---
title: inet_arp_handle_input
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.4+]
path: kernel/1584164-inet_arp_handle_input
---

# inet_arp_handle_input

## Declaration

```occ
errno_t inet_arp_handle_input(ifnet_t ifp, u_int16_t arpop, const struct sockaddr_dl *sender_hw, const struct sockaddr_in *sender_ip, const struct sockaddr_in *target_ip);
```

## Parameters

- `interface`: The interface the packet was received on.
- `arp_op`: The arp operation, ARPOP_REQUEST or ARPOP_REPLY
- `sender_hw`: The sender hardware address from the arp payload.
- `sender_ip`: The sender IP address from the arp payload.
- `target_ip`: The target IP address from the arp payload.

## Return Value

Return Value 0 on success or an errno error value on failure.

## Discussion

Discussion This function should be called by code that handles inbound arp packets. The caller should parse the ARP packet to pull out the operation and the relevant addresses. If a response is required, the proto_media_send_arp function will be called. This function will lookup the sender in the routing table and add an arp entry if necessary. Any queued packets waiting for the arp resolution will also be transmitted.

## See Also

### Address Resolution

- [inet_arp_init_ifaddr](kernel/1584163-inet_arp_init_ifaddr.md)
- [inet_arp_lookup](kernel/1584165-inet_arp_lookup.md)