Pull in files from odr-mmbtools-common

Telnet RC is now single-user only.

9 files changed, 2220 insertions, 1 deletions

diff --git a/lib/ClockTAI.cpp b/lib/ClockTAI.cpp
new file mode 100644
index 0000000..42497f4
--- /dev/null
+++ b/lib/ClockTAI.cpp
@@ -0,0 +1,562 @@
+/*
+   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 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
+
diff --git a/lib/ClockTAI.h b/lib/ClockTAI.h
new file mode 100644
index 0000000..bb85815
--- /dev/null
+++ b/lib/ClockTAI.h
@@ -0,0 +1,102 @@
+/*
+   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/>.
+*/
+
+/* The EDI output needs TAI clock, according to ETSI TS 102 693 Annex F
+ * "EDI Timestamps". This module can set the local CLOCK_TAI clock by
+ * setting the TAI-UTC offset using adjtimex.
+ *
+ * This functionality requires Linux 3.10 (30 Jun 2013) or newer.
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <cstdlib>
+#include <sstream>
+#include <chrono>
+#include <future>
+#include <mutex>
+#include <string>
+#include <vector>
+#include "RemoteControl.h"
+
+// EDI needs to know UTC-TAI, but doesn't need the CLOCK_TAI to be set.
+// We can keep this code, maybe for future use
+#define SUPPORT_SETTING_CLOCK_TAI 0
+
+/* Loads, parses and represents TAI-UTC offset information from the IETF bulletin */
+class ClockTAI : public RemoteControllable {
+    public:
+        ClockTAI(const std::vector<std::string>& bulletin_urls);
+
+        // Fetch the bulletin from the IETF 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:
+        class download_failed {};
+
+        // Either retrieve the bulletin from the cache or if necessarly
+        // download it, and calculate the TAI-UTC offset.
+        // Returns the offset or throws download_failed or a range_error
+        // if the offset is out of bounds.
+        int get_valid_offset(void);
+
+        // Download of new bulletin is done asynchronously
+        std::future<int> m_offset_future;
+
+        // Protect all data members, as RC functions are in another thread
+        mutable std::mutex m_data_mutex;
+
+        // The currently used TAI-UTC offset
+        int m_offset = 0;
+        int m_offset_valid = false;
+
+        std::vector<std::string> m_bulletin_urls;
+
+        std::string m_bulletin;
+        std::chrono::system_clock::time_point m_bulletin_download_time;
+
+        // Update the cache file with the current m_bulletin
+        void update_cache(const char* cache_filename);
+
+
+        /* Remote control */
+        virtual void set_parameter(const std::string& parameter,
+               const std::string& value);
+
+        /* Getting a parameter always returns a string. */
+        virtual const std::string get_parameter(const std::string& parameter) const;
+};
+
diff --git a/lib/Log.cpp b/lib/Log.cpp
new file mode 100644
index 0000000..2417f3a
--- /dev/null
+++ b/lib/Log.cpp
@@ -0,0 +1,194 @@
+/*
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
+   Her Majesty the Queen in Right of Canada (Communications Research
+   Center Canada)
+
+   Copyright (C) 2018
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+    http://www.opendigitalradio.org
+ */
+/*
+   This file is part of the ODR-mmbTools.
+
+   This program 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.
+
+   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <list>
+#include <cstdarg>
+#include <cinttypes>
+#include <chrono>
+
+#include "Log.h"
+
+using namespace std;
+
+/* etiLog is a singleton used in all parts of the program to output log messages.
+ */
+Logger etiLog;
+
+void Logger::register_backend(std::shared_ptr<LogBackend> backend)
+{
+    backends.push_back(backend);
+}
+
+
+void Logger::log(log_level_t level, const char* fmt, ...)
+{
+    if (level == discard) {
+        return;
+    }
+
+    int size = 100;
+    std::string str;
+    va_list ap;
+    while (1) {
+        str.resize(size);
+        va_start(ap, fmt);
+        int n = vsnprintf((char *)str.c_str(), size, fmt, ap);
+        va_end(ap);
+        if (n > -1 && n < size) {
+            str.resize(n);
+            break;
+        }
+        if (n > -1)
+            size = n + 1;
+        else
+            size *= 2;
+    }
+
+    logstr(level, move(str));
+}
+
+void Logger::logstr(log_level_t level, std::string&& message)
+{
+    if (level == discard) {
+        return;
+	}
+
+    log_message_t m(level, move(message));
+    m_message_queue.push(move(m));
+}
+
+void Logger::io_process()
+{
+    while (1) {
+        log_message_t m;
+        try {
+            m_message_queue.wait_and_pop(m);
+        }
+        catch (const ThreadsafeQueueWakeup&) {
+            break;
+        }
+
+        auto message = m.message;
+
+        /* Remove a potential trailing newline.
+         * It doesn't look good in syslog
+         */
+        if (message[message.length()-1] == '\n') {
+            message.resize(message.length()-1);
+        }
+
+        for (auto &backend : backends) {
+            backend->log(m.level, message);
+        }
+
+        if (m.level != log_level_t::trace) {
+            std::lock_guard<std::mutex> guard(m_cerr_mutex);
+            std::cerr << levels_as_str[m.level] << " " << message << std::endl;
+        }
+    }
+}
+
+
+LogLine Logger::level(log_level_t level)
+{
+    return LogLine(this, level);
+}
+
+LogToFile::LogToFile(const std::string& filename) : name("FILE")
+{
+    FILE* fd = fopen(filename.c_str(), "a");
+    if (fd == nullptr) {
+        fprintf(stderr, "Cannot open log file !");
+        throw std::runtime_error("Cannot open log file !");
+    }
+
+    log_file.reset(fd);
+}
+
+void LogToFile::log(log_level_t level, const std::string& message)
+{
+    if (not (level == log_level_t::trace or level == log_level_t::discard)) {
+        const char* log_level_text[] = {
+            "DEBUG", "INFO", "WARN", "ERROR", "ALERT", "EMERG"};
+
+        // fprintf is thread-safe
+        fprintf(log_file.get(), SYSLOG_IDENT ": %s: %s\n",
+                log_level_text[(size_t)level], message.c_str());
+        fflush(log_file.get());
+    }
+}
+
+void LogToSyslog::log(log_level_t level, const std::string& message)
+{
+    if (not (level == log_level_t::trace or level == log_level_t::discard)) {
+        int syslog_level = LOG_EMERG;
+        switch (level) {
+            case debug: syslog_level = LOG_DEBUG; break;
+            case info:  syslog_level = LOG_INFO; break;
+                        /* we don't have the notice level */
+            case warn:  syslog_level = LOG_WARNING; break;
+            case error: syslog_level = LOG_ERR; break;
+            default:    syslog_level = LOG_CRIT; break;
+            case alert: syslog_level = LOG_ALERT; break;
+            case emerg: syslog_level = LOG_EMERG; break;
+        }
+
+        syslog(syslog_level, SYSLOG_IDENT " %s", message.c_str());
+    }
+}
+
+LogTracer::LogTracer(const string& trace_filename) : name("TRACE")
+{
+    etiLog.level(info) << "Setting up TRACE to " << trace_filename;
+
+    FILE* fd = fopen(trace_filename.c_str(), "a");
+    if (fd == nullptr) {
+        fprintf(stderr, "Cannot open trace file !");
+        throw std::runtime_error("Cannot open trace file !");
+    }
+    m_trace_file.reset(fd);
+
+    using namespace std::chrono;
+    auto now = steady_clock::now().time_since_epoch();
+    m_trace_micros_startup = duration_cast<microseconds>(now).count();
+
+    fprintf(m_trace_file.get(),
+            "0,TRACER,startup at %" PRIu64 "\n", m_trace_micros_startup);
+}
+
+void LogTracer::log(log_level_t level, const std::string& message)
+{
+    if (level == log_level_t::trace) {
+        using namespace std::chrono;
+        const auto now = steady_clock::now().time_since_epoch();
+        const auto micros = duration_cast<microseconds>(now).count();
+
+        fprintf(m_trace_file.get(), "%" PRIu64 ",%s\n",
+                micros - m_trace_micros_startup,
+                message.c_str());
+    }
+}
diff --git a/lib/Log.h b/lib/Log.h
new file mode 100644
index 0000000..d5c39e0
--- /dev/null
+++ b/lib/Log.h
@@ -0,0 +1,204 @@
+/*
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
+   Her Majesty the Queen in Right of Canada (Communications Research
+   Center Canada)
+
+   Copyright (C) 2018
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+    http://www.opendigitalradio.org
+ */
+/*
+   This file is part of the ODR-mmbTools.
+
+   This program 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.
+
+   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#ifdef HAVE_CONFIG_H
+#   include "config.h"
+#endif
+
+#include <syslog.h>
+#include <cstdarg>
+#include <cstdio>
+#include <fstream>
+#include <sstream>
+#include <iostream>
+#include <list>
+#include <stdexcept>
+#include <string>
+#include <map>
+#include <mutex>
+#include <memory>
+#include <thread>
+#include "ThreadsafeQueue.h"
+
+#define SYSLOG_IDENT PACKAGE_NAME
+#define SYSLOG_FACILITY LOG_LOCAL0
+
+enum log_level_t {debug = 0, info, warn, error, alert, emerg, trace, discard};
+
+static const std::string levels_as_str[] =
+    { "     ", "     ", "WARN ", "ERROR", "ALERT", "EMERG", "TRACE", "-----"} ;
+
+/** Abstract class all backends must inherit from */
+class LogBackend {
+    public:
+        virtual ~LogBackend() {};
+        virtual void log(log_level_t level, const std::string& message) = 0;
+        virtual std::string get_name() const = 0;
+};
+
+/** A Logging backend for Syslog */
+class LogToSyslog : public LogBackend {
+    public:
+        LogToSyslog() : name("SYSLOG") {
+            openlog(SYSLOG_IDENT, LOG_PID, SYSLOG_FACILITY);
+        }
+
+        virtual ~LogToSyslog() {
+            closelog();
+        }
+
+        void log(log_level_t level, const std::string& message);
+
+        std::string get_name() const { return name; }
+
+    private:
+        const std::string name;
+
+        LogToSyslog(const LogToSyslog& other) = delete;
+        const LogToSyslog& operator=(const LogToSyslog& other) = delete;
+};
+
+class LogToFile : public LogBackend {
+    public:
+        LogToFile(const std::string& filename);
+        void log(log_level_t level, const std::string& message);
+        std::string get_name() const { return name; }
+
+    private:
+        const std::string name;
+
+        struct FILEDeleter{ void operator()(FILE* fd){ if(fd) fclose(fd);}};
+        std::unique_ptr<FILE, FILEDeleter> log_file;
+
+        LogToFile(const LogToFile& other) = delete;
+        const LogToFile& operator=(const LogToFile& other) = delete;
+};
+
+class LogTracer : public LogBackend {
+    public:
+        LogTracer(const std::string& filename);
+        void log(log_level_t level, const std::string& message);
+        std::string get_name() const { return name; }
+    private:
+        std::string name;
+        uint64_t m_trace_micros_startup = 0;
+
+        struct FILEDeleter{ void operator()(FILE* fd){ if(fd) fclose(fd);}};
+        std::unique_ptr<FILE, FILEDeleter> m_trace_file;
+
+        LogTracer(const LogTracer& other) = delete;
+        const LogTracer& operator=(const LogTracer& other) = delete;
+};
+
+class LogLine;
+
+struct log_message_t {
+    log_message_t(log_level_t _level, std::string&& _message) :
+        level(_level),
+        message(move(_message)) {}
+
+    log_message_t() :
+        level(debug),
+        message("") {}
+
+    log_level_t level;
+    std::string message;
+};
+
+class Logger {
+    public:
+        Logger() {
+            m_io_thread = std::thread(&Logger::io_process, this);
+        }
+
+        Logger(const Logger& other) = delete;
+        const Logger& operator=(const Logger& other) = delete;
+        ~Logger() {
+            m_message_queue.trigger_wakeup();
+            m_io_thread.join();
+        }
+
+        void register_backend(std::shared_ptr<LogBackend> backend);
+
+        /* Log the message to all backends */
+        void log(log_level_t level, const char* fmt, ...);
+
+        void logstr(log_level_t level, std::string&& message);
+
+        /* All logging IO is done in another thread */
+        void io_process(void);
+
+        /* Return a LogLine for the given level
+         * so that you can write etiLog.level(info) << "stuff = " << 21 */
+        LogLine level(log_level_t level);
+
+    private:
+        std::list<std::shared_ptr<LogBackend> > backends;
+
+        ThreadsafeQueue<log_message_t> m_message_queue;
+        std::thread m_io_thread;
+        std::mutex m_cerr_mutex;
+};
+
+extern Logger etiLog;
+
+// Accumulate a line of logs, using same syntax as stringstream
+// The line is logged when the LogLine gets destroyed
+class LogLine {
+    public:
+        LogLine(const LogLine& logline);
+        const LogLine& operator=(const LogLine& other) = delete;
+        LogLine(Logger* logger, log_level_t level) :
+            logger_(logger)
+        {
+            level_ = level;
+        }
+
+        // Push the new element into the stringstream
+        template <typename T>
+        LogLine& operator<<(T s) {
+            if (level_ != discard) {
+                os << s;
+            }
+            return *this;
+        }
+
+        ~LogLine()
+        {
+            if (level_ != discard) {
+                logger_->logstr(level_, os.str());
+            }
+        }
+
+    private:
+        std::ostringstream os;
+        log_level_t level_;
+        Logger* logger_;
+};
+
diff --git a/lib/ReedSolomon.cpp b/lib/ReedSolomon.cpp
index 38d8ea8..1bf0b24 100644
--- a/lib/ReedSolomon.cpp
+++ b/lib/ReedSolomon.cpp
@@ -64,7 +64,9 @@ ReedSolomon::ReedSolomon(int N, int K, bool reverse, int gfpoly, int firstRoot,
 
 ReedSolomon::~ReedSolomon()
 {
-    free_rs_char(rsData);
+    if (rsData != nullptr) {
+        free_rs_char(rsData);
+    }
 }
 
 
diff --git a/lib/RemoteControl.cpp b/lib/RemoteControl.cpp
new file mode 100644
index 0000000..878af59
--- /dev/null
+++ b/lib/RemoteControl.cpp
@@ -0,0 +1,581 @@
+/*
+   Copyright (C) 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 program 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.
+
+   This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#include <list>
+#include <string>
+#include <iostream>
+#include <string>
+#include <algorithm>
+
+#include "RemoteControl.h"
+
+using namespace std;
+
+RemoteControllers rcs;
+
+RemoteControllerTelnet::~RemoteControllerTelnet()
+{
+    m_active = false;
+
+    if (m_restarter_thread.joinable()) {
+        m_restarter_thread.join();
+    }
+
+    if (m_child_thread.joinable()) {
+        m_child_thread.join();
+    }
+}
+
+void RemoteControllerTelnet::restart()
+{
+    if (m_restarter_thread.joinable()) {
+        m_restarter_thread.join();
+    }
+
+    m_restarter_thread = std::thread(
+            &RemoteControllerTelnet::restart_thread,
+            this, 0);
+}
+
+RemoteControllable::~RemoteControllable() {
+    rcs.remove_controllable(this);
+}
+
+std::list<std::string> RemoteControllable::get_supported_parameters() const {
+    std::list<std::string> parameterlist;
+    for (const auto& param : m_parameters) {
+        parameterlist.push_back(param[0]);
+    }
+    return parameterlist;
+}
+
+void RemoteControllers::add_controller(std::shared_ptr<BaseRemoteController> rc) {
+    m_controllers.push_back(rc);
+}
+
+void RemoteControllers::enrol(RemoteControllable *rc) {
+    controllables.push_back(rc);
+}
+
+void RemoteControllers::remove_controllable(RemoteControllable *rc) {
+    controllables.remove(rc);
+}
+
+std::list< std::vector<std::string> > RemoteControllers::get_param_list_values(const std::string& name) {
+    RemoteControllable* controllable = get_controllable_(name);
+
+    std::list< std::vector<std::string> > allparams;
+    for (auto &param : controllable->get_supported_parameters()) {
+        std::vector<std::string> item;
+        item.push_back(param);
+        try {
+            item.push_back(controllable->get_parameter(param));
+        }
+        catch (const ParameterError &e) {
+            item.push_back(std::string("error: ") + e.what());
+        }
+
+        allparams.push_back(item);
+    }
+    return allparams;
+}
+
+std::string RemoteControllers::get_param(const std::string& name, const std::string& param) {
+    RemoteControllable* controllable = get_controllable_(name);
+    return controllable->get_parameter(param);
+}
+
+void RemoteControllers::check_faults() {
+    for (auto &controller : m_controllers) {
+        if (controller->fault_detected()) {
+            etiLog.level(warn) <<
+                "Detected Remote Control fault, restarting it";
+            controller->restart();
+        }
+    }
+}
+
+RemoteControllable* RemoteControllers::get_controllable_(const std::string& name)
+{
+    auto rc = std::find_if(controllables.begin(), controllables.end(),
+            [&](RemoteControllable* r) { return r->get_rc_name() == name; });
+
+    if (rc == controllables.end()) {
+        throw ParameterError("Module name unknown");
+    }
+    else {
+        return *rc;
+    }
+}
+
+void RemoteControllers::set_param(
+        const std::string& name,
+        const std::string& param,
+        const std::string& value)
+{
+    etiLog.level(info) << "RC: Setting " << name << " " << param
+        << " to " << value;
+    RemoteControllable* controllable = get_controllable_(name);
+    try {
+        return controllable->set_parameter(param, value);
+    }
+    catch (const ios_base::failure& e) {
+        etiLog.level(info) << "RC: Failed to set " << name << " " << param
+        << " to " << value << ": " << e.what();
+        throw ParameterError("Cannot understand value");
+    }
+}
+
+// This runs in a separate thread, because
+// it would take too long to be done in the main loop
+// thread.
+void RemoteControllerTelnet::restart_thread(long)
+{
+    m_active = false;
+
+    if (m_child_thread.joinable()) {
+        m_child_thread.join();
+    }
+
+    m_child_thread = std::thread(&RemoteControllerTelnet::process, this, 0);
+}
+
+void RemoteControllerTelnet::handle_accept(Socket::TCPSocket&& socket)
+{
+    const std::string welcome = PACKAGE_NAME " Remote Control CLI\n"
+                                "Write 'help' for help.\n"
+                                "**********\n";
+    const std::string prompt = "> ";
+
+    std::string in_message;
+
+    try {
+        etiLog.level(info) << "RC: Accepted";
+
+        socket.sendall(welcome.data(), welcome.size());
+
+        while (m_active and in_message != "quit") {
+            socket.sendall(prompt.data(), prompt.size());
+
+            stringstream in_message_stream;
+
+            char last_char = '\0';
+            try {
+                while (last_char != '\n') {
+                    try {
+                        auto ret = socket.recv(&last_char, 1, 0, 1000);
+                        if (ret == 1) {
+                            in_message_stream << last_char;
+                        }
+                        else {
+                            break;
+                        }
+                    }
+                    catch (const Socket::TCPSocket::Timeout&) {
+                        if (not m_active) {
+                            break;
+                        }
+                    }
+                }
+            }
+            catch (const Socket::TCPSocket::Interrupted&) {
+                in_message_stream.clear();
+            }
+
+
+            if (in_message_stream.str().size() == 0) {
+                etiLog.level(info) << "RC: Connection terminated";
+                break;
+            }
+
+            std::getline(in_message_stream, in_message);
+
+            while (in_message.length() > 0 &&
+                    (in_message[in_message.length()-1] == '\r' ||
+                     in_message[in_message.length()-1] == '\n')) {
+                in_message.erase(in_message.length()-1, 1);
+            }
+
+            if (in_message.length() == 0) {
+                continue;
+            }
+
+            etiLog.level(info) << "RC: Got message '" << in_message << "'";
+
+            dispatch_command(socket, in_message);
+        }
+        etiLog.level(info) << "RC: Closing socket";
+        socket.close();
+    }
+    catch (const std::exception& e) {
+        etiLog.level(error) << "Remote control caught exception: " << e.what();
+    }
+}
+
+void RemoteControllerTelnet::process(long)
+{
+    try {
+        m_active = true;
+
+        m_socket.listen(m_port, "localhost");
+
+        etiLog.level(info) << "RC: Waiting for connection on port " << m_port;
+        while (m_active) {
+            auto sock = m_socket.accept(1000);
+
+            if (sock.valid()) {
+                handle_accept(move(sock));
+                etiLog.level(info) << "RC: Connection closed. Waiting for connection on port " << m_port;
+            }
+        }
+    }
+    catch (const runtime_error& e) {
+        etiLog.level(warn) << "RC: Encountered error: " << e.what();
+    }
+
+    etiLog.level(info) << "RC: Leaving";
+    m_fault = true;
+}
+
+static std::vector<std::string> tokenise(const std::string& message) {
+    stringstream ss(message);
+    std::vector<std::string> all_tokens;
+    std::string item;
+
+    while (std::getline(ss, item, ' ')) {
+        all_tokens.push_back(move(item));
+    }
+    return all_tokens;
+}
+
+
+void RemoteControllerTelnet::dispatch_command(Socket::TCPSocket& socket, string command)
+{
+    vector<string> cmd = tokenise(command);
+
+    if (cmd[0] == "help") {
+        reply(socket,
+                "The following commands are supported:\n"
+                "  list\n"
+                "    * Lists the modules that are loaded and their parameters\n"
+                "  show MODULE\n"
+                "    * Lists all parameters and their values from module MODULE\n"
+                "  get MODULE PARAMETER\n"
+                "    * Gets the value for the specified PARAMETER from module MODULE\n"
+                "  set MODULE PARAMETER VALUE\n"
+                "    * Sets the value for the PARAMETER ofr module MODULE\n"
+                "  quit\n"
+                "    * Terminate this session\n"
+                "\n");
+    }
+    else if (cmd[0] == "list") {
+        stringstream ss;
+
+        if (cmd.size() == 1) {
+            for (auto &controllable : rcs.controllables) {
+                ss << controllable->get_rc_name() << endl;
+
+                list< vector<string> > params = controllable->get_parameter_descriptions();
+                for (auto &param : params) {
+                    ss << "\t" << param[0] << " : " << param[1] << endl;
+                }
+            }
+        }
+        else {
+            reply(socket, "Too many arguments for command 'list'");
+        }
+
+        reply(socket, ss.str());
+    }
+    else if (cmd[0] == "show") {
+        if (cmd.size() == 2) {
+            try {
+                stringstream ss;
+                list< vector<string> > r = rcs.get_param_list_values(cmd[1]);
+                for (auto &param_val : r) {
+                    ss << param_val[0] << ": " << param_val[1] << endl;
+                }
+                reply(socket, ss.str());
+
+            }
+            catch (const ParameterError &e) {
+                reply(socket, e.what());
+            }
+        }
+        else {
+            reply(socket, "Incorrect parameters for command 'show'");
+        }
+    }
+    else if (cmd[0] == "get") {
+        if (cmd.size() == 3) {
+            try {
+                string r = rcs.get_param(cmd[1], cmd[2]);
+                reply(socket, r);
+            }
+            catch (const ParameterError &e) {
+                reply(socket, e.what());
+            }
+        }
+        else {
+            reply(socket, "Incorrect parameters for command 'get'");
+        }
+    }
+    else if (cmd[0] == "set") {
+        if (cmd.size() >= 4) {
+            try {
+                stringstream new_param_value;
+                for (size_t i = 3; i < cmd.size(); i++) {
+                    new_param_value << cmd[i];
+
+                    if (i+1 < cmd.size()) {
+                        new_param_value << " ";
+                    }
+                }
+
+                rcs.set_param(cmd[1], cmd[2], new_param_value.str());
+                reply(socket, "ok");
+            }
+            catch (const ParameterError &e) {
+                reply(socket, e.what());
+            }
+            catch (const exception &e) {
+                reply(socket, "Error: Invalid parameter value. ");
+            }
+        }
+        else {
+            reply(socket, "Incorrect parameters for command 'set'");
+        }
+    }
+    else if (cmd[0] == "quit") {
+        reply(socket, "Goodbye");
+    }
+    else {
+        reply(socket, "Message not understood");
+    }
+}
+
+void RemoteControllerTelnet::reply(Socket::TCPSocket& socket, string message)
+{
+    stringstream ss;
+    ss << message << "\r\n";
+    socket.sendall(message.data(), message.size());
+}
+
+
+#if defined(HAVE_ZEROMQ)
+
+RemoteControllerZmq::~RemoteControllerZmq() {
+    m_active = false;
+    m_fault = false;
+
+    if (m_restarter_thread.joinable()) {
+        m_restarter_thread.join();
+    }
+
+    if (m_child_thread.joinable()) {
+        m_child_thread.join();
+    }
+}
+
+void RemoteControllerZmq::restart()
+{
+    if (m_restarter_thread.joinable()) {
+        m_restarter_thread.join();
+    }
+
+    m_restarter_thread = std::thread(&RemoteControllerZmq::restart_thread, this);
+}
+
+// This runs in a separate thread, because
+// it would take too long to be done in the main loop
+// thread.
+void RemoteControllerZmq::restart_thread()
+{
+    m_active = false;
+
+    if (m_child_thread.joinable()) {
+        m_child_thread.join();
+    }
+
+    m_child_thread = std::thread(&RemoteControllerZmq::process, this);
+}
+
+void RemoteControllerZmq::recv_all(zmq::socket_t& pSocket, std::vector<std::string> &message)
+{
+    bool more = true;
+    do {
+        zmq::message_t msg;
+        pSocket.recv(&msg);
+        std::string incoming((char*)msg.data(), msg.size());
+        message.push_back(incoming);
+        more = msg.more();
+    } while (more);
+}
+
+void RemoteControllerZmq::send_ok_reply(zmq::socket_t &pSocket)
+{
+    zmq::message_t msg(2);
+    char repCode[2] = {'o', 'k'};
+    memcpy ((void*) msg.data(), repCode, 2);
+    pSocket.send(msg, 0);
+}
+
+void RemoteControllerZmq::send_fail_reply(zmq::socket_t &pSocket, const std::string &error)
+{
+    zmq::message_t msg1(4);
+    char repCode[4] = {'f', 'a', 'i', 'l'};
+    memcpy ((void*) msg1.data(), repCode, 4);
+    pSocket.send(msg1, ZMQ_SNDMORE);
+
+    zmq::message_t msg2(error.length());
+    memcpy ((void*) msg2.data(), error.c_str(), error.length());
+    pSocket.send(msg2, 0);
+}
+
+void RemoteControllerZmq::process()
+{
+    m_fault = false;
+
+    // create zmq reply socket for receiving ctrl parameters
+    try {
+        zmq::socket_t repSocket(m_zmqContext, ZMQ_REP);
+
+        // connect the socket
+        int hwm = 100;
+        int linger = 0;
+        repSocket.setsockopt(ZMQ_RCVHWM, &hwm, sizeof(hwm));
+        repSocket.setsockopt(ZMQ_SNDHWM, &hwm, sizeof(hwm));
+        repSocket.setsockopt(ZMQ_LINGER, &linger, sizeof(linger));
+        repSocket.bind(m_endpoint.c_str());
+
+        // create pollitem that polls the  ZMQ sockets
+        zmq::pollitem_t pollItems[] = { {repSocket, 0, ZMQ_POLLIN, 0} };
+        while (m_active) {
+            zmq::poll(pollItems, 1, 100);
+            std::vector<std::string> msg;
+
+            if (pollItems[0].revents & ZMQ_POLLIN) {
+                recv_all(repSocket, msg);
+
+                std::string command((char*)msg[0].data(), msg[0].size());
+
+                if (msg.size() == 1 && command == "ping") {
+                    send_ok_reply(repSocket);
+                }
+                else if (msg.size() == 1 && command == "list") {
+                    size_t cohort_size = rcs.controllables.size();
+                    for (auto &controllable : rcs.controllables) {
+                        std::stringstream ss;
+                        ss << "{ \"name\": \"" << controllable->get_rc_name() << "\"," <<
+                            " \"params\": { ";
+
+                        list< vector<string> > params = controllable->get_parameter_descriptions();
+                        size_t i = 0;
+                        for (auto &param : params) {
+                            if (i > 0) {
+                                ss << ", ";
+                            }
+
+                            ss << "\"" << param[0] << "\": " <<
+                                "\"" << param[1] << "\"";
+
+                            i++;
+                        }
+
+                        ss << " } }";
+
+                        std::string msg_s = ss.str();
+
+                        zmq::message_t zmsg(ss.str().size());
+                        memcpy ((void*) zmsg.data(), msg_s.data(), msg_s.size());
+
+                        int flag = (--cohort_size > 0) ? ZMQ_SNDMORE : 0;
+                        repSocket.send(zmsg, flag);
+                    }
+                }
+                else if (msg.size() == 2 && command == "show") {
+                    std::string module((char*) msg[1].data(), msg[1].size());
+                    try {
+                        list< vector<string> > r = rcs.get_param_list_values(module);
+                        size_t r_size = r.size();
+                        for (auto &param_val : r) {
+                            std::stringstream ss;
+                            ss << param_val[0] << ": " << param_val[1] << endl;
+                            zmq::message_t zmsg(ss.str().size());
+                            memcpy(zmsg.data(), ss.str().data(), ss.str().size());
+
+                            int flag = (--r_size > 0) ? ZMQ_SNDMORE : 0;
+                            repSocket.send(zmsg, flag);
+                        }
+                    }
+                    catch (const ParameterError &err) {
+                        send_fail_reply(repSocket, err.what());
+                    }
+                }
+                else if (msg.size() == 3 && command == "get") {
+                    std::string module((char*) msg[1].data(), msg[1].size());
+                    std::string parameter((char*) msg[2].data(), msg[2].size());
+
+                    try {
+                        std::string value = rcs.get_param(module, parameter);
+                        zmq::message_t zmsg(value.size());
+                        memcpy ((void*) zmsg.data(), value.data(), value.size());
+                        repSocket.send(zmsg, 0);
+                    }
+                    catch (const ParameterError &err) {
+                        send_fail_reply(repSocket, err.what());
+                    }
+                }
+                else if (msg.size() == 4 && command == "set") {
+                    std::string module((char*) msg[1].data(), msg[1].size());
+                    std::string parameter((char*) msg[2].data(), msg[2].size());
+                    std::string value((char*) msg[3].data(), msg[3].size());
+
+                    try {
+                        rcs.set_param(module, parameter, value);
+                        send_ok_reply(repSocket);
+                    }
+                    catch (const ParameterError &err) {
+                        send_fail_reply(repSocket, err.what());
+                    }
+                }
+                else {
+                    send_fail_reply(repSocket,
+                            "Unsupported command. commands: list, show, get, set");
+                }
+            }
+        }
+        repSocket.close();
+    }
+    catch (const zmq::error_t &e) {
+        etiLog.level(error) << "ZMQ RC error: " << std::string(e.what());
+    }
+    catch (const std::exception& e) {
+        etiLog.level(error) << "ZMQ RC caught exception: " << e.what();
+        m_fault = true;
+    }
+}
+
+#endif
+
diff --git a/lib/RemoteControl.h b/lib/RemoteControl.h
new file mode 100644
index 0000000..bd88f82
--- /dev/null
+++ b/lib/RemoteControl.h
@@ -0,0 +1,249 @@
+/*
+   Copyright (C) 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 module adds remote-control capability to some of the dabmux/dabmod modules.
+ */
+/*
+   This program 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.
+
+   This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#if defined(HAVE_ZEROMQ)
+#  include "zmq.hpp"
+#endif
+
+#include <list>
+#include <map>
+#include <memory>
+#include <string>
+#include <atomic>
+#include <iostream>
+#include <thread>
+#include <stdexcept>
+
+#include "Log.h"
+#include "Socket.h"
+
+#define RC_ADD_PARAMETER(p, desc) {   \
+  std::vector<std::string> p; \
+  p.push_back(#p); \
+  p.push_back(desc); \
+  m_parameters.push_back(p); \
+}
+
+class ParameterError : public std::exception
+{
+    public:
+        ParameterError(std::string message) : m_message(message) {}
+        ~ParameterError() throw() {}
+        const char* what() const throw() { return m_message.c_str(); }
+
+    private:
+        std::string m_message;
+};
+
+class RemoteControllable;
+
+/* Remote controllers (that recieve orders from the user)
+ * must implement BaseRemoteController
+ */
+class BaseRemoteController {
+    public:
+        /* When this returns one, the remote controller cannot be
+         * used anymore, and must be restarted
+         */
+        virtual bool fault_detected() = 0;
+
+        /* In case of a fault, the remote controller can be
+         * restarted.
+         */
+        virtual void restart() = 0;
+
+        virtual ~BaseRemoteController() {}
+};
+
+/* Objects that support remote control must implement the following class */
+class RemoteControllable {
+    public:
+        RemoteControllable(const std::string& name) :
+            m_rc_name(name) {}
+
+        RemoteControllable(const RemoteControllable& other) = delete;
+        RemoteControllable& operator=(const RemoteControllable& other) = delete;
+
+        virtual ~RemoteControllable();
+
+        /* return a short name used to identify the controllable.
+         * It might be used in the commands the user has to type, so keep
+         * it short
+         */
+        virtual std::string get_rc_name() const { return m_rc_name; }
+
+        /* Return a list of possible parameters that can be set */
+        virtual std::list<std::string> get_supported_parameters() const;
+
+        /* Return a mapping of the descriptions of all parameters */
+        virtual std::list< std::vector<std::string> >
+            get_parameter_descriptions() const
+            {
+                return m_parameters;
+            }
+
+        /* Base function to set parameters. */
+        virtual void set_parameter(
+                const std::string& parameter,
+                const std::string& value) = 0;
+
+        /* Getting a parameter always returns a string. */
+        virtual const std::string get_parameter(const std::string& parameter) const = 0;
+
+    protected:
+        std::string m_rc_name;
+        std::list< std::vector<std::string> > m_parameters;
+};
+
+/* Holds all our remote controllers and controlled object.
+ */
+class RemoteControllers {
+    public:
+        void add_controller(std::shared_ptr<BaseRemoteController> rc);
+        void enrol(RemoteControllable *rc);
+        void remove_controllable(RemoteControllable *rc);
+        void check_faults();
+        std::list< std::vector<std::string> > get_param_list_values(const std::string& name);
+        std::string get_param(const std::string& name, const std::string& param);
+
+        void set_param(
+                const std::string& name,
+                const std::string& param,
+                const std::string& value);
+
+        std::list<RemoteControllable*> controllables;
+
+    private:
+        RemoteControllable* get_controllable_(const std::string& name);
+
+        std::list<std::shared_ptr<BaseRemoteController> > m_controllers;
+};
+
+extern RemoteControllers rcs;
+
+/* Implements a Remote controller based on a simple telnet CLI
+ * that listens on localhost
+ */
+class RemoteControllerTelnet : public BaseRemoteController {
+    public:
+        RemoteControllerTelnet()
+            : m_active(false),
+            m_fault(false),
+            m_port(0) { }
+
+        RemoteControllerTelnet(int port)
+            : m_active(port > 0),
+            m_fault(false),
+            m_port(port)
+        {
+            restart();
+        }
+
+
+        RemoteControllerTelnet& operator=(const RemoteControllerTelnet& other) = delete;
+        RemoteControllerTelnet(const RemoteControllerTelnet& other) = delete;
+
+        ~RemoteControllerTelnet();
+
+        virtual bool fault_detected() { return m_fault; }
+
+        virtual void restart();
+
+    private:
+        void restart_thread(long);
+
+        void process(long);
+
+        void dispatch_command(Socket::TCPSocket& socket, std::string command);
+        void reply(Socket::TCPSocket& socket, std::string message);
+        void handle_accept(Socket::TCPSocket&& socket);
+
+        std::atomic<bool> m_active;
+
+        /* This is set to true if a fault occurred */
+        std::atomic<bool> m_fault;
+        std::thread m_restarter_thread;
+
+        std::thread m_child_thread;
+
+        Socket::TCPSocket m_socket;
+        int m_port;
+};
+
+#if defined(HAVE_ZEROMQ)
+/* Implements a Remote controller using ZMQ transportlayer
+ * that listens on localhost
+ */
+class RemoteControllerZmq : public BaseRemoteController {
+    public:
+        RemoteControllerZmq()
+            : m_active(false), m_fault(false),
+            m_zmqContext(1),
+            m_endpoint("") { }
+
+        RemoteControllerZmq(const std::string& endpoint)
+            : m_active(not endpoint.empty()), m_fault(false),
+            m_zmqContext(1),
+            m_endpoint(endpoint),
+            m_child_thread(&RemoteControllerZmq::process, this) { }
+
+        RemoteControllerZmq& operator=(const RemoteControllerZmq& other) = delete;
+        RemoteControllerZmq(const RemoteControllerZmq& other) = delete;
+
+        ~RemoteControllerZmq();
+
+        virtual bool fault_detected() { return m_fault; }
+
+        virtual void restart();
+
+    private:
+        void restart_thread();
+
+        void recv_all(zmq::socket_t &pSocket, std::vector<std::string> &message);
+        void send_ok_reply(zmq::socket_t &pSocket);
+        void send_fail_reply(zmq::socket_t &pSocket, const std::string &error);
+        void process();
+
+        std::atomic<bool> m_active;
+
+        /* This is set to true if a fault occurred */
+        std::atomic<bool> m_fault;
+        std::thread m_restarter_thread;
+
+        zmq::context_t m_zmqContext;
+
+        std::string m_endpoint;
+        std::thread m_child_thread;
+};
+#endif
+
diff --git a/lib/crc.c b/lib/crc.c
new file mode 100644
index 0000000..cc02473
--- /dev/null
+++ b/lib/crc.c
@@ -0,0 +1,266 @@
+/*
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Her Majesty the
+   Queen in Right of Canada (Communications Research Center Canada)
+   */
+/*
+   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/>.
+   */
+
+#include "crc.h"
+#ifndef _WIN32
+#    include <unistd.h>
+#    include <netinet/in.h>
+#endif
+#include <stdio.h>
+#include <fcntl.h>
+
+//#define CCITT       0x1021
+
+uint8_t crc8tab[256] = {
+    0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15,
+    0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d,
+    0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65,
+    0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d,
+    0xe0, 0xe7, 0xee, 0xe9, 0xfc, 0xfb, 0xf2, 0xf5,
+    0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd,
+    0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 0x82, 0x85,
+    0xa8, 0xaf, 0xa6, 0xa1, 0xb4, 0xb3, 0xba, 0xbd,
+    0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2,
+    0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4, 0xed, 0xea,
+    0xb7, 0xb0, 0xb9, 0xbe, 0xab, 0xac, 0xa5, 0xa2,
+    0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a,
+    0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32,
+    0x1f, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0d, 0x0a,
+    0x57, 0x50, 0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42,
+    0x6f, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7d, 0x7a,
+    0x89, 0x8e, 0x87, 0x80, 0x95, 0x92, 0x9b, 0x9c,
+    0xb1, 0xb6, 0xbf, 0xb8, 0xad, 0xaa, 0xa3, 0xa4,
+    0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2, 0xeb, 0xec,
+    0xc1, 0xc6, 0xcf, 0xc8, 0xdd, 0xda, 0xd3, 0xd4,
+    0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c,
+    0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44,
+    0x19, 0x1e, 0x17, 0x10, 0x05, 0x02, 0x0b, 0x0c,
+    0x21, 0x26, 0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34,
+    0x4e, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5c, 0x5b,
+    0x76, 0x71, 0x78, 0x7f, 0x6a, 0x6d, 0x64, 0x63,
+    0x3e, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2c, 0x2b,
+    0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d, 0x14, 0x13,
+    0xae, 0xa9, 0xa0, 0xa7, 0xb2, 0xb5, 0xbc, 0xbb,
+    0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83,
+    0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb,
+    0xe6, 0xe1, 0xe8, 0xef, 0xfa, 0xfd, 0xf4, 0xf3
+};
+
+
+uint16_t crc16tab[256] = {
+    0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
+    0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
+    0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
+    0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
+    0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
+    0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
+    0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
+    0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
+    0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
+    0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
+    0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
+    0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
+    0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
+    0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
+    0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
+    0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
+    0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
+    0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
+    0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
+    0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
+    0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
+    0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
+    0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
+    0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
+    0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
+    0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
+    0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
+    0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
+    0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
+    0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
+    0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
+    0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
+};
+
+
+uint32_t crc32tab[256] = {
+    0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9,
+    0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
+    0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
+    0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
+    0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
+    0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
+    0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011,
+    0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
+    0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
+    0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
+    0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81,
+    0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
+    0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49,
+    0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
+    0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
+    0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
+    0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae,
+    0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
+    0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
+    0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
+    0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
+    0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
+    0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066,
+    0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
+    0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
+    0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
+    0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
+    0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
+    0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
+    0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
+    0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686,
+    0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
+    0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
+    0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
+    0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
+    0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
+    0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47,
+    0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
+    0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
+    0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
+    0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7,
+    0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
+    0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f,
+    0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
+    0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
+    0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
+    0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f,
+    0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
+    0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
+    0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
+    0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
+    0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
+    0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30,
+    0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
+    0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088,
+    0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
+    0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
+    0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
+    0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
+    0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
+    0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0,
+    0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
+    0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
+    0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
+};
+
+// This function can be used to create a new table with a different polynom
+void init_crc8tab(uint8_t l_code, uint8_t l_init)
+{
+    unsigned i, j, msb;
+    uint8_t nb;
+    uint8_t crc;
+
+    for (i = 0; i < 256; ++i) {
+        crc = l_init;
+        nb = i ^ 0xff;
+        for (j = 0; j < 8; ++j) {
+            msb = (nb & (0x80 >> j)) && 1;
+            msb ^= (crc >> 7);
+            crc <<= 1;
+            if (msb)
+                crc ^= l_code;
+        }
+        crc8tab[i] = crc;
+    }
+}
+
+
+void init_crc16tab(uint16_t l_code, uint16_t l_init)
+{
+    unsigned i, j, msb;
+    uint8_t nb;
+    uint16_t crc;
+
+    for (i = 0; i < 256; ++i) {
+        crc = l_init;
+        nb = i ^ 0xff;
+        for (j = 0; j < 8; ++j) {
+            msb = (nb & (0x80 >> j)) && 1;
+            msb ^= (crc >> 15);
+            crc <<= 1;
+            if (msb)
+                crc ^= l_code;
+        }
+        crc ^= 0xff00;
+        crc16tab[i] = crc;
+    }
+}
+
+
+void init_crc32tab(uint32_t l_code, uint32_t l_init)
+{
+    unsigned i, j, msb;
+    uint8_t nb;
+    uint32_t crc;
+
+    for (i = 0; i < 256; ++i) {
+        crc = l_init;
+        nb = i ^ 0xff;
+        for (j = 0; j < 8; ++j) {
+            msb = (nb & (0x80 >> j)) && 1;
+            msb ^= (crc >> 31);
+            crc <<= 1;
+            if (msb)
+                crc ^= l_code;
+        }
+        crc ^= 0xffffff00;
+        crc32tab[i] = crc;
+    }
+}
+
+
+uint8_t crc8(uint8_t l_crc, const void *lp_data, unsigned l_nb)
+{
+    const uint8_t* data = (const uint8_t*)lp_data;
+    while (l_nb--) {
+        l_crc = crc8tab[l_crc ^ *(data++)];
+    }
+    return (l_crc);
+}
+
+
+uint16_t crc16(uint16_t l_crc, const void *lp_data, unsigned l_nb)
+{
+    const uint8_t* data = (const uint8_t*)lp_data;
+    while (l_nb--) {
+        l_crc =
+            (l_crc << 8) ^ crc16tab[(l_crc >> 8) ^ *(data++)];
+    }
+    return (l_crc);
+}
+
+
+uint32_t crc32(uint32_t l_crc, const void *lp_data, unsigned l_nb)
+{
+    const uint8_t* data = (const uint8_t*)lp_data;
+    while (l_nb--) {
+        l_crc =
+            (l_crc << 8) ^ crc32tab[((l_crc >> 24) ^ *(data++)) & 0xff];
+    }
+    return (l_crc);
+}
diff --git a/lib/crc.h b/lib/crc.h
new file mode 100644
index 0000000..b1785a1
--- /dev/null
+++ b/lib/crc.h
@@ -0,0 +1,59 @@
+/*
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Her Majesty the
+   Queen in Right of Canada (Communications Research Center Canada)
+   */
+/*
+   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/>.
+   */
+
+#ifndef _CRC
+#define _CRC
+
+#ifdef HAVE_CONFIG_H
+#   include "config.h"
+#endif
+
+#ifndef _WIN32
+  #include <stdint.h>
+#else
+  #include <winsock2.h>	// For types...
+  typedef BYTE uint8_t;
+  typedef WORD uint16_t;
+  typedef DWORD32 uint32_t;
+#endif
+
+
+#ifdef __cplusplus
+extern "C" { // }
+#endif
+
+void init_crc8tab(uint8_t l_code, uint8_t l_init);
+uint8_t crc8(uint8_t l_crc, const void *lp_data, unsigned l_nb);
+extern uint8_t crc8tab[];
+
+void init_crc16tab(uint16_t l_code, uint16_t l_init);
+uint16_t crc16(uint16_t l_crc, const void *lp_data, unsigned l_nb);
+extern uint16_t crc16tab[];
+
+void init_crc32tab(uint32_t l_code, uint32_t l_init);
+uint32_t crc32(uint32_t l_crc, const void *lp_data, unsigned l_nb);
+extern uint32_t crc32tab[];
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif //_CRC