cvs commit: src/sys/contrib/pf/net pf.c pfvar.h

[Andrew Thompson]

On Sun, Dec 18, 2005 at 10:08:22PM +1300, Andrew Thompson wrote:
> On Wed, Jul 20, 2005 at 06:58:27PM +0000, Max Laier wrote:
> > mlaier      2005-07-20 18:58:27 UTC
> > 
> >   FreeBSD src repository
> > 
> >   Modified files:
> >     sys/contrib/pf/net   pf.c pfvar.h 
> >   Log:
> >   Prevent a race condition.  As pf_send_tcp() - called for expired synproxy
> >   states - has to drop the lock when calling back to ip_output(), the state
> >   purge timeout might run and gc the state. This results in a rb-tree
> >   inconsistency.  With this change we flag expiring states while holding the
> >   lock and back off if the flag is already set.
>    
> This commit seems to have broken net/pfflowd in ports. It still recieves
> packets from pfsync0 but nothing with action == PFSYNC_ACT_DEL.

More specifically the pfsync_delete_state() macro is broken.

 pf_purge_expired_state(struct pf_state *cur)
   {
     if (cur->sync_flags & PFSTATE_EXPIRING)
             return;
     cur->sync_flags |= PFSTATE_EXPIRING;
     <...>
     pfsync_delete_state(cur);


But this will not do anything since sync_flags is not non-zero, as it is
checked in the macro.

 #define pfsync_delete_state(st) do {                         \
        if (!st->sync_flags)                                  \
                pfsync_pack_state(PFSYNC_ACT_DEL, (st),       \
                    PFSYNC_FLAG_COMPRESS);                    \
        st->sync_flags &= ~PFSTATE_FROMSYNC;                  \
 } while (0)


--
Andrew