svcauth.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * linux/include/linux/sunrpc/svcauth.h
  4 *
  5 * RPC server-side authentication stuff.
  6 *
  7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  8 */
  9
 10#ifndef _LINUX_SUNRPC_SVCAUTH_H_
 11#define _LINUX_SUNRPC_SVCAUTH_H_
 12
 13#include <linux/string.h>
 14#include <linux/sunrpc/msg_prot.h>
 15#include <linux/sunrpc/cache.h>
 16#include <linux/sunrpc/gss_api.h>
 17#include <linux/sunrpc/clnt.h>
 18#include <linux/hash.h>
 19#include <linux/stringhash.h>
 20#include <linux/cred.h>
 21
 22struct svc_cred {
 23	kuid_t			cr_uid;
 24	kgid_t			cr_gid;
 25	struct group_info	*cr_group_info;
 26	u32			cr_flavor; /* pseudoflavor */
 27	/* name of form servicetype/hostname@REALM, passed down by
 28	 * gss-proxy: */
 29	char			*cr_raw_principal;
 30	/* name of form servicetype@hostname, passed down by
 31	 * rpc.svcgssd, or computed from the above: */
 32	char			*cr_principal;
 33	char			*cr_targ_princ;
 34	struct gss_api_mech	*cr_gss_mech;
 35};
 36
 37static inline void init_svc_cred(struct svc_cred *cred)
 38{
 39	cred->cr_group_info = NULL;
 40	cred->cr_raw_principal = NULL;
 41	cred->cr_principal = NULL;
 42	cred->cr_targ_princ = NULL;
 43	cred->cr_gss_mech = NULL;
 44}
 45
 46static inline void free_svc_cred(struct svc_cred *cred)
 47{
 48	if (cred->cr_group_info)
 49		put_group_info(cred->cr_group_info);
 50	kfree(cred->cr_raw_principal);
 51	kfree(cred->cr_principal);
 52	kfree(cred->cr_targ_princ);
 53	gss_mech_put(cred->cr_gss_mech);
 54	init_svc_cred(cred);
 55}
 56
 57struct svc_rqst;		/* forward decl */
 58struct in6_addr;
 59
 60/* Authentication is done in the context of a domain.
 61 *
 62 * Currently, the nfs server uses the auth_domain to stand
 63 * for the "client" listed in /etc/exports.
 64 *
 65 * More generally, a domain might represent a group of clients using
 66 * a common mechanism for authentication and having a common mapping
 67 * between local identity (uid) and network identity.  All clients
 68 * in a domain have similar general access rights.  Each domain can
 69 * contain multiple principals which will have different specific right
 70 * based on normal Discretionary Access Control.
 71 *
 72 * A domain is created by an authentication flavour module based on name
 73 * only.  Userspace then fills in detail on demand.
 74 *
 75 * In the case of auth_unix and auth_null, the auth_domain is also
 76 * associated with entries in another cache representing the mapping
 77 * of ip addresses to the given client.
 78 */
 79struct auth_domain {
 80	struct kref		ref;
 81	struct hlist_node	hash;
 82	char			*name;
 83	struct auth_ops		*flavour;
 84	struct rcu_head		rcu_head;
 85};
 86
 87enum svc_auth_status {
 88	SVC_GARBAGE = 1,
 89	SVC_VALID,
 90	SVC_NEGATIVE,
 91	SVC_OK,
 92	SVC_DROP,
 93	SVC_CLOSE,
 94	SVC_DENIED,
 95	SVC_PENDING,
 96	SVC_COMPLETE,
 97};
 98
 99/*
100 * Each authentication flavour registers an auth_ops
101 * structure.
102 * name is simply the name.
103 * flavour gives the auth flavour. It determines where the flavour is registered
104 * accept() is given a request and should verify it.
105 *   It should inspect the authenticator and verifier, and possibly the data.
106 *    If there is a problem with the authentication *authp should be set.
107 *    The return value of accept() can indicate:
108 *      OK - authorised. client and credential are set in rqstp.
109 *           reqbuf points to arguments
110 *           resbuf points to good place for results.  verfier
111 *             is (probably) already in place.  Certainly space is
112 *	       reserved for it.
113 *      DROP - simply drop the request. It may have been deferred
114 *      CLOSE - like SVC_DROP, but request is definitely lost.
115 *		If there is a tcp connection, it should be closed.
116 *      GARBAGE - rpc garbage_args error
117 *      SYSERR - rpc system_err error
118 *      DENIED - authp holds reason for denial.
119 *      COMPLETE - the reply is encoded already and ready to be sent; no
120 *		further processing is necessary.  (This is used for processing
121 *		null procedure calls which are used to set up encryption
122 *		contexts.)
123 *
124 *   accept is passed the proc number so that it can accept NULL rpc requests
125 *   even if it cannot authenticate the client (as is sometimes appropriate).
126 *
127 * release() is given a request after the procedure has been run.
128 *  It should sign/encrypt the results if needed
129 *
130 * domain_release()
131 *   This call releases a domain.
132 *
133 * set_client()
134 *   Given a pending request (struct svc_rqst), finds and assigns
135 *   an appropriate 'auth_domain' as the client.
136 *
137 * pseudoflavor()
138 *   Returns RPC_AUTH pseudoflavor in use by @rqstp.
139 */
140struct auth_ops {
141	char *	name;
142	struct module *owner;
143	int	flavour;
144
145	enum svc_auth_status	(*accept)(struct svc_rqst *rqstp);
146	int			(*release)(struct svc_rqst *rqstp);
147	void			(*domain_release)(struct auth_domain *dom);
148	enum svc_auth_status	(*set_client)(struct svc_rqst *rqstp);
149	rpc_authflavor_t	(*pseudoflavor)(struct svc_rqst *rqstp);
150};
151
152struct svc_xprt;
153
154extern rpc_authflavor_t svc_auth_flavor(struct svc_rqst *rqstp);
155extern int	svc_authorise(struct svc_rqst *rqstp);
156extern enum svc_auth_status svc_set_client(struct svc_rqst *rqstp);
157extern int	svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
158extern void	svc_auth_unregister(rpc_authflavor_t flavor);
159
160extern void	svcauth_map_clnt_to_svc_cred_local(struct rpc_clnt *clnt,
161						   const struct cred *,
162						   struct svc_cred *);
163
164extern struct auth_domain *unix_domain_find(char *name);
165extern void auth_domain_put(struct auth_domain *item);
166extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
167extern struct auth_domain *auth_domain_find(char *name);
168extern void svcauth_unix_purge(struct net *net);
169extern void svcauth_unix_info_release(struct svc_xprt *xpt);
170extern enum svc_auth_status svcauth_unix_set_client(struct svc_rqst *rqstp);
171
172extern int unix_gid_cache_create(struct net *net);
173extern void unix_gid_cache_destroy(struct net *net);
174
175/*
176 * The <stringhash.h> functions are good enough that we don't need to
177 * use hash_32() on them; just extracting the high bits is enough.
178 */
179static inline unsigned long hash_str(char const *name, int bits)
180{
181	return hashlen_hash(hashlen_string(NULL, name)) >> (32 - bits);
182}
183
184static inline unsigned long hash_mem(char const *buf, int length, int bits)
185{
186	return full_name_hash(NULL, buf, length) >> (32 - bits);
187}
188
189#endif /* _LINUX_SUNRPC_SVCAUTH_H_ */