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diff --git a/src/ClockTAI.cpp b/src/ClockTAI.cpp
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-/*
- Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
- 2011, 2012 Her Majesty the Queen in Right of Canada (Communications
- Research Center Canada)
-
- Copyright (C) 2019
- Matthias P. Braendli, matthias.braendli@mpb.li
-
- http://www.opendigitalradio.org
- */
-/*
- This file is part of ODR-DabMux.
-
- ODR-DabMux is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as
- published by the Free Software Foundation, either version 3 of the
- License, or (at your option) any later version.
-
- ODR-DabMux is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with ODR-DabMux. If not, see <http://www.gnu.org/licenses/>.
-*/
-
-/* This file downloads the TAI-UTC bulletins from the from IETF and parses them
- * so that correct time can be communicated in EDI timestamps.
- *
- * This file contains self-test code that can be executed by running
- * g++ -g -Wall -DTEST -DHAVE_CURL -std=c++11 -lcurl -pthread \
- * ClockTAI.cpp Log.cpp RemoteControl.cpp -lboost_system -o taitest && ./taitest
- */
-
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
-
-#include "ClockTAI.h"
-#include "Log.h"
-
-#include <time.h>
-#include <stdio.h>
-#include <errno.h>
-#if SUPPORT_SETTING_CLOCK_TAI
-# include <sys/timex.h>
-#endif
-#ifdef HAVE_CURL
-# include <curl/curl.h>
-#endif
-#include <array>
-#include <string>
-#include <iostream>
-#include <algorithm>
-#include <regex>
-
-using namespace std;
-
-#ifdef TEST
-static bool wait_longer = true;
-#endif
-
-constexpr int download_retry_interval_hours = 1;
-
-// Offset between NTP time and POSIX time:
-// timestamp_unix = timestamp_ntp - ntp_unix_offset
-const int64_t ntp_unix_offset = 2208988800L;
-
-// leap seconds insertion bulletin is available from the IETF and in the TZ
-// distribution
-static array<const char*, 2> default_tai_urls = {
- "https://www.ietf.org/timezones/data/leap-seconds.list",
- "https://raw.githubusercontent.com/eggert/tz/master/leap-seconds.list",
-};
-
-// According to the Filesystem Hierarchy Standard, the data in
-// /var/tmp "must not be deleted when the system is booted."
-static const char *tai_cache_location = "/var/tmp/odr-dabmux-leap-seconds.cache";
-
-// read TAI offset from a valid bulletin in IETF format
-static int parse_ietf_bulletin(const std::string& bulletin)
-{
- // Example Line:
- // 3692217600 37 # 1 Jan 2017
- //
- // NTP timestamp<TAB>leap seconds<TAB># some comment
- // The NTP timestamp starts at epoch 1.1.1900.
- // The difference between NTP timestamps and unix epoch is 70
- // years i.e. 2208988800 seconds
-
- std::regex regex_bulletin(R"(([0-9]+)\s+([0-9]+)\s+#.*)");
-
- time_t now = time(nullptr);
-
- int tai_utc_offset = 0;
-
- int tai_utc_offset_valid = false;
-
- stringstream ss(bulletin);
-
- /* We cannot just take the last line, because it might
- * be in the future, announcing an upcoming leap second.
- *
- * So we need to look at the current date, and compare it
- * with the date of the leap second.
- */
- for (string line; getline(ss, line); ) {
-
- std::smatch bulletin_entry;
-
- bool is_match = std::regex_search(line, bulletin_entry, regex_bulletin);
- if (is_match) {
- if (bulletin_entry.size() != 3) {
- throw runtime_error(
- "Incorrect number of matched TAI IETF bulletin entries");
- }
- const string bulletin_ntp_timestamp(bulletin_entry[1]);
- const string bulletin_offset(bulletin_entry[2]);
-
- const int64_t timestamp_unix =
- std::atoll(bulletin_ntp_timestamp.c_str()) - ntp_unix_offset;
-
- const int offset = std::atoi(bulletin_offset.c_str());
- // Ignore entries announcing leap seconds in the future
- if (timestamp_unix < now) {
- tai_utc_offset = offset;
- tai_utc_offset_valid = true;
- }
-#if TEST
- else {
- cerr << "IETF Ignoring offset " << bulletin_offset <<
- " at TS " << bulletin_ntp_timestamp <<
- " in the future" << endl;
- }
-#endif
- }
- }
-
- if (not tai_utc_offset_valid) {
- throw runtime_error("No data in TAI bulletin");
- }
-
- return tai_utc_offset;
-}
-
-
-struct bulletin_state {
- bool valid = false;
- int64_t expiry = 0;
- int offset = 0;
-
- bool usable() const { return valid and expiry > 0; }
-};
-
-static bulletin_state parse_bulletin(const string& bulletin)
-{
- // The bulletin contains one line that specifies an expiration date
- // in NTP time. If that point in time is in the future, we consider
- // the bulletin valid.
- //
- // The entry looks like this:
- //#@ 3707596800
-
- bulletin_state ret;
-
- std::regex regex_expiration(R"(#@\s+([0-9]+))");
-
- time_t now = time(nullptr);
-
- stringstream ss(bulletin);
-
- for (string line; getline(ss, line); ) {
- std::smatch bulletin_entry;
-
- bool is_match = std::regex_search(line, bulletin_entry, regex_expiration);
- if (is_match) {
- if (bulletin_entry.size() != 2) {
- throw runtime_error(
- "Incorrect number of matched TAI IETF bulletin expiration");
- }
- const string expiry_data_str(bulletin_entry[1]);
- const int64_t expiry_unix =
- std::atoll(expiry_data_str.c_str()) - ntp_unix_offset;
-
-#ifdef TEST
- etiLog.level(info) << "Bulletin expires in " << expiry_unix - now;
-#endif
- ret.expiry = expiry_unix - now;
- try {
- ret.offset = parse_ietf_bulletin(bulletin);
- ret.valid = true;
- }
- catch (const runtime_error& e) {
- etiLog.level(warn) << "Bulletin expiry ok but parse error: " << e.what();
- }
- break;
- }
- }
- return ret;
-}
-
-
-// callback that receives data from cURL
-static size_t fill_bulletin(char *ptr, size_t size, size_t nmemb, void *ctx)
-{
- auto *bulletin = reinterpret_cast<stringstream*>(ctx);
-
- size_t len = size * nmemb;
- for (size_t i = 0; i < len; i++) {
- *bulletin << ptr[i];
- }
- return len;
-}
-
-static string download_tai_utc_bulletin(const char* url)
-{
- stringstream bulletin;
-
-#ifdef HAVE_CURL
- CURL *curl;
- CURLcode res;
-
- curl = curl_easy_init();
- if (curl) {
- curl_easy_setopt(curl, CURLOPT_URL, url);
- /* Tell libcurl to follow redirection */
- curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
- curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fill_bulletin);
- curl_easy_setopt(curl, CURLOPT_WRITEDATA, &bulletin);
-
- res = curl_easy_perform(curl);
- /* always cleanup ! */
- curl_easy_cleanup(curl);
-
- if (res != CURLE_OK) {
- throw runtime_error( "TAI-UTC bulletin download failed: " +
- string(curl_easy_strerror(res)));
- }
- }
- return bulletin.str();
-#else
- throw runtime_error("Cannot download TAI Clock information without cURL");
-#endif // HAVE_CURL
-}
-
-static string load_bulletin_from_file(const char* cache_filename)
-{
- // Clear the bulletin
- ifstream f(cache_filename);
- if (not f.good()) {
- return {};
- }
-
- stringstream ss;
- ss << f.rdbuf();
- f.close();
-
- return ss.str();
-}
-
-ClockTAI::ClockTAI(const std::vector<std::string>& bulletin_urls) :
- RemoteControllable("clocktai")
-{
- RC_ADD_PARAMETER(expiry, "Number of seconds until TAI Bulletin expires");
-
- if (bulletin_urls.empty()) {
- etiLog.level(debug) << "Initialising default TAI Bulletin URLs";
- for (const auto url : default_tai_urls) {
- m_bulletin_urls.push_back(url);
- }
- }
- else {
- etiLog.level(debug) << "Initialising user-configured TAI Bulletin URLs";
- m_bulletin_urls = bulletin_urls;
- }
-
- for (const auto url : m_bulletin_urls) {
- etiLog.level(info) << "TAI Bulletin URL: '" << url << "'";
- }
-}
-
-int ClockTAI::get_valid_offset()
-{
- int offset = 0;
- bool offset_valid = false;
-
- std::unique_lock<std::mutex> lock(m_data_mutex);
-
- const auto state = parse_bulletin(m_bulletin);
- if (state.usable()) {
-#if TEST
- etiLog.level(info) << "Bulletin already valid";
-#endif
- offset = state.offset;
- offset_valid = true;
- }
- else {
- const auto cache_bulletin = load_bulletin_from_file(tai_cache_location);
- const auto cache_state = parse_bulletin(cache_bulletin);
-
- if (cache_state.usable()) {
- m_bulletin = cache_bulletin;
- offset = cache_state.offset;
- offset_valid = true;
-#if TEST
- etiLog.level(info) << "Bulletin from cache valid with offset=" << offset;
-#endif
- }
- else {
- for (const auto url : m_bulletin_urls) {
- try {
-#if TEST
- etiLog.level(info) << "Load bulletin from " << url;
-#endif
- const auto new_bulletin = download_tai_utc_bulletin(url.c_str());
- const auto new_state = parse_bulletin(new_bulletin);
- if (new_state.usable()) {
- m_bulletin = new_bulletin;
- offset = new_state.offset;
- offset_valid = true;
-
- etiLog.level(debug) << "Loaded valid TAI Bulletin from " <<
- url << " giving offset=" << offset;
- }
- else {
- etiLog.level(debug) << "Skipping invalid TAI bulletin from "
- << url;
- }
- }
- catch (const runtime_error& e) {
- etiLog.level(warn) <<
- "TAI-UTC offset could not be retrieved from " <<
- url << " : " << e.what();
- }
-
- if (offset_valid) {
- update_cache(tai_cache_location);
- break;
- }
- }
- }
- }
-
- if (offset_valid) {
- // With the current evolution of the offset, we're probably going
- // to reach 500 long after DAB gets replaced by another standard.
- if (offset < 0 or offset > 500) {
- stringstream ss;
- ss << "TAI offset " << offset << " out of range";
- throw range_error(ss.str());
- }
-
- return offset;
- }
- else {
- // Try again later
- throw download_failed();
- }
-}
-
-
-int ClockTAI::get_offset()
-{
- using namespace std::chrono;
- const auto time_now = system_clock::now();
-
- std::unique_lock<std::mutex> lock(m_data_mutex);
-
- if (not m_offset_valid) {
-#ifdef TEST
- // Assume we've downloaded it in the past:
-
- m_offset = 37; // Valid in early 2017
- m_offset_valid = true;
-
- // Simulate requiring a new download
- m_bulletin_download_time = time_now - hours(24 * 40);
-#else
- // First time we run we must block until we know
- // the offset
- lock.unlock();
- try {
- m_offset = get_valid_offset();
- }
- catch (const download_failed&) {
- throw runtime_error("Unable to download TAI bulletin");
- }
- lock.lock();
- m_offset_valid = true;
- m_bulletin_download_time = time_now;
-#endif
- etiLog.level(info) <<
- "Initialised TAI-UTC offset to " << m_offset << "s.";
- }
-
- if (time_now - m_bulletin_download_time > hours(24 * 31)) {
- // Refresh if it's older than one month. Leap seconds are
- // announced several months in advance
- etiLog.level(debug) << "Trying to refresh TAI bulletin";
-
- if (m_offset_future.valid()) {
- auto state = m_offset_future.wait_for(seconds(0));
- switch (state) {
- case future_status::ready:
- try {
- m_offset = m_offset_future.get();
- m_offset_valid = true;
- m_bulletin_download_time = time_now;
-
- etiLog.level(info) <<
- "Updated TAI-UTC offset to " << m_offset << "s.";
- }
- catch (const download_failed&) {
- etiLog.level(warn) <<
- "TAI-UTC download failed, will retry in " <<
- download_retry_interval_hours << " hour(s)";
-
- m_bulletin_download_time += hours(download_retry_interval_hours);
- }
-#ifdef TEST
- wait_longer = false;
-#endif
- break;
-
- case future_status::deferred:
- case future_status::timeout:
- // Not ready yet
-#ifdef TEST
- etiLog.level(debug) << " async not ready yet";
-#endif
- break;
- }
- }
- else {
-#ifdef TEST
- etiLog.level(debug) << " Launch async";
-#endif
- m_offset_future = async(launch::async, &ClockTAI::get_valid_offset, this);
- }
- }
-
- return m_offset;
-}
-
-#if SUPPORT_SETTING_CLOCK_TAI
-int ClockTAI::update_local_tai_clock(int offset)
-{
- struct timex timex_request;
- timex_request.modes = ADJ_TAI;
- timex_request.constant = offset;
-
- int err = adjtimex(&timex_request);
- if (err == -1) {
- perror("adjtimex");
- }
-
- printf("adjtimex: %d, tai %d\n", err, timex_request.tai);
-
- return err;
-}
-#endif
-
-void ClockTAI::update_cache(const char* cache_filename)
-{
- ofstream f(cache_filename);
- if (not f.good()) {
- throw runtime_error("TAI-UTC bulletin open cache for writing");
- }
-
- f << m_bulletin;
- f.close();
-}
-
-
-void ClockTAI::set_parameter(const string& parameter, const string& value)
-{
- if (parameter == "expiry") {
- throw ParameterError("Parameter '" + parameter +
- "' is not read-only in controllable " + get_rc_name());
- }
- else {
- throw ParameterError("Parameter '" + parameter +
- "' is not exported by controllable " + get_rc_name());
- }
-}
-
-const string ClockTAI::get_parameter(const string& parameter) const
-{
- if (parameter == "expiry") {
- std::unique_lock<std::mutex> lock(m_data_mutex);
- const int64_t expiry = parse_bulletin(m_bulletin).expiry;
- if (expiry > 0) {
- return to_string(expiry);
- }
- else {
- return "Bulletin expired or invalid!";
- }
- }
- else {
- throw ParameterError("Parameter '" + parameter +
- "' is not exported by controllable " + get_rc_name());
- }
-}
-
-#if 0
-// Example testing code
-void debug_tai_clk()
-{
- struct timespec rt_clk;
-
- int err = clock_gettime(CLOCK_REALTIME, &rt_clk);
- if (err) {
- perror("REALTIME clock_gettime failed");
- }
-
- struct timespec tai_clk;
-
- err = clock_gettime(CLOCK_TAI, &tai_clk);
- if (err) {
- perror("TAI clock_gettime failed");
- }
-
- printf("RT - TAI = %ld\n", rt_clk.tv_sec - tai_clk.tv_sec);
-
-
- struct timex timex_request;
- timex_request.modes = 0; // Do not set anything
-
- err = adjtimex(&timex_request);
- if (err == -1) {
- perror("adjtimex");
- }
-
- printf("adjtimex: %d, tai %d\n", err, timex_request.tai);
-}
-#endif
-
-#if TEST
-int main(int argc, char **argv)
-{
- using namespace std;
-
- ClockTAI tai({});
-
- while (wait_longer) {
- try {
- etiLog.level(info) <<
- "Offset is " << tai.get_offset();
- }
- catch (const exception &e) {
- etiLog.level(error) <<
- "Exception " << e.what();
- }
-
- this_thread::sleep_for(chrono::seconds(2));
- }
-
- return 0;
-}
-#endif
-