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authorTom Herbert <therbert@google.com>2013-01-22 09:50:24 +0000
committerDavid S. Miller <davem@davemloft.net>2013-01-23 13:44:01 -0500
commitda5e36308d9f7151845018369148201a5d28b46d (patch)
treefff243a12ae5a1d16c2827b3ac41ac23ea2043c4
parent055dc21a1d1d219608cd4baac7d0683fb2cbbe8a (diff)
downloadlinux-da5e36308d9f7151845018369148201a5d28b46d.tar.bz2
soreuseport: TCP/IPv4 implementation
Allow multiple listener sockets to bind to the same port. Motivation for soresuseport would be something like a web server binding to port 80 running with multiple threads, where each thread might have it's own listener socket. This could be done as an alternative to other models: 1) have one listener thread which dispatches completed connections to workers. 2) accept on a single listener socket from multiple threads. In case #1 the listener thread can easily become the bottleneck with high connection turn-over rate. In case #2, the proportion of connections accepted per thread tends to be uneven under high connection load (assuming simple event loop: while (1) { accept(); process() }, wakeup does not promote fairness among the sockets. We have seen the disproportion to be as high as 3:1 ratio between thread accepting most connections and the one accepting the fewest. With so_reusport the distribution is uniform. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/inet_hashtables.h13
-rw-r--r--include/net/netfilter/nf_tproxy_core.h1
-rw-r--r--net/ipv4/inet_connection_sock.c48
-rw-r--r--net/ipv4/inet_hashtables.c28
-rw-r--r--net/ipv4/tcp_ipv4.c4
5 files changed, 73 insertions, 21 deletions
diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 67a8fa098e3a..7b2ae9d37076 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -81,7 +81,9 @@ struct inet_bind_bucket {
struct net *ib_net;
#endif
unsigned short port;
- signed short fastreuse;
+ signed char fastreuse;
+ signed char fastreuseport;
+ kuid_t fastuid;
int num_owners;
struct hlist_node node;
struct hlist_head owners;
@@ -257,15 +259,19 @@ extern void inet_unhash(struct sock *sk);
extern struct sock *__inet_lookup_listener(struct net *net,
struct inet_hashinfo *hashinfo,
+ const __be32 saddr,
+ const __be16 sport,
const __be32 daddr,
const unsigned short hnum,
const int dif);
static inline struct sock *inet_lookup_listener(struct net *net,
struct inet_hashinfo *hashinfo,
+ __be32 saddr, __be16 sport,
__be32 daddr, __be16 dport, int dif)
{
- return __inet_lookup_listener(net, hashinfo, daddr, ntohs(dport), dif);
+ return __inet_lookup_listener(net, hashinfo, saddr, sport,
+ daddr, ntohs(dport), dif);
}
/* Socket demux engine toys. */
@@ -358,7 +364,8 @@ static inline struct sock *__inet_lookup(struct net *net,
struct sock *sk = __inet_lookup_established(net, hashinfo,
saddr, sport, daddr, hnum, dif);
- return sk ? : __inet_lookup_listener(net, hashinfo, daddr, hnum, dif);
+ return sk ? : __inet_lookup_listener(net, hashinfo, saddr, sport,
+ daddr, hnum, dif);
}
static inline struct sock *inet_lookup(struct net *net,
diff --git a/include/net/netfilter/nf_tproxy_core.h b/include/net/netfilter/nf_tproxy_core.h
index 75ca9291cf2c..193796445642 100644
--- a/include/net/netfilter/nf_tproxy_core.h
+++ b/include/net/netfilter/nf_tproxy_core.h
@@ -82,6 +82,7 @@ nf_tproxy_get_sock_v4(struct net *net, const u8 protocol,
break;
case NFT_LOOKUP_LISTENER:
sk = inet_lookup_listener(net, &tcp_hashinfo,
+ saddr, sport,
daddr, dport,
in->ifindex);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index d0670f00d524..8bb623d357ad 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -59,6 +59,8 @@ int inet_csk_bind_conflict(const struct sock *sk,
struct sock *sk2;
struct hlist_node *node;
int reuse = sk->sk_reuse;
+ int reuseport = sk->sk_reuseport;
+ kuid_t uid = sock_i_uid((struct sock *)sk);
/*
* Unlike other sk lookup places we do not check
@@ -73,8 +75,11 @@ int inet_csk_bind_conflict(const struct sock *sk,
(!sk->sk_bound_dev_if ||
!sk2->sk_bound_dev_if ||
sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
- if (!reuse || !sk2->sk_reuse ||
- sk2->sk_state == TCP_LISTEN) {
+ if ((!reuse || !sk2->sk_reuse ||
+ sk2->sk_state == TCP_LISTEN) &&
+ (!reuseport || !sk2->sk_reuseport ||
+ (sk2->sk_state != TCP_TIME_WAIT &&
+ !uid_eq(uid, sock_i_uid(sk2))))) {
const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) ||
sk2_rcv_saddr == sk_rcv_saddr(sk))
@@ -106,6 +111,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
int ret, attempts = 5;
struct net *net = sock_net(sk);
int smallest_size = -1, smallest_rover;
+ kuid_t uid = sock_i_uid(sk);
local_bh_disable();
if (!snum) {
@@ -125,9 +131,12 @@ again:
spin_lock(&head->lock);
inet_bind_bucket_for_each(tb, node, &head->chain)
if (net_eq(ib_net(tb), net) && tb->port == rover) {
- if (tb->fastreuse > 0 &&
- sk->sk_reuse &&
- sk->sk_state != TCP_LISTEN &&
+ if (((tb->fastreuse > 0 &&
+ sk->sk_reuse &&
+ sk->sk_state != TCP_LISTEN) ||
+ (tb->fastreuseport > 0 &&
+ sk->sk_reuseport &&
+ uid_eq(tb->fastuid, uid))) &&
(tb->num_owners < smallest_size || smallest_size == -1)) {
smallest_size = tb->num_owners;
smallest_rover = rover;
@@ -185,14 +194,17 @@ tb_found:
if (sk->sk_reuse == SK_FORCE_REUSE)
goto success;
- if (tb->fastreuse > 0 &&
- sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
+ if (((tb->fastreuse > 0 &&
+ sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
+ (tb->fastreuseport > 0 &&
+ sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
smallest_size == -1) {
goto success;
} else {
ret = 1;
if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
- if (sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
+ if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
+ (sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
smallest_size != -1 && --attempts >= 0) {
spin_unlock(&head->lock);
goto again;
@@ -212,9 +224,23 @@ tb_not_found:
tb->fastreuse = 1;
else
tb->fastreuse = 0;
- } else if (tb->fastreuse &&
- (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
- tb->fastreuse = 0;
+ if (sk->sk_reuseport) {
+ tb->fastreuseport = 1;
+ tb->fastuid = uid;
+ } else {
+ tb->fastreuseport = 0;
+ tb->fastuid = 0;
+ }
+ } else {
+ if (tb->fastreuse &&
+ (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
+ tb->fastreuse = 0;
+ if (tb->fastreuseport &&
+ (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid))) {
+ tb->fastreuseport = 0;
+ tb->fastuid = 0;
+ }
+ }
success:
if (!inet_csk(sk)->icsk_bind_hash)
inet_bind_hash(sk, tb, snum);
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index fa3ae8148710..0ce0595d9861 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -39,6 +39,7 @@ struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
write_pnet(&tb->ib_net, hold_net(net));
tb->port = snum;
tb->fastreuse = 0;
+ tb->fastreuseport = 0;
tb->num_owners = 0;
INIT_HLIST_HEAD(&tb->owners);
hlist_add_head(&tb->node, &head->chain);
@@ -151,16 +152,16 @@ static inline int compute_score(struct sock *sk, struct net *net,
if (net_eq(sock_net(sk), net) && inet->inet_num == hnum &&
!ipv6_only_sock(sk)) {
__be32 rcv_saddr = inet->inet_rcv_saddr;
- score = sk->sk_family == PF_INET ? 1 : 0;
+ score = sk->sk_family == PF_INET ? 2 : 1;
if (rcv_saddr) {
if (rcv_saddr != daddr)
return -1;
- score += 2;
+ score += 4;
}
if (sk->sk_bound_dev_if) {
if (sk->sk_bound_dev_if != dif)
return -1;
- score += 2;
+ score += 4;
}
}
return score;
@@ -176,6 +177,7 @@ static inline int compute_score(struct sock *sk, struct net *net,
struct sock *__inet_lookup_listener(struct net *net,
struct inet_hashinfo *hashinfo,
+ const __be32 saddr, __be16 sport,
const __be32 daddr, const unsigned short hnum,
const int dif)
{
@@ -183,17 +185,29 @@ struct sock *__inet_lookup_listener(struct net *net,
struct hlist_nulls_node *node;
unsigned int hash = inet_lhashfn(net, hnum);
struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
- int score, hiscore;
+ int score, hiscore, matches = 0, reuseport = 0;
+ u32 phash = 0;
rcu_read_lock();
begin:
result = NULL;
- hiscore = -1;
+ hiscore = 0;
sk_nulls_for_each_rcu(sk, node, &ilb->head) {
score = compute_score(sk, net, hnum, daddr, dif);
if (score > hiscore) {
result = sk;
hiscore = score;
+ reuseport = sk->sk_reuseport;
+ if (reuseport) {
+ phash = inet_ehashfn(net, daddr, hnum,
+ saddr, sport);
+ matches = 1;
+ }
+ } else if (score == hiscore && reuseport) {
+ matches++;
+ if (((u64)phash * matches) >> 32 == 0)
+ result = sk;
+ phash = next_pseudo_random32(phash);
}
}
/*
@@ -501,7 +515,8 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
inet_bind_bucket_for_each(tb, node, &head->chain) {
if (net_eq(ib_net(tb), net) &&
tb->port == port) {
- if (tb->fastreuse >= 0)
+ if (tb->fastreuse >= 0 ||
+ tb->fastreuseport >= 0)
goto next_port;
WARN_ON(hlist_empty(&tb->owners));
if (!check_established(death_row, sk,
@@ -518,6 +533,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
break;
}
tb->fastreuse = -1;
+ tb->fastreuseport = -1;
goto ok;
next_port:
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c6ce9ca98d23..bbbdcc5c1973 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -657,7 +657,8 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
* no RST generated if md5 hash doesn't match.
*/
sk1 = __inet_lookup_listener(dev_net(skb_dst(skb)->dev),
- &tcp_hashinfo, ip_hdr(skb)->daddr,
+ &tcp_hashinfo, ip_hdr(skb)->saddr,
+ th->source, ip_hdr(skb)->daddr,
ntohs(th->source), inet_iif(skb));
/* don't send rst if it can't find key */
if (!sk1)
@@ -2074,6 +2075,7 @@ do_time_wait:
case TCP_TW_SYN: {
struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev),
&tcp_hashinfo,
+ iph->saddr, th->source,
iph->daddr, th->dest,
inet_iif(skb));
if (sk2) {