linux-kernel - [PATCH 1/3] tcp: allow to enable repair mode for sockets in any state

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 21 Mar 2014 17:32:59 +0400
From:	Andrey Vagin <avagin@...nvz.org>
To:	linux-kernel@...r.kernel.org
Cc:	criu@...nvz.org, netdev@...r.kernel.org,
	Andrey Vagin <avagin@...nvz.org>,
	"David S. Miller" <davem@...emloft.net>,
	Alexey Kuznetsov <kuznet@....inr.ac.ru>,
	James Morris <jmorris@...ei.org>,
	Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
	Patrick McHardy <kaber@...sh.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Pavel Emelyanov <xemul@...allels.com>,
	Cyrill Gorcunov <gorcunov@...nvz.org>
Subject: [PATCH 1/3] tcp: allow to enable repair mode for sockets in any state

The repair mode is used for dumping state of tcp connections
(sequence numbers, queues, options, etc).

Currently the repair mode can be enalbed only for sockets in the
TCP_ESTABLISHED state. If a socket in another state, its internal
state can not be dumped.

Same time there is no guarantee that a connection won't be in other
states when we are dumping it, thus to be able to dump and restore
such states we need to get rid of CLOSE,ESTABLISHED in-kernel
limitation.

I see nothing wrong to allow enabling of the repair mode for connected
sockets in any states.

Cc: "David S. Miller" <davem@...emloft.net>
Cc: Alexey Kuznetsov <kuznet@....inr.ac.ru>
Cc: James Morris <jmorris@...ei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>
Cc: Patrick McHardy <kaber@...sh.net>
Cc: Eric Dumazet <edumazet@...gle.com>
Cc: Pavel Emelyanov <xemul@...allels.com>
Cc: Cyrill Gorcunov <gorcunov@...nvz.org>
Signed-off-by: Andrey Vagin <avagin@...nvz.org>
---
 net/ipv4/tcp.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 97c8f56..267adb7 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1106,15 +1106,18 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	}
 
 	if (unlikely(tp->repair)) {
+		err = -EINVAL;
+		if (tp->repair_queue == TCP_NO_QUEUE)
+			goto out_err;
+
+		if (sk->sk_state != TCP_ESTABLISHED)
+			goto out_err;
+
 		if (tp->repair_queue == TCP_RECV_QUEUE) {
 			copied = tcp_send_rcvq(sk, msg, size);
 			goto out;
 		}
 
-		err = -EINVAL;
-		if (tp->repair_queue == TCP_NO_QUEUE)
-			goto out_err;
-
 		/* 'common' sending to sendq */
 	}
 
@@ -2375,7 +2378,7 @@ void tcp_sock_destruct(struct sock *sk)
 static inline bool tcp_can_repair_sock(const struct sock *sk)
 {
 	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
-		((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED));
+		(sk->sk_state != TCP_LISTEN);
 }
 
 static int tcp_repair_options_est(struct tcp_sock *tp,
-- 
1.8.5.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/