rds: Enable RDS IPv6 support

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

v5: Fixed syntax problem (David Miller).

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

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

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

Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 47 insertions, 8 deletions

diff --git a/net/rds/ib.c b/net/rds/ib.c
index c712a848957d..756225c5540f 100644
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006, 2017 Oracle and/or its affiliates. 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
@@ -39,6 +39,7 @@
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <net/addrconf.h>
 
 #include "rds_single_path.h"
 #include "rds.h"
@@ -295,6 +296,8 @@ static int rds_ib_conn_info_visitor(struct rds_connection *conn,
         /* We will only ever look at IB transports */
         if (conn->c_trans != &rds_ib_transport)
                 return 0;
+        if (conn->c_isv6)
+                return 0;
 
         iinfo->src_addr = conn->c_laddr.s6_addr32[3];
         iinfo->dst_addr = conn->c_faddr.s6_addr32[3];
@@ -330,7 +333,6 @@ static void rds_ib_ic_info(struct socket *sock, unsigned int len,
                                 sizeof(struct rds_info_rdma_connection));
 }
 
-
 /*
  * Early RDS/IB was built to only bind to an address if there is an IPoIB
  * device with that address set.
@@ -346,8 +348,12 @@ static int rds_ib_laddr_check(struct net *net, const struct in6_addr *addr,
 {
         int ret;
         struct rdma_cm_id *cm_id;
+        struct sockaddr_in6 sin6;
         struct sockaddr_in sin;
+        struct sockaddr *sa;
+        bool isv4;
 
+        isv4 = ipv6_addr_v4mapped(addr);
         /* Create a CMA ID and try to bind it. This catches both
          * IB and iWARP capable NICs.
          */
@@ -356,20 +362,53 @@ static int rds_ib_laddr_check(struct net *net, const struct in6_addr *addr,
         if (IS_ERR(cm_id))
                 return PTR_ERR(cm_id);
 
-        memset(&sin, 0, sizeof(sin));
-        sin.sin_family = AF_INET;
-        sin.sin_addr.s_addr = addr->s6_addr32[3];
+        if (isv4) {
+                memset(&sin, 0, sizeof(sin));
+                sin.sin_family = AF_INET;
+                sin.sin_addr.s_addr = addr->s6_addr32[3];
+                sa = (struct sockaddr *)&sin;
+        } else {
+                memset(&sin6, 0, sizeof(sin6));
+                sin6.sin6_family = AF_INET6;
+                sin6.sin6_addr = *addr;
+                sin6.sin6_scope_id = scope_id;
+                sa = (struct sockaddr *)&sin6;
+
+                /* XXX Do a special IPv6 link local address check here.  The
+                 * reason is that rdma_bind_addr() always succeeds with IPv6
+                 * link local address regardless it is indeed configured in a
+                 * system.
+                 */
+                if (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL) {
+                        struct net_device *dev;
+
+                        if (scope_id == 0)
+                                return -EADDRNOTAVAIL;
+
+                        /* Use init_net for now as RDS is not network
+                         * name space aware.
+                         */
+                        dev = dev_get_by_index(&init_net, scope_id);
+                        if (!dev)
+                                return -EADDRNOTAVAIL;
+                        if (!ipv6_chk_addr(&init_net, addr, dev, 1)) {
+                                dev_put(dev);
+                                return -EADDRNOTAVAIL;
+                        }
+                        dev_put(dev);
+                }
+        }
 
         /* rdma_bind_addr will only succeed for IB & iWARP devices */
-        ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
+        ret = rdma_bind_addr(cm_id, sa);
         /* due to this, we will claim to support iWARP devices unless we
            check node_type. */
         if (ret || !cm_id->device ||
             cm_id->device->node_type != RDMA_NODE_IB_CA)
                 ret = -EADDRNOTAVAIL;
 
-        rdsdebug("addr %pI6c ret %d node type %d\n",
-                 addr, ret,
+        rdsdebug("addr %pI6c%%%u ret %d node type %d\n",
+                 addr, scope_id, ret,
                  cm_id->device ? cm_id->device->node_type : -1);
 
         rdma_destroy_id(cm_id);