sock: Introduce named constants for sk_reuse

Name them in a "backward compatible" manner, i.e. reuse or not
are still 1 and 0 respectively. The reuse value of 2 means that
the socket with it will forcibly reuse everyone else's port.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/block/drbd/drbd_receiver.c

@@ -664,7 +664,7 @@ static struct socket *drbd_wait_for_connect(struct drbd_conf *mdev)
 	timeo = mdev->net_conf->try_connect_int * HZ;
 	timeo += (random32() & 1) ? timeo / 7 : -timeo / 7; /* 28.5% random jitter */
 
-	s_listen->sk->sk_reuse    = 1; /* SO_REUSEADDR */
+	s_listen->sk->sk_reuse    = SK_CAN_REUSE; /* SO_REUSEADDR */
 	s_listen->sk->sk_rcvtimeo = timeo;
 	s_listen->sk->sk_sndtimeo = timeo;
 	drbd_setbufsize(s_listen, mdev->net_conf->sndbuf_size,
@@ -841,8 +841,8 @@ static int drbd_connect(struct drbd_conf *mdev)
 		}
 	} while (1);
 
-	msock->sk->sk_reuse = 1; /* SO_REUSEADDR */
-	sock->sk->sk_reuse = 1; /* SO_REUSEADDR */
+	msock->sk->sk_reuse = SK_CAN_REUSE; /* SO_REUSEADDR */
+	sock->sk->sk_reuse = SK_CAN_REUSE; /* SO_REUSEADDR */
 
 	sock->sk->sk_allocation = GFP_NOIO;
 	msock->sk->sk_allocation = GFP_NOIO;

drivers/scsi/iscsi_tcp.c

@@ -662,7 +662,7 @@ iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
 
 	/* setup Socket parameters */
 	sk = sock->sk;
-	sk->sk_reuse = 1;
+	sk->sk_reuse = SK_CAN_REUSE;
 	sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
 	sk->sk_allocation = GFP_ATOMIC;
 

drivers/staging/ramster/cluster/tcp.c

@@ -2106,7 +2106,7 @@ static int r2net_open_listening_sock(__be32 addr, __be16 port)
 	r2net_listen_sock = sock;
 	INIT_WORK(&r2net_listen_work, r2net_accept_many);
 
-	sock->sk->sk_reuse = 1;
+	sock->sk->sk_reuse = SK_CAN_REUSE;
 	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
 	if (ret < 0) {
 		printk(KERN_ERR "ramster: Error %d while binding socket at "

fs/ocfs2/cluster/tcp.c

@@ -2005,7 +2005,7 @@ static int o2net_open_listening_sock(__be32 addr, __be16 port)
 	o2net_listen_sock = sock;
 	INIT_WORK(&o2net_listen_work, o2net_accept_many);
 
-	sock->sk->sk_reuse = 1;
+	sock->sk->sk_reuse = SK_CAN_REUSE;
 	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
 	if (ret < 0) {
 		printk(KERN_ERR "o2net: Error %d while binding socket at "

include/net/sock.h

@@ -376,6 +376,17 @@ struct sock {
 	void                    (*sk_destruct)(struct sock *sk);
 };
 
+/*
+ * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
+ * or not whether his port will be reused by someone else. SK_FORCE_REUSE
+ * on a socket means that the socket will reuse everybody else's port
+ * without looking at the other's sk_reuse value.
+ */
+
+#define SK_NO_REUSE	0
+#define SK_CAN_REUSE	1
+#define SK_FORCE_REUSE	2
+
 static inline int sk_peek_offset(struct sock *sk, int flags)
 {
 	if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))

net/core/sock.c

@@ -561,7 +561,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
 			sock_valbool_flag(sk, SOCK_DBG, valbool);
 		break;
 	case SO_REUSEADDR:
-		sk->sk_reuse = valbool;
+		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
 		break;
 	case SO_TYPE:
 	case SO_PROTOCOL:

net/econet/af_econet.c

@@ -617,7 +617,7 @@ static int econet_create(struct net *net, struct socket *sock, int protocol,
 	if (sk == NULL)
 		goto out;
 
-	sk->sk_reuse = 1;
+	sk->sk_reuse = SK_CAN_REUSE;
 	sock->ops = &econet_ops;
 	sock_init_data(sock, sk);
 
@@ -1012,7 +1012,7 @@ static int __init aun_udp_initialise(void)
 		return error;
 	}
 
-	udpsock->sk->sk_reuse = 1;
+	udpsock->sk->sk_reuse = SK_CAN_REUSE;
 	udpsock->sk->sk_allocation = GFP_ATOMIC; /* we're going to call it
 						    from interrupts */
 

net/ipv4/af_inet.c

@@ -350,7 +350,7 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
 	err = 0;
 	sk->sk_no_check = answer_no_check;
 	if (INET_PROTOSW_REUSE & answer_flags)
-		sk->sk_reuse = 1;
+		sk->sk_reuse = SK_CAN_REUSE;
 
 	inet = inet_sk(sk);
 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;

net/ipv4/inet_connection_sock.c

@@ -182,6 +182,9 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
 	goto tb_not_found;
 tb_found:
 	if (!hlist_empty(&tb->owners)) {
+		if (sk->sk_reuse == SK_FORCE_REUSE)
+			goto success;
+
 		if (tb->fastreuse > 0 &&
 		    sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
 		    smallest_size == -1) {

net/ipv6/af_inet6.c

@@ -180,7 +180,7 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol,
 	err = 0;
 	sk->sk_no_check = answer_no_check;
 	if (INET_PROTOSW_REUSE & answer_flags)
-		sk->sk_reuse = 1;
+		sk->sk_reuse = SK_CAN_REUSE;
 
 	inet = inet_sk(sk);
 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;

net/netfilter/ipvs/ip_vs_sync.c

@@ -1368,7 +1368,7 @@ static struct socket *make_receive_sock(struct net *net)
 	 */
 	sk_change_net(sock->sk, net);
 	/* it is equivalent to the REUSEADDR option in user-space */
-	sock->sk->sk_reuse = 1;
+	sock->sk->sk_reuse = SK_CAN_REUSE;
 
 	result = sock->ops->bind(sock, (struct sockaddr *) &mcast_addr,
 			sizeof(struct sockaddr));

net/rds/tcp_listen.c

@@ -145,7 +145,7 @@ int rds_tcp_listen_init(void)
 	if (ret < 0)
 		goto out;
 
-	sock->sk->sk_reuse = 1;
+	sock->sk->sk_reuse = SK_CAN_REUSE;
 	rds_tcp_nonagle(sock);
 
 	write_lock_bh(&sock->sk->sk_callback_lock);

net/sunrpc/svcsock.c

@@ -1556,7 +1556,7 @@ static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
 					(char *)&val, sizeof(val));
 
 	if (type == SOCK_STREAM)
-		sock->sk->sk_reuse = 1;		/* allow address reuse */
+		sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */
 	error = kernel_bind(sock, sin, len);
 	if (error < 0)
 		goto bummer;