rds: Remove IPv6 dependency

This patch removes the IPv6 dependency from RDS.
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds/Kconfig

 
 config RDS
 	tristate "The RDS Protocol"
-	depends on INET && IPV6
+	depends on INET
 	---help---
 	  The RDS (Reliable Datagram Sockets) protocol provides reliable,
 	  sequenced delivery of datagrams over Infiniband or TCP.

net/rds/af_rds.c

@@ -156,19 +156,21 @@ static int rds_getname(struct socket *sock, struct sockaddr *uaddr,
 				return sizeof(*sin);
 			}
 
-			if (ipv6_addr_type(&rs->rs_conn_addr) &
-			    IPV6_ADDR_MAPPED) {
-				sin = (struct sockaddr_in *)uaddr;
-				memset(sin, 0, sizeof(*sin));
-				sin->sin_family = AF_INET;
-				return sizeof(*sin);
-			}
-
+#if IS_ENABLED(CONFIG_IPV6)
+			if (!(ipv6_addr_type(&rs->rs_conn_addr) &
+			      IPV6_ADDR_MAPPED)) {
 				sin6 = (struct sockaddr_in6 *)uaddr;
 				memset(sin6, 0, sizeof(*sin6));
 				sin6->sin6_family = AF_INET6;
 				return sizeof(*sin6);
 			}
+#endif
+
+			sin = (struct sockaddr_in *)uaddr;
+			memset(sin, 0, sizeof(*sin));
+			sin->sin_family = AF_INET;
+			return sizeof(*sin);
+		}
 		if (ipv6_addr_v4mapped(&rs->rs_bound_addr)) {
 			sin = (struct sockaddr_in *)uaddr;
 			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
@@ -501,9 +503,7 @@ static int rds_connect(struct socket *sock, struct sockaddr *uaddr,
 {
 	struct sock *sk = sock->sk;
 	struct sockaddr_in *sin;
-	struct sockaddr_in6 *sin6;
 	struct rds_sock *rs = rds_sk_to_rs(sk);
-	int addr_type;
 	int ret = 0;
 
 	lock_sock(sk);
@@ -528,7 +528,11 @@ static int rds_connect(struct socket *sock, struct sockaddr *uaddr,
 		rs->rs_conn_port = sin->sin_port;
 		break;
 
-	case AF_INET6:
+#if IS_ENABLED(CONFIG_IPV6)
+	case AF_INET6: {
+		struct sockaddr_in6 *sin6;
+		int addr_type;
+
 		sin6 = (struct sockaddr_in6 *)uaddr;
 		if (addr_len < sizeof(struct sockaddr_in6)) {
 			ret = -EINVAL;
@@ -575,6 +579,8 @@ static int rds_connect(struct socket *sock, struct sockaddr *uaddr,
 		rs->rs_conn_addr = sin6->sin6_addr;
 		rs->rs_conn_port = sin6->sin6_port;
 		break;
+	}
+#endif
 
 	default:
 		ret = -EAFNOSUPPORT;

net/rds/bind.c

@@ -165,7 +165,6 @@ int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	struct in6_addr v6addr, *binding_addr;
 	struct rds_transport *trans;
 	__u32 scope_id = 0;
-	int addr_type;
 	int ret = 0;
 	__be16 port;
 
@@ -183,8 +182,10 @@ int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, &v6addr);
 		binding_addr = &v6addr;
 		port = sin->sin_port;
+#if IS_ENABLED(CONFIG_IPV6)
 	} else if (uaddr->sa_family == AF_INET6) {
 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)uaddr;
+		int addr_type;
 
 		if (addr_len < sizeof(struct sockaddr_in6))
 			return -EINVAL;
@@ -212,6 +213,7 @@ int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		}
 		binding_addr = &sin6->sin6_addr;
 		port = sin6->sin6_port;
+#endif
 	} else {
 		return -EINVAL;
 	}

net/rds/connection.c

@@ -63,8 +63,12 @@ static struct hlist_head *rds_conn_bucket(const struct in6_addr *laddr,
 	net_get_random_once(&rds6_hash_secret, sizeof(rds6_hash_secret));
 
 	lhash = (__force u32)laddr->s6_addr32[3];
+#if IS_ENABLED(CONFIG_IPV6)
 	fhash = __ipv6_addr_jhash(faddr, rds6_hash_secret);
-	hash = __inet6_ehashfn(lhash, 0, fhash, 0, rds_hash_secret);
+#else
+	fhash = (__force u32)faddr->s6_addr32[3];
+#endif
+	hash = __inet_ehashfn(lhash, 0, fhash, 0, rds_hash_secret);
 
 	return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK];
 }
@@ -201,6 +205,8 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 	conn->c_isv6 = !ipv6_addr_v4mapped(laddr);
 	conn->c_faddr = *faddr;
 	conn->c_dev_if = dev_if;
+
+#if IS_ENABLED(CONFIG_IPV6)
 	/* If the local address is link local, set c_bound_if to be the
 	 * index used for this connection.  Otherwise, set it to 0 as
 	 * the socket is not bound to an interface.  c_bound_if is used
@@ -209,6 +215,7 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 	if (ipv6_addr_type(laddr) & IPV6_ADDR_LINKLOCAL)
 		conn->c_bound_if = dev_if;
 	else
+#endif
 		conn->c_bound_if = 0;
 
 	rds_conn_net_set(conn, net);
@@ -500,9 +507,11 @@ static void __rds_inc_msg_cp(struct rds_incoming *inc,
 			     struct rds_info_iterator *iter,
 			     void *saddr, void *daddr, int flip, bool isv6)
 {
+#if IS_ENABLED(CONFIG_IPV6)
 	if (isv6)
 		rds6_inc_info_copy(inc, iter, saddr, daddr, flip);
 	else
+#endif
 		rds_inc_info_copy(inc, iter, *(__be32 *)saddr,
 				  *(__be32 *)daddr, flip);
 }
@@ -581,6 +590,7 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 	rds_conn_message_info_cmn(sock, len, iter, lens, want_send, false);
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 static void rds6_conn_message_info(struct socket *sock, unsigned int len,
 				   struct rds_info_iterator *iter,
 				   struct rds_info_lengths *lens,
@@ -588,6 +598,7 @@ static void rds6_conn_message_info(struct socket *sock, unsigned int len,
 {
 	rds_conn_message_info_cmn(sock, len, iter, lens, want_send, true);
 }
+#endif
 
 static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
 				       struct rds_info_iterator *iter,
@@ -596,12 +607,14 @@ static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
 	rds_conn_message_info(sock, len, iter, lens, 1);
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 static void rds6_conn_message_info_send(struct socket *sock, unsigned int len,
 					struct rds_info_iterator *iter,
 					struct rds_info_lengths *lens)
 {
 	rds6_conn_message_info(sock, len, iter, lens, 1);
 }
+#endif
 
 static void rds_conn_message_info_retrans(struct socket *sock,
 					  unsigned int len,
@@ -611,6 +624,7 @@ static void rds_conn_message_info_retrans(struct socket *sock,
 	rds_conn_message_info(sock, len, iter, lens, 0);
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 static void rds6_conn_message_info_retrans(struct socket *sock,
 					   unsigned int len,
 					   struct rds_info_iterator *iter,
@@ -618,6 +632,7 @@ static void rds6_conn_message_info_retrans(struct socket *sock,
 {
 	rds6_conn_message_info(sock, len, iter, lens, 0);
 }
+#endif
 
 void rds_for_each_conn_info(struct socket *sock, unsigned int len,
 			  struct rds_info_iterator *iter,
@@ -734,6 +749,7 @@ static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
 	return 1;
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 static int rds6_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
 {
 	struct rds6_info_connection *cinfo6 = buffer;
@@ -761,6 +777,7 @@ static int rds6_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
 	 */
 	return 1;
 }
+#endif
 
 static void rds_conn_info(struct socket *sock, unsigned int len,
 			  struct rds_info_iterator *iter,
@@ -774,6 +791,7 @@ static void rds_conn_info(struct socket *sock, unsigned int len,
 				sizeof(struct rds_info_connection));
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 static void rds6_conn_info(struct socket *sock, unsigned int len,
 			   struct rds_info_iterator *iter,
 			   struct rds_info_lengths *lens)
@@ -785,6 +803,7 @@ static void rds6_conn_info(struct socket *sock, unsigned int len,
 				buffer,
 				sizeof(struct rds6_info_connection));
 }
+#endif
 
 int rds_conn_init(void)
 {
@@ -807,12 +826,13 @@ int rds_conn_init(void)
 			       rds_conn_message_info_send);
 	rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
 			       rds_conn_message_info_retrans);
+#if IS_ENABLED(CONFIG_IPV6)
 	rds_info_register_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
 	rds_info_register_func(RDS6_INFO_SEND_MESSAGES,
 			       rds6_conn_message_info_send);
 	rds_info_register_func(RDS6_INFO_RETRANS_MESSAGES,
 			       rds6_conn_message_info_retrans);
-
+#endif
 	return 0;
 }
 
@@ -830,11 +850,13 @@ void rds_conn_exit(void)
 				 rds_conn_message_info_send);
 	rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
 				 rds_conn_message_info_retrans);
+#if IS_ENABLED(CONFIG_IPV6)
 	rds_info_deregister_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
 	rds_info_deregister_func(RDS6_INFO_SEND_MESSAGES,
 				 rds6_conn_message_info_send);
 	rds_info_deregister_func(RDS6_INFO_RETRANS_MESSAGES,
 				 rds6_conn_message_info_retrans);
+#endif
 }
 
 /*

net/rds/ib.c

@@ -321,6 +321,7 @@ static int rds_ib_conn_info_visitor(struct rds_connection *conn,
 	return 1;
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 /* IPv6 version of rds_ib_conn_info_visitor(). */
 static int rds6_ib_conn_info_visitor(struct rds_connection *conn,
 				     void *buffer)
@@ -357,6 +358,7 @@ static int rds6_ib_conn_info_visitor(struct rds_connection *conn,
 	}
 	return 1;
 }
+#endif
 
 static void rds_ib_ic_info(struct socket *sock, unsigned int len,
 			   struct rds_info_iterator *iter,
@@ -370,6 +372,7 @@ static void rds_ib_ic_info(struct socket *sock, unsigned int len,
 				sizeof(struct rds_info_rdma_connection));
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 /* IPv6 version of rds_ib_ic_info(). */
 static void rds6_ib_ic_info(struct socket *sock, unsigned int len,
 			    struct rds_info_iterator *iter,
@@ -382,6 +385,7 @@ static void rds6_ib_ic_info(struct socket *sock, unsigned int len,
 			       buffer,
 			       sizeof(struct rds6_info_rdma_connection));
 }
+#endif
 
 /*
  * Early RDS/IB was built to only bind to an address if there is an IPoIB
@@ -398,7 +402,9 @@ static int rds_ib_laddr_check(struct net *net, const struct in6_addr *addr,
 {
 	int ret;
 	struct rdma_cm_id *cm_id;
+#if IS_ENABLED(CONFIG_IPV6)
 	struct sockaddr_in6 sin6;
+#endif
 	struct sockaddr_in sin;
 	struct sockaddr *sa;
 	bool isv4;
@@ -418,6 +424,7 @@ static int rds_ib_laddr_check(struct net *net, const struct in6_addr *addr,
 		sin.sin_addr.s_addr = addr->s6_addr32[3];
 		sa = (struct sockaddr *)&sin;
 	} else {
+#if IS_ENABLED(CONFIG_IPV6)
 		memset(&sin6, 0, sizeof(sin6));
 		sin6.sin6_family = AF_INET6;
 		sin6.sin6_addr = *addr;
@@ -432,21 +439,30 @@ static int rds_ib_laddr_check(struct net *net, const struct in6_addr *addr,
 		if (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL) {
 			struct net_device *dev;
 
-			if (scope_id == 0)
-				return -EADDRNOTAVAIL;
+			if (scope_id == 0) {
+				ret = -EADDRNOTAVAIL;
+				goto out;
+			}
 
 			/* Use init_net for now as RDS is not network
 			 * name space aware.
 			 */
 			dev = dev_get_by_index(&init_net, scope_id);
-			if (!dev)
-				return -EADDRNOTAVAIL;
+			if (!dev) {
+				ret = -EADDRNOTAVAIL;
+				goto out;
+			}
 			if (!ipv6_chk_addr(&init_net, addr, dev, 1)) {
 				dev_put(dev);
-				return -EADDRNOTAVAIL;
+				ret = -EADDRNOTAVAIL;
+				goto out;
 			}
 			dev_put(dev);
 		}
+#else
+		ret = -EADDRNOTAVAIL;
+		goto out;
+#endif
 	}
 
 	/* rdma_bind_addr will only succeed for IB & iWARP devices */
@@ -461,6 +477,7 @@ static int rds_ib_laddr_check(struct net *net, const struct in6_addr *addr,
 		 addr, scope_id, ret,
 		 cm_id->device ? cm_id->device->node_type : -1);
 
+out:
 	rdma_destroy_id(cm_id);
 
 	return ret;
@@ -491,7 +508,9 @@ void rds_ib_exit(void)
 	rds_ib_set_unloading();
 	synchronize_rcu();
 	rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
+#if IS_ENABLED(CONFIG_IPV6)
 	rds_info_deregister_func(RDS6_INFO_IB_CONNECTIONS, rds6_ib_ic_info);
+#endif
 	rds_ib_unregister_client();
 	rds_ib_destroy_nodev_conns();
 	rds_ib_sysctl_exit();
@@ -553,7 +572,9 @@ int rds_ib_init(void)
 	rds_trans_register(&rds_ib_transport);
 
 	rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
+#if IS_ENABLED(CONFIG_IPV6)
 	rds_info_register_func(RDS6_INFO_IB_CONNECTIONS, rds6_ib_ic_info);
+#endif
 
 	goto out;
 

net/rds/ib_cm.c

@@ -678,6 +678,7 @@ static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event, bool isv6)
 	return version;
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 /* Given an IPv6 address, find the net_device which hosts that address and
  * return its index.  This is used by the rds_ib_cm_handle_connect() code to
  * find the interface index of where an incoming request comes from when
@@ -704,6 +705,7 @@ static u32 __rds_find_ifindex(struct net *net, const struct in6_addr *addr)
 
 	return idx;
 }
+#endif
 
 int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 			     struct rdma_cm_event *event, bool isv6)
@@ -732,6 +734,7 @@ int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 
 	dp = event->param.conn.private_data;
 	if (isv6) {
+#if IS_ENABLED(CONFIG_IPV6)
 		dp_cmn = &dp->ricp_v6.dp_cmn;
 		saddr6 = &dp->ricp_v6.dp_saddr;
 		daddr6 = &dp->ricp_v6.dp_daddr;
@@ -756,6 +759,10 @@ int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 				goto out;
 			}
 		}
+#else
+		err = -EOPNOTSUPP;
+		goto out;
+#endif
 	} else {
 		dp_cmn = &dp->ricp_v4.dp_cmn;
 		ipv6_addr_set_v4mapped(dp->ricp_v4.dp_saddr, &s_mapped_addr);
@@ -893,9 +900,11 @@ int rds_ib_conn_path_connect(struct rds_conn_path *cp)
 
 	/* XXX I wonder what affect the port space has */
 	/* delegate cm event handler to rdma_transport */
+#if IS_ENABLED(CONFIG_IPV6)
 	if (conn->c_isv6)
 		handler = rds6_rdma_cm_event_handler;
 	else
+#endif
 		handler = rds_rdma_cm_event_handler;
 	ic->i_cm_id = rdma_create_id(&init_net, handler, conn,
 				     RDMA_PS_TCP, IB_QPT_RC);

net/rds/ib_rdma.c

@@ -180,6 +180,7 @@ void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_co
 	iinfo->rdma_mr_size = pool_1m->fmr_attr.max_pages;
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 void rds6_ib_get_mr_info(struct rds_ib_device *rds_ibdev,
 			 struct rds6_info_rdma_connection *iinfo6)
 {
@@ -188,6 +189,7 @@ void rds6_ib_get_mr_info(struct rds_ib_device *rds_ibdev,
 	iinfo6->rdma_mr_max = pool_1m->max_items;
 	iinfo6->rdma_mr_size = pool_1m->fmr_attr.max_pages;
 }
+#endif
 
 struct rds_ib_mr *rds_ib_reuse_mr(struct rds_ib_mr_pool *pool)
 {

net/rds/rdma_transport.c

@@ -39,7 +39,9 @@
 
 /* Global IPv4 and IPv6 RDS RDMA listener cm_id */
 static struct rdma_cm_id *rds_rdma_listen_id;
+#if IS_ENABLED(CONFIG_IPV6)
 static struct rdma_cm_id *rds6_rdma_listen_id;
+#endif
 
 static int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
 					 struct rdma_cm_event *event,
@@ -155,11 +157,13 @@ int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 	return rds_rdma_cm_event_handler_cmn(cm_id, event, false);
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 int rds6_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 			       struct rdma_cm_event *event)
 {
 	return rds_rdma_cm_event_handler_cmn(cm_id, event, true);
 }
+#endif
 
 static int rds_rdma_listen_init_common(rdma_cm_event_handler handler,
 				       struct sockaddr *sa,
@@ -214,7 +218,9 @@ static int rds_rdma_listen_init_common(rdma_cm_event_handler handler,
 static int rds_rdma_listen_init(void)
 {
 	int ret;
+#if IS_ENABLED(CONFIG_IPV6)
 	struct sockaddr_in6 sin6;
+#endif
 	struct sockaddr_in sin;
 
 	sin.sin_family = PF_INET;
@@ -226,6 +232,7 @@ static int rds_rdma_listen_init(void)
 	if (ret != 0)
 		return ret;
 
+#if IS_ENABLED(CONFIG_IPV6)
 	sin6.sin6_family = PF_INET6;
 	sin6.sin6_addr = in6addr_any;
 	sin6.sin6_port = htons(RDS_CM_PORT);
@@ -237,6 +244,7 @@ static int rds_rdma_listen_init(void)
 	/* Keep going even when IPv6 is not enabled in the system. */
 	if (ret != 0)
 		rdsdebug("Cannot set up IPv6 RDMA listener\n");
+#endif
 	return 0;
 }
 
@@ -247,11 +255,13 @@ static void rds_rdma_listen_stop(void)
 		rdma_destroy_id(rds_rdma_listen_id);
 		rds_rdma_listen_id = NULL;
 	}
+#if IS_ENABLED(CONFIG_IPV6)
 	if (rds6_rdma_listen_id) {
 		rdsdebug("cm %p\n", rds6_rdma_listen_id);
 		rdma_destroy_id(rds6_rdma_listen_id);
 		rds6_rdma_listen_id = NULL;
 	}
+#endif
 }
 
 static int rds_rdma_init(void)

net/rds/recv.c

@@ -793,6 +793,7 @@ void rds_inc_info_copy(struct rds_incoming *inc,
 	rds_info_copy(iter, &minfo, sizeof(minfo));
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 void rds6_inc_info_copy(struct rds_incoming *inc,
 			struct rds_info_iterator *iter,
 			struct in6_addr *saddr, struct in6_addr *daddr,
@@ -817,3 +818,4 @@ void rds6_inc_info_copy(struct rds_incoming *inc,
 
 	rds_info_copy(iter, &minfo6, sizeof(minfo6));
 }
+#endif

net/rds/send.c

@@ -1103,6 +1103,7 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 			dport = usin->sin_port;
 			break;
 
+#if IS_ENABLED(CONFIG_IPV6)
 		case AF_INET6: {
 			int addr_type;
 
@@ -1142,6 +1143,7 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 			dport = sin6->sin6_port;
 			break;
 		}
+#endif
 
 		default:
 			ret = -EINVAL;

net/rds/tcp.c

@@ -51,7 +51,9 @@ static LIST_HEAD(rds_tcp_tc_list);
  * rds6_tcp_tc_count counts both IPv4 and IPv6 connections.
  */
 static unsigned int rds_tcp_tc_count;
+#if IS_ENABLED(CONFIG_IPV6)
 static unsigned int rds6_tcp_tc_count;
+#endif
 
 /* Track rds_tcp_connection structs so they can be cleaned up */
 static DEFINE_SPINLOCK(rds_tcp_conn_lock);
@@ -118,7 +120,9 @@ void rds_tcp_restore_callbacks(struct socket *sock,
 	/* done under the callback_lock to serialize with write_space */
 	spin_lock(&rds_tcp_tc_list_lock);
 	list_del_init(&tc->t_list_item);
+#if IS_ENABLED(CONFIG_IPV6)
 	rds6_tcp_tc_count--;
+#endif
 	if (!tc->t_cpath->cp_conn->c_isv6)
 		rds_tcp_tc_count--;
 	spin_unlock(&rds_tcp_tc_list_lock);
@@ -207,7 +211,9 @@ void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp)
 	/* done under the callback_lock to serialize with write_space */
 	spin_lock(&rds_tcp_tc_list_lock);
 	list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
+#if IS_ENABLED(CONFIG_IPV6)
 	rds6_tcp_tc_count++;
+#endif
 	if (!tc->t_cpath->cp_conn->c_isv6)
 		rds_tcp_tc_count++;
 	spin_unlock(&rds_tcp_tc_list_lock);
@@ -273,6 +279,7 @@ static void rds_tcp_tc_info(struct socket *rds_sock, unsigned int len,
 	spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 /* Handle RDS6_INFO_TCP_SOCKETS socket option. It returns both IPv4 and
  * IPv6 connections. IPv4 connection address is returned in an IPv4 mapped
  * address.
@@ -314,12 +321,15 @@ static void rds6_tcp_tc_info(struct socket *sock, unsigned int len,
 
 	spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
 }
+#endif
 
 static int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
 			       __u32 scope_id)
 {
 	struct net_device *dev = NULL;
+#if IS_ENABLED(CONFIG_IPV6)
 	int ret;
+#endif
 
 	if (ipv6_addr_v4mapped(addr)) {
 		if (inet_addr_type(net, addr->s6_addr32[3]) == RTN_LOCAL)
@@ -340,9 +350,11 @@ static int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
 		}
 		rcu_read_unlock();
 	}
+#if IS_ENABLED(CONFIG_IPV6)
 	ret = ipv6_chk_addr(net, addr, dev, 0);
 	if (ret)
 		return 0;
+#endif
 	return -EADDRNOTAVAIL;
 }
 
@@ -545,18 +557,27 @@ static __net_init int rds_tcp_init_net(struct net *net)
 		err = -ENOMEM;
 		goto fail;
 	}
+
+#if IS_ENABLED(CONFIG_IPV6)
 	rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, true);
+#else
+	rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, false);
+#endif
 	if (!rtn->rds_tcp_listen_sock) {
 		pr_warn("could not set up IPv6 listen sock\n");
 
+#if IS_ENABLED(CONFIG_IPV6)
 		/* Try IPv4 as some systems disable IPv6 */
 		rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, false);
 		if (!rtn->rds_tcp_listen_sock) {
+#endif
 			unregister_net_sysctl_table(rtn->rds_tcp_sysctl);
 			rtn->rds_tcp_sysctl = NULL;
 			err = -EAFNOSUPPORT;
 			goto fail;
+#if IS_ENABLED(CONFIG_IPV6)
 		}
+#endif
 	}
 	INIT_WORK(&rtn->rds_tcp_accept_w, rds_tcp_accept_worker);
 	return 0;
@@ -670,7 +691,9 @@ static void rds_tcp_exit(void)
 	rds_tcp_set_unloading();
 	synchronize_rcu();
 	rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
+#if IS_ENABLED(CONFIG_IPV6)
 	rds_info_deregister_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
+#endif
 	unregister_pernet_device(&rds_tcp_net_ops);
 	rds_tcp_destroy_conns();
 	rds_trans_unregister(&rds_tcp_transport);
@@ -702,7 +725,9 @@ static int rds_tcp_init(void)
 	rds_trans_register(&rds_tcp_transport);
 
 	rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
+#if IS_ENABLED(CONFIG_IPV6)
 	rds_info_register_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
+#endif
 
 	goto out;
 out_recv:

net/rds/tcp_listen.c

@@ -132,7 +132,10 @@ int rds_tcp_accept_one(struct socket *sock)
 	int conn_state;
 	struct rds_conn_path *cp;
 	struct in6_addr *my_addr, *peer_addr;
-	int dev_if;
+#if !IS_ENABLED(CONFIG_IPV6)
+	struct in6_addr saddr, daddr;
+#endif
+	int dev_if = 0;
 
 	if (!sock) /* module unload or netns delete in progress */
 		return -ENETUNREACH;
@@ -165,12 +168,21 @@ int rds_tcp_accept_one(struct socket *sock)
 
 	inet = inet_sk(new_sock->sk);
 
+#if IS_ENABLED(CONFIG_IPV6)
 	my_addr = &new_sock->sk->sk_v6_rcv_saddr;
 	peer_addr = &new_sock->sk->sk_v6_daddr;
-	rdsdebug("accepted tcp %pI6c:%u -> %pI6c:%u\n",
+#else
+	ipv6_addr_set_v4mapped(inet->inet_saddr, &saddr);
+	ipv6_addr_set_v4mapped(inet->inet_daddr, &daddr);
+	my_addr = &saddr;
+	peer_addr = &daddr;
+#endif
+	rdsdebug("accepted family %d tcp %pI6c:%u -> %pI6c:%u\n",
+		 sock->sk->sk_family,
 		 my_addr, ntohs(inet->inet_sport),
 		 peer_addr, ntohs(inet->inet_dport));
 
+#if IS_ENABLED(CONFIG_IPV6)
 	/* sk_bound_dev_if is not set if the peer address is not link local
 	 * address.  In this case, it happens that mcast_oif is set.  So
 	 * just use it.
@@ -184,9 +196,10 @@ int rds_tcp_accept_one(struct socket *sock)
 	} else {
 		dev_if = new_sock->sk->sk_bound_dev_if;
 	}
+#endif
+
 	conn = rds_conn_create(sock_net(sock->sk),
-			       &new_sock->sk->sk_v6_rcv_saddr,
-			       &new_sock->sk->sk_v6_daddr,
+			       my_addr, peer_addr,
 			       &rds_tcp_transport, GFP_KERNEL, dev_if);
 
 	if (IS_ERR(conn)) {