summaryrefslogtreecommitdiff
path: root/include/linux/sunrpc/auth.h
blob: b1bc62ba20a26d56df1d43794023a60e80e1ffef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/*
 * linux/include/linux/sunrpc/auth.h
 *
 * Declarations for the RPC client authentication machinery.
 *
 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

#ifndef _LINUX_SUNRPC_AUTH_H
#define _LINUX_SUNRPC_AUTH_H

#ifdef __KERNEL__

#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/xdr.h>

#include <linux/atomic.h>
#include <linux/rcupdate.h>
#include <linux/uidgid.h>
#include <linux/utsname.h>

/*
 * Maximum size of AUTH_NONE authentication information, in XDR words.
 */
#define NUL_CALLSLACK	(4)
#define NUL_REPLYSLACK	(2)

/*
 * Size of the nodename buffer. RFC1831 specifies a hard limit of 255 bytes,
 * but Linux hostnames are actually limited to __NEW_UTS_LEN bytes.
 */
#define UNX_MAXNODENAME	__NEW_UTS_LEN
#define UNX_CALLSLACK	(21 + XDR_QUADLEN(UNX_MAXNODENAME))

struct rpcsec_gss_info;

/* auth_cred ac_flags bits */
enum {
	RPC_CRED_KEY_EXPIRE_SOON = 1, /* underlying cred key will expire soon */
	RPC_CRED_NOTIFY_TIMEOUT = 2,   /* nofity generic cred when underlying
					key will expire soon */
};

/* Work around the lack of a VFS credential */
struct auth_cred {
	kuid_t	uid;
	kgid_t	gid;
	struct group_info *group_info;
	const char *principal;
	unsigned long ac_flags;
	unsigned char machine_cred : 1;
};

/*
 * Client user credentials
 */
struct rpc_auth;
struct rpc_credops;
struct rpc_cred {
	struct hlist_node	cr_hash;	/* hash chain */
	struct list_head	cr_lru;		/* lru garbage collection */
	struct rcu_head		cr_rcu;
	struct rpc_auth *	cr_auth;
	const struct rpc_credops *cr_ops;
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
	unsigned long		cr_magic;	/* 0x0f4aa4f0 */
#endif
	unsigned long		cr_expire;	/* when to gc */
	unsigned long		cr_flags;	/* various flags */
	atomic_t		cr_count;	/* ref count */

	kuid_t			cr_uid;

	/* per-flavor data */
};
#define RPCAUTH_CRED_NEW	0
#define RPCAUTH_CRED_UPTODATE	1
#define RPCAUTH_CRED_HASHED	2
#define RPCAUTH_CRED_NEGATIVE	3

#define RPCAUTH_CRED_MAGIC	0x0f4aa4f0

/* rpc_auth au_flags */
#define RPCAUTH_AUTH_NO_CRKEY_TIMEOUT	0x0001 /* underlying cred has no key timeout */

/*
 * Client authentication handle
 */
struct rpc_cred_cache;
struct rpc_authops;
struct rpc_auth {
	unsigned int		au_cslack;	/* call cred size estimate */
				/* guess at number of u32's auth adds before
				 * reply data; normally the verifier size: */
	unsigned int		au_rslack;
				/* for gss, used to calculate au_rslack: */
	unsigned int		au_verfsize;

	unsigned int		au_flags;	/* various flags */
	const struct rpc_authops *au_ops;		/* operations */
	rpc_authflavor_t	au_flavor;	/* pseudoflavor (note may
						 * differ from the flavor in
						 * au_ops->au_flavor in gss
						 * case) */
	atomic_t		au_count;	/* Reference counter */

	struct rpc_cred_cache *	au_credcache;
	/* per-flavor data */
};

/* rpc_auth au_flags */
#define RPCAUTH_AUTH_DATATOUCH	0x00000002

struct rpc_auth_create_args {
	rpc_authflavor_t pseudoflavor;
	const char *target_name;
};

/* Flags for rpcauth_lookupcred() */
#define RPCAUTH_LOOKUP_NEW		0x01	/* Accept an uninitialised cred */
#define RPCAUTH_LOOKUP_RCU		0x02	/* lock-less lookup */

/*
 * Client authentication ops
 */
struct rpc_authops {
	struct module		*owner;
	rpc_authflavor_t	au_flavor;	/* flavor (RPC_AUTH_*) */
	char *			au_name;
	struct rpc_auth *	(*create)(struct rpc_auth_create_args *, struct rpc_clnt *);
	void			(*destroy)(struct rpc_auth *);

	int			(*hash_cred)(struct auth_cred *, unsigned int);
	struct rpc_cred *	(*lookup_cred)(struct rpc_auth *, struct auth_cred *, int);
	struct rpc_cred *	(*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t);
	int			(*list_pseudoflavors)(rpc_authflavor_t *, int);
	rpc_authflavor_t	(*info2flavor)(struct rpcsec_gss_info *);
	int			(*flavor2info)(rpc_authflavor_t,
						struct rpcsec_gss_info *);
	int			(*key_timeout)(struct rpc_auth *,
						struct rpc_cred *);
};

struct rpc_credops {
	const char *		cr_name;	/* Name of the auth flavour */
	int			(*cr_init)(struct rpc_auth *, struct rpc_cred *);
	void			(*crdestroy)(struct rpc_cred *);

	int			(*crmatch)(struct auth_cred *, struct rpc_cred *, int);
	struct rpc_cred *	(*crbind)(struct rpc_task *, struct rpc_cred *, int);
	__be32 *		(*crmarshal)(struct rpc_task *, __be32 *);
	int			(*crrefresh)(struct rpc_task *);
	__be32 *		(*crvalidate)(struct rpc_task *, __be32 *);
	int			(*crwrap_req)(struct rpc_task *, kxdreproc_t,
						void *, __be32 *, void *);
	int			(*crunwrap_resp)(struct rpc_task *, kxdrdproc_t,
						void *, __be32 *, void *);
	int			(*crkey_timeout)(struct rpc_cred *);
	bool			(*crkey_to_expire)(struct rpc_cred *);
	char *			(*crstringify_acceptor)(struct rpc_cred *);
};

extern const struct rpc_authops	authunix_ops;
extern const struct rpc_authops	authnull_ops;

int __init		rpc_init_authunix(void);
int __init		rpc_init_generic_auth(void);
int __init		rpcauth_init_module(void);
void			rpcauth_remove_module(void);
void			rpc_destroy_generic_auth(void);
void 			rpc_destroy_authunix(void);

struct rpc_cred *	rpc_lookup_cred(void);
struct rpc_cred *	rpc_lookup_cred_nonblock(void);
struct rpc_cred *	rpc_lookup_generic_cred(struct auth_cred *, int, gfp_t);
struct rpc_cred *	rpc_lookup_machine_cred(const char *service_name);
int			rpcauth_register(const struct rpc_authops *);
int			rpcauth_unregister(const struct rpc_authops *);
struct rpc_auth *	rpcauth_create(struct rpc_auth_create_args *,
				struct rpc_clnt *);
void			rpcauth_release(struct rpc_auth *);
rpc_authflavor_t	rpcauth_get_pseudoflavor(rpc_authflavor_t,
				struct rpcsec_gss_info *);
int			rpcauth_get_gssinfo(rpc_authflavor_t,
				struct rpcsec_gss_info *);
int			rpcauth_list_flavors(rpc_authflavor_t *, int);
struct rpc_cred *	rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int, gfp_t);
void			rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *);
struct rpc_cred *	rpcauth_lookupcred(struct rpc_auth *, int);
struct rpc_cred *	rpcauth_generic_bind_cred(struct rpc_task *, struct rpc_cred *, int);
void			put_rpccred(struct rpc_cred *);
__be32 *		rpcauth_marshcred(struct rpc_task *, __be32 *);
__be32 *		rpcauth_checkverf(struct rpc_task *, __be32 *);
int			rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp, __be32 *data, void *obj);
int			rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp, __be32 *data, void *obj);
int			rpcauth_refreshcred(struct rpc_task *);
void			rpcauth_invalcred(struct rpc_task *);
int			rpcauth_uptodatecred(struct rpc_task *);
int			rpcauth_init_credcache(struct rpc_auth *);
void			rpcauth_destroy_credcache(struct rpc_auth *);
void			rpcauth_clear_credcache(struct rpc_cred_cache *);
int			rpcauth_key_timeout_notify(struct rpc_auth *,
						struct rpc_cred *);
bool			rpcauth_cred_key_to_expire(struct rpc_auth *, struct rpc_cred *);
char *			rpcauth_stringify_acceptor(struct rpc_cred *);

static inline
struct rpc_cred *	get_rpccred(struct rpc_cred *cred)
{
	if (cred != NULL)
		atomic_inc(&cred->cr_count);
	return cred;
}

/**
 * get_rpccred_rcu - get a reference to a cred using rcu-protected pointer
 * @cred: cred of which to take a reference
 *
 * In some cases, we may have a pointer to a credential to which we
 * want to take a reference, but don't already have one. Because these
 * objects are freed using RCU, we can access the cr_count while its
 * on its way to destruction and only take a reference if it's not already
 * zero.
 */
static inline struct rpc_cred *
get_rpccred_rcu(struct rpc_cred *cred)
{
	if (atomic_inc_not_zero(&cred->cr_count))
		return cred;
	return NULL;
}

#endif /* __KERNEL__ */
#endif /* _LINUX_SUNRPC_AUTH_H */