Add DuplicateAddressDetection settings for systemd-networkd

  * implement configuration key duplicate-address-detection
  * documentation of the parameter
  * adding a few tests

Author: sanecz

doc/netplan-yaml.md

@@ -422,6 +422,12 @@ Match devices by MAC when setting options like: `wakeonlan` or `*-offload`.
   > In addition to the addresses themselves one can specify configuration
   > parameters as mappings. Current supported options are:
 
+  - **`duplicate-address-detection`** (scalar)
+
+    > Configure the duplicate address detection (DAD). Valid options
+    > are `ipv4`, `ipv6`, `both` or `none`. Currently supported on the
+    > networkd back end only.
+
   - **`lifetime`** (scalar) – since 0.100
 
     > Default: `forever`. This can be `forever` or `0` and corresponds
@@ -445,6 +451,8 @@ Match devices by MAC when setting options like: `wakeonlan` or `*-offload`.
             - "10.0.0.15/24":
                 lifetime: 0
                 label: "maas"
+            - "169.254.10.1/24":
+                duplicate-address-detection: "none"
             - "2001:1::1/64"
     ```
 

python-cffi/netplan/_build_cffi.py

@@ -40,6 +40,7 @@
         char* address;
         char* lifetime;
         char* label;
+        char* duplicate_address_detection;
     } NetplanAddressOptions;
     struct address_iter { ...; };
     struct nameserver_iter { ...; };

python-cffi/netplan/netdef.py

@@ -211,10 +211,11 @@ def __next__(self):
 
 
 class NetplanAddress:
-    def __init__(self, address: str, lifetime: str, label: str):
+    def __init__(self, address: str, lifetime: str, label: str, duplicate_address_detection: str):
         self.address = address
         self.lifetime = lifetime
         self.label = label
+        self.duplicate_address_detection = duplicate_address_detection
 
     def __str__(self) -> str:
         return self.address
@@ -241,7 +242,9 @@ def __next__(self):
         address = ffi.string(content.address).decode('utf-8') if content.address else None
         lifetime = ffi.string(content.lifetime).decode('utf-8') if content.lifetime else None
         label = ffi.string(content.label).decode('utf-8') if content.label else None
-        return NetplanAddress(address, lifetime, label)
+        duplicate_address_detection = ffi.string(content.duplicate_address_detection).decode('utf-8') \
+            if content.duplicate_address_detection else None
+        return NetplanAddress(address, lifetime, label, duplicate_address_detection)
 
 
 class _NetdefNameserverIterator:

src/netplan.c

@@ -420,6 +420,7 @@ write_addresses(yaml_event_t* event, yaml_emitter_t* emitter, const NetplanNetDe
             YAML_MAPPING_OPEN(event, emitter);
             YAML_NONNULL_STRING(event, emitter, "label", opts->label);
             YAML_NONNULL_STRING(event, emitter, "lifetime", opts->lifetime);
+            YAML_NONNULL_STRING(event, emitter, "duplicate-address-detection", opts->duplicate_address_detection);
             YAML_MAPPING_CLOSE(event, emitter);
             YAML_MAPPING_CLOSE(event, emitter);
         }

src/networkd.c

@@ -767,6 +767,8 @@ write_addr_option(NetplanAddressOptions* o, GString* s)
     g_assert(o->address != NULL);
     g_string_append_printf(s, "Address=%s\n", o->address);
 
+    if (o->duplicate_address_detection)
+        g_string_append_printf(s, "DuplicateAddressDetection=%s\n", o->duplicate_address_detection);
     if (o->lifetime)
         g_string_append_printf(s, "PreferredLifetime=%s\n", o->lifetime);
     if (o->label)

src/parse.c

@@ -1393,9 +1393,22 @@ handle_address_option_label(NetplanParser* npp, yaml_node_t* node, const void* d
     return handle_generic_str(npp, node, npp->current.addr_options, data, error);
 }
 
+STATIC gboolean
+handle_address_option_duplicate_address_detection(NetplanParser* npp, yaml_node_t* node, const void* data, GError** error)
+{
+    if (g_ascii_strcasecmp(scalar(node), "ipv4") != 0 &&
+        g_ascii_strcasecmp(scalar(node), "ipv6") != 0 &&
+        g_ascii_strcasecmp(scalar(node), "both") != 0 &&
+        g_ascii_strcasecmp(scalar(node), "none") != 0) {
+        return yaml_error(npp, node, error, "invalid duplicate-address-detection value '%s'", scalar(node));
+    }
+    return handle_generic_str(npp, node, npp->current.addr_options, data, error);
+}
+
 const mapping_entry_handler address_option_handlers[] = {
     {"lifetime", YAML_SCALAR_NODE, {.generic=handle_address_option_lifetime}, addr_option_offset(lifetime)},
     {"label", YAML_SCALAR_NODE, {.generic=handle_address_option_label}, addr_option_offset(label)},
+    {"duplicate-address-detection", YAML_SCALAR_NODE, {.generic=handle_address_option_duplicate_address_detection}, addr_option_offset(duplicate_address_detection)},
     {NULL}
 };
 

src/types-internal.h

@@ -97,6 +97,7 @@ typedef struct {
     char* address;
     char* lifetime;
     char* label;
+    char* duplicate_address_detection;
 } NetplanAddressOptions;
 
 struct address_iter {

src/types.c

@@ -66,6 +66,7 @@ free_address_options(void* ptr)
     g_free(opts->address);
     g_free(opts->label);
     g_free(opts->lifetime);
+    g_free(opts->duplicate_address_detection);
     g_free(opts);
 }
 

src/util.c

@@ -802,6 +802,7 @@ _netplan_address_iter_next(struct address_iter* it)
         options->address = g_strdup(netdef_options->address);
         options->lifetime = g_strdup(netdef_options->lifetime);
         options->label = g_strdup(netdef_options->label);
+        options->duplicate_address_detection = g_strdup(netdef_options->duplicate_address_detection);
         it->last_address = options;
         return options;
     }

tests/config_fuzzer/schemas/common.js

@@ -147,6 +147,11 @@ export const common_properties = {
                                 label: {
                                     type: "string",
                                     maxLength: 15,
+                                },
+                                "duplicate-address-detection": {
+                                {
+                                    type: "string",
+                                    enum: ["ipv4", "ipv6", "both", "none"],
                                 }
                             }
                         }

tests/generator/test_common.py

@@ -392,6 +392,34 @@ def test_eth_address_option_label(self):
 [Address]
 Address=192.168.14.2/24
 Label=test-label
+'''})
+
+    def test_eth_address_option_duplicate_address_detection(self):
+        self.generate('''network:
+  version: 2
+  ethernets:
+    engreen:
+      addresses:
+        - 192.168.14.2/24:
+             duplicate-address-detection: ipv4
+        - 2001:FFfe::1/64:
+            duplicate-address-detection: none
+        - 10.0.0.1/24''')
+
+        self.assert_networkd({'engreen.network': '''[Match]
+Name=engreen
+
+[Network]
+LinkLocalAddressing=ipv6
+Address=10.0.0.1/24
+
+[Address]
+Address=192.168.14.2/24
+DuplicateAddressDetection=ipv4
+
+[Address]
+Address=2001:FFfe::1/64
+DuplicateAddressDetection=none
 '''})
 
     def test_eth_address_option_multi_pass(self):

tests/generator/test_errors.py

@@ -408,6 +408,16 @@ def test_invalid_address_option_lifetime(self):
           lifetime: 1''', expect_fail=True)
         self.assertIn("invalid lifetime value '1'", err)
 
+    def test_invalid_address_option_duplicate_address_detection(self):
+        err = self.generate('''network:
+  version: 2
+  ethernets:
+    engreen:
+      addresses:
+      - 192.168.1.15/24:
+          duplicate-address-detection: a''', expect_fail=True)
+        self.assertIn("invalid duplicate-address-detection value 'a'", err)
+
     def test_invalid_nm_options(self):
         err = self.generate('''network:
   version: 2

tests/test_libnetplan.py

@@ -200,17 +200,23 @@ def test_iter_ethernets_with_options(self):
         - 172.16.0.1/24:
             lifetime: 0
             label: label1
+            duplicate-address-detection: none
         - 1234:4321:abcd::cdef/96:
             lifetime: forever
-            label: label2''')
+            label: label2
+            duplicate-address-detection: both''')
 
         expected_ips = set(["1234:4321:abcd::cdef/96", "192.168.0.1/24", "172.16.0.1/24"])
         expected_lifetime_options = set([None, "0", "forever"])
         expected_label_options = set([None, "label1", "label2"])
+        expected_duplicate_address_detection_options = set([None, "none", "both"])
         netdef = next(netplan.netdef.NetDefinitionIterator(state, "ethernets"))
         self.assertSetEqual(expected_ips, set(ip.address for ip in netdef.addresses))
         self.assertSetEqual(expected_lifetime_options, set(ip.lifetime for ip in netdef.addresses))
         self.assertSetEqual(expected_label_options, set(ip.label for ip in netdef.addresses))
+        self.assertSetEqual(
+            expected_duplicate_address_detection_options, set(ip.duplicate_address_detection for ip in netdef.addresses)
+        )
 
     def test_drop_iterator_before_finishing(self):
         state = state_from_yaml(self.confdir, '''network: