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From 5142239a22219921a7863cf00c9ab853c00689d8 Mon Sep 17 00:00:00 2001
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: Fri, 11 Mar 2022 10:14:18 +0100
Subject: [PATCH] net: veth: Account total xdp_frame len running ndo_xdp_xmit
Even if this is a theoretical issue since it is not possible to perform
XDP_REDIRECT on a non-linear xdp_frame, veth driver does not account
paged area in ndo_xdp_xmit function pointer.
Introduce xdp_get_frame_len utility routine to get the xdp_frame full
length and account total frame size running XDP_REDIRECT of a
non-linear xdp frame into a veth device.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/54f9fd3bb65d190daf2c0bbae2f852ff16cfbaa0.1646989407.git.lorenzo@kernel.org
---
drivers/net/veth.c | 4 ++--
include/net/xdp.h | 14 ++++++++++++++
2 files changed, 16 insertions(+), 2 deletions(-)
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -503,7 +503,7 @@ static int veth_xdp_xmit(struct net_devi
struct xdp_frame *frame = frames[i];
void *ptr = veth_xdp_to_ptr(frame);
- if (unlikely(frame->len > max_len ||
+ if (unlikely(xdp_get_frame_len(frame) > max_len ||
__ptr_ring_produce(&rq->xdp_ring, ptr)))
break;
nxmit++;
@@ -864,7 +864,7 @@ static int veth_xdp_rcv(struct veth_rq *
/* ndo_xdp_xmit */
struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
- stats->xdp_bytes += frame->len;
+ stats->xdp_bytes += xdp_get_frame_len(frame);
frame = veth_xdp_rcv_one(rq, frame, bq, stats);
if (frame) {
/* XDP_PASS */
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -295,6 +295,20 @@ out:
__xdp_release_frame(xdpf->data, mem);
}
+static __always_inline unsigned int xdp_get_frame_len(struct xdp_frame *xdpf)
+{
+ struct skb_shared_info *sinfo;
+ unsigned int len = xdpf->len;
+
+ if (likely(!xdp_frame_has_frags(xdpf)))
+ goto out;
+
+ sinfo = xdp_get_shared_info_from_frame(xdpf);
+ len += sinfo->xdp_frags_size;
+out:
+ return len;
+}
+
int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
struct net_device *dev, u32 queue_index, unsigned int napi_id);
void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq);
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