Class | Net::SSH::Transport::Session |
In: |
lib/net/ssh/transport/session.rb
lib/net/ssh/transport/session.rb |
Parent: | Object |
The transport layer represents the lowest level of the SSH protocol, and implements basic message exchanging and protocol initialization. It will never be instantiated directly (unless you really know what you‘re about), but will instead be created for you automatically when you create a new SSH session via Net::SSH.start.
algorithms | [R] | The Algorithms instance used to perform key exchanges. |
algorithms | [R] | The Algorithms instance used to perform key exchanges. |
host | [R] | The host to connect to, as given to the constructor. |
host | [R] | The host to connect to, as given to the constructor. |
host_key_verifier | [R] | The host-key verifier object used to verify host keys, to ensure that the connection is not being spoofed. |
host_key_verifier | [R] | The host-key verifier object used to verify host keys, to ensure that the connection is not being spoofed. |
options | [R] | The hash of options that were given to the object at initialization. |
options | [R] | The hash of options that were given to the object at initialization. |
port | [R] | The port number to connect to, as given in the options to the constructor. If no port number was given, this will default to DEFAULT_PORT. |
port | [R] | The port number to connect to, as given in the options to the constructor. If no port number was given, this will default to DEFAULT_PORT. |
server_version | [R] | The ServerVersion instance that encapsulates the negotiated protocol version. |
server_version | [R] | The ServerVersion instance that encapsulates the negotiated protocol version. |
socket | [R] | The underlying socket object being used to communicate with the remote host. |
socket | [R] | The underlying socket object being used to communicate with the remote host. |
Instantiates a new transport layer abstraction. This will block until the initial key exchange completes, leaving you with a ready-to-use transport session.
# File lib/net/ssh/transport/session.rb, line 56 56: def initialize(host, options={}) 57: self.logger = options[:logger] 58: 59: @host = host 60: @port = options[:port] || DEFAULT_PORT 61: @options = options 62: 63: debug { "establishing connection to #{@host}:#{@port}" } 64: factory = options[:proxy] || TCPSocket 65: @socket = timeout(options[:timeout] || 0) { factory.open(@host, @port) } 66: @socket.extend(PacketStream) 67: @socket.logger = @logger 68: 69: debug { "connection established" } 70: 71: @queue = [] 72: 73: @host_key_verifier = select_host_key_verifier(options[:paranoid]) 74: 75: @server_version = ServerVersion.new(socket, logger) 76: 77: @algorithms = Algorithms.new(self, options) 78: wait { algorithms.initialized? } 79: end
Instantiates a new transport layer abstraction. This will block until the initial key exchange completes, leaving you with a ready-to-use transport session.
# File lib/net/ssh/transport/session.rb, line 56 56: def initialize(host, options={}) 57: self.logger = options[:logger] 58: 59: @host = host 60: @port = options[:port] || DEFAULT_PORT 61: @options = options 62: 63: debug { "establishing connection to #{@host}:#{@port}" } 64: factory = options[:proxy] || TCPSocket 65: @socket = timeout(options[:timeout] || 0) { factory.open(@host, @port) } 66: @socket.extend(PacketStream) 67: @socket.logger = @logger 68: 69: debug { "connection established" } 70: 71: @queue = [] 72: 73: @host_key_verifier = select_host_key_verifier(options[:paranoid]) 74: 75: @server_version = ServerVersion.new(socket, logger) 76: 77: @algorithms = Algorithms.new(self, options) 78: wait { algorithms.initialized? } 79: end
Cleans up (see PacketStream#cleanup) and closes the underlying socket.
# File lib/net/ssh/transport/session.rb, line 97 97: def close 98: socket.cleanup 99: socket.close 100: end
Cleans up (see PacketStream#cleanup) and closes the underlying socket.
# File lib/net/ssh/transport/session.rb, line 97 97: def close 98: socket.cleanup 99: socket.close 100: end
Configure‘s the packet stream‘s client state with the given set of options. This is typically used to define the cipher, compression, and hmac algorithms to use when sending packets to the server.
# File lib/net/ssh/transport/session.rb, line 215 215: def configure_client(options={}) 216: socket.client.set(options) 217: end
Configure‘s the packet stream‘s client state with the given set of options. This is typically used to define the cipher, compression, and hmac algorithms to use when sending packets to the server.
# File lib/net/ssh/transport/session.rb, line 215 215: def configure_client(options={}) 216: socket.client.set(options) 217: end
Configure‘s the packet stream‘s server state with the given set of options. This is typically used to define the cipher, compression, and hmac algorithms to use when reading packets from the server.
# File lib/net/ssh/transport/session.rb, line 222 222: def configure_server(options={}) 223: socket.server.set(options) 224: end
Configure‘s the packet stream‘s server state with the given set of options. This is typically used to define the cipher, compression, and hmac algorithms to use when reading packets from the server.
# File lib/net/ssh/transport/session.rb, line 222 222: def configure_server(options={}) 223: socket.server.set(options) 224: end
Enqueues the given message, such that it will be sent at the earliest opportunity. This does not block, but returns immediately.
# File lib/net/ssh/transport/session.rb, line 208 208: def enqueue_message(message) 209: socket.enqueue_packet(message) 210: end
Enqueues the given message, such that it will be sent at the earliest opportunity. This does not block, but returns immediately.
# File lib/net/ssh/transport/session.rb, line 208 208: def enqueue_message(message) 209: socket.enqueue_packet(message) 210: end
Returns the host (and possibly IP address) in a format compatible with SSH known-host files.
# File lib/net/ssh/transport/session.rb, line 83 83: def host_as_string 84: @host_as_string ||= begin 85: string = "#{host}" 86: string = "[#{string}]:#{port}" if port != DEFAULT_PORT 87: if socket.peer_ip != host 88: string2 = socket.peer_ip 89: string2 = "[#{string2}]:#{port}" if port != DEFAULT_PORT 90: string << "," << string2 91: end 92: string 93: end 94: end
Returns the host (and possibly IP address) in a format compatible with SSH known-host files.
# File lib/net/ssh/transport/session.rb, line 83 83: def host_as_string 84: @host_as_string ||= begin 85: string = "#{host}" 86: string = "[#{string}]:#{port}" if port != DEFAULT_PORT 87: if socket.peer_ip != host 88: string2 = socket.peer_ip 89: string2 = "[#{string2}]:#{port}" if port != DEFAULT_PORT 90: string << "," << string2 91: end 92: string 93: end 94: end
Blocks until a new packet is available to be read, and returns that packet. See poll_message.
# File lib/net/ssh/transport/session.rb, line 134 134: def next_message 135: poll_message(:block) 136: end
Blocks until a new packet is available to be read, and returns that packet. See poll_message.
# File lib/net/ssh/transport/session.rb, line 134 134: def next_message 135: poll_message(:block) 136: end
Returns a hash of information about the peer (remote) side of the socket, including :ip, :port, :host, and :canonized (see host_as_string).
# File lib/net/ssh/transport/session.rb, line 128 128: def peer 129: @peer ||= { :ip => socket.peer_ip, :port => @port.to_i, :host => @host, :canonized => host_as_string } 130: end
Returns a hash of information about the peer (remote) side of the socket, including :ip, :port, :host, and :canonized (see host_as_string).
# File lib/net/ssh/transport/session.rb, line 128 128: def peer 129: @peer ||= { :ip => socket.peer_ip, :port => @port.to_i, :host => @host, :canonized => host_as_string } 130: end
Tries to read the next packet from the socket. If mode is :nonblock (the default), this will not block and will return nil if there are no packets waiting to be read. Otherwise, this will block until a packet is available. Note that some packet types (DISCONNECT, IGNORE, UNIMPLEMENTED, DEBUG, and KEXINIT) are handled silently by this method, and will never be returned.
If a key-exchange is in process and a disallowed packet type is received, it will be enqueued and otherwise ignored. When a key-exchange is not in process, and consume_queue is true, packets will be first read from the queue before the socket is queried.
# File lib/net/ssh/transport/session.rb, line 149 149: def poll_message(mode=:nonblock, consume_queue=true) 150: loop do 151: if consume_queue && @queue.any? && algorithms.allow?(@queue.first) 152: return @queue.shift 153: end 154: 155: packet = socket.next_packet(mode) 156: return nil if packet.nil? 157: 158: case packet.type 159: when DISCONNECT 160: raise Net::SSH::Disconnect, "disconnected: #{packet[:description]} (#{packet[:reason_code]})" 161: 162: when IGNORE 163: debug { "IGNORE packet recieved: #{packet[:data].inspect}" } 164: 165: when UNIMPLEMENTED 166: lwarn { "UNIMPLEMENTED: #{packet[:number]}" } 167: 168: when DEBUG 169: send(packet[:always_display] ? :fatal : :debug) { packet[:message] } 170: 171: when KEXINIT 172: algorithms.accept_kexinit(packet) 173: 174: else 175: return packet if algorithms.allow?(packet) 176: push(packet) 177: end 178: end 179: end
Tries to read the next packet from the socket. If mode is :nonblock (the default), this will not block and will return nil if there are no packets waiting to be read. Otherwise, this will block until a packet is available. Note that some packet types (DISCONNECT, IGNORE, UNIMPLEMENTED, DEBUG, and KEXINIT) are handled silently by this method, and will never be returned.
If a key-exchange is in process and a disallowed packet type is received, it will be enqueued and otherwise ignored. When a key-exchange is not in process, and consume_queue is true, packets will be first read from the queue before the socket is queried.
# File lib/net/ssh/transport/session.rb, line 149 149: def poll_message(mode=:nonblock, consume_queue=true) 150: loop do 151: if consume_queue && @queue.any? && algorithms.allow?(@queue.first) 152: return @queue.shift 153: end 154: 155: packet = socket.next_packet(mode) 156: return nil if packet.nil? 157: 158: case packet.type 159: when DISCONNECT 160: raise Net::SSH::Disconnect, "disconnected: #{packet[:description]} (#{packet[:reason_code]})" 161: 162: when IGNORE 163: debug { "IGNORE packet recieved: #{packet[:data].inspect}" } 164: 165: when UNIMPLEMENTED 166: lwarn { "UNIMPLEMENTED: #{packet[:number]}" } 167: 168: when DEBUG 169: send(packet[:always_display] ? :fatal : :debug) { packet[:message] } 170: 171: when KEXINIT 172: algorithms.accept_kexinit(packet) 173: 174: else 175: return packet if algorithms.allow?(packet) 176: push(packet) 177: end 178: end 179: end
Adds the given packet to the packet queue. If the queue is non-empty, poll_message will return packets from the queue in the order they were received.
# File lib/net/ssh/transport/session.rb, line 196 196: def push(packet) 197: @queue.push(packet) 198: end
Adds the given packet to the packet queue. If the queue is non-empty, poll_message will return packets from the queue in the order they were received.
# File lib/net/ssh/transport/session.rb, line 196 196: def push(packet) 197: @queue.push(packet) 198: end
Requests a rekey operation, and blocks until the operation completes. If a rekey is already pending, this returns immediately, having no effect.
# File lib/net/ssh/transport/session.rb, line 111 111: def rekey! 112: if !algorithms.pending? 113: algorithms.rekey! 114: wait { algorithms.initialized? } 115: end 116: end
Requests a rekey operation, and blocks until the operation completes. If a rekey is already pending, this returns immediately, having no effect.
# File lib/net/ssh/transport/session.rb, line 111 111: def rekey! 112: if !algorithms.pending? 113: algorithms.rekey! 114: wait { algorithms.initialized? } 115: end 116: end
Returns immediately if a rekey is already in process. Otherwise, if a rekey is needed (as indicated by the socket, see PacketStream#if_needs_rekey?) one is performed, causing this method to block until it completes.
# File lib/net/ssh/transport/session.rb, line 121 121: def rekey_as_needed 122: return if algorithms.pending? 123: socket.if_needs_rekey? { rekey! } 124: end
Returns immediately if a rekey is already in process. Otherwise, if a rekey is needed (as indicated by the socket, see PacketStream#if_needs_rekey?) one is performed, causing this method to block until it completes.
# File lib/net/ssh/transport/session.rb, line 121 121: def rekey_as_needed 122: return if algorithms.pending? 123: socket.if_needs_rekey? { rekey! } 124: end
Sends the given message via the packet stream, blocking until the entire message has been sent.
# File lib/net/ssh/transport/session.rb, line 202 202: def send_message(message) 203: socket.send_packet(message) 204: end
Sends the given message via the packet stream, blocking until the entire message has been sent.
# File lib/net/ssh/transport/session.rb, line 202 202: def send_message(message) 203: socket.send_packet(message) 204: end
Returns a new service_request packet for the given service name, ready for sending to the server.
# File lib/net/ssh/transport/session.rb, line 104 104: def service_request(service) 105: Net::SSH::Buffer.from(:byte, SERVICE_REQUEST, :string, service) 106: end
Returns a new service_request packet for the given service name, ready for sending to the server.
# File lib/net/ssh/transport/session.rb, line 104 104: def service_request(service) 105: Net::SSH::Buffer.from(:byte, SERVICE_REQUEST, :string, service) 106: end
Waits (blocks) until the given block returns true. If no block is given, this just waits long enough to see if there are any pending packets. Any packets read are enqueued (see push).
# File lib/net/ssh/transport/session.rb, line 184 184: def wait 185: loop do 186: break if block_given? && yield 187: message = poll_message(:nonblock, false) 188: push(message) if message 189: break if !block_given? 190: end 191: end
Waits (blocks) until the given block returns true. If no block is given, this just waits long enough to see if there are any pending packets. Any packets read are enqueued (see push).
# File lib/net/ssh/transport/session.rb, line 184 184: def wait 185: loop do 186: break if block_given? && yield 187: message = poll_message(:nonblock, false) 188: push(message) if message 189: break if !block_given? 190: end 191: end