/* SPDX-License-Identifier: GPL-2.0-only */
/* A pointer that can point to either kernel or userspace memory. */
#ifndef _LINUX_BPFPTR_H
#define _LINUX_BPFPTR_H

#include <linux/mm.h>
#include <linux/sockptr.h>

typedef sockptr_t bpfptr_t;

static inline bool bpfptr_is_kernel(bpfptr_t bpfptr)
{
        return bpfptr.is_kernel;
}

static inline bpfptr_t KERNEL_BPFPTR(void *p)
{
        return (bpfptr_t) { .kernel = p, .is_kernel = true };
}

static inline bpfptr_t USER_BPFPTR(void __user *p)
{
        return (bpfptr_t) { .user = p };
}

static inline bpfptr_t make_bpfptr(u64 addr, bool is_kernel)
{
        if (is_kernel)
                return KERNEL_BPFPTR((void*) (uintptr_t) addr);
        else
                return USER_BPFPTR(u64_to_user_ptr(addr));
}

static inline bool bpfptr_is_null(bpfptr_t bpfptr)
{
        if (bpfptr_is_kernel(bpfptr))
                return !bpfptr.kernel;
        return !bpfptr.user;
}

static inline void bpfptr_add(bpfptr_t *bpfptr, size_t val)
{
        if (bpfptr_is_kernel(*bpfptr))
                bpfptr->kernel += val;
        else
                bpfptr->user += val;
}

static inline int copy_from_bpfptr_offset(void *dst, bpfptr_t src,
                                          size_t offset, size_t size)
{
        if (!bpfptr_is_kernel(src))
                return copy_from_user(dst, src.user + offset, size);
        return copy_from_kernel_nofault(dst, src.kernel + offset, size);
}

static inline int copy_from_bpfptr(void *dst, bpfptr_t src, size_t size)
{
        return copy_from_bpfptr_offset(dst, src, 0, size);
}

static inline int copy_to_bpfptr_offset(bpfptr_t dst, size_t offset,
                                        const void *src, size_t size)
{
        return copy_to_sockptr_offset((sockptr_t) dst, offset, src, size);
}

static inline void *kvmemdup_bpfptr_noprof(bpfptr_t src, size_t len)
{
        void *p = kvmalloc_node_align_noprof(len, 1, GFP_USER | __GFP_NOWARN, NUMA_NO_NODE);

        if (!p)
                return ERR_PTR(-ENOMEM);
        if (copy_from_bpfptr(p, src, len)) {
                kvfree(p);
                return ERR_PTR(-EFAULT);
        }
        return p;
}
#define kvmemdup_bpfptr(...)    alloc_hooks(kvmemdup_bpfptr_noprof(__VA_ARGS__))

static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
{
        if (bpfptr_is_kernel(src))
                return strncpy_from_kernel_nofault(dst, src.kernel, count);
        return strncpy_from_user(dst, src.user, count);
}

#endif /* _LINUX_BPFPTR_H */