On Jan 11, 2008, at 12:02 AM, Vikas Jain wrote:
I am developing a dissector for my protocol that uses TCP as the
underlying layer and dissects messages that are destined for TCP
destination port of 50505.
What about messages sent *from* TCP source port 50505?
/* The following statement seems to cause an assertion when I
run the Wireshark executable. I get an assertion on line 697
packet.c file saying assertion failed on sub-dissectors */
dissector_add("tcp.dstport", 50505, foo_handle);
The assertion that fails is the assertion that there *exists* a
dissector table named "tcp.dstport". No such dissector table exists;
there is no mechanism to request that your dissector be called for a
particular destination port.
(It is not, and never will be, the case that there will exist a
dissector table for every single named field in a protocol.)
I presume that if keep tcp.port in my dissector_add invocation, my
dissector is going to be invoked even when tcp.srcport is 50505.
Yes.
I want my dissector to be invoked only when a tcp destination port
is 50505.
Again, why only the destination port?