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/*

 * 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.

 *

 */

#include "virtio.h"

#include "net.h"

#include "qemu-timer.h"

#include "virtio-net.h"

#define VIRTIO_NET_VM_VERSION    4

typedef struct VirtIONet

{

    VirtIODevice vdev;

    uint8_t mac[ETH_ALEN];

    uint16_t status;

    VirtQueue *rx_vq;

    VirtQueue *tx_vq;

    VirtQueue *ctrl_vq;

    VLANClientState *vc;

    QEMUTimer *tx_timer;

    int tx_timer_active;

    int mergeable_rx_bufs;

    int promisc;

    int allmulti;

} VirtIONet;

/* TODO

 * - we could suppress RX interrupt if we were so inclined.

 */

static VirtIONet *to_virtio_net(VirtIODevice *vdev)

{

    return (VirtIONet *)vdev;

}

static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)

{

    VirtIONet *n = to_virtio_net(vdev);

    struct virtio_net_config netcfg;

    netcfg.status = n->status;

    memcpy(netcfg.mac, n->mac, ETH_ALEN);

    memcpy(config, &netcfg, sizeof(netcfg));

}

static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)

{

    VirtIONet *n = to_virtio_net(vdev);

    struct virtio_net_config netcfg;

    memcpy(&netcfg, config, sizeof(netcfg));

    if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {

        memcpy(n->mac, netcfg.mac, ETH_ALEN);

        qemu_format_nic_info_str(n->vc, n->mac);

    }

}

static void virtio_net_set_link_status(VLANClientState *vc)

{

    VirtIONet *n = vc->opaque;

    uint16_t old_status = n->status;

    if (vc->link_down)

        n->status &= ~VIRTIO_NET_S_LINK_UP;

    else

        n->status |= VIRTIO_NET_S_LINK_UP;

    if (n->status != old_status)

        virtio_notify_config(&n->vdev);

}

static void virtio_net_reset(VirtIODevice *vdev)

{

    VirtIONet *n = to_virtio_net(vdev);

    /* Reset back to compatibility mode */

    n->promisc = 1;

    n->allmulti = 0;

}

static uint32_t virtio_net_get_features(VirtIODevice *vdev)

{

    uint32_t features = (1 << VIRTIO_NET_F_MAC) |

                        (1 << VIRTIO_NET_F_STATUS) |

                        (1 << VIRTIO_NET_F_CTRL_VQ);

    return features;

}

static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)

{

    VirtIONet *n = to_virtio_net(vdev);

    n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));

}

static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,

                                     VirtQueueElement *elem)

{

    uint8_t on;

    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {

        fprintf(stderr, "virtio-net ctrl invalid rx mode command\n");

        exit(1);

    }

    on = ldub_p(elem->out_sg[1].iov_base);

    if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)

        n->promisc = on;

    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)

        n->allmulti = on;

    else

        return VIRTIO_NET_ERR;

    return VIRTIO_NET_OK;

}

static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)

{

    VirtIONet *n = to_virtio_net(vdev);

    struct virtio_net_ctrl_hdr ctrl;

    virtio_net_ctrl_ack status = VIRTIO_NET_ERR;

    VirtQueueElement elem;

    while (virtqueue_pop(vq, &elem)) {

        if ((elem.in_num < 1) || (elem.out_num < 1)) {

            fprintf(stderr, "virtio-net ctrl missing headers\n");

            exit(1);

        }

        if (elem.out_sg[0].iov_len < sizeof(ctrl) ||

            elem.out_sg[elem.in_num - 1].iov_len < sizeof(status)) {

            fprintf(stderr, "virtio-net ctrl header not in correct element\n");

            exit(1);

        }

        ctrl.class = ldub_p(elem.out_sg[0].iov_base);

        ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));

        if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)

            status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);

        stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);

        virtqueue_push(vq, &elem, sizeof(status));

        virtio_notify(vdev, vq);

    }

}

/* RX */

static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)

{

}

static int do_virtio_net_can_receive(VirtIONet *n, int bufsize)

{

    if (!virtio_queue_ready(n->rx_vq) ||

        !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))

        return 0;

    if (virtio_queue_empty(n->rx_vq) ||

        (n->mergeable_rx_bufs &&

         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {

        virtio_queue_set_notification(n->rx_vq, 1);

        return 0;

    }

    virtio_queue_set_notification(n->rx_vq, 0);

    return 1;

}

static int virtio_net_can_receive(void *opaque)

{

    VirtIONet *n = opaque;

    return do_virtio_net_can_receive(n, VIRTIO_NET_MAX_BUFSIZE);

}

static int iov_fill(struct iovec *iov, int iovcnt, const void *buf, int count)

{

    int offset, i;

    offset = i = 0;

    while (offset < count && i < iovcnt) {

        int len = MIN(iov[i].iov_len, count - offset);

        memcpy(iov[i].iov_base, buf + offset, len);

        offset += len;

        i++;

    }

    return offset;

}

static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,

                          const void *buf, size_t size, size_t hdr_len)

{

    struct virtio_net_hdr *hdr = iov[0].iov_base;

    int offset = 0;

    hdr->flags = 0;

    hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;

    /* We only ever receive a struct virtio_net_hdr from the tapfd,

     * but we may be passing along a larger header to the guest.

     */

    iov[0].iov_base += hdr_len;

    iov[0].iov_len  -= hdr_len;

    return offset;

}

static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)

{

    static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

    uint8_t *ptr = (uint8_t *)buf;

    if (n->promisc)

        return 1;

#ifdef TAP_VNET_HDR

    if (tap_has_vnet_hdr(n->vc->vlan->first_client))

        ptr += sizeof(struct virtio_net_hdr);

#endif

    if ((ptr[0] & 1) && n->allmulti)

        return 1;

    if (!memcmp(ptr, bcast, sizeof(bcast)))

        return 1;

    if (!memcmp(ptr, n->mac, ETH_ALEN))

        return 1;

    return 0;

}

static void virtio_net_receive(void *opaque, const uint8_t *buf, int size)

{

    VirtIONet *n = opaque;

    struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;

    size_t hdr_len, offset, i;

    if (!do_virtio_net_can_receive(n, size))

        return;

    if (!receive_filter(n, buf, size))

        return;

    /* hdr_len refers to the header we supply to the guest */

    hdr_len = n->mergeable_rx_bufs ?

        sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);

    offset = i = 0;

    while (offset < size) {

        VirtQueueElement elem;

        int len, total;

        struct iovec sg[VIRTQUEUE_MAX_SIZE];

        len = total = 0;

        if ((i != 0 && !n->mergeable_rx_bufs) ||

            virtqueue_pop(n->rx_vq, &elem) == 0) {

            if (i == 0)

                return;

            fprintf(stderr, "virtio-net truncating packet\n");

            exit(1);

        }

        if (elem.in_num < 1) {

            fprintf(stderr, "virtio-net receive queue contains no in buffers\n");

            exit(1);

        }

        if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != hdr_len) {

            fprintf(stderr, "virtio-net header not in first element\n");

            exit(1);

        }

        memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);

        if (i == 0) {

            if (n->mergeable_rx_bufs)

                mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;

            offset += receive_header(n, sg, elem.in_num,

                                     buf + offset, size - offset, hdr_len);

            total += hdr_len;

        }

        /* copy in packet.  ugh */

        len = iov_fill(sg, elem.in_num,

                       buf + offset, size - offset);

        total += len;

        /* signal other side */

        virtqueue_fill(n->rx_vq, &elem, total, i++);

        offset += len;

    }

    if (mhdr)

        mhdr->num_buffers = i;

    virtqueue_flush(n->rx_vq, i);

    virtio_notify(&n->vdev, n->rx_vq);

}

/* TX */

static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)

{

    VirtQueueElement elem;

    int has_vnet_hdr = 0;

    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))

        return;

    while (virtqueue_pop(vq, &elem)) {

        ssize_t len = 0;

        unsigned int out_num = elem.out_num;

        struct iovec *out_sg = &elem.out_sg[0];

        unsigned hdr_len;

        /* hdr_len refers to the header received from the guest */

        hdr_len = n->mergeable_rx_bufs ?

            sizeof(struct virtio_net_hdr_mrg_rxbuf) :

            sizeof(struct virtio_net_hdr);

        if (out_num < 1 || out_sg->iov_len != hdr_len) {

            fprintf(stderr, "virtio-net header not in first element\n");

            exit(1);

        }

        /* ignore the header if GSO is not supported */

        if (!has_vnet_hdr) {

            out_num--;

            out_sg++;

            len += hdr_len;

        } else if (n->mergeable_rx_bufs) {

            /* tapfd expects a struct virtio_net_hdr */

            hdr_len -= sizeof(struct virtio_net_hdr);

            out_sg->iov_len -= hdr_len;

            len += hdr_len;

        }

        len += qemu_sendv_packet(n->vc, out_sg, out_num);

        virtqueue_push(vq, &elem, len);

        virtio_notify(&n->vdev, vq);

    }

}

static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)

{

    VirtIONet *n = to_virtio_net(vdev);

    if (n->tx_timer_active) {

        virtio_queue_set_notification(vq, 1);

        qemu_del_timer(n->tx_timer);

        n->tx_timer_active = 0;

        virtio_net_flush_tx(n, vq);

    } else {

        qemu_mod_timer(n->tx_timer,

                       qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);

        n->tx_timer_active = 1;

        virtio_queue_set_notification(vq, 0);

    }

}

static void virtio_net_tx_timer(void *opaque)

{

    VirtIONet *n = opaque;

    n->tx_timer_active = 0;

    /* Just in case the driver is not ready on more */

    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))

        return;

    virtio_queue_set_notification(n->tx_vq, 1);

    virtio_net_flush_tx(n, n->tx_vq);

}

static void virtio_net_save(QEMUFile *f, void *opaque)

{

    VirtIONet *n = opaque;

    virtio_save(&n->vdev, f);

    qemu_put_buffer(f, n->mac, ETH_ALEN);

    qemu_put_be32(f, n->tx_timer_active);

    qemu_put_be32(f, n->mergeable_rx_bufs);

    qemu_put_be16(f, n->status);

    qemu_put_be32(f, n->promisc);

    qemu_put_be32(f, n->allmulti);

}

static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)

{

    VirtIONet *n = opaque;

    if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)

        return -EINVAL;

    virtio_load(&n->vdev, f);

    qemu_get_buffer(f, n->mac, ETH_ALEN);

    n->tx_timer_active = qemu_get_be32(f);

    n->mergeable_rx_bufs = qemu_get_be32(f);

    if (version_id >= 3)

        n->status = qemu_get_be16(f);

    if (version_id >= 4) {

        n->promisc = qemu_get_be32(f);

        n->allmulti = qemu_get_be32(f);

    }

    if (n->tx_timer_active) {

        qemu_mod_timer(n->tx_timer,

                       qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);

    }

    return 0;

}

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

{

    VirtIONet *n;

    static int virtio_net_id;

    n = (VirtIONet *)virtio_init_pci(bus, "virtio-net",

                                     PCI_VENDOR_ID_REDHAT_QUMRANET,

                                     PCI_DEVICE_ID_VIRTIO_NET,

                                     PCI_VENDOR_ID_REDHAT_QUMRANET,

                                     VIRTIO_ID_NET,

                                     PCI_CLASS_NETWORK_ETHERNET, 0x00,

                                     sizeof(struct virtio_net_config),

                                     sizeof(VirtIONet));

    if (!n)

        return;

    n->vdev.get_config = virtio_net_get_config;

    n->vdev.set_config = virtio_net_set_config;

    n->vdev.get_features = virtio_net_get_features;

    n->vdev.set_features = virtio_net_set_features;

    n->vdev.reset = virtio_net_reset;

    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);

    n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);

    n->ctrl_vq = virtio_add_queue(&n->vdev, 16, virtio_net_handle_ctrl);

    memcpy(n->mac, nd->macaddr, ETH_ALEN);

    n->status = VIRTIO_NET_S_LINK_UP;

    n->vc = qemu_new_vlan_client(nd->vlan, nd->model, nd->name,

                                 virtio_net_receive, virtio_net_can_receive, n);

    n->vc->link_status_changed = virtio_net_set_link_status;

    qemu_format_nic_info_str(n->vc, n->mac);

    n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);

    n->tx_timer_active = 0;

    n->mergeable_rx_bufs = 0;

    n->promisc = 1; /* for compatibility */

    register_savevm("virtio-net", virtio_net_id++, VIRTIO_NET_VM_VERSION,

                    virtio_net_save, virtio_net_load, n);

}