FILE EXISTS error on setting IPV4 address using ioctl

GENERAL Test Forum
1

I am getting a File exists error on using the SIOCSIFADDR ioctl command to set IP address ,but the IP address is changed
to the requested value. Why the error occurs?

Code snippet:

bool setIpv4Address(std::string interfaceName,std::string ipAddr)
{
struct sockaddr_in sin;
int sockFd;
std::string Ip;
struct ifreq ifr;
bool retStatus;

memset(&ifr, 0x00, sizeof(ifr));
memset(&sin, 0x00, sizeof(sin));
retStatus = true;

sin.sin_family = AF_INET;
sin.sin_len = sizeof(sin);
/// check valid ip
if (inet_aton(&ipAddr[0], &sin.sin_addr) == 0) 
{ 
  retStatus = false;
}
else
{
    /// Create socket for INET and update the address information.
    memset(&ifr, 0x00, sizeof(ifr));
    strcpy(ifr.ifr_name, &interfaceName[0]);
    memcpy(&ifr.ifr_addr, &sin, sizeof(ifr.ifr_addr));
    if ((sockFd = socket(AF_INET, SOCK_DGRAM, 0)) != -1) 
    {
        
        /// Set IP address using  SIOCSIFADDR ioctl flag.
        if (ioctl(sockFd, SIOCSIFADDR, &ifr) != -1) 
        {
            /// Set Interface Up
            /// Get ifreq.flags
            ioctl(sockFd, SIOCGIFFLAGS, &ifr);
            
            ifr.ifr_flags |= (IFF_UP| IFF_RUNNING); 
            
            if(ioctl(sockFd, SIOCSIFFLAGS, &ifr) == -1)
            {
                perror("Interface link status change failed");
                retStatus = false;
            }
        }
        else
        {
            perror("setIpv4Address Setting IPV4 address Error :");
            retStatus = false;
        }
    }
    else
    {
        perror("Socket creation failed ");
        retStatus = false;
    }
    close (sockFd);
}

return retStatus;

}