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

static void test_xdp_update_frags(void)
{
        const char *file = "./test_xdp_update_frags.bpf.o";
        int err, prog_fd, max_skb_frags, buf_size, num;
        struct bpf_program *prog;
        struct bpf_object *obj;
        __u32 *offset;
        __u8 *buf;
        FILE *f;
        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))
                return;

        prog_fd = bpf_program__fd(prog);

        buf = malloc(128);
        if (!ASSERT_OK_PTR(buf, "alloc buf 128b"))
                goto out;

        memset(buf, 0, 128);
        offset = (__u32 *)buf;
        *offset = 16;
        buf[*offset] = 0xaa;            /* marker at offset 16 (head) */
        buf[*offset + 15] = 0xaa;       /* marker at offset 31 (head) */

        topts.data_in = buf;
        topts.data_out = buf;
        topts.data_size_in = 128;
        topts.data_size_out = 128;

        err = bpf_prog_test_run_opts(prog_fd, &topts);

        /* test_xdp_update_frags: buf[16,31]: 0xaa -> 0xbb */
        ASSERT_OK(err, "xdp_update_frag");
        ASSERT_EQ(topts.retval, XDP_PASS, "xdp_update_frag retval");
        ASSERT_EQ(buf[16], 0xbb, "xdp_update_frag buf[16]");
        ASSERT_EQ(buf[31], 0xbb, "xdp_update_frag buf[31]");

        free(buf);

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

        memset(buf, 0, 9000);
        offset = (__u32 *)buf;
        *offset = 5000;
        buf[*offset] = 0xaa;            /* marker at offset 5000 (frag0) */
        buf[*offset + 15] = 0xaa;       /* marker at offset 5015 (frag0) */

        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);

        /* test_xdp_update_frags: buf[5000,5015]: 0xaa -> 0xbb */
        ASSERT_OK(err, "xdp_update_frag");
        ASSERT_EQ(topts.retval, XDP_PASS, "xdp_update_frag retval");
        ASSERT_EQ(buf[5000], 0xbb, "xdp_update_frag buf[5000]");
        ASSERT_EQ(buf[5015], 0xbb, "xdp_update_frag buf[5015]");

        memset(buf, 0, 9000);
        offset = (__u32 *)buf;
        *offset = 3510;
        buf[*offset] = 0xaa;            /* marker at offset 3510 (head) */
        buf[*offset + 15] = 0xaa;       /* marker at offset 3525 (frag0) */

        err = bpf_prog_test_run_opts(prog_fd, &topts);

        /* test_xdp_update_frags: buf[3510,3525]: 0xaa -> 0xbb */
        ASSERT_OK(err, "xdp_update_frag");
        ASSERT_EQ(topts.retval, XDP_PASS, "xdp_update_frag retval");
        ASSERT_EQ(buf[3510], 0xbb, "xdp_update_frag buf[3510]");
        ASSERT_EQ(buf[3525], 0xbb, "xdp_update_frag buf[3525]");

        memset(buf, 0, 9000);
        offset = (__u32 *)buf;
        *offset = 7606;
        buf[*offset] = 0xaa;            /* marker at offset 7606 (frag0) */
        buf[*offset + 15] = 0xaa;       /* marker at offset 7621 (frag1) */

        err = bpf_prog_test_run_opts(prog_fd, &topts);

        /* test_xdp_update_frags: buf[7606,7621]: 0xaa -> 0xbb */
        ASSERT_OK(err, "xdp_update_frag");
        ASSERT_EQ(topts.retval, XDP_PASS, "xdp_update_frag retval");
        ASSERT_EQ(buf[7606], 0xbb, "xdp_update_frag buf[7606]");
        ASSERT_EQ(buf[7621], 0xbb, "xdp_update_frag buf[7621]");

        free(buf);

        /* test_xdp_update_frags: unsupported buffer size */
        f = fopen("/proc/sys/net/core/max_skb_frags", "r");
        if (!ASSERT_OK_PTR(f, "max_skb_frag file pointer"))
                goto out;

        num = fscanf(f, "%d", &max_skb_frags);
        fclose(f);

        if (!ASSERT_EQ(num, 1, "max_skb_frags read failed"))
                goto out;

        /* xdp_buff linear area size is always set to 4096 in the
         * bpf_prog_test_run_xdp routine.
         */
        buf_size = 4096 + (max_skb_frags + 1) * sysconf(_SC_PAGE_SIZE);
        buf = malloc(buf_size);
        if (!ASSERT_OK_PTR(buf, "alloc buf"))
                goto out;

        memset(buf, 0, buf_size);
        offset = (__u32 *)buf;
        *offset = 16;
        buf[*offset] = 0xaa;
        buf[*offset + 15] = 0xaa;

        topts.data_in = buf;
        topts.data_out = buf;
        topts.data_size_in = buf_size;
        topts.data_size_out = buf_size;

        err = bpf_prog_test_run_opts(prog_fd, &topts);
        ASSERT_EQ(err, -ENOMEM,
                  "unsupported buf size, possible non-default /proc/sys/net/core/max_skb_flags?");
        free(buf);
out:
        bpf_object__close(obj);
}

void test_xdp_adjust_frags(void)
{
        if (test__start_subtest("xdp_adjust_frags"))
                test_xdp_update_frags();
}