// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include <network_helpers.h>

static void test_xdp_adjust_tail_shrink(void)
{
        const char *file = "./test_xdp_adjust_tail_shrink.bpf.o";
        __u32 expect_sz;
        struct bpf_object *obj;
        int err, prog_fd;
        char buf[128];
        LIBBPF_OPTS(bpf_test_run_opts, topts,
                .data_in = &pkt_v4,
                .data_size_in = sizeof(pkt_v4),
                .data_out = buf,
                .data_size_out = sizeof(buf),
                .repeat = 1,
        );

        err = bpf_prog_test_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
        if (!ASSERT_OK(err, "test_xdp_adjust_tail_shrink"))
                return;

        err = bpf_prog_test_run_opts(prog_fd, &topts);
        ASSERT_OK(err, "ipv4");
        ASSERT_EQ(topts.retval, XDP_DROP, "ipv4 retval");

        expect_sz = sizeof(pkt_v6) - 20;  /* Test shrink with 20 bytes */
        topts.data_in = &pkt_v6;
        topts.data_size_in = sizeof(pkt_v6);
        topts.data_size_out = sizeof(buf);
        err = bpf_prog_test_run_opts(prog_fd, &topts);
        ASSERT_OK(err, "ipv6");
        ASSERT_EQ(topts.retval, XDP_TX, "ipv6 retval");
        ASSERT_EQ(topts.data_size_out, expect_sz, "ipv6 size");

        bpf_object__close(obj);
}

static void test_xdp_adjust_tail_grow(bool is_64k_pagesize)
{
        const char *file = "./test_xdp_adjust_tail_grow.bpf.o";
        struct bpf_object *obj;
        char buf[8192]; /* avoid segfault: large buf to hold grow results */
        __u32 expect_sz;
        int err, prog_fd;
        LIBBPF_OPTS(bpf_test_run_opts, topts,
                .data_in = &pkt_v4,
                .data_out = buf,
                .data_size_out = sizeof(buf),
                .repeat = 1,
        );

        /* topts.data_size_in as a special signal to bpf prog */
        if (is_64k_pagesize)
                topts.data_size_in = sizeof(pkt_v4) - 1;
        else
                topts.data_size_in = sizeof(pkt_v4);

        err = bpf_prog_test_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
        if (!ASSERT_OK(err, "test_xdp_adjust_tail_grow"))
                return;

        err = bpf_prog_test_run_opts(prog_fd, &topts);
        ASSERT_OK(err, "ipv4");
        ASSERT_EQ(topts.retval, XDP_DROP, "ipv4 retval");

        expect_sz = sizeof(pkt_v6) + 40; /* Test grow with 40 bytes */
        topts.data_in = &pkt_v6;
        topts.data_size_in = sizeof(pkt_v6);
        topts.data_size_out = sizeof(buf);
        err = bpf_prog_test_run_opts(prog_fd, &topts);
        ASSERT_OK(err, "ipv6");
        ASSERT_EQ(topts.retval, XDP_TX, "ipv6 retval");
        ASSERT_EQ(topts.data_size_out, expect_sz, "ipv6 size");

        bpf_object__close(obj);
}

static void test_xdp_adjust_tail_grow2(void)
{
        const char *file = "./test_xdp_adjust_tail_grow.bpf.o";
        char buf[4096]; /* avoid segfault: large buf to hold grow results */
        struct bpf_object *obj;
        int err, cnt, i;
        int max_grow, prog_fd;
        /* SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) */
#if defined(__s390x__)
        int tailroom = 512;
#elif defined(__powerpc__)
        int tailroom = 384;
#else
        int tailroom = 320;
#endif

        LIBBPF_OPTS(bpf_test_run_opts, tattr,
                .repeat         = 1,
                .data_in        = &buf,
                .data_out       = &buf,
                .data_size_in   = 0, /* Per test */
                .data_size_out  = 0, /* Per test */
        );

        err = bpf_prog_test_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
        if (!ASSERT_OK(err, "test_xdp_adjust_tail_grow"))
                return;

        /* Test case-64 */
        memset(buf, 1, sizeof(buf));
        tattr.data_size_in  =  64; /* Determine test case via pkt size */
        tattr.data_size_out = 128; /* Limit copy_size */
        /* Kernel side alloc packet memory area that is zero init */
        err = bpf_prog_test_run_opts(prog_fd, &tattr);

        ASSERT_EQ(errno, ENOSPC, "case-64 errno"); /* Due limit copy_size in bpf_test_finish */
        ASSERT_EQ(tattr.retval, XDP_TX, "case-64 retval");
        ASSERT_EQ(tattr.data_size_out, 192, "case-64 data_size_out"); /* Expected grow size */

        /* Extra checks for data contents */
        ASSERT_EQ(buf[0], 1, "case-64-data buf[0]"); /*  0-63  memset to 1 */
        ASSERT_EQ(buf[63], 1, "case-64-data buf[63]");
        ASSERT_EQ(buf[64], 0, "case-64-data buf[64]"); /* 64-127 memset to 0 */
        ASSERT_EQ(buf[127], 0, "case-64-data buf[127]");
        ASSERT_EQ(buf[128], 1, "case-64-data buf[128]"); /* 128-191 memset to 1 */
        ASSERT_EQ(buf[191], 1, "case-64-data buf[191]");

        /* Test case-128 */
        memset(buf, 2, sizeof(buf));
        tattr.data_size_in  = 128; /* Determine test case via pkt size */
        tattr.data_size_out = sizeof(buf);   /* Copy everything */
        err = bpf_prog_test_run_opts(prog_fd, &tattr);

        max_grow = 4096 - XDP_PACKET_HEADROOM - tailroom; /* 3520 */
        ASSERT_OK(err, "case-128");
        ASSERT_EQ(tattr.retval, XDP_TX, "case-128 retval");
        ASSERT_EQ(tattr.data_size_out, max_grow, "case-128 data_size_out"); /* Expect max grow */

        /* Extra checks for data content: Count grow size, will contain zeros */
        for (i = 0, cnt = 0; i < sizeof(buf); i++) {
                if (buf[i] == 0)
                        cnt++;
        }
        ASSERT_EQ(cnt, max_grow - tattr.data_size_in, "case-128-data cnt"); /* Grow increase */
        ASSERT_EQ(tattr.data_size_out, max_grow, "case-128-data data_size_out"); /* Total grow */

        bpf_object__close(obj);
}

static void test_xdp_adjust_frags_tail_shrink(void)
{
        const char *file = "./test_xdp_adjust_tail_shrink.bpf.o";
        __u32 exp_size;
        struct bpf_program *prog;
        struct bpf_object *obj;
        int err, prog_fd;
        __u8 *buf;
        LIBBPF_OPTS(bpf_test_run_opts, topts);

        /* For the individual test cases, the first byte in the packet
         * indicates which test will be run.
         */
        obj = bpf_object__open(file);
        if (libbpf_get_error(obj))
                return;

        prog = bpf_object__next_program(obj, NULL);
        if (bpf_object__load(obj))
                return;

        prog_fd = bpf_program__fd(prog);

        buf = malloc(9000);
        if (!ASSERT_OK_PTR(buf, "alloc buf 9Kb"))
                goto out;

        memset(buf, 0, 9000);

        /* Test case removing 10 bytes from last frag, NOT freeing it */
        exp_size = 8990; /* 9000 - 10 */
        topts.data_in = buf;
        topts.data_out = buf;
        topts.data_size_in = 9000;
        topts.data_size_out = 9000;
        err = bpf_prog_test_run_opts(prog_fd, &topts);

        ASSERT_OK(err, "9Kb-10b");
        ASSERT_EQ(topts.retval, XDP_TX, "9Kb-10b retval");
        ASSERT_EQ(topts.data_size_out, exp_size, "9Kb-10b size");

        /* Test case removing one of two pages, assuming 4K pages */
        buf[0] = 1;
        exp_size = 4900; /* 9000 - 4100 */

        topts.data_size_out = 9000; /* reset from previous invocation */
        err = bpf_prog_test_run_opts(prog_fd, &topts);

        ASSERT_OK(err, "9Kb-4Kb");
        ASSERT_EQ(topts.retval, XDP_TX, "9Kb-4Kb retval");
        ASSERT_EQ(topts.data_size_out, exp_size, "9Kb-4Kb size");

        /* Test case removing two pages resulting in a linear xdp_buff */
        buf[0] = 2;
        exp_size = 800; /* 9000 - 8200 */
        topts.data_size_out = 9000; /* reset from previous invocation */
        err = bpf_prog_test_run_opts(prog_fd, &topts);

        ASSERT_OK(err, "9Kb-9Kb");
        ASSERT_EQ(topts.retval, XDP_TX, "9Kb-9Kb retval");
        ASSERT_EQ(topts.data_size_out, exp_size, "9Kb-9Kb size");

        free(buf);
out:
        bpf_object__close(obj);
}

static void test_xdp_adjust_frags_tail_grow_4k(void)
{
        const char *file = "./test_xdp_adjust_tail_grow.bpf.o";
        __u32 exp_size;
        struct bpf_program *prog;
        struct bpf_object *obj;
        int err, i, prog_fd;
        __u8 *buf;
        LIBBPF_OPTS(bpf_test_run_opts, topts);

        obj = bpf_object__open(file);
        if (libbpf_get_error(obj))
                return;

        prog = bpf_object__next_program(obj, NULL);
        if (bpf_object__load(obj))
                goto out;

        prog_fd = bpf_program__fd(prog);

        buf = malloc(16384);
        if (!ASSERT_OK_PTR(buf, "alloc buf 16Kb"))
                goto out;

        /* Test case add 10 bytes to last frag */
        memset(buf, 1, 16384);
        exp_size = 9000 + 10;

        topts.data_in = buf;
        topts.data_out = buf;
        topts.data_size_in = 9000;
        topts.data_size_out = 16384;
        err = bpf_prog_test_run_opts(prog_fd, &topts);

        ASSERT_OK(err, "9Kb+10b");
        ASSERT_EQ(topts.retval, XDP_TX, "9Kb+10b retval");
        ASSERT_EQ(topts.data_size_out, exp_size, "9Kb+10b size");

        for (i = 0; i < 9000; i++) {
                if (buf[i] != 1)
                        ASSERT_EQ(buf[i], 1, "9Kb+10b-old");
        }

        for (i = 9000; i < 9010; i++) {
                if (buf[i] != 0)
                        ASSERT_EQ(buf[i], 0, "9Kb+10b-new");
        }

        for (i = 9010; i < 16384; i++) {
                if (buf[i] != 1)
                        ASSERT_EQ(buf[i], 1, "9Kb+10b-untouched");
        }

        /* Test a too large grow */
        memset(buf, 1, 16384);
        exp_size = 9001;

        topts.data_in = topts.data_out = buf;
        topts.data_size_in = 9001;
        topts.data_size_out = 16384;
        err = bpf_prog_test_run_opts(prog_fd, &topts);

        ASSERT_OK(err, "9Kb+10b");
        ASSERT_EQ(topts.retval, XDP_DROP, "9Kb+10b retval");
        ASSERT_EQ(topts.data_size_out, exp_size, "9Kb+10b size");

        free(buf);
out:
        bpf_object__close(obj);
}

static void test_xdp_adjust_frags_tail_grow_64k(void)
{
        const char *file = "./test_xdp_adjust_tail_grow.bpf.o";
        __u32 exp_size;
        struct bpf_program *prog;
        struct bpf_object *obj;
        int err, i, prog_fd;
        __u8 *buf;
        LIBBPF_OPTS(bpf_test_run_opts, topts);

        obj = bpf_object__open(file);
        if (libbpf_get_error(obj))
                return;

        prog = bpf_object__next_program(obj, NULL);
        if (bpf_object__load(obj))
                goto out;

        prog_fd = bpf_program__fd(prog);

        buf = malloc(262144);
        if (!ASSERT_OK_PTR(buf, "alloc buf 256Kb"))
                goto out;

        /* Test case add 10 bytes to last frag */
        memset(buf, 1, 262144);
        exp_size = 90000 + 10;

        topts.data_in = buf;
        topts.data_out = buf;
        topts.data_size_in = 90000;
        topts.data_size_out = 262144;
        err = bpf_prog_test_run_opts(prog_fd, &topts);

        ASSERT_OK(err, "90Kb+10b");
        ASSERT_EQ(topts.retval, XDP_TX, "90Kb+10b retval");
        ASSERT_EQ(topts.data_size_out, exp_size, "90Kb+10b size");

        for (i = 0; i < 90000; i++) {
                if (buf[i] != 1)
                        ASSERT_EQ(buf[i], 1, "90Kb+10b-old");
        }

        for (i = 90000; i < 90010; i++) {
                if (buf[i] != 0)
                        ASSERT_EQ(buf[i], 0, "90Kb+10b-new");
        }

        for (i = 90010; i < 262144; i++) {
                if (buf[i] != 1)
                        ASSERT_EQ(buf[i], 1, "90Kb+10b-untouched");
        }

        /* Test a too large grow */
        memset(buf, 1, 262144);
        exp_size = 90001;

        topts.data_in = topts.data_out = buf;
        topts.data_size_in = 90001;
        topts.data_size_out = 262144;
        err = bpf_prog_test_run_opts(prog_fd, &topts);

        ASSERT_OK(err, "90Kb+10b");
        ASSERT_EQ(topts.retval, XDP_DROP, "90Kb+10b retval");
        ASSERT_EQ(topts.data_size_out, exp_size, "90Kb+10b size");

        free(buf);
out:
        bpf_object__close(obj);
}

void test_xdp_adjust_tail(void)
{
        int page_size = getpagesize();

        if (test__start_subtest("xdp_adjust_tail_shrink"))
                test_xdp_adjust_tail_shrink();
        if (test__start_subtest("xdp_adjust_tail_grow"))
                test_xdp_adjust_tail_grow(page_size == 65536);
        if (test__start_subtest("xdp_adjust_tail_grow2"))
                test_xdp_adjust_tail_grow2();
        if (test__start_subtest("xdp_adjust_frags_tail_shrink"))
                test_xdp_adjust_frags_tail_shrink();
        if (test__start_subtest("xdp_adjust_frags_tail_grow")) {
                if (page_size == 65536)
                        test_xdp_adjust_frags_tail_grow_64k();
                else
                        test_xdp_adjust_frags_tail_grow_4k();
        }
}