auth.h

  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
 36struct rpcsec_gss_info;
 37
 38struct 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 */
 46struct rpc_auth;
 47struct rpc_credops;
 48struct 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
 66const struct cred *rpc_machine_cred(void);
 67
 68/*
 69 * Client authentication handle
 70 */
 71struct rpc_cred_cache;
 72struct rpc_authops;
 73struct 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
 95struct 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 */
107struct 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
126struct 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
146extern const struct rpc_authops	authunix_ops;
147extern const struct rpc_authops	authnull_ops;
148extern const struct rpc_authops	authtls_ops;
149
150int __init		rpc_init_authunix(void);
151int __init		rpcauth_init_module(void);
152void			rpcauth_remove_module(void);
153void 			rpc_destroy_authunix(void);
154
155int			rpcauth_register(const struct rpc_authops *);
156int			rpcauth_unregister(const struct rpc_authops *);
157struct rpc_auth *	rpcauth_create(const struct rpc_auth_create_args *,
158				struct rpc_clnt *);
159void			rpcauth_release(struct rpc_auth *);
160rpc_authflavor_t	rpcauth_get_pseudoflavor(rpc_authflavor_t,
161				struct rpcsec_gss_info *);
162int			rpcauth_get_gssinfo(rpc_authflavor_t,
163				struct rpcsec_gss_info *);
164struct rpc_cred *	rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int, gfp_t);
165void			rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *);
166struct rpc_cred *	rpcauth_lookupcred(struct rpc_auth *, int);
167void			put_rpccred(struct rpc_cred *);
168int			rpcauth_marshcred(struct rpc_task *task,
169					  struct xdr_stream *xdr);
170int			rpcauth_checkverf(struct rpc_task *task,
171					  struct xdr_stream *xdr);
172int			rpcauth_wrap_req_encode(struct rpc_task *task,
173						struct xdr_stream *xdr);
174int			rpcauth_wrap_req(struct rpc_task *task,
175					 struct xdr_stream *xdr);
176int			rpcauth_unwrap_resp_decode(struct rpc_task *task,
177						   struct xdr_stream *xdr);
178int			rpcauth_unwrap_resp(struct rpc_task *task,
179					    struct xdr_stream *xdr);
180bool			rpcauth_xmit_need_reencode(struct rpc_task *task);
181int			rpcauth_refreshcred(struct rpc_task *);
182void			rpcauth_invalcred(struct rpc_task *);
183int			rpcauth_uptodatecred(struct rpc_task *);
184int			rpcauth_init_credcache(struct rpc_auth *);
185void			rpcauth_destroy_credcache(struct rpc_auth *);
186void			rpcauth_clear_credcache(struct rpc_cred_cache *);
187char *			rpcauth_stringify_acceptor(struct rpc_cred *);
188
189static inline
190struct 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 */