target/linux/generic/backport-5.15/608-v5.18-net-veth-Account-total-xdp_frame-len-running-ndo_xdp.patch

   1 commit 5142239a22219921a7863cf00c9ab853c00689d8
   2 Author: Lorenzo Bianconi <lorenzo@kernel.org>
   3 Date:   Fri Mar 11 10:14:18 2022 +0100
   4
   5     net: veth: Account total xdp_frame len running ndo_xdp_xmit
   6
   7     Even if this is a theoretical issue since it is not possible to perform
   8     XDP_REDIRECT on a non-linear xdp_frame, veth driver does not account
   9     paged area in ndo_xdp_xmit function pointer.
  10     Introduce xdp_get_frame_len utility routine to get the xdp_frame full
  11     length and account total frame size running XDP_REDIRECT of a
  12     non-linear xdp frame into a veth device.
  13
  14     Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
  15     Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
  16     Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
  17     Acked-by: John Fastabend <john.fastabend@gmail.com>
  18     Link: https://lore.kernel.org/bpf/54f9fd3bb65d190daf2c0bbae2f852ff16cfbaa0.1646989407.git.lorenzo@kernel.org
  19
  20 --- a/drivers/net/veth.c
  21 +++ b/drivers/net/veth.c
  22 @@ -501,7 +501,7 @@ static int veth_xdp_xmit(struct net_devi
  23                 struct xdp_frame *frame = frames[i];
  24                 void *ptr = veth_xdp_to_ptr(frame);
  25
  26 -               if (unlikely(frame->len > max_len ||
  27 +               if (unlikely(xdp_get_frame_len(frame) > max_len ||
  28                              __ptr_ring_produce(&rq->xdp_ring, ptr)))
  29                         break;
  30                 nxmit++;
  31 @@ -862,7 +862,7 @@ static int veth_xdp_rcv(struct veth_rq *
  32                         /* ndo_xdp_xmit */
  33                         struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
  34
  35 -                       stats->xdp_bytes += frame->len;
  36 +                       stats->xdp_bytes += xdp_get_frame_len(frame);
  37                         frame = veth_xdp_rcv_one(rq, frame, bq, stats);
  38                         if (frame) {
  39                                 /* XDP_PASS */
  40 --- a/include/net/xdp.h
  41 +++ b/include/net/xdp.h
  42 @@ -295,6 +295,20 @@ out:
  43         __xdp_release_frame(xdpf->data, mem);
  44  }
  45
  46 +static __always_inline unsigned int xdp_get_frame_len(struct xdp_frame *xdpf)
  47 +{
  48 +       struct skb_shared_info *sinfo;
  49 +       unsigned int len = xdpf->len;
  50 +
  51 +       if (likely(!xdp_frame_has_frags(xdpf)))
  52 +               goto out;
  53 +
  54 +       sinfo = xdp_get_shared_info_from_frame(xdpf);
  55 +       len += sinfo->xdp_frags_size;
  56 +out:
  57 +       return len;
  58 +}
  59 +
  60  int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
  61                      struct net_device *dev, u32 queue_index, unsigned int napi_id);
  62  void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq);