Refactor _at functions, add symlink_at

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/src/libunixonacid/symlink_at.c b/src/libunixonacid/symlink_at.c
new file mode 100644
index 0000000..4d63120
--- /dev/null
+++ b/src/libunixonacid/symlink_at.c
@@ -0,0 +1,60 @@
+/* ISC license. */
+
+#include <skalibs/sysdeps.h>
+
+#ifdef SKALIBS_HASLINKAT
+
+#ifndef _ATFILE_SOURCE
+#define _ATFILE_SOURCE
+#endif
+
+#include <skalibs/nonposix.h>
+
+#include <unistd.h>
+#include <errno.h>
+
+#include <skalibs/fcntl.h>
+#include <skalibs/unix-transactional.h>
+
+int symlink_at (char const *src, int dirfd, char const *dst)
+{
+  int r ;
+  do r = symlinkat(src, dirfd, dst) ;
+  while (r == -1 && errno == EINTR) ;
+  return r ;
+}
+
+#else
+
+#include <unistd.h>
+#include <errno.h>
+
+#include <skalibs/posixplz.h>
+#include <skalibs/unix-transactional.h>
+
+struct symlink_s
+{
+  char const *src ;
+  char const *dst ;
+} ;
+
+static int do_symlink (void *p)
+{
+  struct symlink_s *b = p ;
+  return symlink(b->src, b->dst) ;
+}
+
+static void cancel_symlink (int r, void *p)
+{
+  struct symlink_s *b = p ;
+  (void)r ;
+  unlink_void(b->dst) ;
+}
+
+int symlink_at (char const *src, int dirfd, char const *dst)
+{
+  struct symlink_s args = { .src = src, .dst = dst } ;
+  return emulate_at(dirfd, &do_symlink, &cancel_symlink, &args) ;
+}
+
+#endif