Automatically generate BLKGETSIZE for the platform at buildtime

Ref: #66

Cargo.toml

@@ -47,6 +47,9 @@ version = "0.2"
 [build-dependencies]
 embed-resource = "1.1"
 
+[target.'cfg(not(target_os = "windows"))'.build-dependencies.gcc]
+version = "0.3"
+
 
 [[bin]]
 name = "http"

build.rs

@@ -1,6 +1,56 @@
 extern crate embed_resource;
+#[cfg(not(target_os = "windows"))]
+extern crate gcc;
+
+#[cfg(not(target_os = "windows"))]
+use std::env;
+#[cfg(not(target_os = "windows"))]
+use std::io::Write;
+#[cfg(not(target_os = "windows"))]
+use std::path::Path;
+#[cfg(not(target_os = "windows"))]
+use std::fs::{self, File};
+
+
+/// The last line of this, after running it through a preprocessor, will expand to the value of `BLKGETSIZE`
+static IOCTL_CHECK_SOURCE: &str = r#"
+#include <linux/fs.h>
+
+BLKGETSIZE
+"#;
+
+/// Replace `{}` with the `BLKGETSIZE` expression from `IOCTL_CHECK_SOURCE`
+static IOCTL_INCLUDE_SKELETON: &str = r#"
+/// Return `device size / 512` (`long *` arg)
+static BLKGETSIZE: c_ulong = {};
+"#;
 
 
 fn main() {
+    embed_resources();
+    get_ioctl_data();
+}
+
+fn embed_resources() {
     embed_resource::compile("http-manifest.rc");
 }
+
+#[cfg(target_os = "windows")]
+fn get_ioctl_data() {
+
+}
+
+#[cfg(not(target_os = "windows"))]
+fn get_ioctl_data() {
+    let ioctl_dir = Path::new(&env::var("OUT_DIR").unwrap()).join("ioctl-data");
+    fs::create_dir_all(&ioctl_dir).unwrap();
+
+    let ioctl_source = ioctl_dir.join("ioctl.c");
+    File::create(&ioctl_source).unwrap().write_all(IOCTL_CHECK_SOURCE.as_bytes()).unwrap();
+
+    let ioctl_preprocessed = String::from_utf8(gcc::Build::new().file(ioctl_source).expand()).unwrap();
+    let blkgetsize_expr = ioctl_preprocessed.lines().next_back().unwrap().replace("U", " as c_ulong");
+
+    let ioctl_include = ioctl_dir.join("ioctl.rs");
+    File::create(&ioctl_include).unwrap().write_all(IOCTL_INCLUDE_SKELETON.replace("{}", &blkgetsize_expr).as_bytes()).unwrap();
+}

src/ops.rs

@@ -444,8 +444,8 @@ impl HttpHandler {
                            (Header(headers::Server(USER_AGENT.to_string())),
                             Header(headers::LastModified(headers::HttpDate(file_time_modified(&req_p)))),
                             Header(headers::AcceptRanges(vec![headers::RangeUnit::Bytes]))),
-                           req_p,
-                           Header(headers::ContentLength(file_length(&metadata, &req_p))),
+                           req_p.as_path(),
+                           Header(headers::ContentLength(file_length(&req_p.metadata().expect("Failed to get requested file metadata"), &req_p))),
                            mt)))
     }
 

src/util/os/non_windows.rs

@@ -6,12 +6,7 @@ use std::ffi::CString;
 use std::path::Path;
 
 
-/// Return `device size / 512` (`long *` arg)
-///
-/// Extracted from my armv6l machine
-///
-/// Would be probably a good idea to get this at build time from a build script
-const BLKGETSIZE: c_ulong = (0x12 << 8) | 96;
+include!(concat!(env!("OUT_DIR"), "/ioctl-data/ioctl.rs"));
 
 
 /// OS-specific check for fileness