From: Lukáš Ondráček <lukas.ondracek@nic.cz>
Date: Wed, 6 Nov 2024 17:26:14 +0000 (+0100)
Subject: daemon/io: keep TCP data in system queue on buffer overflow
X-Git-Tag: v6.0.10~6^2~38
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1ea3f10cd0d8668ff1f19fc397f78a7929648403;p=thirdparty%2Fknot-resolver.git

daemon/io: keep TCP data in system queue on buffer overflow
---

diff --git a/daemon/io.c b/daemon/io.c
index 366489075..98500c347 100644
--- a/daemon/io.c
+++ b/daemon/io.c
@@ -324,6 +324,20 @@ static void tcp_recv(uv_stream_t *handle, ssize_t nread, const uv_buf_t *buf)
 		return;
 	}
 
+	if (nread == UV_ENOBUFS) {
+		/* No space available in session buffer.
+		 * The connection may be just waiting in defer.
+		 * Ignore the error and keep the data in system queue for later reading or timeout. */
+		if (kr_log_is_debug(IO, NULL)) {
+			struct sockaddr *peer = session2_get_peer(s);
+			char *peer_str = kr_straddr(peer);
+			kr_log_debug(IO, "=> incoming data from '%s' waiting (%s)\n",
+			         peer_str ? peer_str : "",
+			         uv_strerror(nread));
+		}
+		return;
+	}
+
 	if (nread < 0 || !buf->base) {
 		if (kr_log_is_debug(IO, NULL)) {
 			struct sockaddr *peer = session2_get_peer(s);