RDS: Add TCP transport to RDS

This code allows RDS to be tunneled over a TCP connection.

RDMA operations are disabled when using TCP transport,
but this frees RDS from the IB/RDMA stack dependency, and allows
it to be used with standard Ethernet adapters, or in a VM.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 93 insertions, 0 deletions

diff --git a/net/rds/tcp.h b/net/rds/tcp.h
new file mode 100644
index 000000000000..844fa6b9cf5a
--- /dev/null
+++ b/net/rds/tcp.h
@@ -0,0 +1,93 @@
+#ifndef _RDS_TCP_H
+#define _RDS_TCP_H
+
+#define RDS_TCP_PORT    16385
+
+struct rds_tcp_incoming {
+        struct rds_incoming     ti_inc;
+        struct sk_buff_head     ti_skb_list;
+};
+
+struct rds_tcp_connection {
+
+        struct list_head        t_tcp_node;
+        struct rds_connection   *conn;
+        struct socket           *t_sock;
+        void                    *t_orig_write_space;
+        void                    *t_orig_data_ready;
+        void                    *t_orig_state_change;
+
+        struct rds_tcp_incoming *t_tinc;
+        size_t                  t_tinc_hdr_rem;
+        size_t                  t_tinc_data_rem;
+
+        /* XXX error report? */
+        struct work_struct      t_conn_w;
+        struct work_struct      t_send_w;
+        struct work_struct      t_down_w;
+        struct work_struct      t_recv_w;
+
+        /* for info exporting only */
+        struct list_head        t_list_item;
+        u32                     t_last_sent_nxt;
+        u32                     t_last_expected_una;
+        u32                     t_last_seen_una;
+};
+
+struct rds_tcp_statistics {
+        uint64_t        s_tcp_data_ready_calls;
+        uint64_t        s_tcp_write_space_calls;
+        uint64_t        s_tcp_sndbuf_full;
+        uint64_t        s_tcp_connect_raced;
+        uint64_t        s_tcp_listen_closed_stale;
+};
+
+/* tcp.c */
+int __init rds_tcp_init(void);
+void rds_tcp_exit(void);
+void rds_tcp_tune(struct socket *sock);
+void rds_tcp_nonagle(struct socket *sock);
+void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn);
+void rds_tcp_restore_callbacks(struct socket *sock,
+                               struct rds_tcp_connection *tc);
+u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc);
+u32 rds_tcp_snd_una(struct rds_tcp_connection *tc);
+u64 rds_tcp_map_seq(struct rds_tcp_connection *tc, u32 seq);
+extern struct rds_transport rds_tcp_transport;
+
+/* tcp_connect.c */
+int rds_tcp_conn_connect(struct rds_connection *conn);
+void rds_tcp_conn_shutdown(struct rds_connection *conn);
+void rds_tcp_state_change(struct sock *sk);
+
+/* tcp_listen.c */
+int __init rds_tcp_listen_init(void);
+void rds_tcp_listen_stop(void);
+void rds_tcp_listen_data_ready(struct sock *sk, int bytes);
+
+/* tcp_recv.c */
+int __init rds_tcp_recv_init(void);
+void rds_tcp_recv_exit(void);
+void rds_tcp_data_ready(struct sock *sk, int bytes);
+int rds_tcp_recv(struct rds_connection *conn);
+void rds_tcp_inc_purge(struct rds_incoming *inc);
+void rds_tcp_inc_free(struct rds_incoming *inc);
+int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov,
+                             size_t size);
+
+/* tcp_send.c */
+void rds_tcp_xmit_prepare(struct rds_connection *conn);
+void rds_tcp_xmit_complete(struct rds_connection *conn);
+int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
+                 unsigned int hdr_off, unsigned int sg, unsigned int off);
+void rds_tcp_write_space(struct sock *sk);
+int rds_tcp_xmit_cong_map(struct rds_connection *conn,
+                          struct rds_cong_map *map, unsigned long offset);
+
+/* tcp_stats.c */
+DECLARE_PER_CPU(struct rds_tcp_statistics, rds_tcp_stats);
+#define rds_tcp_stats_inc(member) rds_stats_inc_which(rds_tcp_stats, member)
+unsigned int rds_tcp_stats_info_copy(struct rds_info_iterator *iter,
+                                     unsigned int avail);
+
+#endif