RTOS/TM4C1294NCPDT: NDK - retrieving the default gateway when using DHCP

sjf

Part Number: TM4C1294NCPDT

Tool/software: TI-RTOS

I am having difficulties retrieving the the default gateway when using DHCP with the TI-RTOS NDK (TI-RTOS version 2.16.01.14, NDK version 2.25.00.09).

In my hook function that gets called when new IP address info is received via DHCP, I have the following code, which is intended to retrieve the default gateway address:

int Result;

int NumberOfInstances = CfgGetEntryCnt(0, CFGTAG_IPNET, 1); // success

if (NumberOfInstances >= 1) {

CI_IPNET IpConfig;

bzero(&IpConfig, sizeof(CI_IPNET));

Result = CfgGetImmediate(
0, CFGTAG_IPNET, 1, NumberOfInstances,
sizeof(CI_IPNET), (UINT8*)&IpConfig); // success
...
}

NumberOfInstances = CfgGetEntryCnt(0, CFGTAG_ROUTE, 1); // fails

if (NumberOfInstances >= 1) {

CI_ROUTE RouteConfig;

bzero(&RouteConfig, sizeof(CI_ROUTE));

Result = CfgGetImmediate(
0, CFGTAG_ROUTE, 1, NumberOfInstances,
sizeof(CI_ROUTE), (UINT8*)&RouteConfig);

if (Result) {

...
}

}

NumberOfInstances is always zero after calling CfgGetEntryCnt for tag CFGTAG_ROUTE, implying there is no route information in the configuration.

In looking through other forum posts, I see this post below, which suggests using functions Rt* in routeif.h, with function DumpRouteTable in NDK file conroute.c providing an example of how to use those functions. This function and code seems complicated though.

e2e.ti.com/.../1900996

What is the proper way to get the default gateway IP address when using DHCP. Is my code above right, or do I have to do something like what is found in function DumpRouteTable in NDK file conroute.c?

Thanks in advance

over 6 years ago

0 ToddMullanix over 6 years ago

TI__Guru* 96960 points

Hi,

We've assigned someone to look at this.

Todd

0 Gerardo Gomez Martinez over 6 years ago

TI__Expert 5825 points

Hi,

The way to do this is the way it shows on the thread you linked. You can look at the example found at packages/ti/ndk/tools/console/conroute.c on your NDK installation, then the piece of the code you're interested on is the following:

        /* If the route is a gateway, print the gateway IP address as well */
        if( wFlags & FLG_RTE_GATEWAY )
        {
            llEnter();
            IPAddr = RtGetGateIP( hRt );
            llExit();
            NtIPN2Str( IPAddr, str );
            ConPrintf( "  %-15s  ",str);
        }

You'll have to modify this slightly as some functions such as ConPrintf() are local to that example.

BR,
Gerardo

0 sjf over 6 years ago in reply to Gerardo Gomez Martinez

Intellectual 296 points

I've implemented a method for retrieving the Gateway address as seen in the conroute.c, and it works. I can now obtain the default gateway via DHCP. Thanks for the answer.

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RTOS/TM4C1294NCPDT: NDK - retrieving the default gateway when using DHCP