1/*
2 * linux/include/linux/sunrpc/svcauth.h
3 *
4 * RPC server-side authentication stuff.
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7 */
8
9#ifndef _LINUX_SUNRPC_SVCAUTH_H_
10#define _LINUX_SUNRPC_SVCAUTH_H_
11
12#ifdef __KERNEL__
13
14#include <linux/string.h>
15#include <linux/sunrpc/msg_prot.h>
16#include <linux/sunrpc/cache.h>
17#include <linux/sunrpc/gss_api.h>
18#include <linux/hash.h>
19#include <linux/cred.h>
20
21struct svc_cred {
22	kuid_t			cr_uid;
23	kgid_t			cr_gid;
24	struct group_info	*cr_group_info;
25	u32			cr_flavor; /* pseudoflavor */
26	char			*cr_principal; /* for gss */
27	struct gss_api_mech	*cr_gss_mech;
28};
29
30static inline void init_svc_cred(struct svc_cred *cred)
31{
32	cred->cr_group_info = NULL;
33	cred->cr_principal = NULL;
34	cred->cr_gss_mech = NULL;
35}
36
37static inline void free_svc_cred(struct svc_cred *cred)
38{
39	if (cred->cr_group_info)
40		put_group_info(cred->cr_group_info);
41	kfree(cred->cr_principal);
42	gss_mech_put(cred->cr_gss_mech);
43	init_svc_cred(cred);
44}
45
46struct svc_rqst;		/* forward decl */
47struct in6_addr;
48
49/* Authentication is done in the context of a domain.
50 *
51 * Currently, the nfs server uses the auth_domain to stand
52 * for the "client" listed in /etc/exports.
53 *
54 * More generally, a domain might represent a group of clients using
55 * a common mechanism for authentication and having a common mapping
56 * between local identity (uid) and network identity.  All clients
57 * in a domain have similar general access rights.  Each domain can
58 * contain multiple principals which will have different specific right
59 * based on normal Discretionary Access Control.
60 *
61 * A domain is created by an authentication flavour module based on name
62 * only.  Userspace then fills in detail on demand.
63 *
64 * In the case of auth_unix and auth_null, the auth_domain is also
65 * associated with entries in another cache representing the mapping
66 * of ip addresses to the given client.
67 */
68struct auth_domain {
69	struct kref		ref;
70	struct hlist_node	hash;
71	char			*name;
72	struct auth_ops		*flavour;
73};
74
75/*
76 * Each authentication flavour registers an auth_ops
77 * structure.
78 * name is simply the name.
79 * flavour gives the auth flavour. It determines where the flavour is registered
80 * accept() is given a request and should verify it.
81 *   It should inspect the authenticator and verifier, and possibly the data.
82 *    If there is a problem with the authentication *authp should be set.
83 *    The return value of accept() can indicate:
84 *      OK - authorised. client and credential are set in rqstp.
85 *           reqbuf points to arguments
86 *           resbuf points to good place for results.  verfier
87 *             is (probably) already in place.  Certainly space is
88 *	       reserved for it.
89 *      DROP - simply drop the request. It may have been deferred
90 *      GARBAGE - rpc garbage_args error
91 *      SYSERR - rpc system_err error
92 *      DENIED - authp holds reason for denial.
93 *      COMPLETE - the reply is encoded already and ready to be sent; no
94 *		further processing is necessary.  (This is used for processing
95 *		null procedure calls which are used to set up encryption
96 *		contexts.)
97 *
98 *   accept is passed the proc number so that it can accept NULL rpc requests
99 *   even if it cannot authenticate the client (as is sometimes appropriate).
100 *
101 * release() is given a request after the procedure has been run.
102 *  It should sign/encrypt the results if needed
103 * It should return:
104 *    OK - the resbuf is ready to be sent
105 *    DROP - the reply should be quitely dropped
106 *    DENIED - authp holds a reason for MSG_DENIED
107 *    SYSERR - rpc system_err
108 *
109 * domain_release()
110 *   This call releases a domain.
111 * set_client()
112 *   Givens a pending request (struct svc_rqst), finds and assigns
113 *   an appropriate 'auth_domain' as the client.
114 */
115struct auth_ops {
116	char *	name;
117	struct module *owner;
118	int	flavour;
119	int	(*accept)(struct svc_rqst *rq, __be32 *authp);
120	int	(*release)(struct svc_rqst *rq);
121	void	(*domain_release)(struct auth_domain *);
122	int	(*set_client)(struct svc_rqst *rq);
123};
124
125#define	SVC_GARBAGE	1
126#define	SVC_SYSERR	2
127#define	SVC_VALID	3
128#define	SVC_NEGATIVE	4
129#define	SVC_OK		5
130#define	SVC_DROP	6
131#define	SVC_CLOSE	7	/* Like SVC_DROP, but request is definitely
132				 * lost so if there is a tcp connection, it
133				 * should be closed
134				 */
135#define	SVC_DENIED	8
136#define	SVC_PENDING	9
137#define	SVC_COMPLETE	10
138
139struct svc_xprt;
140
141extern int	svc_authenticate(struct svc_rqst *rqstp, __be32 *authp);
142extern int	svc_authorise(struct svc_rqst *rqstp);
143extern int	svc_set_client(struct svc_rqst *rqstp);
144extern int	svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
145extern void	svc_auth_unregister(rpc_authflavor_t flavor);
146
147extern struct auth_domain *unix_domain_find(char *name);
148extern void auth_domain_put(struct auth_domain *item);
149extern int auth_unix_add_addr(struct net *net, struct in6_addr *addr, struct auth_domain *dom);
150extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
151extern struct auth_domain *auth_domain_find(char *name);
152extern struct auth_domain *auth_unix_lookup(struct net *net, struct in6_addr *addr);
153extern int auth_unix_forget_old(struct auth_domain *dom);
154extern void svcauth_unix_purge(struct net *net);
155extern void svcauth_unix_info_release(struct svc_xprt *xpt);
156extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
157
158extern int unix_gid_cache_create(struct net *net);
159extern void unix_gid_cache_destroy(struct net *net);
160
161static inline unsigned long hash_str(char *name, int bits)
162{
163	unsigned long hash = 0;
164	unsigned long l = 0;
165	int len = 0;
166	unsigned char c;
167	do {
168		if (unlikely(!(c = *name++))) {
169			c = (char)len; len = -1;
170		}
171		l = (l << 8) | c;
172		len++;
173		if ((len & (BITS_PER_LONG/8-1))==0)
174			hash = hash_long(hash^l, BITS_PER_LONG);
175	} while (len);
176	return hash >> (BITS_PER_LONG - bits);
177}
178
179static inline unsigned long hash_mem(char *buf, int length, int bits)
180{
181	unsigned long hash = 0;
182	unsigned long l = 0;
183	int len = 0;
184	unsigned char c;
185	do {
186		if (len == length) {
187			c = (char)len; len = -1;
188		} else
189			c = *buf++;
190		l = (l << 8) | c;
191		len++;
192		if ((len & (BITS_PER_LONG/8-1))==0)
193			hash = hash_long(hash^l, BITS_PER_LONG);
194	} while (len);
195	return hash >> (BITS_PER_LONG - bits);
196}
197
198#endif /* __KERNEL__ */
199
200#endif /* _LINUX_SUNRPC_SVCAUTH_H_ */
201