datapath.c

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/*
 * Copyright (c) 2007-2012 Nicira, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/jhash.h>
#include <linux/delay.h>
#include <linux/time.h>
#include <linux/etherdevice.h>
#include <linux/genetlink.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/percpu.h>
#include <linux/rcupdate.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/ethtool.h>
#include <linux/wait.h>
#include <asm/div64.h>
#include <linux/highmem.h>
#include <linux/netfilter_bridge.h>
#include <linux/netfilter_ipv4.h>
#include <linux/inetdevice.h>
#include <linux/list.h>
#include <linux/openvswitch.h>
#include <linux/rculist.h>
#include <linux/dmi.h>
#include <linux/workqueue.h>
#include <net/genetlink.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>

#include "datapath.h"
#include "flow.h"
#include "vport-internal_dev.h"

struct ovs_net {
    struct list_head dps;
};

static int ovs_net_id __read_mostly;

#define REHASH_FLOW_INTERVAL (10 * 60 * HZ)
static void rehash_flow_table(struct work_struct *work);
static DECLARE_DELAYED_WORK(rehash_flow_wq, rehash_flow_table);

static struct vport *new_vport(const struct vport_parms *);
static int queue_gso_packets(struct net *, int dp_ifindex, struct sk_buff *,
                 const struct dp_upcall_info *);
static int queue_userspace_packet(struct net *, int dp_ifindex,
                  struct sk_buff *,
                  const struct dp_upcall_info *);

/* Must be called with rcu_read_lock, genl_mutex, or RTNL lock. */
static struct datapath *get_dp(struct net *net, int dp_ifindex)
{
    struct datapath *dp = NULL;
    struct net_device *dev;

    rcu_read_lock();
    dev = dev_get_by_index_rcu(net, dp_ifindex);
    if (dev) {
        struct vport *vport = ovs_internal_dev_get_vport(dev);
        if (vport)
            dp = vport->dp;
    }
    rcu_read_unlock();

    return dp;
}

/* Must be called with rcu_read_lock or RTNL lock. */
const char *ovs_dp_name(const struct datapath *dp)
{
    struct vport *vport = ovs_vport_rtnl_rcu(dp, OVSP_LOCAL);
    return vport->ops->get_name(vport);
}

static int get_dpifindex(struct datapath *dp)
{
    struct vport *local;
    int ifindex;

    rcu_read_lock();

    local = ovs_vport_rcu(dp, OVSP_LOCAL);
    if (local)
        ifindex = local->ops->get_ifindex(local);
    else
        ifindex = 0;

    rcu_read_unlock();

    return ifindex;
}

static void destroy_dp_rcu(struct rcu_head *rcu)
{
    struct datapath *dp = container_of(rcu, struct datapath, rcu);

    ovs_flow_tbl_destroy((__force struct flow_table *)dp->table);
    free_percpu(dp->stats_percpu);
    release_net(ovs_dp_get_net(dp));
    kfree(dp->ports);
    kfree(dp);
}

static struct hlist_head *vport_hash_bucket(const struct datapath *dp,
                        u16 port_no)
{
    return &dp->ports[port_no & (DP_VPORT_HASH_BUCKETS - 1)];
}

struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no)
{
    struct vport *vport;
    struct hlist_node *n;
    struct hlist_head *head;

    head = vport_hash_bucket(dp, port_no);
    hlist_for_each_entry_rcu(vport, n, head, dp_hash_node) {
        if (vport->port_no == port_no)
            return vport;
    }
    return NULL;
}

/* Called with RTNL lock and genl_lock. */
static struct vport *new_vport(const struct vport_parms *parms)
{
    struct vport *vport;

    vport = ovs_vport_add(parms);
    if (!IS_ERR(vport)) {
        struct datapath *dp = parms->dp;
        struct hlist_head *head = vport_hash_bucket(dp, vport->port_no);

        hlist_add_head_rcu(&vport->dp_hash_node, head);
    }

    return vport;
}

/* Called with RTNL lock. */
void ovs_dp_detach_port(struct vport *p)
{
    ASSERT_RTNL();

    /* First drop references to device. */
    hlist_del_rcu(&p->dp_hash_node);

    /* Then destroy it. */
    ovs_vport_del(p);
}

/* Must be called with rcu_read_lock. */
void ovs_dp_process_received_packet(struct vport *p, struct sk_buff *skb)
{
    struct datapath *dp = p->dp;
    struct sw_flow *flow;
    struct dp_stats_percpu *stats;
    struct sw_flow_key key;
    u64 *stats_counter;
    int error;
    int key_len;

    stats = per_cpu_ptr(dp->stats_percpu, smp_processor_id());

    /* Extract flow from 'skb' into 'key'. */
    error = ovs_flow_extract(skb, p->port_no, &key, &key_len);
    if (unlikely(error)) {
        kfree_skb(skb);
        return;
    }

    /* Look up flow. */
    flow = ovs_flow_tbl_lookup(rcu_dereference(dp->table), &key, key_len);
    if (unlikely(!flow)) {
        struct dp_upcall_info upcall;

        upcall.cmd = OVS_PACKET_CMD_MISS;
        upcall.key = &key;
        upcall.userdata = NULL;
        upcall.portid = p->upcall_portid;
        ovs_dp_upcall(dp, skb, &upcall);
        consume_skb(skb);
        stats_counter = &stats->n_missed;
        goto out;
    }

    OVS_CB(skb)->flow = flow;

    stats_counter = &stats->n_hit;
    ovs_flow_used(OVS_CB(skb)->flow, skb);
    ovs_execute_actions(dp, skb);

out:
    /* Update datapath statistics. */
    u64_stats_update_begin(&stats->sync);
    (*stats_counter)++;
    u64_stats_update_end(&stats->sync);
}

static struct genl_family dp_packet_genl_family = {
    .id = GENL_ID_GENERATE,
    .hdrsize = sizeof(struct ovs_header),
    .name = OVS_PACKET_FAMILY,
    .version = OVS_PACKET_VERSION,
    .maxattr = OVS_PACKET_ATTR_MAX,
    .netnsok = true
};

int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
          const struct dp_upcall_info *upcall_info)
{
    struct dp_stats_percpu *stats;
    int dp_ifindex;
    int err;

    if (upcall_info->portid == 0) {
        err = -ENOTCONN;
        goto err;
    }

    dp_ifindex = get_dpifindex(dp);
    if (!dp_ifindex) {
        err = -ENODEV;
        goto err;
    }

    if (!skb_is_gso(skb))
        err = queue_userspace_packet(ovs_dp_get_net(dp), dp_ifindex, skb, upcall_info);
    else
        err = queue_gso_packets(ovs_dp_get_net(dp), dp_ifindex, skb, upcall_info);
    if (err)
        goto err;

    return 0;

err:
    stats = per_cpu_ptr(dp->stats_percpu, smp_processor_id());

    u64_stats_update_begin(&stats->sync);
    stats->n_lost++;
    u64_stats_update_end(&stats->sync);

    return err;
}

static int queue_gso_packets(struct net *net, int dp_ifindex,
                 struct sk_buff *skb,
                 const struct dp_upcall_info *upcall_info)
{
    unsigned short gso_type = skb_shinfo(skb)->gso_type;
    struct dp_upcall_info later_info;
    struct sw_flow_key later_key;
    struct sk_buff *segs, *nskb;
    int err;

    segs = skb_gso_segment(skb, NETIF_F_SG | NETIF_F_HW_CSUM);
    if (IS_ERR(segs))
        return PTR_ERR(segs);

    /* Queue all of the segments. */
    skb = segs;
    do {
        err = queue_userspace_packet(net, dp_ifindex, skb, upcall_info);
        if (err)
            break;

        if (skb == segs && gso_type & SKB_GSO_UDP) {
            /* The initial flow key extracted by ovs_flow_extract()
             * in this case is for a first fragment, so we need to
             * properly mark later fragments.
             */
            later_key = *upcall_info->key;
            later_key.ip.frag = OVS_FRAG_TYPE_LATER;

            later_info = *upcall_info;
            later_info.key = &later_key;
            upcall_info = &later_info;
        }
    } while ((skb = skb->next));

    /* Free all of the segments. */
    skb = segs;
    do {
        nskb = skb->next;
        if (err)
            kfree_skb(skb);
        else
            consume_skb(skb);
    } while ((skb = nskb));
    return err;
}

static int queue_userspace_packet(struct net *net, int dp_ifindex,
                  struct sk_buff *skb,
                  const struct dp_upcall_info *upcall_info)
{
    struct ovs_header *upcall;
    struct sk_buff *nskb = NULL;
    struct sk_buff *user_skb; /* to be queued to userspace */
    struct nlattr *nla;
    unsigned int len;
    int err;

    if (vlan_tx_tag_present(skb)) {
        nskb = skb_clone(skb, GFP_ATOMIC);
        if (!nskb)
            return -ENOMEM;

        nskb = __vlan_put_tag(nskb, vlan_tx_tag_get(nskb));
        if (!nskb)
            return -ENOMEM;

        nskb->vlan_tci = 0;
        skb = nskb;
    }

    if (nla_attr_size(skb->len) > USHRT_MAX) {
        err = -EFBIG;
        goto out;
    }

    len = sizeof(struct ovs_header);
    len += nla_total_size(skb->len);
    len += nla_total_size(FLOW_BUFSIZE);
    if (upcall_info->cmd == OVS_PACKET_CMD_ACTION)
        len += nla_total_size(8);

    user_skb = genlmsg_new(len, GFP_ATOMIC);
    if (!user_skb) {
        err = -ENOMEM;
        goto out;
    }

    upcall = genlmsg_put(user_skb, 0, 0, &dp_packet_genl_family,
                 0, upcall_info->cmd);
    upcall->dp_ifindex = dp_ifindex;

    nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_KEY);
    ovs_flow_to_nlattrs(upcall_info->key, user_skb);
    nla_nest_end(user_skb, nla);

    if (upcall_info->userdata)
        nla_put_u64(user_skb, OVS_PACKET_ATTR_USERDATA,
                nla_get_u64(upcall_info->userdata));

    nla = __nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, skb->len);

    skb_copy_and_csum_dev(skb, nla_data(nla));

    err = genlmsg_unicast(net, user_skb, upcall_info->portid);

out:
    kfree_skb(nskb);
    return err;
}

/* Called with genl_mutex. */
static int flush_flows(struct datapath *dp)
{
    struct flow_table *old_table;
    struct flow_table *new_table;

    old_table = genl_dereference(dp->table);
    new_table = ovs_flow_tbl_alloc(TBL_MIN_BUCKETS);
    if (!new_table)
        return -ENOMEM;

    rcu_assign_pointer(dp->table, new_table);

    ovs_flow_tbl_deferred_destroy(old_table);
    return 0;
}

static int validate_actions(const struct nlattr *attr,
                const struct sw_flow_key *key, int depth);

static int validate_sample(const struct nlattr *attr,
                const struct sw_flow_key *key, int depth)
{
    const struct nlattr *attrs[OVS_SAMPLE_ATTR_MAX + 1];
    const struct nlattr *probability, *actions;
    const struct nlattr *a;
    int rem;

    memset(attrs, 0, sizeof(attrs));
    nla_for_each_nested(a, attr, rem) {
        int type = nla_type(a);
        if (!type || type > OVS_SAMPLE_ATTR_MAX || attrs[type])
            return -EINVAL;
        attrs[type] = a;
    }
    if (rem)
        return -EINVAL;

    probability = attrs[OVS_SAMPLE_ATTR_PROBABILITY];
    if (!probability || nla_len(probability) != sizeof(u32))
        return -EINVAL;

    actions = attrs[OVS_SAMPLE_ATTR_ACTIONS];
    if (!actions || (nla_len(actions) && nla_len(actions) < NLA_HDRLEN))
        return -EINVAL;
    return validate_actions(actions, key, depth + 1);
}

static int validate_tp_port(const struct sw_flow_key *flow_key)
{
    if (flow_key->eth.type == htons(ETH_P_IP)) {
        if (flow_key->ipv4.tp.src || flow_key->ipv4.tp.dst)
            return 0;
    } else if (flow_key->eth.type == htons(ETH_P_IPV6)) {
        if (flow_key->ipv6.tp.src || flow_key->ipv6.tp.dst)
            return 0;
    }

    return -EINVAL;
}

static int validate_set(const struct nlattr *a,
            const struct sw_flow_key *flow_key)
{
    const struct nlattr *ovs_key = nla_data(a);
    int key_type = nla_type(ovs_key);

    /* There can be only one key in a action */
    if (nla_total_size(nla_len(ovs_key)) != nla_len(a))
        return -EINVAL;

    if (key_type > OVS_KEY_ATTR_MAX ||
        nla_len(ovs_key) != ovs_key_lens[key_type])
        return -EINVAL;

    switch (key_type) {
    const struct ovs_key_ipv4 *ipv4_key;

    case OVS_KEY_ATTR_PRIORITY:
    case OVS_KEY_ATTR_ETHERNET:
        break;

    case OVS_KEY_ATTR_IPV4:
        if (flow_key->eth.type != htons(ETH_P_IP))
            return -EINVAL;

        if (!flow_key->ip.proto)
            return -EINVAL;

        ipv4_key = nla_data(ovs_key);
        if (ipv4_key->ipv4_proto != flow_key->ip.proto)
            return -EINVAL;

        if (ipv4_key->ipv4_frag != flow_key->ip.frag)
            return -EINVAL;

        break;

    case OVS_KEY_ATTR_TCP:
        if (flow_key->ip.proto != IPPROTO_TCP)
            return -EINVAL;

        return validate_tp_port(flow_key);

    case OVS_KEY_ATTR_UDP:
        if (flow_key->ip.proto != IPPROTO_UDP)
            return -EINVAL;

        return validate_tp_port(flow_key);

    default:
        return -EINVAL;
    }

    return 0;
}

static int validate_userspace(const struct nlattr *attr)
{
    static const struct nla_policy userspace_policy[OVS_USERSPACE_ATTR_MAX + 1] =   {
        [OVS_USERSPACE_ATTR_PID] = {.type = NLA_U32 },
        [OVS_USERSPACE_ATTR_USERDATA] = {.type = NLA_U64 },
    };
    struct nlattr *a[OVS_USERSPACE_ATTR_MAX + 1];
    int error;

    error = nla_parse_nested(a, OVS_USERSPACE_ATTR_MAX,
                 attr, userspace_policy);
    if (error)
        return error;

    if (!a[OVS_USERSPACE_ATTR_PID] ||
        !nla_get_u32(a[OVS_USERSPACE_ATTR_PID]))
        return -EINVAL;

    return 0;
}

static int validate_actions(const struct nlattr *attr,
                const struct sw_flow_key *key,  int depth)
{
    const struct nlattr *a;
    int rem, err;

    if (depth >= SAMPLE_ACTION_DEPTH)
        return -EOVERFLOW;

    nla_for_each_nested(a, attr, rem) {
        /* Expected argument lengths, (u32)-1 for variable length. */
        static const u32 action_lens[OVS_ACTION_ATTR_MAX + 1] = {
            [OVS_ACTION_ATTR_OUTPUT] = sizeof(u32),
            [OVS_ACTION_ATTR_USERSPACE] = (u32)-1,
            [OVS_ACTION_ATTR_PUSH_VLAN] = sizeof(struct ovs_action_push_vlan),
            [OVS_ACTION_ATTR_POP_VLAN] = 0,
            [OVS_ACTION_ATTR_SET] = (u32)-1,
            [OVS_ACTION_ATTR_SAMPLE] = (u32)-1
        };
        const struct ovs_action_push_vlan *vlan;
        int type = nla_type(a);

        if (type > OVS_ACTION_ATTR_MAX ||
            (action_lens[type] != nla_len(a) &&
             action_lens[type] != (u32)-1))
            return -EINVAL;

        switch (type) {
        case OVS_ACTION_ATTR_UNSPEC:
            return -EINVAL;

        case OVS_ACTION_ATTR_USERSPACE:
            err = validate_userspace(a);
            if (err)
                return err;
            break;

        case OVS_ACTION_ATTR_OUTPUT:
            if (nla_get_u32(a) >= DP_MAX_PORTS)
                return -EINVAL;
            break;


        case OVS_ACTION_ATTR_POP_VLAN:
            break;

        case OVS_ACTION_ATTR_PUSH_VLAN:
            vlan = nla_data(a);
            if (vlan->vlan_tpid != htons(ETH_P_8021Q))
                return -EINVAL;
            if (!(vlan->vlan_tci & htons(VLAN_TAG_PRESENT)))
                return -EINVAL;
            break;

        case OVS_ACTION_ATTR_SET:
            err = validate_set(a, key);
            if (err)
                return err;
            break;

        case OVS_ACTION_ATTR_SAMPLE:
            err = validate_sample(a, key, depth);
            if (err)
                return err;
            break;

        default:
            return -EINVAL;
        }
    }

    if (rem > 0)
        return -EINVAL;

    return 0;
}

static void clear_stats(struct sw_flow *flow)
{
    flow->used = 0;
    flow->tcp_flags = 0;
    flow->packet_count = 0;
    flow->byte_count = 0;
}

static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
{
    struct ovs_header *ovs_header = info->userhdr;
    struct nlattr **a = info->attrs;
    struct sw_flow_actions *acts;
    struct sk_buff *packet;
    struct sw_flow *flow;
    struct datapath *dp;
    struct ethhdr *eth;
    int len;
    int err;
    int key_len;

    err = -EINVAL;
    if (!a[OVS_PACKET_ATTR_PACKET] || !a[OVS_PACKET_ATTR_KEY] ||
        !a[OVS_PACKET_ATTR_ACTIONS] ||
        nla_len(a[OVS_PACKET_ATTR_PACKET]) < ETH_HLEN)
        goto err;

    len = nla_len(a[OVS_PACKET_ATTR_PACKET]);
    packet = __dev_alloc_skb(NET_IP_ALIGN + len, GFP_KERNEL);
    err = -ENOMEM;
    if (!packet)
        goto err;
    skb_reserve(packet, NET_IP_ALIGN);

    memcpy(__skb_put(packet, len), nla_data(a[OVS_PACKET_ATTR_PACKET]), len);

    skb_reset_mac_header(packet);
    eth = eth_hdr(packet);

    /* Normally, setting the skb 'protocol' field would be handled by a
     * call to eth_type_trans(), but it assumes there's a sending
     * device, which we may not have. */
    if (ntohs(eth->h_proto) >= 1536)
        packet->protocol = eth->h_proto;
    else
        packet->protocol = htons(ETH_P_802_2);

    /* Build an sw_flow for sending this packet. */
    flow = ovs_flow_alloc();
    err = PTR_ERR(flow);
    if (IS_ERR(flow))
        goto err_kfree_skb;

    err = ovs_flow_extract(packet, -1, &flow->key, &key_len);
    if (err)
        goto err_flow_free;

    err = ovs_flow_metadata_from_nlattrs(&flow->key.phy.priority,
                         &flow->key.phy.in_port,
                         a[OVS_PACKET_ATTR_KEY]);
    if (err)
        goto err_flow_free;

    err = validate_actions(a[OVS_PACKET_ATTR_ACTIONS], &flow->key, 0);
    if (err)
        goto err_flow_free;

    flow->hash = ovs_flow_hash(&flow->key, key_len);

    acts = ovs_flow_actions_alloc(a[OVS_PACKET_ATTR_ACTIONS]);
    err = PTR_ERR(acts);
    if (IS_ERR(acts))
        goto err_flow_free;
    rcu_assign_pointer(flow->sf_acts, acts);

    OVS_CB(packet)->flow = flow;
    packet->priority = flow->key.phy.priority;

    rcu_read_lock();
    dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
    err = -ENODEV;
    if (!dp)
        goto err_unlock;

    local_bh_disable();
    err = ovs_execute_actions(dp, packet);
    local_bh_enable();
    rcu_read_unlock();

    ovs_flow_free(flow);
    return err;

err_unlock:
    rcu_read_unlock();
err_flow_free:
    ovs_flow_free(flow);
err_kfree_skb:
    kfree_skb(packet);
err:
    return err;
}

static const struct nla_policy packet_policy[OVS_PACKET_ATTR_MAX + 1] = {
    [OVS_PACKET_ATTR_PACKET] = { .type = NLA_UNSPEC },
    [OVS_PACKET_ATTR_KEY] = { .type = NLA_NESTED },
    [OVS_PACKET_ATTR_ACTIONS] = { .type = NLA_NESTED },
};

static struct genl_ops dp_packet_genl_ops[] = {
    { .cmd = OVS_PACKET_CMD_EXECUTE,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = packet_policy,
      .doit = ovs_packet_cmd_execute
    }
};

static void get_dp_stats(struct datapath *dp, struct ovs_dp_stats *stats)
{
    int i;
    struct flow_table *table = genl_dereference(dp->table);

    stats->n_flows = ovs_flow_tbl_count(table);

    stats->n_hit = stats->n_missed = stats->n_lost = 0;
    for_each_possible_cpu(i) {
        const struct dp_stats_percpu *percpu_stats;
        struct dp_stats_percpu local_stats;
        unsigned int start;

        percpu_stats = per_cpu_ptr(dp->stats_percpu, i);

        do {
            start = u64_stats_fetch_begin_bh(&percpu_stats->sync);
            local_stats = *percpu_stats;
        } while (u64_stats_fetch_retry_bh(&percpu_stats->sync, start));

        stats->n_hit += local_stats.n_hit;
        stats->n_missed += local_stats.n_missed;
        stats->n_lost += local_stats.n_lost;
    }
}

static const struct nla_policy flow_policy[OVS_FLOW_ATTR_MAX + 1] = {
    [OVS_FLOW_ATTR_KEY] = { .type = NLA_NESTED },
    [OVS_FLOW_ATTR_ACTIONS] = { .type = NLA_NESTED },
    [OVS_FLOW_ATTR_CLEAR] = { .type = NLA_FLAG },
};

static struct genl_family dp_flow_genl_family = {
    .id = GENL_ID_GENERATE,
    .hdrsize = sizeof(struct ovs_header),
    .name = OVS_FLOW_FAMILY,
    .version = OVS_FLOW_VERSION,
    .maxattr = OVS_FLOW_ATTR_MAX,
    .netnsok = true
};

static struct genl_multicast_group ovs_dp_flow_multicast_group = {
    .name = OVS_FLOW_MCGROUP
};

/* Called with genl_lock. */
static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
                  struct sk_buff *skb, u32 portid,
                  u32 seq, u32 flags, u8 cmd)
{
    const int skb_orig_len = skb->len;
    const struct sw_flow_actions *sf_acts;
    struct ovs_flow_stats stats;
    struct ovs_header *ovs_header;
    struct nlattr *nla;
    unsigned long used;
    u8 tcp_flags;
    int err;

    sf_acts = rcu_dereference_protected(flow->sf_acts,
                        lockdep_genl_is_held());

    ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family, flags, cmd);
    if (!ovs_header)
        return -EMSGSIZE;

    ovs_header->dp_ifindex = get_dpifindex(dp);

    nla = nla_nest_start(skb, OVS_FLOW_ATTR_KEY);
    if (!nla)
        goto nla_put_failure;
    err = ovs_flow_to_nlattrs(&flow->key, skb);
    if (err)
        goto error;
    nla_nest_end(skb, nla);

    spin_lock_bh(&flow->lock);
    used = flow->used;
    stats.n_packets = flow->packet_count;
    stats.n_bytes = flow->byte_count;
    tcp_flags = flow->tcp_flags;
    spin_unlock_bh(&flow->lock);

    if (used &&
        nla_put_u64(skb, OVS_FLOW_ATTR_USED, ovs_flow_used_time(used)))
        goto nla_put_failure;

    if (stats.n_packets &&
        nla_put(skb, OVS_FLOW_ATTR_STATS,
            sizeof(struct ovs_flow_stats), &stats))
        goto nla_put_failure;

    if (tcp_flags &&
        nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, tcp_flags))
        goto nla_put_failure;

    /* If OVS_FLOW_ATTR_ACTIONS doesn't fit, skip dumping the actions if
     * this is the first flow to be dumped into 'skb'.  This is unusual for
     * Netlink but individual action lists can be longer than
     * NLMSG_GOODSIZE and thus entirely undumpable if we didn't do this.
     * The userspace caller can always fetch the actions separately if it
     * really wants them.  (Most userspace callers in fact don't care.)
     *
     * This can only fail for dump operations because the skb is always
     * properly sized for single flows.
     */
    err = nla_put(skb, OVS_FLOW_ATTR_ACTIONS, sf_acts->actions_len,
              sf_acts->actions);
    if (err < 0 && skb_orig_len)
        goto error;

    return genlmsg_end(skb, ovs_header);

nla_put_failure:
    err = -EMSGSIZE;
error:
    genlmsg_cancel(skb, ovs_header);
    return err;
}

static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow)
{
    const struct sw_flow_actions *sf_acts;
    int len;

    sf_acts = rcu_dereference_protected(flow->sf_acts,
                        lockdep_genl_is_held());

    /* OVS_FLOW_ATTR_KEY */
    len = nla_total_size(FLOW_BUFSIZE);
    /* OVS_FLOW_ATTR_ACTIONS */
    len += nla_total_size(sf_acts->actions_len);
    /* OVS_FLOW_ATTR_STATS */
    len += nla_total_size(sizeof(struct ovs_flow_stats));
    /* OVS_FLOW_ATTR_TCP_FLAGS */
    len += nla_total_size(1);
    /* OVS_FLOW_ATTR_USED */
    len += nla_total_size(8);

    len += NLMSG_ALIGN(sizeof(struct ovs_header));

    return genlmsg_new(len, GFP_KERNEL);
}

static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
                           struct datapath *dp,
                           u32 portid, u32 seq, u8 cmd)
{
    struct sk_buff *skb;
    int retval;

    skb = ovs_flow_cmd_alloc_info(flow);
    if (!skb)
        return ERR_PTR(-ENOMEM);

    retval = ovs_flow_cmd_fill_info(flow, dp, skb, portid, seq, 0, cmd);
    BUG_ON(retval < 0);
    return skb;
}

static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
{
    struct nlattr **a = info->attrs;
    struct ovs_header *ovs_header = info->userhdr;
    struct sw_flow_key key;
    struct sw_flow *flow;
    struct sk_buff *reply;
    struct datapath *dp;
    struct flow_table *table;
    int error;
    int key_len;

    /* Extract key. */
    error = -EINVAL;
    if (!a[OVS_FLOW_ATTR_KEY])
        goto error;
    error = ovs_flow_from_nlattrs(&key, &key_len, a[OVS_FLOW_ATTR_KEY]);
    if (error)
        goto error;

    /* Validate actions. */
    if (a[OVS_FLOW_ATTR_ACTIONS]) {
        error = validate_actions(a[OVS_FLOW_ATTR_ACTIONS], &key,  0);
        if (error)
            goto error;
    } else if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW) {
        error = -EINVAL;
        goto error;
    }

    dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
    error = -ENODEV;
    if (!dp)
        goto error;

    table = genl_dereference(dp->table);
    flow = ovs_flow_tbl_lookup(table, &key, key_len);
    if (!flow) {
        struct sw_flow_actions *acts;

        /* Bail out if we're not allowed to create a new flow. */
        error = -ENOENT;
        if (info->genlhdr->cmd == OVS_FLOW_CMD_SET)
            goto error;

        /* Expand table, if necessary, to make room. */
        if (ovs_flow_tbl_need_to_expand(table)) {
            struct flow_table *new_table;

            new_table = ovs_flow_tbl_expand(table);
            if (!IS_ERR(new_table)) {
                rcu_assign_pointer(dp->table, new_table);
                ovs_flow_tbl_deferred_destroy(table);
                table = genl_dereference(dp->table);
            }
        }

        /* Allocate flow. */
        flow = ovs_flow_alloc();
        if (IS_ERR(flow)) {
            error = PTR_ERR(flow);
            goto error;
        }
        flow->key = key;
        clear_stats(flow);

        /* Obtain actions. */
        acts = ovs_flow_actions_alloc(a[OVS_FLOW_ATTR_ACTIONS]);
        error = PTR_ERR(acts);
        if (IS_ERR(acts))
            goto error_free_flow;
        rcu_assign_pointer(flow->sf_acts, acts);

        /* Put flow in bucket. */
        flow->hash = ovs_flow_hash(&key, key_len);
        ovs_flow_tbl_insert(table, flow);

        reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
                        info->snd_seq,
                        OVS_FLOW_CMD_NEW);
    } else {
        /* We found a matching flow. */
        struct sw_flow_actions *old_acts;
        struct nlattr *acts_attrs;

        /* Bail out if we're not allowed to modify an existing flow.
         * We accept NLM_F_CREATE in place of the intended NLM_F_EXCL
         * because Generic Netlink treats the latter as a dump
         * request.  We also accept NLM_F_EXCL in case that bug ever
         * gets fixed.
         */
        error = -EEXIST;
        if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW &&
            info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))
            goto error;

        /* Update actions. */
        old_acts = rcu_dereference_protected(flow->sf_acts,
                             lockdep_genl_is_held());
        acts_attrs = a[OVS_FLOW_ATTR_ACTIONS];
        if (acts_attrs &&
           (old_acts->actions_len != nla_len(acts_attrs) ||
           memcmp(old_acts->actions, nla_data(acts_attrs),
              old_acts->actions_len))) {
            struct sw_flow_actions *new_acts;

            new_acts = ovs_flow_actions_alloc(acts_attrs);
            error = PTR_ERR(new_acts);
            if (IS_ERR(new_acts))
                goto error;

            rcu_assign_pointer(flow->sf_acts, new_acts);
            ovs_flow_deferred_free_acts(old_acts);
        }

        reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
                           info->snd_seq, OVS_FLOW_CMD_NEW);

        /* Clear stats. */
        if (a[OVS_FLOW_ATTR_CLEAR]) {
            spin_lock_bh(&flow->lock);
            clear_stats(flow);
            spin_unlock_bh(&flow->lock);
        }
    }

    if (!IS_ERR(reply))
        genl_notify(reply, genl_info_net(info), info->snd_portid,
               ovs_dp_flow_multicast_group.id, info->nlhdr,
               GFP_KERNEL);
    else
        netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
                ovs_dp_flow_multicast_group.id, PTR_ERR(reply));
    return 0;

error_free_flow:
    ovs_flow_free(flow);
error:
    return error;
}

static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
{
    struct nlattr **a = info->attrs;
    struct ovs_header *ovs_header = info->userhdr;
    struct sw_flow_key key;
    struct sk_buff *reply;
    struct sw_flow *flow;
    struct datapath *dp;
    struct flow_table *table;
    int err;
    int key_len;

    if (!a[OVS_FLOW_ATTR_KEY])
        return -EINVAL;
    err = ovs_flow_from_nlattrs(&key, &key_len, a[OVS_FLOW_ATTR_KEY]);
    if (err)
        return err;

    dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
    if (!dp)
        return -ENODEV;

    table = genl_dereference(dp->table);
    flow = ovs_flow_tbl_lookup(table, &key, key_len);
    if (!flow)
        return -ENOENT;

    reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
                    info->snd_seq, OVS_FLOW_CMD_NEW);
    if (IS_ERR(reply))
        return PTR_ERR(reply);

    return genlmsg_reply(reply, info);
}

static int ovs_flow_cmd_del(struct sk_buff *skb, struct genl_info *info)
{
    struct nlattr **a = info->attrs;
    struct ovs_header *ovs_header = info->userhdr;
    struct sw_flow_key key;
    struct sk_buff *reply;
    struct sw_flow *flow;
    struct datapath *dp;
    struct flow_table *table;
    int err;
    int key_len;

    dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
    if (!dp)
        return -ENODEV;

    if (!a[OVS_FLOW_ATTR_KEY])
        return flush_flows(dp);

    err = ovs_flow_from_nlattrs(&key, &key_len, a[OVS_FLOW_ATTR_KEY]);
    if (err)
        return err;

    table = genl_dereference(dp->table);
    flow = ovs_flow_tbl_lookup(table, &key, key_len);
    if (!flow)
        return -ENOENT;

    reply = ovs_flow_cmd_alloc_info(flow);
    if (!reply)
        return -ENOMEM;

    ovs_flow_tbl_remove(table, flow);

    err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
                     info->snd_seq, 0, OVS_FLOW_CMD_DEL);
    BUG_ON(err < 0);

    ovs_flow_deferred_free(flow);

    genl_notify(reply, genl_info_net(info), info->snd_portid,
            ovs_dp_flow_multicast_group.id, info->nlhdr, GFP_KERNEL);
    return 0;
}

static int ovs_flow_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
    struct ovs_header *ovs_header = genlmsg_data(nlmsg_data(cb->nlh));
    struct datapath *dp;
    struct flow_table *table;

    dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
    if (!dp)
        return -ENODEV;

    table = genl_dereference(dp->table);

    for (;;) {
        struct sw_flow *flow;
        u32 bucket, obj;

        bucket = cb->args[0];
        obj = cb->args[1];
        flow = ovs_flow_tbl_next(table, &bucket, &obj);
        if (!flow)
            break;

        if (ovs_flow_cmd_fill_info(flow, dp, skb,
                       NETLINK_CB(cb->skb).portid,
                       cb->nlh->nlmsg_seq, NLM_F_MULTI,
                       OVS_FLOW_CMD_NEW) < 0)
            break;

        cb->args[0] = bucket;
        cb->args[1] = obj;
    }
    return skb->len;
}

static struct genl_ops dp_flow_genl_ops[] = {
    { .cmd = OVS_FLOW_CMD_NEW,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = flow_policy,
      .doit = ovs_flow_cmd_new_or_set
    },
    { .cmd = OVS_FLOW_CMD_DEL,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = flow_policy,
      .doit = ovs_flow_cmd_del
    },
    { .cmd = OVS_FLOW_CMD_GET,
      .flags = 0,           /* OK for unprivileged users. */
      .policy = flow_policy,
      .doit = ovs_flow_cmd_get,
      .dumpit = ovs_flow_cmd_dump
    },
    { .cmd = OVS_FLOW_CMD_SET,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = flow_policy,
      .doit = ovs_flow_cmd_new_or_set,
    },
};

static const struct nla_policy datapath_policy[OVS_DP_ATTR_MAX + 1] = {
    [OVS_DP_ATTR_NAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
    [OVS_DP_ATTR_UPCALL_PID] = { .type = NLA_U32 },
};

static struct genl_family dp_datapath_genl_family = {
    .id = GENL_ID_GENERATE,
    .hdrsize = sizeof(struct ovs_header),
    .name = OVS_DATAPATH_FAMILY,
    .version = OVS_DATAPATH_VERSION,
    .maxattr = OVS_DP_ATTR_MAX,
    .netnsok = true
};

static struct genl_multicast_group ovs_dp_datapath_multicast_group = {
    .name = OVS_DATAPATH_MCGROUP
};

static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
                u32 portid, u32 seq, u32 flags, u8 cmd)
{
    struct ovs_header *ovs_header;
    struct ovs_dp_stats dp_stats;
    int err;

    ovs_header = genlmsg_put(skb, portid, seq, &dp_datapath_genl_family,
                   flags, cmd);
    if (!ovs_header)
        goto error;

    ovs_header->dp_ifindex = get_dpifindex(dp);

    rcu_read_lock();
    err = nla_put_string(skb, OVS_DP_ATTR_NAME, ovs_dp_name(dp));
    rcu_read_unlock();
    if (err)
        goto nla_put_failure;

    get_dp_stats(dp, &dp_stats);
    if (nla_put(skb, OVS_DP_ATTR_STATS, sizeof(struct ovs_dp_stats), &dp_stats))
        goto nla_put_failure;

    return genlmsg_end(skb, ovs_header);

nla_put_failure:
    genlmsg_cancel(skb, ovs_header);
error:
    return -EMSGSIZE;
}

static struct sk_buff *ovs_dp_cmd_build_info(struct datapath *dp, u32 portid,
                         u32 seq, u8 cmd)
{
    struct sk_buff *skb;
    int retval;

    skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
    if (!skb)
        return ERR_PTR(-ENOMEM);

    retval = ovs_dp_cmd_fill_info(dp, skb, portid, seq, 0, cmd);
    if (retval < 0) {
        kfree_skb(skb);
        return ERR_PTR(retval);
    }
    return skb;
}

/* Called with genl_mutex and optionally with RTNL lock also. */
static struct datapath *lookup_datapath(struct net *net,
                    struct ovs_header *ovs_header,
                    struct nlattr *a[OVS_DP_ATTR_MAX + 1])
{
    struct datapath *dp;

    if (!a[OVS_DP_ATTR_NAME])
        dp = get_dp(net, ovs_header->dp_ifindex);
    else {
        struct vport *vport;

        rcu_read_lock();
        vport = ovs_vport_locate(net, nla_data(a[OVS_DP_ATTR_NAME]));
        dp = vport && vport->port_no == OVSP_LOCAL ? vport->dp : NULL;
        rcu_read_unlock();
    }
    return dp ? dp : ERR_PTR(-ENODEV);
}

static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
{
    struct nlattr **a = info->attrs;
    struct vport_parms parms;
    struct sk_buff *reply;
    struct datapath *dp;
    struct vport *vport;
    struct ovs_net *ovs_net;
    int err, i;

    err = -EINVAL;
    if (!a[OVS_DP_ATTR_NAME] || !a[OVS_DP_ATTR_UPCALL_PID])
        goto err;

    rtnl_lock();

    err = -ENOMEM;
    dp = kzalloc(sizeof(*dp), GFP_KERNEL);
    if (dp == NULL)
        goto err_unlock_rtnl;

    ovs_dp_set_net(dp, hold_net(sock_net(skb->sk)));

    /* Allocate table. */
    err = -ENOMEM;
    rcu_assign_pointer(dp->table, ovs_flow_tbl_alloc(TBL_MIN_BUCKETS));
    if (!dp->table)
        goto err_free_dp;

    dp->stats_percpu = alloc_percpu(struct dp_stats_percpu);
    if (!dp->stats_percpu) {
        err = -ENOMEM;
        goto err_destroy_table;
    }

    dp->ports = kmalloc(DP_VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
            GFP_KERNEL);
    if (!dp->ports) {
        err = -ENOMEM;
        goto err_destroy_percpu;
    }

    for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++)
        INIT_HLIST_HEAD(&dp->ports[i]);

    /* Set up our datapath device. */
    parms.name = nla_data(a[OVS_DP_ATTR_NAME]);
    parms.type = OVS_VPORT_TYPE_INTERNAL;
    parms.options = NULL;
    parms.dp = dp;
    parms.port_no = OVSP_LOCAL;
    parms.upcall_portid = nla_get_u32(a[OVS_DP_ATTR_UPCALL_PID]);

    vport = new_vport(&parms);
    if (IS_ERR(vport)) {
        err = PTR_ERR(vport);
        if (err == -EBUSY)
            err = -EEXIST;

        goto err_destroy_ports_array;
    }

    reply = ovs_dp_cmd_build_info(dp, info->snd_portid,
                      info->snd_seq, OVS_DP_CMD_NEW);
    err = PTR_ERR(reply);
    if (IS_ERR(reply))
        goto err_destroy_local_port;

    ovs_net = net_generic(ovs_dp_get_net(dp), ovs_net_id);
    list_add_tail(&dp->list_node, &ovs_net->dps);
    rtnl_unlock();

    genl_notify(reply, genl_info_net(info), info->snd_portid,
            ovs_dp_datapath_multicast_group.id, info->nlhdr,
            GFP_KERNEL);
    return 0;

err_destroy_local_port:
    ovs_dp_detach_port(ovs_vport_rtnl(dp, OVSP_LOCAL));
err_destroy_ports_array:
    kfree(dp->ports);
err_destroy_percpu:
    free_percpu(dp->stats_percpu);
err_destroy_table:
    ovs_flow_tbl_destroy(genl_dereference(dp->table));
err_free_dp:
    release_net(ovs_dp_get_net(dp));
    kfree(dp);
err_unlock_rtnl:
    rtnl_unlock();
err:
    return err;
}

/* Called with genl_mutex. */
static void __dp_destroy(struct datapath *dp)
{
    int i;

    rtnl_lock();

    for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++) {
        struct vport *vport;
        struct hlist_node *node, *n;

        hlist_for_each_entry_safe(vport, node, n, &dp->ports[i], dp_hash_node)
            if (vport->port_no != OVSP_LOCAL)
                ovs_dp_detach_port(vport);
    }

    list_del(&dp->list_node);
    ovs_dp_detach_port(ovs_vport_rtnl(dp, OVSP_LOCAL));

    /* rtnl_unlock() will wait until all the references to devices that
     * are pending unregistration have been dropped.  We do it here to
     * ensure that any internal devices (which contain DP pointers) are
     * fully destroyed before freeing the datapath.
     */
    rtnl_unlock();

    call_rcu(&dp->rcu, destroy_dp_rcu);
}

static int ovs_dp_cmd_del(struct sk_buff *skb, struct genl_info *info)
{
    struct sk_buff *reply;
    struct datapath *dp;
    int err;

    dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
    err = PTR_ERR(dp);
    if (IS_ERR(dp))
        return err;

    reply = ovs_dp_cmd_build_info(dp, info->snd_portid,
                      info->snd_seq, OVS_DP_CMD_DEL);
    err = PTR_ERR(reply);
    if (IS_ERR(reply))
        return err;

    __dp_destroy(dp);

    genl_notify(reply, genl_info_net(info), info->snd_portid,
            ovs_dp_datapath_multicast_group.id, info->nlhdr,
            GFP_KERNEL);

    return 0;
}

static int ovs_dp_cmd_set(struct sk_buff *skb, struct genl_info *info)
{
    struct sk_buff *reply;
    struct datapath *dp;
    int err;

    dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
    if (IS_ERR(dp))
        return PTR_ERR(dp);

    reply = ovs_dp_cmd_build_info(dp, info->snd_portid,
                      info->snd_seq, OVS_DP_CMD_NEW);
    if (IS_ERR(reply)) {
        err = PTR_ERR(reply);
        netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
                ovs_dp_datapath_multicast_group.id, err);
        return 0;
    }

    genl_notify(reply, genl_info_net(info), info->snd_portid,
            ovs_dp_datapath_multicast_group.id, info->nlhdr,
            GFP_KERNEL);

    return 0;
}

static int ovs_dp_cmd_get(struct sk_buff *skb, struct genl_info *info)
{
    struct sk_buff *reply;
    struct datapath *dp;

    dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
    if (IS_ERR(dp))
        return PTR_ERR(dp);

    reply = ovs_dp_cmd_build_info(dp, info->snd_portid,
                      info->snd_seq, OVS_DP_CMD_NEW);
    if (IS_ERR(reply))
        return PTR_ERR(reply);

    return genlmsg_reply(reply, info);
}

static int ovs_dp_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
    struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
    struct datapath *dp;
    int skip = cb->args[0];
    int i = 0;

    list_for_each_entry(dp, &ovs_net->dps, list_node) {
        if (i >= skip &&
            ovs_dp_cmd_fill_info(dp, skb, NETLINK_CB(cb->skb).portid,
                     cb->nlh->nlmsg_seq, NLM_F_MULTI,
                     OVS_DP_CMD_NEW) < 0)
            break;
        i++;
    }

    cb->args[0] = i;

    return skb->len;
}

static struct genl_ops dp_datapath_genl_ops[] = {
    { .cmd = OVS_DP_CMD_NEW,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = datapath_policy,
      .doit = ovs_dp_cmd_new
    },
    { .cmd = OVS_DP_CMD_DEL,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = datapath_policy,
      .doit = ovs_dp_cmd_del
    },
    { .cmd = OVS_DP_CMD_GET,
      .flags = 0,           /* OK for unprivileged users. */
      .policy = datapath_policy,
      .doit = ovs_dp_cmd_get,
      .dumpit = ovs_dp_cmd_dump
    },
    { .cmd = OVS_DP_CMD_SET,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = datapath_policy,
      .doit = ovs_dp_cmd_set,
    },
};

static const struct nla_policy vport_policy[OVS_VPORT_ATTR_MAX + 1] = {
    [OVS_VPORT_ATTR_NAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
    [OVS_VPORT_ATTR_STATS] = { .len = sizeof(struct ovs_vport_stats) },
    [OVS_VPORT_ATTR_PORT_NO] = { .type = NLA_U32 },
    [OVS_VPORT_ATTR_TYPE] = { .type = NLA_U32 },
    [OVS_VPORT_ATTR_UPCALL_PID] = { .type = NLA_U32 },
    [OVS_VPORT_ATTR_OPTIONS] = { .type = NLA_NESTED },
};

static struct genl_family dp_vport_genl_family = {
    .id = GENL_ID_GENERATE,
    .hdrsize = sizeof(struct ovs_header),
    .name = OVS_VPORT_FAMILY,
    .version = OVS_VPORT_VERSION,
    .maxattr = OVS_VPORT_ATTR_MAX,
    .netnsok = true
};

struct genl_multicast_group ovs_dp_vport_multicast_group = {
    .name = OVS_VPORT_MCGROUP
};

/* Called with RTNL lock or RCU read lock. */
static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb,
                   u32 portid, u32 seq, u32 flags, u8 cmd)
{
    struct ovs_header *ovs_header;
    struct ovs_vport_stats vport_stats;
    int err;

    ovs_header = genlmsg_put(skb, portid, seq, &dp_vport_genl_family,
                 flags, cmd);
    if (!ovs_header)
        return -EMSGSIZE;

    ovs_header->dp_ifindex = get_dpifindex(vport->dp);

    if (nla_put_u32(skb, OVS_VPORT_ATTR_PORT_NO, vport->port_no) ||
        nla_put_u32(skb, OVS_VPORT_ATTR_TYPE, vport->ops->type) ||
        nla_put_string(skb, OVS_VPORT_ATTR_NAME, vport->ops->get_name(vport)) ||
        nla_put_u32(skb, OVS_VPORT_ATTR_UPCALL_PID, vport->upcall_portid))
        goto nla_put_failure;

    ovs_vport_get_stats(vport, &vport_stats);
    if (nla_put(skb, OVS_VPORT_ATTR_STATS, sizeof(struct ovs_vport_stats),
            &vport_stats))
        goto nla_put_failure;

    err = ovs_vport_get_options(vport, skb);
    if (err == -EMSGSIZE)
        goto error;

    return genlmsg_end(skb, ovs_header);

nla_put_failure:
    err = -EMSGSIZE;
error:
    genlmsg_cancel(skb, ovs_header);
    return err;
}

/* Called with RTNL lock or RCU read lock. */
struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, u32 portid,
                     u32 seq, u8 cmd)
{
    struct sk_buff *skb;
    int retval;

    skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
    if (!skb)
        return ERR_PTR(-ENOMEM);

    retval = ovs_vport_cmd_fill_info(vport, skb, portid, seq, 0, cmd);
    if (retval < 0) {
        kfree_skb(skb);
        return ERR_PTR(retval);
    }
    return skb;
}

/* Called with RTNL lock or RCU read lock. */
static struct vport *lookup_vport(struct net *net,
                  struct ovs_header *ovs_header,
                  struct nlattr *a[OVS_VPORT_ATTR_MAX + 1])
{
    struct datapath *dp;
    struct vport *vport;

    if (a[OVS_VPORT_ATTR_NAME]) {
        vport = ovs_vport_locate(net, nla_data(a[OVS_VPORT_ATTR_NAME]));
        if (!vport)
            return ERR_PTR(-ENODEV);
        if (ovs_header->dp_ifindex &&
            ovs_header->dp_ifindex != get_dpifindex(vport->dp))
            return ERR_PTR(-ENODEV);
        return vport;
    } else if (a[OVS_VPORT_ATTR_PORT_NO]) {
        u32 port_no = nla_get_u32(a[OVS_VPORT_ATTR_PORT_NO]);

        if (port_no >= DP_MAX_PORTS)
            return ERR_PTR(-EFBIG);

        dp = get_dp(net, ovs_header->dp_ifindex);
        if (!dp)
            return ERR_PTR(-ENODEV);

        vport = ovs_vport_rtnl_rcu(dp, port_no);
        if (!vport)
            return ERR_PTR(-ENOENT);
        return vport;
    } else
        return ERR_PTR(-EINVAL);
}

static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
{
    struct nlattr **a = info->attrs;
    struct ovs_header *ovs_header = info->userhdr;
    struct vport_parms parms;
    struct sk_buff *reply;
    struct vport *vport;
    struct datapath *dp;
    u32 port_no;
    int err;

    err = -EINVAL;
    if (!a[OVS_VPORT_ATTR_NAME] || !a[OVS_VPORT_ATTR_TYPE] ||
        !a[OVS_VPORT_ATTR_UPCALL_PID])
        goto exit;

    rtnl_lock();
    dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
    err = -ENODEV;
    if (!dp)
        goto exit_unlock;

    if (a[OVS_VPORT_ATTR_PORT_NO]) {
        port_no = nla_get_u32(a[OVS_VPORT_ATTR_PORT_NO]);

        err = -EFBIG;
        if (port_no >= DP_MAX_PORTS)
            goto exit_unlock;

        vport = ovs_vport_rtnl_rcu(dp, port_no);
        err = -EBUSY;
        if (vport)
            goto exit_unlock;
    } else {
        for (port_no = 1; ; port_no++) {
            if (port_no >= DP_MAX_PORTS) {
                err = -EFBIG;
                goto exit_unlock;
            }
            vport = ovs_vport_rtnl(dp, port_no);
            if (!vport)
                break;
        }
    }

    parms.name = nla_data(a[OVS_VPORT_ATTR_NAME]);
    parms.type = nla_get_u32(a[OVS_VPORT_ATTR_TYPE]);
    parms.options = a[OVS_VPORT_ATTR_OPTIONS];
    parms.dp = dp;
    parms.port_no = port_no;
    parms.upcall_portid = nla_get_u32(a[OVS_VPORT_ATTR_UPCALL_PID]);

    vport = new_vport(&parms);
    err = PTR_ERR(vport);
    if (IS_ERR(vport))
        goto exit_unlock;

    reply = ovs_vport_cmd_build_info(vport, info->snd_portid, info->snd_seq,
                     OVS_VPORT_CMD_NEW);
    if (IS_ERR(reply)) {
        err = PTR_ERR(reply);
        ovs_dp_detach_port(vport);
        goto exit_unlock;
    }
    genl_notify(reply, genl_info_net(info), info->snd_portid,
            ovs_dp_vport_multicast_group.id, info->nlhdr, GFP_KERNEL);

exit_unlock:
    rtnl_unlock();
exit:
    return err;
}

static int ovs_vport_cmd_set(struct sk_buff *skb, struct genl_info *info)
{
    struct nlattr **a = info->attrs;
    struct sk_buff *reply;
    struct vport *vport;
    int err;

    rtnl_lock();
    vport = lookup_vport(sock_net(skb->sk), info->userhdr, a);
    err = PTR_ERR(vport);
    if (IS_ERR(vport))
        goto exit_unlock;

    err = 0;
    if (a[OVS_VPORT_ATTR_TYPE] &&
        nla_get_u32(a[OVS_VPORT_ATTR_TYPE]) != vport->ops->type)
        err = -EINVAL;

    if (!err && a[OVS_VPORT_ATTR_OPTIONS])
        err = ovs_vport_set_options(vport, a[OVS_VPORT_ATTR_OPTIONS]);
    if (err)
        goto exit_unlock;
    if (a[OVS_VPORT_ATTR_UPCALL_PID])
        vport->upcall_portid = nla_get_u32(a[OVS_VPORT_ATTR_UPCALL_PID]);

    reply = ovs_vport_cmd_build_info(vport, info->snd_portid, info->snd_seq,
                     OVS_VPORT_CMD_NEW);
    if (IS_ERR(reply)) {
        netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
                ovs_dp_vport_multicast_group.id, PTR_ERR(reply));
        goto exit_unlock;
    }

    genl_notify(reply, genl_info_net(info), info->snd_portid,
            ovs_dp_vport_multicast_group.id, info->nlhdr, GFP_KERNEL);

exit_unlock:
    rtnl_unlock();
    return err;
}

static int ovs_vport_cmd_del(struct sk_buff *skb, struct genl_info *info)
{
    struct nlattr **a = info->attrs;
    struct sk_buff *reply;
    struct vport *vport;
    int err;

    rtnl_lock();
    vport = lookup_vport(sock_net(skb->sk), info->userhdr, a);
    err = PTR_ERR(vport);
    if (IS_ERR(vport))
        goto exit_unlock;

    if (vport->port_no == OVSP_LOCAL) {
        err = -EINVAL;
        goto exit_unlock;
    }

    reply = ovs_vport_cmd_build_info(vport, info->snd_portid, info->snd_seq,
                     OVS_VPORT_CMD_DEL);
    err = PTR_ERR(reply);
    if (IS_ERR(reply))
        goto exit_unlock;

    ovs_dp_detach_port(vport);

    genl_notify(reply, genl_info_net(info), info->snd_portid,
            ovs_dp_vport_multicast_group.id, info->nlhdr, GFP_KERNEL);

exit_unlock:
    rtnl_unlock();
    return err;
}

static int ovs_vport_cmd_get(struct sk_buff *skb, struct genl_info *info)
{
    struct nlattr **a = info->attrs;
    struct ovs_header *ovs_header = info->userhdr;
    struct sk_buff *reply;
    struct vport *vport;
    int err;

    rcu_read_lock();
    vport = lookup_vport(sock_net(skb->sk), ovs_header, a);
    err = PTR_ERR(vport);
    if (IS_ERR(vport))
        goto exit_unlock;

    reply = ovs_vport_cmd_build_info(vport, info->snd_portid, info->snd_seq,
                     OVS_VPORT_CMD_NEW);
    err = PTR_ERR(reply);
    if (IS_ERR(reply))
        goto exit_unlock;

    rcu_read_unlock();

    return genlmsg_reply(reply, info);

exit_unlock:
    rcu_read_unlock();
    return err;
}

static int ovs_vport_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
    struct ovs_header *ovs_header = genlmsg_data(nlmsg_data(cb->nlh));
    struct datapath *dp;
    int bucket = cb->args[0], skip = cb->args[1];
    int i, j = 0;

    dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
    if (!dp)
        return -ENODEV;

    rcu_read_lock();
    for (i = bucket; i < DP_VPORT_HASH_BUCKETS; i++) {
        struct vport *vport;
        struct hlist_node *n;

        j = 0;
        hlist_for_each_entry_rcu(vport, n, &dp->ports[i], dp_hash_node) {
            if (j >= skip &&
                ovs_vport_cmd_fill_info(vport, skb,
                            NETLINK_CB(cb->skb).portid,
                            cb->nlh->nlmsg_seq,
                            NLM_F_MULTI,
                            OVS_VPORT_CMD_NEW) < 0)
                goto out;

            j++;
        }
        skip = 0;
    }
out:
    rcu_read_unlock();

    cb->args[0] = i;
    cb->args[1] = j;

    return skb->len;
}

static struct genl_ops dp_vport_genl_ops[] = {
    { .cmd = OVS_VPORT_CMD_NEW,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = vport_policy,
      .doit = ovs_vport_cmd_new
    },
    { .cmd = OVS_VPORT_CMD_DEL,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = vport_policy,
      .doit = ovs_vport_cmd_del
    },
    { .cmd = OVS_VPORT_CMD_GET,
      .flags = 0,           /* OK for unprivileged users. */
      .policy = vport_policy,
      .doit = ovs_vport_cmd_get,
      .dumpit = ovs_vport_cmd_dump
    },
    { .cmd = OVS_VPORT_CMD_SET,
      .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
      .policy = vport_policy,
      .doit = ovs_vport_cmd_set,
    },
};

struct genl_family_and_ops {
    struct genl_family *family;
    struct genl_ops *ops;
    int n_ops;
    struct genl_multicast_group *group;
};

static const struct genl_family_and_ops dp_genl_families[] = {
    { &dp_datapath_genl_family,
      dp_datapath_genl_ops, ARRAY_SIZE(dp_datapath_genl_ops),
      &ovs_dp_datapath_multicast_group },
    { &dp_vport_genl_family,
      dp_vport_genl_ops, ARRAY_SIZE(dp_vport_genl_ops),
      &ovs_dp_vport_multicast_group },
    { &dp_flow_genl_family,
      dp_flow_genl_ops, ARRAY_SIZE(dp_flow_genl_ops),
      &ovs_dp_flow_multicast_group },
    { &dp_packet_genl_family,
      dp_packet_genl_ops, ARRAY_SIZE(dp_packet_genl_ops),
      NULL },
};

static void dp_unregister_genl(int n_families)
{
    int i;

    for (i = 0; i < n_families; i++)
        genl_unregister_family(dp_genl_families[i].family);
}

static int dp_register_genl(void)
{
    int n_registered;
    int err;
    int i;

    n_registered = 0;
    for (i = 0; i < ARRAY_SIZE(dp_genl_families); i++) {
        const struct genl_family_and_ops *f = &dp_genl_families[i];

        err = genl_register_family_with_ops(f->family, f->ops,
                            f->n_ops);
        if (err)
            goto error;
        n_registered++;

        if (f->group) {
            err = genl_register_mc_group(f->family, f->group);
            if (err)
                goto error;
        }
    }

    return 0;

error:
    dp_unregister_genl(n_registered);
    return err;
}

static void rehash_flow_table(struct work_struct *work)
{
    struct datapath *dp;
    struct net *net;

    genl_lock();
    rtnl_lock();
    for_each_net(net) {
        struct ovs_net *ovs_net = net_generic(net, ovs_net_id);

        list_for_each_entry(dp, &ovs_net->dps, list_node) {
            struct flow_table *old_table = genl_dereference(dp->table);
            struct flow_table *new_table;

            new_table = ovs_flow_tbl_rehash(old_table);
            if (!IS_ERR(new_table)) {
                rcu_assign_pointer(dp->table, new_table);
                ovs_flow_tbl_deferred_destroy(old_table);
            }
        }
    }
    rtnl_unlock();
    genl_unlock();

    schedule_delayed_work(&rehash_flow_wq, REHASH_FLOW_INTERVAL);
}

static int __net_init ovs_init_net(struct net *net)
{
    struct ovs_net *ovs_net = net_generic(net, ovs_net_id);

    INIT_LIST_HEAD(&ovs_net->dps);
    return 0;
}

static void __net_exit ovs_exit_net(struct net *net)
{
    struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
    struct datapath *dp, *dp_next;

    genl_lock();
    list_for_each_entry_safe(dp, dp_next, &ovs_net->dps, list_node)
        __dp_destroy(dp);
    genl_unlock();
}

static struct pernet_operations ovs_net_ops = {
    .init = ovs_init_net,
    .exit = ovs_exit_net,
    .id   = &ovs_net_id,
    .size = sizeof(struct ovs_net),
};

static int __init dp_init(void)
{
    struct sk_buff *dummy_skb;
    int err;

    BUILD_BUG_ON(sizeof(struct ovs_skb_cb) > sizeof(dummy_skb->cb));

    pr_info("Open vSwitch switching datapath\n");

    err = ovs_flow_init();
    if (err)
        goto error;

    err = ovs_vport_init();
    if (err)
        goto error_flow_exit;

    err = register_pernet_device(&ovs_net_ops);
    if (err)
        goto error_vport_exit;

    err = register_netdevice_notifier(&ovs_dp_device_notifier);
    if (err)
        goto error_netns_exit;

    err = dp_register_genl();
    if (err < 0)
        goto error_unreg_notifier;

    schedule_delayed_work(&rehash_flow_wq, REHASH_FLOW_INTERVAL);

    return 0;

error_unreg_notifier:
    unregister_netdevice_notifier(&ovs_dp_device_notifier);
error_netns_exit:
    unregister_pernet_device(&ovs_net_ops);
error_vport_exit:
    ovs_vport_exit();
error_flow_exit:
    ovs_flow_exit();
error:
    return err;
}

static void dp_cleanup(void)
{
    cancel_delayed_work_sync(&rehash_flow_wq);
    dp_unregister_genl(ARRAY_SIZE(dp_genl_families));
    unregister_netdevice_notifier(&ovs_dp_device_notifier);
    unregister_pernet_device(&ovs_net_ops);
    rcu_barrier();
    ovs_vport_exit();
    ovs_flow_exit();
}

module_init(dp_init);
module_exit(dp_cleanup);

MODULE_DESCRIPTION("Open vSwitch switching datapath");
MODULE_LICENSE("GPL");