Hi Eddie,
I'm still working on my FireSim project which you will probably remember
from SyClick. I've reworked my scripts a bit in a way that they can now
smoothly terminate themselves instead of some dirty polling trick with
handlers I used till now. However, to stop the scripts in cases where I
generate tcp traffic with the TCPIPSend element I needed a stop parameter
for the send write handler. I also liked the idea of being able to send
multiple copies of the same tcp packet for testing purposes, just like you
can do for udp en icmp by using InfiniteSource in combination with
UDPIPEncap or ICMPIPencap.
So, I've updated the write handler of the TCPIPSend element and now I was
wondering if you would consider adding this small change to the Click
standard. If you have any remarks, please let me know.
Regards,
Jens
/*
* tcpipsend.{cc,hh} -- sends TCP/IP packets
* Thomer M. Gil
*
* Copyright (c) 1999-2000 Massachusetts Institute of Technology
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, subject to the conditions
* listed in the Click LICENSE file. These conditions include: you must
* preserve this copyright notice, and you cannot mention the copyright
* holders in advertising related to the Software without their permission.
* The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
* notice is a summary of the Click LICENSE file; the license in that file is
* legally binding.
*/
#include <click/config.h>
#include "tcpipsend.hh"
#include <clicknet/ip.h>
#include <clicknet/tcp.h>
#include <click/confparse.hh>
#include <click/error.hh>
#include <click/glue.hh>
#include <click/router.hh>
#ifdef CLICK_LINUXMODULE
# include <net/checksum.h>
#endif
CLICK_DECLS
TCPIPSend::TCPIPSend()
{
}
TCPIPSend::~TCPIPSend()
{
}
int
TCPIPSend::send_write_handler(const String &conf, Element *e, void *, ErrorHandler *errh)
{
Vector<String> args;
TCPIPSend* me = (TCPIPSend *) e;
unsigned int saddr, daddr;
uint16_t sport, dport;
unsigned char bits;
unsigned seqn, ackn;
unsigned int limit = 1;
bool stop = false;
if(cp_va_space_kparse(conf, me, errh,
"SRC", cpkP+cpkM, cpIPAddress, &saddr,
"SPORT", cpkP+cpkM, cpTCPPort, &sport,
"DST", cpkP+cpkM, cpIPAddress, &daddr,
"DPORT", cpkP+cpkM, cpTCPPort, &dport,
"SEQNO", cpkP+cpkM, cpUnsigned, &seqn,
"ACKNO", cpkP+cpkM, cpUnsigned, &ackn,
"FLAGS", cpkP+cpkM, cpByte, &bits,
"LIMIT", cpkP, cpUnsigned, &limit,
"STOP", cpkP, cpBool, &stop,
cpEnd) < 0)
return -1;
for(unsigned int i = 0; i < limit; i++) {
Packet *p = me->make_packet(saddr, daddr, sport, dport, seqn, ackn, bits);
me->output(0).push(p);
}
if (stop) {
me->router()->please_stop_driver();
}
return 0;
}
Packet *
TCPIPSend::make_packet(unsigned int saddr, unsigned int daddr,
unsigned short sport, unsigned short dport,
unsigned int seqn, unsigned int ackn,
unsigned char bits)
{
struct click_ip *ip;
struct click_tcp *tcp;
WritablePacket *q = Packet::make(sizeof(*ip) + sizeof(*tcp));
if (q == 0) {
click_chatter("in TCPIPSend: cannot make packet!");
assert(0);
}
memset(q->data(), '\0', q->length());
ip = (struct click_ip *) q->data();
tcp = (struct click_tcp *) (ip + 1);
q->set_ip_header(ip, sizeof(click_ip));
// IP fields
ip->ip_v = 4;
ip->ip_hl = 5;
ip->ip_tos = 0;
ip->ip_len = htons(q->length());
ip->ip_id = htons(0);
ip->ip_off = htons(IP_DF);
ip->ip_ttl = 255;
ip->ip_p = IP_PROTO_TCP;
ip->ip_sum = 0;
memcpy((void *) &(ip->ip_src), (void *) &saddr, sizeof(saddr));
memcpy((void *) &(ip->ip_dst), (void *) &daddr, sizeof(daddr));
ip->ip_sum = click_in_cksum((unsigned char *)ip, sizeof(click_ip));
// TCP fields
sport = htons(sport);
dport = htons(dport);
memcpy((void *) &(tcp->th_sport), (void *) &sport, sizeof(sport));
memcpy((void *) &(tcp->th_dport), (void *) &dport, sizeof(dport));
tcp->th_seq = htonl(seqn);
tcp->th_ack = htonl(ackn);
tcp->th_off = 5;
tcp->th_flags = bits;
tcp->th_win = htons(32120);
tcp->th_sum = htons(0);
tcp->th_urp = htons(0);
// now calculate tcp header cksum
unsigned csum = click_in_cksum((unsigned char *)tcp, sizeof(click_tcp));
tcp->th_sum = click_in_cksum_pseudohdr(csum, ip, sizeof(click_tcp));
return q;
}
void
TCPIPSend::add_handlers()
{
add_write_handler("send", send_write_handler, 0);
}
CLICK_ENDDECLS
EXPORT_ELEMENT(TCPIPSend)
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