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Commit fd2a0437 authored by Mike Rapoport's avatar Mike Rapoport Committed by David S. Miller
Browse files

virtio_net: introduce virtio_net_hdr_{from,to}_skb 



The code for conversion between virtio_net_hdr and skb GSO info is
duplicated at several places. Let's put it to a common place to allow
reuse.

Signed-off-by: default avatarMike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 678ece30

include/linux/virtio_net.h

0 → 100644
+101 −0
Original line number Diff line number Diff line 
#ifndef _LINUX_VIRTIO_NET_H

#define _LINUX_VIRTIO_NET_H



#include <linux/if_vlan.h>

#include <uapi/linux/virtio_net.h>



static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,

					const struct virtio_net_hdr *hdr,

					bool little_endian)

{

	unsigned short gso_type = 0;



	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {

		switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {

		case VIRTIO_NET_HDR_GSO_TCPV4:

			gso_type = SKB_GSO_TCPV4;

			break;

		case VIRTIO_NET_HDR_GSO_TCPV6:

			gso_type = SKB_GSO_TCPV6;

			break;

		case VIRTIO_NET_HDR_GSO_UDP:

			gso_type = SKB_GSO_UDP;

			break;

		default:

			return -EINVAL;

		}



		if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)

			gso_type |= SKB_GSO_TCP_ECN;



		if (hdr->gso_size == 0)

			return -EINVAL;

	}



	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {

		u16 start = __virtio16_to_cpu(little_endian, hdr->csum_start);

		u16 off = __virtio16_to_cpu(little_endian, hdr->csum_offset);



		if (!skb_partial_csum_set(skb, start, off))

			return -EINVAL;

	}



	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {

		u16 gso_size = __virtio16_to_cpu(little_endian, hdr->gso_size);



		skb_shinfo(skb)->gso_size = gso_size;

		skb_shinfo(skb)->gso_type = gso_type;



		/* Header must be checked, and gso_segs computed. */

		skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;

		skb_shinfo(skb)->gso_segs = 0;

	}



	return 0;

}



static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,

					  struct virtio_net_hdr *hdr,

					  bool little_endian)

{

	memset(hdr, 0, sizeof(*hdr));



	if (skb_is_gso(skb)) {

		struct skb_shared_info *sinfo = skb_shinfo(skb);



		/* This is a hint as to how much should be linear. */

		hdr->hdr_len = __cpu_to_virtio16(little_endian,

						 skb_headlen(skb));

		hdr->gso_size = __cpu_to_virtio16(little_endian,

						  sinfo->gso_size);

		if (sinfo->gso_type & SKB_GSO_TCPV4)

			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;

		else if (sinfo->gso_type & SKB_GSO_TCPV6)

			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;

		else if (sinfo->gso_type & SKB_GSO_UDP)

			hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;

		else

			return -EINVAL;

		if (sinfo->gso_type & SKB_GSO_TCP_ECN)

			hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;

	} else

		hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;



	if (skb->ip_summed == CHECKSUM_PARTIAL) {

		hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;

		if (skb_vlan_tag_present(skb))

			hdr->csum_start = __cpu_to_virtio16(little_endian,

				skb_checksum_start_offset(skb) + VLAN_HLEN);

		else

			hdr->csum_start = __cpu_to_virtio16(little_endian,

				skb_checksum_start_offset(skb));

		hdr->csum_offset = __cpu_to_virtio16(little_endian,

				skb->csum_offset);

	} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {

		hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;

	} /* else everything is zero */



	return 0;

}



#endif /* _LINUX_VIRTIO_BYTEORDER */