sntp_opts.h

00001 /**
00002  * @file
00003  * SNTP client options list
00004  */
00005 
00006 /*
00007  * Copyright (c) 2007-2009 Frédéric Bernon, Simon Goldschmidt
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: Frédéric Bernon, Simon Goldschmidt
00035  *
00036  */
00037 #ifndef LWIP_HDR_APPS_SNTP_OPTS_H
00038 #define LWIP_HDR_APPS_SNTP_OPTS_H
00039 
00040 #include "lwip/opt.h"
00041 
00042 /**
00043  * @defgroup sntp_opts Options
00044  * @ingroup sntp
00045  * @{
00046  */
00047 
00048 /** SNTP macro to change system time in seconds
00049  * Define SNTP_SET_SYSTEM_TIME_US(sec, us) to set the time in microseconds instead of this one
00050  * if you need the additional precision.
00051  */
00052 #if !defined SNTP_SET_SYSTEM_TIME || defined __DOXYGEN__
00053 #define SNTP_SET_SYSTEM_TIME(sec)   LWIP_UNUSED_ARG(sec)
00054 #endif
00055 
00056 /** The maximum number of SNTP servers that can be set */
00057 #if !defined SNTP_MAX_SERVERS || defined __DOXYGEN__
00058 #define SNTP_MAX_SERVERS           LWIP_DHCP_MAX_NTP_SERVERS
00059 #endif
00060 
00061 /** Set this to 1 to implement the callback function called by dhcp when
00062  * NTP servers are received. */
00063 #if !defined SNTP_GET_SERVERS_FROM_DHCP || defined __DOXYGEN__
00064 #define SNTP_GET_SERVERS_FROM_DHCP LWIP_DHCP_GET_NTP_SRV
00065 #endif
00066 
00067 /** Set this to 1 to support DNS names (or IP address strings) to set sntp servers
00068  * One server address/name can be defined as default if SNTP_SERVER_DNS == 1:
00069  * \#define SNTP_SERVER_ADDRESS "pool.ntp.org"
00070  */
00071 #if !defined SNTP_SERVER_DNS || defined __DOXYGEN__
00072 #define SNTP_SERVER_DNS            0
00073 #endif
00074 
00075 /**
00076  * SNTP_DEBUG: Enable debugging for SNTP.
00077  */
00078 #if !defined SNTP_DEBUG || defined __DOXYGEN__
00079 #define SNTP_DEBUG                  LWIP_DBG_OFF
00080 #endif
00081 
00082 /** SNTP server port */
00083 #if !defined SNTP_PORT || defined __DOXYGEN__
00084 #define SNTP_PORT                   123
00085 #endif
00086 
00087 /** Set this to 1 to allow config of SNTP server(s) by DNS name */
00088 #if !defined SNTP_SERVER_DNS || defined __DOXYGEN__
00089 #define SNTP_SERVER_DNS             0
00090 #endif
00091 
00092 /** Sanity check:
00093  * Define this to
00094  * - 0 to turn off sanity checks (default; smaller code)
00095  * - >= 1 to check address and port of the response packet to ensure the
00096  *        response comes from the server we sent the request to.
00097  * - >= 2 to check returned Originate Timestamp against Transmit Timestamp
00098  *        sent to the server (to ensure response to older request).
00099  * - >= 3 @todo: discard reply if any of the LI, Stratum, or Transmit Timestamp
00100  *        fields is 0 or the Mode field is not 4 (unicast) or 5 (broadcast).
00101  * - >= 4 @todo: to check that the Root Delay and Root Dispersion fields are each
00102  *        greater than or equal to 0 and less than infinity, where infinity is
00103  *        currently a cozy number like one second. This check avoids using a
00104  *        server whose synchronization source has expired for a very long time.
00105  */
00106 #if !defined SNTP_CHECK_RESPONSE || defined __DOXYGEN__
00107 #define SNTP_CHECK_RESPONSE         0
00108 #endif
00109 
00110 /** According to the RFC, this shall be a random delay
00111  * between 1 and 5 minutes (in milliseconds) to prevent load peaks.
00112  * This can be defined to a random generation function,
00113  * which must return the delay in milliseconds as u32_t.
00114  * Turned off by default.
00115  */
00116 #if !defined SNTP_STARTUP_DELAY || defined __DOXYGEN__
00117 #define SNTP_STARTUP_DELAY          0
00118 #endif
00119 
00120 /** If you want the startup delay to be a function, define this
00121  * to a function (including the brackets) and define SNTP_STARTUP_DELAY to 1.
00122  */
00123 #if !defined SNTP_STARTUP_DELAY_FUNC || defined __DOXYGEN__
00124 #define SNTP_STARTUP_DELAY_FUNC     SNTP_STARTUP_DELAY
00125 #endif
00126 
00127 /** SNTP receive timeout - in milliseconds
00128  * Also used as retry timeout - this shouldn't be too low.
00129  * Default is 3 seconds.
00130  */
00131 #if !defined SNTP_RECV_TIMEOUT || defined __DOXYGEN__
00132 #define SNTP_RECV_TIMEOUT           3000
00133 #endif
00134 
00135 /** SNTP update delay - in milliseconds
00136  * Default is 1 hour. Must not be beolw 15 seconds by specification (i.e. 15000)
00137  */
00138 #if !defined SNTP_UPDATE_DELAY || defined __DOXYGEN__
00139 #define SNTP_UPDATE_DELAY           3600000
00140 #endif
00141 
00142 /** SNTP macro to get system time, used with SNTP_CHECK_RESPONSE >= 2
00143  * to send in request and compare in response.
00144  */
00145 #if !defined SNTP_GET_SYSTEM_TIME || defined __DOXYGEN__
00146 #define SNTP_GET_SYSTEM_TIME(sec, us)     do { (sec) = 0; (us) = 0; } while(0)
00147 #endif
00148 
00149 /** Default retry timeout (in milliseconds) if the response
00150  * received is invalid.
00151  * This is doubled with each retry until SNTP_RETRY_TIMEOUT_MAX is reached.
00152  */
00153 #if !defined SNTP_RETRY_TIMEOUT || defined __DOXYGEN__
00154 #define SNTP_RETRY_TIMEOUT          SNTP_RECV_TIMEOUT
00155 #endif
00156 
00157 /** Maximum retry timeout (in milliseconds). */
00158 #if !defined SNTP_RETRY_TIMEOUT_MAX || defined __DOXYGEN__
00159 #define SNTP_RETRY_TIMEOUT_MAX      (SNTP_RETRY_TIMEOUT * 10)
00160 #endif
00161 
00162 /** Increase retry timeout with every retry sent
00163  * Default is on to conform to RFC.
00164  */
00165 #if !defined SNTP_RETRY_TIMEOUT_EXP || defined __DOXYGEN__
00166 #define SNTP_RETRY_TIMEOUT_EXP      1
00167 #endif
00168 
00169 /**
00170  * @}
00171  */
00172 
00173 #endif /* LWIP_HDR_APPS_SNTP_OPTS_H */