virtio_net.h

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#ifndef _LINUX_VIRTIO_NET_H
#define _LINUX_VIRTIO_NET_H
/* This header is BSD licensed so anyone can use the definitions to implement
 * compatible drivers/servers.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of IBM nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE. */
#include <linux/types.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>
#include <linux/if_ether.h>

/* The feature bitmap for virtio net */
#define VIRTIO_NET_F_CSUM   0   /* Host handles pkts w/ partial csum */
#define VIRTIO_NET_F_GUEST_CSUM 1   /* Guest handles pkts w/ partial csum */
#define VIRTIO_NET_F_MAC    5   /* Host has given MAC address. */
#define VIRTIO_NET_F_GSO    6   /* Host handles pkts w/ any GSO type */
#define VIRTIO_NET_F_GUEST_TSO4 7   /* Guest can handle TSOv4 in. */
#define VIRTIO_NET_F_GUEST_TSO6 8   /* Guest can handle TSOv6 in. */
#define VIRTIO_NET_F_GUEST_ECN  9   /* Guest can handle TSO[6] w/ ECN in. */
#define VIRTIO_NET_F_GUEST_UFO  10  /* Guest can handle UFO in. */
#define VIRTIO_NET_F_HOST_TSO4  11  /* Host can handle TSOv4 in. */
#define VIRTIO_NET_F_HOST_TSO6  12  /* Host can handle TSOv6 in. */
#define VIRTIO_NET_F_HOST_ECN   13  /* Host can handle TSO[6] w/ ECN in. */
#define VIRTIO_NET_F_HOST_UFO   14  /* Host can handle UFO in. */
#define VIRTIO_NET_F_MRG_RXBUF  15  /* Host can merge receive buffers. */
#define VIRTIO_NET_F_STATUS 16  /* virtio_net_config.status available */
#define VIRTIO_NET_F_CTRL_VQ    17  /* Control channel available */
#define VIRTIO_NET_F_CTRL_RX    18  /* Control channel RX mode support */
#define VIRTIO_NET_F_CTRL_VLAN  19  /* Control channel VLAN filtering */
#define VIRTIO_NET_F_CTRL_RX_EXTRA 20   /* Extra RX mode control support */
#define VIRTIO_NET_F_GUEST_ANNOUNCE 21  /* Guest can announce device on the
                     * network */

#define VIRTIO_NET_S_LINK_UP    1   /* Link is up */
#define VIRTIO_NET_S_ANNOUNCE   2   /* Announcement is needed */

struct virtio_net_config {
    /* The config defining mac address (if VIRTIO_NET_F_MAC) */
    __u8 mac[6];
    /* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */
    __u16 status;
} __attribute__((packed));

/* This is the first element of the scatter-gather list.  If you don't
 * specify GSO or CSUM features, you can simply ignore the header. */
struct virtio_net_hdr {
#define VIRTIO_NET_HDR_F_NEEDS_CSUM 1   // Use csum_start, csum_offset
#define VIRTIO_NET_HDR_F_DATA_VALID 2   // Csum is valid
    __u8 flags;
#define VIRTIO_NET_HDR_GSO_NONE     0   // Not a GSO frame
#define VIRTIO_NET_HDR_GSO_TCPV4    1   // GSO frame, IPv4 TCP (TSO)
#define VIRTIO_NET_HDR_GSO_UDP      3   // GSO frame, IPv4 UDP (UFO)
#define VIRTIO_NET_HDR_GSO_TCPV6    4   // GSO frame, IPv6 TCP
#define VIRTIO_NET_HDR_GSO_ECN      0x80    // TCP has ECN set
    __u8 gso_type;
    __u16 hdr_len;      /* Ethernet + IP + tcp/udp hdrs */
    __u16 gso_size;     /* Bytes to append to hdr_len per frame */
    __u16 csum_start;   /* Position to start checksumming from */
    __u16 csum_offset;  /* Offset after that to place checksum */
};

/* This is the version of the header to use when the MRG_RXBUF
 * feature has been negotiated. */
struct virtio_net_hdr_mrg_rxbuf {
    struct virtio_net_hdr hdr;
    __u16 num_buffers;  /* Number of merged rx buffers */
};

/*
 * Control virtqueue data structures
 *
 * The control virtqueue expects a header in the first sg entry
 * and an ack/status response in the last entry.  Data for the
 * command goes in between.
 */
struct virtio_net_ctrl_hdr {
    __u8 class;
    __u8 cmd;
} __attribute__((packed));

typedef __u8 virtio_net_ctrl_ack;

#define VIRTIO_NET_OK     0
#define VIRTIO_NET_ERR    1

/*
 * Control the RX mode, ie. promisucous, allmulti, etc...
 * All commands require an "out" sg entry containing a 1 byte
 * state value, zero = disable, non-zero = enable.  Commands
 * 0 and 1 are supported with the VIRTIO_NET_F_CTRL_RX feature.
 * Commands 2-5 are added with VIRTIO_NET_F_CTRL_RX_EXTRA.
 */
#define VIRTIO_NET_CTRL_RX    0
 #define VIRTIO_NET_CTRL_RX_PROMISC      0
 #define VIRTIO_NET_CTRL_RX_ALLMULTI     1
 #define VIRTIO_NET_CTRL_RX_ALLUNI       2
 #define VIRTIO_NET_CTRL_RX_NOMULTI      3
 #define VIRTIO_NET_CTRL_RX_NOUNI        4
 #define VIRTIO_NET_CTRL_RX_NOBCAST      5

/*
 * Control the MAC filter table.
 *
 * The MAC filter table is managed by the hypervisor, the guest should
 * assume the size is infinite.  Filtering should be considered
 * non-perfect, ie. based on hypervisor resources, the guest may
 * received packets from sources not specified in the filter list.
 *
 * In addition to the class/cmd header, the TABLE_SET command requires
 * two out scatterlists.  Each contains a 4 byte count of entries followed
 * by a concatenated byte stream of the ETH_ALEN MAC addresses.  The
 * first sg list contains unicast addresses, the second is for multicast.
 * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
 * is available.
 */
struct virtio_net_ctrl_mac {
    __u32 entries;
    __u8 macs[][ETH_ALEN];
} __attribute__((packed));

#define VIRTIO_NET_CTRL_MAC    1
 #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0

/*
 * Control VLAN filtering
 *
 * The VLAN filter table is controlled via a simple ADD/DEL interface.
 * VLAN IDs not added may be filterd by the hypervisor.  Del is the
 * opposite of add.  Both commands expect an out entry containing a 2
 * byte VLAN ID.  VLAN filterting is available with the
 * VIRTIO_NET_F_CTRL_VLAN feature bit.
 */
#define VIRTIO_NET_CTRL_VLAN       2
 #define VIRTIO_NET_CTRL_VLAN_ADD             0
 #define VIRTIO_NET_CTRL_VLAN_DEL             1

/*
 * Control link announce acknowledgement
 *
 * The command VIRTIO_NET_CTRL_ANNOUNCE_ACK is used to indicate that
 * driver has recevied the notification; device would clear the
 * VIRTIO_NET_S_ANNOUNCE bit in the status field after it receives
 * this command.
 */
#define VIRTIO_NET_CTRL_ANNOUNCE       3
 #define VIRTIO_NET_CTRL_ANNOUNCE_ACK         0

#endif /* _LINUX_VIRTIO_NET_H */