[ovs-dev] [recirc datapath V2 2/3] datapath: add hash action

[Andy Zhou]

Signed-off-by: Andy Zhou <azhou at nicira.com>
---
 datapath/actions.c      | 19 +++++++++++++++++++
 datapath/flow.h         |  1 +
 datapath/flow_netlink.c | 39 ++++++++++++++++++++++++++++++++++++++-
 3 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/datapath/actions.c b/datapath/actions.c
index 0b66e7c..cb239c8 100644
--- a/datapath/actions.c
+++ b/datapath/actions.c
@@ -460,6 +460,21 @@ static int sample(struct datapath *dp, struct sk_buff *skb,
 				  nla_len(acts_list), true);
 }
 
+static void execute_hash(struct sk_buff *skb, const struct nlattr *attr)
+{
+	const struct ovs_action_hash *act_hash = nla_data(attr);
+	struct sw_flow_key *key = OVS_CB(skb)->pkt_key;
+	u32 dp_hash = 0;
+
+	if (act_hash->hash_alg == OVS_HASH_ALG_L4) {
+		dp_hash = skb_get_rxhash(skb);
+		if (!dp_hash)
+			dp_hash = 0x1;
+	}
+
+	key->dp_hash = dp_hash;
+}
+
 static int execute_set_action(struct sk_buff *skb,
 				 const struct nlattr *nested_attr)
 {
@@ -536,6 +551,10 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 			output_userspace(dp, skb, a);
 			break;
 
+		case OVS_ACTION_ATTR_HASH:
+			execute_hash(skb, a);
+			break;
+
 		case OVS_ACTION_ATTR_PUSH_VLAN:
 			err = push_vlan(skb, nla_data(a));
 			if (unlikely(err)) /* skb already freed. */
diff --git a/datapath/flow.h b/datapath/flow.h
index 1bb6ce0..bcc36d2 100644
--- a/datapath/flow.h
+++ b/datapath/flow.h
@@ -74,6 +74,7 @@ struct sw_flow_key {
 		u32	skb_mark;	/* SKB mark. */
 		u16	in_port;	/* Input switch port (or DP_MAX_PORTS). */
 	} __packed phy; /* Safe when right after 'tun_key'. */
+	u32 dp_hash;			/* Datapath computed hash value.  */
 	struct {
 		u8     src[ETH_ALEN];	/* Ethernet source address. */
 		u8     dst[ETH_ALEN];	/* Ethernet destination address. */
diff --git a/datapath/flow_netlink.c b/datapath/flow_netlink.c
index 5c32cd0..0a1effa 100644
--- a/datapath/flow_netlink.c
+++ b/datapath/flow_netlink.c
@@ -123,6 +123,7 @@ static bool match_validate(const struct sw_flow_match *match,
 			| (1ULL << OVS_KEY_ATTR_ICMP)
 			| (1ULL << OVS_KEY_ATTR_ICMPV6)
 			| (1ULL << OVS_KEY_ATTR_ARP)
+			| (1ULL << OVS_KEY_ATTR_DP_HASH)
 			| (1ULL << OVS_KEY_ATTR_ND));
 
 	/* Always allowed mask fields. */
@@ -131,6 +132,10 @@ static bool match_validate(const struct sw_flow_match *match,
 		       | (1ULL << OVS_KEY_ATTR_ETHERTYPE));
 
 	/* Check key attributes. */
+	if (match->key->dp_hash) {
+		mask_allowed |= (1ULL << OVS_KEY_ATTR_DP_HASH);
+	}
+
 	if (match->key->eth.type == htons(ETH_P_ARP)
 			|| match->key->eth.type == htons(ETH_P_RARP)) {
 		key_expected |= 1ULL << OVS_KEY_ATTR_ARP;
@@ -252,6 +257,7 @@ static const int ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
 	[OVS_KEY_ATTR_ICMPV6] = sizeof(struct ovs_key_icmpv6),
 	[OVS_KEY_ATTR_ARP] = sizeof(struct ovs_key_arp),
 	[OVS_KEY_ATTR_ND] = sizeof(struct ovs_key_nd),
+	[OVS_KEY_ATTR_DP_HASH] = sizeof(u32),
 	[OVS_KEY_ATTR_TUNNEL] = -1,
 };
 
@@ -455,6 +461,19 @@ static int ipv4_tun_to_nlattr(struct sk_buff *skb,
 static int metadata_from_nlattrs(struct sw_flow_match *match,  u64 *attrs,
 				 const struct nlattr **a, bool is_mask)
 {
+
+	if (*attrs & (1ULL << OVS_KEY_ATTR_DP_HASH)) {
+		u32 hash_val = nla_get_u32(a[OVS_KEY_ATTR_DP_HASH]);
+
+		if (!is_mask && !hash_val) {
+			OVS_NLERR("Hash value can not be zero\n");
+			return -EINVAL;
+		}
+
+		SW_FLOW_KEY_PUT(match, dp_hash, hash_val, is_mask);
+		*attrs &= ~(1ULL << OVS_KEY_ATTR_DP_HASH);
+	}
+
 	if (*attrs & (1ULL << OVS_KEY_ATTR_PRIORITY)) {
 		SW_FLOW_KEY_PUT(match, phy.priority,
 			  nla_get_u32(a[OVS_KEY_ATTR_PRIORITY]), is_mask);
@@ -859,6 +878,7 @@ int ovs_nla_get_flow_metadata(struct sw_flow *flow,
 	flow->key.phy.in_port = DP_MAX_PORTS;
 	flow->key.phy.priority = 0;
 	flow->key.phy.skb_mark = 0;
+	flow->key.dp_hash = 0;
 	memset(tun_key, 0, sizeof(flow->key.tun_key));
 
 	err = parse_flow_nlattrs(attr, a, &attrs);
@@ -882,6 +902,10 @@ int ovs_nla_put_flow(const struct sw_flow_key *swkey,
 	struct nlattr *nla, *encap;
 	bool is_mask = (swkey != output);
 
+	if ((swkey->dp_hash) &&
+		(nla_put_u32(skb, OVS_KEY_ATTR_DP_HASH, output->dp_hash)))
+			goto nla_put_failure;
+
 	if (nla_put_u32(skb, OVS_KEY_ATTR_PRIORITY, output->phy.priority))
 		goto nla_put_failure;
 
@@ -1422,7 +1446,8 @@ int ovs_nla_copy_actions(const struct nlattr *attr,
 			[OVS_ACTION_ATTR_PUSH_VLAN] = sizeof(struct ovs_action_push_vlan),
 			[OVS_ACTION_ATTR_POP_VLAN] = 0,
 			[OVS_ACTION_ATTR_SET] = (u32)-1,
-			[OVS_ACTION_ATTR_SAMPLE] = (u32)-1
+			[OVS_ACTION_ATTR_SAMPLE] = (u32)-1,
+			[OVS_ACTION_ATTR_HASH] = sizeof(struct ovs_action_hash)
 		};
 		const struct ovs_action_push_vlan *vlan;
 		int type = nla_type(a);
@@ -1449,6 +1474,18 @@ int ovs_nla_copy_actions(const struct nlattr *attr,
 				return -EINVAL;
 			break;
 
+		case OVS_ACTION_ATTR_HASH: {
+			const struct ovs_action_hash *act_hash = nla_data(a);
+
+			switch (act_hash->hash_alg) {
+			case OVS_HASH_ALG_L4:
+				break;
+			default:
+				return  -EINVAL;
+			}
+
+			break;
+		}
 
 		case OVS_ACTION_ATTR_POP_VLAN:
 			break;
-- 
1.9.1