ICMP errors (such as destination unreachable) should reset TCP socket

[thomaseizinger]

ICMP errors contain at least 64bit of the original packet in their payload. This is enough to identify TCP connections. When receiving an ICMP error for one of its sockets, smoltcp should reset that socket state.

[thvdveld]

I think this is something we let the user decide on. You can make an ICMP socket bound to the same endpoint as your UDP socket (TCP is not implemented yet, but should be trivial). In your application, you should check if this ICMP socket received an ICMP message. Currently, this socket accepts Destination Unreachable and Time Exceeded errors. When receiving such a message in the socket, the user can decide how to react to it.