diff options
Diffstat (limited to 'src/ClockTAI.cpp')
| -rw-r--r-- | src/ClockTAI.cpp | 381 |
1 files changed, 188 insertions, 193 deletions
diff --git a/src/ClockTAI.cpp b/src/ClockTAI.cpp index 7fef72b..90dbab2 100644 --- a/src/ClockTAI.cpp +++ b/src/ClockTAI.cpp @@ -86,6 +86,179 @@ static array<const char*, 2> tai_cache_locations = { "/tmp/odr-dabmux-leap-seconds.cache", }; +struct bulletin_state { + bool valid = false; + int64_t expiry = 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; + ret.valid = true; + break; + } + } + return ret; +} + +// 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; +} + + +// 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") { @@ -114,26 +287,27 @@ int ClockTAI::get_valid_offset() std::unique_lock<std::mutex> lock(m_data_mutex); - if (bulletin_is_valid()) { + if (parse_bulletin(m_bulletin).usable()) { #if TEST etiLog.level(info) << "Bulletin already valid"; #endif - offset = parse_ietf_bulletin(); + offset = parse_ietf_bulletin(m_bulletin); offset_valid = true; } else { for (const auto& cache_file : tai_cache_locations) { - load_bulletin_from_file(cache_file); - if (bulletin_is_valid()) { + const auto cache_bulletin = load_bulletin_from_file(cache_file); + if (parse_bulletin(cache_bulletin).usable()) { + m_bulletin = cache_bulletin; break; } } - if (bulletin_is_valid()) { + if (parse_bulletin(m_bulletin).usable()) { #if TEST etiLog.level(info) << "Bulletin from file valid"; #endif - offset = parse_ietf_bulletin(); + offset = parse_ietf_bulletin(m_bulletin); offset_valid = true; } else { @@ -142,12 +316,14 @@ int ClockTAI::get_valid_offset() #if TEST etiLog.level(info) << "Load bulletin from " << url; #endif - download_tai_utc_bulletin(url.c_str()); - if (bulletin_is_valid()) { - offset = parse_ietf_bulletin(); + const auto new_bulletin = download_tai_utc_bulletin(url.c_str()); + if (parse_bulletin(new_bulletin).usable()) { + m_bulletin = new_bulletin; + offset = parse_ietf_bulletin(m_bulletin); + offset_valid = true; + etiLog.level(debug) << "Loaded valid TAI Bulletin from " << url << " giving offset=" << offset; - offset_valid = true; } else { etiLog.level(debug) << "Skipping invalid TAI bulletin from " @@ -288,102 +464,6 @@ int ClockTAI::update_local_tai_clock(int offset) } #endif -int ClockTAI::parse_ietf_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; - - m_bulletin.clear(); - m_bulletin.seekg(0); - - /* 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(m_bulletin, 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; -} - -size_t ClockTAI::fill_bulletin(char *ptr, size_t size, size_t nmemb) -{ - size_t len = size * nmemb; - for (size_t i = 0; i < len; i++) { - m_bulletin << ptr[i]; - } - return len; -} - -size_t ClockTAI::fill_bulletin_cb( - char *ptr, size_t size, size_t nmemb, void *ctx) -{ - return ((ClockTAI*)ctx)->fill_bulletin(ptr, size, nmemb); -} - -void ClockTAI::load_bulletin_from_file(const char* cache_filename) -{ - // Clear the bulletin - m_bulletin.str(""); - m_bulletin.clear(); - - ifstream f(cache_filename); - if (not f.good()) { - return; - } - - m_bulletin << f.rdbuf(); - f.close(); -} - void ClockTAI::update_cache(const char* cache_filename) { ofstream f(cache_filename); @@ -391,95 +471,10 @@ void ClockTAI::update_cache(const char* cache_filename) throw runtime_error("TAI-UTC bulletin open cache for writing"); } - m_bulletin.clear(); - m_bulletin.seekg(0); -#if TEST - etiLog.level(info) << "Update cache, state:" << - (m_bulletin.eof() ? " eof" : "") << - (m_bulletin.fail() ? " fail" : "") << - (m_bulletin.bad() ? " bad" : ""); -#endif - - f << m_bulletin.rdbuf(); + f << m_bulletin; f.close(); } -bool ClockTAI::bulletin_is_valid() -{ - return bulletin_expiry_delay() > 0; -} - -int64_t ClockTAI::bulletin_expiry_delay() const -{ - // 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 - - std::regex regex_expiration(R"(#@\s+([0-9]+))"); - - time_t now = time(nullptr); - - m_bulletin.clear(); - m_bulletin.seekg(0); - - for (string line; getline(m_bulletin, 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; - - if (expiry_unix > now) { -#ifdef TEST - etiLog.level(info) << "Bulletin expires in " << expiry_unix - now; -#endif - return expiry_unix - now; - } - } - } - return -1; -} - -void ClockTAI::download_tai_utc_bulletin(const char* url) -{ - // Clear the bulletin - m_bulletin.str(""); - m_bulletin.clear(); - -#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, ClockTAI::fill_bulletin_cb); - curl_easy_setopt(curl, CURLOPT_WRITEDATA, this); - - 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))); - } - } -#else - throw runtime_error("Cannot download TAI Clock information without cURL"); -#endif // HAVE_CURL -} void ClockTAI::set_parameter(const string& parameter, const string& value) { @@ -497,7 +492,7 @@ const string ClockTAI::get_parameter(const string& parameter) const { if (parameter == "expiry") { std::unique_lock<std::mutex> lock(m_data_mutex); - int64_t expiry = bulletin_expiry_delay(); + const int64_t expiry = parse_bulletin(m_bulletin).expiry; if (expiry > 0) { return to_string(expiry); } |