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prot/tcp.h
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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
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);
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 TCP_MAX_OPTION_BYTES 40
84 
85 #define TCPH_HDRLEN(phdr) ((u16_t)(lwip_ntohs((phdr)->_hdrlen_rsvd_flags) >> 12))
86 #define TCPH_HDRLEN_BYTES(phdr) ((u8_t)(TCPH_HDRLEN(phdr) << 2))
87 #define TCPH_FLAGS(phdr) ((u8_t)((lwip_ntohs((phdr)->_hdrlen_rsvd_flags) & TCP_FLAGS)))
88 
89 #define TCPH_HDRLEN_SET(phdr, len) (phdr)->_hdrlen_rsvd_flags = lwip_htons(((len) << 12) | TCPH_FLAGS(phdr))
90 #define TCPH_FLAGS_SET(phdr, flags) (phdr)->_hdrlen_rsvd_flags = (((phdr)->_hdrlen_rsvd_flags & PP_HTONS(~TCP_FLAGS)) | lwip_htons(flags))
91 #define TCPH_HDRLEN_FLAGS_SET(phdr, len, flags) (phdr)->_hdrlen_rsvd_flags = (u16_t)(lwip_htons((u16_t)((len) << 12) | (flags)))
92 
93 #define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = ((phdr)->_hdrlen_rsvd_flags | lwip_htons(flags))
94 #define TCPH_UNSET_FLAG(phdr, flags) (phdr)->_hdrlen_rsvd_flags = ((phdr)->_hdrlen_rsvd_flags & ~lwip_htons(flags))
95 
96 #ifdef __cplusplus
97 }
98 #endif
99 
100 #endif /* LWIP_HDR_PROT_TCP_H */
#define PACK_STRUCT_BEGIN
Packed structs support.
Definition: arch.h:307
#define PACK_STRUCT_STRUCT
Packed structs support.
Definition: arch.h:328
#define PACK_STRUCT_END
Packed structs support.
Definition: arch.h:316
Support for different processor and compiler architectures.
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