Method set_wifi_frequency

OpenHD/ohd_interface/src/wifi_command_helper2.cpp:117–179

}

bool wifi::commandhelper2::set_wifi_frequency(
    const std::string &device, uint32_t freq_mhz,
    std::optional<uint32_t> channel_width) {
  if (channel_width.has_value()) {
    get_logger()->debug("set_wifi_frequency {} {}Mhz {}Mhz", device, freq_mhz,
                        channel_width.value());
  } else {
    get_logger()->debug("set_wifi_frequency {} {}Mhz", device, freq_mhz);
  }
  int err = 1;
  struct nl_cb *cb = nl_cb_alloc(NL_CB_DEFAULT);
  int rc;

  // Create the socket and connect to it.
  struct nl_sock *sckt = nl_socket_alloc();
  genl_connect(sckt);

  // Allocate a new message.
  struct nl_msg *mesg = nlmsg_alloc();

  // Check /usr/include/linux/nl80211.h for a list of commands and attributes.
  enum nl80211_commands command = NL80211_CMD_SET_WIPHY;

  // Create the message so it will send a command to the nl80211 interface.
  genlmsg_put(mesg, 0, 0, genl_ctrl_resolve(sckt, "nl80211"), 0, 0, command, 0);

  // Add specific attributes to change the frequency of the device.
  NLA_PUT_U32(mesg, NL80211_ATTR_IFINDEX, if_nametoindex(device.c_str()));
  NLA_PUT_U32(mesg, NL80211_ATTR_WIPHY_FREQ, freq_mhz);
  if (channel_width != std::nullopt) {
    const uint32_t channel_width_given = channel_width.value();
    auto netlink_channel_width = NL80211_CHAN_WIDTH_20;
    switch (channel_width_given) {
      case 10:
        netlink_channel_width = NL80211_CHAN_WIDTH_10;
      case 20:
        netlink_channel_width = NL80211_CHAN_WIDTH_20;
        break;
      case 40:
        netlink_channel_width = NL80211_CHAN_WIDTH_40;
        break;
      default:
        get_logger()->debug("Invalid channel width {}, assuming 20Mhz",
                            channel_width_given);
        break;
    }
    NLA_PUT_U32(mesg, NL80211_ATTR_CHANNEL_WIDTH, channel_width_given);
  }

  // Finally send it and receive the amount of bytes sent.
  nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
  rc = nl_send_auto(sckt, mesg);
  nl_recvmsgs(sckt, cb);
  nl_cb_put(cb);
  nlmsg_free(mesg);
  nl_socket_free(sckt);
  return (err >= 0);