CCS/TM4C1294NCPDT: function DNSGetHostByName() solving wrong IP

Hi,

  Where are you running the DNS code? If you are running in your office network then I will suggest, if possible, try in another network, e.g. home network? If you are getting the same result then I will forward your question to our NDK experts. I just wanted to make sure the problem is not network dependent. 

  Please also refer to the below two posts which might help. 

https://e2e.ti.com/support/legacy_forums/embedded/tirtos/f/355/p/563235/2083624?tisearch=e2e-sitesearch&keymatch=could%20not%20resolve%20host%20name#2083624

https://e2e.ti.com/support/microcontrollers/other/f/908/p/601702/2217180?tisearch=e2e-quicksearch&keymatch=getaddrinfo#2217180

Hi, Charles

Thanks for replying me! I'm running my code in a home network and I'm using the same DNS server my laptop is using. I read the posts you sent, but they didin't help me.

Hi,

  Did you have a chance to run in a different network, e.g. your office network? Is there a firewall in your network? What if you disable the firewall and will it make a difference?

Hi,

Unfortunately, I can't test the application in another network, but I have already disabled the firewall and it didn't make any difference.

Regards,

Ronan

Hi,

  It will be good if you can test in another network. In the meantime, I will forward your question to our NDK experts for advice.

Hi Ronan,

If you have the necessary setup, it would be helpful if you could post a wireshark log of the DNS query and response.

Regards,

Dalton

Hi Dalton,

The wireshark doesn't show any DNS packet coming from/to the device, only the DHCP request when I it's enabled.
I forgot to mention that I'm initiating the NDK stack manually via C code. Is necessary to do anything special in the stack initialization process in order to use DNS?
I'm attaching the stack initialization code below. I have already tested this code and the DHCP is working and I got a successful connection with a TCP server created by me.

#define DHCP        // Comment to static IP

#include <ti/ndk/inc/netmain.h>
#include <ti/ndk/inc/os/oskern.h>
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Task.h>
#include <ti/sysbios/knl/Clock.h>
#include <ti/sysbios/utils/Load.h>
#include <xdc/std.h>
#include <xdc/runtime/System.h>

#include <signal.h>
#include <time.h>


/* Socket file descriptor table */
#define MAXSOCKETS 10
uint32_t ti_ndk_socket_max_fd = MAXSOCKETS;
void *ti_ndk_socket_fdtable[MAXSOCKETS];

// NDK memory manager page size and number of pages [used by mmAlloc()]
#define RAW_PAGE_SIZE 3072
#define RAW_PAGE_COUNT 6

const int ti_ndk_config_Global_rawPageSize  = RAW_PAGE_SIZE;
const int ti_ndk_config_Global_rawPageCount = RAW_PAGE_COUNT;

// P.I.T. (page information table)
#ifdef __ti__
#pragma DATA_SECTION(ti_ndk_config_Global_pit, ".bss:NDK_MMBUFFER");
#pragma DATA_SECTION(ti_ndk_config_Global_pitBuffer, ".bss:NDK_MMBUFFER");
PITENTRY ti_ndk_config_Global_pit[RAW_PAGE_COUNT];
unsigned char ti_ndk_config_Global_pitBuffer[RAW_PAGE_SIZE * RAW_PAGE_COUNT];
#elif defined (__IAR_SYSTEMS_ICC__)
PITENTRY ti_ndk_config_Global_pit[RAW_PAGE_COUNT];
unsigned char ti_ndk_config_Global_pitBuffer[RAW_PAGE_SIZE * RAW_PAGE_COUNT];
#else
PITENTRY ti_ndk_config_Global_pit[RAW_PAGE_COUNT]
        __attribute__ ((section(".bss:NDK_MMBUFFER")));
unsigned char ti_ndk_config_Global_pitBuffer[RAW_PAGE_SIZE * RAW_PAGE_COUNT]
        __attribute__ ((section(".bss:NDK_MMBUFFER")));
#endif

/*
 * ======== ti_ndk_config_global_taskCreateHook ========
 * Automatically call fdOpenSession for dynamically created tasks.
 */
Void ti_ndk_config_global_taskCreateHook(ti_sysbios_knl_Task_Handle h)
{
}

/*
 * ======== ti_ndk_config_global_taskExitHook ========
 * Automatically call fdCloseSession for dynamically created tasks.
 */
Void ti_ndk_config_global_taskExitHook(ti_sysbios_knl_Task_Handle h)
{
}


// Memory bucket sizes
#define SMALLEST 48
#define LARGEST (RAW_PAGE_SIZE)

const int ti_ndk_config_Global_smallest = SMALLEST;
const int ti_ndk_config_Global_largest  = LARGEST;

// Memory Slot Tracking
uint32_t ti_ndk_config_Global_Id2Size[] = {SMALLEST, 96, 128, 256, 512, 1536, LARGEST};

/*
 *  Number of buffers in PBM packet buffer free pool
 *
 *  The number of buffers in the free pool can have a significant effect
 *  on performance, especially in UDP packet loss. Increasing this number
 *  will increase the size of the static packet pool use for both sending
 *  and receiving packets.
 */
#define PKT_NUM_FRAMEBUF 10

// Size of Ethernet frame buffer
#define PKT_SIZE_FRAMEBUF   1536

const int ti_ndk_config_Global_numFrameBuf = PKT_NUM_FRAMEBUF;
const int ti_ndk_config_Global_sizeFrameBuf = PKT_SIZE_FRAMEBUF;

/*
 *  Data space for packet buffers
 *
 *  Buffers are aligned on 4 byte boundaries to satisfy the EMAC's DMA
 */
unsigned char ti_ndk_config_Global_pBufMem[PKT_NUM_FRAMEBUF * PKT_SIZE_FRAMEBUF]
        __attribute__ ((aligned(4)));
unsigned char ti_ndk_config_Global_pHdrMem[PKT_NUM_FRAMEBUF * sizeof(PBM_Pkt)]
        __attribute__ ((aligned(4)));



/* Our NETCTRL callback functions */
static void networkOpen();
static void networkClose();
static void networkIPAddr(uint32_t IPAddr, uint32_t IfIdx, uint32_t fAdd);
static char *hostName = "tisoc";

extern void llTimerTick();

const char *LocalIPAddr = "192.168.1.12";
const char *LocalIPMask = "255.255.255.0";
const char *GatewayIP   = "192.168.1.1";
const char *DNSAddr     = "8.8.8.8";
const char *DomainName  = "demo.net";

/*
 *  ======== networkOpen ========
 *  This function is called after the configuration has booted
 */
static void networkOpen()
{
    System_printf("Network open hook!\n");
    System_flush();
}

/*
 *  ======== networkClose ========
 *  This function is called when the network is shutting down,
 *  or when it no longer has any IP addresses assigned to it.
 */
static void networkClose()
{
    System_printf("Network close hook!\n");
    System_flush();
}

/*
 *  ======== networkIPAddr ========
 *  This function is called whenever an IP address binding is
 *  added or removed from the system.
 */
static void networkIPAddr(uint32_t IPAddr, uint32_t IfIdx, uint32_t fAdd)
{
    uint32_t IPTmp;

    if (fAdd) {
        System_printf("Network Added: ");
    }
    else {
        System_printf("Network Removed: ");
    }

    // print the IP address that was added/removed
    IPTmp = ntohl(IPAddr);
    System_printf("If-%d:%d.%d.%d.%d\n", IfIdx,
                  (uint8_t)(IPTmp>>24)&0xFF, (uint8_t)(IPTmp>>16)&0xFF,
                  (uint8_t)(IPTmp>>8)&0xFF, (uint8_t)IPTmp&0xFF);
    System_flush();
}

/*
 *  ======== serviceReport ========
 *  Function for reporting service status updates.
 */
static char *taskName[] = {"Telnet", "HTTP", "NAT", "DHCPS", "DHCPC", "DNS"};
static char *reportStr[] = {"", "Running", "Updated", "Complete", "Fault"};
static char *statusStr[] = {"Disabled", "Waiting", "IPTerm", "Failed","Enabled"};
static void serviceReport(uint32_t item, uint32_t status, uint32_t report, void *h)
{
    System_printf("Service Status: %-9s: %-9s: %-9s: %03d\n",
                  taskName[item - 1], statusStr[status], reportStr[report / 256],
                  report & 0xFF);
    System_flush();
}

/*
 *  ======== initTcp ========
 *  Configure the stack's TCP settings
 */
static void initTcp(void *hCfg)
{
    int transmitBufSize = 1024;
    int receiveBufSize = 1024;
    int receiveBufLimit = 2048;

    CfgAddEntry(hCfg, CFGTAG_IP, CFGITEM_IP_SOCKTCPTXBUF, CFG_ADDMODE_UNIQUE,
            sizeof(uint32_t), (unsigned char *)&transmitBufSize, NULL);
    CfgAddEntry(hCfg, CFGTAG_IP, CFGITEM_IP_SOCKTCPRXBUF, CFG_ADDMODE_UNIQUE,
            sizeof(uint32_t), (unsigned char *)&receiveBufSize, NULL);
    CfgAddEntry(hCfg, CFGTAG_IP, CFGITEM_IP_SOCKTCPRXLIMIT, CFG_ADDMODE_UNIQUE,
            sizeof(uint32_t), (unsigned char *)&receiveBufLimit, NULL);
}

/*
 *  ======== initIp ========
 *  Configure the stack's IP settings
 */
static void initIp(void *hCfg)
{
#ifdef DHCP
    // DHCP
    CI_SERVICE_DHCPC dhcpc;
    unsigned char DHCP_OPTIONS[] = { DHCPOPT_SUBNET_MASK };

    // hostname
    CfgAddEntry(hCfg, CFGTAG_SYSINFO, CFGITEM_DHCP_HOSTNAME, 0,
                strlen(hostName), (unsigned char *)hostName, NULL);

    // Use DHCP to get IP in interface 1
    memset(&dhcpc, 0, sizeof(dhcpc));
    dhcpc.cisargs.Mode = CIS_FLG_IFIDXVALID;
    dhcpc.cisargs.IfIdx = 1;
    dhcpc.cisargs.pCbSrv = &serviceReport;
    dhcpc.param.pOptions = DHCP_OPTIONS;
    dhcpc.param.len = 1;
    CfgAddEntry(hCfg, CFGTAG_SERVICE, CFGITEM_SERVICE_DHCPCLIENT, 0,
              sizeof(dhcpc), (unsigned char *)&dhcpc, NULL);

#else
    // static IP
    CI_IPNET NA;
    CI_ROUTE RT;

    // hostname
    CfgAddEntry(hCfg, CFGTAG_SYSINFO, CFGITEM_DHCP_HOSTNAME, 0,
                strlen(hostName), (unsigned char *)hostName, NULL);

    // Ip and mask
    bzero(&NA, sizeof(NA));
    NA.IPAddr  = inet_addr(LocalIPAddr);
    NA.IPMask  = inet_addr(LocalIPMask);
    strcpy(NA.Domain, DomainName);
    NA.NetType = CFG_NETTYPE_VIRTUAL;
    CfgAddEntry(hCfg, CFGTAG_IPNET, 1, 0, sizeof(CI_IPNET), (UINT8 *)&NA, 0);

    // Gateway
    bzero(&RT, sizeof(RT));
    RT.IPDestAddr = 0;
    RT.IPDestMask = 0;
    RT.IPGateAddr = inet_addr(GatewayIP);
    CfgAddEntry(hCfg, CFGTAG_ROUTE, 0, 0, sizeof(CI_ROUTE), (UINT8 *)&RT, 0);


    // DNS
    IPN IPTmp;
    IPTmp = inet_addr(DNSAddr);
    CfgAddEntry( hCfg, CFGTAG_SYSINFO, CFGITEM_DHCP_DOMAINNAMESERVER, 0, sizeof(IPTmp),
                 (unsigned char *)&IPTmp, 0 );
#endif
}

/*
 *  ======== initUdp ========
 *  Configure the stack's UDP settings
 */
void initUdp(void *hCfg)
{
    int receiveBufSize = 2048;

    CfgAddEntry(hCfg, CFGTAG_IP, CFGITEM_IP_SOCKUDPRXLIMIT, CFG_ADDMODE_UNIQUE,
            sizeof(uint32_t), (unsigned char *)&receiveBufSize, NULL);
}

/*
 *  ======== ndkStackThread ========
 *  NDK stack's main thread function
 */
void NDKManagerTaskFxn()
{
    void *hCfg;
    int rc;
    Clock_Params clockParams;
    Clock_Handle ndkClockHandle;

    // Create the NDK heart beat
    Clock_Params_init(&clockParams);
    clockParams.startFlag = TRUE;
    clockParams.period = ((100*1000)/Clock_tickPeriod);
    ndkClockHandle = Clock_create((Clock_FuncPtr)llTimerTick, clockParams.period,
                                  &clockParams, NULL);
    if (ndkClockHandle == NULL) {
        System_printf("Problema ao criar relogio\n");
        System_flush();
        return;
    }

    rc = NC_SystemOpen(NC_PRIORITY_LOW, NC_OPMODE_INTERRUPT);
    if (rc) {
        System_printf("ndkStackThread: NC_SystemOpen Failed\n");
        System_flush();
        return;
    }

    // create and build the system configuration from scratch.
    hCfg = CfgNew();
    if (!hCfg) {
        System_printf("ndkStackThread: Unable to create configuration\n");
        System_flush();
        goto main_exit;
    }

    // IP, TCP, and UDP config
    initIp(hCfg);
    initTcp(hCfg);
    initUdp(hCfg);

    // config low priority tasks stack size
    rc = 2048;
    CfgAddEntry(hCfg, CFGTAG_OS, CFGITEM_OS_TASKSTKLOW, CFG_ADDMODE_UNIQUE,
            sizeof(uint32_t), (unsigned char *)&rc, NULL);

    // config norm priority tasks stack size
    rc = 2048;
    CfgAddEntry(hCfg, CFGTAG_OS, CFGITEM_OS_TASKSTKNORM, CFG_ADDMODE_UNIQUE,
            sizeof(uint32_t), (unsigned char *)&rc, NULL);

    // config high priority tasks stack size
    rc = 2048;
    CfgAddEntry(hCfg, CFGTAG_OS, CFGITEM_OS_TASKSTKHIGH, CFG_ADDMODE_UNIQUE,
            sizeof(uint32_t), (unsigned char *)&rc, NULL);

    // Seta handle de configuração hCfg como o default
    CfgSetDefault(hCfg);

    do
    {
        rc = NC_NetStart(hCfg, networkOpen, networkClose, networkIPAddr);
    } while(rc > 0);

    System_printf("Saiu de NC_NetStart\n");
    System_flush();

    /* Shut down the stack */
    CfgFree(hCfg);

main_exit:
    NC_SystemClose();

    Clock_delete(&ndkClockHandle);

    System_printf("ndkStackThread: exiting ...\n");
    System_flush();
}

Thanks in advance,

Ronan

Hi Ronan,

You wouldn't see any DNS traffic from your board unless you have a router/switch capable of port mirroring as the DNS traffic never goes through your computer running wireshark. Your startup function also looks good to me. 

Could you show me the NDK libraries you are linking? The DNS functions can cause odd failures if an IPv6 library is used without IPv6 code. Also, are you throwing a compiler define for _INCLUDE_IPv6_CODE?

It also looks like you are using NDK v2.x, so you could see if you get the correct results when using the getaddrinfo() function.

Regards,

Dalton

Hi Dalton,

Thanks for replying me! These are the libraries that I'm linking:

Is there any problem with the libraries? I tried to remove the stk6 from the list, but when if I do that I get the error unresolved symbol IPv6Init, first referenced in .../netctrl.aem4f.

I'm not defining the _INCLUDE_IPv6_CODE in the compiler options, neither in any part of my code.

About the getaddrinfo(), I didn't know this function. I'm going to read about it now and try to use it.

Thanks in advance,

Ronan

Hi Dalton,

This solved my problem! Thank you so much for helping me!

The NDK docs don't specify how to link the ndk libraries manually, so I tried to discover by myself based on the unresolved symbols returned by the linker. Now, I'm sure I'm using the correct libraries! :D