stop leaking avahi clients (#1802)

* stop leaking avahi clients

* separate avahi to its own binary

Makefile

@@ -1,6 +1,6 @@
 ENVIRONMENT_FILE := $(shell ./check-environment.sh)
 GIT_HASH_FILE := $(shell ./check-git-hash.sh)
-EMBASSY_BINS := backend/target/aarch64-unknown-linux-gnu/release/embassyd backend/target/aarch64-unknown-linux-gnu/release/embassy-init backend/target/aarch64-unknown-linux-gnu/release/embassy-cli backend/target/aarch64-unknown-linux-gnu/release/embassy-sdk
+EMBASSY_BINS := backend/target/aarch64-unknown-linux-gnu/release/embassyd backend/target/aarch64-unknown-linux-gnu/release/embassy-init backend/target/aarch64-unknown-linux-gnu/release/embassy-cli backend/target/aarch64-unknown-linux-gnu/release/embassy-sdk backend/target/aarch64-unknown-linux-gnu/release/avahi-alias
 EMBASSY_UIS := frontend/dist/ui frontend/dist/setup-wizard frontend/dist/diagnostic-ui
 EMBASSY_SRC := raspios.img product_key.txt $(EMBASSY_BINS) backend/embassyd.service backend/embassy-init.service $(EMBASSY_UIS) $(shell find build)
 COMPAT_SRC := $(shell find system-images/compat/src)

backend/Cargo.toml

@@ -36,6 +36,10 @@ path = "src/bin/embassy-sdk.rs"
 name = "embassy-cli"
 path = "src/bin/embassy-cli.rs"
 
+[[bin]]
+name = "avahi-alias"
+path = "src/bin/avahi-alias.rs"
+
 [features]
 avahi = ["avahi-sys"]
 default = ["avahi", "sound", "metal", "js_engine"]

backend/src/bin/avahi-alias.rs

@@ -0,0 +1,163 @@
+use avahi_sys::{
+    self, avahi_client_errno, avahi_entry_group_add_service, avahi_entry_group_commit,
+    avahi_strerror, AvahiClient,
+};
+
+fn log_str_error(action: &str, e: i32) {
+    unsafe {
+        let e_str = avahi_strerror(e);
+        eprintln!(
+            "Could not {}: {:?}",
+            action,
+            std::ffi::CStr::from_ptr(e_str)
+        );
+    }
+}
+
+fn main() {
+    let aliases: Vec<_> = std::env::args().skip(1).collect();
+    unsafe {
+        let simple_poll = avahi_sys::avahi_simple_poll_new();
+        let poll = avahi_sys::avahi_simple_poll_get(simple_poll);
+        let mut box_err = Box::pin(0 as i32);
+        let err_c: *mut i32 = box_err.as_mut().get_mut();
+        let avahi_client = avahi_sys::avahi_client_new(
+            poll,
+            avahi_sys::AvahiClientFlags::AVAHI_CLIENT_NO_FAIL,
+            Some(client_callback),
+            std::ptr::null_mut(),
+            err_c,
+        );
+        if avahi_client == std::ptr::null_mut::<AvahiClient>() {
+            log_str_error("create Avahi client", *box_err);
+            panic!("Failed to create Avahi Client");
+        }
+        let group = avahi_sys::avahi_entry_group_new(
+            avahi_client,
+            Some(entry_group_callback),
+            std::ptr::null_mut(),
+        );
+        if group == std::ptr::null_mut() {
+            log_str_error("create Avahi entry group", avahi_client_errno(avahi_client));
+            panic!("Failed to create Avahi Entry Group");
+        }
+        let mut hostname_buf = vec![0];
+        let hostname_raw = avahi_sys::avahi_client_get_host_name_fqdn(avahi_client);
+        hostname_buf.extend_from_slice(std::ffi::CStr::from_ptr(hostname_raw).to_bytes_with_nul());
+        let buflen = hostname_buf.len();
+        debug_assert!(hostname_buf.ends_with(b".local\0"));
+        debug_assert!(!hostname_buf[..(buflen - 7)].contains(&b'.'));
+        // assume fixed length prefix on hostname due to local address
+        hostname_buf[0] = (buflen - 8) as u8; // set the prefix length to len - 8 (leading byte, .local, nul) for the main address
+        hostname_buf[buflen - 7] = 5; // set the prefix length to 5 for "local"
+        let mut res;
+        let http_tcp_cstr =
+            std::ffi::CString::new("_http._tcp").expect("Could not cast _http._tcp to c string");
+        res = avahi_entry_group_add_service(
+            group,
+            avahi_sys::AVAHI_IF_UNSPEC,
+            avahi_sys::AVAHI_PROTO_UNSPEC,
+            avahi_sys::AvahiPublishFlags_AVAHI_PUBLISH_USE_MULTICAST,
+            hostname_raw,
+            http_tcp_cstr.as_ptr(),
+            std::ptr::null(),
+            std::ptr::null(),
+            443,
+            // below is a secret final argument that the type signature of this function does not tell you that it
+            // needs. This is because the C lib function takes a variable number of final arguments indicating the
+            // desired TXT records to add to this service entry. The way it decides when to stop taking arguments
+            // from the stack and dereferencing them is when it finds a null pointer...because fuck you, that's why.
+            // The consequence of this is that forgetting this last argument will cause segfaults or other undefined
+            // behavior. Welcome back to the stone age motherfucker.
+            std::ptr::null::<libc::c_char>(),
+        );
+        if res < avahi_sys::AVAHI_OK {
+            log_str_error("add service to Avahi entry group", res);
+            panic!("Failed to load Avahi services");
+        }
+        eprintln!("Published {:?}", std::ffi::CStr::from_ptr(hostname_raw));
+        for alias in aliases {
+            let lan_address = alias + ".local";
+            let lan_address_ptr = std::ffi::CString::new(lan_address)
+                .expect("Could not cast lan address to c string");
+            res = avahi_sys::avahi_entry_group_add_record(
+                group,
+                avahi_sys::AVAHI_IF_UNSPEC,
+                avahi_sys::AVAHI_PROTO_UNSPEC,
+                avahi_sys::AvahiPublishFlags_AVAHI_PUBLISH_USE_MULTICAST
+                    | avahi_sys::AvahiPublishFlags_AVAHI_PUBLISH_ALLOW_MULTIPLE,
+                lan_address_ptr.as_ptr(),
+                avahi_sys::AVAHI_DNS_CLASS_IN as u16,
+                avahi_sys::AVAHI_DNS_TYPE_CNAME as u16,
+                avahi_sys::AVAHI_DEFAULT_TTL,
+                hostname_buf.as_ptr().cast(),
+                hostname_buf.len(),
+            );
+            if res < avahi_sys::AVAHI_OK {
+                log_str_error("add CNAME record to Avahi entry group", res);
+                panic!("Failed to load Avahi services");
+            }
+            eprintln!("Published {:?}", lan_address_ptr);
+        }
+        let commit_err = avahi_entry_group_commit(group);
+        if commit_err < avahi_sys::AVAHI_OK {
+            log_str_error("reset Avahi entry group", commit_err);
+            panic!("Failed to load Avahi services: reset");
+        }
+    }
+    std::thread::park()
+}
+
+unsafe extern "C" fn entry_group_callback(
+    _group: *mut avahi_sys::AvahiEntryGroup,
+    state: avahi_sys::AvahiEntryGroupState,
+    _userdata: *mut core::ffi::c_void,
+) {
+    match state {
+        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_FAILURE => {
+            eprintln!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_FAILURE");
+        }
+        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_COLLISION => {
+            eprintln!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_COLLISION");
+        }
+        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_UNCOMMITED => {
+            eprintln!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_UNCOMMITED");
+        }
+        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_ESTABLISHED => {
+            eprintln!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_ESTABLISHED");
+        }
+        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_REGISTERING => {
+            eprintln!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_REGISTERING");
+        }
+        other => {
+            eprintln!("AvahiCallback: EntryGroupState = {}", other);
+        }
+    }
+}
+
+unsafe extern "C" fn client_callback(
+    _group: *mut avahi_sys::AvahiClient,
+    state: avahi_sys::AvahiClientState,
+    _userdata: *mut core::ffi::c_void,
+) {
+    match state {
+        avahi_sys::AvahiClientState_AVAHI_CLIENT_FAILURE => {
+            eprintln!("AvahiCallback: ClientState = AVAHI_CLIENT_FAILURE");
+        }
+        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_RUNNING => {
+            eprintln!("AvahiCallback: ClientState = AVAHI_CLIENT_S_RUNNING");
+        }
+        avahi_sys::AvahiClientState_AVAHI_CLIENT_CONNECTING => {
+            eprintln!("AvahiCallback: ClientState = AVAHI_CLIENT_CONNECTING");
+        }
+        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_COLLISION => {
+            eprintln!("AvahiCallback: ClientState = AVAHI_CLIENT_S_COLLISION");
+        }
+        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_REGISTERING => {
+            eprintln!("AvahiCallback: ClientState = AVAHI_CLIENT_S_REGISTERING");
+        }
+        other => {
+            eprintln!("AvahiCallback: ClientState = {}", other);
+        }
+    }
+}

backend/src/net/mdns.rs

@@ -1,25 +1,20 @@
 use std::collections::BTreeMap;
 use std::net::Ipv4Addr;
 
-use avahi_sys::{
-    self, avahi_client_errno, avahi_entry_group_add_service, avahi_entry_group_commit,
-    avahi_entry_group_free, avahi_free, avahi_strerror, AvahiClient, AvahiEntryGroup,
-};
 use color_eyre::eyre::eyre;
-use libc::c_void;
-use tokio::process::Command;
+use tokio::process::{Child, Command};
 use tokio::sync::Mutex;
 use torut::onion::TorSecretKeyV3;
-use tracing::instrument;
 
 use super::interface::InterfaceId;
 use crate::s9pk::manifest::PackageId;
 use crate::util::Invoke;
-use crate::Error;
+use crate::{Error, ResultExt};
 
 pub async fn resolve_mdns(hostname: &str) -> Result<Ipv4Addr, Error> {
     Ok(String::from_utf8(
         Command::new("avahi-resolve-host-name")
+            .kill_on_drop(true)
             .arg("-4")
             .arg(hostname)
             .invoke(crate::ErrorKind::Network)
@@ -39,258 +34,79 @@ pub async fn resolve_mdns(hostname: &str) -> Result<Ipv4Addr, Error> {
 
 pub struct MdnsController(Mutex<MdnsControllerInner>);
 impl MdnsController {
-    pub fn init() -> Self {
-        MdnsController(Mutex::new(MdnsControllerInner::init()))
+    pub async fn init() -> Result<Self, Error> {
+        Ok(MdnsController(Mutex::new(
+            MdnsControllerInner::init().await?,
+        )))
     }
     pub async fn add<'a, I: IntoIterator<Item = (InterfaceId, TorSecretKeyV3)>>(
         &self,
         pkg_id: &PackageId,
         interfaces: I,
-    ) {
-        self.0.lock().await.add(pkg_id, interfaces)
+    ) -> Result<(), Error> {
+        self.0.lock().await.add(pkg_id, interfaces).await
     }
     pub async fn remove<I: IntoIterator<Item = InterfaceId>>(
         &self,
         pkg_id: &PackageId,
         interfaces: I,
-    ) {
-        self.0.lock().await.remove(pkg_id, interfaces)
+    ) -> Result<(), Error> {
+        self.0.lock().await.remove(pkg_id, interfaces).await
     }
 }
 
 pub struct MdnsControllerInner {
-    entry_group: Option<MdnsEntryGroup>,
+    alias_cmd: Option<Child>,
     services: BTreeMap<(PackageId, InterfaceId), TorSecretKeyV3>,
 }
-unsafe impl Send for MdnsControllerInner {}
-unsafe impl Sync for MdnsControllerInner {}
 
 impl MdnsControllerInner {
-    fn init() -> Self {
-        MdnsControllerInner {
-            entry_group: Some(MdnsEntryGroup::init(&BTreeMap::new())),
+    async fn init() -> Result<Self, Error> {
+        let mut res = MdnsControllerInner {
+            alias_cmd: None,
             services: BTreeMap::new(),
+        };
+        res.sync().await?;
+        Ok(res)
     }
+    async fn sync(&mut self) -> Result<(), Error> {
+        if let Some(mut cmd) = self.alias_cmd.take() {
+            cmd.kill().await.with_kind(crate::ErrorKind::Network)?;
         }
-    fn sync(&mut self) {
-        drop(self.entry_group.take());
-        self.entry_group = Some(MdnsEntryGroup::init(&self.services));
+        self.alias_cmd = Some(
+            Command::new("avahi-alias")
+                .kill_on_drop(true)
+                .args(self.services.iter().map(|(_, key)| {
+                    key.public()
+                        .get_onion_address()
+                        .get_address_without_dot_onion()
+                }))
+                .spawn()?,
+        );
+        Ok(())
     }
-    fn add<'a, I: IntoIterator<Item = (InterfaceId, TorSecretKeyV3)>>(
+    async fn add<'a, I: IntoIterator<Item = (InterfaceId, TorSecretKeyV3)>>(
         &mut self,
         pkg_id: &PackageId,
         interfaces: I,
-    ) {
+    ) -> Result<(), Error> {
         self.services.extend(
             interfaces
                 .into_iter()
                 .map(|(interface_id, key)| ((pkg_id.clone(), interface_id), key)),
         );
-        self.sync();
+        self.sync().await?;
+        Ok(())
     }
-    fn remove<I: IntoIterator<Item = InterfaceId>>(&mut self, pkg_id: &PackageId, interfaces: I) {
+    async fn remove<I: IntoIterator<Item = InterfaceId>>(
+        &mut self,
+        pkg_id: &PackageId,
+        interfaces: I,
+    ) -> Result<(), Error> {
         for interface_id in interfaces {
             self.services.remove(&(pkg_id.clone(), interface_id));
         }
-        self.sync();
-    }
-}
-
-fn log_str_error(action: &str, e: i32) {
-    unsafe {
-        let e_str = avahi_strerror(e);
-        tracing::error!(
-            "Could not {}: {:?}",
-            action,
-            std::ffi::CStr::from_ptr(e_str)
-        );
-    }
-}
-
-struct MdnsEntryGroup {
-    hostname: Vec<u8>,
-    hostname_raw: *const libc::c_char,
-    entry_group: *mut AvahiEntryGroup,
-    _client_error: std::pin::Pin<Box<i32>>,
-}
-impl MdnsEntryGroup {
-    #[instrument(skip(self))]
-    fn load_services(&mut self, services: &BTreeMap<(PackageId, InterfaceId), TorSecretKeyV3>) {
-        unsafe {
-            tracing::debug!("Loading services for mDNS");
-            let mut res;
-            let http_tcp_cstr = std::ffi::CString::new("_http._tcp")
-                .expect("Could not cast _http._tcp to c string");
-            res = avahi_entry_group_add_service(
-                self.entry_group,
-                avahi_sys::AVAHI_IF_UNSPEC,
-                avahi_sys::AVAHI_PROTO_UNSPEC,
-                avahi_sys::AvahiPublishFlags_AVAHI_PUBLISH_USE_MULTICAST,
-                self.hostname_raw,
-                http_tcp_cstr.as_ptr(),
-                std::ptr::null(),
-                std::ptr::null(),
-                443,
-                // below is a secret final argument that the type signature of this function does not tell you that it
-                // needs. This is because the C lib function takes a variable number of final arguments indicating the
-                // desired TXT records to add to this service entry. The way it decides when to stop taking arguments
-                // from the stack and dereferencing them is when it finds a null pointer...because fuck you, that's why.
-                // The consequence of this is that forgetting this last argument will cause segfaults or other undefined
-                // behavior. Welcome back to the stone age motherfucker.
-                std::ptr::null::<libc::c_char>(),
-            );
-            if res < avahi_sys::AVAHI_OK {
-                log_str_error("add service to Avahi entry group", res);
-                panic!("Failed to load Avahi services");
-            }
-            tracing::info!(
-                "Published {:?}",
-                std::ffi::CStr::from_ptr(self.hostname_raw)
-            );
-            for key in services.values() {
-                let lan_address = key
-                    .public()
-                    .get_onion_address()
-                    .get_address_without_dot_onion()
-                    + ".local";
-                tracing::debug!("Adding mdns CNAME entry for {}", &lan_address);
-                let lan_address_ptr = std::ffi::CString::new(lan_address)
-                    .expect("Could not cast lan address to c string");
-                res = avahi_sys::avahi_entry_group_add_record(
-                    self.entry_group,
-                    avahi_sys::AVAHI_IF_UNSPEC,
-                    avahi_sys::AVAHI_PROTO_UNSPEC,
-                    avahi_sys::AvahiPublishFlags_AVAHI_PUBLISH_USE_MULTICAST
-                        | avahi_sys::AvahiPublishFlags_AVAHI_PUBLISH_ALLOW_MULTIPLE,
-                    lan_address_ptr.as_ptr(),
-                    avahi_sys::AVAHI_DNS_CLASS_IN as u16,
-                    avahi_sys::AVAHI_DNS_TYPE_CNAME as u16,
-                    avahi_sys::AVAHI_DEFAULT_TTL,
-                    self.hostname.as_ptr().cast(),
-                    self.hostname.len(),
-                );
-                if res < avahi_sys::AVAHI_OK {
-                    log_str_error("add CNAME record to Avahi entry group", res);
-                    panic!("Failed to load Avahi services");
-                }
-                tracing::info!("Published {:?}", lan_address_ptr);
-            }
-        }
-    }
-    fn init(services: &BTreeMap<(PackageId, InterfaceId), TorSecretKeyV3>) -> Self {
-        unsafe {
-            tracing::debug!("Initializing mDNS controller");
-
-            let simple_poll = avahi_sys::avahi_simple_poll_new();
-            let poll = avahi_sys::avahi_simple_poll_get(simple_poll);
-            let mut box_err = Box::pin(0 as i32);
-            let err_c: *mut i32 = box_err.as_mut().get_mut();
-            let avahi_client = avahi_sys::avahi_client_new(
-                poll,
-                avahi_sys::AvahiClientFlags::AVAHI_CLIENT_NO_FAIL,
-                Some(client_callback),
-                std::ptr::null_mut(),
-                err_c,
-            );
-            if avahi_client == std::ptr::null_mut::<AvahiClient>() {
-                log_str_error("create Avahi client", *box_err);
-                panic!("Failed to create Avahi Client");
-            }
-            let group = avahi_sys::avahi_entry_group_new(
-                avahi_client,
-                Some(entry_group_callback),
-                std::ptr::null_mut(),
-            );
-            if group == std::ptr::null_mut() {
-                log_str_error("create Avahi entry group", avahi_client_errno(avahi_client));
-                panic!("Failed to create Avahi Entry Group");
-            }
-            let mut hostname_buf = vec![0];
-            let hostname_raw = avahi_sys::avahi_client_get_host_name_fqdn(avahi_client);
-            hostname_buf
-                .extend_from_slice(std::ffi::CStr::from_ptr(hostname_raw).to_bytes_with_nul());
-            let buflen = hostname_buf.len();
-            debug_assert!(hostname_buf.ends_with(b".local\0"));
-            debug_assert!(!hostname_buf[..(buflen - 7)].contains(&b'.'));
-            // assume fixed length prefix on hostname due to local address
-            hostname_buf[0] = (buflen - 8) as u8; // set the prefix length to len - 8 (leading byte, .local, nul) for the main address
-            hostname_buf[buflen - 7] = 5; // set the prefix length to 5 for "local"
-            let mut res = MdnsEntryGroup {
-                hostname: hostname_buf,
-                hostname_raw,
-                entry_group: group,
-                _client_error: box_err,
-            };
-            res.load_services(services);
-            let commit_err = avahi_entry_group_commit(res.entry_group);
-            if commit_err < avahi_sys::AVAHI_OK {
-                log_str_error("reset Avahi entry group", commit_err);
-                panic!("Failed to load Avahi services: reset");
-            }
-            res
-        }
-    }
-}
-impl Drop for MdnsEntryGroup {
-    fn drop(&mut self) {
-        unsafe {
-            avahi_free(self.hostname_raw as *mut c_void);
-            avahi_entry_group_free(self.entry_group);
-            // avahi_client_free(self.avahi_client);
-        }
-    }
-}
-
-unsafe extern "C" fn entry_group_callback(
-    _group: *mut avahi_sys::AvahiEntryGroup,
-    state: avahi_sys::AvahiEntryGroupState,
-    _userdata: *mut core::ffi::c_void,
-) {
-    match state {
-        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_FAILURE => {
-            tracing::warn!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_FAILURE");
-        }
-        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_COLLISION => {
-            tracing::warn!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_COLLISION");
-        }
-        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_UNCOMMITED => {
-            tracing::warn!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_UNCOMMITED");
-        }
-        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_ESTABLISHED => {
-            tracing::warn!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_ESTABLISHED");
-        }
-        avahi_sys::AvahiEntryGroupState_AVAHI_ENTRY_GROUP_REGISTERING => {
-            tracing::warn!("AvahiCallback: EntryGroupState = AVAHI_ENTRY_GROUP_REGISTERING");
-        }
-        other => {
-            tracing::warn!("AvahiCallback: EntryGroupState = {}", other);
-        }
-    }
-}
-
-unsafe extern "C" fn client_callback(
-    _group: *mut avahi_sys::AvahiClient,
-    state: avahi_sys::AvahiClientState,
-    _userdata: *mut core::ffi::c_void,
-) {
-    match state {
-        avahi_sys::AvahiClientState_AVAHI_CLIENT_FAILURE => {
-            tracing::warn!("AvahiCallback: ClientState = AVAHI_CLIENT_FAILURE");
-        }
-        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_RUNNING => {
-            tracing::warn!("AvahiCallback: ClientState = AVAHI_CLIENT_S_RUNNING");
-        }
-        avahi_sys::AvahiClientState_AVAHI_CLIENT_CONNECTING => {
-            tracing::warn!("AvahiCallback: ClientState = AVAHI_CLIENT_CONNECTING");
-        }
-        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_COLLISION => {
-            tracing::warn!("AvahiCallback: ClientState = AVAHI_CLIENT_S_COLLISION");
-        }
-        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_REGISTERING => {
-            tracing::warn!("AvahiCallback: ClientState = AVAHI_CLIENT_S_REGISTERING");
-        }
-        other => {
-            tracing::warn!("AvahiCallback: ClientState = {}", other);
-        }
+        self.sync().await?;
+        Ok(())
     }
 }

backend/src/net/mod.rs

@@ -70,7 +70,7 @@ impl NetController {
         Ok(Self {
             tor: TorController::init(embassyd_addr, embassyd_tor_key, tor_control).await?,
             #[cfg(feature = "avahi")]
-            mdns: MdnsController::init(),
+            mdns: MdnsController::init().await?,
             nginx: NginxController::init(PathBuf::from("/etc/nginx"), &ssl, &hostname).await?,
             ssl,
             dns: DnsController::init(dns_bind).await?,

build/write-image.sh

@@ -63,6 +63,7 @@ cd backend/
 sudo cp target/aarch64-unknown-linux-gnu/release/embassy-init /tmp/eos-mnt/usr/local/bin
 sudo cp target/aarch64-unknown-linux-gnu/release/embassyd /tmp/eos-mnt/usr/local/bin
 sudo cp target/aarch64-unknown-linux-gnu/release/embassy-cli /tmp/eos-mnt/usr/local/bin
+sudo cp target/aarch64-unknown-linux-gnu/release/avahi-alias /tmp/eos-mnt/usr/local/bin
 sudo cp *.service /tmp/eos-mnt/etc/systemd/system/
 
 cd ..