Re: [HACKERS] listening addresses

Tom Lane wrote:

>Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
>
>
>>A small problem with it was reported to me a couple of days ago - user
>>had firewalled off all IP6 traffic. The stats collector happily bound
>>and connected to the socket, but all the packets fell in the bit bucket.
>>They found it quite hard to diagnose the problem.
>>
>>
>
>
>
>>Possible solutions that occurred to me:
>>. an initial "hello"-"yes i'm here" exchange to validate the address
>>
>>
>
>That one seems reasonable to me. Seems like it would take just a few
>more lines of code in the loop that tries to find a working socket to
>check that we can send a byte and receive it. You'd have to be careful
>not to block if the socket is indeed not working ... also, is it safe to
>assume that a byte sent with send() is *immediately* ready to recv()?
>
>
>

This patch attempts to implement the idea, with safety in case the
packet is not immediately available.

comments welcome

cheers

andrew