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,
30 #define foreach_tcp4_output_next \
31 _ (DROP, "error-drop") \
32 _ (IP_LOOKUP, "ip4-lookup")
34 #define foreach_tcp6_output_next \
35 _ (DROP, "error-drop") \
36 _ (IP_LOOKUP, "ip6-lookup")
38 static char *tcp_error_strings[] = {
39 #define tcp_error(n,s) s,
40 #include <vnet/tcp/tcp_error.def>
46 tcp_header_t tcp_header;
47 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);
69 tcp_window_compute_scale (u32 window)
72 while (wnd_scale < TCP_MAX_WND_SCALE && (window >> wnd_scale) > TCP_WND_MAX)
78 * Update max segment size we're able to process.
80 * The value is constrained by our interface's MTU and IP options. It is
81 * also what we advertise to our peer.
84 tcp_update_rcv_mss (tcp_connection_t * tc)
86 /* TODO find our iface MTU */
87 tc->mss = dummy_mtu - sizeof (tcp_header_t);
91 * TCP's initial window
94 tcp_initial_wnd_unscaled (tcp_connection_t * tc)
96 /* RFC 6928 recommends the value lower. However at the time our connections
97 * are initialized, fifos may not be allocated. Therefore, advertise the
98 * smallest possible unscaled window size and update once fifos are
99 * assigned to the session.
102 tcp_update_rcv_mss (tc);
103 TCP_IW_N_SEGMENTS * tc->mss;
105 return TCP_MIN_RX_FIFO_SIZE;
109 * Compute initial window and scale factor. As per RFC1323, window field in
110 * SYN and SYN-ACK segments is never scaled.
113 tcp_initial_window_to_advertise (tcp_connection_t * tc)
117 /* Initial wnd for SYN. Fifos are not allocated yet.
118 * Use some predefined value. For SYN-ACK we still want the
119 * scale to be computed in the same way */
120 max_fifo = TCP_MAX_RX_FIFO_SIZE;
122 tc->rcv_wscale = tcp_window_compute_scale (max_fifo);
123 tc->rcv_wnd = tcp_initial_wnd_unscaled (tc);
125 return clib_min (tc->rcv_wnd, TCP_WND_MAX);
129 * Compute and return window to advertise, scaled as per RFC1323
132 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
134 if (state < TCP_STATE_ESTABLISHED)
135 return tcp_initial_window_to_advertise (tc);
137 tcp_update_rcv_wnd (tc);
139 if (tc->rcv_wnd == 0)
141 tc->flags |= TCP_CONN_SENT_RCV_WND0;
145 tc->flags &= ~TCP_CONN_SENT_RCV_WND0;
148 return tc->rcv_wnd >> tc->rcv_wscale;
152 tcp_update_rcv_wnd (tcp_connection_t * tc)
155 u32 available_space, max_fifo, wnd;
158 * Figure out how much space we have available
160 available_space = stream_session_max_rx_enqueue (&tc->connection);
161 max_fifo = stream_session_rx_fifo_size (&tc->connection);
163 ASSERT (tc->rcv_opts.mss < max_fifo);
164 if (available_space < tc->rcv_opts.mss && available_space < max_fifo >> 3)
168 * Use the above and what we know about what we've previously advertised
169 * to compute the new window
171 observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
172 if (observed_wnd < 0)
175 /* Bad. Thou shalt not shrink */
176 if (available_space < observed_wnd)
179 TCP_EVT_DBG (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space);
183 wnd = available_space;
186 /* Make sure we have a multiple of rcv_wscale */
187 if (wnd && tc->rcv_wscale)
189 wnd &= ~(1 << tc->rcv_wscale);
191 wnd = 1 << tc->rcv_wscale;
194 tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale);
198 * Write TCP options to segment.
201 tcp_options_write (u8 * data, tcp_options_t * opts)
204 u32 buf, seq_len = 4;
206 if (tcp_opts_mss (opts))
208 *data++ = TCP_OPTION_MSS;
209 *data++ = TCP_OPTION_LEN_MSS;
210 buf = clib_host_to_net_u16 (opts->mss);
211 clib_memcpy (data, &buf, sizeof (opts->mss));
212 data += sizeof (opts->mss);
213 opts_len += TCP_OPTION_LEN_MSS;
216 if (tcp_opts_wscale (opts))
218 *data++ = TCP_OPTION_WINDOW_SCALE;
219 *data++ = TCP_OPTION_LEN_WINDOW_SCALE;
220 *data++ = opts->wscale;
221 opts_len += TCP_OPTION_LEN_WINDOW_SCALE;
224 if (tcp_opts_sack_permitted (opts))
226 *data++ = TCP_OPTION_SACK_PERMITTED;
227 *data++ = TCP_OPTION_LEN_SACK_PERMITTED;
228 opts_len += TCP_OPTION_LEN_SACK_PERMITTED;
231 if (tcp_opts_tstamp (opts))
233 *data++ = TCP_OPTION_TIMESTAMP;
234 *data++ = TCP_OPTION_LEN_TIMESTAMP;
235 buf = clib_host_to_net_u32 (opts->tsval);
236 clib_memcpy (data, &buf, sizeof (opts->tsval));
237 data += sizeof (opts->tsval);
238 buf = clib_host_to_net_u32 (opts->tsecr);
239 clib_memcpy (data, &buf, sizeof (opts->tsecr));
240 data += sizeof (opts->tsecr);
241 opts_len += TCP_OPTION_LEN_TIMESTAMP;
244 if (tcp_opts_sack (opts))
247 u32 n_sack_blocks = clib_min (vec_len (opts->sacks),
248 TCP_OPTS_MAX_SACK_BLOCKS);
250 if (n_sack_blocks != 0)
252 *data++ = TCP_OPTION_SACK_BLOCK;
253 *data++ = 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
254 for (i = 0; i < n_sack_blocks; i++)
256 buf = clib_host_to_net_u32 (opts->sacks[i].start);
257 clib_memcpy (data, &buf, seq_len);
259 buf = clib_host_to_net_u32 (opts->sacks[i].end);
260 clib_memcpy (data, &buf, seq_len);
263 opts_len += 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
267 /* Terminate TCP options */
270 *data++ = TCP_OPTION_EOL;
271 opts_len += TCP_OPTION_LEN_EOL;
274 /* Pad with zeroes to a u32 boundary */
277 *data++ = TCP_OPTION_NOOP;
278 opts_len += TCP_OPTION_LEN_NOOP;
284 tcp_make_syn_options (tcp_options_t * opts, u8 wnd_scale)
288 opts->flags |= TCP_OPTS_FLAG_MSS;
289 opts->mss = dummy_mtu; /*XXX discover that */
290 len += TCP_OPTION_LEN_MSS;
292 opts->flags |= TCP_OPTS_FLAG_WSCALE;
293 opts->wscale = wnd_scale;
294 len += TCP_OPTION_LEN_WINDOW_SCALE;
296 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
297 opts->tsval = tcp_time_now ();
299 len += TCP_OPTION_LEN_TIMESTAMP;
303 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
304 len += TCP_OPTION_LEN_SACK_PERMITTED;
307 /* Align to needed boundary */
308 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
313 tcp_make_synack_options (tcp_connection_t * tc, tcp_options_t * opts)
317 opts->flags |= TCP_OPTS_FLAG_MSS;
319 len += TCP_OPTION_LEN_MSS;
321 if (tcp_opts_wscale (&tc->rcv_opts))
323 opts->flags |= TCP_OPTS_FLAG_WSCALE;
324 opts->wscale = tc->rcv_wscale;
325 len += TCP_OPTION_LEN_WINDOW_SCALE;
328 if (tcp_opts_tstamp (&tc->rcv_opts))
330 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
331 opts->tsval = tcp_time_now ();
332 opts->tsecr = tc->tsval_recent;
333 len += TCP_OPTION_LEN_TIMESTAMP;
336 if (tcp_opts_sack_permitted (&tc->rcv_opts))
338 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
339 len += TCP_OPTION_LEN_SACK_PERMITTED;
342 /* Align to needed boundary */
343 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
348 tcp_make_established_options (tcp_connection_t * tc, tcp_options_t * opts)
354 if (tcp_opts_tstamp (&tc->rcv_opts))
356 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
357 opts->tsval = tcp_time_now ();
358 opts->tsecr = tc->tsval_recent;
359 len += TCP_OPTION_LEN_TIMESTAMP;
361 if (tcp_opts_sack_permitted (&tc->rcv_opts))
363 if (vec_len (tc->snd_sacks))
365 opts->flags |= TCP_OPTS_FLAG_SACK;
366 opts->sacks = tc->snd_sacks;
367 opts->n_sack_blocks = clib_min (vec_len (tc->snd_sacks),
368 TCP_OPTS_MAX_SACK_BLOCKS);
369 len += 2 + TCP_OPTION_LEN_SACK_BLOCK * opts->n_sack_blocks;
373 /* Align to needed boundary */
374 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
379 tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts,
384 case TCP_STATE_ESTABLISHED:
385 case TCP_STATE_FIN_WAIT_1:
386 return tcp_make_established_options (tc, opts);
387 case TCP_STATE_SYN_RCVD:
388 return tcp_make_synack_options (tc, opts);
389 case TCP_STATE_SYN_SENT:
390 return tcp_make_syn_options (opts, tc->rcv_wscale);
392 clib_warning ("State not handled! %d", state);
398 * Update snd_mss to reflect the effective segment size that we can send
399 * by taking into account all TCP options, including SACKs
402 tcp_update_snd_mss (tcp_connection_t * tc)
404 /* Compute options to be used for connection. These may be reused when
405 * sending data or to compute the effective mss (snd_mss) */
407 tcp_make_options (tc, &tc->snd_opts, TCP_STATE_ESTABLISHED);
409 /* XXX check if MTU has been updated */
410 tc->snd_mss = clib_min (tc->mss, tc->rcv_opts.mss) - tc->snd_opts_len;
411 ASSERT (tc->snd_mss > 0);
415 tcp_init_mss (tcp_connection_t * tc)
417 u16 default_min_mss = 536;
418 tcp_update_rcv_mss (tc);
420 /* TODO cache mss and consider PMTU discovery */
421 tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss);
423 if (tc->snd_mss < 45)
425 clib_warning ("snd mss is 0");
426 /* Assume that at least the min default mss works */
427 tc->snd_mss = default_min_mss;
428 tc->rcv_opts.mss = default_min_mss;
431 /* We should have enough space for 40 bytes of options */
432 ASSERT (tc->snd_mss > 45);
434 /* If we use timestamp option, account for it */
435 if (tcp_opts_tstamp (&tc->rcv_opts))
436 tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP;
440 tcp_alloc_tx_buffers (tcp_main_t * tm, u8 thread_index, u32 n_free_buffers)
442 vlib_main_t *vm = vlib_get_main ();
443 u32 current_length = vec_len (tm->tx_buffers[thread_index]);
446 vec_validate (tm->tx_buffers[thread_index],
447 current_length + n_free_buffers - 1);
449 vlib_buffer_alloc (vm, &tm->tx_buffers[thread_index][current_length],
451 _vec_len (tm->tx_buffers[thread_index]) = current_length + n_allocated;
452 /* buffer shortage, report failure */
453 if (vec_len (tm->tx_buffers[thread_index]) == 0)
455 clib_warning ("out of buffers");
462 tcp_get_free_buffer_index (tcp_main_t * tm, u32 * bidx)
465 u32 thread_index = vlib_get_thread_index ();
467 TCP_DBG_BUFFER_ALLOC_MAYBE_FAIL (thread_index);
469 if (PREDICT_FALSE (vec_len (tm->tx_buffers[thread_index]) == 0))
471 if (tcp_alloc_tx_buffers (tm, thread_index, VLIB_FRAME_SIZE))
474 my_tx_buffers = tm->tx_buffers[thread_index];
475 *bidx = my_tx_buffers[vec_len (my_tx_buffers) - 1];
476 _vec_len (my_tx_buffers) -= 1;
481 tcp_return_buffer (tcp_main_t * tm)
483 _vec_len (tm->tx_buffers[vlib_get_thread_index ()]) += 1;
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;
509 vnet_buffer (b)->tcp.flags = 0;
510 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
511 /* Leave enough space for headers */
512 return vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
519 tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
522 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
523 u8 tcp_opts_len, tcp_hdr_opts_len;
527 wnd = tcp_window_to_advertise (tc, state);
529 /* Make and write options */
530 tcp_opts_len = tcp_make_established_options (tc, snd_opts);
531 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
533 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
534 tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd);
536 tcp_options_write ((u8 *) (th + 1), snd_opts);
537 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
541 * Convert buffer to ACK
544 tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
546 vlib_main_t *vm = vlib_get_main ();
548 tcp_reuse_buffer (vm, b);
549 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
550 TCP_EVT_DBG (TCP_EVT_ACK_SENT, tc);
551 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
552 tc->rcv_las = tc->rcv_nxt;
556 * Convert buffer to FIN-ACK
559 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
561 vlib_main_t *vm = vlib_get_main ();
564 tcp_reuse_buffer (vm, b);
566 flags = TCP_FLAG_FIN | TCP_FLAG_ACK;
567 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, flags);
569 /* Reset flags, make sure ack is sent */
570 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
574 * Convert buffer to SYN
577 tcp_make_syn (tcp_connection_t * tc, vlib_buffer_t * b)
579 u8 tcp_hdr_opts_len, tcp_opts_len;
582 tcp_options_t snd_opts;
584 initial_wnd = tcp_initial_window_to_advertise (tc);
586 /* Make and write options */
587 memset (&snd_opts, 0, sizeof (snd_opts));
588 tcp_opts_len = tcp_make_syn_options (&snd_opts, tc->rcv_wscale);
589 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
591 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
592 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
594 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
595 tcp_options_write ((u8 *) (th + 1), &snd_opts);
599 * Convert buffer to SYN-ACK
602 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
604 vlib_main_t *vm = vlib_get_main ();
605 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
606 u8 tcp_opts_len, tcp_hdr_opts_len;
610 memset (snd_opts, 0, sizeof (*snd_opts));
611 tcp_reuse_buffer (vm, b);
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 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
625 /* Init retransmit timer. Use update instead of set because of
627 tcp_retransmit_timer_force_update (tc);
628 TCP_EVT_DBG (TCP_EVT_SYNACK_SENT, tc);
632 tcp_enqueue_to_ip_lookup_i (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
633 u8 is_ip4, u32 fib_index, u8 flush)
635 tcp_main_t *tm = vnet_get_tcp_main ();
636 u32 thread_index = vlib_get_thread_index ();
637 u32 *to_next, next_index;
640 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
643 vnet_buffer (b)->sw_if_index[VLIB_TX] = fib_index;
644 vnet_buffer (b)->sw_if_index[VLIB_RX] = 0;
646 /* Send to IP lookup */
647 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
648 tcp_trajectory_add_start (b, 1);
650 f = tm->ip_lookup_tx_frames[!is_ip4][thread_index];
653 f = vlib_get_frame_to_node (vm, next_index);
655 tm->ip_lookup_tx_frames[!is_ip4][thread_index] = f;
658 to_next = vlib_frame_vector_args (f);
659 to_next[f->n_vectors] = bi;
661 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
663 vlib_put_frame_to_node (vm, next_index, f);
664 tm->ip_lookup_tx_frames[!is_ip4][thread_index] = 0;
669 tcp_enqueue_to_ip_lookup_now (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
670 u8 is_ip4, u32 fib_index)
672 tcp_enqueue_to_ip_lookup_i (vm, b, bi, is_ip4, fib_index, 1);
676 tcp_enqueue_to_ip_lookup (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
677 u8 is_ip4, u32 fib_index)
679 tcp_enqueue_to_ip_lookup_i (vm, b, bi, is_ip4, fib_index, 0);
683 tcp_enqueue_to_output_i (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
686 tcp_main_t *tm = vnet_get_tcp_main ();
687 u32 thread_index = vlib_get_thread_index ();
688 u32 *to_next, next_index;
691 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
694 /* Decide where to send the packet */
695 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
696 tcp_trajectory_add_start (b, 2);
698 /* Get frame to v4/6 output node */
699 f = tm->tx_frames[!is_ip4][thread_index];
702 f = vlib_get_frame_to_node (vm, next_index);
704 tm->tx_frames[!is_ip4][thread_index] = f;
706 to_next = vlib_frame_vector_args (f);
707 to_next[f->n_vectors] = bi;
709 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
711 vlib_put_frame_to_node (vm, next_index, f);
712 tm->tx_frames[!is_ip4][thread_index] = 0;
717 tcp_enqueue_to_output (vlib_main_t * vm, vlib_buffer_t * b, u32 bi, u8 is_ip4)
719 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 0);
723 tcp_enqueue_to_output_now (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
726 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 1);
730 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
731 tcp_state_t state, u8 thread_index, u8 is_ip4)
736 ip4_address_t src_ip40, dst_ip40;
737 ip6_address_t src_ip60, dst_ip60;
738 u16 src_port, dst_port;
743 /* Find IP and TCP headers */
744 th0 = tcp_buffer_hdr (b0);
746 /* Save src and dst ip */
749 ih4 = vlib_buffer_get_current (b0);
750 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
751 src_ip40.as_u32 = ih4->src_address.as_u32;
752 dst_ip40.as_u32 = ih4->dst_address.as_u32;
756 ih6 = vlib_buffer_get_current (b0);
757 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
758 clib_memcpy (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
759 clib_memcpy (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t));
762 src_port = th0->src_port;
763 dst_port = th0->dst_port;
765 /* Try to determine what/why we're actually resetting */
766 if (state == TCP_STATE_CLOSED)
771 tmp = clib_net_to_host_u32 (th0->seq_number);
773 /* Got a SYN for no listener. */
774 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
775 ack = clib_host_to_net_u32 (tmp + 1);
780 flags = TCP_FLAG_RST;
781 seq = th0->ack_number;
785 tcp_reuse_buffer (vm, b0);
786 tcp_trajectory_add_start (b0, 4);
787 th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack,
788 sizeof (tcp_header_t), flags, 0);
792 ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40,
794 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
799 ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60,
801 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
809 * Send reset without reusing existing buffer
811 * It extracts connection info out of original packet
814 tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt, u8 is_ip4)
817 u32 bi, sw_if_index, fib_index;
818 tcp_main_t *tm = vnet_get_tcp_main ();
819 vlib_main_t *vm = vlib_get_main ();
820 u8 tcp_hdr_len, flags = 0;
821 tcp_header_t *th, *pkt_th;
823 ip4_header_t *ih4, *pkt_ih4;
824 ip6_header_t *ih6, *pkt_ih6;
825 fib_protocol_t fib_proto;
827 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
830 b = vlib_get_buffer (vm, bi);
831 sw_if_index = vnet_buffer (pkt)->sw_if_index[VLIB_RX];
832 fib_proto = is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
833 fib_index = fib_table_get_index_for_sw_if_index (fib_proto, sw_if_index);
834 tcp_init_buffer (vm, b);
836 /* Make and write options */
837 tcp_hdr_len = sizeof (tcp_header_t);
841 pkt_ih4 = vlib_buffer_get_current (pkt);
842 pkt_th = ip4_next_header (pkt_ih4);
846 pkt_ih6 = vlib_buffer_get_current (pkt);
847 pkt_th = ip6_next_header (pkt_ih6);
850 if (tcp_ack (pkt_th))
852 flags = TCP_FLAG_RST;
853 seq = pkt_th->ack_number;
854 ack = (tc && tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
858 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
860 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
863 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
864 seq, ack, tcp_hdr_len, flags, 0);
866 /* Swap src and dst ip */
869 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
870 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
871 &pkt_ih4->src_address, IP_PROTOCOL_TCP, 1);
872 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
877 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
879 ih6 = vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address,
880 &pkt_ih6->src_address, IP_PROTOCOL_TCP);
881 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
885 tcp_enqueue_to_ip_lookup_now (vm, b, bi, is_ip4, fib_index);
886 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc);
890 * Build and set reset packet for connection
893 tcp_send_reset (tcp_connection_t * tc)
895 vlib_main_t *vm = vlib_get_main ();
896 tcp_main_t *tm = vnet_get_tcp_main ();
900 u16 tcp_hdr_opts_len, advertise_wnd, opts_write_len;
903 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
905 b = vlib_get_buffer (vm, bi);
906 tcp_init_buffer (vm, b);
908 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
909 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
910 advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED);
911 flags = TCP_FLAG_RST;
912 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
913 tc->rcv_nxt, tcp_hdr_opts_len, flags,
915 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
916 ASSERT (opts_write_len == tc->snd_opts_len);
917 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
921 ih4 = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip.ip4,
922 &tc->c_rmt_ip.ip4, IP_PROTOCOL_TCP, 0);
923 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
929 ih6 = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip.ip6,
930 &tc->c_rmt_ip.ip6, IP_PROTOCOL_TCP);
931 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
934 tcp_enqueue_to_ip_lookup_now (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
935 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc);
939 tcp_push_ip_hdr (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b)
941 tcp_header_t *th = vlib_buffer_get_current (b);
942 vlib_main_t *vm = vlib_get_main ();
946 ih = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip4,
947 &tc->c_rmt_ip4, IP_PROTOCOL_TCP, 1);
948 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih);
955 ih = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip6,
956 &tc->c_rmt_ip6, IP_PROTOCOL_TCP);
957 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih, &bogus);
965 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
966 * The packet is not forwarded through tcpx_output to avoid doing lookups
967 * in the half_open pool.
970 tcp_send_syn (tcp_connection_t * tc)
974 tcp_main_t *tm = vnet_get_tcp_main ();
975 vlib_main_t *vm = vlib_get_main ();
978 * Setup retransmit and establish timers before requesting buffer
979 * such that we can return if we've ran out.
981 tcp_timer_set (tc, TCP_TIMER_ESTABLISH, TCP_ESTABLISH_TIME);
982 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
983 tc->rto * TCP_TO_TIMER_TICK);
985 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
988 b = vlib_get_buffer (vm, bi);
989 tcp_init_buffer (vm, b);
990 tcp_make_syn (tc, b);
992 /* Measure RTT with this */
993 tc->rtt_ts = tcp_time_now ();
994 tc->rtt_seq = tc->snd_nxt;
997 tcp_push_ip_hdr (tm, tc, b);
998 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
999 TCP_EVT_DBG (TCP_EVT_SYN_SENT, tc);
1003 * Flush tx frame populated by retransmits and timer pops
1006 tcp_flush_frame_to_output (vlib_main_t * vm, u8 thread_index, u8 is_ip4)
1008 if (tcp_main.tx_frames[!is_ip4][thread_index])
1011 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
1012 vlib_put_frame_to_node (vm, next_index,
1013 tcp_main.tx_frames[!is_ip4][thread_index]);
1014 tcp_main.tx_frames[!is_ip4][thread_index] = 0;
1019 * Flush ip lookup tx frames populated by timer pops
1022 tcp_flush_frame_to_ip_lookup (vlib_main_t * vm, u8 thread_index, u8 is_ip4)
1024 if (tcp_main.ip_lookup_tx_frames[!is_ip4][thread_index])
1027 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
1028 vlib_put_frame_to_node (vm, next_index,
1029 tcp_main.ip_lookup_tx_frames[!is_ip4]
1031 tcp_main.ip_lookup_tx_frames[!is_ip4][thread_index] = 0;
1036 * Flush v4 and v6 tcp and ip-lookup tx frames for thread index
1039 tcp_flush_frames_to_output (u8 thread_index)
1041 vlib_main_t *vm = vlib_get_main ();
1042 tcp_flush_frame_to_output (vm, thread_index, 1);
1043 tcp_flush_frame_to_output (vm, thread_index, 0);
1044 tcp_flush_frame_to_ip_lookup (vm, thread_index, 1);
1045 tcp_flush_frame_to_ip_lookup (vm, thread_index, 0);
1052 tcp_send_fin (tcp_connection_t * tc)
1054 tcp_main_t *tm = vnet_get_tcp_main ();
1055 vlib_main_t *vm = vlib_get_main ();
1060 tcp_retransmit_timer_force_update (tc);
1061 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1063 b = vlib_get_buffer (vm, bi);
1064 fin_snt = tc->flags & TCP_CONN_FINSNT;
1066 tc->snd_nxt = tc->snd_una;
1067 tcp_make_fin (tc, b);
1068 tcp_enqueue_to_output_now (vm, b, bi, tc->c_is_ip4);
1071 tc->flags |= TCP_CONN_FINSNT;
1072 tc->flags &= ~TCP_CONN_FINPNDG;
1073 /* Account for the FIN */
1074 tc->snd_una_max += 1;
1075 tc->snd_nxt = tc->snd_una_max;
1079 tc->snd_nxt = tc->snd_una_max;
1081 TCP_EVT_DBG (TCP_EVT_FIN_SENT, tc);
1085 tcp_make_state_flags (tcp_connection_t * tc, tcp_state_t next_state)
1089 case TCP_STATE_ESTABLISHED:
1090 return TCP_FLAG_ACK;
1091 case TCP_STATE_SYN_RCVD:
1092 return TCP_FLAG_SYN | TCP_FLAG_ACK;
1093 case TCP_STATE_SYN_SENT:
1094 return TCP_FLAG_SYN;
1095 case TCP_STATE_LAST_ACK:
1096 case TCP_STATE_FIN_WAIT_1:
1097 if (tc->snd_nxt + 1 < tc->snd_una_max)
1098 return TCP_FLAG_ACK;
1100 return TCP_FLAG_FIN;
1102 clib_warning ("Shouldn't be here!");
1108 * Push TCP header and update connection variables
1111 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
1112 tcp_state_t next_state, u8 compute_opts)
1114 u32 advertise_wnd, data_len;
1115 u8 tcp_hdr_opts_len, opts_write_len, flags;
1118 data_len = b->current_length + b->total_length_not_including_first_buffer;
1119 ASSERT (!b->total_length_not_including_first_buffer
1120 || (b->flags & VLIB_BUFFER_NEXT_PRESENT));
1121 vnet_buffer (b)->tcp.flags = 0;
1124 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1126 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
1127 advertise_wnd = tcp_window_to_advertise (tc, next_state);
1128 flags = tcp_make_state_flags (tc, next_state);
1130 /* Push header and options */
1131 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
1132 tc->rcv_nxt, tcp_hdr_opts_len, flags,
1134 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
1136 ASSERT (opts_write_len == tc->snd_opts_len);
1137 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
1140 * Update connection variables
1143 tc->snd_nxt += data_len;
1144 tc->rcv_las = tc->rcv_nxt;
1146 /* TODO this is updated in output as well ... */
1147 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1149 tc->snd_una_max = tc->snd_nxt;
1150 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1153 TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
1157 tcp_send_ack (tcp_connection_t * tc)
1159 tcp_main_t *tm = vnet_get_tcp_main ();
1160 vlib_main_t *vm = vlib_get_main ();
1166 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1168 b = vlib_get_buffer (vm, bi);
1170 /* Fill in the ACK */
1171 tcp_make_ack (tc, b);
1172 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1176 * Delayed ack timer handler
1178 * Sends delayed ACK when timer expires
1181 tcp_timer_delack_handler (u32 index)
1183 u32 thread_index = vlib_get_thread_index ();
1184 tcp_connection_t *tc;
1186 tc = tcp_connection_get (index, thread_index);
1187 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
1192 * Build a retransmit segment
1194 * @return the number of bytes in the segment or 0 if there's nothing to
1198 tcp_prepare_retransmit_segment (tcp_connection_t * tc, u32 offset,
1199 u32 max_deq_bytes, vlib_buffer_t ** b)
1201 tcp_main_t *tm = vnet_get_tcp_main ();
1202 vlib_main_t *vm = vlib_get_main ();
1204 u32 start, bi, available_bytes, seg_size;
1207 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1208 ASSERT (max_deq_bytes != 0);
1211 * Make sure we can retransmit something
1213 available_bytes = stream_session_tx_fifo_max_dequeue (&tc->connection);
1214 ASSERT (available_bytes >= offset);
1215 available_bytes -= offset;
1216 if (!available_bytes)
1218 max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
1219 max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
1221 /* Start is beyond snd_congestion */
1222 start = tc->snd_una + offset;
1223 if (seq_geq (start, tc->snd_congestion))
1226 /* Don't overshoot snd_congestion */
1227 if (seq_gt (start + max_deq_bytes, tc->snd_congestion))
1229 max_deq_bytes = tc->snd_congestion - start;
1230 if (max_deq_bytes == 0)
1234 seg_size = max_deq_bytes + MAX_HDRS_LEN;
1239 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1242 * Allocate and fill in buffer(s)
1245 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1247 *b = vlib_get_buffer (vm, bi);
1248 data = tcp_init_buffer (vm, *b);
1250 /* Easy case, buffer size greater than mss */
1251 if (PREDICT_TRUE (seg_size <= tm->bytes_per_buffer))
1253 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1255 ASSERT (n_bytes == max_deq_bytes);
1256 b[0]->current_length = n_bytes;
1257 tcp_push_hdr_i (tc, *b, tc->state, 0);
1259 /* Split mss into multiple buffers */
1262 u32 chain_bi = ~0, n_bufs_per_seg;
1263 u32 thread_index = vlib_get_thread_index ();
1264 u16 n_peeked, len_to_deq, available_bufs;
1265 vlib_buffer_t *chain_b, *prev_b;
1268 n_bufs_per_seg = ceil ((double) seg_size / tm->bytes_per_buffer);
1270 /* Make sure we have enough buffers */
1271 available_bufs = vec_len (tm->tx_buffers[thread_index]);
1272 if (n_bufs_per_seg > available_bufs)
1274 if (tcp_alloc_tx_buffers (tm, thread_index,
1275 VLIB_FRAME_SIZE - available_bufs))
1277 tcp_return_buffer (tm);
1283 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1284 tm->bytes_per_buffer -
1286 b[0]->current_length = n_bytes;
1287 b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
1288 b[0]->total_length_not_including_first_buffer = 0;
1289 max_deq_bytes -= n_bytes;
1292 for (i = 1; i < n_bufs_per_seg; i++)
1295 len_to_deq = clib_min (max_deq_bytes, tm->bytes_per_buffer);
1296 tcp_get_free_buffer_index (tm, &chain_bi);
1297 ASSERT (chain_bi != (u32) ~ 0);
1298 chain_b = vlib_get_buffer (vm, chain_bi);
1299 chain_b->current_data = 0;
1300 data = vlib_buffer_get_current (chain_b);
1301 n_peeked = stream_session_peek_bytes (&tc->connection, data,
1302 offset + n_bytes, len_to_deq);
1303 ASSERT (n_peeked == len_to_deq);
1304 n_bytes += n_peeked;
1305 chain_b->current_length = n_peeked;
1306 chain_b->flags &= VLIB_BUFFER_NON_DEFAULT_FREELIST;
1307 chain_b->next_buffer = 0;
1309 /* update previous buffer */
1310 prev_b->next_buffer = chain_bi;
1311 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
1313 max_deq_bytes -= n_peeked;
1314 b[0]->total_length_not_including_first_buffer += n_peeked;
1317 tcp_push_hdr_i (tc, *b, tc->state, 0);
1320 ASSERT (n_bytes > 0);
1321 ASSERT (((*b)->current_data + (*b)->current_length) <=
1322 tm->bytes_per_buffer);
1324 if (tcp_in_fastrecovery (tc))
1325 tc->snd_rxt_bytes += n_bytes;
1328 TCP_EVT_DBG (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1333 * Reset congestion control, switch cwnd to loss window and try again.
1336 tcp_rtx_timeout_cc (tcp_connection_t * tc)
1338 tc->prev_ssthresh = tc->ssthresh;
1339 tc->prev_cwnd = tc->cwnd;
1341 /* Cleanly recover cc (also clears up fast retransmit) */
1342 if (tcp_in_fastrecovery (tc))
1343 tcp_cc_fastrecovery_exit (tc);
1345 /* Start again from the beginning */
1346 tc->ssthresh = clib_max (tcp_flight_size (tc) / 2, 2 * tc->snd_mss);
1347 tc->cwnd = tcp_loss_wnd (tc);
1348 tc->snd_congestion = tc->snd_una_max;
1350 tcp_recovery_on (tc);
1354 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
1356 tcp_main_t *tm = vnet_get_tcp_main ();
1357 vlib_main_t *vm = vlib_get_main ();
1358 u32 thread_index = vlib_get_thread_index ();
1359 tcp_connection_t *tc;
1360 vlib_buffer_t *b = 0;
1365 tc = tcp_half_open_connection_get (index);
1366 /* Note: the connection may have transitioned to ESTABLISHED... */
1367 if (PREDICT_FALSE (tc == 0))
1369 tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
1373 tc = tcp_connection_get (index, thread_index);
1374 /* Note: the connection may have been closed and pool_put */
1375 if (PREDICT_FALSE (tc == 0))
1377 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
1380 if (tc->state >= TCP_STATE_ESTABLISHED)
1382 /* Lost FIN, retransmit and return */
1383 if (tcp_is_lost_fin (tc))
1387 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1391 /* Shouldn't be here */
1392 if (tc->snd_una == tc->snd_una_max)
1394 tcp_recovery_off (tc);
1398 /* We're not in recovery so make sure rto_boff is 0 */
1399 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1402 tcp_update_rto (tc);
1405 /* Increment RTO backoff (also equal to number of retries) and go back
1406 * to first un-acked byte */
1409 /* First retransmit timeout */
1410 if (tc->rto_boff == 1)
1411 tcp_rtx_timeout_cc (tc);
1413 tc->snd_nxt = tc->snd_una;
1414 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1416 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1);
1418 /* Send one segment. Note that n_bytes may be zero due to buffer shortfall */
1419 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1421 /* TODO be less aggressive about this */
1422 scoreboard_clear (&tc->sack_sb);
1426 tcp_retransmit_timer_set (tc);
1430 bi = vlib_get_buffer_index (vm, b);
1432 /* For first retransmit, record timestamp (Eifel detection RFC3522) */
1433 if (tc->rto_boff == 1)
1434 tc->snd_rxt_ts = tcp_time_now ();
1436 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1437 tcp_retransmit_timer_update (tc);
1439 /* Retransmit for SYN */
1440 else if (tc->state == TCP_STATE_SYN_SENT)
1442 /* Half-open connection actually moved to established but we were
1443 * waiting for syn retransmit to pop to call cleanup from the right
1445 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1447 if (tcp_half_open_connection_cleanup (tc))
1449 clib_warning ("could not remove half-open connection");
1455 /* Try without increasing RTO a number of times. If this fails,
1456 * start growing RTO exponentially */
1458 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1459 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1461 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
1462 tc->rto * TCP_TO_TIMER_TICK);
1464 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1467 b = vlib_get_buffer (vm, bi);
1468 tcp_init_buffer (vm, b);
1469 tcp_make_syn (tc, b);
1472 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 0);
1474 /* This goes straight to ipx_lookup. Retransmit timer set already */
1475 tcp_push_ip_hdr (tm, tc, b);
1476 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
1478 /* Retransmit SYN-ACK */
1479 else if (tc->state == TCP_STATE_SYN_RCVD)
1482 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1483 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1486 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1488 tcp_retransmit_timer_force_update (tc);
1492 b = vlib_get_buffer (vm, bi);
1493 tcp_make_synack (tc, b);
1494 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 1);
1496 /* Retransmit timer already updated, just enqueue to output */
1497 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1501 ASSERT (tc->state == TCP_STATE_CLOSED);
1507 tcp_timer_retransmit_handler (u32 index)
1509 tcp_timer_retransmit_handler_i (index, 0);
1513 tcp_timer_retransmit_syn_handler (u32 index)
1515 tcp_timer_retransmit_handler_i (index, 1);
1519 * Got 0 snd_wnd from peer, try to do something about it.
1523 tcp_timer_persist_handler (u32 index)
1525 tcp_main_t *tm = vnet_get_tcp_main ();
1526 vlib_main_t *vm = vlib_get_main ();
1527 u32 thread_index = vlib_get_thread_index ();
1528 tcp_connection_t *tc;
1530 u32 bi, max_snd_bytes, available_bytes, offset;
1534 tc = tcp_connection_get_if_valid (index, thread_index);
1539 /* Make sure timer handle is set to invalid */
1540 tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
1542 /* Problem already solved or worse */
1543 if (tc->state == TCP_STATE_CLOSED || tc->state > TCP_STATE_ESTABLISHED
1544 || tc->snd_wnd > tc->snd_mss || tcp_in_recovery (tc))
1547 available_bytes = stream_session_tx_fifo_max_dequeue (&tc->connection);
1548 offset = tc->snd_una_max - tc->snd_una;
1550 /* Reprogram persist if no new bytes available to send. We may have data
1552 if (!available_bytes)
1554 tcp_persist_timer_set (tc);
1558 if (available_bytes <= offset)
1560 ASSERT (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1564 /* Increment RTO backoff */
1566 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1569 * Try to force the first unsent segment (or buffer)
1571 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1573 b = vlib_get_buffer (vm, bi);
1574 data = tcp_init_buffer (vm, b);
1576 tcp_validate_txf_size (tc, offset);
1577 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1578 max_snd_bytes = clib_min (tc->snd_mss, tm->bytes_per_buffer - MAX_HDRS_LEN);
1579 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1581 b->current_length = n_bytes;
1582 ASSERT (n_bytes != 0 && (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)
1583 || tc->snd_nxt == tc->snd_una_max
1584 || tc->rto_boff > 1));
1586 tcp_push_hdr_i (tc, b, tc->state, 0);
1587 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1589 /* Just sent new data, enable retransmit */
1590 tcp_retransmit_timer_update (tc);
1594 * Retransmit first unacked segment
1597 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1599 vlib_main_t *vm = vlib_get_main ();
1601 u32 bi, old_snd_nxt, n_bytes;
1603 old_snd_nxt = tc->snd_nxt;
1604 tc->snd_nxt = tc->snd_una;
1606 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2);
1607 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1610 bi = vlib_get_buffer_index (vm, b);
1611 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1613 tc->snd_nxt = old_snd_nxt;
1617 * Do fast retransmit with SACKs
1620 tcp_fast_retransmit_sack (tcp_connection_t * tc)
1622 vlib_main_t *vm = vlib_get_main ();
1623 u32 n_written = 0, offset, max_bytes;
1624 vlib_buffer_t *b = 0;
1625 sack_scoreboard_hole_t *hole;
1626 sack_scoreboard_t *sb;
1627 u32 bi, old_snd_nxt;
1629 u8 snd_limited = 0, can_rescue = 0;
1631 ASSERT (tcp_in_fastrecovery (tc));
1632 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1634 old_snd_nxt = tc->snd_nxt;
1636 snd_space = tcp_available_snd_space (tc);
1638 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1639 while (hole && snd_space > 0)
1641 hole = scoreboard_next_rxt_hole (sb, hole,
1642 tcp_fastrecovery_sent_1_smss (tc),
1643 &can_rescue, &snd_limited);
1646 if (!can_rescue || !(seq_lt (sb->rescue_rxt, tc->snd_una)
1647 || seq_gt (sb->rescue_rxt,
1648 tc->snd_congestion)))
1651 /* If rescue rxt undefined or less than snd_una then one segment of
1652 * up to SMSS octets that MUST include the highest outstanding
1653 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1654 * RecoveryPoint. HighRxt MUST NOT be updated.
1656 max_bytes = clib_min (tc->snd_mss,
1657 tc->snd_congestion - tc->snd_una);
1658 max_bytes = clib_min (max_bytes, snd_space);
1659 offset = tc->snd_congestion - tc->snd_una - max_bytes;
1660 sb->rescue_rxt = tc->snd_congestion;
1661 tc->snd_nxt = tc->snd_una + offset;
1662 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes,
1665 bi = vlib_get_buffer_index (vm, b);
1666 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1670 max_bytes = clib_min (hole->end - sb->high_rxt, snd_space);
1671 max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes;
1674 offset = sb->high_rxt - tc->snd_una;
1675 tc->snd_nxt = sb->high_rxt;
1676 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes, &b);
1678 /* Nothing left to retransmit */
1682 bi = vlib_get_buffer_index (vm, b);
1683 sb->high_rxt += n_written;
1684 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1685 ASSERT (n_written <= snd_space);
1686 snd_space -= n_written;
1689 /* If window allows, send 1 SMSS of new data */
1690 tc->snd_nxt = old_snd_nxt;
1694 * Fast retransmit without SACK info
1697 tcp_fast_retransmit_no_sack (tcp_connection_t * tc)
1699 vlib_main_t *vm = vlib_get_main ();
1700 u32 n_written = 0, offset = 0, bi, old_snd_nxt;
1704 ASSERT (tcp_in_fastrecovery (tc));
1705 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1707 /* Start resending from first un-acked segment */
1708 old_snd_nxt = tc->snd_nxt;
1709 tc->snd_nxt = tc->snd_una;
1710 snd_space = tcp_available_snd_space (tc);
1712 while (snd_space > 0)
1714 offset += n_written;
1715 n_written = tcp_prepare_retransmit_segment (tc, offset, snd_space, &b);
1717 /* Nothing left to retransmit */
1721 bi = vlib_get_buffer_index (vm, b);
1722 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1723 snd_space -= n_written;
1726 /* Restore snd_nxt. If window allows, send 1 SMSS of new data */
1727 tc->snd_nxt = old_snd_nxt;
1731 * Do fast retransmit
1734 tcp_fast_retransmit (tcp_connection_t * tc)
1736 if (tcp_opts_sack_permitted (&tc->rcv_opts)
1737 && scoreboard_first_hole (&tc->sack_sb))
1738 tcp_fast_retransmit_sack (tc);
1740 tcp_fast_retransmit_no_sack (tc);
1744 tcp_session_has_ooo_data (tcp_connection_t * tc)
1746 stream_session_t *s = session_get (tc->c_s_index, tc->c_thread_index);
1747 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1751 tcp46_output_inline (vlib_main_t * vm,
1752 vlib_node_runtime_t * node,
1753 vlib_frame_t * from_frame, int is_ip4)
1755 u32 n_left_from, next_index, *from, *to_next;
1756 u32 my_thread_index = vm->thread_index;
1758 from = vlib_frame_vector_args (from_frame);
1759 n_left_from = from_frame->n_vectors;
1760 next_index = node->cached_next_index;
1761 tcp_set_time_now (my_thread_index);
1763 while (n_left_from > 0)
1767 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1769 while (n_left_from > 0 && n_left_to_next > 0)
1773 tcp_connection_t *tc0;
1775 tcp_header_t *th0 = 0;
1776 u32 error0 = TCP_ERROR_PKTS_SENT, next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
1778 if (n_left_from > 1)
1781 pb = vlib_get_buffer (vm, from[1]);
1782 vlib_prefetch_buffer_header (pb, STORE);
1783 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
1791 n_left_to_next -= 1;
1793 b0 = vlib_get_buffer (vm, bi0);
1794 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1796 if (PREDICT_FALSE (tc0 == 0 || tc0->state == TCP_STATE_CLOSED))
1798 error0 = TCP_ERROR_INVALID_CONNECTION;
1799 next0 = TCP_OUTPUT_NEXT_DROP;
1803 th0 = vlib_buffer_get_current (b0);
1804 TCP_EVT_DBG (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
1808 vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
1809 IP_PROTOCOL_TCP, 1);
1810 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1811 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1817 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6,
1818 &tc0->c_rmt_ip6, IP_PROTOCOL_TCP);
1819 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1820 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ih0 - b0->data;
1821 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1825 /* Filter out DUPACKs if there are no OOO segments left */
1827 (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1829 if (!tcp_session_has_ooo_data (tc0))
1831 error0 = TCP_ERROR_FILTERED_DUPACKS;
1832 next0 = TCP_OUTPUT_NEXT_DROP;
1837 /* Stop DELACK timer and fix flags */
1838 tc0->flags &= ~(TCP_CONN_SNDACK);
1839 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1841 /* If not retransmitting
1842 * 1) update snd_una_max (SYN, SYNACK, FIN)
1843 * 2) If we're not tracking an ACK, start tracking */
1844 if (seq_lt (tc0->snd_una_max, tc0->snd_nxt))
1846 tc0->snd_una_max = tc0->snd_nxt;
1847 if (tc0->rtt_ts == 0)
1849 tc0->rtt_ts = tcp_time_now ();
1850 tc0->rtt_seq = tc0->snd_nxt;
1854 /* Set the retransmit timer if not set already and not
1855 * doing a pure ACK */
1856 if (!tcp_timer_is_active (tc0, TCP_TIMER_RETRANSMIT)
1857 && tc0->snd_nxt != tc0->snd_una)
1859 tcp_retransmit_timer_set (tc0);
1864 /* Make sure we haven't lost route to our peer */
1865 if (PREDICT_FALSE (tc0->last_fib_check
1866 < tc0->snd_opts.tsval + TCP_FIB_RECHECK_PERIOD))
1869 (tc0->c_rmt_fei == tcp_lookup_rmt_in_fib (tc0)))
1871 tc0->last_fib_check = tc0->snd_opts.tsval;
1875 clib_warning ("lost connection to peer");
1876 tcp_connection_reset (tc0);
1881 /* Use pre-computed dpo to set next node */
1882 next0 = tc0->c_rmt_dpo.dpoi_next_node;
1883 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = tc0->c_rmt_dpo.dpoi_index;
1886 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
1887 vnet_buffer (b0)->sw_if_index[VLIB_TX] = tc0->c_fib_index;
1889 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
1891 b0->error = node->errors[error0];
1892 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1894 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1897 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1901 memset (&t0->tcp_header, 0, sizeof (t0->tcp_header));
1903 clib_memcpy (&t0->tcp_connection, tc0,
1904 sizeof (t0->tcp_connection));
1907 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1908 n_left_to_next, bi0, next0);
1911 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1914 return from_frame->n_vectors;
1918 tcp4_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1919 vlib_frame_t * from_frame)
1921 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1925 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1926 vlib_frame_t * from_frame)
1928 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1932 VLIB_REGISTER_NODE (tcp4_output_node) =
1934 .function = tcp4_output,.name = "tcp4-output",
1935 /* Takes a vector of packets. */
1936 .vector_size = sizeof (u32),
1937 .n_errors = TCP_N_ERROR,
1938 .error_strings = tcp_error_strings,
1939 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1941 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1942 foreach_tcp4_output_next
1945 .format_buffer = format_tcp_header,
1946 .format_trace = format_tcp_tx_trace,
1950 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output);
1953 VLIB_REGISTER_NODE (tcp6_output_node) =
1955 .function = tcp6_output,
1956 .name = "tcp6-output",
1957 /* Takes a vector of packets. */
1958 .vector_size = sizeof (u32),
1959 .n_errors = TCP_N_ERROR,
1960 .error_strings = tcp_error_strings,
1961 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1963 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1964 foreach_tcp6_output_next
1967 .format_buffer = format_tcp_header,
1968 .format_trace = format_tcp_tx_trace,
1972 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output);
1975 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
1977 tcp_connection_t *tc;
1979 tc = (tcp_connection_t *) tconn;
1980 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, 0);
1981 ASSERT (seq_leq (tc->snd_una_max, tc->snd_una + tc->snd_wnd));
1983 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
1985 tc->rtt_ts = tcp_time_now ();
1986 tc->rtt_seq = tc->snd_nxt;
1988 tcp_trajectory_add_start (b, 3);
1992 typedef enum _tcp_reset_next
1994 TCP_RESET_NEXT_DROP,
1995 TCP_RESET_NEXT_IP_LOOKUP,
1999 #define foreach_tcp4_reset_next \
2000 _(DROP, "error-drop") \
2001 _(IP_LOOKUP, "ip4-lookup")
2003 #define foreach_tcp6_reset_next \
2004 _(DROP, "error-drop") \
2005 _(IP_LOOKUP, "ip6-lookup")
2008 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2009 vlib_frame_t * from_frame, u8 is_ip4)
2011 u32 n_left_from, next_index, *from, *to_next;
2012 u32 my_thread_index = vm->thread_index;
2014 from = vlib_frame_vector_args (from_frame);
2015 n_left_from = from_frame->n_vectors;
2017 next_index = node->cached_next_index;
2019 while (n_left_from > 0)
2023 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2025 while (n_left_from > 0 && n_left_to_next > 0)
2031 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
2038 n_left_to_next -= 1;
2040 b0 = vlib_get_buffer (vm, bi0);
2042 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
2043 my_thread_index, is_ip4))
2045 error0 = TCP_ERROR_LOOKUP_DROPS;
2046 next0 = TCP_RESET_NEXT_DROP;
2050 /* Prepare to send to IP lookup */
2051 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
2052 next0 = TCP_RESET_NEXT_IP_LOOKUP;
2055 b0->error = node->errors[error0];
2056 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
2057 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2059 th0 = vlib_buffer_get_current (b0);
2061 th0 = ip4_next_header ((ip4_header_t *) th0);
2063 th0 = ip6_next_header ((ip6_header_t *) th0);
2064 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2065 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2068 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2069 n_left_to_next, bi0, next0);
2071 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2073 return from_frame->n_vectors;
2077 tcp4_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
2078 vlib_frame_t * from_frame)
2080 return tcp46_send_reset_inline (vm, node, from_frame, 1);
2084 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
2085 vlib_frame_t * from_frame)
2087 return tcp46_send_reset_inline (vm, node, from_frame, 0);
2091 VLIB_REGISTER_NODE (tcp4_reset_node) = {
2092 .function = tcp4_send_reset,
2093 .name = "tcp4-reset",
2094 .vector_size = sizeof (u32),
2095 .n_errors = TCP_N_ERROR,
2096 .error_strings = tcp_error_strings,
2097 .n_next_nodes = TCP_RESET_N_NEXT,
2099 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2100 foreach_tcp4_reset_next
2103 .format_trace = format_tcp_tx_trace,
2107 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset);
2110 VLIB_REGISTER_NODE (tcp6_reset_node) = {
2111 .function = tcp6_send_reset,
2112 .name = "tcp6-reset",
2113 .vector_size = sizeof (u32),
2114 .n_errors = TCP_N_ERROR,
2115 .error_strings = tcp_error_strings,
2116 .n_next_nodes = TCP_RESET_N_NEXT,
2118 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2119 foreach_tcp6_reset_next
2122 .format_trace = format_tcp_tx_trace,
2126 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset);
2129 * fd.io coding-style-patch-verification: ON
2132 * eval: (c-set-style "gnu")