tcp.h

00001 /**
00002  * @file
00003  * TCP protocol definitions
00004  */
00005 
00006 /*
00007  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00008  * All rights reserved.
00009  *
00010  * Redistribution and use in source and binary forms, with or without modification,
00011  * are permitted provided that the following conditions are met:
00012  *
00013  * 1. Redistributions of source code must retain the above copyright notice,
00014  *    this list of conditions and the following disclaimer.
00015  * 2. Redistributions in binary form must reproduce the above copyright notice,
00016  *    this list of conditions and the following disclaimer in the documentation
00017  *    and/or other materials provided with the distribution.
00018  * 3. The name of the author may not be used to endorse or promote products
00019  *    derived from this software without specific prior written permission.
00020  *
00021  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00022  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00023  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00024  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00025  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00026  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00027  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00028  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00029  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00030  * OF SUCH DAMAGE.
00031  *
00032  * This file is part of the lwIP TCP/IP stack.
00033  *
00034  * Author: Adam Dunkels <adam@sics.se>
00035  *
00036  */
00037 #ifndef LWIP_HDR_PROT_TCP_H
00038 #define LWIP_HDR_PROT_TCP_H
00039 
00040 #include "lwip/arch.h"
00041 
00042 #ifdef __cplusplus
00043 extern "C" {
00044 #endif
00045 
00046 /* Length of the TCP header, excluding options. */
00047 #define TCP_HLEN 20
00048 
00049 /* Fields are (of course) in network byte order.
00050  * Some fields are converted to host byte order in tcp_input().
00051  */
00052 #ifdef PACK_STRUCT_USE_INCLUDES
00053 #  include "arch/bpstruct.h"
00054 #endif
00055 PACK_STRUCT_BEGIN
00056 struct tcp_hdr {
00057   PACK_STRUCT_FIELD(u16_t src);
00058   PACK_STRUCT_FIELD(u16_t dest);
00059   PACK_STRUCT_FIELD(u32_t seqno);
00060   PACK_STRUCT_FIELD(u32_t ackno);
00061   PACK_STRUCT_FIELD(u16_t _hdrlen_rsvd_flags);
00062   PACK_STRUCT_FIELD(u16_t wnd);
00063   PACK_STRUCT_FIELD(u16_t chksum);
00064   PACK_STRUCT_FIELD(u16_t urgp);
00065 } PACK_STRUCT_STRUCT;
00066 PACK_STRUCT_END
00067 #ifdef PACK_STRUCT_USE_INCLUDES
00068 #  include "arch/epstruct.h"
00069 #endif
00070 
00071 /* TCP header flags bits */
00072 #define TCP_FIN 0x01U
00073 #define TCP_SYN 0x02U
00074 #define TCP_RST 0x04U
00075 #define TCP_PSH 0x08U
00076 #define TCP_ACK 0x10U
00077 #define TCP_URG 0x20U
00078 #define TCP_ECE 0x40U
00079 #define TCP_CWR 0x80U
00080 /* Valid TCP header flags */
00081 #define TCP_FLAGS 0x3fU
00082 
00083 #define TCPH_HDRLEN(phdr) ((u16_t)(lwip_ntohs((phdr)->_hdrlen_rsvd_flags) >> 12))
00084 #define TCPH_FLAGS(phdr)  ((u16_t)(lwip_ntohs((phdr)->_hdrlen_rsvd_flags) & TCP_FLAGS))
00085 
00086 #define TCPH_HDRLEN_SET(phdr, len) (phdr)->_hdrlen_rsvd_flags = lwip_htons(((len) << 12) | TCPH_FLAGS(phdr))
00087 #define TCPH_FLAGS_SET(phdr, flags) (phdr)->_hdrlen_rsvd_flags = (((phdr)->_hdrlen_rsvd_flags & PP_HTONS(~TCP_FLAGS)) | lwip_htons(flags))
00088 #define TCPH_HDRLEN_FLAGS_SET(phdr, len, flags) (phdr)->_hdrlen_rsvd_flags = (u16_t)(lwip_htons((u16_t)((len) << 12) | (flags)))
00089 
00090 #define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = ((phdr)->_hdrlen_rsvd_flags | lwip_htons(flags))
00091 #define TCPH_UNSET_FLAG(phdr, flags) (phdr)->_hdrlen_rsvd_flags = ((phdr)->_hdrlen_rsvd_flags & ~lwip_htons(flags))
00092 
00093 #ifdef __cplusplus
00094 }
00095 #endif
00096 
00097 #endif /* LWIP_HDR_PROT_TCP_H */