datapath.c 45.4 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;
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	struct genl_info info = {
		.dst_sk = net->genl_sock,
		.snd_portid = upcall_info->portid,
	};
	size_t len;
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	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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	len = upcall_msg_size(skb, upcall_info->userdata);
	user_skb = genlmsg_new_unicast(len, &info, 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 */
629
		+ nla_total_size(key_attr_size()) /* OVS_FLOW_ATTR_MASK */
630 631 632 633 634 635
		+ 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 */
}

636
/* Called with ovs_mutex. */
637
static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
638
				  struct sk_buff *skb, u32 portid,
639 640 641
				  u32 seq, u32 flags, u8 cmd)
{
	const int skb_orig_len = skb->len;
642
	struct nlattr *start;
643 644 645 646 647 648 649
	struct ovs_flow_stats stats;
	struct ovs_header *ovs_header;
	struct nlattr *nla;
	unsigned long used;
	u8 tcp_flags;
	int err;

650
	ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family, flags, cmd);
651 652 653 654 655
	if (!ovs_header)
		return -EMSGSIZE;

	ovs_header->dp_ifindex = get_dpifindex(dp);

656
	/* Fill flow key. */
657 658 659
	nla = nla_nest_start(skb, OVS_FLOW_ATTR_KEY);
	if (!nla)
		goto nla_put_failure;
660

661
	err = ovs_nla_put_flow(&flow->unmasked_key, &flow->unmasked_key, skb);
662 663 664 665 666 667 668 669
	if (err)
		goto error;
	nla_nest_end(skb, nla);

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

670
	err = ovs_nla_put_flow(&flow->key, &flow->mask->key, skb);
671 672
	if (err)
		goto error;
673

674 675 676 677 678 679
	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;
680
	tcp_flags = (u8)ntohs(flow->tcp_flags);
681 682
	spin_unlock_bh(&flow->lock);

683 684 685
	if (used &&
	    nla_put_u64(skb, OVS_FLOW_ATTR_USED, ovs_flow_used_time(used)))
		goto nla_put_failure;
686

687 688 689 690
	if (stats.n_packets &&
	    nla_put(skb, OVS_FLOW_ATTR_STATS,
		    sizeof(struct ovs_flow_stats), &stats))
		goto nla_put_failure;
691

692 693 694
	if (tcp_flags &&
	    nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, tcp_flags))
		goto nla_put_failure;
695 696 697 698 699 700 701 702 703 704 705

	/* 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.
	 */
706 707
	start = nla_nest_start(skb, OVS_FLOW_ATTR_ACTIONS);
	if (start) {
708 709
		const struct sw_flow_actions *sf_acts;

710
		sf_acts = rcu_dereference_ovsl(flow->sf_acts);
711

712 713
		err = ovs_nla_put_actions(sf_acts->actions,
					  sf_acts->actions_len, skb);
714 715 716 717 718 719 720 721 722 723
		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;
724 725 726 727 728 729 730 731 732 733

	return genlmsg_end(skb, ovs_header);

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

734 735
static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow,
					       struct genl_info *info)
736
{
737
	size_t len;
738

739
	len = ovs_flow_cmd_msg_size(ovsl_dereference(flow->sf_acts));
740

741
	return genlmsg_new_unicast(len, info, GFP_KERNEL);
742 743 744 745
}

static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
					       struct datapath *dp,
746 747
					       struct genl_info *info,
					       u8 cmd)
748 749 750 751
{
	struct sk_buff *skb;
	int retval;

752
	skb = ovs_flow_cmd_alloc_info(flow, info);
753 754 755
	if (!skb)
		return ERR_PTR(-ENOMEM);

756 757
	retval = ovs_flow_cmd_fill_info(flow, dp, skb, info->snd_portid,
					info->snd_seq, 0, cmd);
758 759 760 761 762 763 764 765
	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;
766 767 768
	struct sw_flow_key key, masked_key;
	struct sw_flow *flow = NULL;
	struct sw_flow_mask mask;
769 770
	struct sk_buff *reply;
	struct datapath *dp;
771
	struct sw_flow_actions *acts = NULL;
772
	struct sw_flow_match match;
773 774 775 776 777 778
	int error;

	/* Extract key. */
	error = -EINVAL;
	if (!a[OVS_FLOW_ATTR_KEY])
		goto error;
779 780

	ovs_match_init(&match, &key, &mask);
781 782
	error = ovs_nla_get_match(&match,
				  a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]);
783 784 785 786 787
	if (error)
		goto error;

	/* Validate actions. */
	if (a[OVS_FLOW_ATTR_ACTIONS]) {
788
		acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
789 790
		error = PTR_ERR(acts);
		if (IS_ERR(acts))
791
			goto error;
792

793 794 795
		ovs_flow_mask_key(&masked_key, &key, &mask);
		error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
					     &masked_key, 0, &acts);
796 797
		if (error) {
			OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
798
			goto err_kfree;
799
		}
800 801 802 803 804
	} else if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW) {
		error = -EINVAL;
		goto error;
	}

805
	ovs_lock();
806
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
807 808
	error = -ENODEV;
	if (!dp)
809
		goto err_unlock_ovs;
810

811
	/* Check if this is a duplicate flow */
812
	flow = ovs_flow_tbl_lookup(&dp->table, &key);
813 814 815 816
	if (!flow) {
		/* Bail out if we're not allowed to create a new flow. */
		error = -ENOENT;
		if (info->genlhdr->cmd == OVS_FLOW_CMD_SET)
817
			goto err_unlock_ovs;
818 819 820 821 822

		/* Allocate flow. */
		flow = ovs_flow_alloc();
		if (IS_ERR(flow)) {
			error = PTR_ERR(flow);
823
			goto err_unlock_ovs;
824 825 826
		}
		clear_stats(flow);

827 828
		flow->key = masked_key;
		flow->unmasked_key = key;
829 830 831
		rcu_assign_pointer(flow->sf_acts, acts);

		/* Put flow in bucket. */
832 833 834 835 836
		error = ovs_flow_tbl_insert(&dp->table, flow, &mask);
		if (error) {
			acts = NULL;
			goto err_flow_free;
		}
837

838
		reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
839 840 841 842 843 844 845 846 847 848 849 850 851
	} 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))
852
			goto err_unlock_ovs;
853

854 855
		/* The unmasked key has to be the same for flow updates. */
		error = -EINVAL;
856
		if (!ovs_flow_cmp_unmasked_key(flow, &match)) {
857 858 859 860
			OVS_NLERR("Flow modification message rejected, unmasked key does not match.\n");
			goto err_unlock_ovs;
		}

861
		/* Update actions. */
862
		old_acts = ovsl_dereference(flow->sf_acts);
863
		rcu_assign_pointer(flow->sf_acts, acts);
864
		ovs_nla_free_flow_actions(old_acts);
865

866
		reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
867 868 869 870 871 872 873 874

		/* Clear stats. */
		if (a[OVS_FLOW_ATTR_CLEAR]) {
			spin_lock_bh(&flow->lock);
			clear_stats(flow);
			spin_unlock_bh(&flow->lock);
		}
	}
875
	ovs_unlock();
876 877

	if (!IS_ERR(reply))
878
		ovs_notify(&dp_flow_genl_family, reply, info);
879
	else
880
		genl_set_err(&dp_flow_genl_family, sock_net(skb->sk), 0,
881
			     0, PTR_ERR(reply));
882 883
	return 0;

884 885
err_flow_free:
	ovs_flow_free(flow, false);
886 887
err_unlock_ovs:
	ovs_unlock();
888 889
err_kfree:
	kfree(acts);
890 891 892 893 894 895 896 897 898 899 900 901
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;
902
	struct sw_flow_match match;
903 904
	int err;

905 906
	if (!a[OVS_FLOW_ATTR_KEY]) {
		OVS_NLERR("Flow get message rejected, Key attribute missing.\n");
907
		return -EINVAL;
908 909 910
	}

	ovs_match_init(&match, &key, NULL);
911
	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
912 913 914
	if (err)
		return err;

915
	ovs_lock();
916
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
917 918 919 920
	if (!dp) {
		err = -ENODEV;
		goto unlock;
	}
921

922
	flow = ovs_flow_tbl_lookup(&dp->table, &key);
923
	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
924 925 926
		err = -ENOENT;
		goto unlock;
	}
927

928
	reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
929 930 931 932
	if (IS_ERR(reply)) {
		err = PTR_ERR(reply);
		goto unlock;
	}
933

934
	ovs_unlock();
935
	return genlmsg_reply(reply, info);
936 937 938
unlock:
	ovs_unlock();
	return err;
939 940 941 942 943 944 945 946 947 948
}

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;
949
	struct sw_flow_match match;
950 951
	int err;

952
	ovs_lock();
953
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
954 955 956 957
	if (!dp) {
		err = -ENODEV;
		goto unlock;
	}
958

959
	if (!a[OVS_FLOW_ATTR_KEY]) {
960
		err = ovs_flow_tbl_flush(&dp->table);
961 962
		goto unlock;
	}
963 964

	ovs_match_init(&match, &key, NULL);
965
	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
966
	if (err)
967
		goto unlock;
968

969
	flow = ovs_flow_tbl_lookup(&dp->table, &key);
970
	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
971 972 973
		err = -ENOENT;
		goto unlock;
	}
974

975
	reply = ovs_flow_cmd_alloc_info(flow, info);
976 977 978 979
	if (!reply) {
		err = -ENOMEM;
		goto unlock;
	}
980

981
	ovs_flow_tbl_remove(&dp->table, flow);
982

983
	err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
984 985 986
				     info->snd_seq, 0, OVS_FLOW_CMD_DEL);
	BUG_ON(err < 0);

987
	ovs_flow_free(flow, true);
988
	ovs_unlock();
989

990
	ovs_notify(&dp_flow_genl_family, reply, info);
991
	return 0;
992 993 994
unlock:
	ovs_unlock();
	return err;
995 996 997 998 999
}

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));
1000
	struct table_instance *ti;
1001 1002
	struct datapath *dp;

1003
	rcu_read_lock();
1004
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
1005
	if (!dp) {
1006
		rcu_read_unlock();
1007
		return -ENODEV;
1008
	}
1009

1010
	ti = rcu_dereference(dp->table.ti);
1011 1012 1013 1014 1015 1016
	for (;;) {
		struct sw_flow *flow;
		u32 bucket, obj;

		bucket = cb->args[0];
		obj = cb->args[1];
1017
		flow = ovs_flow_tbl_dump_next(ti, &bucket, &obj);
1018 1019 1020 1021
		if (!flow)
			break;

		if (ovs_flow_cmd_fill_info(flow, dp, skb,
1022
					   NETLINK_CB(cb->skb).portid,
1023 1024 1025 1026 1027 1028 1029
					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
					   OVS_FLOW_CMD_NEW) < 0)
			break;

		cb->args[0] = bucket;
		cb->args[1] = obj;
	}
1030
	rcu_read_unlock();
1031 1032 1033
	return skb->len;
}

1034
static const struct genl_ops dp_flow_genl_ops[] = {
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 1063 1064 1065 1066 1067
	{ .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,
1068
	.maxattr = OVS_DP_ATTR_MAX,
1069 1070
	.netnsok = true,
	.parallel_ops = true,
1071 1072 1073 1074 1075 1076
};

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

1077 1078 1079 1080 1081 1082
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));
1083
	msgsize += nla_total_size(sizeof(struct ovs_dp_megaflow_stats));
1084 1085 1086 1087

	return msgsize;
}

1088
static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
1089
				u32 portid, u32 seq, u32 flags, u8 cmd)
1090 1091 1092
{
	struct ovs_header *ovs_header;
	struct ovs_dp_stats dp_stats;