System Calls that do DNS

staticsafe me at
Tue Jun 4 03:39:41 UTC 2013

On Mon, Jun 03, 2013 at 07:57:07PM -0700, Doug Hardie wrote:
> I have an unusual situation.  A program is doing a DNS lookup and often the IP address has no reverse DNS entries.  As a result the program hangs for several timeouts.  The call is not being made directly in its code, but is occurring in a system call.  There are no specific calls to DNS, its something else doing it.  I have been trying to track down which system call is doing it, but without success so far.  I have tried syslog calls around each of the system calls I thought might be the culprit, but my guessing is not very good.  How can I identify the system call that is calling DNS?  If I can find it, I hopefully can find another way to do whatever it does that does not involve a reverse DNS lookup.

Use truss:

The truss utility traces the system calls called by the specified
process or program.
O< ascii ribbon campaign - stop html mail -
Please don't top post -
Don't CC me! I'm subscribed to whatever list I just posted on.

More information about the freebsd-questions mailing list