From: Vladimír Čunát <vladimir.cunat@nic.cz>
Date: Wed, 4 Mar 2020 12:47:02 +0000 (+0100)
Subject: daemon/io: extend logging for TCP Fast Open failure
X-Git-Tag: v5.1.0~37^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8f1fc6e5dd567d26b83d653a6ba2acc021d02e3d;p=thirdparty%2Fknot-resolver.git

daemon/io: extend logging for TCP Fast Open failure

In FreeBSD it's disabled by default, causing this error.
I tried disabling it on Linux via sysctl, but that didn't seem
to cause any errors.
---

diff --git a/daemon/io.c b/daemon/io.c
index eb1f276ab..fb1a1d076 100644
--- a/daemon/io.c
+++ b/daemon/io.c
@@ -440,7 +440,9 @@ int io_listen_tcp(uv_loop_t *loop, uv_tcp_t *handle, int fd, int tcp_backlog, bo
 	val = 1; /* Accepts on/off */
 	#endif
 	if (setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &val, sizeof(val))) {
-		kr_log_error("[ io ] listen TCP (fastopen): %s\n", strerror(errno));
+		kr_log_error("[ io ] listen TCP (fastopen): %s%s\n", strerror(errno),
+			(errno != EPERM ? "" :
+			 ".  This may be caused by TCP Fast Open being disabled in the OS."));
 	}
 #endif