T644: remove prefixing from all scripts and update environment variables with VyOS paths.

1 files changed, 213 insertions, 0 deletions

diff --git a/src/conf_mode/dns_forwarding.py b/src/conf_mode/dns_forwarding.py
new file mode 100755
index 000000000..be48cde60
--- /dev/null
+++ b/src/conf_mode/dns_forwarding.py
@@ -0,0 +1,213 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+#
+
+import sys
+import os
+
+import netifaces
+import jinja2
+
+from vyos.config import Config
+from vyos import ConfigError
+
+config_file = r'/etc/powerdns/recursor.conf'
+
+# XXX: pdns recursor doesn't like whitespace near entry separators,
+# especially in the semicolon-separated lists of name servers.
+# Please be careful if you edit the template.
+config_tmpl = """
+### Autogenerated by vyos-config-dns-forwarding.py ###
+
+# Non-configurable defaults
+daemon=yes
+threads=1
+allow-from=0.0.0.0/0
+log-common-errors=yes
+
+# cache-size
+max-cache-entries={{ cache_size }}
+
+# ignore-hosts-file
+export-etc-hosts={{ export_hosts_file }}
+
+# listen-on
+local-address={{ listen_on | join(',') }}
+
+# domain ... server ...
+{% if domains -%}
+
+forward-zones={% for d in domains %}
+{{ d.name }}={{ d.servers | join(";") }}
+{%- if loop.first %}, {% endif %}
+{% endfor %}
+
+{% endif %}
+
+# name-server
+forward-zones-recurse=.={{ name_servers | join(';') }}
+
+"""
+
+default_config_data = {
+    'cache_size' : 10000,
+    'export_hosts_file': 'yes',
+    'listen_on': [],
+    'interfaces': [],
+    'name_servers': [],
+    'domains': []
+}
+
+
+# borrowed from: https://github.com/donjajo/py-world/blob/master/resolvconfReader.py, THX!
+def get_resolvers(file):
+    resolvers = []
+    try:
+        with open(file, 'r') as resolvconf:
+            for line in resolvconf.readlines():
+                line = line.split('#',1)[0];
+                line = line.rstrip();
+                if 'nameserver' in line:
+                    resolvers.append(line.split()[1])
+        return resolvers
+    except IOError:
+        return []
+
+def get_config():
+    dns = default_config_data
+    conf = Config()
+    if not conf.exists('service dns forwarding'):
+        return None
+    else:
+        conf.set_level('service dns forwarding')
+
+    if conf.exists('cache-size'):
+        cache_size = conf.return_value('cache-size')
+        dns['cache_size'] = cache_size
+
+    if conf.exists('domain'):
+        for node in conf.list_nodes('domain'):
+            server = conf.return_values("domain {0} server".format(node))
+            domain = {
+                "name": node,
+                "servers": server
+            }
+            dns['domains'].append(domain)
+
+    if conf.exists('ignore-hosts-file'):
+        dns.setdefault('export_hosts_file', "no")
+
+    if conf.exists('name-server'):
+        name_servers = conf.return_values('name-server')
+        dns['name_servers'] = dns['name_servers'] + name_servers
+
+    if conf.exists('system'):
+        conf.set_level('system')
+        system_name_servers = []
+        system_name_servers = conf.return_values('name-server')
+        if not system_name_servers:
+            print("DNS forwarding warning: No name-servers set under 'system name-server'\n")
+        else:
+            dns['name_servers'] = dns['name_servers'] + system_name_servers
+        conf.set_level('service dns forwarding')
+
+    ## Hacks and tricks
+
+    # The old VyOS syntax that comes from dnsmasq was "listen-on $interface".
+    # pdns wants addresses instead, so we emulate it by looking up all addresses
+    # of a given interface and writing them to the config
+    if conf.exists('listen-on'):
+        interfaces = conf.return_values('listen-on')
+
+        listen4 = []
+        listen6 = []
+        for interface in interfaces:
+            addrs = netifaces.ifaddresses(interface)
+            for ip4 in addrs[netifaces.AF_INET]:
+                listen4.append(ip4['addr'])
+
+            for ip6 in addrs[netifaces.AF_INET6]:
+                listen6.append(ip6['addr'])
+
+        dns['listen_on'] = listen4 + listen6
+
+        # Save interfaces in the dict for the reference
+        dns['interfaces'] = interfaces
+
+    # Add name servers received from DHCP
+    if conf.exists('dhcp'):
+        interfaces = []
+        interfaces = conf.return_values('dhcp')
+        for interface in interfaces:
+            dhcp_resolvers = get_resolvers("/etc/resolv.conf.dhclient-new-{0}".format(interface))
+            if dhcp_resolvers:
+                dns['name_servers'] = dns['name_servers'] + dhcp_resolvers
+
+    return dns
+
+def verify(dns):
+    # bail out early - looks like removal from running config
+    if dns is None:
+        return None
+
+    if not dns['interfaces']:
+        raise ConfigError('Error: DNS forwarding requires a configured listen interface!')
+
+    for interface in dns['interfaces']:
+        try:
+            netifaces.ifaddresses(interface)[netifaces.AF_INET]
+        except KeyError as e:
+            raise ConfigError('Error: Interface {0} has no IP address assigned'.format(interface))
+
+    if dns['domains']:
+        for domain in dns['domains']:
+            if not domain['servers']:
+                raise ConfigError('Error: No server configured for domain {0}'.format(domain['name']))
+
+    return None
+
+def generate(dns):
+    # bail out early - looks like removal from running config
+    if dns is None:
+        return None
+
+    tmpl = jinja2.Template(config_tmpl, trim_blocks=True)
+
+    config_text = tmpl.render(dns)
+    with open(config_file, 'w') as f:
+        f.write(config_text)
+    return None
+
+def apply(dns):
+    if dns is not None:
+        os.system("systemctl restart pdns-recursor")
+    else:
+        # DNS forwarding is removed in the commit
+        os.system("systemctl stop pdns-recursor")
+        os.unlink(config_file)
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        sys.exit(1)