xref: /linux-6.15/include/linux/sunrpc/svcauth.h (revision 56d06fa2)
1 /*
2  * linux/include/linux/sunrpc/svcauth.h
3  *
4  * RPC server-side authentication stuff.
5  *
6  * Copyright (C) 1995, 1996 Olaf Kirch <[email protected]>
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 	/* name of form servicetype/hostname@REALM, passed down by
27 	 * gss-proxy: */
28 	char			*cr_raw_principal;
29 	/* name of form servicetype@hostname, passed down by
30 	 * rpc.svcgssd, or computed from the above: */
31 	char			*cr_principal;
32 	struct gss_api_mech	*cr_gss_mech;
33 };
34 
35 static inline void init_svc_cred(struct svc_cred *cred)
36 {
37 	cred->cr_group_info = NULL;
38 	cred->cr_raw_principal = NULL;
39 	cred->cr_principal = NULL;
40 	cred->cr_gss_mech = NULL;
41 }
42 
43 static inline void free_svc_cred(struct svc_cred *cred)
44 {
45 	if (cred->cr_group_info)
46 		put_group_info(cred->cr_group_info);
47 	kfree(cred->cr_raw_principal);
48 	kfree(cred->cr_principal);
49 	gss_mech_put(cred->cr_gss_mech);
50 	init_svc_cred(cred);
51 }
52 
53 struct svc_rqst;		/* forward decl */
54 struct in6_addr;
55 
56 /* Authentication is done in the context of a domain.
57  *
58  * Currently, the nfs server uses the auth_domain to stand
59  * for the "client" listed in /etc/exports.
60  *
61  * More generally, a domain might represent a group of clients using
62  * a common mechanism for authentication and having a common mapping
63  * between local identity (uid) and network identity.  All clients
64  * in a domain have similar general access rights.  Each domain can
65  * contain multiple principals which will have different specific right
66  * based on normal Discretionary Access Control.
67  *
68  * A domain is created by an authentication flavour module based on name
69  * only.  Userspace then fills in detail on demand.
70  *
71  * In the case of auth_unix and auth_null, the auth_domain is also
72  * associated with entries in another cache representing the mapping
73  * of ip addresses to the given client.
74  */
75 struct auth_domain {
76 	struct kref		ref;
77 	struct hlist_node	hash;
78 	char			*name;
79 	struct auth_ops		*flavour;
80 };
81 
82 /*
83  * Each authentication flavour registers an auth_ops
84  * structure.
85  * name is simply the name.
86  * flavour gives the auth flavour. It determines where the flavour is registered
87  * accept() is given a request and should verify it.
88  *   It should inspect the authenticator and verifier, and possibly the data.
89  *    If there is a problem with the authentication *authp should be set.
90  *    The return value of accept() can indicate:
91  *      OK - authorised. client and credential are set in rqstp.
92  *           reqbuf points to arguments
93  *           resbuf points to good place for results.  verfier
94  *             is (probably) already in place.  Certainly space is
95  *	       reserved for it.
96  *      DROP - simply drop the request. It may have been deferred
97  *      GARBAGE - rpc garbage_args error
98  *      SYSERR - rpc system_err error
99  *      DENIED - authp holds reason for denial.
100  *      COMPLETE - the reply is encoded already and ready to be sent; no
101  *		further processing is necessary.  (This is used for processing
102  *		null procedure calls which are used to set up encryption
103  *		contexts.)
104  *
105  *   accept is passed the proc number so that it can accept NULL rpc requests
106  *   even if it cannot authenticate the client (as is sometimes appropriate).
107  *
108  * release() is given a request after the procedure has been run.
109  *  It should sign/encrypt the results if needed
110  * It should return:
111  *    OK - the resbuf is ready to be sent
112  *    DROP - the reply should be quitely dropped
113  *    DENIED - authp holds a reason for MSG_DENIED
114  *    SYSERR - rpc system_err
115  *
116  * domain_release()
117  *   This call releases a domain.
118  * set_client()
119  *   Givens a pending request (struct svc_rqst), finds and assigns
120  *   an appropriate 'auth_domain' as the client.
121  */
122 struct auth_ops {
123 	char *	name;
124 	struct module *owner;
125 	int	flavour;
126 	int	(*accept)(struct svc_rqst *rq, __be32 *authp);
127 	int	(*release)(struct svc_rqst *rq);
128 	void	(*domain_release)(struct auth_domain *);
129 	int	(*set_client)(struct svc_rqst *rq);
130 };
131 
132 #define	SVC_GARBAGE	1
133 #define	SVC_SYSERR	2
134 #define	SVC_VALID	3
135 #define	SVC_NEGATIVE	4
136 #define	SVC_OK		5
137 #define	SVC_DROP	6
138 #define	SVC_CLOSE	7	/* Like SVC_DROP, but request is definitely
139 				 * lost so if there is a tcp connection, it
140 				 * should be closed
141 				 */
142 #define	SVC_DENIED	8
143 #define	SVC_PENDING	9
144 #define	SVC_COMPLETE	10
145 
146 struct svc_xprt;
147 
148 extern int	svc_authenticate(struct svc_rqst *rqstp, __be32 *authp);
149 extern int	svc_authorise(struct svc_rqst *rqstp);
150 extern int	svc_set_client(struct svc_rqst *rqstp);
151 extern int	svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
152 extern void	svc_auth_unregister(rpc_authflavor_t flavor);
153 
154 extern struct auth_domain *unix_domain_find(char *name);
155 extern void auth_domain_put(struct auth_domain *item);
156 extern int auth_unix_add_addr(struct net *net, struct in6_addr *addr, struct auth_domain *dom);
157 extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
158 extern struct auth_domain *auth_domain_find(char *name);
159 extern struct auth_domain *auth_unix_lookup(struct net *net, struct in6_addr *addr);
160 extern int auth_unix_forget_old(struct auth_domain *dom);
161 extern void svcauth_unix_purge(struct net *net);
162 extern void svcauth_unix_info_release(struct svc_xprt *xpt);
163 extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
164 
165 extern int unix_gid_cache_create(struct net *net);
166 extern void unix_gid_cache_destroy(struct net *net);
167 
168 static inline unsigned long hash_str(char *name, int bits)
169 {
170 	unsigned long hash = 0;
171 	unsigned long l = 0;
172 	int len = 0;
173 	unsigned char c;
174 	do {
175 		if (unlikely(!(c = *name++))) {
176 			c = (char)len; len = -1;
177 		}
178 		l = (l << 8) | c;
179 		len++;
180 		if ((len & (BITS_PER_LONG/8-1))==0)
181 			hash = hash_long(hash^l, BITS_PER_LONG);
182 	} while (len);
183 	return hash >> (BITS_PER_LONG - bits);
184 }
185 
186 static inline unsigned long hash_mem(char *buf, int length, int bits)
187 {
188 	unsigned long hash = 0;
189 	unsigned long l = 0;
190 	int len = 0;
191 	unsigned char c;
192 	do {
193 		if (len == length) {
194 			c = (char)len; len = -1;
195 		} else
196 			c = *buf++;
197 		l = (l << 8) | c;
198 		len++;
199 		if ((len & (BITS_PER_LONG/8-1))==0)
200 			hash = hash_long(hash^l, BITS_PER_LONG);
201 	} while (len);
202 	return hash >> (BITS_PER_LONG - bits);
203 }
204 
205 #endif /* __KERNEL__ */
206 
207 #endif /* _LINUX_SUNRPC_SVCAUTH_H_ */
208