vlan_netlink.c

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/*
 *  VLAN netlink control interface
 *
 *  Copyright (c) 2007 Patrick McHardy <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  version 2 as published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <net/netlink.h>
#include <net/rtnetlink.h>
#include "vlan.h"


static const struct nla_policy vlan_policy[IFLA_VLAN_MAX + 1] = {
    [IFLA_VLAN_ID]      = { .type = NLA_U16 },
    [IFLA_VLAN_FLAGS]   = { .len = sizeof(struct ifla_vlan_flags) },
    [IFLA_VLAN_EGRESS_QOS]  = { .type = NLA_NESTED },
    [IFLA_VLAN_INGRESS_QOS] = { .type = NLA_NESTED },
};

static const struct nla_policy vlan_map_policy[IFLA_VLAN_QOS_MAX + 1] = {
    [IFLA_VLAN_QOS_MAPPING] = { .len = sizeof(struct ifla_vlan_qos_mapping) },
};


static inline int vlan_validate_qos_map(struct nlattr *attr)
{
    if (!attr)
        return 0;
    return nla_validate_nested(attr, IFLA_VLAN_QOS_MAX, vlan_map_policy);
}

static int vlan_validate(struct nlattr *tb[], struct nlattr *data[])
{
    struct ifla_vlan_flags *flags;
    u16 id;
    int err;

    if (tb[IFLA_ADDRESS]) {
        if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
            return -EINVAL;
        if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
            return -EADDRNOTAVAIL;
    }

    if (!data)
        return -EINVAL;

    if (data[IFLA_VLAN_ID]) {
        id = nla_get_u16(data[IFLA_VLAN_ID]);
        if (id >= VLAN_VID_MASK)
            return -ERANGE;
    }
    if (data[IFLA_VLAN_FLAGS]) {
        flags = nla_data(data[IFLA_VLAN_FLAGS]);
        if ((flags->flags & flags->mask) &
            ~(VLAN_FLAG_REORDER_HDR | VLAN_FLAG_GVRP |
              VLAN_FLAG_LOOSE_BINDING))
            return -EINVAL;
    }

    err = vlan_validate_qos_map(data[IFLA_VLAN_INGRESS_QOS]);
    if (err < 0)
        return err;
    err = vlan_validate_qos_map(data[IFLA_VLAN_EGRESS_QOS]);
    if (err < 0)
        return err;
    return 0;
}

static int vlan_changelink(struct net_device *dev,
               struct nlattr *tb[], struct nlattr *data[])
{
    struct ifla_vlan_flags *flags;
    struct ifla_vlan_qos_mapping *m;
    struct nlattr *attr;
    int rem;

    if (data[IFLA_VLAN_FLAGS]) {
        flags = nla_data(data[IFLA_VLAN_FLAGS]);
        vlan_dev_change_flags(dev, flags->flags, flags->mask);
    }
    if (data[IFLA_VLAN_INGRESS_QOS]) {
        nla_for_each_nested(attr, data[IFLA_VLAN_INGRESS_QOS], rem) {
            m = nla_data(attr);
            vlan_dev_set_ingress_priority(dev, m->to, m->from);
        }
    }
    if (data[IFLA_VLAN_EGRESS_QOS]) {
        nla_for_each_nested(attr, data[IFLA_VLAN_EGRESS_QOS], rem) {
            m = nla_data(attr);
            vlan_dev_set_egress_priority(dev, m->from, m->to);
        }
    }
    return 0;
}

static int vlan_newlink(struct net *src_net, struct net_device *dev,
            struct nlattr *tb[], struct nlattr *data[])
{
    struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
    struct net_device *real_dev;
    int err;

    if (!data[IFLA_VLAN_ID])
        return -EINVAL;

    if (!tb[IFLA_LINK])
        return -EINVAL;
    real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
    if (!real_dev)
        return -ENODEV;

    vlan->vlan_id  = nla_get_u16(data[IFLA_VLAN_ID]);
    vlan->real_dev = real_dev;
    vlan->flags    = VLAN_FLAG_REORDER_HDR;

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

    if (!tb[IFLA_MTU])
        dev->mtu = real_dev->mtu;
    else if (dev->mtu > real_dev->mtu)
        return -EINVAL;

    err = vlan_changelink(dev, tb, data);
    if (err < 0)
        return err;

    return register_vlan_dev(dev);
}

static inline size_t vlan_qos_map_size(unsigned int n)
{
    if (n == 0)
        return 0;
    /* IFLA_VLAN_{EGRESS,INGRESS}_QOS + n * IFLA_VLAN_QOS_MAPPING */
    return nla_total_size(sizeof(struct nlattr)) +
           nla_total_size(sizeof(struct ifla_vlan_qos_mapping)) * n;
}

static size_t vlan_get_size(const struct net_device *dev)
{
    struct vlan_dev_priv *vlan = vlan_dev_priv(dev);

    return nla_total_size(2) +  /* IFLA_VLAN_ID */
           sizeof(struct ifla_vlan_flags) + /* IFLA_VLAN_FLAGS */
           vlan_qos_map_size(vlan->nr_ingress_mappings) +
           vlan_qos_map_size(vlan->nr_egress_mappings);
}

static int vlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
    struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
    struct vlan_priority_tci_mapping *pm;
    struct ifla_vlan_flags f;
    struct ifla_vlan_qos_mapping m;
    struct nlattr *nest;
    unsigned int i;

    if (nla_put_u16(skb, IFLA_VLAN_ID, vlan_dev_priv(dev)->vlan_id))
        goto nla_put_failure;
    if (vlan->flags) {
        f.flags = vlan->flags;
        f.mask  = ~0;
        if (nla_put(skb, IFLA_VLAN_FLAGS, sizeof(f), &f))
            goto nla_put_failure;
    }
    if (vlan->nr_ingress_mappings) {
        nest = nla_nest_start(skb, IFLA_VLAN_INGRESS_QOS);
        if (nest == NULL)
            goto nla_put_failure;

        for (i = 0; i < ARRAY_SIZE(vlan->ingress_priority_map); i++) {
            if (!vlan->ingress_priority_map[i])
                continue;

            m.from = i;
            m.to   = vlan->ingress_priority_map[i];
            if (nla_put(skb, IFLA_VLAN_QOS_MAPPING,
                    sizeof(m), &m))
                goto nla_put_failure;
        }
        nla_nest_end(skb, nest);
    }

    if (vlan->nr_egress_mappings) {
        nest = nla_nest_start(skb, IFLA_VLAN_EGRESS_QOS);
        if (nest == NULL)
            goto nla_put_failure;

        for (i = 0; i < ARRAY_SIZE(vlan->egress_priority_map); i++) {
            for (pm = vlan->egress_priority_map[i]; pm;
                 pm = pm->next) {
                if (!pm->vlan_qos)
                    continue;

                m.from = pm->priority;
                m.to   = (pm->vlan_qos >> 13) & 0x7;
                if (nla_put(skb, IFLA_VLAN_QOS_MAPPING,
                        sizeof(m), &m))
                    goto nla_put_failure;
            }
        }
        nla_nest_end(skb, nest);
    }
    return 0;

nla_put_failure:
    return -EMSGSIZE;
}

struct rtnl_link_ops vlan_link_ops __read_mostly = {
    .kind       = "vlan",
    .maxtype    = IFLA_VLAN_MAX,
    .policy     = vlan_policy,
    .priv_size  = sizeof(struct vlan_dev_priv),
    .setup      = vlan_setup,
    .validate   = vlan_validate,
    .newlink    = vlan_newlink,
    .changelink = vlan_changelink,
    .dellink    = unregister_vlan_dev,
    .get_size   = vlan_get_size,
    .fill_info  = vlan_fill_info,
};

int __init vlan_netlink_init(void)
{
    return rtnl_link_register(&vlan_link_ops);
}

void __exit vlan_netlink_fini(void)
{
    rtnl_link_unregister(&vlan_link_ops);
}

MODULE_ALIAS_RTNL_LINK("vlan");