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 * Compute and return window to advertise, scaled as per RFC1323
138 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
140 if (state < TCP_STATE_ESTABLISHED)
141 return tcp_initial_window_to_advertise (tc);
143 tcp_update_rcv_wnd (tc);
145 if (tc->rcv_wnd == 0)
147 tc->flags |= TCP_CONN_SENT_RCV_WND0;
151 tc->flags &= ~TCP_CONN_SENT_RCV_WND0;
154 return tc->rcv_wnd >> tc->rcv_wscale;
158 tcp_update_rcv_wnd (tcp_connection_t * tc)
161 u32 available_space, max_fifo, wnd;
164 * Figure out how much space we have available
166 available_space = transport_max_rx_enqueue (&tc->connection);
167 max_fifo = transport_rx_fifo_size (&tc->connection);
169 ASSERT (tc->rcv_opts.mss < max_fifo);
170 if (available_space < tc->rcv_opts.mss && available_space < max_fifo >> 3)
174 * Use the above and what we know about what we've previously advertised
175 * to compute the new window
177 observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
178 if (observed_wnd < 0)
181 /* Bad. Thou shalt not shrink */
182 if (available_space < observed_wnd)
185 TCP_EVT_DBG (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space);
189 wnd = available_space;
192 /* Make sure we have a multiple of rcv_wscale */
193 if (wnd && tc->rcv_wscale)
195 wnd &= ~(1 << tc->rcv_wscale);
197 wnd = 1 << tc->rcv_wscale;
200 tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << 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 return tcp_make_established_options (tc, opts);
393 case TCP_STATE_SYN_RCVD:
394 return tcp_make_synack_options (tc, opts);
395 case TCP_STATE_SYN_SENT:
396 return tcp_make_syn_options (opts, tc->rcv_wscale);
398 clib_warning ("State not handled! %d", state);
404 * Update snd_mss to reflect the effective segment size that we can send
405 * by taking into account all TCP options, including SACKs
408 tcp_update_snd_mss (tcp_connection_t * tc)
410 /* Compute options to be used for connection. These may be reused when
411 * sending data or to compute the effective mss (snd_mss) */
413 tcp_make_options (tc, &tc->snd_opts, TCP_STATE_ESTABLISHED);
415 /* XXX check if MTU has been updated */
416 tc->snd_mss = clib_min (tc->mss, tc->rcv_opts.mss) - tc->snd_opts_len;
417 ASSERT (tc->snd_mss > 0);
421 tcp_init_mss (tcp_connection_t * tc)
423 u16 default_min_mss = 536;
424 tcp_update_rcv_mss (tc);
426 /* TODO cache mss and consider PMTU discovery */
427 tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss);
429 if (tc->snd_mss < 45)
431 clib_warning ("snd mss is 0");
432 /* Assume that at least the min default mss works */
433 tc->snd_mss = default_min_mss;
434 tc->rcv_opts.mss = default_min_mss;
437 /* We should have enough space for 40 bytes of options */
438 ASSERT (tc->snd_mss > 45);
440 /* If we use timestamp option, account for it */
441 if (tcp_opts_tstamp (&tc->rcv_opts))
442 tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP;
446 tcp_alloc_tx_buffers (tcp_main_t * tm, u8 thread_index, u16 * n_bufs,
449 vlib_main_t *vm = vlib_get_main ();
452 ASSERT (wanted > *n_bufs);
453 vec_validate_aligned (tm->tx_buffers[thread_index], wanted - 1,
454 CLIB_CACHE_LINE_BYTES);
455 n_alloc = vlib_buffer_alloc (vm, &tm->tx_buffers[thread_index][*n_bufs],
458 _vec_len (tm->tx_buffers[thread_index]) = *n_bufs;
463 tcp_get_free_buffer_index (tcp_main_t * tm, u32 * bidx)
465 u32 thread_index = vlib_get_thread_index ();
466 u16 n_bufs = vec_len (tm->tx_buffers[thread_index]);
468 TCP_DBG_BUFFER_ALLOC_MAYBE_FAIL (thread_index);
470 if (PREDICT_FALSE (!n_bufs))
472 if (!tcp_alloc_tx_buffers (tm, thread_index, &n_bufs, VLIB_FRAME_SIZE))
478 *bidx = tm->tx_buffers[thread_index][--n_bufs];
479 _vec_len (tm->tx_buffers[thread_index]) = n_bufs;
484 tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b)
486 if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
487 vlib_buffer_free_one (vm, b->next_buffer);
488 /* Zero all flags but free list index and trace flag */
489 b->flags &= VLIB_BUFFER_NEXT_PRESENT - 1;
491 b->current_length = 0;
492 b->total_length_not_including_first_buffer = 0;
493 vnet_buffer (b)->tcp.flags = 0;
495 /* Leave enough space for headers */
496 return vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
500 tcp_init_buffer (vlib_main_t * vm, vlib_buffer_t * b)
502 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0);
503 b->flags &= VLIB_BUFFER_NON_DEFAULT_FREELIST;
504 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
505 b->total_length_not_including_first_buffer = 0;
507 vnet_buffer (b)->tcp.flags = 0;
508 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
509 /* Leave enough space for headers */
510 return vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
517 tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
520 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
521 u8 tcp_opts_len, tcp_hdr_opts_len;
525 wnd = tcp_window_to_advertise (tc, state);
527 /* Make and write options */
528 tcp_opts_len = tcp_make_established_options (tc, snd_opts);
529 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
531 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
532 tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd);
534 tcp_options_write ((u8 *) (th + 1), snd_opts);
535 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
539 * Convert buffer to ACK
542 tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
544 vlib_main_t *vm = vlib_get_main ();
546 tcp_reuse_buffer (vm, b);
547 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
548 TCP_EVT_DBG (TCP_EVT_ACK_SENT, tc);
549 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
550 tc->rcv_las = tc->rcv_nxt;
554 * Convert buffer to FIN-ACK
557 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
559 vlib_main_t *vm = vlib_get_main ();
562 tcp_reuse_buffer (vm, b);
564 flags = TCP_FLAG_FIN | TCP_FLAG_ACK;
565 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, flags);
567 /* Reset flags, make sure ack is sent */
568 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
572 * Convert buffer to SYN
575 tcp_make_syn (tcp_connection_t * tc, vlib_buffer_t * b)
577 u8 tcp_hdr_opts_len, tcp_opts_len;
580 tcp_options_t snd_opts;
582 initial_wnd = tcp_initial_window_to_advertise (tc);
584 /* Make and write options */
585 memset (&snd_opts, 0, sizeof (snd_opts));
586 tcp_opts_len = tcp_make_syn_options (&snd_opts, tc->rcv_wscale);
587 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
589 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
590 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
592 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
593 tcp_options_write ((u8 *) (th + 1), &snd_opts);
597 * Convert buffer to SYN-ACK
600 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
602 vlib_main_t *vm = vlib_get_main ();
603 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
604 u8 tcp_opts_len, tcp_hdr_opts_len;
608 memset (snd_opts, 0, sizeof (*snd_opts));
609 tcp_reuse_buffer (vm, b);
611 initial_wnd = tcp_initial_window_to_advertise (tc);
612 tcp_opts_len = tcp_make_synack_options (tc, snd_opts);
613 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
615 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
616 tc->rcv_nxt, tcp_hdr_opts_len,
617 TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd);
618 tcp_options_write ((u8 *) (th + 1), snd_opts);
620 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
621 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
623 /* Init retransmit timer. Use update instead of set because of
625 tcp_retransmit_timer_force_update (tc);
626 TCP_EVT_DBG (TCP_EVT_SYNACK_SENT, tc);
630 tcp_enqueue_to_ip_lookup_i (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
631 u8 is_ip4, u32 fib_index, u8 flush)
633 tcp_main_t *tm = vnet_get_tcp_main ();
634 u32 thread_index = vlib_get_thread_index ();
635 u32 *to_next, next_index;
638 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
641 vnet_buffer (b)->sw_if_index[VLIB_TX] = fib_index;
642 vnet_buffer (b)->sw_if_index[VLIB_RX] = 0;
644 /* Send to IP lookup */
645 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
646 tcp_trajectory_add_start (b, 1);
648 f = tm->ip_lookup_tx_frames[!is_ip4][thread_index];
651 f = vlib_get_frame_to_node (vm, next_index);
653 tm->ip_lookup_tx_frames[!is_ip4][thread_index] = f;
656 to_next = vlib_frame_vector_args (f);
657 to_next[f->n_vectors] = bi;
659 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
661 vlib_put_frame_to_node (vm, next_index, f);
662 tm->ip_lookup_tx_frames[!is_ip4][thread_index] = 0;
667 tcp_enqueue_to_ip_lookup_now (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
668 u8 is_ip4, u32 fib_index)
670 tcp_enqueue_to_ip_lookup_i (vm, b, bi, is_ip4, fib_index, 1);
674 tcp_enqueue_to_ip_lookup (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
675 u8 is_ip4, u32 fib_index)
677 tcp_enqueue_to_ip_lookup_i (vm, b, bi, is_ip4, fib_index, 0);
678 if (vm->thread_index == 0 && vlib_num_workers ())
679 session_flush_frames_main_thread (vm);
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 tcp_init_buffer (vm, b);
1065 fin_snt = tc->flags & TCP_CONN_FINSNT;
1067 tc->snd_nxt = tc->snd_una;
1068 tcp_make_fin (tc, b);
1069 tcp_enqueue_to_output_now (vm, b, bi, tc->c_is_ip4);
1072 tc->flags |= TCP_CONN_FINSNT;
1073 tc->flags &= ~TCP_CONN_FINPNDG;
1074 /* Account for the FIN */
1075 tc->snd_una_max += 1;
1076 tc->snd_nxt = tc->snd_una_max;
1080 tc->snd_nxt = tc->snd_una_max;
1082 TCP_EVT_DBG (TCP_EVT_FIN_SENT, tc);
1086 tcp_make_state_flags (tcp_connection_t * tc, tcp_state_t next_state)
1090 case TCP_STATE_ESTABLISHED:
1091 return TCP_FLAG_ACK;
1092 case TCP_STATE_SYN_RCVD:
1093 return TCP_FLAG_SYN | TCP_FLAG_ACK;
1094 case TCP_STATE_SYN_SENT:
1095 return TCP_FLAG_SYN;
1096 case TCP_STATE_LAST_ACK:
1097 case TCP_STATE_FIN_WAIT_1:
1098 if (tc->snd_nxt + 1 < tc->snd_una_max)
1099 return TCP_FLAG_ACK;
1101 return TCP_FLAG_FIN;
1103 clib_warning ("Shouldn't be here!");
1109 * Push TCP header and update connection variables
1112 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
1113 tcp_state_t next_state, u8 compute_opts)
1115 u32 advertise_wnd, data_len;
1116 u8 tcp_hdr_opts_len, opts_write_len, flags;
1119 data_len = b->current_length + b->total_length_not_including_first_buffer;
1120 ASSERT (!b->total_length_not_including_first_buffer
1121 || (b->flags & VLIB_BUFFER_NEXT_PRESENT));
1122 vnet_buffer (b)->tcp.flags = 0;
1125 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1127 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
1128 advertise_wnd = tcp_window_to_advertise (tc, next_state);
1129 flags = tcp_make_state_flags (tc, next_state);
1131 /* Push header and options */
1132 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
1133 tc->rcv_nxt, tcp_hdr_opts_len, flags,
1135 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
1137 ASSERT (opts_write_len == tc->snd_opts_len);
1138 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
1141 * Update connection variables
1144 tc->snd_nxt += data_len;
1145 tc->rcv_las = tc->rcv_nxt;
1147 /* TODO this is updated in output as well ... */
1148 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1150 tc->snd_una_max = tc->snd_nxt;
1151 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1154 TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
1158 tcp_send_ack (tcp_connection_t * tc)
1160 tcp_main_t *tm = vnet_get_tcp_main ();
1161 vlib_main_t *vm = vlib_get_main ();
1167 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1169 b = vlib_get_buffer (vm, bi);
1170 tcp_init_buffer (vm, b);
1172 /* Fill in the ACK */
1173 tcp_make_ack (tc, b);
1174 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1178 * Delayed ack timer handler
1180 * Sends delayed ACK when timer expires
1183 tcp_timer_delack_handler (u32 index)
1185 u32 thread_index = vlib_get_thread_index ();
1186 tcp_connection_t *tc;
1188 tc = tcp_connection_get (index, thread_index);
1189 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
1194 * Build a retransmit segment
1196 * @return the number of bytes in the segment or 0 if there's nothing to
1200 tcp_prepare_retransmit_segment (tcp_connection_t * tc, u32 offset,
1201 u32 max_deq_bytes, vlib_buffer_t ** b)
1203 tcp_main_t *tm = vnet_get_tcp_main ();
1204 vlib_main_t *vm = vlib_get_main ();
1206 u32 start, bi, available_bytes, seg_size;
1209 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1210 ASSERT (max_deq_bytes != 0);
1213 * Make sure we can retransmit something
1215 available_bytes = stream_session_tx_fifo_max_dequeue (&tc->connection);
1216 ASSERT (available_bytes >= offset);
1217 available_bytes -= offset;
1218 if (!available_bytes)
1220 max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
1221 max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
1223 /* Start is beyond snd_congestion */
1224 start = tc->snd_una + offset;
1225 if (seq_geq (start, tc->snd_congestion))
1228 /* Don't overshoot snd_congestion */
1229 if (seq_gt (start + max_deq_bytes, tc->snd_congestion))
1231 max_deq_bytes = tc->snd_congestion - start;
1232 if (max_deq_bytes == 0)
1236 seg_size = max_deq_bytes + MAX_HDRS_LEN;
1241 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1244 * Allocate and fill in buffer(s)
1247 /* Easy case, buffer size greater than mss */
1248 if (PREDICT_TRUE (seg_size <= tm->bytes_per_buffer))
1250 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1252 *b = vlib_get_buffer (vm, bi);
1253 data = tcp_init_buffer (vm, *b);
1254 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1256 ASSERT (n_bytes == max_deq_bytes);
1257 b[0]->current_length = n_bytes;
1258 tcp_push_hdr_i (tc, *b, tc->state, 0);
1260 /* Split mss into multiple buffers */
1263 u32 chain_bi = ~0, n_bufs_per_seg;
1264 u32 thread_index = vlib_get_thread_index ();
1265 u16 n_peeked, len_to_deq, available_bufs;
1266 vlib_buffer_t *chain_b, *prev_b;
1269 /* Make sure we have enough buffers */
1270 n_bufs_per_seg = ceil ((double) seg_size / tm->bytes_per_buffer);
1271 available_bufs = vec_len (tm->tx_buffers[thread_index]);
1272 if (n_bufs_per_seg > available_bufs)
1274 tcp_alloc_tx_buffers (tm, thread_index, &available_bufs,
1277 if (n_bufs_per_seg > available_bufs)
1284 tcp_get_free_buffer_index (tm, &bi);
1285 ASSERT (bi != (u32) ~ 0);
1286 *b = vlib_get_buffer (vm, bi);
1287 data = tcp_init_buffer (vm, *b);
1288 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1289 tm->bytes_per_buffer -
1291 b[0]->current_length = n_bytes;
1292 b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
1293 b[0]->total_length_not_including_first_buffer = 0;
1294 max_deq_bytes -= n_bytes;
1297 for (i = 1; i < n_bufs_per_seg; i++)
1300 len_to_deq = clib_min (max_deq_bytes, tm->bytes_per_buffer);
1301 tcp_get_free_buffer_index (tm, &chain_bi);
1302 ASSERT (chain_bi != (u32) ~ 0);
1303 chain_b = vlib_get_buffer (vm, chain_bi);
1304 chain_b->current_data = 0;
1305 data = vlib_buffer_get_current (chain_b);
1306 n_peeked = stream_session_peek_bytes (&tc->connection, data,
1307 offset + n_bytes, len_to_deq);
1308 ASSERT (n_peeked == len_to_deq);
1309 n_bytes += n_peeked;
1310 chain_b->current_length = n_peeked;
1311 chain_b->next_buffer = 0;
1313 /* update previous buffer */
1314 prev_b->next_buffer = chain_bi;
1315 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
1317 max_deq_bytes -= n_peeked;
1318 b[0]->total_length_not_including_first_buffer += n_peeked;
1321 tcp_push_hdr_i (tc, *b, tc->state, 0);
1324 ASSERT (n_bytes > 0);
1325 ASSERT (((*b)->current_data + (*b)->current_length) <=
1326 tm->bytes_per_buffer);
1328 if (tcp_in_fastrecovery (tc))
1329 tc->snd_rxt_bytes += n_bytes;
1332 TCP_EVT_DBG (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1337 * Reset congestion control, switch cwnd to loss window and try again.
1340 tcp_rtx_timeout_cc (tcp_connection_t * tc)
1342 tc->prev_ssthresh = tc->ssthresh;
1343 tc->prev_cwnd = tc->cwnd;
1345 /* Cleanly recover cc (also clears up fast retransmit) */
1346 if (tcp_in_fastrecovery (tc))
1347 tcp_cc_fastrecovery_exit (tc);
1349 /* Start again from the beginning */
1350 tc->cc_algo->congestion (tc);
1351 tc->cwnd = tcp_loss_wnd (tc);
1352 tc->snd_congestion = tc->snd_una_max;
1354 tc->cwnd_acc_bytes = 0;
1356 tcp_recovery_on (tc);
1360 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
1362 tcp_main_t *tm = vnet_get_tcp_main ();
1363 vlib_main_t *vm = vlib_get_main ();
1364 u32 thread_index = vlib_get_thread_index ();
1365 tcp_connection_t *tc;
1366 vlib_buffer_t *b = 0;
1371 tc = tcp_half_open_connection_get (index);
1372 /* Note: the connection may have transitioned to ESTABLISHED... */
1373 if (PREDICT_FALSE (tc == 0))
1375 tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
1379 tc = tcp_connection_get (index, thread_index);
1380 /* Note: the connection may have been closed and pool_put */
1381 if (PREDICT_FALSE (tc == 0))
1383 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
1386 if (tc->state >= TCP_STATE_ESTABLISHED)
1388 /* Lost FIN, retransmit and return */
1389 if (tcp_is_lost_fin (tc))
1393 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1397 /* Shouldn't be here */
1398 if (seq_geq (tc->snd_una, tc->snd_congestion))
1400 tcp_recovery_off (tc);
1404 /* We're not in recovery so make sure rto_boff is 0 */
1405 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1408 tcp_update_rto (tc);
1411 /* Increment RTO backoff (also equal to number of retries) and go back
1412 * to first un-acked byte */
1415 /* First retransmit timeout */
1416 if (tc->rto_boff == 1)
1417 tcp_rtx_timeout_cc (tc);
1419 tc->snd_una_max = tc->snd_nxt = tc->snd_una;
1420 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1422 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1);
1424 /* Send one segment. Note that n_bytes may be zero due to buffer shortfall */
1425 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1427 /* TODO be less aggressive about this */
1428 scoreboard_clear (&tc->sack_sb);
1432 tcp_retransmit_timer_set (tc);
1436 bi = vlib_get_buffer_index (vm, b);
1438 /* For first retransmit, record timestamp (Eifel detection RFC3522) */
1439 if (tc->rto_boff == 1)
1440 tc->snd_rxt_ts = tcp_time_now ();
1442 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1443 tcp_retransmit_timer_update (tc);
1445 /* Retransmit for SYN */
1446 else if (tc->state == TCP_STATE_SYN_SENT)
1448 /* Half-open connection actually moved to established but we were
1449 * waiting for syn retransmit to pop to call cleanup from the right
1451 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1453 if (tcp_half_open_connection_cleanup (tc))
1455 clib_warning ("could not remove half-open connection");
1461 /* Try without increasing RTO a number of times. If this fails,
1462 * start growing RTO exponentially */
1464 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1465 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1467 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
1468 tc->rto * TCP_TO_TIMER_TICK);
1470 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1473 b = vlib_get_buffer (vm, bi);
1474 tcp_init_buffer (vm, b);
1475 tcp_make_syn (tc, b);
1478 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 0);
1480 /* This goes straight to ipx_lookup. Retransmit timer set already */
1481 tcp_push_ip_hdr (tm, tc, b);
1482 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
1484 /* Retransmit SYN-ACK */
1485 else if (tc->state == TCP_STATE_SYN_RCVD)
1488 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1489 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1492 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1494 tcp_retransmit_timer_force_update (tc);
1498 b = vlib_get_buffer (vm, bi);
1499 tcp_init_buffer (vm, b);
1500 tcp_make_synack (tc, b);
1501 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 1);
1503 /* Retransmit timer already updated, just enqueue to output */
1504 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1508 ASSERT (tc->state == TCP_STATE_CLOSED);
1514 tcp_timer_retransmit_handler (u32 index)
1516 tcp_timer_retransmit_handler_i (index, 0);
1520 tcp_timer_retransmit_syn_handler (u32 index)
1522 tcp_timer_retransmit_handler_i (index, 1);
1526 * Got 0 snd_wnd from peer, try to do something about it.
1530 tcp_timer_persist_handler (u32 index)
1532 tcp_main_t *tm = vnet_get_tcp_main ();
1533 vlib_main_t *vm = vlib_get_main ();
1534 u32 thread_index = vlib_get_thread_index ();
1535 tcp_connection_t *tc;
1537 u32 bi, max_snd_bytes, available_bytes, offset;
1541 tc = tcp_connection_get_if_valid (index, thread_index);
1546 /* Make sure timer handle is set to invalid */
1547 tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
1549 /* Problem already solved or worse */
1550 if (tc->state == TCP_STATE_CLOSED || tc->state > TCP_STATE_ESTABLISHED
1551 || tc->snd_wnd > tc->snd_mss || tcp_in_recovery (tc))
1554 available_bytes = stream_session_tx_fifo_max_dequeue (&tc->connection);
1555 offset = tc->snd_una_max - tc->snd_una;
1557 /* Reprogram persist if no new bytes available to send. We may have data
1559 if (!available_bytes)
1561 tcp_persist_timer_set (tc);
1565 if (available_bytes <= offset)
1567 ASSERT (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1571 /* Increment RTO backoff */
1573 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1576 * Try to force the first unsent segment (or buffer)
1578 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1580 b = vlib_get_buffer (vm, bi);
1581 data = tcp_init_buffer (vm, b);
1583 tcp_validate_txf_size (tc, offset);
1584 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1585 max_snd_bytes = clib_min (tc->snd_mss, tm->bytes_per_buffer - MAX_HDRS_LEN);
1586 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1588 b->current_length = n_bytes;
1589 ASSERT (n_bytes != 0 && (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)
1590 || tc->snd_nxt == tc->snd_una_max
1591 || tc->rto_boff > 1));
1593 tcp_push_hdr_i (tc, b, tc->state, 0);
1594 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1596 /* Just sent new data, enable retransmit */
1597 tcp_retransmit_timer_update (tc);
1601 * Retransmit first unacked segment
1604 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1606 vlib_main_t *vm = vlib_get_main ();
1608 u32 bi, old_snd_nxt, n_bytes;
1610 old_snd_nxt = tc->snd_nxt;
1611 tc->snd_nxt = tc->snd_una;
1613 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2);
1614 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1617 bi = vlib_get_buffer_index (vm, b);
1618 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1620 tc->snd_nxt = old_snd_nxt;
1624 * Do fast retransmit with SACKs
1627 tcp_fast_retransmit_sack (tcp_connection_t * tc)
1629 vlib_main_t *vm = vlib_get_main ();
1630 u32 n_written = 0, offset, max_bytes;
1631 vlib_buffer_t *b = 0;
1632 sack_scoreboard_hole_t *hole;
1633 sack_scoreboard_t *sb;
1634 u32 bi, old_snd_nxt;
1636 u8 snd_limited = 0, can_rescue = 0;
1638 ASSERT (tcp_in_fastrecovery (tc));
1639 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1641 old_snd_nxt = tc->snd_nxt;
1643 snd_space = tcp_available_snd_space (tc);
1645 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1646 while (hole && snd_space > 0)
1648 hole = scoreboard_next_rxt_hole (sb, hole,
1649 tcp_fastrecovery_sent_1_smss (tc),
1650 &can_rescue, &snd_limited);
1653 if (!can_rescue || !(seq_lt (sb->rescue_rxt, tc->snd_una)
1654 || seq_gt (sb->rescue_rxt,
1655 tc->snd_congestion)))
1658 /* If rescue rxt undefined or less than snd_una then one segment of
1659 * up to SMSS octets that MUST include the highest outstanding
1660 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1661 * RecoveryPoint. HighRxt MUST NOT be updated.
1663 max_bytes = clib_min (tc->snd_mss,
1664 tc->snd_congestion - tc->snd_una);
1665 max_bytes = clib_min (max_bytes, snd_space);
1666 offset = tc->snd_congestion - tc->snd_una - max_bytes;
1667 sb->rescue_rxt = tc->snd_congestion;
1668 tc->snd_nxt = tc->snd_una + offset;
1669 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes,
1674 bi = vlib_get_buffer_index (vm, b);
1675 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1679 max_bytes = clib_min (hole->end - sb->high_rxt, snd_space);
1680 max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes;
1683 offset = sb->high_rxt - tc->snd_una;
1684 tc->snd_nxt = sb->high_rxt;
1685 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes, &b);
1687 /* Nothing left to retransmit */
1691 bi = vlib_get_buffer_index (vm, b);
1692 sb->high_rxt += n_written;
1693 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1694 ASSERT (n_written <= snd_space);
1695 snd_space -= n_written;
1699 /* If window allows, send 1 SMSS of new data */
1700 tc->snd_nxt = old_snd_nxt;
1704 * Fast retransmit without SACK info
1707 tcp_fast_retransmit_no_sack (tcp_connection_t * tc)
1709 vlib_main_t *vm = vlib_get_main ();
1710 u32 n_written = 0, offset = 0, bi, old_snd_nxt;
1714 ASSERT (tcp_in_fastrecovery (tc));
1715 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1717 /* Start resending from first un-acked segment */
1718 old_snd_nxt = tc->snd_nxt;
1719 tc->snd_nxt = tc->snd_una;
1720 snd_space = tcp_available_snd_space (tc);
1722 while (snd_space > 0)
1724 offset += n_written;
1725 n_written = tcp_prepare_retransmit_segment (tc, offset, snd_space, &b);
1727 /* Nothing left to retransmit */
1731 bi = vlib_get_buffer_index (vm, b);
1732 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1733 snd_space -= n_written;
1736 /* Restore snd_nxt. If window allows, send 1 SMSS of new data */
1737 tc->snd_nxt = old_snd_nxt;
1741 * Do fast retransmit
1744 tcp_fast_retransmit (tcp_connection_t * tc)
1746 if (tcp_opts_sack_permitted (&tc->rcv_opts)
1747 && scoreboard_first_hole (&tc->sack_sb))
1748 tcp_fast_retransmit_sack (tc);
1750 tcp_fast_retransmit_no_sack (tc);
1754 tcp_session_has_ooo_data (tcp_connection_t * tc)
1756 stream_session_t *s = session_get (tc->c_s_index, tc->c_thread_index);
1757 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1761 tcp_output_handle_link_local (tcp_connection_t * tc0, vlib_buffer_t * b0,
1762 u32 * next0, u32 * error0)
1764 ip_adjacency_t *adj;
1767 /* Not thread safe but as long as the connection exists the adj should
1769 ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &tc0->c_rmt_ip,
1771 if (ai == ADJ_INDEX_INVALID)
1773 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
1774 *next0 = TCP_OUTPUT_NEXT_DROP;
1775 *error0 = TCP_ERROR_LINK_LOCAL_RW;
1780 if (PREDICT_TRUE (adj->lookup_next_index == IP_LOOKUP_NEXT_REWRITE))
1781 *next0 = TCP_OUTPUT_NEXT_IP_REWRITE;
1782 else if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP)
1783 *next0 = TCP_OUTPUT_NEXT_IP_ARP;
1786 *next0 = TCP_OUTPUT_NEXT_DROP;
1787 *error0 = TCP_ERROR_LINK_LOCAL_RW;
1789 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ai;
1793 tcp46_output_inline (vlib_main_t * vm,
1794 vlib_node_runtime_t * node,
1795 vlib_frame_t * from_frame, int is_ip4)
1797 u32 n_left_from, next_index, *from, *to_next;
1798 u32 my_thread_index = vm->thread_index;
1800 from = vlib_frame_vector_args (from_frame);
1801 n_left_from = from_frame->n_vectors;
1802 next_index = node->cached_next_index;
1803 tcp_set_time_now (my_thread_index);
1805 while (n_left_from > 0)
1809 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1811 while (n_left_from > 0 && n_left_to_next > 0)
1815 tcp_connection_t *tc0;
1817 tcp_header_t *th0 = 0;
1818 u32 error0 = TCP_ERROR_PKTS_SENT, next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
1820 if (n_left_from > 1)
1823 pb = vlib_get_buffer (vm, from[1]);
1824 vlib_prefetch_buffer_header (pb, STORE);
1825 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
1833 n_left_to_next -= 1;
1835 b0 = vlib_get_buffer (vm, bi0);
1836 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1838 if (PREDICT_FALSE (tc0 == 0 || tc0->state == TCP_STATE_CLOSED))
1840 error0 = TCP_ERROR_INVALID_CONNECTION;
1841 next0 = TCP_OUTPUT_NEXT_DROP;
1845 th0 = vlib_buffer_get_current (b0);
1846 TCP_EVT_DBG (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
1847 vnet_buffer (b0)->sw_if_index[VLIB_TX] = tc0->c_fib_index;
1848 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
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;
1869 (ip6_address_is_link_local_unicast (&tc0->c_rmt_ip6)))
1870 tcp_output_handle_link_local (tc0, b0, &next0, &error0);
1873 /* Filter out DUPACKs if there are no OOO segments left */
1875 (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1877 /* N.B. Should not filter burst of dupacks. Two issues:
1878 * 1) dupacks open cwnd on remote peer when congested
1879 * 2) acks leaving should have the latest rcv_wnd since the
1880 * burst may have eaten up all of it, so only the old ones
1881 * could be filtered.
1883 if (!tcp_session_has_ooo_data (tc0))
1885 error0 = TCP_ERROR_FILTERED_DUPACKS;
1886 next0 = TCP_OUTPUT_NEXT_DROP;
1891 /* Stop DELACK timer and fix flags */
1892 tc0->flags &= ~(TCP_CONN_SNDACK);
1893 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1895 /* If not retransmitting
1896 * 1) update snd_una_max (SYN, SYNACK, FIN)
1897 * 2) If we're not tracking an ACK, start tracking */
1898 if (seq_lt (tc0->snd_una_max, tc0->snd_nxt))
1900 tc0->snd_una_max = tc0->snd_nxt;
1901 if (tc0->rtt_ts == 0)
1903 tc0->rtt_ts = tcp_time_now ();
1904 tc0->rtt_seq = tc0->snd_nxt;
1908 /* Set the retransmit timer if not set already and not
1909 * doing a pure ACK */
1910 if (!tcp_timer_is_active (tc0, TCP_TIMER_RETRANSMIT)
1911 && tc0->snd_nxt != tc0->snd_una)
1913 tcp_retransmit_timer_set (tc0);
1918 /* Make sure we haven't lost route to our peer */
1919 if (PREDICT_FALSE (tc0->last_fib_check
1920 < tc0->snd_opts.tsval + TCP_FIB_RECHECK_PERIOD))
1923 (tc0->c_rmt_fei == tcp_lookup_rmt_in_fib (tc0)))
1925 tc0->last_fib_check = tc0->snd_opts.tsval;
1929 clib_warning ("lost connection to peer");
1930 tcp_connection_reset (tc0);
1935 /* Use pre-computed dpo to set next node */
1936 next0 = tc0->c_rmt_dpo.dpoi_next_node;
1937 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = tc0->c_rmt_dpo.dpoi_index;
1941 b0->error = node->errors[error0];
1942 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1944 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1947 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1951 memset (&t0->tcp_header, 0, sizeof (t0->tcp_header));
1953 clib_memcpy (&t0->tcp_connection, tc0,
1954 sizeof (t0->tcp_connection));
1957 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1958 n_left_to_next, bi0, next0);
1961 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1964 return from_frame->n_vectors;
1968 tcp4_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1969 vlib_frame_t * from_frame)
1971 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1975 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1976 vlib_frame_t * from_frame)
1978 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1982 VLIB_REGISTER_NODE (tcp4_output_node) =
1984 .function = tcp4_output,.name = "tcp4-output",
1985 /* Takes a vector of packets. */
1986 .vector_size = sizeof (u32),
1987 .n_errors = TCP_N_ERROR,
1988 .error_strings = tcp_error_strings,
1989 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1991 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1992 foreach_tcp4_output_next
1995 .format_buffer = format_tcp_header,
1996 .format_trace = format_tcp_tx_trace,
2000 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output);
2003 VLIB_REGISTER_NODE (tcp6_output_node) =
2005 .function = tcp6_output,
2006 .name = "tcp6-output",
2007 /* Takes a vector of packets. */
2008 .vector_size = sizeof (u32),
2009 .n_errors = TCP_N_ERROR,
2010 .error_strings = tcp_error_strings,
2011 .n_next_nodes = TCP_OUTPUT_N_NEXT,
2013 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
2014 foreach_tcp6_output_next
2017 .format_buffer = format_tcp_header,
2018 .format_trace = format_tcp_tx_trace,
2022 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output);
2025 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
2027 tcp_connection_t *tc;
2029 tc = (tcp_connection_t *) tconn;
2030 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, 0);
2031 ASSERT (seq_leq (tc->snd_una_max, tc->snd_una + tc->snd_wnd));
2033 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
2035 tc->rtt_ts = tcp_time_now ();
2036 tc->rtt_seq = tc->snd_nxt;
2038 tcp_trajectory_add_start (b, 3);
2042 typedef enum _tcp_reset_next
2044 TCP_RESET_NEXT_DROP,
2045 TCP_RESET_NEXT_IP_LOOKUP,
2049 #define foreach_tcp4_reset_next \
2050 _(DROP, "error-drop") \
2051 _(IP_LOOKUP, "ip4-lookup")
2053 #define foreach_tcp6_reset_next \
2054 _(DROP, "error-drop") \
2055 _(IP_LOOKUP, "ip6-lookup")
2058 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2059 vlib_frame_t * from_frame, u8 is_ip4)
2061 u32 n_left_from, next_index, *from, *to_next;
2062 u32 my_thread_index = vm->thread_index;
2064 from = vlib_frame_vector_args (from_frame);
2065 n_left_from = from_frame->n_vectors;
2067 next_index = node->cached_next_index;
2069 while (n_left_from > 0)
2073 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2075 while (n_left_from > 0 && n_left_to_next > 0)
2081 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
2088 n_left_to_next -= 1;
2090 b0 = vlib_get_buffer (vm, bi0);
2092 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
2093 my_thread_index, is_ip4))
2095 error0 = TCP_ERROR_LOOKUP_DROPS;
2096 next0 = TCP_RESET_NEXT_DROP;
2100 /* Prepare to send to IP lookup */
2101 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
2102 next0 = TCP_RESET_NEXT_IP_LOOKUP;
2105 b0->error = node->errors[error0];
2106 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
2107 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2109 th0 = vlib_buffer_get_current (b0);
2111 th0 = ip4_next_header ((ip4_header_t *) th0);
2113 th0 = ip6_next_header ((ip6_header_t *) th0);
2114 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2115 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2118 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2119 n_left_to_next, bi0, next0);
2121 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2123 return from_frame->n_vectors;
2127 tcp4_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
2128 vlib_frame_t * from_frame)
2130 return tcp46_send_reset_inline (vm, node, from_frame, 1);
2134 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
2135 vlib_frame_t * from_frame)
2137 return tcp46_send_reset_inline (vm, node, from_frame, 0);
2141 VLIB_REGISTER_NODE (tcp4_reset_node) = {
2142 .function = tcp4_send_reset,
2143 .name = "tcp4-reset",
2144 .vector_size = sizeof (u32),
2145 .n_errors = TCP_N_ERROR,
2146 .error_strings = tcp_error_strings,
2147 .n_next_nodes = TCP_RESET_N_NEXT,
2149 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2150 foreach_tcp4_reset_next
2153 .format_trace = format_tcp_tx_trace,
2157 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset);
2160 VLIB_REGISTER_NODE (tcp6_reset_node) = {
2161 .function = tcp6_send_reset,
2162 .name = "tcp6-reset",
2163 .vector_size = sizeof (u32),
2164 .n_errors = TCP_N_ERROR,
2165 .error_strings = tcp_error_strings,
2166 .n_next_nodes = TCP_RESET_N_NEXT,
2168 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2169 foreach_tcp6_reset_next
2172 .format_trace = format_tcp_tx_trace,
2176 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset);
2179 * fd.io coding-style-patch-verification: ON
2182 * eval: (c-set-style "gnu")