linux/net/openvswitch/conntrack.h
Yi-Hung Wei 11efd5cb04 openvswitch: Support conntrack zone limit
Currently, nf_conntrack_max is used to limit the maximum number of
conntrack entries in the conntrack table for every network namespace.
For the VMs and containers that reside in the same namespace,
they share the same conntrack table, and the total # of conntrack entries
for all the VMs and containers are limited by nf_conntrack_max.  In this
case, if one of the VM/container abuses the usage the conntrack entries,
it blocks the others from committing valid conntrack entries into the
conntrack table.  Even if we can possibly put the VM in different network
namespace, the current nf_conntrack_max configuration is kind of rigid
that we cannot limit different VM/container to have different # conntrack
entries.

To address the aforementioned issue, this patch proposes to have a
fine-grained mechanism that could further limit the # of conntrack entries
per-zone.  For example, we can designate different zone to different VM,
and set conntrack limit to each zone.  By providing this isolation, a
mis-behaved VM only consumes the conntrack entries in its own zone, and
it will not influence other well-behaved VMs.  Moreover, the users can
set various conntrack limit to different zone based on their preference.

The proposed implementation utilizes Netfilter's nf_conncount backend
to count the number of connections in a particular zone.  If the number of
connection is above a configured limitation, ovs will return ENOMEM to the
userspace.  If userspace does not configure the zone limit, the limit
defaults to zero that is no limitation, which is backward compatible to
the behavior without this patch.

The following high leve APIs are provided to the userspace:
  - OVS_CT_LIMIT_CMD_SET:
    * set default connection limit for all zones
    * set the connection limit for a particular zone
  - OVS_CT_LIMIT_CMD_DEL:
    * remove the connection limit for a particular zone
  - OVS_CT_LIMIT_CMD_GET:
    * get the default connection limit for all zones
    * get the connection limit for a particular zone

Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-25 16:45:19 -04:00

112 lines
3.1 KiB
C

/*
* Copyright (c) 2015 Nicira, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#ifndef OVS_CONNTRACK_H
#define OVS_CONNTRACK_H 1
#include "flow.h"
struct ovs_conntrack_info;
struct ovs_ct_limit_info;
enum ovs_key_attr;
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
int ovs_ct_init(struct net *);
void ovs_ct_exit(struct net *);
bool ovs_ct_verify(struct net *, enum ovs_key_attr attr);
int ovs_ct_copy_action(struct net *, const struct nlattr *,
const struct sw_flow_key *, struct sw_flow_actions **,
bool log);
int ovs_ct_action_to_attr(const struct ovs_conntrack_info *, struct sk_buff *);
int ovs_ct_execute(struct net *, struct sk_buff *, struct sw_flow_key *,
const struct ovs_conntrack_info *);
int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key);
void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key);
int ovs_ct_put_key(const struct sw_flow_key *swkey,
const struct sw_flow_key *output, struct sk_buff *skb);
void ovs_ct_free_action(const struct nlattr *a);
#define CT_SUPPORTED_MASK (OVS_CS_F_NEW | OVS_CS_F_ESTABLISHED | \
OVS_CS_F_RELATED | OVS_CS_F_REPLY_DIR | \
OVS_CS_F_INVALID | OVS_CS_F_TRACKED | \
OVS_CS_F_SRC_NAT | OVS_CS_F_DST_NAT)
#else
#include <linux/errno.h>
static inline int ovs_ct_init(struct net *net) { return 0; }
static inline void ovs_ct_exit(struct net *net) { }
static inline bool ovs_ct_verify(struct net *net, int attr)
{
return false;
}
static inline int ovs_ct_copy_action(struct net *net, const struct nlattr *nla,
const struct sw_flow_key *key,
struct sw_flow_actions **acts, bool log)
{
return -ENOTSUPP;
}
static inline int ovs_ct_action_to_attr(const struct ovs_conntrack_info *info,
struct sk_buff *skb)
{
return -ENOTSUPP;
}
static inline int ovs_ct_execute(struct net *net, struct sk_buff *skb,
struct sw_flow_key *key,
const struct ovs_conntrack_info *info)
{
kfree_skb(skb);
return -ENOTSUPP;
}
static inline int ovs_ct_clear(struct sk_buff *skb,
struct sw_flow_key *key)
{
return -ENOTSUPP;
}
static inline void ovs_ct_fill_key(const struct sk_buff *skb,
struct sw_flow_key *key)
{
key->ct_state = 0;
key->ct_zone = 0;
key->ct.mark = 0;
memset(&key->ct.labels, 0, sizeof(key->ct.labels));
/* Clear 'ct_orig_proto' to mark the non-existence of original
* direction key fields.
*/
key->ct_orig_proto = 0;
}
static inline int ovs_ct_put_key(const struct sw_flow_key *swkey,
const struct sw_flow_key *output,
struct sk_buff *skb)
{
return 0;
}
static inline void ovs_ct_free_action(const struct nlattr *a) { }
#define CT_SUPPORTED_MASK 0
#endif /* CONFIG_NF_CONNTRACK */
#if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
extern struct genl_family dp_ct_limit_genl_family;
#endif
#endif /* ovs_conntrack.h */