Support NAT/port forwards.

[nodemanager.git] / iptables.py

diff --git a/iptables.py b/iptables.py
new file mode 100644 (file)
index 0000000..fa83ee6
--- /dev/null
+++ b/iptables.py
@@ -0,0 +1,99 @@
+#!/usr/bin/python -tt
+
+# Author: Daniel Hokka Zakrisson <daniel@hozac.com>
+# $Id$
+
+import os
+import logger
+import subprocess
+
+class IPTables:
+    IPTABLES_RESTORE = "/sbin/iptables-restore"
+
+    def __init__(self):
+        self.extifs = []
+        self.intifs = []
+        self.pfs = []
+
+    def add(self, table, chain, rule):
+        self.rules[table][chain].append(rule)
+
+    def add_ext(self, interface):
+        self.extifs.append(interface)
+
+    def add_int(self, interface):
+        self.intifs.append(interface)
+
+    def add_pf(self, pf):
+        # XXX Should make sure the required fields are there
+        self.pfs.append(pf)
+
+    def commit(self):
+        # XXX This should check for errors
+        #     and make sure the new ruleset differs from the current one
+
+        if (len(self.extifs) + len(self.intifs) + len(self.pfs)) == 0:
+            return True
+
+        restore = subprocess.Popen([self.IPTABLES_RESTORE], stdin=subprocess.PIPE)
+        restore.stdin.write("""*filter
+:INPUT ACCEPT [0:0]
+:FORWARD ACCEPT [0:0]
+:OUTPUT ACCEPT [0:0]
+:BLACKLIST - [0:0]
+:LOGDROP - [0:0]
+:SLICESPRE - [0:0]
+:SLICES - [0:0]
+:PORTFW - [0:0]
+
+-A LOGDROP -j LOG
+-A LOGDROP -j DROP
+-A OUTPUT -j BLACKLIST
+-A OUTPUT -m mark ! --mark 0/65535 -j SLICESPRE
+-A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
+""")
+
+        for int in self.intifs:
+            for ext in self.extifs:
+                restore.stdin.write("-A FORWARD -i %s -o %s -j ACCEPT\n" % (int, ext))
+            restore.stdin.write("-A SLICESPRE -o %s -j SLICES\n" % int)
+
+        restore.stdin.write("-A FORWARD -m state --state NEW -j PORTFW\n")
+        for pf in self.pfs:
+            rule = "-A PORTFW -p %s -d %s " % (pf['protocol'], pf['destination'])
+            if 'interface' in pf:
+                rule += "-i %s " % pf['interface']
+            if 'source' in pf:
+                rule += "-s %s " % pf['source']
+            rule += "--dport %s" % pf['new_dport']
+            restore.stdin.write(rule + "\n")
+
+        restore.stdin.write("-A FORWARD -j LOGDROP\n")
+
+        # This should have a way to add rules
+        restore.stdin.write("-A SLICES -j LOGDROP\n")
+        restore.stdin.write("""COMMIT
+*nat
+:PREROUTING ACCEPT [0:0]
+:POSTROUTING ACCEPT [0:0]
+:OUTPUT ACCEPT [0:0]
+:PORTFW - [0:0]
+:MASQ - [0:0]
+""")
+
+        for ext in self.extifs:
+            restore.stdin.write("-A MASQ -o %s -j MASQUERADE\n")
+
+        for pf in self.pfs:
+            rule = "-A PORTFW -p %s " % pf['protocol']
+            if 'interface' in pf:
+                rule += "-i %s " % pf['interface']
+            if 'source' in pf:
+                rule += "-s %s " % pf['source']
+            rule += "--dport %s -j DNAT --to %s:%s" % (pf['dport'], pf['destination'],
+                    pf['new_dport'])
+            restore.stdin.write(rule + "\n")
+
+        restore.stdin.write("COMMIT\n")
+        restore.stdin.close()
+        return restore.wait() == 0