Commit: d4df04d04b0ed0c42dbd7974749d011df390e938 - mingw-get (git)

The MinGW.org Installation Manager Tool

Commit MetaInfo

• Revisión: d4df04d04b0ed0c42dbd7974749d011df390e938 (tree)
• Tiempo: 2013-06-28 18:01:06
• Autor: Keith Marshall <keithmarshall@user...>
• Commiter: Keith Marshall

Log Message

Avoid inadvertent overwrite of existing files.

Cambiar Resumen

• modified: ChangeLog
• modified: src/mkpath.c
• modified: src/tarproc.cpp

Diferencia incremental

--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,20 @@
[phone]  Keith Marshall  <[e-mail]>
+
+	Avoid inadvertent overwrite of existing files.
+
+	* src/mkpath.c (_O_NEWFILE): Conditionally specify attributes...
+	[IMPLEMENTATION_LEVEL == SETUP_TOOL_COMPONENT]: ...as they were...
+	[IMPLEMENTATION_LEVEL != SETUP_TOOL_COMPONENT]: ...else, include
+	_O_EXCL in the specified set; exclude _O_TRUNC.
+
+	* src/tarproc.cpp (dmh_notify_extraction_failed): New static inline
+	function; it encapsulates the diagnostic message factored out from...
+	(pkgArchiveProcessor::ExtractFile): ...here, whence use it.
+	(create_output_stream): Also used in this new static inline function;
+	it adds an appropriate diagnostic wrapper around set_output_stream(),
+	when _O_EXCL prevents overwrite of an existing file.
+	(pkgArchiveProcessor::SetOutputStream): Use it.
+
 2013-06-27  Keith Marshall  <[e-mail]>
 
 	Improve diagnostics for tar archive processing faults.

--- a/src/mkpath.c
+++ b/src/mkpath.c
@@ -4,7 +4,7 @@
  * $Id$
  *
  * Written by Keith Marshall <[e-mail]>
- * Copyright (C) 2009, 2011, MinGW Project
+ * Copyright (C) 2009, 2011, 2013, MinGW.org Project
  *
  *
  * Helper functions for constructing path names, creating directory
@@ -27,6 +27,7 @@
  *
  */
 #include "mkpath.h"
+#include "pkgimpl.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -46,9 +47,18 @@
  /*
   * MS-Windows _O_BINARY vs. _O_TEXT discrimination can't be explicitly
   * resolved in a simple `creat()' call; instead, we will use `_open()',
-  * with the following explicit attribute set...
+  * with one of the following explicit attribute sets...
   */
-# define _O_NEWFILE  _O_RDWR | _O_CREAT | _O_TRUNC | _O_BINARY
+# if IMPLEMENTATION_LEVEL == SETUP_TOOL_COMPONENT
+  /*
+   * ...allowing overwrite in the setup tool implementation...
+   */
+#  define _O_NEWFILE  _O_RDWR | _O_CREAT | _O_TRUNC | _O_BINARY
+# else
+  /* ...but not in the standard mingw-get implementation...
+   */
+#  define _O_NEWFILE  _O_RDWR | _O_CREAT | _O_EXCL | _O_BINARY
+# endif
 # define creat(P,M)  _open( P, _O_NEWFILE, _map_posix_mode(M) )
 
  /* Furthermore, MS-Windows protection modes are naive, in comparison

--- a/src/tarproc.cpp
+++ b/src/tarproc.cpp
@@ -68,6 +68,13 @@ int pkgArchiveProcessor::CreateExtractionDirectory( const char *pathname )
   return status;
 }
 
+static inline int dmh_notify_extraction_failed( const char *name )
+{
+  /* Helper function to emit archive "extraction failed" diagnostics.
+   */
+  return dmh_notify( DMH_ERROR, "%s: extraction failed\n", name );
+}
+
 static inline int dmh_notify_archive_data_exhausted( const char *context )
 {
   /* Helper function to emit "premature end of archive" diagnostics.
@@ -77,13 +84,30 @@ static inline int dmh_notify_archive_data_exhausted( const char *context )
     );
 }
 
+static int create_output_stream( const char *name, int mode )
+{
+  /* Wrapper encapsulating the set_output_stream() function, while
+   * protecting against inadvertently overwriting any unexpectedly
+   * pre-existing file.
+   */
+  int fd = set_output_stream( name, mode );
+  if( (fd == -1) && ((errno == EEXIST) || (errno == EACCES)) )
+  {
+    /* Overwrite prevention was triggered; diagnose.
+     */
+    dmh_notify_extraction_failed( name );
+    dmh_notify( DMH_ERROR, "cannot replace existing file\n" );
+  }
+  return fd;
+}
+
 inline int pkgArchiveProcessor::SetOutputStream( const char *name, int mode )
 {
   /* Wrapper method to facilitate the set up of output streams
    * for writing extracted content to disk, except in the special
    * case where saving of files has been disabled.
    */
-  return save_on_extract ? set_output_stream( name, mode ) : -2;
+  return save_on_extract ? create_output_stream( name, mode ) : -2;
 }
 
 int pkgArchiveProcessor::ExtractFile( int fd, const char *pathname, int status )
@@ -106,7 +130,7 @@ int pkgArchiveProcessor::ExtractFile( int fd, const char *pathname, int status )
        * written; discard it, and diagnose failure.
        */
       unlink( pathname );
-      dmh_notify( DMH_ERROR, "%s: extraction failed\n", pathname );
+      dmh_notify_extraction_failed( pathname );
       switch( status )
       {
 	case TAR_ARCHIVE_DATA_READ_ERROR: