tcp.h

用于嵌入式系统的TCP/IP协议栈

/***********************************************************************/
/*                                                                     */
/*   Module:  tcp_ip/tcp/tcp.h                                         */
/*   Release: 2001.3                                                   */
/*   Version: 99.0                                                     */
/*   Purpose: TCP Private Header File                                  */
/*                                                                     */
/*---------------------------------------------------------------------*/
/*                                                                     */
/*               Copyright 1999, Blunk Microsystems                    */
/*                      ALL RIGHTS RESERVED                            */
/*                                                                     */
/*   Licensees have the non-exclusive right to use, modify, or extract */
/*   this computer program for software development at a single site.  */
/*   This program may be resold or disseminated in executable format   */
/*   only. The source code may not be redistributed or resold.         */
/*                                                                     */
/***********************************************************************/

/***********************************************************************/
/* Configuration                                                       */
/***********************************************************************/
#define TWO_MSL     (120 * TICKS_PER_SEC) /* twice segment lifetime */
#define MAX_RXT     (60 * TICKS_PER_SEC)  /* max retransmit timeout */
#define MIN_RXT     ((3 * TICKS_PER_SEC) / 2)   /* min retrans timeout */
#define INIT_RXT    (6 * TICKS_PER_SEC)   /* init retransmit timeout */
#define MAX_PRS     (60 * TICKS_PER_SEC)  /* max persist timeout */
#define MIN_PRS     (5 * TICKS_PER_SEC)   /* min persist timeout */
#define ACK_DELAY   (TICKS_PER_SEC / 5)   /* acknowledgment delay */
#define KEEPALIVE_TIMEO   (2 * 60 * 60 * TICKS_PER_SEC)

/***********************************************************************/
/* Symbol Definitions                                                  */
/***********************************************************************/
#define TCPMHLEN        20      /* minimum TCP header length */
#define TCPHOFFSET      0x50    /* offset value for TCPMHLEN */
#define TCP_MAXOPT      40      /* largest option field, bytes */
/*
** TCP header length macro must work on possibly unaligned segments
*/
#define TCP_HLEN(tcp) \
  (((((ui8 *)(tcp))[offsetof(Tcp, offset)]) & 0xF0) >> 2)

/*
** Supported TCP Options
*/
#define TPO_EOOL        0       /* end of option list */
#define TPO_NOOP        1       /* no operation */
#define TPO_MSS         2       /* maximum segment size */

/*
** Output States
*/
#define TCPO_IDLE       0
#define TCPO_XMIT       1       /* keep TCPO_IDLE and TCPO_XMIT less */
#define TCPO_REXMT      2       /* than TCPO_REXMT and TCPO_PERSIST */
#define TCPO_PERSIST    3

/*
** Default maximum send and receive window sizes
*/
#define SOCK_RBUF_SIZE   TCP_BIG_SIZE
#define SOCK_SBUF_SIZE   TCP_BIG_SIZE

/***********************************************************************/
/* Type Definitions                                                    */
/***********************************************************************/
/*
** TCP Packet Format
*/
typedef struct tcp
{
  ui16   src_port;      /* source port */
  ui16   dst_port;      /* destination port */
  tcpseq seq_num;       /* sequence */
  tcpseq ack_num;       /* acknowledged sequence */
  ui8    offset;        /* TCP data offset */
  ui8    flags;         /* control flags */
  ui16   window;        /* window advertisement */
  ui16   cksum;         /* check sum */
  ui16   urg_ptr;       /* urgent pointer */
  ui8    options[TCP_MAXOPT];   /* variable length options */
} Tcp;

/***********************************************************************/
/* Global Variable Declarations                                        */
/***********************************************************************/
extern SOCKET Sock;

/***********************************************************************/
/* Function Prototypes                                                 */
/***********************************************************************/
void TcpInit(void);
ui16 TcpCheckSum(const NetBuf *buf);
void TcpReset(void);
void TcpDrop(SOCKET sock, int error);
void TcpJustAck(SOCKET sock);
void TcpTryOut(SOCKET sock);
int  TcpData(SOCKET sock);
void TcpFreeOoQ(SOCKET sock);
int  TcpSendSeg(SOCKET sock, int window);
ui16 TcpRcvWin(SOCKET sock);
void TcpStrip(SOCKET sock, int flag);
#define FREE_RBUF     (1 << 0)
#define FREE_SBUF     (1 << 1)
void *TcpNewSock(int mode);
#define WITH_BUFS     1
#define NO_BUFS       0
void TcpQuerySock(void);
void TcpOutTimeout(void *object);