[ovs-dev] [PATCH] conntrack: check the result of extract_l3_ipv4/6

Darrell Ball dlu998 at gmail.com
Thu Aug 22 00:59:36 UTC 2019


On Wed, Aug 21, 2019 at 3:13 PM Ben Pfaff <blp at ovn.org> wrote:

> On Mon, Aug 19, 2019 at 08:35:11AM -0700, Darrell Ball wrote:
> > Thanks for the patch
> >
> > On Sun, Aug 18, 2019 at 11:01 PM Li RongQing <lirongqing at baidu.com>
> wrote:
> >
> > > the result of extract_l3_ipv4/6 should be checked in reverse_nat_packet
> > > when it is false, meaning this packet is wrong, should not do handle it
> > > continually
> > >
> > > Signed-off-by: Li RongQing <lirongqing at baidu.com>
> > > ---
> > >  lib/conntrack.c | 17 +++++++++++++++--
> > >  1 file changed, 15 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/lib/conntrack.c b/lib/conntrack.c
> > > index 5f60fea18..c26d5438c 100644
> > > --- a/lib/conntrack.c
> > > +++ b/lib/conntrack.c
> > > @@ -695,11 +695,18 @@ reverse_nat_packet(struct dp_packet *pkt, const
> > > struct conn *conn)
> > >      uint16_t orig_l4_ofs = pkt->l4_ofs;
> > >
> > >      if (conn->key.dl_type == htons(ETH_TYPE_IP)) {
> > > +        bool ok;
> > >          struct ip_header *nh = dp_packet_l3(pkt);
> > >          struct icmp_header *icmp = dp_packet_l4(pkt);
> > >          struct ip_header *inner_l3 = (struct ip_header *) (icmp + 1);
> > > -        extract_l3_ipv4(&inner_key, inner_l3, tail - ((char
> *)inner_l3) -
> > > pad,
> > >
> >
> > There is intentionally no checking for success/fail here bcoz the packet
> > has already
> > been parsed and found to be ok during conn_key_extract() code path.
> Reusing
> > the
> > same api here is just convenient.
>
> Maybe a comment would be warranted to make that clear.
>

that's reasonable; maybe RongQing would like to submit a patch ?


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