datapath.c 45.5 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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int ovs_net_id __read_mostly;

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static void ovs_notify(struct genl_family *family,
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		       struct sk_buff *skb, struct genl_info *info)
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{
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	genl_notify(family, skb, genl_info_net(info), info->snd_portid,
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		    0, info->nlhdr, GFP_KERNEL);
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}

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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(&dp->table);
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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;
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	u32 n_mask_hit;
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	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_stats(&dp->table, &key, &n_mask_hit);
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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)++;
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	stats->n_mask_hit += n_mask_hit;
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	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;
}

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 },
};

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

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static void get_dp_stats(struct datapath *dp, struct ovs_dp_stats *stats,
			 struct ovs_dp_megaflow_stats *mega_stats)
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{
	int i;

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	memset(mega_stats, 0, sizeof(*mega_stats));

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	stats->n_flows = ovs_flow_tbl_count(&dp->table);
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	mega_stats->n_masks = ovs_flow_tbl_num_masks(&dp->table);
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	stats->n_hit = stats->n_missed = stats->n_lost = 0;
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	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;
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		mega_stats->n_mask_hit += local_stats.n_mask_hit;
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	}
}

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 */
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		+ nla_total_size(key_attr_size()) /* OVS_FLOW_ATTR_MASK */
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		+ 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 */
}

630
/* Called with ovs_mutex. */
631
static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
632
				  struct sk_buff *skb, u32 portid,
633 634 635
				  u32 seq, u32 flags, u8 cmd)
{
	const int skb_orig_len = skb->len;
636
	struct nlattr *start;
637 638 639 640 641 642 643
	struct ovs_flow_stats stats;
	struct ovs_header *ovs_header;
	struct nlattr *nla;
	unsigned long used;
	u8 tcp_flags;
	int err;

644
	ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family, flags, cmd);
645 646 647 648 649
	if (!ovs_header)
		return -EMSGSIZE;

	ovs_header->dp_ifindex = get_dpifindex(dp);

650
	/* Fill flow key. */
651 652 653
	nla = nla_nest_start(skb, OVS_FLOW_ATTR_KEY);
	if (!nla)
		goto nla_put_failure;
654

655
	err = ovs_nla_put_flow(&flow->unmasked_key, &flow->unmasked_key, skb);
656 657 658 659 660 661 662 663
	if (err)
		goto error;
	nla_nest_end(skb, nla);

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

664
	err = ovs_nla_put_flow(&flow->key, &flow->mask->key, skb);
665 666
	if (err)
		goto error;
667

668 669 670 671 672 673
	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;
674
	tcp_flags = (u8)ntohs(flow->tcp_flags);
675 676
	spin_unlock_bh(&flow->lock);

677 678 679
	if (used &&
	    nla_put_u64(skb, OVS_FLOW_ATTR_USED, ovs_flow_used_time(used)))
		goto nla_put_failure;
680

681 682 683 684
	if (stats.n_packets &&
	    nla_put(skb, OVS_FLOW_ATTR_STATS,
		    sizeof(struct ovs_flow_stats), &stats))
		goto nla_put_failure;
685

686 687 688
	if (tcp_flags &&
	    nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, tcp_flags))
		goto nla_put_failure;
689 690 691 692 693 694 695 696 697 698 699

	/* 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.
	 */
700 701
	start = nla_nest_start(skb, OVS_FLOW_ATTR_ACTIONS);
	if (start) {
702 703 704 705 706
		const struct sw_flow_actions *sf_acts;

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

707 708
		err = ovs_nla_put_actions(sf_acts->actions,
					  sf_acts->actions_len, skb);
709 710 711 712 713 714 715 716 717 718
		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;
719 720 721 722 723 724 725 726 727 728 729 730 731 732

	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;

733
	sf_acts = ovsl_dereference(flow->sf_acts);
734

735
	return genlmsg_new(ovs_flow_cmd_msg_size(sf_acts), GFP_KERNEL);
736 737 738 739
}

static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
					       struct datapath *dp,
740
					       u32 portid, u32 seq, u8 cmd)
741 742 743 744 745 746 747 748
{
	struct sk_buff *skb;
	int retval;

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

749
	retval = ovs_flow_cmd_fill_info(flow, dp, skb, portid, seq, 0, cmd);
750 751 752 753 754 755 756 757
	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;
758 759 760
	struct sw_flow_key key, masked_key;
	struct sw_flow *flow = NULL;
	struct sw_flow_mask mask;
761 762
	struct sk_buff *reply;
	struct datapath *dp;
763
	struct sw_flow_actions *acts = NULL;
764
	struct sw_flow_match match;
765 766 767 768 769 770
	int error;

	/* Extract key. */
	error = -EINVAL;
	if (!a[OVS_FLOW_ATTR_KEY])
		goto error;
771 772

	ovs_match_init(&match, &key, &mask);
773 774
	error = ovs_nla_get_match(&match,
				  a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]);
775 776 777 778 779
	if (error)
		goto error;

	/* Validate actions. */
	if (a[OVS_FLOW_ATTR_ACTIONS]) {
780
		acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
781 782
		error = PTR_ERR(acts);
		if (IS_ERR(acts))
783
			goto error;
784

785 786 787
		ovs_flow_mask_key(&masked_key, &key, &mask);
		error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
					     &masked_key, 0, &acts);
788 789
		if (error) {
			OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
790
			goto err_kfree;
791
		}
792 793 794 795 796
	} else if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW) {
		error = -EINVAL;
		goto error;
	}

797
	ovs_lock();
798
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
799 800
	error = -ENODEV;
	if (!dp)
801
		goto err_unlock_ovs;
802

803
	/* Check if this is a duplicate flow */
804
	flow = ovs_flow_tbl_lookup(&dp->table, &key);
805 806 807 808
	if (!flow) {
		/* Bail out if we're not allowed to create a new flow. */
		error = -ENOENT;
		if (info->genlhdr->cmd == OVS_FLOW_CMD_SET)
809
			goto err_unlock_ovs;
810 811 812 813 814

		/* Allocate flow. */
		flow = ovs_flow_alloc();
		if (IS_ERR(flow)) {
			error = PTR_ERR(flow);
815
			goto err_unlock_ovs;
816 817 818
		}
		clear_stats(flow);

819 820
		flow->key = masked_key;
		flow->unmasked_key = key;
821 822 823
		rcu_assign_pointer(flow->sf_acts, acts);

		/* Put flow in bucket. */
824 825 826 827 828
		error = ovs_flow_tbl_insert(&dp->table, flow, &mask);
		if (error) {
			acts = NULL;
			goto err_flow_free;
		}
829

830
		reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
831
						info->snd_seq, OVS_FLOW_CMD_NEW);
832 833 834 835 836 837 838 839 840 841 842 843 844
	} 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))
845
			goto err_unlock_ovs;
846

847 848
		/* The unmasked key has to be the same for flow updates. */
		error = -EINVAL;
849
		if (!ovs_flow_cmp_unmasked_key(flow, &match)) {
850 851 852 853
			OVS_NLERR("Flow modification message rejected, unmasked key does not match.\n");
			goto err_unlock_ovs;
		}

854
		/* Update actions. */
855
		old_acts = ovsl_dereference(flow->sf_acts);
856
		rcu_assign_pointer(flow->sf_acts, acts);
857
		ovs_nla_free_flow_actions(old_acts);
858

859
		reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
860 861 862 863 864 865 866 867 868
					       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);
		}
	}
869
	ovs_unlock();
870 871

	if (!IS_ERR(reply))
872
		ovs_notify(&dp_flow_genl_family, reply, info);
873
	else
874
		genl_set_err(&dp_flow_genl_family, sock_net(skb->sk), 0,
875
			     0, PTR_ERR(reply));
876 877
	return 0;

878 879
err_flow_free:
	ovs_flow_free(flow, false);
880 881
err_unlock_ovs:
	ovs_unlock();
882 883
err_kfree:
	kfree(acts);
884 885 886 887 888 889 890 891 892 893 894 895
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;
896
	struct sw_flow_match match;
897 898
	int err;

899 900
	if (!a[OVS_FLOW_ATTR_KEY]) {
		OVS_NLERR("Flow get message rejected, Key attribute missing.\n");
901
		return -EINVAL;
902 903 904
	}

	ovs_match_init(&match, &key, NULL);
905
	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
906 907 908
	if (err)
		return err;

909
	ovs_lock();
910
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
911 912 913 914
	if (!dp) {
		err = -ENODEV;
		goto unlock;
	}
915

916
	flow = ovs_flow_tbl_lookup(&dp->table, &key);
917
	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
918 919 920
		err = -ENOENT;
		goto unlock;
	}
921

922
	reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
923
					info->snd_seq, OVS_FLOW_CMD_NEW);
924 925 926 927
	if (IS_ERR(reply)) {
		err = PTR_ERR(reply);
		goto unlock;
	}
928

929
	ovs_unlock();
930
	return genlmsg_reply(reply, info);
931 932 933
unlock:
	ovs_unlock();
	return err;
934 935 936 937 938 939 940 941 942 943
}

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;
944
	struct sw_flow_match match;
945 946
	int err;

947
	ovs_lock();
948
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
949 950 951 952
	if (!dp) {
		err = -ENODEV;
		goto unlock;
	}
953

954
	if (!a[OVS_FLOW_ATTR_KEY]) {
955
		err = ovs_flow_tbl_flush(&dp->table);
956 957
		goto unlock;
	}
958 959

	ovs_match_init(&match, &key, NULL);
960
	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
961
	if (err)
962
		goto unlock;
963

964
	flow = ovs_flow_tbl_lookup(&dp->table, &key);
965
	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
966 967 968
		err = -ENOENT;
		goto unlock;
	}
969 970

	reply = ovs_flow_cmd_alloc_info(flow);
971 972 973 974
	if (!reply) {
		err = -ENOMEM;
		goto unlock;
	}
975

976
	ovs_flow_tbl_remove(&dp->table, flow);
977

978
	err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
979 980 981
				     info->snd_seq, 0, OVS_FLOW_CMD_DEL);
	BUG_ON(err < 0);

982
	ovs_flow_free(flow, true);
983
	ovs_unlock();
984

985
	ovs_notify(&dp_flow_genl_family, reply, info);
986
	return 0;
987 988 989
unlock:
	ovs_unlock();
	return err;
990 991 992 993 994
}

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));
995
	struct table_instance *ti;
996 997
	struct datapath *dp;

998
	rcu_read_lock();
999
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
1000
	if (!dp) {
1001
		rcu_read_unlock();
1002
		return -ENODEV;
1003
	}
1004

1005
	ti = rcu_dereference(dp->table.ti);
1006 1007 1008 1009 1010 1011
	for (;;) {
		struct sw_flow *flow;
		u32 bucket, obj;

		bucket = cb->args[0];
		obj = cb->args[1];
1012
		flow = ovs_flow_tbl_dump_next(ti, &bucket, &obj);
1013 1014 1015 1016
		if (!flow)
			break;

		if (ovs_flow_cmd_fill_info(flow, dp, skb,
1017
					   NETLINK_CB(cb->skb).portid,
1018 1019 1020 1021 1022 1023 1024
					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
					   OVS_FLOW_CMD_NEW) < 0)
			break;

		cb->args[0] = bucket;
		cb->args[1] = obj;
	}
1025
	rcu_read_unlock();
1026 1027 1028
	return skb->len;
}

1029
static const struct genl_ops dp_flow_genl_ops[] = {
1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062
	{ .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,
1063
	.maxattr = OVS_DP_ATTR_MAX,
1064 1065
	.netnsok = true,
	.parallel_ops = true,
1066 1067 1068 1069 1070 1071
};

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

1072 1073 1074 1075 1076 1077
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));
1078
	msgsize += nla_total_size(sizeof(struct ovs_dp_megaflow_stats));
1079 1080 1081 1082

	return msgsize;
}

1083
static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
1084
				u32 portid, u32 seq, u32 flags, u8 cmd)
1085 1086 1087
{
	struct ovs_header *ovs_header;
	struct ovs_dp_stats dp_stats;
1088
	struct ovs_dp_megaflow_stats dp_megaflow_stats;
1089 1090
	int err;

1091
	ovs_header = genlmsg_put(skb, portid, seq, &dp_datapath_genl_family,
1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103
				   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;

1104 1105 1106 1107 1108 1109 1110 1111
	get_dp_stats(dp, &dp_stats<