Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/broadcom/bnxt/bnxt.c
  1e7962114c10 ("bnxt_en: Restore PTP tx_avail count in case of skb_pad() error")
  165f87691a89 ("bnxt_en: add timestamping statistics support")

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 29 insertions, 3 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 9f9b86874173b..b1f8b720733e5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1388,6 +1388,10 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev,
 	if (unlikely(hdr->hdr.gso_type))
 		goto err_xdp;
 
+	/* Partially checksummed packets must be dropped. */
+	if (unlikely(hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM))
+		goto err_xdp;
+
 	buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
 		SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 
@@ -1705,6 +1709,10 @@ static void *mergeable_xdp_get_buf(struct virtnet_info *vi,
 	if (unlikely(hdr->hdr.gso_type))
 		return NULL;
 
+	/* Partially checksummed packets must be dropped. */
+	if (unlikely(hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM))
+		return NULL;
+
 	/* Now XDP core assumes frag size is PAGE_SIZE, but buffers
 	 * with headroom may add hole in truesize, which
 	 * make their length exceed PAGE_SIZE. So we disabled the
@@ -1971,6 +1979,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 	struct net_device *dev = vi->dev;
 	struct sk_buff *skb;
 	struct virtio_net_common_hdr *hdr;
+	u8 flags;
 
 	if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
 		pr_debug("%s: short packet %i\n", dev->name, len);
@@ -1979,6 +1988,15 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 		return;
 	}
 
+	/* 1. Save the flags early, as the XDP program might overwrite them.
+	 * These flags ensure packets marked as VIRTIO_NET_HDR_F_DATA_VALID
+	 * stay valid after XDP processing.
+	 * 2. XDP doesn't work with partially checksummed packets (refer to
+	 * virtnet_xdp_set()), so packets marked as
+	 * VIRTIO_NET_HDR_F_NEEDS_CSUM get dropped during XDP processing.
+	 */
+	flags = ((struct virtio_net_common_hdr *)buf)->hdr.flags;
+
 	if (vi->mergeable_rx_bufs)
 		skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
 					stats);
@@ -1994,7 +2012,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 	if (dev->features & NETIF_F_RXHASH && vi->has_rss_hash_report)
 		virtio_skb_set_hash(&hdr->hash_v1_hdr, skb);
 
-	if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
+	if (flags & VIRTIO_NET_HDR_F_DATA_VALID)
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
 
 	if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
@@ -5699,8 +5717,16 @@ static int virtnet_probe(struct virtio_device *vdev)
 			dev->features |= dev->hw_features & NETIF_F_ALL_TSO;
 		/* (!csum && gso) case will be fixed by register_netdev() */
 	}
-	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
-		dev->features |= NETIF_F_RXCSUM;
+
+	/* 1. With VIRTIO_NET_F_GUEST_CSUM negotiation, the driver doesn't
+	 * need to calculate checksums for partially checksummed packets,
+	 * as they're considered valid by the upper layer.
+	 * 2. Without VIRTIO_NET_F_GUEST_CSUM negotiation, the driver only
+	 * receives fully checksummed packets. The device may assist in
+	 * validating these packets' checksums, so the driver won't have to.
+	 */
+	dev->features |= NETIF_F_RXCSUM;
+
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
 	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
 		dev->features |= NETIF_F_GRO_HW;