2^31 milliseconds is only about 25 days. Also clamps Sleep() to 10 years,
because it currently sleeps for 0 seconds when the sleep time would cross
2^31 seconds since the epoch. Hopefully boost will be fixed by 2028.
Help users avoid insecure configurations a bit by recommending a
secure RPC password and increasing the incorrect password delay.
This may open up a RPC DOS for users with exposed RPC ports and
short passwords. Since users shouldn't have exposed RPC ports OR
short passwords, the DOS risk is preferable to the compromise
risk.
Also logs the client IP address for incorrect attempts.
This also avoids flushing setAddrKnown until 24 hours has passed,
and avoids contacting the external IP services when not listening.
Advertising non-listening nodes is just addr message spam.
It doesn't help the network, in fact it hurts the network,
and it also hurts user's privacy.
Advertising far out of sync nodes doesn't help the network—
they can't even forward (most) transactions and wastes nodes
outbound slots.
Gregory Maxwell