// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Facebook */
#include <test_progs.h>
#include <network_helpers.h>
#include "kfunc_call_fail.skel.h"
#include "kfunc_call_test.skel.h"
#include "kfunc_call_test.lskel.h"
#include "kfunc_call_test_subprog.skel.h"
#include "kfunc_call_test_subprog.lskel.h"
#include "kfunc_call_destructive.skel.h"

#include "cap_helpers.h"

static size_t log_buf_sz = 1048576; /* 1 MB */
static char obj_log_buf[1048576];

enum kfunc_test_type {
        tc_test = 0,
        syscall_test,
        syscall_null_ctx_test,
};

struct kfunc_test_params {
        const char *prog_name;
        unsigned long lskel_prog_desc_offset;
        int retval;
        enum kfunc_test_type test_type;
        const char *expected_err_msg;
};

#define __BPF_TEST_SUCCESS(name, __retval, type) \
        { \
          .prog_name = #name, \
          .lskel_prog_desc_offset = offsetof(struct kfunc_call_test_lskel, progs.name), \
          .retval = __retval, \
          .test_type = type, \
          .expected_err_msg = NULL, \
        }

#define __BPF_TEST_FAIL(name, __retval, type, error_msg) \
        { \
          .prog_name = #name, \
          .lskel_prog_desc_offset = 0 /* unused when test is failing */, \
          .retval = __retval, \
          .test_type = type, \
          .expected_err_msg = error_msg, \
        }

#define TC_TEST(name, retval) __BPF_TEST_SUCCESS(name, retval, tc_test)
#define SYSCALL_TEST(name, retval) __BPF_TEST_SUCCESS(name, retval, syscall_test)
#define SYSCALL_NULL_CTX_TEST(name, retval) __BPF_TEST_SUCCESS(name, retval, syscall_null_ctx_test)

#define TC_FAIL(name, retval, error_msg) __BPF_TEST_FAIL(name, retval, tc_test, error_msg)
#define SYSCALL_NULL_CTX_FAIL(name, retval, error_msg) \
        __BPF_TEST_FAIL(name, retval, syscall_null_ctx_test, error_msg)

static struct kfunc_test_params kfunc_tests[] = {
        /* failure cases:
         * if retval is 0 -> the program will fail to load and the error message is an error
         * if retval is not 0 -> the program can be loaded but running it will gives the
         *                       provided return value. The error message is thus the one
         *                       from a successful load
         */
        SYSCALL_NULL_CTX_FAIL(kfunc_syscall_test_fail, -EINVAL, "processed 4 insns"),
        SYSCALL_NULL_CTX_FAIL(kfunc_syscall_test_null_fail, -EINVAL, "processed 4 insns"),
        TC_FAIL(kfunc_call_test_get_mem_fail_rdonly, 0, "R0 cannot write into rdonly_mem"),
        TC_FAIL(kfunc_call_test_get_mem_fail_use_after_free, 0, "invalid mem access 'scalar'"),
        TC_FAIL(kfunc_call_test_get_mem_fail_oob, 0, "min value is outside of the allowed memory range"),
        TC_FAIL(kfunc_call_test_get_mem_fail_not_const, 0, "is not a const"),
        TC_FAIL(kfunc_call_test_mem_acquire_fail, 0, "acquire kernel function does not return PTR_TO_BTF_ID"),
        TC_FAIL(kfunc_call_test_pointer_arg_type_mismatch, 0, "arg#0 expected pointer to ctx, but got scalar"),

        /* success cases */
        TC_TEST(kfunc_call_test1, 12),
        TC_TEST(kfunc_call_test2, 3),
        TC_TEST(kfunc_call_test4, -1234),
        TC_TEST(kfunc_call_test_ref_btf_id, 0),
        TC_TEST(kfunc_call_test_get_mem, 42),
        SYSCALL_TEST(kfunc_syscall_test, 0),
        SYSCALL_NULL_CTX_TEST(kfunc_syscall_test_null, 0),
        TC_TEST(kfunc_call_test_static_unused_arg, 0),
        TC_TEST(kfunc_call_ctx, 0),
};

struct syscall_test_args {
        __u8 data[16];
        size_t size;
};

static void verify_success(struct kfunc_test_params *param)
{
        struct kfunc_call_test_lskel *lskel = NULL;
        LIBBPF_OPTS(bpf_test_run_opts, topts);
        struct bpf_prog_desc *lskel_prog;
        struct kfunc_call_test *skel;
        struct bpf_program *prog;
        int prog_fd, err;
        struct syscall_test_args args = {
                .size = 10,
        };

        switch (param->test_type) {
        case syscall_test:
                topts.ctx_in = &args;
                topts.ctx_size_in = sizeof(args);
                /* fallthrough */
        case syscall_null_ctx_test:
                break;
        case tc_test:
                topts.data_in = &pkt_v4;
                topts.data_size_in = sizeof(pkt_v4);
                topts.repeat = 1;
                break;
        }

        /* first test with normal libbpf */
        skel = kfunc_call_test__open_and_load();
        if (!ASSERT_OK_PTR(skel, "skel"))
                return;

        prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
        if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
                goto cleanup;

        prog_fd = bpf_program__fd(prog);
        err = bpf_prog_test_run_opts(prog_fd, &topts);
        if (!ASSERT_OK(err, param->prog_name))
                goto cleanup;

        if (!ASSERT_EQ(topts.retval, param->retval, "retval"))
                goto cleanup;

        /* second test with light skeletons */
        lskel = kfunc_call_test_lskel__open_and_load();
        if (!ASSERT_OK_PTR(lskel, "lskel"))
                goto cleanup;

        lskel_prog = (struct bpf_prog_desc *)((char *)lskel + param->lskel_prog_desc_offset);

        prog_fd = lskel_prog->prog_fd;
        err = bpf_prog_test_run_opts(prog_fd, &topts);
        if (!ASSERT_OK(err, param->prog_name))
                goto cleanup;

        ASSERT_EQ(topts.retval, param->retval, "retval");

cleanup:
        kfunc_call_test__destroy(skel);
        if (lskel)
                kfunc_call_test_lskel__destroy(lskel);
}

static void verify_fail(struct kfunc_test_params *param)
{
        LIBBPF_OPTS(bpf_object_open_opts, opts);
        LIBBPF_OPTS(bpf_test_run_opts, topts);
        struct bpf_program *prog;
        struct kfunc_call_fail *skel;
        int prog_fd, err;
        struct syscall_test_args args = {
                .size = 10,
        };

        opts.kernel_log_buf = obj_log_buf;
        opts.kernel_log_size = log_buf_sz;
        opts.kernel_log_level = 1;

        switch (param->test_type) {
        case syscall_test:
                topts.ctx_in = &args;
                topts.ctx_size_in = sizeof(args);
                /* fallthrough */
        case syscall_null_ctx_test:
                break;
        case tc_test:
                topts.data_in = &pkt_v4;
                topts.data_size_in = sizeof(pkt_v4);
                topts.repeat = 1;
                break;
        }

        skel = kfunc_call_fail__open_opts(&opts);
        if (!ASSERT_OK_PTR(skel, "kfunc_call_fail__open_opts"))
                goto cleanup;

        prog = bpf_object__find_program_by_name(skel->obj, param->prog_name);
        if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
                goto cleanup;

        bpf_program__set_autoload(prog, true);

        err = kfunc_call_fail__load(skel);
        if (!param->retval) {
                /* the verifier is supposed to complain and refuses to load */
                if (!ASSERT_ERR(err, "unexpected load success"))
                        goto out_err;

        } else {
                /* the program is loaded but must dynamically fail */
                if (!ASSERT_OK(err, "unexpected load error"))
                        goto out_err;

                prog_fd = bpf_program__fd(prog);
                err = bpf_prog_test_run_opts(prog_fd, &topts);
                if (!ASSERT_EQ(err, param->retval, param->prog_name))
                        goto out_err;
        }

out_err:
        if (!ASSERT_OK_PTR(strstr(obj_log_buf, param->expected_err_msg), "expected_err_msg")) {
                fprintf(stderr, "Expected err_msg: %s\n", param->expected_err_msg);
                fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
        }

cleanup:
        kfunc_call_fail__destroy(skel);
}

static void test_main(void)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(kfunc_tests); i++) {
                if (!test__start_subtest(kfunc_tests[i].prog_name))
                        continue;

                if (!kfunc_tests[i].expected_err_msg)
                        verify_success(&kfunc_tests[i]);
                else
                        verify_fail(&kfunc_tests[i]);
        }
}

static void test_subprog(void)
{
        struct kfunc_call_test_subprog *skel;
        int prog_fd, err;
        LIBBPF_OPTS(bpf_test_run_opts, topts,
                .data_in = &pkt_v4,
                .data_size_in = sizeof(pkt_v4),
                .repeat = 1,
        );

        skel = kfunc_call_test_subprog__open_and_load();
        if (!ASSERT_OK_PTR(skel, "skel"))
                return;

        prog_fd = bpf_program__fd(skel->progs.kfunc_call_test1);
        err = bpf_prog_test_run_opts(prog_fd, &topts);
        ASSERT_OK(err, "bpf_prog_test_run(test1)");
        ASSERT_EQ(topts.retval, 10, "test1-retval");
        ASSERT_NEQ(skel->data->active_res, -1, "active_res");
        ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");

        kfunc_call_test_subprog__destroy(skel);
}

static void test_subprog_lskel(void)
{
        struct kfunc_call_test_subprog_lskel *skel;
        int prog_fd, err;
        LIBBPF_OPTS(bpf_test_run_opts, topts,
                .data_in = &pkt_v4,
                .data_size_in = sizeof(pkt_v4),
                .repeat = 1,
        );

        skel = kfunc_call_test_subprog_lskel__open_and_load();
        if (!ASSERT_OK_PTR(skel, "skel"))
                return;

        prog_fd = skel->progs.kfunc_call_test1.prog_fd;
        err = bpf_prog_test_run_opts(prog_fd, &topts);
        ASSERT_OK(err, "bpf_prog_test_run(test1)");
        ASSERT_EQ(topts.retval, 10, "test1-retval");
        ASSERT_NEQ(skel->data->active_res, -1, "active_res");
        ASSERT_EQ(skel->data->sk_state_res, BPF_TCP_CLOSE, "sk_state_res");

        kfunc_call_test_subprog_lskel__destroy(skel);
}

static int test_destructive_open_and_load(void)
{
        struct kfunc_call_destructive *skel;
        int err;

        skel = kfunc_call_destructive__open();
        if (!ASSERT_OK_PTR(skel, "prog_open"))
                return -1;

        err = kfunc_call_destructive__load(skel);

        kfunc_call_destructive__destroy(skel);

        return err;
}

static void test_destructive(void)
{
        __u64 save_caps = 0;

        ASSERT_OK(test_destructive_open_and_load(), "successful_load");

        if (!ASSERT_OK(cap_disable_effective(1ULL << CAP_SYS_BOOT, &save_caps), "drop_caps"))
                return;

        ASSERT_EQ(test_destructive_open_and_load(), -13, "no_caps_failure");

        cap_enable_effective(save_caps, NULL);
}

void test_kfunc_call(void)
{
        test_main();

        if (test__start_subtest("subprog"))
                test_subprog();

        if (test__start_subtest("subprog_lskel"))
                test_subprog_lskel();

        if (test__start_subtest("destructive"))
                test_destructive();
}