macvtap: set transport header before passing skb to lower device (9b4d669b) · Commits · 戴 / test

Set the transport header for 1) some drivers (e.g ixgbe) needs l4 header 2) precise packet length estimation (introduced in ) needs l4 header to compute header length. For the packets with partial checksum, the patch just set the transport header to csum_start. Otherwise tries to use skb_flow_dissect() to get l4 offset, if it fails, just pretend no l4 header. Cc: Eric Dumazet <edumazet@google.com> Signed-off-by:

Jason Wang <jasowang@redhat.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/macvtap.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@
		#include <net/rtnetlink.h>
		#include <net/sock.h>
		#include <linux/virtio_net.h>
		#include <net/flow_keys.h>

		/*
		* A macvtap queue is the central object of this driver, it connects
		@@ -645,6 +646,7 @@ static ssize_t macvtap_get_user(struct macvtap_queue q, struct msghdr m,
		int vnet_hdr_len = 0;
		int copylen = 0;
		bool zerocopy = false;
		struct flow_keys keys;

		if (q->flags & IFF_VNET_HDR) {
		vnet_hdr_len = q->vnet_hdr_sz;
		@@ -725,6 +727,13 @@ static ssize_t macvtap_get_user(struct macvtap_queue q, struct msghdr m,
		goto err_kfree;
		}

		if (skb->ip_summed == CHECKSUM_PARTIAL)
		skb_set_transport_header(skb, skb_checksum_start_offset(skb));
		else if (skb_flow_dissect(skb, &keys))
		skb_set_transport_header(skb, keys.thoff);
		else
		skb_set_transport_header(skb, ETH_HLEN);

		rcu_read_lock_bh();
		vlan = rcu_dereference_bh(q->vlan);
		/* copy skb_ubuf_info for callback when skb has no error */

Admin message