Commit 1fa1fe8f authored by John Fastabend's avatar John Fastabend Committed by Daniel Borkmann
Browse files

bpf, sockmap: Test shutdown() correctly exits epoll and recv()=0 



When session gracefully shutdowns epoll needs to wake up and any recv()
readers should return 0 not the -EAGAIN they previously returned.

Note we use epoll instead of select to test the epoll wake on shutdown
event as well.

Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarJakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-12-john.fastabend@gmail.com
parent 298970c8

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

+62 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
// Copyright (c) 2020 Cloudflare

#include <error.h>

#include <netinet/tcp.h>

#include <sys/epoll.h>



#include "test_progs.h"

#include "test_skmsg_load_helpers.skel.h"
@@ -9,8 +10,11 @@ 
#include "test_sockmap_invalid_update.skel.h"

#include "test_sockmap_skb_verdict_attach.skel.h"

#include "test_sockmap_progs_query.skel.h"

#include "test_sockmap_pass_prog.skel.h"

#include "bpf_iter_sockmap.skel.h"



#include "sockmap_helpers.h"



#define TCP_REPAIR		19	/* TCP sock is under repair right now */



#define TCP_REPAIR_ON		1
@@ -350,6 +354,62 @@ static void test_sockmap_progs_query(enum bpf_attach_type attach_type) 
	test_sockmap_progs_query__destroy(skel);

}



#define MAX_EVENTS 10

static void test_sockmap_skb_verdict_shutdown(void)

{

	struct epoll_event ev, events[MAX_EVENTS];

	int n, err, map, verdict, s, c1, p1;

	struct test_sockmap_pass_prog *skel;

	int epollfd;

	int zero = 0;

	char b;



	skel = test_sockmap_pass_prog__open_and_load();

	if (!ASSERT_OK_PTR(skel, "open_and_load"))

		return;



	verdict = bpf_program__fd(skel->progs.prog_skb_verdict);

	map = bpf_map__fd(skel->maps.sock_map_rx);



	err = bpf_prog_attach(verdict, map, BPF_SK_SKB_STREAM_VERDICT, 0);

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

		goto out;



	s = socket_loopback(AF_INET, SOCK_STREAM);

	if (s < 0)

		goto out;

	err = create_pair(s, AF_INET, SOCK_STREAM, &c1, &p1);

	if (err < 0)

		goto out;



	err = bpf_map_update_elem(map, &zero, &c1, BPF_NOEXIST);

	if (err < 0)

		goto out_close;



	shutdown(p1, SHUT_WR);



	ev.events = EPOLLIN;

	ev.data.fd = c1;



	epollfd = epoll_create1(0);

	if (!ASSERT_GT(epollfd, -1, "epoll_create(0)"))

		goto out_close;

	err = epoll_ctl(epollfd, EPOLL_CTL_ADD, c1, &ev);

	if (!ASSERT_OK(err, "epoll_ctl(EPOLL_CTL_ADD)"))

		goto out_close;

	err = epoll_wait(epollfd, events, MAX_EVENTS, -1);

	if (!ASSERT_EQ(err, 1, "epoll_wait(fd)"))

		goto out_close;



	n = recv(c1, &b, 1, SOCK_NONBLOCK);

	ASSERT_EQ(n, 0, "recv_timeout(fin)");

out_close:

	close(c1);

	close(p1);

out:

	test_sockmap_pass_prog__destroy(skel);

}



void test_sockmap_basic(void)

{

	if (test__start_subtest("sockmap create_update_free"))
@@ -384,4 +444,6 @@ void test_sockmap_basic(void) 
		test_sockmap_progs_query(BPF_SK_SKB_STREAM_VERDICT);

	if (test__start_subtest("sockmap skb_verdict progs query"))

		test_sockmap_progs_query(BPF_SK_SKB_VERDICT);

	if (test__start_subtest("sockmap skb_verdict shutdown"))

		test_sockmap_skb_verdict_shutdown();

}

tools/testing/selftests/bpf/progs/test_sockmap_pass_prog.c

0 → 100644
+32 −0
Original line number Diff line number Diff line 
#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_endian.h>



struct {

	__uint(type, BPF_MAP_TYPE_SOCKMAP);

	__uint(max_entries, 20);

	__type(key, int);

	__type(value, int);

} sock_map_rx SEC(".maps");



struct {

	__uint(type, BPF_MAP_TYPE_SOCKMAP);

	__uint(max_entries, 20);

	__type(key, int);

	__type(value, int);

} sock_map_tx SEC(".maps");



struct {

	__uint(type, BPF_MAP_TYPE_SOCKMAP);

	__uint(max_entries, 20);

	__type(key, int);

	__type(value, int);

} sock_map_msg SEC(".maps");



SEC("sk_skb")

int prog_skb_verdict(struct __sk_buff *skb)

{

	return SK_PASS;

}



char _license[] SEC("license") = "GPL";