policy: improve args and env variables validation

src/agent/src/policy.rs

@@ -97,6 +97,32 @@ pub async fn is_allowed_copy_file(req: &protocols::agent::CopyFileRequest) -> tt
     allow_request(&mut policy, "CopyFileRequest", &request).await
 }
 
+/// PolicyCreateContainerRequest is very similar to CreateContainerRequest from src/libs/protocols, except:
+/// - It wraps the base CreateContainerRequest.
+/// - It has an env_map field which is a map of environment variable names to expanded values.
+/// This makes it easier to validate the environment variables inside the rego rules.
+#[derive(Debug, serde::Serialize)]
+struct PolicyCreateContainerRequest {
+    base: protocols::agent::CreateContainerRequest,
+    // a map of environment variable names to value
+    env_map: std::collections::BTreeMap<String, String>,
+}
+
+pub async fn is_allowed_create_container(
+    req: &protocols::agent::CreateContainerRequest,
+) -> ttrpc::Result<()> {
+    let env_map = get_env_map(&req.OCI.Process.Env);
+
+    let create_container_request = PolicyCreateContainerRequest {
+        base: req.clone(),
+        env_map,
+    };
+
+    let request = serde_json::to_string(&create_container_request).unwrap();
+    let mut policy = AGENT_POLICY.lock().await;
+    allow_request(&mut policy, "CreateContainerRequest", &request).await
+}
+
 pub async fn do_set_policy(req: &protocols::agent::SetPolicyRequest) -> ttrpc::Result<()> {
     let request = serde_json::to_string(req).unwrap();
     let mut policy = AGENT_POLICY.lock().await;
@@ -331,3 +357,20 @@ pub fn check_policy_hash(policy: &str) -> Result<()> {
 
     Ok(())
 }
+
+// todo: move to common crate shared with genpolicy
+fn get_env_map(env: &[String]) -> std::collections::BTreeMap<String, String> {
+    let env_map: std::collections::BTreeMap<String, String> = env
+        .iter()
+        .filter_map(|v| {
+            // split by leftmost '='
+            let split = v.split_once('=');
+            if let Some((key, value)) = split {
+                Some((key.to_string(), value.to_string()))
+            } else {
+                None
+            }
+        })
+        .collect();
+    env_map
+}

src/agent/src/rpc.rs

@@ -67,7 +67,7 @@ use crate::trace_rpc_call;
 use crate::tracer::extract_carrier_from_ttrpc;
 
 #[cfg(feature = "agent-policy")]
-use crate::policy::{do_set_policy, is_allowed, is_allowed_copy_file};
+use crate::policy::{do_set_policy, is_allowed, is_allowed_copy_file, is_allowed_create_container};
 
 use opentelemetry::global;
 use tracing::span;
@@ -134,6 +134,13 @@ async fn is_allowed_copy_file(_req: &CopyFileRequest) -> ttrpc::Result<()> {
     Ok(())
 }
 
+#[cfg(not(feature = "agent-policy"))]
+async fn is_allowed_create_container(
+    _req: &protocols::agent::CreateContainerRequest,
+) -> ttrpc::Result<()> {
+    Ok(())
+}
+
 fn same<E>(e: E) -> E {
     e
 }
@@ -641,7 +648,7 @@ impl agent_ttrpc::AgentService for AgentService {
         req: protocols::agent::CreateContainerRequest,
     ) -> ttrpc::Result<Empty> {
         trace_rpc_call!(ctx, "create_container", req);
-        is_allowed(&req).await?;
+        is_allowed_create_container(&req).await?;
         self.do_create_container(req).await.map_ttrpc_err(same)?;
         Ok(Empty::new())
     }

src/tools/genpolicy/genpolicy-settings.json

@@ -219,6 +219,8 @@
         "dns_label": "[a-zA-Z0-9_\\.\\-]+",
         "s_source1": "^..2[0-9]{3}_[0-1][0-9]_[0-3][0-9]_[0-2][0-9]_[0-5][0-9]_[0-5][0-9]\\.[0-9]{1,10}$",
         "s_source2": "^..data/",
+        "dns_subdomain": "^[a-z0-9]([-a-z0-9]*[a-z0-9])?$",
+        "pod_uid": "^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$",
         "default_caps": [
             "CAP_CHOWN",
             "CAP_DAC_OVERRIDE",