Build burrow library into iOS and macOS app

This commit adds a build script, build-rust.sh, which compiles the
burrow crate from inside of Xcode. The network extension then links
against this crate.

.github/workflows/build-apple.yml

@@ -18,14 +18,22 @@ jobs:
           destination: generic/platform=iOS
           platform: iOS
           sdk-name: iphoneos
+          rust-targets:
+          - aarch64-apple-ios
         - scheme: Burrow
           destination: platform=iOS Simulator,OS=16.2,name=iPhone 14 Pro
           platform: iOS Simulator
           sdk-name: iphonesimulator
+          rust-targets:
+          - aarch64-apple-ios-sim
+          - x86_64-apple-ios
         - scheme: Burrow
           destination: platform=macOS
           platform: macOS
           sdk-name: macos
+          rust-targets:
+          - x86_64-apple-darwin
+          - aarch64-apple-darwin
     env:
       DEVELOPER_DIR: /Applications/Xcode_14.2.app/Contents/Developer
     steps:
@@ -39,6 +47,11 @@ jobs:
       with:
         certificate: ${{ secrets.DEVELOPER_CERT }}
         password: ${{ secrets.DEVELOPER_CERT_PASSWORD }}
+    - name: Install Rust
+      uses: dtolnay/rust-toolchain@stable
+      with:
+        toolchain: stable
+        targets: ${{ join(matrix.rust-targets, ', ') }}
     - name: Build
       id: build
       uses: ./.github/actions/build-for-testing

.github/workflows/build-rust.yml

@@ -50,7 +50,7 @@ jobs:
       shell: bash
       run: sudo apt-get install -y ${{ join(matrix.packages, ' ') }}
     - name: Install Rust
-      uses: dtolnay/rust-toolchain@master
+      uses: dtolnay/rust-toolchain@stable
       with:
         toolchain: stable
         components: rustfmt

Apple/Burrow.xcodeproj/project.pbxproj

@@ -12,6 +12,7 @@
 		D05B9F7629E39EEC008CB1F9 /* BurrowApp.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05B9F7529E39EEC008CB1F9 /* BurrowApp.swift */; };
 		D05B9F7829E39EEC008CB1F9 /* ContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05B9F7729E39EEC008CB1F9 /* ContentView.swift */; };
 		D05B9F7A29E39EED008CB1F9 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = D05B9F7929E39EED008CB1F9 /* Assets.xcassets */; };
+		D0B98FC529FDA49E004E7149 /* libburrow.a in Frameworks */ = {isa = PBXBuildFile; fileRef = D0B98FC429FDA476004E7149 /* libburrow.a */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -57,6 +58,8 @@
 		D05B9F7529E39EEC008CB1F9 /* BurrowApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BurrowApp.swift; sourceTree = "<group>"; };
 		D05B9F7729E39EEC008CB1F9 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
 		D05B9F7929E39EED008CB1F9 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
+		D0B98FBF29FD8072004E7149 /* build-rust.sh */ = {isa = PBXFileReference; lastKnownFileType = text.script.sh; path = "build-rust.sh"; sourceTree = "<group>"; };
+		D0B98FC429FDA476004E7149 /* libburrow.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; path = libburrow.a; sourceTree = BUILT_PRODUCTS_DIR; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -64,6 +67,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				D0B98FC529FDA49E004E7149 /* libburrow.a in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -84,6 +88,7 @@
 				D020F64A29E4A452002790F6 /* App.xcconfig */,
 				D020F66329E4A703002790F6 /* Extension.xcconfig */,
 				D020F64029E4A1FF002790F6 /* Compiler.xcconfig */,
+				D0B98FBF29FD8072004E7149 /* build-rust.sh */,
 				D020F64229E4A1FF002790F6 /* Info.plist */,
 			);
 			path = Configuration;
@@ -108,6 +113,7 @@
 				D020F65629E4A697002790F6 /* NetworkExtension */,
 				D020F63C29E4A1FF002790F6 /* Configuration */,
 				D05B9F7329E39EEC008CB1F9 /* Products */,
+				D0B98FC129FDA45D004E7149 /* Frameworks */,
 			);
 			sourceTree = "<group>";
 		};
@@ -133,6 +139,14 @@
 			path = App;
 			sourceTree = "<group>";
 		};
+		D0B98FC129FDA45D004E7149 /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				D0B98FC429FDA476004E7149 /* libburrow.a */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -140,6 +154,7 @@
 			isa = PBXNativeTarget;
 			buildConfigurationList = D020F65E29E4A697002790F6 /* Build configuration list for PBXNativeTarget "NetworkExtension" */;
 			buildPhases = (
+				D0B98FC029FD809A004E7149 /* Compile Rust */,
 				D020F64F29E4A697002790F6 /* Sources */,
 				D020F65029E4A697002790F6 /* Frameworks */,
 				D020F65129E4A697002790F6 /* Resources */,
@@ -227,6 +242,30 @@
 		};
 /* End PBXResourcesBuildPhase section */
 
+/* Begin PBXShellScriptBuildPhase section */
+		D0B98FC029FD809A004E7149 /* Compile Rust */ = {
+			isa = PBXShellScriptBuildPhase;
+			alwaysOutOfDate = 1;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			inputFileListPaths = (
+			);
+			inputPaths = (
+			);
+			name = "Compile Rust";
+			outputFileListPaths = (
+			);
+			outputPaths = (
+				"$(BUILT_PRODUCTS_DIR)/libburrow.a",
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+			shellPath = /bin/sh;
+			shellScript = "\"${PROJECT_DIR}/Configuration/build-rust.sh\"\n";
+			showEnvVarsInLog = 0;
+		};
+/* End PBXShellScriptBuildPhase section */
+
 /* Begin PBXSourcesBuildPhase section */
 		D020F64F29E4A697002790F6 /* Sources */ = {
 			isa = PBXSourcesBuildPhase;

Apple/Configuration/build-rust.sh

@@ -0,0 +1,69 @@
+#!/bin/bash
+
+export PATH="${PATH}:${HOME}/.cargo/bin:/opt/homebrew/bin:/usr/local/bin:/etc/profiles/per-user/${USER}/bin"
+
+if ! [[ -x "$(command -v cargo)" ]]; then
+    echo 'error: Unable to find cargo'
+    exit 127
+fi
+
+set -e
+
+cd -- "$(dirname -- "${BASH_SOURCE[0]}")"/../../burrow
+
+RUST_TARGETS=()
+
+IFS=' ' read -a BURROW_ARCHS <<< "${ARCHS[@]}"
+for ARCH in "${BURROW_ARCHS[@]}"; do
+    case $PLATFORM_NAME in
+        iphonesimulator)
+            case $ARCH in
+                arm64) RUST_TARGETS+=("aarch64-apple-ios-sim") ;;
+                x86_64) RUST_TARGETS+=("x86_64-apple-ios") ;;
+                *) echo "error: Unknown $PLATFORM_NAME arch, $ARCH"; exit 1 ;;
+            esac
+            ;;
+        iphoneos)
+            case $ARCH in
+                arm64) RUST_TARGETS+=("aarch64-apple-ios") ;;
+                *) echo "error: Unknown $PLATFORM_NAME arch, $ARCH"; exit 1 ;;
+            esac
+            ;;
+        macos*)
+            case $ARCH in
+                arm64) RUST_TARGETS+=("aarch64-apple-darwin") ;;
+                x86_64) RUST_TARGETS+=("x86_64-apple-darwin") ;;
+                *) echo "error: Unknown $PLATFORM_NAME arch, $ARCH"; exit 1 ;;
+            esac
+            ;;
+        *) echo "error: Unsupported platform $PLATFORM_NAME"; exit 1 ;;
+    esac
+done
+
+CARGO_ARGS=()
+for TARGET in "${RUST_TARGETS[@]}"; do
+    CARGO_ARGS+=("--target")
+    CARGO_ARGS+=("$TARGET")
+done
+
+CARGO_ARGS+=("--lib")
+
+if [[ $SWIFT_ACTIVE_COMPILATION_CONDITIONS == *DEBUG* ]]; then
+    CARGO_DIR="debug"
+else
+    CARGO_ARGS+=("--release")
+    CARGO_DIR="release"
+fi
+
+if [[ -x "$(command -v rustup)" ]]; then
+    CARGO_PATH="$(dirname $(rustup which cargo)):/usr/bin"
+else
+    CARGO_PATH="$(dirname $(readlink -f $(which cargo))):/usr/bin"
+fi
+
+env -i PATH="$CARGO_PATH" cargo build "${CARGO_ARGS[@]}"
+
+mkdir -p "${BUILT_PRODUCTS_DIR}"
+/usr/bin/xcrun --sdk $PLATFORM_NAME lipo \
+    -create $(printf "${PROJECT_DIR}/../target/%q/${CARGO_DIR}/libburrow.a " "${RUST_TARGETS[@]}") \
+    -output "${BUILT_PRODUCTS_DIR}/libburrow.a"

burrow/Cargo.toml

@@ -3,7 +3,8 @@ name = "burrow"
 version = "0.1.0"
 edition = "2021"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[lib]
+crate-type = ["lib", "staticlib"]
 
 [dependencies]
 tokio = { version = "1.21", features = ["rt", "macros"] }

burrow/src/lib.rs

@@ -0,0 +1,3 @@
+pub fn hello_world() {
+    println!("Hello, world!");
+}

burrow/src/main.rs

@@ -1,7 +1,7 @@
 use tokio::io::Result;
 use tun::TunInterface;
 
-async fn lol() -> Result<()> {
+async fn try_main() -> Result<()> {
     let iface = TunInterface::new()?;
     println!("{:?}", iface.name());
 
@@ -10,5 +10,5 @@ async fn lol() -> Result<()> {
 
 #[tokio::main(flavor = "current_thread")]
 async fn main() {
-    lol().await.unwrap();
+    try_main().await.unwrap();
 }