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>

1 files changed, 13 insertions, 0 deletions

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 416dfa004cfb..c22920525e5d 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -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---