rpc: Throw error in setlogfilter if filter reloading fails

src/rpc/server.cpp

@@ -268,7 +268,9 @@ UniValue setlogfilter(const UniValue& params, bool fHelp)
     }
 
     if (pTracingHandle) {
-        tracing_reload(pTracingHandle, newFilter.c_str());
+        if (!tracing_reload(pTracingHandle, newFilter.c_str())) {
+            throw JSONRPCError(RPC_INTERNAL_ERROR, "Filter reload failed; check logs");
+        }
     }
 
     return NullUniValue;

src/rust/include/tracing.h

@@ -33,7 +33,9 @@ TracingHandle* tracing_init(
 void tracing_free(TracingHandle* handle);
 
 /// Reloads the tracing filter.
-void tracing_reload(TracingHandle* handle, const char* new_filter);
+///
+/// Returns `true` if the reload succeeded.
+bool tracing_reload(TracingHandle* handle, const char* new_filter);
 
 struct TracingCallsite;
 typedef struct TracingCallsite TracingCallsite;

src/rust/src/tracing_ffi.rs

@@ -138,14 +138,26 @@ pub extern "C" fn tracing_free(handle: *mut TracingHandle) {
 }
 
 #[no_mangle]
-pub extern "C" fn tracing_reload(handle: *mut TracingHandle, new_filter: *const c_char) {
+pub extern "C" fn tracing_reload(handle: *mut TracingHandle, new_filter: *const c_char) -> bool {
     let handle = unsafe { &mut *handle };
-    let new_filter = unsafe { CStr::from_ptr(new_filter) }
-        .to_str()
-        .expect("new filter should be a valid string");
 
-    let new_filter = EnvFilter::new(new_filter);
-    handle.reload_handle.reload(new_filter).unwrap();
+    match unsafe { CStr::from_ptr(new_filter) }
+        .to_str()
+        .map(EnvFilter::new)
+    {
+        Err(e) => {
+            tracing::error!("New filter is not valid UTF-8: {}", e);
+            false
+        }
+        Ok(new_filter) => {
+            if let Err(e) = handle.reload_handle.reload(new_filter) {
+                tracing::error!("Filter reload failed: {}", e);
+                false
+            } else {
+                true
+            }
+        }
+    }
 }
 
 pub struct FfiCallsite {