xref: /linux-6.15/include/linux/virtio_net.h (revision e73173db)
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/types.h>
6 #include <linux/virtio_config.h>
7 
8 /* The ID for virtio_net */
9 #define VIRTIO_ID_NET	1
10 
11 /* The feature bitmap for virtio net */
12 #define VIRTIO_NET_F_CSUM	0	/* Host handles pkts w/ partial csum */
13 #define VIRTIO_NET_F_GUEST_CSUM	1	/* Guest handles pkts w/ partial csum */
14 #define VIRTIO_NET_F_MAC	5	/* Host has given MAC address. */
15 #define VIRTIO_NET_F_GSO	6	/* Host handles pkts w/ any GSO type */
16 #define VIRTIO_NET_F_GUEST_TSO4	7	/* Guest can handle TSOv4 in. */
17 #define VIRTIO_NET_F_GUEST_TSO6	8	/* Guest can handle TSOv6 in. */
18 #define VIRTIO_NET_F_GUEST_ECN	9	/* Guest can handle TSO[6] w/ ECN in. */
19 #define VIRTIO_NET_F_GUEST_UFO	10	/* Guest can handle UFO in. */
20 #define VIRTIO_NET_F_HOST_TSO4	11	/* Host can handle TSOv4 in. */
21 #define VIRTIO_NET_F_HOST_TSO6	12	/* Host can handle TSOv6 in. */
22 #define VIRTIO_NET_F_HOST_ECN	13	/* Host can handle TSO[6] w/ ECN in. */
23 #define VIRTIO_NET_F_HOST_UFO	14	/* Host can handle UFO in. */
24 #define VIRTIO_NET_F_MRG_RXBUF	15	/* Host can merge receive buffers. */
25 #define VIRTIO_NET_F_STATUS	16	/* virtio_net_config.status available */
26 #define VIRTIO_NET_F_CTRL_VQ	17	/* Control channel available */
27 #define VIRTIO_NET_F_CTRL_RX	18	/* Control channel RX mode support */
28 #define VIRTIO_NET_F_CTRL_VLAN	19	/* Control channel VLAN filtering */
29 
30 #define VIRTIO_NET_S_LINK_UP	1	/* Link is up */
31 
32 struct virtio_net_config
33 {
34 	/* The config defining mac address (if VIRTIO_NET_F_MAC) */
35 	__u8 mac[6];
36 	/* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */
37 	__u16 status;
38 } __attribute__((packed));
39 
40 /* This is the first element of the scatter-gather list.  If you don't
41  * specify GSO or CSUM features, you can simply ignore the header. */
42 struct virtio_net_hdr
43 {
44 #define VIRTIO_NET_HDR_F_NEEDS_CSUM	1	// Use csum_start, csum_offset
45 	__u8 flags;
46 #define VIRTIO_NET_HDR_GSO_NONE		0	// Not a GSO frame
47 #define VIRTIO_NET_HDR_GSO_TCPV4	1	// GSO frame, IPv4 TCP (TSO)
48 #define VIRTIO_NET_HDR_GSO_UDP		3	// GSO frame, IPv4 UDP (UFO)
49 #define VIRTIO_NET_HDR_GSO_TCPV6	4	// GSO frame, IPv6 TCP
50 #define VIRTIO_NET_HDR_GSO_ECN		0x80	// TCP has ECN set
51 	__u8 gso_type;
52 	__u16 hdr_len;		/* Ethernet + IP + tcp/udp hdrs */
53 	__u16 gso_size;		/* Bytes to append to hdr_len per frame */
54 	__u16 csum_start;	/* Position to start checksumming from */
55 	__u16 csum_offset;	/* Offset after that to place checksum */
56 };
57 
58 /* This is the version of the header to use when the MRG_RXBUF
59  * feature has been negotiated. */
60 struct virtio_net_hdr_mrg_rxbuf {
61 	struct virtio_net_hdr hdr;
62 	__u16 num_buffers;	/* Number of merged rx buffers */
63 };
64 
65 /*
66  * Control virtqueue data structures
67  *
68  * The control virtqueue expects a header in the first sg entry
69  * and an ack/status response in the last entry.  Data for the
70  * command goes in between.
71  */
72 struct virtio_net_ctrl_hdr {
73 	__u8 class;
74 	__u8 cmd;
75 } __attribute__((packed));
76 
77 typedef __u8 virtio_net_ctrl_ack;
78 
79 #define VIRTIO_NET_OK     0
80 #define VIRTIO_NET_ERR    1
81 
82 /*
83  * Control the RX mode, ie. promisucous and allmulti.  PROMISC and
84  * ALLMULTI commands require an "out" sg entry containing a 1 byte
85  * state value, zero = disable, non-zero = enable.  These commands
86  * are supported with the VIRTIO_NET_F_CTRL_RX feature.
87  */
88 #define VIRTIO_NET_CTRL_RX    0
89  #define VIRTIO_NET_CTRL_RX_PROMISC      0
90  #define VIRTIO_NET_CTRL_RX_ALLMULTI     1
91 
92 /*
93  * Control the MAC filter table.
94  *
95  * The MAC filter table is managed by the hypervisor, the guest should
96  * assume the size is infinite.  Filtering should be considered
97  * non-perfect, ie. based on hypervisor resources, the guest may
98  * received packets from sources not specified in the filter list.
99  *
100  * In addition to the class/cmd header, the TABLE_SET command requires
101  * two out scatterlists.  Each contains a 4 byte count of entries followed
102  * by a concatenated byte stream of the ETH_ALEN MAC addresses.  The
103  * first sg list contains unicast addresses, the second is for multicast.
104  * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
105  * is available.
106  */
107 struct virtio_net_ctrl_mac {
108 	__u32 entries;
109 	__u8 macs[][ETH_ALEN];
110 } __attribute__((packed));
111 
112 #define VIRTIO_NET_CTRL_MAC    1
113  #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
114 
115 /*
116  * Control VLAN filtering
117  *
118  * The VLAN filter table is controlled via a simple ADD/DEL interface.
119  * VLAN IDs not added may be filterd by the hypervisor.  Del is the
120  * opposite of add.  Both commands expect an out entry containing a 2
121  * byte VLAN ID.  VLAN filterting is available with the
122  * VIRTIO_NET_F_CTRL_VLAN feature bit.
123  */
124 #define VIRTIO_NET_CTRL_VLAN       2
125  #define VIRTIO_NET_CTRL_VLAN_ADD             0
126  #define VIRTIO_NET_CTRL_VLAN_DEL             1
127 
128 #endif /* _LINUX_VIRTIO_NET_H */
129