Current stack:-
Application
CoAP
CoAP-Session
DTLS
Netif
Sockets
Network Stack
Depending on the CoAP protocol, indexing functions through coap_layers_coap[]
(in src/coap_io.c) will invoke the correct layer function when used at the
CoAP and DTLS layers.
It is then easy to add in another protocol layer by updating coap_layers_coap[].
Add in new file src/coap_dtls.c.
Add in coap_(d)tls_establish() functions which are called when netif
accept / connect take place.
Add in coap_session_establish() function which is called when (D)TLS
has established as well as at the session layer if there is no (D)TLS
in preparation for properly supporting protocol layers.
Add in coap_(d)tls_close() functions which are called prior to
coap_netif_close().
Add in skeleton coap_netif.c coap_netif_internal.h files, populated with
coap_netif_dgrm_read(), coap_netif_dgrm_read_ep(), and coap_netif_dgrm_write()
functions that are called by the CoAP and (D)TLS code which in turn call
the appropriate coap_socket_*() functions.
The coap_dtls_send() function parameters are aligned with
coap_netif_dgrm_write().
Add in new function coap_context_set_max_token_size() to define
the maximum supported token size.
Track changes to PDU to support extended tokens.
Update documentation.
coap_resolve_address_info() emulates getaddrinfo() but has the extensibility to
support other socket types based on the address to resolve.
coap-client, coap-server and lwip/client updated to use this new functionality.
coap_address(3) updated to include the new functions.
See https://core-wg.github.io/oscore/test-spec5.html
Add in new test server oscore-interop-server to provide the necessary
functionality.
Add in script and configuration files to run the tests locally.
Based on work done in https://gitlab.informatik.uni-bremen.de/obergman/libcoap
New directories with files
include/oscore
src/oscore
New files
include/coap3/coap_oscore.h
include/coap3/coap_crypto_internal.h
include/coap3/coap_oscore_internal.h
man/coap-oscore-conf.txt.in
man/coap_oscore.txt.in
src/coap_oscore.c
tests/test_oscore.c
tests/test_oscore.h
Supported by new option (enabled by default)
./configure --enable-oscore
cmake .. -DENABLE_OSCORE=ON
Requires a TLS library configured to do the OSCORE encryption and hashing.
Drop the use of syslog LOG_DEBUG etc. for coap_log() and use the
coap_log_debug() etc. macros which make use of COAP_LOG_DEBUG etc.
Application examples updated, as well as the man page examples.
Assemble all the blocks before checking for Observe registration
or de-registration.
Track all the tokens used for the large FETCH registration and
re-use them for the de-registration as the server can elect to use
any of them when re-assembling the body for the registration Token.
If multiple requests (apart from DELETE) are sent at the same time to
the same resource, and the responses need to make use of the Block2 option,
there is no way for the server to differentiate between which block set a
request (if there is a resource content change) is for unless a Request-Tag
is used.
Disable this functionality by setting COAP_BLOCK_NO_PREEMPTIVE_RTAG when
calling coap_context_set_block_mode(). Request-Tag will still be sent
with any request that includes Block1 option.
Clean up / simplify conditions for breaking out of the main coap_io_process()
loop. ready is no longer required here.
Handle mcast Observe requests by continuing to track the token
Make sure that all of the Observe (potentially blocked) response is received
before closing down.
Remove unecessary code.
coap_io_pending() checks to see if there are any PDUs pending transmission,
whether there are any large (block) transmissions in progress, whether
there are still expected response packets(client) or expected request
packets(server), and whether the client is expecting further observe
responses. If any of this is true, then it returns 1, else 0.
coap_io_pending() also invokes coap_io_process() to check that all that can
be transmitted is, as well as processes any impending input packets.
This takes coap_can_exit() a step further who only checks the transmit state.
coap_handle_response_get_block() has been updated to release the current
lg_crcv if all the fragmented body of a large transfer have been received.
Documentation updated.
Set up coap_log_t as an enum, using syslog variable names prefixed by
COAP_.
Add function coap_dtls_log() for logging information from (D)TLS libraries.
Update the log output to have use Lower-case variants for the logging levels to
indicate that output is from the (D)TLS library instead of the CoAP library.
(D)TLS libraries updated to be consistent in the usage of
coap_dtls_set_log_level()/coap_dtls_get_log_level().
Add in coap_log_emerg(), coap_log_alert() etc. as wrappers to reduce the line
length required for log entries. Updating all the coap_log() functions to
no longer use syslog variants will be a part of a separate PR.
Added in the "-V" option to the examples, with an initial default of
COAP_LOG_ERR, separating out the CoAP and (D)TLS logging levels.
Note: TinyDTLS log output will be consistent when built against a TinyDTLS
version that contains support for an external logging handler.
As well as adding in the DTLS_PSK wrappers in the appropriate place. add in
coap_dtls_psk_is_supported(), coap_dtls_pki_is_supported(),
coap_dtls_pkcs11_is_supported() and coap_dtls_rpk_is_supported() functions
to support better granularity of what capabilities are available in the
(D)TLS libraries.
Update coap_string_tls_support() to use these new functions.
Uppdated documentation for these new functions.
The dtls versions of the server and client are built as
server-dtls and client-dtls.
Add in flexible option support for server and client. These are
a subset of the coap-server and coap-client options.
Apart from debug log messages, there is no way for a user to be
notified when a message retransmission happens.
This event can be useful for diagnosing issues related to
lossy networks or unresponsive CoAP servers (e.g. user can
track total retransmissions as an indicator for general link
quality).
Assigned event ID to 0x5002 to avoid creating a new 0x6000
event group, and because it's similar to COAP_EVENT_BAD_PACKET (0x5001).
Delay exit briefly checking if there are any response packets following
observe cancellation and process as appropriate.
If multiple observes are outstanding, cancelling them using CON will
cause issues as NSTART limit is hit. The server then does not know
about all of the cancellations.
Also, this can allow the server to properly shutdown observe
activity when blocks are used.
Simplify code for applications by providing coap_uri_into_options()
which then adds the (optional) port and splits out the path / query
as CoAP options, adding them to the optlist_chain for subsequent use.
Added a new coap_delete_uri() for completeness.
Update documentation to include the uri based functions.
Update examples to use the new coap_uri_into_options() function.
New demo client app.
Update some of the memory sizes.
New coap_lwip_dump_memory_pools() to dump LwIP memory pool usage.
Add in logic to handle new client sessions.
New coap_io_process() to handle LwIP which can invoke a callback handler
to wait / timeout for the next input handler.
New coap_lwip_set_input_wait_handler() to define this handler.
Update coap_io_prepare_io() to handle LwIP.
Support re-use of pbuf for PDU re-transmissions.
Make sure that NSTART is correctly obeyed.
Build the client with client only libcoap code.
Build the server with server only libcoap code.
Update LwIP source to latest stable release.
Reserve memory for a response PDU.
New coap_lwip(3) man page.
Update directory structures for config files.
Update files contained in "make dist" and check lwip rebuilds
in the github workflows.
If a response packet is received that is badly formatted, invoke the
nack handler (if defined) with COAP_NACK_BAD_RESPONSE so that the
requestor knows there is an issue, rather than timing out.
However, if the response packet is so badly formatted, or it is not
possible to find the requesting packet, then this nack event will not
trigger, but an event is triggered with COAP_EVENT_BAD_PACKET.
Add in new event COAP_EVENT_XMIT_BLOCK_FAIL which gets triggered on
detecting transmission failure of large body using BlockX.
Track the last time a lg_xmit was sent, so it can be timed out on failure.
Correctly track the next lg_xmit timeout time (and lg_crcv, lg_srcv) so that
the lg_xmit can be expired.
As an incoming proxy request may delay its response (e.g. initiate an
ongoing connection), send back empty ACK immediately so that the
client does not timeout and re-transmit the request.
Do not process duplicated (i.e. re-transmitted) proxy requests.
Correct a couple of typos in example proxy code.
Add in new function coap_mcast_per_resource() to enable granularity of
handling multicast requests differently at the resource level.
The granularity is handled by how the flags variable is set up in
coap_resource_init(). These additional flags are ignored if
function coap_mcast_per_resource() has not been invoked.
Added 2 functions coap_resource_unknown_init2() and
coap_resource_proxy_uri_init2() that support defining the mcast flags as
per coap_resource_init().
Responses are now delayed rather than the request being delayed before being
passed to the request handler.
Update coap-server with the -r option to enable multicast on specific
resources.
Do not reset wait_ms in coap-client for Block2 transfers.
Create where appropriate default values for the Congestion control base
values and update the derived CC values accordingly.
Move derived value #define to coap_session_internal.h.
Update coap_session_t to hold the new CC values.
Update documentation for the new CC functions that update / get the
appropriate values.
NOTE: PROBING_WAIT is not currently checked in the code.
Always delete PDUs on error before return from coap_send() (aligning with
previous documentation).
Check that the socket is still available before continuing with the PDU
transmission in coap_send().
Update documentation to be clearer on non-usage of PDU on return from
coap_send().
Trap coap_send() errors in coap-client.
Move event handlers setup code to earlier in coap-client to trap events
early on in the CoAP setup process.
Jon Shallow