Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * 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 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;

}

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);

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;

}

/*

 * 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);

        }

}

/*

 * 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;

        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;

                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;

        int             nr = 0;

        if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))

                nr = acred->uid & RPC_CREDCACHE_MASK;

        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;

}

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(rpcauth_init_cred);

struct rpc_cred *

rpcauth_bindcred(struct rpc_task *task)

{

        struct rpc_auth *auth = task->tk_client->cl_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_client->cl_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)

{

        struct rpc_cred *cred = task->tk_msg.rpc_cred;

        if (cred != NULL) {

                get_rpccred(cred);

                dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,

                                cred->cr_auth->au_ops->au_name, cred);

        }

}

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);

}

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();

        register_shrinker(&rpc_cred_shrinker);

}

void __exit rpcauth_remove_module(void)

{

        unregister_shrinker(&rpc_cred_shrinker);

}