47 lines
1.6 KiB
Markdown
47 lines
1.6 KiB
Markdown
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# Protocol Design
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In this document I will define how this document is designed and how it should be implemented.
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# Prelude
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The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL",
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"NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and
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"OPTIONAL" in this document are to be interpreted as described in
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RFC 2119.
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"node" or "nodes" are referring to a device that implements the Domo protocol.
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## Transactions
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All interactions between 2 nodes is called a transaction; a request and response.
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The initial packet sent in the transaction is called the "origin packet".
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A initial packet MUST NOT have a `reply_to`.
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A transaction consists of 2 nodes;
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- "Origin node"; the node who sent the origin packet.
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- "Destination node"; the node who is marked as the destination by the origin packet.
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# Behaviour
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This chapter describes the behaviour of a node.
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## Statuses
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When an error occurs on the destination node in result of a request, the response to the origin node MUST be a `0x0E` (error command).
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This MAY contain error data.
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To mark a success, you MUST send back the request packet altered with the data specified in the protocol.
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## Reserved addresses
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### Broadcast (`0xFFFFFFFF`)
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Nodes MUST listen to this address.
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Owner nodes MUST forward this address to their owners if applicable.
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# Packet inspection
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## Error checking
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If the CRC32 doesn't match up the destination node MUST send a `0x0E` (error) packet to the origin node.
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The error code `0x01`/`net_broken_packet` MUST be used. The metadata MAY contain some textual info on what went wrong.
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The master MUST not track the broken packet's `packet_id`, so the slave can send it again.
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