Add Net::SSH::Proxy::Command.

1 files changed, 75 insertions, 0 deletions

diff --git a/lib/net/ssh/proxy/command.rb b/lib/net/ssh/proxy/command.rb
new file mode 100644
index 0000000..c22ad01
--- /dev/null
+++ b/lib/net/ssh/proxy/command.rb
@@ -0,0 +1,75 @@
+require 'socket'
+require 'net/ssh/proxy/errors'
+require 'net/ssh/ruby_compat'
+
+module Net; module SSH; module Proxy
+
+  # An implementation of a command proxy. To use it, instantiate it,
+  # then pass the instantiated object via the :proxy key to
+  # Net::SSH.start:
+  #
+  #   require 'net/ssh/proxy/command'
+  #
+  #   proxy = Net::SSH::Proxy::Command.new('ssh relay nc %h %p')
+  #   Net::SSH.start('host', 'user', :proxy => proxy) do |ssh|
+  #     ...
+  #   end
+  class Command
+
+    # The command line template
+    attr_reader :command_line_template
+
+    # The command line for the session
+    attr_reader :command_line
+
+    # Create a new socket factory that tunnels via a command executed
+    # with the user's shell, which is composed from the given command
+    # template.  In the command template, `%h' will be substituted by
+    # the host name to connect and `%p' by the port.
+    def initialize(command_line_template)
+      @command_line_template = command_line_template
+      @command_line = nil
+    end
+
+    # Return a new socket connected to the given host and port via the
+    # proxy that was requested when the socket factory was instantiated.
+    def open(host, port)
+      command_line = @command_line_template.gsub(/%(.)/) {
+        case $1
+        when 'h'
+          host
+        when 'p'
+          port.to_s
+        when '%'
+          '%'
+        else
+          raise ArgumentError, "unknown key: #{$1}"
+        end
+      }
+      begin
+        io = IO.popen(command_line, "r+")
+        if result = Net::SSH::Compat.io_select([io], nil, [io], 60)
+          if result.last.any?
+            raise ConnectError, "command failed: #{command_line}"
+          end
+        else
+          raise ConnectError, "command timed out: #{command_line}"
+        end
+      rescue => e
+        raise ConnectError, "#{e}: #{command_line}"
+      end
+      @command_line = command_line
+      class << io
+        def send(data, flag)
+          write_nonblock(data)
+        end
+
+        def recv(size)
+          read_nonblock(size)
+        end
+      end
+      io
+    end
+  end
+
+end; end; end