Crate cjdns_ctrl

Parsing/serializing CTRL messages

Cjdns contains a set of low level messages which are not encrypted. If you send a packet and it cannot be forwarded, the switch, which knows it is not possible to forward, will notify you with a CTRL message, these are not encrypted because, obviously, the switch doesn't know who you are and can't reasonably encrypt anything to you.

CTRL message types

• PING: request that the content of the message be echoed back to you
• PONG: response to a PING message
• KEYPING: Similar to a ping except that the message also sends a public key and requests one back. NOTE: When constructing a keyping, remember that the key you send is your key and the other person's key should be in the response.
• KEYPONG: Response to a KEYPING message, contains the responder's key.
• ERROR: Emitted by the switch in case a message cannot be forwarded.

Error message types

• MALFORMED_ADDRESS: The switch label was malformed
• FLOOD: Packet dropped because link is congested (never sent as of v18)
• LINK_LIMIT_EXCEEDED: Packet dropped because node has oversent its limit (never sent as of v18)
• OVERSIZE_MESSAGE: Message too big to send, caused by differing MTU along a path
• UNDERSIZED_MESSAGE: Message smaller than expected headers
• AUTHENTICATION: Authentication failed (CryptoAuth could not understand the packet)
• INVALID: Header is invalid or checksum failed
• UNDELIVERABLE: Message could not be sent to its destination through no fault of the sender
• LOOP_ROUTE: The route enters and leaves through the same interface in one switch
• RETURN_PATH_INVALID: The switch is unable to represent the return path, this basically means that the label is so long that the inverse label is impossible to put in 64 bits.

Example

use cjdns_ctrl::*;

let test_bytes = hex_to_bytes("994b00050123456700000012a331ebbed8d92ac03b10efed3e389cd0c6ec7331a72dbde198476c5eb4d14a1f02e29842b42aedb6bce2ead3");
let test_message_inst = CtrlMessage {
    msg_type: CtrlMessageType::KeyPing,
    msg_data: CtrlMessageData::PingData(PingData {
        version: 18,
        key: Some(
            CJDNSPublicKey::try_from("3fdqgz2vtqb0wx02hhvx3wjmjqktyt567fcuvj3m72vw5u6ubu70.k").expect("invalid key string")
        ),
        content: hex_to_bytes("02e29842b42aedb6bce2ead3"),
    }),
};

let parsed_msg = CtrlMessage::parse(&test_bytes).expect("invalid message bytes");
let serialized_msg = parsed_msg.serialize().expect("invalid message instance");
assert_eq!(parsed_msg, test_message_inst);
assert_eq!(serialized_msg, test_bytes)

Structs

CtrlMessage	Serialized control message
ErrorData	Body data for error type messages
PingData	Body data for ping type control messages

Enums

CtrlMessageData	Control message serialized body data
CtrlMessageType	Control message type, which is considered as message header
ErrorMessageType	Concrete types of error for control error message