From 59eb2d5de4e6bb0ee037a438dc86a150afcb2300 Mon Sep 17 00:00:00 2001
From: sin-ack <sin-ack@users.noreply.github.com>
Date: Fri, 10 Sep 2021 22:45:28 +0000
Subject: [PATCH] LibC: Implement serenity_open

This syscall is very much similar to open(2), with the difference of
accepting a string and a length, instead of requiring a null-terminated
string. This way, if the string passed is not null-terminated, we can
still perform the syscall.
---
 Userland/Libraries/LibC/serenity.cpp | 25 +++++++++++++++++++++++++
 Userland/Libraries/LibC/serenity.h   |  2 ++
 2 files changed, 27 insertions(+)

diff --git a/Userland/Libraries/LibC/serenity.cpp b/Userland/Libraries/LibC/serenity.cpp
index f1e16b9698..739c8fc8fd 100644
--- a/Userland/Libraries/LibC/serenity.cpp
+++ b/Userland/Libraries/LibC/serenity.cpp
@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <Kernel/API/POSIX/fcntl.h>
+#include <Kernel/API/Syscall.h>
 #include <arpa/inet.h>
 #include <errno.h>
 #include <serenity.h>
@@ -148,4 +150,27 @@ int emuctl(uintptr_t command, uintptr_t arg0, uintptr_t arg1)
 {
     return syscall(SC_emuctl, command, arg0, arg1);
 }
+
+int serenity_open(char const* path, size_t path_length, int options, ...)
+{
+    if (!path) {
+        errno = EFAULT;
+        return -1;
+    }
+
+    if (path_length > INT32_MAX) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    va_list ap;
+    va_start(ap, options);
+    auto mode = (mode_t)va_arg(ap, unsigned);
+    va_end(ap);
+
+    Syscall::SC_open_params params { AT_FDCWD, { path, path_length }, options, mode };
+    int rc = syscall(SC_open, &params);
+
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
 }
diff --git a/Userland/Libraries/LibC/serenity.h b/Userland/Libraries/LibC/serenity.h
index b144746d4e..d411a80161 100644
--- a/Userland/Libraries/LibC/serenity.h
+++ b/Userland/Libraries/LibC/serenity.h
@@ -60,4 +60,6 @@ uint16_t internet_checksum(const void* ptr, size_t count);
 
 int emuctl(uintptr_t command, uintptr_t arg0, uintptr_t arg1);
 
+int serenity_open(char const* path, size_t path_length, int options, ...);
+
 __END_DECLS