IPv6 support for SSDP (for UPNP)

Cargo.lock

@@ -2692,6 +2692,7 @@ dependencies = [
  "gethostname",
  "http 1.1.0",
  "httparse",
+ "libc",
  "librqbit-core",
  "librqbit-sha1-wrapper",
  "librqbit-upnp",

Makefile

@@ -13,7 +13,7 @@ webui-dev: webui-deps
 # NOTE: on LG TV using hostname is unstable for some reason, use IP address.
 export RQBIT_UPNP_SERVER_ENABLE ?= true
 export RQBIT_UPNP_SERVER_FRIENDLY_NAME ?= rqbit-dev
-export RQBIT_HTTP_API_LISTEN_ADDR ?= 0.0.0.0:3030
+export RQBIT_HTTP_API_LISTEN_ADDR ?= [::]:3030
 export RQBIT_FASTRESUME = true
 CARGO_RUN_FLAGS ?=
 RQBIT_OUTPUT_FOLDER ?= /tmp/scratch

crates/upnp-serve/Cargo.toml

@@ -39,6 +39,7 @@ socket2 = "0.5.7"
 quick-xml = { version = "0.36.1", features = ["serialize"] }
 network-interface = "2.0.0"
 futures = "0.3.30"
+libc = "0.2.158"
 
 [dev-dependencies]
 tracing-subscriber = "0.3.18"

crates/upnp-serve/src/ssdp.rs

@@ -1,24 +1,33 @@
 use std::{
-    net::{Ipv4Addr, SocketAddr, SocketAddrV4},
+    collections::HashSet,
+    net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6},
+    os::fd::{AsFd, AsRawFd},
     time::Duration,
 };
 
 use anyhow::{bail, Context};
 use bstr::BStr;
 use network_interface::NetworkInterfaceConfig;
+use parking_lot::Mutex;
 use tokio::net::UdpSocket;
 use tokio_util::sync::CancellationToken;
 use tracing::{debug, trace, warn};
 
 use crate::constants::{UPNP_KIND_MEDIASERVER, UPNP_KIND_ROOT_DEVICE};
 
-const UPNP_PORT: u16 = 1900;
+const SSDP_PORT: u16 = 1900;
-const UPNP_BROADCAST_IP: Ipv4Addr = Ipv4Addr::new(239, 255, 255, 250);
+const SSDM_MCAST_IPV4: Ipv4Addr = Ipv4Addr::new(239, 255, 255, 250);
-const UPNP_BROADCAST_ADDR: SocketAddrV4 = SocketAddrV4::new(UPNP_BROADCAST_IP, UPNP_PORT);
+const SSDP_MCAST_IPV6_LINK_LOCAL: Ipv6Addr = Ipv6Addr::new(0xff02, 0, 0, 0, 0, 0, 0, 0xc);
+const SSDP_MCAST_IPV6_SITE_LOCAL: Ipv6Addr = Ipv6Addr::new(0xff05, 0, 0, 0, 0, 0, 0, 0xc);
 
 const NTS_ALIVE: &str = "ssdp:alive";
 const NTS_BYEBYE: &str = "ssdp:byebye";
 
+fn ipv6_is_link_local(ip: Ipv6Addr) -> bool {
+    let s = ip.segments();
+    [s[0], s[1], s[2], s[3]] == [0xfe80, 0, 0, 0]
+}
+
 #[derive(Debug)]
 pub enum SsdpMessage<'a, 'h> {
     MSearch(SsdpMSearchRequest<'a>),
@@ -30,6 +39,7 @@ pub enum SsdpMessage<'a, 'h> {
 
 #[derive(Debug)]
 pub struct SsdpMSearchRequest<'a> {
+    #[allow(dead_code)]
     pub host: &'a BStr,
     pub man: &'a BStr,
     pub st: &'a BStr,
@@ -37,9 +47,6 @@ pub struct SsdpMSearchRequest<'a> {
 
 impl<'a> SsdpMSearchRequest<'a> {
     fn matches_media_server(&self) -> bool {
-        if self.host != "239.255.255.250:1900" {
-            return false;
-        }
         if self.man != "\"ssdp:discover\"" {
             return false;
         }
@@ -103,61 +110,171 @@ pub struct SsdpRunnerOptions {
 
 pub struct SsdpRunner {
     opts: SsdpRunnerOptions,
-    socket: UdpSocket,
+    socket_v4: Option<UdpSocket>,
+    socket_v6: Option<UdpSocket>,
+}
+
+fn socket_presetup(bind_addr: SocketAddr) -> anyhow::Result<tokio::net::UdpSocket> {
+    let domain = if bind_addr.is_ipv4() {
+        socket2::Domain::IPV4
+    } else {
+        socket2::Domain::IPV6
+    };
+    let sock = socket2::Socket::new(domain, socket2::Type::DGRAM, None)
+        .context(bind_addr)
+        .context("error creating socket")?;
+    #[cfg(not(target_os = "windows"))]
+    sock.set_reuse_port(true)
+        .context("error setting SO_REUSEPORT")?;
+    sock.set_reuse_address(true)
+        .context("error setting SO_REUSEADDR")?;
+
+    trace!(addr=?bind_addr, "binding UDP");
+    sock.bind(&bind_addr.into())
+        .context(bind_addr)
+        .context("error binding")?;
+
+    sock.set_nonblocking(true)?;
+    let socket = tokio::net::UdpSocket::from_std(sock.into())
+        .context("error converting socket2 socket to tokio")?;
+
+    Ok(socket)
+}
+
+async fn bind_v4_socket() -> anyhow::Result<UdpSocket> {
+    let bind_addr = SocketAddrV4::new(Ipv4Addr::UNSPECIFIED, SSDP_PORT);
+    let socket = socket_presetup(bind_addr.into())?;
+
+    let default_multiast_membership_ip = std::iter::once(Ipv4Addr::UNSPECIFIED);
+    let all_multicast_membership_ips = network_interface::NetworkInterface::show()
+        .into_iter()
+        .flatten()
+        .flat_map(|nic| nic.addr.into_iter())
+        .filter_map(|addr| {
+            let ip = addr.ip();
+            match ip {
+                std::net::IpAddr::V4(addr) if addr.is_private() && !addr.is_loopback() => {
+                    Some(addr)
+                }
+                _ => None,
+            }
+        });
+
+    for ifaddr in default_multiast_membership_ip.chain(all_multicast_membership_ips) {
+        trace!(multiaddr=?SSDM_MCAST_IPV4, interface=?ifaddr, "joining multicast v4 group");
+        if let Err(e) = socket.join_multicast_v4(SSDM_MCAST_IPV4, ifaddr) {
+            debug!(multiaddr=?SSDM_MCAST_IPV4, interface=?ifaddr, "error joining multicast v4 group: {e:#}");
+        }
+    }
+
+    Ok(socket)
+}
+
+async fn bind_v6_socket() -> anyhow::Result<UdpSocket> {
+    let bind_addr = SocketAddrV6::new(Ipv6Addr::UNSPECIFIED, SSDP_PORT, 0, 0);
+    let socket = socket_presetup(bind_addr.into())?;
+
+    for nic in network_interface::NetworkInterface::show()
+        .into_iter()
+        .flatten()
+    {
+        let mut has_link_local = false;
+        let mut has_site_local = false;
+        for addr in nic.addr.iter() {
+            let addr = match addr.ip() {
+                IpAddr::V4(_) => continue,
+                IpAddr::V6(v6) => v6,
+            };
+            if addr.is_loopback() {
+                continue;
+            }
+            if ipv6_is_link_local(addr) {
+                has_link_local = true;
+            } else {
+                has_site_local = true;
+            }
+        }
+        for (present, multiaddr) in [
+            (has_link_local, SSDP_MCAST_IPV6_LINK_LOCAL),
+            (has_site_local, SSDP_MCAST_IPV6_SITE_LOCAL),
+        ] {
+            if !present {
+                continue;
+            }
+            if let Err(e) = socket.join_multicast_v6(&multiaddr, nic.index) {
+                debug!(multiaddr=?multiaddr, interface=?nic.index, "error joining multicast v6 group: {e:#}");
+            }
+        }
+    }
+
+    Ok(socket)
+}
+
+struct MulticastOpts {
+    local_interface_ip: IpAddr,
+    #[allow(dead_code)]
+    local_interface_id: u32,
+    addr: SocketAddr,
+}
+
+fn set_mcast_if(sock: &UdpSocket, local_ip: Ipv4Addr) -> std::io::Result<()> {
+    let addr = libc::in_addr {
+        s_addr: u32::from_ne_bytes(local_ip.octets()),
+    };
+    const SZ: usize = std::mem::size_of::<libc::in_addr>();
+
+    trace!(addr = %local_ip, "setting IP_MULTICAST_IF");
+    let ret = unsafe {
+        libc::setsockopt(
+            sock.as_fd().as_raw_fd(),
+            libc::IPPROTO_IP,
+            libc::IP_MULTICAST_IF,
+            &addr as *const _ as _,
+            SZ as u32,
+        )
+    };
+    if ret < 0 {
+        return Err(std::io::Error::last_os_error());
+    }
+    Ok(())
+}
+
+impl MulticastOpts {
+    fn addr_no_scope(&self) -> SocketAddr {
+        let mut addr = self.addr;
+        if let SocketAddr::V6(v6) = &mut addr {
+            v6.set_scope_id(0);
+        }
+        addr
+    }
 }
 
 impl SsdpRunner {
     pub async fn new(opts: SsdpRunnerOptions) -> anyhow::Result<Self> {
-        let bind_addr = SocketAddrV4::new(Ipv4Addr::UNSPECIFIED, UPNP_PORT);
+        let socket_v4 = bind_v4_socket()
-        let sock = socket2::Socket::new(socket2::Domain::IPV4, socket2::Type::DGRAM, None)
+            .await
-            .context("error creating socket")?;
+            .map_err(|e| warn!("error creating IPv4 SSDP socket: {e:#}"))
-        #[cfg(not(target_os = "windows"))]
+            .ok();
-        sock.set_reuse_port(true)
+        let socket_v6 = bind_v6_socket()
-            .context("error setting SO_REUSEPORT")?;
+            .await
-        sock.set_reuse_address(true)
+            .map_err(|e| warn!("error creating IPv6 SSDP socket: {e:#}"))
-            .context("error setting SO_REUSEADDR")?;
+            .ok();
-
+        Ok(Self {
-        trace!(addr=?bind_addr, "binding UDP");
+            opts,
-        sock.bind(&bind_addr.into())
+            socket_v4,
-            .context(bind_addr)
+            socket_v6,
-            .context("error binding")?;
+        })
-
-        sock.set_nonblocking(true)?;
-        let socket = tokio::net::UdpSocket::from_std(sock.into())
-            .context("error converting socket2 socket to tokio")?;
-
-        let default_multiast_membership_ip = std::iter::once(Ipv4Addr::UNSPECIFIED);
-        let all_multicast_membership_ips = network_interface::NetworkInterface::show()
-            .into_iter()
-            .flatten()
-            .flat_map(|nic| nic.addr.into_iter())
-            .filter_map(|addr| {
-                let ip = addr.ip();
-                match ip {
-                    std::net::IpAddr::V4(addr) if addr.is_private() && !addr.is_loopback() => {
-                        Some(addr)
-                    }
-                    _ => None,
-                }
-            });
-
-        for ifaddr in default_multiast_membership_ip.chain(all_multicast_membership_ips) {
-            trace!(multiaddr=?UPNP_BROADCAST_IP, interface=?ifaddr, "joining multicast v4 group");
-            if let Err(e) = socket.join_multicast_v4(UPNP_BROADCAST_IP, ifaddr) {
-                debug!(error=?e, multiaddr=?UPNP_BROADCAST_IP, interface=?ifaddr, "error joining multicast v4 group");
-            }
-        }
-
-        Ok(Self { opts, socket })
     }
 
-    fn generate_notify_message(&self, kind: &str, nts: &str, location: &url::Url) -> String {
+    fn generate_notify_message(&self, kind: &str, nts: &str, opts: &MulticastOpts) -> String {
         let usn: &str = &self.opts.usn;
         let server: &str = &self.opts.server_string;
-        let bcast_addr = UPNP_BROADCAST_ADDR;
+        let host = opts.addr_no_scope();
+        let mut location = self.opts.description_http_location.clone();
+        let _ = location.set_ip_host(opts.local_interface_ip);
         format!(
             "NOTIFY * HTTP/1.1\r
-Host: {bcast_addr}\r
+Host: {host}\r
 Cache-Control: max-age=75\r
 Location: {location}\r
 NT: {kind}\r
@@ -177,7 +294,7 @@ USN: {usn}::{kind}\r
         let local_ip = ::librqbit_upnp::get_local_ip_relative_to(addr.ip())?;
         let location = {
             let mut loc = self.opts.description_http_location.clone();
-            loc.set_host(Some(&format!("{local_ip}")))?;
+            let _ = loc.set_ip_host(local_ip);
             loc
         };
         let usn = &self.opts.usn;
@@ -194,7 +311,10 @@ Content-Length: 0\r\n\r\n"
         ))
     }
 
-    async fn try_send_notifies(&self, nts: &str) {
+    async fn try_send_mcast_everywhere(
+        &self,
+        get_payload: &impl Fn(&MulticastOpts) -> bstr::BString,
+    ) {
         use network_interface::NetworkInterfaceConfig;
         let interfaces = network_interface::NetworkInterface::show();
         let interfaces = match interfaces {
@@ -205,52 +325,79 @@ Content-Length: 0\r\n\r\n"
             }
         };
 
+        let sent = Mutex::new(HashSet::new());
+        let sent = &sent;
+
         let futs = interfaces
             .into_iter()
-            .flat_map(|ni| ni.addr)
+            .flat_map(|ni| ni.addr.into_iter().map(move |a| (ni.index, a)))
-            .filter_map(|addr| {
+            .filter_map(|(ifidx, addr)| match addr.ip() {
-                match addr.ip() {
+                std::net::IpAddr::V4(a) if !a.is_loopback() && a.is_private() => {
-                    std::net::IpAddr::V4(a) if !a.is_loopback() && a.is_private() => Some(a),
+                    Some(MulticastOpts {
-                    _ => None
+                        local_interface_ip: addr.ip(),
+                        local_interface_id: ifidx,
+                        addr: SocketAddr::V4(SocketAddrV4::new(SSDM_MCAST_IPV4, SSDP_PORT)),
+                    })
                 }
+                std::net::IpAddr::V6(a) if !a.is_loopback() => Some(MulticastOpts {
+                    local_interface_ip: addr.ip(),
+                    local_interface_id: ifidx,
+                    addr: {
+                        let bip = if ipv6_is_link_local(a) {
+                            SSDP_MCAST_IPV6_LINK_LOCAL
+                        } else {
+                            SSDP_MCAST_IPV6_SITE_LOCAL
+                        };
+                        SocketAddr::V6(SocketAddrV6::new(bip, SSDP_PORT, 0, ifidx))
+                    },
+                }),
+                _ => None,
             })
-            .map(|ip| async move {
+            .map(|opts| async move {
-                let addr = SocketAddrV4::new(ip, 0);
+                let payload = get_payload(&opts);
-                let sock = match tokio::net::UdpSocket::bind(addr).await {
+                if !sent
-                    Ok(sock) => sock,
+                    .lock()
-                    Err(e) => {
+                    .insert((payload.clone(), opts.local_interface_id, opts.addr))
-                        debug!(%addr, error=?e, "error binding UDP to send NOTIFY");
+                {
-                        return;
+                    // don't send duplicates
+                    return;
+                }
+
+                let sock = match (
+                    opts.local_interface_ip,
+                    self.socket_v4.as_ref(),
+                    self.socket_v6.as_ref(),
+                ) {
+                    (IpAddr::V4(ip), Some(sock_v4), _) => {
+                        if let Err(e) = set_mcast_if(sock_v4, ip) {
+                            debug!(addr=%ip, "error calling set_mcast_if: {e:#}");
+                        }
+                        sock_v4
                     }
+                    (IpAddr::V6(_), _, Some(sock_v6)) => sock_v6,
+                    _ => return,
                 };
 
-                let mut location = self.opts.description_http_location.clone();
+                match sock.send_to(payload.as_slice(), opts.addr).await {
-                location.set_host(Some(&format!("{ip}"))).unwrap();
+                    Ok(sz) => trace!(payload=?payload, addr=%opts.addr, size=sz, "sent"),
-
+                    Err(e) => {
-                macro_rules! gen {
+                        debug!(payload=?payload, addr=%opts.addr, "error sending: {e:#}")
-                    ($kind:expr) => {
-                        async {
-                            let msg = self.generate_notify_message($kind, nts, &location);
-                            trace!(content=?msg, addr=?UPNP_BROADCAST_ADDR, "sending SSDP NOTIFY");
-                            if let Err(e) = sock.send_to(msg.as_bytes(), UPNP_BROADCAST_ADDR).await {
-                                debug!(sock_addr=%addr, error=%e, kind=$kind, nts, "error sending SSDP NOTIFY")
-                            } else {
-                                debug!(kind=$kind, nts, %location, "sent SSDP NOTIFY")
-                            }
-                        }
                     }
-                }
+                };
-
-                let f1 = gen!(UPNP_KIND_ROOT_DEVICE);
-                let f2 = gen!(UPNP_KIND_MEDIASERVER) ;
-
-                tokio::join!(f1, f2);
             });
 
         futures::future::join_all(futs).await;
     }
 
-    async fn task_send_alive_notifies_periodically(&self) -> anyhow::Result<()> {
+    async fn try_send_notifies(&self, nts: &str) {
+        self.try_send_mcast_everywhere(&|opts| {
+            self.generate_notify_message(UPNP_KIND_MEDIASERVER, nts, opts)
+                .into()
+        })
+        .await
+    }
+
+    async fn task_send_alive_notifies_periodically(&self) {
         let mut interval = tokio::time::interval(self.opts.notify_interval);
         loop {
             interval.tick().await;
@@ -258,7 +405,12 @@ Content-Length: 0\r\n\r\n"
         }
     }
 
-    async fn process_incoming_message(&self, msg: &[u8], addr: SocketAddr) -> anyhow::Result<()> {
+    async fn process_incoming_message(
+        &self,
+        msg: &[u8],
+        sock: &UdpSocket,
+        addr: SocketAddr,
+    ) -> anyhow::Result<()> {
         let mut headers = [httparse::EMPTY_HEADER; 16];
         trace!(content = ?BStr::new(msg), ?addr, "received message");
         let parsed = try_parse_ssdp(msg, &mut headers);
@@ -281,8 +433,7 @@ Content-Length: 0\r\n\r\n"
         if let Ok(st) = std::str::from_utf8(msg.st) {
             let response = self.generate_ssdp_discover_response(st, addr)?;
             trace!(content = response, ?addr, "sending SSDP discover response");
-            self.socket
+            sock.send_to(response.as_bytes(), addr)
-                .send_to(response.as_bytes(), addr)
                 .await
                 .context("error sending")?;
         }
@@ -290,51 +441,57 @@ Content-Length: 0\r\n\r\n"
         Ok(())
     }
 
-    async fn task_respond_on_msearches(&self) -> anyhow::Result<()> {
+    async fn task_respond_on_msearches(&self, sock: Option<&UdpSocket>) {
         let mut buf = vec![0u8; 16184];
+        let sock = match sock {
+            Some(sock) => sock,
+            None => return,
+        };
 
         loop {
-            let (sz, addr) = self
+            let (sz, addr) = match sock.recv_from(&mut buf).await {
-                .socket
+                Ok((sz, addr)) => (sz, addr),
-                .recv_from(&mut buf)
+                Err(e) => {
-                .await
+                    warn!(error=?e, "error receving");
-                .context("error receiving")?;
+                    return;
+                }
+            };
             let msg = &buf[..sz];
-            if let Err(e) = self.process_incoming_message(msg, addr).await {
+            if let Err(e) = self.process_incoming_message(msg, sock, addr).await {
                 warn!(error=?e, ?addr, "error processing incoming SSDP message")
             }
         }
     }
 
-    async fn send_msearch(&self) -> anyhow::Result<()> {
+    async fn try_send_example_msearch(&self) {
-        let msearch_msg = "M-SEARCH * HTTP/1.1\r
+        self.try_send_mcast_everywhere(&|opts| {
-HOST: 239.255.255.250:1900\r
+            let dest = opts.addr_no_scope();
+            format!(
+                "M-SEARCH * HTTP/1.1\r
+HOST: {dest}\r
 ST: urn:schemas-upnp-org:device:MediaServer:1\r
 MAN: \"ssdp:discover\"\r
-MX: 2\r\n\r\n";
+MX: 2\r\n\r\n"
-
+            )
-        trace!(content = msearch_msg, "multicasting M-SEARCH");
+            .into()
-
+        })
-        self.socket
+        .await
-            .send_to(msearch_msg.as_bytes(), UPNP_BROADCAST_ADDR)
-            .await
-            .context("error sending msearch")?;
-        Ok(())
     }
 
     pub async fn run_forever(&self) -> anyhow::Result<()> {
         // This isn't necessary, but would show that it works.
-        self.send_msearch().await?;
+        let t0 = self.try_send_example_msearch();
+        let t1 = self.task_respond_on_msearches(self.socket_v4.as_ref());
+        let t2 = self.task_respond_on_msearches(self.socket_v6.as_ref());
+        let t3 = self.task_send_alive_notifies_periodically();
 
-        let t1 = self.task_respond_on_msearches();
+        let wait = async move {
-        let t2 = self.task_send_alive_notifies_periodically();
+            tokio::join!(t0, t1, t2, t3);
-
+            Ok(())
-        tokio::pin!(t1);
+        };
-        tokio::pin!(t2);
 
         tokio::select! {
-            r = &mut t1 => r,
+            r = wait => r,
-            r = &mut t2 => r,
             _ = self.opts.shutdown.cancelled() => {
                 self.try_send_notifies(NTS_BYEBYE).await;
                 bail!("canceled");

crates/upnp/src/lib.rs

@@ -6,7 +6,7 @@ use reqwest::Client;
 use serde::Deserialize;
 use std::{
     collections::HashSet,
-    net::{IpAddr, Ipv4Addr, SocketAddr, SocketAddrV4},
+    net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4},
     time::Duration,
 };
 use tokio::sync::mpsc::{unbounded_channel, UnboundedSender};
@@ -30,21 +30,21 @@ pub fn make_ssdp_search_request(kind: &str) -> String {
     )
 }
 
-pub fn get_local_ip_relative_to(local_dest: IpAddr) -> anyhow::Result<Ipv4Addr> {
+pub fn get_local_ip_relative_to(local_dest: IpAddr) -> anyhow::Result<IpAddr> {
-    let local_dest = match local_dest {
+    fn ip_bits_v4(addr: Ipv4Addr) -> u32 {
-        IpAddr::V4(v4) => v4,
-        IpAddr::V6(v6) => {
-            anyhow::bail!("get_local_ip_relative_to not implemented for IPv6; addr={v6}")
-        }
-    };
-
-    // Ipv4Addr.to_bits() is only there in nightly rust, so copying here for now.
-    fn ip_bits(addr: Ipv4Addr) -> u32 {
         u32::from_be_bytes(addr.octets())
     }
 
-    fn masked(ip: Ipv4Addr, mask: Ipv4Addr) -> u32 {
+    fn masked_v4(ip: Ipv4Addr, mask: Ipv4Addr) -> u32 {
-        ip_bits(ip) & ip_bits(mask)
+        ip_bits_v4(ip) & ip_bits_v4(mask)
+    }
+
+    fn ip_bits_v6(addr: Ipv6Addr) -> u128 {
+        u128::from_be_bytes(addr.octets())
+    }
+
+    fn masked_v6(ip: Ipv6Addr, mask: Ipv6Addr) -> u128 {
+        ip_bits_v6(ip) & ip_bits_v6(mask)
     }
 
     let interfaces =
@@ -52,18 +52,18 @@ pub fn get_local_ip_relative_to(local_dest: IpAddr) -> anyhow::Result<Ipv4Addr>
 
     for i in interfaces {
         for addr in i.addr {
-            if let network_interface::Addr::V4(v4) = addr {
+            match (local_dest, addr.ip(), addr.netmask()) {
-                let ip = v4.ip;
+                (IpAddr::V4(l), IpAddr::V4(a), Some(IpAddr::V4(m)))
-                let mask = match v4.netmask {
+                    if masked_v4(l, m) == masked_v4(a, m) =>
-                    Some(mask) => mask,
+                {
-                    None => continue,
+                    return Ok(addr.ip())
-                };
-                trace!("found local addr {ip}/{mask}");
-                // If the masked address is the same, means we are on the same network, return
-                // the ip address
-                if masked(ip, mask) == masked(local_dest, mask) {
-                    return Ok(ip);
                 }
+                (IpAddr::V6(l), IpAddr::V6(a), Some(IpAddr::V6(m)))
+                    if masked_v6(l, m) == masked_v6(a, m) =>
+                {
+                    return Ok(addr.ip())
+                }
+                _ => continue,
             }
         }
     }
@@ -72,7 +72,7 @@ pub fn get_local_ip_relative_to(local_dest: IpAddr) -> anyhow::Result<Ipv4Addr>
 
 async fn forward_port(
     control_url: Url,
-    local_ip: Ipv4Addr,
+    local_ip: IpAddr,
     port: u16,
     lease_duration: Duration,
 ) -> anyhow::Result<()> {
@@ -229,7 +229,7 @@ impl UpnpEndpoint {
             .flat_map(move |d| d.iter_services(self_span.clone()))
     }
 
-    fn my_local_ip(&self) -> anyhow::Result<Ipv4Addr> {
+    fn my_local_ip(&self) -> anyhow::Result<IpAddr> {
         let dest_ip = self.discover_response.received_from.ip();
         let local_ip = get_local_ip_relative_to(dest_ip)
             .with_context(|| format!("can't determine local IP relative to {dest_ip}"))?;
@@ -419,7 +419,7 @@ impl UpnpPortForwarder {
         }
     }
 
-    async fn manage_port(&self, control_url: Url, local_ip: Ipv4Addr, port: u16) -> ! {
+    async fn manage_port(&self, control_url: Url, local_ip: IpAddr, port: u16) -> ! {
         let lease_duration = self.opts.lease_duration;
         let mut interval = tokio::time::interval(lease_duration / 2);
         interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Delay);
@@ -433,7 +433,7 @@ impl UpnpPortForwarder {
         }
     }
 
-    async fn manage_service(&self, control_url: Url, local_ip: Ipv4Addr) -> anyhow::Result<()> {
+    async fn manage_service(&self, control_url: Url, local_ip: IpAddr) -> anyhow::Result<()> {
         futures::future::join_all(self.ports.iter().cloned().map(|port| {
             self.manage_port(control_url.clone(), local_ip, port)
                 .instrument(error_span!("manage_port", port = port))