Apart from advancing the buffer by RR_TYPE_LENGTH, RR_CLASS_LENGTH,
and RR_TTL_LENGTH the code also attempts to read a two byte unsigned
integer using _get_short(bufpos):
unsigned addrlen = ntohs(_get_short(bufpos));
The bounds check must therefore ensure that the given buffer is large
enough to contain two more bytes after advancing the buffer.
Add a an assertion on the added listener not having a trailing chain
instead of silently overwriting it, point out the precondition in the
documentation, and guide users who want to add more than one listener
towards a more efficient way.
This introduces an additional state to the COAP_MEMO_* series to avoid
enlarging the memo struct needlessly. While they are documented
publicly, practically only the COAP_MEMO_TIMEOUT and COAP_MEMO_RESPONSE
are used in communication with the application, as a
gcoap_request_memo_t is only handed out in that state.
This generalizes the existing code for answering CoAP pings into general
message-layer responses. Such responses are now also sent as a reaction
to CON responses, which can otherwise follow the same code path as
existing other responses.
As a side effect, issues that would crop up when responding to odd empty
requests that have token length set are resolved.
Contributes-To: https://github.com/RIOT-OS/RIOT/issues/14169
This simplifies (written and compiled) code by doing a head rather than
a tail insertion of the new listener into gcoap's list.
As handling of listeners without a link_encoder is now fixed,
gcoap_get_resource_list can handles this now without having to manually
skip over the .well-known/core handler (which is not the first entry any
more now).
Incidentally, this allows the user to install a custom handler for
.well-known/core, as the default handler is now evaluated last.
The NULL case can not regularly be reached (because regularly
gcoap_register_listener sets thel link_encoder to a default one), but if
it is (eg. because an application unsets its link_encoder to hide a
resource set at runtime), the existing `continue` is a good idea (skip
over this entry) but erroneously created an endless loop by skipping the
advancement step.
Using `gnrc_border_router` with `uhcp` is quite noisy.
uhcpc will regularly refresh the prefix and print a bunch of status messages.
Allow the user to tone it down by setting a higher `LOG_LEVEL`.
For this, convert calls to `printf()` and `puts()` to `LOG_xxx()`.
This requires a dummy header for `uhcpd`.
