Function bind_to_local_network_interface

libminifi/src/io/ClientSocket.cpp:97–119

#ifndef WIN32
std::error_code bind_to_local_network_interface(const minifi::io::SocketDescriptor fd, const minifi::io::NetworkInterface& interface) {
  using ifaddrs_uniq_ptr = std::unique_ptr<ifaddrs, util::ifaddrs_deleter>;
  const auto if_list_ptr = []() -> ifaddrs_uniq_ptr {
    ifaddrs *list = nullptr;
    const auto get_ifa_success = getifaddrs(&list) == 0;
    assert(get_ifa_success || !list);
    (void)get_ifa_success;  // unused in release builds
    return ifaddrs_uniq_ptr{ list };
  }();
  if (!if_list_ptr) { return { errno, std::generic_category() }; }

  const auto advance_func = [](const ifaddrs *const p) { return p->ifa_next; };
  const auto predicate = [&interface](const ifaddrs *const item) {
    return item->ifa_addr && item->ifa_name && (item->ifa_addr->sa_family == AF_INET || item->ifa_addr->sa_family == AF_INET6)
        && item->ifa_name == interface.getInterface();
  };
  const auto *const itemFound = find_if_custom_linked_list(if_list_ptr.get(), advance_func, predicate);
  if (itemFound == nullptr) { return std::make_error_code(std::errc::no_such_device_or_address); }

  const socklen_t addrlen = itemFound->ifa_addr->sa_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
  if (bind(fd, itemFound->ifa_addr, addrlen) != 0) { return { errno, std::generic_category() }; }
  return {};
}
#endif /* !WIN32 */

std::error_code set_non_blocking(const minifi::io::SocketDescriptor fd) noexcept {