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

   1 From 5142239a22219921a7863cf00c9ab853c00689d8 Mon Sep 17 00:00:00 2001
   2 From: Lorenzo Bianconi <lorenzo@kernel.org>
   3 Date: Fri, 11 Mar 2022 10:14:18 +0100
   4 Subject: [PATCH] net: veth: Account total xdp_frame len running ndo_xdp_xmit
   5
   6 Even if this is a theoretical issue since it is not possible to perform
   7 XDP_REDIRECT on a non-linear xdp_frame, veth driver does not account
   8 paged area in ndo_xdp_xmit function pointer.
   9 Introduce xdp_get_frame_len utility routine to get the xdp_frame full
  10 length and account total frame size running XDP_REDIRECT of a
  11 non-linear xdp frame into a veth device.
  12
  13 Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
  14 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
  15 Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
  16 Acked-by: John Fastabend <john.fastabend@gmail.com>
  17 Link: https://lore.kernel.org/bpf/54f9fd3bb65d190daf2c0bbae2f852ff16cfbaa0.1646989407.git.lorenzo@kernel.org
  18 ---
  19  drivers/net/veth.c |  4 ++--
  20  include/net/xdp.h  | 14 ++++++++++++++
  21  2 files changed, 16 insertions(+), 2 deletions(-)
  22
  23 --- a/drivers/net/veth.c
  24 +++ b/drivers/net/veth.c
  25 @@ -501,7 +501,7 @@ static int veth_xdp_xmit(struct net_devi
  26                 struct xdp_frame *frame = frames[i];
  27                 void *ptr = veth_xdp_to_ptr(frame);
  28
  29 -               if (unlikely(frame->len > max_len ||
  30 +               if (unlikely(xdp_get_frame_len(frame) > max_len ||
  31                              __ptr_ring_produce(&rq->xdp_ring, ptr)))
  32                         break;
  33                 nxmit++;
  34 @@ -862,7 +862,7 @@ static int veth_xdp_rcv(struct veth_rq *
  35                         /* ndo_xdp_xmit */
  36                         struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
  37
  38 -                       stats->xdp_bytes += frame->len;
  39 +                       stats->xdp_bytes += xdp_get_frame_len(frame);
  40                         frame = veth_xdp_rcv_one(rq, frame, bq, stats);
  41                         if (frame) {
  42                                 /* XDP_PASS */
  43 --- a/include/net/xdp.h
  44 +++ b/include/net/xdp.h
  45 @@ -295,6 +295,20 @@ out:
  46         __xdp_release_frame(xdpf->data, mem);
  47  }
  48
  49 +static __always_inline unsigned int xdp_get_frame_len(struct xdp_frame *xdpf)
  50 +{
  51 +       struct skb_shared_info *sinfo;
  52 +       unsigned int len = xdpf->len;
  53 +
  54 +       if (likely(!xdp_frame_has_frags(xdpf)))
  55 +               goto out;
  56 +
  57 +       sinfo = xdp_get_shared_info_from_frame(xdpf);
  58 +       len += sinfo->xdp_frags_size;
  59 +out:
  60 +       return len;
  61 +}
  62 +
  63  int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
  64                      struct net_device *dev, u32 queue_index, unsigned int napi_id);
  65  void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq);