openssh unix dev - Jan 2001 - PORTING to IBM OS/390: select() always returning 0 in entropy.c

Hello,
    I'm attempting to port OpenSSH to IBM's S/390 mainframe. Things have
gone well but I have come a little unstuck with the internal PRNG. Although the
commands in ssh_prng_cmds are being executed the select() seems to be returning
0 and therefore the cose is assuming that the forked process has timed out. This
could be a difference in the way that select is implemented on OS/390. The Unix
environment provided by OS/390 has many compatability levels from including
several POSIX and XPG variants. I am not a C expert and the debugegr is not very
good, has anyone come across smiliar behavior before. A description of the
select() on OS/390 can be found at:
http://www.s390.ibm.com/bookmgr-cgi/bookmgr.cmd/BOOKS/EDCLB031/4%2e1%2e131?SHELF=CBCBS031

Thanks, Paul Anderson
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.mindrot.org/pipermail/openssh-unix-dev/attachments/20010105/cf07978b/attachment.html

On Fri, 5 Jan 2001, Paul Anderson wrote:
> Hello,
>     I'm attempting to port OpenSSH to IBM's S/390 mainframe. Things
>have gone well but I have come a little unstuck with the internal
>PRNG. Although the commands in ssh_prng_cmds are being executed the
>select() seems to be returning 0 and therefore the cose is assuming that
>the forked process has timed out. This could be a difference in the way
If select() returns 0 it means that the select() timed out.  Look at your
ssh_prng_cmds and consider increasing the number on the left handside by
very small amounts until you hit the magical number that allows you get to
get enough entropy.

And I suggest you hound IBM to put in a /dev/urandom.

that select is implemented on OS/390. The Unix environment provided by OS/390
has many compatability levels from including several POSIX and XPG variants. I
am not a C expert and the debugegr is not very good, has anyone come across
smiliar behavior before. A description of the select() on OS/390 can be found
at:
http://www.s390.ibm.com/bookmgr-cgi/bookmgr.cmd/BOOKS/EDCLB031/4%2e1%2e131?SHELF=CBCBS031
> 
> Thanks, Paul Anderson
>