diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index f7e844d84836..bbe28920e2d8 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -156,33 +156,21 @@ static int inet_csk_bind_conflict(const struct sock *sk, return sk2 != NULL; } -/* Obtain a reference to a local port for the given sock, - * if snum is zero it means select any available local port. - * We try to allocate an odd port (and leave even ports for connect()) +/* + * Find an open port number for the socket. Returns with the + * inet_bind_hashbucket lock held. */ -int inet_csk_get_port(struct sock *sk, unsigned short snum) +static struct inet_bind_hashbucket * +inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *port_ret) { - bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN; struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo; - int ret = 1, port = snum; + int port = 0; struct inet_bind_hashbucket *head; struct net *net = sock_net(sk); int i, low, high, attempt_half; struct inet_bind_bucket *tb; - kuid_t uid = sock_i_uid(sk); u32 remaining, offset; - bool reuseport_ok = !!snum; - if (port) { - head = &hinfo->bhash[inet_bhashfn(net, port, - hinfo->bhash_size)]; - spin_lock_bh(&head->lock); - inet_bind_bucket_for_each(tb, &head->chain) - if (net_eq(ib_net(tb), net) && tb->port == port) - goto tb_found; - - goto tb_not_found; - } attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0; other_half_scan: inet_get_local_port_range(net, &low, &high); @@ -219,11 +207,12 @@ other_parity_scan: spin_lock_bh(&head->lock); inet_bind_bucket_for_each(tb, &head->chain) if (net_eq(ib_net(tb), net) && tb->port == port) { - if (!inet_csk_bind_conflict(sk, tb, false, reuseport_ok)) + if (!inet_csk_bind_conflict(sk, tb, false, false)) goto success; goto next_port; } - goto tb_not_found; + tb = NULL; + goto success; next_port: spin_unlock_bh(&head->lock); cond_resched(); @@ -238,8 +227,41 @@ next_port: attempt_half = 2; goto other_half_scan; } - return ret; + return NULL; +success: + *port_ret = port; + *tb_ret = tb; + return head; +} +/* Obtain a reference to a local port for the given sock, + * if snum is zero it means select any available local port. + * We try to allocate an odd port (and leave even ports for connect()) + */ +int inet_csk_get_port(struct sock *sk, unsigned short snum) +{ + bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN; + struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo; + int ret = 1, port = snum; + struct inet_bind_hashbucket *head; + struct net *net = sock_net(sk); + struct inet_bind_bucket *tb = NULL; + kuid_t uid = sock_i_uid(sk); + + if (!port) { + head = inet_csk_find_open_port(sk, &tb, &port); + if (!head) + return ret; + if (!tb) + goto tb_not_found; + goto success; + } + head = &hinfo->bhash[inet_bhashfn(net, port, + hinfo->bhash_size)]; + spin_lock_bh(&head->lock); + inet_bind_bucket_for_each(tb, &head->chain) + if (net_eq(ib_net(tb), net) && tb->port == port) + goto tb_found; tb_not_found: tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, net, head, port); @@ -255,7 +277,7 @@ tb_found: !rcu_access_pointer(sk->sk_reuseport_cb) && sk->sk_reuseport && uid_eq(tb->fastuid, uid))) goto success; - if (inet_csk_bind_conflict(sk, tb, true, reuseport_ok)) + if (inet_csk_bind_conflict(sk, tb, true, true)) goto fail_unlock; } success: