root/net/8021q/vlan_netlink.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 *      VLAN netlink control interface
 *
 *      Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
 */

#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 },
        [IFLA_VLAN_PROTOCOL]    = { .type = NLA_U16 },
};

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_deprecated(attr, IFLA_VLAN_QOS_MAX,
                                              vlan_map_policy, NULL);
}

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

        if (tb[IFLA_ADDRESS]) {
                if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
                        NL_SET_ERR_MSG_MOD(extack, "Invalid link address");
                        return -EINVAL;
                }
                if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
                        NL_SET_ERR_MSG_MOD(extack, "Invalid link address");
                        return -EADDRNOTAVAIL;
                }
        }

        if (!data) {
                NL_SET_ERR_MSG_MOD(extack, "VLAN properties not specified");
                return -EINVAL;
        }

        if (data[IFLA_VLAN_PROTOCOL]) {
                switch (nla_get_be16(data[IFLA_VLAN_PROTOCOL])) {
                case htons(ETH_P_8021Q):
                case htons(ETH_P_8021AD):
                        break;
                default:
                        NL_SET_ERR_MSG_MOD(extack, "Invalid VLAN protocol");
                        return -EPROTONOSUPPORT;
                }
        }

        if (data[IFLA_VLAN_ID]) {
                id = nla_get_u16(data[IFLA_VLAN_ID]);
                if (id >= VLAN_VID_MASK) {
                        NL_SET_ERR_MSG_MOD(extack, "Invalid VLAN id");
                        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 | VLAN_FLAG_MVRP |
                      VLAN_FLAG_BRIDGE_BINDING)) {
                        NL_SET_ERR_MSG_MOD(extack, "Invalid VLAN flags");
                        return -EINVAL;
                }
        }

        err = vlan_validate_qos_map(data[IFLA_VLAN_INGRESS_QOS]);
        if (err < 0) {
                NL_SET_ERR_MSG_MOD(extack, "Invalid ingress QOS map");
                return err;
        }
        err = vlan_validate_qos_map(data[IFLA_VLAN_EGRESS_QOS]);
        if (err < 0) {
                NL_SET_ERR_MSG_MOD(extack, "Invalid egress QOS map");
                return err;
        }
        return 0;
}

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

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

static int vlan_newlink(struct net_device *dev,
                        struct rtnl_newlink_params *params,
                        struct netlink_ext_ack *extack)
{
        struct net *link_net = rtnl_newlink_link_net(params);
        struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
        struct nlattr **data = params->data;
        struct nlattr **tb = params->tb;
        struct net_device *real_dev;
        unsigned int max_mtu;
        __be16 proto;
        int err;

        if (!data[IFLA_VLAN_ID]) {
                NL_SET_ERR_MSG_MOD(extack, "VLAN id not specified");
                return -EINVAL;
        }

        if (!tb[IFLA_LINK]) {
                NL_SET_ERR_MSG_MOD(extack, "link not specified");
                return -EINVAL;
        }

        real_dev = __dev_get_by_index(link_net, nla_get_u32(tb[IFLA_LINK]));
        if (!real_dev) {
                NL_SET_ERR_MSG_MOD(extack, "link does not exist");
                return -ENODEV;
        }

        proto = nla_get_be16_default(data[IFLA_VLAN_PROTOCOL],
                                     htons(ETH_P_8021Q));

        vlan->vlan_proto = proto;
        vlan->vlan_id    = nla_get_u16(data[IFLA_VLAN_ID]);
        vlan->real_dev   = real_dev;
        dev->priv_flags |= (real_dev->priv_flags & IFF_XMIT_DST_RELEASE);
        vlan->flags      = VLAN_FLAG_REORDER_HDR;

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

        max_mtu = netif_reduces_vlan_mtu(real_dev) ? real_dev->mtu - VLAN_HLEN :
                                                     real_dev->mtu;
        if (!tb[IFLA_MTU])
                dev->mtu = max_mtu;
        else if (dev->mtu > max_mtu)
                return -EINVAL;

        /* Note: If this initial vlan_changelink() fails, we need
         * to call vlan_dev_free_egress_priority() to free memory.
         */
        err = vlan_changelink(dev, tb, data, extack);

        if (!err)
                err = register_vlan_dev(dev, extack);

        if (err)
                vlan_dev_free_egress_priority(dev);
        return err;
}

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_PROTOCOL */
               nla_total_size(2) +      /* IFLA_VLAN_ID */
               nla_total_size(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_be16(skb, IFLA_VLAN_PROTOCOL, vlan->vlan_proto) ||
            nla_put_u16(skb, IFLA_VLAN_ID, vlan->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_noflag(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_noflag(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;
}

static struct net *vlan_get_link_net(const struct net_device *dev)
{
        struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;

        return dev_net(real_dev);
}

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,
        .get_link_net   = vlan_get_link_net,
};

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");