vlan.c

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/*
 * INET     802.1Q VLAN
 *      Ethernet-type device handling.
 *
 * Authors: Ben Greear <[email protected]>
 *              Please send support related email to: [email protected]
 *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
 *
 * Fixes:
 *              Fix for packet capture - Nick Eggleston <[email protected]>;
 *      Add HW acceleration hooks - David S. Miller <[email protected]>;
 *      Correct all the locking - David S. Miller <[email protected]>;
 *      Use hash table for VLAN groups - David S. Miller <[email protected]>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/capability.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/rculist.h>
#include <net/p8022.h>
#include <net/arp.h>
#include <linux/rtnetlink.h>
#include <linux/notifier.h>
#include <net/rtnetlink.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <asm/uaccess.h>

#include <linux/if_vlan.h>
#include "vlan.h"
#include "vlanproc.h"

#define DRV_VERSION "1.8"

/* Global VLAN variables */

int vlan_net_id __read_mostly;

const char vlan_fullname[] = "802.1Q VLAN Support";
const char vlan_version[] = DRV_VERSION;

/* End of global variables definitions. */

static int vlan_group_prealloc_vid(struct vlan_group *vg, u16 vlan_id)
{
    struct net_device **array;
    unsigned int size;

    ASSERT_RTNL();

    array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
    if (array != NULL)
        return 0;

    size = sizeof(struct net_device *) * VLAN_GROUP_ARRAY_PART_LEN;
    array = kzalloc(size, GFP_KERNEL);
    if (array == NULL)
        return -ENOBUFS;

    vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN] = array;
    return 0;
}

void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
{
    struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
    struct net_device *real_dev = vlan->real_dev;
    struct vlan_info *vlan_info;
    struct vlan_group *grp;
    u16 vlan_id = vlan->vlan_id;

    ASSERT_RTNL();

    vlan_info = rtnl_dereference(real_dev->vlan_info);
    BUG_ON(!vlan_info);

    grp = &vlan_info->grp;

    /* Take it out of our own structures, but be sure to interlock with
     * HW accelerating devices or SW vlan input packet processing if
     * VLAN is not 0 (leave it there for 802.1p).
     */
    if (vlan_id)
        vlan_vid_del(real_dev, vlan_id);

    grp->nr_vlan_devs--;

    if (vlan->flags & VLAN_FLAG_GVRP)
        vlan_gvrp_request_leave(dev);

    vlan_group_set_device(grp, vlan_id, NULL);
    /* Because unregister_netdevice_queue() makes sure at least one rcu
     * grace period is respected before device freeing,
     * we dont need to call synchronize_net() here.
     */
    unregister_netdevice_queue(dev, head);

    if (grp->nr_vlan_devs == 0)
        vlan_gvrp_uninit_applicant(real_dev);

    /* Get rid of the vlan's reference to real_dev */
    dev_put(real_dev);
}

int vlan_check_real_dev(struct net_device *real_dev, u16 vlan_id)
{
    const char *name = real_dev->name;
    const struct net_device_ops *ops = real_dev->netdev_ops;

    if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
        pr_info("VLANs not supported on %s\n", name);
        return -EOPNOTSUPP;
    }

    if ((real_dev->features & NETIF_F_HW_VLAN_FILTER) &&
        (!ops->ndo_vlan_rx_add_vid || !ops->ndo_vlan_rx_kill_vid)) {
        pr_info("Device %s has buggy VLAN hw accel\n", name);
        return -EOPNOTSUPP;
    }

    if (vlan_find_dev(real_dev, vlan_id) != NULL)
        return -EEXIST;

    return 0;
}

int register_vlan_dev(struct net_device *dev)
{
    struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
    struct net_device *real_dev = vlan->real_dev;
    u16 vlan_id = vlan->vlan_id;
    struct vlan_info *vlan_info;
    struct vlan_group *grp;
    int err;

    err = vlan_vid_add(real_dev, vlan_id);
    if (err)
        return err;

    vlan_info = rtnl_dereference(real_dev->vlan_info);
    /* vlan_info should be there now. vlan_vid_add took care of it */
    BUG_ON(!vlan_info);

    grp = &vlan_info->grp;
    if (grp->nr_vlan_devs == 0) {
        err = vlan_gvrp_init_applicant(real_dev);
        if (err < 0)
            goto out_vid_del;
    }

    err = vlan_group_prealloc_vid(grp, vlan_id);
    if (err < 0)
        goto out_uninit_applicant;

    err = register_netdevice(dev);
    if (err < 0)
        goto out_uninit_applicant;

    /* Account for reference in struct vlan_dev_priv */
    dev_hold(real_dev);

    netif_stacked_transfer_operstate(real_dev, dev);
    linkwatch_fire_event(dev); /* _MUST_ call rfc2863_policy() */

    /* So, got the sucker initialized, now lets place
     * it into our local structure.
     */
    vlan_group_set_device(grp, vlan_id, dev);
    grp->nr_vlan_devs++;

    return 0;

out_uninit_applicant:
    if (grp->nr_vlan_devs == 0)
        vlan_gvrp_uninit_applicant(real_dev);
out_vid_del:
    vlan_vid_del(real_dev, vlan_id);
    return err;
}

/*  Attach a VLAN device to a mac address (ie Ethernet Card).
 *  Returns 0 if the device was created or a negative error code otherwise.
 */
static int register_vlan_device(struct net_device *real_dev, u16 vlan_id)
{
    struct net_device *new_dev;
    struct net *net = dev_net(real_dev);
    struct vlan_net *vn = net_generic(net, vlan_net_id);
    char name[IFNAMSIZ];
    int err;

    if (vlan_id >= VLAN_VID_MASK)
        return -ERANGE;

    err = vlan_check_real_dev(real_dev, vlan_id);
    if (err < 0)
        return err;

    /* Gotta set up the fields for the device. */
    switch (vn->name_type) {
    case VLAN_NAME_TYPE_RAW_PLUS_VID:
        /* name will look like:  eth1.0005 */
        snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, vlan_id);
        break;
    case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
        /* Put our vlan.VID in the name.
         * Name will look like:  vlan5
         */
        snprintf(name, IFNAMSIZ, "vlan%i", vlan_id);
        break;
    case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
        /* Put our vlan.VID in the name.
         * Name will look like:  eth0.5
         */
        snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, vlan_id);
        break;
    case VLAN_NAME_TYPE_PLUS_VID:
        /* Put our vlan.VID in the name.
         * Name will look like:  vlan0005
         */
    default:
        snprintf(name, IFNAMSIZ, "vlan%.4i", vlan_id);
    }

    new_dev = alloc_netdev(sizeof(struct vlan_dev_priv), name, vlan_setup);

    if (new_dev == NULL)
        return -ENOBUFS;

    dev_net_set(new_dev, net);
    /* need 4 bytes for extra VLAN header info,
     * hope the underlying device can handle it.
     */
    new_dev->mtu = real_dev->mtu;

    vlan_dev_priv(new_dev)->vlan_id = vlan_id;
    vlan_dev_priv(new_dev)->real_dev = real_dev;
    vlan_dev_priv(new_dev)->dent = NULL;
    vlan_dev_priv(new_dev)->flags = VLAN_FLAG_REORDER_HDR;

    new_dev->rtnl_link_ops = &vlan_link_ops;
    err = register_vlan_dev(new_dev);
    if (err < 0)
        goto out_free_newdev;

    return 0;

out_free_newdev:
    free_netdev(new_dev);
    return err;
}

static void vlan_sync_address(struct net_device *dev,
                  struct net_device *vlandev)
{
    struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);

    /* May be called without an actual change */
    if (ether_addr_equal(vlan->real_dev_addr, dev->dev_addr))
        return;

    /* vlan address was different from the old address and is equal to
     * the new address */
    if (!ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
        ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
        dev_uc_del(dev, vlandev->dev_addr);

    /* vlan address was equal to the old address and is different from
     * the new address */
    if (ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
        !ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
        dev_uc_add(dev, vlandev->dev_addr);

    memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
}

static void vlan_transfer_features(struct net_device *dev,
                   struct net_device *vlandev)
{
    vlandev->gso_max_size = dev->gso_max_size;

    if (dev->features & NETIF_F_HW_VLAN_TX)
        vlandev->hard_header_len = dev->hard_header_len;
    else
        vlandev->hard_header_len = dev->hard_header_len + VLAN_HLEN;

#if defined(CONFIG_FCOE) || defined(CONFIG_FCOE_MODULE)
    vlandev->fcoe_ddp_xid = dev->fcoe_ddp_xid;
#endif

    netdev_update_features(vlandev);
}

static void __vlan_device_event(struct net_device *dev, unsigned long event)
{
    switch (event) {
    case NETDEV_CHANGENAME:
        vlan_proc_rem_dev(dev);
        if (vlan_proc_add_dev(dev) < 0)
            pr_warn("failed to change proc name for %s\n",
                dev->name);
        break;
    case NETDEV_REGISTER:
        if (vlan_proc_add_dev(dev) < 0)
            pr_warn("failed to add proc entry for %s\n", dev->name);
        break;
    case NETDEV_UNREGISTER:
        vlan_proc_rem_dev(dev);
        break;
    }
}

static int vlan_device_event(struct notifier_block *unused, unsigned long event,
                 void *ptr)
{
    struct net_device *dev = ptr;
    struct vlan_group *grp;
    struct vlan_info *vlan_info;
    int i, flgs;
    struct net_device *vlandev;
    struct vlan_dev_priv *vlan;
    LIST_HEAD(list);

    if (is_vlan_dev(dev))
        __vlan_device_event(dev, event);

    if ((event == NETDEV_UP) &&
        (dev->features & NETIF_F_HW_VLAN_FILTER)) {
        pr_info("adding VLAN 0 to HW filter on device %s\n",
            dev->name);
        vlan_vid_add(dev, 0);
    }

    vlan_info = rtnl_dereference(dev->vlan_info);
    if (!vlan_info)
        goto out;
    grp = &vlan_info->grp;

    /* It is OK that we do not hold the group lock right now,
     * as we run under the RTNL lock.
     */

    switch (event) {
    case NETDEV_CHANGE:
        /* Propagate real device state to vlan devices */
        for (i = 0; i < VLAN_N_VID; i++) {
            vlandev = vlan_group_get_device(grp, i);
            if (!vlandev)
                continue;

            netif_stacked_transfer_operstate(dev, vlandev);
        }
        break;

    case NETDEV_CHANGEADDR:
        /* Adjust unicast filters on underlying device */
        for (i = 0; i < VLAN_N_VID; i++) {
            vlandev = vlan_group_get_device(grp, i);
            if (!vlandev)
                continue;

            flgs = vlandev->flags;
            if (!(flgs & IFF_UP))
                continue;

            vlan_sync_address(dev, vlandev);
        }
        break;

    case NETDEV_CHANGEMTU:
        for (i = 0; i < VLAN_N_VID; i++) {
            vlandev = vlan_group_get_device(grp, i);
            if (!vlandev)
                continue;

            if (vlandev->mtu <= dev->mtu)
                continue;

            dev_set_mtu(vlandev, dev->mtu);
        }
        break;

    case NETDEV_FEAT_CHANGE:
        /* Propagate device features to underlying device */
        for (i = 0; i < VLAN_N_VID; i++) {
            vlandev = vlan_group_get_device(grp, i);
            if (!vlandev)
                continue;

            vlan_transfer_features(dev, vlandev);
        }

        break;

    case NETDEV_DOWN:
        if (dev->features & NETIF_F_HW_VLAN_FILTER)
            vlan_vid_del(dev, 0);

        /* Put all VLANs for this dev in the down state too.  */
        for (i = 0; i < VLAN_N_VID; i++) {
            vlandev = vlan_group_get_device(grp, i);
            if (!vlandev)
                continue;

            flgs = vlandev->flags;
            if (!(flgs & IFF_UP))
                continue;

            vlan = vlan_dev_priv(vlandev);
            if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
                dev_change_flags(vlandev, flgs & ~IFF_UP);
            netif_stacked_transfer_operstate(dev, vlandev);
        }
        break;

    case NETDEV_UP:
        /* Put all VLANs for this dev in the up state too.  */
        for (i = 0; i < VLAN_N_VID; i++) {
            vlandev = vlan_group_get_device(grp, i);
            if (!vlandev)
                continue;

            flgs = vlandev->flags;
            if (flgs & IFF_UP)
                continue;

            vlan = vlan_dev_priv(vlandev);
            if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
                dev_change_flags(vlandev, flgs | IFF_UP);
            netif_stacked_transfer_operstate(dev, vlandev);
        }
        break;

    case NETDEV_UNREGISTER:
        /* twiddle thumbs on netns device moves */
        if (dev->reg_state != NETREG_UNREGISTERING)
            break;

        for (i = 0; i < VLAN_N_VID; i++) {
            vlandev = vlan_group_get_device(grp, i);
            if (!vlandev)
                continue;

            /* removal of last vid destroys vlan_info, abort
             * afterwards */
            if (vlan_info->nr_vids == 1)
                i = VLAN_N_VID;

            unregister_vlan_dev(vlandev, &list);
        }
        unregister_netdevice_many(&list);
        break;

    case NETDEV_PRE_TYPE_CHANGE:
        /* Forbid underlaying device to change its type. */
        if (vlan_uses_dev(dev))
            return NOTIFY_BAD;
        break;

    case NETDEV_NOTIFY_PEERS:
    case NETDEV_BONDING_FAILOVER:
        /* Propagate to vlan devices */
        for (i = 0; i < VLAN_N_VID; i++) {
            vlandev = vlan_group_get_device(grp, i);
            if (!vlandev)
                continue;

            call_netdevice_notifiers(event, vlandev);
        }
        break;
    }

out:
    return NOTIFY_DONE;
}

static struct notifier_block vlan_notifier_block __read_mostly = {
    .notifier_call = vlan_device_event,
};

/*
 *  VLAN IOCTL handler.
 *  o execute requested action or pass command to the device driver
 *   arg is really a struct vlan_ioctl_args __user *.
 */
static int vlan_ioctl_handler(struct net *net, void __user *arg)
{
    int err;
    struct vlan_ioctl_args args;
    struct net_device *dev = NULL;

    if (copy_from_user(&args, arg, sizeof(struct vlan_ioctl_args)))
        return -EFAULT;

    /* Null terminate this sucker, just in case. */
    args.device1[23] = 0;
    args.u.device2[23] = 0;

    rtnl_lock();

    switch (args.cmd) {
    case SET_VLAN_INGRESS_PRIORITY_CMD:
    case SET_VLAN_EGRESS_PRIORITY_CMD:
    case SET_VLAN_FLAG_CMD:
    case ADD_VLAN_CMD:
    case DEL_VLAN_CMD:
    case GET_VLAN_REALDEV_NAME_CMD:
    case GET_VLAN_VID_CMD:
        err = -ENODEV;
        dev = __dev_get_by_name(net, args.device1);
        if (!dev)
            goto out;

        err = -EINVAL;
        if (args.cmd != ADD_VLAN_CMD && !is_vlan_dev(dev))
            goto out;
    }

    switch (args.cmd) {
    case SET_VLAN_INGRESS_PRIORITY_CMD:
        err = -EPERM;
        if (!capable(CAP_NET_ADMIN))
            break;
        vlan_dev_set_ingress_priority(dev,
                          args.u.skb_priority,
                          args.vlan_qos);
        err = 0;
        break;

    case SET_VLAN_EGRESS_PRIORITY_CMD:
        err = -EPERM;
        if (!capable(CAP_NET_ADMIN))
            break;
        err = vlan_dev_set_egress_priority(dev,
                           args.u.skb_priority,
                           args.vlan_qos);
        break;

    case SET_VLAN_FLAG_CMD:
        err = -EPERM;
        if (!capable(CAP_NET_ADMIN))
            break;
        err = vlan_dev_change_flags(dev,
                        args.vlan_qos ? args.u.flag : 0,
                        args.u.flag);
        break;

    case SET_VLAN_NAME_TYPE_CMD:
        err = -EPERM;
        if (!capable(CAP_NET_ADMIN))
            break;
        if ((args.u.name_type >= 0) &&
            (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
            struct vlan_net *vn;

            vn = net_generic(net, vlan_net_id);
            vn->name_type = args.u.name_type;
            err = 0;
        } else {
            err = -EINVAL;
        }
        break;

    case ADD_VLAN_CMD:
        err = -EPERM;
        if (!capable(CAP_NET_ADMIN))
            break;
        err = register_vlan_device(dev, args.u.VID);
        break;

    case DEL_VLAN_CMD:
        err = -EPERM;
        if (!capable(CAP_NET_ADMIN))
            break;
        unregister_vlan_dev(dev, NULL);
        err = 0;
        break;

    case GET_VLAN_REALDEV_NAME_CMD:
        err = 0;
        vlan_dev_get_realdev_name(dev, args.u.device2);
        if (copy_to_user(arg, &args,
                 sizeof(struct vlan_ioctl_args)))
            err = -EFAULT;
        break;

    case GET_VLAN_VID_CMD:
        err = 0;
        args.u.VID = vlan_dev_vlan_id(dev);
        if (copy_to_user(arg, &args,
                 sizeof(struct vlan_ioctl_args)))
              err = -EFAULT;
        break;

    default:
        err = -EOPNOTSUPP;
        break;
    }
out:
    rtnl_unlock();
    return err;
}

static int __net_init vlan_init_net(struct net *net)
{
    struct vlan_net *vn = net_generic(net, vlan_net_id);
    int err;

    vn->name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;

    err = vlan_proc_init(net);

    return err;
}

static void __net_exit vlan_exit_net(struct net *net)
{
    vlan_proc_cleanup(net);
}

static struct pernet_operations vlan_net_ops = {
    .init = vlan_init_net,
    .exit = vlan_exit_net,
    .id   = &vlan_net_id,
    .size = sizeof(struct vlan_net),
};

static int __init vlan_proto_init(void)
{
    int err;

    pr_info("%s v%s\n", vlan_fullname, vlan_version);

    err = register_pernet_subsys(&vlan_net_ops);
    if (err < 0)
        goto err0;

    err = register_netdevice_notifier(&vlan_notifier_block);
    if (err < 0)
        goto err2;

    err = vlan_gvrp_init();
    if (err < 0)
        goto err3;

    err = vlan_netlink_init();
    if (err < 0)
        goto err4;

    vlan_ioctl_set(vlan_ioctl_handler);
    return 0;

err4:
    vlan_gvrp_uninit();
err3:
    unregister_netdevice_notifier(&vlan_notifier_block);
err2:
    unregister_pernet_subsys(&vlan_net_ops);
err0:
    return err;
}

static void __exit vlan_cleanup_module(void)
{
    vlan_ioctl_set(NULL);
    vlan_netlink_fini();

    unregister_netdevice_notifier(&vlan_notifier_block);

    unregister_pernet_subsys(&vlan_net_ops);
    rcu_barrier(); /* Wait for completion of call_rcu()'s */

    vlan_gvrp_uninit();
}

module_init(vlan_proto_init);
module_exit(vlan_cleanup_module);

MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);