FreeTDS Development Group

["James K. Lowden" <jklowden AT freetds.org>]

Kian Mohageri wrote:
> 19:27:18.240697 12864 (net.c:210):Connecting to 140.160.12.123 port
> 2638 (TDS version 5.0)
> 19:27:18.240926 12864 (net.c:264):tds_open_socket: connect(2) returned
> "Unknown error: 0"

I can tell you what's happening, but not why.  I suspect it's some kind of
local network setup problem, perhaps a firewall or permissions.  

Here's the relevant code from src/tds/net.c:


        retval = connect(tds->s, 
                        (struct sockaddr *) &sin, 
                        sizeof(sin));
        if (retval == 0) {
                tdsdump_log(TDS_DBG_INFO2, 
                        "connection established\n");
        } else {
                tdsdump_log(TDS_DBG_ERROR, 
                        "tds_open_socket: connect(2) returned \"%s\"\n",      
          
strerror(sock_errno));
        ...

http://www.opengroup.org/onlinepubs/000095399/functions/connect.html

connect(2) may return only 0 or -1, and should set errno.  It appears to
be returning nonzero, but not setting errno.  (sock_errno is just errno
except on Win32.)  That is, it reports failure but not why.  

The only conclusion I can draw is that your FreeTDS configuration is
correct, but something is amiss with your network setup that prevents your
PHP application from forming the connection.  Moreover, IMO you have a
FreeBSD bug, because a non-zero return code from connect(2) must be
accompanied by a valid errno value.  

HTH.    :-/

--jkl