2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vnet/tcp/tcp.h>
17 #include <vnet/lisp-cp/packets.h>
20 vlib_node_registration_t tcp4_output_node;
21 vlib_node_registration_t tcp6_output_node;
23 typedef enum _tcp_output_next
26 TCP_OUTPUT_NEXT_IP_LOOKUP,
30 #define foreach_tcp4_output_next \
31 _ (DROP, "error-drop") \
32 _ (IP_LOOKUP, "ip4-lookup")
34 #define foreach_tcp6_output_next \
35 _ (DROP, "error-drop") \
36 _ (IP_LOOKUP, "ip6-lookup")
38 static char *tcp_error_strings[] = {
39 #define tcp_error(n,s) s,
40 #include <vnet/tcp/tcp_error.def>
46 tcp_header_t tcp_header;
47 tcp_connection_t tcp_connection;
53 format_tcp_tx_trace (u8 * s, va_list * args)
55 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
56 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
57 tcp_tx_trace_t *t = va_arg (*args, tcp_tx_trace_t *);
58 uword indent = format_get_indent (s);
60 s = format (s, "%U\n%U%U",
61 format_tcp_header, &t->tcp_header, 128,
62 format_white_space, indent,
63 format_tcp_connection, &t->tcp_connection, 1);
69 tcp_window_compute_scale (u32 available_space)
72 while (wnd_scale < TCP_MAX_WND_SCALE
73 && (available_space >> wnd_scale) > TCP_WND_MAX)
79 * Update max segment size we're able to process.
81 * The value is constrained by our interface's MTU and IP options. It is
82 * also what we advertise to our peer.
85 tcp_update_rcv_mss (tcp_connection_t * tc)
87 /* TODO find our iface MTU */
88 tc->mss = dummy_mtu - sizeof (tcp_header_t);
92 * TCP's initial window
95 tcp_initial_wnd_unscaled (tcp_connection_t * tc)
97 /* RFC 6928 recommends the value lower. However at the time our connections
98 * are initialized, fifos may not be allocated. Therefore, advertise the
99 * smallest possible unscaled window size and update once fifos are
100 * assigned to the session.
103 tcp_update_rcv_mss (tc);
104 TCP_IW_N_SEGMENTS * tc->mss;
106 return TCP_MIN_RX_FIFO_SIZE;
110 * Compute initial window and scale factor. As per RFC1323, window field in
111 * SYN and SYN-ACK segments is never scaled.
114 tcp_initial_window_to_advertise (tcp_connection_t * tc)
118 /* Initial wnd for SYN. Fifos are not allocated yet.
119 * Use some predefined value. For SYN-ACK we still want the
120 * scale to be computed in the same way */
121 max_fifo = TCP_MAX_RX_FIFO_SIZE;
123 tc->rcv_wscale = tcp_window_compute_scale (max_fifo);
124 tc->rcv_wnd = tcp_initial_wnd_unscaled (tc);
126 return clib_min (tc->rcv_wnd, TCP_WND_MAX);
130 * Compute and return window to advertise, scaled as per RFC1323
133 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
135 if (state < TCP_STATE_ESTABLISHED)
136 return tcp_initial_window_to_advertise (tc);
138 tcp_update_rcv_wnd (tc);
140 if (tc->rcv_wnd == 0)
142 tc->flags |= TCP_CONN_SENT_RCV_WND0;
146 tc->flags &= ~TCP_CONN_SENT_RCV_WND0;
149 return tc->rcv_wnd >> tc->rcv_wscale;
153 tcp_update_rcv_wnd (tcp_connection_t * tc)
156 u32 available_space, max_fifo, wnd;
159 * Figure out how much space we have available
161 available_space = stream_session_max_rx_enqueue (&tc->connection);
162 max_fifo = stream_session_rx_fifo_size (&tc->connection);
164 ASSERT (tc->rcv_opts.mss < max_fifo);
165 if (available_space < tc->rcv_opts.mss && available_space < max_fifo >> 3)
169 * Use the above and what we know about what we've previously advertised
170 * to compute the new window
172 observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
173 if (observed_wnd < 0)
176 /* Bad. Thou shalt not shrink */
177 if (available_space < observed_wnd)
180 TCP_EVT_DBG (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space);
184 wnd = available_space;
187 /* Make sure we have a multiple of rcv_wscale */
188 if (wnd && tc->rcv_wscale)
190 wnd &= ~(1 << tc->rcv_wscale);
192 wnd = 1 << tc->rcv_wscale;
195 tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale);
199 * Write TCP options to segment.
202 tcp_options_write (u8 * data, tcp_options_t * opts)
205 u32 buf, seq_len = 4;
207 if (tcp_opts_mss (opts))
209 *data++ = TCP_OPTION_MSS;
210 *data++ = TCP_OPTION_LEN_MSS;
211 buf = clib_host_to_net_u16 (opts->mss);
212 clib_memcpy (data, &buf, sizeof (opts->mss));
213 data += sizeof (opts->mss);
214 opts_len += TCP_OPTION_LEN_MSS;
217 if (tcp_opts_wscale (opts))
219 *data++ = TCP_OPTION_WINDOW_SCALE;
220 *data++ = TCP_OPTION_LEN_WINDOW_SCALE;
221 *data++ = opts->wscale;
222 opts_len += TCP_OPTION_LEN_WINDOW_SCALE;
225 if (tcp_opts_sack_permitted (opts))
227 *data++ = TCP_OPTION_SACK_PERMITTED;
228 *data++ = TCP_OPTION_LEN_SACK_PERMITTED;
229 opts_len += TCP_OPTION_LEN_SACK_PERMITTED;
232 if (tcp_opts_tstamp (opts))
234 *data++ = TCP_OPTION_TIMESTAMP;
235 *data++ = TCP_OPTION_LEN_TIMESTAMP;
236 buf = clib_host_to_net_u32 (opts->tsval);
237 clib_memcpy (data, &buf, sizeof (opts->tsval));
238 data += sizeof (opts->tsval);
239 buf = clib_host_to_net_u32 (opts->tsecr);
240 clib_memcpy (data, &buf, sizeof (opts->tsecr));
241 data += sizeof (opts->tsecr);
242 opts_len += TCP_OPTION_LEN_TIMESTAMP;
245 if (tcp_opts_sack (opts))
248 u32 n_sack_blocks = clib_min (vec_len (opts->sacks),
249 TCP_OPTS_MAX_SACK_BLOCKS);
251 if (n_sack_blocks != 0)
253 *data++ = TCP_OPTION_SACK_BLOCK;
254 *data++ = 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
255 for (i = 0; i < n_sack_blocks; i++)
257 buf = clib_host_to_net_u32 (opts->sacks[i].start);
258 clib_memcpy (data, &buf, seq_len);
260 buf = clib_host_to_net_u32 (opts->sacks[i].end);
261 clib_memcpy (data, &buf, seq_len);
264 opts_len += 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
268 /* Terminate TCP options */
271 *data++ = TCP_OPTION_EOL;
272 opts_len += TCP_OPTION_LEN_EOL;
275 /* Pad with zeroes to a u32 boundary */
278 *data++ = TCP_OPTION_NOOP;
279 opts_len += TCP_OPTION_LEN_NOOP;
285 tcp_make_syn_options (tcp_options_t * opts, u8 wnd_scale)
289 opts->flags |= TCP_OPTS_FLAG_MSS;
290 opts->mss = dummy_mtu; /*XXX discover that */
291 len += TCP_OPTION_LEN_MSS;
293 opts->flags |= TCP_OPTS_FLAG_WSCALE;
294 opts->wscale = wnd_scale;
295 len += TCP_OPTION_LEN_WINDOW_SCALE;
297 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
298 opts->tsval = tcp_time_now ();
300 len += TCP_OPTION_LEN_TIMESTAMP;
304 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
305 len += TCP_OPTION_LEN_SACK_PERMITTED;
308 /* Align to needed boundary */
309 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
314 tcp_make_synack_options (tcp_connection_t * tc, tcp_options_t * opts)
318 opts->flags |= TCP_OPTS_FLAG_MSS;
320 len += TCP_OPTION_LEN_MSS;
322 if (tcp_opts_wscale (&tc->rcv_opts))
324 opts->flags |= TCP_OPTS_FLAG_WSCALE;
325 opts->wscale = tc->rcv_wscale;
326 len += TCP_OPTION_LEN_WINDOW_SCALE;
329 if (tcp_opts_tstamp (&tc->rcv_opts))
331 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
332 opts->tsval = tcp_time_now ();
333 opts->tsecr = tc->tsval_recent;
334 len += TCP_OPTION_LEN_TIMESTAMP;
337 if (tcp_opts_sack_permitted (&tc->rcv_opts))
339 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
340 len += TCP_OPTION_LEN_SACK_PERMITTED;
343 /* Align to needed boundary */
344 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
349 tcp_make_established_options (tcp_connection_t * tc, tcp_options_t * opts)
355 if (tcp_opts_tstamp (&tc->rcv_opts))
357 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
358 opts->tsval = tcp_time_now ();
359 opts->tsecr = tc->tsval_recent;
360 len += TCP_OPTION_LEN_TIMESTAMP;
362 if (tcp_opts_sack_permitted (&tc->rcv_opts))
364 if (vec_len (tc->snd_sacks))
366 opts->flags |= TCP_OPTS_FLAG_SACK;
367 opts->sacks = tc->snd_sacks;
368 opts->n_sack_blocks = clib_min (vec_len (tc->snd_sacks),
369 TCP_OPTS_MAX_SACK_BLOCKS);
370 len += 2 + TCP_OPTION_LEN_SACK_BLOCK * opts->n_sack_blocks;
374 /* Align to needed boundary */
375 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
380 tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts,
385 case TCP_STATE_ESTABLISHED:
386 case TCP_STATE_FIN_WAIT_1:
387 return tcp_make_established_options (tc, opts);
388 case TCP_STATE_SYN_RCVD:
389 return tcp_make_synack_options (tc, opts);
390 case TCP_STATE_SYN_SENT:
391 return tcp_make_syn_options (opts, tc->rcv_wscale);
393 clib_warning ("Not handled!");
399 * Update snd_mss to reflect the effective segment size that we can send
400 * by taking into account all TCP options, including SACKs
403 tcp_update_snd_mss (tcp_connection_t * tc)
405 /* Compute options to be used for connection. These may be reused when
406 * sending data or to compute the effective mss (snd_mss) */
408 tcp_make_options (tc, &tc->snd_opts, TCP_STATE_ESTABLISHED);
410 /* XXX check if MTU has been updated */
411 tc->snd_mss = clib_min (tc->mss, tc->rcv_opts.mss) - tc->snd_opts_len;
412 ASSERT (tc->snd_mss > 0);
416 tcp_init_mss (tcp_connection_t * tc)
418 u16 default_min_mss = 536;
419 tcp_update_rcv_mss (tc);
421 /* TODO cache mss and consider PMTU discovery */
422 tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss);
424 if (tc->snd_mss < 45)
426 clib_warning ("snd mss is 0");
427 /* Assume that at least the min default mss works */
428 tc->snd_mss = default_min_mss;
429 tc->rcv_opts.mss = default_min_mss;
432 /* We should have enough space for 40 bytes of options */
433 ASSERT (tc->snd_mss > 45);
435 /* If we use timestamp option, account for it */
436 if (tcp_opts_tstamp (&tc->rcv_opts))
437 tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP;
441 tcp_alloc_tx_buffers (tcp_main_t * tm, u8 thread_index, u32 n_free_buffers)
443 vec_validate (tm->tx_buffers[thread_index], n_free_buffers - 1);
444 _vec_len (tm->tx_buffers[thread_index]) =
445 vlib_buffer_alloc_from_free_list (vlib_get_main (),
446 tm->tx_buffers[thread_index],
448 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
449 /* buffer shortage, report failure */
450 if (vec_len (tm->tx_buffers[thread_index]) == 0)
452 clib_warning ("out of buffers");
459 tcp_get_free_buffer_index (tcp_main_t * tm, u32 * bidx)
462 u32 thread_index = vlib_get_thread_index ();
463 if (PREDICT_FALSE (vec_len (tm->tx_buffers[thread_index]) == 0))
465 if (tcp_alloc_tx_buffers (tm, thread_index, VLIB_FRAME_SIZE))
468 my_tx_buffers = tm->tx_buffers[thread_index];
469 *bidx = my_tx_buffers[_vec_len (my_tx_buffers) - 1];
470 _vec_len (my_tx_buffers) -= 1;
475 tcp_return_buffer (tcp_main_t * tm)
478 u32 thread_index = vlib_get_thread_index ();
479 my_tx_buffers = tm->tx_buffers[thread_index];
480 _vec_len (my_tx_buffers) += 1;
484 tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b)
486 vlib_buffer_t *it = b;
487 u32 save_free_list = b->flags & VLIB_BUFFER_FREE_LIST_INDEX_MASK;
490 it->current_data = 0;
491 it->current_length = 0;
492 it->total_length_not_including_first_buffer = 0;
494 while ((it->flags & VLIB_BUFFER_NEXT_PRESENT)
495 && (it = vlib_get_buffer (vm, it->next_buffer)));
497 if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
498 vlib_buffer_free_one (vm, b->next_buffer);
499 b->flags = save_free_list;
501 /* Leave enough space for headers */
502 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
503 vnet_buffer (b)->tcp.flags = 0;
510 tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
513 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
514 u8 tcp_opts_len, tcp_hdr_opts_len;
518 wnd = tcp_window_to_advertise (tc, state);
520 /* Make and write options */
521 tcp_opts_len = tcp_make_established_options (tc, snd_opts);
522 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
524 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
525 tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd);
527 tcp_options_write ((u8 *) (th + 1), snd_opts);
528 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
532 * Convert buffer to ACK
535 tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
537 vlib_main_t *vm = vlib_get_main ();
539 tcp_reuse_buffer (vm, b);
540 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
541 TCP_EVT_DBG (TCP_EVT_ACK_SENT, tc);
542 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
543 tc->rcv_las = tc->rcv_nxt;
547 * Convert buffer to FIN-ACK
550 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
552 vlib_main_t *vm = vlib_get_main ();
555 tcp_reuse_buffer (vm, b);
557 flags = TCP_FLAG_FIN | TCP_FLAG_ACK;
558 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, flags);
560 /* Reset flags, make sure ack is sent */
561 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
567 * Convert buffer to SYN-ACK
570 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
572 vlib_main_t *vm = vlib_get_main ();
573 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
574 u8 tcp_opts_len, tcp_hdr_opts_len;
579 memset (snd_opts, 0, sizeof (*snd_opts));
581 tcp_reuse_buffer (vm, b);
583 /* Set random initial sequence */
584 time_now = tcp_time_now ();
586 tc->iss = random_u32 (&time_now);
587 tc->snd_una = tc->iss;
588 tc->snd_nxt = tc->iss + 1;
589 tc->snd_una_max = tc->snd_nxt;
591 initial_wnd = tcp_initial_window_to_advertise (tc);
593 /* Make and write options */
594 tcp_opts_len = tcp_make_synack_options (tc, snd_opts);
595 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
597 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
598 tc->rcv_nxt, tcp_hdr_opts_len,
599 TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd);
601 tcp_options_write ((u8 *) (th + 1), snd_opts);
603 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
604 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
606 /* Init retransmit timer */
607 tcp_retransmit_timer_set (tc);
608 TCP_EVT_DBG (TCP_EVT_SYNACK_SENT, tc);
612 tcp_enqueue_to_ip_lookup (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
615 u32 *to_next, next_index;
618 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
621 /* Default FIB for now */
622 vnet_buffer (b)->sw_if_index[VLIB_TX] = 0;
624 /* Send to IP lookup */
625 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
626 f = vlib_get_frame_to_node (vm, next_index);
628 /* Enqueue the packet */
629 to_next = vlib_frame_vector_args (f);
632 vlib_put_frame_to_node (vm, next_index, f);
636 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
637 tcp_state_t state, u8 thread_index, u8 is_ip4)
642 ip4_address_t src_ip40, dst_ip40;
643 ip6_address_t src_ip60, dst_ip60;
644 u16 src_port, dst_port;
649 /* Find IP and TCP headers */
650 th0 = tcp_buffer_hdr (b0);
652 /* Save src and dst ip */
655 ih4 = vlib_buffer_get_current (b0);
656 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
657 src_ip40.as_u32 = ih4->src_address.as_u32;
658 dst_ip40.as_u32 = ih4->dst_address.as_u32;
662 ih6 = vlib_buffer_get_current (b0);
663 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
664 clib_memcpy (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
665 clib_memcpy (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t));
668 src_port = th0->src_port;
669 dst_port = th0->dst_port;
671 /* Try to determine what/why we're actually resetting */
672 if (state == TCP_STATE_CLOSED)
677 tmp = clib_net_to_host_u32 (th0->seq_number);
679 /* Got a SYN for no listener. */
680 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
681 ack = clib_host_to_net_u32 (tmp + 1);
686 flags = TCP_FLAG_RST;
687 seq = th0->ack_number;
691 tcp_reuse_buffer (vm, b0);
692 th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack,
693 sizeof (tcp_header_t), flags, 0);
697 ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40,
699 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
704 ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60,
706 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
714 * Send reset without reusing existing buffer
717 tcp_send_reset (tcp_connection_t * tc, vlib_buffer_t * pkt, u8 is_ip4)
721 tcp_main_t *tm = vnet_get_tcp_main ();
722 vlib_main_t *vm = vlib_get_main ();
723 u8 tcp_hdr_len, flags = 0;
724 tcp_header_t *th, *pkt_th;
726 ip4_header_t *ih4, *pkt_ih4;
727 ip6_header_t *ih6, *pkt_ih6;
729 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
732 b = vlib_get_buffer (vm, bi);
734 /* Leave enough space for headers */
735 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
737 /* Make and write options */
738 tcp_hdr_len = sizeof (tcp_header_t);
742 pkt_ih4 = vlib_buffer_get_current (pkt);
743 pkt_th = ip4_next_header (pkt_ih4);
747 pkt_ih6 = vlib_buffer_get_current (pkt);
748 pkt_th = ip6_next_header (pkt_ih6);
751 if (tcp_ack (pkt_th))
753 flags = TCP_FLAG_RST;
754 seq = pkt_th->ack_number;
755 ack = (tc && tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
759 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
761 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
764 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
765 seq, ack, tcp_hdr_len, flags, 0);
767 /* Swap src and dst ip */
770 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
771 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
772 &pkt_ih4->src_address, IP_PROTOCOL_TCP, 1);
773 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
778 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
780 ih6 = vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address,
781 &pkt_ih6->src_address, IP_PROTOCOL_TCP);
782 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
786 tcp_enqueue_to_ip_lookup (vm, b, bi, is_ip4);
787 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc);
791 tcp_push_ip_hdr (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b)
793 tcp_header_t *th = vlib_buffer_get_current (b);
794 vlib_main_t *vm = vlib_get_main ();
798 ih = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip4,
799 &tc->c_rmt_ip4, IP_PROTOCOL_TCP, 1);
800 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih);
807 ih = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip6,
808 &tc->c_rmt_ip6, IP_PROTOCOL_TCP);
809 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih, &bogus);
817 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
818 * The packet is not forwarded through tcpx_output to avoid doing lookups
819 * in the half_open pool.
822 tcp_send_syn (tcp_connection_t * tc)
826 tcp_main_t *tm = vnet_get_tcp_main ();
827 vlib_main_t *vm = vlib_get_main ();
828 u8 tcp_hdr_opts_len, tcp_opts_len;
832 tcp_options_t snd_opts;
834 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
837 b = vlib_get_buffer (vm, bi);
839 /* Leave enough space for headers */
840 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
842 /* Set random initial sequence */
843 time_now = tcp_time_now ();
845 tc->iss = random_u32 (&time_now);
846 tc->snd_una = tc->iss;
847 tc->snd_una_max = tc->snd_nxt = tc->iss + 1;
849 initial_wnd = tcp_initial_window_to_advertise (tc);
851 /* Make and write options */
852 memset (&snd_opts, 0, sizeof (snd_opts));
853 tcp_opts_len = tcp_make_syn_options (&snd_opts, tc->rcv_wscale);
854 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
856 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
857 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
860 tcp_options_write ((u8 *) (th + 1), &snd_opts);
862 /* Measure RTT with this */
863 tc->rtt_ts = tcp_time_now ();
864 tc->rtt_seq = tc->snd_nxt;
866 /* Start retransmit trimer */
867 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN, tc->rto * TCP_TO_TIMER_TICK);
870 /* Set the connection establishment timer */
871 tcp_timer_set (tc, TCP_TIMER_ESTABLISH, TCP_ESTABLISH_TIME);
873 tcp_push_ip_hdr (tm, tc, b);
874 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
875 TCP_EVT_DBG (TCP_EVT_SYN_SENT, tc);
879 tcp_enqueue_to_output_i (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
882 tcp_main_t *tm = vnet_get_tcp_main ();
883 u32 thread_index = vlib_get_thread_index ();
884 u32 *to_next, next_index;
887 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
890 /* Decide where to send the packet */
891 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
893 /* Initialize the trajectory trace, if configured */
894 if (VLIB_BUFFER_TRACE_TRAJECTORY > 0)
897 b->pre_data[1] = next_index;
900 /* Get frame to v4/6 output node */
901 f = tm->tx_frames[!is_ip4][thread_index];
904 f = vlib_get_frame_to_node (vm, next_index);
906 tm->tx_frames[!is_ip4][thread_index] = f;
908 to_next = vlib_frame_vector_args (f);
909 to_next[f->n_vectors] = bi;
911 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
913 vlib_put_frame_to_node (vm, next_index, f);
914 tm->tx_frames[!is_ip4][thread_index] = 0;
919 tcp_enqueue_to_output (vlib_main_t * vm, vlib_buffer_t * b, u32 bi, u8 is_ip4)
921 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 0);
925 tcp_enqueue_to_output_now (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
928 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 1);
932 * Flush tx frame populated by retransmits and timer pops
935 tcp_flush_frame_to_output (vlib_main_t * vm, u8 thread_index, u8 is_ip4)
937 if (tcp_main.tx_frames[!is_ip4][thread_index])
940 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
941 vlib_put_frame_to_node (vm, next_index,
942 tcp_main.tx_frames[!is_ip4][thread_index]);
943 tcp_main.tx_frames[!is_ip4][thread_index] = 0;
948 * Flush both v4 and v6 tx frames for thread index
951 tcp_flush_frames_to_output (u8 thread_index)
953 vlib_main_t *vm = vlib_get_main ();
954 tcp_flush_frame_to_output (vm, thread_index, 1);
955 tcp_flush_frame_to_output (vm, thread_index, 0);
962 tcp_send_fin (tcp_connection_t * tc)
966 tcp_main_t *tm = vnet_get_tcp_main ();
967 vlib_main_t *vm = vlib_get_main ();
969 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
971 b = vlib_get_buffer (vm, bi);
973 tcp_make_fin (tc, b);
974 tcp_enqueue_to_output_now (vm, b, bi, tc->c_is_ip4);
975 tc->flags |= TCP_CONN_FINSNT;
976 tc->flags &= ~TCP_CONN_FINPNDG;
977 tcp_retransmit_timer_force_update (tc);
978 TCP_EVT_DBG (TCP_EVT_FIN_SENT, tc);
982 tcp_make_state_flags (tcp_connection_t * tc, tcp_state_t next_state)
986 case TCP_STATE_ESTABLISHED:
988 case TCP_STATE_SYN_RCVD:
989 return TCP_FLAG_SYN | TCP_FLAG_ACK;
990 case TCP_STATE_SYN_SENT:
992 case TCP_STATE_LAST_ACK:
993 case TCP_STATE_FIN_WAIT_1:
994 if (tc->snd_nxt + 1 < tc->snd_una_max)
999 clib_warning ("Shouldn't be here!");
1005 * Push TCP header and update connection variables
1008 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
1009 tcp_state_t next_state, u8 compute_opts)
1011 u32 advertise_wnd, data_len;
1012 u8 tcp_hdr_opts_len, opts_write_len, flags;
1015 data_len = b->current_length + b->total_length_not_including_first_buffer;
1016 vnet_buffer (b)->tcp.flags = 0;
1019 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1021 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
1022 advertise_wnd = tcp_window_to_advertise (tc, next_state);
1023 flags = tcp_make_state_flags (tc, next_state);
1025 /* Push header and options */
1026 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
1027 tc->rcv_nxt, tcp_hdr_opts_len, flags,
1029 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
1031 ASSERT (opts_write_len == tc->snd_opts_len);
1032 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
1035 * Update connection variables
1038 tc->snd_nxt += data_len;
1039 tc->rcv_las = tc->rcv_nxt;
1041 /* TODO this is updated in output as well ... */
1042 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1044 tc->snd_una_max = tc->snd_nxt;
1045 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1048 TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
1052 tcp_send_ack (tcp_connection_t * tc)
1054 tcp_main_t *tm = vnet_get_tcp_main ();
1055 vlib_main_t *vm = vlib_get_main ();
1061 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1063 b = vlib_get_buffer (vm, bi);
1065 /* Fill in the ACK */
1066 tcp_make_ack (tc, b);
1067 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1071 * Delayed ack timer handler
1073 * Sends delayed ACK when timer expires
1076 tcp_timer_delack_handler (u32 index)
1078 u32 thread_index = vlib_get_thread_index ();
1079 tcp_connection_t *tc;
1081 tc = tcp_connection_get (index, thread_index);
1082 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
1087 * Build a retransmit segment
1089 * @return the number of bytes in the segment or 0 if there's nothing to
1093 tcp_prepare_retransmit_segment (tcp_connection_t * tc, u32 offset,
1094 u32 max_deq_bytes, vlib_buffer_t ** b)
1096 tcp_main_t *tm = vnet_get_tcp_main ();
1097 vlib_main_t *vm = vlib_get_main ();
1099 u32 start, bi, available_bytes;
1101 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1102 ASSERT (max_deq_bytes != 0);
1105 * Make sure we can retransmit something
1107 max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
1108 available_bytes = stream_session_tx_fifo_max_dequeue (&tc->connection);
1109 if (!available_bytes)
1111 max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
1112 start = tc->snd_una + offset;
1114 /* Start is beyond snd_congestion */
1115 if (seq_geq (start, tc->snd_congestion))
1120 /* Don't overshoot snd_congestion */
1121 if (seq_gt (start + max_deq_bytes, tc->snd_congestion))
1123 max_deq_bytes = tc->snd_congestion - start;
1124 if (max_deq_bytes == 0)
1133 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1136 * Allocate and fill in buffer(s)
1139 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1141 *b = vlib_get_buffer (vm, bi);
1143 /* Easy case, buffer size greater than mss */
1144 if (PREDICT_TRUE (max_deq_bytes <= tm->bytes_per_buffer))
1146 n_bytes = stream_session_peek_bytes (&tc->connection,
1147 vlib_buffer_get_current (*b),
1148 offset, max_deq_bytes);
1149 ASSERT (n_bytes == max_deq_bytes);
1150 b[0]->current_length = n_bytes;
1151 tcp_push_hdr_i (tc, *b, tc->state, 0);
1153 /* Split mss into multiple buffers */
1156 u32 chain_bi = ~0, n_bufs_per_seg;
1157 u32 thread_index = vlib_get_thread_index ();
1158 u16 n_peeked, len_to_deq, available_bufs;
1159 vlib_buffer_t *chain_b, *prev_b;
1163 n_bufs_per_seg = ceil ((double) max_deq_bytes / tm->bytes_per_buffer);
1164 ASSERT (available_bytes >= max_deq_bytes);
1166 /* Make sure we have enough buffers */
1167 available_bufs = vec_len (tm->tx_buffers[thread_index]);
1168 if (n_bufs_per_seg > available_bufs)
1170 if (tcp_alloc_tx_buffers (tm, thread_index,
1171 VLIB_FRAME_SIZE - available_bufs))
1173 tcp_return_buffer (tm);
1178 n_bytes = stream_session_peek_bytes (&tc->connection,
1179 vlib_buffer_get_current (*b),
1180 offset, tm->bytes_per_buffer);
1181 b[0]->current_length = n_bytes;
1182 b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
1183 b[0]->total_length_not_including_first_buffer = 0;
1185 tcp_push_hdr_i (tc, *b, tc->state, 0);
1186 max_deq_bytes -= n_bytes;
1189 for (i = 1; i < n_bufs_per_seg; i++)
1192 len_to_deq = clib_min (max_deq_bytes, tm->bytes_per_buffer);
1193 tcp_get_free_buffer_index (tm, &chain_bi);
1194 ASSERT (chain_bi != (u32) ~ 0);
1195 chain_b = vlib_get_buffer (vm, chain_bi);
1196 chain_b->current_data = 0;
1197 data0 = vlib_buffer_get_current (chain_b);
1198 n_peeked = stream_session_peek_bytes (&tc->connection, data0,
1199 n_bytes, len_to_deq);
1200 n_bytes += n_peeked;
1201 ASSERT (n_peeked == len_to_deq);
1202 chain_b->current_length = n_peeked;
1203 b[0]->total_length_not_including_first_buffer +=
1204 chain_b->current_length;
1206 /* update previous buffer */
1207 prev_b->next_buffer = chain_bi;
1208 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
1210 /* update current buffer */
1211 chain_b->next_buffer = 0;
1213 max_deq_bytes -= n_peeked;
1217 ASSERT (n_bytes > 0);
1219 if (tcp_in_fastrecovery (tc))
1220 tc->snd_rxt_bytes += n_bytes;
1223 TCP_EVT_DBG (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1228 * Reset congestion control, switch cwnd to loss window and try again.
1231 tcp_rtx_timeout_cc (tcp_connection_t * tc)
1233 tc->prev_ssthresh = tc->ssthresh;
1234 tc->prev_cwnd = tc->cwnd;
1236 /* Cleanly recover cc (also clears up fast retransmit) */
1237 if (tcp_in_fastrecovery (tc))
1238 tcp_cc_fastrecovery_exit (tc);
1240 /* Start again from the beginning */
1241 tc->ssthresh = clib_max (tcp_flight_size (tc) / 2, 2 * tc->snd_mss);
1242 tc->cwnd = tcp_loss_wnd (tc);
1243 tc->snd_congestion = tc->snd_una_max;
1245 tcp_recovery_on (tc);
1249 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
1251 tcp_main_t *tm = vnet_get_tcp_main ();
1252 vlib_main_t *vm = vlib_get_main ();
1253 u32 thread_index = vlib_get_thread_index ();
1254 tcp_connection_t *tc;
1255 vlib_buffer_t *b = 0;
1260 tc = tcp_half_open_connection_get (index);
1261 tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
1265 tc = tcp_connection_get (index, thread_index);
1266 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
1269 if (!tcp_in_recovery (tc) && tc->rto_boff > 0
1270 && tc->state >= TCP_STATE_ESTABLISHED)
1273 tcp_update_rto (tc);
1276 /* Increment RTO backoff (also equal to number of retries) */
1279 /* Go back to first un-acked byte */
1280 tc->snd_nxt = tc->snd_una;
1282 if (tc->state >= TCP_STATE_ESTABLISHED)
1284 /* Lost FIN, retransmit and return */
1285 if (tcp_is_lost_fin (tc))
1291 /* First retransmit timeout */
1292 if (tc->rto_boff == 1)
1293 tcp_rtx_timeout_cc (tc);
1295 /* Exponential backoff */
1296 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1298 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1);
1300 /* Send one segment */
1301 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1303 bi = vlib_get_buffer_index (vm, b);
1304 /* TODO be less aggressive about this */
1305 scoreboard_clear (&tc->sack_sb);
1309 clib_warning ("could not retransmit anything");
1310 clib_warning ("%U", format_tcp_connection, tc, 2);
1312 /* Try again eventually */
1313 tcp_retransmit_timer_set (tc);
1314 ASSERT (0 || (tc->rto_boff > 1
1315 && tc->snd_una == tc->snd_congestion));
1319 /* For first retransmit, record timestamp (Eifel detection RFC3522) */
1320 if (tc->rto_boff == 1)
1321 tc->snd_rxt_ts = tcp_time_now ();
1323 /* Retransmit for SYN/SYNACK */
1324 else if (tc->state == TCP_STATE_SYN_RCVD || tc->state == TCP_STATE_SYN_SENT)
1326 /* Half-open connection actually moved to established but we were
1327 * waiting for syn retransmit to pop to call cleanup from the right
1329 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1331 ASSERT (tc->state == TCP_STATE_SYN_SENT);
1332 if (tcp_half_open_connection_cleanup (tc))
1334 clib_warning ("could not remove half-open connection");
1340 /* Try without increasing RTO a number of times. If this fails,
1341 * start growing RTO exponentially */
1342 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1343 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1345 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1347 b = vlib_get_buffer (vm, bi);
1348 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
1349 tcp_push_hdr_i (tc, b, tc->state, 1);
1351 /* Account for the SYN */
1354 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc,
1355 (tc->state == TCP_STATE_SYN_SENT ? 0 : 1));
1359 ASSERT (tc->state == TCP_STATE_CLOSED);
1360 clib_warning ("connection closed ...");
1366 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1368 /* Re-enable retransmit timer */
1369 tcp_retransmit_timer_set (tc);
1373 ASSERT (tc->state == TCP_STATE_SYN_SENT);
1375 /* This goes straight to ipx_lookup */
1376 tcp_push_ip_hdr (tm, tc, b);
1377 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
1379 /* Re-enable retransmit timer */
1380 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN,
1381 tc->rto * TCP_TO_TIMER_TICK);
1386 tcp_timer_retransmit_handler (u32 index)
1388 tcp_timer_retransmit_handler_i (index, 0);
1392 tcp_timer_retransmit_syn_handler (u32 index)
1394 tcp_timer_retransmit_handler_i (index, 1);
1398 * Got 0 snd_wnd from peer, try to do something about it.
1402 tcp_timer_persist_handler (u32 index)
1404 tcp_main_t *tm = vnet_get_tcp_main ();
1405 vlib_main_t *vm = vlib_get_main ();
1406 u32 thread_index = vlib_get_thread_index ();
1407 tcp_connection_t *tc;
1409 u32 bi, old_snd_nxt, snd_bytes = 0, available_bytes = 0;
1412 tc = tcp_connection_get_if_valid (index, thread_index);
1417 /* Make sure timer handle is set to invalid */
1418 tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
1420 /* Problem already solved or worse */
1421 available_bytes = stream_session_tx_fifo_max_dequeue (&tc->connection);
1422 if (tc->state == TCP_STATE_CLOSED || tc->state > TCP_STATE_ESTABLISHED
1423 || tc->snd_wnd > tc->snd_mss || tcp_in_recovery (tc)
1424 || !available_bytes)
1427 /* Increment RTO backoff */
1429 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1432 * Try to force the first unsent segment (or buffer)
1434 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1436 b = vlib_get_buffer (vm, bi);
1438 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1439 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1440 snd_bytes = clib_min (tc->snd_mss, tm->bytes_per_buffer);
1441 n_bytes = stream_session_peek_bytes (&tc->connection,
1442 vlib_buffer_get_current (b),
1443 tc->snd_una_max - tc->snd_una,
1445 ASSERT (n_bytes != 0);
1446 b->current_length = n_bytes;
1447 ASSERT (tc->snd_nxt == tc->snd_una_max || tc->rto_boff > 1
1448 || tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1450 /* Allow updating of snd_una_max but don't update snd_nxt */
1451 old_snd_nxt = tc->snd_nxt;
1452 tcp_push_hdr_i (tc, b, tc->state, 0);
1453 tc->snd_nxt = old_snd_nxt;
1454 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1456 /* Re-enable persist timer */
1457 tcp_persist_timer_set (tc);
1461 * Retransmit first unacked segment
1464 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1466 vlib_main_t *vm = vlib_get_main ();
1468 u32 bi, old_snd_nxt, n_bytes;
1470 old_snd_nxt = tc->snd_nxt;
1471 tc->snd_nxt = tc->snd_una;
1473 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2);
1474 n_bytes = tcp_prepare_retransmit_segment (tc, 0, tc->snd_mss, &b);
1477 bi = vlib_get_buffer_index (vm, b);
1478 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1480 tc->snd_nxt = old_snd_nxt;
1484 * Do fast retransmit with SACKs
1487 tcp_fast_retransmit_sack (tcp_connection_t * tc)
1489 vlib_main_t *vm = vlib_get_main ();
1490 u32 n_written = 0, offset = 0, max_bytes;
1491 vlib_buffer_t *b = 0;
1492 sack_scoreboard_hole_t *hole;
1493 sack_scoreboard_t *sb;
1494 u32 bi, old_snd_nxt;
1496 u8 snd_limited = 0, can_rescue = 0;
1498 ASSERT (tcp_in_fastrecovery (tc));
1499 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1501 old_snd_nxt = tc->snd_nxt;
1503 snd_space = tcp_available_snd_space (tc);
1505 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1506 while (hole && snd_space > 0)
1508 hole = scoreboard_next_rxt_hole (sb, hole,
1509 tcp_fastrecovery_sent_1_smss (tc),
1510 &can_rescue, &snd_limited);
1513 if (!can_rescue || !(seq_lt (sb->rescue_rxt, tc->snd_una)
1514 || seq_gt (sb->rescue_rxt,
1515 tc->snd_congestion)))
1518 /* If rescue rxt undefined or less than snd_una then one segment of
1519 * up to SMSS octets that MUST include the highest outstanding
1520 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1521 * RecoveryPoint. HighRxt MUST NOT be updated.
1523 max_bytes = clib_min (tc->snd_mss, snd_space);
1524 offset = tc->snd_congestion - tc->snd_una - max_bytes;
1525 sb->rescue_rxt = tc->snd_congestion;
1526 tc->snd_nxt = tc->snd_una + offset;
1527 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes,
1530 bi = vlib_get_buffer_index (vm, b);
1531 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1535 max_bytes = snd_limited ? tc->snd_mss : hole->end - sb->high_rxt;
1536 offset = sb->high_rxt - tc->snd_una;
1537 tc->snd_nxt = tc->snd_una + offset;
1538 n_written = tcp_prepare_retransmit_segment (tc, offset, max_bytes, &b);
1540 /* Nothing left to retransmit */
1544 bi = vlib_get_buffer_index (vm, b);
1545 sb->high_rxt += n_written;
1546 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1547 snd_space -= n_written;
1550 /* If window allows, send 1 SMSS of new data */
1551 tc->snd_nxt = old_snd_nxt;
1555 * Fast retransmit without SACK info
1558 tcp_fast_retransmit_no_sack (tcp_connection_t * tc)
1560 vlib_main_t *vm = vlib_get_main ();
1561 u32 n_written = 0, offset = 0, bi, old_snd_nxt;
1565 ASSERT (tcp_in_fastrecovery (tc));
1566 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1568 /* Start resending from first un-acked segment */
1569 old_snd_nxt = tc->snd_nxt;
1570 tc->snd_nxt = tc->snd_una;
1571 snd_space = tcp_available_snd_space (tc);
1573 while (snd_space > 0)
1575 offset += n_written;
1576 n_written = tcp_prepare_retransmit_segment (tc, offset, snd_space, &b);
1578 /* Nothing left to retransmit */
1582 bi = vlib_get_buffer_index (vm, b);
1583 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1584 snd_space -= n_written;
1587 /* Restore snd_nxt. If window allows, send 1 SMSS of new data */
1588 tc->snd_nxt = old_snd_nxt;
1592 * Do fast retransmit
1595 tcp_fast_retransmit (tcp_connection_t * tc)
1597 if (tcp_opts_sack_permitted (&tc->rcv_opts)
1598 && scoreboard_first_hole (&tc->sack_sb))
1599 tcp_fast_retransmit_sack (tc);
1601 tcp_fast_retransmit_no_sack (tc);
1605 tcp_session_has_ooo_data (tcp_connection_t * tc)
1607 stream_session_t *s =
1608 stream_session_get (tc->c_s_index, tc->c_thread_index);
1609 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1613 tcp46_output_inline (vlib_main_t * vm,
1614 vlib_node_runtime_t * node,
1615 vlib_frame_t * from_frame, int is_ip4)
1617 u32 n_left_from, next_index, *from, *to_next;
1618 u32 my_thread_index = vm->thread_index;
1620 from = vlib_frame_vector_args (from_frame);
1621 n_left_from = from_frame->n_vectors;
1622 next_index = node->cached_next_index;
1623 tcp_set_time_now (my_thread_index);
1625 while (n_left_from > 0)
1629 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1631 while (n_left_from > 0 && n_left_to_next > 0)
1635 tcp_connection_t *tc0;
1637 tcp_header_t *th0 = 0;
1638 u32 error0 = TCP_ERROR_PKTS_SENT, next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
1645 n_left_to_next -= 1;
1647 b0 = vlib_get_buffer (vm, bi0);
1648 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1650 if (PREDICT_FALSE (tc0 == 0 || tc0->state == TCP_STATE_CLOSED))
1652 error0 = TCP_ERROR_INVALID_CONNECTION;
1653 next0 = TCP_OUTPUT_NEXT_DROP;
1657 th0 = vlib_buffer_get_current (b0);
1658 TCP_EVT_DBG (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
1662 vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
1663 IP_PROTOCOL_TCP, 1);
1664 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1665 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1671 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6,
1672 &tc0->c_rmt_ip6, IP_PROTOCOL_TCP);
1673 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1674 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ih0 - b0->data;
1675 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1679 /* Filter out DUPACKs if there are no OOO segments left */
1681 (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1683 if (!tcp_session_has_ooo_data (tc0))
1685 error0 = TCP_ERROR_FILTERED_DUPACKS;
1686 next0 = TCP_OUTPUT_NEXT_DROP;
1691 /* Stop DELACK timer and fix flags */
1692 tc0->flags &= ~(TCP_CONN_SNDACK);
1693 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1695 /* If not retransmitting
1696 * 1) update snd_una_max (SYN, SYNACK, FIN)
1697 * 2) If we're not tracking an ACK, start tracking */
1698 if (seq_lt (tc0->snd_una_max, tc0->snd_nxt))
1700 tc0->snd_una_max = tc0->snd_nxt;
1701 if (tc0->rtt_ts == 0)
1703 tc0->rtt_ts = tcp_time_now ();
1704 tc0->rtt_seq = tc0->snd_nxt;
1708 /* Set the retransmit timer if not set already and not
1709 * doing a pure ACK */
1710 if (!tcp_timer_is_active (tc0, TCP_TIMER_RETRANSMIT)
1711 && tc0->snd_nxt != tc0->snd_una)
1713 tcp_retransmit_timer_set (tc0);
1718 /* Make sure we haven't lost route to our peer */
1719 if (PREDICT_FALSE (tc0->last_fib_check
1720 < tc0->snd_opts.tsval + TCP_FIB_RECHECK_PERIOD))
1723 (tc0->c_rmt_fei == tcp_lookup_rmt_in_fib (tc0)))
1725 tc0->last_fib_check = tc0->snd_opts.tsval;
1729 clib_warning ("lost connection to peer");
1730 tcp_connection_reset (tc0);
1735 /* Use pre-computed dpo to set next node */
1736 next0 = tc0->c_rmt_dpo.dpoi_next_node;
1737 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = tc0->c_rmt_dpo.dpoi_index;
1740 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
1741 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
1743 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
1745 b0->error = node->errors[error0];
1746 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1748 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1751 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1755 memset (&t0->tcp_header, 0, sizeof (t0->tcp_header));
1757 clib_memcpy (&t0->tcp_connection, tc0,
1758 sizeof (t0->tcp_connection));
1761 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1762 n_left_to_next, bi0, next0);
1765 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1768 return from_frame->n_vectors;
1772 tcp4_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1773 vlib_frame_t * from_frame)
1775 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1779 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1780 vlib_frame_t * from_frame)
1782 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1786 VLIB_REGISTER_NODE (tcp4_output_node) =
1788 .function = tcp4_output,.name = "tcp4-output",
1789 /* Takes a vector of packets. */
1790 .vector_size = sizeof (u32),
1791 .n_errors = TCP_N_ERROR,
1792 .error_strings = tcp_error_strings,
1793 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1795 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1796 foreach_tcp4_output_next
1799 .format_buffer = format_tcp_header,
1800 .format_trace = format_tcp_tx_trace,
1804 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output);
1807 VLIB_REGISTER_NODE (tcp6_output_node) =
1809 .function = tcp6_output,
1810 .name = "tcp6-output",
1811 /* Takes a vector of packets. */
1812 .vector_size = sizeof (u32),
1813 .n_errors = TCP_N_ERROR,
1814 .error_strings = tcp_error_strings,
1815 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1817 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1818 foreach_tcp6_output_next
1821 .format_buffer = format_tcp_header,
1822 .format_trace = format_tcp_tx_trace,
1826 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output);
1829 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
1831 tcp_connection_t *tc;
1833 tc = (tcp_connection_t *) tconn;
1834 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, 0);
1836 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
1838 tc->rtt_ts = tcp_time_now ();
1839 tc->rtt_seq = tc->snd_nxt;
1844 typedef enum _tcp_reset_next
1846 TCP_RESET_NEXT_DROP,
1847 TCP_RESET_NEXT_IP_LOOKUP,
1851 #define foreach_tcp4_reset_next \
1852 _(DROP, "error-drop") \
1853 _(IP_LOOKUP, "ip4-lookup")
1855 #define foreach_tcp6_reset_next \
1856 _(DROP, "error-drop") \
1857 _(IP_LOOKUP, "ip6-lookup")
1860 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1861 vlib_frame_t * from_frame, u8 is_ip4)
1863 u32 n_left_from, next_index, *from, *to_next;
1864 u32 my_thread_index = vm->thread_index;
1866 from = vlib_frame_vector_args (from_frame);
1867 n_left_from = from_frame->n_vectors;
1869 next_index = node->cached_next_index;
1871 while (n_left_from > 0)
1875 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1877 while (n_left_from > 0 && n_left_to_next > 0)
1883 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
1890 n_left_to_next -= 1;
1892 b0 = vlib_get_buffer (vm, bi0);
1894 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
1895 my_thread_index, is_ip4))
1897 error0 = TCP_ERROR_LOOKUP_DROPS;
1898 next0 = TCP_RESET_NEXT_DROP;
1902 /* Prepare to send to IP lookup */
1903 vnet_buffer (b0)->sw_if_index[VLIB_TX] = 0;
1904 next0 = TCP_RESET_NEXT_IP_LOOKUP;
1907 b0->error = node->errors[error0];
1908 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
1909 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1911 th0 = vlib_buffer_get_current (b0);
1913 th0 = ip4_next_header ((ip4_header_t *) th0);
1915 th0 = ip6_next_header ((ip6_header_t *) th0);
1916 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1917 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1920 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1921 n_left_to_next, bi0, next0);
1923 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1925 return from_frame->n_vectors;
1929 tcp4_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1930 vlib_frame_t * from_frame)
1932 return tcp46_send_reset_inline (vm, node, from_frame, 1);
1936 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1937 vlib_frame_t * from_frame)
1939 return tcp46_send_reset_inline (vm, node, from_frame, 0);
1943 VLIB_REGISTER_NODE (tcp4_reset_node) = {
1944 .function = tcp4_send_reset,
1945 .name = "tcp4-reset",
1946 .vector_size = sizeof (u32),
1947 .n_errors = TCP_N_ERROR,
1948 .error_strings = tcp_error_strings,
1949 .n_next_nodes = TCP_RESET_N_NEXT,
1951 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
1952 foreach_tcp4_reset_next
1955 .format_trace = format_tcp_tx_trace,
1959 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset);
1962 VLIB_REGISTER_NODE (tcp6_reset_node) = {
1963 .function = tcp6_send_reset,
1964 .name = "tcp6-reset",
1965 .vector_size = sizeof (u32),
1966 .n_errors = TCP_N_ERROR,
1967 .error_strings = tcp_error_strings,
1968 .n_next_nodes = TCP_RESET_N_NEXT,
1970 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
1971 foreach_tcp6_reset_next
1974 .format_trace = format_tcp_tx_trace,
1978 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset);
1981 * fd.io coding-style-patch-verification: ON
1984 * eval: (c-set-style "gnu")