[LTP] [PATCH v1] Add epoll_ctl06 test

[Andrea Cervesato]

The epoll_ctl06 test verifies that EPOLLRDHUP event is correctly
recognised by epoll.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 .../kernel/syscalls/epoll_ctl/.gitignore      |  1 +
 .../kernel/syscalls/epoll_ctl/epoll_ctl06.c   | 86 +++++++++++++++++++
 2 files changed, 87 insertions(+)
 create mode 100644 testcases/kernel/syscalls/epoll_ctl/epoll_ctl06.c

diff --git a/testcases/kernel/syscalls/epoll_ctl/.gitignore b/testcases/kernel/syscalls/epoll_ctl/.gitignore
index 3e05f2e1f..9c555f41b 100644
--- a/testcases/kernel/syscalls/epoll_ctl/.gitignore
+++ b/testcases/kernel/syscalls/epoll_ctl/.gitignore
@@ -3,3 +3,4 @@ epoll_ctl02
 epoll_ctl03
 epoll_ctl04
 epoll_ctl05
+epoll_ctl06
diff --git a/testcases/kernel/syscalls/epoll_ctl/epoll_ctl06.c b/testcases/kernel/syscalls/epoll_ctl/epoll_ctl06.c
new file mode 100644
index 000000000..b3cb80a36
--- /dev/null
+++ b/testcases/kernel/syscalls/epoll_ctl/epoll_ctl06.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2022 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify that epoll receives EPOLLRDHUP event when we hang a reading
+ * half-socket we are polling on.
+ */
+
+#include <poll.h>
+#include <sys/epoll.h>
+#include "tst_test.h"
+
+static int sockfd;
+static int epfd;
+
+static void setup(void)
+{
+	sockfd = SAFE_SOCKET(AF_INET, SOCK_STREAM, 0);
+}
+
+static void cleanup(void)
+{
+	if (epfd > 0)
+		SAFE_CLOSE(epfd);
+
+	if (sockfd > 0)
+		SAFE_CLOSE(sockfd);
+}
+
+static void run(void)
+{
+	int res;
+	pid_t pid;
+	struct epoll_event evt_req;
+	struct epoll_event evt_rec;
+
+	pid = SAFE_FORK();
+	if (pid != 0) {
+		TST_CHECKPOINT_WAIT(0);
+
+		tst_res(TINFO, "Hang reading half-socket");
+		shutdown(sockfd, SHUT_RD);
+
+		TST_CHECKPOINT_WAKE(0);
+
+		return;
+	}
+
+	epfd = epoll_create1(0);
+	if (epfd == -1)
+		tst_brk(TBROK | TERRNO, "fail to create epoll instance");
+
+	tst_res(TINFO, "Looking at EPOLLRDHUP events");
+
+	evt_req.events = EPOLLRDHUP;
+	res = epoll_ctl(epfd, EPOLL_CTL_ADD, sockfd, &evt_req);
+	if (res == -1)
+		tst_brk(TBROK | TERRNO, "epoll_ctl failure");
+
+	TST_CHECKPOINT_WAKE_AND_WAIT(0);
+
+	res = epoll_wait(epfd, &evt_rec, 1, 2000);
+	if (res <= 0) {
+		tst_res(TFAIL | TERRNO, "epoll_wait() returned %i", res);
+		return;
+	}
+
+	if (evt_rec.events & evt_req.events)
+		tst_res(TPASS, "Received EPOLLRDHUP");
+	else
+		tst_res(TFAIL, "EPOLLRDHUP has not been received");
+
+	SAFE_CLOSE(epfd);
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run,
+	.forks_child = 1,
+	.needs_checkpoints = 1,
+};
-- 
2.35.3