// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */

#include <test_progs.h>
#include <stdbool.h>
#include "test_module_attach.skel.h"
#include "testing_helpers.h"

static const char * const read_tests[] = {
        "handle_raw_tp",
        "handle_tp_btf",
        "handle_fentry",
        "handle_fentry_explicit",
        "handle_fmod_ret",
};

static const char * const detach_tests[] = {
        "handle_fentry",
        "handle_fexit",
        "kprobe_multi",
};

static const int READ_SZ = 456;
static const int WRITE_SZ = 457;

static int trigger_module_test_writable(int *val)
{
        int fd, err;
        char buf[65];
        ssize_t rd;

        fd = open(BPF_TESTMOD_TEST_FILE, O_RDONLY);
        err = -errno;
        if (!ASSERT_GE(fd, 0, "testmode_file_open"))
                return err;

        rd = read(fd, buf, sizeof(buf) - 1);
        err = -errno;
        if (!ASSERT_GT(rd, 0, "testmod_file_rd_val")) {
                close(fd);
                return err;
        }

        buf[rd] = '\0';
        *val = strtol(buf, NULL, 0);
        close(fd);

        return 0;
}

static void test_module_attach_prog(const char *prog_name, int sz,
                                    const char *attach_target, int ret)
{
        struct test_module_attach *skel;
        struct bpf_program *prog;
        int err;

        skel = test_module_attach__open();
        if (!ASSERT_OK_PTR(skel, "module_attach open"))
                return;

        prog = bpf_object__find_program_by_name(skel->obj, prog_name);
        if (!ASSERT_OK_PTR(prog, "module_attach find_program"))
                goto cleanup;
        bpf_program__set_autoload(prog, true);

        if (attach_target) {
                err = bpf_program__set_attach_target(prog, 0, attach_target);
                if (!ASSERT_OK(err, attach_target))
                        goto cleanup;
        }

        err = test_module_attach__load(skel);
        if (!ASSERT_OK(err, "module_attach load"))
                goto cleanup;

        err = test_module_attach__attach(skel);
        if (!ASSERT_OK(err, "module_attach attach"))
                goto cleanup;

        if (sz) {
                /* trigger both read and write though each test uses only one */
                ASSERT_OK(trigger_module_test_read(sz), "trigger_read");
                ASSERT_OK(trigger_module_test_write(sz), "trigger_write");

                ASSERT_EQ(skel->bss->sz, sz, prog_name);
        }

        if (ret)
                ASSERT_EQ(skel->bss->retval, ret, "ret");
cleanup:
        test_module_attach__destroy(skel);
}

static void test_module_attach_writable(void)
{
        struct test_module_attach__bss *bss;
        struct test_module_attach *skel;
        int writable_val = 0;
        int err;

        skel = test_module_attach__open();
        if (!ASSERT_OK_PTR(skel, "module_attach open"))
                return;

        bpf_program__set_autoload(skel->progs.handle_raw_tp_writable_bare, true);

        err = test_module_attach__load(skel);
        if (!ASSERT_OK(err, "module_attach load"))
                goto cleanup;

        bss = skel->bss;

        err = test_module_attach__attach(skel);
        if (!ASSERT_OK(err, "module_attach attach"))
                goto cleanup;

        bss->raw_tp_writable_bare_early_ret = true;
        bss->raw_tp_writable_bare_out_val = 0xf1f2f3f4;
        ASSERT_OK(trigger_module_test_writable(&writable_val),
                  "trigger_writable");
        ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test_in");
        ASSERT_EQ(bss->raw_tp_writable_bare_out_val, writable_val,
                  "writable_test_out");
cleanup:
        test_module_attach__destroy(skel);
}

static void test_module_attach_detach(const char *prog_name)
{
        struct test_module_attach *skel;
        struct bpf_program *prog;
        struct bpf_link *link;
        int err;

        skel = test_module_attach__open();
        if (!ASSERT_OK_PTR(skel, "module_attach open"))
                return;

        prog = bpf_object__find_program_by_name(skel->obj, prog_name);
        if (!ASSERT_OK_PTR(prog, "module_attach find_program"))
                goto cleanup;
        bpf_program__set_autoload(prog, true);

        err = test_module_attach__load(skel);
        if (!ASSERT_OK(err, "module_attach load"))
                goto cleanup;

        /* attach and make sure it gets module reference */
        link = bpf_program__attach(prog);
        if (!ASSERT_OK_PTR(link, "module_attach attach"))
                goto cleanup;

        ASSERT_ERR(try_unload_module("bpf_testmod", 1, false), "try_unload_module");
        bpf_link__destroy(link);
cleanup:
        test_module_attach__destroy(skel);
}

void test_module_attach(void)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(read_tests); i++) {
                if (!test__start_subtest(read_tests[i]))
                        continue;
                test_module_attach_prog(read_tests[i], READ_SZ, NULL, 0);
        }
        if (test__start_subtest("handle_raw_tp_bare"))
                test_module_attach_prog("handle_raw_tp_bare", WRITE_SZ, NULL, 0);
        if (test__start_subtest("handle_raw_tp_writable_bare"))
                test_module_attach_writable();
        if (test__start_subtest("handle_fentry_manual")) {
                test_module_attach_prog("handle_fentry_manual", READ_SZ,
                                        "bpf_testmod_test_read", 0);
        }
        if (test__start_subtest("handle_fentry_explicit_manual")) {
                test_module_attach_prog("handle_fentry_explicit_manual",
                                        READ_SZ,
                                        "bpf_testmod:bpf_testmod_test_read", 0);
        }
        if (test__start_subtest("handle_fexit"))
                test_module_attach_prog("handle_fexit", READ_SZ, NULL, -EIO);
        if (test__start_subtest("handle_fexit_ret"))
                test_module_attach_prog("handle_fexit_ret", 0, NULL, 0);
        for (i = 0; i < ARRAY_SIZE(detach_tests); i++) {
                char test_name[50];

                snprintf(test_name, sizeof(test_name), "%s_detach", detach_tests[i]);
                if (!test__start_subtest(test_name))
                        continue;
                test_module_attach_detach(detach_tests[i]);
        }
}