net: Add IPv6 flow label to flow_keys

In flow_dissector set the flow label in flow_keys for IPv6. This also
removes the shortcircuiting of flow dissection when a non-zero label
is present, the flow label can be considered to provide additional
entropy for a hash.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index 08480fb..14d8483 100644 (file)
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -28,7 +28,8 @@ struct flow_dissector_key_basic {
 };
 
 struct flow_dissector_key_tags {
-       u32     vlan_id:12;
+       u32     vlan_id:12,
+               flow_label:20;
 };
 
 /**
@@ -111,6 +112,7 @@ enum flow_dissector_key_id {
        FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
        FLOW_DISSECTOR_KEY_TIPC_ADDRS, /* struct flow_dissector_key_tipc_addrs */
        FLOW_DISSECTOR_KEY_VLANID, /* struct flow_dissector_key_flow_tags */
+       FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */
 
        FLOW_DISSECTOR_KEY_MAX,
 };

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 5c66cb2..70f0567 100644 (file)
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -210,30 +210,17 @@ ipv6:
 
                        memcpy(key_ipv6_addrs, &iph->saddr, sizeof(*key_ipv6_addrs));
                        key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
-                       goto flow_label;
                }
-               break;
-flow_label:
+
                flow_label = ip6_flowlabel(iph);
                if (flow_label) {
-                       /* Awesome, IPv6 packet has a flow label so we can
-                        * use that to represent the ports without any
-                        * further dissection.
-                        */
-
-                       key_basic->n_proto = proto;
-                       key_basic->ip_proto = ip_proto;
-                       key_control->thoff = (u16)nhoff;
-
                        if (skb_flow_dissector_uses_key(flow_dissector,
-                                                       FLOW_DISSECTOR_KEY_PORTS)) {
-                               key_ports = skb_flow_dissector_target(flow_dissector,
-                                                                     FLOW_DISSECTOR_KEY_PORTS,
-                                                                     target_container);
-                               key_ports->ports = flow_label;
+                               FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
+                               key_tags = skb_flow_dissector_target(flow_dissector,
+                                                                    FLOW_DISSECTOR_KEY_FLOW_LABEL,
+                                                                    target_container);
+                               key_tags->flow_label = ntohl(flow_label);
                        }
-
-                       return true;
                }
 
                break;
@@ -659,6 +646,10 @@ static const struct flow_dissector_key flow_keys_dissector_keys[] = {
                .key_id = FLOW_DISSECTOR_KEY_VLANID,
                .offset = offsetof(struct flow_keys, tags),
        },
+       {
+               .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
+               .offset = offsetof(struct flow_keys, tags),
+       },
 };
 
 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {