From 0bbd4d6c34141735d0e4effb6f86facfbec7712f Mon Sep 17 00:00:00 2001
From: evgeny <evgeny@adaptto.ru>
Date: Wed, 14 Oct 2026 18:34:33 +0200
Subject: [PATCH] Verify router ACK accounting across retries and epoch resets

---
 src/routing_layer/route_tx_stats.h |  8 ++++++
 tests/test_etcp_router_unit.c      | 39 ++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/src/routing_layer/route_tx_stats.h b/src/routing_layer/route_tx_stats.h
index c7336117..157d8657 100644
--- a/src/routing_layer/route_tx_stats.h
+++ b/src/routing_layer/route_tx_stats.h
@@ -6,6 +6,10 @@
 
 #include <stdint.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define ROUTE_TX_SAMPLE_US 50000u
 #define ROUTE_TX_WINDOW_US 500000u
 #define ROUTE_TX_BUCKETS 11
@@ -22,4 +26,8 @@ int route_tx_meter_ack(struct route_tx_meter *meter, uint64_t now_us, uint64_t b
 /* Неполное окно после reset возвращает valid=0; текущая незавершённая ячейка исключается. */
 int route_tx_meter_window(const struct route_tx_meter *meter, uint64_t now_us, struct route_tx_window *out);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/tests/test_etcp_router_unit.c b/tests/test_etcp_router_unit.c
index 54d6916a..af696ef4 100644
--- a/tests/test_etcp_router_unit.c
+++ b/tests/test_etcp_router_unit.c
@@ -604,6 +604,44 @@ static int test_ack_receive(void) {
     return 0;
 }
 
+/* Реальные ACK проходят проверку эпохи/диапазона; длины payload не равны размерам криптограмм. */
+static int test_delivery_stats(void) {
+    TEST("delivery stats: payload bytes, duplicate ACK, cancellation and isolated services");
+    struct UASYNC* ua; struct UTUN_INSTANCE inst; etcp_recv_fn recv_cb;
+    SETUP();
+    establish(recv_cb, &inst, TEST_REMOTE_NODE, TEST_SVC_ID, TEST_REMOTE_NODE);
+    struct ETCP_ROUTER_CONN *c = etcp_router_conn_get(&inst, TOPO_GROUP_UTUN, TEST_REMOTE_NODE, TEST_SVC_ID);
+    TESTASSERT(c);
+    for (unsigned i = 0; i < 3; i++) {
+        struct ROUTER_INFLIGHT *inf = u_calloc(1, sizeof(*inf)); TESTASSERT(inf);
+        inf->seq = i; inf->ll.size = 4; inf->ll.len = 100 + i * 10; inf->send_count = 3;
+        inf->dgram_len = inf->ll.len + 128;
+        inf->dgram = u_calloc(1, inf->dgram_len); TESTASSERT(inf->dgram);
+        TESTASSERT(queue_data_put_with_index(c->inflight_q, &inf->ll) == 0);
+    }
+    c->tx_seq = c->tx_sent = 3;
+    struct ETCP_ROUTER_TX_STATS stats;
+    TESTASSERT(etcp_router_tx_stats(&inst, TOPO_GROUP_UTUN, TEST_REMOTE_NODE, TEST_SVC_ID, get_time_us(), &stats) == 0);
+    TESTASSERT(stats.inflight_bytes == 330 && stats.inflight_packets == 3 && stats.acked_bytes == 0);
+    inject(recv_cb, &inst, TEST_REMOTE_NODE, TEST_SVC_ID, 2, NULL, 0, 1, 0);
+    inject(recv_cb, &inst, TEST_REMOTE_NODE, TEST_SVC_ID, 2, NULL, 0, 1, 0);
+    TESTASSERT(etcp_router_tx_stats(&inst, TOPO_GROUP_UTUN, TEST_REMOTE_NODE, TEST_SVC_ID, get_time_us(), &stats) == 0);
+    TESTASSERT(stats.inflight_bytes == 120 && stats.acked_bytes == 210 && stats.acked_packets == 2);
+    TESTASSERT(stats.inflight_packets == 1 && !stats.window.valid);
+    uint64_t old_epoch = stats.local_epoch;
+    struct ETCP_ROUTER_CONN *other = etcp_router_conn_get(&inst, TOPO_GROUP_UTUN, TEST_REMOTE_NODE, TEST_SVC_ID2);
+    TESTASSERT(other);
+    uint8_t body[23] = {0};
+    TESTASSERT(etcp_router_conn_send(other, body, sizeof(body), 0) == 0);
+    TESTASSERT(etcp_router_tx_stats(&inst, TOPO_GROUP_UTUN, TEST_REMOTE_NODE, TEST_SVC_ID2, get_time_us(), &stats) == 0);
+    TESTASSERT(stats.queued_bytes == sizeof(body) && stats.queued_packets == 1 && !stats.acked_bytes);
+    etcp_router_conn_restart(&inst, TOPO_GROUP_UTUN, TEST_REMOTE_NODE, TEST_SVC_ID);
+    TESTASSERT(etcp_router_tx_stats(&inst, TOPO_GROUP_UTUN, TEST_REMOTE_NODE, TEST_SVC_ID, get_time_us(), &stats) == 0);
+    TESTASSERT(stats.local_epoch != old_epoch && !stats.acked_bytes && !stats.inflight_bytes && !stats.window.valid);
+    TESTASSERT(etcp_router_tx_stats(&inst, TOPO_GROUP_UTUN, TEST_REMOTE_NODE2, TEST_SVC_ID, get_time_us(), &stats) == 1);
+    TEARDOWN(); PASS(); return 0;
+}
+
 static int test_ack_timer(void) {
     TEST("ACK timer scheduled on data receive");
     struct UASYNC* ua; struct UTUN_INSTANCE inst; etcp_recv_fn recv_cb;
@@ -1343,6 +1381,7 @@ int main(void) {
     test_circular_wrap();
     test_data_integrity();
     test_ack_receive();
+    test_delivery_stats();
     test_ack_timer();
     test_send_q();
     test_loopback();