netdog: set IPv6 accept-ra for primary interface via config rather than sysctl

sources/api/netdog/src/cli/generate_net_config.rs

@@ -17,6 +17,7 @@ pub(crate) struct GenerateNetConfigArgs {}
 
 /// Generate configuration for network interfaces.
 pub(crate) fn run() -> Result<()> {
+    let mut from_cmd_line = false;
     let maybe_net_config = if Path::exists(Path::new(OVERRIDE_NET_CONFIG_FILE)) {
         net_config::from_path(OVERRIDE_NET_CONFIG_FILE).context(error::NetConfigParseSnafu {
             path: OVERRIDE_NET_CONFIG_FILE,
@@ -26,6 +27,7 @@ pub(crate) fn run() -> Result<()> {
             path: DEFAULT_NET_CONFIG_FILE,
         })?
     } else {
+        from_cmd_line = true;
         net_config::from_command_line(KERNEL_CMDLINE).context(error::NetConfigParseSnafu {
             path: KERNEL_CMDLINE,
         })?
@@ -48,8 +50,16 @@ pub(crate) fn run() -> Result<()> {
     remove_old_primary_interface()?;
     write_primary_interface(&primary_interface)?;
 
-    let wicked_interfaces = net_config.as_wicked_interfaces();
-    for interface in wicked_interfaces {
+    let mut wicked_interfaces = net_config.as_wicked_interfaces();
+    for interface in &mut wicked_interfaces {
+        // The kernel command line is too limited to fully specify an interface's configuration;
+        // fix some defaults to match legacy behavior.
+        // Note: we only allow 1 interface to be listed via kernel command line, so this will only
+        // be added to a single interface
+        if from_cmd_line {
+            interface.accept_ra();
+        }
+
         interface
             .write_config_file()
             .context(error::InterfaceConfigWriteSnafu)?;

sources/api/netdog/src/cli/mod.rs

@@ -155,13 +155,10 @@ where
     // Note: The dash (-) preceding the "net..." variable assignment below is important; it
     // ensures failure to set the variable for any reason will be logged, but not cause the sysctl
     // service to fail
-    // Accept router advertisement (RA) packets even if IPv6 forwarding is enabled on interface
-    let ipv6_accept_ra = format!("-net.ipv6.conf.{}.accept_ra = 2", interface);
     // Enable loose mode for reverse path filter
     let ipv4_rp_filter = format!("-net.ipv4.conf.{}.rp_filter = 2", interface);
 
     let mut output = String::new();
-    writeln!(output, "{}", ipv6_accept_ra).context(error::SysctlConfBuildSnafu)?;
     writeln!(output, "{}", ipv4_rp_filter).context(error::SysctlConfBuildSnafu)?;
 
     fs::write(path, output).context(error::SysctlConfWriteSnafu { path })?;
@@ -176,7 +173,7 @@ mod tests {
     fn default_sysctls() {
         let interface = "eno1";
         let fake_file = tempfile::NamedTempFile::new().unwrap();
-        let expected = "-net.ipv6.conf.eno1.accept_ra = 2\n-net.ipv4.conf.eno1.rp_filter = 2\n";
+        let expected = "-net.ipv4.conf.eno1.rp_filter = 2\n";
         write_interface_sysctl(interface, &fake_file).unwrap();
         assert_eq!(std::fs::read_to_string(&fake_file).unwrap(), expected);
     }

sources/api/netdog/src/wicked/mod.rs

@@ -78,6 +78,9 @@ pub(crate) struct WickedInterface {
     #[serde(rename = "ipv6:static")]
     pub(crate) ipv6_static: Option<WickedStaticAddress>,
     #[serde(skip_serializing_if = "Option::is_none")]
+    #[serde(rename = "ipv6")]
+    pub(crate) ipv6: Option<WickedIpv6>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     #[serde(rename = "vlan")]
     pub(crate) vlan_tag: Option<WickedVlanTag>,
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -162,6 +165,27 @@ struct LinkDetection {
     require_link: (),
 }
 
+#[derive(Debug, Serialize, PartialEq)]
+pub(crate) struct WickedIpv6 {
+    #[serde(rename = "$unflatten=accept-ra")]
+    accept_ra: WickedIpv6AcceptRA,
+}
+
+// There are technically a few options here, but currently we only use "router"
+#[derive(Debug, Clone, Serialize, PartialEq)]
+pub(crate) enum WickedIpv6AcceptRA {
+    #[serde(rename = "$primitive=router")]
+    Router,
+}
+
+impl Default for WickedIpv6 {
+    fn default() -> Self {
+        WickedIpv6 {
+            accept_ra: WickedIpv6AcceptRA::Router,
+        }
+    }
+}
+
 impl WickedInterface {
     pub(crate) fn new<I>(id: I) -> Self
     where
@@ -175,12 +199,19 @@ impl WickedInterface {
             ipv6_dhcp: None,
             ipv4_static: None,
             ipv6_static: None,
+            ipv6: None,
             vlan_tag: None,
             bond: None,
             link: None,
         }
     }
 
+    /// Add config to accept IPv6 router advertisements
+    // TODO: expose a network config option for this
+    pub(crate) fn accept_ra(&mut self) {
+        self.ipv6 = Some(WickedIpv6::default())
+    }
+
     /// Serialize the interface's configuration file
     pub(crate) fn write_config_file(&self) -> Result<()> {
         let mut cfg_path = Path::new(WICKED_CONFIG_DIR).join(self.name.to_string());
@@ -330,15 +361,34 @@ mod tests {
         for ok_str in ok {
             let net_config = NetConfigV1::from_str(ok_str).unwrap();
 
-            let wicked_interfaces = net_config.as_wicked_interfaces();
-            for interface in wicked_interfaces {
+            let mut wicked_interfaces = net_config.as_wicked_interfaces();
+            for interface in &mut wicked_interfaces {
                 let generated = quick_xml::se::to_string(&interface).unwrap();
-
                 let mut path = wicked_config().join(interface.name.to_string());
                 path.set_extension("xml");
-                let expected = fs::read_to_string(path).unwrap();
+                let expected = fs::read_to_string(&path).unwrap();
+
+                assert_eq!(
+                    expected.trim(),
+                    generated,
+                    "Generated output does not match file: {}",
+                    path.display()
+                );
 
-                assert_eq!(expected.trim(), generated)
+                // Add IPv6 `accept-ra` config to the interface, regenerate it, and ensure the
+                // generated config contains the added IPv6 option
+                interface.accept_ra();
+                let generated = quick_xml::se::to_string(&interface).unwrap();
+                let mut path = wicked_config().join(format!("{}-ra", interface.name.to_string()));
+                path.set_extension("xml");
+                let expected = fs::read_to_string(&path).unwrap();
+
+                assert_eq!(
+                    expected.trim(),
+                    generated,
+                    "Generated output does not match file: {}",
+                    path.display()
+                )
             }
         }
     }

sources/api/netdog/test_data/wicked/eno1-ra.xml

@@ -0,0 +1 @@
+<interface><name>eno1</name><control><mode>boot</mode><link-detection><require-link></require-link></link-detection></control><ipv4:dhcp><enabled>true</enabled></ipv4:dhcp><ipv6><accept-ra>router</accept-ra></ipv6></interface>

sources/api/netdog/test_data/wicked/eno10-ra.xml

@@ -0,0 +1 @@
+<interface><name>eno10</name><control><mode>boot</mode><link-detection><require-link></require-link></link-detection></control><ipv6:dhcp><enabled>true</enabled><defer-timeout>1</defer-timeout><flags><optional></optional></flags></ipv6:dhcp><ipv6><accept-ra>router</accept-ra></ipv6></interface>

sources/api/netdog/test_data/wicked/eno2-ra.xml

@@ -0,0 +1 @@
+<interface><name>eno2</name><control><mode>boot</mode><link-detection><require-link></require-link></link-detection></control><ipv6:dhcp><enabled>true</enabled></ipv6:dhcp><ipv6><accept-ra>router</accept-ra></ipv6></interface>

sources/api/netdog/test_data/wicked/eno5-ra.xml

@@ -0,0 +1 @@
+<interface><name>eno5</name><control><mode>boot</mode><link-detection><require-link></require-link></link-detection></control><ipv4:dhcp><enabled>true</enabled></ipv4:dhcp><ipv6:dhcp><enabled>true</enabled></ipv6:dhcp><ipv6><accept-ra>router</accept-ra></ipv6></interface>

sources/api/netdog/test_data/wicked/eno7-ra.xml

@@ -0,0 +1 @@
+<interface><name>eno7</name><control><mode>boot</mode><link-detection><require-link></require-link></link-detection></control><ipv4:dhcp><enabled>true</enabled></ipv4:dhcp><ipv6:dhcp><enabled>true</enabled><defer-timeout>1</defer-timeout><flags><optional></optional></flags></ipv6:dhcp><ipv6><accept-ra>router</accept-ra></ipv6></interface>

sources/api/netdog/test_data/wicked/eno8-ra.xml

@@ -0,0 +1 @@
+<interface><name>eno8</name><control><mode>boot</mode><link-detection><require-link></require-link></link-detection></control><ipv4:dhcp><enabled>true</enabled><defer-timeout>1</defer-timeout><flags><optional></optional></flags></ipv4:dhcp><ipv6:dhcp><enabled>true</enabled><defer-timeout>1</defer-timeout><flags><optional></optional></flags></ipv6:dhcp><ipv6><accept-ra>router</accept-ra></ipv6></interface>

sources/api/netdog/test_data/wicked/eno9-ra.xml

@@ -0,0 +1 @@
+<interface><name>eno9</name><control><mode>boot</mode><link-detection><require-link></require-link></link-detection></control><ipv4:dhcp><enabled>true</enabled><defer-timeout>1</defer-timeout><flags><optional></optional></flags></ipv4:dhcp><ipv6><accept-ra>router</accept-ra></ipv6></interface>