Add basic test

.vscode/launch.json

@@ -0,0 +1,48 @@
+// SPDX-FileCopyrightText: 2022 Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
+// SPDX-License-Identifier: CC0-1.0
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug integration test 'common'",
+            "cargo": {
+                "args": [
+                    "test",
+                    "--no-run",
+                    "--test=common",
+                    "--package=malcontent-nss"
+                ],
+                "filter": {
+                    "name": "common",
+                    "kind": "test"
+                }
+            },
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        },
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug integration test 'integration_test'",
+            "cargo": {
+                "args": [
+                    "test",
+                    "--no-run",
+                    "--test=integration_test",
+                    "--package=malcontent-nss"
+                ],
+                "filter": {
+                    "name": "integration_test",
+                    "kind": "test"
+                }
+            },
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        }
+    ]
+}

CMakeLists.txt

@@ -15,9 +15,8 @@ FetchContent_Declare(
     GIT_TAG v0.2.1
 )
 
-set(Rust_TOOLCHAIN nightly)
 FetchContent_MakeAvailable(Corrosion)
 corrosion_import_crate(MANIFEST_PATH Cargo.toml)
 
-get_target_property(corrosion_install_libraries malcontent-nss INTERFACE_LINK_LIBRARIES)
+get_target_property(corrosion_install_libraries nss_malcontent INTERFACE_LINK_LIBRARIES)
 install(IMPORTED_RUNTIME_ARTIFACTS ${corrosion_install_libraries})

Cargo.toml

@@ -10,6 +10,7 @@ license = "GPL-3.0-or-later"
 
 [lib]
 crate-type = ["cdylib"]
+name = "nss_malcontent"
 
 [dev-dependencies.rusty-hook]
 version = "0.11"
@@ -17,6 +18,12 @@ version = "0.11"
 [build-dependencies.bindgen]
 version = "0.60"
 
+[dev-dependencies.test-cdylib]
+version = "1.1"
+
+[dependencies.anyhow]
+version = "1.0"
+
 [dependencies.libc]
 version = "0.2"
 

build.rs

@@ -7,12 +7,17 @@ use {std::env, std::path::PathBuf};
 
 fn main() {
     println!("cargo:rerun-if-changed=wrapper.h");
+
+    // Required by NSS 2
+    println!("cargo:rustc-link-arg=-Wl,-soname,libnss_malcontent.so.2");
+
     let bindings = bindgen::Builder::default()
         .header("wrapper.h")
         .parse_callbacks(Box::new(bindgen::CargoCallbacks))
         .newtype_enum("nss_status")
         .allowlist_type("nss_status")
         .allowlist_type("gaih_addrtuple")
+        .allowlist_function("__nss_configure_lookup")
         .generate()
         .expect("Unable to generate bindings");
 

src/nss_api.rs

@@ -4,7 +4,7 @@
 include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
 
 use {
-    core::ffi::{c_char, c_int, c_void},
+    ::std::os::raw::{c_char, c_int, c_void},
     libc::{hostent, size_t, socklen_t, AF_INET},
     std::ptr,
 };

tests/common.rs

@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: 2022 Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+use {
+    anyhow::{ensure, Result},
+    std::ffi::CString,
+    std::os::raw::c_int,
+    std::os::unix::fs::symlink,
+    std::path::PathBuf,
+    std::sync::Once,
+};
+
+include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
+
+static SETUP: Once = Once::new();
+
+pub fn setup() -> Result<()> {
+    unsafe {
+        static mut NSS_CONFIG_STATUS: c_int = 0;
+        SETUP.call_once(|| {
+            let out_dir = PathBuf::from(env!("OUT_DIR"));
+            let library_path = test_cdylib::build_current_project();
+            let mut library_filename = library_path.file_name().unwrap().to_owned();
+            library_filename.push(".2"); // required for NSS 2 modules
+
+            let dest = out_dir.join(library_filename);
+            symlink(&library_path, &dest).expect(&format!(
+                "Unable to create symlink to library ({} -> {})",
+                library_path.to_string_lossy(),
+                dest.to_string_lossy()
+            ));
+
+            std::env::set_var("LD_LIBRARY_PATH", out_dir);
+
+            let db = CString::new("hosts").unwrap();
+            let resolvers = CString::new("files malcontent [UNAVAIL=return] dns").unwrap();
+            NSS_CONFIG_STATUS = __nss_configure_lookup(db.as_ptr(), resolvers.as_ptr());
+        });
+
+        ensure!(
+            NSS_CONFIG_STATUS == 0,
+            "Unable to configure NSS to load module: __nss_configure_lookup() returned {}",
+            NSS_CONFIG_STATUS
+        );
+        Ok(())
+    }
+}

tests/integration_test.rs

@@ -0,0 +1,15 @@
+// SPDX-FileCopyrightText: 2022 Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+mod common;
+
+use anyhow::Result;
+
+#[test]
+fn nss_module_is_loaded() -> Result<()> {
+    use std::net::ToSocketAddrs;
+
+    common::setup()?;
+    "www.google.com:443".to_socket_addrs()?;
+    Ok(())
+}