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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/net/sunrpc/svcauth.c
4 *
5 * The generic interface for RPC authentication on the server side.
6 *
7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
8 *
9 * CHANGES
10 * 19-Apr-2000 Chris Evans - Security fix
11 */
12
13#include <linux/types.h>
14#include <linux/module.h>
15#include <linux/sunrpc/types.h>
16#include <linux/sunrpc/xdr.h>
17#include <linux/sunrpc/svcsock.h>
18#include <linux/sunrpc/svcauth.h>
19#include <linux/err.h>
20#include <linux/hash.h>
21
22#include <trace/events/sunrpc.h>
23
24#include "sunrpc.h"
25
26#define RPCDBG_FACILITY RPCDBG_AUTH
27
28
29/*
30 * Table of authenticators
31 */
32extern struct auth_ops svcauth_null;
33extern struct auth_ops svcauth_unix;
34
35static struct auth_ops __rcu *authtab[RPC_AUTH_MAXFLAVOR] = {
36 [RPC_AUTH_NULL] = (struct auth_ops __force __rcu *)&svcauth_null,
37 [RPC_AUTH_UNIX] = (struct auth_ops __force __rcu *)&svcauth_unix,
38};
39
40static struct auth_ops *
41svc_get_auth_ops(rpc_authflavor_t flavor)
42{
43 struct auth_ops *aops;
44
45 if (flavor >= RPC_AUTH_MAXFLAVOR)
46 return NULL;
47 rcu_read_lock();
48 aops = rcu_dereference(authtab[flavor]);
49 if (aops != NULL && !try_module_get(aops->owner))
50 aops = NULL;
51 rcu_read_unlock();
52 return aops;
53}
54
55static void
56svc_put_auth_ops(struct auth_ops *aops)
57{
58 module_put(aops->owner);
59}
60
61int
62svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
63{
64 rpc_authflavor_t flavor;
65 struct auth_ops *aops;
66
67 *authp = rpc_auth_ok;
68
69 flavor = svc_getnl(&rqstp->rq_arg.head[0]);
70
71 dprintk("svc: svc_authenticate (%d)\n", flavor);
72
73 aops = svc_get_auth_ops(flavor);
74 if (aops == NULL) {
75 *authp = rpc_autherr_badcred;
76 return SVC_DENIED;
77 }
78
79 rqstp->rq_auth_slack = 0;
80 init_svc_cred(&rqstp->rq_cred);
81
82 rqstp->rq_authop = aops;
83 return aops->accept(rqstp, authp);
84}
85EXPORT_SYMBOL_GPL(svc_authenticate);
86
87int svc_set_client(struct svc_rqst *rqstp)
88{
89 rqstp->rq_client = NULL;
90 return rqstp->rq_authop->set_client(rqstp);
91}
92EXPORT_SYMBOL_GPL(svc_set_client);
93
94/* A request, which was authenticated, has now executed.
95 * Time to finalise the credentials and verifier
96 * and release and resources
97 */
98int svc_authorise(struct svc_rqst *rqstp)
99{
100 struct auth_ops *aops = rqstp->rq_authop;
101 int rv = 0;
102
103 rqstp->rq_authop = NULL;
104
105 if (aops) {
106 rv = aops->release(rqstp);
107 svc_put_auth_ops(aops);
108 }
109 return rv;
110}
111
112int
113svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
114{
115 struct auth_ops *old;
116 int rv = -EINVAL;
117
118 if (flavor < RPC_AUTH_MAXFLAVOR) {
119 old = cmpxchg((struct auth_ops ** __force)&authtab[flavor], NULL, aops);
120 if (old == NULL || old == aops)
121 rv = 0;
122 }
123 return rv;
124}
125EXPORT_SYMBOL_GPL(svc_auth_register);
126
127void
128svc_auth_unregister(rpc_authflavor_t flavor)
129{
130 if (flavor < RPC_AUTH_MAXFLAVOR)
131 rcu_assign_pointer(authtab[flavor], NULL);
132}
133EXPORT_SYMBOL_GPL(svc_auth_unregister);
134
135/**************************************************
136 * 'auth_domains' are stored in a hash table indexed by name.
137 * When the last reference to an 'auth_domain' is dropped,
138 * the object is unhashed and freed.
139 * If auth_domain_lookup fails to find an entry, it will return
140 * it's second argument 'new'. If this is non-null, it will
141 * have been atomically linked into the table.
142 */
143
144#define DN_HASHBITS 6
145#define DN_HASHMAX (1<<DN_HASHBITS)
146
147static struct hlist_head auth_domain_table[DN_HASHMAX];
148static DEFINE_SPINLOCK(auth_domain_lock);
149
150static void auth_domain_release(struct kref *kref)
151 __releases(&auth_domain_lock)
152{
153 struct auth_domain *dom = container_of(kref, struct auth_domain, ref);
154
155 hlist_del_rcu(&dom->hash);
156 dom->flavour->domain_release(dom);
157 spin_unlock(&auth_domain_lock);
158}
159
160void auth_domain_put(struct auth_domain *dom)
161{
162 kref_put_lock(&dom->ref, auth_domain_release, &auth_domain_lock);
163}
164EXPORT_SYMBOL_GPL(auth_domain_put);
165
166struct auth_domain *
167auth_domain_lookup(char *name, struct auth_domain *new)
168{
169 struct auth_domain *hp;
170 struct hlist_head *head;
171
172 head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
173
174 spin_lock(&auth_domain_lock);
175
176 hlist_for_each_entry(hp, head, hash) {
177 if (strcmp(hp->name, name)==0) {
178 kref_get(&hp->ref);
179 spin_unlock(&auth_domain_lock);
180 return hp;
181 }
182 }
183 if (new)
184 hlist_add_head_rcu(&new->hash, head);
185 spin_unlock(&auth_domain_lock);
186 return new;
187}
188EXPORT_SYMBOL_GPL(auth_domain_lookup);
189
190struct auth_domain *auth_domain_find(char *name)
191{
192 struct auth_domain *hp;
193 struct hlist_head *head;
194
195 head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
196
197 rcu_read_lock();
198 hlist_for_each_entry_rcu(hp, head, hash) {
199 if (strcmp(hp->name, name)==0) {
200 if (!kref_get_unless_zero(&hp->ref))
201 hp = NULL;
202 rcu_read_unlock();
203 return hp;
204 }
205 }
206 rcu_read_unlock();
207 return NULL;
208}
209EXPORT_SYMBOL_GPL(auth_domain_find);
210
211/**
212 * auth_domain_cleanup - check that the auth_domain table is empty
213 *
214 * On module unload the auth_domain_table must be empty. To make it
215 * easier to catch bugs which don't clean up domains properly, we
216 * warn if anything remains in the table at cleanup time.
217 *
218 * Note that we cannot proactively remove the domains at this stage.
219 * The ->release() function might be in a module that has already been
220 * unloaded.
221 */
222
223void auth_domain_cleanup(void)
224{
225 int h;
226 struct auth_domain *hp;
227
228 for (h = 0; h < DN_HASHMAX; h++)
229 hlist_for_each_entry(hp, &auth_domain_table[h], hash)
230 pr_warn("svc: domain %s still present at module unload.\n",
231 hp->name);
232}
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 */
27extern struct auth_ops svcauth_null;
28extern struct auth_ops svcauth_unix;
29
30static DEFINE_SPINLOCK(authtab_lock);
31static struct auth_ops *authtab[RPC_AUTH_MAXFLAVOR] = {
32 [0] = &svcauth_null,
33 [1] = &svcauth_unix,
34};
35
36int
37svc_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_auth_slack = 0;
58 init_svc_cred(&rqstp->rq_cred);
59
60 rqstp->rq_authop = aops;
61 return aops->accept(rqstp, authp);
62}
63EXPORT_SYMBOL_GPL(svc_authenticate);
64
65int svc_set_client(struct svc_rqst *rqstp)
66{
67 rqstp->rq_client = NULL;
68 return rqstp->rq_authop->set_client(rqstp);
69}
70EXPORT_SYMBOL_GPL(svc_set_client);
71
72/* A request, which was authenticated, has now executed.
73 * Time to finalise the credentials and verifier
74 * and release and resources
75 */
76int svc_authorise(struct svc_rqst *rqstp)
77{
78 struct auth_ops *aops = rqstp->rq_authop;
79 int rv = 0;
80
81 rqstp->rq_authop = NULL;
82
83 if (aops) {
84 rv = aops->release(rqstp);
85 module_put(aops->owner);
86 }
87 return rv;
88}
89
90int
91svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
92{
93 int rv = -EINVAL;
94 spin_lock(&authtab_lock);
95 if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) {
96 authtab[flavor] = aops;
97 rv = 0;
98 }
99 spin_unlock(&authtab_lock);
100 return rv;
101}
102EXPORT_SYMBOL_GPL(svc_auth_register);
103
104void
105svc_auth_unregister(rpc_authflavor_t flavor)
106{
107 spin_lock(&authtab_lock);
108 if (flavor < RPC_AUTH_MAXFLAVOR)
109 authtab[flavor] = NULL;
110 spin_unlock(&authtab_lock);
111}
112EXPORT_SYMBOL_GPL(svc_auth_unregister);
113
114/**************************************************
115 * 'auth_domains' are stored in a hash table indexed by name.
116 * When the last reference to an 'auth_domain' is dropped,
117 * the object is unhashed and freed.
118 * If auth_domain_lookup fails to find an entry, it will return
119 * it's second argument 'new'. If this is non-null, it will
120 * have been atomically linked into the table.
121 */
122
123#define DN_HASHBITS 6
124#define DN_HASHMAX (1<<DN_HASHBITS)
125
126static struct hlist_head auth_domain_table[DN_HASHMAX];
127static spinlock_t auth_domain_lock =
128 __SPIN_LOCK_UNLOCKED(auth_domain_lock);
129
130void auth_domain_put(struct auth_domain *dom)
131{
132 if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) {
133 hlist_del(&dom->hash);
134 dom->flavour->domain_release(dom);
135 spin_unlock(&auth_domain_lock);
136 }
137}
138EXPORT_SYMBOL_GPL(auth_domain_put);
139
140struct auth_domain *
141auth_domain_lookup(char *name, struct auth_domain *new)
142{
143 struct auth_domain *hp;
144 struct hlist_head *head;
145
146 head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
147
148 spin_lock(&auth_domain_lock);
149
150 hlist_for_each_entry(hp, head, hash) {
151 if (strcmp(hp->name, name)==0) {
152 kref_get(&hp->ref);
153 spin_unlock(&auth_domain_lock);
154 return hp;
155 }
156 }
157 if (new)
158 hlist_add_head(&new->hash, head);
159 spin_unlock(&auth_domain_lock);
160 return new;
161}
162EXPORT_SYMBOL_GPL(auth_domain_lookup);
163
164struct auth_domain *auth_domain_find(char *name)
165{
166 return auth_domain_lookup(name, NULL);
167}
168EXPORT_SYMBOL_GPL(auth_domain_find);