The Ethereal builds were crashing on tests - the CMIP dissector was
passing a null OID to call_ber_oid_callback() when run with the
snoop.cap dissector from
http://www.ethereal.com/lists/ethereal-users/200506/msg00263.html
I checked in a change to keep it from crashing in that case, but the
packets are either malformed or being misdissected:
BER Error: Wrong field in sequence expected class:0
(Universal) tag:6(OBJECT IDENTIFIER) but found class:2(Context Specific)
tag:6
BER: No OID supplied to call_ber_oid_callback
[16] (len:54 bytes)
ENUMERATED: 1
[17] (len:44 bytes)
[16] (len:19 bytes)
BER: Error can not handle universal tag:0
[2] (len:3 bytes)
ENUMERATED: 12
[16] (len:21 bytes)
BER: Error can not handle universal tag:0
[2] (len:3 bytes)
BOOLEAN: 0x00
INTEGER: 104756
in packet 1813, for example.
Should it do a DISSECTOR_ASSERT() check on the OID passed in, so that
it's reported as a dissector bug? One might argue that the caller of
call_ber_oid_callback() might know better what to do when an expected
OID is missing, although if it's missing because the packet is
malformed, that's not the result of a dissector problem (if the packet
is genuinely malformed).
Also, as we're using a lot of global variables in ASN.1 dissectors,
perhaps they should all be reset when the dissection starts?
(Perhaps at some point the .cnf file should have directives to specify
all the global state variables required to allow one field to be
processed when dissecting another field - and perhaps, instead of
storing that state in global variables, a data structure containing the
state variables should be allocated on the stack in the main dissector,
and a pointer to it passed to the subdissectors.)
