<rdar://problem/15958253> 14A125b: cupsd console output when launching AddPrinter

[thirdparty/cups.git] / scheduler / cups-exec.c

diff --git a/scheduler/cups-exec.c b/scheduler/cups-exec.c
index ee5981751888ed0ab6c5cb9ed03dbcc05f0abb0b..0d8a764d78f78d77358019d2b6f3720b0cc0cf8a 100644 (file)
--- a/scheduler/cups-exec.c
+++ b/scheduler/cups-exec.c
@@ -1,23 +1,19 @@
 /*
  * "$Id$"
  *
- *   Sandbox helper for CUPS.
+ * Sandbox helper for CUPS.
  *
- *   Copyright 2007-2013 by Apple Inc.
+ * Copyright 2007-2014 by Apple Inc.
  *
- *   These coded instructions, statements, and computer programs are the
- *   property of Apple Inc. and are protected by Federal copyright
- *   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
- *   which should have been included with this file.  If this file is
- *   file is missing or damaged, see the license at "http://www.cups.org/".
+ * These coded instructions, statements, and computer programs are the
+ * property of Apple Inc. and are protected by Federal copyright
+ * law.  Distribution and use rights are outlined in the file "LICENSE.txt"
+ * which should have been included with this file.  If this file is
+ * file is missing or damaged, see the license at "http://www.cups.org/".
  *
  * Usage:
  *
- *     cups-exec /path/to/profile /path/to/program argv0 argv1 ... argvN
- *
- * Contents:
- *
- *   main() - Apply sandbox profile and execute program.
+ *     cups-exec /path/to/profile UID GID NICE /path/to/program argv0 argv1 ... argvN
  */
 
 /*
@@ -26,6 +22,8 @@
 
 #include <cups/string-private.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
 #ifdef HAVE_SANDBOX_H
 #  include <sandbox.h>
 #  ifndef SANDBOX_NAMED_EXTERNAL
@@ -43,6 +41,9 @@ int                                   /* O - Exit status */
 main(int  argc,                                /* I - Number of command-line args */
      char *argv[])                     /* I - Command-line arguments */
 {
+  uid_t        uid;                            /* UID */
+  gid_t        gid;                            /* GID */
+  int  niceval;                        /* Nice value */
 #ifdef HAVE_SANDBOX_H
   char *sandbox_error = NULL;          /* Sandbox error, if any */
 #endif /* HAVE_SANDBOX_H */
@@ -52,13 +53,19 @@ main(int  argc,                             /* I - Number of command-line args */
   * Check that we have enough arguments...
   */
 
-  if (argc < 4)
+  if (argc < 7)
   {
-    puts("Usage: cups-exec /path/to/profile /path/to/program argv0 argv1 ... "
-         "argvN");
+    puts("Usage: cups-exec /path/to/profile UID GID NICE /path/to/program argv0 argv1 ... argvN");
     return (1);
   }
 
+ /*
+  * Make sure side and back channel FDs are non-blocking...
+  */
+
+  fcntl(3, F_SETFL, O_NDELAY);
+  fcntl(4, F_SETFL, O_NDELAY);
+
 #ifdef HAVE_SANDBOX_H
  /*
   * Run in a separate security profile...
@@ -74,11 +81,36 @@ main(int  argc,                             /* I - Number of command-line args */
   }
 #endif /* HAVE_SANDBOX_H */
 
+ /*
+  * Change UID, GID, and nice value...
+  */
+
+  uid     = (uid_t)atoi(argv[2]);
+  gid     = (gid_t)atoi(argv[3]);
+  niceval = atoi(argv[4]);
+
+  if (uid)
+    nice(niceval);
+
+  if (!getuid())
+  {
+    if (setgid(gid))
+      exit(errno + 100);
+
+    if (setgroups(1, &gid))
+      exit(errno + 100);
+
+    if (uid && setuid(uid))
+      exit(errno + 100);
+  }
+
+  umask(077);
+
  /*
   * Execute the program...
   */
 
-  execv(argv[2], argv + 3);
+  execv(argv[5], argv + 6);
 
  /*
   * If we get here, execv() failed...