Feat/validators network dhcp misc

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

@@ -413,6 +413,47 @@ fun getAllAIGeneratedValidators(): Map<Validator, OptionValueInformation> {
     Validator("config_parse_socket_service", "0") to ConfigParseSocketServiceOptionValue() as OptionValueInformation,
     Validator("config_parse_service_sockets", "0") to ConfigParseServiceSocketsOptionValue() as OptionValueInformation,
 
+    // Batch 2026-10: network-dhcp-misc
+    Validator("config_parse_dhcp_option_tlv", "0") to ConfigParseDhcpOptionTlvOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_option", "true") to ConfigParseDhcpOptionTypedOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp6_send_option", "0") to ConfigParseDhcp6SendOptionOptionValue() as OptionValueInformation,
+    Validator("config_parse_uplink", "0") to ConfigParseUplinkOptionValue() as OptionValueInformation,
+    Validator("config_parse_fdb_interface", "0") to ConfigParseFdbInterfaceOptionValue() as OptionValueInformation,
+    Validator("config_parse_mud_url", "0") to ConfigParseMudUrlOptionValue() as OptionValueInformation,
+    Validator("config_parse_resolve_support", "0") to ConfigParseResolveSupportOptionValue() as OptionValueInformation,
+    Validator("config_parse_dns_over_tls_mode", "0") to ConfigParseDnsOverTlsModeOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_pd_prefix_route_type", "0") to ConfigParseDhcpPdPrefixRouteTypeOptionValue() as OptionValueInformation,
+    Validator("config_parse_lldp_multicast_mode", "0") to ConfigParseLldpMulticastModeOptionValue() as OptionValueInformation,
+    Validator("config_parse_activation_policy", "0") to ConfigParseActivationPolicyOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_relay_interface_mode", "0") to ConfigParseDhcpRelayInterfaceModeOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_fallback_lease_lifetime", "0") to ConfigParseDhcpFallbackLeaseLifetimeOptionValue() as OptionValueInformation,
+    Validator("config_parse_ipv4ll", "0") to ConfigParseIpv4llOptionValue() as OptionValueInformation,
+    Validator("config_parse_ignore_carrier_loss", "0") to ConfigParseIgnoreCarrierLossOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_server_ipv6_only_preferred", "0") to ConfigParseDhcpServerIpv6OnlyPreferredOptionValue() as OptionValueInformation,
+    Validator("config_parse_bridge_vlan_id", "0") to ConfigParseBridgeVlanIdOptionValue() as OptionValueInformation,
+    Validator("config_parse_link_group", "0") to ConfigParseLinkGroupOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_pd_subnet_id", "0") to ConfigParseDhcpPdSubnetIdOptionValue() as OptionValueInformation,
+    Validator("config_parse_required_for_online", "0") to ConfigParseRequiredForOnlineOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_server_address", "0") to ConfigParseDhcpServerAddressOptionValue() as OptionValueInformation,
+    Validator("config_parse_ipv4ll_address", "0") to ConfigParseIpv4llAddressOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_label", "0") to ConfigParseDhcpLabelOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_static_lease_hostname", "0") to ConfigParseDhcpStaticLeaseHostnameOptionValue() as OptionValueInformation,
+    Validator("config_parse_domains", "0") to ConfigParseDomainsOptionValue() as OptionValueInformation,
+    Validator("config_parse_dnssec_negative_trust_anchors", "0") to ConfigParseDnssecNegativeTrustAnchorsOptionValue() as OptionValueInformation,
+    Validator("config_parse_ntp", "0") to ConfigParseNtpOptionValue() as OptionValueInformation,
+    Validator("config_parse_radv_dns", "0") to ConfigParseRadvDnsOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_request_options", "AF_INET") to ConfigParseDhcpRequestOptionsOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_request_options", "AF_INET6") to ConfigParseDhcpRequestOptionsOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp4_user_class", "0") to ConfigParseDhcp4UserClassOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp6_user_or_vendor_class", "0") to ConfigParseDhcp6UserOrVendorClassOptionValue() as OptionValueInformation,
+    Validator("config_parse_duid_type", "0") to ConfigParseDuidTypeOptionValue("config_parse_duid_type") as OptionValueInformation,
+    Validator("config_parse_network_duid_type", "0") to ConfigParseDuidTypeOptionValue("config_parse_network_duid_type") as OptionValueInformation,
+    Validator("config_parse_duid_rawdata", "0") to ConfigParseDuidRawdataOptionValue("config_parse_duid_rawdata") as OptionValueInformation,
+    Validator("config_parse_network_duid_rawdata", "0") to ConfigParseDuidRawdataOptionValue("config_parse_network_duid_rawdata") as OptionValueInformation,
+    Validator("config_parse_dhcp_or_ra_route_table", "NETWORK_CONFIG_SOURCE_DHCP4") to ConfigParseDhcpOrRaRouteTableOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_or_ra_route_table", "NETWORK_CONFIG_SOURCE_DHCP6") to ConfigParseDhcpOrRaRouteTableOptionValue() as OptionValueInformation,
+    Validator("config_parse_dhcp_or_ra_route_table", "NETWORK_CONFIG_SOURCE_NDISC") to ConfigParseDhcpOrRaRouteTableOptionValue() as OptionValueInformation,
+
   )
 
   return allValidators

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

@@ -0,0 +1,27 @@
+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.EOF
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.FlexibleLiteralChoiceTerminal
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.SequenceCombinator
+
+/*
+ * [Link] ActivationPolicy= (.network).
+ *
+ * man    https://www.freedesktop.org/software/systemd/man/latest/systemd.network.html#ActivationPolicy=
+ * parser https://github.com/systemd/systemd/blob/0f0682b773/src/network/networkd-network.c#L1201         config_parse_activation_policy (0), DEFINE_CONFIG_PARSE_ENUM
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/network/networkd-network.c#L1191-L1198   activation_policy_table
+ * tests  https://github.com/systemd/systemd/blob/0f0682b773/test/test-network/conf/25-activation-policy.network.d/always-down.conf#L2
+ */
+
+/**
+ * Validator for `[Link] ActivationPolicy=`: exactly one of `up`, `always-up`, `manual`, `always-down`,
+ * `down`, `bound` (plain DEFINE_STRING_TABLE_LOOKUP — case-sensitive, no boolean).
+ */
+class ConfigParseActivationPolicyOptionValue : SimpleGrammarOptionValues(
+    "config_parse_activation_policy",
+    SequenceCombinator(
+        FlexibleLiteralChoiceTerminal("up", "always-up", "manual", "always-down", "down", "bound"),
+        EOF(),
+    )
+)

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

@@ -0,0 +1,43 @@
+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.AlternativeCombinator
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.BOOLEAN_FALSE
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.EOF
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.SafeAtoTerminal
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.SequenceCombinator
+
+/*
+ * [BridgeVLAN] PVID= (.network).
+ *
+ * man    https://www.freedesktop.org/software/systemd/man/latest/systemd.network.html#PVID=
+ * parser https://github.com/systemd/systemd/blob/0f0682b773/src/network/networkd-bridge-vlan.c#L341-L381  config_parse_bridge_vlan_id (0)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/shared/vlan-util.c#L8-L23                parse_vlanid (safe_atou16, <= VLANID_MAX = 4094)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/parse-util.c#L23-L46               parse_boolean
+ * tests  https://github.com/systemd/systemd/blob/0f0682b773/test/test-network/conf/26-bridge-vlan-master.network.d/30-override.conf#L3
+ *        https://github.com/systemd/systemd/blob/0f0682b773/test/test-network/conf/26-bridge-vlan-master.network#L9
+ */
+
+/**
+ * Validator for `[BridgeVLAN] PVID=` (config_parse_bridge_vlan_id): a *false* boolean (removes the PVID;
+ * a true one falls through to parse_vlanid and is refused), or a VLAN id 0…4094 read by safe_atou16
+ * (base 0, so `0x10` is legal).
+ */
+class ConfigParseBridgeVlanIdOptionValue : SimpleGrammarOptionValues(
+    "config_parse_bridge_vlan_id",
+    AlternativeCombinator(
+        SequenceCombinator(
+            SafeAtoTerminal(
+                signed = false,
+                base = 0,
+                flags = emptySet(),
+                minInclusive = 0L,
+                maxInclusive = 4_094L,
+                acceptsWhitespace = true,
+                acceptsMinus = true,
+            ),
+            EOF(),
+        ),
+        SequenceCombinator(BOOLEAN_FALSE, EOF()),
+    )
+)

src/main/kotlin/net/sjrx/intellij/plugins/systemdunitfiles/semanticdata/optionvalues/ai/ConfigParseDhcp4UserClassOptionValue.kt

@@ -0,0 +1,35 @@
+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.CUNESCAPE_UNQUOTE_WORD
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.NETWORK_DHCP_MISC_NONEMPTY_UNQUOTE_WORD
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.EOF
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.SequenceCombinator
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.wordList
+
+/*
+ * [DHCPv4] UserClass= (and the old [DHCP] UserClass=) (.network).
+ *
+ * Note: the plugin reports the deprecated [DHCP] section as not allowed in .network files, so this
+ * validator never actually runs for keys there; they are listed only because the gperf shares the parser.
+ *
+ * man    https://www.freedesktop.org/software/systemd/man/latest/systemd.network.html#UserClass=
+ * parser https://github.com/systemd/systemd/blob/0f0682b773/src/network/networkd-dhcp-common.c#L655-L698  config_parse_dhcp4_user_class (0)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/extract-word.c#L10-L188            extract_first_word (EXTRACT_CUNESCAPE|EXTRACT_UNQUOTE)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/escape.c#L104-L296                 cunescape_one
+ */
+
+/**
+ * Validator for `[DHCPv4] UserClass=`: a whitespace-separated list of user-class strings, split by
+ * extract_first_word with EXTRACT_CUNESCAPE|EXTRACT_UNQUOTE — so a class may be quoted to contain spaces
+ * and may use C escapes ([CUNESCAPE_UNQUOTE_WORD]). An unknown escape, a trailing backslash or an
+ * unterminated quote fails the assignment.
+ *
+ * Each class must also be 1…255 bytes long once unquoted/unescaped. An empty one (`""`, `''`) is
+ * dropped with a warning and flagged ([NETWORK_DHCP_MISC_NONEMPTY_UNQUOTE_WORD]); the upper bound is not
+ * modelled (lenient).
+ */
+class ConfigParseDhcp4UserClassOptionValue : SimpleGrammarOptionValues(
+    "config_parse_dhcp4_user_class",
+    SequenceCombinator(wordList(NETWORK_DHCP_MISC_NONEMPTY_UNQUOTE_WORD), EOF())
+)

src/main/kotlin/net/sjrx/intellij/plugins/systemdunitfiles/semanticdata/optionvalues/ai/ConfigParseDhcp6SendOptionOptionValue.kt

@@ -0,0 +1,90 @@
+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.AlternativeCombinator
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.NETWORK_DHCP_MISC_COALESCED_COLONS
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.COLON
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.EOF
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.KeyOrSectionDispatchingGrammarOptionValue
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.SafeAtoTerminal
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.SequenceCombinator
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.ZeroOrMore
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.dhcpOptionTypedData
+import java.math.BigInteger
+
+/*
+ * [DHCPv6] SendOption= / SendVendorOption= (.network).
+ *
+ * man    https://www.freedesktop.org/software/systemd/man/latest/systemd.network.html#SendOption=
+ *        https://www.freedesktop.org/software/systemd/man/latest/systemd.network.html#SendVendorOption=
+ * parser https://github.com/systemd/systemd/blob/0f0682b773/src/network/networkd-dhcp-common.c#L745-L942    config_parse_dhcp6_send_option (0)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/network/networkd-dhcp-common.c#L781         streq(lvalue, "SendVendorOption") — the key decides the shape
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/network/networkd-dhcp-common.c#L1176-L1183  dhcp_option_data_type_table
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/extract-word.c#L10-L188               extract_first_word (":" separator, coalescing)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/parse-util.c#L599-L613                safe_atou16_full (base 0)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/parse-util.c#L429-L478                safe_atou_full (safe_atou32, base 0)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/in-addr-util.c#L517-L529              in_addr_from_string (inet_pton)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/escape.c#L104-L296                    cunescape_one
+ * linux  https://man7.org/linux/man-pages/man3/inet_pton.3.html
+ */
+
+// safe_atou16/safe_atou32 skip leading whitespace, and extract_first_word(…, ":", 0) leaves any that
+// follows a colon inside the next word, so `123: 1:string:x` is fine: hence acceptsWhitespace = true.
+// CODE is safe_atou16 with `u16 < 1 || u16 >= UINT16_MAX` refused, so 1…65534.
+private val CODE_TYPE_DATA = SequenceCombinator(
+    SafeAtoTerminal(
+        signed = false,
+        base = 0,
+        flags = emptySet(),
+        minInclusive = 1L,
+        maxInclusive = 65_534L,
+        acceptsWhitespace = true,
+        acceptsMinus = true,
+    ),
+    NETWORK_DHCP_MISC_COALESCED_COLONS,
+    dhcpOptionTypedData(),
+    EOF(),
+)
+
+private val SEND_OPTION = SequenceCombinator(ZeroOrMore(COLON), CODE_TYPE_DATA)
+
+private val SEND_VENDOR_OPTION = SequenceCombinator(
+    ZeroOrMore(COLON),
+    SafeAtoTerminal(
+        signed = false,
+        base = 0,
+        flags = emptySet(),
+        minInclusive = BigInteger.ZERO,
+        maxInclusive = SafeAtoTerminal.UINT32_MAX,
+        acceptsWhitespace = true,
+        acceptsMinus = true,
+    ),
+    NETWORK_DHCP_MISC_COALESCED_COLONS,
+    CODE_TYPE_DATA,
+)
+
+/**
+ * Validator for `[DHCPv6] SendOption=` (`CODE:TYPE:DATA`) and `[DHCPv6] SendVendorOption=`
+ * (`ENTERPRISE:CODE:TYPE:DATA`), both parsed by config_parse_dhcp6_send_option.
+ *
+ * The parser branches on the *key name*: only for SendVendorOption= does it first read an enterprise
+ * identifier (safe_atou32, any uint32 — the man page says 1…4294967294 but C accepts 0 and 4294967295
+ * too). The validator is registered per (parser, ltype) but dispatches on the key it is checking, so
+ * `SendOption=` takes exactly the three-field form and `SendVendorOption=` exactly the four-field one
+ * (`SendVendorOption=12:string:x` is refused, as systemd's safe_atou16("string") refuses it).
+ *
+ * CODE is safe_atou16 in 1…65534 — the C check is `u16 < 1 || u16 >= UINT16_MAX`, so 65535 is refused
+ * although the man page says "1…65536". The TYPE:DATA tail is [dhcpOptionTypedData]; all six types are
+ * accepted. Every separator coalesces, so leading and doubled colons are harmless.
+ */
+class ConfigParseDhcp6SendOptionOptionValue : KeyOrSectionDispatchingGrammarOptionValue(
+    VALIDATOR_NAME,
+    AlternativeCombinator(SEND_VENDOR_OPTION, SEND_OPTION),
+    { key, _ -> if (key == "SendVendorOption") VENDOR else PLAIN },
+) {
+  private companion object {
+    const val VALIDATOR_NAME = "config_parse_dhcp6_send_option"
+    val PLAIN = SimpleGrammarOptionValues(VALIDATOR_NAME, SEND_OPTION)
+    val VENDOR = SimpleGrammarOptionValues(VALIDATOR_NAME, SEND_VENDOR_OPTION)
+  }
+}

src/main/kotlin/net/sjrx/intellij/plugins/systemdunitfiles/semanticdata/optionvalues/ai/ConfigParseDhcp6UserOrVendorClassOptionValue.kt

@@ -0,0 +1,27 @@
+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.NETWORK_DHCP_MISC_NONEMPTY_UNQUOTE_WORD
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.EOF
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.SequenceCombinator
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.wordList
+
+/*
+ * [DHCPv6] UserClass= / VendorClass= (.network).
+ *
+ * man    https://www.freedesktop.org/software/systemd/man/latest/systemd.network.html#UserClass=
+ *        https://www.freedesktop.org/software/systemd/man/latest/systemd.network.html#VendorClass=
+ * parser https://github.com/systemd/systemd/blob/0f0682b773/src/network/networkd-dhcp-common.c#L700-L743  config_parse_dhcp6_user_or_vendor_class (0)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/extract-word.c#L10-L188            extract_first_word (EXTRACT_CUNESCAPE|EXTRACT_UNQUOTE)
+ * leaf   https://github.com/systemd/systemd/blob/0f0682b773/src/basic/escape.c#L104-L296                 cunescape_one
+ */
+
+/**
+ * Validator for `[DHCPv6] UserClass=` and `[DHCPv6] VendorClass=`: the same quoted/escaped word list as
+ * [ConfigParseDhcp4UserClassOptionValue], with a 1…65535-byte length limit per entry: empty
+ * entries are flagged, the upper bound is not modelled.
+ */
+class ConfigParseDhcp6UserOrVendorClassOptionValue : SimpleGrammarOptionValues(
+    "config_parse_dhcp6_user_or_vendor_class",
+    SequenceCombinator(wordList(NETWORK_DHCP_MISC_NONEMPTY_UNQUOTE_WORD), EOF())
+)

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

@@ -0,0 +1,22 @@
+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.EOF
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.FlexibleLiteralChoiceTerminal
+import net.sjrx.intellij.plugins.systemdunitfiles.semanticdata.optionvalues.grammar.SequenceCombinator
+
+/*
+ * [DHCPv4] FallbackLeaseLifetimeSec= (.network).
+ *
+ * man    https://www.freedesktop.org/software/systemd/man/latest/systemd.network.html#FallbackLeaseLifetimeSec=
+ * parser https://github.com/systemd/systemd/blob/0f0682b773/src/network/networkd-dhcp4.c#L2098-L2133  config_parse_dhcp_fallback_lease_lifetime (0)
+ */
+
+/**
+ * Validator for `[DHCPv4] FallbackLeaseLifetimeSec=`. Despite the `Sec` suffix this is not a time span:
+ * the parser accepts only `forever` or `infinity` (STR_IN_SET, case-sensitive), as the man page says.
+ */
+class ConfigParseDhcpFallbackLeaseLifetimeOptionValue : SimpleGrammarOptionValues(
+    "config_parse_dhcp_fallback_lease_lifetime",
+    SequenceCombinator(FlexibleLiteralChoiceTerminal("forever", "infinity"), EOF())
+)