Server sessions are keyed on (remote address, local port) only, and
session->addr_info.local is overwritten by the destination of every
received packet. When a unicast CON request is parked in a coap_async_t
for a separate response and a multicast packet from the same peer
arrives before the async fires, the re-invoked handle_request() sees a
multicast local address, drops the CON per RFC7252 8.1 ("Invalid
multicast packet received"), and coap_check_async() frees the async:
the response is silently never sent.
Snapshot the local address in coap_register_async() and restore it on
the session before the async fires, so the deferred request is handled
(and its response source selected) against the address it actually
arrived on.
Seen in the field with a CoAP remote control whose GET /endpoint was
answered via the async path while it also multicast periodic
announcements from the same source port: the device received the empty
ACK and then never got the response.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Clean up duplicate MID handling, and just send back last response if MID
matches.
Removed COAP_BLOCK_CACHE_RESPONSE as no longer required for duplicate MID
handling, and so no need to send an Empty ACK response for a subsequent
Separate response as a referenced copy of the last PDU respponse is now kept
for a session.
Note that if a request is sent by a proxy to an upstream server, this always
converts the upstream server's response into a Separate response back to the
client as the upstream server may take time to respond, do any error recovery
etc.
If both MEMP_USE_CUSTOM_POOLS and MEM_USE_POOLS are defined in
lwipopts.h and there is a suitable
LWIP_MALLOC_MEMPOOL_START .. LWIP_MALLOC_MEMPOOL_END
definition in lwippools.h, then any coap_malloc_type(COAP_STRING, ..) will
make use of the defined pools.
A new src/coap_mem_lwip.c file has been added.
Add reference counting to recipient contexts so they can be safely removed
while still in use by active sessions. Expose callback hooks for credential
lookup, echo, and sequence storage to allow custom backends.
Expand example server to demonstrate the external storage via a simple
file based database. Expand coap_oscore_rcp_conf_t to enable settings
preconfigured echo value, sequence counter and window value as uint64
Enable temporary credentials returned by the find function and are destroyed
after use.
Check incoming Uri-Path and Location-Path options for just . or .. (or %2e
hex encoded variants) and treat as being invalid.
Stop insertion of Uri-Path and Location-Path options that contain just
. or .. (or %2e hex encoded variants).
Don't report
WARN coap_socket_accept_tcp: accept: Resource temporarily unavailable
when multiple threads are trying to process the same incoming TCP connection.
If an app request call-back modifies any data associated with a resource,
then multiple threads can attempt to unsafely modify the data at the same time.
Lock the resource when calling the app request handler (as global_lock is
unlocked) to prevent concurrent changes to the resource information.
If the app request handler is definately known to not modify the resource
information, then COAP_RESOURCE_SAFE_REQUEST_HANDLER can be set in the flags
for coap_resource_init(). Usually if there is a PUT, POST, PATCH or IPATCH
handler it is unsafe to set this. Setting this will reduce lock contention.
This is similar to coap_debug_set_packet_loss() which drops packets that are
to be sent, but emulates network reported errors by reporting ECONNREFUSED.
Analyzer run time does not like A -= B or A +=B even if A and B are uint32_t as there is potential
for overflow.
Analyzer run time does not like overflow when doing coap_tick_t - coap_tick_t.
Analyzer run time does not like (uint8_t << 24) as uint8_t is promoted as int, not u_int.
Analyzer run time does not like while(A--) {} even if A is uint32_t, as A is always decremented on
the test, even if the value of A is 0.
Fix potential overflow when analyzing an asn.1 tag.
Fix potential overflow when doing decode_segment() on a % hex value.
Include common system header files in coap_internal.h based on HAVE_*H
definitions.
Remove these system header files from include/*/*.h.
Add in system header files where appropriate in various apps.
Function coap_context_set_max_body_size() added.
For servers, if body size is too large, a 4.13 response is generated.
For clients, if the body size is too large, the server gets a RST and
no date is passed to the application. A new event COAP_EVENT_BLOCK_ISSUE
is generated.
Jon Shallow