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