Want to see the data that gets transmitted between cardano-cli and cardano-node via unix socket? This tool does it for you!
It essentially proxies via another unix socket, and prints out the payload that gets transmitted.
Below is an example of running this on a Mac. After starting the proxy, query the cardano-node.
$ shelley-socket-proxy \
-source-socket-file ~/read.socket \
-destination-socket-file ~/Library/Application\ Support/Daedalus\ Mainnet/cardano-node.socket
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> R E Q U E S T >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
==========================================================================================
Header: Transmission Time: [794923165], Mode: [0], Protocol ID: [0], Payload Length: [17]
------------------------------------------------------------------------------------------
Array: [2]
PositiveInteger8(0)
Map - Items: [2]
- key: PositiveInteger8(1) / value: PositiveInteger32(764824073)
- key: PositiveInteger16(32770) / value: PositiveInteger32(764824073)
==========================================================================================
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< R E S P O N S E <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
==========================================================================================
Header: Transmission Time: [794929988], Mode: [1], Protocol ID: [0], Payload Length: [10]
------------------------------------------------------------------------------------------
Array: [3]
PositiveInteger8(1)
PositiveInteger16(32770)
PositiveInteger32(764824073)
==========================================================================================
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> R E Q U E S T >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
==========================================================================================
Header: Transmission Time: [794937820], Mode: [0], Protocol ID: [5], Payload Length: [2]
------------------------------------------------------------------------------------------
Array: [1]
PositiveInteger8(0)
==========================================================================================
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< R E S P O N S E <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
==========================================================================================
Header: Transmission Time: [794981374], Mode: [1], Protocol ID: [5], Payload Length: [49]
------------------------------------------------------------------------------------------
Array: [3]
PositiveInteger8(3)
Array: [0]
Array: [2]
Array: [2]
PositiveInteger32(12014123)
ByteString - Length: [32]; Value: [bd6e9e1ad793d6dcf25976133216c704f0fcb7ea3cb80b375dbf53acdb198a48];
PositiveInteger32(4862240)
==========================================================================================
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> R E Q U E S T >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
==========================================================================================
Header: Transmission Time: [794982467], Mode: [0], Protocol ID: [5], Payload Length: [2]
------------------------------------------------------------------------------------------
Array: [1]
PositiveInteger8(7)
==========================================================================================
$ export CARDANO_NODE_SOCKET_PATH=~/read.socket
$ cardano-cli shelley query tip --shelley-mode --mainnet
{
"blockNo": 4862240,
"headerHash": "bd6e9e1ad793d6dcf25976133216c704f0fcb7ea3cb80b375dbf53acdb198a48",
"slotNo": 12014123
}
The packets transmitted to/from cardano-node is multiplexed into an envelope (referred to as container in this codebase/library).
Container represent a message envelope that is sent and receive
to/from the Shelley node. It contains one or more segments as payload.
The following is the wire format of a container:
+---------------------------------------------------------------+
|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|
+---------------------------------------------------------------+
| TRANSMISSION TIME |
+---------------------------------------------------------------+
|M| MINI PROTOCOL ID | PAYLOAD LENGTH |
+---------------------------------------------------------------+
| |
| PAYLOAD of n BYTES |
| |
+---------------------------------------------------------------+
Container header:
- Transmission Time The transmission time is a time stamp based the wall clock
of the peer with a resolution of one microsecond.
- Mini Protocol ID The unique ID of the mini protocol as in Table 3.2.
- Payload Length The payload length is the size of the segment payload in Bytes.
The maximum payload length that is supported by the multiplexing wire format
is 2^16 − 1. Note, that an instance of the protocol can choose a smaller
limit for the size of segments it transmits.
- Mode The single bit M (the mode) is used to distinct the dual instances of a
mini protocol. The mode is set to 0 in segments from the initiator, i.e. the
side that initially has agency and 1 in segments from the responder.
The payload is encoded as CBOR (see https://en.wikipedia.org/wiki/CBOR, and https://tools.ietf.org/html/rfc7049).