[ns] Segmentation Fault + AODV

[Felix Ko <felix.ko@mchp.siemens.de>]

Hi all!

I'm having Problems with wireless simulations using AODV, which causes
segmentation faults, when the scenarios get larger (many nodes/sources
or
high traffic)

I have traced this problem down to the AODV-implementation:
When a route is set down in AODV::rt_down, the ifqueue is searched for
any
packets, which have to be sent over the (now) broken link.

If the node is the source of this packet from the ifqueue, a new RREQ
for
the destination of the packet is sent out (by calling
sendRequest(dest)).

Normally it should be guaranteed, that for ANY destination of a packet
in the ifqueue a corresponding routingtable-entry exists.

The Problem is the following: The sendRequest-method relies on an
existing
routingtable-entry for all destinations, for which it is called (it is
"assured",
but this is disabled by compiling it with NDEBUG by default).
I don't know how, but it sometimes happens, that a destination of a
packet
in the ifqueue HASN'T GOT a routingtable-entry, which causes ns2 to
crash
with a segmentation fault, because "rtable.rt_lookup(dst)" returns NULL
and
any further access to this pointer hangs in midair!

QUESTION: Is anybody else experiencing this problem or knows, where
these
packets come from? I would LOVE to share this problem with ANYBODY!!!

So long,

Felix