rds: Extend RDS API for IPv6 support

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.

v4: Revert changes to SO_RDS_TRANSPORT

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, 44 insertions, 0 deletions

diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 890d0e1d8908..7028d6e51947 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -273,6 +273,48 @@ out:
         spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
 }
 
+/* Handle RDS6_INFO_TCP_SOCKETS socket option. It returns both IPv4 and
+ * IPv6 connections. IPv4 connection address is returned in an IPv4 mapped
+ * address.
+ */
+static void rds6_tcp_tc_info(struct socket *sock, unsigned int len,
+                             struct rds_info_iterator *iter,
+                             struct rds_info_lengths *lens)
+{
+        struct rds6_info_tcp_socket tsinfo6;
+        struct rds_tcp_connection *tc;
+        unsigned long flags;
+
+        spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
+
+        if (len / sizeof(tsinfo6) < rds6_tcp_tc_count)
+                goto out;
+
+        list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
+                struct sock *sk = tc->t_sock->sk;
+                struct inet_sock *inet = inet_sk(sk);
+
+                tsinfo6.local_addr = sk->sk_v6_rcv_saddr;
+                tsinfo6.local_port = inet->inet_sport;
+                tsinfo6.peer_addr = sk->sk_v6_daddr;
+                tsinfo6.peer_port = inet->inet_dport;
+
+                tsinfo6.hdr_rem = tc->t_tinc_hdr_rem;
+                tsinfo6.data_rem = tc->t_tinc_data_rem;
+                tsinfo6.last_sent_nxt = tc->t_last_sent_nxt;
+                tsinfo6.last_expected_una = tc->t_last_expected_una;
+                tsinfo6.last_seen_una = tc->t_last_seen_una;
+
+                rds_info_copy(iter, &tsinfo6, sizeof(tsinfo6));
+        }
+
+out:
+        lens->nr = rds6_tcp_tc_count;
+        lens->each = sizeof(tsinfo6);
+
+        spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
+}
+
 static int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
                                __u32 scope_id)
 {
@@ -628,6 +670,7 @@ static void rds_tcp_exit(void)
         rds_tcp_set_unloading();
         synchronize_rcu();
         rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
+        rds_info_deregister_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
         unregister_pernet_device(&rds_tcp_net_ops);
         rds_tcp_destroy_conns();
         rds_trans_unregister(&rds_tcp_transport);
@@ -659,6 +702,7 @@ static int rds_tcp_init(void)
         rds_trans_register(&rds_tcp_transport);
 
         rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
+        rds_info_register_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
 
         goto out;
 out_recv: