fix(agent): widen basic agent config types from Ipv4Addr to IpAddr

crates/agent/src/command_line.rs

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-use std::net::Ipv4Addr;
+use std::net::{IpAddr, Ipv4Addr};
 use std::path::PathBuf;
 
 use carbide_uuid::machine::MachineId;
@@ -88,7 +88,7 @@ pub struct NvueOptions {
     pub site_global_vpc_vni: Option<u32>,
 
     #[clap(long)]
-    pub loopback_ip: Ipv4Addr,
+    pub loopback_ip: IpAddr,
 
     #[clap(long)]
     pub asn: u32,
@@ -222,7 +222,7 @@ pub struct FrrOptions {
     #[clap(long)]
     pub asn: u32,
     #[clap(long)]
-    pub loopback_ip: Ipv4Addr,
+    pub loopback_ip: IpAddr,
     #[clap(long, help = "Format is 'id,host_route', e.g. --vlan 1,xyz. Repeats.")]
     pub vlan: Vec<String>,
     #[clap(long, default_value = "etv")]
@@ -243,7 +243,7 @@ pub struct InterfacesOptions {
     #[clap(long, help = "Full path of interfaces file")]
     pub path: String,
     #[clap(long)]
-    pub loopback_ip: Ipv4Addr,
+    pub loopback_ip: IpAddr,
     #[clap(long, help = "Blank for admin network, vxlan48 for tenant networks")]
     pub vni_device: String,
     #[clap(
@@ -261,6 +261,9 @@ pub struct DhcpOptions {
     pub path: String,
     #[clap(long, help = "vlan numeric id. Repeats")]
     pub vlan: Vec<u32>,
+    // Note that these will be staying IPv4 only for now. This
+    // config block is pretty tailored towards DHCPv4, and may
+    // get refactored a bit as part of adding DHCPv6 support.
     #[clap(long, help = "DHCP server IP address. Repeats")]
     pub dhcp: Vec<Ipv4Addr>,
     #[clap(long, help = "Remote ID to be filled in Option 82 - Agent Remote ID")]

crates/agent/src/ethernet_virtualization.rs

@@ -143,10 +143,14 @@ struct DhcpServerPaths {
     host_config: FPath,
 }
 
-/// Stores addresses of dependent services that the DHCP module announces
+/// Stores addresses of dependent services that the DHCP module announces.
+/// Note that these can apply to both IPv4 and IPv6; pxe_ip is actually
+/// UEFI HTTP boot in this case, and NTP is still NTP. We should be able
+/// to leverage this struct even in DHCPv6 land (whereas other things don't
+/// really carry through to DHCPv6).
 pub struct ServiceAddresses {
-    pub pxe_ip: Ipv4Addr,
-    pub ntpservers: Vec<Ipv4Addr>,
+    pub pxe_ip: IpAddr,
+    pub ntpservers: Vec<IpAddr>,
     pub nameservers: Vec<IpAddr>,
 }
 
@@ -519,6 +523,9 @@ pub async fn update_traffic_intercept_bridging(
         }
     };
 
+    // IPv4 only for now. Internal HBN bridge plumbing uses 169.254.x.x
+    // link-local addressing for DPU to HBN communication. An IPv6 equivalent
+    // (fe80:: or similar) may be needed in the future for dual-stack bridging.
     let bridge_prefix = bridge_config
         .internal_bridge_routing_prefix
         .parse::<Ipv4Net>()?;
@@ -1029,6 +1036,10 @@ pub async fn reset(
 // 2. Copy dhcp_config file
 // 3. Copy host_config file
 // 4. Reload supervisord
+//
+// This is currently scoped to IPv4 only, and there are
+// a few IPv4-specific checks for things like NTP servers,
+// UEFI HTTP/PXE IP, and nameservers below.
 fn write_dhcp_server_config(
     dhcp_relay_path: &FPath,
     dhcp_server_path: &DhcpServerPaths,
@@ -1093,7 +1104,11 @@ fn write_dhcp_server_config(
 
     let loopback_ip = mh_nc.loopback_ip.parse()?;
 
-    let nameservers = service_addrs
+    // Filter nameservers, NTP servers, and our UEFI HTTP server
+    // addresses to IPv4 for the DHCPv4 server config. Now that
+    // ServiceAddresses holds both families, we need to ensure
+    // DHCPv4 options only carry IPv4 addresses.
+    let nameservers_v4 = service_addrs
         .nameservers
         .iter()
         .filter_map(|x| match x {
@@ -1102,6 +1117,25 @@ fn write_dhcp_server_config(
         })
         .collect::<Vec<Ipv4Addr>>();
 
+    let ntpservers_v4 = service_addrs
+        .ntpservers
+        .iter()
+        .filter_map(|x| match x {
+            IpAddr::V4(x) => Some(*x),
+            _ => None,
+        })
+        .collect::<Vec<Ipv4Addr>>();
+
+    let pxe_ip_v4 = match service_addrs.pxe_ip {
+        IpAddr::V4(v4) => v4,
+        IpAddr::V6(_) => {
+            return Err(eyre::eyre!(
+                "DHCPv4 server config requires an IPv4 PXE/UEFI HTTP boot address, got {}",
+                service_addrs.pxe_ip
+            ));
+        }
+    };
+
     let mut has_changes = false;
 
     let next_contents =
@@ -1120,12 +1154,8 @@ fn write_dhcp_server_config(
         Err(err) => tracing::error!("Write DHCP server {}: {err:#}", dhcp_server_path.server),
     }
 
-    let next_contents = dhcp::build_server_config(
-        service_addrs.pxe_ip,
-        service_addrs.ntpservers.clone(),
-        nameservers,
-        loopback_ip,
-    )?;
+    let next_contents =
+        dhcp::build_server_config(pxe_ip_v4, ntpservers_v4, nameservers_v4, loopback_ip)?;
     match write(
         next_contents,
         &dhcp_server_path.config,
@@ -2974,11 +3004,11 @@ mod tests {
         let ip = FPath(PathBuf::from(i.path()));
 
         let service_addrs = ServiceAddresses {
-            pxe_ip: Ipv4Addr::from([10, 0, 0, 1]),
+            pxe_ip: IpAddr::from([10, 0, 0, 1]),
             ntpservers: vec![
-                Ipv4Addr::from([127, 0, 0, 1]),
-                Ipv4Addr::from([127, 0, 0, 2]),
-                Ipv4Addr::from([127, 0, 0, 3]),
+                IpAddr::from([127, 0, 0, 1]),
+                IpAddr::from([127, 0, 0, 2]),
+                IpAddr::from([127, 0, 0, 3]),
             ],
             nameservers: vec![IpAddr::from([10, 1, 1, 1])],
         };
@@ -3042,7 +3072,7 @@ mod tests {
         assert!(host_config_str.contains("mtu: 1500"));
 
         let service_addrs = ServiceAddresses {
-            pxe_ip: Ipv4Addr::from([10, 0, 0, 1]),
+            pxe_ip: IpAddr::from([10, 0, 0, 1]),
             ntpservers: vec![],
             nameservers: vec![IpAddr::from([10, 1, 1, 1])],
         };

crates/agent/src/frr.rs

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-use std::net::Ipv4Addr;
+use std::net::IpAddr;
 
 use gtmpl_derive::Gtmpl;
 
@@ -76,7 +76,7 @@ pub fn blank() -> String {
 /// What we need in order to generate an frr.conf
 pub struct FrrConfig {
     pub asn: u32,
-    pub loopback_ip: Ipv4Addr,
+    pub loopback_ip: IpAddr,
     pub uplinks: Vec<String>,
     pub access_vlans: Vec<FrrVlanConfig>,
     pub vpc_vni: Option<u32>,
@@ -116,6 +116,8 @@ struct TmplFrrConfigParameters {
 
 #[cfg(test)]
 mod tests {
+    use std::net::Ipv4Addr;
+
     use super::{FrrConfig, build};
     use crate::HBNDeviceNames;
 
@@ -128,7 +130,7 @@ mod tests {
                 .iter()
                 .map(|x| x.to_string())
                 .collect(),
-            loopback_ip: [192, 168, 0, 1].into(),
+            loopback_ip: Ipv4Addr::from([192, 168, 0, 1]).into(),
             access_vlans: vec![],
             vpc_vni: None,
             route_servers: vec![],

crates/agent/src/interfaces.rs

@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-use std::net::Ipv4Addr;
+use std::net::IpAddr;
 
 use gtmpl_derive::Gtmpl;
 use serde::Deserialize;
@@ -55,7 +55,7 @@ pub fn blank() -> String {
 }
 
 pub struct InterfacesConfig {
-    pub loopback_ip: Ipv4Addr,
+    pub loopback_ip: IpAddr,
     pub uplinks: Vec<String>,
     pub vni_device: String,
     pub networks: Vec<Network>,

crates/agent/src/main_loop.rs

@@ -17,7 +17,7 @@
 
 use std::collections::HashSet;
 use std::ffi::OsStr;
-use std::net::{IpAddr, Ipv4Addr};
+use std::net::IpAddr;
 use std::ops::Add;
 use std::path::PathBuf;
 use std::str::FromStr;
@@ -230,13 +230,13 @@ pub async fn setup_and_run(
 
         let nameservers = url_resolver.nameservers();
         ServiceAddresses {
-            pxe_ip,
-            ntpservers,
+            pxe_ip: pxe_ip.into(),
+            ntpservers: ntpservers.into_iter().map(IpAddr::from).collect(),
             nameservers,
         }
     } else {
         ServiceAddresses {
-            pxe_ip: Ipv4Addr::from([127, 0, 0, 1]),
+            pxe_ip: IpAddr::from([127, 0, 0, 1]),
             ntpservers: vec![],
             nameservers: vec![IpAddr::from([127, 0, 0, 1])],
         }

crates/agent/src/nvue.rs

@@ -302,6 +302,9 @@ pub fn build(conf: NvueConfig) -> eyre::Result<String> {
         vf_intercept_hbn_representor_ip,
         public_prefix_internal_next_hop,
         intercept_bridge_prefix_len,
+        // IPv4 only for now. Internal HBN bridge plumbing uses 169.254.x.x
+        // link-local addressing for DPU to HBN communication. An IPv6 equivalent
+        // (fe80:: or similar) may be needed in the future for dual-stack bridging.
     ) = if let Some(bridge_prefix) = conf
         .internal_bridge_routing_prefix
         .map(|p| p.parse::<Ipv4Net>())