# PTTH_DIREC - Direct P2P connections

_It could work, even!_

To keep each ridiculous new feature simple, we'll rely on bootstrapping:

1. PTTH is just HTTPS connections
2. PTTH_QUIC uses a PTTH relay to download the QUIC cert and bootstrap
3. PTTH_DIREC will use a PTTH_QUIC relay to bootstrap

# Overview

Given that:

- P2 is connected to P3
- P4 is connected to P3

Steps:

- S1.  P2 starts a bi stream to P3
- S2.0.  P2 says, "I want to initiate a PTTH_DIREC connection..."
- "... And I'll send you cookie X to do hole-punching..."
- "... And I want to connect to end server Y..."
- S3.0.  P3 creates an ID for this connection
- S3.1.  P3 replies "go ahead" to P2
- S4.  P3 starts a bi stream to P4 (end server Y)
- S5.  P3 says, "I want you to accept a PTTH_DIREC connection..."
- "... And you should send me cookie Z to do hole-punching..."
- "... And the client will be client W..."
- S6.  P3 waits for P4 to accept the offer
- S7.  P3 waits for both cookies to arrive
- S8.  When the cookies arrive, P3 learns the WAN addresses of P2 and P4
- S9.  P3 sends the WAN addresses of P2 and P4 to each other (on the existing bi streams)
- S10. P4 tries to connect directly to P2
- S11. P2 does the same to P4
- S12. When P4 sees round-tripped data, it attempts to upgrade to QUIC
- S13. When P2 sees round-tripped data, it attempts to upgrade to QUIC
- Cool stuff happens over QUIC
- ReactorScram implements the rest of the protocol

P2's PoV:

- S1. Start a bi stream to P3
- S2.0. Send cookie and server ID
- S2.1. Wait for go-ahead signal (this may contain the hole-punch address and a new cookie for P4)
- S2.2. Send cookie to hole-punch address repeatedly
- S2.3. While you're sending the cookie, wait to hear P4's WAN address
- S9. Learn P4's WAN address
- S10. Send the new cookie to P4's address
- S12. When you see round-tripped data, upgrade to QUIC

P4's PoV:

- S4. Accept a bi stream from P3
- S5. Receive cookie and client ID
- S6. Reply "OK"
- S7.0. Send cookie to hole-punch address repeatedly
- S7.1. While sending the cookie, wait to hear P2's WAN address
- S9. Learn P2's WAN address
- S10. Try to connect directly to P2
- S12. When you see round-tripped data, upgrade to QUIC

Commands needed:

- ???

# Decisions

I'll add a delay between giving P2's address to P4, and giving P4's address to P2.
This miiiight change things slightly if P4's firewall is suspicious of packets
coming in too early, but I doubt it.

The delay is easy to remove relay-side if it doesn't help.