tunnel: T2028: move interface tunnel to XML/Python

This patch migrates the "interface tunnel" section to xml/python

1 files changed, 316 insertions, 0 deletions

diff --git a/python/vyos/ifconfig/tunnel.py b/python/vyos/ifconfig/tunnel.py
new file mode 100644
index 000000000..c82727eee
--- /dev/null
+++ b/python/vyos/ifconfig/tunnel.py
@@ -0,0 +1,316 @@
+# Copyright 2019 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+# https://developers.redhat.com/blog/2019/05/17/an-introduction-to-linux-virtual-interfaces-tunnels/
+# https://community.hetzner.com/tutorials/linux-setup-gre-tunnel
+
+
+from copy import deepcopy
+
+from vyos.ifconfig.interface import Interface
+from vyos.ifconfig.afi import IP4, IP6
+from vyos.validate import assert_list
+
+def enable_to_on(value):
+    if value == 'enable':
+        return 'on'
+    if value == 'disable':
+        return 'off'
+    raise ValueError(f'expect enable or disable but got "{value}"')
+
+
+
+class _Tunnel(Interface):
+    """
+    _Tunnel: private base class for tunnels
+    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/tunnel.c
+    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/ip6tunnel.c
+    """
+
+    # TODO: This is surely used for more than tunnels
+    # TODO: could be refactored elsewhere
+    _command_set = {**Interface._command_set, **{
+        'multicast': {
+            'validate': lambda v: assert_list(v, ['enable', 'disable']),
+            'convert': enable_to_on,
+            'shellcmd': 'ip link set dev {ifname} multicast {value}',
+        },
+        'allmulticast': {
+            'validate': lambda v: assert_list(v, ['enable', 'disable']),
+            'convert': enable_to_on,
+            'shellcmd': 'ip link set dev {ifname} allmulticast {value}',
+        },
+    }}
+
+    # use for "options" and "updates"
+    # If an key is only in the options list, it can only be set at creation time
+    # the create comand will only be make using the key in options
+
+    # If an option is in the updates list, it can be updated
+    # upon, the creation, all key not yet applied will be updated
+
+    # multicast/allmulticast can not be part of the create command
+
+    # options matrix:
+    # with ip = 4,     we have multicast
+    # wiht ip = 6,     nothing
+    # with tunnel = 4, we have tos, ttl, key
+    # with tunnel = 6, we have encaplimit, hoplimit, tclass, flowlabel
+
+    # TODO: For multicast, it is allowed on IP6IP6 and Sit6RD
+    # TODO: to match vyatta but it should be checked for correctness
+
+    updates = []
+
+    create = ''
+    change = ''
+    delete = ''
+
+    ip = []     # AFI of the families which can be used in the tunnel
+    tunnel = 0  # invalid - need to be set by subclasses
+
+    def __init__(self, ifname, **config):
+        self.config = deepcopy(config) if config else {}
+        super().__init__(ifname, **config)
+
+    def _create(self):
+        # add " option-name option-name-value ..." for all options set
+        options = " ".join(["{} {}".format(k, self.config[k])
+                            for k in self.options if k in self.config and self.config[k]])
+        self._cmd('{} {}'.format(self.create.format(**self.config), options))
+        self.set_interface('state', 'down')
+
+    def _delete(self):
+        self.set_interface('state', 'down')
+        cmd = self.delete.format(**self.config)
+        return self._cmd(cmd)
+
+    def set_interface(self, option, value):
+        try:
+            return Interface.set_interface(self, option, value)
+        except Exception:
+            pass
+
+        if value == '':
+            # remove the value so that it is not used
+            self.config.pop(option, '')
+
+        if self.change:
+            self._cmd('{} {} {}'.format(
+                self.change.format(**self.config), option, value))
+        return True
+
+    @classmethod
+    def get_config(cls):
+        return dict(zip(cls.options, ['']*len(cls.options)))
+
+
+class GREIf(_Tunnel):
+    """
+    GRE: Generic Routing Encapsulation
+
+    For more information please refer to:
+    RFC1701, RFC1702, RFC2784
+    https://tools.ietf.org/html/rfc2784
+    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/link_gre.c
+    """
+
+    ip = [IP4, IP6]
+    tunnel = IP4
+
+    default = {'type': 'gre'}
+    required = ['local', ]  # mGRE is a GRE without remote endpoint
+
+    options = ['local', 'remote', 'ttl', 'tos', 'key']
+    updates = ['local', 'remote', 'ttl', 'tos',
+               'multicast', 'allmulticast']
+
+    create = 'ip tunnel add {ifname} mode {type}'
+    change = 'ip tunnel cha {ifname}'
+    delete = 'ip tunnel del {ifname}'
+
+
+# GreTap also called GRE Bridge
+class GRETapIf(_Tunnel):
+    """
+    GRETapIF: GreIF using TAP instead of TUN
+
+    https://en.wikipedia.org/wiki/TUN/TAP
+    """
+
+    # no multicast, ttl or tos for gretap
+
+    ip = [IP4, ]
+    tunnel = IP4
+
+    default = {'type': 'gretap'}
+    required = ['local', ]
+
+    options = ['local', 'remote', ]
+    updates = []
+
+    create = 'ip link add {ifname} type {type}'
+    change = ''
+    delete = 'ip link del {ifname}'
+
+
+class IP6GREIf(_Tunnel):
+    """
+    IP6Gre: IPv6 Support for Generic Routing Encapsulation (GRE)
+
+    For more information please refer to:
+    https://tools.ietf.org/html/rfc7676
+    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/link_gre6.c
+    """
+
+    ip = [IP4, IP6]
+    tunnel = IP6
+
+    default = {'type': 'ip6gre'}
+    required = ['local', 'remote']
+
+    options = ['local', 'remote', 'encaplimit',
+               'hoplimit', 'tclass', 'flowlabel']
+    updates = ['local', 'remote', 'encaplimit',
+               'hoplimit', 'tclass', 'flowlabel',
+               'multicast', 'allmulticast']
+
+    create = 'ip tunnel add {ifname} mode {type}'
+    change = 'ip tunnel cha {ifname} mode {type}'
+    delete = 'ip tunnel del {ifname}'
+
+    # using "ip tunnel change" without using "mode" causes errors
+    # sudo ip tunnel add tun100 mode ip6gre local ::1 remote 1::1
+    # sudo ip tunnel cha tun100 hoplimit 100
+    # *** stack smashing detected ** *: < unknown > terminated
+    # sudo ip tunnel cha tun100 local: : 2
+    # Error: an IP address is expected rather than "::2"
+    # works if mode is explicit
+
+
+class IPIPIf(_Tunnel):
+    """
+    IPIP: IP Encapsulation within IP
+
+    For more information please refer to:
+    https://tools.ietf.org/html/rfc2003
+    """
+
+    # IPIP does not allow to pass multicast, unlike GRE
+    # but the interface itself can be set with multicast
+
+    ip = [IP4,]
+    tunnel = IP4
+
+    default = {'type': 'ipip'}
+    required = ['local', 'remote']
+
+    options = ['local', 'remote', 'ttl', 'tos', 'key']
+    updates = ['local', 'remote', 'ttl', 'tos',
+               'multicast', 'allmulticast']
+
+    create = 'ip tunnel add {ifname} mode {type}'
+    change = 'ip tunnel cha {ifname}'
+    delete = 'ip tunnel del {ifname}'
+
+
+class IPIP6If(_Tunnel):
+    """
+    IPIP6: IPv4 over IPv6 tunnel
+
+    For more information please refer to:
+    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/link_ip6tnl.c
+    """
+
+    ip = [IP4,]
+    tunnel = IP6
+
+    default = {'type': 'ipip6'}
+    required = ['local', 'remote']
+
+    options = ['local', 'remote', 'encaplimit',
+               'hoplimit', 'tclass', 'flowlabel']
+    updates = ['local', 'remote', 'encaplimit',
+               'hoplimit', 'tclass', 'flowlabel',
+               'multicast', 'allmulticast']
+
+    create = 'ip -6 tunnel add {ifname} mode {type}'
+    change = 'ip -6 tunnel cha {ifname}'
+    delete = 'ip -6 tunnel del {ifname}'
+
+
+class IP6IP6If(IPIP6If):
+    """
+    IP6IP6: IPv6 over IPv6 tunnel
+
+    For more information please refer to:
+    https://tools.ietf.org/html/rfc2473
+    """
+
+    ip = [IP6,]
+
+    default = {'type': 'ip6ip6'}
+
+
+class SitIf(_Tunnel):
+    """
+    Sit: Simple Internet Transition
+
+    For more information please refer to:
+    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/link_iptnl.c
+    """
+
+    ip = [IP6, IP4]
+    tunnel = IP4
+
+    default = {'type': 'sit'}
+    required = ['local', 'remote']
+
+    options = ['local', 'remote', 'ttl', 'tos', 'key']
+    updates = ['local', 'remote', 'ttl', 'tos',
+               'multicast', 'allmulticast']
+
+    create = 'ip tunnel add {ifname} mode {type}'
+    change = 'ip tunnel cha {ifname}'
+    delete = 'ip tunnel del {ifname}'
+
+
+class Sit6RDIf(SitIf):
+    """
+    Sit6RDIf: Simple Internet Transition with 6RD
+
+    https://en.wikipedia.org/wiki/IPv6_rapid_deployment
+    """
+
+    ip = [IP6,]
+
+    required = ['remote', '6rd-prefix']
+
+    # TODO: check if key can really be used with 6RD
+    options = ['remote', 'ttl', 'tos', 'key', '6rd-prefix', '6rd-relay-prefix']
+    updates = ['remote', 'ttl', 'tos',
+               'multicast', 'allmulticast']
+
+    def _create(self):
+        # do not call _Tunnel.create, building fully here
+
+        create = 'ip tunnel add {ifname} mode {type} remote {remote}'
+        self._cmd(create.format(**self.config))
+        self.set_interface('state','down')
+
+        set6rd = 'ip tunnel 6rd dev {ifname} 6rd-prefix {6rd-prefix}'
+        if '6rd-relay-prefix' in self.config:
+            set6rd += ' 6rd-relay-prefix {6rd-relay-prefix}'
+        self._cmd(set6rd.format(**self.config))