From d79b41e993981df80245b0e6d90eb691bdaae648 Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Sat, 4 Mar 2017 05:37:52 -0800 Subject: VPP-659 TCP improvements - builtin test echo server - fix SYN-ACK retransmit canceling - avoid sending spurious ACK if in LAST_ACK - improved client dummy test app - renamed tx fifo dequeuing and sending functions to avoid confusion - improved RST handling Change-Id: Ia14aad3df319540dcf6e6a4e18a9f8d423a4b83b Signed-off-by: Florin Coras Signed-off-by: Dave Barach --- src/vnet/tcp/tcp_input.c | 63 +++++++++++++++++++++++++++++++++--------------- 1 file changed, 44 insertions(+), 19 deletions(-) (limited to 'src/vnet/tcp/tcp_input.c') diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c index 0a907d0a..f19fbf87 100644 --- a/src/vnet/tcp/tcp_input.c +++ b/src/vnet/tcp/tcp_input.c @@ -274,10 +274,7 @@ tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0, /* 2nd: check the RST bit */ if (tcp_rst (th0)) { - /* Notify session that connection has been reset. Switch - * state to closed and await for session to do the cleanup. */ - stream_session_reset_notify (&tc0->connection); - tc0->state = TCP_STATE_CLOSED; + tcp_connection_reset (tc0); return -1; } @@ -1023,6 +1020,12 @@ tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node, tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index, my_thread_index); + if (PREDICT_FALSE (tc0 == 0)) + { + error0 = TCP_ERROR_INVALID_CONNECTION; + goto drop; + } + /* Checksum computed by ipx_local no need to compute again */ if (is_ip4) @@ -1072,12 +1075,12 @@ tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node, /* 8: check the FIN bit */ if (tcp_fin (th0)) { - /* Send ACK and enter CLOSE-WAIT */ - tcp_make_ack (tc0, b0); - tcp_connection_force_ack (tc0, b0); - next0 = tcp_next_output (tc0->c_is_ip4); + /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead + * wait for session to call close. To avoid lingering + * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */ tc0->state = TCP_STATE_CLOSE_WAIT; stream_session_disconnect_notify (&tc0->connection); + tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME); } drop: @@ -1468,7 +1471,7 @@ VLIB_REGISTER_NODE (tcp6_syn_sent_node) = VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv); /** - * Handles reception for all states except LISTEN, SYN-SEND and ESTABLISHED + * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED * as per RFC793 p. 64 */ always_inline uword @@ -1511,6 +1514,11 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, b0 = vlib_get_buffer (vm, bi0); tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index, my_thread_index); + if (PREDICT_FALSE (tc0 == 0)) + { + error0 = TCP_ERROR_INVALID_CONNECTION; + goto drop; + } /* Checksum computed by ipx_local no need to compute again */ @@ -1587,7 +1595,8 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, /* Shoulder tap the server */ stream_session_accept_notify (&tc0->connection); - tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN); + /* Reset SYN-ACK retransmit timer */ + tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT); break; case TCP_STATE_ESTABLISHED: /* We can get packets in established state here because they @@ -1602,9 +1611,14 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, * continue processing in that state. */ if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0)) goto drop; - tc0->state = TCP_STATE_FIN_WAIT_2; - /* Stop all timers, 2MSL will be set lower */ - tcp_connection_timers_reset (tc0); + + /* If FIN is ACKed */ + if (tc0->snd_una == tc0->snd_una_max) + { + tc0->state = TCP_STATE_FIN_WAIT_2; + /* Stop all timers, 2MSL will be set lower */ + tcp_connection_timers_reset (tc0); + } break; case TCP_STATE_FIN_WAIT_2: /* In addition to the processing for the ESTABLISHED state, if @@ -1639,7 +1653,17 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, if (!tcp_rcv_ack_is_acceptable (tc0, b0)) goto drop; - tcp_connection_del (tc0); + tc0->state = TCP_STATE_CLOSED; + + /* Don't delete the connection/session yet. Instead, wait a + * reasonable amount of time until the pipes are cleared. In + * particular, this makes sure that we won't have dead sessions + * when processing events on the tx path */ + tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME); + + /* Stop retransmit */ + tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT); + goto drop; break; @@ -1684,7 +1708,7 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, case TCP_STATE_SYN_RCVD: /* Send FIN-ACK notify app and enter CLOSE-WAIT */ tcp_connection_timers_reset (tc0); - tcp_make_finack (tc0, b0); + tcp_make_fin (tc0, b0); next0 = tcp_next_output (tc0->c_is_ip4); stream_session_disconnect_notify (&tc0->connection); tc0->state = TCP_STATE_CLOSE_WAIT; @@ -1697,12 +1721,12 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, case TCP_STATE_FIN_WAIT_1: tc0->state = TCP_STATE_TIME_WAIT; tcp_connection_timers_reset (tc0); - tcp_timer_set (tc0, TCP_TIMER_2MSL, TCP_2MSL_TIME); + tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME); break; case TCP_STATE_FIN_WAIT_2: /* Got FIN, send ACK! */ tc0->state = TCP_STATE_TIME_WAIT; - tcp_timer_set (tc0, TCP_TIMER_2MSL, TCP_2MSL_TIME); + tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME); tcp_make_ack (tc0, b0); next0 = tcp_next_output (is_ip4); break; @@ -1710,7 +1734,7 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait * timeout. */ - tcp_timer_update (tc0, TCP_TIMER_2MSL, TCP_2MSL_TIME); + tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME); break; } @@ -2113,6 +2137,7 @@ tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node, n_left_to_next -= 1; b0 = vlib_get_buffer (vm, bi0); + vnet_buffer (b0)->tcp.flags = 0; if (is_ip4) { @@ -2168,7 +2193,6 @@ tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node, /* Send reset */ next0 = TCP_INPUT_NEXT_RESET; error0 = TCP_ERROR_NO_LISTENER; - vnet_buffer (b0)->tcp.flags = 0; } b0->error = error0 ? node->errors[error0] : 0; @@ -2288,6 +2312,7 @@ do { \ _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); + _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); /* ACK or FIN-ACK to our FIN */ _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, -- cgit 1.2.3-korg