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" <[email protected]> Cc: Alexey Kuznetsov <[email protected]> Cc: James Morris <[email protected]> Cc: Hideaki YOSHIFUJI <[email protected]> Cc: Patrick McHardy <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Pavel Emelyanov <[email protected]> Cc: Cyrill Gorcunov <[email protected]> Signed-off-by: Andrey Vagin <[email protected]> --- 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
