Commit aacd9289 authored by Alex Copot's avatar Alex Copot Committed by David S. Miller

tcp: bind() use stronger condition for bind_conflict

We must try harder to get unique (addr, port) pairs when
doing port autoselection for sockets with SO_REUSEADDR
option set.

We achieve this by adding a relaxation parameter to
inet_csk_bind_conflict. When 'relax' parameter is off
we return a conflict whenever the current searched
pair (addr, port) is not unique.

This tries to address the problems reported in patch:
	8d238b25
	Revert "tcp: bind() fix when many ports are bound"

Tests where ran for creating and binding(0) many sockets
on 100 IPs. The results are, on average:

	* 60000 sockets, 600 ports / IP:
		* 0.210 s, 620 (IP, port) duplicates without patch
		* 0.219 s, no duplicates with patch
	* 100000 sockets, 1000 ports / IP:
		* 0.371 s, 1720 duplicates without patch
		* 0.373 s, no duplicates with patch
	* 200000 sockets, 2000 ports / IP:
		* 0.766 s, 6900 duplicates without patch
		* 0.768 s, no duplicates with patch
	* 500000 sockets, 5000 ports / IP:
		* 2.227 s, 41500 duplicates without patch
		* 2.284 s, no duplicates with patch
Signed-off-by: default avatarAlex Copot <alex.mihai.c@gmail.com>
Signed-off-by: default avatarDaniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c72e1183
......@@ -23,7 +23,7 @@ struct sock;
struct sockaddr;
extern int inet6_csk_bind_conflict(const struct sock *sk,
const struct inet_bind_bucket *tb);
const struct inet_bind_bucket *tb, bool relax);
extern struct dst_entry* inet6_csk_route_req(struct sock *sk,
const struct request_sock *req);
......
......@@ -60,7 +60,7 @@ struct inet_connection_sock_af_ops {
#endif
void (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
int (*bind_conflict)(const struct sock *sk,
const struct inet_bind_bucket *tb);
const struct inet_bind_bucket *tb, bool relax);
};
/** inet_connection_sock - INET connection oriented sock
......@@ -245,7 +245,7 @@ extern struct request_sock *inet_csk_search_req(const struct sock *sk,
const __be32 raddr,
const __be32 laddr);
extern int inet_csk_bind_conflict(const struct sock *sk,
const struct inet_bind_bucket *tb);
const struct inet_bind_bucket *tb, bool relax);
extern int inet_csk_get_port(struct sock *sk, unsigned short snum);
extern struct dst_entry* inet_csk_route_req(struct sock *sk,
......
......@@ -53,7 +53,7 @@ void inet_get_local_port_range(int *low, int *high)
EXPORT_SYMBOL(inet_get_local_port_range);
int inet_csk_bind_conflict(const struct sock *sk,
const struct inet_bind_bucket *tb)
const struct inet_bind_bucket *tb, bool relax)
{
struct sock *sk2;
struct hlist_node *node;
......@@ -79,6 +79,14 @@ int inet_csk_bind_conflict(const struct sock *sk,
sk2_rcv_saddr == sk_rcv_saddr(sk))
break;
}
if (!relax && reuse && sk2->sk_reuse &&
sk2->sk_state != TCP_LISTEN) {
const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) ||
sk2_rcv_saddr == sk_rcv_saddr(sk))
break;
}
}
}
return node != NULL;
......@@ -122,12 +130,13 @@ again:
(tb->num_owners < smallest_size || smallest_size == -1)) {
smallest_size = tb->num_owners;
smallest_rover = rover;
if (atomic_read(&hashinfo->bsockets) > (high - low) + 1) {
if (atomic_read(&hashinfo->bsockets) > (high - low) + 1 &&
!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
snum = smallest_rover;
goto tb_found;
}
}
if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
snum = rover;
goto tb_found;
}
......@@ -178,12 +187,13 @@ tb_found:
goto success;
} else {
ret = 1;
if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
if (sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
smallest_size != -1 && --attempts >= 0) {
spin_unlock(&head->lock);
goto again;
}
goto fail_unlock;
}
}
......
......@@ -28,7 +28,7 @@
#include <net/inet6_connection_sock.h>
int inet6_csk_bind_conflict(const struct sock *sk,
const struct inet_bind_bucket *tb)
const struct inet_bind_bucket *tb, bool relax)
{
const struct sock *sk2;
const struct hlist_node *node;
......
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