From b8c847a3cdb948f057158cc47a4602ee99168c33 Mon Sep 17 00:00:00 2001
From: Emily Trau <emily@downunderctf.com>
Date: Mon, 5 Jun 2023 17:46:36 -0700
Subject: [PATCH] LibC: Add `lutimes(2)` and `futimes(2)` implementations

Needed for a port of nix
---
 Userland/Libraries/LibC/sys/time.h |  4 +++-
 Userland/Libraries/LibC/time.cpp   | 30 +++++++++++++++++++++++++++---
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/Userland/Libraries/LibC/sys/time.h b/Userland/Libraries/LibC/sys/time.h
index 59e2329b81..00d741f6e9 100644
--- a/Userland/Libraries/LibC/sys/time.h
+++ b/Userland/Libraries/LibC/sys/time.h
@@ -20,7 +20,9 @@ struct timezone {
 int adjtime(const struct timeval* delta, struct timeval* old_delta);
 int gettimeofday(struct timeval* __restrict__, void* __restrict__);
 int settimeofday(struct timeval* __restrict__, void* __restrict__);
-int utimes(char const* pathname, const struct timeval[2]);
+int utimes(char const* pathname, struct timeval const times[2]);
+int lutimes(char const* pathname, struct timeval const times[2]);
+int futimes(int fd, struct timeval const times[2]);
 
 static inline void timeradd(const struct timeval* a, const struct timeval* b, struct timeval* out)
 {
diff --git a/Userland/Libraries/LibC/time.cpp b/Userland/Libraries/LibC/time.cpp
index 127ccf152f..04e44987f8 100644
--- a/Userland/Libraries/LibC/time.cpp
+++ b/Userland/Libraries/LibC/time.cpp
@@ -12,6 +12,7 @@
 #include <assert.h>
 #include <bits/pthread_cancel.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <stdio.h>
 #include <string.h>
@@ -77,16 +78,39 @@ int settimeofday(struct timeval* __restrict__ tv, void* __restrict__)
     return clock_settime(CLOCK_REALTIME, &ts);
 }
 
-int utimes(char const* pathname, const struct timeval times[2])
+int utimes(char const* pathname, struct timeval const times[2])
 {
-    if (!times) {
+    if (!times)
         return utime(pathname, nullptr);
-    }
     // FIXME: implement support for tv_usec in the utime (or a new) syscall
     utimbuf buf = { times[0].tv_sec, times[1].tv_sec };
     return utime(pathname, &buf);
 }
 
+// Not in POSIX, originated in BSD but also supported on Linux.
+// https://man.netbsd.org/NetBSD-6.0/lutimes.2
+int lutimes(char const* pathname, struct timeval const times[2])
+{
+    if (!times)
+        return utimensat(AT_FDCWD, pathname, nullptr, AT_SYMLINK_NOFOLLOW);
+    timespec ts[2];
+    TIMEVAL_TO_TIMESPEC(&times[0], &ts[0]);
+    TIMEVAL_TO_TIMESPEC(&times[1], &ts[1]);
+    return utimensat(AT_FDCWD, pathname, ts, AT_SYMLINK_NOFOLLOW);
+}
+
+// Not in POSIX, originated in BSD but also supported on Linux.
+// https://man.netbsd.org/NetBSD-6.0/futimes.2
+int futimes(int fd, struct timeval const times[2])
+{
+    if (!times)
+        return utimensat(fd, nullptr, nullptr, 0);
+    timespec ts[2];
+    TIMEVAL_TO_TIMESPEC(&times[0], &ts[0]);
+    TIMEVAL_TO_TIMESPEC(&times[1], &ts[1]);
+    return utimensat(fd, nullptr, ts, 0);
+}
+
 char* ctime(time_t const* t)
 {
     return asctime(localtime(t));