Re: [PATCH] ws2_32: Add support to disable networking with envvar WINENONET=1

[Stefan Dösinger]

Am 2016-12-07 um 06:27 schrieb Bruno Jesus:
> @@ -2433,6 +2438,12 @@ static int WS2_send( int fd, struct ws2_async *wsa, int flags )
>      union generic_unix_sockaddr unix_addr;
>      int n, ret;
> - if (network_disabled)
> - {
> -
>    errno = EHOSTUNREACH;
> -
>    return -1;
> - }
> -

Shouldn't it be possible to achieve a similar effect with a LD_PRELOAD library?

[PATCH] ws2_32: Add support to disable networking with envvar WINENONET=1

[Bruno Jesus]

On Thu, Dec 8, 2016 at 4:41 PM, Stefan Dösinger
 wrote:
> Am 2016-12-07 um 06:27 schrieb Bruno Jesus:
> > @@ -2433,6 +2438,12 @@ static int WS2_send( int fd, struct ws2_async *wsa, int flags )
> >      union generic_unix_sockaddr unix_addr;
> >      int n, ret;
> > - if (network_disabled)
> > - {
> > -
> >    errno = EHOSTUNREACH;
> > -
> >    return -1;
> > - }
> > -
>
> Shouldn't it be possible to achieve a similar effect with a LD_PRELOAD library?

Sorry, I don't get what you mean. What would I preload to make Wine
network fail?

[PATCH] ws2_32: Add support to disable networking with envvar WINENONET=1

[Stefan Dösinger]

Am 2016-12-08 um 19:30 schrieb Bruno Jesus:
> Sorry, I don't get what you mean. What would I preload to make Wine
> network fail?

You can write a library that hooks the Linux side of the network related
functions and returns an error, similarly to how you modified the
implementations in Wine. I have used a similar hack to modify bind() to
make multiple instances of Warcraft 3 work on my multiseat gaming box.
Unfortunately I lost the source code to that library, but it was around
10 lines of code.

On OSX there's something called DYLD interposing if I remember
correctly, but I don't know how it works.