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_free (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 tcp_worker_ctx_t *wrk;
213 /* Make sure this is the owning thread */
214 if (tc->c_thread_index != vlib_get_thread_index ())
217 session_half_open_delete_notify (TRANSPORT_PROTO_TCP, tc->c_s_ho_handle);
218 wrk = tcp_get_worker (tc->c_thread_index);
219 tcp_timer_reset (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN);
220 tcp_half_open_connection_free (tc);
224 static tcp_connection_t *
225 tcp_half_open_connection_new (void)
227 tcp_main_t *tm = vnet_get_tcp_main ();
228 tcp_connection_t *tc = 0;
229 ASSERT (vlib_get_thread_index () == 0);
230 pool_get (tm->half_open_connections, tc);
231 clib_memset (tc, 0, sizeof (*tc));
232 tc->c_c_index = tc - tm->half_open_connections;
237 * Cleans up connection state.
242 tcp_connection_cleanup (tcp_connection_t * tc)
244 TCP_EVT (TCP_EVT_DELETE, tc);
246 /* Cleanup local endpoint if this was an active connect */
247 if (!(tc->cfg_flags & TCP_CFG_F_NO_ENDPOINT))
248 transport_endpoint_cleanup (TRANSPORT_PROTO_TCP, &tc->c_lcl_ip,
251 /* Check if connection is not yet fully established */
252 if (tc->state == TCP_STATE_SYN_SENT)
254 /* Try to remove the half-open connection. If this is not the owning
255 * thread, tc won't be removed. Retransmit or establish timers will
256 * eventually expire and call again cleanup on the right thread. */
257 if (tcp_half_open_connection_cleanup (tc))
258 tc->flags |= TCP_CONN_HALF_OPEN_DONE;
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 tcp_connection_free (tc);
282 * Connection removal.
284 * This should be called only once connection enters CLOSED state. Note
285 * that it notifies the session of the removal event, so if the goal is to
286 * just remove the connection, call tcp_connection_cleanup instead.
289 tcp_connection_del (tcp_connection_t * tc)
291 session_transport_delete_notify (&tc->connection);
292 tcp_connection_cleanup (tc);
296 tcp_connection_alloc (u8 thread_index)
298 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
299 tcp_connection_t *tc;
301 pool_get (wrk->connections, tc);
302 clib_memset (tc, 0, sizeof (*tc));
303 tc->c_c_index = tc - wrk->connections;
304 tc->c_thread_index = thread_index;
309 tcp_connection_alloc_w_base (u8 thread_index, tcp_connection_t * base)
311 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
312 tcp_connection_t *tc;
314 pool_get (wrk->connections, tc);
315 clib_memcpy_fast (tc, base, sizeof (*tc));
316 tc->c_c_index = tc - wrk->connections;
317 tc->c_thread_index = thread_index;
322 tcp_connection_free (tcp_connection_t * tc)
324 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
327 clib_memset (tc, 0xFA, sizeof (*tc));
328 pool_put (wrk->connections, tc);
331 pool_put (wrk->connections, tc);
335 tcp_program_cleanup (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
337 tcp_cleanup_req_t *req;
338 clib_time_type_t now;
340 now = transport_time_now (tc->c_thread_index);
341 clib_fifo_add2 (wrk->pending_cleanups, req);
342 req->connection_index = tc->c_c_index;
343 req->free_time = now + tcp_cfg.cleanup_time;
347 * Begin connection closing procedure.
349 * If at the end the connection is not in CLOSED state, it is not removed.
350 * Instead, we rely on on TCP to advance through state machine to either
351 * 1) LAST_ACK (passive close) whereby when the last ACK is received
352 * tcp_connection_del is called. This notifies session of the delete and
354 * 2) TIME_WAIT (active close) whereby after 2MSL the 2MSL timer triggers
355 * and cleanup is called.
357 * N.B. Half-close connections are not supported
360 tcp_connection_close (tcp_connection_t * tc)
362 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
364 TCP_EVT (TCP_EVT_CLOSE, tc);
366 /* Send/Program FIN if needed and switch state */
369 case TCP_STATE_SYN_SENT:
370 /* Try to cleanup. If not on the right thread, mark as half-open done.
371 * Connection will be cleaned up when establish timer pops */
372 tcp_connection_cleanup (tc);
374 case TCP_STATE_SYN_RCVD:
375 tcp_connection_timers_reset (tc);
377 tcp_connection_set_state (tc, TCP_STATE_FIN_WAIT_1);
378 tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE,
379 tcp_cfg.finwait1_time);
381 case TCP_STATE_ESTABLISHED:
382 /* If closing with unread data, reset the connection */
383 if (transport_max_rx_dequeue (&tc->connection))
386 tcp_connection_timers_reset (tc);
387 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
388 session_transport_closed_notify (&tc->connection);
389 tcp_program_cleanup (tcp_get_worker (tc->c_thread_index), tc);
390 tcp_worker_stats_inc (wrk, rst_unread, 1);
393 if (!transport_max_tx_dequeue (&tc->connection))
396 tc->flags |= TCP_CONN_FINPNDG;
397 tcp_connection_set_state (tc, TCP_STATE_FIN_WAIT_1);
398 /* Set a timer in case the peer stops responding. Otherwise the
399 * connection will be stuck here forever. */
400 ASSERT (tc->timers[TCP_TIMER_WAITCLOSE] == TCP_TIMER_HANDLE_INVALID);
401 tcp_timer_set (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE,
402 tcp_cfg.finwait1_time);
404 case TCP_STATE_CLOSE_WAIT:
405 if (!transport_max_tx_dequeue (&tc->connection))
408 tcp_connection_timers_reset (tc);
409 tcp_connection_set_state (tc, TCP_STATE_LAST_ACK);
410 tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE,
411 tcp_cfg.lastack_time);
414 tc->flags |= TCP_CONN_FINPNDG;
416 case TCP_STATE_FIN_WAIT_1:
417 tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE,
418 tcp_cfg.finwait1_time);
420 case TCP_STATE_CLOSED:
421 /* Cleanup should've been programmed already */
424 TCP_DBG ("state: %u", tc->state);
429 tcp_session_close (u32 conn_index, u32 thread_index)
431 tcp_connection_t *tc;
432 tc = tcp_connection_get (conn_index, thread_index);
433 tcp_connection_close (tc);
437 tcp_session_cleanup (u32 conn_index, u32 thread_index)
439 tcp_connection_t *tc;
440 tc = tcp_connection_get (conn_index, thread_index);
443 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
444 tcp_connection_cleanup (tc);
448 tcp_session_cleanup_ho (u32 conn_index)
450 tcp_worker_ctx_t *wrk;
451 tcp_connection_t *tc;
453 tc = tcp_half_open_connection_get (conn_index);
454 wrk = tcp_get_worker (tc->c_thread_index);
455 tcp_timer_reset (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN);
456 tcp_half_open_connection_free (tc);
460 tcp_session_reset (u32 conn_index, u32 thread_index)
462 tcp_connection_t *tc;
463 tc = tcp_connection_get (conn_index, thread_index);
465 tcp_connection_timers_reset (tc);
466 tcp_cong_recovery_off (tc);
467 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
468 session_transport_closed_notify (&tc->connection);
469 tcp_program_cleanup (tcp_get_worker (thread_index), tc);
473 * Initialize all connection timers as invalid
476 tcp_connection_timers_init (tcp_connection_t * tc)
480 /* Set all to invalid */
481 for (i = 0; i < TCP_N_TIMERS; i++)
483 tc->timers[i] = TCP_TIMER_HANDLE_INVALID;
486 tc->rto = TCP_RTO_INIT;
490 * Stop all connection timers
493 tcp_connection_timers_reset (tcp_connection_t * tc)
495 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
498 for (i = 0; i < TCP_N_TIMERS; i++)
499 tcp_timer_reset (&wrk->timer_wheel, tc, i);
503 typedef struct ip4_tcp_hdr
509 typedef struct ip6_tcp_hdr
516 tcp_connection_select_lb_bucket (tcp_connection_t * tc, const dpo_id_t * dpo,
519 const dpo_id_t *choice;
523 lb = load_balance_get (dpo->dpoi_index);
527 clib_memset (&hdr, 0, sizeof (hdr));
528 hdr.ip.protocol = IP_PROTOCOL_TCP;
529 hdr.ip.address_pair.src.as_u32 = tc->c_lcl_ip.ip4.as_u32;
530 hdr.ip.address_pair.dst.as_u32 = tc->c_rmt_ip.ip4.as_u32;
531 hdr.tcp.src_port = tc->c_lcl_port;
532 hdr.tcp.dst_port = tc->c_rmt_port;
533 hash = ip4_compute_flow_hash (&hdr.ip, lb->lb_hash_config);
538 clib_memset (&hdr, 0, sizeof (hdr));
539 hdr.ip.protocol = IP_PROTOCOL_TCP;
540 clib_memcpy_fast (&hdr.ip.src_address, &tc->c_lcl_ip.ip6,
541 sizeof (ip6_address_t));
542 clib_memcpy_fast (&hdr.ip.dst_address, &tc->c_rmt_ip.ip6,
543 sizeof (ip6_address_t));
544 hdr.tcp.src_port = tc->c_lcl_port;
545 hdr.tcp.dst_port = tc->c_rmt_port;
546 hash = ip6_compute_flow_hash (&hdr.ip, lb->lb_hash_config);
548 choice = load_balance_get_bucket_i (lb, hash & lb->lb_n_buckets_minus_1);
549 dpo_copy (result, choice);
553 tcp_lookup_rmt_in_fib (tcp_connection_t * tc)
558 clib_memcpy_fast (&prefix.fp_addr, &tc->c_rmt_ip, sizeof (prefix.fp_addr));
559 prefix.fp_proto = tc->c_is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
560 prefix.fp_len = tc->c_is_ip4 ? 32 : 128;
561 fib_index = fib_table_find (prefix.fp_proto, tc->c_fib_index);
562 return fib_table_lookup (fib_index, &prefix);
566 tcp_connection_stack_on_fib_entry (tcp_connection_t * tc)
568 dpo_id_t choice = DPO_INVALID;
569 u32 output_node_index;
572 fe = fib_entry_get (tc->c_rmt_fei);
573 if (fe->fe_lb.dpoi_type != DPO_LOAD_BALANCE)
576 tcp_connection_select_lb_bucket (tc, &fe->fe_lb, &choice);
579 tc->c_is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
580 dpo_stack_from_node (output_node_index, &tc->c_rmt_dpo, &choice);
584 /** Stack tcp connection on peer's fib entry.
586 * This ultimately populates the dpo the connection will use to send packets.
589 tcp_connection_fib_attach (tcp_connection_t * tc)
591 tc->c_rmt_fei = tcp_lookup_rmt_in_fib (tc);
593 ASSERT (tc->c_rmt_fei != FIB_NODE_INDEX_INVALID);
595 tcp_connection_stack_on_fib_entry (tc);
600 * Generate random iss as per rfc6528
603 tcp_generate_random_iss (tcp_connection_t * tc)
605 tcp_main_t *tm = &tcp_main;
609 tmp = (u64) tc->c_lcl_ip.ip4.as_u32 << 32 | (u64) tc->c_rmt_ip.ip4.as_u32;
611 tmp = tc->c_lcl_ip.ip6.as_u64[0] ^ tc->c_lcl_ip.ip6.as_u64[1]
612 ^ tc->c_rmt_ip.ip6.as_u64[0] ^ tc->c_rmt_ip.ip6.as_u64[1];
614 tmp ^= tm->iss_seed.first | ((u64) tc->c_lcl_port << 16 | tc->c_rmt_port);
615 tmp ^= tm->iss_seed.second;
616 tmp = clib_xxhash (tmp) + clib_cpu_time_now ();
617 return ((tmp >> 32) ^ (tmp & 0xffffffff));
621 * Initialize max segment size we're able to process.
623 * The value is constrained by the output interface's MTU and by the size
624 * of the IP and TCP headers (see RFC6691). It is also what we advertise
628 tcp_init_rcv_mss (tcp_connection_t * tc)
632 /* Already provided at connection init time */
636 ip_hdr_len = tc->c_is_ip4 ? sizeof (ip4_header_t) : sizeof (ip6_header_t);
637 tc->mss = tcp_cfg.default_mtu - sizeof (tcp_header_t) - ip_hdr_len;
641 tcp_init_mss (tcp_connection_t * tc)
643 u16 default_min_mss = 536;
645 tcp_init_rcv_mss (tc);
647 /* TODO consider PMTU discovery */
648 tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss);
650 if (tc->snd_mss < 45)
652 /* Assume that at least the min default mss works */
653 tc->snd_mss = default_min_mss;
654 tc->rcv_opts.mss = default_min_mss;
657 /* We should have enough space for 40 bytes of options */
658 ASSERT (tc->snd_mss > 45);
660 /* If we use timestamp option, account for it */
661 if (tcp_opts_tstamp (&tc->rcv_opts))
662 tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP;
666 * Initialize connection send variables.
669 tcp_init_snd_vars (tcp_connection_t * tc)
672 * We use the time to randomize iss and for setting up the initial
673 * timestamp. Make sure it's updated otherwise syn and ack in the
674 * handshake may make it look as if time has flown in the opposite
677 tcp_set_time_now (tcp_get_worker (vlib_get_thread_index ()));
679 tcp_init_rcv_mss (tc);
680 tc->iss = tcp_generate_random_iss (tc);
681 tc->snd_una = tc->iss;
682 tc->snd_nxt = tc->iss + 1;
683 tc->snd_una_max = tc->snd_nxt;
684 tc->srtt = 100; /* 100 ms */
686 if (!tcp_cfg.csum_offload)
687 tc->cfg_flags |= TCP_CFG_F_NO_CSUM_OFFLOAD;
691 tcp_enable_pacing (tcp_connection_t * tc)
694 byte_rate = tc->cwnd / (tc->srtt * TCP_TICK);
695 transport_connection_tx_pacer_init (&tc->connection, byte_rate, tc->cwnd);
696 tc->mrtt_us = (u32) ~ 0;
699 /** Initialize tcp connection variables
701 * Should be called after having received a msg from the peer, i.e., a SYN or
702 * a SYNACK, such that connection options have already been exchanged. */
704 tcp_connection_init_vars (tcp_connection_t * tc)
706 tcp_connection_timers_init (tc);
708 scoreboard_init (&tc->sack_sb);
709 if (tc->state == TCP_STATE_SYN_RCVD)
710 tcp_init_snd_vars (tc);
714 if (!tc->c_is_ip4 && ip6_address_is_link_local_unicast (&tc->c_rmt_ip6))
715 tcp_add_del_adjacency (tc, 1);
717 /* tcp_connection_fib_attach (tc); */
719 if (transport_connection_is_tx_paced (&tc->connection)
720 || tcp_cfg.enable_tx_pacing)
721 tcp_enable_pacing (tc);
723 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
726 if (!tcp_cfg.allow_tso)
727 tc->cfg_flags |= TCP_CFG_F_NO_TSO;
729 tc->start_ts = tcp_time_now_us (tc->c_thread_index);
733 tcp_alloc_custom_local_endpoint (tcp_main_t * tm, ip46_address_t * lcl_addr,
734 u16 * lcl_port, u8 is_ip4)
739 index = tm->last_v4_addr_rotor++;
740 if (tm->last_v4_addr_rotor >= vec_len (tcp_cfg.ip4_src_addrs))
741 tm->last_v4_addr_rotor = 0;
742 lcl_addr->ip4.as_u32 = tcp_cfg.ip4_src_addrs[index].as_u32;
746 index = tm->last_v6_addr_rotor++;
747 if (tm->last_v6_addr_rotor >= vec_len (tcp_cfg.ip6_src_addrs))
748 tm->last_v6_addr_rotor = 0;
749 clib_memcpy_fast (&lcl_addr->ip6, &tcp_cfg.ip6_src_addrs[index],
750 sizeof (ip6_address_t));
752 port = transport_alloc_local_port (TRANSPORT_PROTO_TCP, lcl_addr);
754 return SESSION_E_NOPORT;
760 tcp_session_open (transport_endpoint_cfg_t * rmt)
762 tcp_main_t *tm = vnet_get_tcp_main ();
763 tcp_connection_t *tc;
764 ip46_address_t lcl_addr;
769 * Allocate local endpoint
771 if ((rmt->is_ip4 && vec_len (tcp_cfg.ip4_src_addrs))
772 || (!rmt->is_ip4 && vec_len (tcp_cfg.ip6_src_addrs)))
773 rv = tcp_alloc_custom_local_endpoint (tm, &lcl_addr, &lcl_port,
776 rv = transport_alloc_local_endpoint (TRANSPORT_PROTO_TCP,
777 rmt, &lcl_addr, &lcl_port);
781 if (rv != SESSION_E_PORTINUSE)
784 if (session_lookup_connection (rmt->fib_index, &lcl_addr, &rmt->ip,
785 lcl_port, rmt->port, TRANSPORT_PROTO_UDP,
787 return SESSION_E_PORTINUSE;
789 /* 5-tuple is available so increase lcl endpoint refcount and proceed
790 * with connection allocation */
791 transport_share_local_endpoint (TRANSPORT_PROTO_UDP, &lcl_addr,
796 * Create connection and send SYN
798 clib_spinlock_lock_if_init (&tm->half_open_lock);
799 tc = tcp_half_open_connection_new ();
800 ip_copy (&tc->c_rmt_ip, &rmt->ip, rmt->is_ip4);
801 ip_copy (&tc->c_lcl_ip, &lcl_addr, rmt->is_ip4);
802 tc->c_rmt_port = rmt->port;
803 tc->c_lcl_port = clib_host_to_net_u16 (lcl_port);
804 tc->c_is_ip4 = rmt->is_ip4;
805 tc->c_proto = TRANSPORT_PROTO_TCP;
806 tc->c_fib_index = rmt->fib_index;
807 tc->cc_algo = tcp_cc_algo_get (tcp_cfg.cc_algo);
808 /* The other connection vars will be initialized after SYN ACK */
809 tcp_connection_timers_init (tc);
812 TCP_EVT (TCP_EVT_OPEN, tc);
813 tc->state = TCP_STATE_SYN_SENT;
814 tcp_init_snd_vars (tc);
816 clib_spinlock_unlock_if_init (&tm->half_open_lock);
818 return tc->c_c_index;
822 format_tcp_session (u8 * s, va_list * args)
824 u32 tci = va_arg (*args, u32);
825 u32 thread_index = va_arg (*args, u32);
826 u32 verbose = va_arg (*args, u32);
827 tcp_connection_t *tc;
829 tc = tcp_connection_get (tci, thread_index);
831 s = format (s, "%U", format_tcp_connection, tc, verbose);
833 s = format (s, "empty\n");
838 format_tcp_listener_session (u8 * s, va_list * args)
840 u32 tci = va_arg (*args, u32);
841 u32 __clib_unused thread_index = va_arg (*args, u32);
842 u32 verbose = va_arg (*args, u32);
843 tcp_connection_t *tc = tcp_listener_get (tci);
844 s = format (s, "%-50U", format_tcp_connection_id, tc);
846 s = format (s, "%-15U", format_tcp_state, tc->state);
851 format_tcp_half_open_session (u8 * s, va_list * args)
853 u32 tci = va_arg (*args, u32);
854 u32 __clib_unused thread_index = va_arg (*args, u32);
855 tcp_connection_t *tc = tcp_half_open_connection_get (tci);
856 return format (s, "%U", format_tcp_connection_id, tc);
859 static transport_connection_t *
860 tcp_session_get_transport (u32 conn_index, u32 thread_index)
862 tcp_connection_t *tc = tcp_connection_get (conn_index, thread_index);
863 if (PREDICT_FALSE (!tc))
865 return &tc->connection;
868 static transport_connection_t *
869 tcp_half_open_session_get_transport (u32 conn_index)
871 tcp_connection_t *tc = tcp_half_open_connection_get (conn_index);
872 return &tc->connection;
876 tcp_session_cal_goal_size (tcp_connection_t * tc)
878 u16 goal_size = tc->snd_mss;
880 goal_size = TCP_MAX_GSO_SZ - tc->snd_mss % TCP_MAX_GSO_SZ;
881 goal_size = clib_min (goal_size, tc->snd_wnd / 2);
883 return goal_size > tc->snd_mss ? goal_size : tc->snd_mss;
887 tcp_round_snd_space (tcp_connection_t * tc, u32 snd_space)
889 if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
891 return tc->snd_wnd <= snd_space ? tc->snd_wnd : 0;
894 /* If not snd_wnd constrained and we can't write at least a segment,
895 * don't try at all */
896 if (PREDICT_FALSE (snd_space < tc->snd_mss))
897 return snd_space < tc->cwnd ? 0 : snd_space;
899 /* round down to mss multiple */
900 return snd_space - (snd_space % tc->snd_mss);
904 * Compute tx window session is allowed to fill.
906 * Takes into account available send space, snd_mss and the congestion
907 * state of the connection. If possible, the value returned is a multiple
910 * @param tc tcp connection
911 * @return number of bytes session is allowed to write
914 tcp_snd_space_inline (tcp_connection_t * tc)
918 if (PREDICT_FALSE (tcp_in_fastrecovery (tc)
919 || tc->state == TCP_STATE_CLOSED))
922 snd_space = tcp_available_output_snd_space (tc);
924 /* If we got dupacks or sacked bytes but we're not yet in recovery, try
925 * to force the peer to send enough dupacks to start retransmitting as
926 * per Limited Transmit (RFC3042)
928 if (PREDICT_FALSE (tc->rcv_dupacks != 0 || tc->sack_sb.sacked_bytes))
930 if (tc->limited_transmit != tc->snd_nxt
931 && (seq_lt (tc->limited_transmit, tc->snd_nxt - 2 * tc->snd_mss)
932 || seq_gt (tc->limited_transmit, tc->snd_nxt)))
933 tc->limited_transmit = tc->snd_nxt;
935 ASSERT (seq_leq (tc->limited_transmit, tc->snd_nxt));
937 int snt_limited = tc->snd_nxt - tc->limited_transmit;
938 snd_space = clib_max ((int) 2 * tc->snd_mss - snt_limited, 0);
940 return tcp_round_snd_space (tc, snd_space);
944 tcp_snd_space (tcp_connection_t * tc)
946 return tcp_snd_space_inline (tc);
950 tcp_session_send_params (transport_connection_t * trans_conn,
951 transport_send_params_t * sp)
953 tcp_connection_t *tc = (tcp_connection_t *) trans_conn;
955 /* Ensure snd_mss does accurately reflect the amount of data we can push
956 * in a segment. This also makes sure that options are updated according to
957 * the current state of the connection. */
958 tcp_update_burst_snd_vars (tc);
960 if (PREDICT_FALSE (tc->cfg_flags & TCP_CFG_F_TSO))
961 sp->snd_mss = tcp_session_cal_goal_size (tc);
963 sp->snd_mss = tc->snd_mss;
965 sp->snd_space = clib_min (tcp_snd_space_inline (tc),
966 tc->snd_wnd - (tc->snd_nxt - tc->snd_una));
968 ASSERT (seq_geq (tc->snd_nxt, tc->snd_una));
969 /* This still works if fast retransmit is on */
970 sp->tx_offset = tc->snd_nxt - tc->snd_una;
972 sp->flags = sp->snd_space ? 0 : TRANSPORT_SND_F_DESCHED;
978 tcp_timer_waitclose_handler (tcp_connection_t * tc)
980 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
984 case TCP_STATE_CLOSE_WAIT:
985 tcp_connection_timers_reset (tc);
986 /* App never returned with a close */
987 if (!(tc->flags & TCP_CONN_FINPNDG))
989 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
990 session_transport_closed_notify (&tc->connection);
991 tcp_program_cleanup (wrk, tc);
992 tcp_worker_stats_inc (wrk, to_closewait, 1);
996 /* Send FIN either way and switch to LAST_ACK. */
997 tcp_cong_recovery_off (tc);
998 /* Make sure we don't try to send unsent data */
999 tc->snd_nxt = tc->snd_una;
1001 tcp_connection_set_state (tc, TCP_STATE_LAST_ACK);
1002 session_transport_closed_notify (&tc->connection);
1004 /* Make sure we don't wait in LAST ACK forever */
1005 tcp_timer_set (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE,
1006 tcp_cfg.lastack_time);
1007 tcp_worker_stats_inc (wrk, to_closewait2, 1);
1009 /* Don't delete the connection yet */
1011 case TCP_STATE_FIN_WAIT_1:
1012 tcp_connection_timers_reset (tc);
1013 if (tc->flags & TCP_CONN_FINPNDG)
1015 /* If FIN pending, we haven't sent everything, but we did try.
1016 * Notify session layer that transport is closed. */
1017 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1018 tcp_send_reset (tc);
1019 tcp_program_cleanup (wrk, tc);
1023 /* We've sent the fin but no progress. Close the connection and
1024 * to make sure everything is flushed, setup a cleanup timer */
1025 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1026 tcp_program_cleanup (wrk, tc);
1028 session_transport_closed_notify (&tc->connection);
1029 tcp_worker_stats_inc (wrk, to_finwait1, 1);
1031 case TCP_STATE_LAST_ACK:
1032 tcp_connection_timers_reset (tc);
1033 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1034 session_transport_closed_notify (&tc->connection);
1035 tcp_program_cleanup (wrk, tc);
1036 tcp_worker_stats_inc (wrk, to_lastack, 1);
1038 case TCP_STATE_CLOSING:
1039 tcp_connection_timers_reset (tc);
1040 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1041 session_transport_closed_notify (&tc->connection);
1042 tcp_program_cleanup (wrk, tc);
1043 tcp_worker_stats_inc (wrk, to_closing, 1);
1045 case TCP_STATE_FIN_WAIT_2:
1046 tcp_send_reset (tc);
1047 tcp_connection_timers_reset (tc);
1048 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1049 session_transport_closed_notify (&tc->connection);
1050 tcp_program_cleanup (wrk, tc);
1051 tcp_worker_stats_inc (wrk, to_finwait2, 1);
1053 case TCP_STATE_TIME_WAIT:
1054 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1055 tcp_program_cleanup (wrk, tc);
1058 clib_warning ("waitclose in state: %U", format_tcp_state, tc->state);
1064 static timer_expiration_handler *timer_expiration_handlers[TCP_N_TIMERS] =
1066 tcp_timer_retransmit_handler,
1067 tcp_timer_delack_handler,
1068 tcp_timer_persist_handler,
1069 tcp_timer_waitclose_handler,
1070 tcp_timer_retransmit_syn_handler,
1075 tcp_dispatch_pending_timers (tcp_worker_ctx_t * wrk)
1077 u32 n_timers, connection_index, timer_id, thread_index, timer_handle;
1078 tcp_connection_t *tc;
1081 if (!(n_timers = clib_fifo_elts (wrk->pending_timers)))
1084 thread_index = wrk->vm->thread_index;
1085 for (i = 0; i < clib_min (n_timers, wrk->max_timers_per_loop); i++)
1087 clib_fifo_sub1 (wrk->pending_timers, timer_handle);
1088 connection_index = timer_handle & 0x0FFFFFFF;
1089 timer_id = timer_handle >> 28;
1091 if (PREDICT_TRUE (timer_id != TCP_TIMER_RETRANSMIT_SYN))
1092 tc = tcp_connection_get (connection_index, thread_index);
1094 tc = tcp_half_open_connection_get (connection_index);
1096 if (PREDICT_FALSE (!tc))
1099 /* Skip timer if it was rearmed while pending dispatch */
1100 if (PREDICT_FALSE (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID))
1103 (*timer_expiration_handlers[timer_id]) (tc);
1106 if (thread_index == 0 && clib_fifo_elts (wrk->pending_timers))
1107 session_queue_run_on_main_thread (wrk->vm);
1111 tcp_handle_cleanups (tcp_worker_ctx_t * wrk, clib_time_type_t now)
1113 u32 thread_index = wrk->vm->thread_index;
1114 tcp_cleanup_req_t *req;
1115 tcp_connection_t *tc;
1117 while (clib_fifo_elts (wrk->pending_cleanups))
1119 req = clib_fifo_head (wrk->pending_cleanups);
1120 if (req->free_time > now)
1122 clib_fifo_sub2 (wrk->pending_cleanups, req);
1123 tc = tcp_connection_get (req->connection_index, thread_index);
1124 if (PREDICT_FALSE (!tc))
1126 session_transport_delete_notify (&tc->connection);
1127 tcp_connection_cleanup (tc);
1132 tcp_update_time (f64 now, u8 thread_index)
1134 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
1136 tcp_set_time_now (wrk);
1137 tcp_handle_cleanups (wrk, now);
1138 tw_timer_expire_timers_16t_2w_512sl (&wrk->timer_wheel, now);
1139 tcp_dispatch_pending_timers (wrk);
1143 tcp_session_flush_data (transport_connection_t * tconn)
1145 tcp_connection_t *tc = (tcp_connection_t *) tconn;
1146 if (tc->flags & TCP_CONN_PSH_PENDING)
1148 tc->flags |= TCP_CONN_PSH_PENDING;
1149 tc->psh_seq = tc->snd_una + transport_max_tx_dequeue (tconn) - 1;
1153 const static transport_proto_vft_t tcp_proto = {
1154 .enable = vnet_tcp_enable_disable,
1155 .start_listen = tcp_session_bind,
1156 .stop_listen = tcp_session_unbind,
1157 .push_header = tcp_session_push_header,
1158 .get_connection = tcp_session_get_transport,
1159 .get_listener = tcp_session_get_listener,
1160 .get_half_open = tcp_half_open_session_get_transport,
1161 .connect = tcp_session_open,
1162 .close = tcp_session_close,
1163 .cleanup = tcp_session_cleanup,
1164 .cleanup_ho = tcp_session_cleanup_ho,
1165 .reset = tcp_session_reset,
1166 .send_params = tcp_session_send_params,
1167 .update_time = tcp_update_time,
1168 .flush_data = tcp_session_flush_data,
1169 .custom_tx = tcp_session_custom_tx,
1170 .format_connection = format_tcp_session,
1171 .format_listener = format_tcp_listener_session,
1172 .format_half_open = format_tcp_half_open_session,
1173 .transport_options = {
1176 .tx_type = TRANSPORT_TX_PEEK,
1177 .service_type = TRANSPORT_SERVICE_VC,
1183 tcp_connection_tx_pacer_update (tcp_connection_t * tc)
1185 if (!transport_connection_is_tx_paced (&tc->connection))
1188 f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us);
1190 transport_connection_tx_pacer_update (&tc->connection,
1191 tcp_cc_get_pacing_rate (tc),
1192 srtt * CLIB_US_TIME_FREQ);
1196 tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window,
1199 f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us);
1200 transport_connection_tx_pacer_reset (&tc->connection,
1201 tcp_cc_get_pacing_rate (tc),
1203 srtt * CLIB_US_TIME_FREQ);
1207 tcp_reschedule (tcp_connection_t * tc)
1209 if (tcp_in_cong_recovery (tc) || tcp_snd_space_inline (tc))
1210 transport_connection_reschedule (&tc->connection);
1214 tcp_expired_timers_dispatch (u32 * expired_timers)
1216 u32 thread_index = vlib_get_thread_index (), n_left, max_per_loop;
1217 u32 connection_index, timer_id, n_expired, max_loops;
1218 tcp_worker_ctx_t *wrk;
1219 tcp_connection_t *tc;
1222 wrk = tcp_get_worker (thread_index);
1223 n_expired = vec_len (expired_timers);
1224 tcp_worker_stats_inc (wrk, timer_expirations, n_expired);
1225 n_left = clib_fifo_elts (wrk->pending_timers);
1228 * Invalidate all timer handles before dispatching. This avoids dangling
1229 * index references to timer wheel pool entries that have been freed.
1231 for (i = 0; i < n_expired; i++)
1233 connection_index = expired_timers[i] & 0x0FFFFFFF;
1234 timer_id = expired_timers[i] >> 28;
1236 if (timer_id != TCP_TIMER_RETRANSMIT_SYN)
1237 tc = tcp_connection_get (connection_index, thread_index);
1239 tc = tcp_half_open_connection_get (connection_index);
1241 TCP_EVT (TCP_EVT_TIMER_POP, connection_index, timer_id);
1243 tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID;
1246 clib_fifo_add (wrk->pending_timers, expired_timers, n_expired);
1248 max_loops = clib_max (1, 0.5 * TCP_TIMER_TICK * wrk->vm->loops_per_second);
1249 max_per_loop = clib_max ((n_left + n_expired) / max_loops, 10);
1250 max_per_loop = clib_min (max_per_loop, VLIB_FRAME_SIZE);
1251 wrk->max_timers_per_loop = clib_max (n_left ? wrk->max_timers_per_loop : 0,
1254 if (thread_index == 0)
1255 session_queue_run_on_main_thread (wrk->vm);
1259 tcp_initialize_timer_wheels (tcp_main_t * tm)
1261 vlib_main_t *vm = vlib_get_main ();
1262 tw_timer_wheel_16t_2w_512sl_t *tw;
1264 foreach_vlib_main (({
1265 tw = &tm->wrk_ctx[ii].timer_wheel;
1266 tw_timer_wheel_init_16t_2w_512sl (tw, tcp_expired_timers_dispatch,
1267 TCP_TIMER_TICK, ~0);
1268 tw->last_run_time = vlib_time_now (vm);
1274 tcp_initialize_iss_seed (tcp_main_t * tm)
1276 u32 default_seed = random_default_seed ();
1277 u64 time_now = clib_cpu_time_now ();
1279 tm->iss_seed.first = (u64) random_u32 (&default_seed) << 32;
1280 tm->iss_seed.second = random_u64 (&time_now);
1283 static clib_error_t *
1284 tcp_main_enable (vlib_main_t * vm)
1286 vlib_thread_main_t *vtm = vlib_get_thread_main ();
1287 u32 num_threads, n_workers, prealloc_conn_per_wrk;
1288 tcp_connection_t *tc __attribute__ ((unused));
1289 tcp_main_t *tm = vnet_get_tcp_main ();
1290 tcp_worker_ctx_t *wrk;
1291 clib_error_t *error = 0;
1294 if ((error = vlib_call_init_function (vm, ip_main_init)))
1296 if ((error = vlib_call_init_function (vm, ip4_lookup_init)))
1298 if ((error = vlib_call_init_function (vm, ip6_lookup_init)))
1305 ip4_register_protocol (IP_PROTOCOL_TCP, tcp4_input_node.index);
1306 ip6_register_protocol (IP_PROTOCOL_TCP, tcp6_input_node.index);
1309 * Initialize data structures
1312 num_threads = 1 /* main thread */ + vtm->n_threads;
1313 vec_validate (tm->wrk_ctx, num_threads - 1);
1314 n_workers = num_threads == 1 ? 1 : vtm->n_threads;
1315 prealloc_conn_per_wrk = tcp_cfg.preallocated_connections / n_workers;
1317 wrk = &tm->wrk_ctx[0];
1318 wrk->tco_next_node[0] = vlib_node_get_next (vm, session_queue_node.index,
1319 tcp4_output_node.index);
1320 wrk->tco_next_node[1] = vlib_node_get_next (vm, session_queue_node.index,
1321 tcp6_output_node.index);
1323 for (thread = 0; thread < num_threads; thread++)
1325 wrk = &tm->wrk_ctx[thread];
1327 vec_validate (wrk->pending_deq_acked, 255);
1328 vec_validate (wrk->pending_disconnects, 255);
1329 vec_validate (wrk->pending_resets, 255);
1330 vec_reset_length (wrk->pending_deq_acked);
1331 vec_reset_length (wrk->pending_disconnects);
1332 vec_reset_length (wrk->pending_resets);
1333 wrk->vm = vlib_mains[thread];
1334 wrk->max_timers_per_loop = 10;
1338 wrk->tco_next_node[0] = tm->wrk_ctx[0].tco_next_node[0];
1339 wrk->tco_next_node[1] = tm->wrk_ctx[0].tco_next_node[1];
1343 * Preallocate connections. Assume that thread 0 won't
1344 * use preallocated threads when running multi-core
1346 if ((thread > 0 || num_threads == 1) && prealloc_conn_per_wrk)
1347 pool_init_fixed (wrk->connections, prealloc_conn_per_wrk);
1351 * Use a preallocated half-open connection pool?
1353 if (tcp_cfg.preallocated_half_open_connections)
1354 pool_init_fixed (tm->half_open_connections,
1355 tcp_cfg.preallocated_half_open_connections);
1357 /* Initialize clocks per tick for TCP timestamp. Used to compute
1358 * monotonically increasing timestamps. */
1359 tm->tstamp_ticks_per_clock = vm->clib_time.seconds_per_clock
1360 / TCP_TSTAMP_RESOLUTION;
1362 if (num_threads > 1)
1364 clib_spinlock_init (&tm->half_open_lock);
1367 tcp_initialize_timer_wheels (tm);
1368 tcp_initialize_iss_seed (tm);
1370 tm->bytes_per_buffer = vlib_buffer_get_default_data_size (vm);
1371 tm->cc_last_type = TCP_CC_LAST;
1373 tm->ipl_next_node[0] = vlib_node_get_next (vm, session_queue_node.index,
1374 ip4_lookup_node.index);
1375 tm->ipl_next_node[1] = vlib_node_get_next (vm, session_queue_node.index,
1376 ip6_lookup_node.index);
1381 vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en)
1385 if (tcp_main.is_enabled)
1388 return tcp_main_enable (vm);
1392 tcp_main.is_enabled = 0;
1399 tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add)
1401 tcp_main_t *tm = &tcp_main;
1403 tm->punt_unknown4 = is_add;
1405 tm->punt_unknown6 = is_add;
1409 * Initialize default values for tcp parameters
1412 tcp_configuration_init (void)
1414 /* Initial wnd for SYN. Fifos are not allocated at that point so use some
1415 * predefined value. For SYN-ACK we still want the scale to be computed in
1417 tcp_cfg.max_rx_fifo = 32 << 20;
1418 tcp_cfg.min_rx_fifo = 4 << 10;
1420 tcp_cfg.default_mtu = 1500;
1421 tcp_cfg.initial_cwnd_multiplier = 0;
1422 tcp_cfg.enable_tx_pacing = 1;
1423 tcp_cfg.allow_tso = 0;
1424 tcp_cfg.csum_offload = 1;
1425 tcp_cfg.cc_algo = TCP_CC_CUBIC;
1426 tcp_cfg.rwnd_min_update_ack = 1;
1428 /* Time constants defined as timer tick (100ms) multiples */
1429 tcp_cfg.delack_time = 1; /* 0.1s */
1430 tcp_cfg.closewait_time = 20; /* 2s */
1431 tcp_cfg.timewait_time = 100; /* 10s */
1432 tcp_cfg.finwait1_time = 600; /* 60s */
1433 tcp_cfg.lastack_time = 300; /* 30s */
1434 tcp_cfg.finwait2_time = 300; /* 30s */
1435 tcp_cfg.closing_time = 300; /* 30s */
1436 tcp_cfg.cleanup_time = 0.1; /* 100ms */
1439 static clib_error_t *
1440 tcp_init (vlib_main_t * vm)
1442 tcp_main_t *tm = vnet_get_tcp_main ();
1443 ip_main_t *im = &ip_main;
1444 ip_protocol_info_t *pi;
1446 /* Session layer, and by implication tcp, are disabled by default */
1449 /* Register with IP for header parsing */
1450 pi = ip_get_protocol_info (im, IP_PROTOCOL_TCP);
1452 return clib_error_return (0, "TCP protocol info AWOL");
1453 pi->format_header = format_tcp_header;
1454 pi->unformat_pg_edit = unformat_pg_tcp_header;
1456 /* Register as transport with session layer */
1457 transport_register_protocol (TRANSPORT_PROTO_TCP, &tcp_proto,
1458 FIB_PROTOCOL_IP4, tcp4_output_node.index);
1459 transport_register_protocol (TRANSPORT_PROTO_TCP, &tcp_proto,
1460 FIB_PROTOCOL_IP6, tcp6_output_node.index);
1462 tcp_configuration_init ();
1464 tm->cc_algo_by_name = hash_create_string (0, sizeof (uword));
1469 VLIB_INIT_FUNCTION (tcp_init);
1472 * fd.io coding-style-patch-verification: ON
1475 * eval: (c-set-style "gnu")