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ICMP Class Reference

#include <ICMP.h>

List of all members.

Detailed Description

ICMP module.


Public Member Functions

void sendErrorMessage (IPDatagram *datagram, ICMPType type, ICMPCode code)
void sendErrorMessage (cMessage *transportPacket, IPControlInfo *ctrl, ICMPType type, ICMPCode code)

Protected Member Functions

virtual void processICMPMessage (ICMPMessage *)
virtual void errorOut (ICMPMessage *)
virtual void processEchoRequest (ICMPMessage *)
virtual void processEchoReply (ICMPMessage *)
virtual void sendEchoRequest (cMessage *)
virtual void sendToIP (ICMPMessage *, const IPAddress &dest)
virtual void sendToIP (ICMPMessage *msg)
virtual void handleMessage (cMessage *msg)

Protected Attributes

RoutingTableAccess routingTableAccess

Member Function Documentation

void ICMP::errorOut (  ICMPMessage *   )  [protected, virtual]
  

00160 {
00161     send(icmpmsg, "errorOut");
00162 }

void ICMP::handleMessage (  cMessage *  msg  )  [protected, virtual]
  

00033 {
00034     cGate *arrivalGate = msg->arrivalGate();
00035 
00036     // process arriving ICMP message
00037     if (!strcmp(arrivalGate->name(), "localIn"))
00038     {
00039         processICMPMessage(check_and_cast<ICMPMessage *>(msg));
00040         return;
00041     }
00042 
00043     // request from application
00044     if (!strcmp(arrivalGate->name(), "pingIn"))
00045     {
00046         sendEchoRequest(msg);
00047         return;
00048     }
00049 }

void ICMP::processEchoReply (  ICMPMessage *   )  [protected, virtual]
  

00183 {
00184     IPControlInfo *ctrl = check_and_cast<IPControlInfo*>(reply->removeControlInfo());
00185     cMessage *payload = reply->decapsulate();
00186     payload->setControlInfo(ctrl);
00187     delete reply;
00188     send(payload, "pingOut");
00189 }

void ICMP::processEchoRequest (  ICMPMessage *   )  [protected, virtual]
  

00165 {
00166     // turn request into a reply
00167     ICMPMessage *reply = request;
00168     reply->setName((std::string(request->name())+"-reply").c_str());
00169     reply->setType(ICMP_ECHO_REPLY);
00170 
00171     // swap src and dest
00172     // TBD check what to do if dest was multicast etc?
00173     IPControlInfo *ctrl = check_and_cast<IPControlInfo *>(reply->controlInfo());
00174     IPAddress src = ctrl->srcAddr();
00175     IPAddress dest = ctrl->destAddr();
00176     ctrl->setSrcAddr(dest);
00177     ctrl->setDestAddr(src);
00178 
00179     sendToIP(reply);
00180 }

void ICMP::processICMPMessage (  ICMPMessage *   )  [protected, virtual]
  

00127 {
00128     switch (icmpmsg->getType())
00129     {
00130         case ICMP_DESTINATION_UNREACHABLE:
00131             errorOut(icmpmsg);
00132             break;
00133         case ICMP_REDIRECT:
00134             errorOut(icmpmsg);
00135             break;
00136         case ICMP_TIME_EXCEEDED:
00137             errorOut(icmpmsg);
00138             break;
00139         case ICMP_PARAMETER_PROBLEM:
00140             errorOut(icmpmsg);
00141             break;
00142         case ICMP_ECHO_REQUEST:
00143             processEchoRequest(icmpmsg);
00144             break;
00145         case ICMP_ECHO_REPLY:
00146             processEchoReply(icmpmsg);
00147             break;
00148         case ICMP_TIMESTAMP_REQUEST:
00149             processEchoRequest(icmpmsg);
00150             break;
00151         case ICMP_TIMESTAMP_REPLY:
00152             processEchoReply(icmpmsg);
00153             break;
00154         default:
00155             opp_error("Unknown ICMP type %d", icmpmsg->getType());
00156     }
00157 }

void ICMP::sendEchoRequest (  cMessage *   )  [protected, virtual]
  

00192 {
00193     IPControlInfo *ctrl = check_and_cast<IPControlInfo*>(msg->removeControlInfo());
00194     ctrl->setProtocol(IP_PROT_ICMP);
00195     ICMPMessage *request = new ICMPMessage(msg->name());
00196     request->setType(ICMP_ECHO_REQUEST);
00197     request->encapsulate(msg);
00198     request->setControlInfo(ctrl);
00199     sendToIP(request);
00200 }

void ICMP::sendErrorMessage (  cMessage *  transportPacket,
IPControlInfo *  ctrl,
ICMPType  type,
ICMPCode  code
) 
 

This method can be called from other modules to send an ICMP error packet in response to a received bogus packet from the transport layer (like UDP). The ICMP error packet needs to include (part of) the original IP datagram, so this function will wrap back the transport packet into the IP datagram based on its IPControlInfo. 

00116 {
00117     Enter_Method("sendErrorMessage(transportPacket, ctrl, type=%d, code=%d)", type, code);
00118 
00119     IPDatagram *datagram = ctrl->removeOrigDatagram();
00120     take(transportPacket);
00121     take(datagram);
00122     datagram->encapsulate(transportPacket);
00123     sendErrorMessage(datagram, type, code);
00124 }

void ICMP::sendErrorMessage (  IPDatagram *  datagram,
ICMPType  type,
ICMPCode  code
) 
 

This method can be called from other modules to send an ICMP error packet in response to a received bogus packet. 

00053 {
00054     Enter_Method("sendErrorMessage(datagram, type=%d, code=%d)", type, code);
00055 
00056     // get ownership
00057     take(origDatagram);
00058 
00059     // don't send ICMP error messages for multicast messages
00060     if (origDatagram->destAddress().isMulticast())
00061     {
00062         EV << "won't send ICMP error messages for multicast message " << origDatagram << endl;
00063         delete origDatagram;
00064         return;
00065     }
00066 
00067     // do not reply with error message to error message
00068     if (origDatagram->transportProtocol() == IP_PROT_ICMP)
00069     {
00070         ICMPMessage *recICMPMsg = check_and_cast<ICMPMessage *>(origDatagram->encapsulatedMsg());
00071         if (recICMPMsg->getType()<128)
00072         {
00073             EV << "ICMP error received -- do not reply to it" << endl;
00074             delete origDatagram;
00075             return;
00076         }
00077     }
00078 
00079     // assemble a message name
00080     char msgname[32];
00081     static long ctr;
00082     sprintf(msgname, "ICMP-error-#%ld-type%d-code%d", ++ctr, type, code);
00083 
00084     // debugging information
00085     EV << "sending ICMP error " << msgname << endl;
00086 
00087     // create and send ICMP packet
00088     ICMPMessage *errorMessage = new ICMPMessage(msgname);
00089     errorMessage->setType(type);
00090     errorMessage->setCode(code);
00091     errorMessage->encapsulate(origDatagram);
00092     // ICMP message length: the internet header plus the first 8 bytes of
00093     // the original datagram's data is returned to the sender
00094     errorMessage->setByteLength(4 + origDatagram->headerLength() + 8);
00095 
00096     // if srcAddr is not filled in, we're still in the src node, so we just
00097     // process the ICMP message locally, right away
00098     if (origDatagram->srcAddress().isUnspecified())
00099     {
00100         // pretend it came from the IP layer
00101         IPControlInfo *controlInfo = new IPControlInfo();
00102         controlInfo->setSrcAddr(IPAddress::LOOPBACK_ADDRESS); // FIXME maybe use configured loopback address
00103         controlInfo->setProtocol(IP_PROT_ICMP);
00104         errorMessage->setControlInfo(controlInfo);
00105 
00106         // then process it locally
00107         processICMPMessage(errorMessage);
00108     }
00109     else
00110     {
00111         sendToIP(errorMessage, origDatagram->srcAddress());
00112     }
00113 }

void ICMP::sendToIP (  ICMPMessage *  msg  )  [protected, virtual]
  

00213 {
00214     // assumes IPControlInfo is already attached
00215     send(msg, "sendOut");
00216 }

void ICMP::sendToIP (  ICMPMessage *  ,
const IPAddress &  dest
)  [protected, virtual]
  

00203 {
00204     IPControlInfo *controlInfo = new IPControlInfo();
00205     controlInfo->setDestAddr(dest);
00206     controlInfo->setProtocol(IP_PROT_ICMP);
00207     msg->setControlInfo(controlInfo);
00208 
00209     send(msg, "sendOut");
00210 }

Member Data Documentation

RoutingTableAccess ICMP::routingTableAccess [protected]
 

The documentation for this class was generated from the following files:
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