[Bug 199136] [if_tap] Added down_on_close sysctl variable to tap(4)

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=199136

            Bug ID: 199136
           Summary: [if_tap] Added down_on_close sysctl variable to tap(4)
           Product: Base System
           Version: 10.1-RELEASE
          Hardware: Any
                OS: Any
            Status: New
          Severity: Affects Only Me
          Priority: ---
         Component: kern
          Assignee: freebsd-bugs at FreeBSD.org
          Reporter: yuri at rawbw.com

Created attachment 155148
  --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=155148&action=edit
patch

New variable down_on_close has two values:
* down_on_close=0: (default value) tap(4) will try to preserve the up state
when tap control device is closed, if it was up when in was opened. Both up
state and inet addresses are preserved.
* down_on_close=1: (previous behavior) always brings tap(4) interface down and
deletes all inet addresses.

The problem solved by this patch is that previously tap(4) interface was always
put into down state when control device was closed, and the user had to bring
it back up, and restore inet addresses again. This is particularly a problem
when VirtualBox VM connected to tap is restarted. The first time tapN could
have been configured by /etc/rc.conf, but subsequent runs required manual
reconfiguration of tap(0) interface. With the new default behavior tap(4) keeps
the state of the interface across open/close cycles.

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