linux/net/sunrpc/svcauth.c
J. Bruce Fields a5cddc885b nfsd4: better reservation of head space for krb5
RPC_MAX_AUTH_SIZE is scattered around several places.  Better to set it
once in the auth code, where this kind of estimate should be made.  And
while we're at it we can leave it zero when we're not using krb5i or
krb5p.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:17 -04:00

167 lines
3.7 KiB
C

/*
* linux/net/sunrpc/svcauth.c
*
* The generic interface for RPC authentication on the server side.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*
* CHANGES
* 19-Apr-2000 Chris Evans - Security fix
*/
#include <linux/types.h>
#include <linux/module.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/err.h>
#include <linux/hash.h>
#define RPCDBG_FACILITY RPCDBG_AUTH
/*
* Table of authenticators
*/
extern struct auth_ops svcauth_null;
extern struct auth_ops svcauth_unix;
static DEFINE_SPINLOCK(authtab_lock);
static struct auth_ops *authtab[RPC_AUTH_MAXFLAVOR] = {
[0] = &svcauth_null,
[1] = &svcauth_unix,
};
int
svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
{
rpc_authflavor_t flavor;
struct auth_ops *aops;
*authp = rpc_auth_ok;
flavor = svc_getnl(&rqstp->rq_arg.head[0]);
dprintk("svc: svc_authenticate (%d)\n", flavor);
spin_lock(&authtab_lock);
if (flavor >= RPC_AUTH_MAXFLAVOR || !(aops = authtab[flavor]) ||
!try_module_get(aops->owner)) {
spin_unlock(&authtab_lock);
*authp = rpc_autherr_badcred;
return SVC_DENIED;
}
spin_unlock(&authtab_lock);
rqstp->rq_auth_slack = 0;
rqstp->rq_authop = aops;
return aops->accept(rqstp, authp);
}
EXPORT_SYMBOL_GPL(svc_authenticate);
int svc_set_client(struct svc_rqst *rqstp)
{
return rqstp->rq_authop->set_client(rqstp);
}
EXPORT_SYMBOL_GPL(svc_set_client);
/* A request, which was authenticated, has now executed.
* Time to finalise the credentials and verifier
* and release and resources
*/
int svc_authorise(struct svc_rqst *rqstp)
{
struct auth_ops *aops = rqstp->rq_authop;
int rv = 0;
rqstp->rq_authop = NULL;
if (aops) {
rv = aops->release(rqstp);
module_put(aops->owner);
}
return rv;
}
int
svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
{
int rv = -EINVAL;
spin_lock(&authtab_lock);
if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) {
authtab[flavor] = aops;
rv = 0;
}
spin_unlock(&authtab_lock);
return rv;
}
EXPORT_SYMBOL_GPL(svc_auth_register);
void
svc_auth_unregister(rpc_authflavor_t flavor)
{
spin_lock(&authtab_lock);
if (flavor < RPC_AUTH_MAXFLAVOR)
authtab[flavor] = NULL;
spin_unlock(&authtab_lock);
}
EXPORT_SYMBOL_GPL(svc_auth_unregister);
/**************************************************
* 'auth_domains' are stored in a hash table indexed by name.
* When the last reference to an 'auth_domain' is dropped,
* the object is unhashed and freed.
* If auth_domain_lookup fails to find an entry, it will return
* it's second argument 'new'. If this is non-null, it will
* have been atomically linked into the table.
*/
#define DN_HASHBITS 6
#define DN_HASHMAX (1<<DN_HASHBITS)
static struct hlist_head auth_domain_table[DN_HASHMAX];
static spinlock_t auth_domain_lock =
__SPIN_LOCK_UNLOCKED(auth_domain_lock);
void auth_domain_put(struct auth_domain *dom)
{
if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) {
hlist_del(&dom->hash);
dom->flavour->domain_release(dom);
spin_unlock(&auth_domain_lock);
}
}
EXPORT_SYMBOL_GPL(auth_domain_put);
struct auth_domain *
auth_domain_lookup(char *name, struct auth_domain *new)
{
struct auth_domain *hp;
struct hlist_head *head;
head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
spin_lock(&auth_domain_lock);
hlist_for_each_entry(hp, head, hash) {
if (strcmp(hp->name, name)==0) {
kref_get(&hp->ref);
spin_unlock(&auth_domain_lock);
return hp;
}
}
if (new)
hlist_add_head(&new->hash, head);
spin_unlock(&auth_domain_lock);
return new;
}
EXPORT_SYMBOL_GPL(auth_domain_lookup);
struct auth_domain *auth_domain_find(char *name)
{
return auth_domain_lookup(name, NULL);
}
EXPORT_SYMBOL_GPL(auth_domain_find);