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authorPeter Oskolkov <posk@google.com>2018-12-12 13:15:35 -0800
committerDavid S. Miller <davem@davemloft.net>2018-12-14 15:55:20 -0800
commitd9fbc7f6431fc0e5c0ddedf72206d7c5175c5c9a (patch)
tree89f1ed973b4df1a7c87041dc26a3c991f0e699da /net/ipv4/inet_hashtables.c
parentnet: udp6: prefer listeners bound to an address (diff)
downloadlinux-dev-d9fbc7f6431fc0e5c0ddedf72206d7c5175c5c9a.tar.xz
linux-dev-d9fbc7f6431fc0e5c0ddedf72206d7c5175c5c9a.zip
net: tcp: 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 '')
-rw-r--r--net/ipv4/inet_hashtables.c60
1 files changed, 8 insertions, 52 deletions
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 13890d5bfc34..cd03ab42705b 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -234,24 +234,16 @@ static inline int compute_score(struct sock *sk, struct net *net,
const int dif, const int sdif, bool exact_dif)
{
int score = -1;
- struct inet_sock *inet = inet_sk(sk);
- bool dev_match;
- if (net_eq(sock_net(sk), net) && inet->inet_num == hnum &&
+ if (net_eq(sock_net(sk), net) && sk->sk_num == hnum &&
!ipv6_only_sock(sk)) {
- __be32 rcv_saddr = inet->inet_rcv_saddr;
- score = sk->sk_family == PF_INET ? 2 : 1;
- if (rcv_saddr) {
- if (rcv_saddr != daddr)
- return -1;
- score += 4;
- }
- dev_match = inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if,
- dif, sdif);
- if (!dev_match)
+ if (sk->sk_rcv_saddr != daddr)
+ return -1;
+
+ if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
return -1;
- score += 4;
+ score = sk->sk_family == PF_INET ? 2 : 1;
if (sk->sk_incoming_cpu == raw_smp_processor_id())
score++;
}
@@ -307,26 +299,12 @@ struct sock *__inet_lookup_listener(struct net *net,
const __be32 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 = inet_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 = ipv4_portaddr_hash(net, daddr, hnum);
ilb2 = inet_lhash2_bucket(hashinfo, hash2);
- if (ilb2->count > ilb->count)
- goto port_lookup;
result = inet_lhash2_lookup(net, ilb2, skb, doff,
saddr, sport, daddr, hnum,
@@ -335,34 +313,12 @@ struct sock *__inet_lookup_listener(struct net *net,
goto done;
/* Lookup lhash2 with INADDR_ANY */
-
hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
ilb2 = inet_lhash2_bucket(hashinfo, hash2);
- if (ilb2->count > ilb->count)
- goto port_lookup;
result = inet_lhash2_lookup(net, ilb2, skb, doff,
- saddr, sport, daddr, hnum,
+ saddr, sport, htonl(INADDR_ANY), hnum,
dif, sdif);
- goto done;
-
-port_lookup:
- sk_for_each_rcu(sk, &ilb->head) {
- score = compute_score(sk, net, hnum, daddr,
- dif, sdif, exact_dif);
- if (score > hiscore) {
- if (sk->sk_reuseport) {
- phash = inet_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;