feat: validate Gateway= in .network files (route_section gateway ltypes)

src/main/kotlin/net/sjrx/intellij/plugins/systemdunitfiles/semanticdata/optionvalues/AiGenerated.kt

@@ -189,6 +189,8 @@ fun getAllAIGeneratedValidators(): Map<Validator, OptionValueInformation> {
     Validator("config_parse_restrict_network_interfaces", "0") to ConfigParseRestrictNetworkInterfacesOptionValue() as OptionValueInformation,
     Validator("config_parse_ring_buffer_or_channel", "0") to ConfigParseRingBufferOrChannelOptionValue() as OptionValueInformation,
     Validator("config_parse_route_prefix_preference", "0") to ConfigParseRoutePrefixPreferenceOptionValue() as OptionValueInformation,
+    Validator("config_parse_route_section", "ROUTE_GATEWAY") to ConfigParseRouteSectionGatewayOptionValue() as OptionValueInformation,
+    Validator("config_parse_route_section", "ROUTE_GATEWAY_NETWORK") to ConfigParseRouteSectionGatewayNetworkOptionValue() as OptionValueInformation,
     Validator("config_parse_route_section", "ROUTE_METRIC_FASTOPEN_NO_COOKIE") to ConfigParseRouteSectionOptionValue() as OptionValueInformation,
     Validator("config_parse_route_section", "ROUTE_METRIC_HOPLIMIT") to ConfigParseRouteSectionOptionValue() as OptionValueInformation,
     Validator("config_parse_route_section", "ROUTE_METRIC_INITRWND") to ConfigParseRouteSectionOptionValue() as OptionValueInformation,

src/main/kotlin/net/sjrx/intellij/plugins/systemdunitfiles/semanticdata/optionvalues/ai/ConfigParseRouteSectionGatewayNetworkOptionValue.kt

@@ -0,0 +1,21 @@
+package net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.ai
+
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.SimpleGrammarOptionValues
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.*
+
+/**
+ * Validator for [Network] Gateway= (config_parse_route_section, ltype ROUTE_GATEWAY_NETWORK).
+ *
+ * systemd.network(5): "The gateway address, which must be in the format described in inet_pton(3).
+ * This is a short-hand for a [Route] section only containing a Gateway= key."
+ *
+ * So it accepts an IPv4 or IPv6 address only — unlike [Route] Gateway=, the special "_dhcp4" /
+ * "_ipv6ra" tokens are NOT accepted in the [Network] short-hand.
+ */
+class ConfigParseRouteSectionGatewayNetworkOptionValue : SimpleGrammarOptionValues(
+    "config_parse_route_section",
+    SequenceCombinator(
+        AlternativeCombinator(IPV4_ADDR, IPV6_ADDR),
+        EOF()
+    )
+)

src/main/kotlin/net/sjrx/intellij/plugins/systemdunitfiles/semanticdata/optionvalues/ai/ConfigParseRouteSectionGatewayOptionValue.kt

@@ -0,0 +1,23 @@
+package net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.ai
+
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.SimpleGrammarOptionValues
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.*
+
+/**
+ * Validator for [Route] Gateway= (config_parse_route_section, ltype ROUTE_GATEWAY).
+ *
+ * systemd.network(5): "Takes the gateway address or the special values "_dhcp4" and "_ipv6ra". If
+ * "_dhcp4" or "_ipv6ra" is set, then the gateway address provided by DHCPv4 or IPv6 RA is used."
+ */
+class ConfigParseRouteSectionGatewayOptionValue : SimpleGrammarOptionValues(
+    "config_parse_route_section",
+    SequenceCombinator(
+        AlternativeCombinator(
+            IPV4_ADDR,
+            IPV6_ADDR,
+            LiteralChoiceTerminal("_dhcp4"),
+            LiteralChoiceTerminal("_ipv6ra")
+        ),
+        EOF()
+    )
+)

src/test/kotlin/net/sjrx/intellij/plugins/systemdunitfiles/inspections/ai/ConfigParseRouteSectionGatewayOptionValueTest.kt

@@ -0,0 +1,54 @@
+package net.sjrx.intellij.plugins.systemdunitfiles.inspections.ai
+
+import net.sjrx.intellij.plugins.systemdunitfiles.AbstractUnitFileTest
+import net.sjrx.intellij.plugins.systemdunitfiles.inspections.InvalidValueInspection
+import org.junit.Test
+
+/**
+ * Gateway= coverage for systemd .network files (config_parse_route_section, ltypes ROUTE_GATEWAY
+ * and ROUTE_GATEWAY_NETWORK). Previously unregistered, so Gateway values were not validated at all.
+ *
+ * [Network] Gateway= is an IPv4/IPv6 address only; [Route] Gateway= also accepts "_dhcp4"/"_ipv6ra".
+ */
+class ConfigParseRouteSectionGatewayOptionValueTest : AbstractUnitFileTest() {
+
+  @Test
+  fun testValidGateways() {
+    // language="unit file (systemd)"
+    val file = """
+            [Network]
+            Gateway=192.168.1.1
+            Gateway=2001:db8::1
+            [Route]
+            Gateway=10.0.0.1
+            Gateway=fe80::1
+            Gateway=_dhcp4
+            Gateway=_ipv6ra
+        """.trimIndent()
+
+    setupFileInEditor("file.network", file)
+    enableInspection(InvalidValueInspection::class.java)
+
+    assertSize(0, myFixture.doHighlighting())
+  }
+
+  @Test
+  fun testInvalidGateways() {
+    // [Network] does not accept the special tokens; bad addresses are rejected in both sections;
+    // [Route] only accepts _dhcp4 / _ipv6ra (not _dhcp6). One highlight per line.
+    // language="unit file (systemd)"
+    val file = """
+            [Network]
+            Gateway=_dhcp4
+            Gateway=notanip
+            [Route]
+            Gateway=_dhcp6
+            Gateway=300.1.2.3
+        """.trimIndent()
+
+    setupFileInEditor("file.network", file)
+    enableInspection(InvalidValueInspection::class.java)
+
+    assertSize(4, myFixture.doHighlighting())
+  }
+}