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/tcp/tcp_inlines.h>
23 #include <vnet/session/session.h>
24 #include <vnet/fib/fib.h>
25 #include <vnet/dpo/load_balance.h>
32 fib_protocol_t nh_proto;
33 vnet_link_t link_type;
37 } tcp_add_del_adj_args_t;
40 tcp_add_del_adj_cb (tcp_add_del_adj_args_t * args)
45 adj_nbr_add_or_lock (args->nh_proto, args->link_type, &args->ip,
50 ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &args->ip,
52 if (ai != ADJ_INDEX_INVALID)
58 tcp_add_del_adjacency (tcp_connection_t * tc, u8 is_add)
60 tcp_add_del_adj_args_t args = {
61 .nh_proto = FIB_PROTOCOL_IP6,
62 .link_type = VNET_LINK_IP6,
64 .sw_if_index = tc->sw_if_index,
67 vlib_rpc_call_main_thread (tcp_add_del_adj_cb, (u8 *) & args,
72 tcp_cc_init (tcp_connection_t * tc)
74 tc->cc_algo->init (tc);
78 tcp_cc_cleanup (tcp_connection_t * tc)
80 if (tc->cc_algo->cleanup)
81 tc->cc_algo->cleanup (tc);
85 tcp_cc_algo_register (tcp_cc_algorithm_type_e type,
86 const tcp_cc_algorithm_t * vft)
88 tcp_main_t *tm = vnet_get_tcp_main ();
89 vec_validate (tm->cc_algos, type);
91 tm->cc_algos[type] = *vft;
92 hash_set_mem (tm->cc_algo_by_name, vft->name, type);
96 tcp_cc_algo_get (tcp_cc_algorithm_type_e type)
98 tcp_main_t *tm = vnet_get_tcp_main ();
99 return &tm->cc_algos[type];
102 tcp_cc_algorithm_type_e
103 tcp_cc_algo_new_type (const tcp_cc_algorithm_t * vft)
105 tcp_main_t *tm = vnet_get_tcp_main ();
106 tcp_cc_algo_register (++tm->cc_last_type, vft);
107 return tm->cc_last_type;
111 tcp_connection_bind (u32 session_index, transport_endpoint_t * lcl)
113 tcp_main_t *tm = &tcp_main;
114 tcp_connection_t *listener;
117 pool_get (tm->listener_pool, listener);
118 clib_memset (listener, 0, sizeof (*listener));
120 listener->c_c_index = listener - tm->listener_pool;
121 listener->c_lcl_port = lcl->port;
123 /* If we are provided a sw_if_index, bind using one of its ips */
124 if (ip_is_zero (&lcl->ip, 1) && lcl->sw_if_index != ENDPOINT_INVALID_INDEX)
126 if ((iface_ip = ip_interface_get_first_ip (lcl->sw_if_index,
128 ip_set (&lcl->ip, iface_ip, lcl->is_ip4);
130 ip_copy (&listener->c_lcl_ip, &lcl->ip, lcl->is_ip4);
131 listener->c_is_ip4 = lcl->is_ip4;
132 listener->c_proto = TRANSPORT_PROTO_TCP;
133 listener->c_s_index = session_index;
134 listener->c_fib_index = lcl->fib_index;
135 listener->state = TCP_STATE_LISTEN;
136 listener->cc_algo = tcp_cc_algo_get (tcp_cfg.cc_algo);
138 tcp_connection_timers_init (listener);
140 TCP_EVT (TCP_EVT_BIND, listener);
142 return listener->c_c_index;
146 tcp_session_bind (u32 session_index, transport_endpoint_t * tep)
148 return tcp_connection_bind (session_index, tep);
152 tcp_connection_unbind (u32 listener_index)
154 tcp_main_t *tm = vnet_get_tcp_main ();
155 tcp_connection_t *tc;
157 tc = pool_elt_at_index (tm->listener_pool, listener_index);
159 TCP_EVT (TCP_EVT_UNBIND, tc);
161 /* Poison the entry */
163 clib_memset (tc, 0xFA, sizeof (*tc));
165 pool_put_index (tm->listener_pool, listener_index);
169 tcp_session_unbind (u32 listener_index)
171 tcp_connection_unbind (listener_index);
175 static transport_connection_t *
176 tcp_session_get_listener (u32 listener_index)
178 tcp_main_t *tm = vnet_get_tcp_main ();
179 tcp_connection_t *tc;
180 tc = pool_elt_at_index (tm->listener_pool, listener_index);
181 return &tc->connection;
185 * Cleanup half-open connection
189 tcp_half_open_connection_del (tcp_connection_t * tc)
191 tcp_main_t *tm = vnet_get_tcp_main ();
192 clib_spinlock_lock_if_init (&tm->half_open_lock);
194 clib_memset (tc, 0xFA, sizeof (*tc));
195 pool_put (tm->half_open_connections, tc);
196 clib_spinlock_unlock_if_init (&tm->half_open_lock);
200 * Try to cleanup half-open connection
202 * If called from a thread that doesn't own tc, the call won't have any
205 * @param tc - connection to be cleaned up
206 * @return non-zero if cleanup failed.
209 tcp_half_open_connection_cleanup (tcp_connection_t * tc)
211 /* Make sure this is the owning thread */
212 if (tc->c_thread_index != vlib_get_thread_index ())
214 tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT_SYN);
215 tcp_half_open_connection_del (tc);
219 static tcp_connection_t *
220 tcp_half_open_connection_new (void)
222 tcp_main_t *tm = vnet_get_tcp_main ();
223 tcp_connection_t *tc = 0;
224 ASSERT (vlib_get_thread_index () == 0);
225 pool_get (tm->half_open_connections, tc);
226 clib_memset (tc, 0, sizeof (*tc));
227 tc->c_c_index = tc - tm->half_open_connections;
232 * Cleans up connection state.
237 tcp_connection_cleanup (tcp_connection_t * tc)
239 TCP_EVT (TCP_EVT_DELETE, tc);
241 /* Cleanup local endpoint if this was an active connect */
242 if (!(tc->cfg_flags & TCP_CFG_F_NO_ENDPOINT))
243 transport_endpoint_cleanup (TRANSPORT_PROTO_TCP, &tc->c_lcl_ip,
246 /* Check if connection is not yet fully established */
247 if (tc->state == TCP_STATE_SYN_SENT)
249 /* Try to remove the half-open connection. If this is not the owning
250 * thread, tc won't be removed. Retransmit or establish timers will
251 * eventually expire and call again cleanup on the right thread. */
252 if (tcp_half_open_connection_cleanup (tc))
253 tc->flags |= TCP_CONN_HALF_OPEN_DONE;
257 /* Make sure all timers are cleared */
258 tcp_connection_timers_reset (tc);
260 if (!tc->c_is_ip4 && ip6_address_is_link_local_unicast (&tc->c_rmt_ip6))
261 tcp_add_del_adjacency (tc, 0);
264 vec_free (tc->snd_sacks);
265 vec_free (tc->snd_sacks_fl);
266 vec_free (tc->rcv_opts.sacks);
267 pool_free (tc->sack_sb.holes);
269 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
272 tcp_connection_free (tc);
277 * Connection removal.
279 * This should be called only once connection enters CLOSED state. Note
280 * that it notifies the session of the removal event, so if the goal is to
281 * just remove the connection, call tcp_connection_cleanup instead.
284 tcp_connection_del (tcp_connection_t * tc)
286 session_transport_delete_notify (&tc->connection);
287 tcp_connection_cleanup (tc);
291 tcp_connection_alloc (u8 thread_index)
293 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
294 tcp_connection_t *tc;
296 pool_get (wrk->connections, tc);
297 clib_memset (tc, 0, sizeof (*tc));
298 tc->c_c_index = tc - wrk->connections;
299 tc->c_thread_index = thread_index;
304 tcp_connection_alloc_w_base (u8 thread_index, tcp_connection_t * base)
306 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
307 tcp_connection_t *tc;
309 pool_get (wrk->connections, tc);
310 clib_memcpy_fast (tc, base, sizeof (*tc));
311 tc->c_c_index = tc - wrk->connections;
312 tc->c_thread_index = thread_index;
317 tcp_connection_free (tcp_connection_t * tc)
319 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
322 clib_memset (tc, 0xFA, sizeof (*tc));
323 pool_put (wrk->connections, tc);
326 pool_put (wrk->connections, tc);
330 tcp_program_cleanup (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
332 tcp_cleanup_req_t *req;
333 clib_time_type_t now;
335 now = transport_time_now (tc->c_thread_index);
336 clib_fifo_add2 (wrk->pending_cleanups, req);
337 req->connection_index = tc->c_c_index;
338 req->free_time = now + tcp_cfg.cleanup_time;
342 * Begin connection closing procedure.
344 * If at the end the connection is not in CLOSED state, it is not removed.
345 * Instead, we rely on on TCP to advance through state machine to either
346 * 1) LAST_ACK (passive close) whereby when the last ACK is received
347 * tcp_connection_del is called. This notifies session of the delete and
349 * 2) TIME_WAIT (active close) whereby after 2MSL the 2MSL timer triggers
350 * and cleanup is called.
352 * N.B. Half-close connections are not supported
355 tcp_connection_close (tcp_connection_t * tc)
357 TCP_EVT (TCP_EVT_CLOSE, tc);
359 /* Send/Program FIN if needed and switch state */
362 case TCP_STATE_SYN_SENT:
363 /* Try to cleanup. If not on the right thread, mark as half-open done.
364 * Connection will be cleaned up when establish timer pops */
365 tcp_connection_cleanup (tc);
367 case TCP_STATE_SYN_RCVD:
368 tcp_connection_timers_reset (tc);
370 tcp_connection_set_state (tc, TCP_STATE_FIN_WAIT_1);
371 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait1_time);
373 case TCP_STATE_ESTABLISHED:
374 /* If closing with unread data, reset the connection */
375 if (transport_max_rx_dequeue (&tc->connection))
378 tcp_connection_timers_reset (tc);
379 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
380 session_transport_closed_notify (&tc->connection);
381 tcp_program_cleanup (tcp_get_worker (tc->c_thread_index), tc);
382 tcp_worker_stats_inc (tc->c_thread_index, rst_unread, 1);
385 if (!transport_max_tx_dequeue (&tc->connection))
388 tc->flags |= TCP_CONN_FINPNDG;
389 tcp_connection_set_state (tc, TCP_STATE_FIN_WAIT_1);
390 /* Set a timer in case the peer stops responding. Otherwise the
391 * connection will be stuck here forever. */
392 ASSERT (tc->timers[TCP_TIMER_WAITCLOSE] == TCP_TIMER_HANDLE_INVALID);
393 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait1_time);
395 case TCP_STATE_CLOSE_WAIT:
396 if (!transport_max_tx_dequeue (&tc->connection))
399 tcp_connection_timers_reset (tc);
400 tcp_connection_set_state (tc, TCP_STATE_LAST_ACK);
401 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
404 tc->flags |= TCP_CONN_FINPNDG;
406 case TCP_STATE_FIN_WAIT_1:
407 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait1_time);
409 case TCP_STATE_CLOSED:
410 /* Cleanup should've been programmed already */
413 TCP_DBG ("state: %u", tc->state);
418 tcp_session_close (u32 conn_index, u32 thread_index)
420 tcp_connection_t *tc;
421 tc = tcp_connection_get (conn_index, thread_index);
422 tcp_connection_close (tc);
426 tcp_session_cleanup (u32 conn_index, u32 thread_index)
428 tcp_connection_t *tc;
429 tc = tcp_connection_get (conn_index, thread_index);
432 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
433 tcp_connection_cleanup (tc);
437 tcp_session_reset (u32 conn_index, u32 thread_index)
439 tcp_connection_t *tc;
440 tc = tcp_connection_get (conn_index, thread_index);
442 tcp_connection_timers_reset (tc);
443 tcp_cong_recovery_off (tc);
444 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
445 session_transport_closed_notify (&tc->connection);
446 tcp_program_cleanup (tcp_get_worker (thread_index), tc);
450 * Initialize all connection timers as invalid
453 tcp_connection_timers_init (tcp_connection_t * tc)
457 /* Set all to invalid */
458 for (i = 0; i < TCP_N_TIMERS; i++)
460 tc->timers[i] = TCP_TIMER_HANDLE_INVALID;
463 tc->rto = TCP_RTO_INIT;
467 * Stop all connection timers
470 tcp_connection_timers_reset (tcp_connection_t * tc)
473 for (i = 0; i < TCP_N_TIMERS; i++)
475 tcp_timer_reset (tc, i);
480 typedef struct ip4_tcp_hdr
486 typedef struct ip6_tcp_hdr
493 tcp_connection_select_lb_bucket (tcp_connection_t * tc, const dpo_id_t * dpo,
496 const dpo_id_t *choice;
500 lb = load_balance_get (dpo->dpoi_index);
504 clib_memset (&hdr, 0, sizeof (hdr));
505 hdr.ip.protocol = IP_PROTOCOL_TCP;
506 hdr.ip.address_pair.src.as_u32 = tc->c_lcl_ip.ip4.as_u32;
507 hdr.ip.address_pair.dst.as_u32 = tc->c_rmt_ip.ip4.as_u32;
508 hdr.tcp.src_port = tc->c_lcl_port;
509 hdr.tcp.dst_port = tc->c_rmt_port;
510 hash = ip4_compute_flow_hash (&hdr.ip, lb->lb_hash_config);
515 clib_memset (&hdr, 0, sizeof (hdr));
516 hdr.ip.protocol = IP_PROTOCOL_TCP;
517 clib_memcpy_fast (&hdr.ip.src_address, &tc->c_lcl_ip.ip6,
518 sizeof (ip6_address_t));
519 clib_memcpy_fast (&hdr.ip.dst_address, &tc->c_rmt_ip.ip6,
520 sizeof (ip6_address_t));
521 hdr.tcp.src_port = tc->c_lcl_port;
522 hdr.tcp.dst_port = tc->c_rmt_port;
523 hash = ip6_compute_flow_hash (&hdr.ip, lb->lb_hash_config);
525 choice = load_balance_get_bucket_i (lb, hash & lb->lb_n_buckets_minus_1);
526 dpo_copy (result, choice);
530 tcp_lookup_rmt_in_fib (tcp_connection_t * tc)
535 clib_memcpy_fast (&prefix.fp_addr, &tc->c_rmt_ip, sizeof (prefix.fp_addr));
536 prefix.fp_proto = tc->c_is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
537 prefix.fp_len = tc->c_is_ip4 ? 32 : 128;
538 fib_index = fib_table_find (prefix.fp_proto, tc->c_fib_index);
539 return fib_table_lookup (fib_index, &prefix);
543 tcp_connection_stack_on_fib_entry (tcp_connection_t * tc)
545 dpo_id_t choice = DPO_INVALID;
546 u32 output_node_index;
549 fe = fib_entry_get (tc->c_rmt_fei);
550 if (fe->fe_lb.dpoi_type != DPO_LOAD_BALANCE)
553 tcp_connection_select_lb_bucket (tc, &fe->fe_lb, &choice);
556 tc->c_is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
557 dpo_stack_from_node (output_node_index, &tc->c_rmt_dpo, &choice);
561 /** Stack tcp connection on peer's fib entry.
563 * This ultimately populates the dpo the connection will use to send packets.
566 tcp_connection_fib_attach (tcp_connection_t * tc)
568 tc->c_rmt_fei = tcp_lookup_rmt_in_fib (tc);
570 ASSERT (tc->c_rmt_fei != FIB_NODE_INDEX_INVALID);
572 tcp_connection_stack_on_fib_entry (tc);
577 * Generate random iss as per rfc6528
580 tcp_generate_random_iss (tcp_connection_t * tc)
582 tcp_main_t *tm = &tcp_main;
586 tmp = (u64) tc->c_lcl_ip.ip4.as_u32 << 32 | (u64) tc->c_rmt_ip.ip4.as_u32;
588 tmp = tc->c_lcl_ip.ip6.as_u64[0] ^ tc->c_lcl_ip.ip6.as_u64[1]
589 ^ tc->c_rmt_ip.ip6.as_u64[0] ^ tc->c_rmt_ip.ip6.as_u64[1];
591 tmp ^= tm->iss_seed.first | ((u64) tc->c_lcl_port << 16 | tc->c_rmt_port);
592 tmp ^= tm->iss_seed.second;
593 tmp = clib_xxhash (tmp) + clib_cpu_time_now ();
594 return ((tmp >> 32) ^ (tmp & 0xffffffff));
598 * Initialize max segment size we're able to process.
600 * The value is constrained by the output interface's MTU and by the size
601 * of the IP and TCP headers (see RFC6691). It is also what we advertise
605 tcp_init_rcv_mss (tcp_connection_t * tc)
609 /* Already provided at connection init time */
613 ip_hdr_len = tc->c_is_ip4 ? sizeof (ip4_header_t) : sizeof (ip6_header_t);
614 tc->mss = tcp_cfg.default_mtu - sizeof (tcp_header_t) - ip_hdr_len;
618 tcp_init_mss (tcp_connection_t * tc)
620 u16 default_min_mss = 536;
622 tcp_init_rcv_mss (tc);
624 /* TODO consider PMTU discovery */
625 tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss);
627 if (tc->snd_mss < 45)
629 /* Assume that at least the min default mss works */
630 tc->snd_mss = default_min_mss;
631 tc->rcv_opts.mss = default_min_mss;
634 /* We should have enough space for 40 bytes of options */
635 ASSERT (tc->snd_mss > 45);
637 /* If we use timestamp option, account for it */
638 if (tcp_opts_tstamp (&tc->rcv_opts))
639 tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP;
643 * Initialize connection send variables.
646 tcp_init_snd_vars (tcp_connection_t * tc)
649 * We use the time to randomize iss and for setting up the initial
650 * timestamp. Make sure it's updated otherwise syn and ack in the
651 * handshake may make it look as if time has flown in the opposite
654 tcp_set_time_now (tcp_get_worker (vlib_get_thread_index ()));
656 tcp_init_rcv_mss (tc);
657 tc->iss = tcp_generate_random_iss (tc);
658 tc->snd_una = tc->iss;
659 tc->snd_nxt = tc->iss + 1;
660 tc->snd_una_max = tc->snd_nxt;
661 tc->srtt = 100; /* 100 ms */
663 if (!tcp_cfg.csum_offload)
664 tc->cfg_flags |= TCP_CFG_F_NO_CSUM_OFFLOAD;
668 tcp_enable_pacing (tcp_connection_t * tc)
671 byte_rate = tc->cwnd / (tc->srtt * TCP_TICK);
672 transport_connection_tx_pacer_init (&tc->connection, byte_rate, tc->cwnd);
673 tc->mrtt_us = (u32) ~ 0;
676 /** Initialize tcp connection variables
678 * Should be called after having received a msg from the peer, i.e., a SYN or
679 * a SYNACK, such that connection options have already been exchanged. */
681 tcp_connection_init_vars (tcp_connection_t * tc)
683 tcp_connection_timers_init (tc);
685 scoreboard_init (&tc->sack_sb);
686 if (tc->state == TCP_STATE_SYN_RCVD)
687 tcp_init_snd_vars (tc);
691 if (!tc->c_is_ip4 && ip6_address_is_link_local_unicast (&tc->c_rmt_ip6))
692 tcp_add_del_adjacency (tc, 1);
694 /* tcp_connection_fib_attach (tc); */
696 if (transport_connection_is_tx_paced (&tc->connection)
697 || tcp_cfg.enable_tx_pacing)
698 tcp_enable_pacing (tc);
700 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
703 if (!tcp_cfg.allow_tso)
704 tc->cfg_flags |= TCP_CFG_F_NO_TSO;
706 tc->start_ts = tcp_time_now_us (tc->c_thread_index);
710 tcp_alloc_custom_local_endpoint (tcp_main_t * tm, ip46_address_t * lcl_addr,
711 u16 * lcl_port, u8 is_ip4)
716 index = tm->last_v4_addr_rotor++;
717 if (tm->last_v4_addr_rotor >= vec_len (tcp_cfg.ip4_src_addrs))
718 tm->last_v4_addr_rotor = 0;
719 lcl_addr->ip4.as_u32 = tcp_cfg.ip4_src_addrs[index].as_u32;
723 index = tm->last_v6_addr_rotor++;
724 if (tm->last_v6_addr_rotor >= vec_len (tcp_cfg.ip6_src_addrs))
725 tm->last_v6_addr_rotor = 0;
726 clib_memcpy_fast (&lcl_addr->ip6, &tcp_cfg.ip6_src_addrs[index],
727 sizeof (ip6_address_t));
729 port = transport_alloc_local_port (TRANSPORT_PROTO_TCP, lcl_addr);
732 clib_warning ("Failed to allocate src port");
740 tcp_session_open (transport_endpoint_cfg_t * rmt)
742 tcp_main_t *tm = vnet_get_tcp_main ();
743 tcp_connection_t *tc;
744 ip46_address_t lcl_addr;
749 * Allocate local endpoint
751 if ((rmt->is_ip4 && vec_len (tcp_cfg.ip4_src_addrs))
752 || (!rmt->is_ip4 && vec_len (tcp_cfg.ip6_src_addrs)))
753 rv = tcp_alloc_custom_local_endpoint (tm, &lcl_addr, &lcl_port,
756 rv = transport_alloc_local_endpoint (TRANSPORT_PROTO_TCP,
757 rmt, &lcl_addr, &lcl_port);
763 * Create connection and send SYN
765 clib_spinlock_lock_if_init (&tm->half_open_lock);
766 tc = tcp_half_open_connection_new ();
767 ip_copy (&tc->c_rmt_ip, &rmt->ip, rmt->is_ip4);
768 ip_copy (&tc->c_lcl_ip, &lcl_addr, rmt->is_ip4);
769 tc->c_rmt_port = rmt->port;
770 tc->c_lcl_port = clib_host_to_net_u16 (lcl_port);
771 tc->c_is_ip4 = rmt->is_ip4;
772 tc->c_proto = TRANSPORT_PROTO_TCP;
773 tc->c_fib_index = rmt->fib_index;
774 tc->cc_algo = tcp_cc_algo_get (tcp_cfg.cc_algo);
775 /* The other connection vars will be initialized after SYN ACK */
776 tcp_connection_timers_init (tc);
779 TCP_EVT (TCP_EVT_OPEN, tc);
780 tc->state = TCP_STATE_SYN_SENT;
781 tcp_init_snd_vars (tc);
783 clib_spinlock_unlock_if_init (&tm->half_open_lock);
785 return tc->c_c_index;
789 format_tcp_session (u8 * s, va_list * args)
791 u32 tci = va_arg (*args, u32);
792 u32 thread_index = va_arg (*args, u32);
793 u32 verbose = va_arg (*args, u32);
794 tcp_connection_t *tc;
796 tc = tcp_connection_get (tci, thread_index);
798 s = format (s, "%U", format_tcp_connection, tc, verbose);
800 s = format (s, "empty\n");
805 format_tcp_listener_session (u8 * s, va_list * args)
807 u32 tci = va_arg (*args, u32);
808 u32 __clib_unused thread_index = va_arg (*args, u32);
809 u32 verbose = va_arg (*args, u32);
810 tcp_connection_t *tc = tcp_listener_get (tci);
811 s = format (s, "%-50U", format_tcp_connection_id, tc);
813 s = format (s, "%-15U", format_tcp_state, tc->state);
818 format_tcp_half_open_session (u8 * s, va_list * args)
820 u32 tci = va_arg (*args, u32);
821 u32 __clib_unused thread_index = va_arg (*args, u32);
822 tcp_connection_t *tc = tcp_half_open_connection_get (tci);
823 return format (s, "%U", format_tcp_connection_id, tc);
826 static transport_connection_t *
827 tcp_session_get_transport (u32 conn_index, u32 thread_index)
829 tcp_connection_t *tc = tcp_connection_get (conn_index, thread_index);
830 if (PREDICT_FALSE (!tc))
832 return &tc->connection;
835 static transport_connection_t *
836 tcp_half_open_session_get_transport (u32 conn_index)
838 tcp_connection_t *tc = tcp_half_open_connection_get (conn_index);
839 return &tc->connection;
843 tcp_session_cal_goal_size (tcp_connection_t * tc)
845 u16 goal_size = tc->snd_mss;
847 goal_size = TCP_MAX_GSO_SZ - tc->snd_mss % TCP_MAX_GSO_SZ;
848 goal_size = clib_min (goal_size, tc->snd_wnd / 2);
850 return goal_size > tc->snd_mss ? goal_size : tc->snd_mss;
854 tcp_round_snd_space (tcp_connection_t * tc, u32 snd_space)
856 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
858 return tc->snd_wnd <= snd_space ? tc->snd_wnd : 0;
861 /* If not snd_wnd constrained and we can't write at least a segment,
862 * don't try at all */
863 if (PREDICT_FALSE (snd_space < tc->snd_mss))
864 return snd_space < tc->cwnd ? 0 : snd_space;
866 /* round down to mss multiple */
867 return snd_space - (snd_space % tc->snd_mss);
871 * Compute tx window session is allowed to fill.
873 * Takes into account available send space, snd_mss and the congestion
874 * state of the connection. If possible, the value returned is a multiple
877 * @param tc tcp connection
878 * @return number of bytes session is allowed to write
881 tcp_snd_space_inline (tcp_connection_t * tc)
885 if (PREDICT_FALSE (tcp_in_fastrecovery (tc)
886 || tc->state == TCP_STATE_CLOSED))
889 snd_space = tcp_available_output_snd_space (tc);
891 /* If we got dupacks or sacked bytes but we're not yet in recovery, try
892 * to force the peer to send enough dupacks to start retransmitting as
893 * per Limited Transmit (RFC3042)
895 if (PREDICT_FALSE (tc->rcv_dupacks != 0 || tc->sack_sb.sacked_bytes))
897 if (tc->limited_transmit != tc->snd_nxt
898 && (seq_lt (tc->limited_transmit, tc->snd_nxt - 2 * tc->snd_mss)
899 || seq_gt (tc->limited_transmit, tc->snd_nxt)))
900 tc->limited_transmit = tc->snd_nxt;
902 ASSERT (seq_leq (tc->limited_transmit, tc->snd_nxt));
904 int snt_limited = tc->snd_nxt - tc->limited_transmit;
905 snd_space = clib_max ((int) 2 * tc->snd_mss - snt_limited, 0);
907 return tcp_round_snd_space (tc, snd_space);
911 tcp_snd_space (tcp_connection_t * tc)
913 return tcp_snd_space_inline (tc);
917 tcp_session_send_params (transport_connection_t * trans_conn,
918 transport_send_params_t * sp)
920 tcp_connection_t *tc = (tcp_connection_t *) trans_conn;
922 /* Ensure snd_mss does accurately reflect the amount of data we can push
923 * in a segment. This also makes sure that options are updated according to
924 * the current state of the connection. */
925 tcp_update_burst_snd_vars (tc);
927 if (PREDICT_FALSE (tc->cfg_flags & TCP_CFG_F_TSO))
928 sp->snd_mss = tcp_session_cal_goal_size (tc);
930 sp->snd_mss = tc->snd_mss;
932 sp->snd_space = clib_min (tcp_snd_space_inline (tc),
933 tc->snd_wnd - (tc->snd_nxt - tc->snd_una));
935 ASSERT (seq_geq (tc->snd_nxt, tc->snd_una));
936 /* This still works if fast retransmit is on */
937 sp->tx_offset = tc->snd_nxt - tc->snd_una;
939 sp->flags = sp->snd_space ? 0 : TRANSPORT_SND_F_DESCHED;
945 tcp_timer_waitclose_handler (tcp_connection_t * tc)
947 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
951 case TCP_STATE_CLOSE_WAIT:
952 tcp_connection_timers_reset (tc);
953 /* App never returned with a close */
954 if (!(tc->flags & TCP_CONN_FINPNDG))
956 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
957 session_transport_closed_notify (&tc->connection);
958 tcp_program_cleanup (wrk, tc);
959 tcp_workerp_stats_inc (wrk, to_closewait, 1);
963 /* Send FIN either way and switch to LAST_ACK. */
964 tcp_cong_recovery_off (tc);
965 /* Make sure we don't try to send unsent data */
966 tc->snd_nxt = tc->snd_una;
968 tcp_connection_set_state (tc, TCP_STATE_LAST_ACK);
969 session_transport_closed_notify (&tc->connection);
971 /* Make sure we don't wait in LAST ACK forever */
972 tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time);
973 tcp_workerp_stats_inc (wrk, to_closewait2, 1);
975 /* Don't delete the connection yet */
977 case TCP_STATE_FIN_WAIT_1:
978 tcp_connection_timers_reset (tc);
979 if (tc->flags & TCP_CONN_FINPNDG)
981 /* If FIN pending, we haven't sent everything, but we did try.
982 * Notify session layer that transport is closed. */
983 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
985 tcp_program_cleanup (wrk, tc);
989 /* We've sent the fin but no progress. Close the connection and
990 * to make sure everything is flushed, setup a cleanup timer */
991 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
992 tcp_program_cleanup (wrk, tc);
994 session_transport_closed_notify (&tc->connection);
995 tcp_workerp_stats_inc (wrk, to_finwait1, 1);
997 case TCP_STATE_LAST_ACK:
998 tcp_connection_timers_reset (tc);
999 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1000 session_transport_closed_notify (&tc->connection);
1001 tcp_program_cleanup (wrk, tc);
1002 tcp_workerp_stats_inc (wrk, to_lastack, 1);
1004 case TCP_STATE_CLOSING:
1005 tcp_connection_timers_reset (tc);
1006 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1007 session_transport_closed_notify (&tc->connection);
1008 tcp_program_cleanup (wrk, tc);
1009 tcp_workerp_stats_inc (wrk, to_closing, 1);
1011 case TCP_STATE_FIN_WAIT_2:
1012 tcp_send_reset (tc);
1013 tcp_connection_timers_reset (tc);
1014 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1015 session_transport_closed_notify (&tc->connection);
1016 tcp_program_cleanup (wrk, tc);
1017 tcp_workerp_stats_inc (wrk, to_finwait2, 1);
1019 case TCP_STATE_TIME_WAIT:
1020 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1021 tcp_program_cleanup (wrk, tc);
1024 clib_warning ("waitclose in state: %U", format_tcp_state, tc->state);
1030 static timer_expiration_handler *timer_expiration_handlers[TCP_N_TIMERS] =
1032 tcp_timer_retransmit_handler,
1033 tcp_timer_delack_handler,
1034 tcp_timer_persist_handler,
1035 tcp_timer_waitclose_handler,
1036 tcp_timer_retransmit_syn_handler,
1041 tcp_dispatch_pending_timers (tcp_worker_ctx_t * wrk)
1043 u32 n_timers, connection_index, timer_id, thread_index, timer_handle;
1044 tcp_connection_t *tc;
1047 if (!(n_timers = clib_fifo_elts (wrk->pending_timers)))
1050 thread_index = wrk->vm->thread_index;
1051 for (i = 0; i < clib_min (n_timers, wrk->max_timers_per_loop); i++)
1053 clib_fifo_sub1 (wrk->pending_timers, timer_handle);
1054 connection_index = timer_handle & 0x0FFFFFFF;
1055 timer_id = timer_handle >> 28;
1057 if (PREDICT_TRUE (timer_id != TCP_TIMER_RETRANSMIT_SYN))
1058 tc = tcp_connection_get (connection_index, thread_index);
1060 tc = tcp_half_open_connection_get (connection_index);
1062 if (PREDICT_FALSE (!tc))
1065 /* Skip timer if it was rearmed while pending dispatch */
1066 if (PREDICT_FALSE (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID))
1069 (*timer_expiration_handlers[timer_id]) (tc);
1072 if (thread_index == 0 && clib_fifo_elts (wrk->pending_timers))
1073 session_queue_run_on_main_thread (wrk->vm);
1077 tcp_handle_cleanups (tcp_worker_ctx_t * wrk, clib_time_type_t now)
1079 u32 thread_index = wrk->vm->thread_index;
1080 tcp_cleanup_req_t *req;
1081 tcp_connection_t *tc;
1083 while (clib_fifo_elts (wrk->pending_cleanups))
1085 req = clib_fifo_head (wrk->pending_cleanups);
1086 if (req->free_time > now)
1088 clib_fifo_sub2 (wrk->pending_cleanups, req);
1089 tc = tcp_connection_get (req->connection_index, thread_index);
1090 if (PREDICT_FALSE (!tc))
1092 session_transport_delete_notify (&tc->connection);
1093 tcp_connection_cleanup (tc);
1098 tcp_update_time (f64 now, u8 thread_index)
1100 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
1102 tcp_set_time_now (wrk);
1103 tcp_handle_cleanups (wrk, now);
1104 tw_timer_expire_timers_16t_2w_512sl (&wrk->timer_wheel, now);
1105 tcp_dispatch_pending_timers (wrk);
1109 tcp_session_flush_data (transport_connection_t * tconn)
1111 tcp_connection_t *tc = (tcp_connection_t *) tconn;
1112 if (tc->flags & TCP_CONN_PSH_PENDING)
1114 tc->flags |= TCP_CONN_PSH_PENDING;
1115 tc->psh_seq = tc->snd_una + transport_max_tx_dequeue (tconn) - 1;
1119 const static transport_proto_vft_t tcp_proto = {
1120 .enable = vnet_tcp_enable_disable,
1121 .start_listen = tcp_session_bind,
1122 .stop_listen = tcp_session_unbind,
1123 .push_header = tcp_session_push_header,
1124 .get_connection = tcp_session_get_transport,
1125 .get_listener = tcp_session_get_listener,
1126 .get_half_open = tcp_half_open_session_get_transport,
1127 .connect = tcp_session_open,
1128 .close = tcp_session_close,
1129 .cleanup = tcp_session_cleanup,
1130 .reset = tcp_session_reset,
1131 .send_params = tcp_session_send_params,
1132 .update_time = tcp_update_time,
1133 .flush_data = tcp_session_flush_data,
1134 .custom_tx = tcp_session_custom_tx,
1135 .format_connection = format_tcp_session,
1136 .format_listener = format_tcp_listener_session,
1137 .format_half_open = format_tcp_half_open_session,
1138 .transport_options = {
1141 .tx_type = TRANSPORT_TX_PEEK,
1142 .service_type = TRANSPORT_SERVICE_VC,
1148 tcp_connection_tx_pacer_update (tcp_connection_t * tc)
1150 if (!transport_connection_is_tx_paced (&tc->connection))
1153 f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us);
1155 transport_connection_tx_pacer_update (&tc->connection,
1156 tcp_cc_get_pacing_rate (tc),
1157 srtt * CLIB_US_TIME_FREQ);
1161 tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window,
1164 f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us);
1165 transport_connection_tx_pacer_reset (&tc->connection,
1166 tcp_cc_get_pacing_rate (tc),
1168 srtt * CLIB_US_TIME_FREQ);
1172 tcp_reschedule (tcp_connection_t * tc)
1174 if (tcp_in_cong_recovery (tc) || tcp_snd_space_inline (tc))
1175 transport_connection_reschedule (&tc->connection);
1179 tcp_expired_timers_dispatch (u32 * expired_timers)
1181 u32 thread_index = vlib_get_thread_index (), n_left, max_per_loop;
1182 u32 connection_index, timer_id, n_expired, max_loops;
1183 tcp_worker_ctx_t *wrk;
1184 tcp_connection_t *tc;
1187 wrk = tcp_get_worker (thread_index);
1188 n_expired = vec_len (expired_timers);
1189 tcp_workerp_stats_inc (wrk, timer_expirations, n_expired);
1190 n_left = clib_fifo_elts (wrk->pending_timers);
1193 * Invalidate all timer handles before dispatching. This avoids dangling
1194 * index references to timer wheel pool entries that have been freed.
1196 for (i = 0; i < n_expired; i++)
1198 connection_index = expired_timers[i] & 0x0FFFFFFF;
1199 timer_id = expired_timers[i] >> 28;
1201 if (timer_id != TCP_TIMER_RETRANSMIT_SYN)
1202 tc = tcp_connection_get (connection_index, thread_index);
1204 tc = tcp_half_open_connection_get (connection_index);
1206 TCP_EVT (TCP_EVT_TIMER_POP, connection_index, timer_id);
1208 tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
1211 clib_fifo_add (wrk->pending_timers, expired_timers, n_expired);
1213 max_loops = clib_max (1, 0.5 * TCP_TIMER_TICK * wrk->vm->loops_per_second);
1214 max_per_loop = clib_max ((n_left + n_expired) / max_loops, 10);
1215 max_per_loop = clib_min (max_per_loop, VLIB_FRAME_SIZE);
1216 wrk->max_timers_per_loop = clib_max (n_left ? wrk->max_timers_per_loop : 0,
1219 if (thread_index == 0)
1220 session_queue_run_on_main_thread (wrk->vm);
1224 tcp_initialize_timer_wheels (tcp_main_t * tm)
1226 tw_timer_wheel_16t_2w_512sl_t *tw;
1228 foreach_vlib_main (({
1229 tw = &tm->wrk_ctx[ii].timer_wheel;
1230 tw_timer_wheel_init_16t_2w_512sl (tw, tcp_expired_timers_dispatch,
1231 TCP_TIMER_TICK, ~0);
1232 tw->last_run_time = vlib_time_now (this_vlib_main);
1238 tcp_initialize_iss_seed (tcp_main_t * tm)
1240 u32 default_seed = random_default_seed ();
1241 u64 time_now = clib_cpu_time_now ();
1243 tm->iss_seed.first = (u64) random_u32 (&default_seed) << 32;
1244 tm->iss_seed.second = random_u64 (&time_now);
1247 static clib_error_t *
1248 tcp_main_enable (vlib_main_t * vm)
1250 vlib_thread_main_t *vtm = vlib_get_thread_main ();
1251 u32 num_threads, n_workers, prealloc_conn_per_wrk;
1252 tcp_connection_t *tc __attribute__ ((unused));
1253 tcp_main_t *tm = vnet_get_tcp_main ();
1254 tcp_worker_ctx_t *wrk;
1255 clib_error_t *error = 0;
1258 if ((error = vlib_call_init_function (vm, ip_main_init)))
1260 if ((error = vlib_call_init_function (vm, ip4_lookup_init)))
1262 if ((error = vlib_call_init_function (vm, ip6_lookup_init)))
1269 ip4_register_protocol (IP_PROTOCOL_TCP, tcp4_input_node.index);
1270 ip6_register_protocol (IP_PROTOCOL_TCP, tcp6_input_node.index);
1273 * Initialize data structures
1276 num_threads = 1 /* main thread */ + vtm->n_threads;
1277 vec_validate (tm->wrk_ctx, num_threads - 1);
1278 n_workers = num_threads == 1 ? 1 : vtm->n_threads;
1279 prealloc_conn_per_wrk = tcp_cfg.preallocated_connections / n_workers;
1281 wrk = &tm->wrk_ctx[0];
1282 wrk->tco_next_node[0] = vlib_node_get_next (vm, session_queue_node.index,
1283 tcp4_output_node.index);
1284 wrk->tco_next_node[1] = vlib_node_get_next (vm, session_queue_node.index,
1285 tcp6_output_node.index);
1287 for (thread = 0; thread < num_threads; thread++)
1289 wrk = &tm->wrk_ctx[thread];
1291 vec_validate (wrk->pending_deq_acked, 255);
1292 vec_validate (wrk->pending_disconnects, 255);
1293 vec_validate (wrk->pending_resets, 255);
1294 vec_reset_length (wrk->pending_deq_acked);
1295 vec_reset_length (wrk->pending_disconnects);
1296 vec_reset_length (wrk->pending_resets);
1297 wrk->vm = vlib_mains[thread];
1298 wrk->max_timers_per_loop = 10;
1302 wrk->tco_next_node[0] = tm->wrk_ctx[0].tco_next_node[0];
1303 wrk->tco_next_node[1] = tm->wrk_ctx[0].tco_next_node[1];
1307 * Preallocate connections. Assume that thread 0 won't
1308 * use preallocated threads when running multi-core
1310 if ((thread > 0 || num_threads == 1) && prealloc_conn_per_wrk)
1311 pool_init_fixed (wrk->connections, prealloc_conn_per_wrk);
1315 * Use a preallocated half-open connection pool?
1317 if (tcp_cfg.preallocated_half_open_connections)
1318 pool_init_fixed (tm->half_open_connections,
1319 tcp_cfg.preallocated_half_open_connections);
1321 /* Initialize clocks per tick for TCP timestamp. Used to compute
1322 * monotonically increasing timestamps. */
1323 tm->tstamp_ticks_per_clock = vm->clib_time.seconds_per_clock
1324 / TCP_TSTAMP_RESOLUTION;
1326 if (num_threads > 1)
1328 clib_spinlock_init (&tm->half_open_lock);
1331 tcp_initialize_timer_wheels (tm);
1332 tcp_initialize_iss_seed (tm);
1334 tm->bytes_per_buffer = vlib_buffer_get_default_data_size (vm);
1335 tm->cc_last_type = TCP_CC_LAST;
1337 tm->ipl_next_node[0] = vlib_node_get_next (vm, session_queue_node.index,
1338 ip4_lookup_node.index);
1339 tm->ipl_next_node[1] = vlib_node_get_next (vm, session_queue_node.index,
1340 ip6_lookup_node.index);
1345 vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en)
1349 if (tcp_main.is_enabled)
1352 return tcp_main_enable (vm);
1356 tcp_main.is_enabled = 0;
1363 tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add)
1365 tcp_main_t *tm = &tcp_main;
1367 tm->punt_unknown4 = is_add;
1369 tm->punt_unknown6 = is_add;
1373 * Initialize default values for tcp parameters
1376 tcp_configuration_init (void)
1378 /* Initial wnd for SYN. Fifos are not allocated at that point so use some
1379 * predefined value. For SYN-ACK we still want the scale to be computed in
1381 tcp_cfg.max_rx_fifo = 32 << 20;
1382 tcp_cfg.min_rx_fifo = 4 << 10;
1384 tcp_cfg.default_mtu = 1500;
1385 tcp_cfg.initial_cwnd_multiplier = 0;
1386 tcp_cfg.enable_tx_pacing = 1;
1387 tcp_cfg.allow_tso = 0;
1388 tcp_cfg.csum_offload = 1;
1389 tcp_cfg.cc_algo = TCP_CC_NEWRENO;
1390 tcp_cfg.rwnd_min_update_ack = 1;
1392 /* Time constants defined as timer tick (100ms) multiples */
1393 tcp_cfg.delack_time = 1; /* 0.1s */
1394 tcp_cfg.closewait_time = 20; /* 2s */
1395 tcp_cfg.timewait_time = 100; /* 10s */
1396 tcp_cfg.finwait1_time = 600; /* 60s */
1397 tcp_cfg.lastack_time = 300; /* 30s */
1398 tcp_cfg.finwait2_time = 300; /* 30s */
1399 tcp_cfg.closing_time = 300; /* 30s */
1400 tcp_cfg.cleanup_time = 0.1; /* 100ms */
1403 static clib_error_t *
1404 tcp_init (vlib_main_t * vm)
1406 tcp_main_t *tm = vnet_get_tcp_main ();
1407 ip_main_t *im = &ip_main;
1408 ip_protocol_info_t *pi;
1410 /* Session layer, and by implication tcp, are disabled by default */
1413 /* Register with IP for header parsing */
1414 pi = ip_get_protocol_info (im, IP_PROTOCOL_TCP);
1416 return clib_error_return (0, "TCP protocol info AWOL");
1417 pi->format_header = format_tcp_header;
1418 pi->unformat_pg_edit = unformat_pg_tcp_header;
1420 /* Register as transport with session layer */
1421 transport_register_protocol (TRANSPORT_PROTO_TCP, &tcp_proto,
1422 FIB_PROTOCOL_IP4, tcp4_output_node.index);
1423 transport_register_protocol (TRANSPORT_PROTO_TCP, &tcp_proto,
1424 FIB_PROTOCOL_IP6, tcp6_output_node.index);
1426 tcp_configuration_init ();
1428 tm->cc_algo_by_name = hash_create_string (0, sizeof (uword));
1433 VLIB_INIT_FUNCTION (tcp_init);
1436 * fd.io coding-style-patch-verification: ON
1439 * eval: (c-set-style "gnu")