From d0ee0341c5691ecfe9b64d423f00cb7ef9446981 Mon Sep 17 00:00:00 2001
From: evgeny <evgeny@adaptto.ru>
Date: Fri, 23 Oct 2026 22:36:39 +0200
Subject: [PATCH] Verify cancelled link constructors and guard UDP handshake
 callbacks

---
 src/transport_layer/etcp_connections.c |  3 ++-
 tests/test_etcp_lifecycle.c            | 24 +++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/transport_layer/etcp_connections.c b/src/transport_layer/etcp_connections.c
index e46aff55..bac5e112 100644
--- a/src/transport_layer/etcp_connections.c
+++ b/src/transport_layer/etcp_connections.c
@@ -349,10 +349,11 @@ void etcp_link_restart_init_timer(struct ETCP_LINK* link) {
 void etcp_link_enter_init(struct ETCP_LINK* link) {
     DEBUG_TRACE(DEBUG_CATEGORY_ETCP, "");
     if (!link) return;
+    struct ETCP_CONN *conn = link->etcp;
     int old_state = link->link_state;
     link->link_state = LINK_STATE_HANDSHAKE; // handshake
     etcp_fire_link_status_cbk(link, old_state, link->link_status);
-    if (!etcp_link_rx_alive(link->etcp, link)) return;
+    if (!etcp_link_rx_alive(conn, link)) return;
     if (link->is_server != 0) return;
     int reset = (link->etcp->got_initial_pkt == 0);
     etcp_link_send_init(link, reset, 0);
diff --git a/tests/test_etcp_lifecycle.c b/tests/test_etcp_lifecycle.c
index 7cd3865d..2de88505 100644
--- a/tests/test_etcp_lifecycle.c
+++ b/tests/test_etcp_lifecycle.c
@@ -172,6 +172,27 @@ static void constructor_close_cases(struct UTUN_INSTANCE *inst) {
 }
 
 struct link_close_case { struct ETCP_LINK *neighbor; unsigned events, nested; };
+static void cancel_created_link(struct ETCP_CONN *conn, struct ETCP_LINK *link, int old_state, int old_status, void *arg) {
+    (void)old_status;
+    unsigned action = (unsigned)(uintptr_t)arg;
+    if (old_state != -1) return;
+    if (action == 1) etcp_link_close(link);
+    else etcp_connection_close(conn);
+}
+static void link_constructor_close_cases(struct UTUN_INSTANCE *inst) {
+    for (unsigned action = 1; action <= 2; action++) {
+        struct ETCP_CONN *conn = etcp_connection_create(inst, "cancel link"); CHECK(conn);
+        CHECK(etcp_conn_ref_take(conn) == 0);
+        etcp_add_link_status_cbk(inst, cancel_created_link, (void*)(uintptr_t)action);
+        CHECK(etcp_link_new(conn, NULL, NULL, 0) == NULL);
+        CHECK(!conn->links);
+        etcp_remove_link_status_cbk(inst, cancel_created_link, (void*)(uintptr_t)action);
+        etcp_connection_close(conn); etcp_conn_ref_free(conn);
+        uasync_drain_immediate(inst->ua); uasync_poll(inst->ua, 0);
+        CHECK(!inst->connections->count);
+        printf("PASS link creation cancelled by closing %s\n", action == 1 ? "link" : "connection");
+    }
+}
 static void close_neighbor(struct ETCP_CONN *conn, struct ETCP_LINK *link, int old_state, int old_status, void *arg) {
     (void)conn; (void)old_state; (void)old_status;
     struct link_close_case *test = arg;
@@ -231,7 +252,8 @@ int main(void) {
         uasync_poll(inst.ua,0); CHECK(inst.connections->count == 0);
         printf("PASS lifecycle scenario %d\n",scenario+1);
     }
-    ncd_cases(&inst); ncd_late_up_case(&inst); recovery_cases(&inst); neighbor_close_case(&inst); constructor_close_cases(&inst);
+    ncd_cases(&inst); ncd_late_up_case(&inst); recovery_cases(&inst); neighbor_close_case(&inst);
+    constructor_close_cases(&inst); link_constructor_close_cases(&inst);
     queue_free(inst.connections); uasync_poll(inst.ua,0);
     CHECK(inst.ua->timer_alloc_count == inst.ua->timer_free_count);
     uasync_destroy(inst.ua,0); CHECK(u_get_allocated_count() == baseline);