flute-receiver.cpp

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// libflute - FLUTE/ALC library
//
// Copyright (C) 2021 Klaus Kühnhammer (Österreichische Rundfunksender GmbH & Co KG)
//
// Licensed under the License terms and conditions for use, reproduction, and
// distribution of 5G-MAG software (the “License”).  You may not use this file
// except in compliance with the License.  You may obtain a copy of the License at
// https://www.5g-mag.com/reference-tools.  Unless required by applicable law or
// agreed to in writing, software distributed under the License is distributed on
// an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
// or implied.
//
// See the License for the specific language governing permissions and limitations
// under the License.
//
#include <cstdio>
#include <cstring>
#include <cerrno>
#include <iostream>
#include <argp.h>
 
#include <cstdlib>
 
#include <fstream>
#include <string>
#include <filesystem>
#include <libconfig.h++>
#include <boost/asio.hpp>
 
#include "spdlog/async.h"
#include "spdlog/spdlog.h"
#include "spdlog/sinks/syslog_sink.h"
 
#include "Version.h"
#include "Receiver.h"
#include "File.h"
 
 
using libconfig::Config;
using libconfig::FileIOException;
using libconfig::ParseException;
 
static void print_version(FILE *stream, struct argp_state *state);
void (*argp_program_version_hook)(FILE *, struct argp_state *) = print_version;
const char *argp_program_bug_address = "Austrian Broadcasting Services <obeca@ors.at>";
static char doc[] = "FLUTE/ALC receiver demo";  // NOLINT
 
static struct argp_option options[] = {  // NOLINT
    {"interface", 'i', "IF", 0, "IP address of the interface to bind flute receivers to (default: 0.0.0.0)", 0},
    {"target", 'm', "IP", 0, "Multicast address to receive on (default: 238.1.1.95)", 0},
    {"port", 'p', "PORT", 0, "Multicast port (default: 40085)", 0},
    {"ipsec-key", 'k', "KEY", 0, "To enable IPSec/ESP decryption of packets, provide a hex-encoded AES key here", 0},
    {"log-level", 'l', "LEVEL", 0,
     "Log verbosity: 0 = trace, 1 = debug, 2 = info, 3 = warn, 4 = error, 5 = "
     "critical, 6 = none. Default: 2.",
     0},
    {"tsi", 'T', "ID", 0, "The TSI to use for the FLUTE session (default: 16)", 0},
    {"output-path", 'o', "PATH", 0, "Directory to save received files", 0},
    {nullptr, 0, nullptr, 0, nullptr, 0}};
 
struct ft_arguments {
  const char *flute_interface = {};  
  const char *mcast_target = {};
  bool enable_ipsec = false;
  const char *aes_key = {};
  unsigned short mcast_port = 40085;
  unsigned log_level = 2;        
  char **files;
  uint64_t tsi = 16;
  const char *output_path = nullptr;
};
 
static auto parse_opt(int key, char *arg, struct argp_state *state) -> error_t {
  auto arguments = static_cast<struct ft_arguments *>(state->input);
  switch (key) {
    case 'm':
      arguments->mcast_target = arg;
      break;
    case 'i':
      arguments->flute_interface = arg;
      break;
    case 'k':
      arguments->aes_key = arg;
      arguments->enable_ipsec = true;
      break;
    case 'p':
      arguments->mcast_port = static_cast<unsigned short>(strtoul(arg, nullptr, 10));
      break;
    case 'l':
      arguments->log_level = static_cast<unsigned>(strtoul(arg, nullptr, 10));
      break;
    case 'T':
      arguments->tsi = static_cast<uint64_t>(strtoul(arg, nullptr, 10));
      break;
    case 'o':
      arguments->output_path = arg;
      break;
    default:
      return ARGP_ERR_UNKNOWN;
  }
  return 0;
}
 
static struct argp argp = {options, parse_opt, nullptr, doc,
                           nullptr, nullptr,   nullptr};
 
void print_version(FILE *stream, struct argp_state * /*state*/) {
  fprintf(stream, "%s.%s.%s\n", std::to_string(VERSION_MAJOR).c_str(),
          std::to_string(VERSION_MINOR).c_str(),
          std::to_string(VERSION_PATCH).c_str());
}
 
 
 
auto main(int argc, char **argv) -> int {
  struct ft_arguments arguments;
  /* Default values */
  arguments.mcast_target = "238.1.1.95";
  arguments.flute_interface= "0.0.0.0";
 
  // Parse the arguments
  argp_parse(&argp, argc, argv, 0, nullptr, &arguments);
 
  // Set up logging
  std::string ident = "flute-receiver";
  auto syslog_logger = spdlog::syslog_logger_mt("syslog", ident, LOG_PID | LOG_PERROR | LOG_CONS );
 
  spdlog::set_level(
      static_cast<spdlog::level::level_enum>(arguments.log_level));
  spdlog::set_pattern("[%H:%M:%S.%f %z] [%^%l%$] [thr %t] %v");
 
  spdlog::set_default_logger(syslog_logger);
  spdlog::info("FLUTE receiver demo starting up");
 
  try {
    // Create a Boost io_context
    boost::asio::io_context io;
 
    // Create the receiver
    LibFlute::Receiver receiver(
        arguments.flute_interface,
        arguments.mcast_target,
        (short)arguments.mcast_port,
        arguments.tsi,
        io);
 
    // Configure IPSEC, if enabled
    if (arguments.enable_ipsec)
    {
      receiver.enable_ipsec(1, arguments.aes_key);
    }
 
    receiver.register_completion_callback(
      [output_path = arguments.output_path](std::shared_ptr<LibFlute::File> file) { //NOLINT
        std::string out_file = file->meta().content_location;
        if (output_path && std::strlen(output_path) > 0) {
          out_file = (std::filesystem::path(output_path) / std::filesystem::path(out_file).filename()).string();
        }
 
        spdlog::info("{} (TOI {}) has been received",
                     out_file, file->meta().toi);
        // content_location is a URL path (e.g. "out/u/bbb/qxa/manifest.m3u8")
        // and its directory component doesn't necessarily exist relative to
        // the current working directory - create it first, and don't
        // dereference a null FILE* if fopen() still fails (e.g. content
        // path with characters invalid in a filename, such as a "?query").
        std::filesystem::path out_path(out_file);
        if (out_path.has_parent_path()) {
          std::filesystem::create_directories(out_path.parent_path());
        }
        FILE *fd = fopen(out_file.c_str(), "wb");
        if (!fd) {
          spdlog::warn("Failed to open {} for writing: {}", out_file, strerror(errno));
          return;
        }
        fwrite(file->buffer(), 1, file->length(), fd);
        fclose(fd);
      });
 
    // Start the IO service
    io.run();
  } catch (std::exception ex ) {
    spdlog::error("Exiting on unhandled exception: %s", ex.what());
  }
 
exit:
  return 0;
}