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

// SPDX-License-Identifier: GPL-2.0
#include <poll.h>
#include <test_progs.h>
#include <bpf/bpf_endian.h>

#include "sock_destroy_prog.skel.h"
#include "sock_destroy_prog_fail.skel.h"
#include "network_helpers.h"

#define TEST_NS "sock_destroy_netns"

static void start_iter_sockets(struct bpf_program *prog)
{
	struct bpf_link *link;
	char buf[50] = {};
	int iter_fd, len;

	link = bpf_program__attach_iter(prog, NULL);
	if (!ASSERT_OK_PTR(link, "attach_iter"))
		return;

	iter_fd = bpf_iter_create(bpf_link__fd(link));
	if (!ASSERT_GE(iter_fd, 0, "create_iter"))
		goto free_link;

	while ((len = read(iter_fd, buf, sizeof(buf))) > 0)
		;
	ASSERT_GE(len, 0, "read");

	close(iter_fd);

free_link:
	bpf_link__destroy(link);
}

static void test_tcp_client(struct sock_destroy_prog *skel)
{
	int serv = -1, clien = -1, accept_serv = -1, n;

	serv = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
	if (!ASSERT_GE(serv, 0, "start_server"))
		goto cleanup;

	clien = connect_to_fd(serv, 0);
	if (!ASSERT_GE(clien, 0, "connect_to_fd"))
		goto cleanup;

	accept_serv = accept(serv, NULL, NULL);
	if (!ASSERT_GE(accept_serv, 0, "serv accept"))
		goto cleanup;

	n = send(clien, "t", 1, 0);
	if (!ASSERT_EQ(n, 1, "client send"))
		goto cleanup;

	/* Run iterator program that destroys connected client sockets. */
	start_iter_sockets(skel->progs.iter_tcp6_client);

	n = send(clien, "t", 1, 0);
	if (!ASSERT_LT(n, 0, "client_send on destroyed socket"))
		goto cleanup;
	ASSERT_EQ(errno, ECONNABORTED, "error code on destroyed socket");

cleanup:
	if (clien != -1)
		close(clien);
	if (accept_serv != -1)
		close(accept_serv);
	if (serv != -1)
		close(serv);
}

static void test_tcp_server(struct sock_destroy_prog *skel)
{
	int serv = -1, clien = -1, accept_serv = -1, n, serv_port;

	serv = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
	if (!ASSERT_GE(serv, 0, "start_server"))
		goto cleanup;
	serv_port = get_socket_local_port(serv);
	if (!ASSERT_GE(serv_port, 0, "get_sock_local_port"))
		goto cleanup;
	skel->bss->serv_port = (__be16) serv_port;

	clien = connect_to_fd(serv, 0);
	if (!ASSERT_GE(clien, 0, "connect_to_fd"))
		goto cleanup;

	accept_serv = accept(serv, NULL, NULL);
	if (!ASSERT_GE(accept_serv, 0, "serv accept"))
		goto cleanup;

	n = send(clien, "t", 1, 0);
	if (!ASSERT_EQ(n, 1, "client send"))
		goto cleanup;

	/* Run iterator program that destroys server sockets. */
	start_iter_sockets(skel->progs.iter_tcp6_server);

	n = send(clien, "t", 1, 0);
	if (!ASSERT_LT(n, 0, "client_send on destroyed socket"))
		goto cleanup;
	ASSERT_EQ(errno, ECONNRESET, "error code on destroyed socket");

cleanup:
	if (clien != -1)
		close(clien);
	if (accept_serv != -1)
		close(accept_serv);
	if (serv != -1)
		close(serv);
}

static void test_tcp_listen_pending(struct sock_destroy_prog *skel)
{
	int serv = -1, clien = -1, accept_serv = -1, n, serv_port;
	struct pollfd pfd = { .events = POLLIN };
	char buf[1];

	serv = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
	if (!ASSERT_GE(serv, 0, "start_server"))
		goto cleanup;
	serv_port = get_socket_local_port(serv);
	if (!ASSERT_GE(serv_port, 0, "get_sock_local_port"))
		goto cleanup;
	skel->bss->serv_port = (__be16)serv_port;

	/*
	 * Connect but never accept, so the child sits in the accept queue
	 * of the listener. Wait until it's actually there.
	 */
	clien = connect_to_fd(serv, 0);
	if (!ASSERT_GE(clien, 0, "connect_to_fd"))
		goto cleanup;
	pfd.fd = serv;
	if (!ASSERT_EQ(poll(&pfd, 1, -1), 1, "poll listener"))
		goto cleanup;

	/* Run iterator program that destroys server sockets. */
	start_iter_sockets(skel->progs.iter_tcp6_server);

	accept_serv = accept(serv, NULL, NULL);
	if (!ASSERT_LT(accept_serv, 0, "accept on destroyed listener"))
		goto cleanup;
	ASSERT_EQ(errno, EINVAL, "error code on destroyed listener");

	/* The unaccepted child was reset along with the listener. */
	n = recv(clien, buf, sizeof(buf), 0);
	if (!ASSERT_LT(n, 0, "client recv on reset child"))
		goto cleanup;
	ASSERT_EQ(errno, ECONNRESET, "error code on reset child");

cleanup:
	if (clien != -1)
		close(clien);
	if (accept_serv != -1)
		close(accept_serv);
	if (serv != -1)
		close(serv);
}

static void test_tcp_timewait(struct sock_destroy_prog *skel)
{
	int serv = -1, clien = -1, accept_serv = -1, n;
	struct timeval tv = {};
	char buf[1];

	serv = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
	if (!ASSERT_GE(serv, 0, "start_server"))
		goto cleanup;

	clien = connect_to_fd(serv, 0);
	if (!ASSERT_GE(clien, 0, "connect_to_fd"))
		goto cleanup;

	accept_serv = accept(serv, NULL, NULL);
	if (!ASSERT_GE(accept_serv, 0, "serv accept"))
		goto cleanup;

	/*
	 * Active close from the client, then close the server side. Once
	 * recv() sees EOF the server FIN has been processed and the client
	 * sock is in TIME_WAIT. Block without timeout so a loaded CI box
	 * can't race us.
	 */
	if (!ASSERT_OK(setsockopt(clien, SOL_SOCKET, SO_RCVTIMEO, &tv,
				  sizeof(tv)), "clear rcvtimeo"))
		goto cleanup;
	if (!ASSERT_OK(shutdown(clien, SHUT_WR), "client shutdown"))
		goto cleanup;

	/*
	 * Make sure the server has seen the client FIN before it closes,
	 * so the two FINs never cross.
	 */
	n = recv(accept_serv, buf, sizeof(buf), 0);
	if (!ASSERT_EQ(n, 0, "server recv EOF"))
		goto cleanup;

	close(accept_serv);
	accept_serv = -1;

	/* block until return EOF */
	n = recv(clien, buf, sizeof(buf), 0);
	if (!ASSERT_EQ(n, 0, "client recv EOF"))
		goto cleanup;

	/* Run iterator program that destroys the timewait client sock. */
	skel->bss->tw_found = 0;
	start_iter_sockets(skel->progs.iter_tcp6_timewait);
	if (!ASSERT_EQ(skel->bss->tw_found, 1, "timewait sock found"))
		goto cleanup;

	ASSERT_OK(skel->bss->tw_destroy_err, "destroy timewait sock");

	/* The destroyed timewait sock must be gone. */
	skel->bss->tw_found = 0;
	start_iter_sockets(skel->progs.iter_tcp6_timewait);
	ASSERT_EQ(skel->bss->tw_found, 0, "timewait sock destroyed");

cleanup:
	if (clien != -1)
		close(clien);
	if (accept_serv != -1)
		close(accept_serv);
	if (serv != -1)
		close(serv);
}

static void test_udp_client(struct sock_destroy_prog *skel)
{
	int serv = -1, clien = -1, n = 0;

	serv = start_server(AF_INET6, SOCK_DGRAM, NULL, 0, 0);
	if (!ASSERT_GE(serv, 0, "start_server"))
		goto cleanup;

	clien = connect_to_fd(serv, 0);
	if (!ASSERT_GE(clien, 0, "connect_to_fd"))
		goto cleanup;

	n = send(clien, "t", 1, 0);
	if (!ASSERT_EQ(n, 1, "client send"))
		goto cleanup;

	/* Run iterator program that destroys sockets. */
	start_iter_sockets(skel->progs.iter_udp6_client);

	n = send(clien, "t", 1, 0);
	if (!ASSERT_LT(n, 0, "client_send on destroyed socket"))
		goto cleanup;
	/* UDP sockets have an overriding error code after they are disconnected,
	 * so we don't check for ECONNABORTED error code.
	 */

cleanup:
	if (clien != -1)
		close(clien);
	if (serv != -1)
		close(serv);
}

static void test_udp_server(struct sock_destroy_prog *skel)
{
	int *listen_fds = NULL, n, i, serv_port;
	unsigned int num_listens = 5;
	char buf[1];

	/* Start reuseport servers. */
	listen_fds = start_reuseport_server(AF_INET6, SOCK_DGRAM,
					    "::1", 0, 0, num_listens);
	if (!ASSERT_OK_PTR(listen_fds, "start_reuseport_server"))
		goto cleanup;
	serv_port = get_socket_local_port(listen_fds[0]);
	if (!ASSERT_GE(serv_port, 0, "get_sock_local_port"))
		goto cleanup;
	skel->bss->serv_port = (__be16) serv_port;

	/* Run iterator program that destroys server sockets. */
	start_iter_sockets(skel->progs.iter_udp6_server);

	for (i = 0; i < num_listens; ++i) {
		n = read(listen_fds[i], buf, sizeof(buf));
		if (!ASSERT_EQ(n, -1, "read") ||
		    !ASSERT_EQ(errno, ECONNABORTED, "error code on destroyed socket"))
			break;
	}
	ASSERT_EQ(i, num_listens, "server socket");

cleanup:
	free_fds(listen_fds, num_listens);
}

void test_sock_destroy(void)
{
	struct sock_destroy_prog *skel;
	struct nstoken *nstoken = NULL;
	int cgroup_fd;

	skel = sock_destroy_prog__open_and_load();
	if (!ASSERT_OK_PTR(skel, "skel_open"))
		return;

	cgroup_fd = test__join_cgroup("/sock_destroy");
	if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup"))
		goto cleanup;

	skel->links.sock_connect = bpf_program__attach_cgroup(
		skel->progs.sock_connect, cgroup_fd);
	if (!ASSERT_OK_PTR(skel->links.sock_connect, "prog_attach"))
		goto cleanup;

	SYS(cleanup, "ip netns add %s", TEST_NS);
	SYS(cleanup, "ip -net %s link set dev lo up", TEST_NS);

	nstoken = open_netns(TEST_NS);
	if (!ASSERT_OK_PTR(nstoken, "open_netns"))
		goto cleanup;

	if (test__start_subtest("tcp_client"))
		test_tcp_client(skel);
	if (test__start_subtest("tcp_server"))
		test_tcp_server(skel);
	if (test__start_subtest("tcp_listen_pending"))
		test_tcp_listen_pending(skel);
	if (test__start_subtest("tcp_timewait"))
		test_tcp_timewait(skel);
	if (test__start_subtest("udp_client"))
		test_udp_client(skel);
	if (test__start_subtest("udp_server"))
		test_udp_server(skel);

	RUN_TESTS(sock_destroy_prog_fail);

cleanup:
	if (nstoken)
		close_netns(nstoken);
	SYS_NOFAIL("ip netns del " TEST_NS);
	if (cgroup_fd >= 0)
		close(cgroup_fd);
	sock_destroy_prog__destroy(skel);
}