2 * Copyright (c) 2016 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>
17 #include <vnet/lisp-cp/packets.h>
20 vlib_node_registration_t tcp4_output_node;
21 vlib_node_registration_t tcp6_output_node;
23 typedef enum _tcp_output_next
26 TCP_OUTPUT_NEXT_IP_LOOKUP,
27 TCP_OUTPUT_NEXT_IP_REWRITE,
28 TCP_OUTPUT_NEXT_IP_ARP,
32 #define foreach_tcp4_output_next \
33 _ (DROP, "error-drop") \
34 _ (IP_LOOKUP, "ip4-lookup") \
35 _ (IP_REWRITE, "ip4-rewrite") \
38 #define foreach_tcp6_output_next \
39 _ (DROP, "error-drop") \
40 _ (IP_LOOKUP, "ip6-lookup") \
41 _ (IP_REWRITE, "ip6-rewrite") \
42 _ (IP_ARP, "ip6-discover-neighbor")
44 static char *tcp_error_strings[] = {
45 #define tcp_error(n,s) s,
46 #include <vnet/tcp/tcp_error.def>
52 tcp_header_t tcp_header;
53 tcp_connection_t tcp_connection;
59 format_tcp_tx_trace (u8 * s, va_list * args)
61 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
62 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
63 tcp_tx_trace_t *t = va_arg (*args, tcp_tx_trace_t *);
64 u32 indent = format_get_indent (s);
66 s = format (s, "%U\n%U%U",
67 format_tcp_header, &t->tcp_header, 128,
68 format_white_space, indent,
69 format_tcp_connection, &t->tcp_connection, 1);
75 tcp_window_compute_scale (u32 window)
78 while (wnd_scale < TCP_MAX_WND_SCALE && (window >> wnd_scale) > TCP_WND_MAX)
84 * Update max segment size we're able to process.
86 * The value is constrained by our interface's MTU and IP options. It is
87 * also what we advertise to our peer.
90 tcp_update_rcv_mss (tcp_connection_t * tc)
92 /* TODO find our iface MTU */
93 tc->mss = dummy_mtu - sizeof (tcp_header_t);
97 * TCP's initial window
100 tcp_initial_wnd_unscaled (tcp_connection_t * tc)
102 /* RFC 6928 recommends the value lower. However at the time our connections
103 * are initialized, fifos may not be allocated. Therefore, advertise the
104 * smallest possible unscaled window size and update once fifos are
105 * assigned to the session.
108 tcp_update_rcv_mss (tc);
109 TCP_IW_N_SEGMENTS * tc->mss;
111 return TCP_MIN_RX_FIFO_SIZE;
115 * Compute initial window and scale factor. As per RFC1323, window field in
116 * SYN and SYN-ACK segments is never scaled.
119 tcp_initial_window_to_advertise (tcp_connection_t * tc)
123 /* Initial wnd for SYN. Fifos are not allocated yet.
124 * Use some predefined value. For SYN-ACK we still want the
125 * scale to be computed in the same way */
126 max_fifo = TCP_MAX_RX_FIFO_SIZE;
128 tc->rcv_wscale = tcp_window_compute_scale (max_fifo);
129 tc->rcv_wnd = tcp_initial_wnd_unscaled (tc);
131 return clib_min (tc->rcv_wnd, TCP_WND_MAX);
135 tcp_update_rcv_wnd (tcp_connection_t * tc)
138 u32 available_space, max_fifo, wnd;
141 * Figure out how much space we have available
143 available_space = transport_max_rx_enqueue (&tc->connection);
144 max_fifo = transport_rx_fifo_size (&tc->connection);
146 ASSERT (tc->rcv_opts.mss < max_fifo);
147 if (available_space < tc->rcv_opts.mss && available_space < max_fifo >> 3)
151 * Use the above and what we know about what we've previously advertised
152 * to compute the new window
154 observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
155 if (observed_wnd < 0)
158 /* Bad. Thou shalt not shrink */
159 if (available_space < observed_wnd)
162 TCP_EVT_DBG (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space);
166 wnd = available_space;
169 /* Make sure we have a multiple of rcv_wscale */
170 if (wnd && tc->rcv_wscale)
172 wnd &= ~(1 << tc->rcv_wscale);
174 wnd = 1 << tc->rcv_wscale;
177 tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale);
181 * Compute and return window to advertise, scaled as per RFC1323
184 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
186 if (state < TCP_STATE_ESTABLISHED)
187 return tcp_initial_window_to_advertise (tc);
189 tcp_update_rcv_wnd (tc);
191 if (tc->rcv_wnd == 0)
193 tc->flags |= TCP_CONN_SENT_RCV_WND0;
197 tc->flags &= ~TCP_CONN_SENT_RCV_WND0;
200 return tc->rcv_wnd >> tc->rcv_wscale;
204 * Write TCP options to segment.
207 tcp_options_write (u8 * data, tcp_options_t * opts)
210 u32 buf, seq_len = 4;
212 if (tcp_opts_mss (opts))
214 *data++ = TCP_OPTION_MSS;
215 *data++ = TCP_OPTION_LEN_MSS;
216 buf = clib_host_to_net_u16 (opts->mss);
217 clib_memcpy (data, &buf, sizeof (opts->mss));
218 data += sizeof (opts->mss);
219 opts_len += TCP_OPTION_LEN_MSS;
222 if (tcp_opts_wscale (opts))
224 *data++ = TCP_OPTION_WINDOW_SCALE;
225 *data++ = TCP_OPTION_LEN_WINDOW_SCALE;
226 *data++ = opts->wscale;
227 opts_len += TCP_OPTION_LEN_WINDOW_SCALE;
230 if (tcp_opts_sack_permitted (opts))
232 *data++ = TCP_OPTION_SACK_PERMITTED;
233 *data++ = TCP_OPTION_LEN_SACK_PERMITTED;
234 opts_len += TCP_OPTION_LEN_SACK_PERMITTED;
237 if (tcp_opts_tstamp (opts))
239 *data++ = TCP_OPTION_TIMESTAMP;
240 *data++ = TCP_OPTION_LEN_TIMESTAMP;
241 buf = clib_host_to_net_u32 (opts->tsval);
242 clib_memcpy (data, &buf, sizeof (opts->tsval));
243 data += sizeof (opts->tsval);
244 buf = clib_host_to_net_u32 (opts->tsecr);
245 clib_memcpy (data, &buf, sizeof (opts->tsecr));
246 data += sizeof (opts->tsecr);
247 opts_len += TCP_OPTION_LEN_TIMESTAMP;
250 if (tcp_opts_sack (opts))
253 u32 n_sack_blocks = clib_min (vec_len (opts->sacks),
254 TCP_OPTS_MAX_SACK_BLOCKS);
256 if (n_sack_blocks != 0)
258 *data++ = TCP_OPTION_SACK_BLOCK;
259 *data++ = 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
260 for (i = 0; i < n_sack_blocks; i++)
262 buf = clib_host_to_net_u32 (opts->sacks[i].start);
263 clib_memcpy (data, &buf, seq_len);
265 buf = clib_host_to_net_u32 (opts->sacks[i].end);
266 clib_memcpy (data, &buf, seq_len);
269 opts_len += 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
273 /* Terminate TCP options */
276 *data++ = TCP_OPTION_EOL;
277 opts_len += TCP_OPTION_LEN_EOL;
280 /* Pad with zeroes to a u32 boundary */
283 *data++ = TCP_OPTION_NOOP;
284 opts_len += TCP_OPTION_LEN_NOOP;
290 tcp_make_syn_options (tcp_options_t * opts, u8 wnd_scale)
294 opts->flags |= TCP_OPTS_FLAG_MSS;
295 opts->mss = dummy_mtu; /*XXX discover that */
296 len += TCP_OPTION_LEN_MSS;
298 opts->flags |= TCP_OPTS_FLAG_WSCALE;
299 opts->wscale = wnd_scale;
300 len += TCP_OPTION_LEN_WINDOW_SCALE;
302 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
303 opts->tsval = tcp_time_now ();
305 len += TCP_OPTION_LEN_TIMESTAMP;
309 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
310 len += TCP_OPTION_LEN_SACK_PERMITTED;
313 /* Align to needed boundary */
314 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
319 tcp_make_synack_options (tcp_connection_t * tc, tcp_options_t * opts)
323 opts->flags |= TCP_OPTS_FLAG_MSS;
325 len += TCP_OPTION_LEN_MSS;
327 if (tcp_opts_wscale (&tc->rcv_opts))
329 opts->flags |= TCP_OPTS_FLAG_WSCALE;
330 opts->wscale = tc->rcv_wscale;
331 len += TCP_OPTION_LEN_WINDOW_SCALE;
334 if (tcp_opts_tstamp (&tc->rcv_opts))
336 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
337 opts->tsval = tcp_time_now ();
338 opts->tsecr = tc->tsval_recent;
339 len += TCP_OPTION_LEN_TIMESTAMP;
342 if (tcp_opts_sack_permitted (&tc->rcv_opts))
344 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
345 len += TCP_OPTION_LEN_SACK_PERMITTED;
348 /* Align to needed boundary */
349 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
354 tcp_make_established_options (tcp_connection_t * tc, tcp_options_t * opts)
360 if (tcp_opts_tstamp (&tc->rcv_opts))
362 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
363 opts->tsval = tcp_time_now ();
364 opts->tsecr = tc->tsval_recent;
365 len += TCP_OPTION_LEN_TIMESTAMP;
367 if (tcp_opts_sack_permitted (&tc->rcv_opts))
369 if (vec_len (tc->snd_sacks))
371 opts->flags |= TCP_OPTS_FLAG_SACK;
372 opts->sacks = tc->snd_sacks;
373 opts->n_sack_blocks = clib_min (vec_len (tc->snd_sacks),
374 TCP_OPTS_MAX_SACK_BLOCKS);
375 len += 2 + TCP_OPTION_LEN_SACK_BLOCK * opts->n_sack_blocks;
379 /* Align to needed boundary */
380 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
385 tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts,
390 case TCP_STATE_ESTABLISHED:
391 case TCP_STATE_FIN_WAIT_1:
392 case TCP_STATE_CLOSED:
393 case TCP_STATE_CLOSE_WAIT:
394 return tcp_make_established_options (tc, opts);
395 case TCP_STATE_SYN_RCVD:
396 return tcp_make_synack_options (tc, opts);
397 case TCP_STATE_SYN_SENT:
398 return tcp_make_syn_options (opts, tc->rcv_wscale);
400 clib_warning ("State not handled! %d", state);
406 * Update snd_mss to reflect the effective segment size that we can send
407 * by taking into account all TCP options, including SACKs
410 tcp_update_snd_mss (tcp_connection_t * tc)
412 /* Compute options to be used for connection. These may be reused when
413 * sending data or to compute the effective mss (snd_mss) */
415 tcp_make_options (tc, &tc->snd_opts, TCP_STATE_ESTABLISHED);
417 /* XXX check if MTU has been updated */
418 tc->snd_mss = clib_min (tc->mss, tc->rcv_opts.mss) - tc->snd_opts_len;
419 ASSERT (tc->snd_mss > 0);
423 tcp_init_mss (tcp_connection_t * tc)
425 u16 default_min_mss = 536;
426 tcp_update_rcv_mss (tc);
428 /* TODO cache mss and consider PMTU discovery */
429 tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss);
431 if (tc->snd_mss < 45)
433 clib_warning ("snd mss is 0");
434 /* Assume that at least the min default mss works */
435 tc->snd_mss = default_min_mss;
436 tc->rcv_opts.mss = default_min_mss;
439 /* We should have enough space for 40 bytes of options */
440 ASSERT (tc->snd_mss > 45);
442 /* If we use timestamp option, account for it */
443 if (tcp_opts_tstamp (&tc->rcv_opts))
444 tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP;
448 tcp_alloc_tx_buffers (tcp_main_t * tm, u8 thread_index, u16 * n_bufs,
451 tcp_worker_ctx_t *ctx = &tm->wrk_ctx[thread_index];
452 vlib_main_t *vm = vlib_get_main ();
455 ASSERT (wanted > *n_bufs);
456 vec_validate_aligned (ctx->tx_buffers, wanted - 1, CLIB_CACHE_LINE_BYTES);
457 n_alloc = vlib_buffer_alloc (vm, &ctx->tx_buffers[*n_bufs],
460 _vec_len (ctx->tx_buffers) = *n_bufs;
465 tcp_get_free_buffer_index (tcp_main_t * tm, u32 * bidx)
467 u32 thread_index = vlib_get_thread_index ();
468 tcp_worker_ctx_t *ctx = &tm->wrk_ctx[thread_index];
469 u16 n_bufs = vec_len (ctx->tx_buffers);
471 TCP_DBG_BUFFER_ALLOC_MAYBE_FAIL (thread_index);
473 if (PREDICT_FALSE (!n_bufs))
475 if (!tcp_alloc_tx_buffers (tm, thread_index, &n_bufs, VLIB_FRAME_SIZE))
481 *bidx = ctx->tx_buffers[--n_bufs];
482 _vec_len (ctx->tx_buffers) = n_bufs;
487 tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b)
489 if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
490 vlib_buffer_free_one (vm, b->next_buffer);
491 /* Zero all flags but free list index and trace flag */
492 b->flags &= VLIB_BUFFER_NEXT_PRESENT - 1;
494 b->current_length = 0;
495 b->total_length_not_including_first_buffer = 0;
496 vnet_buffer (b)->tcp.flags = 0;
498 /* Leave enough space for headers */
499 return vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
503 tcp_init_buffer (vlib_main_t * vm, vlib_buffer_t * b)
505 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0);
506 b->flags &= VLIB_BUFFER_NON_DEFAULT_FREELIST;
507 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
508 b->total_length_not_including_first_buffer = 0;
510 vnet_buffer (b)->tcp.flags = 0;
511 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
512 /* Leave enough space for headers */
513 return vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
520 tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
523 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
524 u8 tcp_opts_len, tcp_hdr_opts_len;
528 wnd = tcp_window_to_advertise (tc, state);
530 /* Make and write options */
531 tcp_opts_len = tcp_make_established_options (tc, snd_opts);
532 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
534 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
535 tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd);
537 tcp_options_write ((u8 *) (th + 1), snd_opts);
538 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
542 * Convert buffer to ACK
545 tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
547 vlib_main_t *vm = vlib_get_main ();
549 tcp_reuse_buffer (vm, b);
550 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
551 TCP_EVT_DBG (TCP_EVT_ACK_SENT, tc);
552 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
553 tc->rcv_las = tc->rcv_nxt;
557 * Convert buffer to FIN-ACK
560 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
562 vlib_main_t *vm = vlib_get_main ();
565 tcp_reuse_buffer (vm, b);
567 flags = TCP_FLAG_FIN | TCP_FLAG_ACK;
568 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, flags);
570 /* Reset flags, make sure ack is sent */
571 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
575 * Convert buffer to SYN
578 tcp_make_syn (tcp_connection_t * tc, vlib_buffer_t * b)
580 u8 tcp_hdr_opts_len, tcp_opts_len;
583 tcp_options_t snd_opts;
585 initial_wnd = tcp_initial_window_to_advertise (tc);
587 /* Make and write options */
588 memset (&snd_opts, 0, sizeof (snd_opts));
589 tcp_opts_len = tcp_make_syn_options (&snd_opts, tc->rcv_wscale);
590 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
592 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
593 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
595 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
596 tcp_options_write ((u8 *) (th + 1), &snd_opts);
600 * Convert buffer to SYN-ACK
603 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
605 vlib_main_t *vm = vlib_get_main ();
606 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
607 u8 tcp_opts_len, tcp_hdr_opts_len;
611 memset (snd_opts, 0, sizeof (*snd_opts));
612 tcp_reuse_buffer (vm, b);
614 initial_wnd = tcp_initial_window_to_advertise (tc);
615 tcp_opts_len = tcp_make_synack_options (tc, snd_opts);
616 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
618 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
619 tc->rcv_nxt, tcp_hdr_opts_len,
620 TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd);
621 tcp_options_write ((u8 *) (th + 1), snd_opts);
623 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
624 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
626 /* Init retransmit timer. Use update instead of set because of
628 tcp_retransmit_timer_force_update (tc);
629 TCP_EVT_DBG (TCP_EVT_SYNACK_SENT, tc);
633 tcp_enqueue_to_ip_lookup_i (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
634 u8 is_ip4, u32 fib_index, u8 flush)
636 tcp_main_t *tm = vnet_get_tcp_main ();
637 u32 thread_index = vlib_get_thread_index ();
638 u32 *to_next, next_index;
641 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
644 vnet_buffer (b)->sw_if_index[VLIB_TX] = fib_index;
645 vnet_buffer (b)->sw_if_index[VLIB_RX] = 0;
647 /* Send to IP lookup */
648 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
649 tcp_trajectory_add_start (b, 1);
651 f = tm->wrk_ctx[thread_index].ip_lookup_tx_frames[!is_ip4];
654 f = vlib_get_frame_to_node (vm, next_index);
656 tm->wrk_ctx[thread_index].ip_lookup_tx_frames[!is_ip4] = f;
659 to_next = vlib_frame_vector_args (f);
660 to_next[f->n_vectors] = bi;
662 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
664 vlib_put_frame_to_node (vm, next_index, f);
665 tm->wrk_ctx[thread_index].ip_lookup_tx_frames[!is_ip4] = 0;
670 tcp_enqueue_to_ip_lookup_now (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
671 u8 is_ip4, u32 fib_index)
673 tcp_enqueue_to_ip_lookup_i (vm, b, bi, is_ip4, fib_index, 1);
677 tcp_enqueue_to_ip_lookup (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
678 u8 is_ip4, u32 fib_index)
680 tcp_enqueue_to_ip_lookup_i (vm, b, bi, is_ip4, fib_index, 0);
681 if (vm->thread_index == 0 && vlib_num_workers ())
682 session_flush_frames_main_thread (vm);
686 tcp_enqueue_to_output_i (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
689 tcp_main_t *tm = vnet_get_tcp_main ();
690 u32 thread_index = vlib_get_thread_index ();
691 u32 *to_next, next_index;
694 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
697 /* Decide where to send the packet */
698 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
699 tcp_trajectory_add_start (b, 2);
701 /* Get frame to v4/6 output node */
702 f = tm->wrk_ctx[thread_index].tx_frames[!is_ip4];
705 f = vlib_get_frame_to_node (vm, next_index);
707 tm->wrk_ctx[thread_index].tx_frames[!is_ip4] = f;
709 to_next = vlib_frame_vector_args (f);
710 to_next[f->n_vectors] = bi;
712 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
714 vlib_put_frame_to_node (vm, next_index, f);
715 tm->wrk_ctx[thread_index].tx_frames[!is_ip4] = 0;
720 tcp_enqueue_to_output (vlib_main_t * vm, vlib_buffer_t * b, u32 bi, u8 is_ip4)
722 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 0);
726 tcp_enqueue_to_output_now (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
729 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 1);
733 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
734 tcp_state_t state, u8 thread_index, u8 is_ip4)
739 ip4_address_t src_ip40, dst_ip40;
740 ip6_address_t src_ip60, dst_ip60;
741 u16 src_port, dst_port;
746 /* Find IP and TCP headers */
747 th0 = tcp_buffer_hdr (b0);
749 /* Save src and dst ip */
752 ih4 = vlib_buffer_get_current (b0);
753 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
754 src_ip40.as_u32 = ih4->src_address.as_u32;
755 dst_ip40.as_u32 = ih4->dst_address.as_u32;
759 ih6 = vlib_buffer_get_current (b0);
760 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
761 clib_memcpy (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
762 clib_memcpy (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t));
765 src_port = th0->src_port;
766 dst_port = th0->dst_port;
768 /* Try to determine what/why we're actually resetting */
769 if (state == TCP_STATE_CLOSED)
774 tmp = clib_net_to_host_u32 (th0->seq_number);
776 /* Got a SYN for no listener. */
777 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
778 ack = clib_host_to_net_u32 (tmp + 1);
783 flags = TCP_FLAG_RST;
784 seq = th0->ack_number;
788 tcp_reuse_buffer (vm, b0);
789 tcp_trajectory_add_start (b0, 4);
790 th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack,
791 sizeof (tcp_header_t), flags, 0);
795 ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40,
797 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
802 ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60,
804 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
812 * Send reset without reusing existing buffer
814 * It extracts connection info out of original packet
817 tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt, u8 is_ip4)
820 u32 bi, sw_if_index, fib_index;
821 tcp_main_t *tm = vnet_get_tcp_main ();
822 vlib_main_t *vm = vlib_get_main ();
823 u8 tcp_hdr_len, flags = 0;
824 tcp_header_t *th, *pkt_th;
826 ip4_header_t *ih4, *pkt_ih4;
827 ip6_header_t *ih6, *pkt_ih6;
828 fib_protocol_t fib_proto;
830 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
833 b = vlib_get_buffer (vm, bi);
834 sw_if_index = vnet_buffer (pkt)->sw_if_index[VLIB_RX];
835 fib_proto = is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
836 fib_index = fib_table_get_index_for_sw_if_index (fib_proto, sw_if_index);
837 tcp_init_buffer (vm, b);
839 /* Make and write options */
840 tcp_hdr_len = sizeof (tcp_header_t);
844 pkt_ih4 = vlib_buffer_get_current (pkt);
845 pkt_th = ip4_next_header (pkt_ih4);
849 pkt_ih6 = vlib_buffer_get_current (pkt);
850 pkt_th = ip6_next_header (pkt_ih6);
853 if (tcp_ack (pkt_th))
855 flags = TCP_FLAG_RST;
856 seq = pkt_th->ack_number;
857 ack = (tc && tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
861 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
863 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
866 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
867 seq, ack, tcp_hdr_len, flags, 0);
869 /* Swap src and dst ip */
872 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
873 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
874 &pkt_ih4->src_address, IP_PROTOCOL_TCP, 1);
875 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
880 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
882 ih6 = vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address,
883 &pkt_ih6->src_address, IP_PROTOCOL_TCP);
884 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
888 tcp_enqueue_to_ip_lookup_now (vm, b, bi, is_ip4, fib_index);
889 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc);
893 * Build and set reset packet for connection
896 tcp_send_reset (tcp_connection_t * tc)
898 vlib_main_t *vm = vlib_get_main ();
899 tcp_main_t *tm = vnet_get_tcp_main ();
903 u16 tcp_hdr_opts_len, advertise_wnd, opts_write_len;
906 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
908 b = vlib_get_buffer (vm, bi);
909 tcp_init_buffer (vm, b);
911 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
912 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
913 advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED);
914 flags = TCP_FLAG_RST;
915 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
916 tc->rcv_nxt, tcp_hdr_opts_len, flags,
918 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
919 ASSERT (opts_write_len == tc->snd_opts_len);
920 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
924 ih4 = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip.ip4,
925 &tc->c_rmt_ip.ip4, IP_PROTOCOL_TCP, 0);
926 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
932 ih6 = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip.ip6,
933 &tc->c_rmt_ip.ip6, IP_PROTOCOL_TCP);
934 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
937 tcp_enqueue_to_ip_lookup_now (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
938 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc);
942 tcp_push_ip_hdr (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b)
944 tcp_header_t *th = vlib_buffer_get_current (b);
945 vlib_main_t *vm = vlib_get_main ();
949 ih = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip4,
950 &tc->c_rmt_ip4, IP_PROTOCOL_TCP, 1);
951 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih);
958 ih = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip6,
959 &tc->c_rmt_ip6, IP_PROTOCOL_TCP);
960 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih, &bogus);
968 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
969 * The packet is not forwarded through tcpx_output to avoid doing lookups
970 * in the half_open pool.
973 tcp_send_syn (tcp_connection_t * tc)
977 tcp_main_t *tm = vnet_get_tcp_main ();
978 vlib_main_t *vm = vlib_get_main ();
981 * Setup retransmit and establish timers before requesting buffer
982 * such that we can return if we've ran out.
984 tcp_timer_set (tc, TCP_TIMER_ESTABLISH, TCP_ESTABLISH_TIME);
985 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
986 tc->rto * TCP_TO_TIMER_TICK);
988 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
991 b = vlib_get_buffer (vm, bi);
992 tcp_init_buffer (vm, b);
993 tcp_make_syn (tc, b);
995 /* Measure RTT with this */
996 tc->rtt_ts = tcp_time_now ();
997 tc->rtt_seq = tc->snd_nxt;
1000 tcp_push_ip_hdr (tm, tc, b);
1001 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
1002 TCP_EVT_DBG (TCP_EVT_SYN_SENT, tc);
1006 * Flush tx frame populated by retransmits and timer pops
1009 tcp_flush_frame_to_output (vlib_main_t * vm, u8 thread_index, u8 is_ip4)
1011 if (tcp_main.wrk_ctx[thread_index].tx_frames[!is_ip4])
1014 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
1015 vlib_put_frame_to_node (vm, next_index,
1017 wrk_ctx[thread_index].tx_frames[!is_ip4]);
1018 tcp_main.wrk_ctx[thread_index].tx_frames[!is_ip4] = 0;
1023 * Flush ip lookup tx frames populated by timer pops
1026 tcp_flush_frame_to_ip_lookup (vlib_main_t * vm, u8 thread_index, u8 is_ip4)
1028 if (tcp_main.wrk_ctx[thread_index].ip_lookup_tx_frames[!is_ip4])
1031 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
1032 vlib_put_frame_to_node (vm, next_index,
1034 wrk_ctx[thread_index].ip_lookup_tx_frames
1036 tcp_main.wrk_ctx[thread_index].ip_lookup_tx_frames[!is_ip4] = 0;
1041 * Flush v4 and v6 tcp and ip-lookup tx frames for thread index
1044 tcp_flush_frames_to_output (u8 thread_index)
1046 vlib_main_t *vm = vlib_get_main ();
1047 tcp_flush_frame_to_output (vm, thread_index, 1);
1048 tcp_flush_frame_to_output (vm, thread_index, 0);
1049 tcp_flush_frame_to_ip_lookup (vm, thread_index, 1);
1050 tcp_flush_frame_to_ip_lookup (vm, thread_index, 0);
1057 tcp_send_fin (tcp_connection_t * tc)
1059 tcp_main_t *tm = vnet_get_tcp_main ();
1060 vlib_main_t *vm = vlib_get_main ();
1065 tcp_retransmit_timer_force_update (tc);
1066 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1068 b = vlib_get_buffer (vm, bi);
1069 tcp_init_buffer (vm, b);
1070 fin_snt = tc->flags & TCP_CONN_FINSNT;
1072 tc->snd_nxt = tc->snd_una;
1073 tcp_make_fin (tc, b);
1074 tcp_enqueue_to_output_now (vm, b, bi, tc->c_is_ip4);
1077 tc->flags |= TCP_CONN_FINSNT;
1078 tc->flags &= ~TCP_CONN_FINPNDG;
1079 /* Account for the FIN */
1080 tc->snd_una_max += 1;
1081 tc->snd_nxt = tc->snd_una_max;
1085 tc->snd_nxt = tc->snd_una_max;
1087 TCP_EVT_DBG (TCP_EVT_FIN_SENT, tc);
1091 tcp_make_state_flags (tcp_connection_t * tc, tcp_state_t next_state)
1095 case TCP_STATE_ESTABLISHED:
1096 case TCP_STATE_CLOSE_WAIT:
1097 return TCP_FLAG_ACK;
1098 case TCP_STATE_SYN_RCVD:
1099 return TCP_FLAG_SYN | TCP_FLAG_ACK;
1100 case TCP_STATE_SYN_SENT:
1101 return TCP_FLAG_SYN;
1102 case TCP_STATE_LAST_ACK:
1103 case TCP_STATE_FIN_WAIT_1:
1104 if (tc->snd_nxt + 1 < tc->snd_una_max)
1105 return TCP_FLAG_ACK;
1107 return TCP_FLAG_FIN;
1109 clib_warning ("Shouldn't be here!");
1115 * Push TCP header and update connection variables
1118 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
1119 tcp_state_t next_state, u8 compute_opts)
1121 u32 advertise_wnd, data_len;
1122 u8 tcp_hdr_opts_len, opts_write_len, flags;
1125 data_len = b->current_length + b->total_length_not_including_first_buffer;
1126 ASSERT (!b->total_length_not_including_first_buffer
1127 || (b->flags & VLIB_BUFFER_NEXT_PRESENT));
1128 vnet_buffer (b)->tcp.flags = 0;
1131 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1133 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
1134 advertise_wnd = tcp_window_to_advertise (tc, next_state);
1135 flags = tcp_make_state_flags (tc, next_state);
1137 /* Push header and options */
1138 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
1139 tc->rcv_nxt, tcp_hdr_opts_len, flags,
1141 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
1143 ASSERT (opts_write_len == tc->snd_opts_len);
1144 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
1147 * Update connection variables
1150 tc->snd_nxt += data_len;
1151 tc->rcv_las = tc->rcv_nxt;
1153 TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
1157 tcp_push_header (tcp_connection_t * tc, vlib_buffer_t * b)
1159 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, 0);
1160 tc->snd_una_max = tc->snd_nxt;
1161 ASSERT (seq_leq (tc->snd_una_max, tc->snd_una + tc->snd_wnd));
1162 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1163 /* If not tracking an ACK, start tracking */
1164 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
1166 tc->rtt_ts = tcp_time_now ();
1167 tc->rtt_seq = tc->snd_nxt;
1169 if (PREDICT_FALSE (!tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)))
1171 tcp_retransmit_timer_set (tc);
1174 tcp_trajectory_add_start (b, 3);
1179 tcp_send_ack (tcp_connection_t * tc)
1181 tcp_main_t *tm = vnet_get_tcp_main ();
1182 vlib_main_t *vm = vlib_get_main ();
1188 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1190 b = vlib_get_buffer (vm, bi);
1191 tcp_init_buffer (vm, b);
1193 /* Fill in the ACK */
1194 tcp_make_ack (tc, b);
1195 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1199 * Delayed ack timer handler
1201 * Sends delayed ACK when timer expires
1204 tcp_timer_delack_handler (u32 index)
1206 u32 thread_index = vlib_get_thread_index ();
1207 tcp_connection_t *tc;
1209 tc = tcp_connection_get (index, thread_index);
1210 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
1215 * Build a retransmit segment
1217 * @return the number of bytes in the segment or 0 if there's nothing to
1221 tcp_prepare_retransmit_segment (tcp_connection_t * tc, u32 offset,
1222 u32 max_deq_bytes, vlib_buffer_t ** b)
1224 tcp_main_t *tm = vnet_get_tcp_main ();
1225 vlib_main_t *vm = vlib_get_main ();
1227 u32 start, bi, available_bytes, seg_size;
1230 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1231 ASSERT (max_deq_bytes != 0);
1234 * Make sure we can retransmit something
1236 available_bytes = session_tx_fifo_max_dequeue (&tc->connection);
1237 ASSERT (available_bytes >= offset);
1238 available_bytes -= offset;
1239 if (!available_bytes)
1241 max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
1242 max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
1244 /* Start is beyond snd_congestion */
1245 start = tc->snd_una + offset;
1246 if (seq_geq (start, tc->snd_congestion))
1249 /* Don't overshoot snd_congestion */
1250 if (seq_gt (start + max_deq_bytes, tc->snd_congestion))
1252 max_deq_bytes = tc->snd_congestion - start;
1253 if (max_deq_bytes == 0)
1257 seg_size = max_deq_bytes + MAX_HDRS_LEN;
1262 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1265 * Allocate and fill in buffer(s)
1268 /* Easy case, buffer size greater than mss */
1269 if (PREDICT_TRUE (seg_size <= tm->bytes_per_buffer))
1271 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1273 *b = vlib_get_buffer (vm, bi);
1274 data = tcp_init_buffer (vm, *b);
1275 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1277 ASSERT (n_bytes == max_deq_bytes);
1278 b[0]->current_length = n_bytes;
1279 tcp_push_hdr_i (tc, *b, tc->state, 0);
1281 /* Split mss into multiple buffers */
1284 u32 chain_bi = ~0, n_bufs_per_seg;
1285 u32 thread_index = vlib_get_thread_index ();
1286 u16 n_peeked, len_to_deq, available_bufs;
1287 vlib_buffer_t *chain_b, *prev_b;
1290 /* Make sure we have enough buffers */
1291 n_bufs_per_seg = ceil ((double) seg_size / tm->bytes_per_buffer);
1292 available_bufs = vec_len (tm->wrk_ctx[thread_index].tx_buffers);
1293 if (n_bufs_per_seg > available_bufs)
1295 tcp_alloc_tx_buffers (tm, thread_index, &available_bufs,
1298 if (n_bufs_per_seg > available_bufs)
1305 tcp_get_free_buffer_index (tm, &bi);
1306 ASSERT (bi != (u32) ~ 0);
1307 *b = vlib_get_buffer (vm, bi);
1308 data = tcp_init_buffer (vm, *b);
1309 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1310 tm->bytes_per_buffer -
1312 b[0]->current_length = n_bytes;
1313 b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
1314 b[0]->total_length_not_including_first_buffer = 0;
1315 max_deq_bytes -= n_bytes;
1318 for (i = 1; i < n_bufs_per_seg; i++)
1321 len_to_deq = clib_min (max_deq_bytes, tm->bytes_per_buffer);
1322 tcp_get_free_buffer_index (tm, &chain_bi);
1323 ASSERT (chain_bi != (u32) ~ 0);
1324 chain_b = vlib_get_buffer (vm, chain_bi);
1325 chain_b->current_data = 0;
1326 data = vlib_buffer_get_current (chain_b);
1327 n_peeked = stream_session_peek_bytes (&tc->connection, data,
1328 offset + n_bytes, len_to_deq);
1329 ASSERT (n_peeked == len_to_deq);
1330 n_bytes += n_peeked;
1331 chain_b->current_length = n_peeked;
1332 chain_b->next_buffer = 0;
1334 /* update previous buffer */
1335 prev_b->next_buffer = chain_bi;
1336 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
1338 max_deq_bytes -= n_peeked;
1339 b[0]->total_length_not_including_first_buffer += n_peeked;
1342 tcp_push_hdr_i (tc, *b, tc->state, 0);
1345 ASSERT (n_bytes > 0);
1346 ASSERT (((*b)->current_data + (*b)->current_length) <=
1347 tm->bytes_per_buffer);
1349 if (tcp_in_fastrecovery (tc))
1350 tc->snd_rxt_bytes += n_bytes;
1353 TCP_EVT_DBG (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1358 * Reset congestion control, switch cwnd to loss window and try again.
1361 tcp_rxt_timeout_cc (tcp_connection_t * tc)
1363 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 6);
1364 tc->prev_ssthresh = tc->ssthresh;
1365 tc->prev_cwnd = tc->cwnd;
1367 /* Cleanly recover cc (also clears up fast retransmit) */
1368 if (tcp_in_fastrecovery (tc))
1369 tcp_cc_fastrecovery_exit (tc);
1371 /* Start again from the beginning */
1372 tc->cc_algo->congestion (tc);
1373 tc->cwnd = tcp_loss_wnd (tc);
1374 tc->snd_congestion = tc->snd_una_max;
1376 tc->cwnd_acc_bytes = 0;
1378 tcp_recovery_on (tc);
1382 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
1384 tcp_main_t *tm = vnet_get_tcp_main ();
1385 vlib_main_t *vm = vlib_get_main ();
1386 u32 thread_index = vlib_get_thread_index ();
1387 tcp_connection_t *tc;
1388 vlib_buffer_t *b = 0;
1393 tc = tcp_half_open_connection_get (index);
1394 /* Note: the connection may have transitioned to ESTABLISHED... */
1395 if (PREDICT_FALSE (tc == 0))
1397 tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
1401 tc = tcp_connection_get (index, thread_index);
1402 /* Note: the connection may have been closed and pool_put */
1403 if (PREDICT_FALSE (tc == 0))
1405 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
1408 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1);
1410 if (tc->state >= TCP_STATE_ESTABLISHED)
1412 /* Lost FIN, retransmit and return */
1413 if (tcp_is_lost_fin (tc))
1417 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1421 /* Shouldn't be here */
1422 if ((tc->rto_boff == 0 && tc->snd_una == tc->snd_una_max)
1423 || (tc->rto_boff > 0 && seq_geq (tc->snd_una, tc->snd_congestion)))
1425 tcp_recovery_off (tc);
1429 /* We're not in recovery so make sure rto_boff is 0 */
1430 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1433 tcp_update_rto (tc);
1436 /* Increment RTO backoff (also equal to number of retries) and go back
1437 * to first un-acked byte */
1440 /* First retransmit timeout */
1441 if (tc->rto_boff == 1)
1442 tcp_rxt_timeout_cc (tc);
1444 tc->snd_una_max = tc->snd_nxt = tc->snd_una;
1445 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1447 /* Send one segment. Note that n_bytes may be zero due to buffer shortfall */
1448 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1450 /* TODO be less aggressive about this */
1451 scoreboard_clear (&tc->sack_sb);
1455 tcp_retransmit_timer_set (tc);
1459 bi = vlib_get_buffer_index (vm, b);
1461 /* For first retransmit, record timestamp (Eifel detection RFC3522) */
1462 if (tc->rto_boff == 1)
1463 tc->snd_rxt_ts = tcp_time_now ();
1465 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1466 tcp_retransmit_timer_update (tc);
1468 /* Retransmit for SYN */
1469 else if (tc->state == TCP_STATE_SYN_SENT)
1471 /* Half-open connection actually moved to established but we were
1472 * waiting for syn retransmit to pop to call cleanup from the right
1474 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1476 if (tcp_half_open_connection_cleanup (tc))
1478 clib_warning ("could not remove half-open connection");
1484 /* Try without increasing RTO a number of times. If this fails,
1485 * start growing RTO exponentially */
1487 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1488 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1490 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
1491 tc->rto * TCP_TO_TIMER_TICK);
1493 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1496 b = vlib_get_buffer (vm, bi);
1497 tcp_init_buffer (vm, b);
1498 tcp_make_syn (tc, b);
1501 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 0);
1503 /* This goes straight to ipx_lookup. Retransmit timer set already */
1504 tcp_push_ip_hdr (tm, tc, b);
1505 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
1507 /* Retransmit SYN-ACK */
1508 else if (tc->state == TCP_STATE_SYN_RCVD)
1511 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1512 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1515 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1517 tcp_retransmit_timer_force_update (tc);
1521 b = vlib_get_buffer (vm, bi);
1522 tcp_init_buffer (vm, b);
1523 tcp_make_synack (tc, b);
1524 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 1);
1526 /* Retransmit timer already updated, just enqueue to output */
1527 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1531 ASSERT (tc->state == TCP_STATE_CLOSED);
1537 tcp_timer_retransmit_handler (u32 index)
1539 tcp_timer_retransmit_handler_i (index, 0);
1543 tcp_timer_retransmit_syn_handler (u32 index)
1545 tcp_timer_retransmit_handler_i (index, 1);
1549 * Got 0 snd_wnd from peer, try to do something about it.
1553 tcp_timer_persist_handler (u32 index)
1555 tcp_main_t *tm = vnet_get_tcp_main ();
1556 vlib_main_t *vm = vlib_get_main ();
1557 u32 thread_index = vlib_get_thread_index ();
1558 tcp_connection_t *tc;
1560 u32 bi, max_snd_bytes, available_bytes, offset;
1564 tc = tcp_connection_get_if_valid (index, thread_index);
1569 /* Make sure timer handle is set to invalid */
1570 tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
1572 /* Problem already solved or worse */
1573 if (tc->state == TCP_STATE_CLOSED || tc->state > TCP_STATE_ESTABLISHED
1574 || tc->snd_wnd > tc->snd_mss || tcp_in_recovery (tc))
1577 available_bytes = session_tx_fifo_max_dequeue (&tc->connection);
1578 offset = tc->snd_una_max - tc->snd_una;
1580 /* Reprogram persist if no new bytes available to send. We may have data
1582 if (!available_bytes)
1584 tcp_persist_timer_set (tc);
1588 if (available_bytes <= offset)
1590 ASSERT (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1594 /* Increment RTO backoff */
1596 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1599 * Try to force the first unsent segment (or buffer)
1601 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1603 b = vlib_get_buffer (vm, bi);
1604 data = tcp_init_buffer (vm, b);
1606 tcp_validate_txf_size (tc, offset);
1607 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1608 max_snd_bytes = clib_min (tc->snd_mss, tm->bytes_per_buffer - MAX_HDRS_LEN);
1609 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1611 b->current_length = n_bytes;
1612 ASSERT (n_bytes != 0 && (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)
1613 || tc->snd_nxt == tc->snd_una_max
1614 || tc->rto_boff > 1));
1616 tcp_push_hdr_i (tc, b, tc->state, 0);
1617 tc->snd_una_max = tc->snd_nxt;
1618 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1619 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1621 /* Just sent new data, enable retransmit */
1622 tcp_retransmit_timer_update (tc);
1626 * Retransmit first unacked segment
1629 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1631 vlib_main_t *vm = vlib_get_main ();
1633 u32 bi, old_snd_nxt, n_bytes;
1635 old_snd_nxt = tc->snd_nxt;
1636 tc->snd_nxt = tc->snd_una;
1638 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2);
1639 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1642 bi = vlib_get_buffer_index (vm, b);
1643 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1645 tc->snd_nxt = old_snd_nxt;
1649 * Do fast retransmit with SACKs
1652 tcp_fast_retransmit_sack (tcp_connection_t * tc)
1654 vlib_main_t *vm = vlib_get_main ();
1655 u32 n_written = 0, offset, max_bytes, n_segs = 0;
1656 vlib_buffer_t *b = 0;
1657 sack_scoreboard_hole_t *hole;
1658 sack_scoreboard_t *sb;
1659 u32 bi, old_snd_nxt;
1661 u8 snd_limited = 0, can_rescue = 0;
1663 ASSERT (tcp_in_fastrecovery (tc));
1665 old_snd_nxt = tc->snd_nxt;
1667 snd_space = tcp_available_cc_snd_space (tc);
1669 if (snd_space < tc->snd_mss)
1672 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1673 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1674 while (hole && snd_space > 0 && n_segs++ < VLIB_FRAME_SIZE)
1676 hole = scoreboard_next_rxt_hole (sb, hole,
1677 tcp_fastrecovery_sent_1_smss (tc),
1678 &can_rescue, &snd_limited);
1681 if (!can_rescue || !(seq_lt (sb->rescue_rxt, tc->snd_una)
1682 || seq_gt (sb->rescue_rxt,
1683 tc->snd_congestion)))
1686 /* If rescue rxt undefined or less than snd_una then one segment of
1687 * up to SMSS octets that MUST include the highest outstanding
1688 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1689 * RecoveryPoint. HighRxt MUST NOT be updated.
1691 max_bytes = clib_min (tc->snd_mss,
1692 tc->snd_congestion - tc->snd_una);
1693 max_bytes = clib_min (max_bytes, snd_space);
1694 offset = tc->snd_congestion - tc->snd_una - max_bytes;
1695 sb->rescue_rxt = tc->snd_congestion;
1696 tc->snd_nxt = tc->snd_una + offset;
1697 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes,
1702 bi = vlib_get_buffer_index (vm, b);
1703 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1707 max_bytes = clib_min (hole->end - sb->high_rxt, snd_space);
1708 max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes;
1711 offset = sb->high_rxt - tc->snd_una;
1712 tc->snd_nxt = sb->high_rxt;
1713 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes, &b);
1715 /* Nothing left to retransmit */
1719 bi = vlib_get_buffer_index (vm, b);
1720 sb->high_rxt += n_written;
1721 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1722 ASSERT (n_written <= snd_space);
1723 snd_space -= n_written;
1727 /* If window allows, send 1 SMSS of new data */
1728 tc->snd_nxt = old_snd_nxt;
1732 * Fast retransmit without SACK info
1735 tcp_fast_retransmit_no_sack (tcp_connection_t * tc)
1737 vlib_main_t *vm = vlib_get_main ();
1738 u32 n_written = 0, offset = 0, bi, old_snd_nxt;
1742 ASSERT (tcp_in_fastrecovery (tc));
1743 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1745 /* Start resending from first un-acked segment */
1746 old_snd_nxt = tc->snd_nxt;
1747 tc->snd_nxt = tc->snd_una;
1748 snd_space = tcp_available_cc_snd_space (tc);
1750 while (snd_space > 0)
1752 offset += n_written;
1753 n_written = tcp_prepare_retransmit_segment (tc, offset, snd_space, &b);
1755 /* Nothing left to retransmit */
1759 bi = vlib_get_buffer_index (vm, b);
1760 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1761 snd_space -= n_written;
1764 /* Restore snd_nxt. If window allows, send 1 SMSS of new data */
1765 tc->snd_nxt = old_snd_nxt;
1769 * Do fast retransmit
1772 tcp_fast_retransmit (tcp_connection_t * tc)
1774 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1775 tcp_fast_retransmit_sack (tc);
1777 tcp_fast_retransmit_no_sack (tc);
1781 tcp_session_has_ooo_data (tcp_connection_t * tc)
1783 stream_session_t *s = session_get (tc->c_s_index, tc->c_thread_index);
1784 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1788 tcp_output_handle_link_local (tcp_connection_t * tc0, vlib_buffer_t * b0,
1789 u16 * next0, u32 * error0)
1791 ip_adjacency_t *adj;
1794 /* Not thread safe but as long as the connection exists the adj should
1796 ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &tc0->c_rmt_ip,
1798 if (ai == ADJ_INDEX_INVALID)
1800 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
1801 *next0 = TCP_OUTPUT_NEXT_DROP;
1802 *error0 = TCP_ERROR_LINK_LOCAL_RW;
1807 if (PREDICT_TRUE (adj->lookup_next_index == IP_LOOKUP_NEXT_REWRITE))
1808 *next0 = TCP_OUTPUT_NEXT_IP_REWRITE;
1809 else if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP)
1810 *next0 = TCP_OUTPUT_NEXT_IP_ARP;
1813 *next0 = TCP_OUTPUT_NEXT_DROP;
1814 *error0 = TCP_ERROR_LINK_LOCAL_RW;
1816 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ai;
1820 tcp46_output_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
1821 u32 * to_next, u32 n_bufs)
1823 u32 n_trace = vlib_get_trace_count (vm, node);
1824 tcp_connection_t *tc;
1830 for (i = 0; i < clib_min (n_trace, n_bufs); i++)
1832 b = vlib_get_buffer (vm, to_next[i]);
1833 th = vlib_buffer_get_current (b);
1834 tc = tcp_connection_get (vnet_buffer (b)->tcp.connection_index,
1836 t = vlib_add_trace (vm, node, b, sizeof (*t));
1837 clib_memcpy (&t->tcp_header, th, sizeof (t->tcp_header));
1838 clib_memcpy (&t->tcp_connection, tc, sizeof (t->tcp_connection));
1843 tcp_output_push_ip (vlib_main_t * vm, vlib_buffer_t * b0,
1844 tcp_connection_t * tc0, u8 is_ip4)
1846 tcp_header_t *th0 = 0;
1848 th0 = vlib_buffer_get_current (b0);
1849 TCP_EVT_DBG (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
1852 vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
1853 IP_PROTOCOL_TCP, 1);
1854 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1855 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1861 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6,
1862 &tc0->c_rmt_ip6, IP_PROTOCOL_TCP);
1863 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1864 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ih0 - b0->data;
1865 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1871 tcp_output_handle_packet (tcp_connection_t * tc0, vlib_buffer_t * b0,
1872 u32 * error0, u16 * next0, u8 is_ip4)
1875 if (PREDICT_FALSE (tc0->state == TCP_STATE_CLOSED))
1877 *error0 = TCP_ERROR_INVALID_CONNECTION;
1878 *next0 = TCP_OUTPUT_NEXT_DROP;
1882 vnet_buffer (b0)->sw_if_index[VLIB_TX] = tc0->c_fib_index;
1883 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
1887 if (PREDICT_FALSE (ip6_address_is_link_local_unicast (&tc0->c_rmt_ip6)))
1888 tcp_output_handle_link_local (tc0, b0, next0, error0);
1891 /* Filter out DUPACKs if there are no OOO segments left */
1892 if (PREDICT_FALSE (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1894 /* N.B. Should not filter burst of dupacks. Two issues:
1895 * 1) dupacks open cwnd on remote peer when congested
1896 * 2) acks leaving should have the latest rcv_wnd since the
1897 * burst may have eaten up all of it, so only the old ones
1898 * could be filtered.
1900 if (!tcp_session_has_ooo_data (tc0))
1902 *error0 = TCP_ERROR_FILTERED_DUPACKS;
1903 *next0 = TCP_OUTPUT_NEXT_DROP;
1908 /* Stop DELACK timer and fix flags */
1909 tc0->flags &= ~(TCP_CONN_SNDACK);
1910 if (!TCP_ALWAYS_ACK)
1911 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1915 tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1916 vlib_frame_t * frame, int is_ip4)
1918 u32 n_left_from, *from, thread_index = vm->thread_index;
1919 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
1920 u16 nexts[VLIB_FRAME_SIZE], *next;
1922 from = vlib_frame_vector_args (frame);
1923 n_left_from = frame->n_vectors;
1924 tcp_set_time_now (thread_index);
1926 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
1927 tcp46_output_trace_frame (vm, node, from, n_left_from);
1929 vlib_get_buffers (vm, from, bufs, n_left_from);
1933 while (n_left_from >= 4)
1935 u32 error0 = TCP_ERROR_PKTS_SENT, error1 = TCP_ERROR_PKTS_SENT;
1936 tcp_connection_t *tc0, *tc1;
1939 vlib_prefetch_buffer_header (b[2], STORE);
1940 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
1942 vlib_prefetch_buffer_header (b[3], STORE);
1943 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
1946 next[0] = next[1] = TCP_OUTPUT_NEXT_IP_LOOKUP;
1948 tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index,
1950 tc1 = tcp_connection_get (vnet_buffer (b[1])->tcp.connection_index,
1953 tcp_output_push_ip (vm, b[0], tc0, is_ip4);
1954 tcp_output_push_ip (vm, b[1], tc1, is_ip4);
1956 tcp_output_handle_packet (tc0, b[0], &error0, &next[0], is_ip4);
1957 tcp_output_handle_packet (tc1, b[1], &error1, &next[1], is_ip4);
1963 while (n_left_from > 0)
1965 u32 error0 = TCP_ERROR_PKTS_SENT;
1966 tcp_connection_t *tc0;
1968 if (n_left_from > 1)
1970 vlib_prefetch_buffer_header (b[0], STORE);
1971 CLIB_PREFETCH (b[0]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
1974 next[0] = TCP_OUTPUT_NEXT_IP_LOOKUP;
1975 tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index,
1978 tcp_output_push_ip (vm, b[0], tc0, is_ip4);
1979 tcp_output_handle_packet (tc0, b[0], &error0, &next[0], is_ip4);
1986 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
1987 return frame->n_vectors;
1991 tcp4_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1992 vlib_frame_t * from_frame)
1994 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1998 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1999 vlib_frame_t * from_frame)
2001 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2005 VLIB_REGISTER_NODE (tcp4_output_node) =
2007 .function = tcp4_output,.name = "tcp4-output",
2008 /* Takes a vector of packets. */
2009 .vector_size = sizeof (u32),
2010 .n_errors = TCP_N_ERROR,
2011 .error_strings = tcp_error_strings,
2012 .n_next_nodes = TCP_OUTPUT_N_NEXT,
2014 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
2015 foreach_tcp4_output_next
2018 .format_buffer = format_tcp_header,
2019 .format_trace = format_tcp_tx_trace,
2023 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output);
2026 VLIB_REGISTER_NODE (tcp6_output_node) =
2028 .function = tcp6_output,
2029 .name = "tcp6-output",
2030 /* Takes a vector of packets. */
2031 .vector_size = sizeof (u32),
2032 .n_errors = TCP_N_ERROR,
2033 .error_strings = tcp_error_strings,
2034 .n_next_nodes = TCP_OUTPUT_N_NEXT,
2036 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
2037 foreach_tcp6_output_next
2040 .format_buffer = format_tcp_header,
2041 .format_trace = format_tcp_tx_trace,
2045 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output);
2047 typedef enum _tcp_reset_next
2049 TCP_RESET_NEXT_DROP,
2050 TCP_RESET_NEXT_IP_LOOKUP,
2054 #define foreach_tcp4_reset_next \
2055 _(DROP, "error-drop") \
2056 _(IP_LOOKUP, "ip4-lookup")
2058 #define foreach_tcp6_reset_next \
2059 _(DROP, "error-drop") \
2060 _(IP_LOOKUP, "ip6-lookup")
2063 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2064 vlib_frame_t * from_frame, u8 is_ip4)
2066 u32 n_left_from, next_index, *from, *to_next;
2067 u32 my_thread_index = vm->thread_index;
2069 from = vlib_frame_vector_args (from_frame);
2070 n_left_from = from_frame->n_vectors;
2072 next_index = node->cached_next_index;
2074 while (n_left_from > 0)
2078 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2080 while (n_left_from > 0 && n_left_to_next > 0)
2086 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
2093 n_left_to_next -= 1;
2095 b0 = vlib_get_buffer (vm, bi0);
2097 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
2098 my_thread_index, is_ip4))
2100 error0 = TCP_ERROR_LOOKUP_DROPS;
2101 next0 = TCP_RESET_NEXT_DROP;
2105 /* Prepare to send to IP lookup */
2106 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
2107 next0 = TCP_RESET_NEXT_IP_LOOKUP;
2110 b0->error = node->errors[error0];
2111 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
2112 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2114 th0 = vlib_buffer_get_current (b0);
2116 th0 = ip4_next_header ((ip4_header_t *) th0);
2118 th0 = ip6_next_header ((ip6_header_t *) th0);
2119 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2120 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2123 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2124 n_left_to_next, bi0, next0);
2126 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2128 return from_frame->n_vectors;
2132 tcp4_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
2133 vlib_frame_t * from_frame)
2135 return tcp46_send_reset_inline (vm, node, from_frame, 1);
2139 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
2140 vlib_frame_t * from_frame)
2142 return tcp46_send_reset_inline (vm, node, from_frame, 0);
2146 VLIB_REGISTER_NODE (tcp4_reset_node) = {
2147 .function = tcp4_send_reset,
2148 .name = "tcp4-reset",
2149 .vector_size = sizeof (u32),
2150 .n_errors = TCP_N_ERROR,
2151 .error_strings = tcp_error_strings,
2152 .n_next_nodes = TCP_RESET_N_NEXT,
2154 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2155 foreach_tcp4_reset_next
2158 .format_trace = format_tcp_tx_trace,
2162 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset);
2165 VLIB_REGISTER_NODE (tcp6_reset_node) = {
2166 .function = tcp6_send_reset,
2167 .name = "tcp6-reset",
2168 .vector_size = sizeof (u32),
2169 .n_errors = TCP_N_ERROR,
2170 .error_strings = tcp_error_strings,
2171 .n_next_nodes = TCP_RESET_N_NEXT,
2173 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2174 foreach_tcp6_reset_next
2177 .format_trace = format_tcp_tx_trace,
2181 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset);
2184 * fd.io coding-style-patch-verification: ON
2187 * eval: (c-set-style "gnu")