
/***************************************************************************
 * EchoClient.h --                                                         *
 *                                                                         *
 ***********************IMPORTANT NMAP LICENSE TERMS************************
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 * This program is distributed under the terms of the Nmap Public Source
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 * release or source code control revision is contained in the LICENSE
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 ***************************************************************************/
#ifndef __ECHOCLIENT_H__
#define __ECHOCLIENT_H__ 1

#include "nping.h"
#include "NpingTarget.h"
#include "NEPContext.h"
#include "ProbeMode.h"

#define ECHO_CONNECT_TIMEOUT (10*1000) /* 10 Seconds */
#define ECHO_READ_TIMEOUT    (10*1000)
#define ECHO_WRITE_TIMEOUT   (10*1000)

/* Max number of bytes that are supplied as data for the PAYLOAD_MAGIC specifier */
#define NEP_PAYLOADMAGIC_MAX_BYTES 8


class EchoClient  {

    private:

        /* Attributes */
        nsock_pool nsp;               /**< Nsock pool (shared with ProbeMode) */
        nsock_iod nsi;                /**< IOD for the side-channel tcp socket*/
        struct sockaddr_in srvaddr4;  /**< Server's IPv4 address */
        struct sockaddr_in6 srvaddr6; /**< Server's IPv6 address */
        int af;                       /**< Address family (AF_INET or AF_INET6)*/
        NEPContext ctx;
        ProbeMode probe;
        u8 lasthdr[MAX_NEP_PACKET_LENGTH];
        size_t readbytes;

        /* Methods */
        int nep_connect(NpingTarget *target, u16 port);
        int nep_handshake();
        int nep_send_packet_spec();
        int nep_recv_ready();
        int nep_recv_echo(u8 *packet, size_t packetlen);

        int parse_hs_server(u8 *pkt, size_t pktlen);
        int parse_hs_final(u8 *pkt, size_t pktlen);
        int parse_ready(u8 *pkt, size_t pktlen);
        int parse_echo(u8 *pkt, size_t pktlen);
        int parse_error(u8 *pkt, size_t pktlen);

        int generate_hs_client(EchoHeader *h);
        int generate_packet_spec(EchoHeader *h);

    public:

        EchoClient();
        ~EchoClient();
        void reset();
        int start(NpingTarget *target, u16 port);
        int cleanup();
        int nep_echoed_packet_handler(nsock_pool nsp, nsock_event nse, void *arg);
        int nep_recv_std_header_handler(nsock_pool nsp, nsock_event nse, void *arg);
        int nep_recv_hs_server_handler(nsock_pool nsp, nsock_event nse, void *arg);
        int nep_recv_hs_final_handler(nsock_pool nsp, nsock_event nse, void *arg);
        int nep_recv_ready_handler(nsock_pool nsp, nsock_event nse, void *arg);

}; /* End of class EchoClient */


/* Handler wrappers */
void echoed_packet_handler(nsock_pool nsp, nsock_event nse, void *arg);
void recv_std_header_handler(nsock_pool nsp, nsock_event nse, void *arg);
void connect_done_handler(nsock_pool nsp, nsock_event nse, void *arg);
void write_done_handler(nsock_pool nsp, nsock_event nse, void *arg);
void recv_hs_server_handler(nsock_pool nsp, nsock_event nse, void *arg);
void recv_hs_final_handler(nsock_pool nsp, nsock_event nse, void *arg);
void recv_ready_handler(nsock_pool nsp, nsock_event nse, void *arg);

#endif /* __ECHOCLIENT_H__ */
