// SPDX-License-Identifier: GPL-2.0-only
#define _GNU_SOURCE
#include <test_progs.h>

struct inst {
        struct bpf_object *obj;
        struct bpf_link   *link;
};

static struct bpf_program *load_prog(char *file, char *name, struct inst *inst)
{
        struct bpf_object *obj;
        struct bpf_program *prog;
        int err;

        obj = bpf_object__open_file(file, NULL);
        if (!ASSERT_OK_PTR(obj, "obj_open_file"))
                return NULL;

        inst->obj = obj;

        err = bpf_object__load(obj);
        if (!ASSERT_OK(err, "obj_load"))
                return NULL;

        prog = bpf_object__find_program_by_name(obj, name);
        if (!ASSERT_OK_PTR(prog, "obj_find_prog"))
                return NULL;

        return prog;
}

/* TODO: use different target function to run in concurrent mode */
void serial_test_trampoline_count(void)
{
        char *file = "test_trampoline_count.bpf.o";
        char *const progs[] = { "fentry_test", "fmod_ret_test", "fexit_test" };
        int bpf_max_tramp_links, err, i, prog_fd;
        struct bpf_program *prog;
        struct bpf_link *link;
        struct inst *inst;
        LIBBPF_OPTS(bpf_test_run_opts, opts);

        bpf_max_tramp_links = get_bpf_max_tramp_links();
        if (!ASSERT_GE(bpf_max_tramp_links, 1, "bpf_max_tramp_links"))
                return;
        inst = calloc(bpf_max_tramp_links + 1, sizeof(*inst));
        if (!ASSERT_OK_PTR(inst, "inst"))
                return;

        /* attach 'allowed' trampoline programs */
        for (i = 0; i < bpf_max_tramp_links; i++) {
                prog = load_prog(file, progs[i % ARRAY_SIZE(progs)], &inst[i]);
                if (!prog)
                        goto cleanup;

                link = bpf_program__attach(prog);
                if (!ASSERT_OK_PTR(link, "attach_prog"))
                        goto cleanup;

                inst[i].link = link;
        }

        /* and try 1 extra.. */
        prog = load_prog(file, "fmod_ret_test", &inst[i]);
        if (!prog)
                goto cleanup;

        /* ..that needs to fail */
        link = bpf_program__attach(prog);
        if (!ASSERT_ERR_PTR(link, "attach_prog")) {
                inst[i].link = link;
                goto cleanup;
        }

        /* with E2BIG error */
        if (!ASSERT_EQ(libbpf_get_error(link), -E2BIG, "E2BIG"))
                goto cleanup;
        if (!ASSERT_EQ(link, NULL, "ptr_is_null"))
                goto cleanup;

        /* and finally execute the probe */
        prog_fd = bpf_program__fd(prog);
        if (!ASSERT_GE(prog_fd, 0, "bpf_program__fd"))
                goto cleanup;

        err = bpf_prog_test_run_opts(prog_fd, &opts);
        if (!ASSERT_OK(err, "bpf_prog_test_run_opts"))
                goto cleanup;

        ASSERT_EQ(opts.retval & 0xffff, 33, "bpf_modify_return_test.result");
        ASSERT_EQ(opts.retval >> 16, 2, "bpf_modify_return_test.side_effect");

cleanup:
        for (; i >= 0; i--) {
                bpf_link__destroy(inst[i].link);
                bpf_object__close(inst[i].obj);
        }
        free(inst);
}