// SPDX-License-Identifier: GPL-2.0

#include <test_progs.h>

#include <linux/if_ether.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/in6.h>
#include <linux/udp.h>
#include <linux/tcp.h>

#include <sys/syscall.h>
#include <bpf/bpf.h>

#include "bpf_gotox.skel.h"

static void __test_run(struct bpf_program *prog, void *ctx_in, size_t ctx_size_in)
{
        LIBBPF_OPTS(bpf_test_run_opts, topts,
                            .ctx_in = ctx_in,
                            .ctx_size_in = ctx_size_in,
                   );
        int err, prog_fd;

        prog_fd = bpf_program__fd(prog);
        err = bpf_prog_test_run_opts(prog_fd, &topts);
        ASSERT_OK(err, "test_run_opts err");
}

static void __subtest(struct bpf_gotox *skel, void (*check)(struct bpf_gotox *))
{
        if (skel->data->skip)
                test__skip();
        else
                check(skel);
}

static void check_simple(struct bpf_gotox *skel,
                         struct bpf_program *prog,
                         __u64 ctx_in,
                         __u64 expected)
{
        skel->bss->ret_user = 0;

        __test_run(prog, &ctx_in, sizeof(ctx_in));

        if (!ASSERT_EQ(skel->bss->ret_user, expected, "skel->bss->ret_user"))
                return;
}

static void check_simple_fentry(struct bpf_gotox *skel,
                                struct bpf_program *prog,
                                __u64 ctx_in,
                                __u64 expected)
{
        skel->bss->in_user = ctx_in;
        skel->bss->ret_user = 0;

        /* trigger */
        usleep(1);

        if (!ASSERT_EQ(skel->bss->ret_user, expected, "skel->bss->ret_user"))
                return;
}

/* validate that for two loads of the same jump table libbpf generates only one map */
static void check_one_map_two_jumps(struct bpf_gotox *skel)
{
        struct bpf_prog_info prog_info;
        struct bpf_map_info map_info;
        __u32 len;
        __u32 map_ids[16];
        int prog_fd, map_fd;
        int ret;
        int i;
        bool seen = false;

        memset(&prog_info, 0, sizeof(prog_info));
        prog_info.map_ids = (long)map_ids;
        prog_info.nr_map_ids = ARRAY_SIZE(map_ids);
        prog_fd = bpf_program__fd(skel->progs.one_map_two_jumps);
        if (!ASSERT_GE(prog_fd, 0, "bpf_program__fd(one_map_two_jumps)"))
                return;

        len = sizeof(prog_info);
        ret = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &len);
        if (!ASSERT_OK(ret, "bpf_obj_get_info_by_fd(prog_fd)"))
                return;

        for (i = 0; i < prog_info.nr_map_ids; i++) {
                map_fd  = bpf_map_get_fd_by_id(map_ids[i]);
                if (!ASSERT_GE(map_fd, 0, "bpf_map_get_fd_by_id"))
                        return;

                len = sizeof(map_info);
                memset(&map_info, 0, len);
                ret = bpf_obj_get_info_by_fd(map_fd, &map_info, &len);
                if (!ASSERT_OK(ret, "bpf_obj_get_info_by_fd(map_fd)")) {
                        close(map_fd);
                        return;
                }

                if (map_info.type == BPF_MAP_TYPE_INSN_ARRAY) {
                        if (!ASSERT_EQ(seen, false, "more than one INSN_ARRAY map")) {
                                close(map_fd);
                                return;
                        }
                        seen = true;
                }
                close(map_fd);
        }

        ASSERT_EQ(seen, true, "no INSN_ARRAY map");
}

static void check_one_switch(struct bpf_gotox *skel)
{
        __u64 in[]   = {0, 1, 2, 3, 4,  5, 77};
        __u64 out[]  = {2, 3, 4, 5, 7, 19, 19};
        int i;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple(skel, skel->progs.one_switch, in[i], out[i]);
}

static void check_one_switch_non_zero_sec_off(struct bpf_gotox *skel)
{
        __u64 in[]   = {0, 1, 2, 3, 4,  5, 77};
        __u64 out[]  = {2, 3, 4, 5, 7, 19, 19};
        int i;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple(skel, skel->progs.one_switch_non_zero_sec_off, in[i], out[i]);
}

static void check_two_switches(struct bpf_gotox *skel)
{
        __u64 in[]   = {0, 1, 2, 3, 4,  5, 77};
        __u64 out[] = {103, 104, 107, 205, 115, 1019, 1019};
        int i;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple(skel, skel->progs.two_switches, in[i], out[i]);
}

static void check_big_jump_table(struct bpf_gotox *skel)
{
        __u64 in[]  = {0, 11, 27, 31, 22, 45, 99};
        __u64 out[] = {2,  3,  4,  5, 19, 19, 19};
        int i;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple(skel, skel->progs.big_jump_table, in[i], out[i]);
}

static void check_one_jump_two_maps(struct bpf_gotox *skel)
{
        __u64 in[]  = {0, 1, 2, 3, 4,  5, 77};
        __u64 out[] = {12, 15, 7 , 15, 12, 15, 15};
        int i;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple(skel, skel->progs.one_jump_two_maps, in[i], out[i]);
}

static void check_static_global(struct bpf_gotox *skel)
{
        __u64 in[]   = {0, 1, 2, 3, 4,  5, 77};
        __u64 out[]  = {2, 3, 4, 5, 7, 19, 19};
        int i;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple(skel, skel->progs.use_static_global1, in[i], out[i]);
        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple(skel, skel->progs.use_static_global2, in[i], out[i]);
}

static void check_nonstatic_global(struct bpf_gotox *skel)
{
        __u64 in[]   = {0, 1, 2, 3, 4,  5, 77};
        __u64 out[]  = {2, 3, 4, 5, 7, 19, 19};
        int i;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple(skel, skel->progs.use_nonstatic_global1, in[i], out[i]);

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple(skel, skel->progs.use_nonstatic_global2, in[i], out[i]);
}

static void check_other_sec(struct bpf_gotox *skel)
{
        struct bpf_link *link;
        __u64 in[]   = {0, 1, 2, 3, 4,  5, 77};
        __u64 out[]  = {2, 3, 4, 5, 7, 19, 19};
        int i;

        link = bpf_program__attach(skel->progs.simple_test_other_sec);
        if (!ASSERT_OK_PTR(link, "link"))
                return;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple_fentry(skel, skel->progs.simple_test_other_sec, in[i], out[i]);

        bpf_link__destroy(link);
}

static void check_static_global_other_sec(struct bpf_gotox *skel)
{
        struct bpf_link *link;
        __u64 in[]   = {0, 1, 2, 3, 4,  5, 77};
        __u64 out[]  = {2, 3, 4, 5, 7, 19, 19};
        int i;

        link = bpf_program__attach(skel->progs.use_static_global_other_sec);
        if (!ASSERT_OK_PTR(link, "link"))
                return;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple_fentry(skel, skel->progs.use_static_global_other_sec, in[i], out[i]);

        bpf_link__destroy(link);
}

static void check_nonstatic_global_other_sec(struct bpf_gotox *skel)
{
        struct bpf_link *link;
        __u64 in[]   = {0, 1, 2, 3, 4,  5, 77};
        __u64 out[]  = {2, 3, 4, 5, 7, 19, 19};
        int i;

        link = bpf_program__attach(skel->progs.use_nonstatic_global_other_sec);
        if (!ASSERT_OK_PTR(link, "link"))
                return;

        for (i = 0; i < ARRAY_SIZE(in); i++)
                check_simple_fentry(skel, skel->progs.use_nonstatic_global_other_sec, in[i], out[i]);

        bpf_link__destroy(link);
}

/*
 * The following subtests do not use skeleton rather than to check
 * if the test should be skipped.
 */

static int create_jt_map(__u32 max_entries)
{
        const char *map_name = "jt";
        __u32 key_size = 4;
        __u32 value_size = sizeof(struct bpf_insn_array_value);

        return bpf_map_create(BPF_MAP_TYPE_INSN_ARRAY, map_name,
                              key_size, value_size, max_entries, NULL);
}

static int prog_load(struct bpf_insn *insns, __u32 insn_cnt)
{
        return bpf_prog_load(BPF_PROG_TYPE_RAW_TRACEPOINT, NULL, "GPL", insns, insn_cnt, NULL);
}

static int __check_ldimm64_off_prog_load(__u32 max_entries, __u32 off)
{
        struct bpf_insn insns[] = {
                BPF_LD_IMM64_RAW(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, 0),
                BPF_MOV64_IMM(BPF_REG_0, 0),
                BPF_EXIT_INSN(),
        };
        int map_fd, ret;

        map_fd = create_jt_map(max_entries);
        if (!ASSERT_GE(map_fd, 0, "create_jt_map"))
                return -1;
        if (!ASSERT_EQ(bpf_map_freeze(map_fd), 0, "bpf_map_freeze")) {
                close(map_fd);
                return -1;
        }

        insns[0].imm = map_fd;
        insns[1].imm = off;

        ret = prog_load(insns, ARRAY_SIZE(insns));
        close(map_fd);
        return ret;
}

/*
 * Check that loads from an instruction array map are only allowed with offsets
 * which are multiples of 8 and do not point to outside of the map.
 */
static void check_ldimm64_off_load(struct bpf_gotox *skel __always_unused)
{
        const __u32 max_entries = 10;
        int prog_fd;
        __u32 off;

        for (off = 0; off < max_entries; off++) {
                prog_fd = __check_ldimm64_off_prog_load(max_entries, off * 8);
                if (!ASSERT_GE(prog_fd, 0, "__check_ldimm64_off_prog_load"))
                        return;
                close(prog_fd);
        }

        prog_fd = __check_ldimm64_off_prog_load(max_entries, 7 /* not a multiple of 8 */);
        if (!ASSERT_EQ(prog_fd, -EACCES, "__check_ldimm64_off_prog_load: should be -EACCES")) {
                close(prog_fd);
                return;
        }

        prog_fd = __check_ldimm64_off_prog_load(max_entries, max_entries * 8 /* too large */);
        if (!ASSERT_EQ(prog_fd, -EACCES, "__check_ldimm64_off_prog_load: should be -EACCES")) {
                close(prog_fd);
                return;
        }
}

static int __check_ldimm64_gotox_prog_load(struct bpf_insn *insns,
                                           __u32 insn_cnt,
                                           __u32 off1, __u32 off2)
{
        const __u32 values[] = {5, 7, 9, 11, 13, 15};
        const __u32 max_entries = ARRAY_SIZE(values);
        struct bpf_insn_array_value val = {};
        int map_fd, ret, i;

        map_fd = create_jt_map(max_entries);
        if (!ASSERT_GE(map_fd, 0, "create_jt_map"))
                return -1;

        for (i = 0; i < max_entries; i++) {
                val.orig_off = values[i];
                if (!ASSERT_EQ(bpf_map_update_elem(map_fd, &i, &val, 0), 0,
                               "bpf_map_update_elem")) {
                        close(map_fd);
                        return -1;
                }
        }

        if (!ASSERT_EQ(bpf_map_freeze(map_fd), 0, "bpf_map_freeze")) {
                close(map_fd);
                return -1;
        }

        /* r1 = &map + offset1 */
        insns[0].imm = map_fd;
        insns[1].imm = off1;

        /* r1 += off2 */
        insns[2].imm = off2;

        ret = prog_load(insns, insn_cnt);
        close(map_fd);
        return ret;
}

static void reject_offsets(struct bpf_insn *insns, __u32 insn_cnt, __u32 off1, __u32 off2)
{
        int prog_fd;

        prog_fd = __check_ldimm64_gotox_prog_load(insns, insn_cnt, off1, off2);
        if (!ASSERT_EQ(prog_fd, -EACCES, "__check_ldimm64_gotox_prog_load"))
                close(prog_fd);
}

/*
 * Verify a bit more complex programs which include indirect jumps
 * and with jump tables loaded with a non-zero offset
 */
static void check_ldimm64_off_gotox(struct bpf_gotox *skel __always_unused)
{
        struct bpf_insn insns[] = {
                /*
                 * The following instructions perform an indirect jump to
                 * labels below. Thus valid offsets in the map are {0,...,5}.
                 * The program rewrites the offsets in the instructions below:
                 *     r1 = &map + offset1
                 *     r1 += offset2
                 *     r1 = *r1
                 *     gotox r1
                 */
                BPF_LD_IMM64_RAW(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, 0),
                BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 0),
                BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, 0),
                BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_1, 0, 0, 0),

                /* case 0: */
                BPF_MOV64_IMM(BPF_REG_0, 0),
                BPF_EXIT_INSN(),
                /* case 1: */
                BPF_MOV64_IMM(BPF_REG_0, 1),
                BPF_EXIT_INSN(),
                /* case 2: */
                BPF_MOV64_IMM(BPF_REG_0, 2),
                BPF_EXIT_INSN(),
                /* case 3: */
                BPF_MOV64_IMM(BPF_REG_0, 3),
                BPF_EXIT_INSN(),
                /* case 4: */
                BPF_MOV64_IMM(BPF_REG_0, 4),
                BPF_EXIT_INSN(),
                /* default: */
                BPF_MOV64_IMM(BPF_REG_0, 5),
                BPF_EXIT_INSN(),
        };
        int prog_fd, err;
        __u32 off1, off2;

        /* allow all combinations off1 + off2 < 6 */
        for (off1 = 0; off1 < 6; off1++) {
                for (off2 = 0; off1 + off2 < 6; off2++) {
                        LIBBPF_OPTS(bpf_test_run_opts, topts);

                        prog_fd = __check_ldimm64_gotox_prog_load(insns, ARRAY_SIZE(insns),
                                                                  off1 * 8, off2 * 8);
                        if (!ASSERT_GE(prog_fd, 0, "__check_ldimm64_gotox_prog_load"))
                                return;

                        err = bpf_prog_test_run_opts(prog_fd, &topts);
                        if (!ASSERT_OK(err, "test_run_opts err")) {
                                close(prog_fd);
                                return;
                        }

                        if (!ASSERT_EQ(topts.retval, off1 + off2, "test_run_opts retval")) {
                                close(prog_fd);
                                return;
                        }

                        close(prog_fd);
                }
        }

        /* reject off1 + off2 >= 6 */
        reject_offsets(insns, ARRAY_SIZE(insns), 8 * 3, 8 * 3);
        reject_offsets(insns, ARRAY_SIZE(insns), 8 * 7, 8 * 0);
        reject_offsets(insns, ARRAY_SIZE(insns), 8 * 0, 8 * 7);

        /* reject (off1 + off2) % 8 != 0 */
        reject_offsets(insns, ARRAY_SIZE(insns), 3, 3);
        reject_offsets(insns, ARRAY_SIZE(insns), 7, 0);
        reject_offsets(insns, ARRAY_SIZE(insns), 0, 7);
}

void test_bpf_gotox(void)
{
        struct bpf_gotox *skel;
        int ret;

        skel = bpf_gotox__open();
        if (!ASSERT_NEQ(skel, NULL, "bpf_gotox__open"))
                return;

        ret = bpf_gotox__load(skel);
        if (!ASSERT_OK(ret, "bpf_gotox__load"))
                return;

        skel->bss->pid = getpid();

        if (test__start_subtest("one-switch"))
                __subtest(skel, check_one_switch);

        if (test__start_subtest("one-switch-non-zero-sec-offset"))
                __subtest(skel, check_one_switch_non_zero_sec_off);

        if (test__start_subtest("two-switches"))
                __subtest(skel, check_two_switches);

        if (test__start_subtest("big-jump-table"))
                __subtest(skel, check_big_jump_table);

        if (test__start_subtest("static-global"))
                __subtest(skel, check_static_global);

        if (test__start_subtest("nonstatic-global"))
                __subtest(skel, check_nonstatic_global);

        if (test__start_subtest("other-sec"))
                __subtest(skel, check_other_sec);

        if (test__start_subtest("static-global-other-sec"))
                __subtest(skel, check_static_global_other_sec);

        if (test__start_subtest("nonstatic-global-other-sec"))
                __subtest(skel, check_nonstatic_global_other_sec);

        if (test__start_subtest("one-jump-two-maps"))
                __subtest(skel, check_one_jump_two_maps);

        if (test__start_subtest("one-map-two-jumps"))
                __subtest(skel, check_one_map_two_jumps);

        if (test__start_subtest("check-ldimm64-off"))
                __subtest(skel, check_ldimm64_off_load);

        if (test__start_subtest("check-ldimm64-off-gotox"))
                __subtest(skel, check_ldimm64_off_gotox);

        bpf_gotox__destroy(skel);
}