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

// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause

/*
 * End-to-end eBPF tunnel test suite
 *   The file tests BPF network tunnels implementation. For each tunnel
 *   type, the test validates that:
 *   - basic communication can first be established between the two veths
 *   - when adding a BPF-based encapsulation on client egress, it now fails
 *   to communicate with the server
 *   - when adding a kernel-based decapsulation on server ingress, client
 *   can now connect
 *   - when replacing the kernel-based decapsulation with a BPF-based one,
 *   the client can still connect
 */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <bpf/libbpf.h>

#include "test_progs.h"
#include "network_helpers.h"
#include "test_tc_tunnel.skel.h"

#define SERVER_NS	"tc-tunnel-server-ns"
#define CLIENT_NS	"tc-tunnel-client-ns"
#define MAC_ADDR_VETH1	"00:11:22:33:44:55"
#define IP4_ADDR_VETH1	"192.168.1.1"
#define IP6_ADDR_VETH1	"fd::1"
#define MAC_ADDR_VETH2	"66:77:88:99:AA:BB"
#define IP4_ADDR_VETH2	"192.168.1.2"
#define IP6_ADDR_VETH2	"fd::2"

#define TEST_NAME_MAX_LEN	64
#define PROG_NAME_MAX_LEN	64
#define TUNNEL_ARGS_MAX_LEN	128
#define BUFFER_LEN		2000
#define DEFAULT_TEST_DATA_SIZE	100
#define GSO_TEST_DATA_SIZE	BUFFER_LEN

#define TIMEOUT_MS			1000
#define TEST_PORT			8000
#define UDP_PORT			5555
#define MPLS_UDP_PORT			6635
#define FOU_MPLS_PROTO			137
#define VXLAN_ID			1
#define VXLAN_PORT			8472
#define MPLS_TABLE_ENTRIES_COUNT	65536

static char tx_buffer[BUFFER_LEN], rx_buffer[BUFFER_LEN];

struct subtest_cfg {
	char *ebpf_tun_type;
	char *iproute_tun_type;
	char *mac_tun_type;
	int ipproto;
	void (*extra_decap_mod_args_cb)(struct subtest_cfg *cfg, char *dst);
	bool tunnel_need_veth_mac;
	bool configure_fou_rx_port;
	char *tmode;
	bool expect_kern_decap_failure;
	bool configure_mpls;
	bool test_gso;
	char *tunnel_client_addr;
	char *tunnel_server_addr;
	char name[TEST_NAME_MAX_LEN];
	char *server_addr;
	int client_egress_prog_fd;
	int server_ingress_prog_fd;
	char extra_decap_mod_args[TUNNEL_ARGS_MAX_LEN];
	int server_fd;
};

struct connection {
	int client_fd;
	int server_fd;
};

static int build_subtest_name(struct subtest_cfg *cfg, char *dst, size_t size)
{
	int ret;

	ret = snprintf(dst, size, "%s_%s", cfg->ebpf_tun_type,
		       cfg->mac_tun_type);

	return ret < 0 ? ret : 0;
}

static int set_subtest_progs(struct subtest_cfg *cfg, struct test_tc_tunnel *skel)
{
	char prog_name[PROG_NAME_MAX_LEN];
	struct bpf_program *prog;
	int ret;

	ret = snprintf(prog_name, PROG_NAME_MAX_LEN, "__encap_");
	if (ret < 0)
		return ret;
	ret = build_subtest_name(cfg, prog_name + ret, PROG_NAME_MAX_LEN - ret);
	if (ret < 0)
		return ret;
	prog = bpf_object__find_program_by_name(skel->obj, prog_name);
	if (!prog)
		return -1;

	cfg->client_egress_prog_fd = bpf_program__fd(prog);
	cfg->server_ingress_prog_fd = bpf_program__fd(skel->progs.decap_f);
	return 0;
}

static void set_subtest_addresses(struct subtest_cfg *cfg)
{
	if (cfg->ipproto == 6)
		cfg->server_addr = IP6_ADDR_VETH2;
	else
		cfg->server_addr = IP4_ADDR_VETH2;

	/* Some specific tunnel types need specific addressing, it then
	 * has been already set in the configuration table. Otherwise,
	 * deduce the relevant addressing from the ipproto
	 */
	if (cfg->tunnel_client_addr && cfg->tunnel_server_addr)
		return;

	if (cfg->ipproto == 6) {
		cfg->tunnel_client_addr = IP6_ADDR_VETH1;
		cfg->tunnel_server_addr = IP6_ADDR_VETH2;
	} else {
		cfg->tunnel_client_addr = IP4_ADDR_VETH1;
		cfg->tunnel_server_addr = IP4_ADDR_VETH2;
	}
}

static int run_server(struct subtest_cfg *cfg)
{
	int family = cfg->ipproto == 6 ? AF_INET6 : AF_INET;
	struct nstoken *nstoken;
	struct network_helper_opts opts = {
		.timeout_ms = TIMEOUT_MS
	};

	nstoken = open_netns(SERVER_NS);
	if (!ASSERT_OK_PTR(nstoken, "open server ns"))
		return -1;

	cfg->server_fd = start_server_str(family, SOCK_STREAM, cfg->server_addr,
					  TEST_PORT, &opts);
	close_netns(nstoken);
	if (!ASSERT_OK_FD(cfg->server_fd, "start server"))
		return -1;

	return 0;
}

static int check_server_rx_data(struct subtest_cfg *cfg,
				struct connection *conn, int len)
{
	int err;

	memset(rx_buffer, 0, BUFFER_LEN);
	err = recv(conn->server_fd, rx_buffer, len, 0);
	if (!ASSERT_EQ(err, len, "check rx data len"))
		return 1;
	if (!ASSERT_MEMEQ(tx_buffer, rx_buffer, len, "check received data"))
		return 1;
	return 0;
}

static struct connection *connect_client_to_server(struct subtest_cfg *cfg)
{
	struct network_helper_opts opts = {.timeout_ms = 1000};
	int family = cfg->ipproto == 6 ? AF_INET6 : AF_INET;
	struct connection *conn = NULL;
	int client_fd, server_fd;

	conn = malloc(sizeof(struct connection));
	if (!conn)
		return conn;

	client_fd = connect_to_addr_str(family, SOCK_STREAM, cfg->server_addr,
					TEST_PORT, &opts);

	if (client_fd < 0) {
		free(conn);
		return NULL;
	}

	server_fd = accept(cfg->server_fd, NULL, NULL);
	if (server_fd < 0) {
		close(client_fd);
		free(conn);
		return NULL;
	}

	conn->server_fd = server_fd;
	conn->client_fd = client_fd;

	return conn;
}

static void disconnect_client_from_server(struct subtest_cfg *cfg,
					  struct connection *conn)
{
	close(conn->server_fd);
	close(conn->client_fd);
	free(conn);
}

static int send_and_test_data(struct subtest_cfg *cfg)
{
	struct connection *conn;
	int err, res = -1;

	conn = connect_client_to_server(cfg);
	if (!ASSERT_OK_PTR(conn, "connect to server"))
		return -1;

	err = send(conn->client_fd, tx_buffer, DEFAULT_TEST_DATA_SIZE, 0);
	if (!ASSERT_EQ(err, DEFAULT_TEST_DATA_SIZE, "send data from client"))
		goto end;
	if (check_server_rx_data(cfg, conn, DEFAULT_TEST_DATA_SIZE))
		goto end;

	if (!cfg->test_gso) {
		res = 0;
		goto end;
	}

	err = send(conn->client_fd, tx_buffer, GSO_TEST_DATA_SIZE, 0);
	if (!ASSERT_EQ(err, GSO_TEST_DATA_SIZE, "send (large) data from client"))
		goto end;
	if (check_server_rx_data(cfg, conn, DEFAULT_TEST_DATA_SIZE))
		goto end;

	res = 0;
end:
	disconnect_client_from_server(cfg, conn);
	return res;
}

static void vxlan_decap_mod_args_cb(struct subtest_cfg *cfg, char *dst)
{
	snprintf(dst, TUNNEL_ARGS_MAX_LEN, "id %d dstport %d udp6zerocsumrx",
		 VXLAN_ID, VXLAN_PORT);
}

static void udp_decap_mod_args_cb(struct subtest_cfg *cfg, char *dst)
{
	bool is_mpls = !strcmp(cfg->mac_tun_type, "mpls");

	snprintf(dst, TUNNEL_ARGS_MAX_LEN,
		 "encap fou encap-sport auto encap-dport %d",
		 is_mpls ? MPLS_UDP_PORT : UDP_PORT);
}

static int configure_fou_rx_port(struct subtest_cfg *cfg, bool add)
{
	bool is_mpls = strcmp(cfg->mac_tun_type, "mpls") == 0;
	int fou_proto;

	if (is_mpls)
		fou_proto = FOU_MPLS_PROTO;
	else
		fou_proto = cfg->ipproto == 6 ? 41 : 4;

	SYS(fail, "ip fou %s port %d ipproto %d%s", add ? "add" : "del",
	    is_mpls ? MPLS_UDP_PORT : UDP_PORT, fou_proto,
	    cfg->ipproto == 6 ? " -6" : "");

	return 0;
fail:
	return 1;
}

static int add_fou_rx_port(struct subtest_cfg *cfg)
{
	return configure_fou_rx_port(cfg, true);
}

static int del_fou_rx_port(struct subtest_cfg *cfg)
{
	return configure_fou_rx_port(cfg, false);
}

static int update_tunnel_intf_addr(struct subtest_cfg *cfg)
{
	SYS(fail, "ip link set dev testtun0 address " MAC_ADDR_VETH2);
	return 0;
fail:
	return -1;
}

static int configure_kernel_for_mpls(struct subtest_cfg *cfg)
{
	SYS(fail, "sysctl -qw net.mpls.platform_labels=%d",
	    MPLS_TABLE_ENTRIES_COUNT);
	SYS(fail, "ip -f mpls route add 1000 dev lo");
	SYS(fail, "ip link set lo up");
	SYS(fail, "sysctl -qw net.mpls.conf.testtun0.input=1");
	SYS(fail, "sysctl -qw net.ipv4.conf.lo.rp_filter=0");
	return 0;
fail:
	return -1;
}

static int configure_encapsulation(struct subtest_cfg *cfg)
{
	int ret;

	ret = tc_prog_attach("veth1", -1, cfg->client_egress_prog_fd);

	return ret;
}

static int configure_kernel_decapsulation(struct subtest_cfg *cfg)
{
	struct nstoken *nstoken = open_netns(SERVER_NS);
	int ret = -1;

	if (!ASSERT_OK_PTR(nstoken, "open server ns"))
		return ret;

	if (cfg->configure_fou_rx_port &&
	    !ASSERT_OK(add_fou_rx_port(cfg), "configure FOU RX port"))
		goto fail;
	SYS(fail, "ip link add name testtun0 type %s %s remote %s local %s %s",
	    cfg->iproute_tun_type, cfg->tmode ? cfg->tmode : "",
	    cfg->tunnel_client_addr, cfg->tunnel_server_addr,
	    cfg->extra_decap_mod_args);
	if (cfg->tunnel_need_veth_mac &&
	    !ASSERT_OK(update_tunnel_intf_addr(cfg), "update testtun0 mac"))
		goto fail;
	if (cfg->configure_mpls &&
	    (!ASSERT_OK(configure_kernel_for_mpls(cfg),
			"configure MPLS decap")))
		goto fail;
	SYS(fail, "sysctl -qw net.ipv4.conf.all.rp_filter=0");
	SYS(fail, "sysctl -qw net.ipv4.conf.testtun0.rp_filter=0");
	SYS(fail, "ip link set dev testtun0 up");

	ret = 0;
fail:
	close_netns(nstoken);
	return ret;
}

static void remove_kernel_decapsulation(struct subtest_cfg *cfg)
{
	SYS_NOFAIL("ip link del testtun0");
	if (cfg->configure_mpls)
		SYS_NOFAIL("ip -f mpls route del 1000 dev lo");
	if (cfg->configure_fou_rx_port)
		del_fou_rx_port(cfg);
}

static int configure_ebpf_decapsulation(struct subtest_cfg *cfg)
{
	struct nstoken *nstoken = open_netns(SERVER_NS);
	int ret = -1;

	if (!ASSERT_OK_PTR(nstoken, "open server ns"))
		return ret;

	if (!cfg->expect_kern_decap_failure)
		SYS(fail, "ip link del testtun0");

	if (!ASSERT_OK(tc_prog_attach("veth2", cfg->server_ingress_prog_fd, -1),
		       "attach_program"))
		goto fail;

	ret = 0;
fail:
	close_netns(nstoken);
	return ret;
}

static void run_test(struct subtest_cfg *cfg)
{
	struct nstoken *nstoken;

	if (!ASSERT_OK(run_server(cfg), "run server"))
		return;

	nstoken = open_netns(CLIENT_NS);
	if (!ASSERT_OK_PTR(nstoken, "open client ns"))
		goto fail;

	/* Basic communication must work */
	if (!ASSERT_OK(send_and_test_data(cfg), "connect without any encap"))
		goto fail;

	/* Attach encapsulation program to client */
	if (!ASSERT_OK(configure_encapsulation(cfg), "configure encapsulation"))
		goto fail;

	/* If supported, insert kernel decap module, connection must succeed */
	if (!cfg->expect_kern_decap_failure) {
		if (!ASSERT_OK(configure_kernel_decapsulation(cfg),
					"configure kernel decapsulation"))
			goto fail;
		if (!ASSERT_OK(send_and_test_data(cfg),
			       "connect with encap prog and kern decap"))
			goto fail;
	}

	/* Replace kernel decapsulation with BPF decapsulation, test must pass */
	if (!ASSERT_OK(configure_ebpf_decapsulation(cfg), "configure ebpf decapsulation"))
		goto fail;
	ASSERT_OK(send_and_test_data(cfg), "connect with encap and decap progs");

fail:
	close_netns(nstoken);
	close(cfg->server_fd);
}

static int setup(void)
{
	struct nstoken *nstoken_client, *nstoken_server;
	int fd, err;

	fd = open("/dev/urandom", O_RDONLY);
	if (!ASSERT_OK_FD(fd, "open urandom"))
		goto fail;
	err = read(fd, tx_buffer, BUFFER_LEN);
	close(fd);

	if (!ASSERT_EQ(err, BUFFER_LEN, "read random bytes"))
		goto fail;

	/* Configure the testing network */
	if (!ASSERT_OK(make_netns(CLIENT_NS), "create client ns") ||
	    !ASSERT_OK(make_netns(SERVER_NS), "create server ns"))
		goto fail;

	nstoken_client = open_netns(CLIENT_NS);
	if (!ASSERT_OK_PTR(nstoken_client, "open client ns"))
		goto fail_delete_ns;
	SYS(fail_close_ns_client, "ip link add %s type veth peer name %s",
	    "veth1 mtu 1500 netns " CLIENT_NS " address " MAC_ADDR_VETH1,
	    "veth2 mtu 1500 netns " SERVER_NS " address " MAC_ADDR_VETH2);
	SYS(fail_close_ns_client, "ip link set veth1 up");
	nstoken_server = open_netns(SERVER_NS);
	if (!ASSERT_OK_PTR(nstoken_server, "open server ns"))
		goto fail_close_ns_client;
	SYS(fail_close_ns_server, "ip link set veth2 up");

	close_netns(nstoken_server);
	close_netns(nstoken_client);
	return 0;

fail_close_ns_server:
	close_netns(nstoken_server);
fail_close_ns_client:
	close_netns(nstoken_client);
fail_delete_ns:
	SYS_NOFAIL("ip netns del " CLIENT_NS);
	SYS_NOFAIL("ip netns del " SERVER_NS);
fail:
	return -1;
}

static int subtest_setup(struct test_tc_tunnel *skel, struct subtest_cfg *cfg)
{
	struct nstoken *nstoken_client, *nstoken_server;
	int ret = -1;

	set_subtest_addresses(cfg);
	if (!ASSERT_OK(set_subtest_progs(cfg, skel),
		       "find subtest progs"))
		goto fail;
	if (cfg->extra_decap_mod_args_cb)
		cfg->extra_decap_mod_args_cb(cfg, cfg->extra_decap_mod_args);

	nstoken_client = open_netns(CLIENT_NS);
	if (!ASSERT_OK_PTR(nstoken_client, "open client ns"))
		goto fail;
	SYS(fail_close_client_ns,
	    "ip -4 addr add " IP4_ADDR_VETH1 "/24 dev veth1");
	SYS(fail_close_client_ns, "ip -4 route flush table main");
	SYS(fail_close_client_ns,
	    "ip -4 route add " IP4_ADDR_VETH2 " mtu 1450 dev veth1");
	SYS(fail_close_client_ns,
	    "ip -6 addr add " IP6_ADDR_VETH1 "/64 dev veth1 nodad");
	SYS(fail_close_client_ns, "ip -6 route flush table main");
	SYS(fail_close_client_ns,
	    "ip -6 route add " IP6_ADDR_VETH2 " mtu 1430 dev veth1");
	nstoken_server = open_netns(SERVER_NS);
	if (!ASSERT_OK_PTR(nstoken_server, "open server ns"))
		goto fail_close_client_ns;
	SYS(fail_close_server_ns,
	    "ip -4 addr add " IP4_ADDR_VETH2 "/24 dev veth2");
	SYS(fail_close_server_ns,
	    "ip -6 addr add " IP6_ADDR_VETH2 "/64 dev veth2 nodad");

	ret = 0;

fail_close_server_ns:
	close_netns(nstoken_server);
fail_close_client_ns:
	close_netns(nstoken_client);
fail:
	return ret;
}


static void subtest_cleanup(struct subtest_cfg *cfg)
{
	struct nstoken *nstoken;

	nstoken = open_netns(CLIENT_NS);
	if (ASSERT_OK_PTR(nstoken, "open clien ns")) {
		SYS_NOFAIL("tc qdisc delete dev veth1 parent ffff:fff1");
		SYS_NOFAIL("ip a flush veth1");
		close_netns(nstoken);
	}
	nstoken = open_netns(SERVER_NS);
	if (ASSERT_OK_PTR(nstoken, "open clien ns")) {
		SYS_NOFAIL("tc qdisc delete dev veth2 parent ffff:fff1");
		SYS_NOFAIL("ip a flush veth2");
		if (!cfg->expect_kern_decap_failure)
			remove_kernel_decapsulation(cfg);
		close_netns(nstoken);
	}
}

static void cleanup(void)
{
	remove_netns(CLIENT_NS);
	remove_netns(SERVER_NS);
}

static struct subtest_cfg subtests_cfg[] = {
	{
		.ebpf_tun_type = "ipip",
		.mac_tun_type = "none",
		.iproute_tun_type = "ipip",
		.ipproto = 4,
	},
	{
		.ebpf_tun_type = "ipip6",
		.mac_tun_type = "none",
		.iproute_tun_type = "ip6tnl",
		.ipproto = 4,
		.tunnel_client_addr = IP6_ADDR_VETH1,
		.tunnel_server_addr = IP6_ADDR_VETH2,
	},
	{
		.ebpf_tun_type = "ip6tnl",
		.iproute_tun_type = "ip6tnl",
		.mac_tun_type = "none",
		.ipproto = 6,
	},
	{
		.mac_tun_type = "none",
		.ebpf_tun_type = "sit",
		.iproute_tun_type = "sit",
		.ipproto = 6,
		.tunnel_client_addr = IP4_ADDR_VETH1,
		.tunnel_server_addr = IP4_ADDR_VETH2,
	},
	{
		.ebpf_tun_type = "vxlan",
		.mac_tun_type = "eth",
		.iproute_tun_type = "vxlan",
		.ipproto = 4,
		.extra_decap_mod_args_cb = vxlan_decap_mod_args_cb,
		.tunnel_need_veth_mac = true
	},
	{
		.ebpf_tun_type = "ip6vxlan",
		.mac_tun_type = "eth",
		.iproute_tun_type = "vxlan",
		.ipproto = 6,
		.extra_decap_mod_args_cb = vxlan_decap_mod_args_cb,
		.tunnel_need_veth_mac = true
	},
	{
		.ebpf_tun_type = "gre",
		.mac_tun_type = "none",
		.iproute_tun_type = "gre",
		.ipproto = 4,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "gre",
		.mac_tun_type = "eth",
		.iproute_tun_type = "gretap",
		.ipproto = 4,
		.tunnel_need_veth_mac = true,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "gre",
		.mac_tun_type = "mpls",
		.iproute_tun_type = "gre",
		.ipproto = 4,
		.configure_mpls = true,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "ip6gre",
		.mac_tun_type = "none",
		.iproute_tun_type = "ip6gre",
		.ipproto = 6,
		.test_gso = true,
	},
	{
		.ebpf_tun_type = "ip6gre",
		.mac_tun_type = "eth",
		.iproute_tun_type = "ip6gretap",
		.ipproto = 6,
		.tunnel_need_veth_mac = true,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "ip6gre",
		.mac_tun_type = "mpls",
		.iproute_tun_type = "ip6gre",
		.ipproto = 6,
		.configure_mpls = true,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "udp",
		.mac_tun_type = "none",
		.iproute_tun_type = "ipip",
		.ipproto = 4,
		.extra_decap_mod_args_cb = udp_decap_mod_args_cb,
		.configure_fou_rx_port = true,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "udp",
		.mac_tun_type = "eth",
		.iproute_tun_type = "ipip",
		.ipproto = 4,
		.extra_decap_mod_args_cb = udp_decap_mod_args_cb,
		.configure_fou_rx_port = true,
		.expect_kern_decap_failure = true,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "udp",
		.mac_tun_type = "mpls",
		.iproute_tun_type = "ipip",
		.ipproto = 4,
		.extra_decap_mod_args_cb = udp_decap_mod_args_cb,
		.configure_fou_rx_port = true,
		.tmode = "mode any ttl 255",
		.configure_mpls = true,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "ip6udp",
		.mac_tun_type = "none",
		.iproute_tun_type = "ip6tnl",
		.ipproto = 6,
		.extra_decap_mod_args_cb = udp_decap_mod_args_cb,
		.configure_fou_rx_port = true,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "ip6udp",
		.mac_tun_type = "eth",
		.iproute_tun_type = "ip6tnl",
		.ipproto = 6,
		.extra_decap_mod_args_cb = udp_decap_mod_args_cb,
		.configure_fou_rx_port = true,
		.expect_kern_decap_failure = true,
		.test_gso = true
	},
	{
		.ebpf_tun_type = "ip6udp",
		.mac_tun_type = "mpls",
		.iproute_tun_type = "ip6tnl",
		.ipproto = 6,
		.extra_decap_mod_args_cb = udp_decap_mod_args_cb,
		.configure_fou_rx_port = true,
		.tmode = "mode any ttl 255",
		.expect_kern_decap_failure = true,
		.test_gso = true
	},
};

void test_tc_tunnel(void)
{
	struct test_tc_tunnel *skel;
	struct subtest_cfg *cfg;
	int i, ret;

	skel = test_tc_tunnel__open_and_load();
	if (!ASSERT_OK_PTR(skel, "skel open and load"))
		return;

	if (!ASSERT_OK(setup(), "global setup"))
		goto out;

	for (i = 0; i < ARRAY_SIZE(subtests_cfg); i++) {
		cfg = &subtests_cfg[i];
		ret = build_subtest_name(cfg, cfg->name, TEST_NAME_MAX_LEN);
		if (ret < 0 || !test__start_subtest(cfg->name))
			continue;
		if (subtest_setup(skel, cfg) == 0)
			run_test(cfg);
		subtest_cleanup(cfg);
	}
	cleanup();

out:
	test_tc_tunnel__destroy(skel);
}