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.
16 #include <vnet/tcp/tcp.h>
19 typedef enum _tcp_output_next
22 TCP_OUTPUT_NEXT_IP_LOOKUP,
23 TCP_OUTPUT_NEXT_IP_REWRITE,
24 TCP_OUTPUT_NEXT_IP_ARP,
28 #define foreach_tcp4_output_next \
29 _ (DROP, "error-drop") \
30 _ (IP_LOOKUP, "ip4-lookup") \
31 _ (IP_REWRITE, "ip4-rewrite") \
34 #define foreach_tcp6_output_next \
35 _ (DROP, "error-drop") \
36 _ (IP_LOOKUP, "ip6-lookup") \
37 _ (IP_REWRITE, "ip6-rewrite") \
38 _ (IP_ARP, "ip6-discover-neighbor")
40 static char *tcp_error_strings[] = {
41 #define tcp_error(n,s) s,
42 #include <vnet/tcp/tcp_error.def>
48 tcp_header_t tcp_header;
49 tcp_connection_t tcp_connection;
53 format_tcp_tx_trace (u8 * s, va_list * args)
55 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
56 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
57 tcp_tx_trace_t *t = va_arg (*args, tcp_tx_trace_t *);
58 u32 indent = format_get_indent (s);
60 s = format (s, "%U\n%U%U",
61 format_tcp_header, &t->tcp_header, 128,
62 format_white_space, indent,
63 format_tcp_connection, &t->tcp_connection, 1);
68 #ifndef CLIB_MARCH_VARIANT
70 tcp_window_compute_scale (u32 window)
73 while (wnd_scale < TCP_MAX_WND_SCALE && (window >> wnd_scale) > TCP_WND_MAX)
79 * TCP's initial window
82 tcp_initial_wnd_unscaled (tcp_connection_t * tc)
84 /* RFC 6928 recommends the value lower. However at the time our connections
85 * are initialized, fifos may not be allocated. Therefore, advertise the
86 * smallest possible unscaled window size and update once fifos are
87 * assigned to the session.
90 tcp_update_rcv_mss (tc);
91 TCP_IW_N_SEGMENTS * tc->mss;
93 return tcp_cfg.min_rx_fifo;
97 * Compute initial window and scale factor. As per RFC1323, window field in
98 * SYN and SYN-ACK segments is never scaled.
101 tcp_initial_window_to_advertise (tcp_connection_t * tc)
103 /* Compute rcv wscale only if peer advertised support for it */
104 if (tc->state != TCP_STATE_SYN_RCVD || tcp_opts_wscale (&tc->rcv_opts))
105 tc->rcv_wscale = tcp_window_compute_scale (tcp_cfg.max_rx_fifo);
107 tc->rcv_wnd = tcp_initial_wnd_unscaled (tc);
109 return clib_min (tc->rcv_wnd, TCP_WND_MAX);
113 tcp_update_rcv_wnd (tcp_connection_t * tc)
115 u32 available_space, wnd;
118 ASSERT (tc->rcv_opts.mss < transport_rx_fifo_size (&tc->connection));
121 * Figure out how much space we have available
123 available_space = transport_max_rx_enqueue (&tc->connection);
124 if (PREDICT_FALSE (available_space < tc->rcv_opts.mss))
131 * Use the above and what we know about what we've previously advertised
132 * to compute the new window
134 observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
136 /* Bad. Thou shalt not shrink */
137 if (PREDICT_FALSE ((i32) available_space < observed_wnd))
139 wnd = clib_max (observed_wnd, 0);
140 TCP_EVT (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space);
144 wnd = available_space;
147 /* Make sure we have a multiple of rcv_wscale */
148 if (wnd && tc->rcv_wscale)
150 wnd &= ~((1 << tc->rcv_wscale) - 1);
152 wnd = 1 << tc->rcv_wscale;
155 tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale);
159 * Compute and return window to advertise, scaled as per RFC1323
162 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
164 if (state < TCP_STATE_ESTABLISHED)
165 return tcp_initial_window_to_advertise (tc);
167 tcp_update_rcv_wnd (tc);
168 return tc->rcv_wnd >> tc->rcv_wscale;
172 * Write TCP options to segment.
175 tcp_options_write (u8 * data, tcp_options_t * opts)
178 u32 buf, seq_len = 4;
180 if (tcp_opts_mss (opts))
182 *data++ = TCP_OPTION_MSS;
183 *data++ = TCP_OPTION_LEN_MSS;
184 buf = clib_host_to_net_u16 (opts->mss);
185 clib_memcpy_fast (data, &buf, sizeof (opts->mss));
186 data += sizeof (opts->mss);
187 opts_len += TCP_OPTION_LEN_MSS;
190 if (tcp_opts_wscale (opts))
192 *data++ = TCP_OPTION_WINDOW_SCALE;
193 *data++ = TCP_OPTION_LEN_WINDOW_SCALE;
194 *data++ = opts->wscale;
195 opts_len += TCP_OPTION_LEN_WINDOW_SCALE;
198 if (tcp_opts_sack_permitted (opts))
200 *data++ = TCP_OPTION_SACK_PERMITTED;
201 *data++ = TCP_OPTION_LEN_SACK_PERMITTED;
202 opts_len += TCP_OPTION_LEN_SACK_PERMITTED;
205 if (tcp_opts_tstamp (opts))
207 *data++ = TCP_OPTION_TIMESTAMP;
208 *data++ = TCP_OPTION_LEN_TIMESTAMP;
209 buf = clib_host_to_net_u32 (opts->tsval);
210 clib_memcpy_fast (data, &buf, sizeof (opts->tsval));
211 data += sizeof (opts->tsval);
212 buf = clib_host_to_net_u32 (opts->tsecr);
213 clib_memcpy_fast (data, &buf, sizeof (opts->tsecr));
214 data += sizeof (opts->tsecr);
215 opts_len += TCP_OPTION_LEN_TIMESTAMP;
218 if (tcp_opts_sack (opts))
222 if (opts->n_sack_blocks != 0)
224 *data++ = TCP_OPTION_SACK_BLOCK;
225 *data++ = 2 + opts->n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
226 for (i = 0; i < opts->n_sack_blocks; i++)
228 buf = clib_host_to_net_u32 (opts->sacks[i].start);
229 clib_memcpy_fast (data, &buf, seq_len);
231 buf = clib_host_to_net_u32 (opts->sacks[i].end);
232 clib_memcpy_fast (data, &buf, seq_len);
235 opts_len += 2 + opts->n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
239 /* Terminate TCP options */
242 *data++ = TCP_OPTION_EOL;
243 opts_len += TCP_OPTION_LEN_EOL;
246 /* Pad with zeroes to a u32 boundary */
249 *data++ = TCP_OPTION_NOOP;
250 opts_len += TCP_OPTION_LEN_NOOP;
256 tcp_make_syn_options (tcp_connection_t * tc, tcp_options_t * opts)
260 opts->flags |= TCP_OPTS_FLAG_MSS;
262 len += TCP_OPTION_LEN_MSS;
264 opts->flags |= TCP_OPTS_FLAG_WSCALE;
265 opts->wscale = tc->rcv_wscale;
266 len += TCP_OPTION_LEN_WINDOW_SCALE;
268 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
269 opts->tsval = tcp_time_now ();
271 len += TCP_OPTION_LEN_TIMESTAMP;
275 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
276 len += TCP_OPTION_LEN_SACK_PERMITTED;
279 /* Align to needed boundary */
280 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
285 tcp_make_synack_options (tcp_connection_t * tc, tcp_options_t * opts)
289 opts->flags |= TCP_OPTS_FLAG_MSS;
291 len += TCP_OPTION_LEN_MSS;
293 if (tcp_opts_wscale (&tc->rcv_opts))
295 opts->flags |= TCP_OPTS_FLAG_WSCALE;
296 opts->wscale = tc->rcv_wscale;
297 len += TCP_OPTION_LEN_WINDOW_SCALE;
300 if (tcp_opts_tstamp (&tc->rcv_opts))
302 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
303 opts->tsval = tcp_time_now ();
304 opts->tsecr = tc->tsval_recent;
305 len += TCP_OPTION_LEN_TIMESTAMP;
308 if (tcp_opts_sack_permitted (&tc->rcv_opts))
310 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
311 len += TCP_OPTION_LEN_SACK_PERMITTED;
314 /* Align to needed boundary */
315 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
320 tcp_make_established_options (tcp_connection_t * tc, tcp_options_t * opts)
326 if (tcp_opts_tstamp (&tc->rcv_opts))
328 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
329 opts->tsval = tcp_tstamp (tc);
330 opts->tsecr = tc->tsval_recent;
331 len += TCP_OPTION_LEN_TIMESTAMP;
333 if (tcp_opts_sack_permitted (&tc->rcv_opts))
335 if (vec_len (tc->snd_sacks))
337 opts->flags |= TCP_OPTS_FLAG_SACK;
338 if (tc->snd_sack_pos >= vec_len (tc->snd_sacks))
339 tc->snd_sack_pos = 0;
340 opts->sacks = &tc->snd_sacks[tc->snd_sack_pos];
341 opts->n_sack_blocks = vec_len (tc->snd_sacks) - tc->snd_sack_pos;
342 opts->n_sack_blocks = clib_min (opts->n_sack_blocks,
343 TCP_OPTS_MAX_SACK_BLOCKS);
344 tc->snd_sack_pos += opts->n_sack_blocks;
345 len += 2 + TCP_OPTION_LEN_SACK_BLOCK * opts->n_sack_blocks;
349 /* Align to needed boundary */
350 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
355 tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts,
360 case TCP_STATE_ESTABLISHED:
361 case TCP_STATE_CLOSE_WAIT:
362 case TCP_STATE_FIN_WAIT_1:
363 case TCP_STATE_LAST_ACK:
364 case TCP_STATE_CLOSING:
365 case TCP_STATE_FIN_WAIT_2:
366 case TCP_STATE_TIME_WAIT:
367 case TCP_STATE_CLOSED:
368 return tcp_make_established_options (tc, opts);
369 case TCP_STATE_SYN_RCVD:
370 return tcp_make_synack_options (tc, opts);
371 case TCP_STATE_SYN_SENT:
372 return tcp_make_syn_options (tc, opts);
374 clib_warning ("State not handled! %d", state);
380 * Update burst send vars
382 * - Updates snd_mss to reflect the effective segment size that we can send
383 * by taking into account all TCP options, including SACKs.
384 * - Cache 'on the wire' options for reuse
385 * - Updates receive window which can be reused for a burst.
387 * This should *only* be called when doing bursts
390 tcp_update_burst_snd_vars (tcp_connection_t * tc)
392 tcp_main_t *tm = &tcp_main;
394 /* Compute options to be used for connection. These may be reused when
395 * sending data or to compute the effective mss (snd_mss) */
396 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts,
397 TCP_STATE_ESTABLISHED);
399 /* XXX check if MTU has been updated */
400 tc->snd_mss = clib_min (tc->mss, tc->rcv_opts.mss) - tc->snd_opts_len;
401 ASSERT (tc->snd_mss > 0);
403 tcp_options_write (tm->wrk_ctx[tc->c_thread_index].cached_opts,
406 tcp_update_rcv_wnd (tc);
408 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
409 tc->flags |= TCP_CONN_TRACK_BURST;
411 if (tc->snd_una == tc->snd_nxt)
413 tcp_cc_event (tc, TCP_CC_EVT_START_TX);
414 tcp_connection_tx_pacer_reset (tc, tc->cwnd, TRANSPORT_PACER_MIN_MSS);
418 #endif /* CLIB_MARCH_VARIANT */
421 tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b)
423 if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
424 vlib_buffer_free_one (vm, b->next_buffer);
425 /* Zero all flags but free list index and trace flag */
426 b->flags &= VLIB_BUFFER_NEXT_PRESENT - 1;
428 b->current_length = 0;
429 b->total_length_not_including_first_buffer = 0;
430 vnet_buffer (b)->tcp.flags = 0;
432 /* Leave enough space for headers */
433 return vlib_buffer_make_headroom (b, TRANSPORT_MAX_HDRS_LEN);
436 #ifndef CLIB_MARCH_VARIANT
438 tcp_init_buffer (vlib_main_t * vm, vlib_buffer_t * b)
440 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0);
441 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
442 b->total_length_not_including_first_buffer = 0;
444 vnet_buffer (b)->tcp.flags = 0;
445 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
446 /* Leave enough space for headers */
447 return vlib_buffer_make_headroom (b, TRANSPORT_MAX_HDRS_LEN);
451 /* Compute TCP checksum in software when offloading is disabled for a connection */
453 ip6_tcp_compute_checksum_custom (vlib_main_t * vm, vlib_buffer_t * p0,
454 ip46_address_t * src, ip46_address_t * dst)
457 u16 payload_length_host_byte_order;
460 /* Initialize checksum with ip header. */
461 sum0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, p0)) +
462 clib_host_to_net_u16 (IP_PROTOCOL_TCP);
463 payload_length_host_byte_order = vlib_buffer_length_in_chain (vm, p0);
465 for (i = 0; i < ARRAY_LEN (src->ip6.as_uword); i++)
467 sum0 = ip_csum_with_carry
468 (sum0, clib_mem_unaligned (&src->ip6.as_uword[i], uword));
469 sum0 = ip_csum_with_carry
470 (sum0, clib_mem_unaligned (&dst->ip6.as_uword[i], uword));
473 return ip_calculate_l4_checksum (vm, p0, sum0,
474 payload_length_host_byte_order, NULL, 0,
479 ip4_tcp_compute_checksum_custom (vlib_main_t * vm, vlib_buffer_t * p0,
480 ip46_address_t * src, ip46_address_t * dst)
483 u32 payload_length_host_byte_order;
485 payload_length_host_byte_order = vlib_buffer_length_in_chain (vm, p0);
487 clib_host_to_net_u32 (payload_length_host_byte_order +
488 (IP_PROTOCOL_TCP << 16));
490 sum0 = ip_csum_with_carry (sum0, clib_mem_unaligned (&src->ip4, u32));
491 sum0 = ip_csum_with_carry (sum0, clib_mem_unaligned (&dst->ip4, u32));
493 return ip_calculate_l4_checksum (vm, p0, sum0,
494 payload_length_host_byte_order, NULL, 0,
499 tcp_compute_checksum (tcp_connection_t * tc, vlib_buffer_t * b)
502 if (PREDICT_FALSE (tc->cfg_flags & TCP_CFG_F_NO_CSUM_OFFLOAD))
504 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
505 vlib_main_t *vm = wrk->vm;
508 checksum = ip4_tcp_compute_checksum_custom
509 (vm, b, &tc->c_lcl_ip, &tc->c_rmt_ip);
511 checksum = ip6_tcp_compute_checksum_custom
512 (vm, b, &tc->c_lcl_ip, &tc->c_rmt_ip);
516 b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
526 tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
529 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
530 u8 tcp_opts_len, tcp_hdr_opts_len;
534 wnd = tcp_window_to_advertise (tc, state);
536 /* Make and write options */
537 tcp_opts_len = tcp_make_established_options (tc, snd_opts);
538 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
540 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
541 tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd);
543 tcp_options_write ((u8 *) (th + 1), snd_opts);
545 th->checksum = tcp_compute_checksum (tc, b);
547 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
550 tcp_zero_rwnd_sent_on (tc);
552 tcp_zero_rwnd_sent_off (tc);
556 * Convert buffer to ACK
559 tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
561 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
562 TCP_EVT (TCP_EVT_ACK_SENT, tc);
563 tc->rcv_las = tc->rcv_nxt;
567 * Convert buffer to FIN-ACK
570 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
572 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK);
576 * Convert buffer to SYN
579 tcp_make_syn (tcp_connection_t * tc, vlib_buffer_t * b)
581 u8 tcp_hdr_opts_len, tcp_opts_len;
584 tcp_options_t snd_opts;
586 initial_wnd = tcp_initial_window_to_advertise (tc);
588 /* Make and write options */
589 clib_memset (&snd_opts, 0, sizeof (snd_opts));
590 tcp_opts_len = tcp_make_syn_options (tc, &snd_opts);
591 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
593 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
594 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
596 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
597 tcp_options_write ((u8 *) (th + 1), &snd_opts);
598 th->checksum = tcp_compute_checksum (tc, b);
602 * Convert buffer to SYN-ACK
605 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
607 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
608 u8 tcp_opts_len, tcp_hdr_opts_len;
612 clib_memset (snd_opts, 0, sizeof (*snd_opts));
613 initial_wnd = tcp_initial_window_to_advertise (tc);
614 tcp_opts_len = tcp_make_synack_options (tc, snd_opts);
615 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
617 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
618 tc->rcv_nxt, tcp_hdr_opts_len,
619 TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd);
620 tcp_options_write ((u8 *) (th + 1), snd_opts);
622 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
623 th->checksum = tcp_compute_checksum (tc, b);
627 tcp_enqueue_to_ip_lookup_i (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
628 u8 is_ip4, u32 fib_index, u8 flush)
630 vlib_main_t *vm = wrk->vm;
631 u32 *to_next, next_index;
634 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
637 vnet_buffer (b)->sw_if_index[VLIB_TX] = fib_index;
638 vnet_buffer (b)->sw_if_index[VLIB_RX] = 0;
640 /* Send to IP lookup */
641 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
642 tcp_trajectory_add_start (b, 1);
644 f = wrk->ip_lookup_tx_frames[!is_ip4];
647 f = vlib_get_frame_to_node (vm, next_index);
649 wrk->ip_lookup_tx_frames[!is_ip4] = f;
652 to_next = vlib_frame_vector_args (f);
653 to_next[f->n_vectors] = bi;
655 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
657 vlib_put_frame_to_node (vm, next_index, f);
658 wrk->ip_lookup_tx_frames[!is_ip4] = 0;
663 tcp_enqueue_to_ip_lookup_now (tcp_worker_ctx_t * wrk, vlib_buffer_t * b,
664 u32 bi, u8 is_ip4, u32 fib_index)
666 tcp_enqueue_to_ip_lookup_i (wrk, b, bi, is_ip4, fib_index, 1);
670 tcp_enqueue_to_ip_lookup (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
671 u8 is_ip4, u32 fib_index)
673 tcp_enqueue_to_ip_lookup_i (wrk, b, bi, is_ip4, fib_index, 0);
674 if (wrk->vm->thread_index == 0 && vlib_num_workers ())
675 session_flush_frames_main_thread (wrk->vm);
679 tcp_enqueue_to_output_i (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
682 u32 *to_next, next_index;
685 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
688 /* Decide where to send the packet */
689 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
690 tcp_trajectory_add_start (b, 2);
692 /* Get frame to v4/6 output node */
693 f = wrk->tx_frames[!is_ip4];
696 f = vlib_get_frame_to_node (wrk->vm, next_index);
698 wrk->tx_frames[!is_ip4] = f;
700 to_next = vlib_frame_vector_args (f);
701 to_next[f->n_vectors] = bi;
703 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
705 vlib_put_frame_to_node (wrk->vm, next_index, f);
706 wrk->tx_frames[!is_ip4] = 0;
711 tcp_enqueue_to_output (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
714 tcp_enqueue_to_output_i (wrk, b, bi, is_ip4, 0);
718 tcp_enqueue_to_output_now (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
721 tcp_enqueue_to_output_i (wrk, b, bi, is_ip4, 1);
723 #endif /* CLIB_MARCH_VARIANT */
726 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
727 tcp_state_t state, u8 thread_index, u8 is_ip4)
732 ip4_address_t src_ip40, dst_ip40;
733 ip6_address_t src_ip60, dst_ip60;
734 u16 src_port, dst_port;
739 /* Find IP and TCP headers */
740 th0 = tcp_buffer_hdr (b0);
742 /* Save src and dst ip */
745 ih4 = vlib_buffer_get_current (b0);
746 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
747 src_ip40.as_u32 = ih4->src_address.as_u32;
748 dst_ip40.as_u32 = ih4->dst_address.as_u32;
752 ih6 = vlib_buffer_get_current (b0);
753 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
754 clib_memcpy_fast (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
755 clib_memcpy_fast (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t));
758 src_port = th0->src_port;
759 dst_port = th0->dst_port;
761 /* Try to determine what/why we're actually resetting */
762 if (state == TCP_STATE_CLOSED)
767 tmp = clib_net_to_host_u32 (th0->seq_number);
769 /* Got a SYN for no listener. */
770 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
771 ack = clib_host_to_net_u32 (tmp + 1);
776 flags = TCP_FLAG_RST;
777 seq = th0->ack_number;
781 tcp_reuse_buffer (vm, b0);
782 tcp_trajectory_add_start (b0, 4);
783 th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack,
784 sizeof (tcp_header_t), flags, 0);
788 ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40,
790 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
795 ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60,
797 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
804 #ifndef CLIB_MARCH_VARIANT
806 * Send reset without reusing existing buffer
808 * It extracts connection info out of original packet
811 tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt,
812 u32 thread_index, u8 is_ip4)
814 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
815 vlib_main_t *vm = wrk->vm;
817 u32 bi, sw_if_index, fib_index;
818 u8 tcp_hdr_len, flags = 0;
819 tcp_header_t *th, *pkt_th;
821 ip4_header_t *ih4, *pkt_ih4;
822 ip6_header_t *ih6, *pkt_ih6;
823 fib_protocol_t fib_proto;
825 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
828 b = vlib_get_buffer (vm, bi);
829 sw_if_index = vnet_buffer (pkt)->sw_if_index[VLIB_RX];
830 fib_proto = is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
831 fib_index = fib_table_get_index_for_sw_if_index (fib_proto, sw_if_index);
832 tcp_init_buffer (vm, b);
834 /* Make and write options */
835 tcp_hdr_len = sizeof (tcp_header_t);
839 pkt_ih4 = vlib_buffer_get_current (pkt);
840 pkt_th = ip4_next_header (pkt_ih4);
844 pkt_ih6 = vlib_buffer_get_current (pkt);
845 pkt_th = ip6_next_header (pkt_ih6);
848 if (tcp_ack (pkt_th))
850 flags = TCP_FLAG_RST;
851 seq = pkt_th->ack_number;
852 ack = (tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
856 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
858 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
861 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
862 seq, ack, tcp_hdr_len, flags, 0);
864 /* Swap src and dst ip */
867 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
868 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
869 &pkt_ih4->src_address, IP_PROTOCOL_TCP,
870 tcp_csum_offload (tc));
871 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
876 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
878 ih6 = vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address,
879 &pkt_ih6->src_address, IP_PROTOCOL_TCP);
880 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
884 tcp_enqueue_to_ip_lookup_now (wrk, b, bi, is_ip4, fib_index);
885 TCP_EVT (TCP_EVT_RST_SENT, tc);
886 vlib_node_increment_counter (vm, tcp_node_index (output, tc->c_is_ip4),
887 TCP_ERROR_RST_SENT, 1);
891 * Build and set reset packet for connection
894 tcp_send_reset (tcp_connection_t * tc)
896 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
897 vlib_main_t *vm = wrk->vm;
901 u16 tcp_hdr_opts_len, advertise_wnd, opts_write_len;
904 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
906 b = vlib_get_buffer (vm, bi);
907 tcp_init_buffer (vm, b);
909 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
910 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
911 advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED);
912 flags = TCP_FLAG_RST;
913 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
914 tc->rcv_nxt, tcp_hdr_opts_len, flags,
916 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
917 th->checksum = tcp_compute_checksum (tc, b);
918 ASSERT (opts_write_len == tc->snd_opts_len);
919 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
920 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
921 TCP_EVT (TCP_EVT_RST_SENT, tc);
922 vlib_node_increment_counter (vm, tcp_node_index (output, tc->c_is_ip4),
923 TCP_ERROR_RST_SENT, 1);
927 tcp_push_ip_hdr (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
930 tcp_header_t *th = vlib_buffer_get_current (b);
931 vlib_main_t *vm = wrk->vm;
935 ih = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip4,
936 &tc->c_rmt_ip4, IP_PROTOCOL_TCP,
937 tcp_csum_offload (tc));
938 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih);
945 ih = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip6,
946 &tc->c_rmt_ip6, IP_PROTOCOL_TCP);
947 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih, &bogus);
955 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
956 * The packet is not forwarded through tcpx_output to avoid doing lookups
957 * in the half_open pool.
960 tcp_send_syn (tcp_connection_t * tc)
962 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
963 vlib_main_t *vm = wrk->vm;
968 * Setup retransmit and establish timers before requesting buffer
969 * such that we can return if we've ran out.
971 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
972 tc->rto * TCP_TO_TIMER_TICK);
974 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
976 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1);
980 b = vlib_get_buffer (vm, bi);
981 tcp_init_buffer (vm, b);
982 tcp_make_syn (tc, b);
984 /* Measure RTT with this */
985 tc->rtt_ts = tcp_time_now_us (vlib_num_workers ()? 1 : 0);
986 tc->rtt_seq = tc->snd_nxt;
989 tcp_push_ip_hdr (wrk, tc, b);
990 tcp_enqueue_to_ip_lookup (wrk, b, bi, tc->c_is_ip4, tc->c_fib_index);
991 TCP_EVT (TCP_EVT_SYN_SENT, tc);
995 tcp_send_synack (tcp_connection_t * tc)
997 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
998 vlib_main_t *vm = wrk->vm;
1002 tcp_retransmit_timer_force_update (tc);
1004 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1006 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
1010 tc->rtt_ts = tcp_time_now_us (tc->c_thread_index);
1011 b = vlib_get_buffer (vm, bi);
1012 tcp_init_buffer (vm, b);
1013 tcp_make_synack (tc, b);
1014 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1015 TCP_EVT (TCP_EVT_SYNACK_SENT, tc);
1019 * Flush tx frame populated by retransmits and timer pops
1022 tcp_flush_frame_to_output (tcp_worker_ctx_t * wrk, u8 is_ip4)
1024 if (wrk->tx_frames[!is_ip4])
1027 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
1028 vlib_put_frame_to_node (wrk->vm, next_index, wrk->tx_frames[!is_ip4]);
1029 wrk->tx_frames[!is_ip4] = 0;
1034 * Flush ip lookup tx frames populated by timer pops
1037 tcp_flush_frame_to_ip_lookup (tcp_worker_ctx_t * wrk, u8 is_ip4)
1039 if (wrk->ip_lookup_tx_frames[!is_ip4])
1042 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
1043 vlib_put_frame_to_node (wrk->vm, next_index,
1044 wrk->ip_lookup_tx_frames[!is_ip4]);
1045 wrk->ip_lookup_tx_frames[!is_ip4] = 0;
1050 * Flush v4 and v6 tcp and ip-lookup tx frames for thread index
1053 tcp_flush_frames_to_output (tcp_worker_ctx_t * wrk)
1055 tcp_flush_frame_to_output (wrk, 1);
1056 tcp_flush_frame_to_output (wrk, 0);
1057 tcp_flush_frame_to_ip_lookup (wrk, 1);
1058 tcp_flush_frame_to_ip_lookup (wrk, 0);
1065 tcp_send_fin (tcp_connection_t * tc)
1067 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
1068 vlib_main_t *vm = wrk->vm;
1073 fin_snt = tc->flags & TCP_CONN_FINSNT;
1077 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1079 /* Out of buffers so program fin retransmit ASAP */
1080 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
1084 /* Make sure retransmit retries a fin not data */
1085 tc->flags |= TCP_CONN_FINSNT;
1089 tcp_retransmit_timer_force_update (tc);
1090 b = vlib_get_buffer (vm, bi);
1091 tcp_init_buffer (vm, b);
1092 tcp_make_fin (tc, b);
1093 tcp_enqueue_to_output_now (wrk, b, bi, tc->c_is_ip4);
1094 TCP_EVT (TCP_EVT_FIN_SENT, tc);
1095 /* Account for the FIN */
1099 tc->flags |= TCP_CONN_FINSNT;
1100 tc->flags &= ~TCP_CONN_FINPNDG;
1101 tc->snd_una_max = seq_max (tc->snd_una_max, tc->snd_nxt);
1106 * Push TCP header and update connection variables. Should only be called
1107 * for segments with data, not for 'control' packets.
1110 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b, u32 snd_nxt,
1111 u8 compute_opts, u8 maybe_burst, u8 update_snd_nxt)
1113 u8 tcp_hdr_opts_len, flags = TCP_FLAG_ACK;
1114 u32 advertise_wnd, data_len;
1115 tcp_main_t *tm = &tcp_main;
1118 data_len = b->current_length;
1119 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
1120 data_len += b->total_length_not_including_first_buffer;
1122 vnet_buffer (b)->tcp.flags = 0;
1123 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
1126 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1128 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
1131 advertise_wnd = tc->rcv_wnd >> tc->rcv_wscale;
1133 advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED);
1135 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
1137 if (seq_geq (tc->psh_seq, snd_nxt)
1138 && seq_lt (tc->psh_seq, snd_nxt + data_len))
1139 flags |= TCP_FLAG_PSH;
1141 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, snd_nxt,
1142 tc->rcv_nxt, tcp_hdr_opts_len, flags,
1147 clib_memcpy_fast ((u8 *) (th + 1),
1148 tm->wrk_ctx[tc->c_thread_index].cached_opts,
1153 u8 len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
1154 ASSERT (len == tc->snd_opts_len);
1158 * Update connection variables
1162 tc->snd_nxt += data_len;
1163 tc->rcv_las = tc->rcv_nxt;
1165 tc->bytes_out += data_len;
1166 tc->data_segs_out += 1;
1169 th->checksum = tcp_compute_checksum (tc, b);
1171 TCP_EVT (TCP_EVT_PKTIZE, tc);
1175 tcp_session_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
1177 tcp_connection_t *tc = (tcp_connection_t *) tconn;
1179 if (tc->flags & TCP_CONN_TRACK_BURST)
1181 tcp_bt_check_app_limited (tc);
1182 tcp_bt_track_tx (tc);
1183 tc->flags &= ~TCP_CONN_TRACK_BURST;
1186 tcp_push_hdr_i (tc, b, tc->snd_nxt, /* compute opts */ 0, /* burst */ 1,
1187 /* update_snd_nxt */ 1);
1189 tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max);
1190 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1191 /* If not tracking an ACK, start tracking */
1192 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
1194 tc->rtt_ts = tcp_time_now_us (tc->c_thread_index);
1195 tc->rtt_seq = tc->snd_nxt;
1197 if (PREDICT_FALSE (!tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)))
1199 tcp_retransmit_timer_set (tc);
1202 tcp_trajectory_add_start (b, 3);
1207 tcp_send_ack (tcp_connection_t * tc)
1209 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
1210 vlib_main_t *vm = wrk->vm;
1214 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1216 tcp_update_rcv_wnd (tc);
1219 b = vlib_get_buffer (vm, bi);
1220 tcp_init_buffer (vm, b);
1221 tcp_make_ack (tc, b);
1222 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1226 tcp_program_ack (tcp_connection_t * tc)
1228 if (!(tc->flags & TCP_CONN_SNDACK))
1230 session_add_self_custom_tx_evt (&tc->connection, 1);
1231 tc->flags |= TCP_CONN_SNDACK;
1236 tcp_program_dupack (tcp_connection_t * tc)
1238 if (!(tc->flags & TCP_CONN_SNDACK))
1240 session_add_self_custom_tx_evt (&tc->connection, 1);
1241 tc->flags |= TCP_CONN_SNDACK;
1243 if (tc->pending_dupacks < 255)
1244 tc->pending_dupacks += 1;
1248 tcp_program_retransmit (tcp_connection_t * tc)
1250 if (!(tc->flags & TCP_CONN_RXT_PENDING))
1252 session_add_self_custom_tx_evt (&tc->connection, 0);
1253 tc->flags |= TCP_CONN_RXT_PENDING;
1258 * Delayed ack timer handler
1260 * Sends delayed ACK when timer expires
1263 tcp_timer_delack_handler (u32 index)
1265 u32 thread_index = vlib_get_thread_index ();
1266 tcp_connection_t *tc;
1268 tc = tcp_connection_get (index, thread_index);
1269 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
1274 * Send window update ack
1276 * Ensures that it will be sent only once, after a zero rwnd has been
1277 * advertised in a previous ack, and only if rwnd has grown beyond a
1278 * configurable value.
1281 tcp_send_window_update_ack (tcp_connection_t * tc)
1283 if (tcp_zero_rwnd_sent (tc))
1285 tcp_update_rcv_wnd (tc);
1286 if (tc->rcv_wnd >= tcp_cfg.rwnd_min_update_ack * tc->snd_mss)
1288 tcp_zero_rwnd_sent_off (tc);
1289 tcp_program_ack (tc);
1295 * Allocate a new buffer and build a new tcp segment
1297 * @param wrk tcp worker
1298 * @param tc connection for which the segment will be allocated
1299 * @param offset offset of the first byte in the tx fifo
1300 * @param max_deq_byte segment size
1301 * @param[out] b pointer to buffer allocated
1303 * @return the number of bytes in the segment or 0 if buffer cannot be
1304 * allocated or no data available
1307 tcp_prepare_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1308 u32 offset, u32 max_deq_bytes, vlib_buffer_t ** b)
1310 u32 bytes_per_buffer = vnet_get_tcp_main ()->bytes_per_buffer;
1311 vlib_main_t *vm = wrk->vm;
1316 seg_size = max_deq_bytes + TRANSPORT_MAX_HDRS_LEN;
1321 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1324 * Allocate and fill in buffer(s)
1327 /* Easy case, buffer size greater than mss */
1328 if (PREDICT_TRUE (seg_size <= bytes_per_buffer))
1330 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1332 *b = vlib_get_buffer (vm, bi);
1333 data = tcp_init_buffer (vm, *b);
1334 n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset,
1336 ASSERT (n_bytes == max_deq_bytes);
1337 b[0]->current_length = n_bytes;
1338 tcp_push_hdr_i (tc, *b, tc->snd_una + offset, /* compute opts */ 0,
1339 /* burst */ 0, /* update_snd_nxt */ 0);
1341 /* Split mss into multiple buffers */
1344 u32 chain_bi = ~0, n_bufs_per_seg, n_bufs;
1345 u16 n_peeked, len_to_deq;
1346 vlib_buffer_t *chain_b, *prev_b;
1349 /* Make sure we have enough buffers */
1350 n_bufs_per_seg = ceil ((double) seg_size / bytes_per_buffer);
1351 vec_validate_aligned (wrk->tx_buffers, n_bufs_per_seg - 1,
1352 CLIB_CACHE_LINE_BYTES);
1353 n_bufs = vlib_buffer_alloc (vm, wrk->tx_buffers, n_bufs_per_seg);
1354 if (PREDICT_FALSE (n_bufs != n_bufs_per_seg))
1357 vlib_buffer_free (vm, wrk->tx_buffers, n_bufs);
1361 *b = vlib_get_buffer (vm, wrk->tx_buffers[--n_bufs]);
1362 data = tcp_init_buffer (vm, *b);
1363 n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset,
1365 TRANSPORT_MAX_HDRS_LEN);
1366 b[0]->current_length = n_bytes;
1367 b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
1368 b[0]->total_length_not_including_first_buffer = 0;
1369 max_deq_bytes -= n_bytes;
1372 for (i = 1; i < n_bufs_per_seg; i++)
1375 len_to_deq = clib_min (max_deq_bytes, bytes_per_buffer);
1376 chain_bi = wrk->tx_buffers[--n_bufs];
1377 chain_b = vlib_get_buffer (vm, chain_bi);
1378 chain_b->current_data = 0;
1379 data = vlib_buffer_get_current (chain_b);
1380 n_peeked = session_tx_fifo_peek_bytes (&tc->connection, data,
1383 ASSERT (n_peeked == len_to_deq);
1384 n_bytes += n_peeked;
1385 chain_b->current_length = n_peeked;
1386 chain_b->next_buffer = 0;
1388 /* update previous buffer */
1389 prev_b->next_buffer = chain_bi;
1390 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
1392 max_deq_bytes -= n_peeked;
1393 b[0]->total_length_not_including_first_buffer += n_peeked;
1396 tcp_push_hdr_i (tc, *b, tc->snd_una + offset, /* compute opts */ 0,
1397 /* burst */ 0, /* update_snd_nxt */ 0);
1399 if (PREDICT_FALSE (n_bufs))
1401 clib_warning ("not all buffers consumed");
1402 vlib_buffer_free (vm, wrk->tx_buffers, n_bufs);
1406 ASSERT (n_bytes > 0);
1407 ASSERT (((*b)->current_data + (*b)->current_length) <= bytes_per_buffer);
1413 * Build a retransmit segment
1415 * @return the number of bytes in the segment or 0 if there's nothing to
1419 tcp_prepare_retransmit_segment (tcp_worker_ctx_t * wrk,
1420 tcp_connection_t * tc, u32 offset,
1421 u32 max_deq_bytes, vlib_buffer_t ** b)
1423 u32 start, available_bytes;
1426 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1427 ASSERT (max_deq_bytes != 0);
1430 * Make sure we can retransmit something
1432 available_bytes = transport_max_tx_dequeue (&tc->connection);
1433 ASSERT (available_bytes >= offset);
1434 available_bytes -= offset;
1435 if (!available_bytes)
1438 max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
1439 max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
1441 start = tc->snd_una + offset;
1442 n_bytes = tcp_prepare_segment (wrk, tc, offset, max_deq_bytes, b);
1446 tc->snd_rxt_bytes += n_bytes;
1448 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1449 tcp_bt_track_rxt (tc, start, start + n_bytes);
1451 tc->bytes_retrans += n_bytes;
1452 tc->segs_retrans += 1;
1453 TCP_EVT (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1459 tcp_check_sack_reneging (tcp_connection_t * tc)
1461 sack_scoreboard_t *sb = &tc->sack_sb;
1462 sack_scoreboard_hole_t *hole;
1464 hole = scoreboard_first_hole (sb);
1465 if (!sb->is_reneging && (!hole || hole->start == tc->snd_una))
1468 scoreboard_clear_reneging (sb, tc->snd_una, tc->snd_nxt);
1472 * Reset congestion control, switch cwnd to loss window and try again.
1475 tcp_cc_init_rxt_timeout (tcp_connection_t * tc)
1477 TCP_EVT (TCP_EVT_CC_EVT, tc, 6);
1479 tc->prev_ssthresh = tc->ssthresh;
1480 tc->prev_cwnd = tc->cwnd;
1482 /* If we entrered loss without fast recovery, notify cc algo of the
1483 * congestion event such that it can update ssthresh and its state */
1484 if (!tcp_in_fastrecovery (tc))
1485 tcp_cc_congestion (tc);
1487 /* Let cc algo decide loss cwnd and ssthresh post unrecovered loss */
1491 tc->cwnd_acc_bytes = 0;
1492 tc->tr_occurences += 1;
1493 tcp_recovery_on (tc);
1497 tcp_timer_retransmit_handler (u32 tc_index)
1499 u32 thread_index = vlib_get_thread_index ();
1500 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
1501 vlib_main_t *vm = wrk->vm;
1502 tcp_connection_t *tc;
1503 vlib_buffer_t *b = 0;
1506 tc = tcp_connection_get (tc_index, thread_index);
1508 /* Note: the connection may have been closed and pool_put */
1509 if (PREDICT_FALSE (tc == 0 || tc->state == TCP_STATE_SYN_SENT))
1512 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
1514 /* Wait-close and retransmit could pop at the same time */
1515 if (tc->state == TCP_STATE_CLOSED)
1518 if (tc->state >= TCP_STATE_ESTABLISHED)
1520 TCP_EVT (TCP_EVT_CC_EVT, tc, 2);
1522 /* Lost FIN, retransmit and return */
1523 if (tc->flags & TCP_CONN_FINSNT)
1527 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1531 /* Shouldn't be here. This condition is tricky because it has to take
1532 * into account boff > 0 due to persist timeout. */
1533 if ((tc->rto_boff == 0 && tc->snd_una == tc->snd_nxt)
1534 || (tc->rto_boff > 0 && seq_geq (tc->snd_una, tc->snd_congestion)
1535 && !tcp_flight_size (tc)))
1537 ASSERT (!tcp_in_recovery (tc));
1542 /* We're not in recovery so make sure rto_boff is 0. Can be non 0 due
1543 * to persist timer timeout */
1544 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1547 tcp_update_rto (tc);
1550 /* Peer is dead or network connectivity is lost. Close connection.
1551 * RFC 1122 section 4.2.3.5 recommends a value of at least 100s. For
1552 * a min rto of 0.2s we need to retry about 8 times. */
1553 if (tc->rto_boff >= TCP_RTO_BOFF_MAX)
1555 tcp_send_reset (tc);
1556 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1557 session_transport_closing_notify (&tc->connection);
1558 tcp_connection_timers_reset (tc);
1559 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1563 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1564 tcp_check_sack_reneging (tc);
1566 /* Update send congestion to make sure that rxt has data to send */
1567 tc->snd_congestion = tc->snd_nxt;
1569 /* Send the first unacked segment. If we're short on buffers, return
1570 * as soon as possible */
1571 n_bytes = tcp_prepare_retransmit_segment (wrk, tc, 0, tc->snd_mss, &b);
1574 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
1578 bi = vlib_get_buffer_index (vm, b);
1579 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1581 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1582 tcp_retransmit_timer_force_update (tc);
1585 if (tc->rto_boff == 1)
1587 tcp_cc_init_rxt_timeout (tc);
1588 /* Record timestamp. Eifel detection algorithm RFC3522 */
1589 tc->snd_rxt_ts = tcp_tstamp (tc);
1592 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1593 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una + n_bytes);
1595 tcp_program_retransmit (tc);
1597 /* Retransmit SYN-ACK */
1598 else if (tc->state == TCP_STATE_SYN_RCVD)
1600 TCP_EVT (TCP_EVT_CC_EVT, tc, 2);
1604 /* Passive open establish timeout */
1605 if (tc->rto > TCP_ESTABLISH_TIME >> 1)
1607 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1608 tcp_connection_timers_reset (tc);
1609 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
1613 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1615 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
1620 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1621 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1623 tcp_retransmit_timer_force_update (tc);
1625 b = vlib_get_buffer (vm, bi);
1626 tcp_init_buffer (vm, b);
1627 tcp_make_synack (tc, b);
1628 TCP_EVT (TCP_EVT_SYN_RXT, tc, 1);
1630 /* Retransmit timer already updated, just enqueue to output */
1631 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1635 ASSERT (tc->state == TCP_STATE_CLOSED);
1641 * SYN retransmit timer handler. Active open only.
1644 tcp_timer_retransmit_syn_handler (u32 tc_index)
1646 u32 thread_index = vlib_get_thread_index ();
1647 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
1648 vlib_main_t *vm = wrk->vm;
1649 tcp_connection_t *tc;
1650 vlib_buffer_t *b = 0;
1653 tc = tcp_half_open_connection_get (tc_index);
1655 /* Note: the connection may have transitioned to ESTABLISHED... */
1656 if (PREDICT_FALSE (tc == 0 || tc->state != TCP_STATE_SYN_SENT))
1659 tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
1661 /* Half-open connection actually moved to established but we were
1662 * waiting for syn retransmit to pop to call cleanup from the right
1664 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1666 if (tcp_half_open_connection_cleanup (tc))
1667 TCP_DBG ("could not remove half-open connection");
1671 TCP_EVT (TCP_EVT_CC_EVT, tc, 2);
1674 /* Active open establish timeout */
1675 if (tc->rto >= TCP_ESTABLISH_TIME >> 1)
1677 session_stream_connect_notify (&tc->connection, 1 /* fail */ );
1678 tcp_connection_cleanup (tc);
1682 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1684 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1);
1688 /* Try without increasing RTO a number of times. If this fails,
1689 * start growing RTO exponentially */
1691 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1692 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1694 b = vlib_get_buffer (vm, bi);
1695 tcp_init_buffer (vm, b);
1696 tcp_make_syn (tc, b);
1698 TCP_EVT (TCP_EVT_SYN_RXT, tc, 0);
1700 /* This goes straight to ipx_lookup */
1701 tcp_push_ip_hdr (wrk, tc, b);
1702 tcp_enqueue_to_ip_lookup (wrk, b, bi, tc->c_is_ip4, tc->c_fib_index);
1704 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
1705 tc->rto * TCP_TO_TIMER_TICK);
1709 * Got 0 snd_wnd from peer, try to do something about it.
1713 tcp_timer_persist_handler (u32 index)
1715 u32 thread_index = vlib_get_thread_index ();
1716 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
1717 u32 bi, max_snd_bytes, available_bytes, offset;
1718 tcp_main_t *tm = vnet_get_tcp_main ();
1719 vlib_main_t *vm = wrk->vm;
1720 tcp_connection_t *tc;
1725 tc = tcp_connection_get_if_valid (index, thread_index);
1729 /* Make sure timer handle is set to invalid */
1730 tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
1732 /* Problem already solved or worse */
1733 if (tc->state == TCP_STATE_CLOSED || tc->snd_wnd > tc->snd_mss
1734 || (tc->flags & TCP_CONN_FINSNT))
1737 available_bytes = transport_max_tx_dequeue (&tc->connection);
1738 offset = tc->snd_nxt - tc->snd_una;
1740 /* Reprogram persist if no new bytes available to send. We may have data
1742 if (!available_bytes)
1744 tcp_persist_timer_set (tc);
1748 if (available_bytes <= offset)
1750 ASSERT (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1754 /* Increment RTO backoff */
1756 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1759 * Try to force the first unsent segment (or buffer)
1761 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1763 tcp_persist_timer_set (tc);
1766 b = vlib_get_buffer (vm, bi);
1767 data = tcp_init_buffer (vm, b);
1769 tcp_validate_txf_size (tc, offset);
1770 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1771 max_snd_bytes = clib_min (tc->snd_mss,
1772 tm->bytes_per_buffer - TRANSPORT_MAX_HDRS_LEN);
1773 n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset,
1775 b->current_length = n_bytes;
1776 ASSERT (n_bytes != 0 && (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)
1777 || tc->snd_nxt == tc->snd_una_max
1778 || tc->rto_boff > 1));
1780 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1782 tcp_bt_check_app_limited (tc);
1783 tcp_bt_track_tx (tc);
1786 tcp_push_hdr_i (tc, b, tc->snd_nxt, /* compute opts */ 0,
1787 /* burst */ 0, /* update_snd_nxt */ 1);
1788 tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max);
1789 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1790 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1792 /* Just sent new data, enable retransmit */
1793 tcp_retransmit_timer_update (tc);
1797 * Retransmit first unacked segment
1800 tcp_retransmit_first_unacked (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1802 vlib_main_t *vm = wrk->vm;
1806 TCP_EVT (TCP_EVT_CC_EVT, tc, 1);
1808 n_bytes = tcp_prepare_retransmit_segment (wrk, tc, 0, tc->snd_mss, &b);
1812 bi = vlib_get_buffer_index (vm, b);
1813 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1819 tcp_transmit_unsent (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1822 u32 offset, n_segs = 0, n_written, bi, available_wnd;
1823 vlib_main_t *vm = wrk->vm;
1824 vlib_buffer_t *b = 0;
1826 offset = tc->snd_nxt - tc->snd_una;
1827 available_wnd = tc->snd_wnd - offset;
1828 burst_size = clib_min (burst_size, available_wnd / tc->snd_mss);
1830 while (n_segs < burst_size)
1832 n_written = tcp_prepare_segment (wrk, tc, offset, tc->snd_mss, &b);
1836 bi = vlib_get_buffer_index (vm, b);
1837 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1838 offset += n_written;
1841 tc->snd_nxt += n_written;
1842 tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max);
1850 * Estimate send space using proportional rate reduction (RFC6937)
1853 tcp_fastrecovery_prr_snd_space (tcp_connection_t * tc)
1858 pipe = tcp_flight_size (tc);
1859 prr_out = tc->snd_rxt_bytes + (tc->snd_nxt - tc->snd_congestion);
1861 if (pipe > tc->ssthresh)
1863 space = ((int) tc->prr_delivered * ((f64) tc->ssthresh / tc->prev_cwnd))
1869 limit = clib_max ((int) (tc->prr_delivered - prr_out), 0) + tc->snd_mss;
1870 space = clib_min (tc->ssthresh - pipe, limit);
1872 space = clib_max (space, prr_out ? 0 : tc->snd_mss);
1877 tcp_retransmit_should_retry_head (tcp_connection_t * tc,
1878 sack_scoreboard_t * sb)
1880 u32 tx_adv_sack = sb->high_sacked - tc->snd_congestion;
1881 f64 rr = (f64) tc->ssthresh / tc->prev_cwnd;
1883 return (tx_adv_sack > (tc->snd_una - tc->prr_start) * rr);
1886 #define scoreboard_rescue_rxt_valid(_sb, _tc) \
1887 (seq_geq (_sb->rescue_rxt, _tc->snd_una) \
1888 && seq_leq (_sb->rescue_rxt, _tc->snd_congestion))
1891 * Do retransmit with SACKs
1894 tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1897 u8 snd_limited = 0, can_rescue = 0, reset_pacer = 0;
1898 u32 n_written = 0, offset, max_bytes, n_segs = 0;
1899 u32 bi, max_deq, burst_bytes, sent_bytes;
1900 sack_scoreboard_hole_t *hole;
1901 vlib_main_t *vm = wrk->vm;
1902 vlib_buffer_t *b = 0;
1903 sack_scoreboard_t *sb;
1907 ASSERT (tcp_in_cong_recovery (tc));
1909 time_now = wrk->vm->clib_time.last_cpu_time;
1910 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
1912 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1915 tcp_program_retransmit (tc);
1919 if (tcp_in_recovery (tc))
1920 snd_space = tcp_available_cc_snd_space (tc);
1922 snd_space = tcp_fastrecovery_prr_snd_space (tc);
1924 if (snd_space < tc->snd_mss)
1926 reset_pacer = burst_bytes > tc->snd_mss;
1930 reset_pacer = snd_space < burst_bytes;
1934 /* Check if snd_una is a lost retransmit */
1935 if (pool_elts (sb->holes)
1936 && seq_gt (sb->high_sacked, tc->snd_congestion)
1937 && tc->rxt_head != tc->snd_una
1938 && tcp_retransmit_should_retry_head (tc, sb))
1940 n_written = tcp_prepare_retransmit_segment (wrk, tc, 0, tc->snd_mss,
1944 tcp_program_retransmit (tc);
1947 bi = vlib_get_buffer_index (vm, b);
1948 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1951 tc->rxt_head = tc->snd_una;
1952 tc->rxt_delivered += n_written;
1953 tc->prr_delivered += n_written;
1954 ASSERT (tc->rxt_delivered <= tc->snd_rxt_bytes);
1957 TCP_EVT (TCP_EVT_CC_EVT, tc, 0);
1958 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1960 max_deq = transport_max_tx_dequeue (&tc->connection);
1961 max_deq -= tc->snd_nxt - tc->snd_una;
1963 while (snd_space > 0 && n_segs < burst_size)
1965 hole = scoreboard_next_rxt_hole (sb, hole, max_deq, &can_rescue,
1969 /* We are out of lost holes to retransmit so send some new data. */
1970 if (max_deq > tc->snd_mss)
1975 av_wnd = (int) tc->snd_wnd - (tc->snd_nxt - tc->snd_una);
1976 av_wnd = clib_max (av_wnd, 0);
1977 snd_space = clib_min (snd_space, av_wnd);
1978 snd_space = clib_min (max_deq, snd_space);
1979 burst_size = clib_min (burst_size - n_segs,
1980 snd_space / tc->snd_mss);
1981 burst_size = clib_min (burst_size, TCP_RXT_MAX_BURST);
1982 n_segs_new = tcp_transmit_unsent (wrk, tc, burst_size);
1983 if (max_deq > n_segs_new * tc->snd_mss)
1984 tcp_program_retransmit (tc);
1986 n_segs += n_segs_new;
1990 if (tcp_in_recovery (tc) || !can_rescue
1991 || scoreboard_rescue_rxt_valid (sb, tc))
1994 /* If rescue rxt undefined or less than snd_una then one segment of
1995 * up to SMSS octets that MUST include the highest outstanding
1996 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1997 * RecoveryPoint. HighRxt MUST NOT be updated.
1999 max_bytes = clib_min (tc->snd_mss,
2000 tc->snd_congestion - tc->snd_una);
2001 max_bytes = clib_min (max_bytes, snd_space);
2002 offset = tc->snd_congestion - tc->snd_una - max_bytes;
2003 sb->rescue_rxt = tc->snd_congestion;
2004 n_written = tcp_prepare_retransmit_segment (wrk, tc, offset,
2009 bi = vlib_get_buffer_index (vm, b);
2010 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
2015 max_bytes = clib_min (hole->end - sb->high_rxt, snd_space);
2016 max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes;
2020 offset = sb->high_rxt - tc->snd_una;
2021 n_written = tcp_prepare_retransmit_segment (wrk, tc, offset, max_bytes,
2023 ASSERT (n_written <= snd_space);
2025 /* Nothing left to retransmit */
2029 bi = vlib_get_buffer_index (vm, b);
2030 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
2032 sb->high_rxt += n_written;
2033 snd_space -= n_written;
2038 tcp_program_retransmit (tc);
2044 transport_connection_tx_pacer_reset_bucket (&tc->connection,
2050 sent_bytes = clib_min (n_segs * tc->snd_mss, burst_bytes);
2051 transport_connection_tx_pacer_update_bytes (&tc->connection,
2059 * Fast retransmit without SACK info
2062 tcp_retransmit_no_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
2065 u32 n_written = 0, offset = 0, bi, max_deq, n_segs_now;
2066 u32 burst_bytes, sent_bytes;
2067 vlib_main_t *vm = wrk->vm;
2068 int snd_space, n_segs = 0;
2073 ASSERT (tcp_in_fastrecovery (tc));
2074 TCP_EVT (TCP_EVT_CC_EVT, tc, 0);
2076 time_now = wrk->vm->clib_time.last_cpu_time;
2077 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection,
2079 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
2082 tcp_program_retransmit (tc);
2086 snd_space = tcp_available_cc_snd_space (tc);
2087 cc_limited = snd_space < burst_bytes;
2089 if (!tcp_fastrecovery_first (tc))
2092 /* RFC 6582: [If a partial ack], retransmit the first unacknowledged
2094 while (snd_space > 0 && n_segs < burst_size)
2096 n_written = tcp_prepare_retransmit_segment (wrk, tc, offset,
2099 /* Nothing left to retransmit */
2103 bi = vlib_get_buffer_index (vm, b);
2104 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
2105 snd_space -= n_written;
2106 offset += n_written;
2110 if (n_segs == burst_size)
2115 /* RFC 6582: Send a new segment if permitted by the new value of cwnd. */
2116 if (snd_space < tc->snd_mss || tc->snd_mss == 0)
2119 max_deq = transport_max_tx_dequeue (&tc->connection);
2120 max_deq -= tc->snd_nxt - tc->snd_una;
2123 snd_space = clib_min (max_deq, snd_space);
2124 burst_size = clib_min (burst_size - n_segs, snd_space / tc->snd_mss);
2125 n_segs_now = tcp_transmit_unsent (wrk, tc, burst_size);
2126 if (max_deq > n_segs_now * tc->snd_mss)
2127 tcp_program_retransmit (tc);
2128 n_segs += n_segs_now;
2132 tcp_fastrecovery_first_off (tc);
2134 sent_bytes = clib_min (n_segs * tc->snd_mss, burst_bytes);
2135 sent_bytes = cc_limited ? burst_bytes : sent_bytes;
2136 transport_connection_tx_pacer_update_bytes (&tc->connection, sent_bytes);
2142 tcp_send_acks (tcp_connection_t * tc, u32 max_burst_size)
2146 if (!tc->pending_dupacks)
2152 /* If we're supposed to send dupacks but have no ooo data
2153 * send only one ack */
2154 if (!vec_len (tc->snd_sacks))
2160 /* Start with first sack block */
2161 tc->snd_sack_pos = 0;
2163 /* Generate enough dupacks to cover all sack blocks. Do not generate
2164 * more sacks than the number of packets received. But do generate at
2165 * least 3, i.e., the number needed to signal congestion, if needed. */
2166 n_acks = vec_len (tc->snd_sacks) / TCP_OPTS_MAX_SACK_BLOCKS;
2167 n_acks = clib_min (n_acks, tc->pending_dupacks);
2168 n_acks = clib_max (n_acks, clib_min (tc->pending_dupacks, 3));
2169 for (j = 0; j < clib_min (n_acks, max_burst_size); j++)
2172 if (n_acks < max_burst_size)
2174 tc->pending_dupacks = 0;
2175 tc->snd_sack_pos = 0;
2176 tc->dupacks_out += n_acks;
2181 TCP_DBG ("constrained by burst size");
2182 tc->pending_dupacks = n_acks - max_burst_size;
2183 tc->dupacks_out += max_burst_size;
2184 tcp_program_dupack (tc);
2185 return max_burst_size;
2190 tcp_do_retransmit (tcp_connection_t * tc, u32 max_burst_size)
2192 tcp_worker_ctx_t *wrk;
2195 wrk = tcp_get_worker (tc->c_thread_index);
2197 if (tcp_opts_sack_permitted (&tc->rcv_opts))
2198 n_segs = tcp_retransmit_sack (wrk, tc, max_burst_size);
2200 n_segs = tcp_retransmit_no_sack (wrk, tc, max_burst_size);
2206 tcp_session_custom_tx (void *conn, u32 max_burst_size)
2208 tcp_connection_t *tc = (tcp_connection_t *) conn;
2211 if (tcp_in_cong_recovery (tc) && (tc->flags & TCP_CONN_RXT_PENDING))
2213 tc->flags &= ~TCP_CONN_RXT_PENDING;
2214 n_segs = tcp_do_retransmit (tc, max_burst_size);
2215 max_burst_size -= n_segs;
2218 if (!(tc->flags & TCP_CONN_SNDACK))
2221 tc->flags &= ~TCP_CONN_SNDACK;
2223 /* We have retransmitted packets and no dupack */
2224 if (n_segs && !tc->pending_dupacks)
2227 if (!max_burst_size)
2229 tcp_program_ack (tc);
2230 return max_burst_size;
2233 n_segs += tcp_send_acks (tc, max_burst_size);
2237 #endif /* CLIB_MARCH_VARIANT */
2240 tcp_output_handle_link_local (tcp_connection_t * tc0, vlib_buffer_t * b0,
2241 u16 * next0, u32 * error0)
2243 ip_adjacency_t *adj;
2246 /* Not thread safe but as long as the connection exists the adj should
2248 ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &tc0->c_rmt_ip,
2250 if (ai == ADJ_INDEX_INVALID)
2252 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
2253 *next0 = TCP_OUTPUT_NEXT_DROP;
2254 *error0 = TCP_ERROR_LINK_LOCAL_RW;
2259 if (PREDICT_TRUE (adj->lookup_next_index == IP_LOOKUP_NEXT_REWRITE))
2260 *next0 = TCP_OUTPUT_NEXT_IP_REWRITE;
2261 else if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP)
2262 *next0 = TCP_OUTPUT_NEXT_IP_ARP;
2265 *next0 = TCP_OUTPUT_NEXT_DROP;
2266 *error0 = TCP_ERROR_LINK_LOCAL_RW;
2268 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ai;
2272 tcp46_output_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2273 u32 * to_next, u32 n_bufs)
2275 u32 n_trace = vlib_get_trace_count (vm, node);
2276 tcp_connection_t *tc;
2282 for (i = 0; i < clib_min (n_trace, n_bufs); i++)
2284 b = vlib_get_buffer (vm, to_next[i]);
2285 th = vlib_buffer_get_current (b);
2286 tc = tcp_connection_get (vnet_buffer (b)->tcp.connection_index,
2288 t = vlib_add_trace (vm, node, b, sizeof (*t));
2289 clib_memcpy_fast (&t->tcp_header, th, sizeof (t->tcp_header));
2290 clib_memcpy_fast (&t->tcp_connection, tc, sizeof (t->tcp_connection));
2295 tcp_output_push_ip (vlib_main_t * vm, vlib_buffer_t * b0,
2296 tcp_connection_t * tc0, u8 is_ip4)
2298 u8 __clib_unused *ih0;
2299 tcp_header_t __clib_unused *th0 = vlib_buffer_get_current (b0);
2301 TCP_EVT (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
2304 ih0 = vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
2305 IP_PROTOCOL_TCP, tcp_csum_offload (tc0));
2307 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6, &tc0->c_rmt_ip6,
2313 tcp_check_if_gso (tcp_connection_t * tc, vlib_buffer_t * b)
2315 if (PREDICT_TRUE (!(tc->cfg_flags & TCP_CFG_F_TSO)))
2318 u16 data_len = b->current_length - sizeof (tcp_header_t) - tc->snd_opts_len;
2320 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID))
2321 data_len += b->total_length_not_including_first_buffer;
2323 if (PREDICT_TRUE (data_len <= tc->snd_mss))
2327 ASSERT ((b->flags & VNET_BUFFER_F_L3_HDR_OFFSET_VALID) != 0);
2328 ASSERT ((b->flags & VNET_BUFFER_F_L4_HDR_OFFSET_VALID) != 0);
2329 b->flags |= VNET_BUFFER_F_GSO;
2330 vnet_buffer2 (b)->gso_l4_hdr_sz =
2331 sizeof (tcp_header_t) + tc->snd_opts_len;
2332 vnet_buffer2 (b)->gso_size = tc->snd_mss;
2337 tcp_output_handle_packet (tcp_connection_t * tc0, vlib_buffer_t * b0,
2338 vlib_node_runtime_t * error_node, u16 * next0,
2341 /* If next_index is not drop use it */
2342 if (tc0->next_node_index)
2344 *next0 = tc0->next_node_index;
2345 vnet_buffer (b0)->tcp.next_node_opaque = tc0->next_node_opaque;
2349 *next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
2352 vnet_buffer (b0)->sw_if_index[VLIB_TX] = tc0->c_fib_index;
2353 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
2359 if (PREDICT_FALSE (ip6_address_is_link_local_unicast (&tc0->c_rmt_ip6)))
2360 tcp_output_handle_link_local (tc0, b0, next0, &error0);
2362 if (PREDICT_FALSE (error0))
2364 b0->error = error_node->errors[error0];
2369 if (!TCP_ALWAYS_ACK)
2370 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
2376 tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2377 vlib_frame_t * frame, int is_ip4)
2379 u32 n_left_from, *from, thread_index = vm->thread_index;
2380 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
2381 u16 nexts[VLIB_FRAME_SIZE], *next;
2382 vlib_node_runtime_t *error_node;
2384 error_node = vlib_node_get_runtime (vm, tcp_node_index (output, is_ip4));
2386 from = vlib_frame_vector_args (frame);
2387 n_left_from = frame->n_vectors;
2388 tcp_set_time_now (tcp_get_worker (thread_index));
2390 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
2391 tcp46_output_trace_frame (vm, node, from, n_left_from);
2393 vlib_get_buffers (vm, from, bufs, n_left_from);
2397 while (n_left_from >= 4)
2399 tcp_connection_t *tc0, *tc1;
2402 vlib_prefetch_buffer_header (b[2], STORE);
2403 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
2405 vlib_prefetch_buffer_header (b[3], STORE);
2406 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
2409 tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index,
2411 tc1 = tcp_connection_get (vnet_buffer (b[1])->tcp.connection_index,
2414 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
2416 tcp_output_push_ip (vm, b[0], tc0, is_ip4);
2417 tcp_output_push_ip (vm, b[1], tc1, is_ip4);
2419 tcp_check_if_gso (tc0, b[0]);
2420 tcp_check_if_gso (tc1, b[1]);
2422 tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
2423 tcp_output_handle_packet (tc1, b[1], error_node, &next[1], is_ip4);
2429 tcp_output_push_ip (vm, b[0], tc0, is_ip4);
2430 tcp_check_if_gso (tc0, b[0]);
2431 tcp_output_handle_packet (tc0, b[0], error_node, &next[0],
2436 b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
2437 next[0] = TCP_OUTPUT_NEXT_DROP;
2441 tcp_output_push_ip (vm, b[1], tc1, is_ip4);
2442 tcp_check_if_gso (tc1, b[1]);
2443 tcp_output_handle_packet (tc1, b[1], error_node, &next[1],
2448 b[1]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
2449 next[1] = TCP_OUTPUT_NEXT_DROP;
2457 while (n_left_from > 0)
2459 tcp_connection_t *tc0;
2461 if (n_left_from > 1)
2463 vlib_prefetch_buffer_header (b[1], STORE);
2464 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
2467 tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index,
2470 if (PREDICT_TRUE (tc0 != 0))
2472 tcp_output_push_ip (vm, b[0], tc0, is_ip4);
2473 tcp_check_if_gso (tc0, b[0]);
2474 tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
2478 b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
2479 next[0] = TCP_OUTPUT_NEXT_DROP;
2487 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
2488 vlib_node_increment_counter (vm, tcp_node_index (output, is_ip4),
2489 TCP_ERROR_PKTS_SENT, frame->n_vectors);
2490 return frame->n_vectors;
2493 VLIB_NODE_FN (tcp4_output_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
2494 vlib_frame_t * from_frame)
2496 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2499 VLIB_NODE_FN (tcp6_output_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
2500 vlib_frame_t * from_frame)
2502 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2506 VLIB_REGISTER_NODE (tcp4_output_node) =
2508 .name = "tcp4-output",
2509 /* Takes a vector of packets. */
2510 .vector_size = sizeof (u32),
2511 .n_errors = TCP_N_ERROR,
2512 .protocol_hint = VLIB_NODE_PROTO_HINT_TCP,
2513 .error_strings = tcp_error_strings,
2514 .n_next_nodes = TCP_OUTPUT_N_NEXT,
2516 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
2517 foreach_tcp4_output_next
2520 .format_buffer = format_tcp_header,
2521 .format_trace = format_tcp_tx_trace,
2526 VLIB_REGISTER_NODE (tcp6_output_node) =
2528 .name = "tcp6-output",
2529 /* Takes a vector of packets. */
2530 .vector_size = sizeof (u32),
2531 .n_errors = TCP_N_ERROR,
2532 .protocol_hint = VLIB_NODE_PROTO_HINT_TCP,
2533 .error_strings = tcp_error_strings,
2534 .n_next_nodes = TCP_OUTPUT_N_NEXT,
2536 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
2537 foreach_tcp6_output_next
2540 .format_buffer = format_tcp_header,
2541 .format_trace = format_tcp_tx_trace,
2545 typedef enum _tcp_reset_next
2547 TCP_RESET_NEXT_DROP,
2548 TCP_RESET_NEXT_IP_LOOKUP,
2552 #define foreach_tcp4_reset_next \
2553 _(DROP, "error-drop") \
2554 _(IP_LOOKUP, "ip4-lookup")
2556 #define foreach_tcp6_reset_next \
2557 _(DROP, "error-drop") \
2558 _(IP_LOOKUP, "ip6-lookup")
2561 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2562 vlib_frame_t * from_frame, u8 is_ip4)
2564 u32 n_left_from, next_index, *from, *to_next;
2565 u32 my_thread_index = vm->thread_index;
2567 from = vlib_frame_vector_args (from_frame);
2568 n_left_from = from_frame->n_vectors;
2570 next_index = node->cached_next_index;
2572 while (n_left_from > 0)
2576 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2578 while (n_left_from > 0 && n_left_to_next > 0)
2584 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
2591 n_left_to_next -= 1;
2593 b0 = vlib_get_buffer (vm, bi0);
2595 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
2596 my_thread_index, is_ip4))
2598 error0 = TCP_ERROR_LOOKUP_DROPS;
2599 next0 = TCP_RESET_NEXT_DROP;
2603 /* Prepare to send to IP lookup */
2604 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
2605 next0 = TCP_RESET_NEXT_IP_LOOKUP;
2608 b0->error = node->errors[error0];
2609 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
2610 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2612 th0 = vlib_buffer_get_current (b0);
2614 th0 = ip4_next_header ((ip4_header_t *) th0);
2616 th0 = ip6_next_header ((ip6_header_t *) th0);
2617 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2618 clib_memcpy_fast (&t0->tcp_header, th0,
2619 sizeof (t0->tcp_header));
2622 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2623 n_left_to_next, bi0, next0);
2625 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2627 return from_frame->n_vectors;
2630 VLIB_NODE_FN (tcp4_reset_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
2631 vlib_frame_t * from_frame)
2633 return tcp46_send_reset_inline (vm, node, from_frame, 1);
2636 VLIB_NODE_FN (tcp6_reset_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
2637 vlib_frame_t * from_frame)
2639 return tcp46_send_reset_inline (vm, node, from_frame, 0);
2643 VLIB_REGISTER_NODE (tcp4_reset_node) = {
2644 .name = "tcp4-reset",
2645 .vector_size = sizeof (u32),
2646 .n_errors = TCP_N_ERROR,
2647 .error_strings = tcp_error_strings,
2648 .n_next_nodes = TCP_RESET_N_NEXT,
2650 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2651 foreach_tcp4_reset_next
2654 .format_trace = format_tcp_tx_trace,
2659 VLIB_REGISTER_NODE (tcp6_reset_node) = {
2660 .name = "tcp6-reset",
2661 .vector_size = sizeof (u32),
2662 .n_errors = TCP_N_ERROR,
2663 .error_strings = tcp_error_strings,
2664 .n_next_nodes = TCP_RESET_N_NEXT,
2666 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2667 foreach_tcp6_reset_next
2670 .format_trace = format_tcp_tx_trace,
2675 * fd.io coding-style-patch-verification: ON
2678 * eval: (c-set-style "gnu")