1 /*
2 * linux/net/sunrpc/svcauth.c
3 *
4 * The generic interface for RPC authentication on the server side.
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7 *
8 * CHANGES
9 * 19-Apr-2000 Chris Evans - Security fix
10 */
11
12 #include <linux/types.h>
13 #include <linux/module.h>
14 #include <linux/sunrpc/types.h>
15 #include <linux/sunrpc/xdr.h>
16 #include <linux/sunrpc/svcsock.h>
17 #include <linux/sunrpc/svcauth.h>
18 #include <linux/err.h>
19 #include <linux/hash.h>
20
21 #define RPCDBG_FACILITY RPCDBG_AUTH
22
23
24 /*
25 * Table of authenticators
26 */
27 extern struct auth_ops svcauth_null;
28 extern struct auth_ops svcauth_unix;
29
30 static DEFINE_SPINLOCK(authtab_lock);
31 static struct auth_ops *authtab[RPC_AUTH_MAXFLAVOR] = {
32 [0] = &svcauth_null,
33 [1] = &svcauth_unix,
34 };
35
36 int
svc_authenticate(struct svc_rqst * rqstp,__be32 * authp)37 svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
38 {
39 rpc_authflavor_t flavor;
40 struct auth_ops *aops;
41
42 *authp = rpc_auth_ok;
43
44 flavor = svc_getnl(&rqstp->rq_arg.head[0]);
45
46 dprintk("svc: svc_authenticate (%d)\n", flavor);
47
48 spin_lock(&authtab_lock);
49 if (flavor >= RPC_AUTH_MAXFLAVOR || !(aops = authtab[flavor]) ||
50 !try_module_get(aops->owner)) {
51 spin_unlock(&authtab_lock);
52 *authp = rpc_autherr_badcred;
53 return SVC_DENIED;
54 }
55 spin_unlock(&authtab_lock);
56
57 rqstp->rq_authop = aops;
58 return aops->accept(rqstp, authp);
59 }
60 EXPORT_SYMBOL_GPL(svc_authenticate);
61
svc_set_client(struct svc_rqst * rqstp)62 int svc_set_client(struct svc_rqst *rqstp)
63 {
64 return rqstp->rq_authop->set_client(rqstp);
65 }
66 EXPORT_SYMBOL_GPL(svc_set_client);
67
68 /* A request, which was authenticated, has now executed.
69 * Time to finalise the credentials and verifier
70 * and release and resources
71 */
svc_authorise(struct svc_rqst * rqstp)72 int svc_authorise(struct svc_rqst *rqstp)
73 {
74 struct auth_ops *aops = rqstp->rq_authop;
75 int rv = 0;
76
77 rqstp->rq_authop = NULL;
78
79 if (aops) {
80 rv = aops->release(rqstp);
81 module_put(aops->owner);
82 }
83 return rv;
84 }
85
86 int
svc_auth_register(rpc_authflavor_t flavor,struct auth_ops * aops)87 svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
88 {
89 int rv = -EINVAL;
90 spin_lock(&authtab_lock);
91 if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) {
92 authtab[flavor] = aops;
93 rv = 0;
94 }
95 spin_unlock(&authtab_lock);
96 return rv;
97 }
98 EXPORT_SYMBOL_GPL(svc_auth_register);
99
100 void
svc_auth_unregister(rpc_authflavor_t flavor)101 svc_auth_unregister(rpc_authflavor_t flavor)
102 {
103 spin_lock(&authtab_lock);
104 if (flavor < RPC_AUTH_MAXFLAVOR)
105 authtab[flavor] = NULL;
106 spin_unlock(&authtab_lock);
107 }
108 EXPORT_SYMBOL_GPL(svc_auth_unregister);
109
110 /**************************************************
111 * 'auth_domains' are stored in a hash table indexed by name.
112 * When the last reference to an 'auth_domain' is dropped,
113 * the object is unhashed and freed.
114 * If auth_domain_lookup fails to find an entry, it will return
115 * it's second argument 'new'. If this is non-null, it will
116 * have been atomically linked into the table.
117 */
118
119 #define DN_HASHBITS 6
120 #define DN_HASHMAX (1<<DN_HASHBITS)
121
122 static struct hlist_head auth_domain_table[DN_HASHMAX];
123 static spinlock_t auth_domain_lock =
124 __SPIN_LOCK_UNLOCKED(auth_domain_lock);
125
auth_domain_put(struct auth_domain * dom)126 void auth_domain_put(struct auth_domain *dom)
127 {
128 if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) {
129 hlist_del(&dom->hash);
130 dom->flavour->domain_release(dom);
131 spin_unlock(&auth_domain_lock);
132 }
133 }
134 EXPORT_SYMBOL_GPL(auth_domain_put);
135
136 struct auth_domain *
auth_domain_lookup(char * name,struct auth_domain * new)137 auth_domain_lookup(char *name, struct auth_domain *new)
138 {
139 struct auth_domain *hp;
140 struct hlist_head *head;
141 struct hlist_node *np;
142
143 head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
144
145 spin_lock(&auth_domain_lock);
146
147 hlist_for_each_entry(hp, np, head, hash) {
148 if (strcmp(hp->name, name)==0) {
149 kref_get(&hp->ref);
150 spin_unlock(&auth_domain_lock);
151 return hp;
152 }
153 }
154 if (new)
155 hlist_add_head(&new->hash, head);
156 spin_unlock(&auth_domain_lock);
157 return new;
158 }
159 EXPORT_SYMBOL_GPL(auth_domain_lookup);
160
auth_domain_find(char * name)161 struct auth_domain *auth_domain_find(char *name)
162 {
163 return auth_domain_lookup(name, NULL);
164 }
165 EXPORT_SYMBOL_GPL(auth_domain_find);
166