bpf: Test BPF_SK_REUSEPORT_SELECT_OR_MIGRATE.

This patch adds a test for BPF_SK_REUSEPORT_SELECT_OR_MIGRATE.

Reviewed-by: Benjamin Herrenschmidt <[email protected]>
Signed-off-by: Kuniyuki Iwashima <[email protected]>

Author: q2ven

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

@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Check if we can migrate child sockets.
+ *
+ *   1. call listen() for 5 server sockets.
+ *   2. update a map to migrate all child socket
+ *        to the last server socket (migrate_map[cookie] = 4)
+ *   3. call connect() for 25 client sockets.
+ *   4. call close() for first 4 server sockets.
+ *   5. call accept() for the last server socket.
+ *
+ * Author: Kuniyuki Iwashima <[email protected]>
+ */
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "test_progs.h"
+#include "test_select_reuseport_migrate.skel.h"
+
+#define ADDRESS "127.0.0.1"
+#define PORT 80
+#define NUM_SERVERS 5
+#define NUM_CLIENTS (NUM_SERVERS * 5)
+
+
+static int test_listen(struct test_select_reuseport_migrate *skel, int server_fds[])
+{
+	int i, err, optval = 1, migrated_to = NUM_SERVERS - 1;
+	int prog_fd, reuseport_map_fd, migrate_map_fd;
+	struct sockaddr_in addr;
+	socklen_t addr_len;
+	__u64 value;
+
+	prog_fd = bpf_program__fd(skel->progs.prog_select_reuseport_migrate);
+	reuseport_map_fd = bpf_map__fd(skel->maps.reuseport_map);
+	migrate_map_fd = bpf_map__fd(skel->maps.migrate_map);
+
+	addr_len = sizeof(addr);
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(PORT);
+	inet_pton(AF_INET, ADDRESS, &addr.sin_addr.s_addr);
+
+	for (i = 0; i < NUM_SERVERS; i++) {
+		server_fds[i] = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+		if (CHECK_FAIL(server_fds[i] == -1))
+			return -1;
+
+		err = setsockopt(server_fds[i], SOL_SOCKET, SO_REUSEPORT,
+				 &optval, sizeof(optval));
+		if (CHECK_FAIL(err == -1))
+			return -1;
+
+		if (i == 0) {
+			err = setsockopt(server_fds[i], SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF,
+					 &prog_fd, sizeof(prog_fd));
+			if (CHECK_FAIL(err == -1))
+				return -1;
+		}
+
+		err = bind(server_fds[i], (struct sockaddr *)&addr, addr_len);
+		if (CHECK_FAIL(err == -1))
+			return -1;
+
+		err = listen(server_fds[i], 32);
+		if (CHECK_FAIL(err == -1))
+			return -1;
+
+		err = bpf_map_update_elem(reuseport_map_fd, &i, &server_fds[i], BPF_NOEXIST);
+		if (CHECK_FAIL(err == -1))
+			return -1;
+
+		err = bpf_map_lookup_elem(reuseport_map_fd, &i, &value);
+		if (CHECK_FAIL(err == -1))
+			return -1;
+
+		err = bpf_map_update_elem(migrate_map_fd, &value, &migrated_to, BPF_NOEXIST);
+		if (CHECK_FAIL(err == -1))
+			return -1;
+	}
+
+	return 0;
+}
+
+static int test_connect(int client_fds[])
+{
+	struct sockaddr_in addr;
+	socklen_t addr_len;
+	int i, err;
+
+	addr_len = sizeof(addr);
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(PORT);
+	inet_pton(AF_INET, ADDRESS, &addr.sin_addr.s_addr);
+
+	for (i = 0; i < NUM_CLIENTS; i++) {
+		client_fds[i] = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+		if (CHECK_FAIL(client_fds[i] == -1))
+			return -1;
+
+		err = connect(client_fds[i], (struct sockaddr *)&addr, addr_len);
+		if (CHECK_FAIL(err == -1))
+			return -1;
+	}
+
+	return 0;
+}
+
+static void test_close(int server_fds[], int num)
+{
+	int i;
+
+	for (i = 0; i < num; i++)
+		if (server_fds[i] > 0)
+			close(server_fds[i]);
+}
+
+static int test_accept(int server_fd)
+{
+	struct sockaddr_in addr;
+	socklen_t addr_len;
+	int cnt, client_fd;
+
+	fcntl(server_fd, F_SETFL, O_NONBLOCK);
+	addr_len = sizeof(addr);
+
+	for (cnt = 0; cnt < NUM_CLIENTS; cnt++) {
+		client_fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
+		if (CHECK_FAIL(client_fd == -1))
+			return -1;
+	}
+
+	return cnt;
+}
+
+
+void test_select_reuseport_migrate(void)
+{
+	struct test_select_reuseport_migrate *skel;
+	int server_fds[NUM_SERVERS] = {0};
+	int client_fds[NUM_CLIENTS] = {0};
+	__u32 duration = 0;
+	int err;
+
+	skel = test_select_reuseport_migrate__open_and_load();
+	if (CHECK_FAIL(!skel))
+		goto destroy;
+
+	err = test_listen(skel, server_fds);
+	if (err)
+		goto close_server;
+
+	err = test_connect(client_fds);
+	if (err)
+		goto close_client;
+
+	test_close(server_fds, NUM_SERVERS - 1);
+
+	err = test_accept(server_fds[NUM_SERVERS - 1]);
+	CHECK(err != NUM_CLIENTS,
+	      "accept",
+	      "expected (%d) != actual (%d)\n",
+	      NUM_CLIENTS, err);
+
+close_client:
+	test_close(client_fds, NUM_CLIENTS);
+
+close_server:
+	test_close(server_fds, NUM_SERVERS);
+
+destroy:
+	test_select_reuseport_migrate__destroy(skel);
+}

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

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Check if we can migrate child sockets.
+ *
+ *   1. If reuse_md->migration is 0 (SYN packet),
+ *        return SK_PASS without selecting a listener.
+ *   2. If reuse_md->migration is not 0 (socket migration),
+ *        select a listener (reuseport_map[migrate_map[cookie]])
+ *
+ * Author: Kuniyuki Iwashima <[email protected]>
+ */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define NULL ((void *)0)
+
+struct bpf_map_def SEC("maps") reuseport_map = {
+	.type = BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
+	.key_size = sizeof(int),
+	.value_size = sizeof(__u64),
+	.max_entries = 256,
+};
+
+struct bpf_map_def SEC("maps") migrate_map = {
+	.type = BPF_MAP_TYPE_HASH,
+	.key_size = sizeof(__u64),
+	.value_size = sizeof(int),
+	.max_entries = 256,
+};
+
+SEC("sk_reuseport/migrate")
+int prog_select_reuseport_migrate(struct sk_reuseport_md *reuse_md)
+{
+	int *key, flags = 0;
+	__u64 cookie;
+
+	if (!reuse_md->migration)
+		return SK_PASS;
+
+	cookie = bpf_get_socket_cookie(reuse_md->sk);
+
+	key = bpf_map_lookup_elem(&migrate_map, &cookie);
+	if (key == NULL)
+		return SK_DROP;
+
+	bpf_sk_select_reuseport(reuse_md, &reuseport_map, key, flags);
+
+	return SK_PASS;
+}
+
+int _version SEC("version") = 1;
+char _license[] SEC("license") = "GPL";