Change-Id: Ic511765a87faf53d9b8afd4a216bfcb1755f5c5e

Change old code to directly return `str` objects instead of pointers to
allocated ones. Largely a no-op change but makes some code easier and
eliminates some old kludges.

Change-Id: I2be19dd24bb7ff046d86cc32a3af235283e65dd0

Introduce global generic memory arena variable, instead of having just
a call-specific memory arena. This makes it possible to use memory arena
outside of call contexts. Define previous call-specific functions in
terms of the generic ones.

Change-Id: Icde4f63f02dacbf8abfbaf107ea8b5bbe18d5eb8

Mark those SDPs which trigger processing
of music-on-hold.

Is defined by the config option:
`moh-attr-name`. If not defined then
is not used.

Will be useful for cases when it's important
for remote components to detect ongoing hold.

Change-Id: I0f2a284955dbc045b51920174f1f4fbefcb93907

Support inactive hold, because some
client implementations (such as Zoiper5)
are using `a=inactive` for their holds.

For us this means, either of this
puts the other side on hold:
- `sendonly: !MEDIA_ISSET(media, SEND) && MEDIA_ISSET(media, RECV)`
- `inactive: !MEDIA_ISSET(media, SEND) && !MEDIA_ISSET(media, RECV)`

Change-Id: I75562eee60220885e233fa965bf22da92850a8f4

Introduce `moh-max-repeats` configuration option,
which controls the `rtpe_config.moh_max_repeats`
used when initializing media player options
for the music-on-hold functionality.

By default is always set to 999,
if not defined otherwise.

Change-Id: I247dc532a6871934e44f9c4002313363356937fb

Make `moh-max-duration` available for both
music-on-hold functionality as well as
for the media player.

For that to work, do the following:
- keep `moh-max-duration` config option only for MoH,
  if not set (so 0) by default is 1800000ms (half an hour)
- for the play media functionality introduce flag option
  `repeat-duration`, by default is disabled

Policy changes:
- duration counter can be used in common with repeats
  counter, but then takes a precedence over it.
  Hence if first a duration is underflown, then EOF triggered.
  Otherwise if the duration counter is still positive, but
  repeats are negative, then do EOF based on repeats.
- the repeats counter will always count down during each
  iteration, even when used together with the duration counter
  For MoH to survive, the repeats counter is simple set to 999
  to let the duration counter always win over repeats one
- MoH cannot take duration disabled, since otherwise
  would make no sense for it. Hence always takes internally
  defined value 1800000ms (half an hour) if not defined
  by the configuration option

Backwards compatibility:
- is kept in regards of repeats counter
- is kept in regards of the play media functionality

Change-Id: I48ff3c17c9bed31f80c3106b275b703a9ccb4b26

This function belongs to a specific scope, which
is rather in media_player than call_interfaces.

Change-Id: I74bda66491f002e6e90767d7d2750cfc270eea96

Sendrecv mode flag controls whether the sendrecv
state is forced to sendrecv, instead of the default
one sendonly, in the SDP body going towards recipient
(the one who will receive the MoH media).

Is declared as: moh=[mode=sendrecv]

Can be useful for corner cases, where the remote side
wants to see sendrecv state for whatever reason,
when getting MoH media and hence also remain in sendrecv
state in regards of the MoH originator.

Must be advertised once during the session origination,
nd then will affect the SDP body as soon as SDP sendonly
body is received (from the behalf of one, who advertised MoH
capabilities).

Backwards compatibility: doesn't affect non-MoH calls.
And doesn't affect offer/answer exchanges within MoH calls,
which do not put the remote side on hold.

Additionally: introduce a common function for the MoH flags
handling: `call_ml_moh_handle_flags()`, which does all
the required iterations/checks for the whole bunch of flags
at once.

Additionally: previously existing MoH tests adopted.

Additionally: new test introduced to check the SDP content,
when using mode sendrecv flag.

Remark: this flag is not mutually exclusive with
the zero-connection MoH flag.

Change-Id: I5bf6699f6890d8b927107cc143a18116efe45087

Zero-connection flag controls whether the connection
address offered in the SDP body going towards recipient
(the one who will receive the MoH media), is set
to all zeroes.

Is declared as: moh=[connection=zero]

Can be useful for older client implementations,
who want to see zeroed media when receiving sendonly
and getting put on hold.

Must be advertised once during the session origination,
and then will affect the SDP body as soon as SDP sendonly
body is received (from the behalf of one, who advertised MoH
capabilities).

SDP body recovers to the real IP addresses being inserted
into recipient's SDP, as soon as the media gets unheld.

Backwards compatibility: doesn't affect non-MoH calls.
And doesn't affect offer/answer exchanges within MoH calls,
which do not put the remote side on hold.

Additionally: previously existing MoH test adopted.

Additionally: new test introduced to check the SDP content,
when using zero-connection flag.

Change-Id: If0c38a3d294e6d5fe3886bee19ff2382e5705f9a

Add duration limit for the moh functionality.
This is required due to a possibility to get
monologues and hence packet streams stuck
forever and sending audio to recipients
which already don't exist.

A configuration option that controls that:
`moh-max-duration` - gets a value in milliseconds.

By default is set to 1800000 (half an hour).

Change-Id: Id50a0a10ce5b52b3876a3122fb16a71accec90ff

Introduced Music on Hold functionality:

- available only for the offer/answer model,
  no other scenarios (publish, subscriber etc.)
  are covered with it
- it gets advertised always at the beginning of
  the call (original offer/answer exchange)
- can be added for both sides: offerer/answerer
- the one who advertises its MoH capabilities
  with its SDP offer or answer, can later trigger
  MoH using sendonly SDP and unhold remote
  party using sendrecv SDP
- MoH covers only audio type of media sessions
- there is no specific selection of media sections
  to be held, thus, if one audio media puts the
  call on hold, the whole call is held
- list of parameters to be given when advertising
  MoH capabilities: a sound source (file, blob or db source);
  sendonly/sendrecv hold; zero-connection hold;
  At least an audio file source must be given
- MoH cannot be mixed with the play media functionality,
  the last one triggered will override previous one
- MoH must be unheld to stop the media being sent
  towards a recipient, otherwise only a termination
  of monologues will stop this packets stream

Change-Id: Iefd83ced79c14dadad936348a1d529007d6e7b3b

Move part of the `call_stop_media_ng` function body
to a separate function, to let it be available
for external function calls not particularly related
to play media NG function call.

Change-Id: I278f7bc5a6663e9232e812d10f6902616c67c497

Add a function to check if any audio medias
are putting the call on sendonly state.

Change-Id: I9667c8e2b65378596183e05ba22e551ae17e158b

Make most of implementations static to file
because used only locally:
- `media_player_play_file()`
- `media_player_play_blob()`
- `media_player_play_db()`
- `media_player_add_file()`
- `media_player_add_blob()`
- `media_player_add_db()`

Change-Id: I0db13e1f851e6c59d29ffb5adf5cb8d01bfd5bcc

`media_player_opts_t` is already used to pass
blob, file and db_id, hence makes no sense to pass
it one more time and reset parameters of
`media_player_opts_t` strcuture in actual implementation
to the same value again.

Change-Id: I97f4236b2c9565f12af44dc4aba85ebfc6d8cefa

Use `media_player_opts_t` object to pass file, blob and db_id
parameters via the following functions:
- `media_player_add_file()`
- `media_player_add_blob()`
- `media_player_add_db()`

Change-Id: I7612cd63d08bc00911ba68c0a5a81796d50d4722

Add a functiona that covers handling of:
- `media_player_add_file()`
- `media_player_add_blob()`
- `media_player_add_db()`

Change-Id: I43ea20649366e45c461d584a811fa91c82b6405c

Rename the following functions into
something more relevant so that it
doesn't correlate with the general
init function `media_player_init()`
which isn't call specific.

- `media_player_init_file()` > `media_player_add_file()`
- `media_player_init_blob()` > `media_player_add_blob()`
- `media_player_init_db()` > `media_player_add_db()`

Change-Id: I8efd877bfd4c7c300aec7efe6fbbb654f52de460

Pass file, blob and db_id via `media_player_opts_t`
structure members instead of using separate arguments
in `call_play_media_for_ml()`.

Change-Id: I8c3b9b7f5ab61238d35463c304246f31a922ac6f

Move part of the `call_play_media_ng` function body
to a separate function, to let it be available
for external function calls not particularly related
to play media NG function call.

Change-Id: Iaf4e8f72f1492446508fd6b49ba36434cae5f5f0

Change-Id: Ie07cb5bd139f5e039c5736009ae18733850b0c55

This function connects two call legs (two monologues), possibly from
different call IDs, into a single media flow. It pays attention to media
types and automatically engages transcoding if needed. The order of
media sections of different types can be differend between the call legs
that are being connected. Subsequent reinvites will produce SDPs with
the media sections in the correct order.

Change-Id: I40c3363997de169edc553733d52acdfd9f0181ad

This function retrieves two calls from the global call hash while
avoiding deadlocks. This is needed because a "call_get(A) + call_get(B)"
would deadlock against a concurrent "call_get(B) + call_get(A)"

Unused at this point.

Change-Id: I95127ce1afa19386a847984ca26eb7d7368e6569

This function merges two distinct call objects into one. All contained
objects are moved, and the "source" call is then destroyed. Both call
IDs can then be used to refer to the same internal call objects. Call ID
aliases are kept in a list in the call object.

Change-Id: I8a37775fe0dc3e7ccfeb83e2a3b7d751601450fc

Change-Id: I6b23305bb8dfbbcd73e97b2a1bd5feca67c2a02c

When media subscriptions are removed implicitly by
__subscribe_medias_both_ways(), we must update all RTP sink pointers of
all the streams of the affected medias. Otherwise these sinks will be
left unchanged despite the subscriptions having been removed.

Change-Id: I6d1ac3bb5cb27443c31f0f3b9ce8f47c416cd3ce

Change-Id: I1c5d28b6e241c60f5c71c7e5f04845a082182778

The `answer` processing empties out the list of codecs and leaves only
those that were accepted in the answer. Side effect of this is that if
another answer with a different list of codecs comes through, them the
codec-accept function is missing the original list of offered codecs and
can yield an incorrect result.

Fix this by storing a copy of the offered codecs at the end of the
`offer` processing, and then restore this list at the beginning of each
`answer` message.

Change-Id: I3c714e80689f3c5689637cc7d1eb2f203c292a15

Change-Id: I53e40d80d813eeee3edaebe557b3aa5c9e5b5733

Aim is to decouple redis read/write/subscribe.

Closes #1881

Change-Id: I9bfc46fa738898ab7fcac4f6a4691a6def6f77ba

Change-Id: Ifad2d5958defc8c7995be8bb6569885ae6749dc9

There is enough overlap between the two enums that it doesn't make sense
to carry along both. Unify.

Change-Id: I9de8fbdb8d78a2002d8c1b62cea57188c937d61d

Change-Id: If5624e3294bff7f677bdb08f98ea920c3b5f929a

Change-Id: I1d757728e22d9d101fa62eebeed6e8d2ca040107

Allow to-tag updates in answers only until a non-provisional response is
received. Add a flag to optionally suppress this feature.

Change-Id: I67110ede662f618ba5a355500d3d84050e6318cc

If we receive an answer from a to-tag that hasn't previously seen and no
corresponding monologue exists (created from a previous offer),
previously we would treat this is a separate and new call branch, create
a brand new monologue and dissociate the previous one. This may lead to
unexpected results as this new monologue has been created without the
same initialisation as was done for the original one, and so may be left
with incorrect or incomplete data (e.g.  SRTP keys, codec information,
interface bindings, etc).

Improve this by treating an unexpected and unseen to-tag as an alias to
the already existing to-tag. Going forward both tags can be used
interchangeably to refer to the same monologue.

Add a flag to suppress this new behaviour, in case some situation is
made worse by it.

Change-Id: Ie8f838eebd50d29d3549031998a2eb1f610b04bb

When re-connecting to the remote redis server
try to re-resolve if the redist hostname
was an FQDN and not IP address.

Change-Id: Ie80e1d1a1ea76811c54123201ad4fe8cb64fc748

In order to be able to control, which media types
one wants to have in the call session,
add support of the "sdp-media-remove" flag.

Syntax:
"sdp-media-remove" : ["<media-type>", "<media-type>", ...]

Additionally, add according unit tests.

Change-Id: Ic52456f8124319992ea9ca8c161daefb1df46b59

Change-Id: Id7982aadf090db18561c50aec127f42860ebb6a4

Make it so that options only need to be managed in one place, and all
code operating on the list of them is streamlined

Change-Id: Ia53b15910ec8973635e61cad1b43eff8d536a577

These are redundant and not used.

Change-Id: I2c994c4b1f222a4065760f4e2f154131f7ce8b34

Change-Id: I82b6b9bb134e89cbc0e8794f01951f35fd9bf6e0

If a monologue is determined to get a new to-tag, don't just overwrite
the previous to-tag, but also save the old one as an alias. Leave the
old one in the hash table as well so that future lookups can use either
to-tag.

Change-Id: I5d2d5cc17c85ec4ca2d8a20c501d2cdb6d793b61

Convert existing sdp manipulation helpers
to work with arrays directly, independently from
which array is actually given.

Moreover, don't use the `G_N_ELEMENTS()`,
since we already have the `__MT_MAX`
as the size of the array, so we can directly use
that instead of relying on the G_N_ELEMENTS macro
(for array size checks).

Change-Id: I38e71dab30a467b933c213c8157fa06651ebaf04

Add a getter function for retrieval of top
most media from given media.

Currently existing getter for the top most
monologue's media subscription, just rename
so it makes more sense and is better to
differentiate:
`call_get_top_media_subscription()` -> `call_ml_get_top_ms()`

Change-Id: I5bf13b69b4d5f67cd6b53018b5a16d759542cd41

The pcre2 API was changed from

	pcre2_substring_list_free(PCRE2_SPTR *)

to

	pcre2_substring_list_free(PCRE2_UCHAR **)

in 10.43. The difference is a `const` qualifier. Work around this.

Closes #1869

Change-Id: Ib3dd3003352f6c3155bb47d69ecb7a1b02f4647a

Change-Id: I516972d85a26d68b9f9c2a9613294a02448391b6

Fixes:

*** CID 1600059:  Null pointer dereferences  (FORWARD_NULL)
/include/call.h: 919 in call_str_cpy()
913             return out;
914     }
915     INLINE str call_str_cpy_len(const char *in, size_t len) {
916             return call_str_cpy_fn(in, len, NULL);
917     }
918     INLINE str call_str_cpy(const str *in) {
>>>     CID 1600059:  Null pointer dereferences  (FORWARD_NULL)
>>>     Dereferencing null pointer "in".
919             return call_str_cpy_fn(in ? in->s : NULL, in ? in->len : 0, in->dup);
920     }
921     INLINE str call_str_cpy_c(const char *in) {
922             return call_str_cpy_len(in, in ? strlen(in) : 0);
923     }
924     INLINE str *call_str_dup(const str *in) {

Change-Id: I975d5bd420edc3605e59e16313dce488eff46e0c

Not needed any more. All strings reside in the call's memory arena, and
SDP rewriting isn't a thing any more.

Change-Id: I594b85fe26f44fa25312eb97fb65de238fc18920