Replace mkostemp+unlink with open(O_TMPFILE)

This will only work on Linux >= 3.11, and probably not on all
filesystems. Fallback code is provided.

2 files changed, 24 insertions, 0 deletions

diff --git a/src/shared/util.c b/src/shared/util.c
index cdd9a48866..27fc9594cd 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -6108,3 +6108,25 @@ int getpeersec(int fd, char **ret) {
         *ret = s;
         return 0;
 }
+
+int open_tmpfile(const char *path, int flags) {
+        int fd;
+        char *p;
+
+#ifdef O_TMPFILE
+        fd = open(path, flags|O_TMPFILE, S_IRUSR|S_IWUSR);
+        if (fd >= 0)
+                return fd;
+#endif
+        p = strappenda(path, "/systemd-tmp-XXXXXX");
+
+        RUN_WITH_UMASK(0077) {
+                fd = mkostemp(p, O_RDWR|O_CLOEXEC);
+        }
+
+        if (fd < 0)
+                return -errno;
+
+        unlink(p);
+        return fd;
+}
diff --git a/src/shared/util.h b/src/shared/util.h
index d6d746bc6a..630137a53a 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -849,3 +849,5 @@ bool pid_valid(pid_t pid);
 
 int getpeercred(int fd, struct ucred *ucred);
 int getpeersec(int fd, char **ret);
+
+int open_tmpfile(const char *path, int flags);