// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
#include "../test_kmods/bpf_testmod_kfunc.h"

struct map_value {
        struct prog_test_ref_kfunc __kptr_untrusted *unref_ptr;
        struct prog_test_ref_kfunc __kptr *ref_ptr;
};

struct array_map {
        __uint(type, BPF_MAP_TYPE_ARRAY);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 1);
} array_map SEC(".maps");

struct pcpu_array_map {
        __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 1);
} pcpu_array_map SEC(".maps");

struct hash_map {
        __uint(type, BPF_MAP_TYPE_HASH);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 1);
} hash_map SEC(".maps");

struct pcpu_hash_map {
        __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 1);
} pcpu_hash_map SEC(".maps");

struct hash_malloc_map {
        __uint(type, BPF_MAP_TYPE_HASH);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 1);
        __uint(map_flags, BPF_F_NO_PREALLOC);
} hash_malloc_map SEC(".maps");

struct pcpu_hash_malloc_map {
        __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 1);
        __uint(map_flags, BPF_F_NO_PREALLOC);
} pcpu_hash_malloc_map SEC(".maps");

struct lru_hash_map {
        __uint(type, BPF_MAP_TYPE_LRU_HASH);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 1);
} lru_hash_map SEC(".maps");

struct lru_pcpu_hash_map {
        __uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 1);
} lru_pcpu_hash_map SEC(".maps");

struct cgrp_ls_map {
        __uint(type, BPF_MAP_TYPE_CGRP_STORAGE);
        __uint(map_flags, BPF_F_NO_PREALLOC);
        __type(key, int);
        __type(value, struct map_value);
} cgrp_ls_map SEC(".maps");

struct task_ls_map {
        __uint(type, BPF_MAP_TYPE_TASK_STORAGE);
        __uint(map_flags, BPF_F_NO_PREALLOC);
        __type(key, int);
        __type(value, struct map_value);
} task_ls_map SEC(".maps");

struct inode_ls_map {
        __uint(type, BPF_MAP_TYPE_INODE_STORAGE);
        __uint(map_flags, BPF_F_NO_PREALLOC);
        __type(key, int);
        __type(value, struct map_value);
} inode_ls_map SEC(".maps");

struct sk_ls_map {
        __uint(type, BPF_MAP_TYPE_SK_STORAGE);
        __uint(map_flags, BPF_F_NO_PREALLOC);
        __type(key, int);
        __type(value, struct map_value);
} sk_ls_map SEC(".maps");

#define DEFINE_MAP_OF_MAP(map_type, inner_map_type, name)       \
        struct {                                                \
                __uint(type, map_type);                         \
                __uint(max_entries, 1);                         \
                __uint(key_size, sizeof(int));                  \
                __uint(value_size, sizeof(int));                \
                __array(values, struct inner_map_type);         \
        } name SEC(".maps") = {                                 \
                .values = { [0] = &inner_map_type },            \
        }

DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, array_map, array_of_array_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, hash_map, array_of_hash_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, hash_malloc_map, array_of_hash_malloc_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, lru_hash_map, array_of_lru_hash_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, pcpu_array_map, array_of_pcpu_array_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_ARRAY_OF_MAPS, pcpu_hash_map, array_of_pcpu_hash_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, array_map, hash_of_array_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, hash_map, hash_of_hash_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, hash_malloc_map, hash_of_hash_malloc_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, lru_hash_map, hash_of_lru_hash_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, pcpu_array_map, hash_of_pcpu_array_maps);
DEFINE_MAP_OF_MAP(BPF_MAP_TYPE_HASH_OF_MAPS, pcpu_hash_map, hash_of_pcpu_hash_maps);

#define WRITE_ONCE(x, val) ((*(volatile typeof(x) *) &(x)) = (val))

static void test_kptr_unref(struct map_value *v)
{
        struct prog_test_ref_kfunc *p;

        p = v->unref_ptr;
        /* store untrusted_ptr_or_null_ */
        WRITE_ONCE(v->unref_ptr, p);
        if (!p)
                return;
        if (p->a + p->b > 100)
                return;
        /* store untrusted_ptr_ */
        WRITE_ONCE(v->unref_ptr, p);
        /* store NULL */
        WRITE_ONCE(v->unref_ptr, NULL);
}

static void test_kptr_ref(struct map_value *v)
{
        struct prog_test_ref_kfunc *p;

        p = v->ref_ptr;
        /* store ptr_or_null_ */
        WRITE_ONCE(v->unref_ptr, p);
        if (!p)
                return;
        /*
         * p is rcu_ptr_prog_test_ref_kfunc,
         * because bpf prog is non-sleepable and runs in RCU CS.
         * p can be passed to kfunc that requires KF_RCU.
         */
        bpf_kfunc_call_test_ref(p);
        if (p->a + p->b > 100)
                return;
        /* store NULL */
        p = bpf_kptr_xchg(&v->ref_ptr, NULL);
        if (!p)
                return;
        /*
         * p is trusted_ptr_prog_test_ref_kfunc.
         * p can be passed to kfunc that requires KF_RCU.
         */
        bpf_kfunc_call_test_ref(p);
        if (p->a + p->b > 100) {
                bpf_kfunc_call_test_release(p);
                return;
        }
        /* store ptr_ */
        WRITE_ONCE(v->unref_ptr, p);
        bpf_kfunc_call_test_release(p);

        p = bpf_kfunc_call_test_acquire(&(unsigned long){0});
        if (!p)
                return;
        /* store ptr_ */
        p = bpf_kptr_xchg(&v->ref_ptr, p);
        if (!p)
                return;
        if (p->a + p->b > 100) {
                bpf_kfunc_call_test_release(p);
                return;
        }
        bpf_kfunc_call_test_release(p);
}

static void test_kptr(struct map_value *v)
{
        test_kptr_unref(v);
        test_kptr_ref(v);
}

SEC("tc")
int test_map_kptr(struct __sk_buff *ctx)
{
        struct map_value *v;
        int key = 0;

#define TEST(map)                                       \
        v = bpf_map_lookup_elem(&map, &key);            \
        if (!v)                                         \
                return 0;                               \
        test_kptr(v)

        TEST(array_map);
        TEST(hash_map);
        TEST(hash_malloc_map);
        TEST(lru_hash_map);
        TEST(pcpu_array_map);
        TEST(pcpu_hash_map);

#undef TEST
        return 0;
}

SEC("tp_btf/cgroup_mkdir")
int BPF_PROG(test_cgrp_map_kptr, struct cgroup *cgrp, const char *path)
{
        struct map_value *v;

        v = bpf_cgrp_storage_get(&cgrp_ls_map, cgrp, NULL, BPF_LOCAL_STORAGE_GET_F_CREATE);
        if (v)
                test_kptr(v);
        return 0;
}

SEC("lsm/inode_unlink")
int BPF_PROG(test_task_map_kptr, struct inode *inode, struct dentry *victim)
{
        struct task_struct *task;
        struct map_value *v;

        task = bpf_get_current_task_btf();
        if (!task)
                return 0;
        v = bpf_task_storage_get(&task_ls_map, task, NULL, BPF_LOCAL_STORAGE_GET_F_CREATE);
        if (v)
                test_kptr(v);
        return 0;
}

SEC("lsm/inode_unlink")
int BPF_PROG(test_inode_map_kptr, struct inode *inode, struct dentry *victim)
{
        struct map_value *v;

        v = bpf_inode_storage_get(&inode_ls_map, inode, NULL, BPF_LOCAL_STORAGE_GET_F_CREATE);
        if (v)
                test_kptr(v);
        return 0;
}

SEC("tc")
int test_sk_map_kptr(struct __sk_buff *ctx)
{
        struct map_value *v;
        struct bpf_sock *sk;

        sk = ctx->sk;
        if (!sk)
                return 0;
        v = bpf_sk_storage_get(&sk_ls_map, sk, NULL, BPF_LOCAL_STORAGE_GET_F_CREATE);
        if (v)
                test_kptr(v);
        return 0;
}

SEC("tc")
int test_map_in_map_kptr(struct __sk_buff *ctx)
{
        struct map_value *v;
        int key = 0;
        void *map;

#define TEST(map_in_map)                                \
        map = bpf_map_lookup_elem(&map_in_map, &key);   \
        if (!map)                                       \
                return 0;                               \
        v = bpf_map_lookup_elem(map, &key);             \
        if (!v)                                         \
                return 0;                               \
        test_kptr(v)

        TEST(array_of_array_maps);
        TEST(array_of_hash_maps);
        TEST(array_of_hash_malloc_maps);
        TEST(array_of_lru_hash_maps);
        TEST(array_of_pcpu_array_maps);
        TEST(array_of_pcpu_hash_maps);
        TEST(hash_of_array_maps);
        TEST(hash_of_hash_maps);
        TEST(hash_of_hash_malloc_maps);
        TEST(hash_of_lru_hash_maps);
        TEST(hash_of_pcpu_array_maps);
        TEST(hash_of_pcpu_hash_maps);

#undef TEST
        return 0;
}

int ref = 1;

static __always_inline
int test_map_kptr_ref_pre(struct map_value *v)
{
        struct prog_test_ref_kfunc *p, *p_st;
        unsigned long arg = 0;
        int ret;

        p = bpf_kfunc_call_test_acquire(&arg);
        if (!p)
                return 1;
        ref++;

        p_st = p->next;
        if (p_st->cnt.refs.counter != ref) {
                ret = 2;
                goto end;
        }

        p = bpf_kptr_xchg(&v->ref_ptr, p);
        if (p) {
                ret = 3;
                goto end;
        }
        if (p_st->cnt.refs.counter != ref)
                return 4;

        p = bpf_kptr_xchg(&v->ref_ptr, NULL);
        if (!p)
                return 5;
        bpf_kfunc_call_test_release(p);
        ref--;
        if (p_st->cnt.refs.counter != ref)
                return 6;

        p = bpf_kfunc_call_test_acquire(&arg);
        if (!p)
                return 7;
        ref++;
        p = bpf_kptr_xchg(&v->ref_ptr, p);
        if (p) {
                ret = 8;
                goto end;
        }
        if (p_st->cnt.refs.counter != ref)
                return 9;
        /* Leave in map */

        return 0;
end:
        ref--;
        bpf_kfunc_call_test_release(p);
        return ret;
}

static __always_inline
int test_map_kptr_ref_post(struct map_value *v)
{
        struct prog_test_ref_kfunc *p, *p_st;

        p_st = v->ref_ptr;
        if (!p_st || p_st->cnt.refs.counter != ref)
                return 1;

        p = bpf_kptr_xchg(&v->ref_ptr, NULL);
        if (!p)
                return 2;
        if (p_st->cnt.refs.counter != ref) {
                bpf_kfunc_call_test_release(p);
                return 3;
        }

        p = bpf_kptr_xchg(&v->ref_ptr, p);
        if (p) {
                bpf_kfunc_call_test_release(p);
                return 4;
        }
        if (p_st->cnt.refs.counter != ref)
                return 5;

        return 0;
}

#define TEST(map)                            \
        v = bpf_map_lookup_elem(&map, &key); \
        if (!v)                              \
                return -1;                   \
        ret = test_map_kptr_ref_pre(v);      \
        if (ret)                             \
                return ret;

#define TEST_PCPU(map)                                 \
        v = bpf_map_lookup_percpu_elem(&map, &key, 0); \
        if (!v)                                        \
                return -1;                             \
        ret = test_map_kptr_ref_pre(v);                \
        if (ret)                                       \
                return ret;

SEC("tc")
int test_map_kptr_ref1(struct __sk_buff *ctx)
{
        struct map_value *v, val = {};
        int key = 0, ret;

        bpf_map_update_elem(&hash_map, &key, &val, 0);
        bpf_map_update_elem(&hash_malloc_map, &key, &val, 0);
        bpf_map_update_elem(&lru_hash_map, &key, &val, 0);

        bpf_map_update_elem(&pcpu_hash_map, &key, &val, 0);
        bpf_map_update_elem(&pcpu_hash_malloc_map, &key, &val, 0);
        bpf_map_update_elem(&lru_pcpu_hash_map, &key, &val, 0);

        TEST(array_map);
        TEST(hash_map);
        TEST(hash_malloc_map);
        TEST(lru_hash_map);

        TEST_PCPU(pcpu_array_map);
        TEST_PCPU(pcpu_hash_map);
        TEST_PCPU(pcpu_hash_malloc_map);
        TEST_PCPU(lru_pcpu_hash_map);

        return 0;
}

#undef TEST
#undef TEST_PCPU

#define TEST(map)                            \
        v = bpf_map_lookup_elem(&map, &key); \
        if (!v)                              \
                return -1;                   \
        ret = test_map_kptr_ref_post(v);     \
        if (ret)                             \
                return ret;

#define TEST_PCPU(map)                                 \
        v = bpf_map_lookup_percpu_elem(&map, &key, 0); \
        if (!v)                                        \
                return -1;                             \
        ret = test_map_kptr_ref_post(v);               \
        if (ret)                                       \
                return ret;

SEC("tc")
int test_map_kptr_ref2(struct __sk_buff *ctx)
{
        struct map_value *v;
        int key = 0, ret;

        TEST(array_map);
        TEST(hash_map);
        TEST(hash_malloc_map);
        TEST(lru_hash_map);

        TEST_PCPU(pcpu_array_map);
        TEST_PCPU(pcpu_hash_map);
        TEST_PCPU(pcpu_hash_malloc_map);
        TEST_PCPU(lru_pcpu_hash_map);

        return 0;
}

#undef TEST
#undef TEST_PCPU

SEC("tc")
int test_map_kptr_ref3(struct __sk_buff *ctx)
{
        struct prog_test_ref_kfunc *p;
        unsigned long sp = 0;

        p = bpf_kfunc_call_test_acquire(&sp);
        if (!p)
                return 1;
        ref++;
        if (p->cnt.refs.counter != ref) {
                bpf_kfunc_call_test_release(p);
                return 2;
        }
        bpf_kfunc_call_test_release(p);
        ref--;
        return 0;
}

int num_of_refs;

SEC("syscall")
int count_ref(void *ctx)
{
        struct prog_test_ref_kfunc *p;
        unsigned long arg = 0;

        p = bpf_kfunc_call_test_acquire(&arg);
        if (!p)
                return 1;

        num_of_refs = p->cnt.refs.counter;

        bpf_kfunc_call_test_release(p);
        return 0;
}

SEC("syscall")
int test_ls_map_kptr_ref1(void *ctx)
{
        struct task_struct *current;
        struct map_value *v;

        current = bpf_get_current_task_btf();
        if (!current)
                return 100;
        v = bpf_task_storage_get(&task_ls_map, current, NULL, 0);
        if (v)
                return 150;
        v = bpf_task_storage_get(&task_ls_map, current, NULL, BPF_LOCAL_STORAGE_GET_F_CREATE);
        if (!v)
                return 200;
        return test_map_kptr_ref_pre(v);
}

SEC("syscall")
int test_ls_map_kptr_ref2(void *ctx)
{
        struct task_struct *current;
        struct map_value *v;

        current = bpf_get_current_task_btf();
        if (!current)
                return 100;
        v = bpf_task_storage_get(&task_ls_map, current, NULL, 0);
        if (!v)
                return 200;
        return test_map_kptr_ref_post(v);
}

SEC("syscall")
int test_ls_map_kptr_ref_del(void *ctx)
{
        struct task_struct *current;
        struct map_value *v;

        current = bpf_get_current_task_btf();
        if (!current)
                return 100;
        v = bpf_task_storage_get(&task_ls_map, current, NULL, 0);
        if (!v)
                return 200;
        if (!v->ref_ptr)
                return 300;
        return bpf_task_storage_delete(&task_ls_map, current);
}

char _license[] SEC("license") = "GPL";