Introduce the following three server parameters:

• ingressConnectionEstablishmentRatePerSec; double; default DBL_MAX (disabled); – the number of new connections that will be allowed to establish per second. Set at startup and runtime.
• ingressConnectionEstablishmentBurstSize; double; default DBL_MAX (disabled) – the maximum number of  connection establishments that will be admitted before rate-limiting kicks in (ie, the burst size of the bucket). Set at startup and runtime. It should have a minimum value of 1.
• ingressConnectionEstablishmentMaxQueueDepth; size_t; default LLONG_MAX  (disabled)– the maximum size of the connection establishment queue, after which the server will begin rejecting new connections. Set at startup and runtime.

These can be added to transport_options.idl, and each should have an associated cpp_class in transport_options.cpp that will allow us to modify the parameter values at runtime. Eventually the CPP classes will call into opCtx->getServiceContext()>getTransportLayerManager()>getSessionManager()>getRateLimiter()>set..... in order to update these parameters at runtime, but adding the RateLimiter to the SessionManager won't happen until SERVER-104415, and so the call to actually make the update stubbed out with a TODO for now.