From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2155) id CC7AC3894C35; Mon, 7 Dec 2020 15:30:15 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CC7AC3894C35 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Corinna Vinschen To: cygwin-cvs@sourceware.org Subject: [newlib-cygwin] Cygwin: Allow to set SO_PEERCRED zero (v2) X-Act-Checkin: newlib-cygwin X-Git-Author: Mark Geisert X-Git-Refname: refs/heads/master X-Git-Oldrev: 58ac5f985c926bfd1b9efbf1a430e826fe3b668c X-Git-Newrev: 9e573ba50f129bff7b6e1be10cf4bbcb70f1efdd Message-Id: <20201207153015.CC7AC3894C35@sourceware.org> Date: Mon, 7 Dec 2020 15:30:15 +0000 (GMT) X-BeenThere: cygwin-cvs@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Cygwin core component git logs List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Dec 2020 15:30:15 -0000 https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=9e573ba50f129bff7b6e1be10cf4bbcb70f1efdd commit 9e573ba50f129bff7b6e1be10cf4bbcb70f1efdd Author: Mark Geisert Date: Mon Dec 7 02:29:36 2020 -0800 Cygwin: Allow to set SO_PEERCRED zero (v2) The existing code errors as EINVAL any attempt to set a value for SO_PEERCRED via setsockopt() on an AF_UNIX/AF_LOCAL socket. But to enable the workaround set_no_getpeereid behavior for Python one has to be able to set SO_PEERCRED to zero. Ergo, this patch. Python has no way to specify a NULL pointer for 'optval'. This v2 of patch allows the original working (i.e., allow NULL,0 for optval,optlen to mean turn off SO_PEERCRED) in addition to the new working described above. The sense of the 'if' stmt is reversed for readability. Diff: --- winsup/cygwin/fhandler_socket_local.cc | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/winsup/cygwin/fhandler_socket_local.cc b/winsup/cygwin/fhandler_socket_local.cc index c94bf828f..964f3e819 100644 --- a/winsup/cygwin/fhandler_socket_local.cc +++ b/winsup/cygwin/fhandler_socket_local.cc @@ -1430,10 +1430,14 @@ fhandler_socket_local::setsockopt (int level, int optname, const void *optval, FIXME: In the long run we should find a more generic solution which doesn't require a blocking handshake in accept/connect to exchange SO_PEERCRED credentials. */ - if (optval || optlen) - set_errno (EINVAL); - else + /* Temporary: Allow SO_PEERCRED to only be zeroed. Two ways to + accomplish this: pass NULL,0 for optval,optlen; or pass the + address,length of an '(int) 0' set up by the caller. */ + if ((!optval && !optlen) || + (optlen == (socklen_t) sizeof (int) && !*(int *) optval)) ret = af_local_set_no_getpeereid (); + else + set_errno (EINVAL); return ret; case SO_REUSEADDR: