c7d8ac622a
Commit 7ff57f9808 introduced a change to try to
use ATTRS{bInterfaceNumber} as a common way to match by interface number, but
this logic is broken because all the rules that we use to match by interface
number (attribute in the interface device) also require matching by idVendor
and idProduct (attributes in the physdev device), and udev rules forbid matches
from more than one parent device at a time.
We could use ATTR{bInterfaceNumber} (instead of ATTRS) to tag the actual USB
interface device, but that would require a change in all the plugins to look for
the tag not in the TTY device, but in its parent.
So, recover the original behavior, where a hidden property is created containing
the first bInterfaceNumber found in the list of parent devices, and then run
the matches against idVendor and idProduct only if the hidden property is found
with the expected value.
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+.