TCP_KEEPIDLE vs TCPTV_KEEP_IDLE

[Richard Sharpe]

On Mon, May 6, 2013 at 6:23 AM, Gleb Smirnoff <glebius at freebsd.org> wrote:
> On Mon, May 06, 2013 at 06:15:11AM -0700, Richard Sharpe wrote:
> R> On Mon, May 6, 2013 at 1:22 AM, Gleb Smirnoff <glebius at freebsd.org> wrote:
> R> > On Sun, May 05, 2013 at 09:40:42AM -0700, Richard Sharpe wrote:
> R> > R> Samba currently has a way to set socket parameters from the smb.conf.
> R> > R>
> R> > R> This works fine for things like SO_SNDBUF etc, but not so well for the
> R> > R> TCP KeepAlive parameters.
> R> > R>
> R> > R> In this area Samba has a Linux bias.
> R> > R>
> R> > R> I am looking at adding support for this under FreeBSD.
> R> > R>
> R> > R> The simplest way, it seems to me, is to enhance configure to find the
> R> > R> appropriate symbols under FreeBSD (and it might be extendable to
> R> > R> NetBSD etc) and then map them to the Linux symbols:
> R> > R>
> R> > R> #ifdef THIS_IS_SOME_SORT_OF_BSD
> R> > R> #define TCP_KEEPIDLE TCPTV_KEEP_IDLE
> R> > R> #endif
> R> > R>
> R> > R> However, that does mean that *BSD types would have to know that this
> R> > R> happening because the names you would use in the smb.conf file would
> R> > R> be Linux-specific, and documentation is often woefully incomplete.
> R> > R>
> R> > R> Is there a better method?
> R> >
> R> > I don't see the problem you are describing. AFAIK, these socket options
> R> > have same names in FreeBSD and Linux.
> R> >
> R> > For example in Samba 3.6.14 sources it just checks for value defined
> R> > and if defined compiles support in. See source3/lib/util_sock.c:
> R>
> R> Yes, I know that. However, when I do a find and grep over /usr/include
> R> looking for files where TCP_KEEPIDLE is defined, I find nothing. When
> R> I do the same for TCPTV_KEEP_IDLE I find
> R> /usr/include/netinet/tcp_timer.h.
> R>
> R> This seems to mean that the symbols Samba is using are not defined on FreeBSD.
> R>
> R> These appear to be the symbols defined in FreeBSD 8,0:
>
> The discussed socket options aren't supported in 8.0.
>
> Please install FreeBSD 9.1 and recompile Samba port. It will pick up
> all supported options.
>
> R>  * connection is idle (no segments received) for TCPTV_KEEP_INIT amount of time,
> R>  * is established, if the connection is idle for TCPTV_KEEP_IDLE time
> R> #define      TCPTV_KEEP_INIT ( 75*hz)                /* initial connect keepalive */
> R> #define      TCPTV_KEEP_IDLE (120*60*hz)             /* dflt time before probing */
> R> #define      TCPTV_KEEPINTVL ( 75*hz)                /* default probe interval */
> R> #define      TCPTV_KEEPCNT   8                       /* max probes before drop */
>
> These defines are not socket options, although they are relevant to discussed
> socket options.

Thank you for that answer. I don't have the option to install FreeBSD
9.1. Maybe we will move to 9.1 in the future.

However, I now understand the issues better. Of course that does
complicate my proposal on Samba technical, just a little.

-- 
Regards,
Richard Sharpe
(何以解憂？唯有杜康。--曹操)