Add TAI handling for EDI with TIST

6 files changed, 404 insertions, 17 deletions

diff --git a/src/ClockTAI.cpp b/src/ClockTAI.cpp
new file mode 100644
index 0000000..1b2d4ef
--- /dev/null
+++ b/src/ClockTAI.cpp
@@ -0,0 +1,220 @@
+/*
+   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) 2016
+   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/>.
+*/
+
+#ifdef HAVE_CONFIG_H
+#   include "config.h"
+#endif
+
+#include "ClockTAI.h"
+
+#include <stdio.h>
+#include <errno.h>
+#include <sys/timex.h>
+#include <curl/curl.h>
+#include <string>
+#include <iostream>
+#include <algorithm>
+#include <regex>
+
+/* Last line from bulletin, example:
+ 2015 JUL  1 =JD 2457204.5  TAI-UTC=  36.0       S + (MJD - 41317.) X 0.0      S
+ */
+
+ClockTAI::ClockTAI()
+{
+    m_offset = 0;
+    m_bulletin_download_time.tv_nsec = 0;
+    m_bulletin_download_time.tv_sec = 0;
+}
+
+int ClockTAI::get_offset()
+{
+    struct timespec time_now;
+
+    int err = clock_gettime(CLOCK_REALTIME, &time_now);
+    if (err) {
+        throw std::runtime_error("ClockTAI::get_offset() clock_gettime failed");
+    }
+
+    if (time_now.tv_sec - m_bulletin_download_time.tv_sec >
+            3600 * 24 * 31) {
+        // Refresh if it's older than one month. Leap seconds are
+        // announced several months in advance
+
+        if (download_tai_utc_bulletin(tai_data_url1) == 0) {
+            m_offset = parse_tai_offset();
+        }
+        else if (download_tai_utc_bulletin(tai_data_url2) == 0) {
+            m_offset = parse_tai_offset();
+        }
+    }
+
+    return m_offset;
+
+    throw std::runtime_error("Could not fetch TAI-UTC 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
+
+int ClockTAI::parse_tai_offset()
+{
+    std::regex regex_offset("TAI-UTC= *([0-9.]+)");
+
+    int tai_utc_offset = 0;
+
+    int linecount = 0;
+
+    for (std::string line; std::getline(m_bulletin, line); ) {
+        linecount++;
+        auto words_begin =
+            std::sregex_token_iterator(
+                    line.begin(), line.end(), regex_offset, 1);
+        auto words_end = std::sregex_token_iterator();
+
+        for (auto w = words_begin; w != words_end; ++w) {
+            std::string s(*w);
+            tai_utc_offset = std::atoi(s.c_str());
+        }
+
+    }
+
+    if (linecount == 0) {
+        throw std::runtime_error("No data in TAI bulletin");
+    }
+
+    // With the current evolution of the offset, we're probably going
+    // to reach 500 long after DAB gets replaced by another standard.
+    if (tai_utc_offset < 0 or tai_utc_offset > 500) {
+        std::stringstream ss;
+        ss << "TAI offset " << tai_utc_offset << " out of range";
+        throw std::range_error(ss.str());
+    }
+
+    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);
+}
+
+int ClockTAI::download_tai_utc_bulletin(const char* url)
+{
+    int r = 0;
+
+    CURL *curl;
+    CURLcode res;
+
+    curl = curl_easy_init();
+    if (curl) {
+        curl_easy_setopt(curl, CURLOPT_URL, url);
+        /* example.com is redirected, so we 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);
+        if (res != CURLE_OK) {
+            fprintf(stderr, "curl_easy_perform() failed: %s\n",
+                    curl_easy_strerror(res));
+
+            r = 1;
+        }
+        else {
+            // Save the download time of the bulletin
+            int err = clock_gettime(CLOCK_REALTIME, &m_bulletin_download_time);
+            if (err) {
+                perror("REALTIME clock_gettime failed");
+                r = 1;
+            }
+        }
+
+        /* always cleanup */
+        curl_easy_cleanup(curl);
+    }
+    return r;
+}
+
+#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
+
diff --git a/src/ClockTAI.h b/src/ClockTAI.h
new file mode 100644
index 0000000..027e6db
--- /dev/null
+++ b/src/ClockTAI.h
@@ -0,0 +1,85 @@
+/*
+   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) 2016
+   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/>.
+*/
+
+/* The EDI output needs TAI clock, according to ETSI TS 102 693 Annex F
+ * "EDI Timestamps". This module sets the local CLOCK_TAI clock by
+ * setting the TAI-UTC offset using adjtimex.
+ *
+ * This functionality requires Linux 3.10 (30 Jun 2013) or newer */
+
+#ifndef __CLOCK_TAI_H_
+#define __CLOCK_TAI_H_
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <sstream>
+#include <time.h>
+
+// EDI needs to know UTC-TAI, but doesn't need the CLOCK_TAI to be set
+#define SUPPORT_SETTING_CLOCK_TAI 0
+
+/* Loads, parses and represents TAI-UTC offset information from the USNO bulletin */
+class ClockTAI {
+    public:
+        ClockTAI();
+
+        // Fetch the bulletin from the USNO website and return the current
+        // TAI-UTC offset.
+        // Throws runtime_error on failure.
+        int get_offset(void);
+
+#if SUPPORT_SETTING_CLOCK_TAI
+        // Update the local TAI clock according to the TAI-UTC offset
+        // return 0 on success
+        int update_local_tai_clock(int offset);
+#endif
+
+    private:
+        // leap seconds insertion bulletin is available at
+        const char* tai_data_url1 = "http://maia.usno.navy.mil/ser7/tai-utc.dat";
+        const char* tai_data_url2 = "http://toshi.nofs.navy.mil/ser7/tai-utc.dat";
+
+        int m_offset;
+        std::stringstream m_bulletin;
+        struct timespec m_bulletin_download_time;
+
+        // Load bulletin into m_bulletin, return 0 on success
+        int download_tai_utc_bulletin(const char* url);
+
+        // read TAI offset from m_bulletin
+        int parse_tai_offset(void);
+
+        // callback that receives data from cURL
+        size_t fill_bulletin(char *ptr, size_t size, size_t nmemb);
+
+        // static callback wrapper for cURL
+        static size_t fill_bulletin_cb(
+                char *ptr, size_t size, size_t nmemb, void *ctx);
+};
+
+#endif // __CLOCK_TAI_H_
+
diff --git a/src/DabMultiplexer.cpp b/src/DabMultiplexer.cpp
index fd59b8f..d9e1a10 100644
--- a/src/DabMultiplexer.cpp
+++ b/src/DabMultiplexer.cpp
@@ -239,6 +239,30 @@ void DabMultiplexer::prepare()
      */
     gettimeofday(&mnsc_time, NULL);
 
+#if HAVE_OUTPUT_EDI
+    // Try to load offset once
+
+    bool tist_enabled = m_pt.get("general.tist", false);
+
+    try {
+        m_clock_tai.get_offset();
+    }
+    catch (std::runtime_error& e) {
+        const char* err_msg =
+            "Could not initialise TAI clock properly required by "
+            "EDI with timestamp. Do you have a working internet "
+            "connection?";
+
+        if (tist_enabled and edi_conf.enabled) {
+            etiLog.level(error) << err_msg;
+            throw e;
+        }
+        else {
+            etiLog.level(warn) << err_msg;
+        }
+    }
+#endif
+
     // Shift ms by 13 to Timestamp level 2, see below in Section TIST
     timestamp = (mnsc_time.tv_usec / 1000) << 13;
 }
@@ -450,6 +474,18 @@ void DabMultiplexer::mux_frame(std::vector<std::shared_ptr<DabOutput> >& outputs
     edi_tagDETI.atstf = 1;
     edi_tagDETI.utco = 0;
     edi_tagDETI.seconds = 0;
+    try {
+        bool tist_enabled = m_pt.get("general.tist", false);
+
+        if (tist_enabled and edi_conf.enabled) {
+            edi_tagDETI.set_utco(m_clock_tai.get_offset());
+        }
+
+        edi_tagDETI.set_seconds(mnsc_time);
+    }
+    catch (std::runtime_error& e) {
+        etiLog.level(error) << "Could not get UTC-TAI offset for EDI timestamp";
+    }
 
     date = getDabTime();
 
diff --git a/src/DabMultiplexer.h b/src/DabMultiplexer.h
index aa468ea..7b3834e 100644
--- a/src/DabMultiplexer.h
+++ b/src/DabMultiplexer.h
@@ -45,6 +45,7 @@
 #include "MuxElements.h"
 #include "RemoteControl.h"
 #include "Eti.h"
+#include "ClockTAI.h"
 #include <exception>
 #include <vector>
 #include <memory>
@@ -136,6 +137,8 @@ class DabMultiplexer : public RemoteControllable {
         std::shared_ptr<dabEnsemble> ensemble_next;
 
 #if HAVE_OUTPUT_EDI
+        ClockTAI m_clock_tai;
+
         std::ofstream edi_debug_file;
         UdpSocket edi_output;
 
diff --git a/src/Makefile.am b/src/Makefile.am
index 1cf8dbb..4c5cd60 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -39,9 +39,16 @@ bin_PROGRAMS=odr-dabmux odr-bridgetest
 ZMQ_LIBS    =
 endif
 
+if HAVE_CURL_TEST
+CURL_LIBS    =-lcurl
+else
+CURL_LIBS    =
+endif
+
 odr_dabmux_CFLAGS   =-Wall -I$(FARSYNC_DIR) $(GITVERSION_FLAGS)
 odr_dabmux_CXXFLAGS =-Wall -I$(FARSYNC_DIR) $(GITVERSION_FLAGS)
-odr_dabmux_LDADD    =$(FEC_LIBS) $(ZMQ_LIBS) -lpthread -lboost_thread -lboost_system
+odr_dabmux_LDADD    =$(FEC_LIBS) $(ZMQ_LIBS) $(CURL_LIBS) \
+					 -lpthread -lboost_thread -lboost_system
 odr_dabmux_SOURCES  =DabMux.cpp DabMux.h \
 					 DabMultiplexer.cpp DabMultiplexer.h \
                      dabInput.h dabInput.cpp \
@@ -76,32 +83,33 @@ odr_dabmux_SOURCES  =DabMux.cpp DabMux.h \
                      dabOutput/edi/TagItems.cpp dabOutput/edi/TagItems.h \
                      dabOutput/edi/TagPacket.cpp dabOutput/edi/TagPacket.h \
                      dabOutput/edi/PFT.cpp dabOutput/edi/PFT.h \
-                     bridge.h bridge.c \
-                     utils.cpp utils.h \
-                     MuxElements.cpp MuxElements.h \
-                     RemoteControl.cpp RemoteControl.h \
-                     ParserCmdline.cpp ParserCmdline.h \
+                     ClockTAI.h ClockTAI.cpp \
                      ConfigParser.cpp ConfigParser.h \
+                     Dmb.h Dmb.cpp \
                      Eti.h Eti.cpp \
-                     Log.h Log.cpp \
-                     UdpSocket.h UdpSocket.cpp \
                      InetAddress.h InetAddress.cpp \
-                     prbs.h prbs.c \
-                     crc.h crc.c \
-                     dabUtils.h dabUtils.cpp \
-                     PcDebug.h \
-                     Dmb.h Dmb.cpp \
                      Interleaver.h Interleaver.cpp \
-                     ReedSolomon.h ReedSolomon.cpp \
-                     mpeg.h mpeg.c \
+                     Log.h Log.cpp \
                      ManagementServer.h ManagementServer.cpp \
+                     MuxElements.cpp MuxElements.h \
+                     ParserCmdline.cpp ParserCmdline.h \
+                     PcDebug.h \
+                     ReedSolomon.h ReedSolomon.cpp \
+                     RemoteControl.cpp RemoteControl.h \
                      TcpServer.h TcpServer.cpp \
                      TcpSocket.h TcpSocket.cpp \
-                     zmq.hpp \
+                     UdpSocket.h UdpSocket.cpp \
+                     bridge.h bridge.c \
+                     crc.h crc.c \
+                     dabUtils.h dabUtils.cpp \
+                     fig/FIG.h \
                      fig/FIG0.cpp fig/FIG0.h \
                      fig/FIG1.cpp fig/FIG1.h \
                      fig/FIGCarousel.cpp fig/FIGCarousel.h \
-                     fig/FIG.h
+                     mpeg.h mpeg.c \
+                     prbs.h prbs.c \
+                     utils.cpp utils.h \
+                     zmq.hpp
 
 odr_bridgetest_CFLAGS   =-DBRIDGE_TEST
 odr_bridgetest_SOURCES  =bridge.c \
diff --git a/src/dabOutput/edi/TagItems.h b/src/dabOutput/edi/TagItems.h
index 355b6e6..dee857a 100644
--- a/src/dabOutput/edi/TagItems.h
+++ b/src/dabOutput/edi/TagItems.h
@@ -74,8 +74,43 @@ class TagDETI : public TagItem
 
         // ATST (optional)
         bool atstf; // presence of atst data
+
+        /* UTCO: Offset (in seconds) between UTC and the Seconds value. The
+         * value is expressed as an unsigned 8-bit quantity. As of February
+         * 2009, the value shall be 2 and shall change as a result of each
+         * modification of the number of leap seconds, as proscribed by
+         * International Earth Rotation and Reference Systems Service (IERS).
+         *
+         * According to Annex F
+         *  EDI = TAI - 32s (constant)
+         *  EDI = UTC + UTCO
+         * we derive
+         *  UTCO = TAI-UTC - 32
+         * where the TAI-UTC offset is given by the USNO bulletin using
+         * the ClockTAI module.
+         */
         uint8_t utco;
+
+        void set_utco(int tai_utc_offset) { utco = tai_utc_offset - 32; }
+
+        /* The number of SI seconds since 2000-01-01 T 00:00:00 UTC as an
+         * unsigned 32-bit quantity
+         */
         uint32_t seconds;
+
+        void set_seconds(struct timeval tv)
+        {
+            time_t posix_timestamp_1_jan_2000 = 946684800;
+            seconds = tv.tv_sec - posix_timestamp_1_jan_2000;
+        }
+
+
+        /* TSTA: Shall be the 24 least significant bits of the Time Stamp
+         * (TIST) field from the STI-D(LI) Frame. The full definition for the
+         * STI TIST can be found in annex B of EN 300 797 [4]. The most
+         * significant 8 bits of the TIST field of the incoming STI-D(LI)
+         * frame, if required, may be carried in the RFAD field.
+         */
         uint32_t tsta;
 
         // the FIC (optional)