From: Vsevolod Stakhov <vsevolod@rspamd.com>
Date: Wed, 8 Oct 2025 09:50:24 +0000 (+0100)
Subject: [Fix] Fuzzy TCP: refresh timeout during active data transfer
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cd330651412de0fc65218c7cf736cc48c0878fad;p=thirdparty%2Frspamd.git

[Fix] Fuzzy TCP: refresh timeout during active data transfer

Prevents active TCP connections from timing out when data is being actively transferred.
The timeout is now refreshed after each successful read/write operation, ensuring that
connections only timeout during actual inactivity, not during normal traffic flow.
---

diff --git a/src/plugins/fuzzy_check.c b/src/plugins/fuzzy_check.c
index 1fb50d14ef..aad5ae3436 100644
--- a/src/plugins/fuzzy_check.c
+++ b/src/plugins/fuzzy_check.c
@@ -570,6 +570,21 @@ fuzzy_tcp_connection_unref(gpointer conn_ptr)
 	FUZZY_TCP_RELEASE(conn);
 }
 
+/**
+ * Refresh TCP connection timeout after successful I/O activity
+ * This prevents active connections from timing out during data transfer
+ */
+static void
+fuzzy_tcp_refresh_timeout(struct fuzzy_tcp_connection *conn)
+{
+	if (conn->rule->tcp_timeout > 0 && ev_is_active(&conn->ev.tm)) {
+		/* Stop and restart timer to extend timeout */
+		ev_timer_stop(conn->event_loop, &conn->ev.tm);
+		ev_timer_set(&conn->ev.tm, conn->rule->tcp_timeout, 0.0);
+		ev_timer_start(conn->event_loop, &conn->ev.tm);
+	}
+}
+
 /**
  * Create new TCP connection structure
  */
@@ -1062,6 +1077,9 @@ fuzzy_tcp_write_handler(struct fuzzy_tcp_connection *conn)
 
 		buf->bytes_written += r;
 
+		/* Refresh timeout after successful write - keeps connection alive during active data transfer */
+		fuzzy_tcp_refresh_timeout(conn);
+
 		if (buf->bytes_written >= buf->total_len) {
 			/* Buffer fully sent, remove from queue and free */
 			g_queue_pop_head(conn->write_queue);
@@ -1367,6 +1385,9 @@ fuzzy_tcp_read_handler(struct fuzzy_tcp_connection *conn)
 
 	conn->bytes_unprocessed += r;
 
+	/* Refresh timeout after successful read - keeps connection alive during active data transfer */
+	fuzzy_tcp_refresh_timeout(conn);
+
 	/* Process frames using state machine */
 	unsigned int processed_offset = 0;