如果输入字符串长于 19 字节，LwIP 套接字上的 UDP 服务器将陷入硬故障

Question

我认为是因为空指针异常。我的嵌入式系统由STM32F4、FreeRTOS和LwIP组成。核心取自 ST 示例。下面是简单UDP服务器的线程代码。

#include <string.h>
#include <stdbool.h>
#include <stdlib.h>
#include "lwip/sockets.h"
#include "./udpCLI.h"
//#include "Sledge.h" //for assert_amsg(), which print what and where fails before stop execution

static void udpCLI_thread(void *arg) 
{
    int sockfd; // socket file descriptor
    const uint16_t serverport = UDP_PORT_NUMBER_CLI;
    struct sockaddr_in serveraddr = {0}, clientaddr = {0};
    socklen_t addrlen;// = sizeof(struct sockaddr_in);
    const uint16_t bufin_SIZE = 200, bufout_SIZE = 1024;
    char *bufin  = malloc(bufin_SIZE);  assert_amsg(bufin != NULL);  // stops execution with printing message "ASSERT FAILED "bufin != NULL" in file udp_cli.c:42" in stdout/stderr
    char *bufout = malloc(bufout_SIZE); assert_amsg(bufout != NULL);

    LWIP_UNUSED_ARG(arg);  //(void)arg;

    debugf2( "udpCLI_thread"NEWLINE );  

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    assert_msg("udpCLI_thread: ERROR opening socket", sockfd>=0);

    /*
     * build the server's Internet address
     */
    serveraddr.sin_family = AF_INET;
    serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
    serveraddr.sin_port = htons(serverport);

    /* 
     * bind: associate the socket with a port 
     */
    if( bind(sockfd, (struct sockaddr *) &serveraddr, sizeof(serveraddr)) < 0 ) 
        error("udpCLI_thread: ERROR on binding");

    // main loop: wait for a datagram, then echo it
    while(1)
    {
        addrlen = sizeof(struct sockaddr_in);  // THIS DID NOT HELP
        // recvfrom: receive a UDP datagram from a client
        int n = recvfrom(sockfd, bufin, bufin_SIZE, /*flags*/0, (struct sockaddr*)&clientaddr, &addrlen);
        // handle rusult
        //if (n < 0)
        // future process and response
        //....
}

如果输入消息长度超过 19 个字节，程序控制永远不会从 recvfrom() 函数中 returns。并且从不 returns from function sys_arch_mbox_fetch(&conn->recvmbox, &buf, 0); in function netconn_recv_data() in file api_lib.c at line 371.
请帮助解决这个问题。

Answer 1

那是我的错误。问题是在另一个任务中错误的内存分配和释放。
谢谢所有同情的人

如果输入字符串长于 19 字节，LwIP 套接字上的 UDP 服务器将陷入硬故障

UDP server on LwIP socket falls into hard fault if input string longer than 19 bytes

c

sockets

freertos

lwip

stm32f4