Commit c01cfc48 authored by Zhenzhong Wu's avatar Zhenzhong Wu Committed by Jakub Kicinski
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selftests/bpf: check epoll readiness during reuseport migration 



Inside migrate_dance(), add epoll checks around shutdown() to
verify that the target listener is not ready before shutdown()
and becomes ready immediately after shutdown() triggers migration.

Cover TCP_ESTABLISHED and TCP_SYN_RECV. Exclude TCP_NEW_SYN_RECV
as it depends on later handshake completion.

Suggested-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: default avatarZhenzhong Wu <jt26wzz@gmail.com>
Link: https://patch.msgid.link/20260422024554.130346-3-jt26wzz@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 3864c6ba

tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c

+42 −7
Original line number Diff line number Diff line
@@ -7,24 +7,29 @@ 
 *   3. call listen() for 1 server socket. (migration target)

 *   4. update a map to migrate all child sockets

 *        to the last server socket (migrate_map[cookie] = 4)

 *   5. call shutdown() for first 4 server sockets

 *   5. for TCP_ESTABLISHED and TCP_SYN_RECV cases, verify via epoll

 *        that the last server socket is not ready before migration.

 *   6. call shutdown() for first 4 server sockets

 *        and migrate the requests in the accept queue

 *        to the last server socket.

 *   6. call listen() for the second server socket.

 *   7. call shutdown() for the last server

 *   7. for TCP_ESTABLISHED and TCP_SYN_RECV cases, verify via epoll

 *        that the last server socket is ready after migration.

 *   8. call listen() for the second server socket.

 *   9. call shutdown() for the last server

 *        and migrate the requests in the accept queue

 *        to the second server socket.

 *   8. call listen() for the last server.

 *   9. call shutdown() for the second server

 *  10. call listen() for the last server.

 *  11. call shutdown() for the second server

 *        and migrate the requests in the accept queue

 *        to the last server socket.

 *  10. call accept() for the last server socket.

 *  12. call accept() for the last server socket.

 *

 * Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

 */



#include <bpf/bpf.h>

#include <bpf/libbpf.h>

#include <sys/epoll.h>



#include "test_progs.h"

#include "test_migrate_reuseport.skel.h"
@@ -350,21 +355,51 @@ static int update_maps(struct migrate_reuseport_test_case *test_case, 


static int migrate_dance(struct migrate_reuseport_test_case *test_case)

{

	struct epoll_event ev = {

		.events = EPOLLIN,

	};

	int epoll = -1, nfds;

	int i, err;



	if (test_case->state != BPF_TCP_NEW_SYN_RECV) {

		epoll = epoll_create1(0);

		if (!ASSERT_NEQ(epoll, -1, "epoll_create1"))

			return -1;



		ev.data.fd = test_case->servers[MIGRATED_TO];

		if (!ASSERT_OK(epoll_ctl(epoll, EPOLL_CTL_ADD,

					 test_case->servers[MIGRATED_TO], &ev),

			       "epoll_ctl"))

			goto close_epoll;



		nfds = epoll_wait(epoll, &ev, 1, 0);

		if (!ASSERT_EQ(nfds, 0, "epoll_wait 1"))

			goto close_epoll;

	}



	/* Migrate TCP_ESTABLISHED and TCP_SYN_RECV requests

	 * to the last listener based on eBPF.

	 */

	for (i = 0; i < MIGRATED_TO; i++) {

		err = shutdown(test_case->servers[i], SHUT_RDWR);

		if (!ASSERT_OK(err, "shutdown"))

			return -1;

			goto close_epoll;

	}



	/* No dance for TCP_NEW_SYN_RECV to migrate based on eBPF */

	if (test_case->state == BPF_TCP_NEW_SYN_RECV)

		return 0;



	nfds = epoll_wait(epoll, &ev, 1, 0);

	if (!ASSERT_EQ(nfds, 1, "epoll_wait 2")) {

close_epoll:

		if (epoll >= 0)

			close(epoll);

		return -1;

	}



	close(epoll);



	/* Note that we use the second listener instead of the

	 * first one here.

	 *