[klibc] Add fdopendir(), fix dirfd()

Add fdopendir() by splitting opendir() into two components.  Note
that the fdopendir() implementation doesn't actually check the
validity of the file descriptor; we just let readdir() return an error
if someone passed us garbage.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

2 files changed, 22 insertions, 9 deletions

diff --git a/usr/include/dirent.h b/usr/include/dirent.h
index d36e9749d71fe..43df503cd47f0 100644
--- a/usr/include/dirent.h
+++ b/usr/include/dirent.h
@@ -5,6 +5,7 @@
 #ifndef _DIRENT_H
 #define _DIRENT_H
 
+#include <klibc/compiler.h>
 #include <klibc/extern.h>
 #include <klibc/sysconfig.h>
 #include <sys/dirent.h>
@@ -23,10 +24,11 @@ struct _IO_dir {
 };
 typedef struct _IO_dir DIR;
 
+__extern DIR *fdopendir(int);
 __extern DIR *opendir(const char *);
 __extern struct dirent *readdir(DIR *);
 __extern int closedir(DIR *);
-static __inline__ int dirfd(DIR * __d)
+__static_inline int dirfd(DIR * __d)
 {
 	return __d->__fd;
 }
diff --git a/usr/klibc/readdir.c b/usr/klibc/readdir.c
index 453fc082ca6ad..8134c92f90e66 100644
--- a/usr/klibc/readdir.c
+++ b/usr/klibc/readdir.c
@@ -5,26 +5,37 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <stdlib.h>
+#include <errno.h>
 
 #define __KLIBC_DIRENT_INTERNALS
 #include <dirent.h>
 
-DIR *opendir(const char *name)
+DIR *fdopendir(int fd)
 {
-	DIR *dp = malloc(sizeof(DIR));
+	DIR *dp = zalloc(sizeof(DIR));
 
 	if (!dp)
 		return NULL;
 
-	dp->__fd = open(name, O_DIRECTORY | O_RDONLY);
+	dp->__fd = fd;
+	return dp;
+}
 
-	if (dp->__fd < 0) {
-		free(dp);
-		return NULL;
-	}
+DIR *opendir(const char *name)
+{
+	int fd, err;
+	DIR *dp;
 
-	dp->bytes_left = 0;
+	fd = open(name, O_DIRECTORY | O_RDONLY);
+	if (fd < 0)
+		return NULL;
 
+	dp = fdopendir(fd);
+	if (!dp) {
+		err = errno;
+		close(fd);
+		errno = err;
+	}
 	return dp;
 }