tcp: add an ability to dump and restore window parameters

[cascardo/linux.git] / net / ipv4 / tcp.c

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 5c7ed14..108ef2a 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2277,6 +2277,38 @@ static inline bool tcp_can_repair_sock(const struct sock *sk)
                ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_ESTABLISHED));
 }
 
+static int tcp_repair_set_window(struct tcp_sock *tp, char __user *optbuf, int len)
+{
+       struct tcp_repair_window opt;
+
+       if (!tp->repair)
+               return -EPERM;
+
+       if (len != sizeof(opt))
+               return -EINVAL;
+
+       if (copy_from_user(&opt, optbuf, sizeof(opt)))
+               return -EFAULT;
+
+       if (opt.max_window < opt.snd_wnd)
+               return -EINVAL;
+
+       if (after(opt.snd_wl1, tp->rcv_nxt + opt.rcv_wnd))
+               return -EINVAL;
+
+       if (after(opt.rcv_wup, tp->rcv_nxt))
+               return -EINVAL;
+
+       tp->snd_wl1     = opt.snd_wl1;
+       tp->snd_wnd     = opt.snd_wnd;
+       tp->max_window  = opt.max_window;
+
+       tp->rcv_wnd     = opt.rcv_wnd;
+       tp->rcv_wup     = opt.rcv_wup;
+
+       return 0;
+}
+
 static int tcp_repair_options_est(struct tcp_sock *tp,
                struct tcp_repair_opt __user *optbuf, unsigned int len)
 {
@@ -2604,6 +2636,9 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
                else
                        tp->tsoffset = val - tcp_time_stamp;
                break;
+       case TCP_REPAIR_WINDOW:
+               err = tcp_repair_set_window(tp, optval, optlen);
+               break;
        case TCP_NOTSENT_LOWAT:
                tp->notsent_lowat = val;
                sk->sk_write_space(sk);
@@ -2860,6 +2895,28 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
                        return -EINVAL;
                break;
 
+       case TCP_REPAIR_WINDOW: {
+               struct tcp_repair_window opt;
+
+               if (get_user(len, optlen))
+                       return -EFAULT;
+
+               if (len != sizeof(opt))
+                       return -EINVAL;
+
+               if (!tp->repair)
+                       return -EPERM;
+
+               opt.snd_wl1     = tp->snd_wl1;
+               opt.snd_wnd     = tp->snd_wnd;
+               opt.max_window  = tp->max_window;
+               opt.rcv_wnd     = tp->rcv_wnd;
+               opt.rcv_wup     = tp->rcv_wup;
+
+               if (copy_to_user(optval, &opt, len))
+                       return -EFAULT;
+               return 0;
+       }
        case TCP_QUEUE_SEQ:
                if (tp->repair_queue == TCP_SEND_QUEUE)
                        val = tp->write_seq;