Loadable Module - Value getting mangled?

[sreed7164]

Short version;
Function returns string correctly in executable version of module seems to return integer (or memory pointer?) when the file is a shared object (for the server). Code is below.



Long Version;
This may be a basic C/C++ Coding issue - I'm definitely not an experienced developer. I apologize in advance that my c and c++ coding does not comply with the zabbix programming guidelines.

I am attempting to develop a loadable module to pull some data out of IP Cameras. During testing I had written my testing code in c++ and successfully pulled data using zabbix's external checks scripting.

I've used 'Extern "C"' to make the C++ function that I'll be calling work with C. I've created the shared Library and everything is linked together. When I call the function (the only one I'm testing so far) it should return the name of the device. If I run the code from Main() it works fine and returns the name i.e. "IP-CAM-1". However, if that same code runs via the (key) function than it returns an integer (usually 87 in my case).

If someone could explain why I'm seeing what I'm seeing I would be extremely grateful.
Thanks!

---Snippit of C++ Code (shared object). This is the only function that is directly called by zabbix module. ---

extern "C" const char *VNConnect (const char *ipAddr, const char *OutputOption)
{
        IF2SetupPacket  packet;
        GloDstIP = ipAddr;                //Global Var - Destination IP Address
        GloOutput = OutputOption;    //Global Var - Sets what will be returned (Name, Mac, HW Info, Etc)
        IF2PacketSend(&packet);      //Function Fills packet data, Creates socket, transmits, etc
        return ReturnVal.c_str();       //ReturnVal is a Global Var
}

-- Snippit 1 of Zabbix Module ----
This I put in for testing purposes. When it is compiled as an executable and not a shared object this code prints out the desired info (camera Name).

int     main()
{
        extern char *VNConnect(char *IPADDRESS, char *OUTPUT);
        const char *VNName = VNConnect("172.17.43.143","Name");
        printf(VNName);
        return 0;
}

-- Snippit 2 of Zabbix Module ----
The demo module is the base of this, I've just modified it as needed. Comments in the code should explain the issue part (as far as I can tell)
I only know how to test this by creating it as a shared object and loading it into the zabbix server.

int     zbx_module_Camera_DevName(AGENT_REQUEST *request, AGENT_RESULT *result)
{
        char    *param;

        if (1 != request->nparam)
        {
                /* set optional error message */
                SET_MSG_RESULT(result, strdup("Invalid number of parameters."));
                return SYSINFO_RET_FAIL;
        }

        param = get_rparam(request, 0);                                   //Gets IP Address
        extern char *VNConnect(char *IPADDRESS, char *OUTPUT);        //Defines External Function
        const char *VNName = VNConnect(param,"Name");         //calls external function and returns name (maybe)
        zabbix_log(LOG_LEVEL_ERR,"VNSetup - %s - %s",param,"Name"); //First logging line
        zabbix_log(LOG_LEVEL_ERR,"VNSetup - Name - %i",VNName);         //Log the result - the %i [I]should[/I] be %s, but that causes zabbix server (or at least the logger) to lock up. With %i it always prints 87.
        SET_STR_RESULT(result, strdup(param));            //ultimatly param will be replaced with VNName

        return SYSINFO_RET_OK;
}

Thanks again!

Steve