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/*
* Copyright (c) 1998 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Network Research
* Group at Lawrence Berkeley National Laboratory.
* 4. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /cvsroot/nsnam/ns-2/emulate/icmp.cc,v 1.5 2000/09/01 03:04:10 haoboy Exp $";
#endif
#include <stdio.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_icmp.h>
#include <arpa/inet.h>
#include "agent.h"
#include "scheduler.h"
#include "packet.h"
#include "emulate/net.h"
#include "emulate/internet.h"
#ifndef IPPROTO_GGP
#define IPPROTO_GGP 3
#endif // IPPROTO_GGP
//
// icmp.cc -- a very limited-functionality set of icmp routines
//
class IcmpAgent : public Agent {
public:
IcmpAgent();
void recv(Packet*, Handler*) { abort(); }
protected:
void sendredirect(in_addr& me, in_addr& target, in_addr& dest, in_addr& gw);
int command(int argc, const char*const* argv);
int ttl_;
};
static class IcmpAgentClass : public TclClass {
public:
IcmpAgentClass() : TclClass("Agent/IcmpAgent") {}
TclObject* create(int , const char*const*) {
return (new IcmpAgent());
}
} class_icmpsagent;
IcmpAgent::IcmpAgent() : Agent(PT_LIVE)
{
bind("ttl_", &ttl_);
}
/*
* sendredirect -- send a packet to "target" containing a redirect
* for the network specified by "dst", so that the gateway "gw" is used
* also, forge the source address so as to appear to come from "me"
*/
void
IcmpAgent::sendredirect(in_addr& me, in_addr& target, in_addr& dst, in_addr& gw)
{
// make a simulator packet to hold the IP packet, which in turn
// holds: ip header, icmp header, embedded ip header, plus 64 bits
// data
int iplen = sizeof(ip) + 8 + sizeof(ip) + 8;
Packet* p = allocpkt(iplen);
hdr_cmn* hc = HDR_CMN(p);
ip* iph = (ip*) p->accessdata();
hc->size() = iplen;
// make an IP packet ready to send to target
// size will be min icmp + a dummy'd-up IP header
Internet::makeip(iph, iplen, ttl_, IPPROTO_ICMP, me, target);
// make an ICMP host redirect, set the gwaddr field
icmp* icp = (icmp*) (iph + 1);
icp->icmp_gwaddr = gw;
// make a dummy IP packet to go in the ICMP data, which will
// be used to indicate to the end host which routing table
// entry to update
ip* dummyhdr = (ip*)((u_char*)icp + 8); // past icmp hdr
// deprecated protocol inside
Internet::makeip(dummyhdr, 20, 254, IPPROTO_GGP, target, dst);
u_short *port = (u_short*) (dummyhdr + 1); // past ip hdr
*port++ = htons(9); // discard port
*port = htons(9); // discard port
icp->icmp_cksum = 0;
icp->icmp_type = ICMP_REDIRECT;
icp->icmp_code = ICMP_REDIRECT_HOST;
icp->icmp_cksum = Internet::in_cksum((u_short*)icp,
8 + sizeof(ip) + 8);
send(p, 0);
return;
}
int
IcmpAgent::command(int argc, const char*const* argv)
{
if (argc > 5) {
// $obj send name src dst [...stuff...]
if (strcmp(argv[1], "send") == 0) {
if (strcmp(argv[2], "redirect") == 0 &&
argc == 7) {
// $obj send redirect src target dst gwaddr
// as src, send to targ, so that it changes
// its route to dst to use gwaddr
u_long s, t, d, g;
s = inet_addr(argv[3]);
t = inet_addr(argv[4]);
d = inet_addr(argv[5]);
g = inet_addr(argv[6]);
in_addr src, targ, dst, gw;
src.s_addr = s;
targ.s_addr = t;
dst.s_addr = d;
gw.s_addr = g;
sendredirect(src, targ, dst, gw);
return (TCL_OK);
}
}
}
return (Agent::command(argc, argv));
}
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