T5474: establish common file name pattern for XML conf mode commands

We will use _ as CLI level divider. The XML definition filename and also
the Python helper should match the CLI node.

Example:
set interfaces ethernet -> interfaces_ethernet.xml.in
set interfaces bond -> interfaces_bond.xml.in
set service dhcp-server -> service_dhcp-server-xml.in

1 files changed, 358 insertions, 0 deletions

diff --git a/src/conf_mode/service_dns_forwarding.py b/src/conf_mode/service_dns_forwarding.py
new file mode 100755
index 000000000..c186f47af
--- /dev/null
+++ b/src/conf_mode/service_dns_forwarding.py
@@ -0,0 +1,358 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018-2022 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 os
+
+from netifaces import interfaces
+from sys import exit
+from glob import glob
+
+from vyos.config import Config
+from vyos.hostsd_client import Client as hostsd_client
+from vyos.template import render
+from vyos.template import bracketize_ipv6
+from vyos.utils.process import call
+from vyos.utils.permission import chown
+from vyos.utils.dict import dict_search
+
+from vyos import ConfigError
+from vyos import airbag
+airbag.enable()
+
+pdns_rec_user = pdns_rec_group = 'pdns'
+pdns_rec_run_dir = '/run/powerdns'
+pdns_rec_lua_conf_file = f'{pdns_rec_run_dir}/recursor.conf.lua'
+pdns_rec_hostsd_lua_conf_file = f'{pdns_rec_run_dir}/recursor.vyos-hostsd.conf.lua'
+pdns_rec_hostsd_zones_file = f'{pdns_rec_run_dir}/recursor.forward-zones.conf'
+pdns_rec_config_file = f'{pdns_rec_run_dir}/recursor.conf'
+
+hostsd_tag = 'static'
+
+def get_config(config=None):
+    if config:
+        conf = config
+    else:
+        conf = Config()
+    base = ['service', 'dns', 'forwarding']
+    if not conf.exists(base):
+        return None
+
+    dns = conf.get_config_dict(base, key_mangling=('-', '_'),
+                               no_tag_node_value_mangle=True,
+                               get_first_key=True,
+                               with_recursive_defaults=True)
+
+    # some additions to the default dictionary
+    if 'system' in dns:
+        base_nameservers = ['system', 'name-server']
+        if conf.exists(base_nameservers):
+            dns.update({'system_name_server': conf.return_values(base_nameservers)})
+
+    if 'authoritative_domain' in dns:
+        dns['authoritative_zones'] = []
+        dns['authoritative_zone_errors'] = []
+        for node in dns['authoritative_domain']:
+            zonedata = dns['authoritative_domain'][node]
+            if ('disable' in zonedata) or (not 'records' in zonedata):
+                continue
+            zone = {
+                'name': node,
+                'file': "{}/zone.{}.conf".format(pdns_rec_run_dir, node),
+                'records': [],
+            }
+
+            recorddata = zonedata['records']
+
+            for rtype in [ 'a', 'aaaa', 'cname', 'mx', 'ns', 'ptr', 'txt', 'spf', 'srv', 'naptr' ]:
+                if rtype not in recorddata:
+                    continue
+                for subnode in recorddata[rtype]:
+                    if 'disable' in recorddata[rtype][subnode]:
+                        continue
+
+                    rdata = recorddata[rtype][subnode]
+
+                    if rtype in [ 'a', 'aaaa' ]:
+                        if not 'address' in rdata:
+                            dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one address is required')
+                            continue
+
+                        if subnode == 'any':
+                            subnode = '*'
+
+                        for address in rdata['address']:
+                            zone['records'].append({
+                                'name': subnode,
+                                'type': rtype.upper(),
+                                'ttl': rdata['ttl'],
+                                'value': address
+                            })
+                    elif rtype in ['cname', 'ptr', 'ns']:
+                        if not 'target' in rdata:
+                            dns['authoritative_zone_errors'].append(f'{subnode}.{node}: target is required')
+                            continue
+
+                        zone['records'].append({
+                            'name': subnode,
+                            'type': rtype.upper(),
+                            'ttl': rdata['ttl'],
+                            'value': '{}.'.format(rdata['target'])
+                        })
+                    elif rtype == 'mx':
+                        if not 'server' in rdata:
+                            dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one server is required')
+                            continue
+
+                        for servername in rdata['server']:
+                            serverdata = rdata['server'][servername]
+                            zone['records'].append({
+                                'name': subnode,
+                                'type': rtype.upper(),
+                                'ttl': rdata['ttl'],
+                                'value': '{} {}.'.format(serverdata['priority'], servername)
+                            })
+                    elif rtype == 'txt':
+                        if not 'value' in rdata:
+                            dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one value is required')
+                            continue
+
+                        for value in rdata['value']:
+                            zone['records'].append({
+                                'name': subnode,
+                                'type': rtype.upper(),
+                                'ttl': rdata['ttl'],
+                                'value': "\"{}\"".format(value.replace("\"", "\\\""))
+                            })
+                    elif rtype == 'spf':
+                        if not 'value' in rdata:
+                            dns['authoritative_zone_errors'].append(f'{subnode}.{node}: value is required')
+                            continue
+
+                        zone['records'].append({
+                            'name': subnode,
+                            'type': rtype.upper(),
+                            'ttl': rdata['ttl'],
+                            'value': '"{}"'.format(rdata['value'].replace("\"", "\\\""))
+                        })
+                    elif rtype == 'srv':
+                        if not 'entry' in rdata:
+                            dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one entry is required')
+                            continue
+
+                        for entryno in rdata['entry']:
+                            entrydata = rdata['entry'][entryno]
+                            if not 'hostname' in entrydata:
+                                dns['authoritative_zone_errors'].append(f'{subnode}.{node}: hostname is required for entry {entryno}')
+                                continue
+
+                            if not 'port' in entrydata:
+                                dns['authoritative_zone_errors'].append(f'{subnode}.{node}: port is required for entry {entryno}')
+                                continue
+
+                            zone['records'].append({
+                                'name': subnode,
+                                'type': rtype.upper(),
+                                'ttl': rdata['ttl'],
+                                'value': '{} {} {} {}.'.format(entrydata['priority'], entrydata['weight'], entrydata['port'], entrydata['hostname'])
+                            })
+                    elif rtype == 'naptr':
+                        if not 'rule' in rdata:
+                            dns['authoritative_zone_errors'].append(f'{subnode}.{node}: at least one rule is required')
+                            continue
+
+                        for ruleno in rdata['rule']:
+                            ruledata = rdata['rule'][ruleno]
+                            flags = ""
+                            if 'lookup-srv' in ruledata:
+                                flags += "S"
+                            if 'lookup-a' in ruledata:
+                                flags += "A"
+                            if 'resolve-uri' in ruledata:
+                                flags += "U"
+                            if 'protocol-specific' in ruledata:
+                                flags += "P"
+
+                            if 'order' in ruledata:
+                                order = ruledata['order']
+                            else:
+                                order = ruleno
+
+                            if 'regexp' in ruledata:
+                                regexp= ruledata['regexp'].replace("\"", "\\\"")
+                            else:
+                                regexp = ''
+
+                            if ruledata['replacement']:
+                                replacement = '{}.'.format(ruledata['replacement'])
+                            else:
+                                replacement = ''
+
+                            zone['records'].append({
+                                'name': subnode,
+                                'type': rtype.upper(),
+                                'ttl': rdata['ttl'],
+                                'value': '{} {} "{}" "{}" "{}" {}'.format(order, ruledata['preference'], flags, ruledata['service'], regexp, replacement)
+                            })
+
+            dns['authoritative_zones'].append(zone)
+
+    return dns
+
+def verify(dns):
+    # bail out early - looks like removal from running config
+    if not dns:
+        return None
+
+    if 'listen_address' not in dns:
+        raise ConfigError('DNS forwarding requires a listen-address')
+
+    if 'allow_from' not in dns:
+        raise ConfigError('DNS forwarding requires an allow-from network')
+
+    # we can not use dict_search() when testing for domain servers
+    # as a domain will contains dot's which is out dictionary delimiter.
+    if 'domain' in dns:
+        for domain in dns['domain']:
+            if 'name_server' not in dns['domain'][domain]:
+                raise ConfigError(f'No server configured for domain {domain}!')
+
+    if 'dns64_prefix' in dns:
+        dns_prefix = dns['dns64_prefix'].split('/')[1]
+        # RFC 6147 requires prefix /96
+        if int(dns_prefix) != 96:
+            raise ConfigError('DNS 6to4 prefix must be of length /96')
+
+    if ('authoritative_zone_errors' in dns) and dns['authoritative_zone_errors']:
+        for error in dns['authoritative_zone_errors']:
+            print(error)
+        raise ConfigError('Invalid authoritative records have been defined')
+
+    if 'system' in dns:
+        if not 'system_name_server' in dns:
+            print('Warning: No "system name-server" configured')
+
+    return None
+
+def generate(dns):
+    # bail out early - looks like removal from running config
+    if not dns:
+        return None
+
+    render(pdns_rec_config_file, 'dns-forwarding/recursor.conf.j2',
+            dns, user=pdns_rec_user, group=pdns_rec_group)
+
+    render(pdns_rec_lua_conf_file, 'dns-forwarding/recursor.conf.lua.j2',
+            dns, user=pdns_rec_user, group=pdns_rec_group)
+
+    for zone_filename in glob(f'{pdns_rec_run_dir}/zone.*.conf'):
+        os.unlink(zone_filename)
+
+    if 'authoritative_zones' in dns:
+        for zone in dns['authoritative_zones']:
+            render(zone['file'], 'dns-forwarding/recursor.zone.conf.j2',
+                    zone, user=pdns_rec_user, group=pdns_rec_group)
+
+
+    # if vyos-hostsd didn't create its files yet, create them (empty)
+    for file in [pdns_rec_hostsd_lua_conf_file, pdns_rec_hostsd_zones_file]:
+        with open(file, 'a'):
+            pass
+        chown(file, user=pdns_rec_user, group=pdns_rec_group)
+
+    return None
+
+def apply(dns):
+    if not dns:
+        # DNS forwarding is removed in the commit
+        call('systemctl stop pdns-recursor.service')
+
+        if os.path.isfile(pdns_rec_config_file):
+            os.unlink(pdns_rec_config_file)
+
+        for zone_filename in glob(f'{pdns_rec_run_dir}/zone.*.conf'):
+            os.unlink(zone_filename)
+    else:
+        ### first apply vyos-hostsd config
+        hc = hostsd_client()
+
+        # add static nameservers to hostsd so they can be joined with other
+        # sources
+        hc.delete_name_servers([hostsd_tag])
+        if 'name_server' in dns:
+            # 'name_server' is of the form
+            # {'192.0.2.1': {'port': 53}, '2001:db8::1': {'port': 853}, ...}
+            # canonicalize them as ['192.0.2.1:53', '[2001:db8::1]:853', ...]
+            nslist = [(lambda h, p: f"{bracketize_ipv6(h)}:{p['port']}")(h, p)
+                      for (h, p) in dns['name_server'].items()]
+            hc.add_name_servers({hostsd_tag: nslist})
+
+        # delete all nameserver tags
+        hc.delete_name_server_tags_recursor(hc.get_name_server_tags_recursor())
+
+        ## add nameserver tags - the order determines the nameserver order!
+        # our own tag (static)
+        hc.add_name_server_tags_recursor([hostsd_tag])
+
+        if 'system' in dns:
+            hc.add_name_server_tags_recursor(['system'])
+        else:
+            hc.delete_name_server_tags_recursor(['system'])
+
+        # add dhcp nameserver tags for configured interfaces
+        if 'system_name_server' in dns:
+            for interface in dns['system_name_server']:
+                # system_name_server key contains both IP addresses and interface
+                # names (DHCP) to use DNS servers. We need to check if the
+                # value is an interface name - only if this is the case, add the
+                # interface based DNS forwarder.
+                if interface in interfaces():
+                    hc.add_name_server_tags_recursor(['dhcp-' + interface,
+                                                      'dhcpv6-' + interface ])
+
+        # hostsd will generate the forward-zones file
+        # the list and keys() are required as get returns a dict, not list
+        hc.delete_forward_zones(list(hc.get_forward_zones().keys()))
+        if 'domain' in dns:
+            zones = dns['domain']
+            for domain in zones.keys():
+                # 'name_server' is of the form
+                # {'192.0.2.1': {'port': 53}, '2001:db8::1': {'port': 853}, ...}
+                # canonicalize them as ['192.0.2.1:53', '[2001:db8::1]:853', ...]
+                zones[domain]['name_server'] = [(lambda h, p: f"{bracketize_ipv6(h)}:{p['port']}")(h, p)
+                                                for (h, p) in zones[domain]['name_server'].items()]
+            hc.add_forward_zones(zones)
+
+        # hostsd generates NTAs for the authoritative zones
+        # the list and keys() are required as get returns a dict, not list
+        hc.delete_authoritative_zones(list(hc.get_authoritative_zones()))
+        if 'authoritative_zones' in dns:
+            hc.add_authoritative_zones(list(map(lambda zone: zone['name'], dns['authoritative_zones'])))
+
+        # call hostsd to generate forward-zones and its lua-config-file
+        hc.apply()
+
+        ### finally (re)start pdns-recursor
+        call('systemctl restart pdns-recursor.service')
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)