How to connect to a node using PHP

Question

I want to make a simple PHP script that connects to a node (on my server) so that I can receive the data it relays.

However, I am new to sockets, and I am having difficulty with the handshake process. This is what I've got so far:

1. Version Message

I have contstructed my own version message. The result looks like this:

Config
------
version:      60002
node:         85.119.83.25:8333
local:        90.213.66.225:8333
start_height: 0


VERSION MESSAGE
---------------
Header:Array
(
    [magicbytes] => F9 BE B4 D9
    [command] => 76 65 72 73 69 6F 6E 00 00 00 00 00
    [payload_size] => 55 00 00 00
    [checksum] => 18 32 C2 E4
)

Payload:Array
(
    [version] => 62 EA 00 00
    [services] => 01 00 00 00 00 00 00 00
    [timestamp] => 18 A3 CA 57 00 00 00 00
    [addr_recv] => 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF FF 55 77 53 19 20 8D
    [addr_from] => 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF FF 5A D5 42 E1 20 8D
    [nonce] => 87 58 8D 22 00 00 00 00
    [user_agent] => 00
    [start_height] => 00 00 00 00
)

Serialized:
F9BEB4D976657273696F6E0000000000550000001832C2E462EA0000010000000000000018A3CA5700000000010000000000000000000000000000000000FFFF55775319208D010000000000000000000000000000000000FFFF5AD542E1208D87588D22000000000000000000

Are there any obvious mistakes? Things I'm unsure of are:

• What is my addr_from port meant to be?

2. Socket Connection

Next I'm trying to send this version message to my node, and get a version message back. Here is my code:

$socket = socket_create(AF_INET, SOCK_STREAM, 6);
socket_connect($socket, $node_ip, $node_port);
socket_send($socket, $message, strlen($message) / 2, 0);
socket_recv($socket, $buf, 2000, MSG_WAITALL);

var_dump($buf);

All of the socket functions appear to be successful, but the result of var_dump($buf) is NULL.

I suppose my biggest problem is that I'm not receiving any error messages, so it's difficult to troubleshoot where I'm going wrong. Can you point me in the right direction?

---

Here's my PHP script so far: http://pastebin.com/q7zf4NMj

Answer 1

I was sending the data across the socket in hexadecimal format, but it appears that it should be in binary.

This does the trick: hex2bin($message)

Link to just-about-working script: https://bitcoin.stackexchange.com/a/48399/24926