1 files changed, 47 insertions, 0 deletions
diff --git a/lib/net/ssh/connection/keepalive.rb b/lib/net/ssh/connection/keepalive.rb
new file mode 100644
index 0000000..6b0daa8
--- /dev/null
+++ b/lib/net/ssh/connection/keepalive.rb
@@ -0,0 +1,47 @@
+module Net; module SSH; module Connection
+
+module Keepalive
+  # Default IO.select timeout threshold
+  DEFAULT_IO_SELECT_TIMEOUT = 300
+
+  def initialize_keepalive
+    @last_keepalive_sent_at = nil
+    @unresponded_keepalive_count = 0
+  end
+
+  def keepalive_enabled?
+    options[:keepalive]
+  end
+
+  def keepalive_interval
+    options[:keepalive_interval] || DEFAULT_IO_SELECT_TIMEOUT
+  end
+
+  def should_send_keepalive?
+    return false unless keepalive_enabled?
+    return true unless @last_keepalive_sent_at
+    Time.now - @last_keepalive_sent_at >= keepalive_interval
+  end
+
+  def keepalive_maxcount
+    (options[:keepalive_maxcount] || 3).to_i
+  end
+
+  def send_keepalive_as_needed(readers, writers)
+    return unless readers.nil? && writers.nil?
+    return unless should_send_keepalive?
+    info { "sending keepalive #{@unresponded_keepalive_count}" }
+
+    @unresponded_keepalive_count += 1
+    send_global_request("keepalive@openssh.com") { |success, response|
+      @unresponded_keepalive_count = 0
+    }
+    if keepalive_maxcount > 0 && @unresponded_keepalive_count > keepalive_maxcount
+      error { "Timeout, server #{host} not responding. Missed #{@unresponded_keepalive_count} timeouts." }
+      raise Net::SSH::Timeout, "Timeout, server #{host} not responding."
+    end
+    @last_keepalive_sent_at = Time.now
+  end
+end
+
+end; end; end
+\ No newline at end of file