From f033793f74f09fa101c69b4386e5b5c75deb9b02 Mon Sep 17 00:00:00 2001
From: Orne Brocaar <info@brocaar.com>
Date: Tue, 19 Apr 2022 12:05:32 +0100
Subject: [PATCH] Make js codec execution time configurable.

Closes #1.
---
 chirpstack/src/cmd/configfile.rs | 10 ++++++
 chirpstack/src/codec/js.rs       | 53 ++++++++++++++++++++++++++++++--
 chirpstack/src/config.rs         | 23 ++++++++++++++
 3 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/chirpstack/src/cmd/configfile.rs b/chirpstack/src/cmd/configfile.rs
index ab479a40..f08323a7 100644
--- a/chirpstack/src/cmd/configfile.rs
+++ b/chirpstack/src/cmd/configfile.rs
@@ -298,6 +298,16 @@ pub fn run() {
     tls_key="{{ integration.mqtt.tls_key }}"
 
 
+# Codec configuration.
+[codec]
+
+  # JS codec configuration.
+  [codec.js]
+
+    # Maximum execution time.
+    max_execution_time="{{ codec.js.max_execution_time }}"
+
+
 # User authentication configuration.
 [user_authentication]
 
diff --git a/chirpstack/src/codec/js.rs b/chirpstack/src/codec/js.rs
index e335acf8..e8af9ad7 100644
--- a/chirpstack/src/codec/js.rs
+++ b/chirpstack/src/codec/js.rs
@@ -1,9 +1,11 @@
 use std::collections::HashMap;
+use std::time::SystemTime;
 
 use anyhow::Result;
 use rquickjs::IntoJs;
 
 use super::convert;
+use crate::config;
 
 pub async fn decode(
     f_port: u8,
@@ -11,7 +13,12 @@ pub async fn decode(
     decode_config: &str,
     b: &[u8],
 ) -> Result<pbjson_types::Struct> {
+    let conf = config::get();
+    let max_run_ts = SystemTime::now() + conf.codec.js.max_execution_time;
+
     let rt = rquickjs::Runtime::new().unwrap();
+    rt.set_interrupt_handler(Some(Box::new(move || SystemTime::now() > max_run_ts)));
+
     let ctx = rquickjs::Context::full(&rt).unwrap();
 
     let script = decode_config.to_string();
@@ -28,7 +35,7 @@ pub async fn decode(
             .unwrap();
         input.set("data", b.into_js(ctx).unwrap()).unwrap();
 
-        let res: rquickjs::Object = func.call((input,)).unwrap();
+        let res: rquickjs::Object = func.call((input,))?;
         Ok(convert::rquickjs_to_struct(&res))
     })
 }
@@ -39,7 +46,12 @@ pub async fn encode(
     encode_config: &str,
     s: &prost_types::Struct,
 ) -> Result<Vec<u8>> {
+    let conf = config::get();
+    let max_run_ts = SystemTime::now() + conf.codec.js.max_execution_time;
+
     let rt = rquickjs::Runtime::new().unwrap();
+    rt.set_interrupt_handler(Some(Box::new(move || SystemTime::now() > max_run_ts)));
+
     let ctx = rquickjs::Context::full(&rt).unwrap();
 
     let script = encode_config.to_string();
@@ -57,7 +69,7 @@ pub async fn encode(
             .set("object", convert::struct_to_rquickjs(ctx, s))
             .unwrap();
 
-        let res: Vec<u8> = func.call((input,)).unwrap();
+        let res: Vec<u8> = func.call((input,))?;
         Ok(res)
     })
 }
@@ -66,6 +78,22 @@ pub async fn encode(
 pub mod test {
     use super::*;
 
+    #[tokio::test]
+    pub async fn test_decode_timeout() {
+        let decoder = r#"
+            export function Decode(input) {
+                while (true) {
+
+                }
+            }
+        "#
+        .to_string();
+
+        let vars: HashMap<String, String> = HashMap::new();
+        let out = decode(10, &vars, &decoder, &[0x01, 0x02, 0x03]).await;
+        assert!(out.is_err());
+    }
+
     #[tokio::test]
     pub async fn test_decode() {
         let decoder = r#"
@@ -143,6 +171,27 @@ pub mod test {
         assert_eq!(expected, out);
     }
 
+    #[tokio::test]
+    pub async fn test_encode_timeout() {
+        let encoder = r#"
+            export function Encode(input) {
+                while (true) {
+
+                }
+            }
+        "#
+        .to_string();
+
+        let vars: HashMap<String, String> = HashMap::new();
+
+        let input = prost_types::Struct {
+            ..Default::default()
+        };
+
+        let out = encode(10, &vars, &encoder, &input).await;
+        assert!(out.is_err());
+    }
+
     #[tokio::test]
     pub async fn test_encode() {
         let encoder = r#"
diff --git a/chirpstack/src/config.rs b/chirpstack/src/config.rs
index af812a77..d7011e60 100644
--- a/chirpstack/src/config.rs
+++ b/chirpstack/src/config.rs
@@ -24,6 +24,7 @@ pub struct Configuration {
     pub network: Network,
     pub monitoring: Monitoring,
     pub integration: Integration,
+    pub codec: Codec,
     pub user_authentication: UserAuthentication,
     pub join_server: JoinServer,
     pub keks: Vec<Kek>,
@@ -41,6 +42,7 @@ impl Default for Configuration {
             network: Default::default(),
             monitoring: Default::default(),
             integration: Default::default(),
+            codec: Default::default(),
             user_authentication: Default::default(),
             join_server: Default::default(),
             keks: Vec::new(),
@@ -293,6 +295,27 @@ impl Default for MqttIntegrationClient {
     }
 }
 
+#[derive(Serialize, Deserialize, Clone, Default)]
+#[serde(default)]
+pub struct Codec {
+    pub js: CodecJs,
+}
+
+#[derive(Serialize, Deserialize, Clone)]
+#[serde(default)]
+pub struct CodecJs {
+    #[serde(with = "humantime_serde")]
+    pub max_execution_time: Duration,
+}
+
+impl Default for CodecJs {
+    fn default() -> Self {
+        CodecJs {
+            max_execution_time: Duration::from_millis(100),
+        }
+    }
+}
+
 #[derive(Serialize, Deserialize, Clone, Default)]
 #[serde(default)]
 pub struct UserAuthentication {