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 #include <trace/events/sunrpc.h>
22
23 #include "sunrpc.h"
24
25 #define RPCDBG_FACILITY RPCDBG_AUTH
26
27
28 /*
29 * Table of authenticators
30 */
31 extern struct auth_ops svcauth_null;
32 extern struct auth_ops svcauth_unix;
33
34 static DEFINE_SPINLOCK(authtab_lock);
35 static struct auth_ops *authtab[RPC_AUTH_MAXFLAVOR] = {
36 [0] = &svcauth_null,
37 [1] = &svcauth_unix,
38 };
39
40 int
svc_authenticate(struct svc_rqst * rqstp,__be32 * authp)41 svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
42 {
43 rpc_authflavor_t flavor;
44 struct auth_ops *aops;
45
46 *authp = rpc_auth_ok;
47
48 flavor = svc_getnl(&rqstp->rq_arg.head[0]);
49
50 dprintk("svc: svc_authenticate (%d)\n", flavor);
51
52 spin_lock(&authtab_lock);
53 if (flavor >= RPC_AUTH_MAXFLAVOR || !(aops = authtab[flavor]) ||
54 !try_module_get(aops->owner)) {
55 spin_unlock(&authtab_lock);
56 *authp = rpc_autherr_badcred;
57 return SVC_DENIED;
58 }
59 spin_unlock(&authtab_lock);
60
61 rqstp->rq_auth_slack = 0;
62 init_svc_cred(&rqstp->rq_cred);
63
64 rqstp->rq_authop = aops;
65 return aops->accept(rqstp, authp);
66 }
67 EXPORT_SYMBOL_GPL(svc_authenticate);
68
svc_set_client(struct svc_rqst * rqstp)69 int svc_set_client(struct svc_rqst *rqstp)
70 {
71 rqstp->rq_client = NULL;
72 return rqstp->rq_authop->set_client(rqstp);
73 }
74 EXPORT_SYMBOL_GPL(svc_set_client);
75
76 /* A request, which was authenticated, has now executed.
77 * Time to finalise the credentials and verifier
78 * and release and resources
79 */
svc_authorise(struct svc_rqst * rqstp)80 int svc_authorise(struct svc_rqst *rqstp)
81 {
82 struct auth_ops *aops = rqstp->rq_authop;
83 int rv = 0;
84
85 rqstp->rq_authop = NULL;
86
87 if (aops) {
88 rv = aops->release(rqstp);
89 module_put(aops->owner);
90 }
91 return rv;
92 }
93
94 int
svc_auth_register(rpc_authflavor_t flavor,struct auth_ops * aops)95 svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
96 {
97 int rv = -EINVAL;
98 spin_lock(&authtab_lock);
99 if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) {
100 authtab[flavor] = aops;
101 rv = 0;
102 }
103 spin_unlock(&authtab_lock);
104 return rv;
105 }
106 EXPORT_SYMBOL_GPL(svc_auth_register);
107
108 void
svc_auth_unregister(rpc_authflavor_t flavor)109 svc_auth_unregister(rpc_authflavor_t flavor)
110 {
111 spin_lock(&authtab_lock);
112 if (flavor < RPC_AUTH_MAXFLAVOR)
113 authtab[flavor] = NULL;
114 spin_unlock(&authtab_lock);
115 }
116 EXPORT_SYMBOL_GPL(svc_auth_unregister);
117
118 /**************************************************
119 * 'auth_domains' are stored in a hash table indexed by name.
120 * When the last reference to an 'auth_domain' is dropped,
121 * the object is unhashed and freed.
122 * If auth_domain_lookup fails to find an entry, it will return
123 * it's second argument 'new'. If this is non-null, it will
124 * have been atomically linked into the table.
125 */
126
127 #define DN_HASHBITS 6
128 #define DN_HASHMAX (1<<DN_HASHBITS)
129
130 static struct hlist_head auth_domain_table[DN_HASHMAX];
131 static DEFINE_SPINLOCK(auth_domain_lock);
132
auth_domain_release(struct kref * kref)133 static void auth_domain_release(struct kref *kref)
134 {
135 struct auth_domain *dom = container_of(kref, struct auth_domain, ref);
136
137 hlist_del(&dom->hash);
138 dom->flavour->domain_release(dom);
139 spin_unlock(&auth_domain_lock);
140 }
141
auth_domain_put(struct auth_domain * dom)142 void auth_domain_put(struct auth_domain *dom)
143 {
144 kref_put_lock(&dom->ref, auth_domain_release, &auth_domain_lock);
145 }
146 EXPORT_SYMBOL_GPL(auth_domain_put);
147
148 struct auth_domain *
auth_domain_lookup(char * name,struct auth_domain * new)149 auth_domain_lookup(char *name, struct auth_domain *new)
150 {
151 struct auth_domain *hp;
152 struct hlist_head *head;
153
154 head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
155
156 spin_lock(&auth_domain_lock);
157
158 hlist_for_each_entry(hp, head, hash) {
159 if (strcmp(hp->name, name)==0) {
160 kref_get(&hp->ref);
161 spin_unlock(&auth_domain_lock);
162 return hp;
163 }
164 }
165 if (new)
166 hlist_add_head(&new->hash, head);
167 spin_unlock(&auth_domain_lock);
168 return new;
169 }
170 EXPORT_SYMBOL_GPL(auth_domain_lookup);
171
auth_domain_find(char * name)172 struct auth_domain *auth_domain_find(char *name)
173 {
174 return auth_domain_lookup(name, NULL);
175 }
176 EXPORT_SYMBOL_GPL(auth_domain_find);
177
178 /**
179 * auth_domain_cleanup - check that the auth_domain table is empty
180 *
181 * On module unload the auth_domain_table must be empty. To make it
182 * easier to catch bugs which don't clean up domains properly, we
183 * warn if anything remains in the table at cleanup time.
184 *
185 * Note that we cannot proactively remove the domains at this stage.
186 * The ->release() function might be in a module that has already been
187 * unloaded.
188 */
189
auth_domain_cleanup(void)190 void auth_domain_cleanup(void)
191 {
192 int h;
193 struct auth_domain *hp;
194
195 for (h = 0; h < DN_HASHMAX; h++)
196 hlist_for_each_entry(hp, &auth_domain_table[h], hash)
197 pr_warn("svc: domain %s still present at module unload.\n",
198 hp->name);
199 }
200