Merge branch 'faster-soreuseport'

Craig Gallek says:

====================
Faster SO_REUSEPORT

This series contains two optimizations for the SO_REUSEPORT feature:
Faster lookup when selecting a socket for an incoming packet and
the ability to select the socket from the group using a BPF program.

This series only includes the UDP path.  I plan to submit a follow-up
including the TCP path if the implementation in this series is
acceptable.

Changes in v4:
- pskb_may_pull is unnecessary with pskb_pull (per Alexei Starovoitov)

Changes in v3:
- skb_pull_inline -> pskb_pull (per Alexei Starovoitov)
- reuseport_attach* -> sk_reuseport_attach* and simple return statement
  syntax change (per Daniel Borkmann)

Changes in v2:
- Fix ARM build; remove unnecessary include.
- Handle case where protocol header is not in linear section (per
  Alexei Starovoitov).
====================

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

1 files changed, 44 insertions, 12 deletions

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 00775ee..56fcb55 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -47,6 +47,7 @@
 #include <net/xfrm.h>
 #include <net/inet6_hashtables.h>
 #include <net/busy_poll.h>
+#include <net/sock_reuseport.h>
 
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
@@ -76,7 +77,14 @@ static u32 udp6_ehashfn(const struct net *net,
 			       udp_ipv6_hash_secret + net_hash_mix(net));
 }
 
-int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
+/* match_wildcard == true:  IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
+ *                          only, and any IPv4 addresses if not IPv6 only
+ * match_wildcard == false: addresses must be exactly the same, i.e.
+ *                          IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
+ *                          and 0.0.0.0 equals to 0.0.0.0 only
+ */
+int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
+			 bool match_wildcard)
 {
 	const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
 	int sk2_ipv6only = inet_v6_ipv6only(sk2);
@@ -84,16 +92,24 @@ int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
 	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
 
 	/* if both are mapped, treat as IPv4 */
-	if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED)
-		return (!sk2_ipv6only &&
-			(!sk->sk_rcv_saddr || !sk2->sk_rcv_saddr ||
-			  sk->sk_rcv_saddr == sk2->sk_rcv_saddr));
+	if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
+		if (!sk2_ipv6only) {
+			if (sk->sk_rcv_saddr == sk2->sk_rcv_saddr)
+				return 1;
+			if (!sk->sk_rcv_saddr || !sk2->sk_rcv_saddr)
+				return match_wildcard;
+		}
+		return 0;
+	}
+
+	if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
+		return 1;
 
-	if (addr_type2 == IPV6_ADDR_ANY &&
+	if (addr_type2 == IPV6_ADDR_ANY && match_wildcard &&
 	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
 		return 1;
 
-	if (addr_type == IPV6_ADDR_ANY &&
+	if (addr_type == IPV6_ADDR_ANY && match_wildcard &&
 	    !(ipv6_only_sock(sk) && addr_type2 == IPV6_ADDR_MAPPED))
 		return 1;
 
@@ -253,8 +269,14 @@ begin:
 			badness = score;
 			reuseport = sk->sk_reuseport;
 			if (reuseport) {
+				struct sock *sk2;
 				hash = udp6_ehashfn(net, daddr, hnum,
 						    saddr, sport);
+				sk2 = reuseport_select_sock(sk, hash, NULL, 0);
+				if (sk2) {
+					result = sk2;
+					goto found;
+				}
 				matches = 1;
 			}
 		} else if (score == badness && reuseport) {
@@ -273,6 +295,7 @@ begin:
 		goto begin;
 
 	if (result) {
+found:
 		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
 			result = NULL;
 		else if (unlikely(compute_score2(result, net, saddr, sport,
@@ -287,7 +310,8 @@ begin:
 struct sock *__udp6_lib_lookup(struct net *net,
 				      const struct in6_addr *saddr, __be16 sport,
 				      const struct in6_addr *daddr, __be16 dport,
-				      int dif, struct udp_table *udptable)
+				      int dif, struct udp_table *udptable,
+				      struct sk_buff *skb)
 {
 	struct sock *sk, *result;
 	struct hlist_nulls_node *node;
@@ -332,8 +356,15 @@ begin:
 			badness = score;
 			reuseport = sk->sk_reuseport;
 			if (reuseport) {
+				struct sock *sk2;
 				hash = udp6_ehashfn(net, daddr, hnum,
 						    saddr, sport);
+				sk2 = reuseport_select_sock(sk, hash, skb,
+							sizeof(struct udphdr));
+				if (sk2) {
+					result = sk2;
+					goto found;
+				}
 				matches = 1;
 			}
 		} else if (score == badness && reuseport) {
@@ -352,6 +383,7 @@ begin:
 		goto begin;
 
 	if (result) {
+found:
 		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
 			result = NULL;
 		else if (unlikely(compute_score(result, net, hnum, saddr, sport,
@@ -377,13 +409,13 @@ static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
 		return sk;
 	return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport,
 				 &iph->daddr, dport, inet6_iif(skb),
-				 udptable);
+				 udptable, skb);
 }
 
 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
 			     const struct in6_addr *daddr, __be16 dport, int dif)
 {
-	return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
+	return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table, NULL);
 }
 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
 
@@ -549,8 +581,8 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	int err;
 	struct net *net = dev_net(skb->dev);
 
-	sk = __udp6_lib_lookup(net, daddr, uh->dest,
-			       saddr, uh->source, inet6_iif(skb), udptable);
+	sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
+			       inet6_iif(skb), udptable, skb);
 	if (!sk) {
 		ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 				   ICMP6_MIB_INERRORS);