incubator-nuttx/include/nuttx/net/tcp.h

196 lines
7.3 KiB
C

/****************************************************************************
* include/nuttx/net/tcp.h
* Header file for the NuttX TCP/IP stack.
*
* This TCP/IP stack header file contains definitions for a number of C
* macros that are used by internal network structures, TCP/IP header
* structures and function declarations.
*
* Copyright (C) 2007, 2009-2010, 2012-2014 Gregory Nutt. All rights
* reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* This logic was leveraged from uIP which also has a BSD-style license:
*
* Author Adam Dunkels <adam@dunkels.com>
* Copyright (c) 2001-2003, Adam Dunkels.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_NET_TCP_H
#define __INCLUDE_NUTTX_NET_TCP_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#ifdef CONFIG_NET_TCP
#include <stdint.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/arp.h>
#include <nuttx/net/ip.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* TCP definitions */
#define TCP_FIN 0x01
#define TCP_SYN 0x02
#define TCP_RST 0x04
#define TCP_PSH 0x08
#define TCP_ACK 0x10
#define TCP_URG 0x20
#define TCP_CTL 0x3f
#define TCP_OPT_END 0 /* End of TCP options list */
#define TCP_OPT_NOOP 1 /* "No-operation" TCP option */
#define TCP_OPT_MSS 2 /* Maximum segment size TCP option */
#define TCP_OPT_MSS_LEN 4 /* Length of TCP MSS option. */
/* The TCP states used in the struct tcp_conn_s tcpstateflags field */
#define TCP_STATE_MASK 0x0f /* Bits 0-3: TCP state */
# define TCP_CLOSED 0x00 /* The connection is not in use and available */
# define TCP_ALLOCATED 0x01 /* The connection is allocated, but not yet initialized */
# define TCP_SYN_RCVD 0x02
# define TCP_SYN_SENT 0x03
# define TCP_ESTABLISHED 0x04
# define TCP_FIN_WAIT_1 0x05
# define TCP_FIN_WAIT_2 0x06
# define TCP_CLOSING 0x07
# define TCP_TIME_WAIT 0x08
# define TCP_LAST_ACK 0x09
# define TCP_STOPPED 0x10 /* Bit 4: stopped */
/* Bit 5-7: Unused, but not available */
/* TCP header sizes
*
* The minimum size header is 5 words and the maximum is 15 words thus
* giving the minimum size of 20 bytes and maximum of 60 bytes, allowing for
* up to 40 bytes of options in the header.
*/
#define TCP_HDRLEN 20 /* Size of TCP header (minimum) */
#define TCP_OPT_HDRLEN(n) (20 + ((n) << 2)) /* Size of TCP header w/options */
#define TCP_MAX_HDRLEN 60 /* Maximum size of TCP header */
#ifdef CONFIG_NET_IPv4
# define IPv4TCP_HDRLEN (TCP_HDRLEN + IPv4_HDRLEN) /* Size of IPv4 + TCP header */
#endif
#ifdef CONFIG_NET_IPv6
# define IPv6TCP_HDRLEN (TCP_HDRLEN + IPv6_HDRLEN) /* Size of IPv4 + TCP header */
#endif
/* Initial minimum MSS according to RFC 879
*
* There have been some assumptions made about using other than the
* default size for datagrams with some unfortunate results.
*
* HOSTS MUST NOT SEND DATAGRAMS LARGER THAN 576 OCTETS UNLESS THEY
* HAVE SPECIFIC KNOWLEDGE THAT THE DESTINATION HOST IS PREPARED TO
* ACCEPT LARGER DATAGRAMS.
*
* This is a long established rule.
*/
#define TCP_INITIAL_MSS(d,h) (TCP_MSS(d,h) > 576 ? 576 : TCP_MSS(d,h))
#define MIN_TCP_INITIAL_MSS(h) (__MIN_TCP_MSS(h) > 576 ? 576 : __MIN_TCP_MSS(h))
#define MAX_TCP_INITIAL_MSS(h) (__MAX_TCP_MSS(h) > 576 ? 576 : __MAX_TCP_MSS(h))
#ifdef CONFIG_NET_IPv4
# define TCP_IPv4_INITIAL_MSS(d) TCP_INITIAL_MSS(d,IPv4_HDRLEN)
# define MIN_IPv4_TCP_INITIAL_MSS MIN_TCP_INITIAL_MSS(IPv4_HDRLEN)
# define MAX_IPv4_TCP_INITIAL_MSS MAX_TCP_INITIAL_MSS(IPv4_HDRLEN)
#endif
#ifdef CONFIG_NET_IPv6
# define TCP_IPv6_INITIAL_MSS(d) TCP_INITIAL_MSS(d,IPv6_HDRLEN)
# define MIN_IPv6_TCP_INITIAL_MSS MIN_TCP_INITIAL_MSS(IPv6_HDRLEN)
# define MAX_IPv6_TCP_INITIAL_MSS MAX_TCP_INITIAL_MSS(IPv6_HDRLEN)
#endif
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/* TCP header */
struct tcp_hdr_s
{
uint16_t srcport;
uint16_t destport;
uint8_t seqno[4];
uint8_t ackno[4];
uint8_t tcpoffset;
uint8_t flags;
uint8_t wnd[2];
uint16_t tcpchksum;
uint8_t urgp[2];
uint8_t optdata[4];
};
/* The structure holding the TCP/IP statistics that are gathered if
* CONFIG_NET_STATISTICS is defined.
*/
#ifdef CONFIG_NET_STATISTICS
struct tcp_stats_s
{
net_stats_t drop; /* Number of dropped TCP segments */
net_stats_t recv; /* Number of received TCP segments */
net_stats_t sent; /* Number of sent TCP segments */
net_stats_t chkerr; /* Number of TCP segments with a bad checksum */
net_stats_t ackerr; /* Number of TCP segments with a bad ACK number */
net_stats_t rst; /* Number of received TCP RST (reset) segments */
net_stats_t rexmit; /* Number of retransmitted TCP segments */
net_stats_t syndrop; /* Number of dropped SYNs due to too few
available connections */
net_stats_t synrst; /* Number of SYNs for closed ports triggering a RST */
};
#endif
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#endif /* CONFIG_NET_TCP */
#endif /* __INCLUDE_NUTTX_NET_TCP_H */