From 2733ceae72c913a4f7ff1344b053e82f79c95002 Mon Sep 17 00:00:00 2001
From: aleks <aleks@espressif.com>
Date: Fri, 13 May 2022 15:15:17 +0200
Subject: [PATCH] fix modbus read dead slave cause wdt timeout

---
 freemodbus/port/port.h                       |  1 +
 freemodbus/tcp_master/port/port_tcp_master.c | 14 +++++++++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/freemodbus/port/port.h b/freemodbus/port/port.h
index b5d8858..bff33be 100644
--- a/freemodbus/port/port.h
+++ b/freemodbus/port/port.h
@@ -90,6 +90,7 @@
 #define MB_TCP_SEND_TIMEOUT_MS          (500) // send event timeout in mS
 #define MB_TCP_SEND_TIMEOUT             (pdMS_TO_TICKS(MB_TCP_SEND_TIMEOUT_MS))
 #define MB_TCP_PORT_MAX_CONN            (CONFIG_FMB_TCP_PORT_MAX_CONN)
+#define MB_TCP_PORT_RESPOND_TIMEOUT     (CONFIG_FMB_MASTER_TIMEOUT_MS_RESPOND * 1000)
 
 #define MB_TCP_FRAME_LOG_BUFSIZE        (256)
 
diff --git a/freemodbus/tcp_master/port/port_tcp_master.c b/freemodbus/tcp_master/port/port_tcp_master.c
index f2ba624..790dcc7 100644
--- a/freemodbus/tcp_master/port/port_tcp_master.c
+++ b/freemodbus/tcp_master/port/port_tcp_master.c
@@ -286,18 +286,22 @@ static int xMBTCPPortMasterGetBuf(MbSlaveInfo_t* pxInfo, UCHAR* pucDstBuf, USHOR
     int xLength = 0;
     UCHAR* pucBuf = pucDstBuf;
     USHORT usBytesLeft = usLength;
+    struct timeval xTime;
 
     MB_PORT_CHECK((pxInfo && pxInfo->xSockId > -1), -1, "Try to read incorrect socket = #%d.", pxInfo->xSockId);
 
+    // Set receive timeout for socket <= slave respond time
+    xTime.tv_sec = 0;
+    xTime.tv_usec = MB_TCP_PORT_RESPOND_TIMEOUT;
+    setsockopt(pxInfo->xSockId, SOL_SOCKET, SO_RCVTIMEO, &xTime, sizeof(xTime));
+
     // Receive data from connected client
     while (usBytesLeft > 0) {
         xMBTCPPortMasterCheckShutdown();
-        // none blocking read from socket with timeout
-        xLength = recv(pxInfo->xSockId, pucBuf, usBytesLeft, MSG_DONTWAIT);
+        xLength = recv(pxInfo->xSockId, pucBuf, usBytesLeft, 0); 
         if (xLength < 0) {
             if (errno == EAGAIN) {
                 // Read timeout occurred, continue reading
-                continue;
             } else if (errno == ENOTCONN) {
                 // Socket connection closed
                 ESP_LOGE(TAG, "Socket(#%d)(%s) connection closed.",
@@ -316,7 +320,6 @@ static int xMBTCPPortMasterGetBuf(MbSlaveInfo_t* pxInfo, UCHAR* pucDstBuf, USHOR
         if (xMBTCPPortMasterGetRespTimeLeft(pxInfo) == 0) {
             return ERR_TIMEOUT;
         }
-        vTaskDelay(1);
     }
     return usLength;
 }
@@ -847,12 +850,13 @@ static void vMBTCPPortMasterTask(void *pvParameters)
                                     pxCurrInfo->xIndex, pxCurrInfo->xSockId, pxCurrInfo->pcIpAddr);
                     } else if ((xRet == ERR_TIMEOUT) || (xMBTCPPortMasterGetRespTimeLeft(pxCurrInfo) == 0)) {
                         // Timeout occurred when receiving frame, process respond timeout
+                        xMBTCPPortMasterFsmSetError(EV_ERROR_RESPOND_TIMEOUT, EV_MASTER_ERROR_PROCESS);
                         ESP_LOGD(TAG, MB_SLAVE_FMT(", frame read timeout."),
                                     pxCurrInfo->xIndex, pxCurrInfo->xSockId, pxCurrInfo->pcIpAddr);
                     } else if (xRet == ERR_BUF) {
                         // After retries a response with incorrect TID received, process failure.
                         xMBTCPPortMasterFsmSetError(EV_ERROR_RECEIVE_DATA, EV_MASTER_ERROR_PROCESS);
-                        ESP_LOGD(TAG, MB_SLAVE_FMT(", frame error."),
+                        ESP_LOGW(TAG, MB_SLAVE_FMT(", frame error."),
                                     pxCurrInfo->xIndex, pxCurrInfo->xSockId, pxCurrInfo->pcIpAddr);
                     } else {
                         ESP_LOGE(TAG, MB_SLAVE_FMT(", critical error=%d."),