This patch adds SL context switching into IPP backend
to implement MLS cups-to-cups printing

diff --git cups/backend/ipp.c cups/backend/ipp.c
index 6c3e7df02..1386762d8 100644
--- cups/backend/ipp.c
+++ cups/backend/ipp.c
@@ -38,6 +38,9 @@ extern void	xpc_connection_set_target_uid(xpc_connection_t connection,
 #endif /* HAVE_GSSAPI && HAVE_XPC */
 
 
+#include <selinux/selinux.h>
+#include <selinux/context.h>
+
 /*
  * Bits for job-state-reasons we care about...
  */
@@ -276,7 +279,8 @@ main(int  argc,				/* I - Number of command-line args */
   ppd_file_t	*ppd = NULL;		/* PPD file */
   _ppd_cache_t	*pc = NULL;		/* PPD cache and mapping data */
   fd_set	input;			/* Input set for select() */
-
+  context_t	con;
+  char		*context;
 
  /*
   * Make sure status messages are not buffered...
@@ -284,6 +288,30 @@ main(int  argc,				/* I - Number of command-line args */
 
   setbuf(stderr, NULL);
 
+/* set selinux context */
+  if (is_selinux_mls_enabled () )
+  {
+	  if ( getcon ( &context ) == 0 )
+	  {
+		  const char *range;
+
+		  int		lnoptions;		/* Number of printer options */
+		  cups_option_t	*loptions;		/* Printer options */
+
+		  lnoptions = cupsParseOptions(argv[5], 0, &loptions);
+		  range = cupsGetOption("security-context-range", lnoptions,
+                        loptions);
+
+		  if( range )
+		  {
+			  con = context_new( context );
+			  context_range_set (con, range );
+			  setcon ( context_str( con ) );
+			  fprintf(stderr, "DEBUG: set context %s\n", context_str( con ));
+		  }
+          }
+  }
+
  /*
   * Ignore SIGPIPE and catch SIGTERM signals...
   */
diff --git a/backend/Makefile b/backend/Makefile
index 2e566ae..c3d7f62 100644
--- cups/backend/Makefile
+++ cups/backend/Makefile
@@ -259,7 +259,7 @@ dnssd:	dnssd.o ../cups/$(LIBCUPS) libbackend.a
 
 ipp:	ipp.o ../cups/$(LIBCUPS) libbackend.a
 	echo Linking $@...
-	$(LD_CC) $(ALL_LDFLAGS) -o ipp ipp.o libbackend.a $(LINKCUPS)
+	$(LD_CC) $(ALL_LDFLAGS) -o ipp ipp.o libbackend.a $(LINKCUPS) $(COMMONLIBS)
 	$(CODE_SIGN) -s "$(CODE_SIGN_IDENTITY)" $@
 	$(RM) http https ipps
 	for file in $(IPPALIASES); do \