openvswitch: Add conntrack action

Expose the kernel connection tracker via OVS. Userspace components can
make use of the CT action to populate the connection state (ct_state)
field for a flow. This state can be subsequently matched.

Exposed connection states are OVS_CS_F_*:
- NEW (0x01) - Beginning of a new connection.
- ESTABLISHED (0x02) - Part of an existing connection.
- RELATED (0x04) - Related to an established connection.
- INVALID (0x20) - Could not track the connection for this packet.
- REPLY_DIR (0x40) - This packet is in the reply direction for the flow.
- TRACKED (0x80) - This packet has been sent through conntrack.

When the CT action is executed by itself, it will send the packet
through the connection tracker and populate the ct_state field with one
or more of the connection state flags above. The CT action will always
set the TRACKED bit.

When the COMMIT flag is passed to the conntrack action, this specifies
that information about the connection should be stored. This allows
subsequent packets for the same (or related) connections to be
correlated with this connection. Sending subsequent packets for the
connection through conntrack allows the connection tracker to consider
the packets as ESTABLISHED, RELATED, and/or REPLY_DIR.

The CT action may optionally take a zone to track the flow within. This
allows connections with the same 5-tuple to be kept logically separate
from connections in other zones. If the zone is specified, then the
"ct_zone" match field will be subsequently populated with the zone id.

IP fragments are handled by transparently assembling them as part of the
CT action. The maximum received unit (MRU) size is tracked so that
refragmentation can occur during output.

IP frag handling contributed by Andy Zhou.

Based on original design by Justin Pettit.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Signed-off-by: Justin Pettit <jpettit@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 55 insertions, 14 deletions

diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index c182b28..4e795b2 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -281,7 +281,7 @@ size_t ovs_key_attr_size(void)
 	/* Whenever adding new OVS_KEY_ FIELDS, we should consider
 	 * updating this function.
 	 */
-	BUILD_BUG_ON(OVS_KEY_ATTR_TUNNEL_INFO != 22);
+	BUILD_BUG_ON(OVS_KEY_ATTR_TUNNEL_INFO != 24);
 
 	return    nla_total_size(4)   /* OVS_KEY_ATTR_PRIORITY */
 		+ nla_total_size(0)   /* OVS_KEY_ATTR_TUNNEL */
@@ -290,6 +290,8 @@ size_t ovs_key_attr_size(void)
 		+ nla_total_size(4)   /* OVS_KEY_ATTR_SKB_MARK */
 		+ nla_total_size(4)   /* OVS_KEY_ATTR_DP_HASH */
 		+ nla_total_size(4)   /* OVS_KEY_ATTR_RECIRC_ID */
+		+ nla_total_size(1)   /* OVS_KEY_ATTR_CT_STATE */
+		+ nla_total_size(2)   /* OVS_KEY_ATTR_CT_ZONE */
 		+ nla_total_size(12)  /* OVS_KEY_ATTR_ETHERNET */
 		+ nla_total_size(2)   /* OVS_KEY_ATTR_ETHERTYPE */
 		+ nla_total_size(4)   /* OVS_KEY_ATTR_VLAN */
@@ -339,6 +341,8 @@ static const struct ovs_len_tbl ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
 	[OVS_KEY_ATTR_TUNNEL]	 = { .len = OVS_ATTR_NESTED,
 				     .next = ovs_tunnel_key_lens, },
 	[OVS_KEY_ATTR_MPLS]	 = { .len = sizeof(struct ovs_key_mpls) },
+	[OVS_KEY_ATTR_CT_STATE]	 = { .len = sizeof(u8) },
+	[OVS_KEY_ATTR_CT_ZONE]	 = { .len = sizeof(u16) },
 };
 
 static bool is_all_zero(const u8 *fp, size_t size)
@@ -768,6 +772,21 @@ static int metadata_from_nlattrs(struct sw_flow_match *match,  u64 *attrs,
 			return -EINVAL;
 		*attrs &= ~(1 << OVS_KEY_ATTR_TUNNEL);
 	}
+
+	if (*attrs & (1 << OVS_KEY_ATTR_CT_STATE) &&
+	    ovs_ct_verify(OVS_KEY_ATTR_CT_STATE)) {
+		u8 ct_state = nla_get_u8(a[OVS_KEY_ATTR_CT_STATE]);
+
+		SW_FLOW_KEY_PUT(match, ct.state, ct_state, is_mask);
+		*attrs &= ~(1ULL << OVS_KEY_ATTR_CT_STATE);
+	}
+	if (*attrs & (1 << OVS_KEY_ATTR_CT_ZONE) &&
+	    ovs_ct_verify(OVS_KEY_ATTR_CT_ZONE)) {
+		u16 ct_zone = nla_get_u16(a[OVS_KEY_ATTR_CT_ZONE]);
+
+		SW_FLOW_KEY_PUT(match, ct.zone, ct_zone, is_mask);
+		*attrs &= ~(1ULL << OVS_KEY_ATTR_CT_ZONE);
+	}
 	return 0;
 }
 
@@ -1266,6 +1285,7 @@ int ovs_nla_get_flow_metadata(const struct nlattr *attr,
 	memset(&match, 0, sizeof(match));
 	match.key = key;
 
+	memset(&key->ct, 0, sizeof(key->ct));
 	key->phy.in_port = DP_MAX_PORTS;
 
 	return metadata_from_nlattrs(&match, &attrs, a, false, log);
@@ -1314,6 +1334,9 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
 	if (nla_put_u32(skb, OVS_KEY_ATTR_SKB_MARK, output->phy.skb_mark))
 		goto nla_put_failure;
 
+	if (ovs_ct_put_key(output, skb))
+		goto nla_put_failure;
+
 	nla = nla_reserve(skb, OVS_KEY_ATTR_ETHERNET, sizeof(*eth_key));
 	if (!nla)
 		goto nla_put_failure;
@@ -1574,6 +1597,9 @@ void ovs_nla_free_flow_actions(struct sw_flow_actions *sf_acts)
 		case OVS_ACTION_ATTR_SET:
 			ovs_nla_free_set_action(a);
 			break;
+		case OVS_ACTION_ATTR_CT:
+			ovs_ct_free_action(a);
+			break;
 		}
 	}
 
@@ -1647,8 +1673,8 @@ static struct nlattr *__add_action(struct sw_flow_actions **sfa,
 	return a;
 }
 
-static int add_action(struct sw_flow_actions **sfa, int attrtype,
-		      void *data, int len, bool log)
+int ovs_nla_add_action(struct sw_flow_actions **sfa, int attrtype, void *data,
+		       int len, bool log)
 {
 	struct nlattr *a;
 
@@ -1663,7 +1689,7 @@ static inline int add_nested_action_start(struct sw_flow_actions **sfa,
 	int used = (*sfa)->actions_len;
 	int err;
 
-	err = add_action(sfa, attrtype, NULL, 0, log);
+	err = ovs_nla_add_action(sfa, attrtype, NULL, 0, log);
 	if (err)
 		return err;
 
@@ -1679,12 +1705,12 @@ static inline void add_nested_action_end(struct sw_flow_actions *sfa,
 	a->nla_len = sfa->actions_len - st_offset;
 }
 
-static int __ovs_nla_copy_actions(const struct nlattr *attr,
+static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 				  const struct sw_flow_key *key,
 				  int depth, struct sw_flow_actions **sfa,
 				  __be16 eth_type, __be16 vlan_tci, bool log);
 
-static int validate_and_copy_sample(const struct nlattr *attr,
+static int validate_and_copy_sample(struct net *net, const struct nlattr *attr,
 				    const struct sw_flow_key *key, int depth,
 				    struct sw_flow_actions **sfa,
 				    __be16 eth_type, __be16 vlan_tci, bool log)
@@ -1716,15 +1742,15 @@ static int validate_and_copy_sample(const struct nlattr *attr,
 	start = add_nested_action_start(sfa, OVS_ACTION_ATTR_SAMPLE, log);
 	if (start < 0)
 		return start;
-	err = add_action(sfa, OVS_SAMPLE_ATTR_PROBABILITY,
-			 nla_data(probability), sizeof(u32), log);
+	err = ovs_nla_add_action(sfa, OVS_SAMPLE_ATTR_PROBABILITY,
+				 nla_data(probability), sizeof(u32), log);
 	if (err)
 		return err;
 	st_acts = add_nested_action_start(sfa, OVS_SAMPLE_ATTR_ACTIONS, log);
 	if (st_acts < 0)
 		return st_acts;
 
-	err = __ovs_nla_copy_actions(actions, key, depth + 1, sfa,
+	err = __ovs_nla_copy_actions(net, actions, key, depth + 1, sfa,
 				     eth_type, vlan_tci, log);
 	if (err)
 		return err;
@@ -2058,7 +2084,7 @@ static int copy_action(const struct nlattr *from,
 	return 0;
 }
 
-static int __ovs_nla_copy_actions(const struct nlattr *attr,
+static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 				  const struct sw_flow_key *key,
 				  int depth, struct sw_flow_actions **sfa,
 				  __be16 eth_type, __be16 vlan_tci, bool log)
@@ -2082,7 +2108,8 @@ static int __ovs_nla_copy_actions(const struct nlattr *attr,
 			[OVS_ACTION_ATTR_SET] = (u32)-1,
 			[OVS_ACTION_ATTR_SET_MASKED] = (u32)-1,
 			[OVS_ACTION_ATTR_SAMPLE] = (u32)-1,
-			[OVS_ACTION_ATTR_HASH] = sizeof(struct ovs_action_hash)
+			[OVS_ACTION_ATTR_HASH] = sizeof(struct ovs_action_hash),
+			[OVS_ACTION_ATTR_CT] = (u32)-1,
 		};
 		const struct ovs_action_push_vlan *vlan;
 		int type = nla_type(a);
@@ -2189,13 +2216,20 @@ static int __ovs_nla_copy_actions(const struct nlattr *attr,
 			break;
 
 		case OVS_ACTION_ATTR_SAMPLE:
-			err = validate_and_copy_sample(a, key, depth, sfa,
+			err = validate_and_copy_sample(net, a, key, depth, sfa,
 						       eth_type, vlan_tci, log);
 			if (err)
 				return err;
 			skip_copy = true;
 			break;
 
+		case OVS_ACTION_ATTR_CT:
+			err = ovs_ct_copy_action(net, a, key, sfa, log);
+			if (err)
+				return err;
+			skip_copy = true;
+			break;
+
 		default:
 			OVS_NLERR(log, "Unknown Action type %d", type);
 			return -EINVAL;
@@ -2214,7 +2248,7 @@ static int __ovs_nla_copy_actions(const struct nlattr *attr,
 }
 
 /* 'key' must be the masked key. */
-int ovs_nla_copy_actions(const struct nlattr *attr,
+int ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 			 const struct sw_flow_key *key,
 			 struct sw_flow_actions **sfa, bool log)
 {
@@ -2225,7 +2259,7 @@ int ovs_nla_copy_actions(const struct nlattr *attr,
 		return PTR_ERR(*sfa);
 
 	(*sfa)->orig_len = nla_len(attr);
-	err = __ovs_nla_copy_actions(attr, key, 0, sfa, key->eth.type,
+	err = __ovs_nla_copy_actions(net, attr, key, 0, sfa, key->eth.type,
 				     key->eth.tci, log);
 	if (err)
 		ovs_nla_free_flow_actions(*sfa);
@@ -2350,6 +2384,13 @@ int ovs_nla_put_actions(const struct nlattr *attr, int len, struct sk_buff *skb)
 			if (err)
 				return err;
 			break;
+
+		case OVS_ACTION_ATTR_CT:
+			err = ovs_ct_action_to_attr(nla_data(a), skb);
+			if (err)
+				return err;
+			break;
+
 		default:
 			if (nla_put(skb, type, nla_len(a), nla_data(a)))
 				return -EMSGSIZE;