---
title: sf_ioctl_func
framework: Kernel
role: symbol
role_heading: Type Alias
platforms: [macOS 10.4+]
path: kernel/sf_ioctl_func
---

# sf_ioctl_func

## Declaration

```occ
typedef errno_t (*sf_ioctl_func)(void *cookie, socket_t so, unsigned long request, const char *argp);
```

## Parameters

- `cookie`: Cookie value specified when the filter attach was called.
- `so`: The socket the filter is attached to.
- `request`: The ioctl name.
- `argp`: A pointer to the ioctl parameter.

## Return Value

Return Value Return: 0 - The caller will continue with normal processing of this ioctl. EJUSTRETURN - The caller will return with a value of 0 (no error) from that point without further processing or propogating the ioctl. Anything Else - The caller will stop processing and return this error.

## Discussion

Discussion sf_ioctl_func is called before performing an ioctl on a socket. All undefined ioctls are reserved for future use by Apple. If you need to communicate with your kext using an ioctl, please use SIOCSIFKPI and SIOCGIFKPI.