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 #ifdef __KERNEL__
14
15 #include <linux/string.h>
16 #include <linux/sunrpc/msg_prot.h>
17 #include <linux/sunrpc/cache.h>
18 #include <linux/sunrpc/gss_api.h>
19 #include <linux/hash.h>
20 #include <linux/stringhash.h>
21 #include <linux/cred.h>
22
23 struct svc_cred {
24 kuid_t cr_uid;
25 kgid_t cr_gid;
26 struct group_info *cr_group_info;
27 u32 cr_flavor; /* pseudoflavor */
28 /* name of form servicetype/hostname@REALM, passed down by
29 * gss-proxy: */
30 char *cr_raw_principal;
31 /* name of form servicetype@hostname, passed down by
32 * rpc.svcgssd, or computed from the above: */
33 char *cr_principal;
34 char *cr_targ_princ;
35 struct gss_api_mech *cr_gss_mech;
36 };
37
38 static inline void init_svc_cred(struct svc_cred *cred)
39 {
40 cred->cr_group_info = NULL;
41 cred->cr_raw_principal = NULL;
42 cred->cr_principal = NULL;
43 cred->cr_targ_princ = NULL;
44 cred->cr_gss_mech = NULL;
45 }
46
47 static inline void free_svc_cred(struct svc_cred *cred)
48 {
49 if (cred->cr_group_info)
50 put_group_info(cred->cr_group_info);
51 kfree(cred->cr_raw_principal);
52 kfree(cred->cr_principal);
53 kfree(cred->cr_targ_princ);
54 gss_mech_put(cred->cr_gss_mech);
55 init_svc_cred(cred);
56 }
57
58 struct svc_rqst; /* forward decl */
59 struct in6_addr;
60
61 /* Authentication is done in the context of a domain.
62 *
63 * Currently, the nfs server uses the auth_domain to stand
64 * for the "client" listed in /etc/exports.
65 *
66 * More generally, a domain might represent a group of clients using
67 * a common mechanism for authentication and having a common mapping
68 * between local identity (uid) and network identity. All clients
69 * in a domain have similar general access rights. Each domain can
70 * contain multiple principals which will have different specific right
71 * based on normal Discretionary Access Control.
72 *
73 * A domain is created by an authentication flavour module based on name
74 * only. Userspace then fills in detail on demand.
75 *
76 * In the case of auth_unix and auth_null, the auth_domain is also
77 * associated with entries in another cache representing the mapping
78 * of ip addresses to the given client.
79 */
80 struct auth_domain {
81 struct kref ref;
82 struct hlist_node hash;
83 char *name;
84 struct auth_ops *flavour;
85 struct rcu_head rcu_head;
86 };
87
88 /*
89 * Each authentication flavour registers an auth_ops
90 * structure.
91 * name is simply the name.
92 * flavour gives the auth flavour. It determines where the flavour is registered
93 * accept() is given a request and should verify it.
94 * It should inspect the authenticator and verifier, and possibly the data.
95 * If there is a problem with the authentication *authp should be set.
96 * The return value of accept() can indicate:
97 * OK - authorised. client and credential are set in rqstp.
98 * reqbuf points to arguments
99 * resbuf points to good place for results. verfier
100 * is (probably) already in place. Certainly space is
101 * reserved for it.
102 * DROP - simply drop the request. It may have been deferred
103 * GARBAGE - rpc garbage_args error
104 * SYSERR - rpc system_err error
105 * DENIED - authp holds reason for denial.
106 * COMPLETE - the reply is encoded already and ready to be sent; no
107 * further processing is necessary. (This is used for processing
108 * null procedure calls which are used to set up encryption
109 * contexts.)
110 *
111 * accept is passed the proc number so that it can accept NULL rpc requests
112 * even if it cannot authenticate the client (as is sometimes appropriate).
113 *
114 * release() is given a request after the procedure has been run.
115 * It should sign/encrypt the results if needed
116 * It should return:
117 * OK - the resbuf is ready to be sent
118 * DROP - the reply should be quitely dropped
119 * DENIED - authp holds a reason for MSG_DENIED
120 * SYSERR - rpc system_err
121 *
122 * domain_release()
123 * This call releases a domain.
124 * set_client()
125 * Givens a pending request (struct svc_rqst), finds and assigns
126 * an appropriate 'auth_domain' as the client.
127 */
128 struct auth_ops {
129 char * name;
130 struct module *owner;
131 int flavour;
132 int (*accept)(struct svc_rqst *rq, __be32 *authp);
133 int (*release)(struct svc_rqst *rq);
134 void (*domain_release)(struct auth_domain *);
135 int (*set_client)(struct svc_rqst *rq);
136 };
137
138 #define SVC_GARBAGE 1
139 #define SVC_SYSERR 2
140 #define SVC_VALID 3
141 #define SVC_NEGATIVE 4
142 #define SVC_OK 5
143 #define SVC_DROP 6
144 #define SVC_CLOSE 7 /* Like SVC_DROP, but request is definitely
145 * lost so if there is a tcp connection, it
146 * should be closed
147 */
148 #define SVC_DENIED 8
149 #define SVC_PENDING 9
150 #define SVC_COMPLETE 10
151
152 struct svc_xprt;
153
154 extern int svc_authenticate(struct svc_rqst *rqstp, __be32 *authp);
155 extern int svc_authorise(struct svc_rqst *rqstp);
156 extern int svc_set_client(struct svc_rqst *rqstp);
157 extern int svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
158 extern void svc_auth_unregister(rpc_authflavor_t flavor);
159
160 extern struct auth_domain *unix_domain_find(char *name);
161 extern void auth_domain_put(struct auth_domain *item);
162 extern int auth_unix_add_addr(struct net *net, struct in6_addr *addr, struct auth_domain *dom);
163 extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
164 extern struct auth_domain *auth_domain_find(char *name);
165 extern struct auth_domain *auth_unix_lookup(struct net *net, struct in6_addr *addr);
166 extern int auth_unix_forget_old(struct auth_domain *dom);
167 extern void svcauth_unix_purge(struct net *net);
168 extern void svcauth_unix_info_release(struct svc_xprt *xpt);
169 extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
170
171 extern int unix_gid_cache_create(struct net *net);
172 extern void unix_gid_cache_destroy(struct net *net);
173
174 /*
175 * The <stringhash.h> functions are good enough that we don't need to
176 * use hash_32() on them; just extracting the high bits is enough.
177 */
178 static inline unsigned long hash_str(char const *name, int bits)
179 {
180 return hashlen_hash(hashlen_string(NULL, name)) >> (32 - bits);
181 }
182
183 static inline unsigned long hash_mem(char const *buf, int length, int bits)
184 {
185 return full_name_hash(NULL, buf, length) >> (32 - bits);
186 }
187
188 #endif /* __KERNEL__ */
189
190 #endif /* _LINUX_SUNRPC_SVCAUTH_H_ */