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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 
21 struct 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 
init_svc_cred(struct svc_cred * cred)30 static 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 
free_svc_cred(struct svc_cred * cred)37 static 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 
46 struct svc_rqst;		/* forward decl */
47 struct 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  */
68 struct 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  */
115 struct 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 
139 struct svc_xprt;
140 
141 extern int	svc_authenticate(struct svc_rqst *rqstp, __be32 *authp);
142 extern int	svc_authorise(struct svc_rqst *rqstp);
143 extern int	svc_set_client(struct svc_rqst *rqstp);
144 extern int	svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
145 extern void	svc_auth_unregister(rpc_authflavor_t flavor);
146 
147 extern struct auth_domain *unix_domain_find(char *name);
148 extern void auth_domain_put(struct auth_domain *item);
149 extern int auth_unix_add_addr(struct net *net, struct in6_addr *addr, struct auth_domain *dom);
150 extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
151 extern struct auth_domain *auth_domain_find(char *name);
152 extern struct auth_domain *auth_unix_lookup(struct net *net, struct in6_addr *addr);
153 extern int auth_unix_forget_old(struct auth_domain *dom);
154 extern void svcauth_unix_purge(struct net *net);
155 extern void svcauth_unix_info_release(struct svc_xprt *xpt);
156 extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
157 
158 extern int unix_gid_cache_create(struct net *net);
159 extern void unix_gid_cache_destroy(struct net *net);
160 
hash_str(char * name,int bits)161 static 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 
hash_mem(char * buf,int length,int bits)179 static 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