/** * @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 implement the callback function called by dhcpv6 when * NTP servers are received. */ #if !defined SNTP_GET_SERVERS_FROM_DHCPV6 || defined __DOXYGEN__ #define SNTP_GET_SERVERS_FROM_DHCPV6 LWIP_DHCP6_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 */