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Support for native vlan id on command line with interfaces #25

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93b0b82
Added support to optionally specify native vlan id with capture inter…
jhogg Nov 3, 2025
f54b512
Changed native vlan command line to use ':' (colon) instead of ',' (c…
jhogg Nov 27, 2025
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1 change: 1 addition & 0 deletions src/main.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -52,6 +52,7 @@ pub struct Cli {
command: Option<Commands>,

/// Network interface(s) to monitor. Can be specified multiple times. If not specified, monitors all interfaces.
/// Use INTERFACE:native_vlan_id to specify native VLAN for untagged traffic.
#[arg(short, long, conflicts_with = "pcap_file")]
interface: Vec<String>,

Expand Down
4 changes: 2 additions & 2 deletions src/ptp.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -739,7 +739,7 @@ pub struct PtpTracker {
// Track recent sync/follow-up senders per domain for transmitter-receiver correlation
recent_sync_senders: HashMap<u8, Vec<(ClockIdentity, Instant)>>,
// Track interfaces for determining inbound interface of packets
interfaces: Vec<(String, Option<std::net::Ipv4Addr>)>,
interfaces: Vec<(String, Option<std::net::Ipv4Addr>, Option<u16>)>,
}

impl PtpTracker {
Expand Down Expand Up @@ -1013,7 +1013,7 @@ impl PtpTracker {
pub fn get_local_ips(&self) -> Vec<IpAddr> {
self.interfaces
.iter()
.filter_map(|(_, ip)| ip.map(std::net::IpAddr::V4))
.filter_map(|(_, ip, _)| ip.map(std::net::IpAddr::V4))
.collect()
}

Expand Down
65 changes: 47 additions & 18 deletions src/source.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,8 @@ const GPTP_ETHERTYPE: u16 = 0x88f7;
/// gPTP multicast MAC address (IEEE 802.1AS)
const GPTP_MULTICAST_MAC: [u8; 6] = [0x01, 0x80, 0xc2, 0x00, 0x00, 0x0e];

type InterfaceSourceType = (String, Option<Ipv4Addr>, Option<u16>);

#[derive(Debug, Clone)]
pub struct RawPacket {
pub timestamp: std::time::SystemTime,
Expand All @@ -43,7 +45,7 @@ pub struct RawPacket {
pub enum PacketSource {
Socket {
receiver: mpsc::UnboundedReceiver<RawPacket>,
interfaces: Vec<(String, Option<Ipv4Addr>)>,
interfaces: Vec<InterfaceSourceType>,
_multicast_sockets: Vec<Socket>,
},
Pcap {
Expand Down Expand Up @@ -77,7 +79,7 @@ impl RawSocketReceiver {
}
}

pub fn get_interfaces(&self) -> &[(String, Option<Ipv4Addr>)] {
pub fn get_interfaces(&self) -> &[InterfaceSourceType] {
match &self.source {
PacketSource::Socket { interfaces, .. } => interfaces,
PacketSource::Pcap { .. } => &[],
Expand Down Expand Up @@ -106,7 +108,7 @@ fn iface_addrs_by_name(ifname: &str) -> io::Result<Option<Ipv4Addr>> {
Ok(v4)
}

fn get_all_interface_addrs() -> io::Result<Vec<(String, Option<Ipv4Addr>)>> {
fn get_all_interface_addrs() -> io::Result<Vec<InterfaceSourceType>> {
let mut interfaces = Vec::new();

// Get available interfaces using pnet datalink
Expand All @@ -119,12 +121,13 @@ fn get_all_interface_addrs() -> io::Result<Vec<(String, Option<Ipv4Addr>)>> {
}

let interface_name = iface.name.clone();
let native_vlan_id: Option<u16> = None;

// Get IPv4 addresses for this interface
for ip in &iface.ips {
if let IpAddr::V4(ipv4) = ip.ip() {
if !ipv4.is_loopback() && is_suitable_interface_name(&interface_name) {
interfaces.push((interface_name.clone(), Some(ipv4)));
interfaces.push((interface_name.clone(), Some(ipv4), native_vlan_id));
break; // Only take first IPv4 address per interface
} else {
println!("Excluding interface: {} (filtered)", interface_name);
Expand Down Expand Up @@ -185,7 +188,11 @@ fn join_multicast_group(interface_name: &str, interface_addr: Ipv4Addr) -> Resul
Ok(socket)
}

fn process_ethernet_packet(packet_data: &[u8], interface_name: &str) -> Option<RawPacket> {
fn process_ethernet_packet(
packet_data: &[u8],
interface_name: &str,
native_vlan_id: Option<u16>,
) -> Option<RawPacket> {
let ethernet = EthernetPacket::new(packet_data)?;

let mut vlan_id: Option<u16> = None;
Expand Down Expand Up @@ -258,7 +265,7 @@ fn process_ethernet_packet(packet_data: &[u8], interface_name: &str) -> Option<R
source_mac,
dest_addr,
dest_mac,
vlan_id,
vlan_id: vlan_id.or(native_vlan_id),
ttl: None, // No TTL in Layer 2
interface_name: interface_name.to_string(),
ptp_payload,
Expand Down Expand Up @@ -306,7 +313,7 @@ fn process_ethernet_packet(packet_data: &[u8], interface_name: &str) -> Option<R
source_mac,
dest_addr,
dest_mac,
vlan_id,
vlan_id: vlan_id.or(native_vlan_id),
ttl,
interface_name: interface_name.to_string(),
ptp_payload,
Expand All @@ -319,6 +326,7 @@ fn process_ethernet_packet(packet_data: &[u8], interface_name: &str) -> Option<R

async fn capture_on_interface(
interface_name: String,
native_vlan_id: Option<u16>,
sender: mpsc::UnboundedSender<RawPacket>,
_multicast_socket: Socket,
) -> Result<()> {
Expand Down Expand Up @@ -354,7 +362,8 @@ async fn capture_on_interface(
loop {
match rx.next() {
Ok(packet_data) => {
if let Some(raw_packet) = process_ethernet_packet(packet_data, &interface_name)
if let Some(raw_packet) =
process_ethernet_packet(packet_data, &interface_name, native_vlan_id)
&& sender.send(raw_packet).is_err()
{
// Receiver has been dropped, exit the loop
Expand Down Expand Up @@ -383,8 +392,18 @@ pub async fn create_raw_socket_receiver(ifnames: &[String]) -> Result<RawSocketR
// Use specified interfaces
let mut interfaces = Vec::new();
for ifname in ifnames {
let iface_v4 = iface_addrs_by_name(ifname)?;
interfaces.push((ifname.clone(), iface_v4));
let parts: Vec<&str> = ifname.split(":").collect();
let mut native_vlan_id: Option<u16> = None;
let mut ifname_clone = ifname.clone();

if parts.len() > 1 {
ifname_clone = parts[0].to_string().clone();
native_vlan_id = parts[1].parse::<u16>().ok();
}

let iface_v4 = iface_addrs_by_name(&ifname_clone)?;

interfaces.push((ifname_clone, iface_v4, native_vlan_id));
}
interfaces
};
Expand All @@ -399,7 +418,11 @@ pub async fn create_raw_socket_receiver(ifnames: &[String]) -> Result<RawSocketR
"Starting live capture on: {}",
target_interfaces
.iter()
.map(|(name, _)| name.as_str())
.map(|(name, _, vlan_id)| format!(
"{0}({1})",
name.as_str(),
vlan_id.unwrap_or_default()
))
.collect::<Vec<_>>()
.join(", ")
);
Expand All @@ -408,9 +431,10 @@ pub async fn create_raw_socket_receiver(ifnames: &[String]) -> Result<RawSocketR

// Set up multicast group membership and start packet capture for each interface
let mut multicast_sockets = Vec::new();
for (interface_name, interface_addr) in &target_interfaces {
for (interface_name, interface_addr, native_vlan_id) in &target_interfaces {
let sender_clone = sender.clone();
let interface_name_clone = interface_name.clone();
let native_vlan_id_clone = *native_vlan_id;

// Try to join multicast group if interface has an IP address
let multicast_socket = if let Some(interface_addr) = interface_addr {
Expand All @@ -435,6 +459,7 @@ pub async fn create_raw_socket_receiver(ifnames: &[String]) -> Result<RawSocketR
}
}
} else {
println!("Registered {} for generic socket", interface_name);
// Create a dummy socket for interfaces without IP addresses
Socket::new(
socket2::Domain::IPV4,
Expand All @@ -448,9 +473,13 @@ pub async fn create_raw_socket_receiver(ifnames: &[String]) -> Result<RawSocketR
// Stagger startup to reduce resource contention
tokio::time::sleep(Duration::from_millis(200)).await;

if let Err(e) =
capture_on_interface(interface_name_clone.clone(), sender_clone, multicast_socket)
.await
if let Err(e) = capture_on_interface(
interface_name_clone.clone(),
native_vlan_id_clone,
sender_clone,
multicast_socket,
)
.await
{
eprintln!("Packet capture error on {}: {}", interface_name_clone, e);
}
Expand Down Expand Up @@ -484,7 +513,7 @@ pub async fn create_pcap_receiver(pcap_path: &str) -> Result<RawSocketReceiver>
match block {
Ok(pcap_file::pcapng::Block::EnhancedPacket(epb)) => {
let packet_data = epb.data;
if let Some(raw_packet) = process_ethernet_packet(&packet_data, "pcap") {
if let Some(raw_packet) = process_ethernet_packet(&packet_data, "pcap", None) {
if last_timestamp.is_none()
|| raw_packet.timestamp > last_timestamp.unwrap()
{
Expand All @@ -495,7 +524,7 @@ pub async fn create_pcap_receiver(pcap_path: &str) -> Result<RawSocketReceiver>
}
Ok(pcap_file::pcapng::Block::SimplePacket(spb)) => {
let packet_data = spb.data;
if let Some(raw_packet) = process_ethernet_packet(&packet_data, "pcap") {
if let Some(raw_packet) = process_ethernet_packet(&packet_data, "pcap", None) {
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Collaborator

@zonque zonque Nov 10, 2025

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Ah, and I also missed this detail. I really think working with pcap files is immensely helpful, especially for more complex features, and hence we need to have a way to express "this pcap was captured with native VLAN X".

if last_timestamp.is_none()
|| raw_packet.timestamp > last_timestamp.unwrap()
{
Expand Down Expand Up @@ -525,7 +554,7 @@ pub async fn create_pcap_receiver(pcap_path: &str) -> Result<RawSocketReceiver>
match pkt {
Ok(packet) => {
let packet_data = packet.data;
if let Some(raw_packet) = process_ethernet_packet(&packet_data, "pcap") {
if let Some(raw_packet) = process_ethernet_packet(&packet_data, "pcap", None) {
if last_timestamp.is_none()
|| raw_packet.timestamp > last_timestamp.unwrap()
{
Expand Down