datapath.c 46.5 KB
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/*
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 * Copyright (c) 2007-2013 Nicira, Inc.
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 *
 * 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>
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#include <linux/lockdep.h>
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#include <linux/openvswitch.h>
#include <linux/rculist.h>
#include <linux/dmi.h>
#include <linux/workqueue.h>
#include <net/genetlink.h>
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#include <net/net_namespace.h>
#include <net/netns/generic.h>
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#include "datapath.h"
#include "flow.h"
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#include "flow_netlink.h"
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#include "vport-internal_dev.h"
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#include "vport-netdev.h"
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#define REHASH_FLOW_INTERVAL (10 * 60 * HZ)

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int ovs_net_id __read_mostly;

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static void ovs_notify(struct sk_buff *skb, struct genl_info *info,
		       struct genl_multicast_group *grp)
{
	genl_notify(skb, genl_info_net(info), info->snd_portid,
		    grp->id, info->nlhdr, GFP_KERNEL);
}

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/**
 * DOC: Locking:
 *
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 * All writes e.g. Writes to device state (add/remove datapath, port, set
 * operations on vports, etc.), Writes to other state (flow table
 * modifications, set miscellaneous datapath parameters, etc.) are protected
 * by ovs_lock.
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 *
 * Reads are protected by RCU.
 *
 * There are a few special cases (mostly stats) that have their own
 * synchronization but they nest under all of above and don't interact with
 * each other.
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 *
 * The RTNL lock nests inside ovs_mutex.
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 */

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static DEFINE_MUTEX(ovs_mutex);

void ovs_lock(void)
{
	mutex_lock(&ovs_mutex);
}

void ovs_unlock(void)
{
	mutex_unlock(&ovs_mutex);
}

#ifdef CONFIG_LOCKDEP
int lockdep_ovsl_is_held(void)
{
	if (debug_locks)
		return lockdep_is_held(&ovs_mutex);
	else
		return 1;
}
#endif

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

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

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

	return dp;
}

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

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

	rcu_read_lock();

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	local = ovs_vport_rcu(dp, OVSP_LOCAL);
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	if (local)
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		ifindex = netdev_vport_priv(local)->dev->ifindex;
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	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);

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

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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_head *head;

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

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/* Called with ovs_mutex. */
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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;
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		struct hlist_head *head = vport_hash_bucket(dp, vport->port_no);
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		hlist_add_head_rcu(&vport->dp_hash_node, head);
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	}
	return vport;
}

void ovs_dp_detach_port(struct vport *p)
{
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	ASSERT_OVSL();
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	/* First drop references to device. */
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	hlist_del_rcu(&p->dp_hash_node);
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	/* 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;

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

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

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

	OVS_CB(skb)->flow = flow;
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	OVS_CB(skb)->pkt_key = &key;
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	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,
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	.maxattr = OVS_PACKET_ATTR_MAX,
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	.netnsok = true,
	.parallel_ops = true,
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};

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

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

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

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

	return 0;

err:
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	stats = this_cpu_ptr(dp->stats_percpu);
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	u64_stats_update_begin(&stats->sync);
	stats->n_lost++;
	u64_stats_update_end(&stats->sync);

	return err;
}

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

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	segs = __skb_gso_segment(skb, NETIF_F_SG | NETIF_F_HW_CSUM, false);
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	if (IS_ERR(segs))
		return PTR_ERR(segs);
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	/* Queue all of the segments. */
	skb = segs;
	do {
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		err = queue_userspace_packet(net, dp_ifindex, skb, upcall_info);
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		if (err)
			break;

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		if (skb == segs && gso_type & SKB_GSO_UDP) {
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			/* 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;
}

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static size_t key_attr_size(void)
{
	return    nla_total_size(4)   /* OVS_KEY_ATTR_PRIORITY */
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		+ nla_total_size(0)   /* OVS_KEY_ATTR_TUNNEL */
		  + nla_total_size(8)   /* OVS_TUNNEL_KEY_ATTR_ID */
		  + nla_total_size(4)   /* OVS_TUNNEL_KEY_ATTR_IPV4_SRC */
		  + nla_total_size(4)   /* OVS_TUNNEL_KEY_ATTR_IPV4_DST */
		  + nla_total_size(1)   /* OVS_TUNNEL_KEY_ATTR_TOS */
		  + nla_total_size(1)   /* OVS_TUNNEL_KEY_ATTR_TTL */
		  + nla_total_size(0)   /* OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT */
		  + nla_total_size(0)   /* OVS_TUNNEL_KEY_ATTR_CSUM */
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		+ nla_total_size(4)   /* OVS_KEY_ATTR_IN_PORT */
		+ nla_total_size(4)   /* OVS_KEY_ATTR_SKB_MARK */
		+ nla_total_size(12)  /* OVS_KEY_ATTR_ETHERNET */
		+ nla_total_size(2)   /* OVS_KEY_ATTR_ETHERTYPE */
		+ nla_total_size(4)   /* OVS_KEY_ATTR_8021Q */
		+ nla_total_size(0)   /* OVS_KEY_ATTR_ENCAP */
		+ nla_total_size(2)   /* OVS_KEY_ATTR_ETHERTYPE */
		+ nla_total_size(40)  /* OVS_KEY_ATTR_IPV6 */
		+ nla_total_size(2)   /* OVS_KEY_ATTR_ICMPV6 */
		+ nla_total_size(28); /* OVS_KEY_ATTR_ND */
}

static size_t upcall_msg_size(const struct sk_buff *skb,
			      const struct nlattr *userdata)
{
	size_t size = NLMSG_ALIGN(sizeof(struct ovs_header))
		+ nla_total_size(skb->len) /* OVS_PACKET_ATTR_PACKET */
		+ nla_total_size(key_attr_size()); /* OVS_PACKET_ATTR_KEY */

	/* OVS_PACKET_ATTR_USERDATA */
	if (userdata)
		size += NLA_ALIGN(userdata->nla_len);

	return size;
}

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static int queue_userspace_packet(struct net *net, int dp_ifindex,
				  struct sk_buff *skb,
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				  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;
	int err;

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

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

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

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

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	user_skb = genlmsg_new(upcall_msg_size(skb, upcall_info->userdata), GFP_ATOMIC);
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	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);
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	ovs_nla_put_flow(upcall_info->key, upcall_info->key, user_skb);
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	nla_nest_end(user_skb, nla);

	if (upcall_info->userdata)
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		__nla_put(user_skb, OVS_PACKET_ATTR_USERDATA,
			  nla_len(upcall_info->userdata),
			  nla_data(upcall_info->userdata));
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	nla = __nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, skb->len);

	skb_copy_and_csum_dev(skb, nla_data(nla));

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	genlmsg_end(user_skb, upcall);
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	err = genlmsg_unicast(net, user_skb, upcall_info->portid);
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out:
	kfree_skb(nskb);
	return err;
}

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

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

	rcu_assign_pointer(dp->table, new_table);

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	ovs_flow_tbl_destroy(old_table, true);
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	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;

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

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	nla_memcpy(__skb_put(packet, len), a[OVS_PACKET_ATTR_PACKET], len);
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	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. */
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	if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN)
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		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;

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

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	err = ovs_nla_get_flow_metadata(flow, a[OVS_PACKET_ATTR_KEY]);
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	if (err)
		goto err_flow_free;
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	acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_PACKET_ATTR_ACTIONS]));
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	err = PTR_ERR(acts);
	if (IS_ERR(acts))
		goto err_flow_free;
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	err = ovs_nla_copy_actions(a[OVS_PACKET_ATTR_ACTIONS],
				   &flow->key, 0, &acts);
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	rcu_assign_pointer(flow->sf_acts, acts);
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	if (err)
		goto err_flow_free;
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	OVS_CB(packet)->flow = flow;
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	OVS_CB(packet)->pkt_key = &flow->key;
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	packet->priority = flow->key.phy.priority;
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	packet->mark = flow->key.phy.skb_mark;
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	rcu_read_lock();
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	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
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	err = -ENODEV;
	if (!dp)
		goto err_unlock;

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

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	ovs_flow_free(flow, false);
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	return err;

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

static const struct nla_policy packet_policy[OVS_PACKET_ATTR_MAX + 1] = {
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	[OVS_PACKET_ATTR_PACKET] = { .len = ETH_HLEN },
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	[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)
{
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	struct flow_table *table;
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	int i;

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	table = rcu_dereference_check(dp->table, lockdep_ovsl_is_held());
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	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,
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	.maxattr = OVS_FLOW_ATTR_MAX,
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	.netnsok = true,
	.parallel_ops = true,
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};

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

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static size_t ovs_flow_cmd_msg_size(const struct sw_flow_actions *acts)
{
	return NLMSG_ALIGN(sizeof(struct ovs_header))
		+ nla_total_size(key_attr_size()) /* OVS_FLOW_ATTR_KEY */
636
		+ nla_total_size(key_attr_size()) /* OVS_FLOW_ATTR_MASK */
637 638 639 640 641 642
		+ nla_total_size(sizeof(struct ovs_flow_stats)) /* OVS_FLOW_ATTR_STATS */
		+ nla_total_size(1) /* OVS_FLOW_ATTR_TCP_FLAGS */
		+ nla_total_size(8) /* OVS_FLOW_ATTR_USED */
		+ nla_total_size(acts->actions_len); /* OVS_FLOW_ATTR_ACTIONS */
}

643
/* Called with ovs_mutex. */
644
static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
645
				  struct sk_buff *skb, u32 portid,
646 647 648
				  u32 seq, u32 flags, u8 cmd)
{
	const int skb_orig_len = skb->len;
649
	struct nlattr *start;
650 651 652 653 654 655 656
	struct ovs_flow_stats stats;
	struct ovs_header *ovs_header;
	struct nlattr *nla;
	unsigned long used;
	u8 tcp_flags;
	int err;

657
	ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family, flags, cmd);
658 659 660 661 662
	if (!ovs_header)
		return -EMSGSIZE;

	ovs_header->dp_ifindex = get_dpifindex(dp);

663
	/* Fill flow key. */
664 665 666
	nla = nla_nest_start(skb, OVS_FLOW_ATTR_KEY);
	if (!nla)
		goto nla_put_failure;
667

668
	err = ovs_nla_put_flow(&flow->unmasked_key, &flow->unmasked_key, skb);
669 670 671 672 673 674 675 676
	if (err)
		goto error;
	nla_nest_end(skb, nla);

	nla = nla_nest_start(skb, OVS_FLOW_ATTR_MASK);
	if (!nla)
		goto nla_put_failure;

677
	err = ovs_nla_put_flow(&flow->key, &flow->mask->key, skb);
678 679
	if (err)
		goto error;
680

681 682 683 684 685 686 687 688 689
	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);

690 691 692
	if (used &&
	    nla_put_u64(skb, OVS_FLOW_ATTR_USED, ovs_flow_used_time(used)))
		goto nla_put_failure;
693

694 695 696 697
	if (stats.n_packets &&
	    nla_put(skb, OVS_FLOW_ATTR_STATS,
		    sizeof(struct ovs_flow_stats), &stats))
		goto nla_put_failure;
698

699 700 701
	if (tcp_flags &&
	    nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, tcp_flags))
		goto nla_put_failure;
702 703 704 705 706 707 708 709 710 711 712

	/* 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.
	 */
713 714
	start = nla_nest_start(skb, OVS_FLOW_ATTR_ACTIONS);
	if (start) {
715 716 717 718 719
		const struct sw_flow_actions *sf_acts;

		sf_acts = rcu_dereference_check(flow->sf_acts,
						lockdep_ovsl_is_held());

720 721
		err = ovs_nla_put_actions(sf_acts->actions,
					  sf_acts->actions_len, skb);
722 723 724 725 726 727 728 729 730 731
		if (!err)
			nla_nest_end(skb, start);
		else {
			if (skb_orig_len)
				goto error;

			nla_nest_cancel(skb, start);
		}
	} else if (skb_orig_len)
		goto nla_put_failure;
732 733 734 735 736 737 738 739 740 741 742 743 744 745

	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;

746
	sf_acts = ovsl_dereference(flow->sf_acts);
747

748
	return genlmsg_new(ovs_flow_cmd_msg_size(sf_acts), GFP_KERNEL);
749 750 751 752
}

static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
					       struct datapath *dp,
753
					       u32 portid, u32 seq, u8 cmd)
754 755 756 757 758 759 760 761
{
	struct sk_buff *skb;
	int retval;

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

762
	retval = ovs_flow_cmd_fill_info(flow, dp, skb, portid, seq, 0, cmd);
763 764 765 766 767 768 769 770
	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;
771 772 773
	struct sw_flow_key key, masked_key;
	struct sw_flow *flow = NULL;
	struct sw_flow_mask mask;
774 775 776
	struct sk_buff *reply;
	struct datapath *dp;
	struct flow_table *table;
777
	struct sw_flow_actions *acts = NULL;
778
	struct sw_flow_match match;
779 780 781 782 783 784
	int error;

	/* Extract key. */
	error = -EINVAL;
	if (!a[OVS_FLOW_ATTR_KEY])
		goto error;
785 786

	ovs_match_init(&match, &key, &mask);
787 788
	error = ovs_nla_get_match(&match,
				  a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]);
789 790 791 792 793
	if (error)
		goto error;

	/* Validate actions. */
	if (a[OVS_FLOW_ATTR_ACTIONS]) {
794
		acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
795 796
		error = PTR_ERR(acts);
		if (IS_ERR(acts))
797
			goto error;
798

799 800 801
		ovs_flow_mask_key(&masked_key, &key, &mask);
		error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
					     &masked_key, 0, &acts);
802 803
		if (error) {
			OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
804
			goto err_kfree;
805
		}
806 807 808 809 810
	} else if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW) {
		error = -EINVAL;
		goto error;
	}

811
	ovs_lock();
812
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
813 814
	error = -ENODEV;
	if (!dp)
815
		goto err_unlock_ovs;
816

817
	table = ovsl_dereference(dp->table);
818 819

	/* Check if this is a duplicate flow */
820
	flow = ovs_flow_tbl_lookup(table, &key);
821
	if (!flow) {
822
		struct flow_table *new_table = NULL;
823
		struct sw_flow_mask *mask_p;
824

825 826 827
		/* Bail out if we're not allowed to create a new flow. */
		error = -ENOENT;
		if (info->genlhdr->cmd == OVS_FLOW_CMD_SET)
828
			goto err_unlock_ovs;
829 830

		/* Expand table, if necessary, to make room. */
831
		if (ovs_flow_tbl_need_to_expand(table))
832
			new_table = ovs_flow_tbl_expand(table);
833 834 835 836 837 838 839 840
		else if (time_after(jiffies, dp->last_rehash + REHASH_FLOW_INTERVAL))
			new_table = ovs_flow_tbl_rehash(table);

		if (new_table && !IS_ERR(new_table)) {
			rcu_assign_pointer(dp->table, new_table);
			ovs_flow_tbl_destroy(table, true);
			table = ovsl_dereference(dp->table);
			dp->last_rehash = jiffies;
841 842 843 844 845 846
		}

		/* Allocate flow. */
		flow = ovs_flow_alloc();
		if (IS_ERR(flow)) {
			error = PTR_ERR(flow);
847
			goto err_unlock_ovs;
848 849 850
		}
		clear_stats(flow);

851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867
		flow->key = masked_key;
		flow->unmasked_key = key;

		/* Make sure mask is unique in the system */
		mask_p = ovs_sw_flow_mask_find(table, &mask);
		if (!mask_p) {
			/* Allocate a new mask if none exsits. */
			mask_p = ovs_sw_flow_mask_alloc();
			if (!mask_p)
				goto err_flow_free;
			mask_p->key = mask.key;
			mask_p->range = mask.range;
			ovs_sw_flow_mask_insert(table, mask_p);
		}

		ovs_sw_flow_mask_add_ref(mask_p);
		flow->mask = mask_p;
868 869 870
		rcu_assign_pointer(flow->sf_acts, acts);

		/* Put flow in bucket. */
871
		ovs_flow_tbl_insert(table, flow);
872

873
		reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
874
						info->snd_seq, OVS_FLOW_CMD_NEW);
875 876 877 878 879 880 881 882 883 884 885 886 887
	} else {
		/* We found a matching flow. */
		struct sw_flow_actions *old_acts;

		/* 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))
888
			goto err_unlock_ovs;
889

890 891
		/* The unmasked key has to be the same for flow updates. */
		error = -EINVAL;
892
		if (!ovs_flow_cmp_unmasked_key(flow, &match)) {
893 894 895 896
			OVS_NLERR("Flow modification message rejected, unmasked key does not match.\n");
			goto err_unlock_ovs;
		}

897
		/* Update actions. */
898
		old_acts = ovsl_dereference(flow->sf_acts);
899
		rcu_assign_pointer(flow->sf_acts, acts);
900
		ovs_nla_free_flow_actions(old_acts);
901

902
		reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
903 904 905 906 907 908 909 910 911
					       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);
		}
	}
912
	ovs_unlock();
913 914

	if (!IS_ERR(reply))
915
		ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
916
	else
917
		netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
918 919 920
				ovs_dp_flow_multicast_group.id, PTR_ERR(reply));
	return 0;

921 922
err_flow_free:
	ovs_flow_free(flow, false);
923 924
err_unlock_ovs:
	ovs_unlock();
925 926
err_kfree:
	kfree(acts);
927 928 929 930 931 932 933 934 935 936 937 938 939
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;
940
	struct sw_flow_match match;
941 942
	int err;

943 944
	if (!a[OVS_FLOW_ATTR_KEY]) {
		OVS_NLERR("Flow get message rejected, Key attribute missing.\n");
945
		return -EINVAL;
946 947 948
	}

	ovs_match_init(&match, &key, NULL);
949
	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
950 951 952
	if (err)
		return err;

953
	ovs_lock();
954
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
955 956 957 958
	if (!dp) {
		err = -ENODEV;
		goto unlock;
	}
959

960
	table = ovsl_dereference(dp->table);
961 962
	flow = ovs_flow_tbl_lookup(table, &key);
	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
963 964 965
		err = -ENOENT;
		goto unlock;
	}
966

967
	reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
968
					info->snd_seq, OVS_FLOW_CMD_NEW);
969 970 971 972
	if (IS_ERR(reply)) {
		err = PTR_ERR(reply);
		goto unlock;
	}
973

974
	ovs_unlock();
975
	return genlmsg_reply(reply, info);
976 977 978
unlock:
	ovs_unlock();
	return err;
979 980 981 982 983 984 985 986 987 988 989
}

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;
990
	struct sw_flow_match match;
991 992
	int err;

993
	ovs_lock();
994
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
995 996 997 998
	if (!dp) {
		err = -ENODEV;
		goto unlock;
	}
999

1000 1001 1002 1003
	if (!a[OVS_FLOW_ATTR_KEY]) {
		err = flush_flows(dp);
		goto unlock;
	}
1004 1005

	ovs_match_init(&match, &key, NULL);
1006
	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
1007
	if (err)
1008
		goto unlock;
1009

1010
	table = ovsl_dereference(dp->table);
1011 1012
	flow = ovs_flow_tbl_lookup(table, &key);
	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
1013 1014 1015
		err = -ENOENT;
		goto unlock;
	}
1016 1017

	reply = ovs_flow_cmd_alloc_info(flow);
1018 1019 1020 1021
	if (!reply) {
		err = -ENOMEM;
		goto unlock;
	}
1022

1023
	ovs_flow_tbl_remove(table, flow);
1024

1025
	err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
1026 1027 1028
				     info->snd_seq, 0, OVS_FLOW_CMD_DEL);
	BUG_ON(err < 0);

1029
	ovs_flow_free(flow, true);
1030
	ovs_unlock();
1031

1032
	ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
1033
	return 0;
1034 1035 1036
unlock:
	ovs_unlock();
	return err;
1037 1038 1039 1040 1041 1042 1043 1044
}

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;

1045
	rcu_read_lock();
1046
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
1047
	if (!dp) {
1048
		rcu_read_unlock();
1049
		return -ENODEV;
1050
	}
1051

1052
	table = rcu_dereference(dp->table);
1053 1054 1055 1056 1057 1058
	for (;;) {
		struct sw_flow *flow;
		u32 bucket, obj;

		bucket = cb->args[0];
		obj = cb->args[1];
1059
		flow = ovs_flow_tbl_dump_next(table, &bucket, &obj);
1060 1061 1062 1063
		if (!flow)
			break;

		if (ovs_flow_cmd_fill_info(flow, dp, skb,
1064
					   NETLINK_CB(cb->skb).portid,
1065 1066 1067 1068 1069 1070 1071
					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
					   OVS_FLOW_CMD_NEW) < 0)
			break;

		cb->args[0] = bucket;
		cb->args[1] = obj;
	}
1072
	rcu_read_unlock();
1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109
	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,
1110
	.maxattr = OVS_DP_ATTR_MAX,
1111 1112
	.netnsok = true,
	.parallel_ops = true,
1113 1114 1115 1116 1117 1118
};

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

1119 1120 1121 1122 1123 1124 1125 1126 1127 1128
static size_t ovs_dp_cmd_msg_size(void)
{
	size_t msgsize = NLMSG_ALIGN(sizeof(struct ovs_header));

	msgsize += nla_total_size(IFNAMSIZ);
	msgsize += nla_total_size(sizeof(struct ovs_dp_stats));

	return msgsize;
}

1129
static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
1130
				u32 portid, u32 seq, u32 flags, u8 cmd)
1131 1132 1133 1134 1135
{
	struct ovs_header *ovs_header;
	struct ovs_dp_stats dp_stats;
	int err;

1136
	ovs_header = genlmsg_put(skb, portid, seq, &dp_datapath_genl_family,
1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149
				   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);
1150 1151
	if (nla_put(skb, OVS_DP_ATTR_STATS, sizeof(struct ovs_dp_stats), &dp_stats))
		goto nla_put_failure;
1152 1153 1154