Add setsockopt(sd, SOL_SOCKET, SO_PEERCRED, NULL, 0) to disable

initial handshake on AF_LOCAL sockets.
	* fhandler.h (class fhandler_socket): Add no_getpeereid status flag.
	(fhandler_socket::af_local_set_no_getpeereid): New prototype.
	* fhandler_socket.cc (fhandler_socket::af_local_connect): Skip handshake
	if no_getpeereid is set.  Add debug output.
	(fhandler_socket::af_local_accept): Likewise.
	(fhandler_socket::af_local_set_no_getpeereid): New function.
	(fhandler_socket::af_local_copy): Copy no_getpeereid.
	(fhandler_socket::getpeereid): Fail if no_getpeereid is set.
	* net.cc (cygwin_setsockopt): Add SO_PEERCRED for AF_LOCAL/SOCK_STREAM
	sockets.  Add comment to explain why we need it.
	* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.

winsup/cygwin/ChangeLog

@@ -1,3 +1,19 @@
+2014-10-11  Christian Franke  <franke@computer.org>
+
+	Add setsockopt(sd, SOL_SOCKET, SO_PEERCRED, NULL, 0) to disable
+	initial handshake on AF_LOCAL sockets.
+	* fhandler.h (class fhandler_socket): Add no_getpeereid status flag.
+	(fhandler_socket::af_local_set_no_getpeereid): New prototype.
+	* fhandler_socket.cc (fhandler_socket::af_local_connect): Skip handshake
+	if no_getpeereid is set.  Add debug output.
+	(fhandler_socket::af_local_accept): Likewise.
+	(fhandler_socket::af_local_set_no_getpeereid): New function.
+	(fhandler_socket::af_local_copy): Copy no_getpeereid.
+	(fhandler_socket::getpeereid): Fail if no_getpeereid is set.
+	* net.cc (cygwin_setsockopt): Add SO_PEERCRED for AF_LOCAL/SOCK_STREAM
+	sockets.  Add comment to explain why we need it.
+	* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.
+
 2014-10-11  Corinna Vinschen  <corinna@vinschen.de>
 
 	* fhandler_socket.cc (fhandler_socket::af_local_connect): Drop outdated

winsup/cygwin/fhandler.h

@@ -504,6 +504,7 @@ class fhandler_socket: public fhandler_base
   int af_local_accept ();
  public:
   int af_local_connect ();
+  int af_local_set_no_getpeereid ();
   void af_local_set_sockpair_cred ();
 
  private:
@@ -531,10 +532,11 @@ class fhandler_socket: public fhandler_base
     unsigned saw_shutdown_write    : 1; /* Socket saw a SHUT_WR */
     unsigned saw_reuseaddr	   : 1; /* Socket saw SO_REUSEADDR call */
     unsigned connect_state	   : 3;
+    unsigned no_getpeereid	   : 1;
    public:
     status_flags () :
       async_io (0), saw_shutdown_read (0), saw_shutdown_write (0),
-      connect_state (unconnected)
+      connect_state (unconnected), no_getpeereid (0)
       {}
   } status;
 
@@ -556,6 +558,7 @@ class fhandler_socket: public fhandler_base
   IMPLEMENT_STATUS_FLAG (bool, saw_shutdown_write)
   IMPLEMENT_STATUS_FLAG (bool, saw_reuseaddr)
   IMPLEMENT_STATUS_FLAG (conn_state, connect_state)
+  IMPLEMENT_STATUS_FLAG (bool, no_getpeereid)
 
   int bind (const struct sockaddr *name, int namelen);
   int connect (const struct sockaddr *name, int namelen);

winsup/cygwin/fhandler_socket.cc

@@ -401,7 +401,10 @@ fhandler_socket::af_local_connect ()
   if (get_addr_family () != AF_LOCAL || get_socket_type () != SOCK_STREAM)
     return 0;
 
-  debug_printf ("af_local_connect called");
+  debug_printf ("af_local_connect called, no_getpeereid=%d", no_getpeereid ());
+  if (no_getpeereid ())
+    return 0;
+
   connect_state (connect_credxchg);
   af_local_setblocking (orig_async_io, orig_is_nonblocking);
   if (!af_local_send_secret () || !af_local_recv_secret ()
@@ -421,7 +424,10 @@ fhandler_socket::af_local_accept ()
 {
   bool orig_async_io, orig_is_nonblocking;
 
-  debug_printf ("af_local_accept called");
+  debug_printf ("af_local_accept called, no_getpeereid=%d", no_getpeereid ());
+  if (no_getpeereid ())
+    return 0;
+
   connect_state (connect_credxchg);
   af_local_setblocking (orig_async_io, orig_is_nonblocking);
   if (!af_local_recv_secret () || !af_local_send_secret ()
@@ -437,6 +443,25 @@ fhandler_socket::af_local_accept ()
   return 0;
 }
 
+int
+fhandler_socket::af_local_set_no_getpeereid ()
+{
+  if (get_addr_family () != AF_LOCAL || get_socket_type () != SOCK_STREAM)
+    {
+      set_errno (EINVAL);
+      return -1;
+    }
+  if (connect_state () != unconnected)
+    {
+      set_errno (EALREADY);
+      return -1;
+    }
+
+  debug_printf ("no_getpeereid set");
+  no_getpeereid (true);
+  return 0;
+}
+
 void
 fhandler_socket::af_local_set_cred ()
 {
@@ -461,6 +486,7 @@ fhandler_socket::af_local_copy (fhandler_socket *sock)
   sock->sec_peer_pid = sec_peer_pid;
   sock->sec_peer_uid = sec_peer_uid;
   sock->sec_peer_gid = sec_peer_gid;
+  sock->no_getpeereid (no_getpeereid ());
 }
 
 void
@@ -2303,6 +2329,11 @@ fhandler_socket::getpeereid (pid_t *pid, uid_t *euid, gid_t *egid)
       set_errno (EINVAL);
       return -1;
     }
+  if (no_getpeereid ())
+    {
+      set_errno (ENOTSUP);
+      return -1;
+    }
   if (connect_state () != connected)
     {
       set_errno (ENOTCONN);

winsup/cygwin/include/cygwin/version.h

@@ -452,12 +452,13 @@ details. */
 	   CW_GETENT, CW_ENDENT, CW_GETNSSSEP, CW_GETPWSID, CW_GETGRSID,
 	   CW_CYGNAME_FROM_WINNAME.
       276: Export ffsl, ffsll.
+      277: Add setsockopt(SO_PEERCRED).
      */
 
      /* Note that we forgot to bump the api for ualarm, strtoll, strtoull */
 
 #define CYGWIN_VERSION_API_MAJOR 0
-#define CYGWIN_VERSION_API_MINOR 276
+#define CYGWIN_VERSION_API_MINOR 277
 
      /* There is also a compatibity version number associated with the
 	shared memory regions.  It is incremented when incompatible

winsup/cygwin/net.cc

@@ -810,6 +810,25 @@ cygwin_setsockopt (int fd, int level, int optname, const void *optval,
       fhandler_socket *fh = get (fd);
       if (!fh)
 	__leave;
+
+      /* Switch off the AF_LOCAL handshake and thus SO_PEERCRED handling
+	 for AF_LOCAL/SOCK_STREAM sockets.  This allows to handle special
+	 situations in which connect is called before a listening socket
+	 accepts connections.
+	 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 (level == SOL_SOCKET && optname == SO_PEERCRED)
+	{
+	  if (optval || optlen
+	      || fh->get_addr_family () != AF_LOCAL
+	      || fh->get_socket_type () != SOCK_STREAM)
+	    set_errno (EINVAL);
+	  else
+	    res = fh->af_local_set_no_getpeereid ();
+	  __leave;
+	}
+
       /* Old applications still use the old WinSock1 IPPROTO_IP values. */
       if (level == IPPROTO_IP && CYGWIN_VERSION_CHECK_FOR_USING_WINSOCK1_VALUES)
 	optname = convert_ws1_ip_optname (optname);