Thread: how to know which ip is binded to the specific port using a c/linux program?

Friends,

I have a program which creates a tcp socket and binds on to the port 5819.

The expected behaviour is it needs to bind to 5819 using the provided ip.

Due to some malfunction ( which i need to trace ) after bind instead of provided ip it is taking some other ip.

when i do a netstat it shows me like below

tcp 0 0 255.255.255.255:5819 0.0.0.0:* LISTEN


Do i have any system call which i can use in my program where i can check like on this port which ip is being bind .

I thought i can use netstat like executing with system command and then output to a textfile . Now parse the text file to know the result . But it is very expensive as lot of file opertaion and then parsing .

So Any system call or any function through which i can get that info ?

I hope iam making some sense if not please let me know to explain with more workds.

regards

Code:

        /* setup address info for our server socket */
		bzero((char *)&addrServer, lenSockAddr);
		addrServer.sin_family = AF_INET;
        addrServer.sin_addr.s_addr = inet_addr(UPNP_SERVER_IP);
        addrServer.sin_port = htons(UPNP_SERVER_PORT);
        /* create our socket */
         if ( UPNP_HTTP_NO_SOCKET == serverSocket )
         {
             serverSocket = socket(AF_INET, SOCK_STREAM, 0);
         }

if ( -1 == serverSocket) 
{
syslog(LOG_ERROR, "Could not create server socket");
continue;
}

        if(setsockopt(serverSocket, SOL_SOCKET, SO_REUSEADDR,(char *)&iAddrReuse, sizeof(iAddrReuse)) == (-1))
        {
          syslog(LOG_ERR, "Setsockopt failed for SO_REUSEADDR \n");
        }

	/* bind address to our socket */
        if ( bindretVal == UPNP_HTTP_BIND_ERROR  )
          {
              bindretVal = bind(serverSocket, (struct sockaddr *)&addrServer, lenSockAddr);
          }

here while running i tried to print the ip address structure using inet_ntoa both before and after bind it shows me as the ip which i provided .

But when i run the netstat command it shows me a other ip as 255.255.255.255

regards

Code:

addrServer.sin_addr.s_addr = inet_addr(UPNP_SERVER_IP);

inet_addr() returns the address in the host encoding, converting the result with htonl() may help.

yeah, you need to convert from little endian byte order to a network byte order by using htonl().

Code:

addrServer.sin_addr.s_addr = htonl(INADDR_LOOPBACK);