Fixed MTP to work with TWRP

net/sunrpc/svcauth.c

@@ -0,0 +1,166 @@
+/*
+ * linux/net/sunrpc/svcauth.c
+ *
+ * The generic interface for RPC authentication on the server side.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ *
+ * CHANGES
+ * 19-Apr-2000 Chris Evans      - Security fix
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/sunrpc/types.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/svcauth.h>
+#include <linux/err.h>
+#include <linux/hash.h>
+
+#define RPCDBG_FACILITY	RPCDBG_AUTH
+
+
+/*
+ * Table of authenticators
+ */
+extern struct auth_ops svcauth_null;
+extern struct auth_ops svcauth_unix;
+
+static DEFINE_SPINLOCK(authtab_lock);
+static struct auth_ops	*authtab[RPC_AUTH_MAXFLAVOR] = {
+	[0] = &svcauth_null,
+	[1] = &svcauth_unix,
+};
+
+int
+svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
+{
+	rpc_authflavor_t	flavor;
+	struct auth_ops		*aops;
+
+	*authp = rpc_auth_ok;
+
+	flavor = svc_getnl(&rqstp->rq_arg.head[0]);
+
+	dprintk("svc: svc_authenticate (%d)\n", flavor);
+
+	spin_lock(&authtab_lock);
+	if (flavor >= RPC_AUTH_MAXFLAVOR || !(aops = authtab[flavor]) ||
+	    !try_module_get(aops->owner)) {
+		spin_unlock(&authtab_lock);
+		*authp = rpc_autherr_badcred;
+		return SVC_DENIED;
+	}
+	spin_unlock(&authtab_lock);
+
+	rqstp->rq_auth_slack = 0;
+
+	rqstp->rq_authop = aops;
+	return aops->accept(rqstp, authp);
+}
+EXPORT_SYMBOL_GPL(svc_authenticate);
+
+int svc_set_client(struct svc_rqst *rqstp)
+{
+	return rqstp->rq_authop->set_client(rqstp);
+}
+EXPORT_SYMBOL_GPL(svc_set_client);
+
+/* A request, which was authenticated, has now executed.
+ * Time to finalise the credentials and verifier
+ * and release and resources
+ */
+int svc_authorise(struct svc_rqst *rqstp)
+{
+	struct auth_ops *aops = rqstp->rq_authop;
+	int rv = 0;
+
+	rqstp->rq_authop = NULL;
+
+	if (aops) {
+		rv = aops->release(rqstp);
+		module_put(aops->owner);
+	}
+	return rv;
+}
+
+int
+svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
+{
+	int rv = -EINVAL;
+	spin_lock(&authtab_lock);
+	if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) {
+		authtab[flavor] = aops;
+		rv = 0;
+	}
+	spin_unlock(&authtab_lock);
+	return rv;
+}
+EXPORT_SYMBOL_GPL(svc_auth_register);
+
+void
+svc_auth_unregister(rpc_authflavor_t flavor)
+{
+	spin_lock(&authtab_lock);
+	if (flavor < RPC_AUTH_MAXFLAVOR)
+		authtab[flavor] = NULL;
+	spin_unlock(&authtab_lock);
+}
+EXPORT_SYMBOL_GPL(svc_auth_unregister);
+
+/**************************************************
+ * 'auth_domains' are stored in a hash table indexed by name.
+ * When the last reference to an 'auth_domain' is dropped,
+ * the object is unhashed and freed.
+ * If auth_domain_lookup fails to find an entry, it will return
+ * it's second argument 'new'.  If this is non-null, it will
+ * have been atomically linked into the table.
+ */
+
+#define	DN_HASHBITS	6
+#define	DN_HASHMAX	(1<<DN_HASHBITS)
+
+static struct hlist_head	auth_domain_table[DN_HASHMAX];
+static spinlock_t	auth_domain_lock =
+	__SPIN_LOCK_UNLOCKED(auth_domain_lock);
+
+void auth_domain_put(struct auth_domain *dom)
+{
+	if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) {
+		hlist_del(&dom->hash);
+		dom->flavour->domain_release(dom);
+		spin_unlock(&auth_domain_lock);
+	}
+}
+EXPORT_SYMBOL_GPL(auth_domain_put);
+
+struct auth_domain *
+auth_domain_lookup(char *name, struct auth_domain *new)
+{
+	struct auth_domain *hp;
+	struct hlist_head *head;
+
+	head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
+
+	spin_lock(&auth_domain_lock);
+
+	hlist_for_each_entry(hp, head, hash) {
+		if (strcmp(hp->name, name)==0) {
+			kref_get(&hp->ref);
+			spin_unlock(&auth_domain_lock);
+			return hp;
+		}
+	}
+	if (new)
+		hlist_add_head(&new->hash, head);
+	spin_unlock(&auth_domain_lock);
+	return new;
+}
+EXPORT_SYMBOL_GPL(auth_domain_lookup);
+
+struct auth_domain *auth_domain_find(char *name)
+{
+	return auth_domain_lookup(name, NULL);
+}
+EXPORT_SYMBOL_GPL(auth_domain_find);