Protocol specification v3
Introduction
This is a DRAFT for the protocol version 3. It describes the changes in protocol version 3 versus version 2. Things which are unchanged from version 2 are not described in detail. So you should use this as a reference for all formates which are not mentioned in this description.
Message types
Most message types are unchanged from version 2 to version 3. Only the four "objecttype" messages are not valid any more. They are summerized into one single message.
version
The version message is identically to protocol version 2. you can lookup details here
Payload:
| Field Size | Description | Data type | Comments |
|---|---|---|---|
| 4 | version | int32_t | Identifies protocol version being used by the node |
| 8 | services | uint64_t | bitfield of features to be enabled for this connection |
| 8 | timestamp | int64_t | standard UNIX timestamp in seconds |
| 26 | addr_recv | net_addr | The network address of the node receiving this message (not including the time or stream number) |
| 26 | addr_from | net_addr | The network address of the node emitting this message (not including the time or stream number and the ip itself is ignored by the receiver) |
| 8 | nonce | uint64_t | Random nonce used to detect connections to self. |
| 1+ | user_agent | var_str | User Agent (0x00 if string is 0 bytes long) |
| 1+ | stream numbers | var_int_list | The stream numbers that the emitting node is interested in. |
A "verack" packet shall be sent if the version packet was accepted. Once you have sent and received a verack messages with the remote node, send an addr message advertising up to 1000 peers of which you are aware, and one or more inv messages advertising all of the valid objects of which you are aware.
The following services are currently assigned:
| Value | Name | Description |
|---|---|---|
| 1 | NODE_NETWORK | This is a normal network node. |
verack
The verack message is sent in reply to version. This message consists of only a message header with the command string "verack". The TCP timeout starts out at 20 seconds; after verack messages are exchanged, the timeout is raised to 10 minutes.
addr
Provide information on known nodes of the network. Non-advertised nodes should be forgotten after typically 3 hours
Payload:
| Field Size | Description | Data type | Comments |
|---|---|---|---|
| 1+ | count | var_int | Number of address entries (max: 1000) |
| 34x? | addr_list | net_addr | Address of other nodes on the network. |
inv
Allows a node to advertise its knowledge of one or more objects. Payload (maximum payload length: 50000 items):
| Field Size | Description | Data type | Comments |
|---|---|---|---|
| ? | count | var_int | Number of inventory entries |
| 32x? | inventory | inv_vect[] | Inventory vectors |
getdata
getdata is used in response to an inv message to retrieve the content of a specific object after filtering known elements.
Payload (maximum payload length: 50000 entries):
| Field Size | Description | Data type | Comments |
|---|---|---|---|
| ? | count | var_int | Number of inventory entries |
| 32x? | inventory | inv_vect[] | Inventory vectors |
