How does SSL_get_error() handle timeouts?

[Hal Murray]

I'm interested in the case where the underlying socket has done
setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, ...
(and/or SO_SNDTIMEO)

The man page doesn't mention timeout.


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These are my opinions. I hate spam.

[Viktor Dukhovni]

On Wed, Jul 09, 2025 at 02:21:57PM -0700, Hal Murray wrote:

> I'm interested in the case where the underlying socket has done
> setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, ...
> (and/or SO_SNDTIMEO)

I wouldn't expect anything special to happen happen here, if a read
times out, that's just a read error, so shouldn't look different from a
TCP reset, or similar transport/network layer problem.

FWIW, Postfix handles this differently, the socket is set non-blocking
and retries of the SSL handshake or read/write operations, after
WANTREAD or WANTWRITE, happen only after the socket polls ready, and if
those polls time out the (SMTP) application processes a timeout above
the TLS layer, abandoning the SSL connection.

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Viktor. 🇺🇦 Слава Україні!