ffac6f17b5
The format of CREG/CGREG/CEREG responses is not very precisely defined in or strictly enforced by the 3GPP specifications. That leads to the fact that some modems put leading zeros in integer type fields (e.g. <n>, <stat>, <AcT>), and not all modems put double quotes around string type fields (e.g. <lac>, <ci>) in those C*REG responses. For example, 0001 can be a valid value for both <stat> and <lac>. The original C*REG parsing code in ModemManager could potentially interpret '+CREG: <stat>,<lac>,<ci>,<AcT>' as '+CREG: <n>,<stat>,<lac>,<ci>'. This patch addresses this issue by refining the regular expressions returned by mm_3gpp_creg_regex_get() with the following assumptions: 1. If a modem puts leading zeros in integer type fields, it puts double quotes around string type fields. 2. If a modem omits double quotes around string type fields, it does not put leading zeros in integer type fields.
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!