build script for copying wintun.dll

Cargo.toml

@@ -61,3 +61,6 @@ windows = { version = "0.51", features = [
     "Win32_Foundation",
 ] }
 wintun = { git = "https://github.com/ssrlive/wintun.git", branch = "main" }
+
+[build-dependencies]
+serde_json = "1.0"

build.rs

@@ -0,0 +1,84 @@
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    #[cfg(target_os = "windows")]
+    if let Ok(cargo_target_dir) = get_cargo_target_dir() {
+        let mut f = std::fs::File::create(cargo_target_dir.join("build.log"))?;
+        use std::io::Write;
+        f.write_all(format!("CARGO_TARGET_DIR: '{}'\r\n", cargo_target_dir.display()).as_bytes())?;
+
+        // The wintun crate's root directory
+        let crate_dir = get_crate_dir("wintun")?;
+
+        // The path to the DLL file, relative to the crate root, depending on the target architecture
+        let dll_path = get_wintun_bin_relative_path()?;
+        let src_path = crate_dir.join(dll_path);
+
+        let dst_path = cargo_target_dir.join("wintun.dll");
+
+        f.write_all(format!("Source path: '{}'\r\n", src_path.display()).as_bytes())?;
+        f.write_all(format!("Target path: '{}'\r\n", dst_path.display()).as_bytes())?;
+
+        // Copy to the target directory
+        if let Err(e) = std::fs::copy(src_path, &dst_path) {
+            f.write_all(format!("Failed to copy 'wintun.dll': {}\r\n", e).as_bytes())?;
+        } else {
+            f.write_all(format!("Copied 'wintun.dll' to '{}'\r\n", dst_path.display()).as_bytes())?;
+        }
+    }
+    Ok(())
+}
+
+#[allow(dead_code)]
+fn get_cargo_target_dir() -> Result<std::path::PathBuf, Box<dyn std::error::Error>> {
+    let out_dir = std::path::PathBuf::from(std::env::var("OUT_DIR")?);
+    let profile = std::env::var("PROFILE")?;
+    let mut target_dir = None;
+    let mut sub_path = out_dir.as_path();
+    while let Some(parent) = sub_path.parent() {
+        if parent.ends_with(&profile) {
+            target_dir = Some(parent);
+            break;
+        }
+        sub_path = parent;
+    }
+    Ok(target_dir.ok_or("not found")?.to_path_buf())
+}
+
+#[cfg(target_os = "windows")]
+fn get_wintun_bin_relative_path() -> Result<std::path::PathBuf, Box<dyn std::error::Error>> {
+    let dll_path = if cfg!(target_arch = "x86") {
+        "wintun/bin/x86/wintun.dll"
+    } else if cfg!(target_arch = "x86_64") {
+        "wintun/bin/amd64/wintun.dll"
+    } else if cfg!(target_arch = "arm") {
+        "wintun/bin/arm/wintun.dll"
+    } else if cfg!(target_arch = "aarch64") {
+        "wintun/bin/arm64/wintun.dll"
+    } else {
+        return Err("Unsupported architecture".into());
+    };
+    Ok(dll_path.into())
+}
+
+#[allow(dead_code)]
+fn get_crate_dir(crate_name: &str) -> Result<std::path::PathBuf, Box<dyn std::error::Error>> {
+    let output = std::process::Command::new("cargo")
+        .arg("metadata")
+        .arg("--format-version=1")
+        .output()?;
+
+    let metadata = serde_json::from_slice::<serde_json::Value>(&output.stdout)?;
+    let packages = metadata["packages"].as_array().ok_or("packages")?;
+
+    let mut crate_dir = None;
+
+    for package in packages {
+        let name = package["name"].as_str().ok_or("name")?;
+        if name == crate_name {
+            let path = package["manifest_path"].as_str().ok_or("manifest_path")?;
+            let path = std::path::PathBuf::from(path);
+            crate_dir = Some(path.parent().ok_or("parent")?.to_path_buf());
+            break;
+        }
+    }
+    Ok(crate_dir.ok_or("crate_dir")?)
+}