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.

1 files changed, 2 insertions, 0 deletions

diff --git a/include/mingw.h b/include/mingw.h
index 09903d582..386540b37 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -30,6 +30,7 @@ int inet_pton(int af, const char *src, void *dst);
 #define FD_CLOEXEC 0x1
 #define O_NONBLOCK 0
 #define O_NOFOLLOW 0
+#define O_SPECIAL 0x800000
 
 /*
  * grp.h
@@ -367,6 +368,7 @@ int kill(pid_t pid, int sig);
 int link(const char *oldpath, const char *newpath);
 NOIMPL(mknod,const char *name UNUSED_PARAM, mode_t mode UNUSED_PARAM, dev_t device UNUSED_PARAM);
 int mingw_open (const char *filename, int oflags, ...);
+int mingw_xopen(const char *filename, int oflags);
 void mingw_read_zero(int fd);
 void mingw_read_random(int fd);
 ssize_t mingw_read(int fd, void *buf, size_t count);