msg-sim revamp, Linux support only

.claude/settings.local.json

@@ -0,0 +1,20 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(cargo check:*)",
+      "Bash(sudo ip netns exec msg-sim-1 tc qdisc show:*)",
+      "Bash(grep:*)",
+      "Bash(find:*)",
+      "Bash(just check:*)",
+      "Bash(just clippy:*)",
+      "Bash(just fmt:*)",
+      "Bash(ls:*)",
+      "Bash(RUSTDOCFLAGS=\"-D warnings\" cargo +nightly doc:*)",
+      "WebSearch",
+      "Bash(cat:*)",
+      "WebFetch(domain:github.com)",
+      "Bash(cargo test:*)",
+      "Bash(git show:*)"
+    ]
+  }
+}

.github/workflows/ci.yml

@@ -32,12 +32,34 @@ jobs:
       - name: Install cargo-nextest
         uses: taiki-e/install-action@nextest
 
-      - name: Run tests (all features)
-        run: cargo nextest run --all --all-features --no-fail-fast
+      - name: Run tests (all features, excluding msg-sim)
+        run: cargo nextest run --all --all-features --no-fail-fast --exclude msg-sim
 
-      - name: Run doc tests
+      - name: Run doc tests (excluding msg-sim)
         run: cargo test --doc --all --all-features
 
+  # msg-sim tests require root privileges to create network namespaces
+  cargo-tests-msg-sim:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v6
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - uses: Swatinem/rust-cache@v2
+        with:
+          cache-on-failure: true
+
+      # Install nextest
+      - name: Install cargo-nextest
+        uses: taiki-e/install-action@nextest
+
+      - name: Run msg-sim tests (requires root for network namespaces)
+        run: sudo env "PATH=$PATH" "HOME=$HOME" cargo nextest run -p msg-sim --all-features --no-fail-fast --test-threads=1
+
   cargo-lint:
     runs-on: ubuntu-latest
     timeout-minutes: 20

CLAUDE.md

@@ -47,7 +47,7 @@ cargo flamegraph --bin example_name
 - **`msg-transport/`** - Transport layer (TCP, QUIC, IPC with pluggable trait design)
 - **`msg-wire/`** - Wire protocol (authentication, compression: gzip/lz4/snappy/zstd)
 - **`msg-common/`** - Shared utilities (channels, task management, time utils)
-- **`msg-sim/`** - Network simulation (macOS: pfctl/dnctl, Linux: tc/netem)
+- **`msg-sim/`** - Network simulation on Linux, powered by rtnetlink.
 
 ### Key Design Patterns
 - **Trait-based extensibility** - Transport, Authenticator traits for pluggability
@@ -69,9 +69,8 @@ cargo flamegraph --bin example_name
 - **debug-maxperf** - Performance with debug symbols
 
 ### Platform-Specific Features
-- **Linux**: JeMalloc integration for memory performance
-- **macOS**: Network simulation via pfctl/dnctl
-- **MSRV**: Rust 1.75
+- **Linux**: JeMalloc integration for memory performance and `msg-sim` support
+- **MSRV**: Rust 1.86
 
 ## Testing Architecture
 
@@ -109,4 +108,4 @@ cargo flamegraph --bin example_name
 ### Current Development Status
 - **Alpha stage** - API may change, not production-ready
 - **Active development** - Regular feature additions
-- **Chainbound/Fiber integration** - Primary use case driving development
+- **Chainbound/Fiber integration** - Primary use case driving development