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