mkostemp: fix implementation

mkostemp(char *template, int flags) generates a unique temporary
filename from a template.  The flags parameter accepts three of
the same flags as open(2): O_APPEND, O_CLOEXEC, and O_SYNC.  The
current implementation of mkostemp(3) does not respect the flags
and in fact confuses the flags with the file mode which should
always be S_IRUSR | S_IWUSR.  This patch corrects this issue.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

2 files changed, 67 insertions, 0 deletions

diff --git a/test/stdlib/test-mkostemp-O_CLOEXEC.c b/test/stdlib/test-mkostemp-O_CLOEXEC.c
new file mode 100644
index 000000000..9ff229af1
--- /dev/null
+++ b/test/stdlib/test-mkostemp-O_CLOEXEC.c
@@ -0,0 +1,45 @@
+#define _XOPEN_SOURCE_EXTENDED
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <errno.h>
+
+#if !defined __ARCH_USE_MMU__
+# define fork vfork
+#endif
+
+int main(int argc, char *argv[]) {
+    int fd, status;
+    char buff[5];
+    char template[] = "/tmp/test-mkostemp.XXXXXX";
+
+    fd = mkostemp(template, O_CLOEXEC);
+    unlink(template);
+
+    snprintf(buff, 5, "%d", fd);
+
+    if(!fork())
+        if(execl("./test-mkostemp-child", "test-mkostemp-child", buff, NULL) == -1)
+            exit(EXIT_FAILURE);
+
+    wait(&status);
+
+    memset(buff, 0, 5);
+    lseek(fd, 0, SEEK_SET);
+    errno = 0;
+    if(read(fd, buff, 5) == -1)
+        exit(EXIT_FAILURE);
+
+    if(!strncmp(buff, "test", 5))
+        exit(EXIT_FAILURE);
+    else
+        exit(EXIT_SUCCESS);
+
+    close(fd);
+    exit(EXIT_SUCCESS);
+}
diff --git a/test/stdlib/test-mkostemp-child.c b/test/stdlib/test-mkostemp-child.c
new file mode 100644
index 000000000..708bd80a1
--- /dev/null
+++ b/test/stdlib/test-mkostemp-child.c
@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[]) {
+    int fd;
+
+    /* This file gets built and run as a test, but its
+     * really just a helper for test-mkostemp-O_CLOEXEC.c.
+     * So, we'll always return succcess.
+     */
+    if(argc != 2)
+        exit(EXIT_SUCCESS);
+
+    sscanf(argv[1], "%d", &fd);
+
+    if(write(fd, "test\0", 5) == -1)
+        ; /* Don't Panic!  Failure is okay here. */
+
+    close(fd);
+    exit(EXIT_SUCCESS);
+}