STM32F4 UDP组播通信：填一填ST官方HAL库的坑

先说写作本文的原因，由于开项目开发中需要用到UDP组播接收的功能，但是ST官方没有提供合适的参考，使用STM32CubeMX生成的代码也是不能直接使用的，而我在网上找了一大圈，也没有一个能够直接解决的方案，deepseek、ChatGPT给的方案也不能直接用，羡慕迷茫阶段。然而随着项目进度告急，我也只能硬着头皮摸着石头过河了，总结了大多数资料的观点，加上deepseek的帮助，最终找到了关键点，因此希望写一个记录文档，同时也给大家参考，若有高手也可以指点指点。

开发环境

单片机型号是STM32F407VGT6，以太网控制器是LAN7820，软件版本如下

STM32CubeMX6.12.1
IAR 9.50.2
STM32Cube FW_F4 V1.28.1

使用STM32CubeMX生成代码

配置JTAG

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配置以太网外设，选择RMII，打开以太网全局中断

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打开串口1方便调试，添加DMA

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启用LWIP

这里的关键是勾选右上角的Show Advance Parameters，然后使能LWIP_MULTICAST_TX_OPTONS (Multicast Tx support)
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使能LWIP_IGMP (IGMP module)

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PHY选择LAN8742，实际上使用的是LAN8720

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设置PHY的复位引脚，默认输出为高

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最后配置时钟

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生成代码

关键代码

生成的代码是不能直接使用的，需要做一些关键修改，这里添加了组播初始化函数和回调函数

/* USER CODE BEGIN Header */
/********************************************************************************* @file           : main.c* @brief          : Main program body******************************************************************************* @attention** Copyright (c) 2025 STMicroelectronics.* All rights reserved.** This software is licensed under terms that can be found in the LICENSE file* in the root directory of this software component.* If no LICENSE file comes with this software, it is provided AS-IS.********************************************************************************/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "dma.h"
#include "lwip.h"
#include "usart.h"
#include "gpio.h"/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <string.h>
#include "lwip/udp.h"
#include "lwip/igmp.h"
/* USER CODE END Includes *//* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD *//* USER CODE END PTD *//* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD *//* USER CODE END PD *//* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM *//* USER CODE END PM *//* Private variables ---------------------------------------------------------*//* USER CODE BEGIN PV *//* USER CODE END PV *//* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP *//* USER CODE END PFP *//* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
// 定义组播地址和端口
u16_t multicast_port=8554;
uint8_t multicast_ip[4]={226,0,0,80};void multicast_receive_callback(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port) {    if (p != NULL) {static uint8_t buff[128];memcpy(buff, p->payload, p->len);HAL_UART_Transmit_DMA(&huart1, (uint8_t *)&buff, p->len);pbuf_free(p);}
}// 初始化MULTICAST接收协议控制块
void multicast_receive_init(void) {struct udp_pcb *pcb;ip4_addr_t ip;IP4_ADDR(&ip, multicast_ip[0], multicast_ip[1], multicast_ip[2], multicast_ip[3]);igmp_joingroup(IP4_ADDR_ANY, &ip);pcb = udp_new();pcb->so_options |= SOF_REUSEADDR; // 允许地址重用
//    pcb->mcast_ttl   = 1;            // 组播TTL（默认1，限制在本地网络）if (pcb != NULL) {udp_bind(pcb, IP4_ADDR_ANY, multicast_port);udp_recv(pcb, multicast_receive_callback, NULL);}
}
/* USER CODE END 0 *//*** @brief  The application entry point.* @retval int*/
int main(void)
{/* USER CODE BEGIN 1 *//* USER CODE END 1 *//* MCU Configuration--------------------------------------------------------*//* Reset of all peripherals, Initializes the Flash interface and the Systick. */HAL_Init();/* USER CODE BEGIN Init *//* USER CODE END Init *//* Configure the system clock */SystemClock_Config();/* USER CODE BEGIN SysInit *//* USER CODE END SysInit *//* Initialize all configured peripherals */MX_GPIO_Init();MX_DMA_Init();MX_USART1_UART_Init();MX_LWIP_Init();/* USER CODE BEGIN 2 */multicast_receive_init();/* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */while (1){MX_LWIP_Process();/* USER CODE END WHILE *//* USER CODE BEGIN 3 */}/* USER CODE END 3 */
}/*** @brief System Clock Configuration* @retval None*/
void SystemClock_Config(void)
{RCC_OscInitTypeDef RCC_OscInitStruct = {0};RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};/** Configure the main internal regulator output voltage*/__HAL_RCC_PWR_CLK_ENABLE();__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);/** Initializes the RCC Oscillators according to the specified parameters* in the RCC_OscInitTypeDef structure.*/RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;RCC_OscInitStruct.HSIState = RCC_HSI_ON;RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;RCC_OscInitStruct.PLL.PLLM = 8;RCC_OscInitStruct.PLL.PLLN = 168;RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;RCC_OscInitStruct.PLL.PLLQ = 4;if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK){Error_Handler();}/** Initializes the CPU, AHB and APB buses clocks*/RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK){Error_Handler();}
}/* USER CODE BEGIN 4 *//* USER CODE END 4 *//*** @brief  Period elapsed callback in non blocking mode* @note   This function is called  when TIM1 interrupt took place, inside* HAL_TIM_IRQHandler(). It makes a direct call to HAL_IncTick() to increment* a global variable "uwTick" used as application time base.* @param  htim : TIM handle* @retval None*/
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{/* USER CODE BEGIN Callback 0 *//* USER CODE END Callback 0 */if (htim->Instance == TIM1) {HAL_IncTick();}/* USER CODE BEGIN Callback 1 *//* USER CODE END Callback 1 */
}/*** @brief  This function is executed in case of error occurrence.* @retval None*/
void Error_Handler(void)
{/* USER CODE BEGIN Error_Handler_Debug *//* User can add his own implementation to report the HAL error return state */__disable_irq();while (1){}/* USER CODE END Error_Handler_Debug */
}#ifdef  USE_FULL_ASSERT
/*** @brief  Reports the name of the source file and the source line number*         where the assert_param error has occurred.* @param  file: pointer to the source file name* @param  line: assert_param error line source number* @retval None*/
void assert_failed(uint8_t *file, uint32_t line)
{/* USER CODE BEGIN 6 *//* User can add his own implementation to report the file name and line number,ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) *//* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

另外一个关键的地方是需要在.\LWIP\Target\ethernetif.c文件中的low_level_init函数添加强制接收所有组播包以及确保启用 IGMP 支持

/*******************************************************************************LL Driver Interface ( LwIP stack --> ETH)
*******************************************************************************/
/*** @brief In this function, the hardware should be initialized.* Called from ethernetif_init().** @param netif the already initialized lwip network interface structure*        for this ethernetif*/
static void low_level_init(struct netif *netif)
{HAL_StatusTypeDef hal_eth_init_status = HAL_OK;/* Start ETH HAL Init */uint8_t MACAddr[6] ;heth.Instance = ETH;MACAddr[0] = 0x00;MACAddr[1] = 0x80;MACAddr[2] = 0xE1;MACAddr[3] = 0x00;MACAddr[4] = 0x00;MACAddr[5] = 0x00;heth.Init.MACAddr = &MACAddr[0];heth.Init.MediaInterface = HAL_ETH_RMII_MODE;heth.Init.TxDesc = DMATxDscrTab;heth.Init.RxDesc = DMARxDscrTab;heth.Init.RxBuffLen = 1536;/* USER CODE BEGIN MACADDRESS *//* USER CODE END MACADDRESS */hal_eth_init_status = HAL_ETH_Init(&heth);memset(&TxConfig, 0 , sizeof(ETH_TxPacketConfig));TxConfig.Attributes = ETH_TX_PACKETS_FEATURES_CSUM | ETH_TX_PACKETS_FEATURES_CRCPAD;TxConfig.ChecksumCtrl = ETH_CHECKSUM_IPHDR_PAYLOAD_INSERT_PHDR_CALC;TxConfig.CRCPadCtrl = ETH_CRC_PAD_INSERT;/* End ETH HAL Init *//* Initialize the RX POOL */LWIP_MEMPOOL_INIT(RX_POOL);#if LWIP_ARP || LWIP_ETHERNET/* set MAC hardware address length */netif->hwaddr_len = ETH_HWADDR_LEN;/* set MAC hardware address */netif->hwaddr[0] =  heth.Init.MACAddr[0];netif->hwaddr[1] =  heth.Init.MACAddr[1];netif->hwaddr[2] =  heth.Init.MACAddr[2];netif->hwaddr[3] =  heth.Init.MACAddr[3];netif->hwaddr[4] =  heth.Init.MACAddr[4];netif->hwaddr[5] =  heth.Init.MACAddr[5];/* maximum transfer unit */netif->mtu = ETH_MAX_PAYLOAD;/* Accept broadcast address and ARP traffic *//* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */#if LWIP_ARPnetif->flags |= NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP;#elsenetif->flags |= NETIF_FLAG_BROADCAST;#endif /* LWIP_ARP *//* USER CODE BEGIN PHY_PRE_CONFIG *//* USER CODE END PHY_PRE_CONFIG *//* Set PHY IO functions */LAN8742_RegisterBusIO(&LAN8742, &LAN8742_IOCtx);/* Initialize the LAN8742 ETH PHY */if(LAN8742_Init(&LAN8742) != LAN8742_STATUS_OK){netif_set_link_down(netif);netif_set_down(netif);return;}if (hal_eth_init_status == HAL_OK){/* Get link state */ethernet_link_check_state(netif);}else{Error_Handler();}
#endif /* LWIP_ARP || LWIP_ETHERNET *//* USER CODE BEGIN LOW_LEVEL_INIT */// --- 核心修复代码：直接操作寄存器 ---ETH->MACFFR |= ETH_MACFFR_PAM;  // 强制接收所有组播包netif->flags |= NETIF_FLAG_IGMP;  // 确保启用 IGMP 支持/* USER CODE END LOW_LEVEL_INIT */
}

上位机软件

为了配合测试，这里用python写了一个简单的上位机测试软件

import socket
import structMCAST_GROUP = '226.0.0.80'
MCAST_PORT = 8554
LOCAL_IP = '192.168.88.2'  # 替换为你的实际 IPv4 地址# 创建 UDP 套接字
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', MCAST_PORT))# 通过 IP 地址绑定到指定接口（Windows 兼容方案）
sock.setsockopt(socket.IPPROTO_IP,socket.IP_ADD_MEMBERSHIP,socket.inet_aton(MCAST_GROUP) + socket.inet_aton(LOCAL_IP)
)print(f"监听组播 {MCAST_GROUP}:{MCAST_PORT}...")
while True:data, addr = sock.recvfrom(1024)print(f"来自 {addr} 的消息: {data.decode()}")

# sender.py
import socketMCAST_GROUP = '226.0.0.80'
MCAST_PORT = 8554
INTERFACE_IP = '192.168.88.2'  # <--- 替换为你的实际 IPv4 地址sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, socket.inet_aton(INTERFACE_IP))message = "Multicast Test"
sock.sendto(message.encode(), (MCAST_GROUP, MCAST_PORT))
print("消息已发送")
sock.close()