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csocketsudpportlwip

empty source port with sending udp data (lwip, Cortex M3, Stellaris LM3S6965 Evaluation Board)

I'm working with Cortex M3, Stellaris® LM3S6965 Evaluation Board. I'm sending an UDP packet to my pc. That works because I checked it with wireshark. But what I do see is that I don't have a source port. And I have no clue how so solve this.

I call this function to sent the a udp packet

void send_udp(){
    RIT128x96x4Enable(1000000);
    RIT128x96x4StringDraw("UDP data verzonden..", 0, 40, 15);

    struct ip_addr  serverIp;
    IP4_ADDR(&serverIp,192,168,1,100);

    u16_t port;
    port = 64000;
    struct udp_pcb * pcb;
    pcb = udp_new();

    udp_bind(pcb, &serverIp, port);
    udp_recv(pcb, udp_echo_recv, NULL);
    struct pbuf *p;
    char msg[]="request";

    //Allocate packet buffer
    p = pbuf_alloc(PBUF_TRANSPORT,sizeof(msg),PBUF_RAM);
    memcpy (p->payload, msg, sizeof(msg));
    udp_sendto(pcb, p, &serverIp, port);
    pbuf_free(p); //De-allocate packet buffer
}

Wireshark example of packet: (click here to enlarge) here

Solution

  • I also saw that "time to live" in the ipv4 pcb was 0. So I added this line, 

    pcb->ttl = UDP_TTL; // Time to live

    This solved my issue