From fc29bfef9d56d6bd1bd00ae6e9d7dde67d01fcac Mon Sep 17 00:00:00 2001
From: Rocker Zhang <zhang.rocker.liyuan@gmail.com>
Date: Fri, 5 Jun 2026 00:51:31 +0800
Subject: [PATCH] zdtm: add test for SO_SNDTIMEO and SO_RCVTIMEO

CRIU dumps and restores the SO_SNDTIMEO and SO_RCVTIMEO socket
send/receive timeout options in dump_socket_opts()/restore_socket_opts()
(criu/sockets.c), but the ZDTM suite has no dedicated coverage for them:
SO_SNDTIMEO is not exercised by any test, and SO_RCVTIMEO is only used
incidentally as a receive timeout in socket_icmp, never asserted across
checkpoint/restore.

Add socket-timeo, which sets distinct send and receive timeouts on a
socket, performs checkpoint/restore, and verifies both values survive.
Whole-second timeouts are used because the kernel stores these options
with jiffy granularity: setsockopt() may round a sub-second value to the
nearest tick depending on HZ, so a literal sub-second expectation could
fail to match the stored value regardless of checkpoint/restore. The
send and receive values differ so a mix-up between the two options is
caught.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Rocker Zhang <zhang.rocker.liyuan@gmail.com>
---
 test/zdtm/static/Makefile       |  1 +
 test/zdtm/static/socket-timeo.c | 75 +++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)
 create mode 100644 test/zdtm/static/socket-timeo.c

diff --git a/test/zdtm/static/Makefile b/test/zdtm/static/Makefile
index 947cafd37..0e2580ed6 100644
--- a/test/zdtm/static/Makefile
+++ b/test/zdtm/static/Makefile
@@ -137,6 +137,7 @@ TST_NOFILE	:=				\
 		socket-tcp-skip-in-flight	\
 		socket-tcp-keepalive		\
 		socket-linger			\
+		socket-timeo			\
 		sock_opts00			\
 		sock_opts01			\
 		sock_opts02			\
diff --git a/test/zdtm/static/socket-timeo.c b/test/zdtm/static/socket-timeo.c
new file mode 100644
index 000000000..8fcaf2f6e
--- /dev/null
+++ b/test/zdtm/static/socket-timeo.c
@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <netinet/in.h>
+
+#include "zdtmtst.h"
+
+const char *test_doc = "Check SO_SNDTIMEO and SO_RCVTIMEO socket options";
+const char *test_author = "Rocker Zhang <zhang.rocker.liyuan@gmail.com>";
+
+/*
+ * Whole-second timeouts are used on purpose. The kernel stores
+ * SO_SNDTIMEO/SO_RCVTIMEO with jiffy granularity, so setsockopt() may
+ * round a sub-second tv_usec to the nearest tick depending on HZ. Such a
+ * value would still survive checkpoint/restore (CRIU saves and restores
+ * whatever the kernel reports), but a literal sub-second expectation in
+ * this test could fail to match the rounded value. Whole seconds avoid
+ * that ambiguity. Distinct send/receive values catch a possible mix-up
+ * between the two options.
+ */
+static int check_timeo(int sk, int opt, const char *name, const struct timeval *want)
+{
+	struct timeval got = { 0, 0 };
+	socklen_t optlen = sizeof(got);
+
+	if (getsockopt(sk, SOL_SOCKET, opt, &got, &optlen) < 0) {
+		pr_perror("getsockopt %s", name);
+		return -1;
+	}
+
+	if (got.tv_sec != want->tv_sec || got.tv_usec != want->tv_usec) {
+		fail("%s has incorrect value (%ld.%06ld != %ld.%06ld)", name, (long)got.tv_sec, (long)got.tv_usec,
+		     (long)want->tv_sec, (long)want->tv_usec);
+		return -1;
+	}
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int sk;
+	struct timeval sndtimeo = { 7, 0 }, rcvtimeo = { 11, 0 };
+
+	test_init(argc, argv);
+
+	sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+	if (sk < 0) {
+		pr_perror("Can't create socket");
+		return 1;
+	}
+
+	if (setsockopt(sk, SOL_SOCKET, SO_SNDTIMEO, &sndtimeo, sizeof(sndtimeo)) < 0) {
+		pr_perror("setsockopt SO_SNDTIMEO");
+		return 1;
+	}
+
+	if (setsockopt(sk, SOL_SOCKET, SO_RCVTIMEO, &rcvtimeo, sizeof(rcvtimeo)) < 0) {
+		pr_perror("setsockopt SO_RCVTIMEO");
+		return 1;
+	}
+
+	test_daemon();
+	test_waitsig();
+
+	if (check_timeo(sk, SO_SNDTIMEO, "SO_SNDTIMEO", &sndtimeo))
+		return 1;
+
+	if (check_timeo(sk, SO_RCVTIMEO, "SO_RCVTIMEO", &rcvtimeo))
+		return 1;
+
+	pass();
+	return 0;
+}