fix: harden tcp tasks around link readiness and connect retries

App/tcp_client.c

@@ -9,8 +9,11 @@
 #include "app_runtime.h"
 #include "config.h"
 #include "debug_log.h"
+#include "ethernetif.h"
 #include "route_msg.h"
 
+#define TCP_CLIENT_CONNECT_TIMEOUT_MS 5000
+
 static err_t tcp_client_worker(struct netconn *conn, uint8_t link_index)
 {
     struct netbuf *buf;
@@ -62,20 +65,15 @@ static void tcp_client_task(uint8_t link_index)
     err_t err;
     uint8_t first_connect_deferred;
 
+    netconn_thread_init();
     first_connect_deferred = (link_index == CONFIG_LINK_C1) ? 1u : 0u;
 
     for (;;) {
-        while (g_netif_ready == pdFALSE) {
+        while ((g_netif_ready == pdFALSE) || (ethernetif_link_is_up() == 0u)) {
             vTaskDelay(pdMS_TO_TICKS(100));
         }
 
         cfg = config_get();
-        debug_log_printf("[CLI] idx=%u hwm=%lu en=%u lport=%u rport=%u\r\n",
-                         (unsigned int)link_index,
-                         (unsigned long)uxTaskGetStackHighWaterMark(NULL),
-                         (unsigned int)cfg->links[link_index].enabled,
-                         (unsigned int)cfg->links[link_index].local_port,
-                         (unsigned int)cfg->links[link_index].remote_port);
         if (cfg->links[link_index].enabled == 0u) {
             vTaskDelay(pdMS_TO_TICKS(500));
             continue;
@@ -99,6 +97,10 @@ static void tcp_client_task(uint8_t link_index)
         if (cfg->links[link_index].local_port != 0u) {
             err = netconn_bind(conn, IP_ADDR_ANY, cfg->links[link_index].local_port);
             if (err != ERR_OK) {
+                debug_log_printf("[CLI] idx=%u bind-fail err=%d lport=%u\r\n",
+                                 (unsigned int)link_index,
+                                 (int)err,
+                                 (unsigned int)cfg->links[link_index].local_port);
                 netconn_delete(conn);
                 vTaskDelay(pdMS_TO_TICKS(delay_ms));
                 continue;
@@ -111,9 +113,31 @@ static void tcp_client_task(uint8_t link_index)
                  cfg->links[link_index].remote_ip[2],
                  cfg->links[link_index].remote_ip[3]);
 
+        netconn_set_recvtimeout(conn, TCP_CLIENT_CONNECT_TIMEOUT_MS);
         err = netconn_connect(conn, &remote_ip, cfg->links[link_index].remote_port);
         if (err == ERR_OK) {
+            debug_log_printf("[CLI] idx=%u connect-ok\r\n", (unsigned int)link_index);
             (void)tcp_client_worker(conn, link_index);
+        } else {
+            if (err == ERR_TIMEOUT) {
+                debug_log_printf("[CLI] idx=%u connect-timeout ms=%u rip=%u.%u.%u.%u rport=%u\r\n",
+                                 (unsigned int)link_index,
+                                 (unsigned int)TCP_CLIENT_CONNECT_TIMEOUT_MS,
+                                 (unsigned int)cfg->links[link_index].remote_ip[0],
+                                 (unsigned int)cfg->links[link_index].remote_ip[1],
+                                 (unsigned int)cfg->links[link_index].remote_ip[2],
+                                 (unsigned int)cfg->links[link_index].remote_ip[3],
+                                 (unsigned int)cfg->links[link_index].remote_port);
+            } else {
+                debug_log_printf("[CLI] idx=%u connect-fail err=%d rip=%u.%u.%u.%u rport=%u\r\n",
+                                 (unsigned int)link_index,
+                                 (int)err,
+                                 (unsigned int)cfg->links[link_index].remote_ip[0],
+                                 (unsigned int)cfg->links[link_index].remote_ip[1],
+                                 (unsigned int)cfg->links[link_index].remote_ip[2],
+                                 (unsigned int)cfg->links[link_index].remote_ip[3],
+                                 (unsigned int)cfg->links[link_index].remote_port);
+            }
         }
 
         netconn_close(conn);

App/tcp_server.c

@@ -58,17 +58,14 @@ static void tcp_server_task(uint8_t link_index)
     struct netconn *listener;
     struct netconn *newconn;
 
+    netconn_thread_init();
+
     for (;;) {
         while (g_netif_ready == pdFALSE) {
             vTaskDelay(pdMS_TO_TICKS(100));
         }
 
         cfg = config_get();
-        debug_log_printf("[SRV] idx=%u hwm=%lu en=%u port=%u\r\n",
-                         (unsigned int)link_index,
-                         (unsigned long)uxTaskGetStackHighWaterMark(NULL),
-                         (unsigned int)cfg->links[link_index].enabled,
-                         (unsigned int)cfg->links[link_index].local_port);
         if (cfg->links[link_index].enabled == 0u) {
             vTaskDelay(pdMS_TO_TICKS(500));
             continue;