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

root/tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c
// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include <network_helpers.h>
#include <linux/ipv6.h>
#include <arpa/inet.h>
#include "test_xdp_context_test_run.skel.h"
#include "test_xdp_meta.skel.h"

#define RX_NAME "veth0"
#define TX_NAME "veth1"
#define TX_NETNS "xdp_context_tx"
#define RX_NETNS "xdp_context_rx"
#define RX_MAC "02:00:00:00:00:01"
#define TX_MAC "02:00:00:00:00:02"
#define TAP_NAME "tap0"
#define DUMMY_NAME "dum0"
#define TAP_NETNS "xdp_context_tuntap"
#define LWT_NETNS "xdp_context_lwt"

#define TEST_PAYLOAD_LEN 32
static const __u8 test_payload[TEST_PAYLOAD_LEN] = {
        0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
        0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
        0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
        0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38,
};

void test_xdp_context_error(int prog_fd, struct bpf_test_run_opts opts,
                            __u32 data_meta, __u32 data, __u32 data_end,
                            __u32 ingress_ifindex, __u32 rx_queue_index,
                            __u32 egress_ifindex)
{
        struct xdp_md ctx = {
                .data = data,
                .data_end = data_end,
                .data_meta = data_meta,
                .ingress_ifindex = ingress_ifindex,
                .rx_queue_index = rx_queue_index,
                .egress_ifindex = egress_ifindex,
        };
        int err;

        opts.ctx_in = &ctx;
        opts.ctx_size_in = sizeof(ctx);
        err = bpf_prog_test_run_opts(prog_fd, &opts);
        ASSERT_EQ(errno, EINVAL, "errno-EINVAL");
        ASSERT_ERR(err, "bpf_prog_test_run");
}

void test_xdp_context_test_run(void)
{
        struct test_xdp_context_test_run *skel = NULL;
        char data[sizeof(pkt_v4) + sizeof(__u32)];
        char bad_ctx[sizeof(struct xdp_md) + 1];
        char large_data[256];
        struct xdp_md ctx_in, ctx_out;
        DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
                            .data_in = &data,
                            .data_size_in = sizeof(data),
                            .ctx_out = &ctx_out,
                            .ctx_size_out = sizeof(ctx_out),
                            .repeat = 1,
                );
        int err, prog_fd;

        skel = test_xdp_context_test_run__open_and_load();
        if (!ASSERT_OK_PTR(skel, "skel"))
                return;
        prog_fd = bpf_program__fd(skel->progs.xdp_context);

        /* Data past the end of the kernel's struct xdp_md must be 0 */
        bad_ctx[sizeof(bad_ctx) - 1] = 1;
        opts.ctx_in = bad_ctx;
        opts.ctx_size_in = sizeof(bad_ctx);
        err = bpf_prog_test_run_opts(prog_fd, &opts);
        ASSERT_EQ(errno, E2BIG, "extradata-errno");
        ASSERT_ERR(err, "bpf_prog_test_run(extradata)");

        *(__u32 *)data = XDP_PASS;
        *(struct ipv4_packet *)(data + sizeof(__u32)) = pkt_v4;
        opts.ctx_in = &ctx_in;
        opts.ctx_size_in = sizeof(ctx_in);
        memset(&ctx_in, 0, sizeof(ctx_in));
        ctx_in.data_meta = 0;
        ctx_in.data = sizeof(__u32);
        ctx_in.data_end = ctx_in.data + sizeof(pkt_v4);
        err = bpf_prog_test_run_opts(prog_fd, &opts);
        ASSERT_OK(err, "bpf_prog_test_run(valid)");
        ASSERT_EQ(opts.retval, XDP_PASS, "valid-retval");
        ASSERT_EQ(opts.data_size_out, sizeof(pkt_v4), "valid-datasize");
        ASSERT_EQ(opts.ctx_size_out, opts.ctx_size_in, "valid-ctxsize");
        ASSERT_EQ(ctx_out.data_meta, 0, "valid-datameta");
        ASSERT_EQ(ctx_out.data, 0, "valid-data");
        ASSERT_EQ(ctx_out.data_end, sizeof(pkt_v4), "valid-dataend");

        /* Meta data's size must be a multiple of 4 */
        test_xdp_context_error(prog_fd, opts, 0, 1, sizeof(data), 0, 0, 0);

        /* data_meta must reference the start of data */
        test_xdp_context_error(prog_fd, opts, 4, sizeof(__u32), sizeof(data),
                               0, 0, 0);

        /* Total size of data must be data_end - data_meta or larger */
        test_xdp_context_error(prog_fd, opts, 0, sizeof(__u32),
                               sizeof(data) + 1, 0, 0, 0);

        /* RX queue cannot be specified without specifying an ingress */
        test_xdp_context_error(prog_fd, opts, 0, sizeof(__u32), sizeof(data),
                               0, 1, 0);

        /* Interface 1 is always the loopback interface which always has only
         * one RX queue (index 0). This makes index 1 an invalid rx queue index
         * for interface 1.
         */
        test_xdp_context_error(prog_fd, opts, 0, sizeof(__u32), sizeof(data),
                               1, 1, 0);

        /* The egress cannot be specified */
        test_xdp_context_error(prog_fd, opts, 0, sizeof(__u32), sizeof(data),
                               0, 0, 1);

        /* Meta data must be 216 bytes or smaller (256 - sizeof(struct
         * xdp_frame)). Test both nearest invalid size and nearest invalid
         * 4-byte-aligned size, and make sure data_in is large enough that we
         * actually hit the check on metadata length
         */
        opts.data_in = large_data;
        opts.data_size_in = sizeof(large_data);
        test_xdp_context_error(prog_fd, opts, 0, 217, sizeof(large_data), 0, 0, 0);
        test_xdp_context_error(prog_fd, opts, 0, 220, sizeof(large_data), 0, 0, 0);

        test_xdp_context_test_run__destroy(skel);
}

static int send_test_packet(int ifindex)
{
        int n, sock = -1;
        __u8 packet[sizeof(struct ethhdr) + TEST_PAYLOAD_LEN];

        /* We use the Ethernet header only to identify the test packet */
        struct ethhdr eth = {
                .h_source = { 0x12, 0x34, 0xDE, 0xAD, 0xBE, 0xEF },
        };

        memcpy(packet, &eth, sizeof(eth));
        memcpy(packet + sizeof(eth), test_payload, TEST_PAYLOAD_LEN);

        sock = socket(AF_PACKET, SOCK_RAW, IPPROTO_RAW);
        if (!ASSERT_GE(sock, 0, "socket"))
                goto err;

        struct sockaddr_ll saddr = {
                .sll_family = PF_PACKET,
                .sll_ifindex = ifindex,
                .sll_halen = ETH_ALEN
        };
        n = sendto(sock, packet, sizeof(packet), 0, (struct sockaddr *)&saddr,
                   sizeof(saddr));
        if (!ASSERT_EQ(n, sizeof(packet), "sendto"))
                goto err;

        close(sock);
        return 0;

err:
        if (sock >= 0)
                close(sock);
        return -1;
}

static int write_test_packet(int tap_fd)
{
        __u8 packet[sizeof(struct ethhdr) + TEST_PAYLOAD_LEN];
        int n;

        /* The Ethernet header is mostly not relevant. We use it to identify the
         * test packet and some BPF helpers we exercise expect to operate on
         * Ethernet frames carrying IP packets. Pretend that's the case.
         */
        struct ethhdr eth = {
                .h_source = { 0x12, 0x34, 0xDE, 0xAD, 0xBE, 0xEF },
                .h_proto = htons(ETH_P_IP),
        };

        memcpy(packet, &eth, sizeof(eth));
        memcpy(packet + sizeof(struct ethhdr), test_payload, TEST_PAYLOAD_LEN);

        n = write(tap_fd, packet, sizeof(packet));
        if (!ASSERT_EQ(n, sizeof(packet), "write packet"))
                return -1;

        return 0;
}

/* Inject Ethernet+IPv6+UDP frame into TAP */
static int write_test_packet_udp(int tap_fd)
{
        __u8 pkt[sizeof(struct ethhdr) + sizeof(struct ipv6hdr) +
                 sizeof(struct udphdr) + TEST_PAYLOAD_LEN] = {};
        struct ethhdr *eth = (void *)pkt;
        struct ipv6hdr *ip6 = (void *)(eth + 1);
        struct udphdr *udp = (void *)(ip6 + 1);
        __u8 *payload = (void *)(udp + 1);
        const __u8 tap_mac[ETH_ALEN] = { 0x02, 0, 0, 0, 0, 0x01 };
        int n;

        memcpy(eth->h_dest, tap_mac, ETH_ALEN);
        eth->h_proto = htons(ETH_P_IPV6);

        ip6->version = 6;
        ip6->hop_limit = 64;
        ip6->nexthdr = IPPROTO_UDP;
        ip6->payload_len = htons(sizeof(*udp) + TEST_PAYLOAD_LEN);
        inet_pton(AF_INET6, "fd00::2", &ip6->saddr);
        inet_pton(AF_INET6, "fd00:1::1", &ip6->daddr);

        udp->source = htons(42);
        udp->dest = htons(42);
        udp->len = htons(sizeof(*udp) + TEST_PAYLOAD_LEN);
        /* UDP checksum is not validated on the forwarding path. */

        memcpy(payload, test_payload, TEST_PAYLOAD_LEN);

        n = write(tap_fd, pkt, sizeof(pkt));
        if (!ASSERT_EQ(n, sizeof(pkt), "write frame"))
                return -1;

        return 0;
}

static void dump_err_stream(const struct bpf_program *prog)
{
        char buf[512];
        int ret;

        ret = 0;
        do {
                ret = bpf_prog_stream_read(bpf_program__fd(prog),
                                           BPF_STREAM_STDERR, buf, sizeof(buf),
                                           NULL);
                if (ret > 0)
                        fwrite(buf, sizeof(buf[0]), ret, stderr);
        } while (ret > 0);
}

void test_xdp_context_veth(void)
{
        LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_INGRESS);
        LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 1);
        struct netns_obj *rx_ns = NULL, *tx_ns = NULL;
        struct bpf_program *tc_prog, *xdp_prog;
        struct test_xdp_meta *skel = NULL;
        struct nstoken *nstoken = NULL;
        int rx_ifindex, tx_ifindex;
        int ret;

        tx_ns = netns_new(TX_NETNS, false);
        if (!ASSERT_OK_PTR(tx_ns, "create tx_ns"))
                return;

        rx_ns = netns_new(RX_NETNS, false);
        if (!ASSERT_OK_PTR(rx_ns, "create rx_ns"))
                goto close;

        SYS(close, "ip link add " RX_NAME " netns " RX_NETNS
            " type veth peer name " TX_NAME " netns " TX_NETNS);

        nstoken = open_netns(RX_NETNS);
        if (!ASSERT_OK_PTR(nstoken, "setns rx_ns"))
                goto close;

        SYS(close, "ip link set dev " RX_NAME " up");

        skel = test_xdp_meta__open_and_load();
        if (!ASSERT_OK_PTR(skel, "open and load skeleton"))
                goto close;

        rx_ifindex = if_nametoindex(RX_NAME);
        if (!ASSERT_GE(rx_ifindex, 0, "if_nametoindex rx"))
                goto close;

        tc_hook.ifindex = rx_ifindex;
        ret = bpf_tc_hook_create(&tc_hook);
        if (!ASSERT_OK(ret, "bpf_tc_hook_create"))
                goto close;

        tc_prog = bpf_object__find_program_by_name(skel->obj, "ing_cls");
        if (!ASSERT_OK_PTR(tc_prog, "open ing_cls prog"))
                goto close;

        tc_opts.prog_fd = bpf_program__fd(tc_prog);
        ret = bpf_tc_attach(&tc_hook, &tc_opts);
        if (!ASSERT_OK(ret, "bpf_tc_attach"))
                goto close;

        xdp_prog = bpf_object__find_program_by_name(skel->obj, "ing_xdp");
        if (!ASSERT_OK_PTR(xdp_prog, "open ing_xdp prog"))
                goto close;

        ret = bpf_xdp_attach(rx_ifindex,
                             bpf_program__fd(xdp_prog),
                             0, NULL);
        if (!ASSERT_GE(ret, 0, "bpf_xdp_attach"))
                goto close;

        close_netns(nstoken);

        nstoken = open_netns(TX_NETNS);
        if (!ASSERT_OK_PTR(nstoken, "setns tx_ns"))
                goto close;

        SYS(close, "ip link set dev " TX_NAME " up");

        tx_ifindex = if_nametoindex(TX_NAME);
        if (!ASSERT_GE(tx_ifindex, 0, "if_nametoindex tx"))
                goto close;

        skel->bss->test_pass = false;

        ret = send_test_packet(tx_ifindex);
        if (!ASSERT_OK(ret, "send_test_packet"))
                goto close;

        if (!ASSERT_TRUE(skel->bss->test_pass, "test_pass"))
                dump_err_stream(tc_prog);

close:
        close_netns(nstoken);
        test_xdp_meta__destroy(skel);
        netns_free(rx_ns);
        netns_free(tx_ns);
}

static void test_tuntap(struct bpf_program *xdp_prog,
                        struct bpf_program *tc_prio_1_prog,
                        struct bpf_program *tc_prio_2_prog,
                        bool *test_pass)
{
        LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_INGRESS);
        LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 1);
        struct netns_obj *ns = NULL;
        int tap_fd = -1;
        int tap_ifindex;
        int ret;

        *test_pass = false;

        ns = netns_new(TAP_NETNS, true);
        if (!ASSERT_OK_PTR(ns, "create and open ns"))
                return;

        tap_fd = open_tuntap(TAP_NAME, true);
        if (!ASSERT_GE(tap_fd, 0, "open_tuntap"))
                goto close;

        SYS(close, "ip link set dev " TAP_NAME " up");

        tap_ifindex = if_nametoindex(TAP_NAME);
        if (!ASSERT_GE(tap_ifindex, 0, "if_nametoindex"))
                goto close;

        tc_hook.ifindex = tap_ifindex;
        ret = bpf_tc_hook_create(&tc_hook);
        if (!ASSERT_OK(ret, "bpf_tc_hook_create"))
                goto close;

        tc_opts.prog_fd = bpf_program__fd(tc_prio_1_prog);
        ret = bpf_tc_attach(&tc_hook, &tc_opts);
        if (!ASSERT_OK(ret, "bpf_tc_attach"))
                goto close;

        if (tc_prio_2_prog) {
                LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 2,
                            .prog_fd = bpf_program__fd(tc_prio_2_prog));

                ret = bpf_tc_attach(&tc_hook, &tc_opts);
                if (!ASSERT_OK(ret, "bpf_tc_attach"))
                        goto close;
        }

        ret = bpf_xdp_attach(tap_ifindex, bpf_program__fd(xdp_prog),
                             0, NULL);
        if (!ASSERT_GE(ret, 0, "bpf_xdp_attach"))
                goto close;

        ret = write_test_packet(tap_fd);
        if (!ASSERT_OK(ret, "write_test_packet"))
                goto close;

        if (!ASSERT_TRUE(*test_pass, "test_pass"))
                dump_err_stream(tc_prio_2_prog ? : tc_prio_1_prog);

close:
        if (tap_fd >= 0)
                close(tap_fd);
        netns_free(ns);
}

/* Write a packet to a tap dev and copy it to ingress of a dummy dev */
static void test_tuntap_mirred(struct bpf_program *xdp_prog,
                               struct bpf_program *tc_prog,
                               bool *test_pass)
{
        LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_INGRESS);
        LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 1);
        struct netns_obj *ns = NULL;
        int dummy_ifindex;
        int tap_fd = -1;
        int tap_ifindex;
        int ret;

        *test_pass = false;

        ns = netns_new(TAP_NETNS, true);
        if (!ASSERT_OK_PTR(ns, "netns_new"))
                return;

        /* Setup dummy interface */
        SYS(close, "ip link add name " DUMMY_NAME " type dummy");
        SYS(close, "ip link set dev " DUMMY_NAME " up");

        dummy_ifindex = if_nametoindex(DUMMY_NAME);
        if (!ASSERT_GE(dummy_ifindex, 0, "if_nametoindex"))
                goto close;

        tc_hook.ifindex = dummy_ifindex;
        ret = bpf_tc_hook_create(&tc_hook);
        if (!ASSERT_OK(ret, "bpf_tc_hook_create"))
                goto close;

        tc_opts.prog_fd = bpf_program__fd(tc_prog);
        ret = bpf_tc_attach(&tc_hook, &tc_opts);
        if (!ASSERT_OK(ret, "bpf_tc_attach"))
                goto close;

        /* Setup TAP interface */
        tap_fd = open_tuntap(TAP_NAME, true);
        if (!ASSERT_GE(tap_fd, 0, "open_tuntap"))
                goto close;

        SYS(close, "ip link set dev " TAP_NAME " up");

        tap_ifindex = if_nametoindex(TAP_NAME);
        if (!ASSERT_GE(tap_ifindex, 0, "if_nametoindex"))
                goto close;

        ret = bpf_xdp_attach(tap_ifindex, bpf_program__fd(xdp_prog), 0, NULL);
        if (!ASSERT_GE(ret, 0, "bpf_xdp_attach"))
                goto close;

        /* Copy all packets received from TAP to dummy ingress */
        SYS(close, "tc qdisc add dev " TAP_NAME " clsact");
        SYS(close, "tc filter add dev " TAP_NAME " ingress "
                   "protocol all matchall "
                   "action mirred ingress mirror dev " DUMMY_NAME);

        /* Receive a packet on TAP */
        ret = write_test_packet(tap_fd);
        if (!ASSERT_OK(ret, "write_test_packet"))
                goto close;

        if (!ASSERT_TRUE(*test_pass, "test_pass"))
                dump_err_stream(tc_prog);

close:
        if (tap_fd >= 0)
                close(tap_fd);
        netns_free(ns);
}

void test_xdp_context_tuntap(void)
{
        struct test_xdp_meta *skel = NULL;

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

        if (test__start_subtest("data_meta"))
                test_tuntap(skel->progs.ing_xdp,
                            skel->progs.ing_cls,
                            NULL, /* tc prio 2 */
                            &skel->bss->test_pass);
        if (test__start_subtest("dynptr_read"))
                test_tuntap(skel->progs.ing_xdp,
                            skel->progs.ing_cls_dynptr_read,
                            NULL, /* tc prio 2 */
                            &skel->bss->test_pass);
        if (test__start_subtest("dynptr_slice"))
                test_tuntap(skel->progs.ing_xdp,
                            skel->progs.ing_cls_dynptr_slice,
                            NULL, /* tc prio 2 */
                            &skel->bss->test_pass);
        if (test__start_subtest("dynptr_write"))
                test_tuntap(skel->progs.ing_xdp_zalloc_meta,
                            skel->progs.ing_cls_dynptr_write,
                            skel->progs.ing_cls_dynptr_read,
                            &skel->bss->test_pass);
        if (test__start_subtest("dynptr_slice_rdwr"))
                test_tuntap(skel->progs.ing_xdp_zalloc_meta,
                            skel->progs.ing_cls_dynptr_slice_rdwr,
                            skel->progs.ing_cls_dynptr_slice,
                            &skel->bss->test_pass);
        if (test__start_subtest("dynptr_offset"))
                test_tuntap(skel->progs.ing_xdp_zalloc_meta,
                            skel->progs.ing_cls_dynptr_offset_wr,
                            skel->progs.ing_cls_dynptr_offset_rd,
                            &skel->bss->test_pass);
        if (test__start_subtest("dynptr_offset_oob"))
                test_tuntap(skel->progs.ing_xdp,
                            skel->progs.ing_cls_dynptr_offset_oob,
                            skel->progs.ing_cls,
                            &skel->bss->test_pass);
        if (test__start_subtest("clone_data_meta_survives_data_write"))
                test_tuntap_mirred(skel->progs.ing_xdp,
                                   skel->progs.clone_data_meta_survives_data_write,
                                   &skel->bss->test_pass);
        if (test__start_subtest("clone_data_meta_survives_meta_write"))
                test_tuntap_mirred(skel->progs.ing_xdp,
                                   skel->progs.clone_data_meta_survives_meta_write,
                                   &skel->bss->test_pass);
        if (test__start_subtest("clone_meta_dynptr_survives_data_slice_write"))
                test_tuntap_mirred(skel->progs.ing_xdp,
                                   skel->progs.clone_meta_dynptr_survives_data_slice_write,
                                   &skel->bss->test_pass);
        if (test__start_subtest("clone_meta_dynptr_survives_meta_slice_write"))
                test_tuntap_mirred(skel->progs.ing_xdp,
                                   skel->progs.clone_meta_dynptr_survives_meta_slice_write,
                                   &skel->bss->test_pass);
        if (test__start_subtest("clone_meta_dynptr_rw_before_data_dynptr_write"))
                test_tuntap_mirred(skel->progs.ing_xdp,
                                   skel->progs.clone_meta_dynptr_rw_before_data_dynptr_write,
                                   &skel->bss->test_pass);
        if (test__start_subtest("clone_meta_dynptr_rw_before_meta_dynptr_write"))
                test_tuntap_mirred(skel->progs.ing_xdp,
                                   skel->progs.clone_meta_dynptr_rw_before_meta_dynptr_write,
                                   &skel->bss->test_pass);
        /* Tests for BPF helpers which touch headroom */
        if (test__start_subtest("helper_skb_vlan_push_pop"))
                test_tuntap(skel->progs.ing_xdp,
                            skel->progs.helper_skb_vlan_push_pop,
                            NULL, /* tc prio 2 */
                            &skel->bss->test_pass);
        if (test__start_subtest("helper_skb_adjust_room"))
                test_tuntap(skel->progs.ing_xdp,
                            skel->progs.helper_skb_adjust_room,
                            NULL, /* tc prio 2 */
                            &skel->bss->test_pass);
        if (test__start_subtest("helper_skb_change_head_tail"))
                test_tuntap(skel->progs.ing_xdp,
                            skel->progs.helper_skb_change_head_tail,
                            NULL, /* tc prio 2 */
                            &skel->bss->test_pass);
        if (test__start_subtest("helper_skb_change_proto"))
                test_tuntap(skel->progs.ing_xdp,
                            skel->progs.helper_skb_change_proto,
                            NULL, /* tc prio 2 */
                            &skel->bss->test_pass);

        test_xdp_meta__destroy(skel);
}

/*
 * Test topology:
 *
 *      tap0 fd00::1
 *        RX:  injected IPv6 UDP frame, XDP ingress sets metadata
 *        fwd: encap route prepends outer header(s)
 *        TX:  TC egress validates metadata
 *
 * A routable IPv6 UDP frame is written into the tap fd, so it enters the RX
 * path where XDP stores metadata. Routing then forwards it back out the same
 * tap through an encapsulating route that prepends outer header(s). The TC
 * egress program checks that the pushed header did not silently corrupt
 * metadata.
 */
#define LWT_PIN_PATH "/sys/fs/bpf/xdp_context_lwt_xmit"

enum lwt_encap_type {
        LWT_ENCAP_BPF,
        LWT_ENCAP_MPLS,
        LWT_ENCAP_SEG6,
        LWT_ENCAP_IOAM6,
};

static void test_lwt_encap(struct test_xdp_meta *skel,
                           enum lwt_encap_type type)
{
        LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_EGRESS);
        LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 1);
        struct bpf_program *lwt_prog = NULL;
        struct netns_obj *ns = NULL;
        const char *encap;
        bool pinned = false;
        int tap_ifindex;
        int tap_fd = -1;
        int ret;

        skel->bss->test_pass = false;

        switch (type) {
        case LWT_ENCAP_BPF:
                encap = "encap bpf xmit pinned " LWT_PIN_PATH " via fd00::2";
                lwt_prog = skel->progs.dummy_lwt_xmit;
                break;
        case LWT_ENCAP_MPLS:
                encap = "encap mpls 100 via inet6 fd00::2";
                break;
        case LWT_ENCAP_SEG6:
                encap = "encap seg6 mode encap segs fd00::2";
                break;
        case LWT_ENCAP_IOAM6:
                encap = "encap ioam6 mode encap tundst fd00::2 "
                        "trace prealloc type 0x800000 ns 0 size 4 via fd00::2";
                break;
        default:
                return;
        }

        if (lwt_prog) {
                unlink(LWT_PIN_PATH);
                ret = bpf_program__pin(lwt_prog, LWT_PIN_PATH);
                if (!ASSERT_OK(ret, "pin lwt prog"))
                        return;
                pinned = true;
        }

        ns = netns_new(LWT_NETNS, true);
        if (!ASSERT_OK_PTR(ns, "netns_new"))
                goto close;

        tap_fd = open_tuntap(TAP_NAME, true);
        if (!ASSERT_GE(tap_fd, 0, "open_tuntap"))
                goto close;

        SYS(close, "ip link set dev " TAP_NAME " address " RX_MAC);
        SYS(close, "sysctl -wq net.ipv6.conf.all.forwarding=1");
        SYS(close, "ip addr add fd00::1/64 dev " TAP_NAME " nodad");
        SYS(close, "ip link set dev " TAP_NAME " up");
        SYS(close, "ip neigh add fd00::2 lladdr " TX_MAC " nud permanent dev " TAP_NAME);
        SYS(close, "ip -6 route add fd00:1::/64 %s dev %s", encap, TAP_NAME);

        tap_ifindex = if_nametoindex(TAP_NAME);
        if (!ASSERT_GE(tap_ifindex, 0, "if_nametoindex"))
                goto close;

        ret = bpf_xdp_attach(tap_ifindex, bpf_program__fd(skel->progs.ing_xdp),
                             0, NULL);
        if (!ASSERT_GE(ret, 0, "bpf_xdp_attach"))
                goto close;

        tc_hook.ifindex = tap_ifindex;
        ret = bpf_tc_hook_create(&tc_hook);
        if (!ASSERT_OK(ret, "bpf_tc_hook_create"))
                goto close;

        tc_opts.prog_fd = bpf_program__fd(skel->progs.tc_is_meta_empty);
        ret = bpf_tc_attach(&tc_hook, &tc_opts);
        if (!ASSERT_OK(ret, "bpf_tc_attach"))
                goto close;

        ret = write_test_packet_udp(tap_fd);
        if (!ASSERT_OK(ret, "write_test_packet_udp"))
                goto close;

        if (!ASSERT_TRUE(skel->bss->test_pass, "test_pass"))
                dump_err_stream(skel->progs.tc_is_meta_empty);

close:
        if (tap_fd >= 0)
                close(tap_fd);
        netns_free(ns);
        if (pinned)
                unlink(LWT_PIN_PATH);
}

void test_xdp_context_lwt_encap(void)
{
        struct test_xdp_meta *skel;

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

        if (test__start_subtest("bpf_encap"))
                test_lwt_encap(skel, LWT_ENCAP_BPF);
        if (test__start_subtest("mpls_encap"))
                test_lwt_encap(skel, LWT_ENCAP_MPLS);
        if (test__start_subtest("seg6_encap"))
                test_lwt_encap(skel, LWT_ENCAP_SEG6);
        if (test__start_subtest("ioam6_encap"))
                test_lwt_encap(skel, LWT_ENCAP_IOAM6);

        test_xdp_meta__destroy(skel);
}
Linux
