Hi,
On Mon, 2018-10-22 at 13:43 +0200, Steffen Klassert wrote:
> On Fri, Oct 19, 2018 at 04:25:16PM +0200, Paolo Abeni wrote:
> > +
> > +static inline struct sk_buff *udp_rcv_segment(struct sock *sk,
> > + struct sk_buff *skb)
> > +{
> > + struct sk_buff *segs;
> > +
> > + /* the GSO CB lays after the UDP one, no need to save and restore any
> > + * CB fragment, just initialize it
> > + */
> > + segs = __skb_gso_segment(skb, NETIF_F_SG, false);
> > + if (unlikely(IS_ERR(segs)))
> > + kfree_skb(skb);
> > + else if (segs)
> > + consume_skb(skb);
> > + return segs;
> > +}
> > +
> > +
>
> One empty line too much.
Thank you, will handle in the next iteration.
> > #define udp_portaddr_for_each_entry(__sk, list) \
> > hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
> >
> > diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
> > index 2331ac9de954..0d55145ce9f5 100644
> > --- a/net/ipv4/udp.c
> > +++ b/net/ipv4/udp.c
> > @@ -1909,7 +1909,7 @@ EXPORT_SYMBOL(udp_encap_enable);
> > * Note that in the success and error cases, the skb is assumed to
> > * have either been requeued or freed.
> > */
> > -static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
> > +static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
> > {
> > struct udp_sock *up = udp_sk(sk);
> > int is_udplite = IS_UDPLITE(sk);
> > @@ -2012,6 +2012,29 @@ static int udp_queue_rcv_skb(struct sock *sk, struct
> > sk_buff *skb)
> > return -1;
> > }
> >
> > +void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int
> > proto);
> > +
> > +static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
> > +{
> > + struct sk_buff *next, *segs;
> > + int ret;
> > +
> > + if (likely(!udp_unexpected_gso(sk, skb)))
> > + return udp_queue_rcv_one_skb(sk, skb);
> > +
> > + BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_SGO_CB_OFFSET);
> > + __skb_push(skb, -skb_mac_offset(skb));
> > + segs = udp_rcv_segment(sk, skb);
> > + for (skb = segs; skb; skb = next) {
> > + next = skb->next;
> > + __skb_pull(skb, skb_transport_offset(skb));
> > + ret = udp_queue_rcv_one_skb(sk, skb);
>
> udp_queue_rcv_one_skb() starts with doing a xfrm4_policy_check().
> Maybe we can do this on the GSO packet instead of the segments.
> So far this code is just for handling a corner case, but this might
> change.
I thought about keeping the policy check here, but then I preferred
what looked the safest option. Perhaps we can improve with a follow-up?
Cheers,
Paolo
