From 014119fec57177135d3ac727b4a307bf6a032d19 Mon Sep 17 00:00:00 2001
From: Johannes Leupolz <dev@leupolz.eu>
Date: Sun, 9 Nov 2025 22:48:25 +0000
Subject: [PATCH] Fixes for compat mode (used by steam)

---
 vuinputd/src/compat.rs             | 34 +++++++++++++++++++++++++
 vuinputd/src/main.rs               | 41 ++++++++++++++++--------------
 vuinputd/src/requesting_process.rs |  4 +--
 3 files changed, 58 insertions(+), 21 deletions(-)
 create mode 100644 vuinputd/src/compat.rs

diff --git a/vuinputd/src/compat.rs b/vuinputd/src/compat.rs
new file mode 100644
index 0000000..b7f609c
--- /dev/null
+++ b/vuinputd/src/compat.rs
@@ -0,0 +1,34 @@
+use libc::{__s32, __u16, c_ulong, input_event};
+
+
+#[repr(C)]
+pub struct input_event_compat {
+    pub input_event_sec: u32,
+    pub input_event_usec: u32,
+    pub type_: __u16,
+    pub code: __u16,
+    pub value: __s32,
+}
+
+// this is static for the architecture
+pub fn compat_uses_64bit_time() -> bool {
+    let uname = nix::sys::utsname::uname().unwrap();
+    let arch = uname.machine().to_str().unwrap();
+
+    match arch {
+        "x86_64" => false,
+        "ppc64" => false, // some setups still 32-bit time_t
+        _ => true, // arm64, riscv64, s390x all use 64-bit
+    }
+}
+
+pub fn map_to_64_bit(compat: &input_event_compat) -> input_event{
+    let mut mapped: input_event = unsafe { std::mem::zeroed() };
+    mapped.time.tv_sec=compat.input_event_sec.into();
+    mapped.time.tv_usec=compat.input_event_usec.into();
+    mapped.type_=compat.type_;
+    mapped.code=compat.code;
+    mapped.value=compat.value;
+
+    mapped
+}
\ No newline at end of file
diff --git a/vuinputd/src/main.rs b/vuinputd/src/main.rs
index 580eb05..204f0c2 100644
--- a/vuinputd/src/main.rs
+++ b/vuinputd/src/main.rs
@@ -39,6 +39,8 @@ use uinput_ioctls::*;
 
 pub mod requesting_process;
 pub mod monitor_udev;
+pub mod compat;
+use crate::compat::input_event_compat;
 use crate::container::inject_in_container_job::InjectInContainerJob;
 use crate::container::remove_from_container_job::RemoveFromContainerJob;
 use crate::monitor_udev::MonitorBackgroundLoop;
@@ -282,19 +284,32 @@ unsafe extern "C" fn vuinput_write(
         return;
     }
 
-    let chunksize = std::mem::size_of::<libc::input_event>();
-
     let mut bytes = 0;
     let mut result = Result::Ok(());
 
-    while bytes + chunksize <= _size && result.is_ok() {
-        result = vuinput_state.file.write_all(&slice[bytes..bytes + chunksize]);
-        bytes += chunksize;
-    }
+    let compat_size= std::mem::size_of::<input_event_compat>();
+    let normal_size= std::mem::size_of::<libc::input_event>();
+    let is_compat = vuinput_state.requesting_process.is_compat;
+    
+    if !is_compat {
+        while bytes + normal_size <= _size && result.is_ok() {
+            result = vuinput_state.file.write_all(&slice[bytes..bytes + normal_size]);
+            bytes += normal_size; 
+        }
+    } else {
+        while bytes + compat_size <= _size && result.is_ok() {
+            let compat = _buf.byte_add(bytes) as *const input_event_compat;
+            let normal = compat::map_to_64_bit(&*compat);
+            let normal_ptr=(&normal as *const libc::input_event) as *const u8;
+            let slice = std::slice::from_raw_parts(normal_ptr,normal_size);
+            result = vuinput_state.file.write_all(&slice);
+            bytes += compat_size; 
+        }
+    };
     
     match result {
         Ok(_) => {
-            debug!("wrote {} bytes", bytes);
+            trace!("wrote {} of {} bytes (compat {})", bytes,_size,is_compat);
             fuse_lowlevel::fuse_reply_write(_req, bytes);
         }
         Err(e) => {
@@ -711,18 +726,6 @@ fn check_permissions() -> Result<(), std::io::Error> {
         })
 }
 
-// this is static for the architecture
-pub fn compat_uses_64bit_time() -> bool {
-    let uname = nix::sys::utsname::uname().unwrap();
-    let arch = uname.machine().to_str().unwrap();
-
-    match arch {
-        "x86_64" => false,
-        "ppc64" => false, // some setups still 32-bit time_t
-        _ => true, // arm64, riscv64, s390x all use 64-bit
-    }
-}
-
 fn main() -> std::io::Result<()> {
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("debug")).init();
 
diff --git a/vuinputd/src/requesting_process.rs b/vuinputd/src/requesting_process.rs
index 4397e82..546199a 100644
--- a/vuinputd/src/requesting_process.rs
+++ b/vuinputd/src/requesting_process.rs
@@ -189,11 +189,11 @@ pub fn get_requesting_process(pid: Pid) -> RequestingProcess {
         Pid::Pid(_) =>
         {
             let is_compat = match is_compat_process(pid) {
-                Some(true) => {
+                Some(false) => {
                     debug!("identified process {} as 64 bit process",pid.path());
                     false
                 },
-                Some(false) => {
+                Some(true) => {
                     debug!("identified process {} as 32 bit process",pid.path());
                     true
                 },