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-rw-r--r--include/net/tcp.h5
-rw-r--r--net/ipv4/tcp_input.c13
-rw-r--r--net/ipv4/tcp_output.c33
3 files changed, 22 insertions, 29 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 0d637e9..6fa8083 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -61,9 +61,6 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo);
*/
#define MAX_TCP_WINDOW 32767U
-/* Offer an initial receive window of 10 mss. */
-#define TCP_DEFAULT_INIT_RCVWND 10
-
/* Minimal accepted MSS. It is (60+60+8) - (20+20). */
#define TCP_MIN_MSS 88U
@@ -1047,6 +1044,8 @@ static inline void tcp_sack_reset(struct tcp_options_received *rx_opt)
rx_opt->num_sacks = 0;
}
+extern u32 tcp_default_init_rwnd(u32 mss);
+
/* Determine a window scaling and initial window to offer. */
extern void tcp_select_initial_window(int __space, __u32 mss,
__u32 *rcv_wnd, __u32 *window_clamp,
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 907311c..46271cdc 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -347,22 +347,13 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb)
}
/* 3. Tuning rcvbuf, when connection enters established state. */
-
static void tcp_fixup_rcvbuf(struct sock *sk)
{
u32 mss = tcp_sk(sk)->advmss;
- u32 icwnd = TCP_DEFAULT_INIT_RCVWND;
int rcvmem;
- /* Limit to 10 segments if mss <= 1460,
- * or 14600/mss segments, with a minimum of two segments.
- */
- if (mss > 1460)
- icwnd = max_t(u32, (1460 * TCP_DEFAULT_INIT_RCVWND) / mss, 2);
-
- rcvmem = 2 * SKB_TRUESIZE(mss + MAX_TCP_HEADER);
-
- rcvmem *= icwnd;
+ rcvmem = 2 * SKB_TRUESIZE(mss + MAX_TCP_HEADER) *
+ tcp_default_init_rwnd(mss);
if (sk->sk_rcvbuf < rcvmem)
sk->sk_rcvbuf = min(rcvmem, sysctl_tcp_rmem[2]);
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index ec335fa..3dd46ea 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -181,6 +181,21 @@ static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
}
+
+u32 tcp_default_init_rwnd(u32 mss)
+{
+ /* Initial receive window should be twice of TCP_INIT_CWND to
+ * enable proper sending of new unset data during fast recovery
+ * (RFC 3517, Section 4, NextSeg() rule (2)). Further place a
+ * limit when mss is larger than 1460.
+ */
+ u32 init_rwnd = TCP_INIT_CWND * 2;
+
+ if (mss > 1460)
+ init_rwnd = max((1460 * init_rwnd) / mss, 2U);
+ return init_rwnd;
+}
+
/* Determine a window scaling and initial window to offer.
* Based on the assumption that the given amount of space
* will be offered. Store the results in the tp structure.
@@ -230,22 +245,10 @@ void tcp_select_initial_window(int __space, __u32 mss,
}
}
- /* Set initial window to a value enough for senders starting with
- * initial congestion window of TCP_DEFAULT_INIT_RCVWND. Place
- * a limit on the initial window when mss is larger than 1460.
- */
if (mss > (1 << *rcv_wscale)) {
- int init_cwnd = TCP_DEFAULT_INIT_RCVWND;
- if (mss > 1460)
- init_cwnd =
- max_t(u32, (1460 * TCP_DEFAULT_INIT_RCVWND) / mss, 2);
- /* when initializing use the value from init_rcv_wnd
- * rather than the default from above
- */
- if (init_rcv_wnd)
- *rcv_wnd = min(*rcv_wnd, init_rcv_wnd * mss);
- else
- *rcv_wnd = min(*rcv_wnd, init_cwnd * mss);
+ if (!init_rcv_wnd) /* Use default unless specified otherwise */
+ init_rcv_wnd = tcp_default_init_rwnd(mss);
+ *rcv_wnd = min(*rcv_wnd, init_rcv_wnd * mss);
}
/* Set the clamp no higher than max representable value */
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