// 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 = 500};
        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, bool must_succeed)
{
        struct connection *conn;
        int err, res = -1;

        conn = connect_client_to_server(cfg);
        if (!must_succeed && !ASSERT_ERR_PTR(conn, "connection that must fail"))
                goto end;
        else if (!must_succeed)
                return 0;

        if (!ASSERT_OK_PTR(conn, "connection that must succeed"))
                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, true), "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, true),
                               "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, true), "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, "ethtool -K veth1 tso off");
        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);
}