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>

1 files changed, 63 insertions, 28 deletions

diff --git a/net/rds/bind.c b/net/rds/bind.c
index 5aa3a64aa4f0..c401776ad938 100644
--- a/net/rds/bind.c
+++ b/net/rds/bind.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
@@ -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;
 	}