Resend packet captured from Wireshark

[wyxcoder]

With Wireshark, I capture a websoket packet with the below code
var device = Cap.findDevice('192.168.1.161');
var filter = 'tcp and dst port 54592';

Now I have hex stream of a packet like d5404e297c8575b980c20b32501801fcb35c0000

I want to send the packet from nodejs code, but the below code doesn't work?

var Cap = require('cap').Cap;
var c = new Cap();
var device = Cap.findDevice('192.168.1.161');
var filter = 'tcp';
var bufSize = 10 * 1024 * 1024;
var buffer = Buffer.alloc(65535);

var linkType = c.open(device, filter, bufSize, buffer);

var buffer = Buffer.from("d5404e297c8575b980c20b32501801fcb35c0000");
try {
c.send(buffer, buffer.length);
console.log("sent");
} catch (e) {
console.log("Error sending packet:", e);
}

[mscdex]

Assuming you're not getting an exception thrown, that doesn't look like a complete packet. You need to include every layer (including the Ethernet frame for example) and not just a TCP/UDP payload since the buffer you're sending here is what will be literally transmitted by the network card.

[wyxcoder]

Assuming you're not getting an exception thrown, that doesn't look like a complete packet. You need to include every layer (including the Ethernet frame for example) and not just a TCP/UDP payload since the buffer you're sending here is what will be literally transmitted by the network card.

Great! Thank you for the quick reply. Cap is great. I cannot believe the capture part just work without any problem.
So the send part. Seems the filter does nothing. I thought set filter to TCP means you can send TCP packet. So what filter I should set for sending?

[mscdex]

The filter is only for the traffic you want to capture. send() literally just sends the provided data over the network card and is not affected by anything else.

[wyxcoder]

I just tested, in Wireshark, I captured a packet sent from an app from my machine to a remote server. The packet size is 81, so I copied the Hex stream, and send it out. But I did't capture it in Wireshark. Any idea? Thanks!

var buffer = Buffer.from("a84e3f6c6642281878fe6aeb08004500004319c4400080060000c0a801a1ca27f132eb5b4e235bbc04e725b9a329501802007dd900008295872d0c178e280e10872d0c17872d0c1ea9370d17841c3e2487");

[erfanmola]

Same issue, The library can not do any .send() with any data, as example here is my full packet :

var buffer = Buffer.from("01005E0000FB0A0027000011080045000051CB700000FF111686C0A83801E00000FB14E914E9003D119F000000000001000000000000095F7733787032373266045F737562095F626C697A7A617264045F756470056C6F63616C00000C0001");