This enables proper negotiation of the codec when answering calls, which
previously also responded with codecs that were not part of the users
preferred ones.
Fixes: #413
A property of type SipMediaEncryption is added to both the origin and
the call which allows to state if we want the media session to be
encrypted with SRTP.
Logic is added to interact with the CallsSdpCryptoContext if encryption
is desired.
by adding functions to the public API which determine if state changes
should be shown to the user and use them (instead of duplicating similar
logic).
We're not setting the desired ports from the outside anymore, but rather
querying the ports that have been allocated by the operating system.
Therefore the lport-rtp and lport-rtcp property have become superfluous and are
being removed. We also adapt to changes outside of the pipeline code.
The id property will be used to keep track of which origin was used for a call,
so that we can default to reusing the same origin when placing a call from the
history.
Introduce a state-changed signal which also gives a reason for why the state
changed. This will allow the UI to give some meaningful feedback to the user.
Additionally we can get rid of a number of things that were not really states,
but rather reasons for why a state changed (f.e. authentication failures).
Sofia detects a NAT by presence of the "received" parameter in the Via header in
the response to a REGISTER. Sofia will then update the Contact header to use the
IP as reported by the registrar.
The "received" parameter MUST be included in the response according to
https://datatracker.ietf.org/doc/html/rfc3261#section-18.2.1
when the registrar detects a difference between the domain part of the top Via
header and the packet source address but practice has shown that this will not
always be the case.
Addditionally this change allows us to have origins bound to different network
interfaces which would be useful when a registrar can only be accessed through a
VPN.
This also fixes an issue with SDP introduced in
36880c3d34 which was only seen on some SIP
providers:
The session name ("s=") line is not relevant for establishing a connection,
the connection data (c=") line is.
See https://datatracker.ietf.org/doc/html/rfc4566 section 5.3 and 5.7
Since we cannot do encrypted media streams yet, we should hardcode whether or
not we want to use SRTP to FALSE, so that sips target URLs can be used in SIP
calls at all.
If the origin is used for PSTN telephony extract the number from the
SIP dialstring (i.e. sip:+49160123456789@my-sip-host.de) and pass that
to call object for contact matching.
This let's us get rid of a lot of duplication in the derived classes.
Additionally we set the initial state to CALLS_CALL_STATE_INCOMING if
inbound is TRUE and CALLS_CALL_STATE_DIALING otherwise.
In this case network changes will not be detected.
Additionally fall back to binding on all network interfaces (in this case a user
will have problems when using multiple network interfaces, but there is really
not much we can do without a functioning CallsNetworkWatch).
Otherwise we might miss the IP of the remote peer leaving us unable to
establish a connection for RTP.
From https://datatracker.ietf.org/doc/html/rfc4566#section-5.7
A session description MUST contain either at least one "c=" field in
each media description or a single "c=" field at the session level.
It MAY contain a single session-level "c=" field and additional "c="
field(s) per media description, in which case the per-media values
override the session-level settings for the respective media.
The assumption that the IP of the remote peer can always be found in the
sdp_connection member of the sdp_session_s struct does not always hold true
and we should handle this case gracefully (i.e. without crashing).
