rds: Changing IP address internal representation to struct in6_addr

This patch changes the internal representation of an IP address to use
struct in6_addr.  IPv4 address is stored as an IPv4 mapped address.
All the functions which take an IP address as argument are also
changed to use struct in6_addr.  But RDS socket layer is not modified
such that it still does not accept IPv6 address from an application.
And RDS layer does not accept nor initiate IPv6 connections.

v2: Fixed sparse warnings.
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/af_rds.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -35,6 +35,7 @@
 #include <linux/kernel.h>
 #include <linux/gfp.h>
 #include <linux/in.h>
+#include <linux/ipv6.h>
 #include <linux/poll.h>
 #include <net/sock.h>
 
@@ -113,26 +114,63 @@ void rds_wake_sk_sleep(struct rds_sock *rs)
 static int rds_getname(struct socket *sock, struct sockaddr *uaddr,
 		       int peer)
 {
-	struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 	struct rds_sock *rs = rds_sk_to_rs(sock->sk);
-
-	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+	struct sockaddr_in6 *sin6;
+	struct sockaddr_in *sin;
+	int uaddr_len;
 
 	/* racey, don't care */
 	if (peer) {
-		if (!rs->rs_conn_addr)
+		if (ipv6_addr_any(&rs->rs_conn_addr))
 			return -ENOTCONN;
 
-		sin->sin_port = rs->rs_conn_port;
-		sin->sin_addr.s_addr = rs->rs_conn_addr;
+		if (ipv6_addr_v4mapped(&rs->rs_conn_addr)) {
+			sin = (struct sockaddr_in *)uaddr;
+			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+			sin->sin_family = AF_INET;
+			sin->sin_port = rs->rs_conn_port;
+			sin->sin_addr.s_addr = rs->rs_conn_addr_v4;
+			uaddr_len = sizeof(*sin);
+		} else {
+			sin6 = (struct sockaddr_in6 *)uaddr;
+			sin6->sin6_family = AF_INET6;
+			sin6->sin6_port = rs->rs_conn_port;
+			sin6->sin6_addr = rs->rs_conn_addr;
+			sin6->sin6_flowinfo = 0;
+			/* scope_id is the same as in the bound address. */
+			sin6->sin6_scope_id = rs->rs_bound_scope_id;
+			uaddr_len = sizeof(*sin6);
+		}
 	} else {
-		sin->sin_port = rs->rs_bound_port;
-		sin->sin_addr.s_addr = rs->rs_bound_addr;
+		/* If socket is not yet bound, set the return address family
+		 * to be AF_UNSPEC (value 0) and the address size to be that
+		 * of an IPv4 address.
+		 */
+		if (ipv6_addr_any(&rs->rs_bound_addr)) {
+			sin = (struct sockaddr_in *)uaddr;
+			memset(sin, 0, sizeof(*sin));
+			sin->sin_family = AF_UNSPEC;
+			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));
+			sin->sin_family = AF_INET;
+			sin->sin_port = rs->rs_bound_port;
+			sin->sin_addr.s_addr = rs->rs_bound_addr_v4;
+			uaddr_len = sizeof(*sin);
+		} else {
+			sin6 = (struct sockaddr_in6 *)uaddr;
+			sin6->sin6_family = AF_INET6;
+			sin6->sin6_port = rs->rs_bound_port;
+			sin6->sin6_addr = rs->rs_bound_addr;
+			sin6->sin6_flowinfo = 0;
+			sin6->sin6_scope_id = rs->rs_bound_scope_id;
+			uaddr_len = sizeof(*sin6);
+		}
 	}
 
-	sin->sin_family = AF_INET;
-
-	return sizeof(*sin);
+	return uaddr_len;
 }
 
 /*
@@ -203,11 +241,12 @@ static int rds_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 static int rds_cancel_sent_to(struct rds_sock *rs, char __user *optval,
 			      int len)
 {
+	struct sockaddr_in6 sin6;
 	struct sockaddr_in sin;
 	int ret = 0;
 
 	/* racing with another thread binding seems ok here */
-	if (rs->rs_bound_addr == 0) {
+	if (ipv6_addr_any(&rs->rs_bound_addr)) {
 		ret = -ENOTCONN; /* XXX not a great errno */
 		goto out;
 	}
@@ -215,14 +254,23 @@ static int rds_cancel_sent_to(struct rds_sock *rs, char __user *optval,
 	if (len < sizeof(struct sockaddr_in)) {
 		ret = -EINVAL;
 		goto out;
+	} else if (len < sizeof(struct sockaddr_in6)) {
+		/* Assume IPv4 */
+		if (copy_from_user(&sin, optval, sizeof(struct sockaddr_in))) {
+			ret = -EFAULT;
+			goto out;
+		}
+		ipv6_addr_set_v4mapped(sin.sin_addr.s_addr, &sin6.sin6_addr);
+		sin6.sin6_port = sin.sin_port;
+	} else {
+		if (copy_from_user(&sin6, optval,
+				   sizeof(struct sockaddr_in6))) {
+			ret = -EFAULT;
+			goto out;
+		}
 	}
 
-	if (copy_from_user(&sin, optval, sizeof(sin))) {
-		ret = -EFAULT;
-		goto out;
-	}
-
-	rds_send_drop_to(rs, &sin);
+	rds_send_drop_to(rs, &sin6);
 out:
 	return ret;
 }
@@ -435,31 +483,41 @@ static int rds_connect(struct socket *sock, struct sockaddr *uaddr,
 		       int addr_len, int flags)
 {
 	struct sock *sk = sock->sk;
-	struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
+	struct sockaddr_in *sin;
 	struct rds_sock *rs = rds_sk_to_rs(sk);
 	int ret = 0;
 
 	lock_sock(sk);
 
-	if (addr_len != sizeof(struct sockaddr_in)) {
-		ret = -EINVAL;
-		goto out;
-	}
+	switch (addr_len) {
+	case sizeof(struct sockaddr_in):
+		sin = (struct sockaddr_in *)uaddr;
+		if (sin->sin_family != AF_INET) {
+			ret = -EAFNOSUPPORT;
+			break;
+		}
+		if (sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
+			ret = -EDESTADDRREQ;
+			break;
+		}
+		if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)) ||
+		    sin->sin_addr.s_addr == htonl(INADDR_BROADCAST)) {
+			ret = -EINVAL;
+			break;
+		}
+		ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, &rs->rs_conn_addr);
+		rs->rs_conn_port = sin->sin_port;
+		break;
 
-	if (sin->sin_family != AF_INET) {
-		ret = -EAFNOSUPPORT;
-		goto out;
-	}
+	case sizeof(struct sockaddr_in6):
+		ret = -EPROTONOSUPPORT;
+		break;
 
-	if (sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
-		ret = -EDESTADDRREQ;
-		goto out;
+	default:
+		ret = -EINVAL;
+		break;
 	}
 
-	rs->rs_conn_addr = sin->sin_addr.s_addr;
-	rs->rs_conn_port = sin->sin_port;
-
-out:
 	release_sock(sk);
 	return ret;
 }
@@ -578,8 +636,10 @@ static void rds_sock_inc_info(struct socket *sock, unsigned int len,
 		list_for_each_entry(inc, &rs->rs_recv_queue, i_item) {
 			total++;
 			if (total <= len)
-				rds_inc_info_copy(inc, iter, inc->i_saddr,
-						  rs->rs_bound_addr, 1);
+				rds_inc_info_copy(inc, iter,
+						  inc->i_saddr.s6_addr32[3],
+						  rs->rs_bound_addr_v4,
+						  1);
 		}
 
 		read_unlock(&rs->rs_recv_lock);
@@ -608,8 +668,8 @@ static void rds_sock_info(struct socket *sock, unsigned int len,
 	list_for_each_entry(rs, &rds_sock_list, rs_item) {
 		sinfo.sndbuf = rds_sk_sndbuf(rs);
 		sinfo.rcvbuf = rds_sk_rcvbuf(rs);
-		sinfo.bound_addr = rs->rs_bound_addr;
-		sinfo.connected_addr = rs->rs_conn_addr;
+		sinfo.bound_addr = rs->rs_bound_addr_v4;
+		sinfo.connected_addr = rs->rs_conn_addr_v4;
 		sinfo.bound_port = rs->rs_bound_port;
 		sinfo.connected_port = rs->rs_conn_port;
 		sinfo.inum = sock_i_ino(rds_rs_to_sk(rs));

net/rds/bind.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -33,6 +33,7 @@
 #include <linux/kernel.h>
 #include <net/sock.h>
 #include <linux/in.h>
+#include <linux/ipv6.h>
 #include <linux/if_arp.h>
 #include <linux/jhash.h>
 #include <linux/ratelimit.h>
@@ -42,42 +43,58 @@ static struct rhashtable bind_hash_table;
 
 static const struct rhashtable_params ht_parms = {
 	.nelem_hint = 768,
-	.key_len = sizeof(u64),
+	.key_len = RDS_BOUND_KEY_LEN,
 	.key_offset = offsetof(struct rds_sock, rs_bound_key),
 	.head_offset = offsetof(struct rds_sock, rs_bound_node),
 	.max_size = 16384,
 	.min_size = 1024,
 };
 
+/* Create a key for the bind hash table manipulation.  Port is in network byte
+ * order.
+ */
+static inline void __rds_create_bind_key(u8 *key, const struct in6_addr *addr,
+					 __be16 port, __u32 scope_id)
+{
+	memcpy(key, addr, sizeof(*addr));
+	key += sizeof(*addr);
+	memcpy(key, &port, sizeof(port));
+	key += sizeof(port);
+	memcpy(key, &scope_id, sizeof(scope_id));
+}
+
 /*
  * Return the rds_sock bound at the given local address.
  *
  * The rx path can race with rds_release.  We notice if rds_release() has
  * marked this socket and don't return a rs ref to the rx path.
  */
-struct rds_sock *rds_find_bound(__be32 addr, __be16 port)
+struct rds_sock *rds_find_bound(const struct in6_addr *addr, __be16 port,
+				__u32 scope_id)
 {
-	u64 key = ((u64)addr << 32) | port;
+	u8 key[RDS_BOUND_KEY_LEN];
 	struct rds_sock *rs;
 
-	rs = rhashtable_lookup_fast(&bind_hash_table, &key, ht_parms);
+	__rds_create_bind_key(key, addr, port, scope_id);
+	rs = rhashtable_lookup_fast(&bind_hash_table, key, ht_parms);
 	if (rs && !sock_flag(rds_rs_to_sk(rs), SOCK_DEAD))
 		rds_sock_addref(rs);
 	else
 		rs = NULL;
 
-	rdsdebug("returning rs %p for %pI4:%u\n", rs, &addr,
-		ntohs(port));
+	rdsdebug("returning rs %p for %pI6c:%u\n", rs, addr,
+		 ntohs(port));
 
 	return rs;
 }
 
 /* returns -ve errno or +ve port */
-static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)
+static int rds_add_bound(struct rds_sock *rs, const struct in6_addr *addr,
+			 __be16 *port, __u32 scope_id)
 {
 	int ret = -EADDRINUSE;
 	u16 rover, last;
-	u64 key;
+	u8 key[RDS_BOUND_KEY_LEN];
 
 	if (*port != 0) {
 		rover = be16_to_cpu(*port);
@@ -95,12 +112,13 @@ static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)
 
 		if (rover == RDS_FLAG_PROBE_PORT)
 			continue;
-		key = ((u64)addr << 32) | cpu_to_be16(rover);
-		if (rhashtable_lookup_fast(&bind_hash_table, &key, ht_parms))
+		__rds_create_bind_key(key, addr, cpu_to_be16(rover),
+				      scope_id);
+		if (rhashtable_lookup_fast(&bind_hash_table, key, ht_parms))
 			continue;
 
-		rs->rs_bound_key = key;
-		rs->rs_bound_addr = addr;
+		memcpy(rs->rs_bound_key, key, sizeof(rs->rs_bound_key));
+		rs->rs_bound_addr = *addr;
 		net_get_random_once(&rs->rs_hash_initval,
 				    sizeof(rs->rs_hash_initval));
 		rs->rs_bound_port = cpu_to_be16(rover);
@@ -114,7 +132,7 @@ static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)
 			  rs, &addr, (int)ntohs(*port));
 			break;
 		} else {
-			rs->rs_bound_addr = 0;
+			rs->rs_bound_addr = in6addr_any;
 			rds_sock_put(rs);
 			ret = -ENOMEM;
 			break;
@@ -127,44 +145,61 @@ static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)
 void rds_remove_bound(struct rds_sock *rs)
 {
 
-	if (!rs->rs_bound_addr)
+	if (ipv6_addr_any(&rs->rs_bound_addr))
 		return;
 
-	rdsdebug("rs %p unbinding from %pI4:%d\n",
+	rdsdebug("rs %p unbinding from %pI6c:%d\n",
 		 rs, &rs->rs_bound_addr,
 		 ntohs(rs->rs_bound_port));
 
 	rhashtable_remove_fast(&bind_hash_table, &rs->rs_bound_node, ht_parms);
 	rds_sock_put(rs);
-	rs->rs_bound_addr = 0;
+	rs->rs_bound_addr = in6addr_any;
 }
 
 int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 {
 	struct sock *sk = sock->sk;
-	struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 	struct rds_sock *rs = rds_sk_to_rs(sk);
+	struct in6_addr v6addr, *binding_addr;
 	struct rds_transport *trans;
+	__u32 scope_id = 0;
 	int ret = 0;
+	__be16 port;
 
+	/* We only allow an RDS socket to be bound to an IPv4 address. IPv6
+	 * address support will be added later.
+	 */
+	if (addr_len == sizeof(struct sockaddr_in)) {
+		struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
+
+		if (sin->sin_family != AF_INET ||
+		    sin->sin_addr.s_addr == htonl(INADDR_ANY))
+			return -EINVAL;
+		ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, &v6addr);
+		binding_addr = &v6addr;
+		port = sin->sin_port;
+	} else if (addr_len == sizeof(struct sockaddr_in6)) {
+		return -EPROTONOSUPPORT;
+	} else {
+		return -EINVAL;
+	}
 	lock_sock(sk);
 
-	if (addr_len != sizeof(struct sockaddr_in) ||
-	    sin->sin_family != AF_INET ||
-	    rs->rs_bound_addr ||
-	    sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
+	/* RDS socket does not allow re-binding. */
+	if (!ipv6_addr_any(&rs->rs_bound_addr)) {
 		ret = -EINVAL;
 		goto out;
 	}
 
-	ret = rds_add_bound(rs, sin->sin_addr.s_addr, &sin->sin_port);
+	ret = rds_add_bound(rs, binding_addr, &port, scope_id);
 	if (ret)
 		goto out;
 
 	if (rs->rs_transport) { /* previously bound */
 		trans = rs->rs_transport;
 		if (trans->laddr_check(sock_net(sock->sk),
-				       sin->sin_addr.s_addr) != 0) {
+				       binding_addr, scope_id) != 0) {
 			ret = -ENOPROTOOPT;
 			rds_remove_bound(rs);
 		} else {
@@ -172,13 +207,13 @@ int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		}
 		goto out;
 	}
-	trans = rds_trans_get_preferred(sock_net(sock->sk),
-					sin->sin_addr.s_addr);
+	trans = rds_trans_get_preferred(sock_net(sock->sk), binding_addr,
+					scope_id);
 	if (!trans) {
 		ret = -EADDRNOTAVAIL;
 		rds_remove_bound(rs);
-		pr_info_ratelimited("RDS: %s could not find a transport for %pI4, load rds_tcp or rds_rdma?\n",
-				    __func__, &sin->sin_addr.s_addr);
+		pr_info_ratelimited("RDS: %s could not find a transport for %pI6c, load rds_tcp or rds_rdma?\n",
+				    __func__, binding_addr);
 		goto out;
 	}
 

net/rds/cong.c

 /*
- * Copyright (c) 2007 Oracle.  All rights reserved.
+ * Copyright (c) 2007, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -101,7 +101,7 @@ static DEFINE_RWLOCK(rds_cong_monitor_lock);
 static DEFINE_SPINLOCK(rds_cong_lock);
 static struct rb_root rds_cong_tree = RB_ROOT;
 
-static struct rds_cong_map *rds_cong_tree_walk(__be32 addr,
+static struct rds_cong_map *rds_cong_tree_walk(const struct in6_addr *addr,
 					       struct rds_cong_map *insert)
 {
 	struct rb_node **p = &rds_cong_tree.rb_node;
@@ -109,12 +109,15 @@ static struct rds_cong_map *rds_cong_tree_walk(__be32 addr,
 	struct rds_cong_map *map;
 
 	while (*p) {
+		int diff;
+
 		parent = *p;
 		map = rb_entry(parent, struct rds_cong_map, m_rb_node);
 
-		if (addr < map->m_addr)
+		diff = rds_addr_cmp(addr, &map->m_addr);
+		if (diff < 0)
 			p = &(*p)->rb_left;
-		else if (addr > map->m_addr)
+		else if (diff > 0)
 			p = &(*p)->rb_right;
 		else
 			return map;
@@ -132,7 +135,7 @@ static struct rds_cong_map *rds_cong_tree_walk(__be32 addr,
  * these bitmaps in the process getting pointers to them.  The bitmaps are only
  * ever freed as the module is removed after all connections have been freed.
  */
-static struct rds_cong_map *rds_cong_from_addr(__be32 addr)
+static struct rds_cong_map *rds_cong_from_addr(const struct in6_addr *addr)
 {
 	struct rds_cong_map *map;
 	struct rds_cong_map *ret = NULL;
@@ -144,7 +147,7 @@ static struct rds_cong_map *rds_cong_from_addr(__be32 addr)
 	if (!map)
 		return NULL;
 
-	map->m_addr = addr;
+	map->m_addr = *addr;
 	init_waitqueue_head(&map->m_waitq);
 	INIT_LIST_HEAD(&map->m_conn_list);
 
@@ -171,7 +174,7 @@ static struct rds_cong_map *rds_cong_from_addr(__be32 addr)
 		kfree(map);
 	}
 
-	rdsdebug("map %p for addr %x\n", ret, be32_to_cpu(addr));
+	rdsdebug("map %p for addr %pI6c\n", ret, addr);
 
 	return ret;
 }
@@ -202,8 +205,8 @@ void rds_cong_remove_conn(struct rds_connection *conn)
 
 int rds_cong_get_maps(struct rds_connection *conn)
 {
-	conn->c_lcong = rds_cong_from_addr(conn->c_laddr);
-	conn->c_fcong = rds_cong_from_addr(conn->c_faddr);
+	conn->c_lcong = rds_cong_from_addr(&conn->c_laddr);
+	conn->c_fcong = rds_cong_from_addr(&conn->c_faddr);
 
 	if (!(conn->c_lcong && conn->c_fcong))
 		return -ENOMEM;
@@ -353,7 +356,7 @@ void rds_cong_remove_socket(struct rds_sock *rs)
 
 	/* update congestion map for now-closed port */
 	spin_lock_irqsave(&rds_cong_lock, flags);
-	map = rds_cong_tree_walk(rs->rs_bound_addr, NULL);
+	map = rds_cong_tree_walk(&rs->rs_bound_addr, NULL);
 	spin_unlock_irqrestore(&rds_cong_lock, flags);
 
 	if (map && rds_cong_test_bit(map, rs->rs_bound_port)) {

net/rds/connection.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -34,7 +34,8 @@
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/export.h>
-#include <net/inet_hashtables.h>
+#include <net/ipv6.h>
+#include <net/inet6_hashtables.h>
 
 #include "rds.h"
 #include "loop.h"
@@ -49,18 +50,21 @@ static unsigned long rds_conn_count;
 static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
 static struct kmem_cache *rds_conn_slab;
 
-static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
+static struct hlist_head *rds_conn_bucket(const struct in6_addr *laddr,
+					  const struct in6_addr *faddr)
 {
+	static u32 rds6_hash_secret __read_mostly;
 	static u32 rds_hash_secret __read_mostly;
 
-	unsigned long hash;
+	u32 lhash, fhash, hash;
 
 	net_get_random_once(&rds_hash_secret, sizeof(rds_hash_secret));
+	net_get_random_once(&rds6_hash_secret, sizeof(rds6_hash_secret));
+
+	lhash = (__force u32)laddr->s6_addr32[3];
+	fhash = __ipv6_addr_jhash(faddr, rds6_hash_secret);
+	hash = __inet6_ehashfn(lhash, 0, fhash, 0, rds_hash_secret);
 
-	/* Pass NULL, don't need struct net for hash */
-	hash = __inet_ehashfn(be32_to_cpu(laddr), 0,
-			      be32_to_cpu(faddr), 0,
-			      rds_hash_secret);
 	return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK];
 }
 
@@ -72,20 +76,25 @@ static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
 /* rcu read lock must be held or the connection spinlock */
 static struct rds_connection *rds_conn_lookup(struct net *net,
 					      struct hlist_head *head,
-					      __be32 laddr, __be32 faddr,
-					      struct rds_transport *trans)
+					      const struct in6_addr *laddr,
+					      const struct in6_addr *faddr,
+					      struct rds_transport *trans,
+					      int dev_if)
 {
 	struct rds_connection *conn, *ret = NULL;
 
 	hlist_for_each_entry_rcu(conn, head, c_hash_node) {
-		if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
-		    conn->c_trans == trans && net == rds_conn_net(conn)) {
+		if (ipv6_addr_equal(&conn->c_faddr, faddr) &&
+		    ipv6_addr_equal(&conn->c_laddr, laddr) &&
+		    conn->c_trans == trans &&
+		    net == rds_conn_net(conn) &&
+		    conn->c_dev_if == dev_if) {
 			ret = conn;
 			break;
 		}
 	}
-	rdsdebug("returning conn %p for %pI4 -> %pI4\n", ret,
-		 &laddr, &faddr);
+	rdsdebug("returning conn %p for %pI6c -> %pI6c\n", ret,
+		 laddr, faddr);
 	return ret;
 }
 
@@ -99,8 +108,8 @@ static void rds_conn_path_reset(struct rds_conn_path *cp)
 {
 	struct rds_connection *conn = cp->cp_conn;
 
-	rdsdebug("connection %pI4 to %pI4 reset\n",
-	  &conn->c_laddr, &conn->c_faddr);
+	rdsdebug("connection %pI6c to %pI6c reset\n",
+		 &conn->c_laddr, &conn->c_faddr);
 
 	rds_stats_inc(s_conn_reset);
 	rds_send_path_reset(cp);
@@ -142,9 +151,12 @@ static void __rds_conn_path_init(struct rds_connection *conn,
  * are torn down as the module is removed, if ever.
  */
 static struct rds_connection *__rds_conn_create(struct net *net,
-						__be32 laddr, __be32 faddr,
-				       struct rds_transport *trans, gfp_t gfp,
-				       int is_outgoing)
+						const struct in6_addr *laddr,
+						const struct in6_addr *faddr,
+						struct rds_transport *trans,
+						gfp_t gfp,
+						int is_outgoing,
+						int dev_if)
 {
 	struct rds_connection *conn, *parent = NULL;
 	struct hlist_head *head = rds_conn_bucket(laddr, faddr);
@@ -154,9 +166,12 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 	int npaths = (trans->t_mp_capable ? RDS_MPATH_WORKERS : 1);
 
 	rcu_read_lock();
-	conn = rds_conn_lookup(net, head, laddr, faddr, trans);
-	if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
-	    laddr == faddr && !is_outgoing) {
+	conn = rds_conn_lookup(net, head, laddr, faddr, trans, dev_if);
+	if (conn &&
+	    conn->c_loopback &&
+	    conn->c_trans != &rds_loop_transport &&
+	    ipv6_addr_equal(laddr, faddr) &&
+	    !is_outgoing) {
 		/* This is a looped back IB connection, and we're
 		 * called by the code handling the incoming connect.
 		 * We need a second connection object into which we
@@ -181,8 +196,10 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 	}
 
 	INIT_HLIST_NODE(&conn->c_hash_node);
-	conn->c_laddr = laddr;
-	conn->c_faddr = faddr;
+	conn->c_laddr = *laddr;
+	conn->c_isv6 = !ipv6_addr_v4mapped(laddr);
+	conn->c_faddr = *faddr;
+	conn->c_dev_if = dev_if;
 
 	rds_conn_net_set(conn, net);
 
@@ -199,7 +216,7 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 	 * can bind to the destination address then we'd rather the messages
 	 * flow through loopback rather than either transport.
 	 */
-	loop_trans = rds_trans_get_preferred(net, faddr);
+	loop_trans = rds_trans_get_preferred(net, faddr, conn->c_dev_if);
 	if (loop_trans) {
 		rds_trans_put(loop_trans);
 		conn->c_loopback = 1;
@@ -233,10 +250,10 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 		goto out;
 	}
 
-	rdsdebug("allocated conn %p for %pI4 -> %pI4 over %s %s\n",
-	  conn, &laddr, &faddr,
-	  strnlen(trans->t_name, sizeof(trans->t_name)) ? trans->t_name :
-	  "[unknown]", is_outgoing ? "(outgoing)" : "");
+	rdsdebug("allocated conn %p for %pI6c -> %pI6c over %s %s\n",
+		 conn, laddr, faddr,
+		 strnlen(trans->t_name, sizeof(trans->t_name)) ?
+		 trans->t_name : "[unknown]", is_outgoing ? "(outgoing)" : "");
 
 	/*
 	 * Since we ran without holding the conn lock, someone could
@@ -262,7 +279,8 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 		/* Creating normal conn */
 		struct rds_connection *found;
 
-		found = rds_conn_lookup(net, head, laddr, faddr, trans);
+		found = rds_conn_lookup(net, head, laddr, faddr, trans,
+					dev_if);
 		if (found) {
 			struct rds_conn_path *cp;
 			int i;
@@ -295,18 +313,22 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 }
 
 struct rds_connection *rds_conn_create(struct net *net,
-				       __be32 laddr, __be32 faddr,
-				       struct rds_transport *trans, gfp_t gfp)
+				       const struct in6_addr *laddr,
+				       const struct in6_addr *faddr,
+				       struct rds_transport *trans, gfp_t gfp,
+				       int dev_if)
 {
-	return __rds_conn_create(net, laddr, faddr, trans, gfp, 0);
+	return __rds_conn_create(net, laddr, faddr, trans, gfp, 0, dev_if);
 }
 EXPORT_SYMBOL_GPL(rds_conn_create);
 
 struct rds_connection *rds_conn_create_outgoing(struct net *net,
-						__be32 laddr, __be32 faddr,
-				       struct rds_transport *trans, gfp_t gfp)
+						const struct in6_addr *laddr,
+						const struct in6_addr *faddr,
+						struct rds_transport *trans,
+						gfp_t gfp, int dev_if)
 {
-	return __rds_conn_create(net, laddr, faddr, trans, gfp, 1);
+	return __rds_conn_create(net, laddr, faddr, trans, gfp, 1, dev_if);
 }
 EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
 
@@ -502,12 +524,17 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 
 				/* XXX too lazy to maintain counts.. */
 				list_for_each_entry(rm, list, m_conn_item) {
+					__be32 laddr;
+					__be32 faddr;
+
 					total++;
+					laddr = conn->c_laddr.s6_addr32[3];
+					faddr = conn->c_faddr.s6_addr32[3];
 					if (total <= len)
 						rds_inc_info_copy(&rm->m_inc,
 								  iter,
-								  conn->c_laddr,
-								  conn->c_faddr,
+								  laddr,
+								  faddr,
 								  0);
 				}
 
@@ -584,7 +611,6 @@ static void rds_walk_conn_path_info(struct socket *sock, unsigned int len,
 	struct hlist_head *head;
 	struct rds_connection *conn;
 	size_t i;
-	int j;
 
 	rcu_read_lock();
 
@@ -595,17 +621,20 @@ static void rds_walk_conn_path_info(struct socket *sock, unsigned int len,
 	     i++, head++) {
 		hlist_for_each_entry_rcu(conn, head, c_hash_node) {
 			struct rds_conn_path *cp;
-			int npaths;
 
-			npaths = (conn->c_trans->t_mp_capable ?
-				 RDS_MPATH_WORKERS : 1);
-			for (j = 0; j < npaths; j++) {
-				cp = &conn->c_path[j];
+			/* XXX We only copy the information from the first
+			 * path for now.  The problem is that if there are
+			 * more than one underlying paths, we cannot report
+			 * information of all of them using the existing
+			 * API.  For example, there is only one next_tx_seq,
+			 * which path's next_tx_seq should we report?  It is
+			 * a bug in the design of MPRDS.
+			 */
+			cp = conn->c_path;
 
-				/* XXX no cp_lock usage.. */
-				if (!visitor(cp, buffer))
-					continue;
-			}
+			/* XXX no cp_lock usage.. */
+			if (!visitor(cp, buffer))
+				continue;
 
 			/* We copy as much as we can fit in the buffer,
 			 * but we count all items so that the caller
@@ -624,12 +653,13 @@ static void rds_walk_conn_path_info(struct socket *sock, unsigned int len,
 static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
 {
 	struct rds_info_connection *cinfo = buffer;
+	struct rds_connection *conn = cp->cp_conn;
 
 	cinfo->next_tx_seq = cp->cp_next_tx_seq;
 	cinfo->next_rx_seq = cp->cp_next_rx_seq;
-	cinfo->laddr = cp->cp_conn->c_laddr;
-	cinfo->faddr = cp->cp_conn->c_faddr;
-	strncpy(cinfo->transport, cp->cp_conn->c_trans->t_name,
+	cinfo->laddr = conn->c_laddr.s6_addr32[3];
+	cinfo->faddr = conn->c_faddr.s6_addr32[3];
+	strncpy(cinfo->transport, conn->c_trans->t_name,
 		sizeof(cinfo->transport));
 	cinfo->flags = 0;
 

net/rds/ib.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -296,8 +296,8 @@ static int rds_ib_conn_info_visitor(struct rds_connection *conn,
 	if (conn->c_trans != &rds_ib_transport)
 		return 0;
 
-	iinfo->src_addr = conn->c_laddr;
-	iinfo->dst_addr = conn->c_faddr;
+	iinfo->src_addr = conn->c_laddr.s6_addr32[3];
+	iinfo->dst_addr = conn->c_faddr.s6_addr32[3];
 
 	memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
 	memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
@@ -341,7 +341,8 @@ static void rds_ib_ic_info(struct socket *sock, unsigned int len,
  * allowed to influence which paths have priority.  We could call userspace
  * asserting this policy "routing".
  */
-static int rds_ib_laddr_check(struct net *net, __be32 addr)
+static int rds_ib_laddr_check(struct net *net, const struct in6_addr *addr,
+			      __u32 scope_id)
 {
 	int ret;
 	struct rdma_cm_id *cm_id;
@@ -357,7 +358,7 @@ static int rds_ib_laddr_check(struct net *net, __be32 addr)
 
 	memset(&sin, 0, sizeof(sin));
 	sin.sin_family = AF_INET;
-	sin.sin_addr.s_addr = addr;
+	sin.sin_addr.s_addr = addr->s6_addr32[3];
 
 	/* rdma_bind_addr will only succeed for IB & iWARP devices */
 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
@@ -367,9 +368,9 @@ static int rds_ib_laddr_check(struct net *net, __be32 addr)
 	    cm_id->device->node_type != RDMA_NODE_IB_CA)
 		ret = -EADDRNOTAVAIL;
 
-	rdsdebug("addr %pI4 ret %d node type %d\n",
-		&addr, ret,
-		cm_id->device ? cm_id->device->node_type : -1);
+	rdsdebug("addr %pI6c ret %d node type %d\n",
+		 addr, ret,
+		 cm_id->device ? cm_id->device->node_type : -1);
 
 	rdma_destroy_id(cm_id);
 

net/rds/ib.h

@@ -57,16 +57,44 @@ struct rds_ib_refill_cache {
 	struct list_head	 *ready;
 };
 
+/* This is the common structure for the IB private data exchange in setting up
+ * an RDS connection.  The exchange is different for IPv4 and IPv6 connections.
+ * The reason is that the address size is different and the addresses
+ * exchanged are in the beginning of the structure.  Hence it is not possible
+ * for interoperability if same structure is used.
+ */
+struct rds_ib_conn_priv_cmn {
+	u8			ricpc_protocol_major;
+	u8			ricpc_protocol_minor;
+	__be16			ricpc_protocol_minor_mask;	/* bitmask */
+	__be32			ricpc_reserved1;
+	__be64			ricpc_ack_seq;
+	__be32			ricpc_credit;	/* non-zero enables flow ctl */
+};
+
 struct rds_ib_connect_private {
 	/* Add new fields at the end, and don't permute existing fields. */
-	__be32			dp_saddr;
-	__be32			dp_daddr;
-	u8			dp_protocol_major;
-	u8			dp_protocol_minor;
-	__be16			dp_protocol_minor_mask; /* bitmask */
-	__be32			dp_reserved1;
-	__be64			dp_ack_seq;
-	__be32			dp_credit;		/* non-zero enables flow ctl */
+	__be32				dp_saddr;
+	__be32				dp_daddr;
+	struct rds_ib_conn_priv_cmn	dp_cmn;
+};
+
+struct rds6_ib_connect_private {
+	/* Add new fields at the end, and don't permute existing fields. */
+	struct in6_addr			dp_saddr;
+	struct in6_addr			dp_daddr;
+	struct rds_ib_conn_priv_cmn	dp_cmn;
+};
+
+#define dp_protocol_major	dp_cmn.ricpc_protocol_major
+#define dp_protocol_minor	dp_cmn.ricpc_protocol_minor
+#define dp_protocol_minor_mask	dp_cmn.ricpc_protocol_minor_mask
+#define dp_ack_seq		dp_cmn.ricpc_ack_seq
+#define dp_credit		dp_cmn.ricpc_credit
+
+union rds_ib_conn_priv {
+	struct rds_ib_connect_private	ricp_v4;
+	struct rds6_ib_connect_private	ricp_v6;
 };
 
 struct rds_ib_send_work {
@@ -351,8 +379,8 @@ void rds_ib_listen_stop(void);
 __printf(2, 3)
 void __rds_ib_conn_error(struct rds_connection *conn, const char *, ...);
 int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
-			     struct rdma_cm_event *event);
-int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id);
+			     struct rdma_cm_event *event, bool isv6);
+int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id, bool isv6);
 void rds_ib_cm_connect_complete(struct rds_connection *conn,
 				struct rdma_cm_event *event);
 
@@ -361,7 +389,8 @@ void rds_ib_cm_connect_complete(struct rds_connection *conn,
 	__rds_ib_conn_error(conn, KERN_WARNING "RDS/IB: " fmt)
 
 /* ib_rdma.c */
-int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr);
+int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev,
+			 struct in6_addr *ipaddr);
 void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn);
 void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn);
 void rds_ib_destroy_nodev_conns(void);

net/rds/ib_rdma.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -100,18 +100,19 @@ static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
 		kfree_rcu(to_free, rcu);
 }
 
-int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
+int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev,
+			 struct in6_addr *ipaddr)
 {
 	struct rds_ib_device *rds_ibdev_old;
 
-	rds_ibdev_old = rds_ib_get_device(ipaddr);
+	rds_ibdev_old = rds_ib_get_device(ipaddr->s6_addr32[3]);
 	if (!rds_ibdev_old)
-		return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
+		return rds_ib_add_ipaddr(rds_ibdev, ipaddr->s6_addr32[3]);
 
 	if (rds_ibdev_old != rds_ibdev) {
-		rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr);
+		rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr->s6_addr32[3]);
 		rds_ib_dev_put(rds_ibdev_old);
-		return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
+		return rds_ib_add_ipaddr(rds_ibdev, ipaddr->s6_addr32[3]);
 	}
 	rds_ib_dev_put(rds_ibdev_old);
 
@@ -544,7 +545,7 @@ void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
 	struct rds_ib_connection *ic = rs->rs_conn->c_transport_data;
 	int ret;
 
-	rds_ibdev = rds_ib_get_device(rs->rs_bound_addr);
+	rds_ibdev = rds_ib_get_device(rs->rs_bound_addr.s6_addr32[3]);
 	if (!rds_ibdev) {
 		ret = -ENODEV;
 		goto out;

net/rds/ib_recv.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -266,7 +266,7 @@ static struct rds_ib_incoming *rds_ib_refill_one_inc(struct rds_ib_connection *i
 		rds_ib_stats_inc(s_ib_rx_total_incs);
 	}
 	INIT_LIST_HEAD(&ibinc->ii_frags);
-	rds_inc_init(&ibinc->ii_inc, ic->conn, ic->conn->c_faddr);
+	rds_inc_init(&ibinc->ii_inc, ic->conn, &ic->conn->c_faddr);
 
 	return ibinc;
 }
@@ -418,7 +418,7 @@ void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp)
 		ret = ib_post_recv(ic->i_cm_id->qp, &recv->r_wr, &failed_wr);
 		if (ret) {
 			rds_ib_conn_error(conn, "recv post on "
-			       "%pI4 returned %d, disconnecting and "
+			       "%pI6c returned %d, disconnecting and "
 			       "reconnecting\n", &conn->c_faddr,
 			       ret);
 			break;
@@ -848,7 +848,7 @@ static void rds_ib_process_recv(struct rds_connection *conn,
 
 	if (data_len < sizeof(struct rds_header)) {
 		rds_ib_conn_error(conn, "incoming message "
-		       "from %pI4 didn't include a "
+		       "from %pI6c didn't include a "
 		       "header, disconnecting and "
 		       "reconnecting\n",
 		       &conn->c_faddr);
@@ -861,7 +861,7 @@ static void rds_ib_process_recv(struct rds_connection *conn,
 	/* Validate the checksum. */
 	if (!rds_message_verify_checksum(ihdr)) {
 		rds_ib_conn_error(conn, "incoming message "
-		       "from %pI4 has corrupted header - "
+		       "from %pI6c has corrupted header - "
 		       "forcing a reconnect\n",
 		       &conn->c_faddr);
 		rds_stats_inc(s_recv_drop_bad_checksum);
@@ -941,10 +941,10 @@ static void rds_ib_process_recv(struct rds_connection *conn,
 		ic->i_recv_data_rem = 0;
 		ic->i_ibinc = NULL;
 
-		if (ibinc->ii_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP)
+		if (ibinc->ii_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP) {
 			rds_ib_cong_recv(conn, ibinc);
-		else {
-			rds_recv_incoming(conn, conn->c_faddr, conn->c_laddr,
+		} else {
+			rds_recv_incoming(conn, &conn->c_faddr, &conn->c_laddr,
 					  &ibinc->ii_inc, GFP_ATOMIC);
 			state->ack_next = be64_to_cpu(hdr->h_sequence);
 			state->ack_next_valid = 1;
@@ -988,7 +988,7 @@ void rds_ib_recv_cqe_handler(struct rds_ib_connection *ic,
 	} else {
 		/* We expect errors as the qp is drained during shutdown */
 		if (rds_conn_up(conn) || rds_conn_connecting(conn))
-			rds_ib_conn_error(conn, "recv completion on <%pI4,%pI4> had status %u (%s), disconnecting and reconnecting\n",
+			rds_ib_conn_error(conn, "recv completion on <%pI6c,%pI6c> had status %u (%s), disconnecting and reconnecting\n",
 					  &conn->c_laddr, &conn->c_faddr,
 					  wc->status,
 					  ib_wc_status_msg(wc->status));

net/rds/ib_send.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -305,7 +305,7 @@ void rds_ib_send_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
 
 	/* We expect errors as the qp is drained during shutdown */
 	if (wc->status != IB_WC_SUCCESS && rds_conn_up(conn)) {
-		rds_ib_conn_error(conn, "send completion on <%pI4,%pI4> had status %u (%s), disconnecting and reconnecting\n",
+		rds_ib_conn_error(conn, "send completion on <%pI6c,%pI6c> had status %u (%s), disconnecting and reconnecting\n",
 				  &conn->c_laddr, &conn->c_faddr, wc->status,
 				  ib_wc_status_msg(wc->status));
 	}
@@ -730,7 +730,7 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
 		 first, &first->s_wr, ret, failed_wr);
 	BUG_ON(failed_wr != &first->s_wr);
 	if (ret) {
-		printk(KERN_WARNING "RDS/IB: ib_post_send to %pI4 "
+		printk(KERN_WARNING "RDS/IB: ib_post_send to %pI6c "
 		       "returned %d\n", &conn->c_faddr, ret);
 		rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
 		rds_ib_sub_signaled(ic, nr_sig);
@@ -827,7 +827,7 @@ int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op)
 		 send, &send->s_atomic_wr, ret, failed_wr);
 	BUG_ON(failed_wr != &send->s_atomic_wr.wr);
 	if (ret) {
-		printk(KERN_WARNING "RDS/IB: atomic ib_post_send to %pI4 "
+		printk(KERN_WARNING "RDS/IB: atomic ib_post_send to %pI6c "
 		       "returned %d\n", &conn->c_faddr, ret);
 		rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
 		rds_ib_sub_signaled(ic, nr_sig);
@@ -967,7 +967,7 @@ int rds_ib_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op)
 		 first, &first->s_rdma_wr.wr, ret, failed_wr);
 	BUG_ON(failed_wr != &first->s_rdma_wr.wr);
 	if (ret) {
-		printk(KERN_WARNING "RDS/IB: rdma ib_post_send to %pI4 "
+		printk(KERN_WARNING "RDS/IB: rdma ib_post_send to %pI6c "
 		       "returned %d\n", &conn->c_faddr, ret);
 		rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
 		rds_ib_sub_signaled(ic, nr_sig);

net/rds/loop.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -35,6 +35,7 @@
 #include <linux/in.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
+#include <linux/ipv6.h>
 
 #include "rds_single_path.h"
 #include "rds.h"
@@ -88,11 +89,11 @@ static int rds_loop_xmit(struct rds_connection *conn, struct rds_message *rm,
 
 	BUG_ON(hdr_off || sg || off);
 
-	rds_inc_init(&rm->m_inc, conn, conn->c_laddr);
+	rds_inc_init(&rm->m_inc, conn, &conn->c_laddr);
 	/* For the embedded inc. Matching put is in loop_inc_free() */
 	rds_message_addref(rm);
 
-	rds_recv_incoming(conn, conn->c_laddr, conn->c_faddr, &rm->m_inc,
+	rds_recv_incoming(conn, &conn->c_laddr, &conn->c_faddr, &rm->m_inc,
 			  GFP_KERNEL);
 
 	rds_send_drop_acked(conn, be64_to_cpu(rm->m_inc.i_hdr.h_sequence),

net/rds/rdma.c

 /*
- * Copyright (c) 2007 Oracle.  All rights reserved.
+ * Copyright (c) 2007, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -183,7 +183,7 @@ static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args,
 	long i;
 	int ret;
 
-	if (rs->rs_bound_addr == 0 || !rs->rs_transport) {
+	if (ipv6_addr_any(&rs->rs_bound_addr) || !rs->rs_transport) {
 		ret = -ENOTCONN; /* XXX not a great errno */
 		goto out;
 	}
@@ -574,7 +574,7 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
 
 	args = CMSG_DATA(cmsg);
 
-	if (rs->rs_bound_addr == 0) {
+	if (ipv6_addr_any(&rs->rs_bound_addr)) {
 		ret = -ENOTCONN; /* XXX not a great errno */
 		goto out_ret;
 	}

net/rds/rdma_transport.c

 /*
- * Copyright (c) 2009 Oracle.  All rights reserved.
+ * Copyright (c) 2009, 2018 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -39,8 +39,9 @@
 
 static struct rdma_cm_id *rds_rdma_listen_id;
 
-int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
-			      struct rdma_cm_event *event)
+static int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
+					 struct rdma_cm_event *event,
+					 bool isv6)
 {
 	/* this can be null in the listening path */
 	struct rds_connection *conn = cm_id->context;
@@ -72,7 +73,7 @@ int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 
 	switch (event->event) {
 	case RDMA_CM_EVENT_CONNECT_REQUEST:
-		ret = trans->cm_handle_connect(cm_id, event);
+		ret = trans->cm_handle_connect(cm_id, event, isv6);
 		break;
 
 	case RDMA_CM_EVENT_ADDR_RESOLVED:
@@ -90,7 +91,7 @@ int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 
 			ibic = conn->c_transport_data;
 			if (ibic && ibic->i_cm_id == cm_id)
-				ret = trans->cm_initiate_connect(cm_id);
+				ret = trans->cm_initiate_connect(cm_id, isv6);
 			else
 				rds_conn_drop(conn);
 		}
@@ -116,14 +117,14 @@ int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 
 	case RDMA_CM_EVENT_DISCONNECTED:
 		rdsdebug("DISCONNECT event - dropping connection "
-			"%pI4->%pI4\n", &conn->c_laddr,
+			 "%pI6c->%pI6c\n", &conn->c_laddr,
 			 &conn->c_faddr);
 		rds_conn_drop(conn);
 		break;
 
 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 		if (conn) {
-			pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI4->%pI4\n",
+			pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI6c->%pI6c\n",
 				&conn->c_laddr, &conn->c_faddr);
 			rds_conn_drop(conn);
 		}
@@ -146,13 +147,20 @@ int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 	return ret;
 }
 
-static int rds_rdma_listen_init(void)
+int rds_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, false);
+}
+
+static int rds_rdma_listen_init_common(rdma_cm_event_handler handler,
+				       struct sockaddr *sa,
+				       struct rdma_cm_id **ret_cm_id)
 {
-	struct sockaddr_in sin;
 	struct rdma_cm_id *cm_id;
 	int ret;
 
-	cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, NULL,
+	cm_id = rdma_create_id(&init_net, handler, NULL,
 			       RDMA_PS_TCP, IB_QPT_RC);
 	if (IS_ERR(cm_id)) {
 		ret = PTR_ERR(cm_id);
@@ -161,15 +169,11 @@ static int rds_rdma_listen_init(void)
 		return ret;
 	}
 
-	sin.sin_family = AF_INET;
-	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
-	sin.sin_port = (__force u16)htons(RDS_PORT);
-
 	/*
 	 * XXX I bet this binds the cm_id to a device.  If we want to support
 	 * fail-over we'll have to take this into consideration.
 	 */
-	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
+	ret = rdma_bind_addr(cm_id, sa);
 	if (ret) {
 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 		       "rdma_bind_addr() returned %d\n", ret);
@@ -185,7 +189,7 @@ static int rds_rdma_listen_init(void)
 
 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 
-	rds_rdma_listen_id = cm_id;
+	*ret_cm_id = cm_id;
 	cm_id = NULL;
 out:
 	if (cm_id)
@@ -193,6 +197,26 @@ static int rds_rdma_listen_init(void)
 	return ret;
 }
 
+/* Initialize the RDS RDMA listeners.  We create two listeners for
+ * compatibility reason.  The one on RDS_PORT is used for IPv4
+ * requests only.  The one on RDS_CM_PORT is used for IPv6 requests
+ * only.  So only IPv6 enabled RDS module will communicate using this
+ * port.
+ */
+static int rds_rdma_listen_init(void)
+{
+	int ret;
+	struct sockaddr_in sin;
+
+	sin.sin_family = PF_INET;
+	sin.sin_addr.s_addr = htonl(INADDR_ANY);
+	sin.sin_port = htons(RDS_PORT);
+	ret = rds_rdma_listen_init_common(rds_rdma_cm_event_handler,
+					  (struct sockaddr *)&sin,
+					  &rds_rdma_listen_id);
+	return ret;
+}
+
 static void rds_rdma_listen_stop(void)
 {
 	if (rds_rdma_listen_id) {

net/rds/rds.h

@@ -10,6 +10,7 @@
 #include <linux/rds.h>
 #include <linux/rhashtable.h>
 #include <linux/refcount.h>
+#include <linux/in6.h>
 
 #include "info.h"
 
@@ -30,6 +31,7 @@
  * userspace from listening.
  */
 #define RDS_PORT	18634
+#define RDS_CM_PORT	16385
 
 #ifdef ATOMIC64_INIT
 #define KERNEL_HAS_ATOMIC64
@@ -61,7 +63,7 @@ void rdsdebug(char *fmt, ...)
 
 struct rds_cong_map {
 	struct rb_node		m_rb_node;
-	__be32			m_addr;
+	struct in6_addr		m_addr;
 	wait_queue_head_t	m_waitq;
 	struct list_head	m_conn_list;
 	unsigned long		m_page_addrs[RDS_CONG_MAP_PAGES];
@@ -136,11 +138,13 @@ struct rds_conn_path {
 /* One rds_connection per RDS address pair */
 struct rds_connection {
 	struct hlist_node	c_hash_node;
-	__be32			c_laddr;
-	__be32			c_faddr;
+	struct in6_addr		c_laddr;
+	struct in6_addr		c_faddr;
+	int			c_dev_if; /* c_laddrs's interface index */
 	unsigned int		c_loopback:1,
+				c_isv6:1,
 				c_ping_triggered:1,
-				c_pad_to_32:30;
+				c_pad_to_32:29;
 	int			c_npaths;
 	struct rds_connection	*c_passive;
 	struct rds_transport	*c_trans;
@@ -269,7 +273,7 @@ struct rds_incoming {
 	struct rds_conn_path	*i_conn_path;
 	struct rds_header	i_hdr;
 	unsigned long		i_rx_jiffies;
-	__be32			i_saddr;
+	struct in6_addr		i_saddr;
 
 	rds_rdma_cookie_t	i_rdma_cookie;
 	struct timeval		i_rx_tstamp;
@@ -386,7 +390,7 @@ struct rds_message {
 	struct list_head	m_conn_item;
 	struct rds_incoming	m_inc;
 	u64			m_ack_seq;
-	__be32			m_daddr;
+	struct in6_addr		m_daddr;
 	unsigned long		m_flags;
 
 	/* Never access m_rs without holding m_rs_lock.
@@ -519,7 +523,8 @@ struct rds_transport {
 				t_mp_capable:1;
 	unsigned int		t_type;
 
-	int (*laddr_check)(struct net *net, __be32 addr);
+	int (*laddr_check)(struct net *net, const struct in6_addr *addr,
+			   __u32 scope_id);
 	int (*conn_alloc)(struct rds_connection *conn, gfp_t gfp);
 	void (*conn_free)(void *data);
 	int (*conn_path_connect)(struct rds_conn_path *cp);
@@ -535,8 +540,8 @@ struct rds_transport {
 	void (*inc_free)(struct rds_incoming *inc);
 
 	int (*cm_handle_connect)(struct rdma_cm_id *cm_id,
-				 struct rdma_cm_event *event);
-	int (*cm_initiate_connect)(struct rdma_cm_id *cm_id);
+				 struct rdma_cm_event *event, bool isv6);
+	int (*cm_initiate_connect)(struct rdma_cm_id *cm_id, bool isv6);
 	void (*cm_connect_complete)(struct rds_connection *conn,
 				    struct rdma_cm_event *event);
 
@@ -551,6 +556,12 @@ struct rds_transport {
 	bool (*t_unloading)(struct rds_connection *conn);
 };
 
+/* Bind hash table key length.  It is the sum of the size of a struct
+ * in6_addr, a scope_id  and a port.
+ */
+#define RDS_BOUND_KEY_LEN \
+	(sizeof(struct in6_addr) + sizeof(__u32) + sizeof(__be16))
+
 struct rds_sock {
 	struct sock		rs_sk;
 
@@ -562,10 +573,14 @@ struct rds_sock {
 	 * support.
 	 */
 	struct rhash_head	rs_bound_node;
-	u64			rs_bound_key;
-	__be32			rs_bound_addr;
-	__be32			rs_conn_addr;
-	__be16			rs_bound_port;
+	u8			rs_bound_key[RDS_BOUND_KEY_LEN];
+	struct sockaddr_in6	rs_bound_sin6;
+#define rs_bound_addr		rs_bound_sin6.sin6_addr
+#define rs_bound_addr_v4	rs_bound_sin6.sin6_addr.s6_addr32[3]
+#define rs_bound_port		rs_bound_sin6.sin6_port
+#define rs_bound_scope_id	rs_bound_sin6.sin6_scope_id
+	struct in6_addr		rs_conn_addr;
+#define rs_conn_addr_v4		rs_conn_addr.s6_addr32[3]
 	__be16			rs_conn_port;
 	struct rds_transport    *rs_transport;
 
@@ -701,7 +716,8 @@ extern wait_queue_head_t rds_poll_waitq;
 /* bind.c */
 int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
 void rds_remove_bound(struct rds_sock *rs);
-struct rds_sock *rds_find_bound(__be32 addr, __be16 port);
+struct rds_sock *rds_find_bound(const struct in6_addr *addr, __be16 port,
+				__u32 scope_id);
 int rds_bind_lock_init(void);
 void rds_bind_lock_destroy(void);
 
@@ -725,11 +741,15 @@ extern u32 rds_gen_num;
 int rds_conn_init(void);
 void rds_conn_exit(void);
 struct rds_connection *rds_conn_create(struct net *net,
-				       __be32 laddr, __be32 faddr,
-				       struct rds_transport *trans, gfp_t gfp);
+				       const struct in6_addr *laddr,
+				       const struct in6_addr *faddr,
+				       struct rds_transport *trans, gfp_t gfp,
+				       int dev_if);
 struct rds_connection *rds_conn_create_outgoing(struct net *net,
-						__be32 laddr, __be32 faddr,
-			       struct rds_transport *trans, gfp_t gfp);
+						const struct in6_addr *laddr,
+						const struct in6_addr *faddr,
+						struct rds_transport *trans,
+						gfp_t gfp, int dev_if);
 void rds_conn_shutdown(struct rds_conn_path *cpath);
 void rds_conn_destroy(struct rds_connection *conn);
 void rds_conn_drop(struct rds_connection *conn);
@@ -840,11 +860,12 @@ void rds_page_exit(void);
 
 /* recv.c */
 void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
-		  __be32 saddr);
+		  struct in6_addr *saddr);
 void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *conn,
-		       __be32 saddr);
+		       struct in6_addr *saddr);
 void rds_inc_put(struct rds_incoming *inc);
-void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
+void rds_recv_incoming(struct rds_connection *conn, struct in6_addr *saddr,
+		       struct in6_addr *daddr,
 		       struct rds_incoming *inc, gfp_t gfp);
 int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		int msg_flags);
@@ -859,7 +880,7 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len);
 void rds_send_path_reset(struct rds_conn_path *conn);
 int rds_send_xmit(struct rds_conn_path *cp);
 struct sockaddr_in;
-void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest);
+void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in6 *dest);
 typedef int (*is_acked_func)(struct rds_message *rm, uint64_t ack);
 void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
 			 is_acked_func is_acked);
@@ -946,11 +967,14 @@ void rds_send_worker(struct work_struct *);
 void rds_recv_worker(struct work_struct *);
 void rds_connect_path_complete(struct rds_conn_path *conn, int curr);
 void rds_connect_complete(struct rds_connection *conn);
+int rds_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2);
 
 /* transport.c */
 void rds_trans_register(struct rds_transport *trans);
 void rds_trans_unregister(struct rds_transport *trans);
-struct rds_transport *rds_trans_get_preferred(struct net *net, __be32 addr);
+struct rds_transport *rds_trans_get_preferred(struct net *net,
+					      const struct in6_addr *addr,
+					      __u32 scope_id);
 void rds_trans_put(struct rds_transport *trans);
 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
 				       unsigned int avail);

net/rds/recv.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -41,14 +41,14 @@
 #include "rds.h"
 
 void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
-		  __be32 saddr)
+		 struct in6_addr *saddr)
 {
 	int i;
 
 	refcount_set(&inc->i_refcount, 1);
 	INIT_LIST_HEAD(&inc->i_item);
 	inc->i_conn = conn;
-	inc->i_saddr = saddr;
+	inc->i_saddr = *saddr;
 	inc->i_rdma_cookie = 0;
 	inc->i_rx_tstamp.tv_sec = 0;
 	inc->i_rx_tstamp.tv_usec = 0;
@@ -59,13 +59,13 @@ void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
 EXPORT_SYMBOL_GPL(rds_inc_init);
 
 void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *cp,
-		       __be32 saddr)
+		       struct in6_addr  *saddr)
 {
 	refcount_set(&inc->i_refcount, 1);
 	INIT_LIST_HEAD(&inc->i_item);
 	inc->i_conn = cp->cp_conn;
 	inc->i_conn_path = cp;
-	inc->i_saddr = saddr;
+	inc->i_saddr = *saddr;
 	inc->i_rdma_cookie = 0;
 	inc->i_rx_tstamp.tv_sec = 0;
 	inc->i_rx_tstamp.tv_usec = 0;
@@ -110,7 +110,7 @@ static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk,
 
 	now_congested = rs->rs_rcv_bytes > rds_sk_rcvbuf(rs);
 
-	rdsdebug("rs %p (%pI4:%u) recv bytes %d buf %d "
+	rdsdebug("rs %p (%pI6c:%u) recv bytes %d buf %d "
 	  "now_cong %d delta %d\n",
 	  rs, &rs->rs_bound_addr,
 	  ntohs(rs->rs_bound_port), rs->rs_rcv_bytes,
@@ -260,7 +260,7 @@ static void rds_start_mprds(struct rds_connection *conn)
 	struct rds_conn_path *cp;
 
 	if (conn->c_npaths > 1 &&
-	    IS_CANONICAL(conn->c_laddr, conn->c_faddr)) {
+	    rds_addr_cmp(&conn->c_laddr, &conn->c_faddr) < 0) {
 		for (i = 0; i < conn->c_npaths; i++) {
 			cp = &conn->c_path[i];
 			rds_conn_path_connect_if_down(cp);
@@ -284,7 +284,8 @@ static void rds_start_mprds(struct rds_connection *conn)
  * conn.  This lets loopback, who only has one conn for both directions,
  * tell us which roles the addrs in the conn are playing for this message.
  */
-void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
+void rds_recv_incoming(struct rds_connection *conn, struct in6_addr *saddr,
+		       struct in6_addr *daddr,
 		       struct rds_incoming *inc, gfp_t gfp)
 {
 	struct rds_sock *rs = NULL;
@@ -339,7 +340,8 @@ void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
 
 	if (rds_sysctl_ping_enable && inc->i_hdr.h_dport == 0) {
 		if (inc->i_hdr.h_sport == 0) {
-			rdsdebug("ignore ping with 0 sport from 0x%x\n", saddr);
+			rdsdebug("ignore ping with 0 sport from %pI6c\n",
+				 saddr);
 			goto out;
 		}
 		rds_stats_inc(s_recv_ping);
@@ -362,7 +364,7 @@ void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
 		goto out;
 	}
 
-	rs = rds_find_bound(daddr, inc->i_hdr.h_dport);
+	rs = rds_find_bound(daddr, inc->i_hdr.h_dport, conn->c_dev_if);
 	if (!rs) {
 		rds_stats_inc(s_recv_drop_no_sock);
 		goto out;
@@ -625,6 +627,7 @@ int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	struct rds_sock *rs = rds_sk_to_rs(sk);
 	long timeo;
 	int ret = 0, nonblock = msg_flags & MSG_DONTWAIT;
+	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 	struct rds_incoming *inc = NULL;
 
@@ -673,7 +676,7 @@ int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 			break;
 		}
 
-		rdsdebug("copying inc %p from %pI4:%u to user\n", inc,
+		rdsdebug("copying inc %p from %pI6c:%u to user\n", inc,
 			 &inc->i_conn->c_faddr,
 			 ntohs(inc->i_hdr.h_sport));
 		ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &msg->msg_iter);
@@ -707,12 +710,26 @@ int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 
 		rds_stats_inc(s_recv_delivered);
 
-		if (sin) {
-			sin->sin_family = AF_INET;
-			sin->sin_port = inc->i_hdr.h_sport;
-			sin->sin_addr.s_addr = inc->i_saddr;
-			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
-			msg->msg_namelen = sizeof(*sin);
+		if (msg->msg_name) {
+			if (ipv6_addr_v4mapped(&inc->i_saddr)) {
+				sin = (struct sockaddr_in *)msg->msg_name;
+
+				sin->sin_family = AF_INET;
+				sin->sin_port = inc->i_hdr.h_sport;
+				sin->sin_addr.s_addr =
+				    inc->i_saddr.s6_addr32[3];
+				memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+				msg->msg_namelen = sizeof(*sin);
+			} else {
+				sin6 = (struct sockaddr_in6 *)msg->msg_name;
+
+				sin6->sin6_family = AF_INET6;
+				sin6->sin6_port = inc->i_hdr.h_sport;
+				sin6->sin6_addr = inc->i_saddr;
+				sin6->sin6_flowinfo = 0;
+				sin6->sin6_scope_id = rs->rs_bound_scope_id;
+				msg->msg_namelen = sizeof(*sin6);
+			}
 		}
 		break;
 	}

net/rds/send.c

@@ -709,7 +709,7 @@ void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
 }
 EXPORT_SYMBOL_GPL(rds_send_drop_acked);
 
-void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
+void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in6 *dest)
 {
 	struct rds_message *rm, *tmp;
 	struct rds_connection *conn;
@@ -721,8 +721,9 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
 	spin_lock_irqsave(&rs->rs_lock, flags);
 
 	list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) {
-		if (dest && (dest->sin_addr.s_addr != rm->m_daddr ||
-			     dest->sin_port != rm->m_inc.i_hdr.h_dport))
+		if (dest &&
+		    (!ipv6_addr_equal(&dest->sin6_addr, &rm->m_daddr) ||
+		     dest->sin6_port != rm->m_inc.i_hdr.h_dport))
 			continue;
 
 		list_move(&rm->m_sock_item, &list);
@@ -1059,8 +1060,8 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 {
 	struct sock *sk = sock->sk;
 	struct rds_sock *rs = rds_sk_to_rs(sk);
+	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 	DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
-	__be32 daddr;
 	__be16 dport;
 	struct rds_message *rm = NULL;
 	struct rds_connection *conn;
@@ -1069,10 +1070,13 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 	int nonblock = msg->msg_flags & MSG_DONTWAIT;
 	long timeo = sock_sndtimeo(sk, nonblock);
 	struct rds_conn_path *cpath;
+	struct in6_addr daddr;
+	__u32 scope_id = 0;
 	size_t total_payload_len = payload_len, rdma_payload_len = 0;
 	bool zcopy = ((msg->msg_flags & MSG_ZEROCOPY) &&
 		      sock_flag(rds_rs_to_sk(rs), SOCK_ZEROCOPY));
 	int num_sgs = ceil(payload_len, PAGE_SIZE);
+	int namelen;
 
 	/* Mirror Linux UDP mirror of BSD error message compatibility */
 	/* XXX: Perhaps MSG_MORE someday */
@@ -1081,27 +1085,59 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 		goto out;
 	}
 
-	if (msg->msg_namelen) {
-		/* XXX fail non-unicast destination IPs? */
-		if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) {
+	namelen = msg->msg_namelen;
+	if (namelen != 0) {
+		if (namelen < sizeof(*usin)) {
+			ret = -EINVAL;
+			goto out;
+		}
+		switch (namelen) {
+		case sizeof(*usin):
+			if (usin->sin_family != AF_INET ||
+			    usin->sin_addr.s_addr == htonl(INADDR_ANY) ||
+			    usin->sin_addr.s_addr == htonl(INADDR_BROADCAST) ||
+			    IN_MULTICAST(ntohl(usin->sin_addr.s_addr))) {
+				ret = -EINVAL;
+				goto out;
+			}
+			ipv6_addr_set_v4mapped(usin->sin_addr.s_addr, &daddr);
+			dport = usin->sin_port;
+			break;
+
+		case sizeof(*sin6): {
+			ret = -EPROTONOSUPPORT;
+			goto out;
+		}
+
+		default:
 			ret = -EINVAL;
 			goto out;
 		}
-		daddr = usin->sin_addr.s_addr;
-		dport = usin->sin_port;
 	} else {
 		/* We only care about consistency with ->connect() */
 		lock_sock(sk);
 		daddr = rs->rs_conn_addr;
 		dport = rs->rs_conn_port;
+		scope_id = rs->rs_bound_scope_id;
 		release_sock(sk);
 	}
 
 	lock_sock(sk);
-	if (daddr == 0 || rs->rs_bound_addr == 0) {
+	if (ipv6_addr_any(&rs->rs_bound_addr) || ipv6_addr_any(&daddr)) {
 		release_sock(sk);
-		ret = -ENOTCONN; /* XXX not a great errno */
+		ret = -ENOTCONN;
 		goto out;
+	} else if (namelen != 0) {
+		/* Cannot send to an IPv4 address using an IPv6 source
+		 * address and cannot send to an IPv6 address using an
+		 * IPv4 source address.
+		 */
+		if (ipv6_addr_v4mapped(&daddr) ^
+		    ipv6_addr_v4mapped(&rs->rs_bound_addr)) {
+			release_sock(sk);
+			ret = -EOPNOTSUPP;
+			goto out;
+		}
 	}
 	release_sock(sk);
 
@@ -1155,13 +1191,14 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 
 	/* rds_conn_create has a spinlock that runs with IRQ off.
 	 * Caching the conn in the socket helps a lot. */
-	if (rs->rs_conn && rs->rs_conn->c_faddr == daddr)
+	if (rs->rs_conn && ipv6_addr_equal(&rs->rs_conn->c_faddr, &daddr))
 		conn = rs->rs_conn;
 	else {
 		conn = rds_conn_create_outgoing(sock_net(sock->sk),
-						rs->rs_bound_addr, daddr,
-					rs->rs_transport,
-					sock->sk->sk_allocation);
+						&rs->rs_bound_addr, &daddr,
+						rs->rs_transport,
+						sock->sk->sk_allocation,
+						scope_id);
 		if (IS_ERR(conn)) {
 			ret = PTR_ERR(conn);
 			goto out;

net/rds/tcp.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -37,6 +37,8 @@
 #include <net/tcp.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
+#include <net/tcp.h>
+#include <net/addrconf.h>
 
 #include "rds.h"
 #include "tcp.h"
@@ -262,9 +264,33 @@ static void rds_tcp_tc_info(struct socket *rds_sock, unsigned int len,
 	spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
 }
 
-static int rds_tcp_laddr_check(struct net *net, __be32 addr)
+static int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
+			       __u32 scope_id)
 {
-	if (inet_addr_type(net, addr) == RTN_LOCAL)
+	struct net_device *dev = NULL;
+	int ret;
+
+	if (ipv6_addr_v4mapped(addr)) {
+		if (inet_addr_type(net, addr->s6_addr32[3]) == RTN_LOCAL)
+			return 0;
+		return -EADDRNOTAVAIL;
+	}
+
+	/* If the scope_id is specified, check only those addresses
+	 * hosted on the specified interface.
+	 */
+	if (scope_id != 0) {
+		rcu_read_lock();
+		dev = dev_get_by_index_rcu(net, scope_id);
+		/* scope_id is not valid... */
+		if (!dev) {
+			rcu_read_unlock();
+			return -EADDRNOTAVAIL;
+		}
+		rcu_read_unlock();
+	}
+	ret = ipv6_chk_addr(net, addr, dev, 0);
+	if (ret)
 		return 0;
 	return -EADDRNOTAVAIL;
 }

net/rds/tcp_connect.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -66,7 +66,8 @@ void rds_tcp_state_change(struct sock *sk)
 		 * RDS connection as RDS_CONN_UP until the reconnect,
 		 * to avoid RDS datagram loss.
 		 */
-		if (!IS_CANONICAL(cp->cp_conn->c_laddr, cp->cp_conn->c_faddr) &&
+		if (rds_addr_cmp(&cp->cp_conn->c_laddr,
+				 &cp->cp_conn->c_faddr) >= 0 &&
 		    rds_conn_path_transition(cp, RDS_CONN_CONNECTING,
 					     RDS_CONN_ERROR)) {
 			rds_conn_path_drop(cp, false);
@@ -88,7 +89,9 @@ void rds_tcp_state_change(struct sock *sk)
 int rds_tcp_conn_path_connect(struct rds_conn_path *cp)
 {
 	struct socket *sock = NULL;
-	struct sockaddr_in src, dest;
+	struct sockaddr_in sin;
+	struct sockaddr *addr;
+	int addrlen;
 	int ret;
 	struct rds_connection *conn = cp->cp_conn;
 	struct rds_tcp_connection *tc = cp->cp_transport_data;
@@ -112,30 +115,33 @@ int rds_tcp_conn_path_connect(struct rds_conn_path *cp)
 
 	rds_tcp_tune(sock);
 
-	src.sin_family = AF_INET;
-	src.sin_addr.s_addr = (__force u32)conn->c_laddr;
-	src.sin_port = (__force u16)htons(0);
+	sin.sin_family = AF_INET;
+	sin.sin_addr.s_addr = conn->c_laddr.s6_addr32[3];
+	sin.sin_port = 0;
+	addr = (struct sockaddr *)&sin;
+	addrlen = sizeof(sin);
 
-	ret = sock->ops->bind(sock, (struct sockaddr *)&src, sizeof(src));
+	ret = sock->ops->bind(sock, addr, addrlen);
 	if (ret) {
-		rdsdebug("bind failed with %d at address %pI4\n",
+		rdsdebug("bind failed with %d at address %pI6c\n",
 			 ret, &conn->c_laddr);
 		goto out;
 	}
 
-	dest.sin_family = AF_INET;
-	dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
-	dest.sin_port = (__force u16)htons(RDS_TCP_PORT);
+	sin.sin_family = AF_INET;
+	sin.sin_addr.s_addr = conn->c_faddr.s6_addr32[3];
+	sin.sin_port = htons(RDS_TCP_PORT);
+	addr = (struct sockaddr *)&sin;
+	addrlen = sizeof(sin);
 
 	/*
 	 * once we call connect() we can start getting callbacks and they
 	 * own the socket
 	 */
 	rds_tcp_set_callbacks(sock, cp);
-	ret = sock->ops->connect(sock, (struct sockaddr *)&dest, sizeof(dest),
-				 O_NONBLOCK);
+	ret = sock->ops->connect(sock, addr, addrlen, O_NONBLOCK);
 
-	rdsdebug("connect to address %pI4 returned %d\n", &conn->c_faddr, ret);
+	rdsdebug("connect to address %pI6c returned %d\n", &conn->c_faddr, ret);
 	if (ret == -EINPROGRESS)
 		ret = 0;
 	if (ret == 0) {

net/rds/tcp_listen.c

 /*
- * Copyright (c) 2006, 2018 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -83,13 +83,12 @@ static
 struct rds_tcp_connection *rds_tcp_accept_one_path(struct rds_connection *conn)
 {
 	int i;
-	bool peer_is_smaller = IS_CANONICAL(conn->c_faddr, conn->c_laddr);
 	int npaths = max_t(int, 1, conn->c_npaths);
 
 	/* for mprds, all paths MUST be initiated by the peer
 	 * with the smaller address.
 	 */
-	if (!peer_is_smaller) {
+	if (rds_addr_cmp(&conn->c_faddr, &conn->c_laddr) >= 0) {
 		/* Make sure we initiate at least one path if this
 		 * has not already been done; rds_start_mprds() will
 		 * take care of additional paths, if necessary.
@@ -164,13 +163,16 @@ int rds_tcp_accept_one(struct socket *sock)
 
 	inet = inet_sk(new_sock->sk);
 
-	rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
-		 &inet->inet_saddr, ntohs(inet->inet_sport),
-		 &inet->inet_daddr, ntohs(inet->inet_dport));
+	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));
 
 	conn = rds_conn_create(sock_net(sock->sk),
-			       inet->inet_saddr, inet->inet_daddr,
-			       &rds_tcp_transport, GFP_KERNEL);
+			       &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);
+
 	if (IS_ERR(conn)) {
 		ret = PTR_ERR(conn);
 		goto out;

net/rds/tcp_recv.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -179,7 +179,7 @@ static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb,
 			tc->t_tinc = tinc;
 			rdsdebug("alloced tinc %p\n", tinc);
 			rds_inc_path_init(&tinc->ti_inc, cp,
-					  cp->cp_conn->c_faddr);
+					  &cp->cp_conn->c_faddr);
 			tinc->ti_inc.i_rx_lat_trace[RDS_MSG_RX_HDR] =
 					local_clock();
 
@@ -239,8 +239,9 @@ static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb,
 			if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP)
 				rds_tcp_cong_recv(conn, tinc);
 			else
-				rds_recv_incoming(conn, conn->c_faddr,
-						  conn->c_laddr, &tinc->ti_inc,
+				rds_recv_incoming(conn, &conn->c_faddr,
+						  &conn->c_laddr,
+						  &tinc->ti_inc,
 						  arg->gfp);
 
 			tc->t_tinc_hdr_rem = sizeof(struct rds_header);

net/rds/tcp_send.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -153,7 +153,7 @@ int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
 			 * an incoming RST.
 			 */
 			if (rds_conn_path_up(cp)) {
-				pr_warn("RDS/tcp: send to %pI4 on cp [%d]"
+				pr_warn("RDS/tcp: send to %pI6c on cp [%d]"
 					"returned %d, "
 					"disconnecting and reconnecting\n",
 					&conn->c_faddr, cp->cp_index, ret);

net/rds/threads.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -82,8 +82,8 @@ void rds_connect_path_complete(struct rds_conn_path *cp, int curr)
 		return;
 	}
 
-	rdsdebug("conn %p for %pI4 to %pI4 complete\n",
-	  cp->cp_conn, &cp->cp_conn->c_laddr, &cp->cp_conn->c_faddr);
+	rdsdebug("conn %p for %pI6c to %pI6c complete\n",
+		 cp->cp_conn, &cp->cp_conn->c_laddr, &cp->cp_conn->c_faddr);
 
 	cp->cp_reconnect_jiffies = 0;
 	set_bit(0, &cp->cp_conn->c_map_queued);
@@ -125,13 +125,13 @@ void rds_queue_reconnect(struct rds_conn_path *cp)
 	unsigned long rand;
 	struct rds_connection *conn = cp->cp_conn;
 
-	rdsdebug("conn %p for %pI4 to %pI4 reconnect jiffies %lu\n",
-	  conn, &conn->c_laddr, &conn->c_faddr,
-	  cp->cp_reconnect_jiffies);
+	rdsdebug("conn %p for %pI6c to %pI6c reconnect jiffies %lu\n",
+		 conn, &conn->c_laddr, &conn->c_faddr,
+		 cp->cp_reconnect_jiffies);
 
 	/* let peer with smaller addr initiate reconnect, to avoid duels */
 	if (conn->c_trans->t_type == RDS_TRANS_TCP &&
-	    !IS_CANONICAL(conn->c_laddr, conn->c_faddr))
+	    rds_addr_cmp(&conn->c_laddr, &conn->c_faddr) >= 0)
 		return;
 
 	set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags);
@@ -145,7 +145,7 @@ void rds_queue_reconnect(struct rds_conn_path *cp)
 	}
 
 	get_random_bytes(&rand, sizeof(rand));
-	rdsdebug("%lu delay %lu ceil conn %p for %pI4 -> %pI4\n",
+	rdsdebug("%lu delay %lu ceil conn %p for %pI6c -> %pI6c\n",
 		 rand % cp->cp_reconnect_jiffies, cp->cp_reconnect_jiffies,
 		 conn, &conn->c_laddr, &conn->c_faddr);
 	rcu_read_lock();
@@ -167,14 +167,14 @@ void rds_connect_worker(struct work_struct *work)
 	int ret;
 
 	if (cp->cp_index > 0 &&
-	    !IS_CANONICAL(cp->cp_conn->c_laddr, cp->cp_conn->c_faddr))
+	    rds_addr_cmp(&cp->cp_conn->c_laddr, &cp->cp_conn->c_faddr) >= 0)
 		return;
 	clear_bit(RDS_RECONNECT_PENDING, &cp->cp_flags);
 	ret = rds_conn_path_transition(cp, RDS_CONN_DOWN, RDS_CONN_CONNECTING);
 	if (ret) {
 		ret = conn->c_trans->conn_path_connect(cp);
-		rdsdebug("conn %p for %pI4 to %pI4 dispatched, ret %d\n",
-			conn, &conn->c_laddr, &conn->c_faddr, ret);
+		rdsdebug("conn %p for %pI6c to %pI6c dispatched, ret %d\n",
+			 conn, &conn->c_laddr, &conn->c_faddr, ret);
 
 		if (ret) {
 			if (rds_conn_path_transition(cp,
@@ -259,3 +259,50 @@ int rds_threads_init(void)
 
 	return 0;
 }
+
+/* Compare two IPv6 addresses.  Return 0 if the two addresses are equal.
+ * Return 1 if the first is greater.  Return -1 if the second is greater.
+ */
+int rds_addr_cmp(const struct in6_addr *addr1,
+		 const struct in6_addr *addr2)
+{
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
+	const __be64 *a1, *a2;
+	u64 x, y;
+
+	a1 = (__be64 *)addr1;
+	a2 = (__be64 *)addr2;
+
+	if (*a1 != *a2) {
+		if (be64_to_cpu(*a1) < be64_to_cpu(*a2))
+			return -1;
+		else
+			return 1;
+	} else {
+		x = be64_to_cpu(*++a1);
+		y = be64_to_cpu(*++a2);
+		if (x < y)
+			return -1;
+		else if (x > y)
+			return 1;
+		else
+			return 0;
+	}
+#else
+	u32 a, b;
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		if (addr1->s6_addr32[i] != addr2->s6_addr32[i]) {
+			a = ntohl(addr1->s6_addr32[i]);
+			b = ntohl(addr2->s6_addr32[i]);
+			if (a < b)
+				return -1;
+			else if (a > b)
+				return 1;
+		}
+	}
+	return 0;
+#endif
+}
+EXPORT_SYMBOL_GPL(rds_addr_cmp);

net/rds/transport.c

 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -33,6 +33,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/in.h>
+#include <linux/ipv6.h>
 
 #include "rds.h"
 #include "loop.h"
@@ -75,20 +76,26 @@ void rds_trans_put(struct rds_transport *trans)
 		module_put(trans->t_owner);
 }
 
-struct rds_transport *rds_trans_get_preferred(struct net *net, __be32 addr)
+struct rds_transport *rds_trans_get_preferred(struct net *net,
+					      const struct in6_addr *addr,
+					      __u32 scope_id)
 {
 	struct rds_transport *ret = NULL;
 	struct rds_transport *trans;
 	unsigned int i;
 
-	if (IN_LOOPBACK(ntohl(addr)))
+	if (ipv6_addr_v4mapped(addr)) {
+		if (*(u_int8_t *)&addr->s6_addr32[3] == IN_LOOPBACKNET)
+			return &rds_loop_transport;
+	} else if (ipv6_addr_loopback(addr)) {
 		return &rds_loop_transport;
+	}
 
 	down_read(&rds_trans_sem);
 	for (i = 0; i < RDS_TRANS_COUNT; i++) {
 		trans = transports[i];
 
-		if (trans && (trans->laddr_check(net, addr) == 0) &&
+		if (trans && (trans->laddr_check(net, addr, scope_id) == 0) &&
 		    (!trans->t_owner || try_module_get(trans->t_owner))) {
 			ret = trans;
 			break;