diff options
Diffstat (limited to 'src/vnet/tcp/tcp_newreno.c')
-rw-r--r-- | src/vnet/tcp/tcp_newreno.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/vnet/tcp/tcp_newreno.c b/src/vnet/tcp/tcp_newreno.c new file mode 100644 index 00000000..103fea4c --- /dev/null +++ b/src/vnet/tcp/tcp_newreno.c @@ -0,0 +1,107 @@ +/* + * Copyright (c) 2017 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: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <vnet/tcp/tcp.h> + +void +newreno_congestion (tcp_connection_t * tc) +{ + tc->ssthresh = clib_max (tcp_flight_size (tc) / 2, 2 * tc->snd_mss); +} + +void +newreno_recovered (tcp_connection_t * tc) +{ + tc->cwnd = tc->ssthresh; +} + +void +newreno_rcv_ack (tcp_connection_t * tc) +{ + if (tcp_in_slowstart (tc)) + { + tc->cwnd += clib_min (tc->snd_mss, tc->bytes_acked); + } + else + { + /* Round up to 1 if needed */ + tc->cwnd += clib_max ((tc->snd_mss * tc->snd_mss) / tc->cwnd, 1); + } +} + +void +newreno_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type) +{ + if (ack_type == TCP_CC_DUPACK) + { + if (!tcp_opts_sack_permitted (tc)) + tc->cwnd += tc->snd_mss; + } + else if (ack_type == TCP_CC_PARTIALACK) + { + /* RFC 6582 Sec. 3.2 */ + if (!tcp_opts_sack_permitted (&tc->rcv_opts)) + { + /* Deflate the congestion window by the amount of new data + * acknowledged by the Cumulative Acknowledgment field. + * If the partial ACK acknowledges at least one SMSS of new data, + * then add back SMSS bytes to the congestion window. This + * artificially inflates the congestion window in order to reflect + * the additional segment that has left the network. This "partial + * window deflation" attempts to ensure that, when fast recovery + * eventually ends, approximately ssthresh amount of data will be + * outstanding in the network.*/ + tc->cwnd = (tc->cwnd > tc->bytes_acked + tc->snd_mss) ? + tc->cwnd - tc->bytes_acked : tc->snd_mss; + if (tc->bytes_acked > tc->snd_mss) + tc->cwnd += tc->snd_mss; + } + } +} + +void +newreno_conn_init (tcp_connection_t * tc) +{ + tc->ssthresh = tc->snd_wnd; + tc->cwnd = tcp_initial_cwnd (tc); +} + +const static tcp_cc_algorithm_t tcp_newreno = { + .congestion = newreno_congestion, + .recovered = newreno_recovered, + .rcv_ack = newreno_rcv_ack, + .rcv_cong_ack = newreno_rcv_cong_ack, + .init = newreno_conn_init +}; + +clib_error_t * +newreno_init (vlib_main_t * vm) +{ + clib_error_t *error = 0; + + tcp_cc_algo_register (TCP_CC_NEWRENO, &tcp_newreno); + + return error; +} + +VLIB_INIT_FUNCTION (newreno_init); + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |