test: add end-to-end integration script

scripts/integration-test.sh

@@ -0,0 +1,96 @@
+#!/usr/bin/env bash
+#
+# prx integration test.
+#
+# Exercises the real nftables and policy-routing layer on the local host:
+#   on -> assert rules exist -> on again (idempotent) -> off -> assert clean.
+#
+# The proxy engine is skipped (--skip-engine) so this does not require sing-box.
+# Run it with root, e.g.:
+#
+#   sudo -E PRX_BIN="$PWD/bin/prx" ./scripts/integration-test.sh
+#
+set -euo pipefail
+
+BIN="${PRX_BIN:-$(pwd)/bin/prx}"
+
+if [[ ! -x "$BIN" ]]; then
+  echo "prx binary not found at $BIN (build it first: make build)" >&2
+  exit 1
+fi
+if [[ "${EUID}" -ne 0 ]]; then
+  echo "this test needs root; re-run with sudo -E $0" >&2
+  exit 1
+fi
+
+TMP="$(mktemp -d)"
+CONFIG="$TMP/config.json"
+STATE="$TMP/state.json"
+
+cat >"$CONFIG" <<EOF
+{
+  "state": { "path": "$STATE" }
+}
+EOF
+
+PRX=("$BIN" --config "$CONFIG")
+
+cleanup() {
+  echo "--- cleanup ---"
+  "${PRX[@]}" off >/dev/null 2>&1 || true
+  rm -rf "$TMP"
+}
+trap cleanup EXIT
+
+pass() { echo "  ok: $1"; }
+fail() { echo "  FAIL: $1" >&2; exit 1; }
+
+rule_count() {
+  ip rule show | grep -c "fwmark 0x100" || true
+}
+
+echo "--- enabling (skip engine) ---"
+"${PRX[@]}" on --skip-engine
+
+echo "--- assertions after on ---"
+nft list table inet prx >/dev/null 2>&1 || fail "nftables table inet prx missing"
+pass "nftables table inet prx present"
+
+ip rule show | grep -q "fwmark 0x100 lookup 100" || fail "policy rule missing"
+pass "policy rule present"
+
+ip route show table 100 | grep -q "^default via" || fail "table 100 has no default route"
+pass "table 100 default route present"
+
+[[ "$(rule_count)" -eq 1 ]] || fail "expected exactly one mark rule, got $(rule_count)"
+pass "exactly one mark rule"
+
+echo "--- enabling again (idempotency) ---"
+"${PRX[@]}" on --skip-engine
+[[ "$(rule_count)" -eq 1 ]] || fail "duplicate rule after second on ($(rule_count))"
+pass "no duplicate rule after second on"
+
+nft list table inet prx | grep -c "meta mark set" >/dev/null || fail "nft rules missing"
+pass "nft rules intact after re-apply"
+
+echo "--- status ---"
+"${PRX[@]}" status
+
+echo "--- disabling ---"
+"${PRX[@]}" off
+
+echo "--- assertions after off ---"
+if nft list table inet prx >/dev/null 2>&1; then
+  fail "nftables table inet prx still present after off"
+fi
+pass "nftables table removed"
+
+[[ "$(rule_count)" -eq 0 ]] || fail "policy rule still present after off"
+pass "policy rule removed"
+
+echo "--- disabling again (idempotency) ---"
+"${PRX[@]}" off
+pass "second off succeeded"
+
+echo
+echo "ALL INTEGRATION CHECKS PASSED"