//Note this sample requires Mac OS X 10.2.x or later and 
//ProjectBuilder version 2.1 or later.

#if !defined(__DTSSampleCode_SimplePing__)
#define __DTSSampleCode_SimplePing__ 1

#ifdef __cplusplus
extern "C"
{
#endif

#include <sys/time.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>

struct PingICMPPacket 
{
    struct icmp 	icmpHeader; //required icmp header
    struct timeval 	packetTimeStamp; //our optional data will be the packet send time.
};

/*****************************************************
 * LookupHostAddress
 *****************************************************
 * Purpose:  This function provides a mechanism to get a host address
 * as a internet address structure given only a string describing the
 * remote host.  The string passed will be either a host name
 * (e.g. www.apple.com) or an IP address (e.g. 17.203.23.111)
 *
 * Parameters:
 * 	HostToPing		A constant C-string.  On calling
 * LookupHostAddress this variable holds a CString describing the
 * remote host.  The string can either be a host name (e.g. www.google.com)
 * or an IP address (e.g. 17.203.23.112)
 *
 * 	HostAddress	A pointer to a pre-allocated array of sockaddr_in structure.
 * On calling LookupHostAddress this variable must be a pointer to a
 * pre-allocated sockaddr_in structure.  On successful return from LookupHostAddress
 * this variable will hold the host address expressed as an sockaddr_in structure.
 * On failed return the value of this variable is undefined
 *
 * 	*Function Result* 	A UNIX error integer return value as described in:
 *				/usr/include/sys/errno.h on a BSD system.
 * 				Note: This value will be zero on success.
 *****************************************************/
int LookupHostAddress(const char* HostToPing, struct sockaddr_in* HostAddress);

/*****************************************************
 * CreateSocketForCommunicationWithHost
 *****************************************************
 * Purpose:  This function sets up a socket for communicating
 * with the given remote host and also sets the parameters of 
 * that socket to our required specifications (timeout of 1 second
 * and larger receive buffer).
 *
 * Parameters:
 * 	HostAddress		A sockaddr_in structure.  On calling 
 * CreateSocketForCommunicationWithHost this variable has an address
 * of the host the socket will be established with expressed in sockaddr_in format.
 *
 * 	SocketToReturn	A pointer to a pre-allocated integer.  On successful 
 * return from CreateSocketForCommunicationWithHost this variable will hold
 * a socket descriptor used to communicate with the socket in future calls.  On
 * failed result this variable will be undefined.  Note on successful result its
 * the caller's responsibility to close the socket.
 *
 * 	*Function Result* 	A UNIX error integer return value as described in:
 *				/usr/include/sys/errno.h on a BSD system.
 * 				Note: This value will be zero on success.
 *****************************************************/
int CreateSocketForCommunicationWithHost(const struct sockaddr_in HostAddress, int* SocketToReturn);

/*****************************************************
 * CreateAndSendICMPPacket
 *****************************************************
 * Purpose:  This function creates an ICMP packet with the necessary information
 * inside of it to make it a ping packet.  This function also sends that ping packet to
 * the remote host.
 *
 * Parameters:
 * 	HostAddress		A sockaddr_in structure.  On calling 
 * CreateAndSendICMPPacket this variable has an address
 * of the host where the ping will be sent.
 *
 * 	SequenceNumber	A integer.  when calling CreateAndSendICMPPacket this variable 
 * will hold the sequence number of the ping packet being sent.  This information is
 * then put in the ping packet sent to the host so when they reply we know which
 * send the reply is associated with.
 *
 *	SocketConnectionToHost A socket descriptor expressed as an integer.  On calling
 * CreateAndSendICMPPacket this variable will be a valid socket which is already setup
 * for communicating with the remote host.  
 *
 * 	*Function Result* 	A UNIX error integer return value as described in:
 *				/usr/include/sys/errno.h on a BSD system.
 * 				Note: This value will be zero on success.
 *****************************************************/
int CreateAndSendICMPPacket(struct sockaddr_in HostAddress, int SequenceNumber, int SocketConnectionToHost);

/*****************************************************
 * WaitAndPrintICMPs
 *****************************************************
 * Purpose:  This function creates an ICMP packet with the necessary information
 * inside of it to make it a ping packet.  This function also sends that ping packet to
 * the remote host.
 *
 * Parameters:
 *	SocketConnectionToHost A socket descriptor expressed as an integer.  On calling
 * WaitAndPrintICMPs this variable will be a valid socket which is already setup
 * for communicating with the remote host.  This will be used in getting the reply
 * packets from the host.
 *
 * 	TimeoutInSeconds	A timeout expressed as an integer.  On calling 
 * WaitAndPrintICMPs this variable will have the number of seconds to wait for
 * ICMP replies.  Note even if a valid ICMP reply comes that matches what we expect
 * we will still wait for additional ICMP packets until the timeout has occurred.
 *
 * 	GotResponse		A pre-allocated integer.  when calling WaitAndPrintICMPs
 * this variable will be a pre-allocated integer.  On successful return from WaitAndPrintICMPs this
 * variable will hold a value of 1 if a ICMP packet response to our ping was received.
 * And a zero otherwise.  On failed return the value of this variable will be undefined.
 *
 * 	*Function Result* 	A UNIX error integer return value as described in:
 *				/usr/include/sys/errno.h on a BSD system.
 * 				Note: This value will be zero on success.
 *****************************************************/
int WaitAndPrintICMPs(int socketConnectionToHost, int TimeoutInSeconds, int ReturnimmediatelyAfterReply, int* GotResponse);

/*****************************************************
 * SimplePing
 *****************************************************
 * Purpose:  This function uses the above functions to ping a given remote host with
 * a given number of packets and with a given timeout to wait for responses on each packet.
 *
 * Parameters:
 *	HostToPing 		A C-String describing the remote host.  On calling
 * SimplePing this variable will hold a description of the host as a C-String.  The string
 * can either be a hostname (e.g. www.google.com) or an IP address (e.g. 17.203.23.111)
 *
 * 	NumberOfPacketsToSend	An integer.  On calling SimplePing this variable holds
 * the number of ping packets to send to the host before stopping.
 *
 * 	PingTimeoutInSeconds	An integer.  On calling Simple Ping this variable holds
 * the amount of time SimplePing will wait for responses from the ping before going onto the next packet.
 * Note even if a ping reply is received we will continue waiting until the timeout has occurred.
 *
 * 	*Function Result* 	A UNIX error integer return value as described in:
 *				/usr/include/sys/errno.h on a BSD system.
 * 				Note: This value will be zero on success.
 *****************************************************/
int SimplePing(const char* HostToPing, const int NumberOfPacketsToSend, const int PingTimeoutInSeconds, const int ReturnimmediatelyAfterReply,  int *numberPacketsReceived );
//Checksum function stolen from original ping ;-)
int in_cksum(u_short *addr, int len);

#ifdef __cplusplus
}
#endif

#endif