xref: /linux/include/linux/sunrpc/auth.h (revision cdd5b5a9761fd66d17586e4f4ba6588c70e640ea)
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 <okir@monad.swb.de>
8  */
9 
10 #ifndef _LINUX_SUNRPC_AUTH_H
11 #define _LINUX_SUNRPC_AUTH_H
12 
13 #include <linux/sunrpc/sched.h>
14 #include <linux/sunrpc/msg_prot.h>
15 #include <linux/sunrpc/xdr.h>
16 
17 #include <linux/atomic.h>
18 #include <linux/rcupdate.h>
19 #include <linux/uidgid.h>
20 #include <linux/utsname.h>
21 
22 /*
23  * Maximum size of AUTH_NONE authentication information, in XDR words.
24  */
25 #define NUL_CALLSLACK	(4)
26 #define NUL_REPLYSLACK	(2)
27 
28 /*
29  * Size of the nodename buffer. RFC1831 specifies a hard limit of 255 bytes,
30  * but Linux hostnames are actually limited to __NEW_UTS_LEN bytes.
31  */
32 #define UNX_MAXNODENAME	__NEW_UTS_LEN
33 #define UNX_CALLSLACK	(21 + XDR_QUADLEN(UNX_MAXNODENAME))
34 #define UNX_NGROUPS	16
35 
36 struct rpcsec_gss_info;
37 
38 struct auth_cred {
39 	const struct cred *cred;
40 	const char *principal;	/* If present, this is a machine credential */
41 };
42 
43 /*
44  * Client user credentials
45  */
46 struct rpc_auth;
47 struct rpc_credops;
48 struct rpc_cred {
49 	struct hlist_node	cr_hash;	/* hash chain */
50 	struct list_head	cr_lru;		/* lru garbage collection */
51 	struct rcu_head		cr_rcu;
52 	struct rpc_auth *	cr_auth;
53 	const struct rpc_credops *cr_ops;
54 	unsigned long		cr_expire;	/* when to gc */
55 	unsigned long		cr_flags;	/* various flags */
56 	refcount_t		cr_count;	/* ref count */
57 	const struct cred	*cr_cred;
58 
59 	/* per-flavor data */
60 };
61 #define RPCAUTH_CRED_NEW	0
62 #define RPCAUTH_CRED_UPTODATE	1
63 #define RPCAUTH_CRED_HASHED	2
64 #define RPCAUTH_CRED_NEGATIVE	3
65 
66 const struct cred *rpc_machine_cred(void);
67 
68 /*
69  * Client authentication handle
70  */
71 struct rpc_cred_cache;
72 struct rpc_authops;
73 struct rpc_auth {
74 	unsigned int		au_cslack;	/* call cred size estimate */
75 	unsigned int		au_rslack;	/* reply cred size estimate */
76 	unsigned int		au_verfsize;	/* size of reply verifier */
77 	unsigned int		au_ralign;	/* words before UL header */
78 
79 	unsigned long		au_flags;
80 	const struct rpc_authops *au_ops;
81 	rpc_authflavor_t	au_flavor;	/* pseudoflavor (note may
82 						 * differ from the flavor in
83 						 * au_ops->au_flavor in gss
84 						 * case) */
85 	refcount_t		au_count;	/* Reference counter */
86 
87 	struct rpc_cred_cache *	au_credcache;
88 	/* per-flavor data */
89 };
90 
91 /* rpc_auth au_flags */
92 #define RPCAUTH_AUTH_DATATOUCH		(1)
93 #define RPCAUTH_AUTH_UPDATE_SLACK	(2)
94 
95 struct rpc_auth_create_args {
96 	rpc_authflavor_t pseudoflavor;
97 	const char *target_name;
98 };
99 
100 /* Flags for rpcauth_lookupcred() */
101 #define RPCAUTH_LOOKUP_NEW		0x01	/* Accept an uninitialised cred */
102 #define RPCAUTH_LOOKUP_ASYNC		0x02	/* Don't block waiting for memory */
103 
104 /*
105  * Client authentication ops
106  */
107 struct rpc_authops {
108 	struct module		*owner;
109 	rpc_authflavor_t	au_flavor;	/* flavor (RPC_AUTH_*) */
110 	char *			au_name;
111 	struct rpc_auth *	(*create)(const struct rpc_auth_create_args *,
112 					  struct rpc_clnt *);
113 	void			(*destroy)(struct rpc_auth *);
114 
115 	int			(*hash_cred)(struct auth_cred *, unsigned int);
116 	struct rpc_cred *	(*lookup_cred)(struct rpc_auth *, struct auth_cred *, int);
117 	struct rpc_cred *	(*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t);
118 	rpc_authflavor_t	(*info2flavor)(struct rpcsec_gss_info *);
119 	int			(*flavor2info)(rpc_authflavor_t,
120 						struct rpcsec_gss_info *);
121 	int			(*key_timeout)(struct rpc_auth *,
122 						struct rpc_cred *);
123 	int			(*ping)(struct rpc_clnt *clnt);
124 };
125 
126 struct rpc_credops {
127 	const char *		cr_name;	/* Name of the auth flavour */
128 	int			(*cr_init)(struct rpc_auth *, struct rpc_cred *);
129 	void			(*crdestroy)(struct rpc_cred *);
130 
131 	int			(*crmatch)(struct auth_cred *, struct rpc_cred *, int);
132 	int			(*crmarshal)(struct rpc_task *task,
133 					     struct xdr_stream *xdr);
134 	int			(*crrefresh)(struct rpc_task *);
135 	int			(*crvalidate)(struct rpc_task *task,
136 					      struct xdr_stream *xdr);
137 	int			(*crwrap_req)(struct rpc_task *task,
138 					      struct xdr_stream *xdr);
139 	int			(*crunwrap_resp)(struct rpc_task *task,
140 						 struct xdr_stream *xdr);
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 extern const struct rpc_authops	authtls_ops;
149 
150 int __init		rpc_init_authunix(void);
151 int __init		rpcauth_init_module(void);
152 void			rpcauth_remove_module(void);
153 void 			rpc_destroy_authunix(void);
154 
155 int			rpcauth_register(const struct rpc_authops *);
156 int			rpcauth_unregister(const struct rpc_authops *);
157 struct rpc_auth *	rpcauth_create(const struct rpc_auth_create_args *,
158 				struct rpc_clnt *);
159 void			rpcauth_release(struct rpc_auth *);
160 rpc_authflavor_t	rpcauth_get_pseudoflavor(rpc_authflavor_t,
161 				struct rpcsec_gss_info *);
162 int			rpcauth_get_gssinfo(rpc_authflavor_t,
163 				struct rpcsec_gss_info *);
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 int			rpcauth_marshcred(struct rpc_task *task,
169 					  struct xdr_stream *xdr);
170 int			rpcauth_checkverf(struct rpc_task *task,
171 					  struct xdr_stream *xdr);
172 int			rpcauth_wrap_req_encode(struct rpc_task *task,
173 						struct xdr_stream *xdr);
174 int			rpcauth_wrap_req(struct rpc_task *task,
175 					 struct xdr_stream *xdr);
176 int			rpcauth_unwrap_resp_decode(struct rpc_task *task,
177 						   struct xdr_stream *xdr);
178 int			rpcauth_unwrap_resp(struct rpc_task *task,
179 					    struct xdr_stream *xdr);
180 bool			rpcauth_xmit_need_reencode(struct rpc_task *task);
181 int			rpcauth_refreshcred(struct rpc_task *);
182 void			rpcauth_invalcred(struct rpc_task *);
183 int			rpcauth_uptodatecred(struct rpc_task *);
184 int			rpcauth_init_credcache(struct rpc_auth *);
185 void			rpcauth_destroy_credcache(struct rpc_auth *);
186 void			rpcauth_clear_credcache(struct rpc_cred_cache *);
187 char *			rpcauth_stringify_acceptor(struct rpc_cred *);
188 
189 static inline
get_rpccred(struct rpc_cred * cred)190 struct rpc_cred *get_rpccred(struct rpc_cred *cred)
191 {
192 	if (cred != NULL && refcount_inc_not_zero(&cred->cr_count))
193 		return cred;
194 	return NULL;
195 }
196 
197 #endif /* _LINUX_SUNRPC_AUTH_H */
198