#pragma once

#include "icmp.h"

#ifndef ICMP_ECHO
#define ICMP_ECHO 8
#endif
#ifndef ICMP_ECHOREPLY
#define ICMP_ECHOREPLY 0
#endif


struct icmp_server_incoming {
	const uint8_t *data;  // points to internal buffer
	size_t length;  // length of 'data'

	int type;  // ICMP_ECHO or ICMP_ECHOREPLY
	int id, seqnum;
	uint32_t source_addr;
};

// Returns -1 on error with errno.
int icmp_server_open_socket(void);

// Returns {.data=NULL} on error with errno.
struct icmp_server_incoming icmp_server_receive(int sock);

// Returns -1 on error with errno.
int icmp_server_send_reply(
		int sock, uint32_t addr,
		int id, int seqnum,
		const void *data, size_t length);