Messages in this thread | | | Date | Tue, 10 Nov 2009 12:37:03 -0600 | From | "Chris Friesen" <> | Subject | Re: sunrpc port allocation and IANA reserved list |
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On 11/10/2009 11:53 AM, Ben Hutchings wrote: > On Tue, 2009-11-10 at 11:43 -0600, Chris Friesen wrote:
>> Given that a userspace application can be stopped and restarted at any >> time, and a sunrpc registration can happen at any time, what is the >> expected mechanism to prevent the kernel from allocating a port for use >> by sunrpc that reserved or well-known? >> >> Apparently Redhat and Debian have distro-specific ways of dealing with >> this, but is there a standard solution? Should there be? >> >> The current setup seems suboptimal. > > I believe both RH and Debian are using the same implementation: > <http://cyberelk.net/tim/software/portreserve/>.
That helps with the startup case, but still leaves a possible hole if an app using a fixed port number is restarted at runtime. During the window where nobody is bound to the port, the kernel could randomly assign it to someone else.
Chris
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