1 files changed, 395 insertions, 0 deletions

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
new file mode 100644
index 00000000000..9bcec9b927b
--- /dev/null
+++ b/net/sunrpc/auth.c
@@ -0,0 +1,395 @@
+/*
+ * 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/socket.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/spinlock.h>
+
+#ifdef RPC_DEBUG
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+static 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(struct rpc_authops *ops)
+{
+	rpc_authflavor_t flavor;
+
+	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
+		return -EINVAL;
+	if (auth_flavors[flavor] != NULL)
+		return -EPERM;		/* what else? */
+	auth_flavors[flavor] = ops;
+	return 0;
+}
+
+int
+rpcauth_unregister(struct rpc_authops *ops)
+{
+	rpc_authflavor_t flavor;
+
+	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
+		return -EINVAL;
+	if (auth_flavors[flavor] != ops)
+		return -EPERM;		/* what else? */
+	auth_flavors[flavor] = NULL;
+	return 0;
+}
+
+struct rpc_auth *
+rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
+{
+	struct rpc_auth		*auth;
+	struct rpc_authops	*ops;
+	u32			flavor = pseudoflavor_to_flavor(pseudoflavor);
+
+	if (flavor >= RPC_AUTH_MAXFLAVOR || !(ops = auth_flavors[flavor]))
+		return NULL;
+	auth = ops->create(clnt, pseudoflavor);
+	if (!auth)
+		return NULL;
+	if (clnt->cl_auth)
+		rpcauth_destroy(clnt->cl_auth);
+	clnt->cl_auth = auth;
+	return auth;
+}
+
+void
+rpcauth_destroy(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 = (struct rpc_cred_cache *)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_free_credcache(struct rpc_auth *auth)
+{
+	struct rpc_cred_cache *cache = auth->au_credcache;
+	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);
+}
+
+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))
+		cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
+	if (!(cred->cr_flags & RPCAUTH_CRED_UPTODATE)) {
+		__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 taskflags)
+{
+	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 (!(taskflags & RPC_TASK_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, taskflags)) {
+			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, taskflags);
+		if (!IS_ERR(new)) {
+#ifdef RPC_DEBUG
+			new->cr_magic = RPCAUTH_CRED_MAGIC;
+#endif
+			goto retry;
+		} else
+			cred = new;
+	}
+
+	return (struct rpc_cred *) cred;
+}
+
+struct rpc_cred *
+rpcauth_lookupcred(struct rpc_auth *auth, int taskflags)
+{
+	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, taskflags);
+	put_group_info(acred.group_info);
+	return ret;
+}
+
+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;
+
+	dprintk("RPC: %4d looking up %s cred\n",
+		task->tk_pid, task->tk_auth->au_ops->au_name);
+	get_group_info(acred.group_info);
+	ret = auth->au_ops->lookup_cred(auth, &acred, task->tk_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: %4d 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_auth	*auth = task->tk_auth;
+	struct rpc_cred	*cred = task->tk_msg.rpc_cred;
+
+	dprintk("RPC: %4d releasing %s cred %p\n",
+		task->tk_pid, auth->au_ops->au_name, cred);
+
+	put_rpccred(cred);
+	task->tk_msg.rpc_cred = NULL;
+}
+
+u32 *
+rpcauth_marshcred(struct rpc_task *task, u32 *p)
+{
+	struct rpc_auth	*auth = task->tk_auth;
+	struct rpc_cred	*cred = task->tk_msg.rpc_cred;
+
+	dprintk("RPC: %4d marshaling %s cred %p\n",
+		task->tk_pid, auth->au_ops->au_name, cred);
+	return cred->cr_ops->crmarshal(task, p);
+}
+
+u32 *
+rpcauth_checkverf(struct rpc_task *task, u32 *p)
+{
+	struct rpc_auth	*auth = task->tk_auth;
+	struct rpc_cred	*cred = task->tk_msg.rpc_cred;
+
+	dprintk("RPC: %4d validating %s cred %p\n",
+		task->tk_pid, 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,
+		u32 *data, void *obj)
+{
+	struct rpc_cred *cred = task->tk_msg.rpc_cred;
+
+	dprintk("RPC: %4d 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,
+		u32 *data, void *obj)
+{
+	struct rpc_cred *cred = task->tk_msg.rpc_cred;
+
+	dprintk("RPC: %4d 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_auth	*auth = task->tk_auth;
+	struct rpc_cred	*cred = task->tk_msg.rpc_cred;
+	int err;
+
+	dprintk("RPC: %4d refreshing %s cred %p\n",
+		task->tk_pid, 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)
+{
+	dprintk("RPC: %4d invalidating %s cred %p\n",
+		task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
+	spin_lock(&rpc_credcache_lock);
+	if (task->tk_msg.rpc_cred)
+		task->tk_msg.rpc_cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
+	spin_unlock(&rpc_credcache_lock);
+}
+
+int
+rpcauth_uptodatecred(struct rpc_task *task)
+{
+	return !(task->tk_msg.rpc_cred) ||
+		(task->tk_msg.rpc_cred->cr_flags & RPCAUTH_CRED_UPTODATE);
+}