win32: restrict visibility of special devices

Handling of the special devices /dev/zero and /dev/urandom was
inconsistent:

- they could be used as arguments to 'cat' but not 'od';
- they could not be used in shell redirection.

Restrict the use of these devices to two places:

- as input files to 'dd' with the 'if=' argument;
- internally within 'shred'.

See GitHub issue #98.

2 files changed, 7 insertions, 1 deletions

diff --git a/coreutils/dd.c b/coreutils/dd.c
index 4362ae798..10066575e 100644
--- a/coreutils/dd.c
+++ b/coreutils/dd.c
@@ -429,8 +429,10 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
 #endif
 
         if (infile) {
+#if !ENABLE_PLATFORM_MINGW32
                 xmove_fd(xopen(infile, O_RDONLY), ifd);
-#if ENABLE_PLATFORM_MINGW32
+#else
+                xmove_fd(mingw_xopen(infile, O_RDONLY), ifd);
                 if (!strcmp(infile, "/dev/zero")) {
                         mingw_read_zero(ifd);
                 }
diff --git a/coreutils/shred.c b/coreutils/shred.c
index 1b65a359e..0ebbc39ca 100644
--- a/coreutils/shred.c
+++ b/coreutils/shred.c
@@ -38,6 +38,10 @@
 
 #include "libbb.h"
 
+#if ENABLE_PLATFORM_MINGW32
+#define xopen mingw_xopen
+#endif
+
 int shred_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int shred_main(int argc UNUSED_PARAM, char **argv)
 {