netvsc_drv.c

Go to the documentation of this file.

/*
 * Copyright (c) 2009, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * Authors:
 *   Haiyang Zhang <[email protected]>
 *   Hank Janssen  <[email protected]>
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/atomic.h>
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <net/arp.h>
#include <net/route.h>
#include <net/sock.h>
#include <net/pkt_sched.h>

#include "hyperv_net.h"

struct net_device_context {
    /* point back to our device context */
    struct hv_device *device_ctx;
    struct delayed_work dwork;
    struct work_struct work;
};

#define RING_SIZE_MIN 64
static int ring_size = 128;
module_param(ring_size, int, S_IRUGO);
MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");

static void do_set_multicast(struct work_struct *w)
{
    struct net_device_context *ndevctx =
        container_of(w, struct net_device_context, work);
    struct netvsc_device *nvdev;
    struct rndis_device *rdev;

    nvdev = hv_get_drvdata(ndevctx->device_ctx);
    if (nvdev == NULL || nvdev->ndev == NULL)
        return;

    rdev = nvdev->extension;
    if (rdev == NULL)
        return;

    if (nvdev->ndev->flags & IFF_PROMISC)
        rndis_filter_set_packet_filter(rdev,
            NDIS_PACKET_TYPE_PROMISCUOUS);
    else
        rndis_filter_set_packet_filter(rdev,
            NDIS_PACKET_TYPE_BROADCAST |
            NDIS_PACKET_TYPE_ALL_MULTICAST |
            NDIS_PACKET_TYPE_DIRECTED);
}

static void netvsc_set_multicast_list(struct net_device *net)
{
    struct net_device_context *net_device_ctx = netdev_priv(net);

    schedule_work(&net_device_ctx->work);
}

static int netvsc_open(struct net_device *net)
{
    struct net_device_context *net_device_ctx = netdev_priv(net);
    struct hv_device *device_obj = net_device_ctx->device_ctx;
    int ret = 0;

    /* Open up the device */
    ret = rndis_filter_open(device_obj);
    if (ret != 0) {
        netdev_err(net, "unable to open device (ret %d).\n", ret);
        return ret;
    }

    netif_start_queue(net);

    return ret;
}

static int netvsc_close(struct net_device *net)
{
    struct net_device_context *net_device_ctx = netdev_priv(net);
    struct hv_device *device_obj = net_device_ctx->device_ctx;
    int ret;

    netif_tx_disable(net);

    /* Make sure netvsc_set_multicast_list doesn't re-enable filter! */
    cancel_work_sync(&net_device_ctx->work);
    ret = rndis_filter_close(device_obj);
    if (ret != 0)
        netdev_err(net, "unable to close device (ret %d).\n", ret);

    return ret;
}

static void netvsc_xmit_completion(void *context)
{
    struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)context;
    struct sk_buff *skb = (struct sk_buff *)
        (unsigned long)packet->completion.send.send_completion_tid;

    kfree(packet);

    if (skb)
        dev_kfree_skb_any(skb);
}

static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
{
    struct net_device_context *net_device_ctx = netdev_priv(net);
    struct hv_netvsc_packet *packet;
    int ret;
    unsigned int i, num_pages, npg_data;

    /* Add multipages for skb->data and additional 2 for RNDIS */
    npg_data = (((unsigned long)skb->data + skb_headlen(skb) - 1)
        >> PAGE_SHIFT) - ((unsigned long)skb->data >> PAGE_SHIFT) + 1;
    num_pages = skb_shinfo(skb)->nr_frags + npg_data + 2;

    /* Allocate a netvsc packet based on # of frags. */
    packet = kzalloc(sizeof(struct hv_netvsc_packet) +
             (num_pages * sizeof(struct hv_page_buffer)) +
             sizeof(struct rndis_filter_packet) +
             NDIS_VLAN_PPI_SIZE, GFP_ATOMIC);
    if (!packet) {
        /* out of memory, drop packet */
        netdev_err(net, "unable to allocate hv_netvsc_packet\n");

        dev_kfree_skb(skb);
        net->stats.tx_dropped++;
        return NETDEV_TX_OK;
    }

    packet->vlan_tci = skb->vlan_tci;

    packet->extension = (void *)(unsigned long)packet +
                sizeof(struct hv_netvsc_packet) +
                    (num_pages * sizeof(struct hv_page_buffer));

    /* If the rndis msg goes beyond 1 page, we will add 1 later */
    packet->page_buf_cnt = num_pages - 1;

    /* Initialize it from the skb */
    packet->total_data_buflen = skb->len;

    /* Start filling in the page buffers starting after RNDIS buffer. */
    packet->page_buf[1].pfn = virt_to_phys(skb->data) >> PAGE_SHIFT;
    packet->page_buf[1].offset
        = (unsigned long)skb->data & (PAGE_SIZE - 1);
    if (npg_data == 1)
        packet->page_buf[1].len = skb_headlen(skb);
    else
        packet->page_buf[1].len = PAGE_SIZE
            - packet->page_buf[1].offset;

    for (i = 2; i <= npg_data; i++) {
        packet->page_buf[i].pfn = virt_to_phys(skb->data
            + PAGE_SIZE * (i-1)) >> PAGE_SHIFT;
        packet->page_buf[i].offset = 0;
        packet->page_buf[i].len = PAGE_SIZE;
    }
    if (npg_data > 1)
        packet->page_buf[npg_data].len = (((unsigned long)skb->data
            + skb_headlen(skb) - 1) & (PAGE_SIZE - 1)) + 1;

    /* Additional fragments are after SKB data */
    for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
        const skb_frag_t *f = &skb_shinfo(skb)->frags[i];

        packet->page_buf[i+npg_data+1].pfn =
            page_to_pfn(skb_frag_page(f));
        packet->page_buf[i+npg_data+1].offset = f->page_offset;
        packet->page_buf[i+npg_data+1].len = skb_frag_size(f);
    }

    /* Set the completion routine */
    packet->completion.send.send_completion = netvsc_xmit_completion;
    packet->completion.send.send_completion_ctx = packet;
    packet->completion.send.send_completion_tid = (unsigned long)skb;

    ret = rndis_filter_send(net_device_ctx->device_ctx,
                  packet);
    if (ret == 0) {
        net->stats.tx_bytes += skb->len;
        net->stats.tx_packets++;
    } else {
        kfree(packet);
        if (ret != -EAGAIN) {
            dev_kfree_skb_any(skb);
            net->stats.tx_dropped++;
        }
    }

    return (ret == -EAGAIN) ? NETDEV_TX_BUSY : NETDEV_TX_OK;
}

/*
 * netvsc_linkstatus_callback - Link up/down notification
 */
void netvsc_linkstatus_callback(struct hv_device *device_obj,
                       unsigned int status)
{
    struct net_device *net;
    struct net_device_context *ndev_ctx;
    struct netvsc_device *net_device;

    net_device = hv_get_drvdata(device_obj);
    net = net_device->ndev;

    if (!net) {
        netdev_err(net, "got link status but net device "
                "not initialized yet\n");
        return;
    }

    if (status == 1) {
        netif_carrier_on(net);
        netif_wake_queue(net);
        ndev_ctx = netdev_priv(net);
        schedule_delayed_work(&ndev_ctx->dwork, 0);
        schedule_delayed_work(&ndev_ctx->dwork, msecs_to_jiffies(20));
    } else {
        netif_carrier_off(net);
        netif_tx_disable(net);
    }
}

/*
 * netvsc_recv_callback -  Callback when we receive a packet from the
 * "wire" on the specified device.
 */
int netvsc_recv_callback(struct hv_device *device_obj,
                struct hv_netvsc_packet *packet)
{
    struct net_device *net;
    struct sk_buff *skb;

    net = ((struct netvsc_device *)hv_get_drvdata(device_obj))->ndev;
    if (!net) {
        netdev_err(net, "got receive callback but net device"
            " not initialized yet\n");
        packet->status = NVSP_STAT_FAIL;
        return 0;
    }

    /* Allocate a skb - TODO direct I/O to pages? */
    skb = netdev_alloc_skb_ip_align(net, packet->total_data_buflen);
    if (unlikely(!skb)) {
        ++net->stats.rx_dropped;
        packet->status = NVSP_STAT_FAIL;
        return 0;
    }

    /*
     * Copy to skb. This copy is needed here since the memory pointed by
     * hv_netvsc_packet cannot be deallocated
     */
    memcpy(skb_put(skb, packet->total_data_buflen), packet->data,
        packet->total_data_buflen);

    skb->protocol = eth_type_trans(skb, net);
    skb->ip_summed = CHECKSUM_NONE;
    skb->vlan_tci = packet->vlan_tci;

    net->stats.rx_packets++;
    net->stats.rx_bytes += packet->total_data_buflen;

    /*
     * Pass the skb back up. Network stack will deallocate the skb when it
     * is done.
     * TODO - use NAPI?
     */
    netif_rx(skb);

    return 0;
}

static void netvsc_get_drvinfo(struct net_device *net,
                   struct ethtool_drvinfo *info)
{
    strcpy(info->driver, KBUILD_MODNAME);
    strcpy(info->version, HV_DRV_VERSION);
    strcpy(info->fw_version, "N/A");
}

static int netvsc_change_mtu(struct net_device *ndev, int mtu)
{
    struct net_device_context *ndevctx = netdev_priv(ndev);
    struct hv_device *hdev =  ndevctx->device_ctx;
    struct netvsc_device *nvdev = hv_get_drvdata(hdev);
    struct netvsc_device_info device_info;
    int limit = ETH_DATA_LEN;

    if (nvdev == NULL || nvdev->destroy)
        return -ENODEV;

    if (nvdev->nvsp_version == NVSP_PROTOCOL_VERSION_2)
        limit = NETVSC_MTU;

    if (mtu < 68 || mtu > limit)
        return -EINVAL;

    nvdev->start_remove = true;
    cancel_delayed_work_sync(&ndevctx->dwork);
    cancel_work_sync(&ndevctx->work);
    netif_tx_disable(ndev);
    rndis_filter_device_remove(hdev);

    ndev->mtu = mtu;

    ndevctx->device_ctx = hdev;
    hv_set_drvdata(hdev, ndev);
    device_info.ring_size = ring_size;
    rndis_filter_device_add(hdev, &device_info);
    netif_wake_queue(ndev);

    return 0;
}


static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
{
    struct net_device_context *ndevctx = netdev_priv(ndev);
    struct hv_device *hdev =  ndevctx->device_ctx;
    struct sockaddr *addr = p;
    char save_adr[14];
    unsigned char save_aatype;
    int err;

    memcpy(save_adr, ndev->dev_addr, ETH_ALEN);
    save_aatype = ndev->addr_assign_type;

    err = eth_mac_addr(ndev, p);
    if (err != 0)
        return err;

    err = rndis_filter_set_device_mac(hdev, addr->sa_data);
    if (err != 0) {
        /* roll back to saved MAC */
        memcpy(ndev->dev_addr, save_adr, ETH_ALEN);
        ndev->addr_assign_type = save_aatype;
    }

    return err;
}


static const struct ethtool_ops ethtool_ops = {
    .get_drvinfo    = netvsc_get_drvinfo,
    .get_link   = ethtool_op_get_link,
};

static const struct net_device_ops device_ops = {
    .ndo_open =         netvsc_open,
    .ndo_stop =         netvsc_close,
    .ndo_start_xmit =       netvsc_start_xmit,
    .ndo_set_rx_mode =      netvsc_set_multicast_list,
    .ndo_change_mtu =       netvsc_change_mtu,
    .ndo_validate_addr =        eth_validate_addr,
    .ndo_set_mac_address =      netvsc_set_mac_addr,
};

/*
 * Send GARP packet to network peers after migrations.
 * After Quick Migration, the network is not immediately operational in the
 * current context when receiving RNDIS_STATUS_MEDIA_CONNECT event. So, add
 * another netif_notify_peers() into a delayed work, otherwise GARP packet
 * will not be sent after quick migration, and cause network disconnection.
 */
static void netvsc_send_garp(struct work_struct *w)
{
    struct net_device_context *ndev_ctx;
    struct net_device *net;
    struct netvsc_device *net_device;

    ndev_ctx = container_of(w, struct net_device_context, dwork.work);
    net_device = hv_get_drvdata(ndev_ctx->device_ctx);
    net = net_device->ndev;
    netdev_notify_peers(net);
}


static int netvsc_probe(struct hv_device *dev,
            const struct hv_vmbus_device_id *dev_id)
{
    struct net_device *net = NULL;
    struct net_device_context *net_device_ctx;
    struct netvsc_device_info device_info;
    int ret;

    net = alloc_etherdev(sizeof(struct net_device_context));
    if (!net)
        return -ENOMEM;

    /* Set initial state */
    netif_carrier_off(net);

    net_device_ctx = netdev_priv(net);
    net_device_ctx->device_ctx = dev;
    hv_set_drvdata(dev, net);
    INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_send_garp);
    INIT_WORK(&net_device_ctx->work, do_set_multicast);

    net->netdev_ops = &device_ops;

    /* TODO: Add GSO and Checksum offload */
    net->hw_features = NETIF_F_SG;
    net->features = NETIF_F_SG | NETIF_F_HW_VLAN_TX;

    SET_ETHTOOL_OPS(net, &ethtool_ops);
    SET_NETDEV_DEV(net, &dev->device);

    ret = register_netdev(net);
    if (ret != 0) {
        pr_err("Unable to register netdev.\n");
        free_netdev(net);
        goto out;
    }

    /* Notify the netvsc driver of the new device */
    device_info.ring_size = ring_size;
    ret = rndis_filter_device_add(dev, &device_info);
    if (ret != 0) {
        netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
        unregister_netdev(net);
        free_netdev(net);
        hv_set_drvdata(dev, NULL);
        return ret;
    }
    memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);

    netif_carrier_on(net);

out:
    return ret;
}

static int netvsc_remove(struct hv_device *dev)
{
    struct net_device *net;
    struct net_device_context *ndev_ctx;
    struct netvsc_device *net_device;

    net_device = hv_get_drvdata(dev);
    net = net_device->ndev;

    if (net == NULL) {
        dev_err(&dev->device, "No net device to remove\n");
        return 0;
    }

    net_device->start_remove = true;

    ndev_ctx = netdev_priv(net);
    cancel_delayed_work_sync(&ndev_ctx->dwork);
    cancel_work_sync(&ndev_ctx->work);

    /* Stop outbound asap */
    netif_tx_disable(net);

    unregister_netdev(net);

    /*
     * Call to the vsc driver to let it know that the device is being
     * removed
     */
    rndis_filter_device_remove(dev);

    free_netdev(net);
    return 0;
}

static const struct hv_vmbus_device_id id_table[] = {
    /* Network guid */
    { VMBUS_DEVICE(0x63, 0x51, 0x61, 0xF8, 0x3E, 0xDF, 0xc5, 0x46,
               0x91, 0x3F, 0xF2, 0xD2, 0xF9, 0x65, 0xED, 0x0E) },
    { },
};

MODULE_DEVICE_TABLE(vmbus, id_table);

/* The one and only one */
static struct  hv_driver netvsc_drv = {
    .name = KBUILD_MODNAME,
    .id_table = id_table,
    .probe = netvsc_probe,
    .remove = netvsc_remove,
};

static void __exit netvsc_drv_exit(void)
{
    vmbus_driver_unregister(&netvsc_drv);
}

static int __init netvsc_drv_init(void)
{
    if (ring_size < RING_SIZE_MIN) {
        ring_size = RING_SIZE_MIN;
        pr_info("Increased ring_size to %d (min allowed)\n",
            ring_size);
    }
    return vmbus_driver_register(&netvsc_drv);
}

MODULE_LICENSE("GPL");
MODULE_VERSION(HV_DRV_VERSION);
MODULE_DESCRIPTION("Microsoft Hyper-V network driver");

module_init(netvsc_drv_init);
module_exit(netvsc_drv_exit);