gnrc_tcp_option.h
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1 /*
2  * Copyright (C) 2015-2017 Simon Brummer
3  *
4  * This file is subject to the terms and conditions of the GNU Lesser
5  * General Public License v2.1. See the file LICENSE in the top level
6  * directory for more details.
7  */
8 
9 #pragma once
10 
22 #include <stdint.h>
23 #include "assert.h"
24 #include "net/tcp.h"
25 #include "net/gnrc/tcp/tcb.h"
26 
27 #ifdef __cplusplus
28 extern "C" {
29 #endif
30 
38 static inline uint32_t _gnrc_tcp_option_build_mss(uint16_t mss)
39 {
40  return (((uint32_t) TCP_OPTION_KIND_MSS << 24) |
41  ((uint32_t) TCP_OPTION_LENGTH_MSS << 16) | mss);
42 }
43 
52 static inline uint16_t _gnrc_tcp_option_build_offset_control(uint16_t nopts, uint16_t ctl)
53 {
54  assert(TCP_HDR_OFFSET_MIN <= nopts && nopts <= TCP_HDR_OFFSET_MAX);
55  return (nopts << 12) | ctl;
56 }
57 
68 
69 #ifdef __cplusplus
70 }
71 #endif
72 
POSIX.1-2008 compliant version of the assert macro.
#define assert(cond)
abort the program if assertion is false
Definition: assert.h:135
int _gnrc_tcp_option_parse(gnrc_tcp_tcb_t *tcb, tcp_hdr_t *hdr)
Parses options of a given TCP header.
static uint32_t _gnrc_tcp_option_build_mss(uint16_t mss)
Helper function to build the MSS option.
static uint16_t _gnrc_tcp_option_build_offset_control(uint16_t nopts, uint16_t ctl)
Helper function to build the combined option and control flag field.
#define TCP_OPTION_KIND_MSS
"Maximum Segment Size"-Option
Definition: tcp.h:44
#define TCP_OPTION_LENGTH_MSS
MSS Option Size always 4.
Definition: tcp.h:52
#define TCP_HDR_OFFSET_MAX
Header offset maximum value.
Definition: tcp.h:35
#define TCP_HDR_OFFSET_MIN
TCP offset value boundaries.
Definition: tcp.h:34
TCP sock type.
Definition: sock_types.h:101
TCP header definition.
Definition: tcp.h:58
GNRC TCP transmission control block (TCB)
TCP header and helper functions.