Commit Graph

8 Commits

Author SHA1 Message Date
Vadim Yanitskiy 8e7c49649e vty: use install_lib_element() and install_lib_element_ve()
See https://lists.osmocom.org/pipermail/openbsc/2020-October/013278.html.

Change-Id: Ic541126ffd4975daf87199abfafb465e2055e44f
Related: SYS#4937
2020-10-06 00:22:22 +07:00
Vadim Yanitskiy df4f6085cd tdef_vty: do not enforce enum 'node_type' in osmo_tdef_vty_groups_init()
Some osmo-* applications may need to use their own VTY node as a
parent for the timer configuration commands. Therefore it makes
more sense to use 'unsigned int' instead of 'enum node_type'.

Let's also clarify that osmo_tdef_vty_groups_init() accepts parent
node for configuration commands only: 'parent_node' -> 'parent_cfg_node'.

Change-Id: Ifb4c406c85d76a25fc53fc235484599aa87dc77c
2020-02-06 01:06:14 +07:00
Pau Espin 0cbe8f0100 tdef: Introduce min_val and max_val fields
This is useful for timers expected to have a range of valid or expected
values.

Validation is done at runtime when timer values are set by the app or by
the user through the VTY.

Related: OS#4190
Change-Id: I4661ac41c29a009a1d5fc57d87aaee6041c7d1b2
2019-10-07 13:14:14 +00:00
Harald Welte 581a34da60 tdef: Fix license: GPLv2+ instead of AGPLv3+
libosmo{core,gsm,vty} code is GPLv2+.  The tdef code originated in
osmo-msc.git and was moved here without changing the license. That
was a mistake, it always was meant to be under GPLv2-or-later after
moving to libosmocore.git.

Copyright is with sysmocom, so I as the managing director can
approve the license change.

Change-Id: Ie483ff6f6ea0a56c477649677b4b163c49df11d7
2019-05-27 23:26:45 +02:00
Neels Hofmeyr d79ccc65f7 add osmo_str_startswith()
Move from a static implementation in tdef_vty.c to utils.c, I also want to use
this in osmo-msc.

The point is that the telnet VTY allows unambiguous partly matches of keyword
args. For example, if I have a command definition of:

    compare (apples|oranges)

then it is perfectly legal as for the vty parser to write only

    compare app

One could expect the VTY to then pass the unambiguous match of "apples" to the
parsing function, but that is not the case.

Hence a VTY function implementation is faced with parsing a keyword of "app"
instead of the expected "apples".

This is actually a very widespread bug in our VTY implementations, which assume
that exactly one full keyword will always be found. I am now writing new
commands in a way that are able to manage only the starts of keywords.

Arguably, strstr(a, b) == a does the same thing, but it searches the entire
string unnecessarily.

Change-Id: Ib2ffb0e9a870dd52e081c7e66d8818057d159513
2019-04-11 05:36:36 +00:00
Vadim Yanitskiy 54f5f4da59 vty/tdef_vty.c: drop redundant comparison
The amount of arguments is already being checked a few lines before:

  /* If any arguments are missing, redirect to 'show' */
  if (argc < 3)
    return show_timer(self, vty, argc, argv);

so we cannot reach the expression NULL inside this statement:

  group_arg = argc > 0 ? argv[0] : NULL;

Change-Id: Ice59d1a46c2080cd02060e3410706c502db4ce0b
Fixes: CID#190873 Logically dead code (DEADCODE)
2019-03-19 13:44:58 +00:00
Neels Hofmeyr 5734bff3b0 represent negative T-timers as Osmocom-specific X-timers
fi->T values are int, i.e. can be negative. Do not log them as unsigned, but
define a distinct timer class "Xnnnn" for negative T values: i.e. for T == -1,
print "Timeout of X1" instead of "Timeout of T4294967295".

The negative T timer number space is useful to distinguish freely invented
timers from proper 3GPP defined T numbers. So far I was using numbers like
T993210 or T9999 for invented T, but X1, X2 etc. is a better solution. This way
we can make sure to not accidentally define an invented timer number that
actually collides with a proper 3GPP specified timer number that the author was
not aware of at the time of writing.

Add OSMO_T_FMT and OSMO_T_FMT_ARGS() macros as standardized timer number print
format. Use that in fsm.c, tdef_vty.c, and adjust vty tests accordingly.

Mention the two timer classes in various API docs and VTY online-docs.

Change-Id: I3a59457623da9309fbbda235fe18fadd1636bff6
2019-03-06 00:51:15 +01:00
Neels Hofmeyr 0fd615fd7b add osmo_tdef API, originally adopted from osmo-bsc T_def
Move T_def from osmo-bsc to libosmocore as osmo_tdef. Adjust naming to be more
consistent. Upgrade to first class API:
- add timer grouping
- add generic vty support
- add mising API doc
- add C test
- add VTY transcript tests, also as examples for using the API

From osmo_fsm_inst_state_chg() API doc, cross reference to osmo_tdef API.

The root reason for moving to libosmocore is that I want to use the
mgw_endpoint_fsm in osmo-msc for inter-MSC handover, and hence want to move the
FSM to libosmo-mgcp-client. This FSM uses the T_def from osmo-bsc. Though the
mgw_endpoint_fsm's use of T_def is minimal, I intend to use the osmo_tdef API
in osmo-msc (and probably elsewhere) as well. libosmocore is the most sensible
place for this.

osmo_tdef provides:

- a list of Tnnnn (GSM) timers with description, unit and default value.
- vty UI to allow users to configure non-default timeouts.
- API to tie T timers to osmo_fsm states and set them on state transitions.

- a few standard units (minute, second, millisecond) as well as a custom unit
  (which relies on the timer's human readable description to indicate the
  meaning of the value).
- conversion for standard units: for example, some GSM timers are defined in
  minutes, while our FSM definitions need timeouts in seconds. Conversion is
  for convenience only and can be easily avoided via the custom unit.

By keeping separate osmo_tdef arrays, several groups of timers can be kept
separately. The VTY tests in tests/tdef/ showcase different schemes:

- tests/vty/tdef_vty_test_config_root.c:
  Keep several timer definitions in separately named groups: showcase the
  osmo_tdef_vty_groups*() API. Each timer group exists exactly once.

- tests/vty/tdef_vty_test_config_subnode.c:
  Keep a single list of timers without separate grouping.
  Put this list on a specific subnode below the CONFIG_NODE.
  There could be several separate subnodes with timers like this, i.e.
  continuing from this example, sets timers could be separated by placing
  timers in specific config subnodes instead of using the global group name.

- tests/vty/tdef_vty_test_dynamic.c:
  Dynamically allocate timer definitions per each new created object.
  Thus there can be an arbitrary number of independent timer definitions, one
  per allocated object.

T_def was introduced during the recent osmo-bsc refactoring for inter-BSC
handover, and has proven useful:

- without osmo_tdef, each invocation of osmo_fsm_inst_state_chg() needs to be
  programmed with the right timeout value, for all code paths that invoke this
  state change. It is a likely source of errors to get one of them wrong.  By
  defining a T timer exactly for an FSM state, the caller can merely invoke the
  state change and trust on the original state definition to apply the correct
  timeout.

- it is helpful to have a standardized config file UI to provide user
  configurable timeouts, instead of inventing new VTY commands for each
  separate application of T timer numbers.

Change-Id: Ibd6b1ed7f1bd6e1f2e0fde53352055a4468f23e5
2019-02-04 18:52:16 +01:00