clean up use of iptables chains

1 files changed, 78 insertions, 26 deletions

diff --git a/nova/network/linux_net.py b/nova/network/linux_net.py
index 0fefd9415..8aca1c80a 100644
--- a/nova/network/linux_net.py
+++ b/nova/network/linux_net.py
@@ -19,7 +19,6 @@ Implements vlans, bridges, and iptables rules using linux utilities.
 
 import logging
 import os
-import signal
 
 # TODO(ja): does the definition of network_path belong here?
 
@@ -48,39 +47,88 @@ flags.DEFINE_string('dhcpbridge', _bin_file('nova-dhcpbridge'),
                         'location of nova-dhcpbridge')
 flags.DEFINE_string('cc_host', utils.get_my_ip(), 'ip of api server')
 flags.DEFINE_integer('cc_port', 8773, 'cloud controller port')
-flags.DEFINE_string('routing_source_ip', '127.0.0.1',
+flags.DEFINE_string('routing_source_ip', utils.get_my_ip(),
                     'Public IP of network host')
 flags.DEFINE_bool('use_nova_chains', False,
                   'use the nova_ routing chains instead of default')
-
-DEFAULT_PORTS = [("tcp", 80), ("tcp", 22), ("udp", 1194), ("tcp", 443)]
+flags.DEFINE_string('dns_server', None,
+                    'if set, uses specific dns server for dnsmasq')
 
 
 def metadata_forward():
     """Create forwarding rule for metadata"""
     _confirm_rule("PREROUTING", "-t nat -s 0.0.0.0/0 "
              "-d 169.254.169.254/32 -p tcp -m tcp --dport 80 -j DNAT "
-             "--to-destination %s:%s" % (FLAGS.cc_host, FLAGS.cc_port))
+             "--to-destination %s:%s" % (FLAGS.cc_dmz, FLAGS.cc_port))
 
 
 def init_host():
     """Basic networking setup goes here"""
+
+    if FLAGS.use_nova_chains:
+        _execute("sudo iptables -N nova_input", check_exit_code=False)
+        _execute("sudo iptables -D %s -j nova_input" % FLAGS.input_chain,
+                 check_exit_code=False)
+        _execute("sudo iptables -A %s -j nova_input" % FLAGS.input_chain)
+
+        _execute("sudo iptables -N nova_forward", check_exit_code=False)
+        _execute("sudo iptables -D FORWARD -j nova_forward",
+                 check_exit_code=False)
+        _execute("sudo iptables -A FORWARD -j nova_forward")
+
+        _execute("sudo iptables -N nova_output", check_exit_code=False)
+        _execute("sudo iptables -D OUTPUT -j nova_output",
+                 check_exit_code=False)
+        _execute("sudo iptables -A OUTPUT -j nova_output")
+
+        _execute("sudo iptables -t nat -N nova_prerouting",
+                 check_exit_code=False)
+        _execute("sudo iptables -t nat -D PREROUTING -j nova_prerouting",
+                 check_exit_code=False)
+        _execute("sudo iptables -t nat -A PREROUTING -j nova_prerouting")
+
+        _execute("sudo iptables -t nat -N nova_postrouting",
+                 check_exit_code=False)
+        _execute("sudo iptables -t nat -D POSTROUTING -j nova_postrouting",
+                 check_exit_code=False)
+        _execute("sudo iptables -t nat -A POSTROUTING -j nova_postrouting")
+
+        _execute("sudo iptables -t nat -N nova_snatting",
+                 check_exit_code=False)
+        _execute("sudo iptables -t nat -D POSTROUTING -j nova_snatting",
+                 check_exit_code=False)
+        _execute("sudo iptables -t nat -A POSTROUTING -j nova_snatting")
+
+        _execute("sudo iptables -t nat -N nova_output", check_exit_code=False)
+        _execute("sudo iptables -t nat -D OUTPUT -j nova_output",
+                 check_exit_code=False)
+        _execute("sudo iptables -t nat -A OUTPUT -j nova_output")
+    else:
+        # NOTE(vish): This makes it easy to ensure snatting rules always
+        #             come after the accept rules in the postrouting chain
+        _execute("sudo iptables -t nat -N SNATTING",
+                 check_exit_code=False)
+        _execute("sudo iptables -t nat -D POSTROUTING -j SNATTING",
+                 check_exit_code=False)
+        _execute("sudo iptables -t nat -A POSTROUTING -j SNATTING")
+
     # NOTE(devcamcar): Cloud public SNAT entries and the default
     # SNAT rule for outbound traffic.
-    _confirm_rule("POSTROUTING", "-t nat -s %s "
+    _confirm_rule("SNATTING", "-t nat -s %s "
              "-j SNAT --to-source %s"
-             % (FLAGS.fixed_range, FLAGS.routing_source_ip))
+             % (FLAGS.fixed_range, FLAGS.routing_source_ip), append=True)
 
-    _confirm_rule("POSTROUTING", "-t nat -s %s -j MASQUERADE" %
-                  FLAGS.fixed_range)
+    _confirm_rule("POSTROUTING", "-t nat -s %s -d %s -j ACCEPT" %
+                  (FLAGS.fixed_range, FLAGS.dmz_cidr))
     _confirm_rule("POSTROUTING", "-t nat -s %(range)s -d %(range)s -j ACCEPT" %
                   {'range': FLAGS.fixed_range})
 
 
-def bind_floating_ip(floating_ip):
+def bind_floating_ip(floating_ip, check_exit_code=True):
     """Bind ip to public interface"""
     _execute("sudo ip addr add %s dev %s" % (floating_ip,
-                                             FLAGS.public_interface))
+                                             FLAGS.public_interface),
+             check_exit_code=check_exit_code)
 
 
 def unbind_floating_ip(floating_ip):
@@ -102,27 +150,16 @@ def ensure_floating_forward(floating_ip, fixed_ip):
     """Ensure floating ip forwarding rule"""
     _confirm_rule("PREROUTING", "-t nat -d %s -j DNAT --to %s"
                            % (floating_ip, fixed_ip))
-    _confirm_rule("POSTROUTING", "-t nat -s %s -j SNAT --to %s"
+    _confirm_rule("SNATTING", "-t nat -s %s -j SNAT --to %s"
                            % (fixed_ip, floating_ip))
-    # TODO(joshua): Get these from the secgroup datastore entries
-    _confirm_rule("FORWARD", "-d %s -p icmp -j ACCEPT"
-                           % (fixed_ip))
-    for (protocol, port) in DEFAULT_PORTS:
-        _confirm_rule("FORWARD", "-d %s -p %s --dport %s -j ACCEPT"
-            % (fixed_ip, protocol, port))
 
 
 def remove_floating_forward(floating_ip, fixed_ip):
     """Remove forwarding for floating ip"""
     _remove_rule("PREROUTING", "-t nat -d %s -j DNAT --to %s"
                           % (floating_ip, fixed_ip))
-    _remove_rule("POSTROUTING", "-t nat -s %s -j SNAT --to %s"
+    _remove_rule("SNATTING", "-t nat -s %s -j SNAT --to %s"
                           % (fixed_ip, floating_ip))
-    _remove_rule("FORWARD", "-d %s -p icmp -j ACCEPT"
-                          % (fixed_ip))
-    for (protocol, port) in DEFAULT_PORTS:
-        _remove_rule("FORWARD", "-d %s -p %s --dport %s -j ACCEPT"
-                              % (fixed_ip, protocol, port))
 
 
 def ensure_vlan_bridge(vlan_num, bridge, net_attrs=None):
@@ -160,6 +197,15 @@ def ensure_bridge(bridge, interface, net_attrs=None):
                  net_attrs['netmask']))
     else:
         _execute("sudo ifconfig %s up" % bridge)
+    if FLAGS.use_nova_chains:
+        (out, err) = _execute("sudo iptables -N nova_forward",
+                              check_exit_code=False)
+        if err != 'iptables: Chain already exists.\n':
+            # NOTE(vish): chain didn't exist link chain
+            _execute("sudo iptables -D FORWARD -j nova_forward",
+                     check_exit_code=False)
+            _execute("sudo iptables -A FORWARD -j nova_forward")
+
     _confirm_rule("FORWARD", "--in-interface %s -j ACCEPT" % bridge)
     _confirm_rule("FORWARD", "--out-interface %s -j ACCEPT" % bridge)
 
@@ -236,13 +282,17 @@ def _device_exists(device):
     return not err
 
 
-def _confirm_rule(chain, cmd):
+def _confirm_rule(chain, cmd, append=False):
     """Delete and re-add iptables rule"""
     if FLAGS.use_nova_chains:
         chain = "nova_%s" % chain.lower()
+    if append:
+        loc = "-A"
+    else:
+        loc = "-I"
     _execute("sudo iptables --delete %s %s" % (chain, cmd),
              check_exit_code=False)
-    _execute("sudo iptables -I %s %s" % (chain, cmd))
+    _execute("sudo iptables %s %s %s" % (loc, chain, cmd))
 
 
 def _remove_rule(chain, cmd):
@@ -265,6 +315,8 @@ def _dnsmasq_cmd(net):
            ' --dhcp-hostsfile=%s' % _dhcp_file(net['bridge'], 'conf'),
            ' --dhcp-script=%s' % FLAGS.dhcpbridge,
            ' --leasefile-ro']
+    if FLAGS.dns_server:
+        cmd.append(' -h -R --server=%s' % FLAGS.dns_server)
     return ''.join(cmd)