rds: Enable RDS IPv6 support

This patch enables RDS to use IPv6 addresses. For RDS/TCP, the
listener is now an IPv6 endpoint which accepts both IPv4 and IPv6
connection requests.  RDS/RDMA/IB uses a private data (struct
rds_ib_connect_private) exchange between endpoints at RDS connection
establishment time to support RDMA. This private data exchange uses a
32 bit integer to represent an IP address. This needs to be changed in
order to support IPv6. A new private data struct
rds6_ib_connect_private is introduced to handle this. To ensure
backward compatibility, an IPv6 capable RDS stack uses another RDMA
listener port (RDS_CM_PORT) to accept IPv6 connection. And it
continues to use the original RDS_PORT for IPv4 RDS connections. When
it needs to communicate with an IPv6 peer, it uses the RDS_CM_PORT to
send the connection set up request.

v5: Fixed syntax problem (David Miller).

v4: Changed port history comments in rds.h (Sowmini Varadhan).

v3: Added support to set up IPv4 connection using mapped address
    (David Miller).
    Added support to set up connection between link local and non-link
    addresses.
    Various review comments from Santosh Shilimkar and Sowmini Varadhan.

v2: Fixed bound and peer address scope mismatched issue.
    Added back rds_connect() IPv6 changes.

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>

1 files changed, 51 insertions, 13 deletions

diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c
index 4fdf5b3a47df..0cf0147117d8 100644
--- a/net/rds/tcp_listen.c
+++ b/net/rds/tcp_listen.c
@@ -131,6 +131,8 @@ int rds_tcp_accept_one(struct socket *sock)
 	struct rds_tcp_connection *rs_tcp = NULL;
 	int conn_state;
 	struct rds_conn_path *cp;
+	struct in6_addr *my_addr, *peer_addr;
+	int dev_if;
 
 	if (!sock) /* module unload or netns delete in progress */
 		return -ENETUNREACH;
@@ -163,15 +165,29 @@ int rds_tcp_accept_one(struct socket *sock)
 
 	inet = inet_sk(new_sock->sk);
 
+	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",
-		 &new_sock->sk->sk_v6_rcv_saddr, ntohs(inet->inet_sport),
-		 &new_sock->sk->sk_v6_daddr, ntohs(inet->inet_dport));
+		 my_addr, ntohs(inet->inet_sport),
+		 peer_addr, ntohs(inet->inet_dport));
 
+	/* 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.
+	 */
+	if ((ipv6_addr_type(my_addr) & IPV6_ADDR_LINKLOCAL) &&
+	    !(ipv6_addr_type(peer_addr) & IPV6_ADDR_LINKLOCAL)) {
+		struct ipv6_pinfo *inet6;
+
+		inet6 = inet6_sk(new_sock->sk);
+		dev_if = inet6->mcast_oif;
+	} else {
+		dev_if = new_sock->sk->sk_bound_dev_if;
+	}
 	conn = rds_conn_create(sock_net(sock->sk),
 			       &new_sock->sk->sk_v6_rcv_saddr,
 			       &new_sock->sk->sk_v6_daddr,
-			       &rds_tcp_transport, GFP_KERNEL,
-			       new_sock->sk->sk_bound_dev_if);
+			       &rds_tcp_transport, GFP_KERNEL, dev_if);
 
 	if (IS_ERR(conn)) {
 		ret = PTR_ERR(conn);
@@ -256,15 +272,22 @@ out:
 		ready(sk);
 }
 
-struct socket *rds_tcp_listen_init(struct net *net)
+struct socket *rds_tcp_listen_init(struct net *net, bool isv6)
 {
-	struct sockaddr_in sin;
 	struct socket *sock = NULL;
+	struct sockaddr_storage ss;
+	struct sockaddr_in6 *sin6;
+	struct sockaddr_in *sin;
+	int addr_len;
 	int ret;
 
-	ret = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
-	if (ret < 0)
+	ret = sock_create_kern(net, isv6 ? PF_INET6 : PF_INET, SOCK_STREAM,
+			       IPPROTO_TCP, &sock);
+	if (ret < 0) {
+		rdsdebug("could not create %s listener socket: %d\n",
+			 isv6 ? "IPv6" : "IPv4", ret);
 		goto out;
+	}
 
 	sock->sk->sk_reuse = SK_CAN_REUSE;
 	rds_tcp_nonagle(sock);
@@ -274,13 +297,28 @@ struct socket *rds_tcp_listen_init(struct net *net)
 	sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
 	write_unlock_bh(&sock->sk->sk_callback_lock);
 
-	sin.sin_family = PF_INET;
-	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
-	sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
+	if (isv6) {
+		sin6 = (struct sockaddr_in6 *)&ss;
+		sin6->sin6_family = PF_INET6;
+		sin6->sin6_addr = in6addr_any;
+		sin6->sin6_port = (__force u16)htons(RDS_TCP_PORT);
+		sin6->sin6_scope_id = 0;
+		sin6->sin6_flowinfo = 0;
+		addr_len = sizeof(*sin6);
+	} else {
+		sin = (struct sockaddr_in *)&ss;
+		sin->sin_family = PF_INET;
+		sin->sin_addr.s_addr = INADDR_ANY;
+		sin->sin_port = (__force u16)htons(RDS_TCP_PORT);
+		addr_len = sizeof(*sin);
+	}
 
-	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
-	if (ret < 0)
+	ret = sock->ops->bind(sock, (struct sockaddr *)&ss, addr_len);
+	if (ret < 0) {
+		rdsdebug("could not bind %s listener socket: %d\n",
+			 isv6 ? "IPv6" : "IPv4", ret);
 		goto out;
+	}
 
 	ret = sock->ops->listen(sock, 64);
 	if (ret < 0)