feat(runner): use per-benchmark TLS mode instead of global mode

runner/src/config/mod.rs

@@ -12,7 +12,7 @@ use std::{fs::read_to_string, net::SocketAddr, path::Path};
 
 #[derive(Debug, Clone, Deserialize)]
 pub struct BenchmarkConfig {
-    pub mode: String,
+    pub mode: KeyExchangeMode,
     pub payload: u32,
     pub iters: u32,
     pub warmup: u32,
@@ -61,7 +61,7 @@ pub fn load_from_file(path: &Path) -> error::Result<Config> {
 pub fn load_from_cli(args: &Args) -> error::Result<Config> {
     Ok(Config {
         benchmarks: vec![BenchmarkConfig {
-            mode: args.mode.to_string(),
+            mode: args.mode,
             payload: args.payload_bytes,
             iters: args.iters,
             warmup: args.warmup,
@@ -73,21 +73,10 @@ pub fn load_from_cli(args: &Args) -> error::Result<Config> {
     })
 }
 
-impl Config {
-    /// Get the key exchange mode from the first benchmark configuration.
-    #[must_use]
-    pub fn server_mode(&self) -> KeyExchangeMode {
-        self.benchmarks
-            .first()
-            .and_then(|b| b.mode.parse().ok())
-            .unwrap_or(KeyExchangeMode::X25519)
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
-    use claims::assert_ok;
+    use claims::{assert_err, assert_ok, assert_some};
 
     const VALID_CONFIG: &str = r#"
 [[benchmarks]]
@@ -124,7 +113,7 @@ server = "127.0.0.1:4433"
 "#;
         let config = get_config_from_str(toml);
         assert_eq!(config.benchmarks.len(), 1);
-        assert_eq!(config.benchmarks[0].mode, "x25519");
+        assert_eq!(config.benchmarks[0].mode, KeyExchangeMode::X25519);
         assert_eq!(config.benchmarks[0].payload, 1024);
     }
 
@@ -132,8 +121,8 @@ server = "127.0.0.1:4433"
     fn valid_multiple_benchmarks() {
         let config = get_config_from_str(VALID_CONFIG);
         assert_eq!(config.benchmarks.len(), 2);
-        assert_eq!(config.benchmarks[0].mode, "x25519");
-        assert_eq!(config.benchmarks[1].mode, "x25519mlkem768");
+        assert_eq!(config.benchmarks[0].mode, KeyExchangeMode::X25519);
+        assert_eq!(config.benchmarks[1].mode, KeyExchangeMode::X25519Mlkem768);
     }
 
     #[test]
@@ -147,8 +136,7 @@ warmup = 10
 concurrency = 1
 server = "127.0.0.1:4433"
 "#;
-        let config = get_config_from_str(toml);
-        assert!(config.server_mode() == KeyExchangeMode::X25519); // fallback
+        assert_err!(toml::from_str::<Config>(toml));
     }
 
     #[test]
@@ -163,8 +151,7 @@ concurrency = 1
 server = "127.0.0.1:4433"
 "#;
         let config = get_config_from_str(toml);
-        let result = validate_config(&config, toml, std::path::Path::new("test.toml"));
-        assert!(result.is_err());
+        assert_err!(validate_config(&config, toml, Path::new("test.toml")));
     }
 
     #[test]
@@ -179,8 +166,7 @@ concurrency = 1
 server = "127.0.0.1:4433"
 "#;
         let config = get_config_from_str(toml);
-        let result = validate_config(&config, toml, std::path::Path::new("test.toml"));
-        assert!(result.is_err());
+        assert_err!(validate_config(&config, toml, Path::new("test.toml")));
     }
 
     #[test]
@@ -195,8 +181,7 @@ concurrency = 0
 server = "127.0.0.1:4433"
 "#;
         let config = get_config_from_str(toml);
-        let result = validate_config(&config, toml, std::path::Path::new("test.toml"));
-        assert!(result.is_err());
+        assert_err!(validate_config(&config, toml, Path::new("test.toml")));
     }
 
     #[test]
@@ -218,7 +203,8 @@ concurrency = 1
 server = "127.0.0.1:4433"
 "#;
         let config = get_config_from_str(toml);
-        assert_eq!(config.server_mode(), KeyExchangeMode::X25519);
+        let benchmark = assert_some!(config.benchmarks.first());
+        assert_eq!(benchmark.mode, KeyExchangeMode::X25519);
     }
 
     #[test]
@@ -233,6 +219,7 @@ concurrency = 1
 server = "127.0.0.1:4433"
 "#;
         let config = get_config_from_str(toml);
-        assert_eq!(config.server_mode(), KeyExchangeMode::X25519Mlkem768);
+        let benchmark = assert_some!(config.benchmarks.first());
+        assert_eq!(benchmark.mode, KeyExchangeMode::X25519Mlkem768);
     }
 }

runner/src/config/utils.rs

@@ -2,7 +2,6 @@ use crate::{
     config::{BenchmarkConfig, Config},
     error::{self, ConfigError},
 };
-use common::{self, KeyExchangeMode};
 use miette::{NamedSource, SourceSpan};
 use std::path::Path;
 
@@ -31,21 +30,6 @@ fn validate_benchmark(
 ) -> error::Result<()> {
     let src = NamedSource::new(path.display().to_string(), content.to_string());
 
-    // Validate mode
-    if benchmark.mode.parse::<KeyExchangeMode>().is_err() {
-        return Err(ConfigError::ValidationError {
-            src,
-            span: find_field_span(content, idx, "mode"),
-            field: "mode".into(),
-            idx,
-            message: format!(
-                "Invalid key exchange mode '{}'. Valid values: 'x25519', 'x25519mlkem768'",
-                benchmark.mode
-            ),
-        }
-        .into());
-    }
-
     validate_positive_field(src.clone(), content, idx, "payload", benchmark.payload)?;
     validate_positive_field(src.clone(), content, idx, "iters", benchmark.iters)?;
     validate_positive_field(src, content, idx, "concurrency", benchmark.concurrency)?;

runner/src/main.rs

@@ -14,7 +14,7 @@ use common::{
 use miette::{Context, IntoDiagnostic};
 use runner::{
     args::Args,
-    config::{load_from_cli, load_from_file},
+    config::{BenchmarkConfig, load_from_cli, load_from_file},
 };
 use rustls::{
     ClientConfig, DigitallySignedStruct, SignatureScheme,
@@ -97,7 +97,7 @@ impl ServerCertVerifier for NoVerifier {
 }
 
 /// Build TLS client config for the given key exchange mode.
-fn build_tls_config(mode: KeyExchangeMode) -> miette::Result<Arc<ClientConfig>> {
+fn build_tls_config(mode: KeyExchangeMode) -> miette::Result<ClientConfig> {
     let mut provider = aws_lc_rs::default_provider();
     provider.kx_groups = match mode {
         KeyExchangeMode::X25519 => vec![X25519],
@@ -112,7 +112,7 @@ fn build_tls_config(mode: KeyExchangeMode) -> miette::Result<Arc<ClientConfig>>
         .with_custom_certificate_verifier(Arc::new(NoVerifier))
         .with_no_client_auth();
 
-    Ok(Arc::new(config))
+    Ok(config)
 }
 
 /// Run a single benchmark iteration over TLS.
@@ -156,9 +156,8 @@ async fn run_iteration(
     })
 }
 
-#[allow(clippy::future_not_send)] // References held across await points
 async fn run_benchmark(
-    config: &runner::config::BenchmarkConfig,
+    config: &BenchmarkConfig,
     tls_connector: &TlsConnector,
     server_name: &ServerName<'static>,
 ) -> miette::Result<()> {
@@ -195,7 +194,6 @@ async fn run_benchmark(
     let semaphore = Arc::new(Semaphore::new(config.concurrency as usize));
     let tasks = spawn_benchmark_tasks(config, &semaphore, tls_connector, server_name);
 
-    // Output to stdout for now
     {
         let mut output = stdout();
         write_results(&mut output, tasks).await?;
@@ -219,17 +217,13 @@ fn spawn_benchmark_tasks(
 ) -> Vec<ReturnHandle> {
     let server = config.server;
     let payload_bytes = config.payload;
-    let mode = config
-        .mode
-        .parse::<KeyExchangeMode>()
-        .expect("mode should be valid");
 
     (0..config.iters)
         .map(|i| {
             spawn_single_iteration(
                 i,
                 payload_bytes,
-                mode,
+                config.mode,
                 server,
                 semaphore.clone(),
                 tls_connector.clone(),
@@ -314,9 +308,6 @@ async fn main() -> miette::Result<()> {
         load_from_cli(&args)?
     };
 
-    let tls_config = build_tls_config(config.server_mode())?;
-    let tls_connector = TlsConnector::from(tls_config);
-
     let server_name = ServerName::try_from("localhost".to_string())
         .into_diagnostic()
         .context("invalid server name")?;
@@ -331,6 +322,9 @@ async fn main() -> miette::Result<()> {
             "running benchmark"
         );
 
+        let tls_config = build_tls_config(benchmark.mode)?;
+        let tls_connector = TlsConnector::from(Arc::new(tls_config));
+
         run_benchmark(benchmark, &tls_connector, &server_name).await?;
     }