/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- pseudoflavor_to_flavor
- rpcauth_register
- rpcauth_unregister
- rpcauth_create
- rpcauth_release
- rpcauth_unhash_cred_locked
- rpcauth_unhash_cred
- rpcauth_init_credcache
- rpcauth_destroy_credlist
- rpcauth_clear_credcache
- rpcauth_destroy_credcache
- rpcauth_prune_expired
- rpcauth_cache_shrinker
- rpcauth_lookup_credcache
- rpcauth_lookupcred
- rpcauth_init_cred
- rpcauth_generic_bind_cred
- rpcauth_bind_root_cred
- rpcauth_bind_new_cred
- rpcauth_bindcred
- put_rpccred
- rpcauth_unbindcred
- rpcauth_marshcred
- rpcauth_checkverf
- rpcauth_wrap_req
- rpcauth_unwrap_resp
- rpcauth_refreshcred
- rpcauth_invalcred
- rpcauth_uptodatecred
- rpcauth_init_module
- rpcauth_remove_module
/*
* linux/net/sunrpc/auth.c
*
* Generic RPC client authentication API.
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/hash.h>
#include <linux/sunrpc/clnt.h>
#include <linux/spinlock.h>
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
static DEFINE_SPINLOCK(rpc_authflavor_lock);
static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
&authnull_ops, /* AUTH_NULL */
&authunix_ops, /* AUTH_UNIX */
NULL, /* others can be loadable modules */
};
static LIST_HEAD(cred_unused);
static unsigned long number_cred_unused;
static u32
pseudoflavor_to_flavor(u32 flavor) {
if (flavor >= RPC_AUTH_MAXFLAVOR)
return RPC_AUTH_GSS;
return flavor;
}
int
rpcauth_register(const struct rpc_authops *ops)
{
rpc_authflavor_t flavor;
int ret = -EPERM;
if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
return -EINVAL;
spin_lock(&rpc_authflavor_lock);
if (auth_flavors[flavor] == NULL) {
auth_flavors[flavor] = ops;
ret = 0;
}
spin_unlock(&rpc_authflavor_lock);
return ret;
}
EXPORT_SYMBOL_GPL(rpcauth_register);
int
rpcauth_unregister(const struct rpc_authops *ops)
{
rpc_authflavor_t flavor;
int ret = -EPERM;
if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
return -EINVAL;
spin_lock(&rpc_authflavor_lock);
if (auth_flavors[flavor] == ops) {
auth_flavors[flavor] = NULL;
ret = 0;
}
spin_unlock(&rpc_authflavor_lock);
return ret;
}
EXPORT_SYMBOL_GPL(rpcauth_unregister);
struct rpc_auth *
rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
{
struct rpc_auth *auth;
const struct rpc_authops *ops;
u32 flavor = pseudoflavor_to_flavor(pseudoflavor);
auth = ERR_PTR(-EINVAL);
if (flavor >= RPC_AUTH_MAXFLAVOR)
goto out;
#ifdef CONFIG_KMOD
if ((ops = auth_flavors[flavor]) == NULL)
request_module("rpc-auth-%u", flavor);
#endif
spin_lock(&rpc_authflavor_lock);
ops = auth_flavors[flavor];
if (ops == NULL || !try_module_get(ops->owner)) {
spin_unlock(&rpc_authflavor_lock);
goto out;
}
spin_unlock(&rpc_authflavor_lock);
auth = ops->create(clnt, pseudoflavor);
module_put(ops->owner);
if (IS_ERR(auth))
return auth;
if (clnt->cl_auth)
rpcauth_release(clnt->cl_auth);
clnt->cl_auth = auth;
out:
return auth;
}
EXPORT_SYMBOL_GPL(rpcauth_create);
void
rpcauth_release(struct rpc_auth *auth)
{
if (!atomic_dec_and_test(&auth->au_count))
return;
auth->au_ops->destroy(auth);
}
static DEFINE_SPINLOCK(rpc_credcache_lock);
static void
rpcauth_unhash_cred_locked(struct rpc_cred *cred)
{
hlist_del_rcu(&cred->cr_hash);
smp_mb__before_clear_bit();
clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
}
static void
rpcauth_unhash_cred(struct rpc_cred *cred)
{
spinlock_t *cache_lock;
cache_lock = &cred->cr_auth->au_credcache->lock;
spin_lock(cache_lock);
if (atomic_read(&cred->cr_count) == 0)
rpcauth_unhash_cred_locked(cred);
spin_unlock(cache_lock);
}
/*
* Initialize RPC credential cache
*/
int
rpcauth_init_credcache(struct rpc_auth *auth)
{
struct rpc_cred_cache *new;
int i;
new = kmalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return -ENOMEM;
for (i = 0; i < RPC_CREDCACHE_NR; i++)
INIT_HLIST_HEAD(&new->hashtable[i]);
spin_lock_init(&new->lock);
auth->au_credcache = new;
return 0;
}
EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
/*
* Destroy a list of credentials
*/
static inline
void rpcauth_destroy_credlist(struct list_head *head)
{
struct rpc_cred *cred;
while (!list_empty(head)) {
cred = list_entry(head->next, struct rpc_cred, cr_lru);
list_del_init(&cred->cr_lru);
put_rpccred(cred);
}
}
/*
* Clear the RPC credential cache, and delete those credentials
* that are not referenced.
*/
void
rpcauth_clear_credcache(struct rpc_cred_cache *cache)
{
LIST_HEAD(free);
struct hlist_head *head;
struct rpc_cred *cred;
int i;
spin_lock(&rpc_credcache_lock);
spin_lock(&cache->lock);
for (i = 0; i < RPC_CREDCACHE_NR; i++) {
head = &cache->hashtable[i];
while (!hlist_empty(head)) {
cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
get_rpccred(cred);
if (!list_empty(&cred->cr_lru)) {
list_del(&cred->cr_lru);
number_cred_unused--;
}
list_add_tail(&cred->cr_lru, &free);
rpcauth_unhash_cred_locked(cred);
}
}
spin_unlock(&cache->lock);
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(&free);
}
/*
* Destroy the RPC credential cache
*/
void
rpcauth_destroy_credcache(struct rpc_auth *auth)
{
struct rpc_cred_cache *cache = auth->au_credcache;
if (cache) {
auth->au_credcache = NULL;
rpcauth_clear_credcache(cache);
kfree(cache);
}
}
EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
/*
* Remove stale credentials. Avoid sleeping inside the loop.
*/
static int
rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
{
spinlock_t *cache_lock;
struct rpc_cred *cred;
unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
while (!list_empty(&cred_unused)) {
cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
list_del_init(&cred->cr_lru);
number_cred_unused--;
if (atomic_read(&cred->cr_count) != 0)
continue;
/* Enforce a 5 second garbage collection moratorium */
if (time_in_range(cred->cr_expire, expired, jiffies) &&
test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0)
continue;
cache_lock = &cred->cr_auth->au_credcache->lock;
spin_lock(cache_lock);
if (atomic_read(&cred->cr_count) == 0) {
get_rpccred(cred);
list_add_tail(&cred->cr_lru, free);
rpcauth_unhash_cred_locked(cred);
nr_to_scan--;
}
spin_unlock(cache_lock);
if (nr_to_scan == 0)
break;
}
return nr_to_scan;
}
/*
* Run memory cache shrinker.
*/
static int
rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
{
LIST_HEAD(free);
int res;
if (list_empty(&cred_unused))
return 0;
spin_lock(&rpc_credcache_lock);
nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(&free);
return res;
}
/*
* Look up a process' credentials in the authentication cache
*/
struct rpc_cred *
rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
int flags)
{
LIST_HEAD(free);
struct rpc_cred_cache *cache = auth->au_credcache;
struct hlist_node *pos;
struct rpc_cred *cred = NULL,
*entry, *new;
unsigned int nr;
nr = hash_long(acred->uid, RPC_CREDCACHE_HASHBITS);
rcu_read_lock();
hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
if (!entry->cr_ops->crmatch(acred, entry, flags))
continue;
spin_lock(&cache->lock);
if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
spin_unlock(&cache->lock);
continue;
}
cred = get_rpccred(entry);
spin_unlock(&cache->lock);
break;
}
rcu_read_unlock();
if (cred != NULL)
goto found;
new = auth->au_ops->crcreate(auth, acred, flags);
if (IS_ERR(new)) {
cred = new;
goto out;
}
spin_lock(&cache->lock);
hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
if (!entry->cr_ops->crmatch(acred, entry, flags))
continue;
cred = get_rpccred(entry);
break;
}
if (cred == NULL) {
cred = new;
set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
} else
list_add_tail(&new->cr_lru, &free);
spin_unlock(&cache->lock);
found:
if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)
&& cred->cr_ops->cr_init != NULL
&& !(flags & RPCAUTH_LOOKUP_NEW)) {
int res = cred->cr_ops->cr_init(auth, cred);
if (res < 0) {
put_rpccred(cred);
cred = ERR_PTR(res);
}
}
rpcauth_destroy_credlist(&free);
out:
return cred;
}
EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
struct rpc_cred *
rpcauth_lookupcred(struct rpc_auth *auth, int flags)
{
struct auth_cred acred = {
.uid = current->fsuid,
.gid = current->fsgid,
.group_info = current->group_info,
};
struct rpc_cred *ret;
dprintk("RPC: looking up %s cred\n",
auth->au_ops->au_name);
get_group_info(acred.group_info);
ret = auth->au_ops->lookup_cred(auth, &acred, flags);
put_group_info(acred.group_info);
return ret;
}
void
rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
struct rpc_auth *auth, const struct rpc_credops *ops)
{
INIT_HLIST_NODE(&cred->cr_hash);
INIT_LIST_HEAD(&cred->cr_lru);
atomic_set(&cred->cr_count, 1);
cred->cr_auth = auth;
cred->cr_ops = ops;
cred->cr_expire = jiffies;
#ifdef RPC_DEBUG
cred->cr_magic = RPCAUTH_CRED_MAGIC;
#endif
cred->cr_uid = acred->uid;
}
EXPORT_SYMBOL_GPL(rpcauth_init_cred);
void
rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred)
{
task->tk_msg.rpc_cred = get_rpccred(cred);
dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
cred->cr_auth->au_ops->au_name, cred);
}
EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
static void
rpcauth_bind_root_cred(struct rpc_task *task)
{
struct rpc_auth *auth = task->tk_client->cl_auth;
struct auth_cred acred = {
.uid = 0,
.gid = 0,
};
struct rpc_cred *ret;
dprintk("RPC: %5u looking up %s cred\n",
task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
ret = auth->au_ops->lookup_cred(auth, &acred, 0);
if (!IS_ERR(ret))
task->tk_msg.rpc_cred = ret;
else
task->tk_status = PTR_ERR(ret);
}
static void
rpcauth_bind_new_cred(struct rpc_task *task)
{
struct rpc_auth *auth = task->tk_client->cl_auth;
struct rpc_cred *ret;
dprintk("RPC: %5u looking up %s cred\n",
task->tk_pid, auth->au_ops->au_name);
ret = rpcauth_lookupcred(auth, 0);
if (!IS_ERR(ret))
task->tk_msg.rpc_cred = ret;
else
task->tk_status = PTR_ERR(ret);
}
void
rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
{
if (cred != NULL)
cred->cr_ops->crbind(task, cred);
else if (flags & RPC_TASK_ROOTCREDS)
rpcauth_bind_root_cred(task);
else
rpcauth_bind_new_cred(task);
}
void
put_rpccred(struct rpc_cred *cred)
{
/* Fast path for unhashed credentials */
if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
goto need_lock;
if (!atomic_dec_and_test(&cred->cr_count))
return;
goto out_destroy;
need_lock:
if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
return;
if (!list_empty(&cred->cr_lru)) {
number_cred_unused--;
list_del_init(&cred->cr_lru);
}
if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
rpcauth_unhash_cred(cred);
else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
cred->cr_expire = jiffies;
list_add_tail(&cred->cr_lru, &cred_unused);
number_cred_unused++;
spin_unlock(&rpc_credcache_lock);
return;
}
spin_unlock(&rpc_credcache_lock);
out_destroy:
cred->cr_ops->crdestroy(cred);
}
EXPORT_SYMBOL_GPL(put_rpccred);
void
rpcauth_unbindcred(struct rpc_task *task)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %5u releasing %s cred %p\n",
task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
put_rpccred(cred);
task->tk_msg.rpc_cred = NULL;
}
__be32 *
rpcauth_marshcred(struct rpc_task *task, __be32 *p)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %5u marshaling %s cred %p\n",
task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
return cred->cr_ops->crmarshal(task, p);
}
__be32 *
rpcauth_checkverf(struct rpc_task *task, __be32 *p)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %5u validating %s cred %p\n",
task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
return cred->cr_ops->crvalidate(task, p);
}
int
rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
__be32 *data, void *obj)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
task->tk_pid, cred->cr_ops->cr_name, cred);
if (cred->cr_ops->crwrap_req)
return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
/* By default, we encode the arguments normally. */
return rpc_call_xdrproc(encode, rqstp, data, obj);
}
int
rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
__be32 *data, void *obj)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
task->tk_pid, cred->cr_ops->cr_name, cred);
if (cred->cr_ops->crunwrap_resp)
return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
data, obj);
/* By default, we decode the arguments normally. */
return rpc_call_xdrproc(decode, rqstp, data, obj);
}
int
rpcauth_refreshcred(struct rpc_task *task)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
int err;
dprintk("RPC: %5u refreshing %s cred %p\n",
task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
err = cred->cr_ops->crrefresh(task);
if (err < 0)
task->tk_status = err;
return err;
}
void
rpcauth_invalcred(struct rpc_task *task)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %5u invalidating %s cred %p\n",
task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
if (cred)
clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
}
int
rpcauth_uptodatecred(struct rpc_task *task)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
return cred == NULL ||
test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
}
static struct shrinker rpc_cred_shrinker = {
.shrink = rpcauth_cache_shrinker,
.seeks = DEFAULT_SEEKS,
};
void __init rpcauth_init_module(void)
{
rpc_init_authunix();
rpc_init_generic_auth();
register_shrinker(&rpc_cred_shrinker);
}
void __exit rpcauth_remove_module(void)
{
unregister_shrinker(&rpc_cred_shrinker);
}