PACKET SENDER TUTRIAL HOW TO
PACKET SENDER TUTRIAL DRIVER
PACKET SENDER TUTRIAL SOFTWARE
PACKET SENDER TUTRIAL CODE
PACKET SENDER TUTRIAL SERIES

PACKET SENDER TUTRIAL SOFTWARE

* * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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. Neither the name of the Politecnico di Torino, CACE Technologies * nor the names of its contributors may be used to endorse or promote * products derived from this software without specific prior written * permission. 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.

PACKET SENDER TUTRIAL CODE

Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. * * Copyright (c) 1999 - 2005 NetGroup, Politecnico di Torino (Italy) * Copyright (c) 2005 - 2006 CACE Technologies, Davis (California) * All rights reserved. Note that the link-layer of the dumpfile is compared with the one of the interface that will send the packets using pcap_datalink(), and a warning is printed if they are different - it is important that the capture-file link-layer be the same as the adapter's link layer for otherwise the tranmission is pointless. At his point it transmits the queue, synchronizing it if requested by the user. It opens a capture file with pcap_open_offline(), then it moves the packets from the file to a properly allocated send queue.

PACKET SENDER TUTRIAL HOW TO

The next program shows how to use send queues. When a queue is no longer needed, it can be deleted with pcap_sendqueue_destroy() that frees all the buffers associated with the send queue.

PACKET SENDER TUTRIAL SERIES

Note that transmitting a send queue with pcap_sendqueue_transmit() is much more efficient than performing a series of pcap_sendpacket(), because the send queue is buffered at kernel level drastically decreasing the number of context switches.

Although this operation is quite CPU intensive, it often results in very high precision packet transmissions (often around few microseconds or less).

PACKET SENDER TUTRIAL DRIVER

This operation requires a remarkable amount of CPU, because the synchronization takes place in the kernel driver using 'busy wait' loops. the relative timestamps of the packets will be respected. Note the third parameter: if nonzero, the send will be synchronized, i.e. To transmit a send queue, WinPcap provides the pcap_sendqueue_transmit() function. These parameters are the same as those received by pcap_next_ex() and pcap_handler(), therefore queuing a packet that was just captured or read from a file is a matter of passing these parameters to pcap_sendqueue_queue(). This function takes a pcap_pkthdr with the timestamp and the length and a buffer with the data of the packet. Once the send queue is created, pcap_sendqueue_queue() can be used to add a packet to the send queue.

It has a size, that represents the maximum amount of bytes it can store.Ī send queue is created calling the pcap_sendqueue_alloc() function, specifying the size of the new send queue.

A send queue is a container for a variable number of packets that will be sent to the network. While pcap_sendpacket() offers a simple and immediate way to send a single packet, send queues provides an advanced, powerful and optimized mechanism to send a collection of packets. * Send down the packet */ if ( pcap_sendpacket(fp, packet, 100 /* size */) != 0)įprintf(stderr, ' Error sending the packet: %s ', pcap_geterr(fp)) * Fill the rest of the packet */ for(i=12 i<100 i++) * Supposing to be on ethernet, set mac destination to 1:1:1:1:1:1 */ %s is not supported by WinPcap ', argv) NULL, // authentication on the remote machineįprintf(stderr, ' Unable to open the adapter. * Open the output device */ if ( (fp= pcap_open(argv, // name of the deviceġ00, // portion of the packet to capture (only the first 100 bytes) PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode * Check the validity of the command line */ if (argc != 2) #include #include #include void main( int argc, char **argv)

Packet sender tutrial