#include <stddef.h>

#include "icmp.h"
#include "internal/icmp_internal.h"
#include "internal/icmp_packet_internal.h"
#include "internal/icmp_send.h"

/* MTU(1500) - IP header(20) - ICMP header(8) = 1472 */
#define MAX_PAYLOAD_SIZE 1472
#define ICMP_HEADER_SIZE 8

/* Forward declarations */
static int validate_payload(struct icmp_handle *h, const void *payload,
		size_t len);
/* -------------------- */

int
icmp_send_raw(icmp_handle_t *h, uint8_t type, uint8_t code,
		uint32_t header_rest, const void *payload, size_t len,
		struct in_addr dest, uint8_t ttl)
{
	uint8_t buffer[ICMP_HEADER_SIZE + MAX_PAYLOAD_SIZE];
	int packet_len;

	if (0 == send_validate_handle(h))
		return -1;

	if (0 == validate_payload(h, payload, len))
		return -1;


	packet_len = icmp_build_packet(buffer, sizeof(buffer),
			type, code, header_rest, payload, len);
	if (-1 == packet_len)
	{
		icmp_set_error_fmt(h, ICMP_ERR_INVALID,
				"Failed to build ICMP packet");
		return -1;
	}

	return send_to_destination(h, buffer, (size_t)(packet_len), dest, ttl);
}

static int
validate_payload(struct icmp_handle *h, const void *payload, size_t len)
{
	if (len > 0 && NULL == payload)
	{
		icmp_set_error_fmt(h, ICMP_ERR_INVALID, "Payload is NULL");
		return 0;
	}

	if (len > MAX_PAYLOAD_SIZE)
	{
		icmp_set_error_fmt(h, ICMP_ERR_INVALID,
				"Payload too large (max %d bytes)", MAX_PAYLOAD_SIZE);
		return 0;
	}
	return 1;
}