| Message ID | 20201223150046.3910206-1-eyal.birger@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [ipsec] xfrm: fix disable_xfrm sysctl when used on xfrm interfaces | expand |
On Wed, Dec 23, 2020 at 05:00:46PM +0200, Eyal Birger wrote: > The disable_xfrm flag signals that xfrm should not be performed during > routing towards a device before reaching device xmit. > > For xfrm interfaces this is usually desired as they perform the outbound > policy lookup as part of their xmit using their if_id. > > Before this change enabling this flag on xfrm interfaces prevented them > from xmitting as xfrm_lookup_with_ifid() would not perform a policy lookup > in case the original dst had the DST_NOXFRM flag. > > This optimization is incorrect when the lookup is done by the xfrm > interface xmit logic. > > Fix by performing policy lookup when invoked by xfrmi as if_id != 0. > > Similarly it's unlikely for the 'no policy exists on net' check to yield > any performance benefits when invoked from xfrmi. > > Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") > Signed-off-by: Eyal Birger <eyal.birger@gmail.com> Applied, thanks a lot Eyal!
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index d622c2548d22..2f84136af48a 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -3078,8 +3078,8 @@ struct dst_entry *xfrm_lookup_with_ifid(struct net *net, xflo.flags = flags; /* To accelerate a bit... */ - if ((dst_orig->flags & DST_NOXFRM) || - !net->xfrm.policy_count[XFRM_POLICY_OUT]) + if (!if_id && ((dst_orig->flags & DST_NOXFRM) || + !net->xfrm.policy_count[XFRM_POLICY_OUT])) goto nopol; xdst = xfrm_bundle_lookup(net, fl, family, dir, &xflo, if_id);
The disable_xfrm flag signals that xfrm should not be performed during routing towards a device before reaching device xmit. For xfrm interfaces this is usually desired as they perform the outbound policy lookup as part of their xmit using their if_id. Before this change enabling this flag on xfrm interfaces prevented them from xmitting as xfrm_lookup_with_ifid() would not perform a policy lookup in case the original dst had the DST_NOXFRM flag. This optimization is incorrect when the lookup is done by the xfrm interface xmit logic. Fix by performing policy lookup when invoked by xfrmi as if_id != 0. Similarly it's unlikely for the 'no policy exists on net' check to yield any performance benefits when invoked from xfrmi. Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Signed-off-by: Eyal Birger <eyal.birger@gmail.com> --- net/xfrm/xfrm_policy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)