Merge branch 'rds-ipv6'

Ka-Cheong Poon says:

====================
rds: IPv6 support

This patch set adds IPv6 support to the kernel RDS and related
modules.  Existing RDS apps using IPv4 address continue to run without
any problem.  New RDS apps which want to use IPv6 address can do so by
passing the address in struct sockaddr_in6 to bind(), connect() or
sendmsg().  And those apps also need to use the new IPv6 equivalents
of some of the existing socket options as the existing options use a
32 bit integer to store IP address.

All RDS code now use struct in6_addr to store IP address.  IPv4
address is stored as an IPv4 mapped address.

Header file changes

There are many data structures (RDS socket options) used by RDS apps
which use a 32 bit integer to store IP address. To support IPv6,
struct in6_addr needs to be used. To ensure backward compatibility, a
new data structure is introduced for each of those data structures
which use a 32 bit integer to represent an IP address. And new socket
options are introduced to use those new structures. This means that
existing apps should work without a problem with the new RDS module.
For apps which want to use IPv6, those new data structures and socket
options can be used. IPv4 mapped address is used to represent IPv4
address in the new data structures.

Internally, all RDS data structures which contain an IP address are
changed to use struct in6_addr to store the address. 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.

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_TCP_PORT to send the connection set up request.

RDS/TCP changes

TCP related code is changed to support IPv6.  Note that only an IPv6
TCP listener on port RDS_TCP_PORT is created as it can accept both
IPv4 and IPv6 connection requests.

IB/RDMA changes

The initial private data exchange between IB endpoints using RDMA is
changed to support IPv6 address instead, if the peer address is IPv6.
To ensure backward compatibility, annother RDMA listener port
(RDS_CM_PORT) is used to accept IPv6 connection. An IPv6 capable RDS
module 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.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 199 insertions, 60 deletions

diff --git a/net/rds/connection.c b/net/rds/connection.c
index cfb05953b0e5..051e35c1e7c6 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -1,5 +1,5 @@
 /*
- * 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
@@ -34,7 +34,9 @@
 #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 <net/addrconf.h>
 
 #include "rds.h"
 #include "loop.h"
@@ -49,18 +51,21 @@ 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 +77,25 @@ 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 +109,8 @@ 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 +152,12 @@ 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 +167,12 @@ 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 +197,19 @@ 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;
+	/* 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
+	 * to look up a socket when a packet is received
+	 */
+	if (ipv6_addr_type(laddr) & IPV6_ADDR_LINKLOCAL)
+		conn->c_bound_if = dev_if;
+	else
+		conn->c_bound_if = 0;
 
 	rds_conn_net_set(conn, net);
 
@@ -199,7 +226,7 @@ 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 +260,10 @@ 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 +289,8 @@ 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 +323,22 @@ out:
 }
 
 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);
 
@@ -464,10 +496,21 @@ void rds_conn_destroy(struct rds_connection *conn)
 }
 EXPORT_SYMBOL_GPL(rds_conn_destroy);
 
-static void rds_conn_message_info(struct socket *sock, unsigned int len,
-				  struct rds_info_iterator *iter,
-				  struct rds_info_lengths *lens,
-				  int want_send)
+static void __rds_inc_msg_cp(struct rds_incoming *inc,
+			     struct rds_info_iterator *iter,
+			     void *saddr, void *daddr, int flip, bool isv6)
+{
+	if (isv6)
+		rds6_inc_info_copy(inc, iter, saddr, daddr, flip);
+	else
+		rds_inc_info_copy(inc, iter, *(__be32 *)saddr,
+				  *(__be32 *)daddr, flip);
+}
+
+static void rds_conn_message_info_cmn(struct socket *sock, unsigned int len,
+				      struct rds_info_iterator *iter,
+				      struct rds_info_lengths *lens,
+				      int want_send, bool isv6)
 {
 	struct hlist_head *head;
 	struct list_head *list;
@@ -478,7 +521,10 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 	size_t i;
 	int j;
 
-	len /= sizeof(struct rds_info_message);
+	if (isv6)
+		len /= sizeof(struct rds6_info_message);
+	else
+		len /= sizeof(struct rds_info_message);
 
 	rcu_read_lock();
 
@@ -488,6 +534,9 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 			struct rds_conn_path *cp;
 			int npaths;
 
+			if (!isv6 && conn->c_isv6)
+				continue;
+
 			npaths = (conn->c_trans->t_mp_capable ?
 				 RDS_MPATH_WORKERS : 1);
 
@@ -504,11 +553,11 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 				list_for_each_entry(rm, list, m_conn_item) {
 					total++;
 					if (total <= len)
-						rds_inc_info_copy(&rm->m_inc,
-								  iter,
-								  conn->c_laddr,
-								  conn->c_faddr,
-								  0);
+						__rds_inc_msg_cp(&rm->m_inc,
+								 iter,
+								 &conn->c_laddr,
+								 &conn->c_faddr,
+								 0, isv6);
 				}
 
 				spin_unlock_irqrestore(&cp->cp_lock, flags);
@@ -518,7 +567,26 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 	rcu_read_unlock();
 
 	lens->nr = total;
-	lens->each = sizeof(struct rds_info_message);
+	if (isv6)
+		lens->each = sizeof(struct rds6_info_message);
+	else
+		lens->each = sizeof(struct rds_info_message);
+}
+
+static void rds_conn_message_info(struct socket *sock, unsigned int len,
+				  struct rds_info_iterator *iter,
+				  struct rds_info_lengths *lens,
+				  int want_send)
+{
+	rds_conn_message_info_cmn(sock, len, iter, lens, want_send, false);
+}
+
+static void rds6_conn_message_info(struct socket *sock, unsigned int len,
+				   struct rds_info_iterator *iter,
+				   struct rds_info_lengths *lens,
+				   int want_send)
+{
+	rds_conn_message_info_cmn(sock, len, iter, lens, want_send, true);
 }
 
 static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
@@ -528,6 +596,13 @@ static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
 	rds_conn_message_info(sock, len, iter, lens, 1);
 }
 
+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);
+}
+
 static void rds_conn_message_info_retrans(struct socket *sock,
 					  unsigned int len,
 					  struct rds_info_iterator *iter,
@@ -536,6 +611,14 @@ static void rds_conn_message_info_retrans(struct socket *sock,
 	rds_conn_message_info(sock, len, iter, lens, 0);
 }
 
+static void rds6_conn_message_info_retrans(struct socket *sock,
+					   unsigned int len,
+					   struct rds_info_iterator *iter,
+					   struct rds_info_lengths *lens)
+{
+	rds6_conn_message_info(sock, len, iter, lens, 0);
+}
+
 void rds_for_each_conn_info(struct socket *sock, unsigned int len,
 			  struct rds_info_iterator *iter,
 			  struct rds_info_lengths *lens,
@@ -584,7 +667,6 @@ 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 +677,20 @@ 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 +709,16 @@ 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;
+
+	if (conn->c_isv6)
+		return 0;
 
 	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;
 
@@ -645,6 +734,34 @@ static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
 	return 1;
 }
 
+static int rds6_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
+{
+	struct rds6_info_connection *cinfo6 = buffer;
+	struct rds_connection *conn = cp->cp_conn;
+
+	cinfo6->next_tx_seq = cp->cp_next_tx_seq;
+	cinfo6->next_rx_seq = cp->cp_next_rx_seq;
+	cinfo6->laddr = conn->c_laddr;
+	cinfo6->faddr = conn->c_faddr;
+	strncpy(cinfo6->transport, conn->c_trans->t_name,
+		sizeof(cinfo6->transport));
+	cinfo6->flags = 0;
+
+	rds_conn_info_set(cinfo6->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
+			  SENDING);
+	/* XXX Future: return the state rather than these funky bits */
+	rds_conn_info_set(cinfo6->flags,
+			  atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
+			  CONNECTING);
+	rds_conn_info_set(cinfo6->flags,
+			  atomic_read(&cp->cp_state) == RDS_CONN_UP,
+			  CONNECTED);
+	/* Just return 1 as there is no error case. This is a helper function
+	 * for rds_walk_conn_path_info() and it wants a return value.
+	 */
+	return 1;
+}
+
 static void rds_conn_info(struct socket *sock, unsigned int len,
 			  struct rds_info_iterator *iter,
 			  struct rds_info_lengths *lens)
@@ -657,6 +774,18 @@ static void rds_conn_info(struct socket *sock, unsigned int len,
 				sizeof(struct rds_info_connection));
 }
 
+static void rds6_conn_info(struct socket *sock, unsigned int len,
+			   struct rds_info_iterator *iter,
+			   struct rds_info_lengths *lens)
+{
+	u64 buffer[(sizeof(struct rds6_info_connection) + 7) / 8];
+
+	rds_walk_conn_path_info(sock, len, iter, lens,
+				rds6_conn_info_visitor,
+				buffer,
+				sizeof(struct rds6_info_connection));
+}
+
 int rds_conn_init(void)
 {
 	int ret;
@@ -678,6 +807,11 @@ int rds_conn_init(void)
 			       rds_conn_message_info_send);
 	rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
 			       rds_conn_message_info_retrans);
+	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);
 
 	return 0;
 }
@@ -696,6 +830,11 @@ void rds_conn_exit(void)
 				 rds_conn_message_info_send);
 	rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
 				 rds_conn_message_info_retrans);
+	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);
 }
 
 /*