datapath: add hash action

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/actions.c b/datapath/actions.c
index 82cfd2d..c4b4605 100644 (file)
--- 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)
+{
+       struct sw_flow_key *key = OVS_CB(skb)->pkt_key;
+       struct ovs_action_hash *hash_act = nla_data(attr);
+       u32 hash = 0;
+
+       /* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
+       hash = skb_get_rxhash(skb);
+       hash = jhash_1word(hash, hash_act->hash_basis);
+       if (!hash)
+               hash = 0x1;
+
+       key->ovs_flow_hash = 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..a4cb57e 100644 (file)
--- 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 ovs_flow_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..7db14de 100644 (file)
--- a/datapath/flow_netlink.c
+++ b/datapath/flow_netlink.c
@@ -252,6 +252,7 @@ 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 +456,13 @@ 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]);
+
+               SW_FLOW_KEY_PUT(match, ovs_flow_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 +867,7 @@ 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.ovs_flow_hash = 0;
        memset(tun_key, 0, sizeof(flow->key.tun_key));
 
        err = parse_flow_nlattrs(attr, a, &attrs);
@@ -882,6 +891,9 @@ int ovs_nla_put_flow(const struct sw_flow_key *swkey,
        struct nlattr *nla, *encap;
        bool is_mask = (swkey != output);
 
+       if (nla_put_u32(skb, OVS_KEY_ATTR_DP_HASH, output->ovs_flow_hash))
+               goto nla_put_failure;
+
        if (nla_put_u32(skb, OVS_KEY_ATTR_PRIORITY, output->phy.priority))
                goto nla_put_failure;
 
@@ -1422,7 +1434,8 @@ 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 +1462,18 @@ 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;

diff --git a/include/linux/openvswitch.h b/include/linux/openvswitch.h
index 1aa9158..544c5ba 100644 (file)
--- a/include/linux/openvswitch.h
+++ b/include/linux/openvswitch.h
@@ -312,7 +312,8 @@ enum ovs_key_attr {
        OVS_KEY_ATTR_TUNNEL,    /* Nested set of ovs_tunnel attributes */
        OVS_KEY_ATTR_SCTP,      /* struct ovs_key_sctp */
        OVS_KEY_ATTR_TCP_FLAGS, /* be16 TCP flags. */
-       OVS_KEY_ATTR_DP_HASH,   /* u32 hash value */
+       OVS_KEY_ATTR_DP_HASH,   /* u32 hash value. Value 0 indicates the hash
+                                  is not computed by the datapath. */
        OVS_KEY_ATTR_RECIRC_ID, /* u32 recirc id */
 #ifdef __KERNEL__
        /* Only used within kernel data path. */