Aleksander Morgado
950abbf8ee
Back in Linux < 3.6 days, the cdc-wdm ports exposed by the QMI driver were flagged as owned by the 'usb' subsystem. That changed in 3.6 when the subsystem was renamed to 'usbmisc': https://mail.gnome.org/archives/networkmanager-list/2012-June/msg00125.html This patch removes all monitoring of the 'usb' subsystem completely, which is anyway a valid subsystem but for which we shouldn't need any special handling. Right now, with newer kernels, we were using that monitoring exclusively to get notified of full USB device remove events, which is really not required as we already process the port removals one by one. We simplify the logic everywhere that attempted to match either the 'usb' or 'usbmisc' subsystems, and we no longer require the explicit checks for the port name being named 'cdc-wdm[0-9]*' in the code, as that is already taken care of by the ID_MM_CANDIDATE udev tag rule.
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 provide 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+.