_lookup_cred,
	.crcreate	= unx_create_cred,
};

static
struct rpc_auth		unix_auth = {
	.au_cslack	= UNX_CALLSLACK,
	.au_rslack	= NUL_REPLYSLACK,
	.au_flags	= RPCAUTH_AUTH_NO_CRKEY_TIMEOUT,
	.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
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* linux/net/sunrpc/auth_unix.c
	4	*
	5	* UNIX-style authentication; no AUTH_SHORT support
	6	*
	7	* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
	8	*/
	9
	10	#include <linux/slab.h>
	11	#include <linux/types.h>
	12	#include <linux/sched.h>
	13	#include <linux/module.h>
	14	#include <linux/sunrpc/clnt.h>
	15	#include <linux/sunrpc/auth.h>
	16	#include <linux/user_namespace.h>
	17
	18	struct unx_cred {
	19	struct rpc_cred uc_base;
	20	kgid_t uc_gid;
	21	kgid_t uc_gids[UNX_NGROUPS];
	22	};
	23	#define uc_uid uc_base.cr_uid
	24
	25	#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
	26	# define RPCDBG_FACILITY RPCDBG_AUTH
	27	#endif
	28
	29	static struct rpc_auth unix_auth;
	30	static const struct rpc_credops unix_credops;
	31
	32	static struct rpc_auth *
	33	unx_create(struct rpc_auth_create_args args, struct rpc_clnt clnt)
	34	{
	35	dprintk("RPC: creating UNIX authenticator for client %p\n",
	36	clnt);
	37	atomic_inc(&unix_auth.au_count);
	38	return &unix_auth;
	39	}
	40
	41	static void
	42	unx_destroy(struct rpc_auth *auth)
	43	{
	44	dprintk("RPC: destroying UNIX authenticator %p\n", auth);
	45	rpcauth_clear_credcache(auth->au_credcache);
	46	}
	47
	48	static int
	49	unx_hash_cred(struct auth_cred *acred, unsigned int hashbits)
	50	{
	51	return hash_64(from_kgid(&init_user_ns, acred->gid) \|
	52	((u64)from_kuid(&init_user_ns, acred->uid) <<
	53	(sizeof(gid_t) * 8)), hashbits);
	54	}
	55
	56	/*
	57	* Lookup AUTH_UNIX creds for current process
	58	*/
	59	static struct rpc_cred *
	60	unx_lookup_cred(struct rpc_auth auth, struct auth_cred acred, int flags)
	61	{
	62	return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
	63	}
	64
	65	static struct rpc_cred *
	66	unx_create_cred(struct rpc_auth auth, struct auth_cred acred, int flags, gfp_t gfp)
	67	{
	68	struct unx_cred *cred;
	69	unsigned int groups = 0;
	70	unsigned int i;
	71
	72	dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
	73	from_kuid(&init_user_ns, acred->uid),
	74	from_kgid(&init_user_ns, acred->gid));
	75
	76	if (!(cred = kmalloc(sizeof(*cred), gfp)))
	77	return ERR_PTR(-ENOMEM);
	78
	79	rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
	80	cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
	81
	82	if (acred->group_info != NULL)
	83	groups = acred->group_info->ngroups;
	84	if (groups > UNX_NGROUPS)
	85	groups = UNX_NGROUPS;
	86
	87	cred->uc_gid = acred->gid;
	88	for (i = 0; i < groups; i++)
	89	cred->uc_gids[i] = acred->group_info->gid[i];
	90	if (i < UNX_NGROUPS)
	91	cred->uc_gids[i] = INVALID_GID;
	92
	93	return &cred->uc_base;
	94	}
	95
	96	static void
	97	unx_free_cred(struct unx_cred *unx_cred)
	98	{
	99	dprintk("RPC: unx_free_cred %p\n", unx_cred);
	100	kfree(unx_cred);
	101	}
	102
	103	static void
	104	unx_free_cred_callback(struct rcu_head *head)
	105	{
	106	struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
	107	unx_free_cred(unx_cred);
	108	}
	109
	110	static void
	111	unx_destroy_cred(struct rpc_cred *cred)
	112	{
	113	call_rcu(&cred->cr_rcu, unx_free_cred_callback);
	114	}
	115
	116	/*
	117	* Match credentials against current process creds.
	118	* The root_override argument takes care of cases where the caller may
	119	* request root creds (e.g. for NFS swapping).
	120	*/
	121	static int
	122	unx_match(struct auth_cred acred, struct rpc_cred rcred, int flags)
	123	{
	124	struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
	125	unsigned int groups = 0;
	126	unsigned int i;
	127
	128
	129	if (!uid_eq(cred->uc_uid, acred->uid) \|\| !gid_eq(cred->uc_gid, acred->gid))
	130	return 0;
	131
	132	if (acred->group_info != NULL)
	133	groups = acred->group_info->ngroups;
	134	if (groups > UNX_NGROUPS)
	135	groups = UNX_NGROUPS;
	136	for (i = 0; i < groups ; i++)
	137	if (!gid_eq(cred->uc_gids[i], acred->group_info->gid[i]))
	138	return 0;
	139	if (groups < UNX_NGROUPS && gid_valid(cred->uc_gids[groups]))
	140	return 0;
	141	return 1;
	142	}
	143
	144	/*
	145	* Marshal credentials.
	146	* Maybe we should keep a cached credential for performance reasons.
	147	*/
	148	static __be32 *
	149	unx_marshal(struct rpc_task task, __be32 p)
	150	{
	151	struct rpc_clnt *clnt = task->tk_client;
	152	struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
	153	__be32 base, hold;
	154	int i;
	155
	156	*p++ = htonl(RPC_AUTH_UNIX);
	157	base = p++;
	158	*p++ = htonl(jiffies/HZ);
	159
	160	/*
	161	* Copy the UTS nodename captured when the client was created.
	162	*/
	163	p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
	164
	165	*p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid));
	166	*p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid));
	167	hold = p++;
	168	for (i = 0; i < UNX_NGROUPS && gid_valid(cred->uc_gids[i]); i++)
	169	*p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gids[i]));
	170	hold = htonl(p - hold - 1); / gid array length */
	171	base = htonl((p - base - 1) << 2); / cred length */
	172
	173	*p++ = htonl(RPC_AUTH_NULL);
	174	*p++ = htonl(0);
	175
	176	return p;
	177	}
	178
	179	/*
	180	* Refresh credentials. This is a no-op for AUTH_UNIX
	181	*/
	182	static int
	183	unx_refresh(struct rpc_task *task)
	184	{
	185	set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
	186	return 0;
	187	}
	188
	189	static __be32 *
	190	unx_validate(struct rpc_task task, __be32 p)
	191	{
	192	rpc_authflavor_t flavor;
	193	u32 size;
	194
	195	flavor = ntohl(*p++);
	196	if (flavor != RPC_AUTH_NULL &&
	197	flavor != RPC_AUTH_UNIX &&
	198	flavor != RPC_AUTH_SHORT) {
	199	printk("RPC: bad verf flavor: %u\n", flavor);
	200	return ERR_PTR(-EIO);
	201	}
	202
	203	size = ntohl(*p++);
	204	if (size > RPC_MAX_AUTH_SIZE) {
	205	printk("RPC: giant verf size: %u\n", size);
	206	return ERR_PTR(-EIO);
	207	}
	208	task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
	209	p += (size >> 2);
	210
	211	return p;
	212	}
	213
	214	int __init rpc_init_authunix(void)
	215	{
	216	return rpcauth_init_credcache(&unix_auth);
	217	}
	218
	219	void rpc_destroy_authunix(void)
	220	{
	221	rpcauth_destroy_credcache(&unix_auth);
	222	}
	223
	224	const struct rpc_authops authunix_ops = {
	225	.owner = THIS_MODULE,
	226	.au_flavor = RPC_AUTH_UNIX,
	227	.au_name = "UNIX",
	228	.create = unx_create,
	229	.destroy = unx_destroy,
	230	.hash_cred = unx_hash_cred,
	231	.lookup_cred = unx_lookup_cred,
	232	.crcreate = unx_create_cred,
	233	};
	234
	235	static
	236	struct rpc_auth unix_auth = {
	237	.au_cslack = UNX_CALLSLACK,
	238	.au_rslack = NUL_REPLYSLACK,
	239	.au_flags = RPCAUTH_AUTH_NO_CRKEY_TIMEOUT,
	240	.au_ops = &authunix_ops,
	241	.au_flavor = RPC_AUTH_UNIX,
	242	.au_count = ATOMIC_INIT(0),
	243	};
	244
	245	static
	246	const struct rpc_credops unix_credops = {
	247	.cr_name = "AUTH_UNIX",
	248	.crdestroy = unx_destroy_cred,
	249	.crbind = rpcauth_generic_bind_cred,
	250	.crmatch = unx_match,
	251	.crmarshal = unx_marshal,
	252	.crrefresh = unx_refresh,
	253	.crvalidate = unx_validate,
	254	};