From b5f02d0a47c9b1eec10ced2a36dd4bb6f10fbc91 Mon Sep 17 00:00:00 2001
From: Hendrik Groove <hendrikgroove@gmail.com>
Date: Tue, 9 Sep 2025 10:53:37 +0200
Subject: [PATCH] truma_inetbox(stream): enqueue keepalive/test; add
 SO_SNDTIMEO on UDP socket

---
 components/truma_inetbox/LinBusListener.cpp | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/components/truma_inetbox/LinBusListener.cpp b/components/truma_inetbox/LinBusListener.cpp
index 8bf698d..ff7795c 100644
--- a/components/truma_inetbox/LinBusListener.cpp
+++ b/components/truma_inetbox/LinBusListener.cpp
@@ -5,6 +5,7 @@
 #ifdef USE_ESP32
 #include <lwip/sockets.h>
 #include <lwip/inet.h>
+#include <sys/time.h>
 #endif
 
 namespace esphome {
@@ -438,12 +439,11 @@ void LinBusListener::process_log_queue(TickType_t xTicksToWait) {
 void LinBusListener::stream_send_test(const std::string &line) {
   if (!this->stream_enabled_) return;
   if (this->udp_sock_ < 0) this->stream_try_init_();
-  if (this->udp_sock_ < 0) return;
+  // Always enqueue to avoid blocking the main loop
   std::string msg = line;
   if (msg.empty()) msg = "STREAM TEST";
   msg.push_back('\n');
-  ::sendto(this->udp_sock_, msg.c_str(), msg.size(), 0, (struct sockaddr *) &this->udp_addr_, sizeof(this->udp_addr_));
-  this->last_stream_send_ms_ = millis();
+  this->stream_enqueue_line_(msg);
 }
 void LinBusListener::stream_try_init_() {
   if (!this->stream_enabled_) return;
@@ -457,6 +457,11 @@ void LinBusListener::stream_try_init_() {
     ESP_LOGW(TAG, "UDP socket create failed");
     return;
   }
+  // Set a small send timeout so UDP sendto doesn't block long on ARP
+  struct timeval tv;
+  tv.tv_sec = 0;
+  tv.tv_usec = 50000;  // 50ms
+  setsockopt(this->udp_sock_, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
   memset(&this->udp_addr_, 0, sizeof(this->udp_addr_));
   this->udp_addr_.sin_family = AF_INET;
   this->udp_addr_.sin_port = htons(this->udp_port_);
@@ -484,12 +489,12 @@ static std::string hex_bytes_(const uint8_t *data, uint8_t len) {
 }
 
 void LinBusListener::stream_maybe_keepalive_() {
-  if (!this->stream_enabled_ || this->udp_sock_ < 0) return;
+  if (!this->stream_enabled_) return;
   const uint32_t now = millis();
   if (this->stream_keepalive_ms_ == 0) return;
   if (now - this->last_stream_send_ms_ >= this->stream_keepalive_ms_) {
-    const char *msg = "KEEPALIVE";
-    ::sendto(this->udp_sock_, msg, strlen(msg), 0, (struct sockaddr *) &this->udp_addr_, sizeof(this->udp_addr_));
+    // Enqueue keepalive to be sent from the background sender task
+    this->stream_enqueue_line_(std::string("KEEPALIVE\n"));
     this->last_stream_send_ms_ = now;
   }
 }