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>
19 vlib_node_registration_t tcp4_output_node;
20 vlib_node_registration_t tcp6_output_node;
22 typedef enum _tcp_output_next
25 TCP_OUTPUT_NEXT_IP_LOOKUP,
29 #define foreach_tcp4_output_next \
30 _ (DROP, "error-drop") \
31 _ (IP_LOOKUP, "ip4-lookup")
33 #define foreach_tcp6_output_next \
34 _ (DROP, "error-drop") \
35 _ (IP_LOOKUP, "ip6-lookup")
37 static char *tcp_error_strings[] = {
38 #define tcp_error(n,s) s,
39 #include <vnet/tcp/tcp_error.def>
45 tcp_header_t tcp_header;
46 tcp_connection_t tcp_connection;
52 format_tcp_tx_trace (u8 * s, va_list * args)
54 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
55 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
56 tcp_tx_trace_t *t = va_arg (*args, tcp_tx_trace_t *);
57 uword indent = format_get_indent (s);
59 s = format (s, "%U\n%U%U",
60 format_tcp_header, &t->tcp_header, 128,
61 format_white_space, indent,
62 format_tcp_connection, &t->tcp_connection, 1);
68 tcp_window_compute_scale (u32 available_space)
71 while (wnd_scale < TCP_MAX_WND_SCALE
72 && (available_space >> wnd_scale) > TCP_WND_MAX)
78 * Update max segment size we're able to process.
80 * The value is constrained by our interface's MTU and IP options. It is
81 * also what we advertise to our peer.
84 tcp_update_rcv_mss (tcp_connection_t * tc)
86 /* TODO find our iface MTU */
91 * TCP's initial window
94 tcp_initial_wnd_unscaled (tcp_connection_t * tc)
96 /* RFC 6928 recommends the value lower. However at the time our connections
97 * are initialized, fifos may not be allocated. Therefore, advertise the
98 * smallest possible unscaled window size and update once fifos are
99 * assigned to the session.
102 tcp_update_rcv_mss (tc);
103 TCP_IW_N_SEGMENTS * tc->mss;
105 return TCP_MIN_RX_FIFO_SIZE;
109 * Compute initial window and scale factor. As per RFC1323, window field in
110 * SYN and SYN-ACK segments is never scaled.
113 tcp_initial_window_to_advertise (tcp_connection_t * tc)
117 /* Initial wnd for SYN. Fifos are not allocated yet.
118 * Use some predefined value. For SYN-ACK we still want the
119 * scale to be computed in the same way */
120 max_fifo = TCP_MAX_RX_FIFO_SIZE;
122 tc->rcv_wscale = tcp_window_compute_scale (max_fifo);
123 tc->rcv_wnd = tcp_initial_wnd_unscaled (tc);
125 return clib_min (tc->rcv_wnd, TCP_WND_MAX);
129 * Compute and return window to advertise, scaled as per RFC1323
132 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
134 if (state < TCP_STATE_ESTABLISHED)
135 return tcp_initial_window_to_advertise (tc);
137 tcp_update_rcv_wnd (tc);
139 if (tc->rcv_wnd == 0)
141 tc->flags |= TCP_CONN_SENT_RCV_WND0;
145 tc->flags &= ~TCP_CONN_SENT_RCV_WND0;
148 return tc->rcv_wnd >> tc->rcv_wscale;
152 tcp_update_rcv_wnd (tcp_connection_t * tc)
155 u32 available_space, max_fifo, wnd;
158 * Figure out how much space we have available
160 available_space = stream_session_max_rx_enqueue (&tc->connection);
161 max_fifo = stream_session_rx_fifo_size (&tc->connection);
163 ASSERT (tc->rcv_opts.mss < max_fifo);
164 if (available_space < tc->rcv_opts.mss && available_space < max_fifo >> 3)
168 * Use the above and what we know about what we've previously advertised
169 * to compute the new window
171 observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
172 if (observed_wnd < 0)
175 /* Bad. Thou shalt not shrink */
176 if (available_space < observed_wnd)
179 TCP_EVT_DBG (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space);
183 wnd = available_space;
186 /* Make sure we have a multiple of rcv_wscale */
187 if (wnd && tc->rcv_wscale)
189 wnd &= ~(1 << tc->rcv_wscale);
191 wnd = 1 << tc->rcv_wscale;
194 tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale);
198 * Write TCP options to segment.
201 tcp_options_write (u8 * data, tcp_options_t * opts)
204 u32 buf, seq_len = 4;
206 if (tcp_opts_mss (opts))
208 *data++ = TCP_OPTION_MSS;
209 *data++ = TCP_OPTION_LEN_MSS;
210 buf = clib_host_to_net_u16 (opts->mss);
211 clib_memcpy (data, &buf, sizeof (opts->mss));
212 data += sizeof (opts->mss);
213 opts_len += TCP_OPTION_LEN_MSS;
216 if (tcp_opts_wscale (opts))
218 *data++ = TCP_OPTION_WINDOW_SCALE;
219 *data++ = TCP_OPTION_LEN_WINDOW_SCALE;
220 *data++ = opts->wscale;
221 opts_len += TCP_OPTION_LEN_WINDOW_SCALE;
224 if (tcp_opts_sack_permitted (opts))
226 *data++ = TCP_OPTION_SACK_PERMITTED;
227 *data++ = TCP_OPTION_LEN_SACK_PERMITTED;
228 opts_len += TCP_OPTION_LEN_SACK_PERMITTED;
231 if (tcp_opts_tstamp (opts))
233 *data++ = TCP_OPTION_TIMESTAMP;
234 *data++ = TCP_OPTION_LEN_TIMESTAMP;
235 buf = clib_host_to_net_u32 (opts->tsval);
236 clib_memcpy (data, &buf, sizeof (opts->tsval));
237 data += sizeof (opts->tsval);
238 buf = clib_host_to_net_u32 (opts->tsecr);
239 clib_memcpy (data, &buf, sizeof (opts->tsecr));
240 data += sizeof (opts->tsecr);
241 opts_len += TCP_OPTION_LEN_TIMESTAMP;
244 if (tcp_opts_sack (opts))
247 u32 n_sack_blocks = clib_min (vec_len (opts->sacks),
248 TCP_OPTS_MAX_SACK_BLOCKS);
250 if (n_sack_blocks != 0)
252 *data++ = TCP_OPTION_SACK_BLOCK;
253 *data++ = 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
254 for (i = 0; i < n_sack_blocks; i++)
256 buf = clib_host_to_net_u32 (opts->sacks[i].start);
257 clib_memcpy (data, &buf, seq_len);
259 buf = clib_host_to_net_u32 (opts->sacks[i].end);
260 clib_memcpy (data, &buf, seq_len);
263 opts_len += 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
267 /* Terminate TCP options */
270 *data++ = TCP_OPTION_EOL;
271 opts_len += TCP_OPTION_LEN_EOL;
274 /* Pad with zeroes to a u32 boundary */
277 *data++ = TCP_OPTION_NOOP;
278 opts_len += TCP_OPTION_LEN_NOOP;
284 tcp_make_syn_options (tcp_options_t * opts, u8 wnd_scale)
288 opts->flags |= TCP_OPTS_FLAG_MSS;
289 opts->mss = dummy_mtu; /*XXX discover that */
290 len += TCP_OPTION_LEN_MSS;
292 opts->flags |= TCP_OPTS_FLAG_WSCALE;
293 opts->wscale = wnd_scale;
294 len += TCP_OPTION_LEN_WINDOW_SCALE;
296 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
297 opts->tsval = tcp_time_now ();
299 len += TCP_OPTION_LEN_TIMESTAMP;
303 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
304 len += TCP_OPTION_LEN_SACK_PERMITTED;
307 /* Align to needed boundary */
308 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
313 tcp_make_synack_options (tcp_connection_t * tc, tcp_options_t * opts)
317 opts->flags |= TCP_OPTS_FLAG_MSS;
319 len += TCP_OPTION_LEN_MSS;
321 if (tcp_opts_wscale (&tc->rcv_opts))
323 opts->flags |= TCP_OPTS_FLAG_WSCALE;
324 opts->wscale = tc->rcv_wscale;
325 len += TCP_OPTION_LEN_WINDOW_SCALE;
328 if (tcp_opts_tstamp (&tc->rcv_opts))
330 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
331 opts->tsval = tcp_time_now ();
332 opts->tsecr = tc->tsval_recent;
333 len += TCP_OPTION_LEN_TIMESTAMP;
336 if (tcp_opts_sack_permitted (&tc->rcv_opts))
338 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
339 len += TCP_OPTION_LEN_SACK_PERMITTED;
342 /* Align to needed boundary */
343 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
348 tcp_make_established_options (tcp_connection_t * tc, tcp_options_t * opts)
354 if (tcp_opts_tstamp (&tc->rcv_opts))
356 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
357 opts->tsval = tcp_time_now ();
358 opts->tsecr = tc->tsval_recent;
359 len += TCP_OPTION_LEN_TIMESTAMP;
361 if (tcp_opts_sack_permitted (&tc->rcv_opts))
363 if (vec_len (tc->snd_sacks))
365 opts->flags |= TCP_OPTS_FLAG_SACK;
366 opts->sacks = tc->snd_sacks;
367 opts->n_sack_blocks = clib_min (vec_len (tc->snd_sacks),
368 TCP_OPTS_MAX_SACK_BLOCKS);
369 len += 2 + TCP_OPTION_LEN_SACK_BLOCK * opts->n_sack_blocks;
373 /* Align to needed boundary */
374 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
379 tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts,
384 case TCP_STATE_ESTABLISHED:
385 case TCP_STATE_FIN_WAIT_1:
386 return tcp_make_established_options (tc, opts);
387 case TCP_STATE_SYN_RCVD:
388 return tcp_make_synack_options (tc, opts);
389 case TCP_STATE_SYN_SENT:
390 return tcp_make_syn_options (opts, tc->rcv_wscale);
392 clib_warning ("Not handled!");
398 * Update snd_mss to reflect the effective segment size that we can send
399 * by taking into account all TCP options, including SACKs
402 tcp_update_snd_mss (tcp_connection_t * tc)
404 /* Compute options to be used for connection. These may be reused when
405 * sending data or to compute the effective mss (snd_mss) */
407 tcp_make_options (tc, &tc->snd_opts, TCP_STATE_ESTABLISHED);
409 /* XXX check if MTU has been updated */
410 tc->snd_mss = clib_min (tc->mss, tc->rcv_opts.mss) - tc->snd_opts_len;
411 ASSERT (tc->snd_mss > 0);
415 tcp_init_mss (tcp_connection_t * tc)
417 u16 default_min_mss = 536;
418 tcp_update_rcv_mss (tc);
420 /* TODO cache mss and consider PMTU discovery */
421 tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss);
423 if (tc->snd_mss < 45)
425 clib_warning ("snd mss is 0");
426 /* Assume that at least the min default mss works */
427 tc->snd_mss = default_min_mss;
428 tc->rcv_opts.mss = default_min_mss;
431 /* We should have enough space for 40 bytes of options */
432 ASSERT (tc->snd_mss > 45);
434 /* If we use timestamp option, account for it */
435 if (tcp_opts_tstamp (&tc->rcv_opts))
436 tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP;
440 tcp_get_free_buffer_index (tcp_main_t * tm, u32 * bidx)
442 u32 *my_tx_buffers, n_free_buffers;
443 u32 thread_index = vlib_get_thread_index ();
444 my_tx_buffers = tm->tx_buffers[thread_index];
445 if (PREDICT_FALSE (vec_len (my_tx_buffers) == 0))
447 n_free_buffers = VLIB_FRAME_SIZE;
448 vec_validate (my_tx_buffers, n_free_buffers - 1);
449 _vec_len (my_tx_buffers) =
450 vlib_buffer_alloc_from_free_list (vlib_get_main (), my_tx_buffers,
452 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
453 /* buffer shortage, report failure */
454 if (vec_len (my_tx_buffers) == 0)
456 clib_warning ("out of buffers");
459 tm->tx_buffers[thread_index] = my_tx_buffers;
461 *bidx = my_tx_buffers[_vec_len (my_tx_buffers) - 1];
462 _vec_len (my_tx_buffers) -= 1;
467 tcp_return_buffer (tcp_main_t * tm)
470 u32 thread_index = vlib_get_thread_index ();
471 my_tx_buffers = tm->tx_buffers[thread_index];
472 _vec_len (my_tx_buffers) += 1;
476 tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b)
478 vlib_buffer_t *it = b;
481 it->current_data = 0;
482 it->current_length = 0;
483 it->total_length_not_including_first_buffer = 0;
485 while ((it->flags & VLIB_BUFFER_NEXT_PRESENT)
486 && (it = vlib_get_buffer (vm, it->next_buffer)));
488 /* Leave enough space for headers */
489 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
490 vnet_buffer (b)->tcp.flags = 0;
497 tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
500 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
501 u8 tcp_opts_len, tcp_hdr_opts_len;
505 wnd = tcp_window_to_advertise (tc, state);
507 /* Make and write options */
508 tcp_opts_len = tcp_make_established_options (tc, snd_opts);
509 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
511 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
512 tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd);
514 tcp_options_write ((u8 *) (th + 1), snd_opts);
515 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
519 * Convert buffer to ACK
522 tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
524 vlib_main_t *vm = vlib_get_main ();
526 tcp_reuse_buffer (vm, b);
527 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
528 TCP_EVT_DBG (TCP_EVT_ACK_SENT, tc);
529 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
530 tc->rcv_las = tc->rcv_nxt;
534 * Convert buffer to FIN-ACK
537 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
539 vlib_main_t *vm = vlib_get_main ();
542 tcp_reuse_buffer (vm, b);
544 flags = TCP_FLAG_FIN | TCP_FLAG_ACK;
545 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, flags);
547 /* Reset flags, make sure ack is sent */
548 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
554 * Convert buffer to SYN-ACK
557 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
559 vlib_main_t *vm = vlib_get_main ();
560 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
561 u8 tcp_opts_len, tcp_hdr_opts_len;
566 memset (snd_opts, 0, sizeof (*snd_opts));
568 tcp_reuse_buffer (vm, b);
570 /* Set random initial sequence */
571 time_now = tcp_time_now ();
573 tc->iss = random_u32 (&time_now);
574 tc->snd_una = tc->iss;
575 tc->snd_nxt = tc->iss + 1;
576 tc->snd_una_max = tc->snd_nxt;
578 initial_wnd = tcp_initial_window_to_advertise (tc);
580 /* Make and write options */
581 tcp_opts_len = tcp_make_synack_options (tc, snd_opts);
582 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
584 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
585 tc->rcv_nxt, tcp_hdr_opts_len,
586 TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd);
588 tcp_options_write ((u8 *) (th + 1), snd_opts);
590 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
591 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
593 /* Init retransmit timer */
594 tcp_retransmit_timer_set (tc);
595 TCP_EVT_DBG (TCP_EVT_SYNACK_SENT, tc);
599 tcp_enqueue_to_ip_lookup (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
602 u32 *to_next, next_index;
605 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
608 /* Default FIB for now */
609 vnet_buffer (b)->sw_if_index[VLIB_TX] = 0;
611 /* Send to IP lookup */
612 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
613 f = vlib_get_frame_to_node (vm, next_index);
615 /* Enqueue the packet */
616 to_next = vlib_frame_vector_args (f);
619 vlib_put_frame_to_node (vm, next_index, f);
623 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
624 tcp_state_t state, u8 thread_index, u8 is_ip4)
629 ip4_address_t src_ip40, dst_ip40;
630 ip6_address_t src_ip60, dst_ip60;
631 u16 src_port, dst_port;
636 /* Find IP and TCP headers */
637 th0 = tcp_buffer_hdr (b0);
639 /* Save src and dst ip */
642 ih4 = vlib_buffer_get_current (b0);
643 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
644 src_ip40.as_u32 = ih4->src_address.as_u32;
645 dst_ip40.as_u32 = ih4->dst_address.as_u32;
649 ih6 = vlib_buffer_get_current (b0);
650 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
651 clib_memcpy (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
652 clib_memcpy (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t));
655 src_port = th0->src_port;
656 dst_port = th0->dst_port;
658 /* Try to determine what/why we're actually resetting */
659 if (state == TCP_STATE_CLOSED)
664 tmp = clib_net_to_host_u32 (th0->seq_number);
666 /* Got a SYN for no listener. */
667 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
668 ack = clib_host_to_net_u32 (tmp + 1);
673 flags = TCP_FLAG_RST;
674 seq = th0->ack_number;
678 tcp_reuse_buffer (vm, b0);
679 th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack,
680 sizeof (tcp_header_t), flags, 0);
684 ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40,
686 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
691 ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60,
693 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
701 * Send reset without reusing existing buffer
704 tcp_send_reset (tcp_connection_t * tc, vlib_buffer_t * pkt, u8 is_ip4)
708 tcp_main_t *tm = vnet_get_tcp_main ();
709 vlib_main_t *vm = vlib_get_main ();
710 u8 tcp_hdr_len, flags = 0;
711 tcp_header_t *th, *pkt_th;
713 ip4_header_t *ih4, *pkt_ih4;
714 ip6_header_t *ih6, *pkt_ih6;
716 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
719 b = vlib_get_buffer (vm, bi);
721 /* Leave enough space for headers */
722 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
724 /* Make and write options */
725 tcp_hdr_len = sizeof (tcp_header_t);
729 pkt_ih4 = vlib_buffer_get_current (pkt);
730 pkt_th = ip4_next_header (pkt_ih4);
734 pkt_ih6 = vlib_buffer_get_current (pkt);
735 pkt_th = ip6_next_header (pkt_ih6);
738 if (tcp_ack (pkt_th))
740 flags = TCP_FLAG_RST;
741 seq = pkt_th->ack_number;
742 ack = (tc && tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
746 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
748 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
751 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
752 seq, ack, tcp_hdr_len, flags, 0);
754 /* Swap src and dst ip */
757 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
758 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
759 &pkt_ih4->src_address, IP_PROTOCOL_TCP, 1);
760 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
765 pkt_ih6 = (ip6_header_t *) (pkt_th - 1);
766 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
769 vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address,
770 &pkt_ih6->src_address, IP_PROTOCOL_TCP);
771 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
775 tcp_enqueue_to_ip_lookup (vm, b, bi, is_ip4);
776 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc);
780 tcp_push_ip_hdr (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b)
782 tcp_header_t *th = vlib_buffer_get_current (b);
783 vlib_main_t *vm = vlib_get_main ();
787 ih = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip4,
788 &tc->c_rmt_ip4, IP_PROTOCOL_TCP, 1);
789 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih);
796 ih = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip6,
797 &tc->c_rmt_ip6, IP_PROTOCOL_TCP);
798 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih, &bogus);
806 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
807 * The packet is not forwarded through tcpx_output to avoid doing lookups
808 * in the half_open pool.
811 tcp_send_syn (tcp_connection_t * tc)
815 tcp_main_t *tm = vnet_get_tcp_main ();
816 vlib_main_t *vm = vlib_get_main ();
817 u8 tcp_hdr_opts_len, tcp_opts_len;
821 tcp_options_t snd_opts;
823 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
826 b = vlib_get_buffer (vm, bi);
828 /* Leave enough space for headers */
829 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
831 /* Set random initial sequence */
832 time_now = tcp_time_now ();
834 tc->iss = random_u32 (&time_now);
835 tc->snd_una = tc->iss;
836 tc->snd_una_max = tc->snd_nxt = tc->iss + 1;
838 initial_wnd = tcp_initial_window_to_advertise (tc);
840 /* Make and write options */
841 memset (&snd_opts, 0, sizeof (snd_opts));
842 tcp_opts_len = tcp_make_syn_options (&snd_opts, tc->rcv_wscale);
843 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
845 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
846 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
849 tcp_options_write ((u8 *) (th + 1), &snd_opts);
851 /* Measure RTT with this */
852 tc->rtt_ts = tcp_time_now ();
853 tc->rtt_seq = tc->snd_nxt;
855 /* Start retransmit trimer */
856 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN, tc->rto * TCP_TO_TIMER_TICK);
859 /* Set the connection establishment timer */
860 tcp_timer_set (tc, TCP_TIMER_ESTABLISH, TCP_ESTABLISH_TIME);
862 tcp_push_ip_hdr (tm, tc, b);
863 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
864 TCP_EVT_DBG (TCP_EVT_SYN_SENT, tc);
868 tcp_enqueue_to_output_i (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
871 tcp_main_t *tm = vnet_get_tcp_main ();
872 u32 thread_index = vlib_get_thread_index ();
873 u32 *to_next, next_index;
876 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
879 /* Decide where to send the packet */
880 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
882 /* Initialize the trajectory trace, if configured */
883 if (VLIB_BUFFER_TRACE_TRAJECTORY > 0)
886 b->pre_data[1] = next_index;
889 /* Get frame to v4/6 output node */
890 f = tm->tx_frames[!is_ip4][thread_index];
893 f = vlib_get_frame_to_node (vm, next_index);
895 tm->tx_frames[!is_ip4][thread_index] = f;
897 to_next = vlib_frame_vector_args (f);
898 to_next[f->n_vectors] = bi;
900 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
902 vlib_put_frame_to_node (vm, next_index, f);
903 tm->tx_frames[!is_ip4][thread_index] = 0;
908 tcp_enqueue_to_output (vlib_main_t * vm, vlib_buffer_t * b, u32 bi, u8 is_ip4)
910 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 0);
914 tcp_enqueue_to_output_now (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
917 tcp_enqueue_to_output_i (vm, b, bi, is_ip4, 1);
921 * Flush tx frame populated by retransmits and timer pops
924 tcp_flush_frame_to_output (vlib_main_t * vm, u8 thread_index, u8 is_ip4)
926 if (tcp_main.tx_frames[!is_ip4][thread_index])
929 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
930 vlib_put_frame_to_node (vm, next_index,
931 tcp_main.tx_frames[!is_ip4][thread_index]);
932 tcp_main.tx_frames[!is_ip4][thread_index] = 0;
937 * Flush both v4 and v6 tx frames for thread index
940 tcp_flush_frames_to_output (u8 thread_index)
942 vlib_main_t *vm = vlib_get_main ();
943 tcp_flush_frame_to_output (vm, thread_index, 1);
944 tcp_flush_frame_to_output (vm, thread_index, 0);
951 tcp_send_fin (tcp_connection_t * tc)
955 tcp_main_t *tm = vnet_get_tcp_main ();
956 vlib_main_t *vm = vlib_get_main ();
958 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
960 b = vlib_get_buffer (vm, bi);
962 /* Leave enough space for headers */
963 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
965 tcp_make_fin (tc, b);
966 tcp_enqueue_to_output_now (vm, b, bi, tc->c_is_ip4);
967 tc->flags |= TCP_CONN_FINSNT;
968 tcp_retransmit_timer_force_update (tc);
969 TCP_EVT_DBG (TCP_EVT_FIN_SENT, tc);
973 tcp_make_state_flags (tcp_state_t next_state)
977 case TCP_STATE_ESTABLISHED:
979 case TCP_STATE_SYN_RCVD:
980 return TCP_FLAG_SYN | TCP_FLAG_ACK;
981 case TCP_STATE_SYN_SENT:
983 case TCP_STATE_LAST_ACK:
984 case TCP_STATE_FIN_WAIT_1:
987 clib_warning ("Shouldn't be here!");
993 * Push TCP header and update connection variables
996 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
997 tcp_state_t next_state, u8 compute_opts)
999 u32 advertise_wnd, data_len;
1000 u8 tcp_hdr_opts_len, opts_write_len, flags;
1003 data_len = b->current_length + b->total_length_not_including_first_buffer;
1004 vnet_buffer (b)->tcp.flags = 0;
1007 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1009 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
1010 advertise_wnd = tcp_window_to_advertise (tc, next_state);
1011 flags = tcp_make_state_flags (next_state);
1013 /* Push header and options */
1014 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
1015 tc->rcv_nxt, tcp_hdr_opts_len, flags,
1017 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
1019 ASSERT (opts_write_len == tc->snd_opts_len);
1020 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
1023 * Update connection variables
1026 tc->snd_nxt += data_len;
1027 tc->rcv_las = tc->rcv_nxt;
1029 /* TODO this is updated in output as well ... */
1030 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
1032 tc->snd_una_max = tc->snd_nxt;
1033 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1036 TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
1040 tcp_send_ack (tcp_connection_t * tc)
1042 tcp_main_t *tm = vnet_get_tcp_main ();
1043 vlib_main_t *vm = vlib_get_main ();
1049 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1051 b = vlib_get_buffer (vm, bi);
1053 /* Fill in the ACK */
1054 tcp_make_ack (tc, b);
1055 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1058 /* Send delayed ACK when timer expires */
1060 tcp_timer_delack_handler (u32 index)
1062 u32 thread_index = vlib_get_thread_index ();
1063 tcp_connection_t *tc;
1065 tc = tcp_connection_get (index, thread_index);
1066 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
1070 /** Build a retransmit segment
1072 * @return the number of bytes in the segment or 0 if there's nothing to
1076 tcp_prepare_retransmit_segment (tcp_connection_t * tc, vlib_buffer_t * b,
1077 u32 offset, u32 max_bytes)
1079 vlib_main_t *vm = vlib_get_main ();
1083 tcp_reuse_buffer (vm, b);
1085 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1086 ASSERT (max_bytes != 0);
1088 max_bytes = clib_min (tc->snd_mss, max_bytes);
1089 start = tc->snd_una + offset;
1091 /* Start is beyond snd_congestion */
1092 if (seq_geq (start, tc->snd_congestion))
1095 /* Don't overshoot snd_congestion */
1096 if (seq_gt (start + max_bytes, tc->snd_congestion))
1098 max_bytes = tc->snd_congestion - start;
1103 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1105 ASSERT (max_bytes <= tc->snd_mss);
1107 n_bytes = stream_session_peek_bytes (&tc->connection,
1108 vlib_buffer_get_current (b), offset,
1110 ASSERT (n_bytes > 0);
1111 b->current_length = n_bytes;
1112 tcp_push_hdr_i (tc, b, tc->state, 0);
1114 if (tcp_in_fastrecovery (tc))
1115 tc->snd_rxt_bytes += n_bytes;
1118 TCP_EVT_DBG (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1123 * Reset congestion control, switch cwnd to loss window and try again.
1126 tcp_rtx_timeout_cc (tcp_connection_t * tc)
1128 tc->prev_ssthresh = tc->ssthresh;
1129 tc->prev_cwnd = tc->cwnd;
1131 /* Cleanly recover cc (also clears up fast retransmit) */
1132 if (tcp_in_fastrecovery (tc))
1133 tcp_cc_fastrecovery_exit (tc);
1135 /* Start again from the beginning */
1136 tc->ssthresh = clib_max (tcp_flight_size (tc) / 2, 2 * tc->snd_mss);
1137 tc->cwnd = tcp_loss_wnd (tc);
1138 tc->snd_congestion = tc->snd_una_max;
1140 tcp_recovery_on (tc);
1144 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
1146 tcp_main_t *tm = vnet_get_tcp_main ();
1147 vlib_main_t *vm = vlib_get_main ();
1148 u32 thread_index = vlib_get_thread_index ();
1149 tcp_connection_t *tc;
1155 tc = tcp_half_open_connection_get (index);
1156 tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
1160 tc = tcp_connection_get (index, thread_index);
1161 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
1164 if (!tcp_in_recovery (tc) && tc->rto_boff > 0
1165 && tc->state >= TCP_STATE_ESTABLISHED)
1168 tcp_update_rto (tc);
1171 /* Increment RTO backoff (also equal to number of retries) */
1174 /* Go back to first un-acked byte */
1175 tc->snd_nxt = tc->snd_una;
1177 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1180 b = vlib_get_buffer (vm, bi);
1182 if (tc->state >= TCP_STATE_ESTABLISHED)
1184 /* Lost FIN, retransmit and return */
1185 if (tc->flags & TCP_CONN_FINSNT)
1187 tcp_return_buffer (tm);
1192 /* First retransmit timeout */
1193 if (tc->rto_boff == 1)
1194 tcp_rtx_timeout_cc (tc);
1196 /* Exponential backoff */
1197 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1199 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1);
1201 /* Send one segment */
1202 n_bytes = tcp_prepare_retransmit_segment (tc, b, 0, tc->snd_mss);
1203 /* TODO be less aggressive about this */
1204 scoreboard_clear (&tc->sack_sb);
1208 clib_warning ("could not retransmit anything");
1209 clib_warning ("%U", format_tcp_connection, tc, 2);
1211 /* Try again eventually */
1212 tcp_retransmit_timer_set (tc);
1213 ASSERT (0 || (tc->rto_boff > 1
1214 && tc->snd_una == tc->snd_congestion));
1215 tcp_return_buffer (tm);
1219 /* For first retransmit, record timestamp (Eifel detection RFC3522) */
1220 if (tc->rto_boff == 1)
1221 tc->snd_rxt_ts = tcp_time_now ();
1223 /* Retransmit for SYN/SYNACK */
1224 else if (tc->state == TCP_STATE_SYN_RCVD || tc->state == TCP_STATE_SYN_SENT)
1226 /* Half-open connection actually moved to established but we were
1227 * waiting for syn retransmit to pop to call cleanup from the right
1229 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1231 ASSERT (tc->state == TCP_STATE_SYN_SENT);
1232 if (tcp_half_open_connection_cleanup (tc))
1234 clib_warning ("could not remove half-open connection");
1237 tcp_return_buffer (tm);
1241 /* Try without increasing RTO a number of times. If this fails,
1242 * start growing RTO exponentially */
1243 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1244 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1246 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
1247 tcp_push_hdr_i (tc, b, tc->state, 1);
1249 /* Account for the SYN */
1252 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc,
1253 (tc->state == TCP_STATE_SYN_SENT ? 0 : 1));
1257 ASSERT (tc->state == TCP_STATE_CLOSED);
1258 clib_warning ("connection closed ...");
1259 tcp_return_buffer (tm);
1265 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1267 /* Re-enable retransmit timer */
1268 tcp_retransmit_timer_set (tc);
1272 ASSERT (tc->state == TCP_STATE_SYN_SENT);
1274 /* This goes straight to ipx_lookup */
1275 tcp_push_ip_hdr (tm, tc, b);
1276 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
1278 /* Re-enable retransmit timer */
1279 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN,
1280 tc->rto * TCP_TO_TIMER_TICK);
1285 tcp_timer_retransmit_handler (u32 index)
1287 tcp_timer_retransmit_handler_i (index, 0);
1291 tcp_timer_retransmit_syn_handler (u32 index)
1293 tcp_timer_retransmit_handler_i (index, 1);
1297 * Got 0 snd_wnd from peer, try to do something about it.
1301 tcp_timer_persist_handler (u32 index)
1303 tcp_main_t *tm = vnet_get_tcp_main ();
1304 vlib_main_t *vm = vlib_get_main ();
1305 u32 thread_index = vlib_get_thread_index ();
1306 tcp_connection_t *tc;
1308 u32 bi, old_snd_nxt;
1311 tc = tcp_connection_get_if_valid (index, thread_index);
1316 /* Make sure timer handle is set to invalid */
1317 tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
1319 /* Problem already solved or worse */
1320 if (tc->state == TCP_STATE_CLOSED || tc->state > TCP_STATE_ESTABLISHED
1321 || tc->snd_wnd > tc->snd_mss || tcp_in_recovery (tc))
1324 /* Increment RTO backoff */
1326 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1328 /* Try to force the first unsent segment */
1329 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1332 b = vlib_get_buffer (vm, bi);
1334 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1335 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1336 n_bytes = stream_session_peek_bytes (&tc->connection,
1337 vlib_buffer_get_current (b),
1338 tc->snd_una_max - tc->snd_una,
1340 /* Nothing to send */
1343 // clib_warning ("persist found nothing to send");
1344 tcp_return_buffer (tm);
1348 b->current_length = n_bytes;
1349 ASSERT (tc->snd_nxt == tc->snd_una_max || tc->rto_boff > 1
1350 || tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1352 /* Allow updating of snd_una_max but don't update snd_nxt */
1353 old_snd_nxt = tc->snd_nxt;
1354 tcp_push_hdr_i (tc, b, tc->state, 0);
1355 tc->snd_nxt = old_snd_nxt;
1356 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1358 /* Re-enable persist timer */
1359 tcp_persist_timer_set (tc);
1363 * Retransmit first unacked segment
1366 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1368 tcp_main_t *tm = vnet_get_tcp_main ();
1369 vlib_main_t *vm = vlib_get_main ();
1371 u32 bi, n_bytes, old_snd_nxt;
1373 old_snd_nxt = tc->snd_nxt;
1374 tc->snd_nxt = tc->snd_una;
1377 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1380 b = vlib_get_buffer (vm, bi);
1382 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2);
1384 n_bytes = tcp_prepare_retransmit_segment (tc, b, 0, tc->snd_mss);
1387 tcp_return_buffer (tm);
1391 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1394 tc->snd_nxt = old_snd_nxt;
1398 * Do fast retransmit with SACKs
1401 tcp_fast_retransmit_sack (tcp_connection_t * tc)
1403 tcp_main_t *tm = vnet_get_tcp_main ();
1404 vlib_main_t *vm = vlib_get_main ();
1405 u32 n_written = 0, offset = 0, max_bytes;
1407 sack_scoreboard_hole_t *hole;
1408 sack_scoreboard_t *sb;
1409 u32 bi, old_snd_nxt;
1411 u8 snd_limited = 0, can_rescue = 0;
1413 ASSERT (tcp_in_fastrecovery (tc));
1414 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1416 old_snd_nxt = tc->snd_nxt;
1418 snd_space = tcp_available_snd_space (tc);
1420 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1421 while (hole && snd_space > 0)
1423 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1426 b = vlib_get_buffer (vm, bi);
1427 hole = scoreboard_next_rxt_hole (sb, hole,
1428 tcp_fastrecovery_sent_1_smss (tc),
1429 &can_rescue, &snd_limited);
1432 if (!can_rescue || !(seq_lt (sb->rescue_rxt, tc->snd_una)
1433 || seq_gt (sb->rescue_rxt,
1434 tc->snd_congestion)))
1437 /* If rescue rxt undefined or less than snd_una then one segment of
1438 * up to SMSS octets that MUST include the highest outstanding
1439 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1440 * RecoveryPoint. HighRxt MUST NOT be updated.
1442 max_bytes = clib_min (tc->snd_mss, snd_space);
1443 offset = tc->snd_congestion - tc->snd_una - max_bytes;
1444 sb->rescue_rxt = tc->snd_congestion;
1445 tc->snd_nxt = tc->snd_una + offset;
1446 tcp_prepare_retransmit_segment (tc, b, offset, max_bytes);
1447 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1451 max_bytes = snd_limited ? tc->snd_mss : hole->end - sb->high_rxt;
1452 offset = sb->high_rxt - tc->snd_una;
1453 tc->snd_nxt = tc->snd_una + offset;
1454 n_written = tcp_prepare_retransmit_segment (tc, b, offset, max_bytes);
1456 /* Nothing left to retransmit */
1459 tcp_return_buffer (tm);
1463 sb->high_rxt += n_written;
1464 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1465 snd_space -= n_written;
1468 /* If window allows, send 1 SMSS of new data */
1469 tc->snd_nxt = old_snd_nxt;
1473 * Fast retransmit without SACK info
1476 tcp_fast_retransmit_no_sack (tcp_connection_t * tc)
1478 tcp_main_t *tm = vnet_get_tcp_main ();
1479 vlib_main_t *vm = vlib_get_main ();
1480 u32 n_written = 0, offset = 0, bi, old_snd_nxt;
1484 ASSERT (tcp_in_fastrecovery (tc));
1485 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1487 /* Start resending from first un-acked segment */
1488 old_snd_nxt = tc->snd_nxt;
1489 tc->snd_nxt = tc->snd_una;
1490 snd_space = tcp_available_snd_space (tc);
1492 while (snd_space > 0)
1494 if (PREDICT_FALSE (tcp_get_free_buffer_index (tm, &bi)))
1496 b = vlib_get_buffer (vm, bi);
1497 offset += n_written;
1498 n_written = tcp_prepare_retransmit_segment (tc, b, offset, snd_space);
1500 /* Nothing left to retransmit */
1503 tcp_return_buffer (tm);
1507 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1508 snd_space -= n_written;
1511 /* Restore snd_nxt. If window allows, send 1 SMSS of new data */
1512 tc->snd_nxt = old_snd_nxt;
1516 * Do fast retransmit
1519 tcp_fast_retransmit (tcp_connection_t * tc)
1521 if (tcp_opts_sack_permitted (&tc->rcv_opts)
1522 && scoreboard_first_hole (&tc->sack_sb))
1523 tcp_fast_retransmit_sack (tc);
1525 tcp_fast_retransmit_no_sack (tc);
1529 tcp_session_has_ooo_data (tcp_connection_t * tc)
1531 stream_session_t *s =
1532 stream_session_get (tc->c_s_index, tc->c_thread_index);
1533 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1537 tcp46_output_inline (vlib_main_t * vm,
1538 vlib_node_runtime_t * node,
1539 vlib_frame_t * from_frame, int is_ip4)
1541 u32 n_left_from, next_index, *from, *to_next;
1542 u32 my_thread_index = vm->thread_index;
1544 from = vlib_frame_vector_args (from_frame);
1545 n_left_from = from_frame->n_vectors;
1547 next_index = node->cached_next_index;
1549 while (n_left_from > 0)
1553 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1555 while (n_left_from > 0 && n_left_to_next > 0)
1559 tcp_connection_t *tc0;
1561 tcp_header_t *th0 = 0;
1562 u32 error0 = TCP_ERROR_PKTS_SENT, next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
1569 n_left_to_next -= 1;
1571 b0 = vlib_get_buffer (vm, bi0);
1572 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1574 if (PREDICT_FALSE (tc0 == 0 || tc0->state == TCP_STATE_CLOSED))
1576 error0 = TCP_ERROR_INVALID_CONNECTION;
1577 next0 = TCP_OUTPUT_NEXT_DROP;
1581 th0 = vlib_buffer_get_current (b0);
1582 TCP_EVT_DBG (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
1586 vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
1587 IP_PROTOCOL_TCP, 1);
1588 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1589 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1595 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6,
1596 &tc0->c_rmt_ip6, IP_PROTOCOL_TCP);
1597 b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1598 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ih0 - b0->data;
1599 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1603 /* Filter out DUPACKs if there are no OOO segments left */
1605 (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1607 if (!tcp_session_has_ooo_data (tc0))
1609 error0 = TCP_ERROR_FILTERED_DUPACKS;
1610 next0 = TCP_OUTPUT_NEXT_DROP;
1615 /* Stop DELACK timer and fix flags */
1616 tc0->flags &= ~(TCP_CONN_SNDACK);
1617 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1619 /* If not retransmitting
1620 * 1) update snd_una_max (SYN, SYNACK, FIN)
1621 * 2) If we're not tracking an ACK, start tracking */
1622 if (seq_lt (tc0->snd_una_max, tc0->snd_nxt))
1624 tc0->snd_una_max = tc0->snd_nxt;
1625 if (tc0->rtt_ts == 0)
1627 tc0->rtt_ts = tcp_time_now ();
1628 tc0->rtt_seq = tc0->snd_nxt;
1632 /* Set the retransmit timer if not set already and not
1633 * doing a pure ACK */
1634 if (!tcp_timer_is_active (tc0, TCP_TIMER_RETRANSMIT)
1635 && tc0->snd_nxt != tc0->snd_una)
1637 tcp_retransmit_timer_set (tc0);
1642 /* Make sure we haven't lost route to our peer */
1643 if (PREDICT_FALSE (tc0->last_fib_check
1644 < tc0->snd_opts.tsval + TCP_FIB_RECHECK_PERIOD))
1647 (tc0->c_rmt_fei == tcp_lookup_rmt_in_fib (tc0)))
1649 tc0->last_fib_check = tc0->snd_opts.tsval;
1653 clib_warning ("lost connection to peer");
1654 tcp_connection_reset (tc0);
1659 /* Use pre-computed dpo to set next node */
1660 next0 = tc0->c_rmt_dpo.dpoi_next_node;
1661 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = tc0->c_rmt_dpo.dpoi_index;
1664 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
1665 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
1667 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
1669 b0->error = node->errors[error0];
1670 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1672 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1675 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1679 memset (&t0->tcp_header, 0, sizeof (t0->tcp_header));
1681 clib_memcpy (&t0->tcp_connection, tc0,
1682 sizeof (t0->tcp_connection));
1685 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1686 n_left_to_next, bi0, next0);
1689 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1692 return from_frame->n_vectors;
1696 tcp4_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1697 vlib_frame_t * from_frame)
1699 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1703 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1704 vlib_frame_t * from_frame)
1706 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1710 VLIB_REGISTER_NODE (tcp4_output_node) =
1712 .function = tcp4_output,.name = "tcp4-output",
1713 /* Takes a vector of packets. */
1714 .vector_size = sizeof (u32),
1715 .n_errors = TCP_N_ERROR,
1716 .error_strings = tcp_error_strings,
1717 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1719 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1720 foreach_tcp4_output_next
1723 .format_buffer = format_tcp_header,
1724 .format_trace = format_tcp_tx_trace,
1728 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output);
1731 VLIB_REGISTER_NODE (tcp6_output_node) =
1733 .function = tcp6_output,
1734 .name = "tcp6-output",
1735 /* Takes a vector of packets. */
1736 .vector_size = sizeof (u32),
1737 .n_errors = TCP_N_ERROR,
1738 .error_strings = tcp_error_strings,
1739 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1741 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1742 foreach_tcp6_output_next
1745 .format_buffer = format_tcp_header,
1746 .format_trace = format_tcp_tx_trace,
1750 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output);
1753 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
1755 tcp_connection_t *tc;
1757 tc = (tcp_connection_t *) tconn;
1758 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, 0);
1760 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
1762 tc->rtt_ts = tcp_time_now ();
1763 tc->rtt_seq = tc->snd_nxt;
1768 typedef enum _tcp_reset_next
1770 TCP_RESET_NEXT_DROP,
1771 TCP_RESET_NEXT_IP_LOOKUP,
1775 #define foreach_tcp4_reset_next \
1776 _(DROP, "error-drop") \
1777 _(IP_LOOKUP, "ip4-lookup")
1779 #define foreach_tcp6_reset_next \
1780 _(DROP, "error-drop") \
1781 _(IP_LOOKUP, "ip6-lookup")
1784 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1785 vlib_frame_t * from_frame, u8 is_ip4)
1787 u32 n_left_from, next_index, *from, *to_next;
1788 u32 my_thread_index = vm->thread_index;
1790 from = vlib_frame_vector_args (from_frame);
1791 n_left_from = from_frame->n_vectors;
1793 next_index = node->cached_next_index;
1795 while (n_left_from > 0)
1799 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1801 while (n_left_from > 0 && n_left_to_next > 0)
1807 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
1814 n_left_to_next -= 1;
1816 b0 = vlib_get_buffer (vm, bi0);
1818 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
1819 my_thread_index, is_ip4))
1821 error0 = TCP_ERROR_LOOKUP_DROPS;
1822 next0 = TCP_RESET_NEXT_DROP;
1826 /* Prepare to send to IP lookup */
1827 vnet_buffer (b0)->sw_if_index[VLIB_TX] = 0;
1828 next0 = TCP_RESET_NEXT_IP_LOOKUP;
1831 b0->error = node->errors[error0];
1832 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
1833 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1835 th0 = vlib_buffer_get_current (b0);
1837 th0 = ip4_next_header ((ip4_header_t *) th0);
1839 th0 = ip6_next_header ((ip6_header_t *) th0);
1840 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1841 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1844 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1845 n_left_to_next, bi0, next0);
1847 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1849 return from_frame->n_vectors;
1853 tcp4_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1854 vlib_frame_t * from_frame)
1856 return tcp46_send_reset_inline (vm, node, from_frame, 1);
1860 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1861 vlib_frame_t * from_frame)
1863 return tcp46_send_reset_inline (vm, node, from_frame, 0);
1867 VLIB_REGISTER_NODE (tcp4_reset_node) = {
1868 .function = tcp4_send_reset,
1869 .name = "tcp4-reset",
1870 .vector_size = sizeof (u32),
1871 .n_errors = TCP_N_ERROR,
1872 .error_strings = tcp_error_strings,
1873 .n_next_nodes = TCP_RESET_N_NEXT,
1875 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
1876 foreach_tcp4_reset_next
1879 .format_trace = format_tcp_tx_trace,
1883 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset);
1886 VLIB_REGISTER_NODE (tcp6_reset_node) = {
1887 .function = tcp6_send_reset,
1888 .name = "tcp6-reset",
1889 .vector_size = sizeof (u32),
1890 .n_errors = TCP_N_ERROR,
1891 .error_strings = tcp_error_strings,
1892 .n_next_nodes = TCP_RESET_N_NEXT,
1894 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
1895 foreach_tcp6_reset_next
1898 .format_trace = format_tcp_tx_trace,
1902 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset);
1905 * fd.io coding-style-patch-verification: ON
1908 * eval: (c-set-style "gnu")