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
22 struct 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
init_svc_cred(struct svc_cred * cred)37 static 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
free_svc_cred(struct svc_cred * cred)46 static 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
57 struct svc_rqst; /* forward decl */
58 struct 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 */
79 struct 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
87 enum svc_auth_status {
88 SVC_GARBAGE = 1,
89 SVC_SYSERR,
90 SVC_VALID,
91 SVC_NEGATIVE,
92 SVC_OK,
93 SVC_DROP,
94 SVC_CLOSE,
95 SVC_DENIED,
96 SVC_PENDING,
97 SVC_COMPLETE,
98 };
99
100 /*
101 * Each authentication flavour registers an auth_ops
102 * structure.
103 * name is simply the name.
104 * flavour gives the auth flavour. It determines where the flavour is registered
105 * accept() is given a request and should verify it.
106 * It should inspect the authenticator and verifier, and possibly the data.
107 * If there is a problem with the authentication *authp should be set.
108 * The return value of accept() can indicate:
109 * OK - authorised. client and credential are set in rqstp.
110 * reqbuf points to arguments
111 * resbuf points to good place for results. verfier
112 * is (probably) already in place. Certainly space is
113 * reserved for it.
114 * DROP - simply drop the request. It may have been deferred
115 * CLOSE - like SVC_DROP, but request is definitely lost.
116 * If there is a tcp connection, it should be closed.
117 * GARBAGE - rpc garbage_args error
118 * SYSERR - rpc system_err error
119 * DENIED - authp holds reason for denial.
120 * COMPLETE - the reply is encoded already and ready to be sent; no
121 * further processing is necessary. (This is used for processing
122 * null procedure calls which are used to set up encryption
123 * contexts.)
124 *
125 * accept is passed the proc number so that it can accept NULL rpc requests
126 * even if it cannot authenticate the client (as is sometimes appropriate).
127 *
128 * release() is given a request after the procedure has been run.
129 * It should sign/encrypt the results if needed
130 *
131 * domain_release()
132 * This call releases a domain.
133 *
134 * set_client()
135 * Given a pending request (struct svc_rqst), finds and assigns
136 * an appropriate 'auth_domain' as the client.
137 *
138 * pseudoflavor()
139 * Returns RPC_AUTH pseudoflavor in use by @rqstp.
140 */
141 struct auth_ops {
142 char * name;
143 struct module *owner;
144 int flavour;
145
146 enum svc_auth_status (*accept)(struct svc_rqst *rqstp);
147 int (*release)(struct svc_rqst *rqstp);
148 void (*domain_release)(struct auth_domain *dom);
149 enum svc_auth_status (*set_client)(struct svc_rqst *rqstp);
150 rpc_authflavor_t (*pseudoflavor)(struct svc_rqst *rqstp);
151 };
152
153 struct svc_xprt;
154
155 extern rpc_authflavor_t svc_auth_flavor(struct svc_rqst *rqstp);
156 extern int svc_authorise(struct svc_rqst *rqstp);
157 extern enum svc_auth_status svc_set_client(struct svc_rqst *rqstp);
158 extern int svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
159 extern void svc_auth_unregister(rpc_authflavor_t flavor);
160
161 extern void svcauth_map_clnt_to_svc_cred_local(struct rpc_clnt *clnt,
162 const struct cred *,
163 struct svc_cred *);
164
165 extern struct auth_domain *unix_domain_find(char *name);
166 extern void auth_domain_put(struct auth_domain *item);
167 extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
168 extern struct auth_domain *auth_domain_find(char *name);
169 extern void svcauth_unix_purge(struct net *net);
170 extern void svcauth_unix_info_release(struct svc_xprt *xpt);
171 extern enum svc_auth_status svcauth_unix_set_client(struct svc_rqst *rqstp);
172
173 extern int unix_gid_cache_create(struct net *net);
174 extern void unix_gid_cache_destroy(struct net *net);
175
176 /*
177 * The <stringhash.h> functions are good enough that we don't need to
178 * use hash_32() on them; just extracting the high bits is enough.
179 */
hash_str(char const * name,int bits)180 static inline unsigned long hash_str(char const *name, int bits)
181 {
182 return hashlen_hash(hashlen_string(NULL, name)) >> (32 - bits);
183 }
184
hash_mem(char const * buf,int length,int bits)185 static inline unsigned long hash_mem(char const *buf, int length, int bits)
186 {
187 return full_name_hash(NULL, buf, length) >> (32 - bits);
188 }
189
190 #endif /* _LINUX_SUNRPC_SVCAUTH_H_ */
191