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v5.9
  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}
v5.4
  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#define RPCDBG_FACILITY	RPCDBG_AUTH
 23
 24
 25/*
 26 * Table of authenticators
 27 */
 28extern struct auth_ops svcauth_null;
 29extern struct auth_ops svcauth_unix;
 30
 31static struct auth_ops __rcu *authtab[RPC_AUTH_MAXFLAVOR] = {
 32	[RPC_AUTH_NULL] = (struct auth_ops __force __rcu *)&svcauth_null,
 33	[RPC_AUTH_UNIX] = (struct auth_ops __force __rcu *)&svcauth_unix,
 34};
 35
 36static struct auth_ops *
 37svc_get_auth_ops(rpc_authflavor_t flavor)
 38{
 39	struct auth_ops		*aops;
 40
 41	if (flavor >= RPC_AUTH_MAXFLAVOR)
 42		return NULL;
 43	rcu_read_lock();
 44	aops = rcu_dereference(authtab[flavor]);
 45	if (aops != NULL && !try_module_get(aops->owner))
 46		aops = NULL;
 47	rcu_read_unlock();
 48	return aops;
 49}
 50
 51static void
 52svc_put_auth_ops(struct auth_ops *aops)
 53{
 54	module_put(aops->owner);
 55}
 56
 57int
 58svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
 59{
 60	rpc_authflavor_t	flavor;
 61	struct auth_ops		*aops;
 62
 63	*authp = rpc_auth_ok;
 64
 65	flavor = svc_getnl(&rqstp->rq_arg.head[0]);
 66
 67	dprintk("svc: svc_authenticate (%d)\n", flavor);
 68
 69	aops = svc_get_auth_ops(flavor);
 70	if (aops == NULL) {
 71		*authp = rpc_autherr_badcred;
 72		return SVC_DENIED;
 73	}
 74
 75	rqstp->rq_auth_slack = 0;
 76	init_svc_cred(&rqstp->rq_cred);
 77
 78	rqstp->rq_authop = aops;
 79	return aops->accept(rqstp, authp);
 80}
 81EXPORT_SYMBOL_GPL(svc_authenticate);
 82
 83int svc_set_client(struct svc_rqst *rqstp)
 84{
 85	rqstp->rq_client = NULL;
 86	return rqstp->rq_authop->set_client(rqstp);
 87}
 88EXPORT_SYMBOL_GPL(svc_set_client);
 89
 90/* A request, which was authenticated, has now executed.
 91 * Time to finalise the credentials and verifier
 92 * and release and resources
 93 */
 94int svc_authorise(struct svc_rqst *rqstp)
 95{
 96	struct auth_ops *aops = rqstp->rq_authop;
 97	int rv = 0;
 98
 99	rqstp->rq_authop = NULL;
100
101	if (aops) {
102		rv = aops->release(rqstp);
103		svc_put_auth_ops(aops);
104	}
105	return rv;
106}
107
108int
109svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
110{
111	struct auth_ops *old;
112	int rv = -EINVAL;
113
114	if (flavor < RPC_AUTH_MAXFLAVOR) {
115		old = cmpxchg((struct auth_ops ** __force)&authtab[flavor], NULL, aops);
116		if (old == NULL || old == aops)
117			rv = 0;
118	}
119	return rv;
120}
121EXPORT_SYMBOL_GPL(svc_auth_register);
122
123void
124svc_auth_unregister(rpc_authflavor_t flavor)
125{
126	if (flavor < RPC_AUTH_MAXFLAVOR)
127		rcu_assign_pointer(authtab[flavor], NULL);
128}
129EXPORT_SYMBOL_GPL(svc_auth_unregister);
130
131/**************************************************
132 * 'auth_domains' are stored in a hash table indexed by name.
133 * When the last reference to an 'auth_domain' is dropped,
134 * the object is unhashed and freed.
135 * If auth_domain_lookup fails to find an entry, it will return
136 * it's second argument 'new'.  If this is non-null, it will
137 * have been atomically linked into the table.
138 */
139
140#define	DN_HASHBITS	6
141#define	DN_HASHMAX	(1<<DN_HASHBITS)
142
143static struct hlist_head	auth_domain_table[DN_HASHMAX];
144static DEFINE_SPINLOCK(auth_domain_lock);
145
146static void auth_domain_release(struct kref *kref)
147	__releases(&auth_domain_lock)
148{
149	struct auth_domain *dom = container_of(kref, struct auth_domain, ref);
150
151	hlist_del_rcu(&dom->hash);
152	dom->flavour->domain_release(dom);
153	spin_unlock(&auth_domain_lock);
154}
155
156void auth_domain_put(struct auth_domain *dom)
157{
158	kref_put_lock(&dom->ref, auth_domain_release, &auth_domain_lock);
159}
160EXPORT_SYMBOL_GPL(auth_domain_put);
161
162struct auth_domain *
163auth_domain_lookup(char *name, struct auth_domain *new)
164{
165	struct auth_domain *hp;
166	struct hlist_head *head;
167
168	head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
169
170	spin_lock(&auth_domain_lock);
171
172	hlist_for_each_entry(hp, head, hash) {
173		if (strcmp(hp->name, name)==0) {
174			kref_get(&hp->ref);
175			spin_unlock(&auth_domain_lock);
176			return hp;
177		}
178	}
179	if (new)
180		hlist_add_head_rcu(&new->hash, head);
181	spin_unlock(&auth_domain_lock);
182	return new;
183}
184EXPORT_SYMBOL_GPL(auth_domain_lookup);
185
186struct auth_domain *auth_domain_find(char *name)
187{
188	struct auth_domain *hp;
189	struct hlist_head *head;
190
191	head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
192
193	rcu_read_lock();
194	hlist_for_each_entry_rcu(hp, head, hash) {
195		if (strcmp(hp->name, name)==0) {
196			if (!kref_get_unless_zero(&hp->ref))
197				hp = NULL;
198			rcu_read_unlock();
199			return hp;
200		}
201	}
202	rcu_read_unlock();
203	return NULL;
204}
205EXPORT_SYMBOL_GPL(auth_domain_find);