/*
 * INET         802.1Q VLAN
 *              Ethernet-type device handling.
 *
 * Authors:     Ben Greear <greearb@candelatech.com>
 *              Please send support related email to: netdev@vger.kernel.org
 *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
 *
 * Fixes:
 *              Fix for packet capture - Nick Eggleston <nick@dccinc.com>;
 *              Add HW acceleration hooks - David S. Miller <davem@redhat.com>;
 *              Correct all the locking - David S. Miller <davem@redhat.com>;
 *              Use hash table for VLAN groups - David S. Miller <davem@redhat.com>
 *
 *              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,
                                   __be16 vlan_proto, u16 vlan_id)
{
        struct net_device **array;
        unsigned int pidx, vidx;
        unsigned int size;

        ASSERT_RTNL();

        pidx  = vlan_proto_idx(vlan_proto);
        vidx  = vlan_id / VLAN_GROUP_ARRAY_PART_LEN;
        array = vg->vlan_devices_arrays[pidx][vidx];
        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[pidx][vidx] = 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;

        grp->nr_vlan_devs--;

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

        vlan_group_set_device(grp, vlan->vlan_proto, 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);

        netdev_upper_dev_unlink(real_dev, dev);

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

        /* 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->vlan_proto, vlan_id);

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

int vlan_check_real_dev(struct net_device *real_dev,
                        __be16 protocol, u16 vlan_id)
{
        const char *name = real_dev->name;

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

        if (vlan_find_dev(real_dev, protocol, 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->vlan_proto, 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_mvrp_init_applicant(real_dev);
                if (err < 0)
                        goto out_uninit_gvrp;
        }

        err = vlan_group_prealloc_vid(grp, vlan->vlan_proto, vlan_id);
        if (err < 0)
                goto out_uninit_mvrp;

        err = netdev_upper_dev_link(real_dev, dev);
        if (err)
                goto out_uninit_mvrp;

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

        /* 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->vlan_proto, vlan_id, dev);
        grp->nr_vlan_devs++;

        return 0;

out_upper_dev_unlink:
        netdev_upper_dev_unlink(real_dev, dev);
out_uninit_mvrp:
        if (grp->nr_vlan_devs == 0)
                vlan_mvrp_uninit_applicant(real_dev);
out_uninit_gvrp:
        if (grp->nr_vlan_devs == 0)
                vlan_gvrp_uninit_applicant(real_dev);
out_vid_del:
        vlan_vid_del(real_dev, vlan->vlan_proto, 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, htons(ETH_P_8021Q), 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;
        new_dev->priv_flags |= (real_dev->priv_flags & IFF_UNICAST_FLT);

        vlan_dev_priv(new_dev)->vlan_proto = htons(ETH_P_8021Q);
        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_CTAG_TX)
                vlandev->hard_header_len = dev->hard_header_len;
        else
                vlandev->hard_header_len = dev->hard_header_len + VLAN_HLEN;

#if IS_ENABLED(CONFIG_FCOE)
        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 = netdev_notifier_info_to_dev(ptr);
        struct vlan_group *grp;
        struct vlan_info *vlan_info;
        int i, flgs;
        struct net_device *vlandev;
        struct vlan_dev_priv *vlan;
        bool last = false;
        LIST_HEAD(list);

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

        if ((event == NETDEV_UP) &&
            (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)) {
                pr_info("adding VLAN 0 to HW filter on device %s\n",
                        dev->name);
                vlan_vid_add(dev, htons(ETH_P_8021Q), 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 */
                vlan_group_for_each_dev(grp, i, vlandev)
                        netif_stacked_transfer_operstate(dev, vlandev);
                break;

        case NETDEV_CHANGEADDR:
                /* Adjust unicast filters on underlying device */
                vlan_group_for_each_dev(grp, i, vlandev) {
                        flgs = vlandev->flags;
                        if (!(flgs & IFF_UP))
                                continue;

                        vlan_sync_address(dev, vlandev);
                }
                break;

        case NETDEV_CHANGEMTU:
                vlan_group_for_each_dev(grp, i, vlandev) {
                        if (vlandev->mtu <= dev->mtu)
                                continue;

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

        case NETDEV_FEAT_CHANGE:
                /* Propagate device features to underlying device */
                vlan_group_for_each_dev(grp, i, vlandev)
                        vlan_transfer_features(dev, vlandev);
                break;

        case NETDEV_DOWN:
                if (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
                        vlan_vid_del(dev, htons(ETH_P_8021Q), 0);

                /* Put all VLANs for this dev in the down state too.  */
                vlan_group_for_each_dev(grp, i, vlandev) {
                        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.  */
                vlan_group_for_each_dev(grp, i, vlandev) {
                        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;

                vlan_group_for_each_dev(grp, i, vlandev) {
                        /* removal of last vid destroys vlan_info, abort
                         * afterwards */
                        if (vlan_info->nr_vids == 1)
                                last = true;

                        unregister_vlan_dev(vlandev, &list);
                        if (last)
                                break;
                }
                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 */
                vlan_group_for_each_dev(grp, i, vlandev)
                        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 (!ns_capable(net->user_ns, 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 (!ns_capable(net->user_ns, 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 (!ns_capable(net->user_ns, 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 (!ns_capable(net->user_ns, 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 (!ns_capable(net->user_ns, CAP_NET_ADMIN))
                        break;
                err = register_vlan_device(dev, args.u.VID);
                break;

        case DEL_VLAN_CMD:
                err = -EPERM;
                if (!ns_capable(net->user_ns, 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_mvrp_init();
        if (err < 0)
                goto err4;

        err = vlan_netlink_init();
        if (err < 0)
                goto err5;

        vlan_ioctl_set(vlan_ioctl_handler);
        return 0;

err5:
        vlan_mvrp_uninit();
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_mvrp_uninit();
        vlan_gvrp_uninit();
}

module_init(vlan_proto_init);
module_exit(vlan_cleanup_module);

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