nm:parse-nm: handle differing ip6-privacy default value (#263)

Commit 64e381e (#244) changed netplan's
behaviour to always write out the ipv6-privacy value (default to 0=off),
in order to comply with what is written in our documentation and how it is
implemented in the networkd backend.

This is a problem for our NetworkManager integration, as NM's default value
is -1=unknown. Netplan only supports values 0=off and 2=on while NM supports
-1, 0, 1 and 2. We need to handle unsupported cases (-1 and 1) via passthrough.

src/nm.c

@@ -531,7 +531,12 @@ write_fallback_key_value(GQuark key_id, gpointer value, gpointer user_data)
     /* delete the dummy key, if this was just an empty group */
     if (!g_strcmp0(k, NETPLAN_NM_EMPTY_GROUP))
         g_key_file_remove_key(kf, group, k, NULL);
-    else if (!has_key) {
+    /* handle differing defaults:
+     * ipv6.ip6-privacy is "-1 (unknown)" by default in NM, it is "0 (off)" in netplan */
+    else if (g_strcmp0(key, "ipv6.ip6-privacy") == 0 && g_strcmp0(val, "-1") == 0) {
+        g_debug("NetworkManager: default override: clearing %s.%s", group, k);
+        g_key_file_remove_key(kf, group, k, NULL);
+    } else if (!has_key) {
         g_debug("NetworkManager: passing through fallback key: %s.%s=%s", group, k, val);
         g_key_file_set_comment(kf, group, k, "Netplan: passthrough setting", NULL);
     } else if (!!g_strcmp0(val, old_key)) {

src/parse-nm.c

@@ -497,6 +497,15 @@ netplan_parser_load_keyfile(NetplanParser* npp, const char* filename, GError** e
     if (nd_type == NETPLAN_DEF_TYPE_NM)
         goto only_passthrough; //do not try to handle any keys for connections types unknown to netplan
 
+    /* Handle some differing NM/netplan defaults */
+    tmp_str = g_key_file_get_string(kf, "ipv6", "method", NULL);
+    if ( g_key_file_has_group(kf, "ipv6") && g_strcmp0(tmp_str, "ignore") != 0 &&
+        !g_key_file_has_key(kf, "ipv6", "ip6-privacy", NULL)) {
+        /* put NM's default into passthrough, as this is not currently supported by netplan */
+        g_key_file_set_integer(kf, "ipv6", "ip6-privacy", -1);
+    }
+    g_free(tmp_str);
+
     /* remove supported values from passthrough, which have been handled */
     if (   nd_type == NETPLAN_DEF_TYPE_ETHERNET
         || nd_type == NETPLAN_DEF_TYPE_WIFI
@@ -556,6 +565,21 @@ netplan_parser_load_keyfile(NetplanParser* npp, const char* filename, GError** e
     g_free(tmp_str);
     handle_generic_str(kf, "ipv6", "token", &nd->ip6_addr_gen_token);
 
+    /* ip6-privacy is not fully supported, NM supports additional modes, like -1 or 1
+     * handle known modes, but keep any unsupported "ip6-privacy" value in passthrough */
+    if (g_key_file_has_group(kf, "ipv6")) {
+        if (g_key_file_has_key(kf, "ipv6", "ip6-privacy", NULL)) {
+            int ip6_privacy = g_key_file_get_integer(kf, "ipv6", "ip6-privacy", NULL);
+            if (ip6_privacy == 0) {
+                nd->ip6_privacy = FALSE;
+                _kf_clear_key(kf, "ipv6", "ip6-privacy");
+            } else if (ip6_privacy == 2) {
+                nd->ip6_privacy = TRUE;
+                _kf_clear_key(kf, "ipv6", "ip6-privacy");
+            }
+        }
+    }
+
     /* Modem parameters
      * NM differentiates between GSM and CDMA connections, while netplan
      * combines them as "modems". We need to parse a basic set of parameters

tests/generator/test_passthrough.py

@@ -283,4 +283,35 @@ def test_passthrough_interface_rename_existing_id(self):
 
 [ipv6]
 method=ignore
+'''})
+
+    def test_passthrough_ip6_privacy_default(self):
+        self.generate('''network:
+  version: 2
+  renderer: NetworkManager
+  ethernets:
+    eth0:
+      dhcp4: true
+      dhcp6: true
+      networkmanager:
+        uuid: 626dd384-8b3d-3690-9511-192b2c79b3fd
+        name: "netplan-eth0"
+        passthrough:
+          "ipv6.ip6-privacy": "-1"
+''')
+
+        self.assert_nm({'eth0': '''[connection]
+id=netplan-eth0
+type=ethernet
+uuid=626dd384-8b3d-3690-9511-192b2c79b3fd
+interface-name=eth0
+
+[ethernet]
+wake-on-lan=0
+
+[ipv4]
+method=auto
+
+[ipv6]
+method=auto
 '''})

tests/parser/test_keyfile.py

@@ -69,6 +69,7 @@ def test_keyfile_gsm(self):
 [ipv6]
 dns-search=
 method=auto
+ip6-privacy=0
 '''.format(UUID))
         self.assert_netplan({UUID: '''network:
   version: 2
@@ -204,6 +205,7 @@ def test_keyfile_method_auto(self):
 addr-gen-mode=eui64
 dns-search=
 method=auto
+ip6-privacy=0
 ignore-auto-routes=true
 never-default=true
 route-metric=4242
@@ -280,6 +282,7 @@ def test_keyfile_method_manual(self):
 dns-search=bar.local
 dns=dead:beef::2;
 method=manual
+ip6-privacy=2
 address1=1:2:3::9/128
 gateway=6:6::6
 route1=dead:beef::1/128,2001:1234::2
@@ -310,6 +313,7 @@ def test_keyfile_method_manual(self):
       gateway4: 6.6.6.6
       gateway6: 6:6::6
       ipv6-address-generation: "stable-privacy"
+      ipv6-privacy: true
       routes:
       - metric: 42
         table: 102
@@ -710,6 +714,7 @@ def test_keyfile_yaml_wifi_hotspot(self):
 method=ignore
 addr-gen-mode=1
 dns-search=
+ip6-privacy=0
 
 [wifi]
 ssid=my-hotspot
@@ -1018,6 +1023,7 @@ def test_keyfile_customer_A2(self):
 [ipv6]
 method=auto
 addr-gen-mode=1
+ip6-privacy=0
 '''.format(UUID))
         self.assert_netplan({UUID: '''network:
   version: 2
@@ -1080,6 +1086,7 @@ def test_keyfile_netplan0103_compat(self):
 dns=1::cafe;2::cafe;
 dns-search=wallaceandgromit.com;
 method=manual
+ip6-privacy=1
 route1=1:2:3:4:5:6:7:8/64,8:7:6:5:4:3:2:1,3
 route2=2001::1000/56,2001::1111,1
 route3=4:5:6:7:8:9:0:1/63,::,5
@@ -1151,6 +1158,7 @@ def test_keyfile_netplan0103_compat(self):
           ipv4.route4: "3.3.3.3/6,0.0.0.0,4"
           ipv4.route4_options: "cwnd=10,mtu=1492,src=1.2.3.4"
           ipv6.dns-search: "wallaceandgromit.com;"
+          ipv6.ip6-privacy: "1"
           proxy._: ""
 '''.format(UUID, UUID)})
 
@@ -1202,3 +1210,35 @@ def test_keyfile_tunnel_regression_lp1952967(self):
           ipv6.method: "auto"
           proxy._: ""
 '''.format(UUID, UUID)})
+
+    def test_keyfile_ip6_privacy_default_netplan_0104_compat(self):
+        self.generate_from_keyfile('''[connection]
+id=Test
+uuid={}
+type=ethernet
+
+[ethernet]
+mac-address=99:88:77:66:55:44
+
+[ipv4]
+method=auto
+
+[ipv6]
+method=auto
+'''.format(UUID))
+        self.assert_netplan({UUID: '''network:
+  version: 2
+  ethernets:
+    NM-{}:
+      renderer: NetworkManager
+      match:
+        macaddress: "99:88:77:66:55:44"
+      dhcp4: true
+      dhcp6: true
+      wakeonlan: true
+      networkmanager:
+        uuid: "{}"
+        name: "Test"
+        passthrough:
+          ipv6.ip6-privacy: "-1"
+'''.format(UUID, UUID)})