linux/include/net/tcp_states.h
Guillaume Nault 91051f0039 tcp: Dump bound-only sockets in inet_diag.
Walk the hashinfo->bhash2 table so that inet_diag can dump TCP sockets
that are bound but haven't yet called connect() or listen().

The code is inspired by the ->lhash2 loop. However there's no manual
test of the source port, since this kind of filtering is already
handled by inet_diag_bc_sk(). Also, a maximum of 16 sockets are dumped
at a time, to avoid running with bh disabled for too long.

There's no TCP state for bound but otherwise inactive sockets. Such
sockets normally map to TCP_CLOSE. However, "ss -l", which is supposed
to only dump listening sockets, actually requests the kernel to dump
sockets in either the TCP_LISTEN or TCP_CLOSE states. To avoid dumping
bound-only sockets with "ss -l", we therefore need to define a new
pseudo-state (TCP_BOUND_INACTIVE) that user space will be able to set
explicitly.

With an IPv4, an IPv6 and an IPv6-only socket, bound respectively to
40000, 64000, 60000, an updated version of iproute2 could work as
follow:

  $ ss -t state bound-inactive
  Recv-Q   Send-Q     Local Address:Port       Peer Address:Port   Process
  0        0                0.0.0.0:40000           0.0.0.0:*
  0        0                   [::]:60000              [::]:*
  0        0                      *:64000                 *:*

Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/b3a84ae61e19c06806eea9c602b3b66e8f0cfc81.1701362867.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-04 14:45:26 -08:00

51 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Definitions for the TCP protocol sk_state field.
*/
#ifndef _LINUX_TCP_STATES_H
#define _LINUX_TCP_STATES_H
enum {
TCP_ESTABLISHED = 1,
TCP_SYN_SENT,
TCP_SYN_RECV,
TCP_FIN_WAIT1,
TCP_FIN_WAIT2,
TCP_TIME_WAIT,
TCP_CLOSE,
TCP_CLOSE_WAIT,
TCP_LAST_ACK,
TCP_LISTEN,
TCP_CLOSING, /* Now a valid state */
TCP_NEW_SYN_RECV,
TCP_BOUND_INACTIVE, /* Pseudo-state for inet_diag */
TCP_MAX_STATES /* Leave at the end! */
};
#define TCP_STATE_MASK 0xF
#define TCP_ACTION_FIN (1 << TCP_CLOSE)
enum {
TCPF_ESTABLISHED = (1 << TCP_ESTABLISHED),
TCPF_SYN_SENT = (1 << TCP_SYN_SENT),
TCPF_SYN_RECV = (1 << TCP_SYN_RECV),
TCPF_FIN_WAIT1 = (1 << TCP_FIN_WAIT1),
TCPF_FIN_WAIT2 = (1 << TCP_FIN_WAIT2),
TCPF_TIME_WAIT = (1 << TCP_TIME_WAIT),
TCPF_CLOSE = (1 << TCP_CLOSE),
TCPF_CLOSE_WAIT = (1 << TCP_CLOSE_WAIT),
TCPF_LAST_ACK = (1 << TCP_LAST_ACK),
TCPF_LISTEN = (1 << TCP_LISTEN),
TCPF_CLOSING = (1 << TCP_CLOSING),
TCPF_NEW_SYN_RECV = (1 << TCP_NEW_SYN_RECV),
TCPF_BOUND_INACTIVE = (1 << TCP_BOUND_INACTIVE),
};
#endif /* _LINUX_TCP_STATES_H */