text: /*
   * Copyright (C) 2013 Andreas Steffen
   * HSR 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 "imv_scanner_agent.h"
  #include "imv_scanner_state.h"
  
  #include <imcv.h>
  #include <imv/imv_agent.h>
  #include <imv/imv_msg.h>
  #include <ietf/ietf_attr.h>
  #include <ietf/ietf_attr_attr_request.h>
  #include <ietf/ietf_attr_pa_tnc_error.h>
  #include <ietf/ietf_attr_port_filter.h>
  
  #include <tncif_names.h>
  #include <tncif_pa_subtypes.h>
  
  #include <pen/pen.h>
  #include <utils/debug.h>
  #include <utils/lexparser.h>
  
  typedef struct private_imv_scanner_agent_t private_imv_scanner_agent_t;
  
  /* Subscribed PA-TNC message subtypes */
  static pen_type_t msg_types[] = {
  	{ PEN_IETF, PA_SUBTYPE_IETF_VPN }
  };
  
  /**
   * Private data of an imv_scanner_agent_t object.
   */
  struct private_imv_scanner_agent_t {
  
  	/**
  	 * Public members of imv_scanner_agent_t
  	 */
  	imv_agent_if_t public;
  
  	/**
  	 * IMV agent responsible for generic functions
  	 */
  	imv_agent_t *agent;
  
  };
  
  METHOD(imv_agent_if_t, bind_functions, TNC_Result,
  	private_imv_scanner_agent_t *this, TNC_TNCS_BindFunctionPointer bind_function)
  {
  	return this->agent->bind_functions(this->agent, bind_function);
  }
  
  METHOD(imv_agent_if_t, notify_connection_change, TNC_Result,
  	private_imv_scanner_agent_t *this, TNC_ConnectionID id,
  	TNC_ConnectionState new_state)
  {
  	imv_state_t *state;
  
  	switch (new_state)
  	{
  		case TNC_CONNECTION_STATE_CREATE:
  			state = imv_scanner_state_create(id);
  			return this->agent->create_state(this->agent, state);
  		case TNC_CONNECTION_STATE_DELETE:
  			return this->agent->delete_state(this->agent, id);
  		default:
  			return this->agent->change_state(this->agent, id, new_state, NULL);
  	}
  }
  
  /**
   * Process a received message
   */
  static TNC_Result receive_msg(private_imv_scanner_agent_t *this,
  							  imv_state_t *state, imv_msg_t *in_msg)
  {
  	imv_msg_t *out_msg;
  	imv_scanner_state_t *scanner_state;
  	enumerator_t *enumerator;
  	pa_tnc_attr_t *attr;
  	pen_type_t type;
  	TNC_Result result;
  	ietf_attr_port_filter_t *port_filter_attr;
  	bool fatal_error = FALSE;
  
  	/* parse received PA-TNC message and handle local and remote errors */
  	result = in_msg->receive(in_msg, &fatal_error);
  	if (result != TNC_RESULT_SUCCESS)
  	{
  		return result;
  	}
  
  	/* analyze PA-TNC attributes */
  	enumerator = in_msg->create_attribute_enumerator(in_msg);
  	while (enumerator->enumerate(enumerator, &attr))
  	{
  		type = attr->get_type(attr);
  
  		if (type.vendor_id == PEN_IETF && type.type == IETF_ATTR_PORT_FILTER)
  		{
  			scanner_state = (imv_scanner_state_t*)state;
  			port_filter_attr = (ietf_attr_port_filter_t*)attr->get_ref(attr);
  			scanner_state->set_port_filter_attr(scanner_state, port_filter_attr);
  		}
  	}
  	enumerator->destroy(enumerator);
  
  	if (fatal_error)
  	{
  		state->set_recommendation(state,
  								TNC_IMV_ACTION_RECOMMENDATION_NO_RECOMMENDATION,
  								TNC_IMV_EVALUATION_RESULT_ERROR);
  		out_msg = imv_msg_create_as_reply(in_msg);
  		result = out_msg->send_assessment(out_msg);
  		out_msg->destroy(out_msg);
  		if (result != TNC_RESULT_SUCCESS)
  		{
  			return result;
  		}
  		return this->agent->provide_recommendation(this->agent, state);
  	}
  
  	return TNC_RESULT_SUCCESS;
  }
  
  METHOD(imv_agent_if_t, receive_message, TNC_Result,
  	private_imv_scanner_agent_t *this, TNC_ConnectionID id,
  	TNC_MessageType msg_type, chunk_t msg)
  {
  	imv_state_t *state;
  	imv_msg_t *in_msg;
  	TNC_Result result;
  
  	if (!this->agent->get_state(this->agent, id, &state))
  	{
  		return TNC_RESULT_FATAL;
  	}
  	in_msg = imv_msg_create_from_data(this->agent, state, id, msg_type, msg);
  	result = receive_msg(this, state, in_msg);
  	in_msg->destroy(in_msg);
  
  	return result;
  }
  
  METHOD(imv_agent_if_t, receive_message_long, TNC_Result,
  	private_imv_scanner_agent_t *this, TNC_ConnectionID id,
  	TNC_UInt32 src_imc_id, TNC_UInt32 dst_imv_id,
  	TNC_VendorID msg_vid, TNC_MessageSubtype msg_subtype, chunk_t msg)
  {
  	imv_state_t *state;
  	imv_msg_t *in_msg;
  	TNC_Result result;
  
  	if (!this->agent->get_state(this->agent, id, &state))
  	{
  		return TNC_RESULT_FATAL;
  	}
  	in_msg = imv_msg_create_from_long_data(this->agent, state, id,
  					src_imc_id, dst_imv_id, msg_vid, msg_subtype, msg);
  	result = receive_msg(this, state, in_msg);
  	in_msg->destroy(in_msg);
  
  	return result;
  
  }
  
  typedef struct port_range_t port_range_t;
  
  struct port_range_t {
  	u_int16_t start, stop;
  };
  
  /**
   * Parse a TCP or UDP port list from an argument string
   */
  static linked_list_t* get_port_list(u_int8_t protocol_family,
  									bool closed_port_policy, char *arg_str)
  {
  	chunk_t port_list, port_item, port_start;
  	port_range_t *port_range;
  	linked_list_t *list;
  
  	list = linked_list_create();
  
  	port_list = chunk_from_str(arg_str);
  	DBG2(DBG_IMV, "list of %s ports that %s:",
  		 (protocol_family == IPPROTO_TCP) ? "tcp" : "udp",
  		 closed_port_policy ? "are allowed to be open" : "must be closed");
  
  	while (eat_whitespace(&port_list))
  	{
  		if (!extract_token(&port_item, ' ', &port_list))
  		{
  			/* reached last port item */
  			port_item = port_list;
  			port_list = chunk_empty;
  		}
  		port_range = malloc_thing(port_range_t);
  		port_range->start = atoi(port_item.ptr);
  
  		if (extract_token(&port_start, '-', &port_item) && port_item.len)
  		{
  			port_range->stop = atoi(port_item.ptr);
  		}
  		else
  		{
  			port_range->stop = port_range->start;
  		}
  		DBG2(DBG_IMV, "%5u - %5u", port_range->start, port_range->stop);
  		list->insert_last(list, port_range);
  	}
  
  	return list;
  }
  
  METHOD(imv_agent_if_t, batch_ending, TNC_Result,
  	private_imv_scanner_agent_t *this, TNC_ConnectionID id)
  {
  	imv_msg_t *out_msg;
  	imv_state_t *state;
  	imv_session_t *session;
  	imv_workitem_t *workitem;
  	imv_scanner_state_t *scanner_state;
  	imv_scanner_handshake_state_t handshake_state;
  	pa_tnc_attr_t *attr;
  	ietf_attr_port_filter_t *port_filter_attr;
  	TNC_IMVID imv_id;
  	TNC_Result result = TNC_RESULT_SUCCESS;
  	bool no_workitems = TRUE;
  	enumerator_t *enumerator;
  
  	if (!this->agent->get_state(this->agent, id, &state))
  	{
  		return TNC_RESULT_FATAL;
  	}
  	scanner_state = (imv_scanner_state_t*)state;
  	handshake_state = scanner_state->get_handshake_state(scanner_state);
  	port_filter_attr = scanner_state->get_port_filter_attr(scanner_state);
  	session = state->get_session(state);
  	imv_id = this->agent->get_id(this->agent);
  
  	if (handshake_state == IMV_SCANNER_STATE_END)
  	{
  		return TNC_RESULT_SUCCESS;
  	}
  
  	/* create an empty out message - we might need it */
  	out_msg = imv_msg_create(this->agent, state, id, imv_id, TNC_IMCID_ANY,
  							 msg_types[0]);
  
  	if (!session)
  	{
  		DBG2(DBG_IMV, "no workitems available - no evaluation possible");
  		state->set_recommendation(state,
  							TNC_IMV_ACTION_RECOMMENDATION_ALLOW,
  							TNC_IMV_EVALUATION_RESULT_DONT_KNOW);
  		result = out_msg->send_assessment(out_msg);
  		out_msg->destroy(out_msg);
  		scanner_state->set_handshake_state(scanner_state, IMV_SCANNER_STATE_END);
  
  		if (result != TNC_RESULT_SUCCESS)
  		{
  			return result;
  		}
  		return this->agent->provide_recommendation(this->agent, state);
  	}
  
  	if (handshake_state == IMV_SCANNER_STATE_INIT)
  	{
  		enumerator = session->create_workitem_enumerator(session);
  		if (enumerator)
  		{
  			while (enumerator->enumerate(enumerator, &workitem))
  			{
  				if (workitem->get_imv_id(workitem) != TNC_IMVID_ANY)
  				{
  					continue;
  				}
  
  				switch (workitem->get_type(workitem))
  				{
  					case IMV_WORKITEM_TCP_PORT_OPEN:
  					case IMV_WORKITEM_TCP_PORT_BLOCK:
  					case IMV_WORKITEM_UDP_PORT_OPEN:
  					case IMV_WORKITEM_UDP_PORT_BLOCK:
  						if (!port_filter_attr &&
  							handshake_state != IMV_SCANNER_STATE_ATTR_REQ)
  						{
  							attr = ietf_attr_attr_request_create(PEN_IETF,
  											IETF_ATTR_PORT_FILTER);
  							out_msg->add_attribute(out_msg, attr);
  							handshake_state = IMV_SCANNER_STATE_ATTR_REQ;
  						}
  						break;
  					default:
  						continue;
  				}
  				workitem->set_imv_id(workitem, imv_id);
  				no_workitems = FALSE;
  			}
  			enumerator->destroy(enumerator);
  
  			if (no_workitems)
  			{
  				DBG2(DBG_IMV, "IMV %d has no workitems - "
  							  "no evaluation requested", imv_id);
  				state->set_recommendation(state,
  								TNC_IMV_ACTION_RECOMMENDATION_ALLOW,
  								TNC_IMV_EVALUATION_RESULT_DONT_KNOW);
  			}
  			handshake_state = IMV_SCANNER_STATE_WORKITEMS;
  			scanner_state->set_handshake_state(scanner_state, handshake_state);
  		}
  	}
  
  	if (handshake_state == IMV_SCANNER_STATE_WORKITEMS && port_filter_attr)
  	{
  		TNC_IMV_Evaluation_Result eval;
  		TNC_IMV_Action_Recommendation rec;
  		u_int8_t protocol_family, protocol;
  		u_int16_t port;
  		bool closed_port_policy, blocked, first;
  		char result_str[BUF_LEN], *pos, *protocol_str;
  		size_t len;
  		int written;
  		linked_list_t *port_list;
  		enumerator_t *e1, *e2;
  
  		enumerator = session->create_workitem_enumerator(session);
  		while (enumerator->enumerate(enumerator, &workitem))
  		{
  			if (workitem->get_imv_id(workitem) != imv_id)
  			{
  				continue;
  			}
  			eval = TNC_IMV_EVALUATION_RESULT_COMPLIANT;
  
  			switch (workitem->get_type(workitem))
  			{
  				case IMV_WORKITEM_TCP_PORT_OPEN:
  					protocol_family = IPPROTO_TCP;
  					closed_port_policy = TRUE;
  					break;
  				case IMV_WORKITEM_TCP_PORT_BLOCK:
  					protocol_family = IPPROTO_TCP;
  					closed_port_policy = FALSE;
  					break;
  				case IMV_WORKITEM_UDP_PORT_OPEN:
  					protocol_family = IPPROTO_UDP;
  					closed_port_policy = TRUE;
  					break;
  				case IMV_WORKITEM_UDP_PORT_BLOCK:
  					protocol_family = IPPROTO_UDP;
  					closed_port_policy = FALSE;
  					break;
  				default:
  					continue;
  			}
  			port_list = get_port_list(protocol_family, closed_port_policy,
  									  workitem->get_arg_str(workitem));
  			protocol_str = (protocol_family == IPPROTO_TCP) ? "tcp" : "udp";
  			result_str[0] = '\0';
  			pos = result_str;
  			len = BUF_LEN;
  			first = TRUE;
  
  			e1 = port_filter_attr->create_port_enumerator(port_filter_attr);
  			while (e1->enumerate(e1, &blocked, &protocol, &port))
  			{
  				port_range_t *port_range;
  				bool passed, found = FALSE;
  				char buf[20];
  
  				if (blocked || protocol != protocol_family)
  				{
  					/* ignore closed ports or non-matching protocols */
  					continue;
  				}
  
  				e2 = port_list->create_enumerator(port_list);
  				while (e2->enumerate(e2, &port_range))
  				{
  					if (port >= port_range->start && port <= port_range->stop)
  					{
  						found = TRUE;
  						break;
  					}
  				}
  				e2->destroy(e2);
  
  				passed = (closed_port_policy == found);
  				DBG2(DBG_IMV, "%s port %5u open: %s", protocol_str, port,
  							   passed ? "ok" : "fatal");
  				if (!passed)
  				{
  					eval = TNC_IMV_EVALUATION_RESULT_NONCOMPLIANT_MINOR;
  					snprintf(buf, sizeof(buf), "%s/%u", protocol_str, port);
  					scanner_state->add_violating_port(scanner_state, strdup(buf));
  					if (first)
  					{
  						written = snprintf(pos, len, "violating %s ports:",
  													  protocol_str);
  						if (written > 0 && written < len)
  						{
  							pos += written;
  							len -= written;
  						}
  						first = FALSE;
  					}
  					written = snprintf(pos, len, " %u", port);
  					if (written < 0 || written >= len)
  					{
  						pos += len - 1;
  						*pos = '\0';
  					}
  					else
  					{
  						pos += written;
  						len -= written;
  					}
  				}
  			}
  			e1->destroy(e1);
  
  			if (first)
  			{
  				snprintf(pos, len, "no violating %s ports", protocol_str);
  			}
  			port_list->destroy(port_list);
  
  			session->remove_workitem(session, enumerator);
  			rec = workitem->set_result(workitem, result_str, eval);
  			state->update_recommendation(state, rec, eval);
  			imcv_db->finalize_workitem(imcv_db, workitem);
  			workitem->destroy(workitem);
  		}
  		enumerator->destroy(enumerator);
  	}
  
  	/* finalized all workitems ? */
  	if (handshake_state == IMV_SCANNER_STATE_WORKITEMS &&
  		session->get_workitem_count(session, imv_id) == 0)
  	{
  		result = out_msg->send_assessment(out_msg);
  		out_msg->destroy(out_msg);
  		scanner_state->set_handshake_state(scanner_state, IMV_SCANNER_STATE_END);
  
  		if (result != TNC_RESULT_SUCCESS)
  		{
  			return result;
  		}
  		return this->agent->provide_recommendation(this->agent, state);
  	}
  
  	/* send non-empty PA-TNC message with excl flag not set */
  	if (out_msg->get_attribute_count(out_msg))
  	{
  		result = out_msg->send(out_msg, FALSE);
  	}
  	out_msg->destroy(out_msg);
  
  	return result;
  }
  
  METHOD(imv_agent_if_t, solicit_recommendation, TNC_Result,
  	private_imv_scanner_agent_t *this, TNC_ConnectionID id)
  {
  	imv_state_t *state;
  
  	if (!this->agent->get_state(this->agent, id, &state))
  	{
  		return TNC_RESULT_FATAL;
  	}
  	return this->agent->provide_recommendation(this->agent, state);
  }
  
  METHOD(imv_agent_if_t, destroy, void,
  	private_imv_scanner_agent_t *this)
  {
  	this->agent->destroy(this->agent);
  	free(this);
  }
  
  /**
   * Described in header.
   */
  imv_agent_if_t *imv_scanner_agent_create(const char *name, TNC_IMVID id,
  										 TNC_Version *actual_version)
  {
  	private_imv_scanner_agent_t *this;
  	imv_agent_t *agent;
  
  	agent = imv_agent_create(name, msg_types, countof(msg_types), id,
  							 actual_version);
  	if (!agent)
  	{
  		return NULL;
  	}
  
  	INIT(this,
  		.public = {
  			.bind_functions = _bind_functions,
  			.notify_connection_change = _notify_connection_change,
  			.receive_message = _receive_message,
  			.receive_message_long = _receive_message_long,
  			.batch_ending = _batch_ending,
  			.solicit_recommendation = _solicit_recommendation,
  			.destroy = _destroy,
  		},
  		.agent = agent,
  	);
  
  	return &this->public;
  }
  
  