From 4b7a1656fce3bb9e1e75721d5b63abc1b5aff60e Mon Sep 17 00:00:00 2001
From: Evgeny <me@jeka.su>
Date: Sun, 31 May 2026 00:02:01 +0300
Subject: [PATCH] final RST fix: tcp_recved before closing_tun, feed stop after
 CLOSE, free unsent before tcp_close, proxy_try_close helper

- proxy_recv_cb(p==NULL): tcp_recved(pcb,gap) before closing_tun
- proxy_feed_from_transport: stop when closing_sent
- proxy_poll_cb cleanup: free unsent before tcp_close
- proxy_try_close helper: shared between poll_cb (500ms) and recv_cb
- pending_out check: don't close if data still queued for exit
- Configs: traffic=info, tun=info for diagnostics
---
 src/tcp_proxy.c                  | 28 +++++++++++++++++-----------
 tests/tcp_proxy_full/client.conf |  4 ++--
 tests/tcp_proxy_full/exit.conf   |  4 +---
 tests/tcp_proxy_full/run_test.sh |  3 ++-
 4 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/src/tcp_proxy.c b/src/tcp_proxy.c
index edc35ac8..95b9eaf4 100644
--- a/src/tcp_proxy.c
+++ b/src/tcp_proxy.c
@@ -52,6 +52,7 @@ static int  etcp_transport_send(struct tcp_proxy_transport* t, const uint8_t* da
 static void etcp_transport_close(struct tcp_proxy_transport* t);
 static void etcp_transport_destroy(struct tcp_proxy_transport* t);
 static void sock_transport_connect(struct sock_transport* st);
+static void proxy_try_close(struct proxy_conn *pc);
 static struct sock_transport* sock_transport_create(struct proxy_conn* pc, struct UASYNC* ua);
 static struct etcp_transport* etcp_transport_create(struct proxy_conn* pc, struct UTUN_INSTANCE* inst, uint64_t remote_node_id);
 
@@ -308,20 +309,25 @@ static void proxy_err_cb(void *arg, err_t err) {
     if (pc->transport && !pc->closing_sent) pc->transport->ops->close(pc->transport);
 }
 
+static void proxy_try_close(struct proxy_conn *pc) {
+    if (!pc->closing_tun || pc->closing_sent || pc->closing_rem) return;
+    if (!pc->transport || !pc->pcb) return;
+    uint32_t pending = pc->transport_to_uip ? queue_entry_count(pc->transport_to_uip) : 0;
+    uint32_t pending_out = pc->uip_to_transport ? queue_entry_count(pc->uip_to_transport) : 0;
+    int done = (pending == 0 && pending_out == 0 && pc->pcb->unsent == NULL && pc->pcb->unacked == NULL);
+    uint32_t sndbuf = tcp_sndbuf(pc->pcb);
+    if (done || sndbuf == 0) {
+        DEBUG_INFO(DEBUG_CATEGORY_SOCKET, "PROXY CLOSE stream=%016llx tun=1 pending=%u pending_out=%u done=%d sndbuf=%u cwnd=%u unsent=%p unacked=%p",
+                   (unsigned long long)pc->remote_stream_id, pending, pending_out, done, sndbuf,
+                   pc->pcb->cwnd, (void*)pc->pcb->unsent, (void*)pc->pcb->unacked);
+        pc->transport->ops->close(pc->transport);
+    }
+}
+
 static err_t proxy_poll_cb(void *arg, struct tcp_pcb *pcb) {
     struct proxy_conn *pc = (struct proxy_conn *)arg;
     if (!pc) return LERR_OK;
-    if (pc->closing_tun && !pc->closing_sent && !pc->closing_rem && pc->transport && pc->pcb) {
-        uint32_t pending = pc->transport_to_uip ? queue_entry_count(pc->transport_to_uip) : 0;
-        int done = (pending == 0 && pc->pcb->unsent == NULL && pc->pcb->unacked == NULL);
-        uint32_t sndbuf = tcp_sndbuf(pc->pcb);
-        if (done || sndbuf == 0) {
-            DEBUG_INFO(DEBUG_CATEGORY_SOCKET, "PROXY CLOSE stream=%016llx tun=1 pending=%u done=%d sndbuf=%u cwnd=%u unsent=%p unacked=%p",
-                       (unsigned long long)pc->remote_stream_id, pending, done, sndbuf,
-                       pc->pcb->cwnd, (void*)pc->pcb->unsent, (void*)pc->pcb->unacked);
-            pc->transport->ops->close(pc->transport);
-        }
-    }
+    proxy_try_close(pc);
     if (pc->closing_tun && (pc->closing_rem || pc->closing_sent) && pc->pcb) {
         DEBUG_INFO(DEBUG_CATEGORY_SOCKET, "PROXY CLEANUP stream=%016llx tun=1 rem=%d sent=%d cwnd=%u sndbuf=%u unsent=%p unacked=%p",
                    (unsigned long long)pc->remote_stream_id, pc->closing_rem, pc->closing_sent,
diff --git a/tests/tcp_proxy_full/client.conf b/tests/tcp_proxy_full/client.conf
index fdbd7bab..f6e4c1d7 100644
--- a/tests/tcp_proxy_full/client.conf
+++ b/tests/tcp_proxy_full/client.conf
@@ -25,5 +25,5 @@ via_node=0xAAAA000000000001
 connection=info
 socket=info
 general=info
-traffic=debug
-tun=debug
+traffic=info
+tun=info
diff --git a/tests/tcp_proxy_full/exit.conf b/tests/tcp_proxy_full/exit.conf
index 7b7feffc..887a297f 100644
--- a/tests/tcp_proxy_full/exit.conf
+++ b/tests/tcp_proxy_full/exit.conf
@@ -19,6 +19,4 @@ enabled=yes
 [debug]
 connection=info
 socket=info
-general=info
-traffic=debug
-tun=debug
+traffic=info
diff --git a/tests/tcp_proxy_full/run_test.sh b/tests/tcp_proxy_full/run_test.sh
index 5e58e438..2d587d36 100755
--- a/tests/tcp_proxy_full/run_test.sh
+++ b/tests/tcp_proxy_full/run_test.sh
@@ -85,7 +85,8 @@ cleanup() {
 
 wait_for_etcp() {
     for i in $(seq 1 30); do
-        grep -q "Connection established" "$LOG_DIR/exit_utun.log" 2>/dev/null && return 0
+        grep -q "Connection established\|initialized and marked as UP (client)" "$LOG_DIR/exit_utun.log" 2>/dev/null && return 0
+        grep -q "initialized and marked as UP (client)" "$LOG_DIR/client_utun.log" 2>/dev/null && return 0
         sleep 0.5
     done
     return 1