Have you tried SO_REUSEPOR?

> -----Original Message-----
> From: Thomas Allen [mailto:community-noreply@qnx.com]
> Sent: January-19-09 1:40 PM
> To: ostech-core_os
> Subject: bind error on TCP/IP connection
> 
> Hi,
> 
> I have an application where I am opening a TCP/IP socket, binding to a
> port then listening/accepting a connection from a client.
> 
> The problem I have is I want to be able to close the socket and later
> on create a new socket, bind to the same port and listen/accept a
> connection.
> 
> What is happening is it works fine the first time.  However when I
> close the socket and later create a new socket, and then try to bind it
> to the same port I get and EINVAL (22) error.  This docs say this means
> that the socket is already bound to an address.
> 
> Seems that I am not closing the socket correctly, or should be doing an
> 'unbind' of some sort???!!!
> 
> I am calling close(sock) and have also tried doing a shutdown(sock,2)
> first.
> 
> Opening the socket I am doing the following (and this works the first
> time)
> 	sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
> 	setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (char *)&c_opt_on,
> sizeof(OPT_TYPE));
> 
>                  serverservice.sin_family = AF_INET;
> 	 serverservice.sin_port	= ntohs(nPort);
> 	serverservice.sin_addr.s_addr = INADDR_ANY;
> 
>  	    setsockopt(sock, IPPROTO_TCP, SO_REUSEADDR, (char
> *)&c_opt_on, sizeof(OPT_TYPE));
> 
> 	    bind(sock, (sockaddr *)&m_serverservice,
> sizeof(m_serverservice));
> 
> The bind fails the second time and sets errno to 22.
> 
> Any ideas would be appreciated.
> 
> Thanks
> Thom
> 
> 
> _______________________________________________
> OSTech
> http://community.qnx.com/sf/go/post20335
> 

On Mon, Jan 19, 2009 at 01:40:15PM -0500, Thomas Allen wrote:
> Hi,
> 
> I have an application where I am opening a TCP/IP socket, binding to a port then listening/accepting a connection from
 a client.
> 
> The problem I have is I want to be able to close the socket and later on create a new socket, bind to the same port 
and listen/accept a connection.
> 
> What is happening is it works fine the first time.  However when I close the socket and later create a new socket, and
 then try to bind it to the same port I get and EINVAL (22) error.  This docs say this means that the socket is already 
bound to an address.  
> 
> Seems that I am not closing the socket correctly, or should be doing an 'unbind' of some sort???!!!
> 
> I am calling close(sock) and have also tried doing a shutdown(sock,2) first.
> 
> Opening the socket I am doing the following (and this works the first time)
> 	sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
> 	setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (char *)&c_opt_on, sizeof(OPT_TYPE));
> 
>                  serverservice.sin_family = AF_INET;
> 	 serverservice.sin_port	= ntohs(nPort);
> 	serverservice.sin_addr.s_addr = INADDR_ANY;
> 
>  	    setsockopt(sock, IPPROTO_TCP, SO_REUSEADDR, (char *)&c_opt_on, sizeof(OPT_TYPE));
> 
> 	    bind(sock, (sockaddr *)&m_serverservice, sizeof(m_serverservice));
> 
> The bind fails the second time and sets errno to 22.
> 
> Any ideas would be appreciated.
> 

Set the SO_REUSEADDR socket option (setsockopt) before the bind.

Regards,

-seanb