/* * 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: * * 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 #include #include #include #include #include #include static char *tcp_error_strings[] = { #define tcp_error(n,s) s, #include #undef tcp_error }; /* All TCP nodes have the same outgoing arcs */ #define foreach_tcp_state_next \ _ (DROP4, "ip4-drop") \ _ (DROP6, "ip6-drop") \ _ (TCP4_OUTPUT, "tcp4-output") \ _ (TCP6_OUTPUT, "tcp6-output") typedef enum _tcp_established_next { #define _(s,n) TCP_ESTABLISHED_NEXT_##s, foreach_tcp_state_next #undef _ TCP_ESTABLISHED_N_NEXT, } tcp_established_next_t; typedef enum _tcp_rcv_process_next { #define _(s,n) TCP_RCV_PROCESS_NEXT_##s, foreach_tcp_state_next #undef _ TCP_RCV_PROCESS_N_NEXT, } tcp_rcv_process_next_t; typedef enum _tcp_syn_sent_next { #define _(s,n) TCP_SYN_SENT_NEXT_##s, foreach_tcp_state_next #undef _ TCP_SYN_SENT_N_NEXT, } tcp_syn_sent_next_t; typedef enum _tcp_listen_next { #define _(s,n) TCP_LISTEN_NEXT_##s, foreach_tcp_state_next #undef _ TCP_LISTEN_N_NEXT, } tcp_listen_next_t; /* Generic, state independent indices */ typedef enum _tcp_state_next { #define _(s,n) TCP_NEXT_##s, foreach_tcp_state_next #undef _ TCP_STATE_N_NEXT, } tcp_state_next_t; #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \ : TCP_NEXT_TCP6_OUTPUT) #define tcp_next_drop(is_ip4) (is_ip4 ? TCP_NEXT_DROP4 \ : TCP_NEXT_DROP6) /** * Validate segment sequence number. As per RFC793: * * Segment Receive Test * Length Window * ------- ------- ------------------------------------------- * 0 0 SEG.SEQ = RCV.NXT * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND * >0 0 not acceptable * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND * * This ultimately consists in checking if segment falls within the window. * The one important difference compared to RFC793 is that we use rcv_las, * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the * peer's reference when computing our receive window. * * This: * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las) * however, is too strict when we have retransmits. Instead we just check that * the seq is not beyond the right edge and that the end of the segment is not * less than the left edge. * * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so * use rcv_nxt in the right edge window test instead of rcv_las. * */ always_inline u8 tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq) { return (seq_geq (end_seq, tc->rcv_las) && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd)); } /** * RFC1323: Check against wrapped sequence numbers (PAWS). If we have * timestamp to echo and it's less than tsval_recent, drop segment * but still send an ACK in order to retain TCP's mechanism for detecting * and recovering from half-open connections * * Or at least that's what the theory says. It seems that this might not work * very well with packet reordering and fast retransmit. XXX */ always_inline int tcp_segment_check_paws (tcp_connection_t * tc) { return tcp_opts_tstamp (&tc->rcv_opts) && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent); } /** * Update tsval recent */ always_inline void tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end) { /* * RFC1323: If Last.ACK.sent falls within the range of sequence numbers * of an incoming segment: * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN * then the TSval from the segment is copied to TS.Recent; * otherwise, the TSval is ignored. */ if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las) && seq_leq (tc->rcv_las, seq_end)) { ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval)); tc->tsval_recent = tc->rcv_opts.tsval; tc->tsval_recent_age = tcp_time_now_w_thread (tc->c_thread_index); } } static void tcp_handle_rst (tcp_connection_t * tc) { switch (tc->rst_state) { case TCP_STATE_SYN_RCVD: /* Cleanup everything. App wasn't notified yet */ session_transport_delete_notify (&tc->connection); tcp_connection_cleanup (tc); break; case TCP_STATE_SYN_SENT: session_stream_connect_notify (&tc->connection, 1 /* fail */ ); tcp_connection_cleanup (tc); break; case TCP_STATE_ESTABLISHED: session_transport_reset_notify (&tc->connection); session_transport_closed_notify (&tc->connection); break; case TCP_STATE_CLOSE_WAIT: case TCP_STATE_FIN_WAIT_1: case TCP_STATE_FIN_WAIT_2: case TCP_STATE_CLOSING: case TCP_STATE_LAST_ACK: session_transport_closed_notify (&tc->connection); break; case TCP_STATE_CLOSED: case TCP_STATE_TIME_WAIT: break; default: TCP_DBG ("reset state: %u", tc->state); } } static void tcp_program_reset_ntf (tcp_worker_ctx_t * wrk, tcp_connection_t * tc) { if (!tcp_disconnect_pending (tc)) { tc->rst_state = tc->state; vec_add1 (wrk->pending_resets, tc->c_c_index); tcp_disconnect_pending_on (tc); } } /** * Handle reset packet * * Programs disconnect/reset notification that should be sent * later by calling @ref tcp_handle_disconnects */ static void tcp_rcv_rst (tcp_worker_ctx_t * wrk, tcp_connection_t * tc) { TCP_EVT (TCP_EVT_RST_RCVD, tc); switch (tc->state) { case TCP_STATE_SYN_RCVD: tcp_program_reset_ntf (wrk, tc); tcp_connection_set_state (tc, TCP_STATE_CLOSED); break; case TCP_STATE_SYN_SENT: /* Do not program ntf because the connection is half-open */ tcp_handle_rst (tc); break; case TCP_STATE_ESTABLISHED: tcp_connection_timers_reset (tc); tcp_cong_recovery_off (tc); tcp_program_reset_ntf (wrk, tc); tcp_connection_set_state (tc, TCP_STATE_CLOSED); tcp_program_cleanup (wrk, tc); break; case TCP_STATE_CLOSE_WAIT: case TCP_STATE_FIN_WAIT_1: case TCP_STATE_FIN_WAIT_2: case TCP_STATE_CLOSING: case TCP_STATE_LAST_ACK: tcp_connection_timers_reset (tc); tcp_cong_recovery_off (tc); tcp_program_reset_ntf (wrk, tc); /* Make sure we mark the session as closed. In some states we may * be still trying to send data */ tcp_connection_set_state (tc, TCP_STATE_CLOSED); tcp_program_cleanup (wrk, tc); break; case TCP_STATE_CLOSED: case TCP_STATE_TIME_WAIT: break; default: TCP_DBG ("reset state: %u", tc->state); } } /** * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19 * * It first verifies if segment has a wrapped sequence number (PAWS) and then * does the processing associated to the first four steps (ignoring security * and precedence): sequence number, rst bit and syn bit checks. * * @return 0 if segments passes validation. */ static int tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0, vlib_buffer_t * b0, tcp_header_t * th0, u32 * error0) { /* We could get a burst of RSTs interleaved with acks */ if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED)) { tcp_send_reset (tc0); *error0 = TCP_ERROR_CONNECTION_CLOSED; goto error; } if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0))) { *error0 = TCP_ERROR_SEGMENT_INVALID; goto error; } if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts, 0))) { *error0 = TCP_ERROR_OPTIONS; goto error; } if (PREDICT_FALSE (tcp_segment_check_paws (tc0))) { *error0 = TCP_ERROR_PAWS; TCP_EVT (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number, vnet_buffer (b0)->tcp.seq_end); /* If it just so happens that a segment updates tsval_recent for a * segment over 24 days old, invalidate tsval_recent. */ if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE, tcp_time_now_w_thread (tc0->c_thread_index))) { tc0->tsval_recent = tc0->rcv_opts.tsval; clib_warning ("paws failed: 24-day old segment"); } /* Drop after ack if not rst. Resets can fail paws check as per * RFC 7323 sec. 5.2: When an segment is received, it MUST NOT * be subjected to the PAWS check by verifying an acceptable value in * SEG.TSval */ else if (!tcp_rst (th0)) { tcp_program_ack (tc0); TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp); goto error; } } /* 1st: check sequence number */ if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number, vnet_buffer (b0)->tcp.seq_end)) { /* SYN/SYN-ACK retransmit */ if (tcp_syn (th0) && vnet_buffer (b0)->tcp.seq_number == tc0->rcv_nxt - 1) { tcp_options_parse (th0, &tc0->rcv_opts, 1); if (tc0->state == TCP_STATE_SYN_RCVD) { tcp_send_synack (tc0); TCP_EVT (TCP_EVT_SYN_RCVD, tc0, 0); *error0 = TCP_ERROR_SYNS_RCVD; } else { tcp_program_ack (tc0); TCP_EVT (TCP_EVT_SYNACK_RCVD, tc0); *error0 = TCP_ERROR_SYN_ACKS_RCVD; } goto error; } /* If our window is 0 and the packet is in sequence, let it pass * through for ack processing. It should be dropped later. */ if (tc0->rcv_wnd < tc0->snd_mss && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number) goto check_reset; /* If we entered recovery and peer did so as well, there's a chance that * dup acks won't be acceptable on either end because seq_end may be less * than rcv_las. This can happen if acks are lost in both directions. */ if (tcp_in_recovery (tc0) && seq_geq (vnet_buffer (b0)->tcp.seq_number, tc0->rcv_las - tc0->rcv_wnd) && seq_leq (vnet_buffer (b0)->tcp.seq_end, tc0->rcv_nxt + tc0->rcv_wnd)) goto check_reset; *error0 = TCP_ERROR_RCV_WND; /* If we advertised a zero rcv_wnd and the segment is in the past or the * next one that we expect, it is probably a window probe */ if ((tc0->flags & TCP_CONN_ZERO_RWND_SENT) && seq_lt (vnet_buffer (b0)->tcp.seq_end, tc0->rcv_las + tc0->rcv_opts.mss)) *error0 = TCP_ERROR_ZERO_RWND; tc0->errors.below_data_wnd += seq_lt (vnet_buffer (b0)->tcp.seq_end, tc0->rcv_las); /* If not RST, send dup ack */ if (!tcp_rst (th0)) { tcp_program_dupack (tc0); TCP_EVT (TCP_EVT_DUPACK_SENT, tc0, vnet_buffer (b0)->tcp); } goto error; check_reset: ; } /* 2nd: check the RST bit */ if (PREDICT_FALSE (tcp_rst (th0))) { tcp_rcv_rst (wrk, tc0); *error0 = TCP_ERROR_RST_RCVD; goto error; } /* 3rd: check security and precedence (skip) */ /* 4th: check the SYN bit (in window) */ if (PREDICT_FALSE (tcp_syn (th0))) { /* As per RFC5961 send challenge ack instead of reset */ tcp_program_ack (tc0); *error0 = TCP_ERROR_SPURIOUS_SYN; goto error; } /* If segment in window, save timestamp */ tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number, vnet_buffer (b0)->tcp.seq_end); return 0; error: return -1; } always_inline int tcp_rcv_ack_no_cc (tcp_connection_t * tc, vlib_buffer_t * b, u32 * error) { /* SND.UNA =< SEG.ACK =< SND.NXT */ if (!(seq_leq (tc->snd_una, vnet_buffer (b)->tcp.ack_number) && seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt))) { if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max) && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)) { tc->snd_nxt = vnet_buffer (b)->tcp.ack_number; goto acceptable; } *error = TCP_ERROR_ACK_INVALID; return -1; } acceptable: tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una; tc->snd_una = vnet_buffer (b)->tcp.ack_number; *error = TCP_ERROR_ACK_OK; return 0; } /** * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298 * * Note that although the original article, srtt and rttvar are scaled * to minimize round-off errors, here we don't. Instead, we rely on * better precision time measurements. * * TODO support us rtt resolution */ static void tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt) { int err, diff; if (tc->srtt != 0) { err = mrtt - tc->srtt; /* XXX Drop in RTT results in RTTVAR increase and bigger RTO. * The increase should be bound */ tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1); diff = (clib_abs (err) - (int) tc->rttvar) >> 2; tc->rttvar = clib_max ((int) tc->rttvar + diff, 1); } else { /* First measurement. */ tc->srtt = mrtt; tc->rttvar = mrtt >> 1; } } /** * Update RTT estimate and RTO timer * * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK * timing. Middle boxes are known to fiddle with TCP options so we * should give higher priority to ACK timing. * * This should be called only if previously sent bytes have been acked. * * return 1 if valid rtt 0 otherwise */ static int tcp_update_rtt (tcp_connection_t * tc, tcp_rate_sample_t * rs, u32 ack) { u32 mrtt = 0; /* Karn's rule, part 1. Don't use retransmitted segments to estimate * RTT because they're ambiguous. */ if (tcp_in_cong_recovery (tc)) { /* Accept rtt estimates for samples that have not been retransmitted */ if ((tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) && !(rs->flags & TCP_BTS_IS_RXT)) { mrtt = rs->rtt_time * THZ; goto estimate_rtt; } goto done; } if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq)) { f64 sample = tcp_time_now_us (tc->c_thread_index) - tc->rtt_ts; tc->mrtt_us = tc->mrtt_us + (sample - tc->mrtt_us) * 0.125; mrtt = clib_max ((u32) (sample * THZ), 1); /* Allow measuring of a new RTT */ tc->rtt_ts = 0; } /* As per RFC7323 TSecr can be used for RTTM only if the segment advances * snd_una, i.e., the left side of the send window: * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */ else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr) { u32 now = tcp_tstamp (tc); mrtt = clib_max (now - tc->rcv_opts.tsecr, 1); } estimate_rtt: /* Ignore dubious measurements */ if (mrtt == 0 || mrtt > TCP_RTT_MAX) goto done; tcp_estimate_rtt (tc, mrtt); done: /* If we got here something must've been ACKed so make sure boff is 0, * even if mrtt is not valid since we update the rto lower */ tc->rto_boff = 0; tcp_update_rto (tc); return 0; } static void tcp_estimate_initial_rtt (tcp_connection_t * tc) { u8 thread_index = vlib_num_workers ()? 1 : 0; int mrtt; if (tc->rtt_ts) { tc->mrtt_us = tcp_time_now_us (thread_index) - tc->rtt_ts; tc->mrtt_us = clib_max (tc->mrtt_us, 0.0001); mrtt = clib_max ((u32) (tc->mrtt_us * THZ), 1); tc->rtt_ts = 0; } else { mrtt = tcp_time_now_w_thread (thread_index) - tc->rcv_opts.tsecr; mrtt = clib_max (mrtt, 1); /* Due to retransmits we don't know the initial mrtt */ if (tc->rto_boff && mrtt > 1 * THZ) mrtt = 1 * THZ; tc->mrtt_us = (f64) mrtt *TCP_TICK; } if (mrtt > 0 && mrtt < TCP_RTT_MAX) tcp_estimate_rtt (tc, mrtt); tcp_update_rto (tc); } /** * Dequeue bytes for connections that have received acks in last burst */ static void tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk) { u32 thread_index = wrk->vm->thread_index; u32 *pending_deq_acked; tcp_connection_t *tc; int i; if (!vec_len (wrk->pending_deq_acked)) return; pending_deq_acked = wrk->pending_deq_acked; for (i = 0; i < vec_len (pending_deq_acked); i++) { tc = tcp_connection_get (pending_deq_acked[i], thread_index); tc->flags &= ~TCP_CONN_DEQ_PENDING; if (PREDICT_FALSE (!tc->burst_acked)) continue; /* Dequeue the newly ACKed bytes */ session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked); tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una); if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING)) { if (seq_leq (tc->psh_seq, tc->snd_una)) tc->flags &= ~TCP_CONN_PSH_PENDING; } if (tcp_is_descheduled (tc)) tcp_reschedule (tc); /* If everything has been acked, stop retransmit timer * otherwise update. */ tcp_retransmit_timer_update (&wrk->timer_wheel, tc); /* Update pacer based on our new cwnd estimate */ tcp_connection_tx_pacer_update (tc); tc->burst_acked = 0; } _vec_len (wrk->pending_deq_acked) = 0; } static void tcp_program_dequeue (tcp_worker_ctx_t * wrk, tcp_connection_t * tc) { if (!(tc->flags & TCP_CONN_DEQ_PENDING)) { vec_add1 (wrk->pending_deq_acked, tc->c_c_index); tc->flags |= TCP_CONN_DEQ_PENDING; } tc->burst_acked += tc->bytes_acked; } /** * Try to update snd_wnd based on feedback received from peer. * * If successful, and new window is 'effectively' 0, activate persist * timer. */ static void tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd) { /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */ if (seq_lt (tc->snd_wl1, seq) || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack))) { tc->snd_wnd = snd_wnd; tc->snd_wl1 = seq; tc->snd_wl2 = ack; TCP_EVT (TCP_EVT_SND_WND, tc); if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss)) { /* Set persist timer if not set and we just got 0 wnd */ if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST) && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); tcp_persist_timer_set (&wrk->timer_wheel, tc); } } else { if (PREDICT_FALSE (tcp_timer_is_active (tc, TCP_TIMER_PERSIST))) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); tcp_persist_timer_reset (&wrk->timer_wheel, tc); } if (PREDICT_FALSE (tcp_is_descheduled (tc))) tcp_reschedule (tc); if (PREDICT_FALSE (!tcp_in_recovery (tc) && tc->rto_boff > 0)) { tc->rto_boff = 0; tcp_update_rto (tc); } } } } /** * Init loss recovery/fast recovery. * * Triggered by dup acks as opposed to timer timeout. Note that cwnd is * updated in @ref tcp_cc_handle_event after fast retransmit */ static void tcp_cc_init_congestion (tcp_connection_t * tc) { tcp_fastrecovery_on (tc); tc->snd_congestion = tc->snd_nxt; tc->cwnd_acc_bytes = 0; tc->snd_rxt_bytes = 0; tc->rxt_delivered = 0; tc->prr_delivered = 0; tc->prr_start = tc->snd_una; tc->prev_ssthresh = tc->ssthresh; tc->prev_cwnd = tc->cwnd; tc->snd_rxt_ts = tcp_tstamp (tc); tcp_cc_congestion (tc); /* Post retransmit update cwnd to ssthresh and account for the * three segments that have left the network and should've been * buffered at the receiver XXX */ if (!tcp_opts_sack_permitted (&tc->rcv_opts)) tc->cwnd += 3 * tc->snd_mss; tc->fr_occurences += 1; TCP_EVT (TCP_EVT_CC_EVT, tc, 4); } static void tcp_cc_congestion_undo (tcp_connection_t * tc) { tc->cwnd = tc->prev_cwnd; tc->ssthresh = tc->prev_ssthresh; tcp_cc_undo_recovery (tc); ASSERT (tc->rto_boff == 0); TCP_EVT (TCP_EVT_CC_EVT, tc, 5); } static inline u8 tcp_cc_is_spurious_timeout_rxt (tcp_connection_t * tc) { return (tcp_in_recovery (tc) && tc->rto_boff == 1 && tc->snd_rxt_ts && tcp_opts_tstamp (&tc->rcv_opts) && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts)); } static inline u8 tcp_cc_is_spurious_retransmit (tcp_connection_t * tc) { return (tcp_cc_is_spurious_timeout_rxt (tc)); } static inline u8 tcp_should_fastrecover_sack (tcp_connection_t * tc) { return (tc->sack_sb.lost_bytes || ((TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes)); } static inline u8 tcp_should_fastrecover (tcp_connection_t * tc, u8 has_sack) { if (!has_sack) { /* If of of the two conditions lower hold, reset dupacks because * we're probably after timeout (RFC6582 heuristics). * If Cumulative ack does not cover more than congestion threshold, * and: * 1) The following doesn't hold: The congestion window is greater * than SMSS bytes and the difference between highest_ack * and prev_highest_ack is at most 4*SMSS bytes * 2) Echoed timestamp in the last non-dup ack does not equal the * stored timestamp */ if (seq_leq (tc->snd_una, tc->snd_congestion) && ((!(tc->cwnd > tc->snd_mss && tc->bytes_acked <= 4 * tc->snd_mss)) || (tc->rcv_opts.tsecr != tc->tsecr_last_ack))) { tc->rcv_dupacks = 0; return 0; } } return ((tc->rcv_dupacks == TCP_DUPACK_THRESHOLD) || tcp_should_fastrecover_sack (tc)); } static int tcp_cc_recover (tcp_connection_t * tc) { sack_scoreboard_hole_t *hole; u8 is_spurious = 0; ASSERT (tcp_in_cong_recovery (tc)); if (tcp_cc_is_spurious_retransmit (tc)) { tcp_cc_congestion_undo (tc); is_spurious = 1; } tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ ); tc->rcv_dupacks = 0; /* Previous recovery left us congested. Continue sending as part * of the current recovery event with an updated snd_congestion */ if (tc->sack_sb.sacked_bytes) { tc->snd_congestion = tc->snd_nxt; tcp_program_retransmit (tc); return is_spurious; } tc->rxt_delivered = 0; tc->snd_rxt_bytes = 0; tc->snd_rxt_ts = 0; tc->prr_delivered = 0; tc->rtt_ts = 0; tc->flags &= ~TCP_CONN_RXT_PENDING; hole = scoreboard_first_hole (&tc->sack_sb); if (hole && hole->start == tc->snd_una && hole->end == tc->snd_nxt) scoreboard_clear (&tc->sack_sb); if (!tcp_in_recovery (tc) && !is_spurious) tcp_cc_recovered (tc); tcp_fastrecovery_off (tc); tcp_fastrecovery_first_off (tc); tcp_recovery_off (tc); TCP_EVT (TCP_EVT_CC_EVT, tc, 3); ASSERT (tc->rto_boff == 0); ASSERT (!tcp_in_cong_recovery (tc)); ASSERT (tcp_scoreboard_is_sane_post_recovery (tc)); return is_spurious; } static void tcp_cc_update (tcp_connection_t * tc, tcp_rate_sample_t * rs) { ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc)); /* Congestion avoidance */ tcp_cc_rcv_ack (tc, rs); /* If a cumulative ack, make sure dupacks is 0 */ tc->rcv_dupacks = 0; /* When dupacks hits the threshold we only enter fast retransmit if * cumulative ack covers more than snd_congestion. Should snd_una * wrap this test may fail under otherwise valid circumstances. * Therefore, proactively update snd_congestion when wrap detected. */ if (PREDICT_FALSE (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked) && seq_gt (tc->snd_congestion, tc->snd_una))) tc->snd_congestion = tc->snd_una - 1; } /** * One function to rule them all ... and in the darkness bind them */ static void tcp_cc_handle_event (tcp_connection_t * tc, tcp_rate_sample_t * rs, u32 is_dack) { u8 has_sack = tcp_opts_sack_permitted (&tc->rcv_opts); /* If reneging, wait for timer based retransmits */ if (PREDICT_FALSE (tcp_is_lost_fin (tc) || tc->sack_sb.is_reneging)) return; /* * If not in recovery, figure out if we should enter */ if (!tcp_in_cong_recovery (tc)) { ASSERT (is_dack); tc->rcv_dupacks++; TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1); tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs); if (tcp_should_fastrecover (tc, has_sack)) { tcp_cc_init_congestion (tc); if (has_sack) scoreboard_init_rxt (&tc->sack_sb, tc->snd_una); tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ ); tcp_program_retransmit (tc); } return; } /* * Already in recovery */ /* * Process (re)transmit feedback. Output path uses this to decide how much * more data to release into the network */ if (has_sack) { if (!tc->bytes_acked && tc->sack_sb.rxt_sacked) tcp_fastrecovery_first_on (tc); tc->rxt_delivered += tc->sack_sb.rxt_sacked; tc->prr_delivered += tc->bytes_acked + tc->sack_sb.last_sacked_bytes - tc->sack_sb.last_bytes_delivered; } else { if (is_dack) { tc->rcv_dupacks += 1; TCP_EVT (TCP_EVT_DUPACK_RCVD, tc, 1); } tc->rxt_delivered = clib_min (tc->rxt_delivered + tc->bytes_acked, tc->snd_rxt_bytes); if (is_dack) tc->prr_delivered += clib_min (tc->snd_mss, tc->snd_nxt - tc->snd_una); else tc->prr_delivered += tc->bytes_acked - clib_min (tc->bytes_acked, tc->snd_mss * tc->rcv_dupacks); /* If partial ack, assume that the first un-acked segment was lost */ if (tc->bytes_acked || tc->rcv_dupacks == TCP_DUPACK_THRESHOLD) tcp_fastrecovery_first_on (tc); } /* * See if we can exit and stop retransmitting */ if (seq_geq (tc->snd_una, tc->snd_congestion)) { /* If spurious return, we've already updated everything */ if (tcp_cc_recover (tc)) { tc->tsecr_last_ack = tc->rcv_opts.tsecr; return; } /* Treat as congestion avoidance ack */ tcp_cc_rcv_ack (tc, rs); return; } tcp_program_retransmit (tc); /* * Notify cc of the event */ if (!tc->bytes_acked) { tcp_cc_rcv_cong_ack (tc, TCP_CC_DUPACK, rs); return; } /* RFC6675: If the incoming ACK is a cumulative acknowledgment, * reset dupacks to 0. Also needed if in congestion recovery */ tc->rcv_dupacks = 0; if (tcp_in_recovery (tc)) tcp_cc_rcv_ack (tc, rs); else tcp_cc_rcv_cong_ack (tc, TCP_CC_PARTIALACK, rs); } static void tcp_handle_old_ack (tcp_connection_t * tc, tcp_rate_sample_t * rs) { if (!tcp_in_cong_recovery (tc)) return; if (tcp_opts_sack_permitted (&tc->rcv_opts)) tcp_rcv_sacks (tc, tc->snd_una); tc->bytes_acked = 0; if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) tcp_bt_sample_delivery_rate (tc, rs); tcp_cc_handle_event (tc, rs, 1); } /** * Check if duplicate ack as per RFC5681 Sec. 2 */ always_inline u8 tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd, u32 prev_snd_una) { return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una) && seq_gt (tc->snd_nxt, tc->snd_una) && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number) && (prev_snd_wnd == tc->snd_wnd)); } /** * Checks if ack is a congestion control event. */ static u8 tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack) { /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are * defined to be 'duplicate' as well */ *is_dack = tc->sack_sb.last_sacked_bytes || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una); return (*is_dack || tcp_in_cong_recovery (tc)); } /** * Process incoming ACK */ static int tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b, tcp_header_t * th, u32 * error) { u32 prev_snd_wnd, prev_snd_una; tcp_rate_sample_t rs = { 0 }; u8 is_dack; TCP_EVT (TCP_EVT_CC_STAT, tc); /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */ if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt))) { /* We've probably entered recovery and the peer still has some * of the data we've sent. Update snd_nxt and accept the ack */ if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max) && seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)) { tc->snd_nxt = vnet_buffer (b)->tcp.ack_number; goto process_ack; } tc->errors.above_ack_wnd += 1; *error = TCP_ERROR_ACK_FUTURE; TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 0, vnet_buffer (b)->tcp.ack_number); return -1; } /* If old ACK, probably it's an old dupack */ if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))) { tc->errors.below_ack_wnd += 1; *error = TCP_ERROR_ACK_OLD; TCP_EVT (TCP_EVT_ACK_RCV_ERR, tc, 1, vnet_buffer (b)->tcp.ack_number); if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una - tc->rcv_wnd)) return -1; tcp_handle_old_ack (tc, &rs); /* Don't drop yet */ return 0; } process_ack: /* * Looks okay, process feedback */ if (tcp_opts_sack_permitted (&tc->rcv_opts)) tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number); prev_snd_wnd = tc->snd_wnd; prev_snd_una = tc->snd_una; tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number, vnet_buffer (b)->tcp.ack_number, clib_net_to_host_u16 (th->window) << tc->snd_wscale); tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una; tc->snd_una = vnet_buffer (b)->tcp.ack_number; tcp_validate_txf_size (tc, tc->bytes_acked); if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) tcp_bt_sample_delivery_rate (tc, &rs); if (tc->bytes_acked) { tcp_program_dequeue (wrk, tc); tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number); } TCP_EVT (TCP_EVT_ACK_RCVD, tc); /* * Check if we have congestion event */ if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack)) { tcp_cc_handle_event (tc, &rs, is_dack); tc->dupacks_in += is_dack; if (!tcp_in_cong_recovery (tc)) { *error = TCP_ERROR_ACK_OK; return 0; } *error = TCP_ERROR_ACK_DUP; if (vnet_buffer (b)->tcp.data_len || tcp_is_fin (th)) return 0; return -1; } /* * Update congestion control (slow start/congestion avoidance) */ tcp_cc_update (tc, &rs); *error = TCP_ERROR_ACK_OK; return 0; } static void tcp_program_disconnect (tcp_worker_ctx_t * wrk, tcp_connection_t * tc) { if (!tcp_disconnect_pending (tc)) { vec_add1 (wrk->pending_disconnects, tc->c_c_index); tcp_disconnect_pending_on (tc); } } static void tcp_handle_disconnects (tcp_worker_ctx_t * wrk) { u32 thread_index, *pending_disconnects, *pending_resets; tcp_connection_t *tc; int i; if (vec_len (wrk->pending_disconnects)) { thread_index = wrk->vm->thread_index; pending_disconnects = wrk->pending_disconnects; for (i = 0; i < vec_len (pending_disconnects); i++) { tc = tcp_connection_get (pending_disconnects[i], thread_index); tcp_disconnect_pending_off (tc); session_transport_closing_notify (&tc->connection); } _vec_len (wrk->pending_disconnects) = 0; } if (vec_len (wrk->pending_resets)) { thread_index = wrk->vm->thread_index; pending_resets = wrk->pending_resets; for (i = 0; i < vec_len (pending_resets); i++) { tc = tcp_connection_get (pending_resets[i], thread_index); tcp_disconnect_pending_off (tc); tcp_handle_rst (tc); } _vec_len (wrk->pending_resets) = 0; } } static void tcp_rcv_fin (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b, u32 * error) { /* Reject out-of-order fins */ if (vnet_buffer (b)->tcp.seq_end != tc->rcv_nxt) return; /* Account for the FIN and send ack */ tc->rcv_nxt += 1; tc->flags |= TCP_CONN_FINRCVD; tcp_program_ack (tc); /* Enter CLOSE-WAIT and notify session. To avoid lingering * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */ tcp_connection_set_state (tc, TCP_STATE_CLOSE_WAIT); tcp_program_disconnect (wrk, tc); tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time); TCP_EVT (TCP_EVT_FIN_RCVD, tc); *error = TCP_ERROR_FIN_RCVD; } /** Enqueue data for delivery to application */ static int tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b, u16 data_len) { int written, error = TCP_ERROR_ENQUEUED; ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt)); ASSERT (data_len); written = session_enqueue_stream_connection (&tc->connection, b, 0, 1 /* queue event */ , 1); tc->bytes_in += written; TCP_EVT (TCP_EVT_INPUT, tc, 0, data_len, written); /* Update rcv_nxt */ if (PREDICT_TRUE (written == data_len)) { tc->rcv_nxt += written; } /* If more data written than expected, account for out-of-order bytes. */ else if (written > data_len) { tc->rcv_nxt += written; TCP_EVT (TCP_EVT_CC_INPUT, tc, data_len, written); } else if (written > 0) { /* We've written something but FIFO is probably full now */ tc->rcv_nxt += written; error = TCP_ERROR_PARTIALLY_ENQUEUED; } else { /* Packet made it through for ack processing */ if (tc->rcv_wnd < tc->snd_mss) return TCP_ERROR_ZERO_RWND; return TCP_ERROR_FIFO_FULL; } /* Update SACK list if need be */ if (tcp_opts_sack_permitted (&tc->rcv_opts)) { /* Remove SACK blocks that have been delivered */ tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt); } return error; } /** Enqueue out-of-order data */ static int tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b, u16 data_len) { session_t *s0; int rv, offset; ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt)); ASSERT (data_len); /* Enqueue out-of-order data with relative offset */ rv = session_enqueue_stream_connection (&tc->connection, b, vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt, 0 /* queue event */ , 0); /* Nothing written */ if (rv) { TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, 0); return TCP_ERROR_FIFO_FULL; } TCP_EVT (TCP_EVT_INPUT, tc, 1, data_len, data_len); tc->bytes_in += data_len; /* Update SACK list if in use */ if (tcp_opts_sack_permitted (&tc->rcv_opts)) { ooo_segment_t *newest; u32 start, end; s0 = session_get (tc->c_s_index, tc->c_thread_index); /* Get the newest segment from the fifo */ newest = svm_fifo_newest_ooo_segment (s0->rx_fifo); if (newest) { offset = ooo_segment_offset_prod (s0->rx_fifo, newest); ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt); start = tc->rcv_nxt + offset; end = start + ooo_segment_length (s0->rx_fifo, newest); tcp_update_sack_list (tc, start, end); svm_fifo_newest_ooo_segment_reset (s0->rx_fifo); TCP_EVT (TCP_EVT_CC_SACKS, tc); } } return TCP_ERROR_ENQUEUED_OOO; } /** * Check if ACK could be delayed. If ack can be delayed, it should return * true for a full frame. If we're always acking return 0. */ always_inline int tcp_can_delack (tcp_connection_t * tc) { /* Send ack if ... */ if (TCP_ALWAYS_ACK /* just sent a rcv wnd 0 || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 */ /* constrained to send ack */ || (tc->flags & TCP_CONN_SNDACK) != 0 /* we're almost out of tx wnd */ || tcp_available_cc_snd_space (tc) < 4 * tc->snd_mss) return 0; return 1; } static int tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop) { u32 discard, first = b->current_length; vlib_main_t *vm = vlib_get_main (); /* Handle multi-buffer segments */ if (n_bytes_to_drop > b->current_length) { if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT)) return -1; do { discard = clib_min (n_bytes_to_drop, b->current_length); vlib_buffer_advance (b, discard); b = vlib_get_buffer (vm, b->next_buffer); n_bytes_to_drop -= discard; } while (n_bytes_to_drop); if (n_bytes_to_drop > first) b->total_length_not_including_first_buffer -= n_bytes_to_drop - first; } else vlib_buffer_advance (b, n_bytes_to_drop); vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop; return 0; } /** * Receive buffer for connection and handle acks * * It handles both in order or out-of-order data. */ static int tcp_segment_rcv (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b) { u32 error, n_bytes_to_drop, n_data_bytes; vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset); n_data_bytes = vnet_buffer (b)->tcp.data_len; ASSERT (n_data_bytes); tc->data_segs_in += 1; /* Handle out-of-order data */ if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt)) { /* Old sequence numbers allowed through because they overlapped * the rx window */ if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt)) { /* Completely in the past (possible retransmit). Ack * retransmissions since we may not have any data to send */ if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt)) { tcp_program_dupack (tc); tc->errors.below_data_wnd++; error = TCP_ERROR_SEGMENT_OLD; goto done; } /* Chop off the bytes in the past and see if what is left * can be enqueued in order */ n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number; n_data_bytes -= n_bytes_to_drop; vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt; if (tcp_buffer_discard_bytes (b, n_bytes_to_drop)) { error = TCP_ERROR_SEGMENT_OLD; goto done; } goto in_order; } /* RFC2581: Enqueue and send DUPACK for fast retransmit */ error = tcp_session_enqueue_ooo (tc, b, n_data_bytes); tcp_program_dupack (tc); TCP_EVT (TCP_EVT_DUPACK_SENT, tc, vnet_buffer (b)->tcp); tc->errors.above_data_wnd += seq_gt (vnet_buffer (b)->tcp.seq_end, tc->rcv_las + tc->rcv_wnd); goto done; } in_order: /* In order data, enqueue. Fifo figures out by itself if any out-of-order * segments can be enqueued after fifo tail offset changes. */ error = tcp_session_enqueue_data (tc, b, n_data_bytes); if (tcp_can_delack (tc)) { if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK)) tcp_timer_set (&wrk->timer_wheel, tc, TCP_TIMER_DELACK, tcp_cfg.delack_time); goto done; } tcp_program_ack (tc); done: return error; } typedef struct { tcp_header_t tcp_header; tcp_connection_t tcp_connection; } tcp_rx_trace_t; static u8 * format_tcp_rx_trace (u8 * s, va_list * args) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *); tcp_connection_t *tc = &t->tcp_connection; u32 indent = format_get_indent (s); s = format (s, "%U state %U\n%U%U", format_tcp_connection_id, tc, format_tcp_state, tc->state, format_white_space, indent, format_tcp_header, &t->tcp_header, 128); return s; } static u8 * format_tcp_rx_trace_short (u8 * s, va_list * args) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *); s = format (s, "%d -> %d (%U)", clib_net_to_host_u16 (t->tcp_header.dst_port), clib_net_to_host_u16 (t->tcp_header.src_port), format_tcp_state, t->tcp_connection.state); return s; } static void tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0, tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4) { if (tc0) { clib_memcpy_fast (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection)); } else { th0 = tcp_buffer_hdr (b0); } clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header)); } static void tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, u8 is_ip4) { u32 *from, n_left; n_left = frame->n_vectors; from = vlib_frame_vector_args (frame); while (n_left >= 1) { tcp_connection_t *tc0; tcp_rx_trace_t *t0; tcp_header_t *th0; vlib_buffer_t *b0; u32 bi0; bi0 = from[0]; b0 = vlib_get_buffer (vm, bi0); if (b0->flags & VLIB_BUFFER_IS_TRACED) { t0 = vlib_add_trace (vm, node, b0, sizeof (*t0)); tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index, vm->thread_index); th0 = tcp_buffer_hdr (b0); tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4); } from += 1; n_left -= 1; } } always_inline void tcp_node_inc_counter_i (vlib_main_t * vm, u32 tcp4_node, u32 tcp6_node, u8 is_ip4, u32 evt, u32 val) { if (is_ip4) vlib_node_increment_counter (vm, tcp4_node, evt, val); else vlib_node_increment_counter (vm, tcp6_node, evt, val); } #define tcp_maybe_inc_counter(node_id, err, count) \ { \ if (next0 != tcp_next_drop (is_ip4)) \ tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \ tcp6_##node_id##_node.index, is_ip4, err, \ 1); \ } #define tcp_inc_counter(node_id, err, count) \ tcp_node_inc_counter_i (vm, tcp4_##node_id##_node.index, \ tcp6_##node_id##_node.index, is_ip4, \ err, count) #define tcp_maybe_inc_err_counter(cnts, err) \ { \ cnts[err] += (next0 != tcp_next_drop (is_ip4)); \ } #define tcp_inc_err_counter(cnts, err, val) \ { \ cnts[err] += val; \ } #define tcp_store_err_counters(node_id, cnts) \ { \ int i; \ for (i = 0; i < TCP_N_ERROR; i++) \ if (cnts[i]) \ tcp_inc_counter(node_id, i, cnts[i]); \ } always_inline uword tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, int is_ip4) { u32 thread_index = vm->thread_index, errors = 0; tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); u32 n_left_from, *from, *first_buffer; u16 err_counters[TCP_N_ERROR] = { 0 }; if (node->flags & VLIB_NODE_FLAG_TRACE) tcp_established_trace_frame (vm, node, frame, is_ip4); first_buffer = from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; while (n_left_from > 0) { u32 bi0, error0 = TCP_ERROR_ACK_OK; vlib_buffer_t *b0; tcp_header_t *th0; tcp_connection_t *tc0; if (n_left_from > 1) { vlib_buffer_t *pb; pb = vlib_get_buffer (vm, from[1]); vlib_prefetch_buffer_header (pb, LOAD); CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD); } bi0 = from[0]; from += 1; n_left_from -= 1; b0 = vlib_get_buffer (vm, bi0); tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index, thread_index); if (PREDICT_FALSE (tc0 == 0)) { error0 = TCP_ERROR_INVALID_CONNECTION; goto done; } th0 = tcp_buffer_hdr (b0); /* TODO header prediction fast path */ /* 1-4: check SEQ, RST, SYN */ if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, th0, &error0))) { TCP_EVT (TCP_EVT_SEG_INVALID, tc0, vnet_buffer (b0)->tcp); goto done; } /* 5: check the ACK field */ if (PREDICT_FALSE (tcp_rcv_ack (wrk, tc0, b0, th0, &error0))) goto done; /* 6: check the URG bit TODO */ /* 7: process the segment text */ if (vnet_buffer (b0)->tcp.data_len) error0 = tcp_segment_rcv (wrk, tc0, b0); /* 8: check the FIN bit */ if (PREDICT_FALSE (tcp_is_fin (th0))) tcp_rcv_fin (wrk, tc0, b0, &error0); done: tcp_inc_err_counter (err_counters, error0, 1); } errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP, thread_index); err_counters[TCP_ERROR_MSG_QUEUE_FULL] = errors; tcp_store_err_counters (established, err_counters); tcp_handle_postponed_dequeues (wrk); tcp_handle_disconnects (wrk); vlib_buffer_free (vm, first_buffer, frame->n_vectors); return frame->n_vectors; } VLIB_NODE_FN (tcp4_established_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ ); } VLIB_NODE_FN (tcp6_established_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp4_established_node) = { .name = "tcp4-established", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_ESTABLISHED_N_NEXT, .next_nodes = { #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n, foreach_tcp_state_next #undef _ }, .format_trace = format_tcp_rx_trace_short, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp6_established_node) = { .name = "tcp6-established", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_ESTABLISHED_N_NEXT, .next_nodes = { #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n, foreach_tcp_state_next #undef _ }, .format_trace = format_tcp_rx_trace_short, }; /* *INDENT-ON* */ static u8 tcp_lookup_is_valid (tcp_connection_t * tc, vlib_buffer_t * b, tcp_header_t * hdr) { transport_connection_t *tmp = 0; u64 handle; if (!tc) return 1; /* Proxy case */ if (tc->c_lcl_port == 0 && tc->state == TCP_STATE_LISTEN) return 1; u8 is_ip_valid = 0, val_l, val_r; if (tc->connection.is_ip4) { ip4_header_t *ip4_hdr = (ip4_header_t *) vlib_buffer_get_current (b); val_l = !ip4_address_compare (&ip4_hdr->dst_address, &tc->connection.lcl_ip.ip4); val_l = val_l || ip_is_zero (&tc->connection.lcl_ip, 1); val_r = !ip4_address_compare (&ip4_hdr->src_address, &tc->connection.rmt_ip.ip4); val_r = val_r || tc->state == TCP_STATE_LISTEN; is_ip_valid = val_l && val_r; } else { ip6_header_t *ip6_hdr = (ip6_header_t *) vlib_buffer_get_current (b); val_l = !ip6_address_compare (&ip6_hdr->dst_address, &tc->connection.lcl_ip.ip6); val_l = val_l || ip_is_zero (&tc->connection.lcl_ip, 0); val_r = !ip6_address_compare (&ip6_hdr->src_address, &tc->connection.rmt_ip.ip6); val_r = val_r || tc->state == TCP_STATE_LISTEN; is_ip_valid = val_l && val_r; } u8 is_valid = (tc->c_lcl_port == hdr->dst_port && (tc->state == TCP_STATE_LISTEN || tc->c_rmt_port == hdr->src_port) && is_ip_valid); if (!is_valid) { handle = session_lookup_half_open_handle (&tc->connection); tmp = session_lookup_half_open_connection (handle & 0xFFFFFFFF, tc->c_proto, tc->c_is_ip4); if (tmp) { if (tmp->lcl_port == hdr->dst_port && tmp->rmt_port == hdr->src_port) { TCP_DBG ("half-open is valid!"); is_valid = 1; } } } return is_valid; } /** * Lookup transport connection */ static tcp_connection_t * tcp_lookup_connection (u32 fib_index, vlib_buffer_t * b, u8 thread_index, u8 is_ip4) { tcp_header_t *tcp; transport_connection_t *tconn; tcp_connection_t *tc; u8 is_filtered = 0; if (is_ip4) { ip4_header_t *ip4; ip4 = vlib_buffer_get_current (b); tcp = ip4_next_header (ip4); tconn = session_lookup_connection_wt4 (fib_index, &ip4->dst_address, &ip4->src_address, tcp->dst_port, tcp->src_port, TRANSPORT_PROTO_TCP, thread_index, &is_filtered); tc = tcp_get_connection_from_transport (tconn); ASSERT (tcp_lookup_is_valid (tc, b, tcp)); } else { ip6_header_t *ip6; ip6 = vlib_buffer_get_current (b); tcp = ip6_next_header (ip6); tconn = session_lookup_connection_wt6 (fib_index, &ip6->dst_address, &ip6->src_address, tcp->dst_port, tcp->src_port, TRANSPORT_PROTO_TCP, thread_index, &is_filtered); tc = tcp_get_connection_from_transport (tconn); ASSERT (tcp_lookup_is_valid (tc, b, tcp)); } return tc; } static tcp_connection_t * tcp_lookup_listener (vlib_buffer_t * b, u32 fib_index, int is_ip4) { session_t *s; if (is_ip4) { ip4_header_t *ip4 = vlib_buffer_get_current (b); tcp_header_t *tcp = tcp_buffer_hdr (b); s = session_lookup_listener4 (fib_index, &ip4->dst_address, tcp->dst_port, TRANSPORT_PROTO_TCP, 1); } else { ip6_header_t *ip6 = vlib_buffer_get_current (b); tcp_header_t *tcp = tcp_buffer_hdr (b); s = session_lookup_listener6 (fib_index, &ip6->dst_address, tcp->dst_port, TRANSPORT_PROTO_TCP, 1); } if (PREDICT_TRUE (s != 0)) return tcp_get_connection_from_transport (transport_get_listener (TRANSPORT_PROTO_TCP, s->connection_index)); else return 0; } always_inline void tcp_check_tx_offload (tcp_connection_t * tc, int is_ipv4) { vnet_main_t *vnm = vnet_get_main (); const dpo_id_t *dpo; const load_balance_t *lb; vnet_hw_interface_t *hw_if; u32 sw_if_idx, lb_idx; if (is_ipv4) { ip4_address_t *dst_addr = &(tc->c_rmt_ip.ip4); lb_idx = ip4_fib_forwarding_lookup (tc->c_fib_index, dst_addr); } else { ip6_address_t *dst_addr = &(tc->c_rmt_ip.ip6); lb_idx = ip6_fib_table_fwding_lookup (tc->c_fib_index, dst_addr); } lb = load_balance_get (lb_idx); if (PREDICT_FALSE (lb->lb_n_buckets > 1)) return; dpo = load_balance_get_bucket_i (lb, 0); sw_if_idx = dpo_get_urpf (dpo); if (PREDICT_FALSE (sw_if_idx == ~0)) return; hw_if = vnet_get_sup_hw_interface (vnm, sw_if_idx); if (hw_if->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) tc->cfg_flags |= TCP_CFG_F_TSO; } always_inline uword tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame, int is_ip4) { u32 n_left_from, *from, *first_buffer, errors = 0; u32 my_thread_index = vm->thread_index; tcp_worker_ctx_t *wrk = tcp_get_worker (my_thread_index); from = first_buffer = vlib_frame_vector_args (from_frame); n_left_from = from_frame->n_vectors; while (n_left_from > 0) { u32 bi0, ack0, seq0, error0 = TCP_ERROR_NONE; tcp_connection_t *tc0, *new_tc0; tcp_header_t *tcp0 = 0; tcp_rx_trace_t *t0; vlib_buffer_t *b0; bi0 = from[0]; from += 1; n_left_from -= 1; b0 = vlib_get_buffer (vm, bi0); tc0 = tcp_half_open_connection_get (vnet_buffer (b0)->tcp.connection_index); if (PREDICT_FALSE (tc0 == 0)) { error0 = TCP_ERROR_INVALID_CONNECTION; goto drop; } /* Half-open completed recently but the connection was't removed * yet by the owning thread */ if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE)) { /* Make sure the connection actually exists */ ASSERT (tcp_lookup_connection (tc0->c_fib_index, b0, my_thread_index, is_ip4)); error0 = TCP_ERROR_SPURIOUS_SYN_ACK; goto drop; } ack0 = vnet_buffer (b0)->tcp.ack_number; seq0 = vnet_buffer (b0)->tcp.seq_number; tcp0 = tcp_buffer_hdr (b0); /* Crude check to see if the connection handle does not match * the packet. Probably connection just switched to established */ if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port || tcp0->src_port != tc0->c_rmt_port)) { error0 = TCP_ERROR_INVALID_CONNECTION; goto drop; } if (PREDICT_FALSE (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0))) { error0 = TCP_ERROR_SEGMENT_INVALID; goto drop; } /* SYNs consume sequence numbers */ vnet_buffer (b0)->tcp.seq_end += tcp_is_syn (tcp0); /* * 1. check the ACK bit */ /* * If the ACK bit is set * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless * the RST bit is set, if so drop the segment and return) * * and discard the segment. Return. * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable. */ if (tcp_ack (tcp0)) { if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt)) { if (!tcp_rst (tcp0)) tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4); error0 = TCP_ERROR_RCV_WND; goto drop; } /* Make sure ACK is valid */ if (seq_gt (tc0->snd_una, ack0)) { error0 = TCP_ERROR_ACK_INVALID; goto drop; } } /* * 2. check the RST bit */ if (tcp_rst (tcp0)) { /* If ACK is acceptable, signal client that peer is not * willing to accept connection and drop connection*/ if (tcp_ack (tcp0)) tcp_rcv_rst (wrk, tc0); error0 = TCP_ERROR_RST_RCVD; goto drop; } /* * 3. check the security and precedence (skipped) */ /* * 4. check the SYN bit */ /* No SYN flag. Drop. */ if (!tcp_syn (tcp0)) { error0 = TCP_ERROR_SEGMENT_INVALID; goto drop; } /* Parse options */ if (tcp_options_parse (tcp0, &tc0->rcv_opts, 1)) { error0 = TCP_ERROR_OPTIONS; goto drop; } /* Valid SYN or SYN-ACK. Move connection from half-open pool to * current thread pool. */ new_tc0 = tcp_connection_alloc_w_base (my_thread_index, tc0); new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end; new_tc0->irs = seq0; new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID; new_tc0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX]; if (tcp_opts_tstamp (&new_tc0->rcv_opts)) { new_tc0->tsval_recent = new_tc0->rcv_opts.tsval; new_tc0->tsval_recent_age = tcp_time_now (); } if (tcp_opts_wscale (&new_tc0->rcv_opts)) new_tc0->snd_wscale = new_tc0->rcv_opts.wscale; else new_tc0->rcv_wscale = 0; new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window) << new_tc0->snd_wscale; new_tc0->snd_wl1 = seq0; new_tc0->snd_wl2 = ack0; tcp_connection_init_vars (new_tc0); /* SYN-ACK: See if we can switch to ESTABLISHED state */ if (PREDICT_TRUE (tcp_ack (tcp0))) { /* Our SYN is ACKed: we have iss < ack = snd_una */ /* TODO Dequeue acknowledged segments if we support Fast Open */ new_tc0->snd_una = ack0; new_tc0->state = TCP_STATE_ESTABLISHED; /* Make sure las is initialized for the wnd computation */ new_tc0->rcv_las = new_tc0->rcv_nxt; /* Notify app that we have connection. If session layer can't * allocate session send reset */ if (session_stream_connect_notify (&new_tc0->connection, SESSION_E_NONE)) { tcp_send_reset_w_pkt (new_tc0, b0, my_thread_index, is_ip4); tcp_connection_cleanup (new_tc0); error0 = TCP_ERROR_CREATE_SESSION_FAIL; goto cleanup_ho; } new_tc0->tx_fifo_size = transport_tx_fifo_size (&new_tc0->connection); /* Update rtt with the syn-ack sample */ tcp_estimate_initial_rtt (new_tc0); TCP_EVT (TCP_EVT_SYNACK_RCVD, new_tc0); error0 = TCP_ERROR_SYN_ACKS_RCVD; } /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */ else { new_tc0->state = TCP_STATE_SYN_RCVD; /* Notify app that we have connection */ if (session_stream_connect_notify (&new_tc0->connection, SESSION_E_NONE)) { tcp_connection_cleanup (new_tc0); tcp_send_reset_w_pkt (tc0, b0, my_thread_index, is_ip4); TCP_EVT (TCP_EVT_RST_SENT, tc0); error0 = TCP_ERROR_CREATE_SESSION_FAIL; goto cleanup_ho; } new_tc0->tx_fifo_size = transport_tx_fifo_size (&new_tc0->connection); new_tc0->rtt_ts = 0; tcp_init_snd_vars (new_tc0); tcp_send_synack (new_tc0); error0 = TCP_ERROR_SYNS_RCVD; goto cleanup_ho; } if (!(new_tc0->cfg_flags & TCP_CFG_F_NO_TSO)) tcp_check_tx_offload (new_tc0, is_ip4); /* Read data, if any */ if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len)) { clib_warning ("rcvd data in syn-sent"); error0 = tcp_segment_rcv (wrk, new_tc0, b0); if (error0 == TCP_ERROR_ACK_OK) error0 = TCP_ERROR_SYN_ACKS_RCVD; } else { /* Send ack now instead of programming it because connection was * just established and it's not optional. */ tcp_send_ack (new_tc0); } cleanup_ho: /* If this is not the owning thread, wait for syn retransmit to * expire and cleanup then */ if (tcp_half_open_connection_cleanup (tc0)) tc0->flags |= TCP_CONN_HALF_OPEN_DONE; drop: tcp_inc_counter (syn_sent, error0, 1); if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0)) { t0 = vlib_add_trace (vm, node, b0, sizeof (*t0)); clib_memcpy_fast (&t0->tcp_header, tcp0, sizeof (t0->tcp_header)); clib_memcpy_fast (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection)); } } errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP, my_thread_index); tcp_inc_counter (syn_sent, TCP_ERROR_MSG_QUEUE_FULL, errors); vlib_buffer_free (vm, first_buffer, from_frame->n_vectors); tcp_handle_disconnects (wrk); return from_frame->n_vectors; } VLIB_NODE_FN (tcp4_syn_sent_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ ); } VLIB_NODE_FN (tcp6_syn_sent_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp4_syn_sent_node) = { .name = "tcp4-syn-sent", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_SYN_SENT_N_NEXT, .next_nodes = { #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n, foreach_tcp_state_next #undef _ }, .format_trace = format_tcp_rx_trace_short, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp6_syn_sent_node) = { .name = "tcp6-syn-sent", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_SYN_SENT_N_NEXT, .next_nodes = { #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n, foreach_tcp_state_next #undef _ }, .format_trace = format_tcp_rx_trace_short, }; /* *INDENT-ON* */ /** * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED * as per RFC793 p. 64 */ always_inline uword tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame, int is_ip4) { u32 thread_index = vm->thread_index, errors = 0, *first_buffer; tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); u32 n_left_from, *from, max_dequeue; from = first_buffer = vlib_frame_vector_args (from_frame); n_left_from = from_frame->n_vectors; while (n_left_from > 0) { u32 bi0, error0 = TCP_ERROR_NONE; tcp_header_t *tcp0 = 0; tcp_connection_t *tc0; vlib_buffer_t *b0; u8 is_fin0; bi0 = from[0]; from += 1; n_left_from -= 1; b0 = vlib_get_buffer (vm, bi0); tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index, thread_index); if (PREDICT_FALSE (tc0 == 0)) { error0 = TCP_ERROR_INVALID_CONNECTION; goto drop; } tcp0 = tcp_buffer_hdr (b0); is_fin0 = tcp_is_fin (tcp0); if (CLIB_DEBUG) { if (!(tc0->connection.flags & TRANSPORT_CONNECTION_F_NO_LOOKUP)) { tcp_connection_t *tmp; tmp = tcp_lookup_connection (tc0->c_fib_index, b0, thread_index, is_ip4); if (tmp->state != tc0->state) { if (tc0->state != TCP_STATE_CLOSED) clib_warning ("state changed"); goto drop; } } } /* * Special treatment for CLOSED */ if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED)) { error0 = TCP_ERROR_CONNECTION_CLOSED; goto drop; } /* * For all other states (except LISTEN) */ /* 1-4: check SEQ, RST, SYN */ if (PREDICT_FALSE (tcp_segment_validate (wrk, tc0, b0, tcp0, &error0))) goto drop; /* 5: check the ACK field */ switch (tc0->state) { case TCP_STATE_SYN_RCVD: /* Make sure the segment is exactly right */ if (tc0->rcv_nxt != vnet_buffer (b0)->tcp.seq_number || is_fin0) { tcp_send_reset_w_pkt (tc0, b0, thread_index, is_ip4); error0 = TCP_ERROR_SEGMENT_INVALID; goto drop; } /* * If the segment acknowledgment is not acceptable, form a * reset segment, * * and send it. */ if (tcp_rcv_ack_no_cc (tc0, b0, &error0)) { tcp_send_reset_w_pkt (tc0, b0, thread_index, is_ip4); error0 = TCP_ERROR_SEGMENT_INVALID; goto drop; } /* Update rtt and rto */ tcp_estimate_initial_rtt (tc0); tcp_connection_tx_pacer_update (tc0); /* Switch state to ESTABLISHED */ tc0->state = TCP_STATE_ESTABLISHED; TCP_EVT (TCP_EVT_STATE_CHANGE, tc0); if (!(tc0->cfg_flags & TCP_CFG_F_NO_TSO)) tcp_check_tx_offload (tc0, is_ip4); /* Initialize session variables */ tc0->snd_una = vnet_buffer (b0)->tcp.ack_number; tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window) << tc0->rcv_opts.wscale; tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number; tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number; /* Reset SYN-ACK retransmit and SYN_RCV establish timers */ tcp_retransmit_timer_reset (&wrk->timer_wheel, tc0); if (session_stream_accept_notify (&tc0->connection)) { error0 = TCP_ERROR_MSG_QUEUE_FULL; tcp_send_reset (tc0); session_transport_delete_notify (&tc0->connection); tcp_connection_cleanup (tc0); goto drop; } error0 = TCP_ERROR_ACK_OK; break; case TCP_STATE_ESTABLISHED: /* We can get packets in established state here because they * were enqueued before state change */ if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0)) goto drop; break; case TCP_STATE_FIN_WAIT_1: /* In addition to the processing for the ESTABLISHED state, if * our FIN is now acknowledged then enter FIN-WAIT-2 and * continue processing in that state. */ if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0)) goto drop; /* Still have to send the FIN */ if (tc0->flags & TCP_CONN_FINPNDG) { /* TX fifo finally drained */ max_dequeue = transport_max_tx_dequeue (&tc0->connection); if (max_dequeue <= tc0->burst_acked) tcp_send_fin (tc0); /* If a fin was received and data was acked extend wait */ else if ((tc0->flags & TCP_CONN_FINRCVD) && tc0->bytes_acked) tcp_timer_update (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time); } /* If FIN is ACKed */ else if (tc0->snd_una == tc0->snd_nxt) { /* Stop all retransmit timers because we have nothing more * to send. */ tcp_connection_timers_reset (tc0); /* We already have a FIN but didn't transition to CLOSING * because of outstanding tx data. Close the connection. */ if (tc0->flags & TCP_CONN_FINRCVD) { tcp_connection_set_state (tc0, TCP_STATE_CLOSED); session_transport_closed_notify (&tc0->connection); tcp_program_cleanup (wrk, tc0); goto drop; } tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2); /* Enable waitclose because we're willing to wait for peer's * FIN but not indefinitely. */ tcp_timer_set (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait2_time); /* Don't try to deq the FIN acked */ if (tc0->burst_acked > 1) session_tx_fifo_dequeue_drop (&tc0->connection, tc0->burst_acked - 1); tc0->burst_acked = 0; } break; case TCP_STATE_FIN_WAIT_2: /* In addition to the processing for the ESTABLISHED state, if * the retransmission queue is empty, the user's CLOSE can be * acknowledged ("ok") but do not delete the TCB. */ if (tcp_rcv_ack_no_cc (tc0, b0, &error0)) goto drop; tc0->burst_acked = 0; break; case TCP_STATE_CLOSE_WAIT: /* Do the same processing as for the ESTABLISHED state. */ if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0)) goto drop; if (!(tc0->flags & TCP_CONN_FINPNDG)) break; /* Still have outstanding tx data */ max_dequeue = transport_max_tx_dequeue (&tc0->connection); if (max_dequeue > tc0->burst_acked) break; tcp_send_fin (tc0); tcp_connection_timers_reset (tc0); tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK); tcp_timer_set (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time); break; case TCP_STATE_CLOSING: /* In addition to the processing for the ESTABLISHED state, if * the ACK acknowledges our FIN then enter the TIME-WAIT state, * otherwise ignore the segment. */ if (tcp_rcv_ack_no_cc (tc0, b0, &error0)) goto drop; if (tc0->snd_una != tc0->snd_nxt) goto drop; tcp_connection_timers_reset (tc0); tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT); tcp_timer_set (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time); session_transport_closed_notify (&tc0->connection); goto drop; break; case TCP_STATE_LAST_ACK: /* The only thing that [should] arrive in this state is an * acknowledgment of our FIN. If our FIN is now acknowledged, * delete the TCB, enter the CLOSED state, and return. */ if (tcp_rcv_ack_no_cc (tc0, b0, &error0)) goto drop; /* Apparently our ACK for the peer's FIN was lost */ if (is_fin0 && tc0->snd_una != tc0->snd_nxt) { tcp_send_fin (tc0); goto drop; } tcp_connection_set_state (tc0, TCP_STATE_CLOSED); session_transport_closed_notify (&tc0->connection); /* Don't free the connection from the data path since * we can't ensure that we have no packets already enqueued * to output. Rely instead on the waitclose timer */ tcp_connection_timers_reset (tc0); tcp_program_cleanup (tcp_get_worker (tc0->c_thread_index), tc0); goto drop; break; case TCP_STATE_TIME_WAIT: /* The only thing that can arrive in this state is a * retransmission of the remote FIN. Acknowledge it, and restart * the 2 MSL timeout. */ if (tcp_rcv_ack_no_cc (tc0, b0, &error0)) goto drop; if (!is_fin0) goto drop; tcp_program_ack (tc0); tcp_timer_update (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time); goto drop; break; default: ASSERT (0); } /* 6: check the URG bit TODO */ /* 7: process the segment text */ switch (tc0->state) { case TCP_STATE_ESTABLISHED: case TCP_STATE_FIN_WAIT_1: case TCP_STATE_FIN_WAIT_2: if (vnet_buffer (b0)->tcp.data_len) error0 = tcp_segment_rcv (wrk, tc0, b0); break; case TCP_STATE_CLOSE_WAIT: case TCP_STATE_CLOSING: case TCP_STATE_LAST_ACK: case TCP_STATE_TIME_WAIT: /* This should not occur, since a FIN has been received from the * remote side. Ignore the segment text. */ break; } /* 8: check the FIN bit */ if (!is_fin0) goto drop; TCP_EVT (TCP_EVT_FIN_RCVD, tc0); switch (tc0->state) { case TCP_STATE_ESTABLISHED: /* Account for the FIN and send ack */ tc0->rcv_nxt += 1; tcp_program_ack (tc0); tcp_connection_set_state (tc0, TCP_STATE_CLOSE_WAIT); tcp_program_disconnect (wrk, tc0); tcp_timer_update (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time); break; case TCP_STATE_SYN_RCVD: /* Send FIN-ACK, enter LAST-ACK and because the app was not * notified yet, set a cleanup timer instead of relying on * disconnect notify and the implicit close call. */ tcp_connection_timers_reset (tc0); tc0->rcv_nxt += 1; tcp_send_fin (tc0); tcp_connection_set_state (tc0, TCP_STATE_LAST_ACK); tcp_timer_set (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time); break; case TCP_STATE_CLOSE_WAIT: case TCP_STATE_CLOSING: case TCP_STATE_LAST_ACK: /* move along .. */ break; case TCP_STATE_FIN_WAIT_1: tc0->rcv_nxt += 1; if (tc0->flags & TCP_CONN_FINPNDG) { /* If data is outstanding, stay in FIN_WAIT_1 and try to finish * sending it. Since we already received a fin, do not wait * for too long. */ tc0->flags |= TCP_CONN_FINRCVD; tcp_timer_update (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time); } else { tcp_connection_set_state (tc0, TCP_STATE_CLOSING); tcp_program_ack (tc0); /* Wait for ACK for our FIN but not forever */ tcp_timer_update (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.closing_time); } break; case TCP_STATE_FIN_WAIT_2: /* Got FIN, send ACK! Be more aggressive with resource cleanup */ tc0->rcv_nxt += 1; tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT); tcp_connection_timers_reset (tc0); tcp_timer_set (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time); tcp_program_ack (tc0); session_transport_closed_notify (&tc0->connection); break; case TCP_STATE_TIME_WAIT: /* Remain in the TIME-WAIT state. Restart the time-wait * timeout. */ tcp_timer_update (&wrk->timer_wheel, tc0, TCP_TIMER_WAITCLOSE, tcp_cfg.timewait_time); break; } error0 = TCP_ERROR_FIN_RCVD; drop: tcp_inc_counter (rcv_process, error0, 1); if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) { tcp_rx_trace_t *t0 = vlib_add_trace (vm, node, b0, sizeof (*t0)); tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4); } } errors = session_main_flush_enqueue_events (TRANSPORT_PROTO_TCP, thread_index); tcp_inc_counter (rcv_process, TCP_ERROR_MSG_QUEUE_FULL, errors); tcp_handle_postponed_dequeues (wrk); tcp_handle_disconnects (wrk); vlib_buffer_free (vm, first_buffer, from_frame->n_vectors); return from_frame->n_vectors; } VLIB_NODE_FN (tcp4_rcv_process_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ ); } VLIB_NODE_FN (tcp6_rcv_process_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp4_rcv_process_node) = { .name = "tcp4-rcv-process", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_RCV_PROCESS_N_NEXT, .next_nodes = { #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n, foreach_tcp_state_next #undef _ }, .format_trace = format_tcp_rx_trace_short, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp6_rcv_process_node) = { .name = "tcp6-rcv-process", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_RCV_PROCESS_N_NEXT, .next_nodes = { #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n, foreach_tcp_state_next #undef _ }, .format_trace = format_tcp_rx_trace_short, }; /* *INDENT-ON* */ /** * LISTEN state processing as per RFC 793 p. 65 */ always_inline uword tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame, int is_ip4) { u32 n_left_from, *from, n_syns = 0, *first_buffer; u32 thread_index = vm->thread_index; from = first_buffer = vlib_frame_vector_args (from_frame); n_left_from = from_frame->n_vectors; while (n_left_from > 0) { u32 bi, error = TCP_ERROR_NONE; tcp_connection_t *lc, *child; vlib_buffer_t *b; bi = from[0]; from += 1; n_left_from -= 1; b = vlib_get_buffer (vm, bi); lc = tcp_listener_get (vnet_buffer (b)->tcp.connection_index); if (PREDICT_FALSE (lc == 0)) { tcp_connection_t *tc; tc = tcp_connection_get (vnet_buffer (b)->tcp.connection_index, thread_index); if (tc->state != TCP_STATE_TIME_WAIT) { error = TCP_ERROR_CREATE_EXISTS; goto done; } lc = tcp_lookup_listener (b, tc->c_fib_index, is_ip4); /* clean up the old session */ tcp_connection_del (tc); } /* Make sure connection wasn't just created */ child = tcp_lookup_connection (lc->c_fib_index, b, thread_index, is_ip4); if (PREDICT_FALSE (child->state != TCP_STATE_LISTEN)) { error = TCP_ERROR_CREATE_EXISTS; goto done; } /* Create child session. For syn-flood protection use filter */ /* 1. first check for an RST: handled in dispatch */ /* if (tcp_rst (th0)) goto drop; */ /* 2. second check for an ACK: handled in dispatch */ /* if (tcp_ack (th0)) { tcp_send_reset (b0, is_ip4); goto drop; } */ /* 3. check for a SYN (did that already) */ /* Create child session and send SYN-ACK */ child = tcp_connection_alloc (thread_index); if (tcp_options_parse (tcp_buffer_hdr (b), &child->rcv_opts, 1)) { error = TCP_ERROR_OPTIONS; tcp_connection_free (child); goto done; } tcp_init_w_buffer (child, b, is_ip4); child->state = TCP_STATE_SYN_RCVD; child->c_fib_index = lc->c_fib_index; child->cc_algo = lc->cc_algo; tcp_connection_init_vars (child); child->rto = TCP_RTO_MIN; if (session_stream_accept (&child->connection, lc->c_s_index, lc->c_thread_index, 0 /* notify */ )) { tcp_connection_cleanup (child); error = TCP_ERROR_CREATE_SESSION_FAIL; goto done; } child->tx_fifo_size = transport_tx_fifo_size (&child->connection); tcp_send_synack (child); TCP_EVT (TCP_EVT_SYN_RCVD, child, 1); done: if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED)) { tcp_rx_trace_t *t; t = vlib_add_trace (vm, node, b, sizeof (*t)); clib_memcpy_fast (&t->tcp_header, tcp_buffer_hdr (b), sizeof (t->tcp_header)); clib_memcpy_fast (&t->tcp_connection, lc, sizeof (t->tcp_connection)); } n_syns += (error == TCP_ERROR_NONE); } tcp_inc_counter (listen, TCP_ERROR_SYNS_RCVD, n_syns); vlib_buffer_free (vm, first_buffer, from_frame->n_vectors); return from_frame->n_vectors; } VLIB_NODE_FN (tcp4_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ ); } VLIB_NODE_FN (tcp6_listen_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp4_listen_node) = { .name = "tcp4-listen", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_LISTEN_N_NEXT, .next_nodes = { #define _(s,n) [TCP_LISTEN_NEXT_##s] = n, foreach_tcp_state_next #undef _ }, .format_trace = format_tcp_rx_trace_short, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp6_listen_node) = { .name = "tcp6-listen", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_LISTEN_N_NEXT, .next_nodes = { #define _(s,n) [TCP_LISTEN_NEXT_##s] = n, foreach_tcp_state_next #undef _ }, .format_trace = format_tcp_rx_trace_short, }; /* *INDENT-ON* */ typedef enum _tcp_input_next { TCP_INPUT_NEXT_DROP, TCP_INPUT_NEXT_LISTEN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_INPUT_NEXT_SYN_SENT, TCP_INPUT_NEXT_ESTABLISHED, TCP_INPUT_NEXT_RESET, TCP_INPUT_NEXT_PUNT, TCP_INPUT_N_NEXT } tcp_input_next_t; #define foreach_tcp4_input_next \ _ (DROP, "ip4-drop") \ _ (LISTEN, "tcp4-listen") \ _ (RCV_PROCESS, "tcp4-rcv-process") \ _ (SYN_SENT, "tcp4-syn-sent") \ _ (ESTABLISHED, "tcp4-established") \ _ (RESET, "tcp4-reset") \ _ (PUNT, "ip4-punt") #define foreach_tcp6_input_next \ _ (DROP, "ip6-drop") \ _ (LISTEN, "tcp6-listen") \ _ (RCV_PROCESS, "tcp6-rcv-process") \ _ (SYN_SENT, "tcp6-syn-sent") \ _ (ESTABLISHED, "tcp6-established") \ _ (RESET, "tcp6-reset") \ _ (PUNT, "ip6-punt") #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN) static void tcp_input_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_buffer_t ** bs, u32 n_bufs, u8 is_ip4) { tcp_connection_t *tc; tcp_header_t *tcp; tcp_rx_trace_t *t; int i; for (i = 0; i < n_bufs; i++) { if (bs[i]->flags & VLIB_BUFFER_IS_TRACED) { t = vlib_add_trace (vm, node, bs[i], sizeof (*t)); tc = tcp_connection_get (vnet_buffer (bs[i])->tcp.connection_index, vm->thread_index); tcp = vlib_buffer_get_current (bs[i]); tcp_set_rx_trace_data (t, tc, tcp, bs[i], is_ip4); } } } static void tcp_input_set_error_next (tcp_main_t * tm, u16 * next, u32 * error, u8 is_ip4) { if (*error == TCP_ERROR_FILTERED || *error == TCP_ERROR_WRONG_THREAD) { *next = TCP_INPUT_NEXT_DROP; } else if ((is_ip4 && tm->punt_unknown4) || (!is_ip4 && tm->punt_unknown6)) { *next = TCP_INPUT_NEXT_PUNT; *error = TCP_ERROR_PUNT; } else { *next = TCP_INPUT_NEXT_RESET; *error = TCP_ERROR_NO_LISTENER; } } static inline void tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b, u16 * next, vlib_node_runtime_t * error_node) { tcp_header_t *tcp; u32 error; u8 flags; tcp = tcp_buffer_hdr (b); flags = tcp->flags & filter_flags; *next = tm->dispatch_table[tc->state][flags].next; error = tm->dispatch_table[tc->state][flags].error; tc->segs_in += 1; if (PREDICT_FALSE (error != TCP_ERROR_NONE)) { b->error = error_node->errors[error]; if (error == TCP_ERROR_DISPATCH) clib_warning ("tcp conn %u disp error state %U flags %U", tc->c_c_index, format_tcp_state, tc->state, format_tcp_flags, (int) flags); } } always_inline uword tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, int is_ip4, u8 is_nolookup) { u32 n_left_from, *from, thread_index = vm->thread_index; tcp_main_t *tm = vnet_get_tcp_main (); vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b; u16 nexts[VLIB_FRAME_SIZE], *next; tcp_set_time_now (tcp_get_worker (thread_index)); from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; vlib_get_buffers (vm, from, bufs, n_left_from); b = bufs; next = nexts; while (n_left_from >= 4) { u32 error0 = TCP_ERROR_NO_LISTENER, error1 = TCP_ERROR_NO_LISTENER; tcp_connection_t *tc0, *tc1; { vlib_prefetch_buffer_header (b[2], STORE); CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD); vlib_prefetch_buffer_header (b[3], STORE); CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD); } next[0] = next[1] = TCP_INPUT_NEXT_DROP; tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4, is_nolookup); tc1 = tcp_input_lookup_buffer (b[1], thread_index, &error1, is_ip4, is_nolookup); if (PREDICT_TRUE (!tc0 + !tc1 == 0)) { ASSERT (tcp_lookup_is_valid (tc0, b[0], tcp_buffer_hdr (b[0]))); ASSERT (tcp_lookup_is_valid (tc1, b[1], tcp_buffer_hdr (b[1]))); vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index; vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index; tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], node); tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], node); } else { if (PREDICT_TRUE (tc0 != 0)) { ASSERT (tcp_lookup_is_valid (tc0, b[0], tcp_buffer_hdr (b[0]))); vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index; tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], node); } else { tcp_input_set_error_next (tm, &next[0], &error0, is_ip4); b[0]->error = node->errors[error0]; } if (PREDICT_TRUE (tc1 != 0)) { ASSERT (tcp_lookup_is_valid (tc1, b[1], tcp_buffer_hdr (b[1]))); vnet_buffer (b[1])->tcp.connection_index = tc1->c_c_index; tcp_input_dispatch_buffer (tm, tc1, b[1], &next[1], node); } else { tcp_input_set_error_next (tm, &next[1], &error1, is_ip4); b[1]->error = node->errors[error1]; } } b += 2; next += 2; n_left_from -= 2; } while (n_left_from > 0) { tcp_connection_t *tc0; u32 error0 = TCP_ERROR_NO_LISTENER; if (n_left_from > 1) { vlib_prefetch_buffer_header (b[1], STORE); CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD); } next[0] = TCP_INPUT_NEXT_DROP; tc0 = tcp_input_lookup_buffer (b[0], thread_index, &error0, is_ip4, is_nolookup); if (PREDICT_TRUE (tc0 != 0)) { ASSERT (tcp_lookup_is_valid (tc0, b[0], tcp_buffer_hdr (b[0]))); vnet_buffer (b[0])->tcp.connection_index = tc0->c_c_index; tcp_input_dispatch_buffer (tm, tc0, b[0], &next[0], node); } else { tcp_input_set_error_next (tm, &next[0], &error0, is_ip4); b[0]->error = node->errors[error0]; } b += 1; next += 1; n_left_from -= 1; } if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE)) tcp_input_trace_frame (vm, node, bufs, frame->n_vectors, is_ip4); vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors); return frame->n_vectors; } VLIB_NODE_FN (tcp4_input_nolookup_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ , 1 /* is_nolookup */ ); } VLIB_NODE_FN (tcp6_input_nolookup_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ , 1 /* is_nolookup */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp4_input_nolookup_node) = { .name = "tcp4-input-nolookup", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_INPUT_N_NEXT, .next_nodes = { #define _(s,n) [TCP_INPUT_NEXT_##s] = n, foreach_tcp4_input_next #undef _ }, .format_buffer = format_tcp_header, .format_trace = format_tcp_rx_trace, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp6_input_nolookup_node) = { .name = "tcp6-input-nolookup", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_INPUT_N_NEXT, .next_nodes = { #define _(s,n) [TCP_INPUT_NEXT_##s] = n, foreach_tcp6_input_next #undef _ }, .format_buffer = format_tcp_header, .format_trace = format_tcp_rx_trace, }; /* *INDENT-ON* */ VLIB_NODE_FN (tcp4_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ , 0 /* is_nolookup */ ); } VLIB_NODE_FN (tcp6_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ , 0 /* is_nolookup */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp4_input_node) = { .name = "tcp4-input", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_INPUT_N_NEXT, .next_nodes = { #define _(s,n) [TCP_INPUT_NEXT_##s] = n, foreach_tcp4_input_next #undef _ }, .format_buffer = format_tcp_header, .format_trace = format_tcp_rx_trace, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp6_input_node) = { .name = "tcp6-input", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_INPUT_N_NEXT, .next_nodes = { #define _(s,n) [TCP_INPUT_NEXT_##s] = n, foreach_tcp6_input_next #undef _ }, .format_buffer = format_tcp_header, .format_trace = format_tcp_rx_trace, }; /* *INDENT-ON* */ #ifndef CLIB_MARCH_VARIANT static void tcp_dispatch_table_init (tcp_main_t * tm) { int i, j; for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++) for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++) { tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP; tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH; } #define _(t,f,n,e) \ do { \ tm->dispatch_table[TCP_STATE_##t][f].next = (n); \ tm->dispatch_table[TCP_STATE_##t][f].error = (e); \ } while (0) /* RFC 793: In LISTEN if RST drop and if ACK return RST */ _(LISTEN, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID); _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION); _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE); _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_ACK_INVALID); _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_INVALID_CONNECTION); _(LISTEN, TCP_FLAG_FIN, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); /* ACK for for a SYN-ACK -> tcp-rcv-process. */ _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(SYN_RCVD, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); /* SYN-ACK for a SYN */ _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE); _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE); _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE); _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE); _(SYN_SENT, TCP_FLAG_FIN, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE); _(SYN_SENT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE); /* ACK for for established connection -> tcp-established. */ _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); /* FIN for for established connection -> tcp-established. */ _(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_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); _(ESTABLISHED, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); /* 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, TCP_ERROR_NONE); /* FIN in reply to our FIN from the other side */ _(FIN_WAIT_1, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_1, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(CLOSING, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSING, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); /* FIN confirming that the peer (app) has closed */ _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_2, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(FIN_WAIT_2, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSE_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(CLOSE_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, 0, TCP_INPUT_NEXT_DROP, TCP_ERROR_SEGMENT_INVALID); _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(LAST_ACK, TCP_FLAG_SYN | TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(TIME_WAIT, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE); _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(TIME_WAIT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); /* RFC793 CLOSED: An incoming segment containing a RST is discarded. An * incoming segment not containing a RST causes a RST to be sent in * response.*/ _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED); _(CLOSED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED); _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED); _(CLOSED, TCP_FLAG_SYN, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED); _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_CONNECTION_CLOSED); #undef _ } static clib_error_t * tcp_input_init (vlib_main_t * vm) { clib_error_t *error = 0; tcp_main_t *tm = vnet_get_tcp_main (); if ((error = vlib_call_init_function (vm, tcp_init))) return error; /* Initialize dispatch table. */ tcp_dispatch_table_init (tm); return error; } VLIB_INIT_FUNCTION (tcp_input_init); #endif /* CLIB_MARCH_VARIANT */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */