metadata: Add metadata factory and implementation for integer types

Co-authored-by: Thomas Egerer <[email protected]>

src/libstrongswan/metadata/metadata.h

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2021 Tobias Brunner, codelabs GmbH
+ * Copyright (C) 2021 Thomas Egerer, secunet AG
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * @defgroup metadata metadata
+ * @ingroup libstrongswan
+ *
+ * @defgroup metadata_t metadata
+ * @{ @ingroup metadata
+ */
+
+#ifndef METADATA_H_
+#define METADATA_H_
+
+#include <utils/utils.h>
+
+typedef struct metadata_t metadata_t;
+
+/**
+ * Pre-defined metadata type for int values. Note that while the constructor and
+ * equals() work with integer values/types smaller than int (such values get
+ * promoted to int when passed via ...), get() does not and expects a pointer to
+ * an int variable.
+ */
+#define METADATA_TYPE_INT "int"
+
+/**
+ * Pre-defined metadata type for uint64_t values. Make sure to pass only
+ * uint64_t values/variables also to the constructor and equals() (or cast them
+ * appropriately there).
+ */
+#define METADATA_TYPE_UINT64 "uint64"
+
+/**
+ * Metadata object to allow storing arbitrary values in an encapsulated
+ * object.
+ */
+struct metadata_t {
+
+	/**
+	 * Return the type of the metadata object.
+	 *
+	 * @return		string type of the metadata object
+	 */
+	const char *(*get_type)(metadata_t *this);
+
+	/**
+	 * Clone this metadata object.
+	 *
+	 * @return		a cloned instance
+	 */
+	metadata_t *(*clone)(metadata_t *this);
+
+	/**
+	 * Compare this to another value (or values, depending on the type).
+	 *
+	 * @param ...	value(s) (raw, not metadata_t) to compare this to
+	 * @return		TRUE if value is equal to metadata value
+	 */
+	bool (*equals)(metadata_t *this, ...);
+
+	/**
+	 * Retrieve the values via variadic argument(s).
+	 *
+	 * @param ...	pointer(s) to obtain metadata value(s)
+	 */
+	void (*get)(metadata_t *this, ...);
+
+	/**
+	 * Destroy this metadata object.
+	 */
+	void (*destroy)(metadata_t *this);
+};
+
+/**
+ * Constructor type for metadata objects.
+ *
+ * @param type		type of the metadata object, allows using the same
+ *					constructor for different types
+ * @param args		type-specific arguments
+ * @return			metadata object, NULL on failure
+ */
+typedef metadata_t *(*metadata_create_t)(const char *type, va_list args);
+
+#endif /** METADATA_H_ @}*/

src/libstrongswan/metadata/metadata_factory.c

@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2021 Tobias Brunner, codelabs GmbH
+ * Copyright (C) 2021 Thomas Egerer, secunet AG
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "metadata_factory.h"
+#include "metadata_int.h"
+
+#include <library.h>
+#include <collections/hashtable.h>
+
+typedef struct private_metadata_factory_t private_metadata_factory_t;
+
+/**
+ * Private data
+ */
+struct private_metadata_factory_t {
+
+	/**
+	 * Public interface
+	 */
+	metadata_factory_t public;
+
+	/**
+	 * Registered metadata types (entry_t)
+	 */
+	hashtable_t *types;
+};
+
+/**
+ * Registered constructor data
+ */
+typedef struct {
+	/** Type name */
+	char *type;
+	/** Constructor */
+	metadata_create_t create;
+} entry_t;
+
+/**
+ * Destroy an entry
+ */
+static void destroy_entry(entry_t *this)
+{
+	if (this)
+	{
+		free(this->type);
+		free(this);
+	}
+}
+
+METHOD(metadata_factory_t, create, metadata_t*,
+	private_metadata_factory_t *this, const char *type, ...)
+{
+	metadata_t *metadata = NULL;
+	entry_t *entry;
+	va_list args;
+
+	entry = this->types->get(this->types, type);
+	if (entry)
+	{
+		va_start(args, type);
+		metadata = entry->create(type, args);
+		va_end(args);
+	}
+	return metadata;
+}
+
+METHOD(metadata_factory_t, register_type, void,
+	private_metadata_factory_t *this, const char *type,
+	metadata_create_t create)
+{
+	entry_t *entry;
+
+	INIT(entry,
+		.type = strdup(type),
+		.create = create,
+	);
+
+	destroy_entry(this->types->put(this->types, entry->type, entry));
+}
+
+METHOD(metadata_factory_t, destroy, void,
+	private_metadata_factory_t *this)
+{
+	this->types->destroy_function(this->types, (void*)destroy_entry);
+	free(this);
+}
+
+metadata_factory_t *metadata_factory_create()
+{
+	private_metadata_factory_t *this;
+
+	INIT(this,
+		.public = {
+			.create = _create,
+			.register_type = _register_type,
+			.destroy = _destroy,
+		},
+		.types = hashtable_create(hashtable_hash_str, hashtable_equals_str, 0),
+	);
+
+	/* register pre-defined types */
+	register_type(this, METADATA_TYPE_INT, metadata_create_int);
+	register_type(this, METADATA_TYPE_UINT64, metadata_create_int);
+
+	return &this->public;
+}

src/libstrongswan/metadata/metadata_factory.h

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2021 Tobias Brunner, codelabs GmbH
+ * Copyright (C) 2021 Thomas Egerer, secunet AG
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * @defgroup metadata_factory metadata_factory
+ * @{ @ingroup metadata
+ */
+
+#ifndef METADATA_FACTORY_H_
+#define METADATA_FACTORY_H_
+
+#include "metadata.h"
+
+typedef struct metadata_factory_t metadata_factory_t;
+
+/**
+ * Create a factory for dealing with metadata objects.
+ */
+struct metadata_factory_t {
+
+	/**
+	 * Create a metadata object of the given type.
+	 *
+	 * @param type		type of the desired metadata object
+	 * @param ...		data to wrap into the metadata object
+	 * @return			metadata handler on success, NULL otherwise
+	 */
+	metadata_t *(*create)(metadata_factory_t *this, const char *type, ...);
+
+	/**
+	 * Register a constructor for a given type.
+	 *
+	 * @param type		type to register
+	 * @param create	metadata constructor
+	 */
+	void (*register_type)(metadata_factory_t *this, const char *type,
+						  metadata_create_t create);
+
+	/**
+	 * Destroy a metadata_factory_t instance.
+	 */
+	void (*destroy)(metadata_factory_t *this);
+};
+
+/**
+ * Create a metadata_factory_t instance.
+ */
+metadata_factory_t *metadata_factory_create();
+
+#endif /** METADATA_FACTORY_H_ @}*/

src/libstrongswan/metadata/metadata_int.c

@@ -0,0 +1,158 @@
+/*
+ * Copyright (C) 2021 Tobias Brunner, codelabs GmbH
+ * Copyright (C) 2021 Thomas Egerer, secunet AG
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "metadata_int.h"
+
+#include <library.h>
+
+typedef struct private_metadata_t private_metadata_t;
+
+/**
+ * Private data
+ */
+struct private_metadata_t {
+
+	/**
+	 * Public interface
+	 */
+	metadata_t public;
+
+	/**
+	 * String representation of type.
+	 */
+	const char *type;
+
+	/**
+	 * Stored value.
+	 */
+	uint64_t value;
+};
+
+/* forward declaration */
+static metadata_t *create_generic(const char *type, uint64_t value);
+
+METHOD(metadata_t, get_type, const char*,
+	private_metadata_t *this)
+{
+	return this->type;
+}
+
+METHOD(metadata_t, clone_, metadata_t*,
+	private_metadata_t *this)
+{
+	return create_generic(this->type, this->value);
+}
+
+METHOD(metadata_t, equals, bool,
+	private_metadata_t *this, ...)
+{
+	/* bool, uint8, uint16 etc. are promoted to int when passed via ... */
+	if (streq(METADATA_TYPE_INT, this->type))
+	{
+		int value;
+
+		VA_ARGS_GET(this, value);
+		return value == (int)this->value;
+	}
+	else if (streq(METADATA_TYPE_UINT64, this->type))
+	{
+		uint64_t value;
+
+		VA_ARGS_GET(this, value);
+		return value == this->value;
+	}
+	return FALSE;
+}
+
+METHOD(metadata_t, get, void,
+	private_metadata_t *this, ...)
+{
+	/* pointers here have to match exactly, so passing e.g. a bool* or uint16_t
+	 * are illegal */
+	if (streq(METADATA_TYPE_INT, this->type))
+	{
+		int *value;
+
+		VA_ARGS_GET(this, value);
+		*value = this->value;
+	}
+	else if (streq(METADATA_TYPE_UINT64, this->type))
+	{
+		uint64_t *value;
+
+		VA_ARGS_GET(this, value);
+		*value = this->value;
+	}
+}
+
+METHOD(metadata_t, destroy, void,
+	private_metadata_t *this)
+{
+	free(this);
+}
+
+/**
+ * Generic constructor
+ */
+static metadata_t *create_generic(const char *type, uint64_t value)
+{
+	private_metadata_t *this;
+
+	INIT(this,
+		.public = {
+			.get_type = _get_type,
+			.clone = _clone_,
+			.equals = _equals,
+			.get = _get,
+			.destroy = _destroy,
+		},
+		.type = type,
+		.value = value,
+	);
+	return &this->public;
+}
+
+/*
+ * Described in header
+ */
+metadata_t *metadata_create_int(const char *type, va_list args)
+{
+	metadata_t *this = NULL;
+
+	/* bool, uint8, uint16 etc. are promoted to int when passed via ... */
+	if (streq(METADATA_TYPE_INT, type))
+	{
+		int int_val;
+
+		VA_ARGS_VGET(args, int_val);
+		this = create_generic(METADATA_TYPE_INT, int_val);
+	}
+	else if (streq(METADATA_TYPE_UINT64, type))
+	{
+		uint64_t uint64_val;
+
+		VA_ARGS_VGET(args, uint64_val);
+		this = create_generic(METADATA_TYPE_UINT64, uint64_val);
+	}
+	return this;
+}

src/libstrongswan/metadata/metadata_int.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2021 Tobias Brunner, codelabs GmbH
+ * Copyright (C) 2021 Thomas Egerer, secunet AG
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * @defgroup metadata_int metadata_int
+ * @{ @ingroup metadata
+ */
+
+#ifndef METADATA_INT_H_
+#define METADATA_INT_H_
+
+#include "metadata.h"
+
+/**
+ * Create a metadata object of an integer type.
+ *
+ * @param type      type name
+ * @param args      integer of the specified type
+ * @return          successfully created object, NULL on failure
+ */
+metadata_t *metadata_create_int(const char *type, va_list args);
+
+#endif /** METADATA_INT_H_ @}*/