Hi,
Recently we found that we have to restore more parameters for tcp
sockets.
https://patchwork.kernel.org/patch/9144995/
As for your problem, criu saves and restores mss_clamp. Could you check
that it works for your case?
on dump:
static int tcp_stream_get_options(int sk, struct tcp_info *ti,
TcpStreamEntry *tse)
{
int ret;
socklen_t auxl;
int val;
auxl = sizeof(tse->mss_clamp);
ret = getsockopt(sk, SOL_TCP, TCP_MAXSEG, &tse->mss_clamp,
&auxl);
if (ret < 0)
goto err_sopt;
on restore:
pr_debug("Will set mss clamp to %u\n", tse->mss_clamp);
opts[onr].opt_code = TCPOPT_MAXSEG;
opts[onr].opt_val = tse->mss_clamp;
onr++;
if (setsockopt(sk, SOL_TCP, TCP_REPAIR_OPTIONS,
opts, onr * sizeof(struct tcp_repair_opt)) < 0)
{
pr_perror("Can't repair options");
return -1;
}
Thanks,
Andrew
On Tue, Jun 14, 2016 at 11:40:01AM +0000, Eggert, Lars wrote:
> On 2016-06-14, at 13:28, Pavel Emelyanov <xe...@virtuozzo.com> wrote:
> > Andrey (in Cc) has played with TCP_REPAIR recently, I guess he can know
> > something.
>
> Thanks for CC'ing him. We looked a little bit more into this:
>
> When TCP_REPAIR is on, tcp_connect() directly calls tcp_finish_connect()
> before returning, passing NULL for skb, which causes sk_rx_dst_set() to be
> bypassed. Later, when TCP_REPAIR is being turned off, do_tcp_setsockopt()
> just does tcp_send_window_probe(), but apparently all the "dst" stuff is
> being bypassed then also, so the mss remains at TCP_MSS_DEFAULT.
>
> Lars
