broker trait

[jordens]

could this be simplified to an enum Broker { Ip, Named } instead of having the trait and type param propagation through the stack?

The two issues are:

• the resolver type/Dns trait: where the stack may or may not provide the trait. maybe that could be made fallible/late fallible. Or we could always require Dns.
• the name String size: maybe not so critical.

[jordens]

Low priority. Can't see good solutions currently, the network stack being so "local".
I do think a fallible and thus optional resolver might be worth it though. Same as standard OS networking stacks that look the same whether they can resolve or not.

[ryan-summers]

• the resolver type/Dns trait: where the stack may or may not provide the trait. maybe that could be made fallible/late fallible. Or we could always require Dns.

Given that Dns is a principle function of a network stack, it almost feels like the Dns trait should be provided for all the embedded-nal traits as some kind of base trait. There could easily be a default implementation that returns Err() if DNS is not supported, and then stack implementers could override that if their stack does support DNS.

[jordens]

Sounds good. Since lookups are already fallible they can just be perma-fallible when there is no DNS support.