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
59	rqstp->rq_authop = aops;
60	return aops->accept(rqstp, authp);
61}
62EXPORT_SYMBOL_GPL(svc_authenticate);
63
64int svc_set_client(struct svc_rqst *rqstp)
65{
66	return rqstp->rq_authop->set_client(rqstp);
67}
68EXPORT_SYMBOL_GPL(svc_set_client);
69
70/* A request, which was authenticated, has now executed.
71 * Time to finalise the credentials and verifier
72 * and release and resources
73 */
74int svc_authorise(struct svc_rqst *rqstp)
75{
76	struct auth_ops *aops = rqstp->rq_authop;
77	int rv = 0;
78
79	rqstp->rq_authop = NULL;
80
81	if (aops) {
82		rv = aops->release(rqstp);
83		module_put(aops->owner);
84	}
85	return rv;
86}
87
88int
89svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
90{
91	int rv = -EINVAL;
92	spin_lock(&authtab_lock);
93	if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) {
94		authtab[flavor] = aops;
95		rv = 0;
96	}
97	spin_unlock(&authtab_lock);
98	return rv;
99}
100EXPORT_SYMBOL_GPL(svc_auth_register);
101
102void
103svc_auth_unregister(rpc_authflavor_t flavor)
104{
105	spin_lock(&authtab_lock);
106	if (flavor < RPC_AUTH_MAXFLAVOR)
107		authtab[flavor] = NULL;
108	spin_unlock(&authtab_lock);
109}
110EXPORT_SYMBOL_GPL(svc_auth_unregister);
111
112/**************************************************
113 * 'auth_domains' are stored in a hash table indexed by name.
114 * When the last reference to an 'auth_domain' is dropped,
115 * the object is unhashed and freed.
116 * If auth_domain_lookup fails to find an entry, it will return
117 * it's second argument 'new'.  If this is non-null, it will
118 * have been atomically linked into the table.
119 */
120
121#define	DN_HASHBITS	6
122#define	DN_HASHMAX	(1<<DN_HASHBITS)
123
124static struct hlist_head	auth_domain_table[DN_HASHMAX];
125static spinlock_t	auth_domain_lock =
126	__SPIN_LOCK_UNLOCKED(auth_domain_lock);
127
128void auth_domain_put(struct auth_domain *dom)
129{
130	if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) {
131		hlist_del(&dom->hash);
132		dom->flavour->domain_release(dom);
133		spin_unlock(&auth_domain_lock);
134	}
135}
136EXPORT_SYMBOL_GPL(auth_domain_put);
137
138struct auth_domain *
139auth_domain_lookup(char *name, struct auth_domain *new)
140{
141	struct auth_domain *hp;
142	struct hlist_head *head;
143
144	head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
145
146	spin_lock(&auth_domain_lock);
147
148	hlist_for_each_entry(hp, head, hash) {
149		if (strcmp(hp->name, name)==0) {
150			kref_get(&hp->ref);
151			spin_unlock(&auth_domain_lock);
152			return hp;
153		}
154	}
155	if (new)
156		hlist_add_head(&new->hash, head);
157	spin_unlock(&auth_domain_lock);
158	return new;
159}
160EXPORT_SYMBOL_GPL(auth_domain_lookup);
161
162struct auth_domain *auth_domain_find(char *name)
163{
164	return auth_domain_lookup(name, NULL);
165}
166EXPORT_SYMBOL_GPL(auth_domain_find);
167