Some of the AT-based connection methods don't have any way to query
connection status, or we don't have a proper implementation for those
yet. Ignore the reload operation in all those.

By default, fallback to "unknown" mobile equipment error when the
modem gets disconnected by the network and we don't have any way to
know a more detailed reason.

This is now a requirement when using glib 2.56.

Each different plugin or protocol had a different connection attempt
value. E.g. QMI and MBIM both used 60s max for the connection attempt,
while the u-blox plugin had up to 180s for ECM based connection
setups.

This commit consolidates all plugins and protocols to use the same
timeout values for commands that may take long to respond, e.g. a
connection atempt under low signal quality conditions.

A value of 180s for the connection attempt steps and 120s for a
disconnection attempt step is considered. Note, though, that in some
cases (like a IPv4v6 setup attempt using QMI) we may have more than
one such long step, so this doesn't mean that a connection attempt
will always take less than 180s.

Users of the connection/disconnection APIs should be able to handle
the case where the attempt times out in their side (e.g. with a lower
DBus request timeout), and which would not mean the actual request
they did really failed. E.g. a connection attempt with a DBus timeout
of 30s may fail in the user with a timeout error, but the attempt
would still go on for as much as the plugin/protocol needs.

Fixes #270

The two connection and disconnection methods are ported to GTask, and
are also updated so that the reception of the unsolicited message
reporting either connect/disconnection is able to right away complete
the pending connection/disconnection attempts, as done in other
plugins like the Icera or HSO ones.

Ben Chan authored 8 years ago and Aleksander Morgado committed 8 years ago

g_free and g_object_unref are in form of  `void (*)(gpointer)`, which
matches the GDestroyNotify signature. An explicit GDestroyNotify cast on
g_free and g_object_unref is thus not needed.

A default implementation to monitor the ongoing connection is provided in the
generic MMBroadbandModem, based on AT+CGACT? to check whether the PDP context
of the connection (identified by the cached cid) is active or not.

This commit also disables the connection monitoring logic in those plugins that
have custom connection methods.

Otherwise we may leave a bearer connected when ModemManager doesn't
think it's connected.  Prevents a CME ERROR 277 loop on connect when
the bearer hasn't been torn down correctly.

Wait for either an E2NAP unsolicited disconnect status or (for older
devices) an ENAP poll response before completing the disconnect.
Otherwise the client may start connecting again (such as
NetworkManager autoconnect retry) and the unsolicited E2NAP may
abort it, or the modem may return CME ERROR 277 ("not disconnected
yet") for the next connection attempt.

https://bugs.freedesktop.org/attachment.cgi?id=123525

There are a few key parts to this patch:

1) move the poll id into the Dial3gppContext structure as it is
conceptually part of the connection context data.  This simplifies
context cleanup by keeping the poll id cleanup in one place.

2) move unsolicited connection status (E2NAP) handling into the
normal connection codepath, instead of completing the connection
context from the report_connection_status() E2NAP handler.  This
simplifies connect code by not requiring checks for a NULL context
everywhere, and allows us to pass the Dial3gppContext structure
around instead of the Bearer object, since the Dial3gppContext
will never be comleted/freed outside the normal connection flow
codepaths like GLib idles and AT command requests.

3) use the connect context cancellable for all AT command requests
in the connect path.  This lets us use the error return from
mm_base_modem_at_command_full_finish() to handle cancellation and
also not bother listening to the 'cancelled' signal of the
cancellable, since we can just check for cancellation the next time
the ENAP poll function runs.

https://bugs.freedesktop.org/show_bug.cgi?id=95304

Otherwise the dangling pointer to the context that's being deallocated causes a
crash on spontaneous E2NAP receipt:

  ModemManager[1567]: <info>  [1462468083.031326] [mm-iface-modem.c:1431] __iface_modem_update_state_internal(): Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> registered)
  ModemManager[1567]: <debug> [1462468083.053745] [mm-port-serial-at.c:459] debug_log(): (ttyACM0): <-- '<CR><LF>*E2NAP: 0,36<CR><LF>'
  ModemManager[1567]: <debug> [1462468083.053857] [mbm/mm-broadband-modem-mbm.c:824] e2nap_received(): disconnected

  (ModemManager:1567): GLib-GIO-CRITICAL **: g_simple_async_result_set_error: assertion 'G_IS_SIMPLE_ASYNC_RESULT (simple)' failed

  Program received signal SIGTRAP, Trace/breakpoint trap.
  g_logv (log_domain=0x7ffff7086798 "GLib-GIO", log_level=G_LOG_LEVEL_CRITICAL, format=<optimized out>, args=args@entry=0x7fffffffcda0) at gmessages.c:1046
  1046              g_private_set (&g_log_depth, GUINT_TO_POINTER (depth));
  Missing separate debuginfos, use: debuginfo-install libmbim-1.12.4-2.el7.centos.x86_64 libqmi-1.14.2-1.el7.centos.x86_64
  (gdb) bt
  #0  0x00007ffff6a508c3 in g_logv (log_domain=0x7ffff7086798 "GLib-GIO", log_level=G_LOG_LEVEL_CRITICAL, format=<optimized out>, args=args@entry=0x7fffffffcda0) at gmessages.c:1046
  #1  0x00007ffff6a50a3f in g_log (log_domain=log_domain@entry=0x7ffff7086798 "GLib-GIO", log_level=log_level@entry=G_LOG_LEVEL_CRITICAL, format=format@entry=0x7ffff6abe73d "%s: assertion '%s' failed") at gmessages.c:1079
  #2  0x00007ffff6a50a79 in g_return_if_fail_warning (log_domain=log_domain@entry=0x7ffff7086798 "GLib-GIO", pretty_function=pretty_function@entry=0x7ffff7092ce0 <__FUNCTION__.13394> "g_simple_async_result_set_error", expression=expression@entry=0x7ffff7092a40 "G_IS_SIMPLE_ASYNC_RESULT (simple)") at gmessages.c:1088
  #3  0x00007ffff6ff9d3d in g_simple_async_result_set_error (simple=0x7fffe8006e40, domain=297, code=0, format=0x7ffff175b53f "Call setup failed") at gsimpleasyncresult.c:719
  #4  0x00007ffff17569ea in report_connection_status (bearer=0x7fffe4008a40 [MMBroadbandBearerMbm], status=MM_BEARER_CONNECTION_STATUS_DISCONNECTED) at mbm/mm-broadband-bearer-mbm.c:174
  #5  0x000055555559c9f1 in mm_base_bearer_report_connection_status (self=0x7fffe4008a40 [MMBroadbandBearerMbm], status=MM_BEARER_CONNECTION_STATUS_DISCONNECTED) at mm-base-bearer.c:1118
  #6  0x00007ffff17548ed in bearer_list_report_status_foreach (bearer=0x7fffe4008a40 [MMBroadbandBearerMbm], ctx=0x7fffffffd060) at mbm/mm-broadband-modem-mbm.c:805
  #7  0x00007ffff6a45f18 in g_list_foreach (list=<optimized out>, func=0x7ffff17548c9 <bearer_list_report_status_foreach>, user_data=0x7fffffffd060) at glist.c:994
  #8  0x00005555555a224b in mm_bearer_list_foreach (self=0x5555558e0680 [MMBearerList], func=0x7ffff17548c9 <bearer_list_report_status_foreach>, user_data=0x7fffffffd060) at mm-bearer-list.c:146
  #9  0x00007ffff1754a3d in e2nap_received (port=0x5555558e24c0 [MMPortSerialAt], info=0x555555935730, self=0x555555900330 [MMBroadbandModemMbm]) at mbm/mm-broadband-modem-mbm.c:850
  #10 0x000055555563d9fd in parse_unsolicited (port=0x5555558e24c0 [MMPortSerialAt], response=0x7fffe80054f0) at mm-port-serial-at.c:280
  #11 0x0000555555639915 in parse_response_buffer (self=0x5555558e24c0 [MMPortSerialAt]) at mm-port-serial.c:889
  #12 0x0000555555639f0b in common_input_available (self=0x5555558e24c0 [MMPortSerialAt], condition=G_IO_IN) at mm-port-serial.c:1019
  #13 0x0000555555639fc7 in iochannel_input_available (iochannel=0x555555926df0, condition=G_IO_IN, data=0x5555558e24c0) at mm-port-serial.c:1042
  #14 0x00007ffff6a4979a in g_main_context_dispatch (context=0x5555558a4a00) at gmain.c:3109
  #15 0x00007ffff6a4979a in g_main_context_dispatch (context=context@entry=0x5555558a4a00) at gmain.c:3708
  #16 0x00007ffff6a49ae8 in g_main_context_iterate (context=0x5555558a4a00, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3779
  #17 0x00007ffff6a49dba in g_main_loop_run (loop=0x5555558acf10) at gmain.c:3973
  #18 0x000055555558d068 in main (argc=2, argv=0x7fffffffdc38) at main.c:181
  (gdb)

https://bugzilla.redhat.com/show_bug.cgi?id=1333293
https://bugs.freedesktop.org/show_bug.cgi?id=95303

Just so that we don't have same header names in src/ and /libmm-glib.

Originally developed by:
  Ben Chan <benchan@chromium.org>

This patch replaces mm_bearer_report_disconnection() with a more generic
mm_bearer_report_connection_status(), which allows reporting any
connection status of a bearer. This further allows getting rid of those
custom report_connection_status functions in plugic specific bearer
subclasses.

Note that while plugin-specific implementations can receive multiple
'MMBearerConnectionStatus' values, the generic implementation is only allowed
to receive DISCONNECTED. Plugins need to make sure that they process all the
other status values, and only report DISCONNECTED to the parent when required.

MBM:
  The MBM bearer implementation of report_connection_status() expects either
  CONNECTED or DISCONNECTED. If any of these is received and there is an ongoing
  connection attempt, the corresponding operation will be completed. If there is
  no connection attempt, we will just handle the DISCONNECTED state, calling the
  parent method to notify that the modem got network-disconnected.

Icera:
  The Icera bearer implementation of report_connection_status() expects either
  CONNECTED, CONNECT FAILED or DISCONNECTED. If any of these is received and
  there is an ongoing connection or disconnection attempt, the corresponding
  operation will be completed. If there is no connection or disconnection
  attempt, we will just handle the CONNECT FAILED and DISCONNECTED states,
  calling the parent method (always with DISCONNECTED) to notify that the modem
  got network-disconnected.

Option/HSO:
  The Option/HSO bearer implementation of report_connection_status() expects
  either CONNECTED, CONNECTION FAILED or DISCONNECTED. If any of these is
  received and there is an ongoing connection or disconnection attempt, the
  corresponding operation will be completed. If there is no connection or
  disconnection attempt, we will just handle the CONNECTION FAILED and
  DISCONNECTED states, calling the parent method (always with DISCONNECTED) to
  notify that the modem got network-disconnected.

Huawei:
  The Huawei bearer implementation of report_connection_status() expects either
  CONNECTED or DISCONNECTED. These messages are not used to process pending
  connection or disconnection attempts; so if they are received while one of
  these is on-going, it will just be ignored. CONNECTED reports are also
  ignored, so we will just handle the DISCONNECTED state, calling the parent
  method to notify that the modem got network-disconnected.

Altair-LTE:
  The Altair-LTE bearers will only report DISCONNECTED on network-disconnected
  cases. There is no custom report_connection_status().

Novatel-LTE:
  The Novatel-LTE bearers will only report DISCONNECTED on network-disconnected
  cases. There is no custom report_connection_status().

E.g. instead of:
  (ttyACM1): --> 'AT*EIAAUW=2,1,"(null)","vodafone"<CR>'
  (ttyACM1): <-- '<CR><LF>OK<CR><LF>'

Better pass:
  (ttyACM1): --> 'AT*EIAAUW=2,1,"","vodafone"<CR>'
  (ttyACM1): <-- '<CR><LF>OK<CR><LF>'

Instead of deciding in advance which data port to use, we let the dialling
operation gather it. For the generic dialling logic, ATD-based, always an
'AT' port will be used as data port, even if we grabbed a 'net' port. Those
plugins that can work with 'net' ports will grab the specific 'net' port
themselves.

Both the ModemManager daemon and the mmcli will now include `libmm-glib.h' only.

We also handle two new special `_LIBMM_INSIDE_MM' and `LIBMM_INSIDE_MMCLI'
symbols, which if included before the `libmm-glib.h' library allow us to:

 * Don't include the libmm-glib high level API in the ModemManager daemon, as
   the object names would clash with those in the core.

 * Define some of the methods of helper objects to be included only if compiling
   ModemManager daemon or the mmcli.

Moved the utils to play with binary to hex strings into libmm-common.