svcauth.c revision cca5172a7ec10dfdb0b787cd8e9d5b0b8f179793 
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/sched.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 DEFINE_SPINLOCK(authtab_lock);
32static struct auth_ops	*authtab[RPC_AUTH_MAXFLAVOR] = {
33	[0] = &svcauth_null,
34	[1] = &svcauth_unix,
35};
36
37int
38svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
39{
40	rpc_authflavor_t	flavor;
41	struct auth_ops		*aops;
42
43	*authp = rpc_auth_ok;
44
45	flavor = svc_getnl(&rqstp->rq_arg.head[0]);
46
47	dprintk("svc: svc_authenticate (%d)\n", flavor);
48
49	spin_lock(&authtab_lock);
50	if (flavor >= RPC_AUTH_MAXFLAVOR || !(aops = authtab[flavor])
51			|| !try_module_get(aops->owner)) {
52		spin_unlock(&authtab_lock);
53		*authp = rpc_autherr_badcred;
54		return SVC_DENIED;
55	}
56	spin_unlock(&authtab_lock);
57
58	rqstp->rq_authop = aops;
59	return aops->accept(rqstp, authp);
60}
61
62int svc_set_client(struct svc_rqst *rqstp)
63{
64	return rqstp->rq_authop->set_client(rqstp);
65}
66
67/* A request, which was authenticated, has now executed.
68 * Time to finalise the the credentials and verifier
69 * and release and resources
70 */
71int svc_authorise(struct svc_rqst *rqstp)
72{
73	struct auth_ops *aops = rqstp->rq_authop;
74	int rv = 0;
75
76	rqstp->rq_authop = NULL;
77
78	if (aops) {
79		rv = aops->release(rqstp);
80		module_put(aops->owner);
81	}
82	return rv;
83}
84
85int
86svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
87{
88	int rv = -EINVAL;
89	spin_lock(&authtab_lock);
90	if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) {
91		authtab[flavor] = aops;
92		rv = 0;
93	}
94	spin_unlock(&authtab_lock);
95	return rv;
96}
97
98void
99svc_auth_unregister(rpc_authflavor_t flavor)
100{
101	spin_lock(&authtab_lock);
102	if (flavor < RPC_AUTH_MAXFLAVOR)
103		authtab[flavor] = NULL;
104	spin_unlock(&authtab_lock);
105}
106EXPORT_SYMBOL(svc_auth_unregister);
107
108/**************************************************
109 * 'auth_domains' are stored in a hash table indexed by name.
110 * When the last reference to an 'auth_domain' is dropped,
111 * the object is unhashed and freed.
112 * If auth_domain_lookup fails to find an entry, it will return
113 * it's second argument 'new'.  If this is non-null, it will
114 * have been atomically linked into the table.
115 */
116
117#define	DN_HASHBITS	6
118#define	DN_HASHMAX	(1<<DN_HASHBITS)
119#define	DN_HASHMASK	(DN_HASHMAX-1)
120
121static struct hlist_head	auth_domain_table[DN_HASHMAX];
122static spinlock_t	auth_domain_lock =
123	__SPIN_LOCK_UNLOCKED(auth_domain_lock);
124
125void auth_domain_put(struct auth_domain *dom)
126{
127	if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) {
128		hlist_del(&dom->hash);
129		dom->flavour->domain_release(dom);
130		spin_unlock(&auth_domain_lock);
131	}
132}
133
134struct auth_domain *
135auth_domain_lookup(char *name, struct auth_domain *new)
136{
137	struct auth_domain *hp;
138	struct hlist_head *head;
139	struct hlist_node *np;
140
141	head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
142
143	spin_lock(&auth_domain_lock);
144
145	hlist_for_each_entry(hp, np, head, hash) {
146		if (strcmp(hp->name, name)==0) {
147			kref_get(&hp->ref);
148			spin_unlock(&auth_domain_lock);
149			return hp;
150		}
151	}
152	if (new)
153		hlist_add_head(&new->hash, head);
154	spin_unlock(&auth_domain_lock);
155	return new;
156}
157
158struct auth_domain *auth_domain_find(char *name)
159{
160	return auth_domain_lookup(name, NULL);
161}
162