include/linux/virtio_net.h

   1 #ifndef _LINUX_VIRTIO_NET_H
   2 #define _LINUX_VIRTIO_NET_H
   3 #include <linux/virtio_config.h>
   4
   5 /* The ID for virtio_net */
   6 #define VIRTIO_ID_NET   1
   7
   8 /* The feature bitmap for virtio net */
   9 #define VIRTIO_NET_F_CSUM       0       /* Can handle pkts w/ partial csum */
  10 #define VIRTIO_NET_F_MAC        5       /* Host has given MAC address. */
  11 #define VIRTIO_NET_F_GSO        6       /* Can handle pkts w/ any GSO type */
  12
  13 struct virtio_net_config
  14 {
  15         /* The config defining mac address (if VIRTIO_NET_F_MAC) */
  16         __u8 mac[6];
  17 } __attribute__((packed));
  18
  19 /* This is the first element of the scatter-gather list.  If you don't
  20  * specify GSO or CSUM features, you can simply ignore the header. */
  21 struct virtio_net_hdr
  22 {
  23 #define VIRTIO_NET_HDR_F_NEEDS_CSUM     1       // Use csum_start, csum_offset
  24         __u8 flags;
  25 #define VIRTIO_NET_HDR_GSO_NONE         0       // Not a GSO frame
  26 #define VIRTIO_NET_HDR_GSO_TCPV4        1       // GSO frame, IPv4 TCP (TSO)
  27 #define VIRTIO_NET_HDR_GSO_UDP          3       // GSO frame, IPv4 UDP (UFO)
  28 #define VIRTIO_NET_HDR_GSO_TCPV6        4       // GSO frame, IPv6 TCP
  29 #define VIRTIO_NET_HDR_GSO_ECN          0x80    // TCP has ECN set
  30         __u8 gso_type;
  31         __u16 hdr_len;          /* Ethernet + IP + tcp/udp hdrs */
  32         __u16 gso_size;         /* Bytes to append to gso_hdr_len per frame */
  33         __u16 csum_start;       /* Position to start checksumming from */
  34         __u16 csum_offset;      /* Offset after that to place checksum */
  35 };
  36 #endif /* _LINUX_VIRTIO_NET_H */