test-network: add test case for [IPv6RoutePrefix] Preference=

man/systemd.network.xml

@@ -4397,6 +4397,15 @@ ServerAddress=192.168.0.1/24</programlisting>
         <xi:include href="version-info.xml" xpointer="v244"/></listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term><varname>Preference=</varname></term>
+
+        <listitem><para>Specifies the preference of the route option. Takes one of <literal>high</literal>,
+        <literal>medium</literal>, or <literal>low</literal>. Defaults to <literal>medium</literal>.</para>
+
+        <xi:include href="version-info.xml" xpointer="v258"/></listitem>
+      </varlistentry>
+
     </variablelist>
   </refsect1>
 

src/network/networkd-network-gperf.gperf

@@ -406,7 +406,7 @@ IPv6SendRA.ReachableTimeSec,                 config_parse_router_uint32_msec_use
 IPv6SendRA.RetransmitSec,                    config_parse_router_uint32_msec_usec,                     0,                             offsetof(Network, router_retransmit_usec)
 IPv6SendRA.Managed,                          config_parse_bool,                                        0,                             offsetof(Network, router_managed)
 IPv6SendRA.OtherInformation,                 config_parse_bool,                                        0,                             offsetof(Network, router_other_information)
-IPv6SendRA.RouterPreference,                 config_parse_router_preference,                           0,                             0
+IPv6SendRA.RouterPreference,                 config_parse_router_preference,                           0,                             offsetof(Network, router_preference)
 IPv6SendRA.HopLimit,                         config_parse_uint8,                                       0,                             offsetof(Network, router_hop_limit)
 IPv6SendRA.EmitDNS,                          config_parse_bool,                                        0,                             offsetof(Network, router_emit_dns)
 IPv6SendRA.DNS,                              config_parse_radv_dns,                                    0,                             0
@@ -427,6 +427,7 @@ IPv6Prefix.RouteMetric,                      config_parse_prefix_metric,
 IPv6Prefix.Token,                            config_parse_prefix_token,                                0,                             0
 IPv6RoutePrefix.Route,                       config_parse_route_prefix,                                0,                             0
 IPv6RoutePrefix.LifetimeSec,                 config_parse_route_prefix_lifetime,                       0,                             0
+IPv6RoutePrefix.Preference,                  config_parse_route_prefix_preference,                     0,                             0
 IPv6PREF64Prefix.Prefix,                     config_parse_pref64_prefix,                               0,                             0
 IPv6PREF64Prefix.LifetimeSec,                config_parse_pref64_prefix_lifetime,                      0,                             0
 LLDP.MUDURL,                                 config_parse_mud_url,                                     0,                             offsetof(Network, lldp_mudurl)

src/network/networkd-radv.c

@@ -1134,6 +1134,37 @@ int config_parse_route_prefix_lifetime(
         return 0;
 }
 
+int config_parse_route_prefix_preference(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        _cleanup_(route_prefix_free_or_set_invalidp) RoutePrefix *p = NULL;
+        Network *network = ASSERT_PTR(userdata);
+        int r;
+
+        assert(filename);
+
+        r = route_prefix_new_static(network, filename, section_line, &p);
+        if (r < 0)
+                return log_oom();
+
+        r = config_parse_router_preference(unit, filename, line, section, section_line,
+                                           lvalue, ltype, rvalue, &p->route.preference, NULL);
+        if (r <= 0)
+                return r;
+
+        TAKE_PTR(p);
+        return 0;
+}
+
 int config_parse_pref64_prefix(
                 const char *unit,
                 const char *filename,
@@ -1511,25 +1542,18 @@ int config_parse_router_preference(
                 void *data,
                 void *userdata) {
 
-        Network *network = userdata;
+        uint8_t *preference = ASSERT_PTR(data);
 
-        assert(filename);
-        assert(section);
-        assert(lvalue);
-        assert(rvalue);
-        assert(data);
-
-        if (streq(rvalue, "high"))
-                network->router_preference = SD_NDISC_PREFERENCE_HIGH;
-        else if (STR_IN_SET(rvalue, "medium", "normal", "default"))
-                network->router_preference = SD_NDISC_PREFERENCE_MEDIUM;
+        if (isempty(rvalue) || STR_IN_SET(rvalue, "medium", "normal", "default"))
+                *preference = SD_NDISC_PREFERENCE_MEDIUM;
+        else if (streq(rvalue, "high"))
+                *preference = SD_NDISC_PREFERENCE_HIGH;
         else if (streq(rvalue, "low"))
-                network->router_preference = SD_NDISC_PREFERENCE_LOW;
+                *preference = SD_NDISC_PREFERENCE_LOW;
         else
-                log_syntax(unit, LOG_WARNING, filename, line, 0,
-                           "Invalid router preference, ignoring assignment: %s", rvalue);
+                return log_syntax_parse_error(unit, filename, line, 0, lvalue, rvalue);
 
-        return 0;
+        return 1;
 }
 
 int config_parse_router_home_agent_lifetime(

src/network/networkd-radv.h

@@ -86,6 +86,7 @@ CONFIG_PARSER_PROTOTYPE(config_parse_radv_dns);
 CONFIG_PARSER_PROTOTYPE(config_parse_radv_search_domains);
 CONFIG_PARSER_PROTOTYPE(config_parse_route_prefix);
 CONFIG_PARSER_PROTOTYPE(config_parse_route_prefix_lifetime);
+CONFIG_PARSER_PROTOTYPE(config_parse_route_prefix_preference);
 CONFIG_PARSER_PROTOTYPE(config_parse_pref64_prefix);
 CONFIG_PARSER_PROTOTYPE(config_parse_pref64_prefix_lifetime);
 CONFIG_PARSER_PROTOTYPE(config_parse_router_home_agent_lifetime);

test/test-network/systemd-networkd-tests.py

@@ -6472,6 +6472,22 @@ class NetworkdRATests(unittest.TestCase, Utilities):
         networkctl_reload()
         self.check_router_preference('01', 100, 'high', 300, 'low')
 
+        # Use route options with preference to configure default routes.
+        with open(os.path.join(network_unit_dir, '25-veth-router-high.network'), mode='a', encoding='utf-8') as f:
+            f.write('LifetimeSec=1200\nPreference=low\n')
+        with open(os.path.join(network_unit_dir, '25-veth-router-low.network'), mode='a', encoding='utf-8') as f:
+            f.write('LifetimeSec=1200\nPreference=high\n')
+        networkctl_reload()
+        self.check_router_preference('01', 300, 'low', 100, 'high')
+
+        # Set zero lifetime again to the route options.
+        with open(os.path.join(network_unit_dir, '25-veth-router-high.network'), mode='a', encoding='utf-8') as f:
+            f.write('LifetimeSec=0\n')
+        with open(os.path.join(network_unit_dir, '25-veth-router-low.network'), mode='a', encoding='utf-8') as f:
+            f.write('LifetimeSec=0\n')
+        networkctl_reload()
+        self.check_router_preference('01', 100, 'high', 300, 'low')
+
     def _test_ndisc_vs_static_route(self, manage_foreign_nexthops):
         if not manage_foreign_nexthops:
             copy_networkd_conf_dropin('networkd-manage-foreign-nexthops-no.conf')