/*
 * Virtio Network Device
 *
 * Copyright IBM, Corp. 2007
 *
 * Authors:
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#ifndef _QEMU_VIRTIO_NET_H
#define _QEMU_VIRTIO_NET_H

#include "virtio.h"
#include "net.h"
#include "pci.h"

#define ETH_ALEN    6

/* from Linux's virtio_net.h */

/* The ID for virtio_net */
#define VIRTIO_ID_NET   1

/* 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_S_LINK_UP    1       /* Link is up */

#define TX_TIMER_INTERVAL 150000 /* 150 us */

/* Maximum packet size we can receive from tap device: header + 64k */
#define VIRTIO_NET_MAX_BUFSIZE (sizeof(struct virtio_net_hdr) + (64 << 10))

struct virtio_net_config
{
    /* The config defining mac address (6 bytes) */
    uint8_t mac[6];
    /* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */
    uint16_t 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
    uint8_t 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
    uint8_t gso_type;
    uint16_t hdr_len;
    uint16_t gso_size;
    uint16_t csum_start;
    uint16_t csum_offset;
};

/* 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;
    uint16_t num_buffers;   /* Number of merged rx buffers */
};

void virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn);

/*
 * 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 {
    uint8_t class;
    uint8_t cmd;
};

typedef uint8_t virtio_net_ctrl_ack;

#define VIRTIO_NET_OK     0
#define VIRTIO_NET_ERR    1

#endif