handle client failure state during initialization

Signed-off-by: Walker Crouse <Walker.Crouse@bjss.com>
windy1 · Jan 28, 2024 · bc05415 · bc05415
1 parent a94af65
commit bc05415
Show file tree

Hide file tree

Showing 4 changed files with 27 additions and 15 deletions.
diff --git a/zeroconf/src/avahi/avahi_util.rs b/zeroconf/src/avahi/avahi_util.rs
@@ -1,6 +1,6 @@
 //! Utilities related to Avahi
 
-use avahi_sys::{avahi_address_snprint, avahi_strerror, AvahiAddress};
+use avahi_sys::{avahi_address_snprint, avahi_strerror, AvahiAddress, AvahiClient};
 use libc::c_char;
 use std::ffi::CStr;
 
@@ -38,6 +38,14 @@ pub fn get_error<'a>(code: i32) -> &'a str {
     }
 }
 
+/// Returns the last error message associated with the specified `*mut AvahiClient`.
+///
+/// # Safety
+/// This function is unsafe because of internal Avahi calls.
+pub unsafe fn get_last_error<'a>(client: *mut AvahiClient) -> &'a str {
+    get_error(avahi_sys::avahi_client_errno(client))
+}
+
 /// Converts the specified [`NetworkInterface`] to the Avahi expected value.
 ///
 /// [`NetworkInterface`]: ../../enum.NetworkInterface.html

diff --git a/zeroconf/src/avahi/browser.rs b/zeroconf/src/avahi/browser.rs
@@ -134,14 +134,15 @@ unsafe extern "C" fn client_callback(
     state: AvahiClientState,
     userdata: *mut c_void,
 ) {
+    let context = AvahiBrowserContext::from_raw(userdata);
+
     match state {
-        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_RUNNING => {
-            create_browser(client, AvahiBrowserContext::from_raw(userdata))
-                .unwrap_or_else(|e| panic!("failed to create browser: {}", e))
-        }
-        _ => {
-            // TODO: handle other states
+        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_RUNNING => create_browser(client, context)
+            .unwrap_or_else(|e| panic!("failed to create browser: {}", e)),
+        avahi_sys::AvahiClientState_AVAHI_CLIENT_FAILURE => {
+            context.invoke_callback(Err(avahi_util::get_last_error(client).into()))
         }
+        _ => {}
     }
 }
 

diff --git a/zeroconf/src/avahi/service.rs b/zeroconf/src/avahi/service.rs
@@ -162,7 +162,7 @@ impl AvahiServiceContext {
         if let Some(f) = &self.registered_callback {
             f(result, self.user_context.clone());
         } else {
-            panic!("attempted to invoke service callback but none was set");
+            warn!("attempted to invoke service callback but none was set");
         }
     }
 }
@@ -183,14 +183,15 @@ unsafe extern "C" fn client_callback(
     state: AvahiClientState,
     userdata: *mut c_void,
 ) {
+    let context = AvahiServiceContext::from_raw(userdata);
+
     match state {
-        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_RUNNING => {
-            create_service(client, AvahiServiceContext::from_raw(userdata))
-                .unwrap_or_else(|e| panic!("failed to create service: {}", e))
-        }
-        _ => {
-            // TODO: handle other states
+        avahi_sys::AvahiClientState_AVAHI_CLIENT_S_RUNNING => create_service(client, context)
+            .unwrap_or_else(|e| panic!("failed to create service: {}", e)),
+        avahi_sys::AvahiClientState_AVAHI_CLIENT_FAILURE => {
+            context.invoke_callback(Err(avahi_util::get_last_error(client).into()))
         }
+        _ => {}
     }
 }
 

diff --git a/zeroconf/src/tests/service_test.rs b/zeroconf/src/tests/service_test.rs
@@ -31,7 +31,9 @@ fn service_register_is_browsable() {
     service.set_context(Box::new(context.clone()));
     service.set_txt_record(txt.clone());
 
-    service.set_registered_callback(Box::new(|_, context| {
+    service.set_registered_callback(Box::new(|result, context| {
+        assert!(result.is_ok());
+
         let mut browser =
             MdnsBrowser::new(ServiceType::with_sub_types("http", "tcp", vec!["printer"]).unwrap());