From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Colitti Subject: [PATCH v2 4/4] net: diag: Support destroying TCP sockets. Date: Wed, 18 Nov 2015 13:41:03 +0900 Message-ID: <1447821663-31246-4-git-send-email-lorenzo@google.com> References: <1447821663-31246-1-git-send-email-lorenzo@google.com> Cc: edumazet@google.com, ek@google.com, maze@google.com, dtor@google.com, tom@herbertland.com, Lorenzo Colitti To: netdev@vger.kernel.org Return-path: Received: from mail-pa0-f43.google.com ([209.85.220.43]:33315 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932080AbbKREl2 (ORCPT ); Tue, 17 Nov 2015 23:41:28 -0500 Received: by pabfh17 with SMTP id fh17so32746263pab.0 for ; Tue, 17 Nov 2015 20:41:28 -0800 (PST) In-Reply-To: <1447821663-31246-1-git-send-email-lorenzo@google.com> Sender: netdev-owner@vger.kernel.org List-ID: This implements SOCK_DESTROY for TCP sockets. It causes all blocking calls on the socket to fail fast with ETIMEDOUT, which is the same thing that would eventually happen if the socket was left stuck on an IP address that the host no longer has. Signed-off-by: Lorenzo Colitti --- net/ipv4/tcp_diag.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c index b316040..867159c 100644 --- a/net/ipv4/tcp_diag.c +++ b/net/ipv4/tcp_diag.c @@ -10,6 +10,7 @@ */ #include +#include #include #include @@ -46,12 +47,52 @@ 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); } +static int tcp_diag_destroy(struct sk_buff *in_skb, + const struct inet_diag_req_v2 *req) +{ + struct sock *sk; + struct net *net = sock_net(in_skb->sk); + + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + sk = inet_diag_find_one_icsk(net, &tcp_hashinfo, req); + if (IS_ERR(sk)) + return PTR_ERR(sk); + + 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)) { + smp_wmb(); /* Be consistent with tcp_reset */ + sk->sk_err = ETIMEDOUT; + sk->sk_error_report(sk); + tcp_done(sk); + } + + bh_unlock_sock(sk); + local_bh_enable(); + release_sock(sk); + sock_put(sk); + return 0; +} + 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), + .destroy = tcp_diag_destroy, }; static int __init tcp_diag_init(void) -- 2.6.0.rc2.230.g3dd15c0