modules/up/src/Core/network/ICMProbe.cc
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FUNCTIONS
This source file includes following functions.
- icmprobeTimerHandler
- ICMProbe
- ICMProbe
- send
- handleTimer
- receive
//
// $Id: ICMProbe.cc,v 1.1.1.1 2000/03/10 16:32:19 engin Exp $
//
// Author(s): Ramesh Govindan
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
extern "C" {
#include <sys/types.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
}
#include "util/Types.hh"
#include "util/Trail.hh"
#include "util/Handler.hh"
#include "util/Buffer.hh"
#include "sys/File.hh"
#include "sys/Pipe.hh"
#include "sys/Time.hh"
#include "sched/Timer.hh"
#include "sched/Dispatcher.hh"
#include "network/ICMProbe.hh"
#include "network/Headers.hh"
#include "network/Network.hh"
// Constants
static const unsigned char UDPProtocol = 17;
// Locals
static TraceCode traceICMProbe("net");
static TimeShort maxWait(10, 0);
static unsigned int probeNumber = 0x80000000;
static void
icmprobeTimerHandler(void* ptr,
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void*)
{
((ICMProbe*) ptr)->handleTimer();
}
ICMProbe::ICMProbe(Address* a,
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Handler& cb,
int hc,
Address* v)
: ListNode()
{
done = cb;
to = *a;
hopcount = hc;
if (v) {
via = *v;
}
timer = NULL;
result = ICMProbeResultNone;
residualHops = 0;
network->pendingICMProbes.append(this);
probeId = 0;
lastRtt = InfiniteInterval;
sent = 0;
}
ICMProbe::~ICMProbe()
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{
network->pendingICMProbes.remove(this);
if (timer) {
delete timer;
}
}
void
ICMProbe::send()
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{
Handler th(icmprobeTimerHandler, this);
Handler nh(NULL, NULL);
Buffer* buf;
IP* ip;
IPOptLSRR* ipopt;
ICMP* icmp;
RawSocket* raw;
U32* t;
TimeLong at;
Address srcaddr;
responder.set(0);
result = ICMProbeResultNone;
sent++;
network->icmprobesSent++;
// Send packet
raw = new RawSocket(nh, nh, RawSocketICMP);
if (via.get()) {
buf = new Buffer(sizeof(IP) + sizeof(IPOptLSRR) + sizeof(ICMP) + 8);
} else {
buf = new Buffer(sizeof(IP) + sizeof(ICMP) + 8);
}
buf->zeroFill();
ip = (IP*) buf->contents;
ip->headerLength = via.get() ?
(sizeof(IP) + sizeof(IPOptLSRR)) >> 2 :
sizeof(IP) >> 2;
ip->version = 4;
ip->typeOfService = 0;
ip->totalLength = (ip->headerLength << 2) + sizeof(ICMP);
ip->identifier = 0;
ip->fragmentOffset = 0;
ip->timeToLive = hopcount;
ip->protocol = IPPROTO_ICMP;
ip->source = (network->interfaces.head())->address.get();
ip->destination = (via.get()) ? via.get() : to.get();
ip->hton();
ip->checksum = 0;
ip->checksum = network->cksum((U16*) ip, ip->headerLength << 2);
if (via.get()) {
IPOptLSRR* lsrr;
lsrr = (IPOptLSRR*) (ip + 1);
lsrr->nullopt = IPOPT_NOP;
lsrr->lsrropt = IPOPT_LSRR;
lsrr->length = sizeof(U32) + 3;
lsrr->pointer = IPOPT_MINOFF;
lsrr->gateway = to.get();
lsrr->hton();
icmp = (ICMP*) (lsrr + 1);
} else {
icmp = (ICMP*) (ip + 1);
}
ASSERT(probeNumber != 0xffffffff); // Wrap around
probeNumber++;
probeId = probeNumber;
icmp->type = ICMPTypeEcho;
icmp->code = 0;
icmp->gateway = probeNumber;
icmp->hton();
icmp->checksum = 0;
icmp->checksum = network->cksum((U16*) icmp, sizeof(ICMP) + 8);
dispatcher.systemClock.sync();
sentAt = dispatcher.systemClock;
raw->sendTo(buf->contents, buf->size, to, 0);
TRACE(traceICMProbe, "icmprobe to %s:%d\n", to.name(), hopcount);
delete raw;
delete buf;
if (timer) {
delete timer;
}
at = dispatcher.systemClock;
at = at + maxWait;
timer = new Timer(th, at);
return;
}
void
ICMProbe::handleTimer()
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{
TRACE(traceICMProbe, "icmprobe failed to %s\n", to.name());
timer = NULL;
network->icmprobesTimedOut++;
done.callBack((void*) this);
lastRtt = InfiniteInterval;
return;
}
Boolean
ICMProbe::receive(IP* ip)
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{
ICMP* icmp;
unsigned short sum;
IP* iip;
int datalen;
// Verify signature to see if it is for us
icmp = (struct ICMP*) ((char*) ip + (ip->headerLength << 2));
if (icmp->type != ICMPTypeTimeExceeded &&
icmp->type != ICMPTypeDestinationUnreachable &&
icmp->type != ICMPTypeEchoReply)
return false;
if (icmp->type == ICMPTypeTimeExceeded ||
icmp->type == ICMPTypeDestinationUnreachable) {
datalen = ip->totalLength - (ip->headerLength << 2) - sizeof(ICMP);
if (datalen < sizeof(IP))
return false; // Malformed response, discard
iip = (struct IP*) (icmp + 1);
iip->ntoh();
if (datalen < ((iip->headerLength << 2) + 2 * sizeof(unsigned long)))
return false; // Timestamp not there, discard
if (iip->destination != to.get())
return false;
ICMP* icmpi = (ICMP*) (((char*) iip) + (iip->headerLength<<2));
icmpi->ntoh();
if (icmpi->gateway != probeNumber) // it is not the pkt we sent
return false;
}
dispatcher.systemClock.sync();
lastRtt = dispatcher.systemClock - sentAt;
switch (icmp->type) {
case ICMPTypeEchoReply:
if (ip->source != to.get()) {
return false;
}
if (icmp->gateway != probeNumber) {
return false;
}
responder.set(ip->source);
residualHops = 0;
result = ICMProbeResultReachedNode;
TRACE(traceICMProbe, "received icmprobe for %s:%d from %s\n",
to.name(), hopcount, responder.name());
done.callBack((void*) this);
break;
case ICMPTypeTimeExceeded:
if (iip->timeToLive <= 1) {
responder.set(ip->source);
result = ICMProbeResultTimeExpired;
TRACE(traceICMProbe, "received icmprobe for %s:%d from %s\n",
to.name(), hopcount, responder.name());
} else {
responder.set(ip->source);
ERROR("unexpected ttl %d in ICMP TimeExceeded from %s\n",
iip->timeToLive, responder.name());
result = ICMProbeResultDontCare;
}
done.callBack((void*) this);
break;
case ICMPTypeDestinationUnreachable:
residualHops = iip->timeToLive;
responder.set(ip->source);
switch (icmp->code) {
case ICMPUnreachNet:
case ICMPUnreachHost:
result = ICMProbeResultUnreachable;
break;
case ICMPUnreachProto:
case ICMPUnreachPort:
result = ICMProbeResultReachedNode;
break;
case ICMPUnreachSrtFail:
result = ICMProbeResultSourceRouteFailed;
break;
case ICMPUnreachNeedFrag:
default:
result = ICMProbeResultDontCare;
break;
}
TRACE(traceICMProbe, "received icmprobe for %s:%d from %s\n",
to.name(), hopcount, responder.name());
done.callBack((void*) this);
// FallThrough
default:
break;
}
return true;
}
// Copyright (c) 1994 by the University of Southern California.
// All rights reserved.
//
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// non-commercial purposes and without fee is hereby granted, provided
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// the copyright notice and this permission notice appear in supporting
// documentation, and that any documentation, advertising materials,
// and other materials related to such distribution and use acknowledge
// that the software was developed by the University of Southern
// California and/or Information Sciences Institute.
// The name of the University of Southern California may not
// be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THE UNIVERSITY OF SOUTHERN CALIFORNIA DOES NOT MAKE ANY REPRESENTATIONS
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// PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
// INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND
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//