Merge pull request #200 from net-ssh/keepalive-maxcount

Implemented keepalive_maxcount

5 files changed, 76 insertions, 28 deletions

diff --git a/lib/net/ssh.rb b/lib/net/ssh.rb
index d9a1f57..d4eb307 100644
--- a/lib/net/ssh.rb
+++ b/lib/net/ssh.rb
@@ -63,7 +63,7 @@ module Net
     VALID_OPTIONS = [
       :auth_methods, :bind_address, :compression, :compression_level, :config,
       :encryption, :forward_agent, :hmac, :host_key,
-      :keepalive, :keepalive_interval, :kex, :keys, :key_data,
+      :keepalive, :keepalive_interval, :keepalive_maxcount, :kex, :keys, :key_data,
       :languages, :logger, :paranoid, :password, :port, :proxy,
       :rekey_blocks_limit,:rekey_limit, :rekey_packet_limit, :timeout, :verbose,
       :global_known_hosts_file, :user_known_hosts_file, :host_key_alias,
@@ -130,6 +130,7 @@ module Net
     #   the keepalive_interval seconds. Defaults to +false+.
     #   :keepalive_interval => the interval seconds for keepalive.
     #   Defaults to +300+ seconds.
+    #   :keepalive_countmax => the maximun number of keepalive packet miss allowed.
     # * :kex => the key exchange algorithm (or algorithms) to use
     # * :keys => an array of file names of private keys to use for publickey
     #   and hostbased authentication
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
diff --git a/lib/net/ssh/connection/session.rb b/lib/net/ssh/connection/session.rb
index 9be74e8..3137514 100644
--- a/lib/net/ssh/connection/session.rb
+++ b/lib/net/ssh/connection/session.rb
@@ -3,6 +3,7 @@ require 'net/ssh/ruby_compat'
 require 'net/ssh/connection/channel'
 require 'net/ssh/connection/constants'
 require 'net/ssh/service/forward'
+require 'net/ssh/connection/keepalive'
 
 module Net; module SSH; module Connection
 
@@ -23,10 +24,7 @@ module Net; module SSH; module Connection
   #     ssh.exec! "/etc/init.d/some_process start"
   #   end
   class Session
-    include Constants, Loggable
-
-    # Default IO.select timeout threshold
-    DEFAULT_IO_SELECT_TIMEOUT = 300
+    include Constants, Loggable, Keepalive
 
     # The underlying transport layer abstraction (see Net::SSH::Transport::Session).
     attr_reader :transport
@@ -79,7 +77,7 @@ module Net; module SSH; module Connection
       @max_pkt_size = (options.has_key?(:max_pkt_size) ? options[:max_pkt_size] : 0x8000)
       @max_win_size = (options.has_key?(:max_win_size) ? options[:max_win_size] : 0x20000)
 
-      @last_keepalive_sent_at = nil
+      initialize_keepalive
     end
 
     # Retrieves a custom property from this instance. This can be used to
@@ -598,29 +596,10 @@ module Net; module SSH; module Connection
 
       def io_select_wait(wait)
         return wait if wait
-        return wait unless options[:keepalive]
+        return wait unless keepalive_enabled?
         keepalive_interval
       end
 
-      def keepalive_interval
-        options[:keepalive_interval] || DEFAULT_IO_SELECT_TIMEOUT
-      end
-
-      def should_send_keepalive?
-        return false unless options[:keepalive]
-        return true unless @last_keepalive_sent_at
-        Time.now - @last_keepalive_sent_at >= keepalive_interval
-      end
-
-      def send_keepalive_as_needed(readers, writers)
-        return unless readers.nil? && writers.nil?
-        return unless should_send_keepalive?
-        info { "sending keepalive" }
-        msg = Net::SSH::Buffer.from(:byte, Packet::IGNORE, :string, "keepalive")
-        send_message(msg)
-        @last_keepalive_sent_at = Time.now
-      end
-
       MAP = Constants.constants.inject({}) do |memo, name|
         value = const_get(name)
         next unless Integer === value
diff --git a/lib/net/ssh/errors.rb b/lib/net/ssh/errors.rb
index 8f5a136..910c961 100644
--- a/lib/net/ssh/errors.rb
+++ b/lib/net/ssh/errors.rb
@@ -14,6 +14,10 @@ module Net; module SSH
   # unexpectedly.
   class Disconnect < Exception; end
 
+  # This exception is raised when the remote host has disconnected/
+  # timeouted unexpectedly.
+  class Timeout < Disconnect; end
+
   # This exception is primarily used internally, but if you have a channel
   # request handler (see Net::SSH::Connection::Channel#on_request) that you
   # want to fail in such a way that the server knows it failed, you can
diff --git a/test/connection/test_session.rb b/test/connection/test_session.rb
index 8af6cd3..268afb9 100644
--- a/test/connection/test_session.rb
+++ b/test/connection/test_session.rb
@@ -366,12 +366,29 @@ module Connection
     def test_process_should_call_enqueue_message_if_io_select_timed_out
       timeout = Net::SSH::Connection::Session::DEFAULT_IO_SELECT_TIMEOUT
       options = { :keepalive => true }
-      expected_packet = P(:byte, Net::SSH::Packet::IGNORE, :string, "keepalive")
+      expected_packet = P(:byte, Net::SSH::Packet::GLOBAL_REQUEST, :string, "keepalive@openssh.com", :bool, true)
       IO.stubs(:select).with([socket],[],nil,timeout).returns(nil)
-      transport.expects(:enqueue_message).with{ |msg| msg.content == expected_packet.content  }
+      transport.expects(:enqueue_message).with{ |msg| msg.content == expected_packet.content }
       session(options).process
     end
 
+    def test_process_should_raise_if_keepalives_not_answered
+      timeout = Net::SSH::Connection::Session::DEFAULT_IO_SELECT_TIMEOUT
+      options = { :keepalive => true, :keepalive_interval => 300, :keepalive_maxcount => 3 }
+      expected_packet = P(:byte, Net::SSH::Packet::GLOBAL_REQUEST, :string, "keepalive@openssh.com", :bool, true)
+      [1,2,3].each do |i|
+        Time.stubs(:now).returns(i*300)
+        IO.stubs(:select).with([socket],[],nil,timeout).returns(nil)
+        transport.expects(:enqueue_message).with{ |msg| msg.content == expected_packet.content  }
+        session(options).process
+      end
+
+      Time.stubs(:now).returns(4*300)
+      IO.stubs(:select).with([socket],[],nil,timeout).returns(nil)
+      transport.expects(:enqueue_message).with{ |msg| msg.content == expected_packet.content }
+      assert_raises(Net::SSH::Timeout) { session(options).process }
+    end
+
     def test_process_should_not_call_enqueue_message_unless_io_select_timed_out
       timeout = Net::SSH::Connection::Session::DEFAULT_IO_SELECT_TIMEOUT
       options = { :keepalive => true }