linux/net/rds/tcp.h
Sowmini Varadhan 335b48d980 RDS: TCP: Add/use rds_tcp_reset_callbacks to reset tcp socket safely
When rds_tcp_accept_one() has to replace the existing tcp socket
with a newer tcp socket (duelling-syn resolution), it must lock_sock()
to suppress the rds_tcp_data_recv() path while callbacks are being
changed.  Also, existing RDS datagram reassembly state must be reset,
so that the next datagram on the new socket  does not have corrupted
state. Similarly when resetting the newly accepted socket, appropriate
locks and synchronization is needed.

This commit ensures correct synchronization by invoking
kernel_sock_shutdown to reset a newly accepted sock, and by taking
appropriate lock_sock()s (for old and new sockets) when resetting
existing callbacks.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 15:10:15 -07:00

96 lines
2.9 KiB
C

#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;
/* t_conn_lock synchronizes the connection establishment between
* rds_tcp_accept_one and rds_tcp_conn_connect
*/
struct mutex t_conn_lock;
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 */
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_reset_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;
void rds_tcp_accept_work(struct sock *sk);
/* 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 */
struct socket *rds_tcp_listen_init(struct net *);
void rds_tcp_listen_stop(struct socket *);
void rds_tcp_listen_data_ready(struct sock *sk);
int rds_tcp_accept_one(struct socket *sock);
int rds_tcp_keepalive(struct socket *sock);
/* tcp_recv.c */
int rds_tcp_recv_init(void);
void rds_tcp_recv_exit(void);
void rds_tcp_data_ready(struct sock *sk);
int rds_tcp_recv(struct rds_connection *conn);
void rds_tcp_inc_free(struct rds_incoming *inc);
int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
/* 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);
/* 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