linux/net/sunrpc/svcauth.c

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/*
* 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/sched.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, u32 *authp)
{
rpc_authflavor_t flavor;
struct auth_ops *aops;
*authp = rpc_auth_ok;
flavor = ntohl(svc_getu32(&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_authop = aops;
return aops->accept(rqstp, authp);
}
int svc_set_client(struct svc_rqst *rqstp)
{
return rqstp->rq_authop->set_client(rqstp);
}
/* A request, which was authenticated, has now executed.
* Time to finalise the 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;
}
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(svc_auth_unregister);
/**************************************************
* cache for domain name to auth_domain
* Entries are only added by flavours which will normally
* have a structure that 'inherits' from auth_domain.
* e.g. when an IP -> domainname is given to auth_unix,
* and the domain name doesn't exist, it will create a
* auth_unix_domain and add it to this hash table.
* If it finds the name does exist, but isn't AUTH_UNIX,
* it will complain.
*/
/*
* Auth auth_domain cache is somewhat different to other caches,
* largely because the entries are possibly of different types:
* each auth flavour has it's own type.
* One consequence of this that DefineCacheLookup cannot
* allocate a new structure as it cannot know the size.
* Notice that the "INIT" code fragment is quite different
* from other caches. When auth_domain_lookup might be
* creating a new domain, the new domain is passed in
* complete and it is used as-is rather than being copied into
* another structure.
*/
#define DN_HASHBITS 6
#define DN_HASHMAX (1<<DN_HASHBITS)
#define DN_HASHMASK (DN_HASHMAX-1)
static struct cache_head *auth_domain_table[DN_HASHMAX];
static void auth_domain_drop(struct cache_head *item, struct cache_detail *cd)
{
struct auth_domain *dom = container_of(item, struct auth_domain, h);
if (cache_put(item,cd))
authtab[dom->flavour]->domain_release(dom);
}
struct cache_detail auth_domain_cache = {
.owner = THIS_MODULE,
.hash_size = DN_HASHMAX,
.hash_table = auth_domain_table,
.name = "auth.domain",
.cache_put = auth_domain_drop,
};
void auth_domain_put(struct auth_domain *dom)
{
auth_domain_drop(&dom->h, &auth_domain_cache);
}
static inline int auth_domain_hash(struct auth_domain *item)
{
return hash_str(item->name, DN_HASHBITS);
}
static inline int auth_domain_match(struct auth_domain *tmp, struct auth_domain *item)
{
return strcmp(tmp->name, item->name) == 0;
}
struct auth_domain *
auth_domain_lookup(struct auth_domain *item, int set)
{
struct auth_domain *tmp = NULL;
struct cache_head **hp, **head;
head = &auth_domain_cache.hash_table[auth_domain_hash(item)];
if (set)
write_lock(&auth_domain_cache.hash_lock);
else
read_lock(&auth_domain_cache.hash_lock);
for (hp=head; *hp != NULL; hp = &tmp->h.next) {
tmp = container_of(*hp, struct auth_domain, h);
if (!auth_domain_match(tmp, item))
continue;
if (!set) {
cache_get(&tmp->h);
goto out_noset;
}
*hp = tmp->h.next;
tmp->h.next = NULL;
auth_domain_drop(&tmp->h, &auth_domain_cache);
goto out_set;
}
/* Didn't find anything */
if (!set)
goto out_nada;
auth_domain_cache.entries++;
out_set:
item->h.next = *head;
*head = &item->h;
cache_get(&item->h);
write_unlock(&auth_domain_cache.hash_lock);
cache_fresh(&auth_domain_cache, &item->h, item->h.expiry_time);
cache_get(&item->h);
return item;
out_nada:
tmp = NULL;
out_noset:
read_unlock(&auth_domain_cache.hash_lock);
return tmp;
}
struct auth_domain *auth_domain_find(char *name)
{
struct auth_domain *rv, ad;
ad.name = name;
rv = auth_domain_lookup(&ad, 0);
return rv;
}