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