mpls: T915: Basic MPLS implementation

1 files changed, 237 insertions, 0 deletions

diff --git a/src/conf_mode/protocols_mpls.py b/src/conf_mode/protocols_mpls.py
new file mode 100755
index 000000000..5f2497660
--- /dev/null
+++ b/src/conf_mode/protocols_mpls.py
@@ -0,0 +1,237 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2019 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 jinja2
+import copy
+import os
+import vyos.validate
+
+from vyos import ConfigError
+from vyos.config import Config
+
+config_file = r'/tmp/ldpd.frr'
+
+# Please be careful if you edit the template.
+config_tmpl = """
+!
+{% if mpls_ldp -%}
+mpls ldp
+{% if old_router_id -%}
+no router-id {{ old_router_id }}
+{% endif -%}
+{% if router_id -%}
+router-id {{ router_id }}
+{% endif -%}
+{% for neighbor_id in old_ldp.neighbors -%}
+no neighbor {{neighbor_id}} password {{old_ldp.neighbors[neighbor_id].password}}
+{% endfor -%}
+{% for neighbor_id in ldp.neighbors -%}
+neighbor {{neighbor_id}} password {{ldp.neighbors[neighbor_id].password}}
+{% endfor -%}
+address-family ipv4
+label local allocate host-routes
+{% if old_ldp.d_transp_ipv4 -%}
+no discovery transport-address {{ old_ldp.d_transp_ipv4 }}
+{% endif -%}
+{% if ldp.d_transp_ipv4 -%}
+discovery transport-address {{ ldp.d_transp_ipv4 }}
+{% endif -%}
+{% for interface in old_ldp.interfaces -%}
+no interface {{interface}}
+{% endfor -%}
+{% for interface in ldp.interfaces -%}
+interface {{interface}}
+{% endfor -%}
+!
+!
+exit-address-family
+!
+{% if ldp.d_transp_ipv6 -%}
+address-family ipv6
+label local allocate host-routes
+{% if old_ldp.d_transp_ipv6 -%}
+no discovery transport-address {{ old_ldp.d_transp_ipv6 }}
+{% endif -%}
+{% if ldp.d_transp_ipv6 -%}
+discovery transport-address {{ ldp.d_transp_ipv6 }}
+{% endif -%}
+{% for interface in old_ldp.interfaces -%}
+no interface {{interface}}
+{% endfor -%}
+{% for interface in ldp.interfaces -%}
+interface {{interface}}
+{% endfor -%}
+!
+exit-address-family
+{% else -%}
+no address-family ipv6
+{% endif -%}
+!
+{% else -%}
+no mpls ldp
+{% endif -%}
+!
+"""
+
+def sysctl(name, value):
+    os.system('sysctl -wq {}={}'.format(name, value))
+
+def get_config():
+    conf = Config()
+    mpls_conf = {
+        'router_id'  : None,
+        'mpls_ldp'   : False,
+        'old_ldp'    : {
+                'interfaces'          : [],
+                'neighbors'           : {},
+                'd_transp_ipv4'       : None,
+                'd_transp_ipv6'       : None
+        },
+        'ldp'        : {
+                'interfaces'          : [],
+                'neighbors'           : {},
+                'd_transp_ipv4'       : None,
+                'd_transp_ipv6'       : None
+        }
+    }
+    if not (conf.exists('protocols mpls') or conf.exists_effective('protocols mpls')):
+        return None
+
+    if conf.exists('protocols mpls ldp'):
+        mpls_conf['mpls_ldp'] = True
+
+    conf.set_level('protocols mpls ldp')
+
+    # Get router-id
+    if conf.exists_effective('router-id'):
+        mpls_conf['old_router_id'] = conf.return_effective_value('router-id')
+    if conf.exists('router-id'):
+        mpls_conf['router_id'] = conf.return_value('router-id')
+
+    # Get discovery transport-ipv4-address
+    if conf.exists_effective('discovery transport-ipv4-address'):
+        mpls_conf['old_ldp']['d_transp_ipv4'] = conf.return_effective_value('discovery transport-ipv4-address')
+
+    if conf.exists('discovery transport-ipv4-address'):
+        mpls_conf['ldp']['d_transp_ipv4'] = conf.return_value('discovery transport-ipv4-address')
+
+    # Get discovery transport-ipv6-address
+    if conf.exists_effective('discovery transport-ipv6-address'):
+        mpls_conf['old_ldp']['d_transp_ipv6'] = conf.return_effective_value('discovery transport-ipv6-address')
+
+    if conf.exists('discovery transport-ipv6-address'):
+        mpls_conf['ldp']['d_transp_ipv6'] = conf.return_value('discovery transport-ipv6-address')
+
+    # Get interfaces
+    if conf.exists_effective('interface'):
+        mpls_conf['old_ldp']['interfaces'] = conf.return_effective_values('interface')
+
+    if conf.exists('interface'):
+        mpls_conf['ldp']['interfaces'] = conf.return_values('interface')
+
+    # Get neighbors
+    for neighbor in conf.list_effective_nodes('neighbor'):
+        mpls_conf['old_ldp']['neighbors'].update({
+            neighbor : {
+                'password' : conf.return_effective_value('neighbor {0} password'.format(neighbor))
+            }
+        })
+
+    for neighbor in conf.list_nodes('neighbor'):
+        mpls_conf['ldp']['neighbors'].update({
+            neighbor : {
+                'password' : conf.return_value('neighbor {0} password'.format(neighbor))
+            }
+        })
+
+    # print(mpls_conf)
+    # sys.exit(1)
+    return mpls_conf
+
+def operate_mpls_on_intfc(interfaces, action):
+    rp_filter = 0 
+    if action == 1:
+        rp_filter = 2
+    for iface in interfaces:
+        sysctl('net.mpls.conf.{0}.input'.format(iface), action)
+        # Operate rp filter
+        sysctl('net.ipv4.conf.{0}.rp_filter'.format(iface), rp_filter)
+
+def verify(mpls):
+    if mpls is None:
+        return None
+
+    if mpls['mpls_ldp']:
+        # Requre router-id
+        if not mpls['router_id']:
+            raise ConfigError(f"MPLS ldp router-id is mandatory!")
+
+        # Requre discovery transport-address
+        if not mpls['ldp']['d_transp_ipv4'] and not mpls['ldp']['d_transp_ipv6']:
+            raise ConfigError(f"MPLS ldp discovery transport address is mandatory!")
+
+        # Requre interface
+        if not mpls['ldp']['interfaces']:
+            raise ConfigError(f"MPLS ldp interface is mandatory!")
+
+def generate(mpls):
+    if mpls is None:
+        return None
+
+    tmpl = jinja2.Template(config_tmpl)
+    config_text = tmpl.render(mpls)
+    with open(config_file, 'w') as f:
+        f.write(config_text)
+
+    return None
+
+def apply(mpls):
+    if mpls is None:
+        return None
+
+     # Set number of entries in the platform label table
+    if mpls['mpls_ldp']:
+        sysctl('net.mpls.platform_labels', '1048575')
+    else:
+        sysctl('net.mpls.platform_labels', '0')
+
+    # Do not copy IP TTL to MPLS header
+    sysctl('net.mpls.ip_ttl_propagate', '0')
+
+    # Allow mpls on interfaces
+    operate_mpls_on_intfc(mpls['ldp']['interfaces'], 1)
+
+    # Disable mpls on deleted interfaces
+    diactive_ifaces = set(mpls['old_ldp']['interfaces']).difference(mpls['ldp']['interfaces'])
+    operate_mpls_on_intfc(diactive_ifaces, 0)
+
+    if os.path.exists(config_file):
+        os.system("sudo vtysh -d ldpd -f " + config_file)
+        os.remove(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)