From 3f2d6be7dd2ca2411f04b22fdbdab80578bb5f9b Mon Sep 17 00:00:00 2001
From: brent s <bts@square-r00t.net>
Date: Tue, 12 May 2020 01:21:52 -0400
Subject: [PATCH] adding some config stuff

---
 utils/example.he_tunnelbroker.ini |  31 ---------
 utils/he_ipv6/config.py           | 100 ++++++++++++++++++++++++++++++
 utils/he_ipv6/example.he_ipv6.xml |  60 ++++++++++++++++--
 3 files changed, 156 insertions(+), 35 deletions(-)
 delete mode 100644 utils/example.he_tunnelbroker.ini
 create mode 100644 utils/he_ipv6/config.py

diff --git a/utils/example.he_tunnelbroker.ini b/utils/example.he_tunnelbroker.ini
deleted file mode 100644
index fb799c7..0000000
--- a/utils/example.he_tunnelbroker.ini
+++ /dev/null
@@ -1,31 +0,0 @@
-# This is a sample INI file to use with he_ipv6.py.
-# If you do not yet have an IPv6 Tunnelbroker.net allocation, you can get one (for free!) at:
-# https://www.tunnelbroker.net/tunnel_detail.php?tid=584532
-##
-# This is the tunnel ID. To get it, log into your tunnelbroker.net account and click on the tunnel you wish to use.
-# The tunnel ID is the numerical string in the URL. e.g.:
-#   https://www.tunnelbroker.net/tunnel_detail.php?tid=12345
-# The tunnel ID would be 12345 in the above example.
-[12345]
-# This is your tunnelbroker.net username.
-user = ipv6user
-# This is your update key for the above user. You can find it in the "Advanced" tab.
-update_key = xXxXxXxXxXxXxXXX
-# This is the server IP ("IPv6 Tunnel Endpoints" section). *Be sure to use the IPv4 address!* ("Server IPv4 Address")
-server = 192.0.2.1
-# And these are all the allocations you wish to add to this machine. Be sure to add the prefix (e.g. /64, /48)!
-# You can specify multiple allocations with a comma-separated list.
-# ("Routed IPv6 Prefixes")
-allocations = 2001:DB8:1::/64,2001:DB8:2::/64
-# This is the address to actually set on the interface. There should be only one here. Be sure to include the prefix!
-# ("Client IPv6 Address")
-address = 2001:DB8:3::1/64
-
-# You can specify multiple tunnel profiles for your machine.
-[54321]
-# And you can even reference values from other sections.
-user = ${12345:user}
-update_key = ${12345:update_key}
-server = 192.0.2.2
-allocations = 2001:DB8:4::/64
-address = 2001:DB8:5::2/64
diff --git a/utils/he_ipv6/config.py b/utils/he_ipv6/config.py
new file mode 100644
index 0000000..88feaa3
--- /dev/null
+++ b/utils/he_ipv6/config.py
@@ -0,0 +1,100 @@
+import os
+import re
+##
+import requests
+from lxml import etree
+
+
+class Config(object):
+    default_xsd = 'http://schema.xml.r00t2.io/projects/he_ipv6.xsd'
+
+    def __init__(self, xml_path, *args, **kwargs):
+        self.xml_path = os.path.abspath(os.path.expanduser(xml_path))
+        if not os.path.isfile(self.xml_path):
+            raise ValueError('xml_path does not exist')
+        self.tree = None
+        self.ns_tree = None
+        self.xml = None
+        self.ns_xml = None
+        self.raw = None
+        self.xsd = None
+        self.defaults_parser = None
+        self.obj = None
+        self.tunnels = {}
+        self.creds = {}
+        self.parse_raw()
+        self.get_xsd()
+        self.populate_defaults()
+        self.validate()
+
+    def get_xsd(self):
+        raw_xsd = None
+        base_url = None
+        xsi = self.xml.nsmap.get('xsi', 'http://www.w3.org/2001/XMLSchema-instance')
+        schemaLocation = '{{{0}}}schemaLocation'.format(xsi)
+        schemaURL = self.xml.attrib.get(schemaLocation, self.default_xsd)
+        split_url = schemaURL.split()
+        if len(split_url) == 2:  # a properly defined schemaLocation
+            schemaURL = split_url[1]
+        else:
+            schemaURL = split_url[0]  # a LAZY schemaLocation
+        if schemaURL.startswith('file://'):
+            schemaURL = re.sub(r'^file://', r'', schemaURL)
+            with open(schemaURL, 'rb') as fh:
+                raw_xsd = fh.read()
+            base_url = os.path.dirname(schemaURL) + '/'
+        else:
+            req = requests.get(schemaURL)
+            if not req.ok:
+                raise RuntimeError('Could not download XSD')
+            raw_xsd = req.content
+            base_url = os.path.split(req.url)[0] + '/'  # This makes me feel dirty.
+        self.xsd = etree.XMLSchema(etree.XML(raw_xsd, base_url = base_url))
+        return(None)
+
+    def parse_raw(self, parser = None):
+        if not self.raw:
+            with open(self.xml_path, 'rb') as fh:
+                self.raw = fh.read()
+        self.xml = etree.fromstring(self.raw, parser = parser)
+        self.ns_xml = etree.fromstring(self.raw, parser = parser)
+        self.tree = self.xml.getroottree()
+        self.ns_tree = self.ns_xml.getroottree()
+        self.tree.xinclude()
+        self.ns_tree.xinclude()
+        self.strip_ns()
+        return(None)
+
+    def populate_defaults(self):
+        if not self.xsd:
+            self.get_xsd()
+        if not self.defaults_parser:
+            self.defaults_parser = etree.XMLParser(schema = self.xsd, attribute_defaults = True)
+        self.parse_raw(parser = self.defaults_parser)
+        return(None)
+
+    def remove_defaults(self):
+        self.parse_raw()
+        return(None)
+
+    def strip_ns(self, obj = None):
+        # https://stackoverflow.com/questions/30232031/how-can-i-strip-namespaces-out-of-an-lxml-tree/30233635#30233635
+        xpathq = "descendant-or-self::*[namespace-uri()!='']"
+        if not obj:
+            for x in (self.tree, self.xml):
+                for e in x.xpath(xpathq):
+                    e.tag = etree.QName(e).localname
+        elif isinstance(obj, (etree._Element, etree._ElementTree)):
+            obj = copy.deepcopy(obj)
+            for e in obj.xpath(xpathq):
+                e.tag = etree.QName(e).localname
+            return(obj)
+        else:
+            raise ValueError('Did not know how to parse obj parameter')
+        return(None)
+
+    def validate(self):
+        if not self.xsd:
+            self.get_xsd()
+        self.xsd.assertValid(self.ns_tree)
+        return(None)
diff --git a/utils/he_ipv6/example.he_ipv6.xml b/utils/he_ipv6/example.he_ipv6.xml
index db1d5b9..7b2c685 100644
--- a/utils/he_ipv6/example.he_ipv6.xml
+++ b/utils/he_ipv6/example.he_ipv6.xml
@@ -2,7 +2,19 @@
 <heIPv6 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="https://tunnelbroker.net/"
         xsi:schemaLocation="https://tunnelbroker.net/ http://schema.xml.r00t2.io/projects/he_ipv6.xsd">
+  <!--
+  This is a sample XML configuration file to use with he_ipv6.py.
+  If you do not yet have an IPv6 Tunnelbroker.net allocation, you can get one (for free!) at:
+    https://www.tunnelbroker.net/tunnel_detail.php?tid=584532
+  I highly recommend their (free) certification as well if you're brand-new to IPv6:
+    https://ipv6.he.net/certification/
+  -->
   <creds>
+    <!--
+    Credentials are kept separate from tunnel configuration because you can have multiple (up to 5) tunnels per user.
+    The updateKey is *not* your password! You can find it in the "Advanced" tab of your tunnel's configuration on
+    your tunnelbroker.net panel.
+    -->
     <cred id="ipv6user">
       <user>ipv6user</user>
       <updateKey>xXxXxXxXxXxXxXXX</updateKey>
@@ -13,19 +25,59 @@
     </cred>
   </creds>
   <tunnels>
+    <!--
+    Each tunnel MUST have an "id" and a "creds" attribute. The "creds" attribute should reference an "id" of a
+    creds/cred object.
+    The tunnel ID can be found by logging into your tunnelbroker.net pannel, clicking on the tunnel you wish to use, and
+    looking at the URL in your browser.
+    It is in the format of https://www.tunnelbroker.net/tunnel_detail.php?tid=[TUNNEL ID]
+    So if it takes you to e.g. https://www.tunnelbroker.net/tunnel_detail.php?tid=12345, your tunnel ID would
+    be "12345".
+    The below directives give you a Section and Value Name. This refers to the tunnelbroker.net panel page for the
+    specific tunnel you're configuring. e.g. To use the above example, this information is found at
+      https://www.tunnelbroker.net/tunnel_detail.php?tid=12345
+    -->
     <tunnel id="12345" creds="ipv6user">
+      <!--
+      The "server" element is the remote SIT endpoint.
+      Section: IPv6 Tunnel Endpoints
+      Value Name: Server IPv4 Address
+      -->
       <server>192.0.2.1</server>
+      <!--
+      Allocations that are handed to your tunnel.
+      -->
+      <!--
+      Section: Routed IPv6 Prefixes
+      -->
       <allocs>
-        <alloc prefix="64">2001:DB8:1:2:</alloc>
-        <alloc prefix="48">2001:DB8:2::</alloc>
+        <!--
+        Each alloc has (in addition to a "prefix" attribute) an "iface" attribute. This is the network interface on
+        this machine that the allocation should be added to.
+        Value Name: Routed /64
+        -->
+        <alloc prefix="64" iface="eth0">2001:DB8:1:2::</alloc>
+        <!--
+        You may not have a /48 as it's opt-in.
+        Value Name: Routed /48
+        -->
+        <alloc prefix="48" iface="eth0">2001:DB8:2::</alloc>
       </allocs>
+      <!--
+      The "client" element is the local SIT endpoint.
+      Section: IPv6 Tunnel Endpoints
+      Value Name: Client IPv6 Address
+      -->
       <client prefix="64">2001:DB8:3::2</client>
     </tunnel>
+    <!--
+    And you can, of course, specify multiple tunnels.
+    -->
     <tunnel id="54321" creds="ipv6user">
       <server>192.0.2.1</server>
       <allocs>
-        <alloc prefix="64">2001:DB8:4:2:</alloc>
-        <alloc prefix="48">2001:DB8:5::</alloc>
+        <alloc prefix="64" iface="eth1">2001:DB8:4:2:</alloc>
+        <alloc prefix="48" iface="eth1">2001:DB8:5::</alloc>
       </allocs>
       <client prefix="64">2001:DB8:6::2</client>
     </tunnel>