console: factor out ssh tunnel code, add multi-connexion Tunnels class

This commit is contained in:
Marc-André Lureau 2010-12-21 22:34:36 +01:00
parent 41b38c4856
commit ae450d9b1d

View File

@ -1,6 +1,8 @@
# -*- coding: utf-8 -*-
#
# Copyright (C) 2006-2008 Red Hat, Inc.
# Copyright (C) 2006 Daniel P. Berrange <berrange@redhat.com>
# Copyright (C) 2010 Marc-André Lureau <marcandre.lureau@redhat.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
@ -46,6 +48,146 @@ def has_property(obj, setting):
return False
return True
class Tunnel(object):
def __init__(self):
self.outfd = None
self.errfd = None
self.pid = None
def open(self, server, addr, port, username, sshport):
if self.outfd is not None:
return -1
# Build SSH cmd
argv = ["ssh", "ssh"]
if sshport:
argv += ["-p", str(sshport)]
if username:
argv += ['-l', username]
argv += [server]
# Build 'nc' command run on the remote host
#
# This ugly thing is a shell script to detect availability of
# the -q option for 'nc': debian and suse based distros need this
# flag to ensure the remote nc will exit on EOF, so it will go away
# when we close the VNC tunnel. If it doesn't go away, subsequent
# VNC connection attempts will hang.
#
# Fedora's 'nc' doesn't have this option, and apparently defaults
# to the desired behavior.
#
nc_params = "%s %s" % (addr, str(port))
nc_cmd = (
"""nc -q 2>&1 | grep -q "requires an argument";"""
"""if [ $? -eq 0 ] ; then"""
""" CMD="nc -q 0 %(nc_params)s";"""
"""else"""
""" CMD="nc %(nc_params)s";"""
"""fi;"""
"""eval "$CMD";""" %
{'nc_params': nc_params})
argv.append("sh -c")
argv.append("'%s'" % nc_cmd)
argv_str = reduce(lambda x, y: x + " " + y, argv[1:])
logging.debug("Creating SSH tunnel: %s" % argv_str)
fds = socket.socketpair()
errorfds = socket.socketpair()
pid = os.fork()
if pid == 0:
fds[0].close()
errorfds[0].close()
os.close(0)
os.close(1)
os.close(2)
os.dup(fds[1].fileno())
os.dup(fds[1].fileno())
os.dup(errorfds[1].fileno())
os.execlp(*argv)
os._exit(1)
else:
fds[1].close()
errorfds[1].close()
logging.debug("Tunnel PID=%d OUTFD=%d ERRFD=%d" %
(pid, fds[0].fileno(), errorfds[0].fileno()))
errorfds[0].setblocking(0)
self.outfd = fds[0]
self.errfd = errorfds[0]
self.pid = pid
fd = fds[0].fileno()
if fd < 0:
raise SystemError("can't open a new tunnel: fd=%d" % fd)
return fd
def close(self):
if self.outfd is None:
return
logging.debug("Shutting down tunnel PID=%d OUTFD=%d ERRFD=%d" %
(self.pid, self.outfd.fileno(),
self.errfd.fileno()))
self.outfd.close()
self.outfd = None
self.errfd.close()
self.errfd = None
os.kill(self.pid, signal.SIGKILL)
self.pid = None
def get_err_output(self):
errout = ""
while True:
try:
new = self.errfd.recv(1024)
except:
break
if not new:
break
errout += new
return errout
class Tunnels(object):
def __init__(self, server, addr, port, username, sshport):
self.server = server
self.addr = addr
self.port = port
self.username = username
self.sshport = sshport
self._tunnels = []
def open_new(self):
t = Tunnel()
fd = t.open(self.server, self.addr, self.port,
self.username, self.sshport)
self._tunnels.append(t)
return fd
def close_all(self):
for l in self._tunnels:
l.close()
def get_err_output(self):
errout = ""
for l in self._tunnels:
errout += l.get_err_output()
return errout
class vmmConsolePages(vmmGObjectUI):
def __init__(self, vm, window):
vmmGObjectUI.__init__(self, None, None)
@ -70,7 +212,7 @@ class vmmConsolePages(vmmGObjectUI):
# Initialize display widget
self.scale_type = self.vm.get_console_scaling()
self.vncTunnel = None
self.tunnels = None
self.vncViewerRetriesScheduled = 0
self.vncViewerRetryDelay = 125
self.vnc_connected = False
@ -428,9 +570,10 @@ class vmmConsolePages(vmmGObjectUI):
def _vnc_disconnected(self, src_ignore):
errout = ""
if self.vncTunnel is not None:
errout = self.get_tunnel_err_output()
self.close_tunnel()
if self.tunnels is not None:
errout = self.tunnels.get_err_output()
self.tunnels.close_all()
self.tunnels = None
self.vnc_connected = False
logging.debug("VNC disconnected")
@ -474,104 +617,6 @@ class vmmConsolePages(vmmGObjectUI):
if self.vncViewerRetryDelay < 2000:
self.vncViewerRetryDelay = self.vncViewerRetryDelay * 2
def open_tunnel(self, server, vncaddr, vncport, username, sshport):
if self.vncTunnel is not None:
return -1
# Build SSH cmd
argv = ["ssh", "ssh"]
if sshport:
argv += ["-p", str(sshport)]
if username:
argv += ['-l', username]
argv += [server]
# Build 'nc' command run on the remote host
#
# This ugly thing is a shell script to detect availability of
# the -q option for 'nc': debian and suse based distros need this
# flag to ensure the remote nc will exit on EOF, so it will go away
# when we close the VNC tunnel. If it doesn't go away, subsequent
# VNC connection attempts will hang.
#
# Fedora's 'nc' doesn't have this option, and apparently defaults
# to the desired behavior.
#
nc_params = "%s %s" % (vncaddr, str(vncport))
nc_cmd = (
"""nc -q 2>&1 | grep -q "requires an argument";"""
"""if [ $? -eq 0 ] ; then"""
""" CMD="nc -q 0 %(nc_params)s";"""
"""else"""
""" CMD="nc %(nc_params)s";"""
"""fi;"""
"""eval "$CMD";""" %
{'nc_params': nc_params})
argv.append("sh -c")
argv.append("'%s'" % nc_cmd)
argv_str = reduce(lambda x, y: x + " " + y, argv[1:])
logging.debug("Creating SSH tunnel: %s" % argv_str)
fds = socket.socketpair()
errorfds = socket.socketpair()
pid = os.fork()
if pid == 0:
fds[0].close()
errorfds[0].close()
os.close(0)
os.close(1)
os.close(2)
os.dup(fds[1].fileno())
os.dup(fds[1].fileno())
os.dup(errorfds[1].fileno())
os.execlp(*argv)
os._exit(1)
else:
fds[1].close()
errorfds[1].close()
logging.debug("Tunnel PID=%d OUTFD=%d ERRFD=%d" %
(pid, fds[0].fileno(), errorfds[0].fileno()))
errorfds[0].setblocking(0)
self.vncTunnel = [fds[0], errorfds[0], pid]
return fds[0].fileno()
def close_tunnel(self):
if self.vncTunnel is None:
return
logging.debug("Shutting down tunnel PID=%d OUTFD=%d ERRFD=%d" %
(self.vncTunnel[2], self.vncTunnel[0].fileno(),
self.vncTunnel[1].fileno()))
self.vncTunnel[0].close()
self.vncTunnel[1].close()
os.kill(self.vncTunnel[2], signal.SIGKILL)
self.vncTunnel = None
def get_tunnel_err_output(self):
errfd = self.vncTunnel[1]
errout = ""
while True:
try:
new = errfd.recv(1024)
except:
break
if not new:
break
errout += new
return errout
def skip_connect_attempt(self):
return (self.vnc_connected or
not self.is_visible())
@ -628,12 +673,13 @@ class vmmConsolePages(vmmGObjectUI):
try:
if trans in ("ssh", "ext"):
if self.vncTunnel:
if self.tunnels:
# Tunnel already open, no need to continue
return
fd = self.open_tunnel(connhost, "127.0.0.1", vncport,
username, connport)
self.tunnels = Tunnels(connhost, "127.0.0.1", vncport,
username, connport)
fd = self.tunnels.open_new()
if fd >= 0:
self.vncViewer.open_fd(fd)