linux/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019 Facebook */

#include <linux/err.h>
#include <netinet/tcp.h>
#include <test_progs.h>
#include "network_helpers.h"
#include "bpf_dctcp.skel.h"
#include "bpf_cubic.skel.h"
#include "bpf_tcp_nogpl.skel.h"
#include "tcp_ca_update.skel.h"
#include "bpf_dctcp_release.skel.h"
#include "tcp_ca_write_sk_pacing.skel.h"
#include "tcp_ca_incompl_cong_ops.skel.h"
#include "tcp_ca_unsupp_cong_op.skel.h"
#include "tcp_ca_kfunc.skel.h"
#include "bpf_cc_cubic.skel.h"

#ifndef ENOTSUPP
#define ENOTSUPP 524
#endif

static const unsigned int total_bytes = 10 * 1024 * 1024;
static int expected_stg = 0xeB9F;

struct cb_opts {
	const char *cc;
	int map_fd;
};

static int settcpca(int fd, const char *tcp_ca)
{
	int err;

	err = setsockopt(fd, IPPROTO_TCP, TCP_CONGESTION, tcp_ca, strlen(tcp_ca));
	if (!ASSERT_NEQ(err, -1, "setsockopt"))
		return -1;

	return 0;
}

static bool start_test(char *addr_str,
		       const struct network_helper_opts *srv_opts,
		       const struct network_helper_opts *cli_opts,
		       int *srv_fd, int *cli_fd)
{
	*srv_fd = start_server_str(AF_INET6, SOCK_STREAM, addr_str, 0, srv_opts);
	if (!ASSERT_NEQ(*srv_fd, -1, "start_server_str"))
		goto err;

	/* connect to server */
	*cli_fd = connect_to_fd_opts(*srv_fd, SOCK_STREAM, cli_opts);
	if (!ASSERT_NEQ(*cli_fd, -1, "connect_to_fd_opts"))
		goto err;

	return true;

err:
	if (*srv_fd != -1) {
		close(*srv_fd);
		*srv_fd = -1;
	}
	if (*cli_fd != -1) {
		close(*cli_fd);
		*cli_fd = -1;
	}
	return false;
}

static void do_test(const struct network_helper_opts *opts)
{
	int lfd = -1, fd = -1;

	if (!start_test(NULL, opts, opts, &lfd, &fd))
		goto done;

	ASSERT_OK(send_recv_data(lfd, fd, total_bytes), "send_recv_data");

done:
	if (lfd != -1)
		close(lfd);
	if (fd != -1)
		close(fd);
}

static int cc_cb(int fd, void *opts)
{
	struct cb_opts *cb_opts = (struct cb_opts *)opts;

	return settcpca(fd, cb_opts->cc);
}

static void test_cubic(void)
{
	struct cb_opts cb_opts = {
		.cc = "bpf_cubic",
	};
	struct network_helper_opts opts = {
		.post_socket_cb	= cc_cb,
		.cb_opts	= &cb_opts,
	};
	struct bpf_cubic *cubic_skel;
	struct bpf_link *link;

	cubic_skel = bpf_cubic__open_and_load();
	if (!ASSERT_OK_PTR(cubic_skel, "bpf_cubic__open_and_load"))
		return;

	link = bpf_map__attach_struct_ops(cubic_skel->maps.cubic);
	if (!ASSERT_OK_PTR(link, "bpf_map__attach_struct_ops")) {
		bpf_cubic__destroy(cubic_skel);
		return;
	}

	do_test(&opts);

	ASSERT_EQ(cubic_skel->bss->bpf_cubic_acked_called, 1, "pkts_acked called");

	bpf_link__destroy(link);
	bpf_cubic__destroy(cubic_skel);
}

static int stg_post_socket_cb(int fd, void *opts)
{
	struct cb_opts *cb_opts = (struct cb_opts *)opts;
	int err;

	err = settcpca(fd, cb_opts->cc);
	if (err)
		return err;

	err = bpf_map_update_elem(cb_opts->map_fd, &fd,
				  &expected_stg, BPF_NOEXIST);
	if (!ASSERT_OK(err, "bpf_map_update_elem(sk_stg_map)"))
		return err;

	return 0;
}

static void test_dctcp(void)
{
	struct cb_opts cb_opts = {
		.cc = "bpf_dctcp",
	};
	struct network_helper_opts opts = {
		.post_socket_cb	= cc_cb,
		.cb_opts	= &cb_opts,
	};
	struct network_helper_opts cli_opts = {
		.post_socket_cb	= stg_post_socket_cb,
		.cb_opts	= &cb_opts,
	};
	int lfd = -1, fd = -1, tmp_stg, err;
	struct bpf_dctcp *dctcp_skel;
	struct bpf_link *link;

	dctcp_skel = bpf_dctcp__open_and_load();
	if (!ASSERT_OK_PTR(dctcp_skel, "bpf_dctcp__open_and_load"))
		return;

	link = bpf_map__attach_struct_ops(dctcp_skel->maps.dctcp);
	if (!ASSERT_OK_PTR(link, "bpf_map__attach_struct_ops")) {
		bpf_dctcp__destroy(dctcp_skel);
		return;
	}

	cb_opts.map_fd = bpf_map__fd(dctcp_skel->maps.sk_stg_map);
	if (!start_test(NULL, &opts, &cli_opts, &lfd, &fd))
		goto done;

	err = bpf_map_lookup_elem(cb_opts.map_fd, &fd, &tmp_stg);
	if (!ASSERT_ERR(err, "bpf_map_lookup_elem(sk_stg_map)") ||
			!ASSERT_EQ(errno, ENOENT, "bpf_map_lookup_elem(sk_stg_map)"))
		goto done;

	ASSERT_OK(send_recv_data(lfd, fd, total_bytes), "send_recv_data");
	ASSERT_EQ(dctcp_skel->bss->stg_result, expected_stg, "stg_result");

done:
	bpf_link__destroy(link);
	bpf_dctcp__destroy(dctcp_skel);
	if (lfd != -1)
		close(lfd);
	if (fd != -1)
		close(fd);
}

static void test_dctcp_autoattach_map(void)
{
	struct cb_opts cb_opts = {
		.cc = "bpf_dctcp",
	};
	struct network_helper_opts opts = {
		.post_socket_cb	= cc_cb,
		.cb_opts	= &cb_opts,
	};
	struct bpf_dctcp *dctcp_skel;
	struct bpf_link *link;

	dctcp_skel = bpf_dctcp__open_and_load();
	if (!ASSERT_OK_PTR(dctcp_skel, "bpf_dctcp__open_and_load"))
		return;

	bpf_map__set_autoattach(dctcp_skel->maps.dctcp, true);
	bpf_map__set_autoattach(dctcp_skel->maps.dctcp_nouse, false);

	if (!ASSERT_OK(bpf_dctcp__attach(dctcp_skel), "bpf_dctcp__attach"))
		goto destroy;

	/* struct_ops is auto-attached  */
	link = dctcp_skel->links.dctcp;
	if (!ASSERT_OK_PTR(link, "link"))
		goto destroy;

	do_test(&opts);

destroy:
	bpf_dctcp__destroy(dctcp_skel);
}

static char *err_str;
static bool found;

static int libbpf_debug_print(enum libbpf_print_level level,
			      const char *format, va_list args)
{
	const char *prog_name, *log_buf;

	if (level != LIBBPF_WARN ||
	    !strstr(format, "-- BEGIN PROG LOAD LOG --")) {
		vprintf(format, args);
		return 0;
	}

	prog_name = va_arg(args, char *);
	log_buf = va_arg(args, char *);
	if (!log_buf)
		goto out;
	if (err_str && strstr(log_buf, err_str) != NULL)
		found = true;
out:
	printf(format, prog_name, log_buf);
	return 0;
}

static void test_invalid_license(void)
{
	libbpf_print_fn_t old_print_fn;
	struct bpf_tcp_nogpl *skel;

	err_str = "struct ops programs must have a GPL compatible license";
	found = false;
	old_print_fn = libbpf_set_print(libbpf_debug_print);

	skel = bpf_tcp_nogpl__open_and_load();
	ASSERT_NULL(skel, "bpf_tcp_nogpl");
	ASSERT_EQ(found, true, "expected_err_msg");

	bpf_tcp_nogpl__destroy(skel);
	libbpf_set_print(old_print_fn);
}

static void test_dctcp_fallback(void)
{
	int err, lfd = -1, cli_fd = -1, srv_fd = -1;
	struct bpf_dctcp *dctcp_skel;
	struct bpf_link *link = NULL;
	struct cb_opts dctcp = {
		.cc = "bpf_dctcp",
	};
	struct network_helper_opts srv_opts = {
		.post_socket_cb = cc_cb,
		.cb_opts = &dctcp,
	};
	struct cb_opts cubic = {
		.cc = "cubic",
	};
	struct network_helper_opts cli_opts = {
		.post_socket_cb = cc_cb,
		.cb_opts = &cubic,
	};
	char srv_cc[16];
	socklen_t cc_len = sizeof(srv_cc);

	dctcp_skel = bpf_dctcp__open();
	if (!ASSERT_OK_PTR(dctcp_skel, "dctcp_skel"))
		return;
	strcpy(dctcp_skel->rodata->fallback, "cubic");
	if (!ASSERT_OK(bpf_dctcp__load(dctcp_skel), "bpf_dctcp__load"))
		goto done;

	link = bpf_map__attach_struct_ops(dctcp_skel->maps.dctcp);
	if (!ASSERT_OK_PTR(link, "dctcp link"))
		goto done;

	if (!start_test("::1", &srv_opts, &cli_opts, &lfd, &cli_fd))
		goto done;

	srv_fd = accept(lfd, NULL, 0);
	if (!ASSERT_GE(srv_fd, 0, "srv_fd"))
		goto done;
	ASSERT_STREQ(dctcp_skel->bss->cc_res, "cubic", "cc_res");
	ASSERT_EQ(dctcp_skel->bss->tcp_cdg_res, -ENOTSUPP, "tcp_cdg_res");
	/* All setsockopt(TCP_CONGESTION) in the recurred
	 * bpf_dctcp->init() should fail with -EBUSY.
	 */
	ASSERT_EQ(dctcp_skel->bss->ebusy_cnt, 3, "ebusy_cnt");

	err = getsockopt(srv_fd, SOL_TCP, TCP_CONGESTION, srv_cc, &cc_len);
	if (!ASSERT_OK(err, "getsockopt(srv_fd, TCP_CONGESTION)"))
		goto done;
	ASSERT_STREQ(srv_cc, "cubic", "srv_fd cc");

done:
	bpf_link__destroy(link);
	bpf_dctcp__destroy(dctcp_skel);
	if (lfd != -1)
		close(lfd);
	if (srv_fd != -1)
		close(srv_fd);
	if (cli_fd != -1)
		close(cli_fd);
}

static void test_rel_setsockopt(void)
{
	struct bpf_dctcp_release *rel_skel;
	libbpf_print_fn_t old_print_fn;

	err_str = "program of this type cannot use helper bpf_setsockopt";
	found = false;

	old_print_fn = libbpf_set_print(libbpf_debug_print);
	rel_skel = bpf_dctcp_release__open_and_load();
	libbpf_set_print(old_print_fn);

	ASSERT_ERR_PTR(rel_skel, "rel_skel");
	ASSERT_TRUE(found, "expected_err_msg");

	bpf_dctcp_release__destroy(rel_skel);
}

static void test_write_sk_pacing(void)
{
	struct tcp_ca_write_sk_pacing *skel;
	struct bpf_link *link;

	skel = tcp_ca_write_sk_pacing__open_and_load();
	if (!ASSERT_OK_PTR(skel, "open_and_load"))
		return;

	link = bpf_map__attach_struct_ops(skel->maps.write_sk_pacing);
	ASSERT_OK_PTR(link, "attach_struct_ops");

	bpf_link__destroy(link);
	tcp_ca_write_sk_pacing__destroy(skel);
}

static void test_incompl_cong_ops(void)
{
	struct tcp_ca_incompl_cong_ops *skel;
	struct bpf_link *link;

	skel = tcp_ca_incompl_cong_ops__open_and_load();
	if (!ASSERT_OK_PTR(skel, "open_and_load"))
		return;

	/* That cong_avoid() and cong_control() are missing is only reported at
	 * this point:
	 */
	link = bpf_map__attach_struct_ops(skel->maps.incompl_cong_ops);
	ASSERT_ERR_PTR(link, "attach_struct_ops");

	bpf_link__destroy(link);
	tcp_ca_incompl_cong_ops__destroy(skel);
}

static void test_unsupp_cong_op(void)
{
	libbpf_print_fn_t old_print_fn;
	struct tcp_ca_unsupp_cong_op *skel;

	err_str = "attach to unsupported member get_info";
	found = false;
	old_print_fn = libbpf_set_print(libbpf_debug_print);

	skel = tcp_ca_unsupp_cong_op__open_and_load();
	ASSERT_NULL(skel, "open_and_load");
	ASSERT_EQ(found, true, "expected_err_msg");

	tcp_ca_unsupp_cong_op__destroy(skel);
	libbpf_set_print(old_print_fn);
}

static void test_update_ca(void)
{
	struct cb_opts cb_opts = {
		.cc = "tcp_ca_update",
	};
	struct network_helper_opts opts = {
		.post_socket_cb	= cc_cb,
		.cb_opts	= &cb_opts,
	};
	struct tcp_ca_update *skel;
	struct bpf_link *link;
	int saved_ca1_cnt;
	int err;

	skel = tcp_ca_update__open_and_load();
	if (!ASSERT_OK_PTR(skel, "open"))
		return;

	link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
	if (!ASSERT_OK_PTR(link, "attach_struct_ops"))
		goto out;

	do_test(&opts);
	saved_ca1_cnt = skel->bss->ca1_cnt;
	ASSERT_GT(saved_ca1_cnt, 0, "ca1_ca1_cnt");

	err = bpf_link__update_map(link, skel->maps.ca_update_2);
	ASSERT_OK(err, "update_map");

	do_test(&opts);
	ASSERT_EQ(skel->bss->ca1_cnt, saved_ca1_cnt, "ca2_ca1_cnt");
	ASSERT_GT(skel->bss->ca2_cnt, 0, "ca2_ca2_cnt");

	bpf_link__destroy(link);
out:
	tcp_ca_update__destroy(skel);
}

static void test_update_wrong(void)
{
	struct cb_opts cb_opts = {
		.cc = "tcp_ca_update",
	};
	struct network_helper_opts opts = {
		.post_socket_cb	= cc_cb,
		.cb_opts	= &cb_opts,
	};
	struct tcp_ca_update *skel;
	struct bpf_link *link;
	int saved_ca1_cnt;
	int err;

	skel = tcp_ca_update__open_and_load();
	if (!ASSERT_OK_PTR(skel, "open"))
		return;

	link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
	if (!ASSERT_OK_PTR(link, "attach_struct_ops"))
		goto out;

	do_test(&opts);
	saved_ca1_cnt = skel->bss->ca1_cnt;
	ASSERT_GT(saved_ca1_cnt, 0, "ca1_ca1_cnt");

	err = bpf_link__update_map(link, skel->maps.ca_wrong);
	ASSERT_ERR(err, "update_map");

	do_test(&opts);
	ASSERT_GT(skel->bss->ca1_cnt, saved_ca1_cnt, "ca2_ca1_cnt");

	bpf_link__destroy(link);
out:
	tcp_ca_update__destroy(skel);
}

static void test_mixed_links(void)
{
	struct cb_opts cb_opts = {
		.cc = "tcp_ca_update",
	};
	struct network_helper_opts opts = {
		.post_socket_cb	= cc_cb,
		.cb_opts	= &cb_opts,
	};
	struct tcp_ca_update *skel;
	struct bpf_link *link, *link_nl;
	int err;

	skel = tcp_ca_update__open_and_load();
	if (!ASSERT_OK_PTR(skel, "open"))
		return;

	link_nl = bpf_map__attach_struct_ops(skel->maps.ca_no_link);
	if (!ASSERT_OK_PTR(link_nl, "attach_struct_ops_nl"))
		goto out;

	link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
	ASSERT_OK_PTR(link, "attach_struct_ops");

	do_test(&opts);
	ASSERT_GT(skel->bss->ca1_cnt, 0, "ca1_ca1_cnt");

	err = bpf_link__update_map(link, skel->maps.ca_no_link);
	ASSERT_ERR(err, "update_map");

	bpf_link__destroy(link);
	bpf_link__destroy(link_nl);
out:
	tcp_ca_update__destroy(skel);
}

static void test_multi_links(void)
{
	struct tcp_ca_update *skel;
	struct bpf_link *link;

	skel = tcp_ca_update__open_and_load();
	if (!ASSERT_OK_PTR(skel, "open"))
		return;

	link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
	ASSERT_OK_PTR(link, "attach_struct_ops_1st");
	bpf_link__destroy(link);

	/* A map should be able to be used to create links multiple
	 * times.
	 */
	link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
	ASSERT_OK_PTR(link, "attach_struct_ops_2nd");
	bpf_link__destroy(link);

	tcp_ca_update__destroy(skel);
}

static void test_link_replace(void)
{
	DECLARE_LIBBPF_OPTS(bpf_link_update_opts, opts);
	struct tcp_ca_update *skel;
	struct bpf_link *link;
	int err;

	skel = tcp_ca_update__open_and_load();
	if (!ASSERT_OK_PTR(skel, "open"))
		return;

	link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
	ASSERT_OK_PTR(link, "attach_struct_ops_1st");
	bpf_link__destroy(link);

	link = bpf_map__attach_struct_ops(skel->maps.ca_update_2);
	if (!ASSERT_OK_PTR(link, "attach_struct_ops_2nd"))
		goto out;

	/* BPF_F_REPLACE with a wrong old map Fd. It should fail!
	 *
	 * With BPF_F_REPLACE, the link should be updated only if the
	 * old map fd given here matches the map backing the link.
	 */
	opts.old_map_fd = bpf_map__fd(skel->maps.ca_update_1);
	opts.flags = BPF_F_REPLACE;
	err = bpf_link_update(bpf_link__fd(link),
			      bpf_map__fd(skel->maps.ca_update_1),
			      &opts);
	ASSERT_ERR(err, "bpf_link_update_fail");

	/* BPF_F_REPLACE with a correct old map Fd. It should success! */
	opts.old_map_fd = bpf_map__fd(skel->maps.ca_update_2);
	err = bpf_link_update(bpf_link__fd(link),
			      bpf_map__fd(skel->maps.ca_update_1),
			      &opts);
	ASSERT_OK(err, "bpf_link_update_success");

	bpf_link__destroy(link);

out:
	tcp_ca_update__destroy(skel);
}

static void test_tcp_ca_kfunc(void)
{
	struct tcp_ca_kfunc *skel;

	skel = tcp_ca_kfunc__open_and_load();
	ASSERT_OK_PTR(skel, "tcp_ca_kfunc__open_and_load");
	tcp_ca_kfunc__destroy(skel);
}

static void test_cc_cubic(void)
{
	struct cb_opts cb_opts = {
		.cc = "bpf_cc_cubic",
	};
	struct network_helper_opts opts = {
		.post_socket_cb	= cc_cb,
		.cb_opts	= &cb_opts,
	};
	struct bpf_cc_cubic *cc_cubic_skel;
	struct bpf_link *link;

	cc_cubic_skel = bpf_cc_cubic__open_and_load();
	if (!ASSERT_OK_PTR(cc_cubic_skel, "bpf_cc_cubic__open_and_load"))
		return;

	link = bpf_map__attach_struct_ops(cc_cubic_skel->maps.cc_cubic);
	if (!ASSERT_OK_PTR(link, "bpf_map__attach_struct_ops")) {
		bpf_cc_cubic__destroy(cc_cubic_skel);
		return;
	}

	do_test(&opts);

	bpf_link__destroy(link);
	bpf_cc_cubic__destroy(cc_cubic_skel);
}

void test_bpf_tcp_ca(void)
{
	if (test__start_subtest("dctcp"))
		test_dctcp();
	if (test__start_subtest("cubic"))
		test_cubic();
	if (test__start_subtest("invalid_license"))
		test_invalid_license();
	if (test__start_subtest("dctcp_fallback"))
		test_dctcp_fallback();
	if (test__start_subtest("rel_setsockopt"))
		test_rel_setsockopt();
	if (test__start_subtest("write_sk_pacing"))
		test_write_sk_pacing();
	if (test__start_subtest("incompl_cong_ops"))
		test_incompl_cong_ops();
	if (test__start_subtest("unsupp_cong_op"))
		test_unsupp_cong_op();
	if (test__start_subtest("update_ca"))
		test_update_ca();
	if (test__start_subtest("update_wrong"))
		test_update_wrong();
	if (test__start_subtest("mixed_links"))
		test_mixed_links();
	if (test__start_subtest("multi_links"))
		test_multi_links();
	if (test__start_subtest("link_replace"))
		test_link_replace();
	if (test__start_subtest("tcp_ca_kfunc"))
		test_tcp_ca_kfunc();
	if (test__start_subtest("cc_cubic"))
		test_cc_cubic();
	if (test__start_subtest("dctcp_autoattach_map"))
		test_dctcp_autoattach_map();
}