c1aa658802
The u-blox plugin was originally written to support the TOBY-L4 only. This caused issues with mmcli reporting the correct supported and current bands because the logic was based only for the TOBY-L4 and the AT commands used in the implementaion are only supported by a couple of modems. There is now a hard-coded modem list that contains the supported bands and the supported modes. A hard-coded list was chosen over a logic based list because ublox modems only report the frequency of the bands they support in the current mode they are in. For further justification, the reported frequency could relate to multiple bands that are not all supported by the modem, and not all the supported bands are always caught depending on the mode the modem is in (e.g. 2G, 3G, 4G). The only realiable way to retrieve the correct supported bands is to have the list hard-coded. Based off of the modem, the code chooses whether it is appropriate to issue +UACT or +UBANDSEL to retrieve the current bands list. Additionally, the appropriate AT command of +CFUN=4 or +COPS=2 is chosen to detach from the network when the mmcli --set-current-bands command is issued. The new setup also adds a header file that contains the modem list. This should make adding support for future additional modems easier as long as future modems stick to the same AT command interface that is currently supported by the plugin.
ModemManager. ModemManager provides a unified high level API for communicating with mobile broadband modems, regardless of the protocol used to communicate with the actual device (Generic AT, vendor-specific AT, QCDM, QMI, MBIM...). Using. ModemManager is a system daemon and is not meant to be used directly from the command line. However, since it provides a DBus API, it is possible to use 'dbus-send' commands or the new 'mmcli' command line interface to control it from the terminal. The devices are queried from udev and automatically updated based on hardware events, although a manual re-scan can also be requested to look for RS232 modems. Implementation. ModemManager is a DBus system bus activated service (meaning it's started automatically when a request arrives). It is written in C, using glib and gio. Several GInterfaces specify different features that the modems support, including the generic MMIfaceModem3gpp and MMIfaceModemCdma which provice basic operations for 3GPP (GSM, UMTS, LTE) or CDMA (CDMA1x, EV-DO) modems. If a given feature is not available in the modem, the specific interface will not be exported in DBus. Plugins. Plugins are loaded on startup, and must implement the MMPlugin interface. It consists of a couple of methods which tell the daemon whether the plugin supports a port and to create custom MMBroadbandModem implementations. It most likely makes sense to derive custom modem implementations from one of the generic classes and just add (or override) operations which are not standard. There are multiple fully working plugins in the plugins/ directory that can be used as an example for writing new plugins. Writing new plugins is highly encouraged! The plugin API is open for changes, so if you're writing a plugin and need to add or change some public method, feel free to suggest it! License. The ModemManager and mmcli binaries are both GPLv2+. The libmm-glib library is LGPLv2+.