rpc-sniffer
This tool captures network traffic and decode them if they contain (Ethereum) JSON RPC. This might be useful in the following scenarios:
- You want to know the exact RPC requests and responses sent to and from your Ethereum node.
- You want to debug and understand what
web3sends out. - You want to capture the contents
web3sends out in order to use them in a different program.
Installation
The following assumes you already have Python virtualenv activated.
If not you may need to add sudo in front of the setup.py command.
- Via the
setup.pyscript
(activate python virtualenv)
git clone https://github.com/alext234/rpc-sniffer
cd rpc-sniffer
python setup.py installUsage
A pcap file can be given as the parameter:
> rpc-sniffer.py tests/data/web3_clientVersion.pcap
INFO:root:Sniff network packets and decode JSONRPC on HTTP
id method params result
1 web3_clientVersion []
1 Geth/v1.8.2-stable/linux-amd64/go1.9.2
Or a network interface can be given, for example with the local loopback interface lo (superuser is needed):
> sudo su
> (activate python virtualenv)
> rpc-sniffer.py lo
You will able to see the decoded traffic when you interact with a local RPC node via web3, for example.
id method params result
1 eth_accounts []
1 eth_getTransactionCount ['0x70974f6673fa922eac3c2cd433d762e93db9399e', 'latest']
1 0x30
1 net_version []
1 99
1 eth_gasPrice []
1 0x430e23400 Limitations
-
This tool does not support encrypted SSL traffic (e.g. when you interact with an infura.io node).
-
This tool does not support RPC traffic that spans multiple packets (development is in progress for this feature).