Re: Example socket program to send data to a non IBM i device

[Scott Klement <midrange-l@xxxxxxxxxxxxxxxx>]

Darryl,

You appear to be reading the flags with F_GETFL, then changing the value 
to include O_NONBLOCK.   But, you're never calling F_SETFL to set the 
new value on the socket.

With the way this is coded, once you set the non-blocking flag the code 
will immediately fail because connect() will always return -1 because 
its non-blocking.

-SK


On 3/4/2019 11:30 AM, a4g atl wrote:
> I finally got the code from the older hardware. I still have the long
> timeout. I am posting the code for review.
>
> Thanks
>
> Darryl Freinkel.
>
>       C*************************************************
>       C* Create a socket
>       C*************************************************
>       c                   eval      sock = socket(AF_INET: SOCK_STREAM:
>       c                                           IPPROTO_IP)
>       c                   if        sock < 0
>       c                   eval      msg = 'Error calling socket()!'
>       c                   dsply                   msg
>       c                   return
>       c                   endif
>
>       C*************************************************
>       C* Create a socket address structure that
>       C*   describes the host & port we wanted to
>       C*   connect to
>       C*************************************************
>       c                   eval      addrlen = %size(sockaddr)
>       c                   alloc     addrlen       p_connto
>
>       c                   eval      p_sockaddr = p_connto
>       c                   eval      sin_family = AF_INET
>       c                   eval      sin_addr = IP_address
>       c                   eval      sin_port = port
>       c                   eval      sin_zero = *ALLx'00'
>
>       c                   eval      flags = fcntl(sock: F_GETFL)
>       c                   if        flags < 0
>       c                   eval      flags = flags
>      debug
>       c                   Endif
>
>       c*                  callp     FD_ZERO(writeset)
>
>       c*                  eval      flags = flags + O_NONBLOCK
>       c                   eval      flags = %bitor(flags : O_NONBLOCK)
>
>       c                   callp     FD_SET(sock : writeset)
>
>       c                   select
>       c                   when      rc = -1
>       c                   exsr      error_message
>       c                   callp     close(sock)
>       c                   return
>       c                   Endsl
>
>       C*************************************************
>       C* Connect to the requested host
>       C*************************************************
>       C                   if        connect(sock: p_connto: addrlen) < 0
>       c                   eval      msg = 'unable to connect to server!'
>       c*                  dsply                   msg
>       c                   exsr      error_message
>
>
> On Thu, Feb 28, 2019 at 5:21 PM a4g atl <a4ginatl2@xxxxxxxxx> wrote:
>
> > Scott
> >
> > Apologies for the delay in responding. The system I developed the code on
> > was the old hardware and to my surprise it was decommissioned with the
> > admins checking with me. I am waiting for the Library to be restored so
> > that I can be more specific with what I tested. I do remember trying the
> > non blocking option too but will confirm tomorrow I hope.
> >
> > @Richard, unfortunately I am not a .net person.
> >
> > I will look at Python as it will run on the IBMi, but everyone would
> > prefer the RPG option.
> >
> > Thanks
> >
> > On Thu, Feb 28, 2019 at 8:53 AM Richard Schoen via MIDRANGE-L <
> > midrange-l@xxxxxxxxxxxxxxxxxx> wrote:
> >
> > > I haven't been following this thread closely, but I have a thought for
> > > you.
> > >
> > > You should be able to create a VB.Net or C# app that connects to the
> > > device.
> > >
> > > Once you test it on the PC in Visual Studio you can move the EXE over to
> > > IBMi using the new Mono .Net functionality.
> > >
> > > You'll probably more readily find .Net examples than RPG ones.
> > >
> > > Food for thought.......
> > >
> > > Regards,
> > > Richard Schoen
> > > Director of Document Management
> > > e. richard.schoen@xxxxxxxxxxxxxxx
> > > p. 952.486.6802
> > > w. helpsystems.com
> > > ------------------------------
> > >
> > > message: 2
> > > date: Wed, 27 Feb 2019 17:50:48 -0500
> > > from: a4g atl <a4ginatl2@xxxxxxxxx>
> > > subject: Re: Example socket program to send data to a non IBM i device
> > >
> > > The problem is
> > >
> > > If the device is online,
> > > - I can connect to the device. The socket() is successful.
> > > - If the device is on line but the port is not in listen mode, the
> > > program goes into a wait/retry mode at the connect(). This takes 3.5
> > > minutes before returning control to the RPG program.
> > >
> > > I tried adding the setsock() functions and trying that, but it would not
> > > change the situation.
> > >
> > > Darryl.
> > >
> > >
> > >
> > >
> > >
> > >
> > > --
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