Merge branch 'skb_hash'

Tom Herbert says:

====================
net: Add rxhash utility hash functions

v3:

There's really nothing specific about rxhash that constrains
it to be a value just for these receive path. Drop the 'rx'
part in utility functions, including skb_get_rxhash. In subsequent
patches, we can change the rxhash and l4_rxhash names also, as
well as abstracting out the interface to the hash.

Added comments about hash types per feedback.

In this version I'm omitting the changes to drivers to make the
patch set manageable. Will add those changes in followup pathes.

-----
This patch series introduce skb_set_rxhash and skb_clear_rxhash
which are called to set the rxhash (from network drivers) and
to clear the rxhash. This API should be used instead of updating
fields in the skbuff directly.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

10 files changed, 19 insertions, 21 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 9d4369ece679..c482fe8abf87 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3006,7 +3006,7 @@ static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
 	}
 
 	skb_reset_network_header(skb);
-	if (!skb_get_rxhash(skb))
+	if (!skb_get_hash(skb))
 		goto done;
 
 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
@@ -3151,7 +3151,7 @@ static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
 	rcu_read_lock();
 	fl = rcu_dereference(sd->flow_limit);
 	if (fl) {
-		new_flow = skb_get_rxhash(skb) & (fl->num_buckets - 1);
+		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
 		old_flow = fl->history[fl->history_head];
 		fl->history[fl->history_head] = new_flow;
 
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index d6ef17322500..b324bfa3485c 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -202,12 +202,12 @@ static __always_inline u32 __flow_hash_1word(u32 a)
 }
 
 /*
- * __skb_get_rxhash: calculate a flow hash based on src/dst addresses
+ * __skb_get_hash: calculate a flow hash based on src/dst addresses
  * and src/dst port numbers.  Sets rxhash in skb to non-zero hash value
  * on success, zero indicates no valid hash.  Also, sets l4_rxhash in skb
  * if hash is a canonical 4-tuple hash over transport ports.
  */
-void __skb_get_rxhash(struct sk_buff *skb)
+void __skb_get_hash(struct sk_buff *skb)
 {
 	struct flow_keys keys;
 	u32 hash;
@@ -234,7 +234,7 @@ void __skb_get_rxhash(struct sk_buff *skb)
 
 	skb->rxhash = hash;
 }
-EXPORT_SYMBOL(__skb_get_rxhash);
+EXPORT_SYMBOL(__skb_get_hash);
 
 /*
  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 06e72d3cdf60..2b6b863f51f2 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -712,9 +712,8 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
 	new->inner_network_header = old->inner_network_header;
 	new->inner_mac_header = old->inner_mac_header;
 	skb_dst_copy(new, old);
-	new->rxhash		= old->rxhash;
+	skb_copy_hash(new, old);
 	new->ooo_okay		= old->ooo_okay;
-	new->l4_rxhash		= old->l4_rxhash;
 	new->no_fcs		= old->no_fcs;
 	new->encapsulation	= old->encapsulation;
 #ifdef CONFIG_XFRM
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 2481993a4970..c10a3ce5cbff 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -704,7 +704,7 @@ struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
 			memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 			if (ip_defrag(skb, user))
 				return NULL;
-			skb->rxhash = 0;
+			skb_clear_hash(skb);
 		}
 	}
 	return skb;
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 42ffbc8d65c6..6156f4ef5e91 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -56,7 +56,7 @@ int iptunnel_xmit(struct rtable *rt, struct sk_buff *skb,
 
 	skb_scrub_packet(skb, xnet);
 
-	skb->rxhash = 0;
+	skb_clear_hash(skb);
 	skb_dst_set(skb, &rt->dst);
 	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 
@@ -107,8 +107,7 @@ int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
 
 	nf_reset(skb);
 	secpath_reset(skb);
-	if (!skb->l4_rxhash)
-		skb->rxhash = 0;
+	skb_clear_hash_if_not_l4(skb);
 	skb_dst_drop(skb);
 	skb->vlan_tci = 0;
 	skb_set_queue_mapping(skb, 0);
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 65cfaa816075..716b7eebfe70 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -165,7 +165,7 @@ static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
 	}
 
 	csum_replace4(&nh->check, *addr, new_addr);
-	skb->rxhash = 0;
+	skb_clear_hash(skb);
 	*addr = new_addr;
 }
 
@@ -199,7 +199,7 @@ static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
 	if (recalculate_csum)
 		update_ipv6_checksum(skb, l4_proto, addr, new_addr);
 
-	skb->rxhash = 0;
+	skb_clear_hash(skb);
 	memcpy(addr, new_addr, sizeof(__be32[4]));
 }
 
@@ -296,7 +296,7 @@ static void set_tp_port(struct sk_buff *skb, __be16 *port,
 {
 	inet_proto_csum_replace2(check, skb, *port, new_port, 0);
 	*port = new_port;
-	skb->rxhash = 0;
+	skb_clear_hash(skb);
 }
 
 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
@@ -310,7 +310,7 @@ static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
 			uh->check = CSUM_MANGLED_0;
 	} else {
 		*port = new_port;
-		skb->rxhash = 0;
+		skb_clear_hash(skb);
 	}
 }
 
@@ -381,7 +381,7 @@ static int set_sctp(struct sk_buff *skb,
 		/* Carry any checksum errors through. */
 		sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
 
-		skb->rxhash = 0;
+		skb_clear_hash(skb);
 	}
 
 	return 0;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index cc803c63059a..24675f06f4fd 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -963,7 +963,7 @@ static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 			struct tpacket3_hdr *ppd)
 {
-	ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
+	ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
 }
 
 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
@@ -1295,7 +1295,7 @@ static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
 			if (!skb)
 				return 0;
 		}
-		skb_get_rxhash(skb);
+		skb_get_hash(skb);
 		idx = fanout_demux_hash(f, skb, num);
 		break;
 	case PACKET_FANOUT_LB:
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 7881e2fccbc2..83a6322b7751 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -220,7 +220,7 @@ static u32 flow_get_vlan_tag(const struct sk_buff *skb)
 
 static u32 flow_get_rxhash(struct sk_buff *skb)
 {
-	return skb_get_rxhash(skb);
+	return skb_get_hash(skb);
 }
 
 static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c
index 382519a5d7f9..9b8c0b0e60d7 100644
--- a/net/sched/em_meta.c
+++ b/net/sched/em_meta.c
@@ -222,7 +222,7 @@ META_COLLECTOR(int_maclen)
 
 META_COLLECTOR(int_rxhash)
 {
-	dst->value = skb_get_rxhash(skb);
+	dst->value = skb_get_hash(skb);
 }
 
 /**************************************************************************
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index f2fb92dd970d..08ef7a42c0e4 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -226,7 +226,7 @@ static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
 		/* By forcing low order bit to 1, we make sure to not
 		 * collide with a local flow (socket pointers are word aligned)
 		 */
-		sk = (struct sock *)(skb_get_rxhash(skb) | 1L);
+		sk = (struct sock *)(skb_get_hash(skb) | 1L);
 	}
 
 	root = &q->fq_root[hash_32((u32)(long)sk, q->fq_trees_log)];