[PATCH bpf v5 10/12] bpf: sockmap, test shutdown() correctly exits epoll and recv()=0

John Fastabend
2023-04-06T01:01:53Z

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: John Fastabend <john.fastabend@gmail.com>
---
.../selftests/bpf/prog_tests/sockmap_basic.c | 68 +++++++++++++++++++
.../bpf/progs/test_sockmap_pass_prog.c | 32 +++++++++
2 files changed, 100 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_pass_prog.c

diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
index 0ce25a967481..f9f611618e45 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
@@ -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 +354,68 @@ 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)
+{
+ int n, err, map, verdict, s, c0, c1, p0, p1;
+ struct epoll_event ev, events[MAX_EVENTS];
+ 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_socket_pairs(s, AF_INET, SOCK_STREAM, &c0, &c1, &p0, &p1);
+ if (err < 0)
+ goto out;
+
+ err = bpf_map_update_elem(map, &zero, &c1, BPF_NOEXIST);
+ if (err < 0)
+ goto out_close;
+
+ shutdown(c0, SHUT_RDWR);
+ 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)");
+ n = recv(p0, &b, 1, SOCK_NONBLOCK);
+ ASSERT_EQ(n, 0, "recv_timeout(fin)");
+
+out_close:
+ close(c0);
+ close(p0);
+ 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 +450,6 @@ 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();
}
diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_pass_prog.c b/tools/testing/selftests/bpf/progs/test_sockmap_pass_prog.c
new file mode 100644
index 000000000000..1d86a717a290
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_sockmap_pass_prog.c
@@ -0,0 +1,32 @@
+#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";
--
2.33.0