UPSTREAM: broadband-modem: exit with error if enable() is called in enabling state

We should not assert. We can error out the latest enabling attempt and let
the previous enabling gracefully reach an end.

Issue log:
"2025-06-22T21:56:52.972448Z NOTICE ModemManager[1842]: <msg> [modem2] state changed (disabled -> enabling)
...
2025-06-22T21:57:53.146572Z ERR ModemManager[1842]: <err> [modem2] port cdc-wdm0 timed out 10 consecutive times, marking modem as invalid
...
2025-06-22T21:57:53.185751Z INFO shill[870]: INFO shill: [modem_info.cc(120)] RemoveModem: /org/freedesktop/ModemManager1/Modem/2
2025-06-22T21:57:53.187595Z INFO ModemManager[1842]: <inf> [modem2] processing user request to enable modem...
"

which led to a crash:
"
0x00007c474ceb979f (libc.so.6 -pthread_kill.c:44)               ??__pthread_kill_implementation
0x00007c474ce6d92c (libc.so.6 -raise.c:26)                      ??raise
0x00007c474ce584aa (libc.so.6 -abort.c:79)                      ??abort
0x00007c474d72b269 (libglib-2.0.so.0 -gtestutils.c:3450)        ??g_assertion_message
0x00007c474d72b2e3 (libglib-2.0.so.0 -gtestutils.c:3476)        ??g_assertion_message_expr
0x00005979074b4b6a (ModemManager -mm-broadband-modem.c)         enable
0x00005979074e3b9c (ModemManager -mm-iface-modem.c:2340)        handle_enable_auth_ready
0x00007c474d591997 (libgio-2.0.so.0 -gtask.c:1309)              g_task_return_now
0x00007c474d590555 (libgio-2.0.so.0 -gtask.c:1378)              g_task_return
0x00005979074a57bd (ModemManager -mm-base-modem.c:2011)         lock_after_authorize_ready
0x00007c474d591997 (libgio-2.0.so.0 -gtask.c:1309)              g_task_return_now
0x00007c474d590555 (libgio-2.0.so.0 -gtask.c:1378)              g_task_return
0x00005979074a3fa8 (ModemManager -mm-base-modem.c:1841)         base_modem_operation_run
...
"
(cherry picked from commit ca4334de94c5cb2419e36430972acc3176028e47)

BUG=b:391542444
TEST=CQ passes

Change-Id: I1423e8a8c71bd98bebe2b0572e411cac83ad98ac

Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/modemmanager-next/+/6719443
Reviewed-by: Aleksander Morgado <aleksandermj@google.com>
Commit-Queue: Rukun Mao <rmao@google.com>
Tested-by: Rukun Mao <rmao@google.com>
1 file changed
tree: 6df2eeabc9ddf66a80db26a4a0fc080a666b2f42
  1. build-aux/
  2. cli/
  3. data/
  4. docs/
  5. examples/
  6. include/
  7. introspection/
  8. libmm-glib/
  9. libqcdm/
  10. po/
  11. src/
  12. test/
  13. tools/
  14. vapi/
  15. .editorconfig
  16. .gitignore
  17. .gitlab-ci.yml
  18. AUTHORS
  19. COPYING
  20. COPYING.LIB
  21. DIR_METADATA
  22. meson.build
  23. meson_options.txt
  24. NEWS
  25. OWNERS
  26. PRESUBMIT.cfg
  27. README.chromium
  28. README.md
  29. RELEASING
  30. unblocked_terms.txt
README.md

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...).

Getting Started

ModemManager uses the meson build system. Meson is likely available as a package from your Linux distribution, but if not please refer to the Meson project for installation instructions. Once you have Meson installed you'll probably want to install libmbim and libqmi which most modems require.

After dependencies are installed you can build ModemManager with:

$ meson setup build --prefix=/usr --buildtype=release
$ ninja -C build

And after a successful build, install with:

$ sudo ninja -C build install

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+ (See COPYING). The libmm-glib library and the ModemManager API headers are LGPLv2+ (See COPYING.LIB).

Code of Conduct

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms, which you can find in the following link: https://www.freedesktop.org/wiki/CodeOfConduct

CoC issues may be raised to the project maintainers at the following address: modemmanager-devel-owner@lists.freedesktop.org