Files
jsix_import/src/kernel/syscalls/helpers.h
Justin C. Miller e93f48e2f7 [kernel] Track capability reference counts
First pass at reference-counting capabilities.
2023-01-14 15:43:07 -08:00

75 lines
1.8 KiB
C++

#pragma once
/// \file syscalls/helpers.h
/// Utility functions for use in syscall handler implementations
#include <j6/types.h>
#include "capabilities.h"
#include "objects/kobject.h"
#include "objects/process.h"
namespace syscalls {
template <typename T, typename... Args>
T * construct_handle(j6_handle_t *id, Args... args)
{
T *o = new T {args...};
*id = g_cap_table.create(o, T::creation_caps);
obj::process &p = obj::process::current();
p.add_handle(*id);
return o;
}
template <typename T>
j6_status_t get_handle(j6_handle_t id, j6_cap_t caps, T *&object)
{
if (id == j6_handle_invalid) {
object = nullptr;
return j6_status_ok;
}
capability *capdata = g_cap_table.retain(id);
if (!capdata || capdata->type != T::type)
return j6_err_invalid_arg;
obj::process &p = obj::process::current();
if (!p.has_handle(id) || (capdata->caps & caps) != caps)
return j6_err_denied;
object = static_cast<T*>(capdata->object);
return j6_status_ok;
}
template <typename T>
inline j6_status_t get_handle(j6_handle_t *id, j6_cap_t caps, T *&object)
{
return get_handle<T>(*id, caps, object);
}
template <>
inline j6_status_t get_handle<obj::kobject>(j6_handle_t id, j6_cap_t caps, obj::kobject *&object)
{
if (id == j6_handle_invalid) {
object = nullptr;
return j6_status_ok;
}
capability *capdata = g_cap_table.retain(id);
if (!capdata)
return j6_err_invalid_arg;
obj::process &p = obj::process::current();
if (!p.has_handle(id) || (capdata->caps & caps) != caps)
return j6_err_denied;
object = capdata->object;
return j6_status_ok;
}
inline void release_handle(j6_handle_t id) { g_cap_table.release(id); }
inline void release_handle(j6_handle_t *id) { g_cap_table.release(*id); }
} // namespace syscalls