coap, thread: special-case application/octet-stream for CoAP for TMF.

Have a "CoAP for TMF" dissector that the user can use Decode As to
assign to a UDP port.

Have a "coap_tmf_media_type" dissector table in which the TMF code can
register itself for the media type "application/octet-stream".

Have the "CoAP for TMF" dissector pass a "this is for TMF" flag to the
common dissection code.  In the common dissection code, if that flag is
set, first try the media type with the "coap_tmf_media_type" dissector
table before trying it in the regular "media_type" table.

This allows a user to specify UDP ports that 1) should be decoded as
CoAP and 2) should have an application/octet-stream payload dissected as
a TMF message, which should address concerns raised for Thread in issue

1 files changed, 1 insertions, 0 deletions

diff --git a/epan/dissectors/packet-thread.c b/epan/dissectors/packet-thread.c
index 808ab838ac..efa08351b1 100644
--- a/epan/dissectors/packet-thread.c
+++ b/epan/dissectors/packet-thread.c
@@ -3391,6 +3391,7 @@ proto_register_thread_coap(void)
     proto_thread_coap = proto_register_protocol("Thread CoAP", "Thread CoAP", "thread_coap");
     thread_coap_handle = register_dissector("thread_coap", dissect_thread_coap, proto_thread_coap);
 
+    dissector_add_string("coap_tmf_media_type", "application/octet-stream", thread_coap_handle);
     thread_coap_namespace = register_dissector_table("thread.coap_namespace", "Thread CoAP namespace", proto_thread_coap, FT_STRING, BASE_NONE);
 }