Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Moved msg type description from BOLT#2 to BOLT#1 #35

Merged
merged 7 commits into from
Dec 6, 2016
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
36 changes: 27 additions & 9 deletions 01-messaging.md
Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,21 @@

## Overview
This protocol assumes an underlying authenticated and ordered transport mechanism that takes care of framing individual messages.
[BOLT 08](08-transport.md) specifies the canonical transport layer used in Lightning, though it can be replaced by any transport that fulfills the above guarantees.
[BOLT #8](08-transport.md) specifies the canonical transport layer used in Lightning, though it can be replaced by any transport that fulfills the above guarantees.

The default TCP port is 9735. This corresponds to hexadecimal `0x2607`, the unicode code point for LIGHTNING.<sup>[2](#reference-2)</sup>

All data fields are big-endian unless otherwise specified.

## Table of Contents
* [Lightning Message Format](#lightning-message-format)
* [Setup Messages](#setup-messages)
* [The `init` message](#the-init-message)
* [The `error` message](#the-error-message)
* [Acknowledgements](#acknowledgements)
* [References](#references)
* [Authors](#authors)

## Lightning Message Format

After decryption, all lightning messages are of the form:
Expand All @@ -23,6 +32,13 @@ A node MUST NOT send an evenly-typed message not listed here without prior negot
A node MUST ignore a received message of unknown type, if that type is odd.
A node MUST fail the channels if it receives a message of unknown type, if that type is even.

The messages are grouped logically into 4 groups by their most significant set bit:

- Setup & signalling (types `0`-`31`): messages related to supported features and error reporting. These are described below.
- Channel (types `32`-`127`): comprises messages used to setup, update and tear down micropayment channels. These are described in [BOLT #2](02-peer-protocol.md).
- HTLC (types `128`-`255`: comprises messages related to adding, revoking and settling HTLCs on a micropayment channel. These are described in [BOLT #2](02-peer-protocol.md).
- Routing (types `256`-`511`): node and channel announcements, as well as any active route exploration. These are described in [BOLT #7](07-routing-gossip.md).

The size of the message is required to fit into a 2 byte unsigned int by the transport layer, therefore the maximum possible size is 65535 bytes.
A node MUST ignore any additional data within a message, beyond the length it expects for that type.
A node MUST fail the channels if it receives a known message with insufficient length for the contents.
Expand All @@ -46,7 +62,9 @@ but adding a 6 byte padding after the type field was considered
wasteful: alignment may be achieved by decrypting the message into
a buffer with 6 bytes of pre-padding.

## Initialization Message
## Setup Messages

### The `init` message

Once authentication is complete, the first message reveals the features supported or required by this node.
Odd features are optional, even features are compulsory (_it's OK to be odd_).
Expand All @@ -61,7 +79,7 @@ The meaning of these bits will be defined in the future.

The 2 byte `gflen` and `lflen` fields indicate the number of bytes in the immediately following field.

### Requirements
#### Requirements

The sending node SHOULD use the minimum lengths required to represent
the feature fields. The sending node MUST set feature bits
Expand All @@ -74,7 +92,7 @@ not understand.

Each node MUST wait to receive `init` before sending any other messages.

### Rationale
#### Rationale

The even/odd semantic allows future incompatible changes, or backward
compatible changes. Bits should generally be assigned in pairs, so
Expand All @@ -87,7 +105,7 @@ The feature masks are split into local features which only affect the
protocol between these two nodes, and global features which can affect
HTLCs and thus are also advertised to other nodes.

## Error Message
### The `error` message

For simplicity of diagnosis, it is often useful to tell the peer that something is incorrect.

Expand All @@ -99,7 +117,7 @@ For simplicity of diagnosis, it is often useful to tell the peer that something

The 2-byte `len` field indicates the number of bytes in the immediately following field.

### Requirements
#### Requirements

A node SHOULD send `error` for protocol violations or internal
errors which make channels unusable or further communication unusable.
Expand All @@ -116,7 +134,7 @@ all channels and MUST close the connection. A receiving node MUST truncate
A receiving node SHOULD only print out `data` verbatim if it is a
valid string.

### Rationale
#### Rationale

There are unrecoverable errors which require an abort of conversations;
if the connection is simply dropped then the peer may retry the
Expand All @@ -131,11 +149,11 @@ it leak information, thus the optional data field.
TODO(roasbeef); fin


# References
## References
1. <a id="reference-1">https://en.bitcoin.it/wiki/Secp256k1</a>
2. <a id="reference-2">http://www.unicode.org/charts/PDF/U2600.pdf</a>

# Authors
## Authors

FIXME

Expand Down
7 changes: 0 additions & 7 deletions 02-peer-protocol.md
Original file line number Diff line number Diff line change
Expand Up @@ -3,13 +3,6 @@
The peer channel protocol has three phases: establishment, normal
operation, and closing.

The messages described in this document are grouped logically into 4 groups by their most significant set bit:

- Setup & signalling (types `0`-`31`): comprises setup of the cryptographic transport, communication of supported features and error reporting. These are described in BOLT #1.
- Channel (types `32`-`127`): comprises messages used to setup, update and tear down micropayment channels
- HTLC (types `128`-`255`: comprises messages related to adding, revoking and settling HTLCs on a micropayment channel
- Routing (types `256`-`511`): node and channel announcements, as well as any active route exploration.

# Table of Contents
* [Channel](#channel)
* [Channel Establishment](#channel-establishment)
Expand Down