tcptrans.h

用于嵌入式系统的TCP/IP协议栈及若干服务

/*
*            Copyright (c) 1998-2001 by NETsilicon Inc.
*
*  This software is copyrighted by and is the sole property of
*  NETsilicon.  All rights, title, ownership, or other interests
*  in the software remain the property of NETsilicon.  This
*  software may only be used in accordance with the corresponding
*  license agreement.  Any unauthorized use, duplication, transmission,
*  distribution, or disclosure of this software is expressly forbidden.
*
*  This Copyright notice may not be removed or modified without prior
*  written consent of NETsilicon.
*
*  NETsilicon, reserves the right to modify this software
*  without notice.
*
*  NETsilicon
*  411 Waverley Oaks Road                  USA 781.647.1234
*  Suite 227                               http://www.netsilicon.com
*  Waltham, MA 02452                       [e-mail]
*
*************************************************************************
*  $Name: Fusion 6.52 Fusion 6.51 $
*  $Date: 2001/12/19 14:44:27 $
*  $Source: M:/psisrc/stack/incl/rcs/tcptrans.h $
*  $Revision: 1.1 $
**************************************************************************
*  File Description:  TCP (Transmission Control Protocol) for transaction TCP
*
**************************************************************************/

#ifndef _TCPTRANS_
#define _TCPTRANS_



#ifdef TCP_TRANSACTION_TCP
/***********************************************************/
/* data structure for per-foreign-host cache entry */
typedef struct _t_tcp_fh_cache_entry_ {
	int ce_ttl;         /* number of seconds before this entry becomes available
						   for use/reuse -- a zero means that it is available for
						   use or reuse */
    u32 ce_hostaddr;    /* The IP address of this host -- host order            */
	u32 ce_cc;          /* The last connection count received from this host    */
	u32 ce_ccsent;      /* The last connection count we sent to this host       */
    u32 ce_init_cwnd;   /* The initial send window for connections to this host 
				           (initialized at 4K, adjusted according to what happens
				            during transactions with this host */
#define T_TCP_CWND_DEFAULT 4096
	u16 ce_mss;    /* The last mss option value we received from this host */
	u32 ce_srtt;   /* The measured (smoothed) round trip time as of the end of
		 		      the last connection with this host. Transaction TCP remembers
				      round-trip time measurments across connections with a host */

} t_tcp_cache_entry_;

#ifndef T_TCP_DEFAULT_CACHE_SIZE_LIMIT
#define T_TCP_DEFAULT_CACHE_SIZE_LIMIT 20
#endif

#ifndef T_TCP_CACHE_ENTRY_LIFETIME
#define T_TCP_CACHE_ENTRY_LIFETIME 60
#endif

#ifndef T_TCP_DEFAULT_SEND_WINDOW
#define T_TCP_DEFAULT_SEND_WINDOW 4096
#endif

#ifndef T_TCP_TWTRUNC_MULTIPLIER
#define T_TCP_TWTRUNC_MULTIPLIER 8
#endif

/* The following macro is used to determine whether the passive side of a 
   transaction TCP connection is presently in the state where the data from
   an incoming SYN-DATA-(and possibly FIN) segment has been received, the 
   data has been delivered to the application, and we are in the period of
   delaying our SYN-ACK until either the application does a write or we have
   a timeout. */
#define TRANSACTION_DELAYING_SYNACK(s)                            \
			   ( ((s)->sv_t_tcp_flags & SV_TRANSACTION)  &&    \
				 ((s)->sv_flags & SV_PASSIVE)            &&    \
				 ((s)->sv_flags & SV_TSYNFLG)  )  



/***** flags for the sv_t_tcp_flags field of the svp ******/
#define SV_TRANSACTION      ((u16)0x1) /* This connection uses the transaction
										  TCP (RFC 1644) protocol */
#define SV_CC               ((u16)0x2) /* Indicates whether or not a CC option should
                                          be sent in the SYN on this connection */
#define SV_CCNEW            ((u16)0x4) /* If a CC is to be sent in the SYN on this
										  connection, indicates whether or not it should
										  be a straight CC or a CC.NEW. */
#define SV_CCECHO           ((u16)0x8) /* Indicates whether or not a CC.ECHO should be
										  sent on the SYN (actually SYN-ACK) of this 
										  connection */
#define SV_CCNEW_RECVD      ((u16)0x10) /* On incoming initial SYNs, if a CC or CC.NEW
										  option is received, the value of the option is
										  stored in sv_ccrecv (otherwise, sv_ccrecv is
										  zero). This flag remembers whether it was a
										  CC.NEW or a CC */
#define SV_LESS_THAN_MSL    ((u16)0x20) /* When and if the connection closes or goes into 
										   the TIME_WAIT state, this flag is set if the 
										   duration of the connection was less than an
										   MSL */
#define SV_SUCCESFUL_TAO_TEST ((u16)0x40) /* For a passive connection, a CC was received
										     and succesfully passed the TAO test */




#endif /* TCP_TRANSACTION_TCP */



#endif  /*_TCP_TRANS*/