linux-brain/net/rds/tcp.h
Rao Shoaib a3842219a6 RDS tcp loopback connection can hang
[ Upstream commit aced3ce57cd37b5ca332bcacd370d01f5a8c5371 ]

When TCP is used as transport and a program on the
system connects to RDS port 16385, connection is
accepted but denied per the rules of RDS. However,
RDS connections object is left in the list. Next
loopback connection will select that connection
object as it is at the head of list. The connection
attempt will hang as the connection object is set
to connect over TCP which is not allowed

The issue can be reproduced easily, use rds-ping
to ping a local IP address. After that use any
program like ncat to connect to the same IP
address and port 16385. This will hang so ctrl-c out.
Now try rds-ping, it will hang.

To fix the issue this patch adds checks to disallow
the connection object creation and destroys the
connection object.

Signed-off-by: Rao Shoaib <rao.shoaib@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-16 11:59:35 +02:00

101 lines
3.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#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;
bool t_tcp_node_detached;
struct rds_conn_path *t_cpath;
/* t_conn_path_lock synchronizes the connection establishment between
* rds_tcp_accept_one and rds_tcp_conn_path_connect
*/
struct mutex t_conn_path_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_conn_path *cp);
void rds_tcp_reset_callbacks(struct socket *sock, struct rds_conn_path *cp);
void rds_tcp_restore_callbacks(struct socket *sock,
struct rds_tcp_connection *tc);
u32 rds_tcp_write_seq(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);
int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
__u32 scope_id);
/* tcp_connect.c */
int rds_tcp_conn_path_connect(struct rds_conn_path *cp);
void rds_tcp_conn_path_shutdown(struct rds_conn_path *conn);
void rds_tcp_state_change(struct sock *sk);
/* tcp_listen.c */
struct socket *rds_tcp_listen_init(struct net *net, bool isv6);
void rds_tcp_listen_stop(struct socket *sock, struct work_struct *acceptor);
void rds_tcp_listen_data_ready(struct sock *sk);
int rds_tcp_accept_one(struct socket *sock);
int rds_tcp_keepalive(struct socket *sock);
void *rds_tcp_listen_sock_def_readable(struct net *net);
void rds_tcp_set_linger(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_path(struct rds_conn_path *cp);
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_path_prepare(struct rds_conn_path *cp);
void rds_tcp_xmit_path_complete(struct rds_conn_path *cp);
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