minix/lib/liblwip/dist/src/include/lwip/prot/tcp.h

   1 /**
   2  * @file
   3  * TCP protocol definitions
   4  */
   5
   6 /*
   7  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without modification,
  11  * are permitted provided that the following conditions are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright notice,
  14  *    this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright notice,
  16  *    this list of conditions and the following disclaimer in the documentation
  17  *    and/or other materials provided with the distribution.
  18  * 3. The name of the author may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  22  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  23  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  24  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  26  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  29  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  30  * OF SUCH DAMAGE.
  31  *
  32  * This file is part of the lwIP TCP/IP stack.
  33  *
  34  * Author: Adam Dunkels <adam@sics.se>
  35  *
  36  */
  37 #ifndef LWIP_HDR_PROT_TCP_H
  38 #define LWIP_HDR_PROT_TCP_H
  39
  40 #include "lwip/arch.h"
  41
  42 #ifdef __cplusplus
  43 extern "C" {
  44 #endif
  45
  46 /* Length of the TCP header, excluding options. */
  47 #define TCP_HLEN 20
  48
  49 /* Fields are (of course) in network byte order.
  50  * Some fields are converted to host byte order in tcp_input().
  51  */
  52 #ifdef PACK_STRUCT_USE_INCLUDES
  53 #  include "arch/bpstruct.h"
  54 #endif
  55 PACK_STRUCT_BEGIN
  56 struct tcp_hdr {
  57   PACK_STRUCT_FIELD(u16_t src);
  58   PACK_STRUCT_FIELD(u16_t dest);
  59   PACK_STRUCT_FIELD(u32_t seqno);
  60   PACK_STRUCT_FIELD(u32_t ackno);
  61   PACK_STRUCT_FIELD(u16_t _hdrlen_rsvd_flags);
  62   PACK_STRUCT_FIELD(u16_t wnd);
  63   PACK_STRUCT_FIELD(u16_t chksum);
  64   PACK_STRUCT_FIELD(u16_t urgp);
  65 } PACK_STRUCT_STRUCT;
  66 PACK_STRUCT_END
  67 #ifdef PACK_STRUCT_USE_INCLUDES
  68 #  include "arch/epstruct.h"
  69 #endif
  70
  71 /* TCP header flags bits */
  72 #define TCP_FIN 0x01U
  73 #define TCP_SYN 0x02U
  74 #define TCP_RST 0x04U
  75 #define TCP_PSH 0x08U
  76 #define TCP_ACK 0x10U
  77 #define TCP_URG 0x20U
  78 #define TCP_ECE 0x40U
  79 #define TCP_CWR 0x80U
  80 /* Valid TCP header flags */
  81 #define TCP_FLAGS 0x3fU
  82
  83 #define TCPH_HDRLEN(phdr) ((u16_t)(lwip_ntohs((phdr)->_hdrlen_rsvd_flags) >> 12))
  84 #define TCPH_FLAGS(phdr)  ((u16_t)(lwip_ntohs((phdr)->_hdrlen_rsvd_flags) & TCP_FLAGS))
  85
  86 #define TCPH_HDRLEN_SET(phdr, len) (phdr)->_hdrlen_rsvd_flags = lwip_htons(((len) << 12) | TCPH_FLAGS(phdr))
  87 #define TCPH_FLAGS_SET(phdr, flags) (phdr)->_hdrlen_rsvd_flags = (((phdr)->_hdrlen_rsvd_flags & PP_HTONS(~TCP_FLAGS)) | lwip_htons(flags))
  88 #define TCPH_HDRLEN_FLAGS_SET(phdr, len, flags) (phdr)->_hdrlen_rsvd_flags = (u16_t)(lwip_htons((u16_t)((len) << 12) | (flags)))
  89
  90 #define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = ((phdr)->_hdrlen_rsvd_flags | lwip_htons(flags))
  91 #define TCPH_UNSET_FLAG(phdr, flags) (phdr)->_hdrlen_rsvd_flags = ((phdr)->_hdrlen_rsvd_flags & ~lwip_htons(flags))
  92
  93 #ifdef __cplusplus
  94 }
  95 #endif
  96
  97 #endif /* LWIP_HDR_PROT_TCP_H */