Sergey Pastor
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Diff: cyclone_tcp/ppp/ppp_fsm.c
- Revision:
- 0:8918a71cdbe9
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/cyclone_tcp/ppp/ppp_fsm.c Sat Feb 04 18:15:49 2017 +0000
@@ -0,0 +1,954 @@
+/**
+ * @file ppp_fsm.c
+ * @brief PPP finite state machine
+ *
+ * @section License
+ *
+ * Copyright (C) 2010-2017 Oryx Embedded SARL. All rights reserved.
+ *
+ * This file is part of CycloneTCP Open.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * @author Oryx Embedded SARL (www.oryx-embedded.com)
+ * @version 1.7.6
+ **/
+
+//Switch to the appropriate trace level
+#define TRACE_LEVEL PPP_TRACE_LEVEL
+
+//Dependencies
+#include "core/net.h"
+#include "ppp/ppp_fsm.h"
+#include "debug.h"
+
+//Check TCP/IP stack configuration
+#if (PPP_SUPPORT == ENABLED)
+
+
+/**
+ * @brief Process Up event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ **/
+
+void pppUpEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_0_INITIAL:
+ //Switch to the Closed state
+ pppChangeState(fsm, PPP_STATE_2_CLOSED);
+ break;
+ case PPP_STATE_1_STARTING:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_CONFIGURE);
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+
+/**
+ * @brief Process Down event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ **/
+
+void pppDownEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ //Switch to the Initial state
+ pppChangeState(fsm, PPP_STATE_0_INITIAL);
+ break;
+ case PPP_STATE_3_STOPPED:
+ //Switch to the Starting state
+ pppChangeState(fsm, PPP_STATE_1_STARTING);
+ //Indicate to the lower layers that the automaton is entering the
+ //Starting state. The lower layer is needed for the link
+ callbacks->thisLayerStarted(context);
+ break;
+ case PPP_STATE_4_CLOSING:
+ //Switch to the Initial state
+ pppChangeState(fsm, PPP_STATE_0_INITIAL);
+ break;
+ case PPP_STATE_5_STOPPING:
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ case PPP_STATE_8_ACK_SENT:
+ //Switch to the Starting state
+ pppChangeState(fsm, PPP_STATE_1_STARTING);
+ break;
+ case PPP_STATE_9_OPENED:
+ //Switch to the Starting state
+ pppChangeState(fsm, PPP_STATE_1_STARTING);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+
+/**
+ * @brief Process Open event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ **/
+
+void pppOpenEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_0_INITIAL:
+ //Switch to the Starting state
+ pppChangeState(fsm, PPP_STATE_1_STARTING);
+ //Indicate to the lower layers that the automaton is entering the
+ //Starting state. The lower layer is needed for the link
+ callbacks->thisLayerStarted(context);
+ break;
+ case PPP_STATE_1_STARTING:
+ //Stay in current state
+ break;
+ case PPP_STATE_2_CLOSED:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_CONFIGURE);
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_3_STOPPED:
+ //Stay in current state
+ break;
+ case PPP_STATE_4_CLOSING:
+ //Switch to the Stopping state
+ pppChangeState(fsm, PPP_STATE_5_STOPPING);
+ break;
+ case PPP_STATE_5_STOPPING:
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ case PPP_STATE_8_ACK_SENT:
+ case PPP_STATE_9_OPENED:
+ //Stay in current state
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+
+/**
+ * @brief Process Close event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ **/
+
+void pppCloseEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_0_INITIAL:
+ //Stay in current state
+ break;
+ case PPP_STATE_1_STARTING:
+ //Switch to the Initial state
+ pppChangeState(fsm, PPP_STATE_0_INITIAL);
+ //Indicate to the lower layers that the automaton is entering the
+ //Initial, Closed or Stopped states. The lower layer is no longer
+ //needed for the link
+ callbacks->thisLayerFinished(context);
+ break;
+ case PPP_STATE_2_CLOSED:
+ //Stay in current state
+ break;
+ case PPP_STATE_3_STOPPED:
+ //Switch to the Closed state
+ pppChangeState(fsm, PPP_STATE_2_CLOSED);
+ break;
+ case PPP_STATE_4_CLOSING:
+ //Stay in current state
+ break;
+ case PPP_STATE_5_STOPPING:
+ //Switch to the Closing state
+ pppChangeState(fsm, PPP_STATE_4_CLOSING);
+ break;
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ case PPP_STATE_8_ACK_SENT:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_TERMINATE);
+ //Send Terminate-Request packet
+ callbacks->sendTerminateReq(context);
+ //Switch to the Closing state
+ pppChangeState(fsm, PPP_STATE_4_CLOSING);
+ break;
+ case PPP_STATE_9_OPENED:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_TERMINATE);
+ //Send Terminate-Request packet
+ callbacks->sendTerminateReq(context);
+ //Switch to the Closing state
+ pppChangeState(fsm, PPP_STATE_4_CLOSING);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+
+/**
+ * @brief Process Timeout event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ **/
+
+void pppTimeoutEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks)
+{
+ //The restart counter is greater than zero (TO+ event)
+ if(fsm->restartCounter > 0)
+ {
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ //Send Terminate-Request packet
+ callbacks->sendTerminateReq(context);
+ //Stay in current state
+ break;
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ //Send Configuration-Request packet
+ callbacks->sendConfigureReq(context);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_8_ACK_SENT:
+ //Send Configuration-Request packet
+ callbacks->sendConfigureReq(context);
+ //Stay in current state
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+ }
+ //The restart counter is not greater than zero (TO- event)
+ else
+ {
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_4_CLOSING:
+ //Switch to the Closed state
+ pppChangeState(fsm, PPP_STATE_2_CLOSED);
+ //Indicate to the lower layers that the automaton is entering the
+ //Initial, Closed or Stopped states. The lower layer is no longer
+ //needed for the link
+ callbacks->thisLayerFinished(context);
+ break;
+ case PPP_STATE_5_STOPPING:
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ case PPP_STATE_8_ACK_SENT:
+ //Switch to the Stopped state
+ pppChangeState(fsm, PPP_STATE_3_STOPPED);
+ //Indicate to the lower layers that the automaton is entering the
+ //Initial, Closed or Stopped states. The lower layer is no longer
+ //needed for the link
+ callbacks->thisLayerFinished(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+ }
+}
+
+
+/**
+ * @brief Process Receive-Configure-Request event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ * @param[in] configureReqPacket Configure-Request packet received from the peer
+ * @param[in] code Tells whether the configuration options are acceptable
+ **/
+
+void pppRcvConfigureReqEvent(PppContext *context, PppFsm *fsm, const PppCallbacks *callbacks,
+ const PppConfigurePacket *configureReqPacket, PppCode code)
+{
+ //Check whether the configuration options are acceptable
+ if(code == PPP_CODE_CONFIGURE_ACK)
+ {
+ //If every configuration option received in the Configure-Request is
+ //recognizable and all values are acceptable, then the implementation
+ //must transmit a Configure-Ack
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ //Send Terminate-Ack packet
+ callbacks->sendTerminateAck(context, NULL);
+ //Stay in current state
+ break;
+ case PPP_STATE_3_STOPPED:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_CONFIGURE);
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Send Configure-Ack packet
+ callbacks->sendConfigureAck(context, configureReqPacket);
+ //Switch to the Ack-Sent state
+ pppChangeState(fsm, PPP_STATE_8_ACK_SENT);
+ break;
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ //Stay in current state
+ break;
+ case PPP_STATE_6_REQ_SENT:
+ //Send Configure-Ack packet
+ callbacks->sendConfigureAck(context, configureReqPacket);
+ //Switch to the Ack-Sent state
+ pppChangeState(fsm, PPP_STATE_8_ACK_SENT);
+ break;
+ case PPP_STATE_7_ACK_RCVD:
+ //Send Configure-Ack packet
+ callbacks->sendConfigureAck(context, configureReqPacket);
+ //Switch to the Opened state
+ pppChangeState(fsm, PPP_STATE_9_OPENED);
+ //Indicate to the upper layers that the automaton is entering the
+ //Opened state. The link is available for network traffic
+ callbacks->thisLayerUp(context);
+ break;
+ case PPP_STATE_8_ACK_SENT:
+ //Send Configure-Ack packet
+ callbacks->sendConfigureAck(context, configureReqPacket);
+ //Stay in current state
+ break;
+ case PPP_STATE_9_OPENED:
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Send Configure-Ack packet
+ callbacks->sendConfigureAck(context, configureReqPacket);
+ //Switch to the Ack-Sent state
+ pppChangeState(fsm, PPP_STATE_8_ACK_SENT);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+ }
+ else if(code == PPP_CODE_CONFIGURE_NAK)
+ {
+ //If all configuration options are recognizable, but some values are not
+ //acceptable, then the implementation must transmit a Configure-Nak
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ //Send Terminate-Ack packet
+ callbacks->sendTerminateAck(context, NULL);
+ //Stay in current state
+ break;
+ case PPP_STATE_3_STOPPED:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_CONFIGURE);
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Send Configure-Nak packet
+ callbacks->sendConfigureNak(context, configureReqPacket);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ //Stay in current state
+ break;
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ //Send Configure-Nak packet
+ callbacks->sendConfigureNak(context, configureReqPacket);
+ //Stay in current state
+ break;
+ case PPP_STATE_8_ACK_SENT:
+ //Send Configure-Nak packet
+ callbacks->sendConfigureNak(context, configureReqPacket);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_9_OPENED:
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Send Configure-Nak packet
+ callbacks->sendConfigureNak(context, configureReqPacket);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+ }
+ else if(code == PPP_CODE_CONFIGURE_REJ)
+ {
+ //If some configuration options received in the Configure-Request are not
+ //recognizable or not acceptable for negotiation, then the implementation
+ //must transmit a Configure-Reject
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ //Send Terminate-Ack packet
+ callbacks->sendTerminateAck(context, NULL);
+ //Stay in current state
+ break;
+ case PPP_STATE_3_STOPPED:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_CONFIGURE);
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Send Configure-Reject packet
+ callbacks->sendConfigureRej(context, configureReqPacket);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ //Stay in current state
+ break;
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ //Send Configure-Reject packet
+ callbacks->sendConfigureRej(context, configureReqPacket);
+ //Stay in current state
+ break;
+ case PPP_STATE_8_ACK_SENT:
+ //Send Configure-Reject packet
+ callbacks->sendConfigureRej(context, configureReqPacket);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_9_OPENED:
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Send Configure-Reject packet
+ callbacks->sendConfigureRej(context, configureReqPacket);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+ }
+}
+
+
+/**
+ * @brief Process Receive-Configure-Ack event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ **/
+
+void pppRcvConfigureAckEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ case PPP_STATE_3_STOPPED:
+ //Send Terminate-Ack packet
+ callbacks->sendTerminateAck(context, NULL);
+ //Stay in current state
+ break;
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ //Stay in current state
+ break;
+ case PPP_STATE_6_REQ_SENT:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_CONFIGURE);
+ //Switch to the Ack-Rcvd state
+ fsm->state = PPP_STATE_7_ACK_RCVD;
+ break;
+ case PPP_STATE_7_ACK_RCVD:
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_8_ACK_SENT:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_CONFIGURE);
+ //Switch to the Opened state
+ pppChangeState(fsm, PPP_STATE_9_OPENED);
+ //Indicate to the upper layers that the automaton is entering the
+ //Opened state. The link is available for network traffic
+ callbacks->thisLayerUp(context);
+ break;
+ case PPP_STATE_9_OPENED:
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+
+/**
+ * @brief Process Receive-Configure-Nak event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ **/
+
+void pppRcvConfigureNakEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ case PPP_STATE_3_STOPPED:
+ //Send Terminate-Ack packet
+ callbacks->sendTerminateAck(context, NULL);
+ //Stay in current state
+ break;
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ //Stay in current state
+ break;
+ case PPP_STATE_6_REQ_SENT:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_CONFIGURE);
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Stay in current state
+ break;
+ case PPP_STATE_7_ACK_RCVD:
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_8_ACK_SENT:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_CONFIGURE);
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Stay in current state
+ break;
+ case PPP_STATE_9_OPENED:
+ //Send Configure-Request packet
+ callbacks->sendConfigureReq(context);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+
+/**
+ * @brief Process Receive-Terminate-Req event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ * @param[in] terminateReqPacket Terminate-Request packet received from the peer
+ **/
+
+void pppRcvTerminateReqEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks, const PppTerminatePacket *terminateReqPacket)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ case PPP_STATE_3_STOPPED:
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ //Send Terminate-Ack packet
+ callbacks->sendTerminateAck(context, terminateReqPacket);
+ //Stay in current state
+ break;
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ case PPP_STATE_8_ACK_SENT:
+ //Send Terminate-Ack packet
+ callbacks->sendTerminateAck(context, terminateReqPacket);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_9_OPENED:
+ //Zero restart counter
+ callbacks->zeroRestartCount(context);
+ //Send Terminate-Ack packet
+ callbacks->sendTerminateAck(context, terminateReqPacket);
+ //Switch to the Stopping state
+ pppChangeState(fsm, PPP_STATE_5_STOPPING);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+
+/**
+ * @brief Process Receive-Terminate-Ack event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ **/
+
+void pppRcvTerminateAckEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ case PPP_STATE_3_STOPPED:
+ //Stay in current state
+ break;
+ case PPP_STATE_4_CLOSING:
+ //Switch to the Closed state
+ pppChangeState(fsm, PPP_STATE_2_CLOSED);
+ //Indicate to the lower layers that the automaton is entering the
+ //Initial, Closed or Stopped states. The lower layer is no longer
+ //needed for the link
+ callbacks->thisLayerFinished(context);
+ break;
+ case PPP_STATE_5_STOPPING:
+ //Switch to the Stopped state
+ pppChangeState(fsm, PPP_STATE_3_STOPPED);
+ //Indicate to the lower layers that the automaton is entering the
+ //Initial, Closed or Stopped states. The lower layer is no longer
+ //needed for the link
+ callbacks->thisLayerFinished(context);
+ break;
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_8_ACK_SENT:
+ //Stay in current state
+ break;
+ case PPP_STATE_9_OPENED:
+ //Send Configure-Req packet
+ callbacks->sendConfigureReq(context);
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+
+/**
+ * @brief Process Receive-Unknown-Code event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ * @param[in] packet Un-interpretable packet received from the peer
+ **/
+
+void pppRcvUnknownCodeEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks, const PppPacket *packet)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ case PPP_STATE_3_STOPPED:
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ case PPP_STATE_8_ACK_SENT:
+ case PPP_STATE_9_OPENED:
+ //Send Reject-Code packet
+ callbacks->sendCodeRej(context, packet);
+ //Stay in current state
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+/**
+ * @brief Process Receive-Code-Reject or Receive-Protocol-Reject event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ * @param[in] acceptable This parameter tells whether the rejected value
+ * is acceptable or catastrophic
+ **/
+
+void pppRcvCodeRejEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks, bool_t acceptable)
+{
+ //Check whether the rejected value is acceptable or catastrophic
+ if(acceptable)
+ {
+ //The RXJ+ event arises when the rejected value is acceptable, such
+ //as a Code-Reject of an extended code, or a Protocol-Reject of a
+ //NCP. These are within the scope of normal operation
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ case PPP_STATE_3_STOPPED:
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ case PPP_STATE_6_REQ_SENT:
+ //Stay in current state
+ break;
+ case PPP_STATE_7_ACK_RCVD:
+ //Switch to the Req-Sent state
+ pppChangeState(fsm, PPP_STATE_6_REQ_SENT);
+ break;
+ case PPP_STATE_8_ACK_SENT:
+ case PPP_STATE_9_OPENED:
+ //Stay in current state
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+ }
+ else
+ {
+ //The RXJ- event arises when the rejected value is catastrophic,
+ //such as a Code-Reject of Configure-Request, or a Protocol-Reject
+ //of LCP! This event communicates an unrecoverable error that
+ //terminates the connection
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ case PPP_STATE_3_STOPPED:
+ //Indicate to the lower layers that the automaton is entering the
+ //Initial, Closed or Stopped states. The lower layer is no longer
+ //needed for the link
+ callbacks->thisLayerFinished(context);
+ //Stay in current state
+ break;
+ case PPP_STATE_4_CLOSING:
+ //Switch to the Closed state
+ pppChangeState(fsm, PPP_STATE_2_CLOSED);
+ //Indicate to the lower layers that the automaton is entering the
+ //Initial, Closed or Stopped states. The lower layer is no longer
+ //needed for the link
+ callbacks->thisLayerFinished(context);
+ break;
+ case PPP_STATE_5_STOPPING:
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ case PPP_STATE_8_ACK_SENT:
+ //Switch to the Stopped state
+ pppChangeState(fsm, PPP_STATE_3_STOPPED);
+ //Indicate to the lower layers that the automaton is entering the
+ //Initial, Closed or Stopped states. The lower layer is no longer
+ //needed for the link
+ callbacks->thisLayerFinished(context);
+ break;
+ case PPP_STATE_9_OPENED:
+ //Initialize restart counter
+ callbacks->initRestartCount(context, PPP_MAX_TERMINATE);
+ //Send Terminate-Req packet
+ callbacks->sendTerminateReq(context);
+ //Switch to the Stopping state
+ pppChangeState(fsm, PPP_STATE_5_STOPPING);
+ //Indicate to the upper layers that the automaton is leaving the Opened
+ //state. The link is no longer available for network traffic
+ callbacks->thisLayerDown(context);
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+ }
+}
+
+
+/**
+ * @brief Process Receive-Echo-Request event
+ * @param[in] context PPP context
+ * @param[in,out] fsm Finite state machine
+ * @param[in] callbacks FSM actions
+ * @param[in] echoReqPacket Echo-Request packet received from the peer
+ **/
+
+void pppRcvEchoReqEvent(PppContext *context, PppFsm *fsm,
+ const PppCallbacks *callbacks, const PppEchoPacket *echoReqPacket)
+{
+ //Check current state
+ switch(fsm->state)
+ {
+ case PPP_STATE_2_CLOSED:
+ case PPP_STATE_3_STOPPED:
+ case PPP_STATE_4_CLOSING:
+ case PPP_STATE_5_STOPPING:
+ case PPP_STATE_6_REQ_SENT:
+ case PPP_STATE_7_ACK_RCVD:
+ case PPP_STATE_8_ACK_SENT:
+ //Stay in current state
+ break;
+ case PPP_STATE_9_OPENED:
+ //Send Echo-Reply packet
+ callbacks->sendEchoRep(context, echoReqPacket);
+ //Stay in current state
+ break;
+ default:
+ //This event cannot occur in a properly implemented automaton.
+ //No transition is taken, and the implementation should not
+ //reset or freeze
+ break;
+ }
+}
+
+
+/**
+ * @brief Update PPP FSM state
+ * @param[in,out] fsm Finite state machine
+ * @param[in] newState New PPP state to switch to
+ **/
+
+void pppChangeState(PppFsm *fsm, PppState newState)
+{
+#if (PPP_TRACE_LEVEL >= TRACE_LEVEL_INFO)
+ //PPP FSM states
+ static const char_t *stateLabel[] =
+ {
+ "INITIAL", //0
+ "STARTING", //1
+ "CLOSED", //2
+ "STOPPED", //3
+ "CLOSING", //4
+ "STOPPING", //5
+ "REQ_SENT", //6
+ "ACK_RCVD", //7
+ "ACK_SENT", //8
+ "OPENED" //9
+ };
+
+ //Sanity check
+ if(fsm->state < arraysize(stateLabel) && newState < arraysize(stateLabel))
+ {
+ //Debug message
+ TRACE_INFO("PPP FSM: %s (%u) -> %s (%u)\r\n", stateLabel[fsm->state],
+ fsm->state, stateLabel[newState], newState);
+ }
+#endif
+
+ //Switch to the new state
+ fsm->state = newState;
+}
+
+#endif
+