Re: fork w/o execv

[Luke Small]

Thanks! I like to use kqueue and it is to redis database update for
multiple processes, possibly among multiple machines. I can have a sentinel
programs spawn off secondary IP sockets to threads and through database
listings, it could notify the thread that a unified operation on sessions
from possibly multiple threads are complete and need to notify the client
and free data. That probably isn't clear enough either. I have a complex
project for allowing folks to notify others of their positive or negative
sexually transmitted disease status, in which I've garnered interest
especially from an epidemiologist from Maryland for a federal grant. I just
need the program to be scalable, and it won't be possible without
multithreading. The iris scanning takes a lng time; on the order of
seconds!!! I came up with the idea, patented it, and programmed it all
myself.

On Sun, Jul 31, 2016, 05:58 Peter J. Philipp  wrote:

> On Sun, Jul 31, 2016 at 09:05:52AM +, Luke Small wrote:
> > I'm trying to do some operations in which I fork and the child closes and
> > simplifies socketpair listings and sends the simpler list of malloced
> file
> > descriptors to a function and sends ioctl data after it opens a socket.
> The
> > parent sends a short greeting to the child to show that it is ready. The
> > child is supposed to receive it and send back an ip4 address to the
> parent,
> > but it seems to be hung up and very busy. Any ideas?
>
> I couldn't make out what you meant by reading this a few times, however let
> me try.  fork() is a common operation to create a new process... you can
> for example use it to keep a root owned process around and the child does
> privilege seperation however does InterProcess Communication with the root
> owned parent.  The IPC can be shared memory, a socketpair, a pipe, a named
> pipe or socket.  I think you mean to set up a socketpair between the parent
> and the child.  Right here with this kind of model of IPC it is perhaps
> wise to use the imsg framework that is in OpenBSD.
>
> http://man.openbsd.org/OpenBSD-current/man3/imsg_init.3
>
> This is probably what you want to use.  The child sends an IP4 address to
> the parent via the socketpair?  OK, you don't even need a greeting just
> select or poll around the descriptors and test for received data.  And then
> process it to do your ioctl operations and possibly return data via the
> socketpair.
>
> BTW at work I wrote such a program, hence this looks fairly familiar what
> you
> described.  It takes an IP address on a listening socket and sends via a
> socketpair to a root owned process which then inserts the IP4 into a pf
> table
> via ioctl, and then does another ioctl to flush the states for that IP4.
> Unfortunately I can't share the code, it's not licensed for sharing.
>
> Cheers,
>
> -peter

Re: fork w/o execv

[Peter J. Philipp]

On Sun, Jul 31, 2016 at 09:05:52AM +, Luke Small wrote:
> I'm trying to do some operations in which I fork and the child closes and
> simplifies socketpair listings and sends the simpler list of malloced file
> descriptors to a function and sends ioctl data after it opens a socket. The
> parent sends a short greeting to the child to show that it is ready. The
> child is supposed to receive it and send back an ip4 address to the parent,
> but it seems to be hung up and very busy. Any ideas?

I couldn't make out what you meant by reading this a few times, however let
me try.  fork() is a common operation to create a new process... you can
for example use it to keep a root owned process around and the child does
privilege seperation however does InterProcess Communication with the root
owned parent.  The IPC can be shared memory, a socketpair, a pipe, a named
pipe or socket.  I think you mean to set up a socketpair between the parent
and the child.  Right here with this kind of model of IPC it is perhaps
wise to use the imsg framework that is in OpenBSD.

http://man.openbsd.org/OpenBSD-current/man3/imsg_init.3

This is probably what you want to use.  The child sends an IP4 address to
the parent via the socketpair?  OK, you don't even need a greeting just
select or poll around the descriptors and test for received data.  And then
process it to do your ioctl operations and possibly return data via the 
socketpair.

BTW at work I wrote such a program, hence this looks fairly familiar what you
described.  It takes an IP address on a listening socket and sends via a 
socketpair to a root owned process which then inserts the IP4 into a pf table
via ioctl, and then does another ioctl to flush the states for that IP4.
Unfortunately I can't share the code, it's not licensed for sharing.

Cheers,

-peter

fork w/o execv

[Luke Small]

I'm trying to do some operations in which I fork and the child closes and
simplifies socketpair listings and sends the simpler list of malloced file
descriptors to a function and sends ioctl data after it opens a socket. The
parent sends a short greeting to the child to show that it is ready. The
child is supposed to receive it and send back an ip4 address to the parent,
but it seems to be hung up and very busy. Any ideas?