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 case TCP_STATE_CLOSE_WAIT:
1094 return TCP_FLAG_ACK;
1095 case TCP_STATE_SYN_RCVD:
1096 return TCP_FLAG_SYN | TCP_FLAG_ACK;
1097 case TCP_STATE_SYN_SENT:
1098 return TCP_FLAG_SYN;
1099 case TCP_STATE_LAST_ACK:
1100 case TCP_STATE_FIN_WAIT_1:
1101 if (tc->snd_nxt + 1 < tc->snd_una_max)
1102 return TCP_FLAG_ACK;
1104 return TCP_FLAG_FIN;
1106 clib_warning ("Shouldn't be here!");
1112 * Push TCP header and update connection variables
1115 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
1116 tcp_state_t next_state, u8 compute_opts)
1118 u32 advertise_wnd, data_len;
1119 u8 tcp_hdr_opts_len, opts_write_len, flags;
1122 data_len = b->current_length + b->total_length_not_including_first_buffer;
1123 ASSERT (!b->total_length_not_including_first_buffer
1124 || (b->flags & VLIB_BUFFER_NEXT_PRESENT));
1125 vnet_buffer (b)->tcp.flags = 0;
1128 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1130 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
1131 advertise_wnd = tcp_window_to_advertise (tc, next_state);
1132 flags = tcp_make_state_flags (tc, next_state);
1134 /* Push header and options */
1135 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
1136 tc->rcv_nxt, tcp_hdr_opts_len, flags,
1138 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
1140 ASSERT (opts_write_len == tc->snd_opts_len);
1141 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
1144 * Update connection variables
1147 tc->snd_nxt += data_len;
1148 tc->rcv_las = tc->rcv_nxt;
1150 /* TODO this is updated in output as well ... */
1151 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1153 tc->snd_una_max = tc->snd_nxt;
1154 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1157 TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
1161 tcp_send_ack (tcp_connection_t * tc)
1163 tcp_main_t *tm = vnet_get_tcp_main ();
1164 vlib_main_t *vm = vlib_get_main ();
1170 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1172 b = vlib_get_buffer (vm, bi);
1173 tcp_init_buffer (vm, b);
1175 /* Fill in the ACK */
1176 tcp_make_ack (tc, b);
1177 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1181 * Delayed ack timer handler
1183 * Sends delayed ACK when timer expires
1186 tcp_timer_delack_handler (u32 index)
1188 u32 thread_index = vlib_get_thread_index ();
1189 tcp_connection_t *tc;
1191 tc = tcp_connection_get (index, thread_index);
1192 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
1197 * Build a retransmit segment
1199 * @return the number of bytes in the segment or 0 if there's nothing to
1203 tcp_prepare_retransmit_segment (tcp_connection_t * tc, u32 offset,
1204 u32 max_deq_bytes, vlib_buffer_t ** b)
1206 tcp_main_t *tm = vnet_get_tcp_main ();
1207 vlib_main_t *vm = vlib_get_main ();
1209 u32 start, bi, available_bytes, seg_size;
1212 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1213 ASSERT (max_deq_bytes != 0);
1216 * Make sure we can retransmit something
1218 available_bytes = session_tx_fifo_max_dequeue (&tc->connection);
1219 ASSERT (available_bytes >= offset);
1220 available_bytes -= offset;
1221 if (!available_bytes)
1223 max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
1224 max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
1226 /* Start is beyond snd_congestion */
1227 start = tc->snd_una + offset;
1228 if (seq_geq (start, tc->snd_congestion))
1231 /* Don't overshoot snd_congestion */
1232 if (seq_gt (start + max_deq_bytes, tc->snd_congestion))
1234 max_deq_bytes = tc->snd_congestion - start;
1235 if (max_deq_bytes == 0)
1239 seg_size = max_deq_bytes + MAX_HDRS_LEN;
1244 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1247 * Allocate and fill in buffer(s)
1250 /* Easy case, buffer size greater than mss */
1251 if (PREDICT_TRUE (seg_size <= tm->bytes_per_buffer))
1253 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1255 *b = vlib_get_buffer (vm, bi);
1256 data = tcp_init_buffer (vm, *b);
1257 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1259 ASSERT (n_bytes == max_deq_bytes);
1260 b[0]->current_length = n_bytes;
1261 tcp_push_hdr_i (tc, *b, tc->state, 0);
1263 /* Split mss into multiple buffers */
1266 u32 chain_bi = ~0, n_bufs_per_seg;
1267 u32 thread_index = vlib_get_thread_index ();
1268 u16 n_peeked, len_to_deq, available_bufs;
1269 vlib_buffer_t *chain_b, *prev_b;
1272 /* Make sure we have enough buffers */
1273 n_bufs_per_seg = ceil ((double) seg_size / tm->bytes_per_buffer);
1274 available_bufs = vec_len (tm->tx_buffers[thread_index]);
1275 if (n_bufs_per_seg > available_bufs)
1277 tcp_alloc_tx_buffers (tm, thread_index, &available_bufs,
1280 if (n_bufs_per_seg > available_bufs)
1287 tcp_get_free_buffer_index (tm, &bi);
1288 ASSERT (bi != (u32) ~ 0);
1289 *b = vlib_get_buffer (vm, bi);
1290 data = tcp_init_buffer (vm, *b);
1291 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1292 tm->bytes_per_buffer -
1294 b[0]->current_length = n_bytes;
1295 b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
1296 b[0]->total_length_not_including_first_buffer = 0;
1297 max_deq_bytes -= n_bytes;
1300 for (i = 1; i < n_bufs_per_seg; i++)
1303 len_to_deq = clib_min (max_deq_bytes, tm->bytes_per_buffer);
1304 tcp_get_free_buffer_index (tm, &chain_bi);
1305 ASSERT (chain_bi != (u32) ~ 0);
1306 chain_b = vlib_get_buffer (vm, chain_bi);
1307 chain_b->current_data = 0;
1308 data = vlib_buffer_get_current (chain_b);
1309 n_peeked = stream_session_peek_bytes (&tc->connection, data,
1310 offset + n_bytes, len_to_deq);
1311 ASSERT (n_peeked == len_to_deq);
1312 n_bytes += n_peeked;
1313 chain_b->current_length = n_peeked;
1314 chain_b->next_buffer = 0;
1316 /* update previous buffer */
1317 prev_b->next_buffer = chain_bi;
1318 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
1320 max_deq_bytes -= n_peeked;
1321 b[0]->total_length_not_including_first_buffer += n_peeked;
1324 tcp_push_hdr_i (tc, *b, tc->state, 0);
1327 ASSERT (n_bytes > 0);
1328 ASSERT (((*b)->current_data + (*b)->current_length) <=
1329 tm->bytes_per_buffer);
1331 if (tcp_in_fastrecovery (tc))
1332 tc->snd_rxt_bytes += n_bytes;
1335 TCP_EVT_DBG (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1340 * Reset congestion control, switch cwnd to loss window and try again.
1343 tcp_rxt_timeout_cc (tcp_connection_t * tc)
1345 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 6);
1346 tc->prev_ssthresh = tc->ssthresh;
1347 tc->prev_cwnd = tc->cwnd;
1349 /* Cleanly recover cc (also clears up fast retransmit) */
1350 if (tcp_in_fastrecovery (tc))
1351 tcp_cc_fastrecovery_exit (tc);
1353 /* Start again from the beginning */
1354 tc->cc_algo->congestion (tc);
1355 tc->cwnd = tcp_loss_wnd (tc);
1356 tc->snd_congestion = tc->snd_una_max;
1358 tc->cwnd_acc_bytes = 0;
1360 tcp_recovery_on (tc);
1364 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
1366 tcp_main_t *tm = vnet_get_tcp_main ();
1367 vlib_main_t *vm = vlib_get_main ();
1368 u32 thread_index = vlib_get_thread_index ();
1369 tcp_connection_t *tc;
1370 vlib_buffer_t *b = 0;
1375 tc = tcp_half_open_connection_get (index);
1376 /* Note: the connection may have transitioned to ESTABLISHED... */
1377 if (PREDICT_FALSE (tc == 0))
1379 tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
1383 tc = tcp_connection_get (index, thread_index);
1384 /* Note: the connection may have been closed and pool_put */
1385 if (PREDICT_FALSE (tc == 0))
1387 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
1390 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1);
1392 if (tc->state >= TCP_STATE_ESTABLISHED)
1394 /* Lost FIN, retransmit and return */
1395 if (tcp_is_lost_fin (tc))
1399 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1403 /* Shouldn't be here */
1404 if ((tc->rto_boff == 0 && tc->snd_una == tc->snd_una_max)
1405 || (tc->rto_boff > 0 && seq_geq (tc->snd_una, tc->snd_congestion)))
1407 tcp_recovery_off (tc);
1411 /* We're not in recovery so make sure rto_boff is 0 */
1412 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1415 tcp_update_rto (tc);
1418 /* Increment RTO backoff (also equal to number of retries) and go back
1419 * to first un-acked byte */
1422 /* First retransmit timeout */
1423 if (tc->rto_boff == 1)
1424 tcp_rxt_timeout_cc (tc);
1426 tc->snd_una_max = tc->snd_nxt = tc->snd_una;
1427 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1429 /* Send one segment. Note that n_bytes may be zero due to buffer shortfall */
1430 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1432 /* TODO be less aggressive about this */
1433 scoreboard_clear (&tc->sack_sb);
1437 tcp_retransmit_timer_set (tc);
1441 bi = vlib_get_buffer_index (vm, b);
1443 /* For first retransmit, record timestamp (Eifel detection RFC3522) */
1444 if (tc->rto_boff == 1)
1445 tc->snd_rxt_ts = tcp_time_now ();
1447 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1448 tcp_retransmit_timer_update (tc);
1450 /* Retransmit for SYN */
1451 else if (tc->state == TCP_STATE_SYN_SENT)
1453 /* Half-open connection actually moved to established but we were
1454 * waiting for syn retransmit to pop to call cleanup from the right
1456 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1458 if (tcp_half_open_connection_cleanup (tc))
1460 clib_warning ("could not remove half-open connection");
1466 /* Try without increasing RTO a number of times. If this fails,
1467 * start growing RTO exponentially */
1469 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1470 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1472 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
1473 tc->rto * TCP_TO_TIMER_TICK);
1475 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1478 b = vlib_get_buffer (vm, bi);
1479 tcp_init_buffer (vm, b);
1480 tcp_make_syn (tc, b);
1483 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 0);
1485 /* This goes straight to ipx_lookup. Retransmit timer set already */
1486 tcp_push_ip_hdr (tm, tc, b);
1487 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4, tc->c_fib_index);
1489 /* Retransmit SYN-ACK */
1490 else if (tc->state == TCP_STATE_SYN_RCVD)
1493 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1494 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1497 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1499 tcp_retransmit_timer_force_update (tc);
1503 b = vlib_get_buffer (vm, bi);
1504 tcp_init_buffer (vm, b);
1505 tcp_make_synack (tc, b);
1506 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc, 1);
1508 /* Retransmit timer already updated, just enqueue to output */
1509 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1513 ASSERT (tc->state == TCP_STATE_CLOSED);
1519 tcp_timer_retransmit_handler (u32 index)
1521 tcp_timer_retransmit_handler_i (index, 0);
1525 tcp_timer_retransmit_syn_handler (u32 index)
1527 tcp_timer_retransmit_handler_i (index, 1);
1531 * Got 0 snd_wnd from peer, try to do something about it.
1535 tcp_timer_persist_handler (u32 index)
1537 tcp_main_t *tm = vnet_get_tcp_main ();
1538 vlib_main_t *vm = vlib_get_main ();
1539 u32 thread_index = vlib_get_thread_index ();
1540 tcp_connection_t *tc;
1542 u32 bi, max_snd_bytes, available_bytes, offset;
1546 tc = tcp_connection_get_if_valid (index, thread_index);
1551 /* Make sure timer handle is set to invalid */
1552 tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
1554 /* Problem already solved or worse */
1555 if (tc->state == TCP_STATE_CLOSED || tc->state > TCP_STATE_ESTABLISHED
1556 || tc->snd_wnd > tc->snd_mss || tcp_in_recovery (tc))
1559 available_bytes = session_tx_fifo_max_dequeue (&tc->connection);
1560 offset = tc->snd_una_max - tc->snd_una;
1562 /* Reprogram persist if no new bytes available to send. We may have data
1564 if (!available_bytes)
1566 tcp_persist_timer_set (tc);
1570 if (available_bytes <= offset)
1572 ASSERT (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1576 /* Increment RTO backoff */
1578 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1581 * Try to force the first unsent segment (or buffer)
1583 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1585 b = vlib_get_buffer (vm, bi);
1586 data = tcp_init_buffer (vm, b);
1588 tcp_validate_txf_size (tc, offset);
1589 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1590 max_snd_bytes = clib_min (tc->snd_mss, tm->bytes_per_buffer - MAX_HDRS_LEN);
1591 n_bytes = stream_session_peek_bytes (&tc->connection, data, offset,
1593 b->current_length = n_bytes;
1594 ASSERT (n_bytes != 0 && (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)
1595 || tc->snd_nxt == tc->snd_una_max
1596 || tc->rto_boff > 1));
1598 tcp_push_hdr_i (tc, b, tc->state, 0);
1599 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1601 /* Just sent new data, enable retransmit */
1602 tcp_retransmit_timer_update (tc);
1606 * Retransmit first unacked segment
1609 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1611 vlib_main_t *vm = vlib_get_main ();
1613 u32 bi, old_snd_nxt, n_bytes;
1615 old_snd_nxt = tc->snd_nxt;
1616 tc->snd_nxt = tc->snd_una;
1618 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2);
1619 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1622 bi = vlib_get_buffer_index (vm, b);
1623 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1625 tc->snd_nxt = old_snd_nxt;
1629 * Do fast retransmit with SACKs
1632 tcp_fast_retransmit_sack (tcp_connection_t * tc)
1634 vlib_main_t *vm = vlib_get_main ();
1635 u32 n_written = 0, offset, max_bytes, n_segs = 0;
1636 vlib_buffer_t *b = 0;
1637 sack_scoreboard_hole_t *hole;
1638 sack_scoreboard_t *sb;
1639 u32 bi, old_snd_nxt;
1641 u8 snd_limited = 0, can_rescue = 0;
1643 ASSERT (tcp_in_fastrecovery (tc));
1645 old_snd_nxt = tc->snd_nxt;
1647 snd_space = tcp_available_cc_snd_space (tc);
1649 if (snd_space < tc->snd_mss)
1652 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1653 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1654 while (hole && snd_space > 0 && n_segs++ < VLIB_FRAME_SIZE)
1656 hole = scoreboard_next_rxt_hole (sb, hole,
1657 tcp_fastrecovery_sent_1_smss (tc),
1658 &can_rescue, &snd_limited);
1661 if (!can_rescue || !(seq_lt (sb->rescue_rxt, tc->snd_una)
1662 || seq_gt (sb->rescue_rxt,
1663 tc->snd_congestion)))
1666 /* If rescue rxt undefined or less than snd_una then one segment of
1667 * up to SMSS octets that MUST include the highest outstanding
1668 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1669 * RecoveryPoint. HighRxt MUST NOT be updated.
1671 max_bytes = clib_min (tc->snd_mss,
1672 tc->snd_congestion - tc->snd_una);
1673 max_bytes = clib_min (max_bytes, snd_space);
1674 offset = tc->snd_congestion - tc->snd_una - max_bytes;
1675 sb->rescue_rxt = tc->snd_congestion;
1676 tc->snd_nxt = tc->snd_una + offset;
1677 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes,
1682 bi = vlib_get_buffer_index (vm, b);
1683 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1687 max_bytes = clib_min (hole->end - sb->high_rxt, snd_space);
1688 max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes;
1691 offset = sb->high_rxt - tc->snd_una;
1692 tc->snd_nxt = sb->high_rxt;
1693 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes, &b);
1695 /* Nothing left to retransmit */
1699 bi = vlib_get_buffer_index (vm, b);
1700 sb->high_rxt += n_written;
1701 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1702 ASSERT (n_written <= snd_space);
1703 snd_space -= n_written;
1707 /* If window allows, send 1 SMSS of new data */
1708 tc->snd_nxt = old_snd_nxt;
1712 * Fast retransmit without SACK info
1715 tcp_fast_retransmit_no_sack (tcp_connection_t * tc)
1717 vlib_main_t *vm = vlib_get_main ();
1718 u32 n_written = 0, offset = 0, bi, old_snd_nxt;
1722 ASSERT (tcp_in_fastrecovery (tc));
1723 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1725 /* Start resending from first un-acked segment */
1726 old_snd_nxt = tc->snd_nxt;
1727 tc->snd_nxt = tc->snd_una;
1728 snd_space = tcp_available_cc_snd_space (tc);
1730 while (snd_space > 0)
1732 offset += n_written;
1733 n_written = tcp_prepare_retransmit_segment (tc, offset, snd_space, &b);
1735 /* Nothing left to retransmit */
1739 bi = vlib_get_buffer_index (vm, b);
1740 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1741 snd_space -= n_written;
1744 /* Restore snd_nxt. If window allows, send 1 SMSS of new data */
1745 tc->snd_nxt = old_snd_nxt;
1749 * Do fast retransmit
1752 tcp_fast_retransmit (tcp_connection_t * tc)
1754 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1755 tcp_fast_retransmit_sack (tc);
1757 tcp_fast_retransmit_no_sack (tc);
1761 tcp_session_has_ooo_data (tcp_connection_t * tc)
1763 stream_session_t *s = session_get (tc->c_s_index, tc->c_thread_index);
1764 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1768 tcp_output_handle_link_local (tcp_connection_t * tc0, vlib_buffer_t * b0,
1769 u32 * next0, u32 * error0)
1771 ip_adjacency_t *adj;
1774 /* Not thread safe but as long as the connection exists the adj should
1776 ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &tc0->c_rmt_ip,
1778 if (ai == ADJ_INDEX_INVALID)
1780 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
1781 *next0 = TCP_OUTPUT_NEXT_DROP;
1782 *error0 = TCP_ERROR_LINK_LOCAL_RW;
1787 if (PREDICT_TRUE (adj->lookup_next_index == IP_LOOKUP_NEXT_REWRITE))
1788 *next0 = TCP_OUTPUT_NEXT_IP_REWRITE;
1789 else if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP)
1790 *next0 = TCP_OUTPUT_NEXT_IP_ARP;
1793 *next0 = TCP_OUTPUT_NEXT_DROP;
1794 *error0 = TCP_ERROR_LINK_LOCAL_RW;
1796 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ai;
1800 tcp46_output_inline (vlib_main_t * vm,
1801 vlib_node_runtime_t * node,
1802 vlib_frame_t * from_frame, int is_ip4)
1804 u32 n_left_from, next_index, *from, *to_next;
1805 u32 my_thread_index = vm->thread_index;
1807 from = vlib_frame_vector_args (from_frame);
1808 n_left_from = from_frame->n_vectors;
1809 next_index = node->cached_next_index;
1810 tcp_set_time_now (my_thread_index);
1812 while (n_left_from > 0)
1816 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1818 while (n_left_from > 0 && n_left_to_next > 0)
1822 tcp_connection_t *tc0;
1824 tcp_header_t *th0 = 0;
1825 u32 error0 = TCP_ERROR_PKTS_SENT, next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
1827 if (n_left_from > 1)
1830 pb = vlib_get_buffer (vm, from[1]);
1831 vlib_prefetch_buffer_header (pb, STORE);
1832 CLIB_PREFETCH (pb->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
1840 n_left_to_next -= 1;
1842 b0 = vlib_get_buffer (vm, bi0);
1843 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1845 if (PREDICT_FALSE (tc0 == 0 || tc0->state == TCP_STATE_CLOSED))
1847 error0 = TCP_ERROR_INVALID_CONNECTION;
1848 next0 = TCP_OUTPUT_NEXT_DROP;
1852 th0 = vlib_buffer_get_current (b0);
1853 TCP_EVT_DBG (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
1854 vnet_buffer (b0)->sw_if_index[VLIB_TX] = tc0->c_fib_index;
1855 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
1859 vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
1860 IP_PROTOCOL_TCP, 1);
1861 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1862 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1868 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6,
1869 &tc0->c_rmt_ip6, IP_PROTOCOL_TCP);
1870 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1871 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ih0 - b0->data;
1872 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1876 (ip6_address_is_link_local_unicast (&tc0->c_rmt_ip6)))
1877 tcp_output_handle_link_local (tc0, b0, &next0, &error0);
1880 /* Filter out DUPACKs if there are no OOO segments left */
1882 (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1884 /* N.B. Should not filter burst of dupacks. Two issues:
1885 * 1) dupacks open cwnd on remote peer when congested
1886 * 2) acks leaving should have the latest rcv_wnd since the
1887 * burst may have eaten up all of it, so only the old ones
1888 * could be filtered.
1890 if (!tcp_session_has_ooo_data (tc0))
1892 error0 = TCP_ERROR_FILTERED_DUPACKS;
1893 next0 = TCP_OUTPUT_NEXT_DROP;
1898 /* Stop DELACK timer and fix flags */
1899 tc0->flags &= ~(TCP_CONN_SNDACK);
1900 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1902 /* If not retransmitting
1903 * 1) update snd_una_max (SYN, SYNACK, FIN)
1904 * 2) If we're not tracking an ACK, start tracking */
1905 if (seq_lt (tc0->snd_una_max, tc0->snd_nxt))
1907 tc0->snd_una_max = tc0->snd_nxt;
1908 if (tc0->rtt_ts == 0)
1910 tc0->rtt_ts = tcp_time_now ();
1911 tc0->rtt_seq = tc0->snd_nxt;
1915 /* Set the retransmit timer if not set already and not
1916 * doing a pure ACK */
1917 if (!tcp_timer_is_active (tc0, TCP_TIMER_RETRANSMIT)
1918 && tc0->snd_nxt != tc0->snd_una)
1920 tcp_retransmit_timer_set (tc0);
1925 /* Make sure we haven't lost route to our peer */
1926 if (PREDICT_FALSE (tc0->last_fib_check
1927 < tc0->snd_opts.tsval + TCP_FIB_RECHECK_PERIOD))
1930 (tc0->c_rmt_fei == tcp_lookup_rmt_in_fib (tc0)))
1932 tc0->last_fib_check = tc0->snd_opts.tsval;
1936 clib_warning ("lost connection to peer");
1937 tcp_connection_reset (tc0);
1942 /* Use pre-computed dpo to set next node */
1943 next0 = tc0->c_rmt_dpo.dpoi_next_node;
1944 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = tc0->c_rmt_dpo.dpoi_index;
1948 b0->error = node->errors[error0];
1949 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1951 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1954 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1958 memset (&t0->tcp_header, 0, sizeof (t0->tcp_header));
1960 clib_memcpy (&t0->tcp_connection, tc0,
1961 sizeof (t0->tcp_connection));
1964 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1965 n_left_to_next, bi0, next0);
1968 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1971 return from_frame->n_vectors;
1975 tcp4_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, 1 /* is_ip4 */ );
1982 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1983 vlib_frame_t * from_frame)
1985 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1989 VLIB_REGISTER_NODE (tcp4_output_node) =
1991 .function = tcp4_output,.name = "tcp4-output",
1992 /* Takes a vector of packets. */
1993 .vector_size = sizeof (u32),
1994 .n_errors = TCP_N_ERROR,
1995 .error_strings = tcp_error_strings,
1996 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1998 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1999 foreach_tcp4_output_next
2002 .format_buffer = format_tcp_header,
2003 .format_trace = format_tcp_tx_trace,
2007 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output);
2010 VLIB_REGISTER_NODE (tcp6_output_node) =
2012 .function = tcp6_output,
2013 .name = "tcp6-output",
2014 /* Takes a vector of packets. */
2015 .vector_size = sizeof (u32),
2016 .n_errors = TCP_N_ERROR,
2017 .error_strings = tcp_error_strings,
2018 .n_next_nodes = TCP_OUTPUT_N_NEXT,
2020 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
2021 foreach_tcp6_output_next
2024 .format_buffer = format_tcp_header,
2025 .format_trace = format_tcp_tx_trace,
2029 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output);
2032 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
2034 tcp_connection_t *tc;
2036 tc = (tcp_connection_t *) tconn;
2037 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, 0);
2038 ASSERT (seq_leq (tc->snd_una_max, tc->snd_una + tc->snd_wnd));
2040 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
2042 tc->rtt_ts = tcp_time_now ();
2043 tc->rtt_seq = tc->snd_nxt;
2045 tcp_trajectory_add_start (b, 3);
2049 typedef enum _tcp_reset_next
2051 TCP_RESET_NEXT_DROP,
2052 TCP_RESET_NEXT_IP_LOOKUP,
2056 #define foreach_tcp4_reset_next \
2057 _(DROP, "error-drop") \
2058 _(IP_LOOKUP, "ip4-lookup")
2060 #define foreach_tcp6_reset_next \
2061 _(DROP, "error-drop") \
2062 _(IP_LOOKUP, "ip6-lookup")
2065 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2066 vlib_frame_t * from_frame, u8 is_ip4)
2068 u32 n_left_from, next_index, *from, *to_next;
2069 u32 my_thread_index = vm->thread_index;
2071 from = vlib_frame_vector_args (from_frame);
2072 n_left_from = from_frame->n_vectors;
2074 next_index = node->cached_next_index;
2076 while (n_left_from > 0)
2080 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2082 while (n_left_from > 0 && n_left_to_next > 0)
2088 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
2095 n_left_to_next -= 1;
2097 b0 = vlib_get_buffer (vm, bi0);
2099 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
2100 my_thread_index, is_ip4))
2102 error0 = TCP_ERROR_LOOKUP_DROPS;
2103 next0 = TCP_RESET_NEXT_DROP;
2107 /* Prepare to send to IP lookup */
2108 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
2109 next0 = TCP_RESET_NEXT_IP_LOOKUP;
2112 b0->error = node->errors[error0];
2113 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
2114 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2116 th0 = vlib_buffer_get_current (b0);
2118 th0 = ip4_next_header ((ip4_header_t *) th0);
2120 th0 = ip6_next_header ((ip6_header_t *) th0);
2121 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2122 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
2125 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2126 n_left_to_next, bi0, next0);
2128 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2130 return from_frame->n_vectors;
2134 tcp4_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, 1);
2141 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
2142 vlib_frame_t * from_frame)
2144 return tcp46_send_reset_inline (vm, node, from_frame, 0);
2148 VLIB_REGISTER_NODE (tcp4_reset_node) = {
2149 .function = tcp4_send_reset,
2150 .name = "tcp4-reset",
2151 .vector_size = sizeof (u32),
2152 .n_errors = TCP_N_ERROR,
2153 .error_strings = tcp_error_strings,
2154 .n_next_nodes = TCP_RESET_N_NEXT,
2156 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2157 foreach_tcp4_reset_next
2160 .format_trace = format_tcp_tx_trace,
2164 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset);
2167 VLIB_REGISTER_NODE (tcp6_reset_node) = {
2168 .function = tcp6_send_reset,
2169 .name = "tcp6-reset",
2170 .vector_size = sizeof (u32),
2171 .n_errors = TCP_N_ERROR,
2172 .error_strings = tcp_error_strings,
2173 .n_next_nodes = TCP_RESET_N_NEXT,
2175 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2176 foreach_tcp6_reset_next
2179 .format_trace = format_tcp_tx_trace,
2183 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset);
2186 * fd.io coding-style-patch-verification: ON
2189 * eval: (c-set-style "gnu")