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-rw-r--r--src/vnet/tcp/tcp.h6
-rw-r--r--src/vnet/tcp/tcp_output.c27
2 files changed, 33 insertions, 0 deletions
diff --git a/src/vnet/tcp/tcp.h b/src/vnet/tcp/tcp.h
index b0c3ecc8c15..e4980dd64eb 100644
--- a/src/vnet/tcp/tcp.h
+++ b/src/vnet/tcp/tcp.h
@@ -130,6 +130,7 @@ extern timer_expiration_handler tcp_timer_retransmit_syn_handler;
_(FINRCVD, "FIN received") \
_(RATE_SAMPLE, "Conn does rate sampling") \
_(TRACK_BURST, "Track burst") \
+ _(ZERO_RWND_SENT, "Zero RWND sent") \
typedef enum _tcp_connection_flag_bits
{
@@ -412,6 +413,10 @@ tcp_cong_recovery_off (tcp_connection_t * tc)
tcp_fastrecovery_first_off (tc);
}
+#define tcp_zero_rwnd_sent(tc) (tc)->flags &= TCP_CONN_ZERO_RWND_SENT
+#define tcp_zero_rwnd_sent_on(tc) (tc)->flags |= TCP_CONN_ZERO_RWND_SENT
+#define tcp_zero_rwnd_sent_off(tc) (tc)->flags &= ~TCP_CONN_ZERO_RWND_SENT
+
typedef enum _tcp_error
{
#define tcp_error(n,s) TCP_ERROR_##n,
@@ -682,6 +687,7 @@ void tcp_do_fastretransmits (tcp_worker_ctx_t * wrk);
void tcp_program_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc);
void tcp_program_dupack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc);
void tcp_send_acks (tcp_worker_ctx_t * wrk);
+void tcp_send_window_update_ack (tcp_connection_t * tc);
/*
* Rate estimation
diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index d3c4ca4a314..7cf85c3bdce 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -505,6 +505,11 @@ tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
tcp_options_write ((u8 *) (th + 1), snd_opts);
vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
+
+ if (wnd == 0)
+ tcp_zero_rwnd_sent_on (tc);
+ else
+ tcp_zero_rwnd_sent_off (tc);
}
/**
@@ -1266,6 +1271,28 @@ tcp_timer_delack_handler (u32 index)
}
/**
+ * Send Window Update ACK,
+ * ensuring that it will be sent once, if RWND became non-zero,
+ * after zero RWND has been advertised in ACK before
+ */
+void
+tcp_send_window_update_ack (tcp_connection_t * tc)
+{
+ tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
+ u32 win;
+
+ if (tcp_zero_rwnd_sent (tc))
+ {
+ win = tcp_window_to_advertise (tc, tc->state);
+ if (win > 0)
+ {
+ tcp_zero_rwnd_sent_off (tc);
+ tcp_program_ack (wrk, tc);
+ }
+ }
+}
+
+/**
* Allocate a new buffer and build a new tcp segment
*
* @param wrk tcp worker