[comp.unix.aux] A/UX yellow pages bug

pst@anise.acc.com (Paul Traina) (08/28/89)

Just a general FYI:

In A/UX 1.1 I've notices a bug with getnetbyaddr() when running YP.
This might be causing hangs or problems when working with software
that wishes to do reverse-network lookups (like nntp or YP itself).

Description:

my /etc/networks looks like this:
...
acc-net		129.192		# main-class-b-net
acc-ucsb-link	129.192.32	# point-to-point internet link
acc-ether	129.192.64	# santa barbara ethernet
acc-pdn		129.192.128	# X.25 net and bridges
acc-col-ether	129.192.224	# columbia ethernet
...

Now a netstat -i with out YP running shows:

Name  Mtu   Network     Address            Ipkts Ierrs    Opkts Oerrs  Coll
ae0   1500  acc-ether   ANISE.ACC.COM     455873   105   384083     0     0
lo0   1536  loopnet     localhost          34658     0    34658     0     0

With YP running, the output looks like:
Name  Mtu   Network     Address            Ipkts Ierrs    Opkts Oerrs  Coll
ae0   1500  acc-net     ANISE.ACC.COM     455873   105   384083     0     0
lo0   1536  loopnet     localhost          34658     0    34658     0     0

As you can see, getnetbyaddr() is matching the text from "129.192" instead
of "129.192.64".  I've twisted the /etc/networks file 10 ways, and played
with it quite a bit.  It's definitely a bug.  It may catch you when trying
to run software that validates hosts by domains (i.e. nntp daemons).
-- 
A program should follow the 'Law of Least Astonishment.'  What is this law?
It is simply that the program should always respond to the user in the way
that astonishes him or her the least.
		-- from 'The Tao of Programming'