From 5c106011c1d684cf626a2d6b1886fd4a9dfee3d7 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Fri, 20 Apr 2018 11:44:14 +0000 Subject: [PATCH] net/imap: set SO_KEEPALIVE on TCP sockets Otherwise connections (commonly on IDLE, but it could be any command) may never receive notifications of link errors. --- lib/net/imap.rb | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/net/imap.rb b/lib/net/imap.rb index 3d33b94fdd..b42186dce0 100644 --- a/lib/net/imap.rb +++ b/lib/net/imap.rb @@ -1129,7 +1129,9 @@ def initialize(host, port_or_options = {}, end def tcp_socket(host, port) - Socket.tcp(host, port, :connect_timeout => @open_timeout) + s = Socket.tcp(host, port, :connect_timeout => @open_timeout) + s.setsockopt(:SOL_SOCKET, :SO_KEEPALIVE, true) + s rescue Errno::ETIMEDOUT raise Net::OpenTimeout, "Timeout to open TCP connection to " + "#{host}:#{port} (exceeds #{@open_timeout} seconds)" -- EW