1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/**
* @file
* SNTP client options list
*/
/*
* Copyright (c) 2007-2009 Frédéric Bernon, Simon Goldschmidt
* 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.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Frédéric Bernon, Simon Goldschmidt
*
*/
#ifndef LWIP_HDR_APPS_SNTP_OPTS_H
#define LWIP_HDR_APPS_SNTP_OPTS_H
#include "lwip/opt.h"
#include "lwip/prot/iana.h"
/**
* @defgroup sntp_opts Options
* @ingroup sntp
* @{
*/
/** SNTP macro to change system time in seconds
* Define SNTP_SET_SYSTEM_TIME_US(sec, us) to set the time in microseconds
* instead of this one if you need the additional precision. Alternatively,
* define SNTP_SET_SYSTEM_TIME_NTP(sec, frac) in order to work with native
* NTP timestamps instead.
*/
#if !defined SNTP_SET_SYSTEM_TIME || defined __DOXYGEN__
#define SNTP_SET_SYSTEM_TIME(sec) LWIP_UNUSED_ARG(sec)
#endif
/** The maximum number of SNTP servers that can be set */
#if !defined SNTP_MAX_SERVERS || defined __DOXYGEN__
#define SNTP_MAX_SERVERS LWIP_DHCP_MAX_NTP_SERVERS
#endif
/** Set this to 1 to implement the callback function called by dhcp when
* NTP servers are received. */
#if !defined SNTP_GET_SERVERS_FROM_DHCP || defined __DOXYGEN__
#define SNTP_GET_SERVERS_FROM_DHCP LWIP_DHCP_GET_NTP_SRV
#endif
/** Set this to 1 to support DNS names (or IP address strings) to set sntp servers
* One server address/name can be defined as default if SNTP_SERVER_DNS == 1:
* \#define SNTP_SERVER_ADDRESS "pool.ntp.org"
*/
#if !defined SNTP_SERVER_DNS || defined __DOXYGEN__
#define SNTP_SERVER_DNS 0
#endif
/**
* SNTP_DEBUG: Enable debugging for SNTP.
*/
#if !defined SNTP_DEBUG || defined __DOXYGEN__
#define SNTP_DEBUG LWIP_DBG_OFF
#endif
/** SNTP server port */
#if !defined SNTP_PORT || defined __DOXYGEN__
#define SNTP_PORT LWIP_IANA_PORT_SNTP
#endif
/** Sanity check:
* Define this to
* - 0 to turn off sanity checks (default; smaller code)
* - >= 1 to check address and port of the response packet to ensure the
* response comes from the server we sent the request to.
* - >= 2 to check returned Originate Timestamp against Transmit Timestamp
* sent to the server (to ensure response to older request).
* - >= 3 @todo: discard reply if any of the VN, Stratum, or Transmit Timestamp
* fields is 0 or the Mode field is not 4 (unicast) or 5 (broadcast).
* - >= 4 @todo: to check that the Root Delay and Root Dispersion fields are each
* greater than or equal to 0 and less than infinity, where infinity is
* currently a cozy number like one second. This check avoids using a
* server whose synchronization source has expired for a very long time.
*/
#if !defined SNTP_CHECK_RESPONSE || defined __DOXYGEN__
#define SNTP_CHECK_RESPONSE 0
#endif
/** Enable round-trip delay compensation.
* Compensate for the round-trip delay by calculating the clock offset from
* the originate, receive, transmit and destination timestamps, as per RFC.
*
* The calculation requires compiler support for 64-bit integers. Also, either
* SNTP_SET_SYSTEM_TIME_US or SNTP_SET_SYSTEM_TIME_NTP has to be implemented
* for setting the system clock with sub-second precision. Likewise, either
* SNTP_GET_SYSTEM_TIME or SNTP_GET_SYSTEM_TIME_NTP needs to be implemented
* with sub-second precision.
*
* Although not strictly required, it makes sense to combine this option with
* SNTP_CHECK_RESPONSE >= 2 for sanity-checking of the received timestamps.
* Also, in order for the round-trip calculation to work, the difference
* between the local clock and the NTP server clock must not be larger than
* about 34 years. If that limit is exceeded, the implementation will fall back
* to setting the clock without compensation. In order to ensure that the local
* clock is always within the permitted range for compensation, even at first
* try, it may be necessary to store at least the current year in non-volatile
* memory.
*/
#if !defined SNTP_COMP_ROUNDTRIP || defined __DOXYGEN__
#define SNTP_COMP_ROUNDTRIP 0
#endif
/** According to the RFC, this shall be a random delay
* between 1 and 5 minutes (in milliseconds) to prevent load peaks.
* This can be defined to a random generation function,
* which must return the delay in milliseconds as u32_t.
* Turned off by default.
*/
#if !defined SNTP_STARTUP_DELAY || defined __DOXYGEN__
#ifdef LWIP_RAND
#define SNTP_STARTUP_DELAY 1
#else
#define SNTP_STARTUP_DELAY 0
#endif
#endif
/** If you want the startup delay to be a function, define this
* to a function (including the brackets) and define SNTP_STARTUP_DELAY to 1.
*/
#if !defined SNTP_STARTUP_DELAY_FUNC || defined __DOXYGEN__
#define SNTP_STARTUP_DELAY_FUNC (LWIP_RAND() % 5000)
#endif
/** SNTP receive timeout - in milliseconds
* Also used as retry timeout - this shouldn't be too low.
* Default is 15 seconds. Must not be beolw 15 seconds by specification (i.e. 15000)
*/
#if !defined SNTP_RECV_TIMEOUT || defined __DOXYGEN__
#define SNTP_RECV_TIMEOUT 15000
#endif
/** SNTP update delay - in milliseconds
* Default is 1 hour. Must not be beolw 60 seconds by specification (i.e. 60000)
*/
#if !defined SNTP_UPDATE_DELAY || defined __DOXYGEN__
#define SNTP_UPDATE_DELAY 3600000
#endif
/** SNTP macro to get system time, used with SNTP_CHECK_RESPONSE >= 2
* to send in request and compare in response. Also used for round-trip
* delay compensation if SNTP_COMP_ROUNDTRIP != 0.
* Alternatively, define SNTP_GET_SYSTEM_TIME_NTP(sec, frac) in order to
* work with native NTP timestamps instead.
*/
#if !defined SNTP_GET_SYSTEM_TIME || defined __DOXYGEN__
#define SNTP_GET_SYSTEM_TIME(sec, us) do { (sec) = 0; (us) = 0; } while(0)
#endif
/** Default retry timeout (in milliseconds) if the response
* received is invalid.
* This is doubled with each retry until SNTP_RETRY_TIMEOUT_MAX is reached.
*/
#if !defined SNTP_RETRY_TIMEOUT || defined __DOXYGEN__
#define SNTP_RETRY_TIMEOUT SNTP_RECV_TIMEOUT
#endif
/** Maximum retry timeout (in milliseconds). */
#if !defined SNTP_RETRY_TIMEOUT_MAX || defined __DOXYGEN__
#define SNTP_RETRY_TIMEOUT_MAX (SNTP_RETRY_TIMEOUT * 10)
#endif
/** Increase retry timeout with every retry sent
* Default is on to conform to RFC.
*/
#if !defined SNTP_RETRY_TIMEOUT_EXP || defined __DOXYGEN__
#define SNTP_RETRY_TIMEOUT_EXP 1
#endif
/** Keep a reachability shift register per server
* Default is on to conform to RFC.
*/
#if !defined SNTP_MONITOR_SERVER_REACHABILITY || defined __DOXYGEN__
#define SNTP_MONITOR_SERVER_REACHABILITY 1
#endif
/**
* @}
*/
#endif /* LWIP_HDR_APPS_SNTP_OPTS_H */
|
