blob: 4d7c78b05d1edeaf79760d395b7a3c5bc73beadd [file] [log] [blame]
/*
* 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/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 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;
}
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;
}
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;
}
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);
/*
* Initialize RPC credential cache
*/
int
rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
{
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]);
new->expire = expire;
new->nextgc = jiffies + (expire >> 1);
auth->au_credcache = new;
return 0;
}
/*
* Destroy a list of credentials
*/
static inline
void rpcauth_destroy_credlist(struct hlist_head *head)
{
struct rpc_cred *cred;
while (!hlist_empty(head)) {
cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
hlist_del_init(&cred->cr_hash);
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)
{
HLIST_HEAD(free);
struct hlist_node *pos, *next;
struct rpc_cred *cred;
int i;
spin_lock(&rpc_credcache_lock);
for (i = 0; i < RPC_CREDCACHE_NR; i++) {
hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
cred = hlist_entry(pos, struct rpc_cred, cr_hash);
__hlist_del(&cred->cr_hash);
hlist_add_head(&cred->cr_hash, &free);
}
}
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);
}
}
static void
rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist_head *free)
{
if (atomic_read(&cred->cr_count) != 1)
return;
if (time_after(jiffies, cred->cr_expire + auth->au_credcache->expire))
clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0) {
__hlist_del(&cred->cr_hash);
hlist_add_head(&cred->cr_hash, free);
}
}
/*
* Remove stale credentials. Avoid sleeping inside the loop.
*/
static void
rpcauth_gc_credcache(struct rpc_auth *auth, struct hlist_head *free)
{
struct rpc_cred_cache *cache = auth->au_credcache;
struct hlist_node *pos, *next;
struct rpc_cred *cred;
int i;
dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth);
for (i = 0; i < RPC_CREDCACHE_NR; i++) {
hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
cred = hlist_entry(pos, struct rpc_cred, cr_hash);
rpcauth_prune_expired(auth, cred, free);
}
}
cache->nextgc = jiffies + cache->expire;
}
/*
* 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)
{
struct rpc_cred_cache *cache = auth->au_credcache;
HLIST_HEAD(free);
struct hlist_node *pos, *next;
struct rpc_cred *new = NULL,
*cred = NULL;
int nr = 0;
if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
nr = acred->uid & RPC_CREDCACHE_MASK;
retry:
spin_lock(&rpc_credcache_lock);
if (time_before(cache->nextgc, jiffies))
rpcauth_gc_credcache(auth, &free);
hlist_for_each_safe(pos, next, &cache->hashtable[nr]) {
struct rpc_cred *entry;
entry = hlist_entry(pos, struct rpc_cred, cr_hash);
if (entry->cr_ops->crmatch(acred, entry, flags)) {
hlist_del(&entry->cr_hash);
cred = entry;
break;
}
rpcauth_prune_expired(auth, entry, &free);
}
if (new) {
if (cred)
hlist_add_head(&new->cr_hash, &free);
else
cred = new;
}
if (cred) {
hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
get_rpccred(cred);
}
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(&free);
if (!cred) {
new = auth->au_ops->crcreate(auth, acred, flags);
if (!IS_ERR(new))
goto retry;
cred = new;
} else 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);
}
}
return (struct rpc_cred *) cred;
}
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);
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(rpcauth_init_cred);
struct rpc_cred *
rpcauth_bindcred(struct rpc_task *task)
{
struct rpc_auth *auth = task->tk_auth;
struct auth_cred acred = {
.uid = current->fsuid,
.gid = current->fsgid,
.group_info = current->group_info,
};
struct rpc_cred *ret;
int flags = 0;
dprintk("RPC: %5u looking up %s cred\n",
task->tk_pid, task->tk_auth->au_ops->au_name);
get_group_info(acred.group_info);
if (task->tk_flags & RPC_TASK_ROOTCREDS)
flags |= RPCAUTH_LOOKUP_ROOTCREDS;
ret = auth->au_ops->lookup_cred(auth, &acred, flags);
if (!IS_ERR(ret))
task->tk_msg.rpc_cred = ret;
else
task->tk_status = PTR_ERR(ret);
put_group_info(acred.group_info);
return ret;
}
void
rpcauth_holdcred(struct rpc_task *task)
{
dprintk("RPC: %5u holding %s cred %p\n",
task->tk_pid, task->tk_auth->au_ops->au_name,
task->tk_msg.rpc_cred);
if (task->tk_msg.rpc_cred)
get_rpccred(task->tk_msg.rpc_cred);
}
void
put_rpccred(struct rpc_cred *cred)
{
cred->cr_expire = jiffies;
if (!atomic_dec_and_test(&cred->cr_count))
return;
cred->cr_ops->crdestroy(cred);
}
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, task->tk_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, task->tk_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, task->tk_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 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 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, task->tk_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, task->tk_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;
}