From 222e1f4160a5828bb2b5bf62716cd76664f6100b Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Sat, 16 Feb 2019 20:47:32 -0800 Subject: tcp: harden for high scale scenarios - Better handle buffer starvation scenarios - Handle case when both peers enter recovery due to packet loss. - Fix passive open establish cleanup Change-Id: I2f28baa2ff0383bb8f5f6d2452b49aa38ce69bce Signed-off-by: Florin Coras --- src/vnet/tcp/tcp_output.c | 43 ++++++++++++++++++++++++++++++------------- 1 file changed, 30 insertions(+), 13 deletions(-) (limited to 'src/vnet/tcp/tcp_output.c') diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c index 9f38851b026..725ffec0852 100644 --- a/src/vnet/tcp/tcp_output.c +++ b/src/vnet/tcp/tcp_output.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2016 Cisco and/or its affiliates. + * Copyright (c) 2016-2019 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: @@ -587,11 +587,6 @@ tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b) tcp_options_write ((u8 *) (th + 1), snd_opts); vnet_buffer (b)->tcp.connection_index = tc->c_c_index; - - /* Init retransmit timer. Use update instead of set because of - * retransmissions */ - tcp_retransmit_timer_force_update (tc); - TCP_EVT_DBG (TCP_EVT_SYNACK_SENT, tc); } always_inline void @@ -951,7 +946,10 @@ tcp_send_syn (tcp_connection_t * tc) tc->rto * TCP_TO_TIMER_TICK); if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) - return; + { + tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1); + return; + } b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); @@ -975,14 +973,20 @@ tcp_send_synack (tcp_connection_t * tc) vlib_buffer_t *b; u32 bi; + tcp_retransmit_timer_force_update (tc); + if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) - return; + { + tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1); + return; + } tc->rtt_ts = tcp_time_now_us (tc->c_thread_index); b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); tcp_make_synack (tc, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); + TCP_EVT_DBG (TCP_EVT_SYNACK_SENT, tc); } /** @@ -1050,6 +1054,9 @@ tcp_send_fin (tcp_connection_t * tc) tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1); if (fin_snt) tc->snd_nxt = tc->snd_una_max; + else + /* Make sure retransmit retries a fin not data */ + tc->flags |= TCP_CONN_FINSNT; return; } @@ -1195,7 +1202,10 @@ tcp_send_ack (tcp_connection_t * tc) u32 bi; if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) - return; + { + tcp_update_rcv_wnd (tc); + return; + } b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); tcp_make_ack (tc, b); @@ -1458,6 +1468,8 @@ tcp_rxt_timeout_cc (tcp_connection_t * tc) scoreboard_clear (&tc->sack_sb); tcp_cc_fastrecovery_exit (tc); } + else + tc->rcv_dupacks = 0; /* Start again from the beginning */ tc->cc_algo->congestion (tc); @@ -1504,7 +1516,7 @@ tcp_timer_retransmit_handler_i (u32 index, u8 is_syn) TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2); /* Lost FIN, retransmit and return */ - if (tcp_is_lost_fin (tc)) + if (tc->flags & TCP_CONN_FINSNT) { tcp_send_fin (tc); tc->rto_boff += 1; @@ -1553,7 +1565,7 @@ tcp_timer_retransmit_handler_i (u32 index, u8 is_syn) n_bytes = tcp_prepare_retransmit_segment (wrk, tc, 0, tc->snd_mss, &b); if (!n_bytes) { - tcp_retransmit_timer_force_update (tc); + tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1); return; } @@ -1591,7 +1603,10 @@ tcp_timer_retransmit_handler_i (u32 index, u8 is_syn) tc->rto * TCP_TO_TIMER_TICK); if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) - return; + { + tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1); + return; + } b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); @@ -1614,9 +1629,11 @@ tcp_timer_retransmit_handler_i (u32 index, u8 is_syn) tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX); tc->rtt_ts = 0; + tcp_retransmit_timer_force_update (tc); + if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) { - tcp_retransmit_timer_force_update (tc); + tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1); return; } -- cgit 1.2.3-korg