Package p2p (PoC7)

[fjl]

Here we go. That took a bit longer than expected.
The tests could be better, but we can improve them while integrating PoC 8 changes.

@zelig PTAL
This is still part of #155.

[fjl]

@obscuren, @zelig does one of you own a UPnP-cabable router?
The one I have only implements NAT-PMP.

[obscuren]

Yeh, have one. The one that is (was?) in the codebase worked

[fjl]

The UPnP code is still there. On my machine, the multicast write times out. Can you go run testpoc7.go when you're at home? (change NAT to p2p.UPNP())

[fjl]

We need something like p2p.AutoNAT() that tries all supported methods concurrently. This needs to be the default. It's really hard to find peers because everyone is behind NAT and can't listen.

[obscuren]

Agreed

[obscuren]

Suggestion

type ErrorCode int
var errorCodeToString = []string{
  "Error 1", "Error 2", "etc",
}
func (self ErrorCode) String() string {
    if len(errorCodeToString) <= int(self) {
        // Could panic here, you seem to be panicing on a few lines below. Why?
        return "Invalid error code"
    }
    return errorCodeToString[int(self)]
}

See http://play.golang.org/p/x7qvoQlOl1

[fjl]

Error codes are meant to be used as an argument to newPeerError. They
shouldn't be used on their own. The panic ensures that newPeerError
can only be called with valid error codes. Using it with an unknown
error code would be an (internal) bug and therefore panics. The panic
will have newPeerError and its caller on the stack which should
indicate the source of the problem.