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 case TCP_STATE_CLOSED:
393 case TCP_STATE_CLOSE_WAIT:
394 return tcp_make_established_options (tc, opts);
395 case TCP_STATE_SYN_RCVD:
396 return tcp_make_synack_options (tc, opts);
397 case TCP_STATE_SYN_SENT:
398 return tcp_make_syn_options (opts, tc->rcv_wscale);
400 clib_warning ("State not handled! %d", state);
406 * Update snd_mss to reflect the effective segment size that we can send
407 * by taking into account all TCP options, including SACKs
410 tcp_update_snd_mss (tcp_connection_t * tc)
412 /* Compute options to be used for connection. These may be reused when
413 * sending data or to compute the effective mss (snd_mss) */
415 tcp_make_options (tc, &tc->snd_opts, TCP_STATE_ESTABLISHED);
417 /* XXX check if MTU has been updated */
418 tc->snd_mss = clib_min (tc->mss, tc->rcv_opts.mss) - tc->snd_opts_len;
419 ASSERT (tc->snd_mss > 0);
423 tcp_init_mss (tcp_connection_t * tc)
425 u16 default_min_mss = 536;
426 tcp_update_rcv_mss (tc);
428 /* TODO cache mss and consider PMTU discovery */
429 tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss);
431 if (tc->snd_mss < 45)
433 clib_warning ("snd mss is 0");
434 /* Assume that at least the min default mss works */
435 tc->snd_mss = default_min_mss;
436 tc->rcv_opts.mss = default_min_mss;
439 /* We should have enough space for 40 bytes of options */
440 ASSERT (tc->snd_mss > 45);
442 /* If we use timestamp option, account for it */
443 if (tcp_opts_tstamp (&tc->rcv_opts))
444 tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP;
448 tcp_alloc_tx_buffers (tcp_main_t * tm, u8 thread_index, u16 * n_bufs,
451 vlib_main_t *vm = vlib_get_main ();
454 ASSERT (wanted > *n_bufs);
455 vec_validate_aligned (tm->tx_buffers[thread_index], wanted - 1,
456 CLIB_CACHE_LINE_BYTES);
457 n_alloc = vlib_buffer_alloc (vm, &tm->tx_buffers[thread_index][*n_bufs],
460 _vec_len (tm->tx_buffers[thread_index]) = *n_bufs;
465 tcp_get_free_buffer_index (tcp_main_t * tm, u32 * bidx)
467 u32 thread_index = vlib_get_thread_index ();
468 u16 n_bufs = vec_len (tm->tx_buffers[thread_index]);
470 TCP_DBG_BUFFER_ALLOC_MAYBE_FAIL (thread_index);
472 if (PREDICT_FALSE (!n_bufs))
474 if (!tcp_alloc_tx_buffers (tm, thread_index, &n_bufs, VLIB_FRAME_SIZE))
480 *bidx = tm->tx_buffers[thread_index][--n_bufs];
481 _vec_len (tm->tx_buffers[thread_index]) = n_bufs;
486 tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b)
488 if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
489 vlib_buffer_free_one (vm, b->next_buffer);
490 /* Zero all flags but free list index and trace flag */
491 b->flags &= VLIB_BUFFER_NEXT_PRESENT - 1;
493 b->current_length = 0;
494 b->total_length_not_including_first_buffer = 0;
495 vnet_buffer (b)->tcp.flags = 0;
497 /* Leave enough space for headers */
498 return vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
502 tcp_init_buffer (vlib_main_t * vm, vlib_buffer_t * b)
504 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0);
505 b->flags &= VLIB_BUFFER_NON_DEFAULT_FREELIST;
506 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
507 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);
680 if (vm->thread_index == 0 && vlib_num_workers ())
681 session_flush_frames_main_thread (vm);
685 tcp_enqueue_to_output_i (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
688 tcp_main_t *tm = vnet_get_tcp_main ();
689 u32 thread_index = vlib_get_thread_index ();
690 u32 *to_next, next_index;
693 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
696 /* Decide where to send the packet */
697 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
698 tcp_trajectory_add_start (b, 2);
700 /* Get frame to v4/6 output node */
701 f = tm->tx_frames[!is_ip4][thread_index];
704 f = vlib_get_frame_to_node (vm, next_index);
706 tm->tx_frames[!is_ip4][thread_index] = f;
708 to_next = vlib_frame_vector_args (f);
709 to_next[f->n_vectors] = bi;
711 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
713 vlib_put_frame_to_node (vm, next_index, f);
714 tm->tx_frames[!is_ip4][thread_index] = 0;
719 tcp_enqueue_to_output (vlib_main_t * vm, vlib_buffer_t * b, u32 bi, u8 is_ip4)
721 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 0);
725 tcp_enqueue_to_output_now (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
728 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 1);
732 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
733 tcp_state_t state, u8 thread_index, u8 is_ip4)
738 ip4_address_t src_ip40, dst_ip40;
739 ip6_address_t src_ip60, dst_ip60;
740 u16 src_port, dst_port;
745 /* Find IP and TCP headers */
746 th0 = tcp_buffer_hdr (b0);
748 /* Save src and dst ip */
751 ih4 = vlib_buffer_get_current (b0);
752 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
753 src_ip40.as_u32 = ih4->src_address.as_u32;
754 dst_ip40.as_u32 = ih4->dst_address.as_u32;
758 ih6 = vlib_buffer_get_current (b0);
759 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
760 clib_memcpy (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
761 clib_memcpy (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t));
764 src_port = th0->src_port;
765 dst_port = th0->dst_port;
767 /* Try to determine what/why we're actually resetting */
768 if (state == TCP_STATE_CLOSED)
773 tmp = clib_net_to_host_u32 (th0->seq_number);
775 /* Got a SYN for no listener. */
776 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
777 ack = clib_host_to_net_u32 (tmp + 1);
782 flags = TCP_FLAG_RST;
783 seq = th0->ack_number;
787 tcp_reuse_buffer (vm, b0);
788 tcp_trajectory_add_start (b0, 4);
789 th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack,
790 sizeof (tcp_header_t), flags, 0);
794 ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40,
796 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
801 ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60,
803 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
811 * Send reset without reusing existing buffer
813 * It extracts connection info out of original packet
816 tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt, u8 is_ip4)
819 u32 bi, sw_if_index, fib_index;
820 tcp_main_t *tm = vnet_get_tcp_main ();
821 vlib_main_t *vm = vlib_get_main ();
822 u8 tcp_hdr_len, flags = 0;
823 tcp_header_t *th, *pkt_th;
825 ip4_header_t *ih4, *pkt_ih4;
826 ip6_header_t *ih6, *pkt_ih6;
827 fib_protocol_t fib_proto;
829 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
832 b = vlib_get_buffer (vm, bi);
833 sw_if_index = vnet_buffer (pkt)->sw_if_index[VLIB_RX];
834 fib_proto = is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
835 fib_index = fib_table_get_index_for_sw_if_index (fib_proto, sw_if_index);
836 tcp_init_buffer (vm, b);
838 /* Make and write options */
839 tcp_hdr_len = sizeof (tcp_header_t);
843 pkt_ih4 = vlib_buffer_get_current (pkt);
844 pkt_th = ip4_next_header (pkt_ih4);
848 pkt_ih6 = vlib_buffer_get_current (pkt);
849 pkt_th = ip6_next_header (pkt_ih6);
852 if (tcp_ack (pkt_th))
854 flags = TCP_FLAG_RST;
855 seq = pkt_th->ack_number;
856 ack = (tc && tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
860 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
862 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
865 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
866 seq, ack, tcp_hdr_len, flags, 0);
868 /* Swap src and dst ip */
871 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
872 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
873 &pkt_ih4->src_address, IP_PROTOCOL_TCP, 1);
874 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
879 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
881 ih6 = vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address,
882 &pkt_ih6->src_address, IP_PROTOCOL_TCP);
883 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
887 tcp_enqueue_to_ip_lookup_now (vm, b, bi, is_ip4, fib_index);
888 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc);
892 * Build and set reset packet for connection
895 tcp_send_reset (tcp_connection_t * tc)
897 vlib_main_t *vm = vlib_get_main ();
898 tcp_main_t *tm = vnet_get_tcp_main ();
902 u16 tcp_hdr_opts_len, advertise_wnd, opts_write_len;
905 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
907 b = vlib_get_buffer (vm, bi);
908 tcp_init_buffer (vm, b);
910 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
911 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
912 advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED);
913 flags = TCP_FLAG_RST;
914 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
915 tc->rcv_nxt, tcp_hdr_opts_len, flags,
917 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
918 ASSERT (opts_write_len == tc->snd_opts_len);
919 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
923 ih4 = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip.ip4,
924 &tc->c_rmt_ip.ip4, IP_PROTOCOL_TCP, 0);
925 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
931 ih6 = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip.ip6,
932 &tc->c_rmt_ip.ip6, IP_PROTOCOL_TCP);
933 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
936 tcp_enqueue_to_ip_lookup_now (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
937 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc);
941 tcp_push_ip_hdr (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b)
943 tcp_header_t *th = vlib_buffer_get_current (b);
944 vlib_main_t *vm = vlib_get_main ();
948 ih = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip4,
949 &tc->c_rmt_ip4, IP_PROTOCOL_TCP, 1);
950 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih);
957 ih = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip6,
958 &tc->c_rmt_ip6, IP_PROTOCOL_TCP);
959 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih, &bogus);
967 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
968 * The packet is not forwarded through tcpx_output to avoid doing lookups
969 * in the half_open pool.
972 tcp_send_syn (tcp_connection_t * tc)
976 tcp_main_t *tm = vnet_get_tcp_main ();
977 vlib_main_t *vm = vlib_get_main ();
980 * Setup retransmit and establish timers before requesting buffer
981 * such that we can return if we've ran out.
983 tcp_timer_set (tc, TCP_TIMER_ESTABLISH, TCP_ESTABLISH_TIME);
984 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
985 tc->rto * TCP_TO_TIMER_TICK);
987 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
990 b = vlib_get_buffer (vm, bi);
991 tcp_init_buffer (vm, b);
992 tcp_make_syn (tc, b);
994 /* Measure RTT with this */
995 tc->rtt_ts = tcp_time_now ();
996 tc->rtt_seq = tc->snd_nxt;
999 tcp_push_ip_hdr (tm, tc, b);
1000 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
1001 TCP_EVT_DBG (TCP_EVT_SYN_SENT, tc);
1005 * Flush tx frame populated by retransmits and timer pops
1008 tcp_flush_frame_to_output (vlib_main_t * vm, u8 thread_index, u8 is_ip4)
1010 if (tcp_main.tx_frames[!is_ip4][thread_index])
1013 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
1014 vlib_put_frame_to_node (vm, next_index,
1015 tcp_main.tx_frames[!is_ip4][thread_index]);
1016 tcp_main.tx_frames[!is_ip4][thread_index] = 0;
1021 * Flush ip lookup tx frames populated by timer pops
1024 tcp_flush_frame_to_ip_lookup (vlib_main_t * vm, u8 thread_index, u8 is_ip4)
1026 if (tcp_main.ip_lookup_tx_frames[!is_ip4][thread_index])
1029 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
1030 vlib_put_frame_to_node (vm, next_index,
1031 tcp_main.ip_lookup_tx_frames[!is_ip4]
1033 tcp_main.ip_lookup_tx_frames[!is_ip4][thread_index] = 0;
1038 * Flush v4 and v6 tcp and ip-lookup tx frames for thread index
1041 tcp_flush_frames_to_output (u8 thread_index)
1043 vlib_main_t *vm = vlib_get_main ();
1044 tcp_flush_frame_to_output (vm, thread_index, 1);
1045 tcp_flush_frame_to_output (vm, thread_index, 0);
1046 tcp_flush_frame_to_ip_lookup (vm, thread_index, 1);
1047 tcp_flush_frame_to_ip_lookup (vm, thread_index, 0);
1054 tcp_send_fin (tcp_connection_t * tc)
1056 tcp_main_t *tm = vnet_get_tcp_main ();
1057 vlib_main_t *vm = vlib_get_main ();
1062 tcp_retransmit_timer_force_update (tc);
1063 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1065 b = vlib_get_buffer (vm, bi);
1066 tcp_init_buffer (vm, b);
1067 fin_snt = tc->flags & TCP_CONN_FINSNT;
1069 tc->snd_nxt = tc->snd_una;
1070 tcp_make_fin (tc, b);
1071 tcp_enqueue_to_output_now (vm, b, bi, tc->c_is_ip4);
1074 tc->flags |= TCP_CONN_FINSNT;
1075 tc->flags &= ~TCP_CONN_FINPNDG;
1076 /* Account for the FIN */
1077 tc->snd_una_max += 1;
1078 tc->snd_nxt = tc->snd_una_max;
1082 tc->snd_nxt = tc->snd_una_max;
1084 TCP_EVT_DBG (TCP_EVT_FIN_SENT, tc);
1088 tcp_make_state_flags (tcp_connection_t * tc, tcp_state_t next_state)
1092 case TCP_STATE_ESTABLISHED:
1093 return TCP_FLAG_ACK;
1094 case TCP_STATE_SYN_RCVD:
1095 return TCP_FLAG_SYN | TCP_FLAG_ACK;
1096 case TCP_STATE_SYN_SENT:
1097 return TCP_FLAG_SYN;
1098 case TCP_STATE_LAST_ACK:
1099 case TCP_STATE_FIN_WAIT_1:
1100 if (tc->snd_nxt + 1 < tc->snd_una_max)
1101 return TCP_FLAG_ACK;
1103 return TCP_FLAG_FIN;
1105 clib_warning ("Shouldn't be here!");
1111 * Push TCP header and update connection variables
1114 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
1115 tcp_state_t next_state, u8 compute_opts)
1117 u32 advertise_wnd, data_len;
1118 u8 tcp_hdr_opts_len, opts_write_len, flags;
1121 data_len = b->current_length + b->total_length_not_including_first_buffer;
1122 ASSERT (!b->total_length_not_including_first_buffer
1123 || (b->flags & VLIB_BUFFER_NEXT_PRESENT));
1124 vnet_buffer (b)->tcp.flags = 0;
1127 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1129 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
1130 advertise_wnd = tcp_window_to_advertise (tc, next_state);
1131 flags = tcp_make_state_flags (tc, next_state);
1133 /* Push header and options */
1134 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
1135 tc->rcv_nxt, tcp_hdr_opts_len, flags,
1137 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
1139 ASSERT (opts_write_len == tc->snd_opts_len);
1140 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
1143 * Update connection variables
1146 tc->snd_nxt += data_len;
1147 tc->rcv_las = tc->rcv_nxt;
1149 /* TODO this is updated in output as well ... */
1150 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1152 tc->snd_una_max = tc->snd_nxt;
1153 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1156 TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
1160 tcp_send_ack (tcp_connection_t * tc)
1162 tcp_main_t *tm = vnet_get_tcp_main ();
1163 vlib_main_t *vm = vlib_get_main ();
1169 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1171 b = vlib_get_buffer (vm, bi);
1172 tcp_init_buffer (vm, b);
1174 /* Fill in the ACK */
1175 tcp_make_ack (tc, b);
1176 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1180 * Delayed ack timer handler
1182 * Sends delayed ACK when timer expires
1185 tcp_timer_delack_handler (u32 index)
1187 u32 thread_index = vlib_get_thread_index ();
1188 tcp_connection_t *tc;
1190 tc = tcp_connection_get (index, thread_index);
1191 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
1196 * Build a retransmit segment
1198 * @return the number of bytes in the segment or 0 if there's nothing to
1202 tcp_prepare_retransmit_segment (tcp_connection_t * tc, u32 offset,
1203 u32 max_deq_bytes, vlib_buffer_t ** b)
1205 tcp_main_t *tm = vnet_get_tcp_main ();
1206 vlib_main_t *vm = vlib_get_main ();
1208 u32 start, bi, available_bytes, seg_size;
1211 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1212 ASSERT (max_deq_bytes != 0);
1215 * Make sure we can retransmit something
1217 available_bytes = session_tx_fifo_max_dequeue (&tc->connection);
1218 ASSERT (available_bytes >= offset);
1219 available_bytes -= offset;
1220 if (!available_bytes)
1222 max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
1223 max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
1225 /* Start is beyond snd_congestion */
1226 start = tc->snd_una + offset;
1227 if (seq_geq (start, tc->snd_congestion))
1230 /* Don't overshoot snd_congestion */
1231 if (seq_gt (start + max_deq_bytes, tc->snd_congestion))
1233 max_deq_bytes = tc->snd_congestion - start;
1234 if (max_deq_bytes == 0)
1238 seg_size = max_deq_bytes + MAX_HDRS_LEN;
1243 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1246 * Allocate and fill in buffer(s)
1249 /* Easy case, buffer size greater than mss */
1250 if (PREDICT_TRUE (seg_size <= tm->bytes_per_buffer))
1252 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1254 *b = vlib_get_buffer (vm, bi);
1255 data = tcp_init_buffer (vm, *b);
1256 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1258 ASSERT (n_bytes == max_deq_bytes);
1259 b[0]->current_length = n_bytes;
1260 tcp_push_hdr_i (tc, *b, tc->state, 0);
1262 /* Split mss into multiple buffers */
1265 u32 chain_bi = ~0, n_bufs_per_seg;
1266 u32 thread_index = vlib_get_thread_index ();
1267 u16 n_peeked, len_to_deq, available_bufs;
1268 vlib_buffer_t *chain_b, *prev_b;
1271 /* Make sure we have enough buffers */
1272 n_bufs_per_seg = ceil ((double) seg_size / tm->bytes_per_buffer);
1273 available_bufs = vec_len (tm->tx_buffers[thread_index]);
1274 if (n_bufs_per_seg > available_bufs)
1276 tcp_alloc_tx_buffers (tm, thread_index, &available_bufs,
1279 if (n_bufs_per_seg > available_bufs)
1286 tcp_get_free_buffer_index (tm, &bi);
1287 ASSERT (bi != (u32) ~ 0);
1288 *b = vlib_get_buffer (vm, bi);
1289 data = tcp_init_buffer (vm, *b);
1290 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1291 tm->bytes_per_buffer -
1293 b[0]->current_length = n_bytes;
1294 b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
1295 b[0]->total_length_not_including_first_buffer = 0;
1296 max_deq_bytes -= n_bytes;
1299 for (i = 1; i < n_bufs_per_seg; i++)
1302 len_to_deq = clib_min (max_deq_bytes, tm->bytes_per_buffer);
1303 tcp_get_free_buffer_index (tm, &chain_bi);
1304 ASSERT (chain_bi != (u32) ~ 0);
1305 chain_b = vlib_get_buffer (vm, chain_bi);
1306 chain_b->current_data = 0;
1307 data = vlib_buffer_get_current (chain_b);
1308 n_peeked = stream_session_peek_bytes (&tc->connection, data,
1309 offset + n_bytes, len_to_deq);
1310 ASSERT (n_peeked == len_to_deq);
1311 n_bytes += n_peeked;
1312 chain_b->current_length = n_peeked;
1313 chain_b->next_buffer = 0;
1315 /* update previous buffer */
1316 prev_b->next_buffer = chain_bi;
1317 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
1319 max_deq_bytes -= n_peeked;
1320 b[0]->total_length_not_including_first_buffer += n_peeked;
1323 tcp_push_hdr_i (tc, *b, tc->state, 0);
1326 ASSERT (n_bytes > 0);
1327 ASSERT (((*b)->current_data + (*b)->current_length) <=
1328 tm->bytes_per_buffer);
1330 if (tcp_in_fastrecovery (tc))
1331 tc->snd_rxt_bytes += n_bytes;
1334 TCP_EVT_DBG (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1339 * Reset congestion control, switch cwnd to loss window and try again.
1342 tcp_rxt_timeout_cc (tcp_connection_t * tc)
1344 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 6);
1345 tc->prev_ssthresh = tc->ssthresh;
1346 tc->prev_cwnd = tc->cwnd;
1348 /* Cleanly recover cc (also clears up fast retransmit) */
1349 if (tcp_in_fastrecovery (tc))
1350 tcp_cc_fastrecovery_exit (tc);
1352 /* Start again from the beginning */
1353 tc->cc_algo->congestion (tc);
1354 tc->cwnd = tcp_loss_wnd (tc);
1355 tc->snd_congestion = tc->snd_una_max;
1357 tc->cwnd_acc_bytes = 0;
1359 tcp_recovery_on (tc);
1363 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
1365 tcp_main_t *tm = vnet_get_tcp_main ();
1366 vlib_main_t *vm = vlib_get_main ();
1367 u32 thread_index = vlib_get_thread_index ();
1368 tcp_connection_t *tc;
1369 vlib_buffer_t *b = 0;
1374 tc = tcp_half_open_connection_get (index);
1375 /* Note: the connection may have transitioned to ESTABLISHED... */
1376 if (PREDICT_FALSE (tc == 0))
1378 tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
1382 tc = tcp_connection_get (index, thread_index);
1383 /* Note: the connection may have been closed and pool_put */
1384 if (PREDICT_FALSE (tc == 0))
1386 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
1389 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1);
1391 if (tc->state >= TCP_STATE_ESTABLISHED)
1393 /* Lost FIN, retransmit and return */
1394 if (tcp_is_lost_fin (tc))
1398 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1402 /* Shouldn't be here */
1403 if ((tc->rto_boff == 0 && tc->snd_una == tc->snd_una_max)
1404 || (tc->rto_boff > 0 && seq_geq (tc->snd_una, tc->snd_congestion)))
1406 tcp_recovery_off (tc);
1410 /* We're not in recovery so make sure rto_boff is 0 */
1411 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1414 tcp_update_rto (tc);
1417 /* Increment RTO backoff (also equal to number of retries) and go back
1418 * to first un-acked byte */
1421 /* First retransmit timeout */
1422 if (tc->rto_boff == 1)
1423 tcp_rxt_timeout_cc (tc);
1425 tc->snd_una_max = tc->snd_nxt = tc->snd_una;
1426 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1428 /* Send one segment. Note that n_bytes may be zero due to buffer shortfall */
1429 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1431 /* TODO be less aggressive about this */
1432 scoreboard_clear (&tc->sack_sb);
1436 tcp_retransmit_timer_set (tc);
1440 bi = vlib_get_buffer_index (vm, b);
1442 /* For first retransmit, record timestamp (Eifel detection RFC3522) */
1443 if (tc->rto_boff == 1)
1444 tc->snd_rxt_ts = tcp_time_now ();
1446 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1447 tcp_retransmit_timer_update (tc);
1449 /* Retransmit for SYN */
1450 else if (tc->state == TCP_STATE_SYN_SENT)
1452 /* Half-open connection actually moved to established but we were
1453 * waiting for syn retransmit to pop to call cleanup from the right
1455 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1457 if (tcp_half_open_connection_cleanup (tc))
1459 clib_warning ("could not remove half-open connection");
1465 /* Try without increasing RTO a number of times. If this fails,
1466 * start growing RTO exponentially */
1468 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1469 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1471 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
1472 tc->rto * TCP_TO_TIMER_TICK);
1474 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1477 b = vlib_get_buffer (vm, bi);
1478 tcp_init_buffer (vm, b);
1479 tcp_make_syn (tc, b);
1482 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 0);
1484 /* This goes straight to ipx_lookup. Retransmit timer set already */
1485 tcp_push_ip_hdr (tm, tc, b);
1486 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
1488 /* Retransmit SYN-ACK */
1489 else if (tc->state == TCP_STATE_SYN_RCVD)
1492 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1493 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1496 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1498 tcp_retransmit_timer_force_update (tc);
1502 b = vlib_get_buffer (vm, bi);
1503 tcp_init_buffer (vm, b);
1504 tcp_make_synack (tc, b);
1505 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 1);
1507 /* Retransmit timer already updated, just enqueue to output */
1508 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1512 ASSERT (tc->state == TCP_STATE_CLOSED);
1518 tcp_timer_retransmit_handler (u32 index)
1520 tcp_timer_retransmit_handler_i (index, 0);
1524 tcp_timer_retransmit_syn_handler (u32 index)
1526 tcp_timer_retransmit_handler_i (index, 1);
1530 * Got 0 snd_wnd from peer, try to do something about it.
1534 tcp_timer_persist_handler (u32 index)
1536 tcp_main_t *tm = vnet_get_tcp_main ();
1537 vlib_main_t *vm = vlib_get_main ();
1538 u32 thread_index = vlib_get_thread_index ();
1539 tcp_connection_t *tc;
1541 u32 bi, max_snd_bytes, available_bytes, offset;
1545 tc = tcp_connection_get_if_valid (index, thread_index);
1550 /* Make sure timer handle is set to invalid */
1551 tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
1553 /* Problem already solved or worse */
1554 if (tc->state == TCP_STATE_CLOSED || tc->state > TCP_STATE_ESTABLISHED
1555 || tc->snd_wnd > tc->snd_mss || tcp_in_recovery (tc))
1558 available_bytes = session_tx_fifo_max_dequeue (&tc->connection);
1559 offset = tc->snd_una_max - tc->snd_una;
1561 /* Reprogram persist if no new bytes available to send. We may have data
1563 if (!available_bytes)
1565 tcp_persist_timer_set (tc);
1569 if (available_bytes <= offset)
1571 ASSERT (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1575 /* Increment RTO backoff */
1577 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1580 * Try to force the first unsent segment (or buffer)
1582 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1584 b = vlib_get_buffer (vm, bi);
1585 data = tcp_init_buffer (vm, b);
1587 tcp_validate_txf_size (tc, offset);
1588 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1589 max_snd_bytes = clib_min (tc->snd_mss, tm->bytes_per_buffer - MAX_HDRS_LEN);
1590 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1592 b->current_length = n_bytes;
1593 ASSERT (n_bytes != 0 && (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)
1594 || tc->snd_nxt == tc->snd_una_max
1595 || tc->rto_boff > 1));
1597 tcp_push_hdr_i (tc, b, tc->state, 0);
1598 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1600 /* Just sent new data, enable retransmit */
1601 tcp_retransmit_timer_update (tc);
1605 * Retransmit first unacked segment
1608 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1610 vlib_main_t *vm = vlib_get_main ();
1612 u32 bi, old_snd_nxt, n_bytes;
1614 old_snd_nxt = tc->snd_nxt;
1615 tc->snd_nxt = tc->snd_una;
1617 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2);
1618 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1621 bi = vlib_get_buffer_index (vm, b);
1622 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1624 tc->snd_nxt = old_snd_nxt;
1628 * Do fast retransmit with SACKs
1631 tcp_fast_retransmit_sack (tcp_connection_t * tc)
1633 vlib_main_t *vm = vlib_get_main ();
1634 u32 n_written = 0, offset, max_bytes, n_segs = 0;
1635 vlib_buffer_t *b = 0;
1636 sack_scoreboard_hole_t *hole;
1637 sack_scoreboard_t *sb;
1638 u32 bi, old_snd_nxt;
1640 u8 snd_limited = 0, can_rescue = 0;
1642 ASSERT (tcp_in_fastrecovery (tc));
1644 old_snd_nxt = tc->snd_nxt;
1646 snd_space = tcp_available_cc_snd_space (tc);
1648 if (snd_space < tc->snd_mss)
1651 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1652 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1653 while (hole && snd_space > 0 && n_segs++ < VLIB_FRAME_SIZE)
1655 hole = scoreboard_next_rxt_hole (sb, hole,
1656 tcp_fastrecovery_sent_1_smss (tc),
1657 &can_rescue, &snd_limited);
1660 if (!can_rescue || !(seq_lt (sb->rescue_rxt, tc->snd_una)
1661 || seq_gt (sb->rescue_rxt,
1662 tc->snd_congestion)))
1665 /* If rescue rxt undefined or less than snd_una then one segment of
1666 * up to SMSS octets that MUST include the highest outstanding
1667 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1668 * RecoveryPoint. HighRxt MUST NOT be updated.
1670 max_bytes = clib_min (tc->snd_mss,
1671 tc->snd_congestion - tc->snd_una);
1672 max_bytes = clib_min (max_bytes, snd_space);
1673 offset = tc->snd_congestion - tc->snd_una - max_bytes;
1674 sb->rescue_rxt = tc->snd_congestion;
1675 tc->snd_nxt = tc->snd_una + offset;
1676 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes,
1681 bi = vlib_get_buffer_index (vm, b);
1682 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1686 max_bytes = clib_min (hole->end - sb->high_rxt, snd_space);
1687 max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes;
1690 offset = sb->high_rxt - tc->snd_una;
1691 tc->snd_nxt = sb->high_rxt;
1692 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes, &b);
1694 /* Nothing left to retransmit */
1698 bi = vlib_get_buffer_index (vm, b);
1699 sb->high_rxt += n_written;
1700 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1701 ASSERT (n_written <= snd_space);
1702 snd_space -= n_written;
1706 /* If window allows, send 1 SMSS of new data */
1707 tc->snd_nxt = old_snd_nxt;
1711 * Fast retransmit without SACK info
1714 tcp_fast_retransmit_no_sack (tcp_connection_t * tc)
1716 vlib_main_t *vm = vlib_get_main ();
1717 u32 n_written = 0, offset = 0, bi, old_snd_nxt;
1721 ASSERT (tcp_in_fastrecovery (tc));
1722 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1724 /* Start resending from first un-acked segment */
1725 old_snd_nxt = tc->snd_nxt;
1726 tc->snd_nxt = tc->snd_una;
1727 snd_space = tcp_available_cc_snd_space (tc);
1729 while (snd_space > 0)
1731 offset += n_written;
1732 n_written = tcp_prepare_retransmit_segment (tc, offset, snd_space, &b);
1734 /* Nothing left to retransmit */
1738 bi = vlib_get_buffer_index (vm, b);
1739 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1740 snd_space -= n_written;
1743 /* Restore snd_nxt. If window allows, send 1 SMSS of new data */
1744 tc->snd_nxt = old_snd_nxt;
1748 * Do fast retransmit
1751 tcp_fast_retransmit (tcp_connection_t * tc)
1753 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1754 tcp_fast_retransmit_sack (tc);
1756 tcp_fast_retransmit_no_sack (tc);
1760 tcp_session_has_ooo_data (tcp_connection_t * tc)
1762 stream_session_t *s = session_get (tc->c_s_index, tc->c_thread_index);
1763 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1767 tcp_output_handle_link_local (tcp_connection_t * tc0, vlib_buffer_t * b0,
1768 u32 * next0, u32 * error0)
1770 ip_adjacency_t *adj;
1773 /* Not thread safe but as long as the connection exists the adj should
1775 ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &tc0->c_rmt_ip,
1777 if (ai == ADJ_INDEX_INVALID)
1779 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
1780 *next0 = TCP_OUTPUT_NEXT_DROP;
1781 *error0 = TCP_ERROR_LINK_LOCAL_RW;
1786 if (PREDICT_TRUE (adj->lookup_next_index == IP_LOOKUP_NEXT_REWRITE))
1787 *next0 = TCP_OUTPUT_NEXT_IP_REWRITE;
1788 else if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP)
1789 *next0 = TCP_OUTPUT_NEXT_IP_ARP;
1792 *next0 = TCP_OUTPUT_NEXT_DROP;
1793 *error0 = TCP_ERROR_LINK_LOCAL_RW;
1795 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ai;
1799 tcp46_output_inline (vlib_main_t * vm,
1800 vlib_node_runtime_t * node,
1801 vlib_frame_t * from_frame, int is_ip4)
1803 u32 n_left_from, next_index, *from, *to_next;
1804 u32 my_thread_index = vm->thread_index;
1806 from = vlib_frame_vector_args (from_frame);
1807 n_left_from = from_frame->n_vectors;
1808 next_index = node->cached_next_index;
1809 tcp_set_time_now (my_thread_index);
1811 while (n_left_from > 0)
1815 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1817 while (n_left_from > 0 && n_left_to_next > 0)
1821 tcp_connection_t *tc0;
1823 tcp_header_t *th0 = 0;
1824 u32 error0 = TCP_ERROR_PKTS_SENT, next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
1826 if (n_left_from > 1)
1829 pb = vlib_get_buffer (vm, from[1]);
1830 vlib_prefetch_buffer_header (pb, STORE);
1831 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
1839 n_left_to_next -= 1;
1841 b0 = vlib_get_buffer (vm, bi0);
1842 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1844 if (PREDICT_FALSE (tc0 == 0 || tc0->state == TCP_STATE_CLOSED))
1846 error0 = TCP_ERROR_INVALID_CONNECTION;
1847 next0 = TCP_OUTPUT_NEXT_DROP;
1851 th0 = vlib_buffer_get_current (b0);
1852 TCP_EVT_DBG (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
1853 vnet_buffer (b0)->sw_if_index[VLIB_TX] = tc0->c_fib_index;
1854 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
1858 vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
1859 IP_PROTOCOL_TCP, 1);
1860 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1861 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1867 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6,
1868 &tc0->c_rmt_ip6, IP_PROTOCOL_TCP);
1869 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1870 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ih0 - b0->data;
1871 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1875 (ip6_address_is_link_local_unicast (&tc0->c_rmt_ip6)))
1876 tcp_output_handle_link_local (tc0, b0, &next0, &error0);
1879 /* Filter out DUPACKs if there are no OOO segments left */
1881 (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1883 /* N.B. Should not filter burst of dupacks. Two issues:
1884 * 1) dupacks open cwnd on remote peer when congested
1885 * 2) acks leaving should have the latest rcv_wnd since the
1886 * burst may have eaten up all of it, so only the old ones
1887 * could be filtered.
1889 if (!tcp_session_has_ooo_data (tc0))
1891 error0 = TCP_ERROR_FILTERED_DUPACKS;
1892 next0 = TCP_OUTPUT_NEXT_DROP;
1897 /* Stop DELACK timer and fix flags */
1898 tc0->flags &= ~(TCP_CONN_SNDACK);
1899 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1901 /* If not retransmitting
1902 * 1) update snd_una_max (SYN, SYNACK, FIN)
1903 * 2) If we're not tracking an ACK, start tracking */
1904 if (seq_lt (tc0->snd_una_max, tc0->snd_nxt))
1906 tc0->snd_una_max = tc0->snd_nxt;
1907 if (tc0->rtt_ts == 0)
1909 tc0->rtt_ts = tcp_time_now ();
1910 tc0->rtt_seq = tc0->snd_nxt;
1914 /* Set the retransmit timer if not set already and not
1915 * doing a pure ACK */
1916 if (!tcp_timer_is_active (tc0, TCP_TIMER_RETRANSMIT)
1917 && tc0->snd_nxt != tc0->snd_una)
1919 tcp_retransmit_timer_set (tc0);
1924 /* Make sure we haven't lost route to our peer */
1925 if (PREDICT_FALSE (tc0->last_fib_check
1926 < tc0->snd_opts.tsval + TCP_FIB_RECHECK_PERIOD))
1929 (tc0->c_rmt_fei == tcp_lookup_rmt_in_fib (tc0)))
1931 tc0->last_fib_check = tc0->snd_opts.tsval;
1935 clib_warning ("lost connection to peer");
1936 tcp_connection_reset (tc0);
1941 /* Use pre-computed dpo to set next node */
1942 next0 = tc0->c_rmt_dpo.dpoi_next_node;
1943 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = tc0->c_rmt_dpo.dpoi_index;
1947 b0->error = node->errors[error0];
1948 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1950 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1953 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1957 memset (&t0->tcp_header, 0, sizeof (t0->tcp_header));
1959 clib_memcpy (&t0->tcp_connection, tc0,
1960 sizeof (t0->tcp_connection));
1963 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1964 n_left_to_next, bi0, next0);
1967 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1970 return from_frame->n_vectors;
1974 tcp4_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1975 vlib_frame_t * from_frame)
1977 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1981 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1982 vlib_frame_t * from_frame)
1984 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1988 VLIB_REGISTER_NODE (tcp4_output_node) =
1990 .function = tcp4_output,.name = "tcp4-output",
1991 /* Takes a vector of packets. */
1992 .vector_size = sizeof (u32),
1993 .n_errors = TCP_N_ERROR,
1994 .error_strings = tcp_error_strings,
1995 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1997 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1998 foreach_tcp4_output_next
2001 .format_buffer = format_tcp_header,
2002 .format_trace = format_tcp_tx_trace,
2006 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output);
2009 VLIB_REGISTER_NODE (tcp6_output_node) =
2011 .function = tcp6_output,
2012 .name = "tcp6-output",
2013 /* Takes a vector of packets. */
2014 .vector_size = sizeof (u32),
2015 .n_errors = TCP_N_ERROR,
2016 .error_strings = tcp_error_strings,
2017 .n_next_nodes = TCP_OUTPUT_N_NEXT,
2019 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
2020 foreach_tcp6_output_next
2023 .format_buffer = format_tcp_header,
2024 .format_trace = format_tcp_tx_trace,
2028 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output);
2031 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
2033 tcp_connection_t *tc;
2035 tc = (tcp_connection_t *) tconn;
2036 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, 0);
2037 ASSERT (seq_leq (tc->snd_una_max, tc->snd_una + tc->snd_wnd));
2039 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
2041 tc->rtt_ts = tcp_time_now ();
2042 tc->rtt_seq = tc->snd_nxt;
2044 tcp_trajectory_add_start (b, 3);
2048 typedef enum _tcp_reset_next
2050 TCP_RESET_NEXT_DROP,
2051 TCP_RESET_NEXT_IP_LOOKUP,
2055 #define foreach_tcp4_reset_next \
2056 _(DROP, "error-drop") \
2057 _(IP_LOOKUP, "ip4-lookup")
2059 #define foreach_tcp6_reset_next \
2060 _(DROP, "error-drop") \
2061 _(IP_LOOKUP, "ip6-lookup")
2064 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2065 vlib_frame_t * from_frame, u8 is_ip4)
2067 u32 n_left_from, next_index, *from, *to_next;
2068 u32 my_thread_index = vm->thread_index;
2070 from = vlib_frame_vector_args (from_frame);
2071 n_left_from = from_frame->n_vectors;
2073 next_index = node->cached_next_index;
2075 while (n_left_from > 0)
2079 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2081 while (n_left_from > 0 && n_left_to_next > 0)
2087 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
2094 n_left_to_next -= 1;
2096 b0 = vlib_get_buffer (vm, bi0);
2098 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
2099 my_thread_index, is_ip4))
2101 error0 = TCP_ERROR_LOOKUP_DROPS;
2102 next0 = TCP_RESET_NEXT_DROP;
2106 /* Prepare to send to IP lookup */
2107 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
2108 next0 = TCP_RESET_NEXT_IP_LOOKUP;
2111 b0->error = node->errors[error0];
2112 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
2113 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2115 th0 = vlib_buffer_get_current (b0);
2117 th0 = ip4_next_header ((ip4_header_t *) th0);
2119 th0 = ip6_next_header ((ip6_header_t *) th0);
2120 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2121 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2124 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2125 n_left_to_next, bi0, next0);
2127 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2129 return from_frame->n_vectors;
2133 tcp4_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
2134 vlib_frame_t * from_frame)
2136 return tcp46_send_reset_inline (vm, node, from_frame, 1);
2140 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
2141 vlib_frame_t * from_frame)
2143 return tcp46_send_reset_inline (vm, node, from_frame, 0);
2147 VLIB_REGISTER_NODE (tcp4_reset_node) = {
2148 .function = tcp4_send_reset,
2149 .name = "tcp4-reset",
2150 .vector_size = sizeof (u32),
2151 .n_errors = TCP_N_ERROR,
2152 .error_strings = tcp_error_strings,
2153 .n_next_nodes = TCP_RESET_N_NEXT,
2155 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2156 foreach_tcp4_reset_next
2159 .format_trace = format_tcp_tx_trace,
2163 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset);
2166 VLIB_REGISTER_NODE (tcp6_reset_node) = {
2167 .function = tcp6_send_reset,
2168 .name = "tcp6-reset",
2169 .vector_size = sizeof (u32),
2170 .n_errors = TCP_N_ERROR,
2171 .error_strings = tcp_error_strings,
2172 .n_next_nodes = TCP_RESET_N_NEXT,
2174 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2175 foreach_tcp6_reset_next
2178 .format_trace = format_tcp_tx_trace,
2182 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset);
2185 * fd.io coding-style-patch-verification: ON
2188 * eval: (c-set-style "gnu")