here's a snippet from the postfix-users mailing list (I'm patching postfix
to use poll instead of select, principally for the benefit of Solaris users
(like a current client :-) )
Andrew:
>According to Stevens "Unix Network Programming" 2nd ed. v.1 pp151-153 the
>arrival of something like HOSTUNREACHABLE would mark the socket as
readable,
>and a read on it will fail with errno set appropriately, but only arrival
of
>OOB data will mark an exception condition on the socket.
Wietse Venema:
>Postfix has to run on real machines in the real world, and therefore
>we cannot blindly use Stevens or the RFC as gospel.
>The select() calls have a mask for exceptions simply because of LINUX.
Andrew:
>What does Linux do differently?
Wietse:
>Under some conditions LINUX sets the exception bits instead of the
>readable bits like everyone else does. This broke the satan port
>scanner.
So ... is this still the behaviour? If so, is it due to the kernel TCP/IP
stack? If so, should it be modified?
cheers
andrew
(replies just to the list are fine)
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