xref: /linux-6.15/include/linux/virtio_net.h (revision 17c324fa)
1 #ifndef _LINUX_VIRTIO_NET_H
2 #define _LINUX_VIRTIO_NET_H
3 /* This header is BSD licensed so anyone can use the definitions to implement
4  * compatible drivers/servers. */
5 #include <linux/virtio_config.h>
6 
7 /* The ID for virtio_net */
8 #define VIRTIO_ID_NET	1
9 
10 /* The feature bitmap for virtio net */
11 #define VIRTIO_NET_F_CSUM	0	/* Host handles pkts w/ partial csum */
12 #define VIRTIO_NET_F_GUEST_CSUM	1	/* Guest handles pkts w/ partial csum */
13 #define VIRTIO_NET_F_MAC	5	/* Host has given MAC address. */
14 #define VIRTIO_NET_F_GSO	6	/* Host handles pkts w/ any GSO type */
15 #define VIRTIO_NET_F_GUEST_TSO4	7	/* Guest can handle TSOv4 in. */
16 #define VIRTIO_NET_F_GUEST_TSO6	8	/* Guest can handle TSOv6 in. */
17 #define VIRTIO_NET_F_GUEST_ECN	9	/* Guest can handle TSO[6] w/ ECN in. */
18 #define VIRTIO_NET_F_GUEST_UFO	10	/* Guest can handle UFO in. */
19 #define VIRTIO_NET_F_HOST_TSO4	11	/* Host can handle TSOv4 in. */
20 #define VIRTIO_NET_F_HOST_TSO6	12	/* Host can handle TSOv6 in. */
21 #define VIRTIO_NET_F_HOST_ECN	13	/* Host can handle TSO[6] w/ ECN in. */
22 #define VIRTIO_NET_F_HOST_UFO	14	/* Host can handle UFO in. */
23 #define VIRTIO_NET_F_MRG_RXBUF	15	/* Host can merge receive buffers. */
24 
25 struct virtio_net_config
26 {
27 	/* The config defining mac address (if VIRTIO_NET_F_MAC) */
28 	__u8 mac[6];
29 } __attribute__((packed));
30 
31 /* This is the first element of the scatter-gather list.  If you don't
32  * specify GSO or CSUM features, you can simply ignore the header. */
33 struct virtio_net_hdr
34 {
35 #define VIRTIO_NET_HDR_F_NEEDS_CSUM	1	// Use csum_start, csum_offset
36 	__u8 flags;
37 #define VIRTIO_NET_HDR_GSO_NONE		0	// Not a GSO frame
38 #define VIRTIO_NET_HDR_GSO_TCPV4	1	// GSO frame, IPv4 TCP (TSO)
39 #define VIRTIO_NET_HDR_GSO_UDP		3	// GSO frame, IPv4 UDP (UFO)
40 #define VIRTIO_NET_HDR_GSO_TCPV6	4	// GSO frame, IPv6 TCP
41 #define VIRTIO_NET_HDR_GSO_ECN		0x80	// TCP has ECN set
42 	__u8 gso_type;
43 	__u16 hdr_len;		/* Ethernet + IP + tcp/udp hdrs */
44 	__u16 gso_size;		/* Bytes to append to hdr_len per frame */
45 	__u16 csum_start;	/* Position to start checksumming from */
46 	__u16 csum_offset;	/* Offset after that to place checksum */
47 };
48 
49 /* This is the version of the header to use when the MRG_RXBUF
50  * feature has been negotiated. */
51 struct virtio_net_hdr_mrg_rxbuf {
52 	struct virtio_net_hdr hdr;
53 	__u16 num_buffers;	/* Number of merged rx buffers */
54 };
55 
56 #endif /* _LINUX_VIRTIO_NET_H */
57