net: diag: Support destroying TCP sockets.

This implements SOCK_DESTROY for TCP sockets. It causes all
blocking calls on the socket to fail fast with ECONNABORTED and
causes a protocol close of the socket. It informs the other end
of the connection by sending a RST, i.e., initiating a TCP ABORT
as per RFC 793. ECONNABORTED was chosen for consistency with
FreeBSD.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lorenzo Colitti 2015-12-16 12:30:05 +09:00 committed by David S. Miller
parent 6eb5d2e08f
commit c1e64e298b
6 changed files with 68 additions and 0 deletions

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@ -1170,6 +1170,8 @@ void tcp_set_state(struct sock *sk, int state);
void tcp_done(struct sock *sk);
int tcp_abort(struct sock *sk, int err);
static inline void tcp_sack_reset(struct tcp_options_received *rx_opt)
{
rx_opt->dsack = 0;

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@ -436,6 +436,19 @@ config INET_UDP_DIAG
Support for UDP socket monitoring interface used by the ss tool.
If unsure, say Y.
config INET_DIAG_DESTROY
bool "INET: allow privileged process to administratively close sockets"
depends on INET_DIAG
default n
---help---
Provides a SOCK_DESTROY operation that allows privileged processes
(e.g., a connection manager or a network administration tool such as
ss) to close sockets opened by other processes. Closing a socket in
this way interrupts any blocking read/write/connect operations on
the socket and causes future socket calls to behave as if the socket
had been disconnected.
If unsure, say N.
menuconfig TCP_CONG_ADVANCED
bool "TCP: advanced congestion control"
---help---

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@ -3080,6 +3080,38 @@ void tcp_done(struct sock *sk)
}
EXPORT_SYMBOL_GPL(tcp_done);
int tcp_abort(struct sock *sk, int err)
{
if (!sk_fullsock(sk)) {
sock_gen_put(sk);
return -EOPNOTSUPP;
}
/* Don't race with userspace socket closes such as tcp_close. */
lock_sock(sk);
/* Don't race with BH socket closes such as inet_csk_listen_stop. */
local_bh_disable();
bh_lock_sock(sk);
if (!sock_flag(sk, SOCK_DEAD)) {
sk->sk_err = err;
/* This barrier is coupled with smp_rmb() in tcp_poll() */
smp_wmb();
sk->sk_error_report(sk);
if (tcp_need_reset(sk->sk_state))
tcp_send_active_reset(sk, GFP_ATOMIC);
tcp_done(sk);
}
bh_unlock_sock(sk);
local_bh_enable();
release_sock(sk);
sock_put(sk);
return 0;
}
EXPORT_SYMBOL_GPL(tcp_abort);
extern struct tcp_congestion_ops tcp_reno;
static __initdata unsigned long thash_entries;

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@ -10,6 +10,8 @@
*/
#include <linux/module.h>
#include <linux/net.h>
#include <linux/sock_diag.h>
#include <linux/inet_diag.h>
#include <linux/tcp.h>
@ -46,12 +48,29 @@ static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req);
}
#ifdef CONFIG_INET_DIAG_DESTROY
static int tcp_diag_destroy(struct sk_buff *in_skb,
const struct inet_diag_req_v2 *req)
{
struct net *net = sock_net(in_skb->sk);
struct sock *sk = inet_diag_find_one_icsk(net, &tcp_hashinfo, req);
if (IS_ERR(sk))
return PTR_ERR(sk);
return sock_diag_destroy(sk, ECONNABORTED);
}
#endif
static const struct inet_diag_handler tcp_diag_handler = {
.dump = tcp_diag_dump,
.dump_one = tcp_diag_dump_one,
.idiag_get_info = tcp_diag_get_info,
.idiag_type = IPPROTO_TCP,
.idiag_info_size = sizeof(struct tcp_info),
#ifdef CONFIG_INET_DIAG_DESTROY
.destroy = tcp_diag_destroy,
#endif
};
static int __init tcp_diag_init(void)

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@ -2342,6 +2342,7 @@ struct proto tcp_prot = {
.destroy_cgroup = tcp_destroy_cgroup,
.proto_cgroup = tcp_proto_cgroup,
#endif
.diag_destroy = tcp_abort,
};
EXPORT_SYMBOL(tcp_prot);

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@ -1890,6 +1890,7 @@ struct proto tcpv6_prot = {
.proto_cgroup = tcp_proto_cgroup,
#endif
.clear_sk = tcp_v6_clear_sk,
.diag_destroy = tcp_abort,
};
static const struct inet6_protocol tcpv6_protocol = {