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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;
34extern struct auth_ops svcauth_tls;
35
36static struct auth_ops __rcu *authtab[RPC_AUTH_MAXFLAVOR] = {
37 [RPC_AUTH_NULL] = (struct auth_ops __force __rcu *)&svcauth_null,
38 [RPC_AUTH_UNIX] = (struct auth_ops __force __rcu *)&svcauth_unix,
39 [RPC_AUTH_TLS] = (struct auth_ops __force __rcu *)&svcauth_tls,
40};
41
42static struct auth_ops *
43svc_get_auth_ops(rpc_authflavor_t flavor)
44{
45 struct auth_ops *aops;
46
47 if (flavor >= RPC_AUTH_MAXFLAVOR)
48 return NULL;
49 rcu_read_lock();
50 aops = rcu_dereference(authtab[flavor]);
51 if (aops != NULL && !try_module_get(aops->owner))
52 aops = NULL;
53 rcu_read_unlock();
54 return aops;
55}
56
57static void
58svc_put_auth_ops(struct auth_ops *aops)
59{
60 module_put(aops->owner);
61}
62
63/**
64 * svc_authenticate - Initialize an outgoing credential
65 * @rqstp: RPC execution context
66 *
67 * Return values:
68 * %SVC_OK: XDR encoding of the result can begin
69 * %SVC_DENIED: Credential or verifier is not valid
70 * %SVC_GARBAGE: Failed to decode credential or verifier
71 * %SVC_COMPLETE: GSS context lifetime event; no further action
72 * %SVC_DROP: Drop this request; no further action
73 * %SVC_CLOSE: Like drop, but also close transport connection
74 */
75enum svc_auth_status svc_authenticate(struct svc_rqst *rqstp)
76{
77 struct auth_ops *aops;
78 u32 flavor;
79
80 rqstp->rq_auth_stat = rpc_auth_ok;
81
82 /*
83 * Decode the Call credential's flavor field. The credential's
84 * body field is decoded in the chosen ->accept method below.
85 */
86 if (xdr_stream_decode_u32(&rqstp->rq_arg_stream, &flavor) < 0)
87 return SVC_GARBAGE;
88
89 aops = svc_get_auth_ops(flavor);
90 if (aops == NULL) {
91 rqstp->rq_auth_stat = rpc_autherr_badcred;
92 return SVC_DENIED;
93 }
94
95 rqstp->rq_auth_slack = 0;
96 init_svc_cred(&rqstp->rq_cred);
97
98 rqstp->rq_authop = aops;
99 return aops->accept(rqstp);
100}
101EXPORT_SYMBOL_GPL(svc_authenticate);
102
103/**
104 * svc_set_client - Assign an appropriate 'auth_domain' as the client
105 * @rqstp: RPC execution context
106 *
107 * Return values:
108 * %SVC_OK: Client was found and assigned
109 * %SVC_DENY: Client was explicitly denied
110 * %SVC_DROP: Ignore this request
111 * %SVC_CLOSE: Ignore this request and close the connection
112 */
113enum svc_auth_status svc_set_client(struct svc_rqst *rqstp)
114{
115 rqstp->rq_client = NULL;
116 return rqstp->rq_authop->set_client(rqstp);
117}
118EXPORT_SYMBOL_GPL(svc_set_client);
119
120/**
121 * svc_authorise - Finalize credentials/verifier and release resources
122 * @rqstp: RPC execution context
123 *
124 * Returns zero on success, or a negative errno.
125 */
126int svc_authorise(struct svc_rqst *rqstp)
127{
128 struct auth_ops *aops = rqstp->rq_authop;
129 int rv = 0;
130
131 rqstp->rq_authop = NULL;
132
133 if (aops) {
134 rv = aops->release(rqstp);
135 svc_put_auth_ops(aops);
136 }
137 return rv;
138}
139
140int
141svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
142{
143 struct auth_ops *old;
144 int rv = -EINVAL;
145
146 if (flavor < RPC_AUTH_MAXFLAVOR) {
147 old = cmpxchg((struct auth_ops ** __force)&authtab[flavor], NULL, aops);
148 if (old == NULL || old == aops)
149 rv = 0;
150 }
151 return rv;
152}
153EXPORT_SYMBOL_GPL(svc_auth_register);
154
155void
156svc_auth_unregister(rpc_authflavor_t flavor)
157{
158 if (flavor < RPC_AUTH_MAXFLAVOR)
159 rcu_assign_pointer(authtab[flavor], NULL);
160}
161EXPORT_SYMBOL_GPL(svc_auth_unregister);
162
163/**
164 * svc_auth_flavor - return RPC transaction's RPC_AUTH flavor
165 * @rqstp: RPC transaction context
166 *
167 * Returns an RPC flavor or GSS pseudoflavor.
168 */
169rpc_authflavor_t svc_auth_flavor(struct svc_rqst *rqstp)
170{
171 struct auth_ops *aops = rqstp->rq_authop;
172
173 if (!aops->pseudoflavor)
174 return aops->flavour;
175 return aops->pseudoflavor(rqstp);
176}
177EXPORT_SYMBOL_GPL(svc_auth_flavor);
178
179/**************************************************
180 * 'auth_domains' are stored in a hash table indexed by name.
181 * When the last reference to an 'auth_domain' is dropped,
182 * the object is unhashed and freed.
183 * If auth_domain_lookup fails to find an entry, it will return
184 * it's second argument 'new'. If this is non-null, it will
185 * have been atomically linked into the table.
186 */
187
188#define DN_HASHBITS 6
189#define DN_HASHMAX (1<<DN_HASHBITS)
190
191static struct hlist_head auth_domain_table[DN_HASHMAX];
192static DEFINE_SPINLOCK(auth_domain_lock);
193
194static void auth_domain_release(struct kref *kref)
195 __releases(&auth_domain_lock)
196{
197 struct auth_domain *dom = container_of(kref, struct auth_domain, ref);
198
199 hlist_del_rcu(&dom->hash);
200 dom->flavour->domain_release(dom);
201 spin_unlock(&auth_domain_lock);
202}
203
204void auth_domain_put(struct auth_domain *dom)
205{
206 kref_put_lock(&dom->ref, auth_domain_release, &auth_domain_lock);
207}
208EXPORT_SYMBOL_GPL(auth_domain_put);
209
210struct auth_domain *
211auth_domain_lookup(char *name, struct auth_domain *new)
212{
213 struct auth_domain *hp;
214 struct hlist_head *head;
215
216 head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
217
218 spin_lock(&auth_domain_lock);
219
220 hlist_for_each_entry(hp, head, hash) {
221 if (strcmp(hp->name, name)==0) {
222 kref_get(&hp->ref);
223 spin_unlock(&auth_domain_lock);
224 return hp;
225 }
226 }
227 if (new)
228 hlist_add_head_rcu(&new->hash, head);
229 spin_unlock(&auth_domain_lock);
230 return new;
231}
232EXPORT_SYMBOL_GPL(auth_domain_lookup);
233
234struct auth_domain *auth_domain_find(char *name)
235{
236 struct auth_domain *hp;
237 struct hlist_head *head;
238
239 head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
240
241 rcu_read_lock();
242 hlist_for_each_entry_rcu(hp, head, hash) {
243 if (strcmp(hp->name, name)==0) {
244 if (!kref_get_unless_zero(&hp->ref))
245 hp = NULL;
246 rcu_read_unlock();
247 return hp;
248 }
249 }
250 rcu_read_unlock();
251 return NULL;
252}
253EXPORT_SYMBOL_GPL(auth_domain_find);
254
255/**
256 * auth_domain_cleanup - check that the auth_domain table is empty
257 *
258 * On module unload the auth_domain_table must be empty. To make it
259 * easier to catch bugs which don't clean up domains properly, we
260 * warn if anything remains in the table at cleanup time.
261 *
262 * Note that we cannot proactively remove the domains at this stage.
263 * The ->release() function might be in a module that has already been
264 * unloaded.
265 */
266
267void auth_domain_cleanup(void)
268{
269 int h;
270 struct auth_domain *hp;
271
272 for (h = 0; h < DN_HASHMAX; h++)
273 hlist_for_each_entry(hp, &auth_domain_table[h], hash)
274 pr_warn("svc: domain %s still present at module unload.\n",
275 hp->name);
276}
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_authop = aops;
58 return aops->accept(rqstp, authp);
59}
60EXPORT_SYMBOL_GPL(svc_authenticate);
61
62int svc_set_client(struct svc_rqst *rqstp)
63{
64 return rqstp->rq_authop->set_client(rqstp);
65}
66EXPORT_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 */
72int 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
86int
87svc_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}
98EXPORT_SYMBOL_GPL(svc_auth_register);
99
100void
101svc_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}
108EXPORT_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
122static struct hlist_head auth_domain_table[DN_HASHMAX];
123static spinlock_t auth_domain_lock =
124 __SPIN_LOCK_UNLOCKED(auth_domain_lock);
125
126void 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}
134EXPORT_SYMBOL_GPL(auth_domain_put);
135
136struct auth_domain *
137auth_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}
159EXPORT_SYMBOL_GPL(auth_domain_lookup);
160
161struct auth_domain *auth_domain_find(char *name)
162{
163 return auth_domain_lookup(name, NULL);
164}
165EXPORT_SYMBOL_GPL(auth_domain_find);