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-rw-r--r--net/sunrpc/auth.c584
1 files changed, 584 insertions, 0 deletions
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
new file mode 100644
index 0000000..cb216b2
--- /dev/null
+++ b/net/sunrpc/auth.c
@@ -0,0 +1,584 @@
+/*
+ * 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;
+
+ if ((ops = auth_flavors[flavor]) == NULL)
+ request_module("rpc-auth-%u", flavor);
+ 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, *next;
+ unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
+
+ list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
+
+ /* Enforce a 60 second garbage collection moratorium */
+ if (time_in_range(cred->cr_expire, expired, jiffies) &&
+ test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
+ continue;
+
+ 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;
+ 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);
+ 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);
+}
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