fix the handling of negative name query responses and the handling of

packets with no answer section in general.

The fix has 2 parts:

1) set ans_name to the name we queried if nmb->answers == NULL

2) check for nmb->answers == NULL in several other places where we
currently check for nmb->answers->data

While doing this, I noticed there are lots of places in our nmbd code
where we make assumptions about the packets being well formed. Someone
could easily implement a denial of service attack on nmbd by sending a
packet that causes a null pointer dereference. Does anyone feel like
going through the code and adding checks? Probably the best solution
is to have a single function that "validates" a packet, making sure
that all the required fields are there. This will be a bit tricky as
what fields are required varies a lot between packets. A first pass
would be a function that prints "SUSPECT PACKET" when it hits a packet
that it suspects does not have a required field (or the field is badly
formatted), then we could use this on a live system to find any cases
we've missed.

Any takers?
(This used to be commit e02c21b0b8e3ed6f2d294458160c4f632af67ed3)

0 files changed, 0 insertions, 0 deletions