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authorPeter Oskolkov <posk@google.com>2018-12-13 00:15:36 +0300
committerDavid S. Miller <davem@davemloft.net>2018-12-15 02:55:20 +0300
commit0ee58dad5b065f5910c2c926d8c9f07cbe2db86c (patch)
treed3ddf14a070b7e5ad536fe0357b6cbcd783eb40f /net/ipv6/inet6_hashtables.c
parentd9fbc7f6431fc0e5c0ddedf72206d7c5175c5c9a (diff)
downloadlinux-0ee58dad5b065f5910c2c926d8c9f07cbe2db86c.tar.xz
net: tcp6: prefer listeners bound to an address
A relatively common use case is to have several IPs configured on a host, and have different listeners for each of them. We would like to add a "catch all" listener on addr_any, to match incoming connections not served by any of the listeners bound to a specific address. However, port-only lookups can match addr_any sockets when sockets listening on specific addresses are present if so_reuseport flag is set. This patch eliminates lookups into port-only hashtable, as lookups by (addr,port) tuple are easily available. In addition, compute_score() is tweaked to _not_ match addr_any sockets to specific addresses, as hash collisions could result in the unwanted behavior described above. Tested: the patch compiles; full test in the last patch in this patchset. Existing reuseport_* selftests also pass. Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Peter Oskolkov <posk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/inet6_hashtables.c')
-rw-r--r--net/ipv6/inet6_hashtables.c54
1 files changed, 6 insertions, 48 deletions
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index 5eeeba7181a1..f3515ebe9b3a 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -99,23 +99,16 @@ static inline int compute_score(struct sock *sk, struct net *net,
const int dif, const int sdif, bool exact_dif)
{
int score = -1;
- bool dev_match;
if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
sk->sk_family == PF_INET6) {
+ if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
+ return -1;
- score = 1;
- if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
- if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
- return -1;
- score++;
- }
- dev_match = inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if,
- dif, sdif);
- if (!dev_match)
+ if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
return -1;
- score++;
+ score = 1;
if (sk->sk_incoming_cpu == raw_smp_processor_id())
score++;
}
@@ -164,26 +157,12 @@ struct sock *inet6_lookup_listener(struct net *net,
const __be16 sport, const struct in6_addr *daddr,
const unsigned short hnum, const int dif, const int sdif)
{
- unsigned int hash = inet_lhashfn(net, hnum);
- struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
- bool exact_dif = inet6_exact_dif_match(net, skb);
struct inet_listen_hashbucket *ilb2;
- struct sock *sk, *result = NULL;
- int score, hiscore = 0;
+ struct sock *result = NULL;
unsigned int hash2;
- u32 phash = 0;
-
- if (ilb->count <= 10 || !hashinfo->lhash2)
- goto port_lookup;
-
- /* Too many sk in the ilb bucket (which is hashed by port alone).
- * Try lhash2 (which is hashed by port and addr) instead.
- */
hash2 = ipv6_portaddr_hash(net, daddr, hnum);
ilb2 = inet_lhash2_bucket(hashinfo, hash2);
- if (ilb2->count > ilb->count)
- goto port_lookup;
result = inet6_lhash2_lookup(net, ilb2, skb, doff,
saddr, sport, daddr, hnum,
@@ -192,33 +171,12 @@ struct sock *inet6_lookup_listener(struct net *net,
goto done;
/* Lookup lhash2 with in6addr_any */
-
hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
ilb2 = inet_lhash2_bucket(hashinfo, hash2);
- if (ilb2->count > ilb->count)
- goto port_lookup;
result = inet6_lhash2_lookup(net, ilb2, skb, doff,
- saddr, sport, daddr, hnum,
+ saddr, sport, &in6addr_any, hnum,
dif, sdif);
- goto done;
-
-port_lookup:
- sk_for_each(sk, &ilb->head) {
- score = compute_score(sk, net, hnum, daddr, dif, sdif, exact_dif);
- if (score > hiscore) {
- if (sk->sk_reuseport) {
- phash = inet6_ehashfn(net, daddr, hnum,
- saddr, sport);
- result = reuseport_select_sock(sk, phash,
- skb, doff);
- if (result)
- goto done;
- }
- result = sk;
- hiscore = score;
- }
- }
done:
if (unlikely(IS_ERR(result)))
return NULL;