xref: /linux-6.15/include/linux/sunrpc/auth.h (revision dfd32cad)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * linux/include/linux/sunrpc/auth.h
4  *
5  * Declarations for the RPC client authentication machinery.
6  *
7  * Copyright (C) 1996, Olaf Kirch <[email protected]>
8  */
9 
10 #ifndef _LINUX_SUNRPC_AUTH_H
11 #define _LINUX_SUNRPC_AUTH_H
12 
13 #ifdef __KERNEL__
14 
15 #include <linux/sunrpc/sched.h>
16 #include <linux/sunrpc/msg_prot.h>
17 #include <linux/sunrpc/xdr.h>
18 
19 #include <linux/atomic.h>
20 #include <linux/rcupdate.h>
21 #include <linux/uidgid.h>
22 #include <linux/utsname.h>
23 
24 /*
25  * Maximum size of AUTH_NONE authentication information, in XDR words.
26  */
27 #define NUL_CALLSLACK	(4)
28 #define NUL_REPLYSLACK	(2)
29 
30 /*
31  * Size of the nodename buffer. RFC1831 specifies a hard limit of 255 bytes,
32  * but Linux hostnames are actually limited to __NEW_UTS_LEN bytes.
33  */
34 #define UNX_MAXNODENAME	__NEW_UTS_LEN
35 #define UNX_CALLSLACK	(21 + XDR_QUADLEN(UNX_MAXNODENAME))
36 #define UNX_NGROUPS	16
37 
38 struct rpcsec_gss_info;
39 
40 struct auth_cred {
41 	const struct cred *cred;
42 	const char *principal;	/* If present, this is a machine credential */
43 };
44 
45 /*
46  * Client user credentials
47  */
48 struct rpc_auth;
49 struct rpc_credops;
50 struct rpc_cred {
51 	struct hlist_node	cr_hash;	/* hash chain */
52 	struct list_head	cr_lru;		/* lru garbage collection */
53 	struct rcu_head		cr_rcu;
54 	struct rpc_auth *	cr_auth;
55 	const struct rpc_credops *cr_ops;
56 	unsigned long		cr_expire;	/* when to gc */
57 	unsigned long		cr_flags;	/* various flags */
58 	refcount_t		cr_count;	/* ref count */
59 	const struct cred	*cr_cred;
60 
61 	/* per-flavor data */
62 };
63 #define RPCAUTH_CRED_NEW	0
64 #define RPCAUTH_CRED_UPTODATE	1
65 #define RPCAUTH_CRED_HASHED	2
66 #define RPCAUTH_CRED_NEGATIVE	3
67 
68 const struct cred *rpc_machine_cred(void);
69 
70 /*
71  * Client authentication handle
72  */
73 struct rpc_cred_cache;
74 struct rpc_authops;
75 struct rpc_auth {
76 	unsigned int		au_cslack;	/* call cred size estimate */
77 				/* guess at number of u32's auth adds before
78 				 * reply data; normally the verifier size: */
79 	unsigned int		au_rslack;
80 				/* for gss, used to calculate au_rslack: */
81 	unsigned int		au_verfsize;
82 
83 	unsigned int		au_flags;	/* various flags */
84 	const struct rpc_authops *au_ops;		/* operations */
85 	rpc_authflavor_t	au_flavor;	/* pseudoflavor (note may
86 						 * differ from the flavor in
87 						 * au_ops->au_flavor in gss
88 						 * case) */
89 	refcount_t		au_count;	/* Reference counter */
90 
91 	struct rpc_cred_cache *	au_credcache;
92 	/* per-flavor data */
93 };
94 
95 /* rpc_auth au_flags */
96 #define RPCAUTH_AUTH_DATATOUCH	0x00000002
97 
98 struct rpc_auth_create_args {
99 	rpc_authflavor_t pseudoflavor;
100 	const char *target_name;
101 };
102 
103 /* Flags for rpcauth_lookupcred() */
104 #define RPCAUTH_LOOKUP_NEW		0x01	/* Accept an uninitialised cred */
105 
106 /*
107  * Client authentication ops
108  */
109 struct rpc_authops {
110 	struct module		*owner;
111 	rpc_authflavor_t	au_flavor;	/* flavor (RPC_AUTH_*) */
112 	char *			au_name;
113 	struct rpc_auth *	(*create)(const struct rpc_auth_create_args *,
114 					  struct rpc_clnt *);
115 	void			(*destroy)(struct rpc_auth *);
116 
117 	int			(*hash_cred)(struct auth_cred *, unsigned int);
118 	struct rpc_cred *	(*lookup_cred)(struct rpc_auth *, struct auth_cred *, int);
119 	struct rpc_cred *	(*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t);
120 	int			(*list_pseudoflavors)(rpc_authflavor_t *, int);
121 	rpc_authflavor_t	(*info2flavor)(struct rpcsec_gss_info *);
122 	int			(*flavor2info)(rpc_authflavor_t,
123 						struct rpcsec_gss_info *);
124 	int			(*key_timeout)(struct rpc_auth *,
125 						struct rpc_cred *);
126 };
127 
128 struct rpc_credops {
129 	const char *		cr_name;	/* Name of the auth flavour */
130 	int			(*cr_init)(struct rpc_auth *, struct rpc_cred *);
131 	void			(*crdestroy)(struct rpc_cred *);
132 
133 	int			(*crmatch)(struct auth_cred *, struct rpc_cred *, int);
134 	__be32 *		(*crmarshal)(struct rpc_task *, __be32 *);
135 	int			(*crrefresh)(struct rpc_task *);
136 	__be32 *		(*crvalidate)(struct rpc_task *, __be32 *);
137 	int			(*crwrap_req)(struct rpc_task *, kxdreproc_t,
138 						void *, __be32 *, void *);
139 	int			(*crunwrap_resp)(struct rpc_task *, kxdrdproc_t,
140 						void *, __be32 *, void *);
141 	int			(*crkey_timeout)(struct rpc_cred *);
142 	char *			(*crstringify_acceptor)(struct rpc_cred *);
143 	bool			(*crneed_reencode)(struct rpc_task *);
144 };
145 
146 extern const struct rpc_authops	authunix_ops;
147 extern const struct rpc_authops	authnull_ops;
148 
149 int __init		rpc_init_authunix(void);
150 int __init		rpcauth_init_module(void);
151 void			rpcauth_remove_module(void);
152 void 			rpc_destroy_authunix(void);
153 
154 int			rpcauth_register(const struct rpc_authops *);
155 int			rpcauth_unregister(const struct rpc_authops *);
156 struct rpc_auth *	rpcauth_create(const struct rpc_auth_create_args *,
157 				struct rpc_clnt *);
158 void			rpcauth_release(struct rpc_auth *);
159 rpc_authflavor_t	rpcauth_get_pseudoflavor(rpc_authflavor_t,
160 				struct rpcsec_gss_info *);
161 int			rpcauth_get_gssinfo(rpc_authflavor_t,
162 				struct rpcsec_gss_info *);
163 int			rpcauth_list_flavors(rpc_authflavor_t *, int);
164 struct rpc_cred *	rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int, gfp_t);
165 void			rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *);
166 struct rpc_cred *	rpcauth_lookupcred(struct rpc_auth *, int);
167 void			put_rpccred(struct rpc_cred *);
168 __be32 *		rpcauth_marshcred(struct rpc_task *, __be32 *);
169 __be32 *		rpcauth_checkverf(struct rpc_task *, __be32 *);
170 int			rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp, __be32 *data, void *obj);
171 int			rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp, __be32 *data, void *obj);
172 bool			rpcauth_xmit_need_reencode(struct rpc_task *task);
173 int			rpcauth_refreshcred(struct rpc_task *);
174 void			rpcauth_invalcred(struct rpc_task *);
175 int			rpcauth_uptodatecred(struct rpc_task *);
176 int			rpcauth_init_credcache(struct rpc_auth *);
177 void			rpcauth_destroy_credcache(struct rpc_auth *);
178 void			rpcauth_clear_credcache(struct rpc_cred_cache *);
179 char *			rpcauth_stringify_acceptor(struct rpc_cred *);
180 
181 static inline
182 struct rpc_cred *get_rpccred(struct rpc_cred *cred)
183 {
184 	if (cred != NULL && refcount_inc_not_zero(&cred->cr_count))
185 		return cred;
186 	return NULL;
187 }
188 
189 #endif /* __KERNEL__ */
190 #endif /* _LINUX_SUNRPC_AUTH_H */
191