44 lines
1.2 KiB
Markdown
44 lines
1.2 KiB
Markdown
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Notes:
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Friend requests need to be routed.
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The current DHT should be capable of punching all NATs except symmetric ones.
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######
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Symmetric NAT hole punching:
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If we are not connected to the friend and if the DHT is queried and ips
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returned for the friend are the same but the port is different, the friend is
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assumed to be behind a symmetric NAT.
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Before attempting the procedure we first send a routed ping request to the
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friend. This request is to be routed through the nodes who returned the ip of
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the peer.
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As soon as we receive one routed ping request from the other peer, we respond
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with a ping response.
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Ping request/response packet:
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See: Crypto request packets in [[Crypto]]
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Message:
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For the ping request:
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[char with a value of 254][char with 0][8 byte random number]
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For the ping response:
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[char with a value of 254][char with 1][8 byte random number (The same that was sent in the request)]
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As soon as we get a proper ping response from the other we run the different
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ports returned by the DHT through our port guessing algorithm.
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######
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Port guessing algorithm:
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Right now it just tries all the ports directly beside the known ports.(A better one is needed)
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######
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We send DHT ping requests to all the guessed ports, only a couple at a time.
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