net: coap_client: Move send buffer into request context
Keep a separate buffer for each request context instead of having a
single common buffer for the entire client context. This allows to
simplify the retransmission logic, as parallel requests will no longer
overwrite the buffer for each other. That way, we can simply retransmit
the packet w/o a need to recreate it, and thus reach to the payload
pointer or callback.
This removes the requirement to keep the payload pointer, provided to
asynchronous coap_client_req() call, valid throughout the exchange
lifetime for simple cases (i.e. no block transfer used). In case of
block transfer, this is unavoidable and needs to be documented.
Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
2 files changed
