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Commit c1e64e29 authored by Lorenzo Colitti's avatar Lorenzo Colitti Committed by David S. Miller
Browse files

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: default avatarLorenzo Colitti <lorenzo@google.com>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6eb5d2e0

include/net/tcp.h

+2 −0
Original line number Diff line number Diff line
@@ -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;

net/ipv4/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -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---

net/ipv4/tcp.c

+32 −0
Original line number Diff line number Diff line
@@ -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;

net/ipv4/tcp_diag.c

+19 −0
Original line number Diff line number Diff line
@@ -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)

net/ipv4/tcp_ipv4.c

+1 −0
Original line number Diff line number Diff line
@@ -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);