2 * Copyright (c) 2016-2019 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
18 * @brief TCP host stack utilities
21 #include <vnet/tcp/tcp.h>
22 #include <vnet/session/session.h>
23 #include <vnet/fib/fib.h>
24 #include <vnet/dpo/load_balance.h>
25 #include <vnet/dpo/receive_dpo.h>
26 #include <vnet/ip/ip6_neighbor.h>
28 #include <vnet/ethernet/arp.h>
34 fib_protocol_t nh_proto;
35 vnet_link_t link_type;
39 } tcp_add_del_adj_args_t;
42 tcp_add_del_adj_cb (tcp_add_del_adj_args_t * args)
47 adj_nbr_add_or_lock (args->nh_proto, args->link_type, &args->ip,
52 ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &args->ip,
54 if (ai != ADJ_INDEX_INVALID)
60 tcp_add_del_adjacency (tcp_connection_t * tc, u8 is_add)
62 tcp_add_del_adj_args_t args = {
63 .nh_proto = FIB_PROTOCOL_IP6,
64 .link_type = VNET_LINK_IP6,
66 .sw_if_index = tc->sw_if_index,
69 vlib_rpc_call_main_thread (tcp_add_del_adj_cb, (u8 *) & args,
74 tcp_cc_init (tcp_connection_t * tc)
76 tc->cc_algo->init (tc);
80 tcp_cc_cleanup (tcp_connection_t * tc)
82 if (tc->cc_algo->cleanup)
83 tc->cc_algo->cleanup (tc);
87 tcp_cc_algo_register (tcp_cc_algorithm_type_e type,
88 const tcp_cc_algorithm_t * vft)
90 tcp_main_t *tm = vnet_get_tcp_main ();
91 vec_validate (tm->cc_algos, type);
93 tm->cc_algos[type] = *vft;
94 hash_set_mem (tm->cc_algo_by_name, vft->name, type);
98 tcp_cc_algo_get (tcp_cc_algorithm_type_e type)
100 tcp_main_t *tm = vnet_get_tcp_main ();
101 return &tm->cc_algos[type];
104 tcp_cc_algorithm_type_e
105 tcp_cc_algo_new_type (const tcp_cc_algorithm_t * vft)
107 tcp_main_t *tm = vnet_get_tcp_main ();
108 tcp_cc_algo_register (++tm->cc_last_type, vft);
109 return tm->cc_last_type;
113 tcp_connection_bind (u32 session_index, transport_endpoint_t * lcl)
115 tcp_main_t *tm = &tcp_main;
116 tcp_connection_t *listener;
119 pool_get (tm->listener_pool, listener);
120 clib_memset (listener, 0, sizeof (*listener));
122 listener->c_c_index = listener - tm->listener_pool;
123 listener->c_lcl_port = lcl->port;
125 /* If we are provided a sw_if_index, bind using one of its ips */
126 if (ip_is_zero (&lcl->ip, 1) && lcl->sw_if_index != ENDPOINT_INVALID_INDEX)
128 if ((iface_ip = ip_interface_get_first_ip (lcl->sw_if_index,
130 ip_set (&lcl->ip, iface_ip, lcl->is_ip4);
132 ip_copy (&listener->c_lcl_ip, &lcl->ip, lcl->is_ip4);
133 listener->c_is_ip4 = lcl->is_ip4;
134 listener->c_proto = TRANSPORT_PROTO_TCP;
135 listener->c_s_index = session_index;
136 listener->c_fib_index = lcl->fib_index;
137 listener->state = TCP_STATE_LISTEN;
138 listener->cc_algo = tcp_cc_algo_get (tcp_cfg.cc_algo);
140 tcp_connection_timers_init (listener);
142 TCP_EVT (TCP_EVT_BIND, listener);
144 return listener->c_c_index;
148 tcp_session_bind (u32 session_index, transport_endpoint_t * tep)
150 return tcp_connection_bind (session_index, tep);
154 tcp_connection_unbind (u32 listener_index)
156 tcp_main_t *tm = vnet_get_tcp_main ();
157 tcp_connection_t *tc;
159 tc = pool_elt_at_index (tm->listener_pool, listener_index);
161 TCP_EVT (TCP_EVT_UNBIND, tc);
163 /* Poison the entry */
165 clib_memset (tc, 0xFA, sizeof (*tc));
167 pool_put_index (tm->listener_pool, listener_index);
171 tcp_session_unbind (u32 listener_index)
173 tcp_connection_unbind (listener_index);
177 static transport_connection_t *
178 tcp_session_get_listener (u32 listener_index)
180 tcp_main_t *tm = vnet_get_tcp_main ();
181 tcp_connection_t *tc;
182 tc = pool_elt_at_index (tm->listener_pool, listener_index);
183 return &tc->connection;
187 * Cleanup half-open connection
191 tcp_half_open_connection_del (tcp_connection_t * tc)
193 tcp_main_t *tm = vnet_get_tcp_main ();
194 clib_spinlock_lock_if_init (&tm->half_open_lock);
196 clib_memset (tc, 0xFA, sizeof (*tc));
197 pool_put (tm->half_open_connections, tc);
198 clib_spinlock_unlock_if_init (&tm->half_open_lock);
202 * Try to cleanup half-open connection
204 * If called from a thread that doesn't own tc, the call won't have any
207 * @param tc - connection to be cleaned up
208 * @return non-zero if cleanup failed.
211 tcp_half_open_connection_cleanup (tcp_connection_t * tc)
213 /* Make sure this is the owning thread */
214 if (tc->c_thread_index != vlib_get_thread_index ())
216 tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT_SYN);
217 tcp_half_open_connection_del (tc);
221 static tcp_connection_t *
222 tcp_half_open_connection_new (void)
224 tcp_main_t *tm = vnet_get_tcp_main ();
225 tcp_connection_t *tc = 0;
226 ASSERT (vlib_get_thread_index () == 0);
227 pool_get (tm->half_open_connections, tc);
228 clib_memset (tc, 0, sizeof (*tc));
229 tc->c_c_index = tc - tm->half_open_connections;
234 * Cleans up connection state.
239 tcp_connection_cleanup (tcp_connection_t * tc)
241 tcp_main_t *tm = &tcp_main;
243 TCP_EVT (TCP_EVT_DELETE, tc);
245 /* Cleanup local endpoint if this was an active connect */
246 transport_endpoint_cleanup (TRANSPORT_PROTO_TCP, &tc->c_lcl_ip,
249 /* Check if connection is not yet fully established */
250 if (tc->state == TCP_STATE_SYN_SENT)
252 /* Try to remove the half-open connection. If this is not the owning
253 * thread, tc won't be removed. Retransmit or establish timers will
254 * eventually expire and call again cleanup on the right thread. */
255 if (tcp_half_open_connection_cleanup (tc))
256 tc->flags |= TCP_CONN_HALF_OPEN_DONE;
260 int thread_index = tc->c_thread_index;
262 /* Make sure all timers are cleared */
263 tcp_connection_timers_reset (tc);
265 if (!tc->c_is_ip4 && ip6_address_is_link_local_unicast (&tc->c_rmt_ip6))
266 tcp_add_del_adjacency (tc, 0);
269 vec_free (tc->snd_sacks);
270 vec_free (tc->snd_sacks_fl);
271 vec_free (tc->rcv_opts.sacks);
272 pool_free (tc->sack_sb.holes);
274 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
277 /* Poison the entry */
279 clib_memset (tc, 0xFA, sizeof (*tc));
280 pool_put (tm->connections[thread_index], tc);
285 * Connection removal.
287 * This should be called only once connection enters CLOSED state. Note
288 * that it notifies the session of the removal event, so if the goal is to
289 * just remove the connection, call tcp_connection_cleanup instead.
292 tcp_connection_del (tcp_connection_t * tc)
294 session_transport_delete_notify (&tc->connection);
295 tcp_connection_cleanup (tc);
299 tcp_connection_alloc (u8 thread_index)
301 tcp_main_t *tm = vnet_get_tcp_main ();
302 tcp_connection_t *tc;
304 pool_get (tm->connections[thread_index], tc);
305 clib_memset (tc, 0, sizeof (*tc));
306 tc->c_c_index = tc - tm->connections[thread_index];
307 tc->c_thread_index = thread_index;
312 tcp_connection_alloc_w_base (u8 thread_index, tcp_connection_t * base)
314 tcp_main_t *tm = vnet_get_tcp_main ();
315 tcp_connection_t *tc;
317 pool_get (tm->connections[thread_index], tc);
318 clib_memcpy_fast (tc, base, sizeof (*tc));
319 tc->c_c_index = tc - tm->connections[thread_index];
320 tc->c_thread_index = thread_index;
325 tcp_connection_free (tcp_connection_t * tc)
327 tcp_main_t *tm = &tcp_main;
330 u8 thread_index = tc->c_thread_index;
331 clib_memset (tc, 0xFA, sizeof (*tc));
332 pool_put (tm->connections[thread_index], tc);
335 pool_put (tm->connections[tc->c_thread_index], tc);
338 /** Notify session that connection has been reset.
340 * Switch state to closed and wait for session to call cleanup.
343 tcp_connection_reset (tcp_connection_t * tc)
345 TCP_EVT (TCP_EVT_RST_RCVD, tc);
348 case TCP_STATE_SYN_RCVD:
349 /* Cleanup everything. App wasn't notified yet */
350 session_transport_delete_notify (&tc->connection);
351 tcp_connection_cleanup (tc);
353 case TCP_STATE_SYN_SENT:
354 session_stream_connect_notify (&tc->connection, 1 /* fail */ );
355 tcp_connection_cleanup (tc);
357 case TCP_STATE_ESTABLISHED:
358 tcp_connection_timers_reset (tc);
359 /* Set the cleanup timer, in case the session layer/app don't
360 * cleanly close the connection */
361 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
362 session_transport_reset_notify (&tc->connection);
363 tcp_cong_recovery_off (tc);
364 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
365 session_transport_closed_notify (&tc->connection);
367 case TCP_STATE_CLOSE_WAIT:
368 case TCP_STATE_FIN_WAIT_1:
369 case TCP_STATE_FIN_WAIT_2:
370 case TCP_STATE_CLOSING:
371 case TCP_STATE_LAST_ACK:
372 tcp_connection_timers_reset (tc);
373 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
374 tcp_cong_recovery_off (tc);
375 /* Make sure we mark the session as closed. In some states we may
376 * be still trying to send data */
377 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
378 session_transport_closed_notify (&tc->connection);
380 case TCP_STATE_CLOSED:
381 case TCP_STATE_TIME_WAIT:
384 TCP_DBG ("reset state: %u", tc->state);
389 * Begin connection closing procedure.
391 * If at the end the connection is not in CLOSED state, it is not removed.
392 * Instead, we rely on on TCP to advance through state machine to either
393 * 1) LAST_ACK (passive close) whereby when the last ACK is received
394 * tcp_connection_del is called. This notifies session of the delete and
396 * 2) TIME_WAIT (active close) whereby after 2MSL the 2MSL timer triggers
397 * and cleanup is called.
399 * N.B. Half-close connections are not supported
402 tcp_connection_close (tcp_connection_t * tc)
404 TCP_EVT (TCP_EVT_CLOSE, tc);
406 /* Send/Program FIN if needed and switch state */
409 case TCP_STATE_SYN_SENT:
410 /* Try to cleanup. If not on the right thread, mark as half-open done.
411 * Connection will be cleaned up when establish timer pops */
412 tcp_connection_cleanup (tc);
414 case TCP_STATE_SYN_RCVD:
415 tcp_connection_timers_reset (tc);
417 tcp_connection_set_state (tc, TCP_STATE_FIN_WAIT_1);
418 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait1_time);
420 case TCP_STATE_ESTABLISHED:
421 /* If closing with unread data, reset the connection */
422 if (transport_max_rx_dequeue (&tc->connection))
425 tcp_connection_timers_reset (tc);
426 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
427 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
428 session_transport_closed_notify (&tc->connection);
431 if (!transport_max_tx_dequeue (&tc->connection))
434 tc->flags |= TCP_CONN_FINPNDG;
435 tcp_connection_set_state (tc, TCP_STATE_FIN_WAIT_1);
436 /* Set a timer in case the peer stops responding. Otherwise the
437 * connection will be stuck here forever. */
438 ASSERT (tc->timers[TCP_TIMER_WAITCLOSE] == TCP_TIMER_HANDLE_INVALID);
439 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait1_time);
441 case TCP_STATE_CLOSE_WAIT:
442 if (!transport_max_tx_dequeue (&tc->connection))
445 tcp_connection_timers_reset (tc);
446 tcp_connection_set_state (tc, TCP_STATE_LAST_ACK);
447 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
450 tc->flags |= TCP_CONN_FINPNDG;
452 case TCP_STATE_FIN_WAIT_1:
453 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait1_time);
455 case TCP_STATE_CLOSED:
456 tcp_connection_timers_reset (tc);
457 /* Delete connection but instead of doing it now wait until next
458 * dispatch cycle to give the session layer a chance to clear
459 * unhandled events */
460 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
463 TCP_DBG ("state: %u", tc->state);
468 tcp_session_close (u32 conn_index, u32 thread_index)
470 tcp_connection_t *tc;
471 tc = tcp_connection_get (conn_index, thread_index);
472 tcp_connection_close (tc);
476 tcp_session_cleanup (u32 conn_index, u32 thread_index)
478 tcp_connection_t *tc;
479 tc = tcp_connection_get (conn_index, thread_index);
482 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
483 tcp_connection_cleanup (tc);
487 tcp_session_reset (u32 conn_index, u32 thread_index)
489 tcp_connection_t *tc;
490 tc = tcp_connection_get (conn_index, thread_index);
491 session_transport_closed_notify (&tc->connection);
493 tcp_connection_timers_reset (tc);
494 tcp_cong_recovery_off (tc);
495 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
496 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
500 * Initialize all connection timers as invalid
503 tcp_connection_timers_init (tcp_connection_t * tc)
507 /* Set all to invalid */
508 for (i = 0; i < TCP_N_TIMERS; i++)
510 tc->timers[i] = TCP_TIMER_HANDLE_INVALID;
513 tc->rto = TCP_RTO_INIT;
517 * Stop all connection timers
520 tcp_connection_timers_reset (tcp_connection_t * tc)
523 for (i = 0; i < TCP_N_TIMERS; i++)
525 tcp_timer_reset (tc, i);
530 typedef struct ip4_tcp_hdr
536 typedef struct ip6_tcp_hdr
543 tcp_connection_select_lb_bucket (tcp_connection_t * tc, const dpo_id_t * dpo,
546 const dpo_id_t *choice;
550 lb = load_balance_get (dpo->dpoi_index);
554 clib_memset (&hdr, 0, sizeof (hdr));
555 hdr.ip.protocol = IP_PROTOCOL_TCP;
556 hdr.ip.address_pair.src.as_u32 = tc->c_lcl_ip.ip4.as_u32;
557 hdr.ip.address_pair.dst.as_u32 = tc->c_rmt_ip.ip4.as_u32;
558 hdr.tcp.src_port = tc->c_lcl_port;
559 hdr.tcp.dst_port = tc->c_rmt_port;
560 hash = ip4_compute_flow_hash (&hdr.ip, lb->lb_hash_config);
565 clib_memset (&hdr, 0, sizeof (hdr));
566 hdr.ip.protocol = IP_PROTOCOL_TCP;
567 clib_memcpy_fast (&hdr.ip.src_address, &tc->c_lcl_ip.ip6,
568 sizeof (ip6_address_t));
569 clib_memcpy_fast (&hdr.ip.dst_address, &tc->c_rmt_ip.ip6,
570 sizeof (ip6_address_t));
571 hdr.tcp.src_port = tc->c_lcl_port;
572 hdr.tcp.dst_port = tc->c_rmt_port;
573 hash = ip6_compute_flow_hash (&hdr.ip, lb->lb_hash_config);
575 choice = load_balance_get_bucket_i (lb, hash & lb->lb_n_buckets_minus_1);
576 dpo_copy (result, choice);
580 tcp_lookup_rmt_in_fib (tcp_connection_t * tc)
585 clib_memcpy_fast (&prefix.fp_addr, &tc->c_rmt_ip, sizeof (prefix.fp_addr));
586 prefix.fp_proto = tc->c_is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
587 prefix.fp_len = tc->c_is_ip4 ? 32 : 128;
588 fib_index = fib_table_find (prefix.fp_proto, tc->c_fib_index);
589 return fib_table_lookup (fib_index, &prefix);
593 tcp_connection_stack_on_fib_entry (tcp_connection_t * tc)
595 dpo_id_t choice = DPO_INVALID;
596 u32 output_node_index;
599 fe = fib_entry_get (tc->c_rmt_fei);
600 if (fe->fe_lb.dpoi_type != DPO_LOAD_BALANCE)
603 tcp_connection_select_lb_bucket (tc, &fe->fe_lb, &choice);
606 tc->c_is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
607 dpo_stack_from_node (output_node_index, &tc->c_rmt_dpo, &choice);
611 /** Stack tcp connection on peer's fib entry.
613 * This ultimately populates the dpo the connection will use to send packets.
616 tcp_connection_fib_attach (tcp_connection_t * tc)
618 tc->c_rmt_fei = tcp_lookup_rmt_in_fib (tc);
620 ASSERT (tc->c_rmt_fei != FIB_NODE_INDEX_INVALID);
622 tcp_connection_stack_on_fib_entry (tc);
627 * Generate random iss as per rfc6528
630 tcp_generate_random_iss (tcp_connection_t * tc)
632 tcp_main_t *tm = &tcp_main;
636 tmp = (u64) tc->c_lcl_ip.ip4.as_u32 << 32 | (u64) tc->c_rmt_ip.ip4.as_u32;
638 tmp = tc->c_lcl_ip.ip6.as_u64[0] ^ tc->c_lcl_ip.ip6.as_u64[1]
639 ^ tc->c_rmt_ip.ip6.as_u64[0] ^ tc->c_rmt_ip.ip6.as_u64[1];
641 tmp ^= tm->iss_seed.first | ((u64) tc->c_lcl_port << 16 | tc->c_rmt_port);
642 tmp ^= tm->iss_seed.second;
643 tmp = clib_xxhash (tmp) + clib_cpu_time_now ();
644 return ((tmp >> 32) ^ (tmp & 0xffffffff));
648 * Initialize max segment size we're able to process.
650 * The value is constrained by the output interface's MTU and by the size
651 * of the IP and TCP headers (see RFC6691). It is also what we advertise
655 tcp_init_rcv_mss (tcp_connection_t * tc)
659 ip_hdr_len = tc->c_is_ip4 ? sizeof (ip4_header_t) : sizeof (ip6_header_t);
660 tc->mss = tcp_cfg.default_mtu - sizeof (tcp_header_t) - ip_hdr_len;
664 tcp_init_mss (tcp_connection_t * tc)
666 u16 default_min_mss = 536;
668 tcp_init_rcv_mss (tc);
670 /* TODO consider PMTU discovery */
671 tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss);
673 if (tc->snd_mss < 45)
675 /* Assume that at least the min default mss works */
676 tc->snd_mss = default_min_mss;
677 tc->rcv_opts.mss = default_min_mss;
680 /* We should have enough space for 40 bytes of options */
681 ASSERT (tc->snd_mss > 45);
683 /* If we use timestamp option, account for it */
684 if (tcp_opts_tstamp (&tc->rcv_opts))
685 tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP;
689 * Initialize connection send variables.
692 tcp_init_snd_vars (tcp_connection_t * tc)
695 * We use the time to randomize iss and for setting up the initial
696 * timestamp. Make sure it's updated otherwise syn and ack in the
697 * handshake may make it look as if time has flown in the opposite
700 tcp_set_time_now (tcp_get_worker (vlib_get_thread_index ()));
702 tcp_init_rcv_mss (tc);
703 tc->iss = tcp_generate_random_iss (tc);
704 tc->snd_una = tc->iss;
705 tc->snd_nxt = tc->iss + 1;
706 tc->snd_una_max = tc->snd_nxt;
707 tc->srtt = 100; /* 100 ms */
711 tcp_enable_pacing (tcp_connection_t * tc)
714 byte_rate = tc->cwnd / (tc->srtt * TCP_TICK);
715 transport_connection_tx_pacer_init (&tc->connection, byte_rate, tc->cwnd);
716 tc->mrtt_us = (u32) ~ 0;
719 /** Initialize tcp connection variables
721 * Should be called after having received a msg from the peer, i.e., a SYN or
722 * a SYNACK, such that connection options have already been exchanged. */
724 tcp_connection_init_vars (tcp_connection_t * tc)
726 tcp_connection_timers_init (tc);
728 scoreboard_init (&tc->sack_sb);
729 if (tc->state == TCP_STATE_SYN_RCVD)
730 tcp_init_snd_vars (tc);
734 if (!tc->c_is_ip4 && ip6_address_is_link_local_unicast (&tc->c_rmt_ip6))
735 tcp_add_del_adjacency (tc, 1);
737 /* tcp_connection_fib_attach (tc); */
739 if (transport_connection_is_tx_paced (&tc->connection)
740 || tcp_cfg.enable_tx_pacing)
741 tcp_enable_pacing (tc);
743 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
746 if (!tcp_cfg.allow_tso)
747 tc->cfg_flags |= TCP_CFG_F_NO_TSO;
749 tc->start_ts = tcp_time_now_us (tc->c_thread_index);
753 tcp_alloc_custom_local_endpoint (tcp_main_t * tm, ip46_address_t * lcl_addr,
754 u16 * lcl_port, u8 is_ip4)
759 index = tm->last_v4_addr_rotor++;
760 if (tm->last_v4_addr_rotor >= vec_len (tcp_cfg.ip4_src_addrs))
761 tm->last_v4_addr_rotor = 0;
762 lcl_addr->ip4.as_u32 = tcp_cfg.ip4_src_addrs[index].as_u32;
766 index = tm->last_v6_addr_rotor++;
767 if (tm->last_v6_addr_rotor >= vec_len (tcp_cfg.ip6_src_addrs))
768 tm->last_v6_addr_rotor = 0;
769 clib_memcpy_fast (&lcl_addr->ip6, &tcp_cfg.ip6_src_addrs[index],
770 sizeof (ip6_address_t));
772 port = transport_alloc_local_port (TRANSPORT_PROTO_TCP, lcl_addr);
775 clib_warning ("Failed to allocate src port");
783 tcp_session_open (transport_endpoint_cfg_t * rmt)
785 tcp_main_t *tm = vnet_get_tcp_main ();
786 tcp_connection_t *tc;
787 ip46_address_t lcl_addr;
792 * Allocate local endpoint
794 if ((rmt->is_ip4 && vec_len (tcp_cfg.ip4_src_addrs))
795 || (!rmt->is_ip4 && vec_len (tcp_cfg.ip6_src_addrs)))
796 rv = tcp_alloc_custom_local_endpoint (tm, &lcl_addr, &lcl_port,
799 rv = transport_alloc_local_endpoint (TRANSPORT_PROTO_TCP,
800 rmt, &lcl_addr, &lcl_port);
806 * Create connection and send SYN
808 clib_spinlock_lock_if_init (&tm->half_open_lock);
809 tc = tcp_half_open_connection_new ();
810 ip_copy (&tc->c_rmt_ip, &rmt->ip, rmt->is_ip4);
811 ip_copy (&tc->c_lcl_ip, &lcl_addr, rmt->is_ip4);
812 tc->c_rmt_port = rmt->port;
813 tc->c_lcl_port = clib_host_to_net_u16 (lcl_port);
814 tc->c_is_ip4 = rmt->is_ip4;
815 tc->c_proto = TRANSPORT_PROTO_TCP;
816 tc->c_fib_index = rmt->fib_index;
817 tc->cc_algo = tcp_cc_algo_get (tcp_cfg.cc_algo);
818 /* The other connection vars will be initialized after SYN ACK */
819 tcp_connection_timers_init (tc);
821 TCP_EVT (TCP_EVT_OPEN, tc);
822 tc->state = TCP_STATE_SYN_SENT;
823 tcp_init_snd_vars (tc);
825 clib_spinlock_unlock_if_init (&tm->half_open_lock);
827 return tc->c_c_index;
830 const char *tcp_fsm_states[] = {
831 #define _(sym, str) str,
832 foreach_tcp_fsm_state
837 format_tcp_state (u8 * s, va_list * args)
839 u32 state = va_arg (*args, u32);
841 if (state < TCP_N_STATES)
842 s = format (s, "%s", tcp_fsm_states[state]);
844 s = format (s, "UNKNOWN (%d (0x%x))", state, state);
848 const char *tcp_cfg_flags_str[] = {
849 #define _(sym, str) str,
855 format_tcp_cfg_flags (u8 * s, va_list * args)
857 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
860 for (i = 0; i < TCP_CFG_N_FLAG_BITS; i++)
861 if (tc->cfg_flags & (1 << i))
863 for (i = 0; i < last; i++)
865 if (tc->cfg_flags & (1 << i))
866 s = format (s, "%s, ", tcp_cfg_flags_str[i]);
869 s = format (s, "%s", tcp_cfg_flags_str[last]);
873 const char *tcp_connection_flags_str[] = {
874 #define _(sym, str) str,
875 foreach_tcp_connection_flag
880 format_tcp_connection_flags (u8 * s, va_list * args)
882 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
885 for (i = 0; i < TCP_CONN_N_FLAG_BITS; i++)
886 if (tc->flags & (1 << i))
888 for (i = 0; i < last; i++)
890 if (tc->flags & (1 << i))
891 s = format (s, "%s, ", tcp_connection_flags_str[i]);
894 s = format (s, "%s", tcp_connection_flags_str[last]);
898 const char *tcp_conn_timers[] = {
899 #define _(sym, str) str,
905 format_tcp_timers (u8 * s, va_list * args)
907 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
910 for (i = 0; i < TCP_N_TIMERS; i++)
911 if (tc->timers[i] != TCP_TIMER_HANDLE_INVALID)
914 for (i = 0; i < last; i++)
916 if (tc->timers[i] != TCP_TIMER_HANDLE_INVALID)
917 s = format (s, "%s,", tcp_conn_timers[i]);
921 s = format (s, "%s", tcp_conn_timers[i]);
927 format_tcp_congestion_status (u8 * s, va_list * args)
929 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
930 if (tcp_in_recovery (tc))
931 s = format (s, "recovery");
932 else if (tcp_in_fastrecovery (tc))
933 s = format (s, "fastrecovery");
935 s = format (s, "none");
940 tcp_rcv_wnd_available (tcp_connection_t * tc)
942 return (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
946 format_tcp_congestion (u8 * s, va_list * args)
948 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
949 u32 indent = format_get_indent (s), prr_space = 0;
951 s = format (s, "%U ", format_tcp_congestion_status, tc);
952 s = format (s, "algo %s cwnd %u ssthresh %u bytes_acked %u\n",
953 tc->cc_algo->name, tc->cwnd, tc->ssthresh, tc->bytes_acked);
954 s = format (s, "%Ucc space %u prev_cwnd %u prev_ssthresh %u\n",
955 format_white_space, indent, tcp_available_cc_snd_space (tc),
956 tc->prev_cwnd, tc->prev_ssthresh);
957 s = format (s, "%Usnd_cong %u dupack %u limited_tx %u\n",
958 format_white_space, indent, tc->snd_congestion - tc->iss,
959 tc->rcv_dupacks, tc->limited_transmit - tc->iss);
960 s = format (s, "%Urxt_bytes %u rxt_delivered %u rxt_head %u rxt_ts %u\n",
961 format_white_space, indent, tc->snd_rxt_bytes,
962 tc->rxt_delivered, tc->rxt_head - tc->iss,
963 tcp_time_now_w_thread (tc->c_thread_index) - tc->snd_rxt_ts);
964 if (tcp_in_fastrecovery (tc))
965 prr_space = tcp_fastrecovery_prr_snd_space (tc);
966 s = format (s, "%Uprr_start %u prr_delivered %u prr space %u\n",
967 format_white_space, indent, tc->prr_start - tc->iss,
968 tc->prr_delivered, prr_space);
973 format_tcp_stats (u8 * s, va_list * args)
975 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
976 u32 indent = format_get_indent (s);
977 s = format (s, "in segs %lu dsegs %lu bytes %lu dupacks %u\n",
978 tc->segs_in, tc->data_segs_in, tc->bytes_in, tc->dupacks_in);
979 s = format (s, "%Uout segs %lu dsegs %lu bytes %lu dupacks %u\n",
980 format_white_space, indent, tc->segs_out,
981 tc->data_segs_out, tc->bytes_out, tc->dupacks_out);
982 s = format (s, "%Ufr %u tr %u rxt segs %lu bytes %lu duration %.3f\n",
983 format_white_space, indent, tc->fr_occurences,
984 tc->tr_occurences, tc->segs_retrans, tc->bytes_retrans,
985 tcp_time_now_us (tc->c_thread_index) - tc->start_ts);
986 s = format (s, "%Uerr wnd data below %u above %u ack below %u above %u",
987 format_white_space, indent, tc->errors.below_data_wnd,
988 tc->errors.above_data_wnd, tc->errors.below_ack_wnd,
989 tc->errors.above_ack_wnd);
994 format_tcp_vars (u8 * s, va_list * args)
996 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
997 s = format (s, " index: %u cfg: %U flags: %U timers: %U\n", tc->c_c_index,
998 format_tcp_cfg_flags, tc, format_tcp_connection_flags, tc,
999 format_tcp_timers, tc);
1000 s = format (s, " snd_una %u snd_nxt %u snd_una_max %u",
1001 tc->snd_una - tc->iss, tc->snd_nxt - tc->iss,
1002 tc->snd_una_max - tc->iss);
1003 s = format (s, " rcv_nxt %u rcv_las %u\n",
1004 tc->rcv_nxt - tc->irs, tc->rcv_las - tc->irs);
1005 s = format (s, " snd_wnd %u rcv_wnd %u rcv_wscale %u ",
1006 tc->snd_wnd, tc->rcv_wnd, tc->rcv_wscale);
1007 s = format (s, "snd_wl1 %u snd_wl2 %u\n", tc->snd_wl1 - tc->irs,
1008 tc->snd_wl2 - tc->iss);
1009 s = format (s, " flight size %u out space %u rcv_wnd_av %u",
1010 tcp_flight_size (tc), tcp_available_output_snd_space (tc),
1011 tcp_rcv_wnd_available (tc));
1012 s = format (s, " tsval_recent %u\n", tc->tsval_recent);
1013 s = format (s, " tsecr %u tsecr_last_ack %u tsval_recent_age %u",
1014 tc->rcv_opts.tsecr, tc->tsecr_last_ack,
1015 tcp_time_now () - tc->tsval_recent_age);
1016 s = format (s, " snd_mss %u\n", tc->snd_mss);
1017 s = format (s, " rto %u rto_boff %u srtt %u us %.3f rttvar %u rtt_ts %.4f",
1018 tc->rto, tc->rto_boff, tc->srtt, tc->mrtt_us * 1000, tc->rttvar,
1020 s = format (s, " rtt_seq %u\n", tc->rtt_seq - tc->iss);
1021 s = format (s, " cong: %U", format_tcp_congestion, tc);
1023 if (tc->state >= TCP_STATE_ESTABLISHED)
1025 s = format (s, " sboard: %U\n", format_tcp_scoreboard, &tc->sack_sb,
1027 s = format (s, " stats: %U\n", format_tcp_stats, tc);
1029 if (vec_len (tc->snd_sacks))
1030 s = format (s, " sacks tx: %U\n", format_tcp_sacks, tc);
1036 format_tcp_connection_id (u8 * s, va_list * args)
1038 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
1043 s = format (s, "[%d:%d][%s] %U:%d->%U:%d", tc->c_thread_index,
1044 tc->c_s_index, "T", format_ip4_address, &tc->c_lcl_ip4,
1045 clib_net_to_host_u16 (tc->c_lcl_port), format_ip4_address,
1046 &tc->c_rmt_ip4, clib_net_to_host_u16 (tc->c_rmt_port));
1050 s = format (s, "[%d:%d][%s] %U:%d->%U:%d", tc->c_thread_index,
1051 tc->c_s_index, "T", format_ip6_address, &tc->c_lcl_ip6,
1052 clib_net_to_host_u16 (tc->c_lcl_port), format_ip6_address,
1053 &tc->c_rmt_ip6, clib_net_to_host_u16 (tc->c_rmt_port));
1060 format_tcp_connection (u8 * s, va_list * args)
1062 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
1063 u32 verbose = va_arg (*args, u32);
1067 s = format (s, "%-50U", format_tcp_connection_id, tc);
1070 s = format (s, "%-15U", format_tcp_state, tc->state);
1072 s = format (s, "\n%U", format_tcp_vars, tc);
1079 format_tcp_session (u8 * s, va_list * args)
1081 u32 tci = va_arg (*args, u32);
1082 u32 thread_index = va_arg (*args, u32);
1083 u32 verbose = va_arg (*args, u32);
1084 tcp_connection_t *tc;
1086 tc = tcp_connection_get (tci, thread_index);
1088 s = format (s, "%U", format_tcp_connection, tc, verbose);
1090 s = format (s, "empty\n");
1095 format_tcp_listener_session (u8 * s, va_list * args)
1097 u32 tci = va_arg (*args, u32);
1098 u32 __clib_unused thread_index = va_arg (*args, u32);
1099 u32 verbose = va_arg (*args, u32);
1100 tcp_connection_t *tc = tcp_listener_get (tci);
1101 s = format (s, "%-50U", format_tcp_connection_id, tc);
1103 s = format (s, "%-15U", format_tcp_state, tc->state);
1108 format_tcp_half_open_session (u8 * s, va_list * args)
1110 u32 tci = va_arg (*args, u32);
1111 u32 __clib_unused thread_index = va_arg (*args, u32);
1112 tcp_connection_t *tc = tcp_half_open_connection_get (tci);
1113 return format (s, "%U", format_tcp_connection_id, tc);
1117 format_tcp_sacks (u8 * s, va_list * args)
1119 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
1120 sack_block_t *sacks = tc->snd_sacks;
1121 sack_block_t *block;
1124 len = vec_len (sacks);
1125 for (i = 0; i < len - 1; i++)
1128 s = format (s, " start %u end %u\n", block->start - tc->irs,
1129 block->end - tc->irs);
1133 block = &sacks[len - 1];
1134 s = format (s, " start %u end %u", block->start - tc->irs,
1135 block->end - tc->irs);
1141 format_tcp_rcv_sacks (u8 * s, va_list * args)
1143 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
1144 sack_block_t *sacks = tc->rcv_opts.sacks;
1145 sack_block_t *block;
1148 len = vec_len (sacks);
1149 for (i = 0; i < len - 1; i++)
1152 s = format (s, " start %u end %u\n", block->start - tc->iss,
1153 block->end - tc->iss);
1157 block = &sacks[len - 1];
1158 s = format (s, " start %u end %u", block->start - tc->iss,
1159 block->end - tc->iss);
1165 format_tcp_sack_hole (u8 * s, va_list * args)
1167 sack_scoreboard_hole_t *hole = va_arg (*args, sack_scoreboard_hole_t *);
1168 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
1170 s = format (s, " [%u, %u]", hole->start - tc->iss, hole->end - tc->iss);
1172 s = format (s, " [%u, %u]", hole->start, hole->end);
1177 format_tcp_scoreboard (u8 * s, va_list * args)
1179 sack_scoreboard_t *sb = va_arg (*args, sack_scoreboard_t *);
1180 tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
1181 sack_scoreboard_hole_t *hole;
1182 u32 indent = format_get_indent (s);
1184 s = format (s, "sacked %u last_sacked %u lost %u last_lost %u"
1186 sb->sacked_bytes, sb->last_sacked_bytes, sb->lost_bytes,
1187 sb->last_lost_bytes, sb->rxt_sacked);
1188 s = format (s, "%Ulast_delivered %u high_sacked %u is_reneging %u\n",
1189 format_white_space, indent, sb->last_bytes_delivered,
1190 sb->high_sacked - tc->iss, sb->is_reneging);
1191 s = format (s, "%Ucur_rxt_hole %u high_rxt %u rescue_rxt %u",
1192 format_white_space, indent, sb->cur_rxt_hole,
1193 sb->high_rxt - tc->iss, sb->rescue_rxt - tc->iss);
1195 hole = scoreboard_first_hole (sb);
1197 s = format (s, "\n%Uhead %u tail %u %u holes:\n%U", format_white_space,
1198 indent, sb->head, sb->tail, pool_elts (sb->holes),
1199 format_white_space, indent);
1203 s = format (s, "%U", format_tcp_sack_hole, hole, tc);
1204 hole = scoreboard_next_hole (sb, hole);
1210 static transport_connection_t *
1211 tcp_session_get_transport (u32 conn_index, u32 thread_index)
1213 tcp_connection_t *tc = tcp_connection_get (conn_index, thread_index);
1214 if (PREDICT_FALSE (!tc))
1216 return &tc->connection;
1219 static transport_connection_t *
1220 tcp_half_open_session_get_transport (u32 conn_index)
1222 tcp_connection_t *tc = tcp_half_open_connection_get (conn_index);
1223 return &tc->connection;
1227 tcp_session_cal_goal_size (tcp_connection_t * tc)
1229 u16 goal_size = tc->snd_mss;
1231 goal_size = TCP_MAX_GSO_SZ - tc->snd_mss % TCP_MAX_GSO_SZ;
1232 goal_size = clib_min (goal_size, tc->snd_wnd / 2);
1234 return goal_size > tc->snd_mss ? goal_size : tc->snd_mss;
1238 * Compute maximum segment size for session layer.
1240 * Since the result needs to be the actual data length, it first computes
1241 * the tcp options to be used in the next burst and subtracts their
1242 * length from the connection's snd_mss.
1245 tcp_session_send_mss (transport_connection_t * trans_conn)
1247 tcp_connection_t *tc = (tcp_connection_t *) trans_conn;
1249 /* Ensure snd_mss does accurately reflect the amount of data we can push
1250 * in a segment. This also makes sure that options are updated according to
1251 * the current state of the connection. */
1252 tcp_update_burst_snd_vars (tc);
1254 if (PREDICT_FALSE (tc->cfg_flags & TCP_CFG_F_TSO))
1255 return tcp_session_cal_goal_size (tc);
1261 tcp_round_snd_space (tcp_connection_t * tc, u32 snd_space)
1263 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
1265 return tc->snd_wnd <= snd_space ? tc->snd_wnd : 0;
1268 /* If not snd_wnd constrained and we can't write at least a segment,
1269 * don't try at all */
1270 if (PREDICT_FALSE (snd_space < tc->snd_mss))
1271 return snd_space < tc->cwnd ? 0 : snd_space;
1273 /* round down to mss multiple */
1274 return snd_space - (snd_space % tc->snd_mss);
1278 * Compute tx window session is allowed to fill.
1280 * Takes into account available send space, snd_mss and the congestion
1281 * state of the connection. If possible, the value returned is a multiple
1284 * @param tc tcp connection
1285 * @return number of bytes session is allowed to write
1288 tcp_snd_space_inline (tcp_connection_t * tc)
1292 if (PREDICT_FALSE (tcp_in_fastrecovery (tc)
1293 || tc->state == TCP_STATE_CLOSED))
1296 snd_space = tcp_available_output_snd_space (tc);
1298 /* If we got dupacks or sacked bytes but we're not yet in recovery, try
1299 * to force the peer to send enough dupacks to start retransmitting as
1300 * per Limited Transmit (RFC3042)
1302 if (PREDICT_FALSE (tc->rcv_dupacks != 0 || tc->sack_sb.sacked_bytes))
1304 if (tc->limited_transmit != tc->snd_nxt
1305 && (seq_lt (tc->limited_transmit, tc->snd_nxt - 2 * tc->snd_mss)
1306 || seq_gt (tc->limited_transmit, tc->snd_nxt)))
1307 tc->limited_transmit = tc->snd_nxt;
1309 ASSERT (seq_leq (tc->limited_transmit, tc->snd_nxt));
1311 int snt_limited = tc->snd_nxt - tc->limited_transmit;
1312 snd_space = clib_max ((int) 2 * tc->snd_mss - snt_limited, 0);
1314 return tcp_round_snd_space (tc, snd_space);
1318 tcp_snd_space (tcp_connection_t * tc)
1320 return tcp_snd_space_inline (tc);
1324 tcp_session_send_space (transport_connection_t * trans_conn)
1326 tcp_connection_t *tc = (tcp_connection_t *) trans_conn;
1327 return clib_min (tcp_snd_space_inline (tc),
1328 tc->snd_wnd - (tc->snd_nxt - tc->snd_una));
1332 tcp_session_tx_fifo_offset (transport_connection_t * trans_conn)
1334 tcp_connection_t *tc = (tcp_connection_t *) trans_conn;
1336 ASSERT (seq_geq (tc->snd_nxt, tc->snd_una));
1338 /* This still works if fast retransmit is on */
1339 return (tc->snd_nxt - tc->snd_una);
1343 tcp_update_time (f64 now, u8 thread_index)
1345 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
1347 tcp_set_time_now (wrk);
1348 tw_timer_expire_timers_16t_2w_512sl (&wrk->timer_wheel, now);
1349 tcp_flush_frames_to_output (wrk);
1353 tcp_session_flush_data (transport_connection_t * tconn)
1355 tcp_connection_t *tc = (tcp_connection_t *) tconn;
1356 if (tc->flags & TCP_CONN_PSH_PENDING)
1358 tc->flags |= TCP_CONN_PSH_PENDING;
1359 tc->psh_seq = tc->snd_una + transport_max_tx_dequeue (tconn) - 1;
1363 const static transport_proto_vft_t tcp_proto = {
1364 .enable = vnet_tcp_enable_disable,
1365 .start_listen = tcp_session_bind,
1366 .stop_listen = tcp_session_unbind,
1367 .push_header = tcp_session_push_header,
1368 .get_connection = tcp_session_get_transport,
1369 .get_listener = tcp_session_get_listener,
1370 .get_half_open = tcp_half_open_session_get_transport,
1371 .connect = tcp_session_open,
1372 .close = tcp_session_close,
1373 .cleanup = tcp_session_cleanup,
1374 .reset = tcp_session_reset,
1375 .send_mss = tcp_session_send_mss,
1376 .send_space = tcp_session_send_space,
1377 .update_time = tcp_update_time,
1378 .tx_fifo_offset = tcp_session_tx_fifo_offset,
1379 .flush_data = tcp_session_flush_data,
1380 .custom_tx = tcp_session_custom_tx,
1381 .format_connection = format_tcp_session,
1382 .format_listener = format_tcp_listener_session,
1383 .format_half_open = format_tcp_half_open_session,
1384 .transport_options = {
1385 .tx_type = TRANSPORT_TX_PEEK,
1386 .service_type = TRANSPORT_SERVICE_VC,
1392 tcp_connection_tx_pacer_update (tcp_connection_t * tc)
1394 if (!transport_connection_is_tx_paced (&tc->connection))
1397 transport_connection_tx_pacer_update (&tc->connection,
1398 tcp_cc_get_pacing_rate (tc));
1402 tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window,
1405 f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us);
1406 u64 rate = (u64) window / srtt;
1407 transport_connection_tx_pacer_reset (&tc->connection, rate, start_bucket);
1411 tcp_timer_waitclose_handler (u32 conn_index)
1413 u32 thread_index = vlib_get_thread_index ();
1414 tcp_connection_t *tc;
1416 tc = tcp_connection_get (conn_index, thread_index);
1420 tc->timers[TCP_TIMER_WAITCLOSE] = TCP_TIMER_HANDLE_INVALID;
1424 case TCP_STATE_CLOSE_WAIT:
1425 tcp_connection_timers_reset (tc);
1426 session_transport_closed_notify (&tc->connection);
1428 if (!(tc->flags & TCP_CONN_FINPNDG))
1430 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1431 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
1435 /* Session didn't come back with a close. Send FIN either way
1436 * and switch to LAST_ACK. */
1437 tcp_cong_recovery_off (tc);
1438 /* Make sure we don't try to send unsent data */
1439 tc->snd_nxt = tc->snd_una;
1441 tcp_connection_set_state (tc, TCP_STATE_LAST_ACK);
1443 /* Make sure we don't wait in LAST ACK forever */
1444 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
1446 /* Don't delete the connection yet */
1448 case TCP_STATE_FIN_WAIT_1:
1449 tcp_connection_timers_reset (tc);
1450 session_transport_closed_notify (&tc->connection);
1451 if (tc->flags & TCP_CONN_FINPNDG)
1453 /* If FIN pending, we haven't sent everything, but we did try.
1454 * Notify session layer that transport is closed. */
1455 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1456 tcp_send_reset (tc);
1457 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
1461 /* We've sent the fin but no progress. Close the connection and
1462 * to make sure everything is flushed, setup a cleanup timer */
1463 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1464 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
1467 case TCP_STATE_LAST_ACK:
1468 case TCP_STATE_CLOSING:
1469 tcp_connection_timers_reset (tc);
1470 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1471 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
1472 session_transport_closed_notify (&tc->connection);
1475 tcp_connection_del (tc);
1481 static timer_expiration_handler *timer_expiration_handlers[TCP_N_TIMERS] =
1483 tcp_timer_retransmit_handler,
1484 tcp_timer_delack_handler,
1485 tcp_timer_persist_handler,
1486 tcp_timer_waitclose_handler,
1487 tcp_timer_retransmit_syn_handler,
1492 tcp_expired_timers_dispatch (u32 * expired_timers)
1495 u32 connection_index, timer_id;
1497 for (i = 0; i < vec_len (expired_timers); i++)
1499 /* Get session index and timer id */
1500 connection_index = expired_timers[i] & 0x0FFFFFFF;
1501 timer_id = expired_timers[i] >> 28;
1503 TCP_EVT (TCP_EVT_TIMER_POP, connection_index, timer_id);
1505 /* Handle expiration */
1506 (*timer_expiration_handlers[timer_id]) (connection_index);
1511 tcp_initialize_timer_wheels (tcp_main_t * tm)
1513 tw_timer_wheel_16t_2w_512sl_t *tw;
1515 foreach_vlib_main (({
1516 tw = &tm->wrk_ctx[ii].timer_wheel;
1517 tw_timer_wheel_init_16t_2w_512sl (tw, tcp_expired_timers_dispatch,
1518 TCP_TIMER_TICK, ~0);
1519 tw->last_run_time = vlib_time_now (this_vlib_main);
1525 tcp_initialize_iss_seed (tcp_main_t * tm)
1527 u32 default_seed = random_default_seed ();
1528 u64 time_now = clib_cpu_time_now ();
1530 tm->iss_seed.first = (u64) random_u32 (&default_seed) << 32;
1531 tm->iss_seed.second = random_u64 (&time_now);
1534 static clib_error_t *
1535 tcp_main_enable (vlib_main_t * vm)
1537 vlib_thread_main_t *vtm = vlib_get_thread_main ();
1538 u32 num_threads, n_workers, prealloc_conn_per_wrk;
1539 tcp_connection_t *tc __attribute__ ((unused));
1540 tcp_main_t *tm = vnet_get_tcp_main ();
1541 clib_error_t *error = 0;
1544 if ((error = vlib_call_init_function (vm, ip_main_init)))
1546 if ((error = vlib_call_init_function (vm, ip4_lookup_init)))
1548 if ((error = vlib_call_init_function (vm, ip6_lookup_init)))
1555 ip4_register_protocol (IP_PROTOCOL_TCP, tcp4_input_node.index);
1556 ip6_register_protocol (IP_PROTOCOL_TCP, tcp6_input_node.index);
1559 * Initialize data structures
1562 num_threads = 1 /* main thread */ + vtm->n_threads;
1563 vec_validate (tm->connections, num_threads - 1);
1564 vec_validate (tm->wrk_ctx, num_threads - 1);
1565 n_workers = num_threads == 1 ? 1 : vtm->n_threads;
1566 prealloc_conn_per_wrk = tcp_cfg.preallocated_connections / n_workers;
1568 for (thread = 0; thread < num_threads; thread++)
1570 vec_validate (tm->wrk_ctx[thread].pending_deq_acked, 255);
1571 vec_validate (tm->wrk_ctx[thread].pending_disconnects, 255);
1572 vec_reset_length (tm->wrk_ctx[thread].pending_deq_acked);
1573 vec_reset_length (tm->wrk_ctx[thread].pending_disconnects);
1574 tm->wrk_ctx[thread].vm = vlib_mains[thread];
1577 * Preallocate connections. Assume that thread 0 won't
1578 * use preallocated threads when running multi-core
1580 if ((thread > 0 || num_threads == 1) && prealloc_conn_per_wrk)
1581 pool_init_fixed (tm->connections[thread], prealloc_conn_per_wrk);
1585 * Use a preallocated half-open connection pool?
1587 if (tcp_cfg.preallocated_half_open_connections)
1588 pool_init_fixed (tm->half_open_connections,
1589 tcp_cfg.preallocated_half_open_connections);
1591 /* Initialize clocks per tick for TCP timestamp. Used to compute
1592 * monotonically increasing timestamps. */
1593 tm->tstamp_ticks_per_clock = vm->clib_time.seconds_per_clock
1594 / TCP_TSTAMP_RESOLUTION;
1596 if (num_threads > 1)
1598 clib_spinlock_init (&tm->half_open_lock);
1601 tcp_initialize_timer_wheels (tm);
1602 tcp_initialize_iss_seed (tm);
1604 tm->bytes_per_buffer = vlib_buffer_get_default_data_size (vm);
1605 tm->cc_last_type = TCP_CC_LAST;
1610 vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en)
1614 if (tcp_main.is_enabled)
1617 return tcp_main_enable (vm);
1621 tcp_main.is_enabled = 0;
1628 tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add)
1630 tcp_main_t *tm = &tcp_main;
1632 tm->punt_unknown4 = is_add;
1634 tm->punt_unknown6 = is_add;
1638 * Initialize default values for tcp parameters
1641 tcp_configuration_init (void)
1643 /* Initial wnd for SYN. Fifos are not allocated at that point so use some
1644 * predefined value. For SYN-ACK we still want the scale to be computed in
1646 tcp_cfg.max_rx_fifo = 32 << 20;
1647 tcp_cfg.min_rx_fifo = 4 << 10;
1649 tcp_cfg.default_mtu = 1500;
1650 tcp_cfg.initial_cwnd_multiplier = 0;
1651 tcp_cfg.enable_tx_pacing = 1;
1652 tcp_cfg.allow_tso = 0;
1653 tcp_cfg.cc_algo = TCP_CC_NEWRENO;
1654 tcp_cfg.rwnd_min_update_ack = 1;
1656 /* Time constants defined as timer tick (100ms) multiples */
1657 tcp_cfg.delack_time = 1; /* 0.1s */
1658 tcp_cfg.closewait_time = 20; /* 2s */
1659 tcp_cfg.timewait_time = 100; /* 10s */
1660 tcp_cfg.finwait1_time = 600; /* 60s */
1661 tcp_cfg.lastack_time = 300; /* 30s */
1662 tcp_cfg.finwait2_time = 300; /* 30s */
1663 tcp_cfg.closing_time = 300; /* 30s */
1664 tcp_cfg.cleanup_time = 1; /* 0.1s */
1667 static clib_error_t *
1668 tcp_init (vlib_main_t * vm)
1670 tcp_main_t *tm = vnet_get_tcp_main ();
1671 ip_main_t *im = &ip_main;
1672 ip_protocol_info_t *pi;
1674 /* Session layer, and by implication tcp, are disabled by default */
1677 /* Register with IP for header parsing */
1678 pi = ip_get_protocol_info (im, IP_PROTOCOL_TCP);
1680 return clib_error_return (0, "TCP protocol info AWOL");
1681 pi->format_header = format_tcp_header;
1682 pi->unformat_pg_edit = unformat_pg_tcp_header;
1684 /* Register as transport with session layer */
1685 transport_register_protocol (TRANSPORT_PROTO_TCP, &tcp_proto,
1686 FIB_PROTOCOL_IP4, tcp4_output_node.index);
1687 transport_register_protocol (TRANSPORT_PROTO_TCP, &tcp_proto,
1688 FIB_PROTOCOL_IP6, tcp6_output_node.index);
1690 tcp_api_reference ();
1691 tcp_configuration_init ();
1693 tm->cc_algo_by_name = hash_create_string (0, sizeof (uword));
1698 VLIB_INIT_FUNCTION (tcp_init);
1701 unformat_tcp_cc_algo (unformat_input_t * input, va_list * va)
1703 tcp_cc_algorithm_type_e *result = va_arg (*va, tcp_cc_algorithm_type_e *);
1704 tcp_main_t *tm = &tcp_main;
1709 if (unformat (input, "%s", &cc_algo_name)
1710 && ((p = hash_get_mem (tm->cc_algo_by_name, cc_algo_name))))
1716 vec_free (cc_algo_name);
1721 unformat_tcp_cc_algo_cfg (unformat_input_t * input, va_list * va)
1723 tcp_main_t *tm = vnet_get_tcp_main ();
1724 tcp_cc_algorithm_t *cc_alg;
1725 unformat_input_t sub_input;
1728 vec_foreach (cc_alg, tm->cc_algos)
1730 if (!unformat (input, cc_alg->name))
1733 if (cc_alg->unformat_cfg
1734 && unformat (input, "%U", unformat_vlib_cli_sub_input, &sub_input))
1736 if (cc_alg->unformat_cfg (&sub_input))
1743 static clib_error_t *
1744 tcp_config_fn (vlib_main_t * vm, unformat_input_t * input)
1746 u32 cwnd_multiplier, tmp_time;
1749 while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1751 if (unformat (input, "preallocated-connections %d",
1752 &tcp_cfg.preallocated_connections))
1754 else if (unformat (input, "preallocated-half-open-connections %d",
1755 &tcp_cfg.preallocated_half_open_connections))
1757 else if (unformat (input, "buffer-fail-fraction %f",
1758 &tcp_cfg.buffer_fail_fraction))
1760 else if (unformat (input, "max-rx-fifo %U", unformat_memory_size,
1763 if (memory_size >= 0x100000000)
1765 return clib_error_return
1766 (0, "max-rx-fifo %llu (0x%llx) too large", memory_size,
1769 tcp_cfg.max_rx_fifo = memory_size;
1771 else if (unformat (input, "min-rx-fifo %U", unformat_memory_size,
1774 if (memory_size >= 0x100000000)
1776 return clib_error_return
1777 (0, "min-rx-fifo %llu (0x%llx) too large", memory_size,
1780 tcp_cfg.min_rx_fifo = memory_size;
1782 else if (unformat (input, "mtu %u", &tcp_cfg.default_mtu))
1784 else if (unformat (input, "rwnd-min-update-ack %d",
1785 &tcp_cfg.rwnd_min_update_ack))
1787 else if (unformat (input, "initial-cwnd-multiplier %u",
1789 tcp_cfg.initial_cwnd_multiplier = cwnd_multiplier;
1790 else if (unformat (input, "no-tx-pacing"))
1791 tcp_cfg.enable_tx_pacing = 0;
1792 else if (unformat (input, "tso"))
1793 tcp_cfg.allow_tso = 1;
1794 else if (unformat (input, "cc-algo %U", unformat_tcp_cc_algo,
1797 else if (unformat (input, "%U", unformat_tcp_cc_algo_cfg))
1799 else if (unformat (input, "closewait-time %u", &tmp_time))
1800 tcp_cfg.closewait_time = tmp_time / TCP_TIMER_TICK;
1801 else if (unformat (input, "timewait-time %u", &tmp_time))
1802 tcp_cfg.timewait_time = tmp_time / TCP_TIMER_TICK;
1803 else if (unformat (input, "finwait1-time %u", &tmp_time))
1804 tcp_cfg.finwait1_time = tmp_time / TCP_TIMER_TICK;
1805 else if (unformat (input, "finwait2-time %u", &tmp_time))
1806 tcp_cfg.finwait2_time = tmp_time / TCP_TIMER_TICK;
1807 else if (unformat (input, "lastack-time %u", &tmp_time))
1808 tcp_cfg.lastack_time = tmp_time / TCP_TIMER_TICK;
1809 else if (unformat (input, "closing-time %u", &tmp_time))
1810 tcp_cfg.closing_time = tmp_time / TCP_TIMER_TICK;
1811 else if (unformat (input, "cleanup-time %u", &tmp_time))
1812 tcp_cfg.cleanup_time = tmp_time / TCP_TIMER_TICK;
1814 return clib_error_return (0, "unknown input `%U'",
1815 format_unformat_error, input);
1820 VLIB_CONFIG_FUNCTION (tcp_config_fn, "tcp");
1824 * \brief Configure an ipv4 source address range
1825 * @param vm vlib_main_t pointer
1826 * @param start first ipv4 address in the source address range
1827 * @param end last ipv4 address in the source address range
1828 * @param table_id VRF / table ID, 0 for the default FIB
1829 * @return 0 if all OK, else an error indication from api_errno.h
1833 tcp_configure_v4_source_address_range (vlib_main_t * vm,
1834 ip4_address_t * start,
1835 ip4_address_t * end, u32 table_id)
1837 vnet_main_t *vnm = vnet_get_main ();
1838 u32 start_host_byte_order, end_host_byte_order;
1839 fib_prefix_t prefix;
1840 fib_node_index_t fei;
1845 clib_memset (&prefix, 0, sizeof (prefix));
1847 fib_index = fib_table_find (FIB_PROTOCOL_IP4, table_id);
1849 if (fib_index == ~0)
1850 return VNET_API_ERROR_NO_SUCH_FIB;
1852 start_host_byte_order = clib_net_to_host_u32 (start->as_u32);
1853 end_host_byte_order = clib_net_to_host_u32 (end->as_u32);
1855 /* sanity check for reversed args or some such */
1856 if ((end_host_byte_order - start_host_byte_order) > (10 << 10))
1857 return VNET_API_ERROR_INVALID_ARGUMENT;
1859 /* Lookup the last address, to identify the interface involved */
1861 prefix.fp_proto = FIB_PROTOCOL_IP4;
1862 memcpy (&prefix.fp_addr.ip4, end, sizeof (ip4_address_t));
1864 fei = fib_table_lookup (fib_index, &prefix);
1866 /* Couldn't find route to destination. Bail out. */
1867 if (fei == FIB_NODE_INDEX_INVALID)
1868 return VNET_API_ERROR_NEXT_HOP_NOT_IN_FIB;
1870 sw_if_index = fib_entry_get_resolving_interface (fei);
1872 /* Configure proxy arp across the range */
1873 rv = vnet_proxy_arp_add_del (start, end, fib_index, 0 /* is_del */ );
1878 rv = vnet_proxy_arp_enable_disable (vnm, sw_if_index, 1);
1885 dpo_id_t dpo = DPO_INVALID;
1887 vec_add1 (tcp_cfg.ip4_src_addrs, start[0]);
1889 /* Add local adjacencies for the range */
1891 receive_dpo_add_or_lock (DPO_PROTO_IP4, ~0 /* sw_if_index */ ,
1894 prefix.fp_proto = FIB_PROTOCOL_IP4;
1895 prefix.fp_addr.ip4.as_u32 = start->as_u32;
1897 fib_table_entry_special_dpo_update (fib_index,
1900 FIB_ENTRY_FLAG_EXCLUSIVE, &dpo);
1903 start_host_byte_order++;
1904 start->as_u32 = clib_host_to_net_u32 (start_host_byte_order);
1906 while (start_host_byte_order <= end_host_byte_order);
1912 * \brief Configure an ipv6 source address range
1913 * @param vm vlib_main_t pointer
1914 * @param start first ipv6 address in the source address range
1915 * @param end last ipv6 address in the source address range
1916 * @param table_id VRF / table ID, 0 for the default FIB
1917 * @return 0 if all OK, else an error indication from api_errno.h
1921 tcp_configure_v6_source_address_range (vlib_main_t * vm,
1922 ip6_address_t * start,
1923 ip6_address_t * end, u32 table_id)
1925 fib_prefix_t prefix;
1927 fib_node_index_t fei;
1930 clib_memset (&prefix, 0, sizeof (prefix));
1932 fib_index = fib_table_find (FIB_PROTOCOL_IP6, table_id);
1934 if (fib_index == ~0)
1935 return VNET_API_ERROR_NO_SUCH_FIB;
1941 dpo_id_t dpo = DPO_INVALID;
1943 /* Remember this address */
1944 vec_add1 (tcp_cfg.ip6_src_addrs, start[0]);
1946 /* Lookup the prefix, to identify the interface involved */
1947 prefix.fp_len = 128;
1948 prefix.fp_proto = FIB_PROTOCOL_IP6;
1949 memcpy (&prefix.fp_addr.ip6, start, sizeof (ip6_address_t));
1951 fei = fib_table_lookup (fib_index, &prefix);
1953 /* Couldn't find route to destination. Bail out. */
1954 if (fei == FIB_NODE_INDEX_INVALID)
1955 return VNET_API_ERROR_NEXT_HOP_NOT_IN_FIB;
1957 sw_if_index = fib_entry_get_resolving_interface (fei);
1959 if (sw_if_index == (u32) ~ 0)
1960 return VNET_API_ERROR_NO_MATCHING_INTERFACE;
1962 /* Add a proxy neighbor discovery entry for this address */
1963 ip6_neighbor_proxy_add_del (sw_if_index, start, 0 /* is_del */ );
1965 /* Add a receive adjacency for this address */
1966 receive_dpo_add_or_lock (DPO_PROTO_IP6, ~0 /* sw_if_index */ ,
1969 fib_table_entry_special_dpo_update (fib_index,
1972 FIB_ENTRY_FLAG_EXCLUSIVE, &dpo);
1975 /* Done with the entire range? */
1976 if (!memcmp (start, end, sizeof (start[0])))
1979 /* Increment the address. DGMS. */
1981 for (i = 15; i >= 0; i--)
1984 if (tmp.as_u8[i] != 0)
1992 static clib_error_t *
1993 tcp_src_address (vlib_main_t * vm,
1994 unformat_input_t * input, vlib_cli_command_t * cmd_arg)
1996 ip4_address_t v4start, v4end;
1997 ip6_address_t v6start, v6end;
2003 while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
2005 if (unformat (input, "%U - %U", unformat_ip4_address, &v4start,
2006 unformat_ip4_address, &v4end))
2008 else if (unformat (input, "%U", unformat_ip4_address, &v4start))
2010 memcpy (&v4end, &v4start, sizeof (v4start));
2013 else if (unformat (input, "%U - %U", unformat_ip6_address, &v6start,
2014 unformat_ip6_address, &v6end))
2016 else if (unformat (input, "%U", unformat_ip6_address, &v6start))
2018 memcpy (&v6end, &v6start, sizeof (v6start));
2021 else if (unformat (input, "fib-table %d", &table_id))
2027 if (!v4set && !v6set)
2028 return clib_error_return (0, "at least one v4 or v6 address required");
2032 rv = tcp_configure_v4_source_address_range (vm, &v4start, &v4end,
2039 case VNET_API_ERROR_NO_SUCH_FIB:
2040 return clib_error_return (0, "Invalid table-id %d", table_id);
2042 case VNET_API_ERROR_INVALID_ARGUMENT:
2043 return clib_error_return (0, "Invalid address range %U - %U",
2044 format_ip4_address, &v4start,
2045 format_ip4_address, &v4end);
2047 return clib_error_return (0, "error %d", rv);
2053 rv = tcp_configure_v6_source_address_range (vm, &v6start, &v6end,
2060 case VNET_API_ERROR_NO_SUCH_FIB:
2061 return clib_error_return (0, "Invalid table-id %d", table_id);
2064 return clib_error_return (0, "error %d", rv);
2072 VLIB_CLI_COMMAND (tcp_src_address_command, static) =
2074 .path = "tcp src-address",
2075 .short_help = "tcp src-address <ip-addr> [- <ip-addr>] add src address range",
2076 .function = tcp_src_address,
2081 tcp_scoreboard_dump_trace (u8 * s, sack_scoreboard_t * sb)
2083 #if TCP_SCOREBOARD_TRACE
2085 scoreboard_trace_elt_t *block;
2091 s = format (s, "scoreboard trace:");
2092 vec_foreach (block, sb->trace)
2094 s = format (s, "{%u, %u, %u, %u, %u}, ", block->start, block->end,
2095 block->ack, block->snd_una_max, block->group);
2097 s = format (s, "\n");
2105 static clib_error_t *
2106 tcp_show_scoreboard_trace_fn (vlib_main_t * vm, unformat_input_t * input,
2107 vlib_cli_command_t * cmd_arg)
2109 transport_connection_t *tconn = 0;
2110 tcp_connection_t *tc;
2112 while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
2114 if (unformat (input, "%U", unformat_transport_connection, &tconn,
2115 TRANSPORT_PROTO_TCP))
2118 return clib_error_return (0, "unknown input `%U'",
2119 format_unformat_error, input);
2122 if (!TCP_SCOREBOARD_TRACE)
2124 vlib_cli_output (vm, "scoreboard tracing not enabled");
2128 tc = tcp_get_connection_from_transport (tconn);
2129 s = tcp_scoreboard_dump_trace (s, &tc->sack_sb);
2130 vlib_cli_output (vm, "%v", s);
2135 VLIB_CLI_COMMAND (tcp_show_scoreboard_trace_command, static) =
2137 .path = "show tcp scoreboard trace",
2138 .short_help = "show tcp scoreboard trace <connection>",
2139 .function = tcp_show_scoreboard_trace_fn,
2144 tcp_scoreboard_replay (u8 * s, tcp_connection_t * tc, u8 verbose)
2147 scoreboard_trace_elt_t *trace;
2148 u32 next_ack, left, group, has_new_ack = 0;
2149 tcp_connection_t _dummy_tc, *dummy_tc = &_dummy_tc;
2150 sack_block_t *block;
2152 if (!TCP_SCOREBOARD_TRACE)
2154 s = format (s, "scoreboard tracing not enabled");
2161 clib_memset (dummy_tc, 0, sizeof (*dummy_tc));
2162 tcp_connection_timers_init (dummy_tc);
2163 scoreboard_init (&dummy_tc->sack_sb);
2164 dummy_tc->rcv_opts.flags |= TCP_OPTS_FLAG_SACK;
2166 #if TCP_SCOREBOARD_TRACE
2167 trace = tc->sack_sb.trace;
2168 trace_len = vec_len (tc->sack_sb.trace);
2171 for (i = 0; i < trace_len; i++)
2173 if (trace[i].ack != 0)
2175 dummy_tc->snd_una = trace[i].ack - 1448;
2176 dummy_tc->snd_una_max = trace[i].ack;
2181 while (left < trace_len)
2183 group = trace[left].group;
2184 vec_reset_length (dummy_tc->rcv_opts.sacks);
2186 while (trace[left].group == group)
2188 if (trace[left].ack != 0)
2191 s = format (s, "Adding ack %u, snd_una_max %u, segs: ",
2192 trace[left].ack, trace[left].snd_una_max);
2193 dummy_tc->snd_una_max = trace[left].snd_una_max;
2194 next_ack = trace[left].ack;
2200 s = format (s, "[%u, %u], ", trace[left].start,
2202 vec_add2 (dummy_tc->rcv_opts.sacks, block, 1);
2203 block->start = trace[left].start;
2204 block->end = trace[left].end;
2210 tcp_rcv_sacks (dummy_tc, next_ack);
2212 dummy_tc->snd_una = next_ack;
2215 s = format (s, "result: %U", format_tcp_scoreboard,
2216 &dummy_tc->sack_sb);
2219 s = format (s, "result: %U", format_tcp_scoreboard, &dummy_tc->sack_sb);
2224 static clib_error_t *
2225 tcp_scoreboard_trace_fn (vlib_main_t * vm, unformat_input_t * input,
2226 vlib_cli_command_t * cmd_arg)
2228 transport_connection_t *tconn = 0;
2229 tcp_connection_t *tc = 0;
2231 while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
2233 if (unformat (input, "%U", unformat_transport_connection, &tconn,
2234 TRANSPORT_PROTO_TCP))
2237 return clib_error_return (0, "unknown input `%U'",
2238 format_unformat_error, input);
2241 if (!TCP_SCOREBOARD_TRACE)
2243 vlib_cli_output (vm, "scoreboard tracing not enabled");
2247 tc = tcp_get_connection_from_transport (tconn);
2250 vlib_cli_output (vm, "connection not found");
2253 str = tcp_scoreboard_replay (str, tc, 1);
2254 vlib_cli_output (vm, "%v", str);
2259 VLIB_CLI_COMMAND (tcp_replay_scoreboard_command, static) =
2261 .path = "tcp replay scoreboard",
2262 .short_help = "tcp replay scoreboard <connection>",
2263 .function = tcp_scoreboard_trace_fn,
2267 static clib_error_t *
2268 show_tcp_punt_fn (vlib_main_t * vm, unformat_input_t * input,
2269 vlib_cli_command_t * cmd_arg)
2271 tcp_main_t *tm = vnet_get_tcp_main ();
2272 if (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
2273 return clib_error_return (0, "unknown input `%U'", format_unformat_error,
2275 vlib_cli_output (vm, "IPv4 TCP punt: %s",
2276 tm->punt_unknown4 ? "enabled" : "disabled");
2277 vlib_cli_output (vm, "IPv6 TCP punt: %s",
2278 tm->punt_unknown6 ? "enabled" : "disabled");
2282 VLIB_CLI_COMMAND (show_tcp_punt_command, static) =
2284 .path = "show tcp punt",
2285 .short_help = "show tcp punt",
2286 .function = show_tcp_punt_fn,
2291 * fd.io coding-style-patch-verification: ON
2294 * eval: (c-set-style "gnu")