ipsec: T2816: IPSec python rework, includes DMVPN and VTI support

1 files changed, 82 insertions, 0 deletions

diff --git a/src/etc/ipsec.d/vti-up-down b/src/etc/ipsec.d/vti-up-down
new file mode 100644
index 000000000..416966056
--- /dev/null
+++ b/src/etc/ipsec.d/vti-up-down
@@ -0,0 +1,82 @@
+#!/usr/bin/env python3
+## Script called up strongswan to bring the vti interface up/down based on the state of the IPSec tunnel.
+## Called as vti_up_down vti_intf_name
+
+import os
+import sys
+
+from vyos.config import Config
+from vyos.util import call, get_interface_config, get_interface_address
+
+def get_config(config, base):
+    if not config.exists(base):
+        return None
+
+    return conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True, no_tag_node_value_mangle=True)
+
+def get_dhcp_address(interface):
+    addr = get_interface_address(interface)
+    if not addr:
+        return None
+    if len(addr['addr_info']) == 0:
+        return None
+    return addr['addr_info'][0]['local']
+
+if __name__ == '__main__':
+    verb = os.getenv('PLUTO_VERB')
+    connection = os.getenv('PLUTO_CONNECTION')
+    parent_conn = connection[:-3]
+    interface = sys.argv[1]
+
+    print(f'vti-up-down: start: {verb} {connection} {interface}')
+
+    if verb in ['up-client', 'up-host']:
+        call('sudo /usr/sbin/ip route delete default table 220')
+
+    vti_base = ['interfaces', 'vti', interface]
+    ipsec_base = ['vpn', 'ipsec', 'site-to-site']
+
+    conf = Config()
+    vti_conf = get_config(conf, vti_base)
+    ipsec_conf = get_config(conf, ipsec_base)
+
+    if not vti_conf or 'disable' in vti_conf or not ipsec_conf or 'peer' not in ipsec_conf:
+        print('vti-up-down: exit: vti not found, disabled or no peers found')
+        sys.exit(0)
+
+    peer_conf = None
+
+    for peer, peer_tmp_conf in ipsec_conf['peer'].items():
+        if 'vti' in peer_tmp_conf and 'bind' in peer_tmp_conf['vti']:
+            bind = peer_tmp_conf['vti']['bind']
+            if isinstance(bind, str):
+                bind = [bind]
+            if interface in bind:
+                peer_conf = peer_tmp_conf
+                break
+
+    if not peer_conf:
+        print(f'vti-up-down: exit: No peer found for {interface}')
+        sys.exit(0)
+
+    vti_link = get_interface_config(interface)
+    vti_link_up = vti_link['operstate'] == 'UP' if vti_link else False
+
+    child_sa_installed = False
+    try:
+        child_sa_installed = (call(f'sudo /usr/sbin/swanctl -l -r -i {connection} {parent_conn} | grep -s -q state=INSTALLED', timeout = 5) == 0)
+    except:
+        print('vti-up-down: child-sa check failed')
+
+    if verb in ['up-client', 'up-host']:
+        if not vti_link_up:
+            if 'dhcp_interface' in peer_conf:
+                local_ip = get_dhcp_address(peer_conf['dhcp_interface'])
+                call(f'sudo /usr/sbin/ip tunnel change {interface} local {local_ip}')
+            if child_sa_installed:
+                call(f'sudo /usr/sbin/ip link set {interface} up')
+    elif verb in ['down-client', 'down-host']:
+        if vti_link_up and not child_sa_installed:
+            call(f'sudo /usr/sbin/ip link set {interface} down')
+
+    print('vti-up-down: finish')