The _parse_reply function iterates over the DHCPv6 message options
twice but only performs sanity checks on the option length in the
first iteration. As such, both loop iterations need to be identical.
Unfortunately, there aren't without this commit as (1) they use
different maximum length values and (2) the first iteration stops
parsing as soon as it encounters a zero option while the second
doesn't. As such, it is possible for out-of-bounds read to be
performed by the second loop iteration. This commit fixes this.
The handlers for these MQTT message lock the connection mutex on
function entry. During automated testing of asymcute, I discovered
return paths for these function which do not unlock the connection
mutex. This results in a deadlock which prevents asymcute from
sending any further messages.
The assertion is a bit overeager.
In case of receiving a wrong message ID, we re-try receive without
entering the STATE_REQUEST_SEND state again, so it is expected that
we get a non-NULL ctx/response from sock_udp_recv_buf().
What this assert should actually check is that we don't get a non-NULL
ctx after calling sock_udp_recv_buf() with a non-NULL ctx.
So make this explicit to not falsely fail the assertion.
Most of the caching operation was moved to the client code. Since the
forward proxy is using that code for upstream messaging, interacting
with the cache directly is not necessary anymore.
The only cache-related thing necessary for the proxy is validating ETags
from upstream. However, that can be done by just looking at the ETags
from the upstream response (which may or may not have come from the
cache).
Some user callbacks might just return the result of some other operation
that returns written bytes or negative error.
Let's not break those, only consider negative callback returns an error.
This adds a coap_handler_t function that can be used to parse new
subtrees. The subtree information is included in the context pointer of
the call and must be of type coap_resource_subtree_t. This object then
contains the pointer and length of a different coap_resource_t instance.
