#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/timeb.h>
#include <sys/ioctl.h>


#include <net/if.h>
#include <netinet/in.h>

#include <errno.h>
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <pwd.h>

typedef struct sockaddr_in Sockaddr;

# define DISPATCHER_PORT      1300
# define AGENT_START_PORT     1302
# define USER_NAME_SIZE         20
# define MACHINE_NAME_SIZE      40
# define AGENT_NAME_SIZE        20
# define ALIAS_NAME_SIZE        20
# define PACKET_MAX_SIZE      1024

# define PACKET_TYPE_REGISTER       1    
# define PACKET_TYPE_SEARCH_AGENT   2
# define PACKET_TYPE_MESSAGE        3
# define PACKET_TYPE_UNREGISTER     4
# define PACKET_TYPE_UNKNOWN_AGENT  5
# define PACKET_TYPE_AGENT_INFO     6



# define DEBUG_PRINT_AGENTS     100



/* Network message header. */
typedef struct {
   unsigned long  msg_type;
   char  from_machine[MACHINE_NAME_SIZE];
   char  from_user[USER_NAME_SIZE];
   char  from_agent[AGENT_NAME_SIZE];
   char  to_machine[MACHINE_NAME_SIZE];
   char  to_user[USER_NAME_SIZE];
   char  to_agent[AGENT_NAME_SIZE];
   unsigned long data_length;
   Sockaddr agent_addr;
} netMsgHeader;


typedef struct {
   netMsgHeader header;
   char *data;
} netMsg;



/* Function Declarations. */
extern int netInit(char *user_name);
extern int getSocketNum();
extern void sendNetMessage(char msg_type, char *from_agent, char *to_machine,
                       char *to_user, char *to_agent, char *data, int data_length);
extern netMsg *recieveNetMessage();
extern void dispalyPacket(netMsgHeader *header, char *data);