[Bug 267178] security/softether

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=267178

            Bug ID: 267178
           Summary: security/softether
           Product: Ports & Packages
           Version: Latest
          Hardware: amd64
                OS: Any
            Status: New
          Severity: Affects Some People
          Priority: ---
         Component: Individual Port(s)
          Assignee: meta@FreeBSD.org
          Reporter: karl@denninger.net
          Assignee: meta@FreeBSD.org
             Flags: maintainer-feedback?(meta@FreeBSD.org)

Created attachment 237439
  --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=237439&action=edit
Shut off MTU increases if compiled on FreeBSD

This may impact everyone -- not sure, so labeling it "affects some people."

The vpnserver code attempts to use jumbo frames and, when it tries to send
larger frames than the current MTU, attempts to set the interface MTU high
enough to accommodate it.  This occurs unless the interface was opened "Raw",
which is only supported in the code on Linux; for all other BSD variants the
assumption is made that the MTU can be raised high enough to allow a
transmission to fit.  That would seem to be wishful thinking and the code does
indeed try to send data that won't fit in the default ethernet MTU.

The result is a cascade of up/down events on the interface which never ends as
the server will try to send something larger than even a typical jumbo frame
capability (e.g. 8k) and when it does, it will continually bang on the MTU
trying to raise it, logging each such event as well.

The following couple-of-line patch shuts this off if the code is built on
FreeBSD and stops that behavior.  As near as I can tell this has no bad side
effects but my work with the package is, thus far, quite rudimentary so further
testing is likely called for before accepting this as a build-time patch to be
applied.

I've also reported this on the forum for the package itself here:
https://www.vpnusers.com/viewtopic.php?f=7&t=67841

-- 
You are receiving this mail because:
You are the assignee for the bug.