With selected_sfd being protected by in_lock, we pretty much have to
hold at least in_lock everywhere, and end up requiring both locks in
many places. The distinction has become pointless.

Change-Id: Ic0ad976c2d68d9639b9434da7f0e6e9c0d84c185
(cherry picked from commit e03f814855)
(cherry picked from commit 222fcaa4b0)

Protect selected_sfd with in_lock.

Protect RTCP sending with in_lock and out_lock as appropriate.

Has the odd side effect of RTCP reports expected in tests to be sent one
packet later than before.

Closes #1966
Probably fixes #1927

Change-Id: I225b43dff8e8fbb938d3be6aad50249997615d77
(cherry picked from commit ffc539c0d8)
(cherry picked from commit 65cd565bae)

Change-Id: I2bfd09eefaf6a13f1c7435efa2e07c9ccecfa964
(cherry picked from commit 9068638a4d)
(cherry picked from commit df4dcb0193)

to a more appropriate place to remove an otherwise unneeded dependency

Change-Id: If82707e937a9102de1a405a25f7f3f436df878e6

Change-Id: I9b9ef39859f196a9c0ea8a7aee657311a70a5d03

Special codec handler to support not forwarding (nor any processing
whatsoever) of particular payload types at all. Support this in the
kernel module as well.

Change-Id: If10227affa54307e1e9b448eadd0bf2bfc5774ba

Change-Id: I49c9f786d0826c090df348eb7ae600f6887611bd

Change-Id: I2113b76d97f5cf6cc8927f92b8a178795322a77e

Instead of explicitly triggering an update of subscribers for A and B
during an offer/answer, trigger it only for one side (A) and then
iterate through all subscribers and subsriptions and update them all.
This automatically triggers an update for B, as well as any other
existing subscriptions that might be affected. Use a monotonically
increading update iterator counter to track which medias have been
updated so we don't run into infinite recursion.

Change-Id: Ie2fba8ff9c5a011bbe932559ac06e1634029a091

to distinguish it from the media-level function

Change-Id: Ied359a62040e35bdff934c6be9273f520e58b2e4

Change-Id: I34b619371f2d9d3f683cd9ebb4993a57367f4c35

Unused.

Change-Id: Ib4c2ddbe7f97af3863ed3fe5af5a1f4bc64917dd

Change-Id: Id1b25c1868b3537cbb50b7c484bb3b675e5f8f74

0x40000000 was already used by SHARED_FLAG_END_OF_CANDIDATES. Move
MEDIA_FLAG_REORDER_FORCED to unused slot 0x00800000 instead.

Change-Id: I0aa33854f814757869c7a98ba209d9aeb94d3d91

Directly return the just-created subscription from the respective
function. Saves a hash table lookup.

Change-Id: I42d9c75ebae2cc92619e78badb8ac594397b614b

These must be present. Skip NULL check.

Change-Id: Ieced33fbb28ba2ae2c7b874f80a34a41bdc21ab5

Change-Id: I637d28ca01fb5caffeb2e523ea91a51da03a8a59

We know whether we're printing for monologues or for medias, so there's
no need to have a generic function signature.

Change-Id: I356747686adb34c19ba2ba4c77c2d0a77b85a364

Closes #1912

Change-Id: I2ac29b8cf97f20637f693589dcf82fdba5b60026

When MoH is triggered with `sendrecv` flag (so that
the recipient, the one who is put on hold, sees
the sendrecv state instead of sendonly/inactive),
we have to correctly process the answer coming back
to the MoH originator.

The originator of MoH must see:
- recvonly to his sendonly
- inactive to his inactive

Hence OA model is kept correct for the originator's leg.

Additionally: accordingly correct MoH tests.
Change-Id: Ida5f074d302c419c1e57e4fd624a55bfddae5587

Change-Id: I015a931d7e726815d2a7d06fa4d74a1418dfec0b

A call that gets created but then doesn't get initialised would have its
Redis DB left at zero. At destruction it would then try to switch to DB
zero. Fix this by using an appropriate initial value.

Closes #1905

Change-Id: I852e48c5a06b732b37d2ccd5c478de4760aacd4e

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

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

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

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

Change-Id: I9667c8e2b65378596183e05ba22e551ae17e158b

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

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

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

Change-Id: I9de8fbdb8d78a2002d8c1b62cea57188c937d61d

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

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

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

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

Avoids allocating and duplicating the string. Should be safe as all
strings that use it are allocated in read-write memory.

Requires changing some struct members to non-const.

Change-Id: Idc81a84a1454898c76d8514666c385307043bb6f

If a string is already stored within the call's memory arena, skip
duplicating the string content when making a copy, and simply return the
same pointer.

Change-Id: I50107d87b2625234a395da21e1e4551585966a60

Instead of keeping one global hash/list of all received ICE fragments,
indexed by string call ID and from-tag, move the hash/list of ICE
fragments into the call object, now indxed only by the from-tag.

This requires a call object to exist before an ICE fragment can be
stored. Change the order of operations to always create a call object
first, then parse the SDP, then check for ICE fragment processing. The
determining factor now is only whether the monologue exists.

Duplicate the raw SDP into the call's memory arena instead of onto the
heap.

ICE fragments now don't need to store the pre-parsed SDP any more, and
the trickle ICE handling code is guaranteed to always have the fully
parsed SDP information.

Strings for fragment indexes can now be allocated from the call's memory
arena.

Obsolete the extra thread used to delete old ICE fragments. This is now
done in-line with regular call timeout processing.

Change-Id: I7acbc4c52666c4cdf1c02324bf33cf0bfcb4f0d0

Flag the media via stream params, when it's
trickle or non-trickle offer/answer, and,
unflag it always only when it's non-trickle.

Change-Id: Ia85ce5792684a4121e224aff1a8e941e061fe5a8

So we can attach other attributes to the strings

Change-Id: I3e6090c8557879efb40ddeb6635ed4b10e742112

Change-Id: I338f1a90890701fe202179f8079f564a50dce5f0

This should be protected by the master_lock already.

Change-Id: I5369546803c2b5ca9cb821ac7f8d3e7246d6af87

Change-Id: I870731978d51b542ebd93a5070b9fc39ea1592b4

Remove unneeded intermediate buffer

Change-Id: I17f6c0f4b9ac27ab1b3b8e33fc49d0662e687970