BROKEN_FD_PASSING (Bug 269)

[Thomas Binder]

Hi!

On Wed, Jun 26, 2002 at 02:32:36PM -0400, Jim Knoble wrote:
> : Nope, at least not for me on i386-Linux 2.0.39, as it already
> : breaks earlier with:
> : 
> : mm_receive_fd: recvmsg: expected received 1 got 2
> 
> Is that repeatable?  Can you strace it?

It is repeatable, but astonishingly not straceable.

Calling

./sshd -p 2222 -d -d -d

and connecting as a user (authenticated via public key; it does
not fail when connecting as root, btw.) will result in

mm_receive_fd: recvmsg: expected received 1 got 2

As soon as I add strace, as in

strace -f -o /tmp/strace.user ./sshd -p 2222 -d -d -d

it fails with the "expected" message

mm_receive_fd: expected type 1 got 1074277169

(unless patched as suggested).

Running as a daemon behaves as in case 1, i.e. needs
BROKEN_FD_PASSING.

Further investigating this issue, I found out that linking with
TransArc's AFS libraries is the culprit. Without them,
everything's fine (except, of course, one can't login as a user).

Thus, it seems to be a local problem only, nothing to worry about
here. Of course, it unfortunately forces me to define
BROKEN_FD_PASSING, but I'll have to live with that.

But it's really interesting that running sshd with and without
strace behaves differently.


Ciao

Thomas