ip_forward() crash

[Haijin Yan]

Hi,
  I am using freebsd 4.5 and in the ip_input.c at the place
where IP decides to forward a mbuf not destined to itself,
I added one of my function which included a call of ip_forward() to send
out a my m_copyed mbuf to the sender. so basically there are two calls to
ip_forward(), one is to relay mbuf from the sender and the other is
forward back a copy of it. However, this behavior crashed my freebsd with
trap 12 saying page fault in kernel. Does anyone have the same experience
and know what's wrong with this?

 Any suggestion is highly appreciated.
please cc to me because I am not on the list.

Thanks,

-Haijin Yan