Payload added to handle IKE fragments

2012-12-24 10:24:48 +01:00
parent 656e01eab3
commit 8f0ab6dd36
6 changed files with 314 additions and 11 deletions
@@ -0,0 +1,208 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "fragment_payload.h"
+
+#include <encoding/payloads/encodings.h>
+
+/** Flag that is set in case the given fragment is the last for the message */
+#define LAST_FRAGMENT 0x01
+
+typedef struct private_fragment_payload_t private_fragment_payload_t;
+
+/**
+ * Private data of an fragment_payload_t object.
+ */
+struct private_fragment_payload_t {
+
+	/**
+	 * Public fragment_payload_t interface.
+	 */
+	fragment_payload_t public;
+
+	/**
+	 * Next payload type.
+	 */
+	u_int8_t next_payload;
+
+	/**
+	 * Reserved byte
+	 */
+	u_int8_t reserved;
+
+	/**
+	 * Length of this payload.
+	 */
+	u_int16_t payload_length;
+
+	/**
+	 * Fragment ID.
+	 */
+	u_int16_t fragment_id;
+
+	/**
+	 * Fragment number.
+	 */
+	u_int8_t fragment_number;
+
+	/**
+	 * Flags
+	 */
+	u_int8_t flags;
+
+	/**
+	 * The contained fragment data.
+	 */
+	chunk_t data;
+};
+
+/**
+ * Encoding rules for an IKEv1 fragment payload
+ */
+static encoding_rule_t encodings[] = {
+	/* 1 Byte next payload type, stored in the field next_payload */
+	{ U_INT_8,			offsetof(private_fragment_payload_t, next_payload)		},
+	{ RESERVED_BYTE,	offsetof(private_fragment_payload_t, reserved)			},
+	/* Length of the whole payload*/
+	{ PAYLOAD_LENGTH,	offsetof(private_fragment_payload_t, payload_length)	},
+	{ U_INT_16,			offsetof(private_fragment_payload_t, fragment_id)		},
+	{ U_INT_8,			offsetof(private_fragment_payload_t, fragment_number)	},
+	{ U_INT_8,			offsetof(private_fragment_payload_t, flags)				},
+	/* Fragment data is of variable size */
+	{ CHUNK_DATA,		offsetof(private_fragment_payload_t, data)				},
+};
+
+/*
+                           1                   2                   3
+       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      ! Next Payload  !    RESERVED   !         Payload Length        !
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      !         Fragment ID           !  Fragment Num !     Flags     !
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      !                                                               !
+      ~                       Fragment Data                           ~
+      !                                                               !
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+*/
+
+METHOD(payload_t, verify, status_t,
+	private_fragment_payload_t *this)
+{
+	if (this->fragment_number == 0)
+	{
+		return FAILED;
+	}
+	return SUCCESS;
+}
+
+METHOD(payload_t, get_encoding_rules, int,
+	private_fragment_payload_t *this, encoding_rule_t **rules)
+{
+	*rules = encodings;
+	return countof(encodings);
+}
+
+METHOD(payload_t, get_header_length, int,
+	private_fragment_payload_t *this)
+{
+	return 8;
+}
+
+METHOD(payload_t, get_type, payload_type_t,
+	private_fragment_payload_t *this)
+{
+	return FRAGMENT_V1;
+}
+
+METHOD(payload_t, get_next_type, payload_type_t,
+	private_fragment_payload_t *this)
+{
+	return this->next_payload;
+}
+
+METHOD(payload_t, set_next_type, void,
+	private_fragment_payload_t *this, payload_type_t type)
+{
+	this->next_payload = type;
+}
+
+METHOD(payload_t, get_length, size_t,
+	private_fragment_payload_t *this)
+{
+	return this->payload_length;
+}
+
+METHOD(fragment_payload_t, get_id, u_int16_t,
+	private_fragment_payload_t *this)
+{
+	return this->fragment_id;
+}
+
+METHOD(fragment_payload_t, get_number, u_int8_t,
+	private_fragment_payload_t *this)
+{
+	return this->fragment_number;
+}
+
+METHOD(fragment_payload_t, is_last, bool,
+	private_fragment_payload_t *this)
+{
+	return (this->flags & LAST_FRAGMENT) == LAST_FRAGMENT;
+}
+
+METHOD(fragment_payload_t, get_data, chunk_t,
+	private_fragment_payload_t *this)
+{
+	return this->data;
+}
+
+METHOD2(payload_t, fragment_payload_t, destroy, void,
+	private_fragment_payload_t *this)
+{
+	free(this->data.ptr);
+	free(this);
+}
+
+/*
+ * Described in header
+ */
+fragment_payload_t *fragment_payload_create()
+{
+	private_fragment_payload_t *this;
+
+	INIT(this,
+		.public = {
+			.payload_interface = {
+				.verify = _verify,
+				.get_encoding_rules = _get_encoding_rules,
+				.get_header_length = _get_header_length,
+				.get_length = _get_length,
+				.get_next_type = _get_next_type,
+				.set_next_type = _set_next_type,
+				.get_type = _get_type,
+				.destroy = _destroy,
+			},
+			.get_id = _get_id,
+			.get_number = _get_number,
+			.is_last = _is_last,
+			.get_data = _get_data,
+			.destroy = _destroy,
+		},
+		.next_payload = NO_PAYLOAD,
+	);
+	this->payload_length = get_header_length(this);
+	return &this->public;
+}