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;
439 #define tcp_get_free_buffer_index(tm, bidx) \
441 u32 *my_tx_buffers, n_free_buffers; \
442 u32 thread_index = vlib_get_thread_index(); \
443 my_tx_buffers = tm->tx_buffers[thread_index]; \
444 if (PREDICT_FALSE(vec_len (my_tx_buffers) == 0)) \
446 n_free_buffers = 32; /* TODO config or macro */ \
447 vec_validate (my_tx_buffers, n_free_buffers - 1); \
448 _vec_len(my_tx_buffers) = vlib_buffer_alloc_from_free_list ( \
449 vlib_get_main(), my_tx_buffers, n_free_buffers, \
450 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX); \
451 tm->tx_buffers[thread_index] = my_tx_buffers; \
453 /* buffer shortage */ \
454 if (PREDICT_FALSE (vec_len (my_tx_buffers) == 0)) \
456 *bidx = my_tx_buffers[_vec_len (my_tx_buffers)-1]; \
457 _vec_len (my_tx_buffers) -= 1; \
460 #define tcp_return_buffer(tm) \
462 u32 *my_tx_buffers; \
463 u32 thread_index = vlib_get_thread_index(); \
464 my_tx_buffers = tm->tx_buffers[thread_index]; \
465 _vec_len (my_tx_buffers) +=1; \
469 tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b)
471 vlib_buffer_t *it = b;
474 it->current_data = 0;
475 it->current_length = 0;
476 it->total_length_not_including_first_buffer = 0;
478 while ((it->flags & VLIB_BUFFER_NEXT_PRESENT)
479 && (it = vlib_get_buffer (vm, it->next_buffer)));
481 /* Leave enough space for headers */
482 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
483 vnet_buffer (b)->tcp.flags = 0;
490 tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
493 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
494 u8 tcp_opts_len, tcp_hdr_opts_len;
498 wnd = tcp_window_to_advertise (tc, state);
500 /* Make and write options */
501 tcp_opts_len = tcp_make_established_options (tc, snd_opts);
502 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
504 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
505 tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd);
507 tcp_options_write ((u8 *) (th + 1), snd_opts);
508 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
512 * Convert buffer to ACK
515 tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
517 vlib_main_t *vm = vlib_get_main ();
519 tcp_reuse_buffer (vm, b);
520 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
521 TCP_EVT_DBG (TCP_EVT_ACK_SENT, tc);
522 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
523 tc->rcv_las = tc->rcv_nxt;
527 * Convert buffer to FIN-ACK
530 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
532 vlib_main_t *vm = vlib_get_main ();
535 tcp_reuse_buffer (vm, b);
537 flags = TCP_FLAG_FIN | TCP_FLAG_ACK;
538 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, flags);
540 /* Reset flags, make sure ack is sent */
541 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
547 * Convert buffer to SYN-ACK
550 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
552 vlib_main_t *vm = vlib_get_main ();
553 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
554 u8 tcp_opts_len, tcp_hdr_opts_len;
559 memset (snd_opts, 0, sizeof (*snd_opts));
561 tcp_reuse_buffer (vm, b);
563 /* Set random initial sequence */
564 time_now = tcp_time_now ();
566 tc->iss = random_u32 (&time_now);
567 tc->snd_una = tc->iss;
568 tc->snd_nxt = tc->iss + 1;
569 tc->snd_una_max = tc->snd_nxt;
571 initial_wnd = tcp_initial_window_to_advertise (tc);
573 /* Make and write options */
574 tcp_opts_len = tcp_make_synack_options (tc, snd_opts);
575 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
577 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
578 tc->rcv_nxt, tcp_hdr_opts_len,
579 TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd);
581 tcp_options_write ((u8 *) (th + 1), snd_opts);
583 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
584 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
586 /* Init retransmit timer */
587 tcp_retransmit_timer_set (tc);
588 TCP_EVT_DBG (TCP_EVT_SYNACK_SENT, tc);
592 tcp_enqueue_to_ip_lookup (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
595 u32 *to_next, next_index;
598 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
601 /* Default FIB for now */
602 vnet_buffer (b)->sw_if_index[VLIB_TX] = 0;
604 /* Send to IP lookup */
605 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
606 f = vlib_get_frame_to_node (vm, next_index);
608 /* Enqueue the packet */
609 to_next = vlib_frame_vector_args (f);
612 vlib_put_frame_to_node (vm, next_index, f);
616 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
617 tcp_state_t state, u8 thread_index, u8 is_ip4)
622 ip4_address_t src_ip40, dst_ip40;
623 ip6_address_t src_ip60, dst_ip60;
624 u16 src_port, dst_port;
629 /* Find IP and TCP headers */
630 th0 = tcp_buffer_hdr (b0);
632 /* Save src and dst ip */
635 ih4 = vlib_buffer_get_current (b0);
636 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
637 src_ip40.as_u32 = ih4->src_address.as_u32;
638 dst_ip40.as_u32 = ih4->dst_address.as_u32;
642 ih6 = vlib_buffer_get_current (b0);
643 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
644 clib_memcpy (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
645 clib_memcpy (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t));
648 src_port = th0->src_port;
649 dst_port = th0->dst_port;
651 /* Try to determine what/why we're actually resetting */
652 if (state == TCP_STATE_CLOSED)
657 tmp = clib_net_to_host_u32 (th0->seq_number);
659 /* Got a SYN for no listener. */
660 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
661 ack = clib_host_to_net_u32 (tmp + 1);
666 flags = TCP_FLAG_RST;
667 seq = th0->ack_number;
671 tcp_reuse_buffer (vm, b0);
672 th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack,
673 sizeof (tcp_header_t), flags, 0);
677 ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40,
679 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
684 ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60,
686 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
694 * Send reset without reusing existing buffer
697 tcp_send_reset (tcp_connection_t * tc, vlib_buffer_t * pkt, u8 is_ip4)
701 tcp_main_t *tm = vnet_get_tcp_main ();
702 vlib_main_t *vm = vlib_get_main ();
703 u8 tcp_hdr_len, flags = 0;
704 tcp_header_t *th, *pkt_th;
706 ip4_header_t *ih4, *pkt_ih4;
707 ip6_header_t *ih6, *pkt_ih6;
709 tcp_get_free_buffer_index (tm, &bi);
710 b = vlib_get_buffer (vm, bi);
712 /* Leave enough space for headers */
713 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
715 /* Make and write options */
716 tcp_hdr_len = sizeof (tcp_header_t);
720 pkt_ih4 = vlib_buffer_get_current (pkt);
721 pkt_th = ip4_next_header (pkt_ih4);
725 pkt_ih6 = vlib_buffer_get_current (pkt);
726 pkt_th = ip6_next_header (pkt_ih6);
729 if (tcp_ack (pkt_th))
731 flags = TCP_FLAG_RST;
732 seq = pkt_th->ack_number;
733 ack = (tc && tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
737 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
739 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
742 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
743 seq, ack, tcp_hdr_len, flags, 0);
745 /* Swap src and dst ip */
748 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
749 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
750 &pkt_ih4->src_address, IP_PROTOCOL_TCP, 1);
751 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
756 pkt_ih6 = (ip6_header_t *) (pkt_th - 1);
757 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
760 vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address,
761 &pkt_ih6->src_address, IP_PROTOCOL_TCP);
762 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
766 tcp_enqueue_to_ip_lookup (vm, b, bi, is_ip4);
767 TCP_EVT_DBG (TCP_EVT_RST_SENT, tc);
771 tcp_push_ip_hdr (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b)
773 tcp_header_t *th = vlib_buffer_get_current (b);
774 vlib_main_t *vm = vlib_get_main ();
778 ih = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip4,
779 &tc->c_rmt_ip4, IP_PROTOCOL_TCP, 1);
780 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih);
787 ih = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip6,
788 &tc->c_rmt_ip6, IP_PROTOCOL_TCP);
789 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih, &bogus);
797 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
798 * The packet is not forwarded through tcpx_output to avoid doing lookups
799 * in the half_open pool.
802 tcp_send_syn (tcp_connection_t * tc)
806 tcp_main_t *tm = vnet_get_tcp_main ();
807 vlib_main_t *vm = vlib_get_main ();
808 u8 tcp_hdr_opts_len, tcp_opts_len;
812 tcp_options_t snd_opts;
814 tcp_get_free_buffer_index (tm, &bi);
815 b = vlib_get_buffer (vm, bi);
817 /* Leave enough space for headers */
818 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
820 /* Set random initial sequence */
821 time_now = tcp_time_now ();
823 tc->iss = random_u32 (&time_now);
824 tc->snd_una = tc->iss;
825 tc->snd_una_max = tc->snd_nxt = tc->iss + 1;
827 initial_wnd = tcp_initial_window_to_advertise (tc);
829 /* Make and write options */
830 memset (&snd_opts, 0, sizeof (snd_opts));
831 tcp_opts_len = tcp_make_syn_options (&snd_opts, tc->rcv_wscale);
832 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
834 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
835 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
838 tcp_options_write ((u8 *) (th + 1), &snd_opts);
840 /* Measure RTT with this */
841 tc->rtt_ts = tcp_time_now ();
842 tc->rtt_seq = tc->snd_nxt;
844 /* Start retransmit trimer */
845 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN, tc->rto * TCP_TO_TIMER_TICK);
848 /* Set the connection establishment timer */
849 tcp_timer_set (tc, TCP_TIMER_ESTABLISH, TCP_ESTABLISH_TIME);
851 tcp_push_ip_hdr (tm, tc, b);
852 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
853 TCP_EVT_DBG (TCP_EVT_SYN_SENT, tc);
857 tcp_enqueue_to_output (vlib_main_t * vm, vlib_buffer_t * b, u32 bi, u8 is_ip4)
859 u32 *to_next, next_index;
862 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
865 /* Decide where to send the packet */
866 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
868 /* Initialize the trajectory trace, if configured */
869 if (VLIB_BUFFER_TRACE_TRAJECTORY > 0)
872 b->pre_data[1] = next_index;
875 /* Enqueue the packet */
876 f = vlib_get_frame_to_node (vm, next_index);
877 to_next = vlib_frame_vector_args (f);
880 vlib_put_frame_to_node (vm, next_index, f);
887 tcp_send_fin (tcp_connection_t * tc)
891 tcp_main_t *tm = vnet_get_tcp_main ();
892 vlib_main_t *vm = vlib_get_main ();
894 tcp_get_free_buffer_index (tm, &bi);
895 b = vlib_get_buffer (vm, bi);
897 /* Leave enough space for headers */
898 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
900 tcp_make_fin (tc, b);
901 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
902 tc->flags |= TCP_CONN_FINSNT;
903 tcp_retransmit_timer_force_update (tc);
904 TCP_EVT_DBG (TCP_EVT_FIN_SENT, tc);
908 tcp_make_state_flags (tcp_state_t next_state)
912 case TCP_STATE_ESTABLISHED:
914 case TCP_STATE_SYN_RCVD:
915 return TCP_FLAG_SYN | TCP_FLAG_ACK;
916 case TCP_STATE_SYN_SENT:
918 case TCP_STATE_LAST_ACK:
919 case TCP_STATE_FIN_WAIT_1:
922 clib_warning ("Shouldn't be here!");
928 * Push TCP header and update connection variables
931 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
932 tcp_state_t next_state, u8 compute_opts)
934 u32 advertise_wnd, data_len;
935 u8 tcp_hdr_opts_len, opts_write_len, flags;
938 data_len = b->current_length + b->total_length_not_including_first_buffer;
939 vnet_buffer (b)->tcp.flags = 0;
942 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
944 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
945 advertise_wnd = tcp_window_to_advertise (tc, next_state);
946 flags = tcp_make_state_flags (next_state);
948 /* Push header and options */
949 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
950 tc->rcv_nxt, tcp_hdr_opts_len, flags,
952 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
954 ASSERT (opts_write_len == tc->snd_opts_len);
955 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
958 * Update connection variables
961 tc->snd_nxt += data_len;
962 tc->rcv_las = tc->rcv_nxt;
964 /* TODO this is updated in output as well ... */
965 if (seq_gt (tc->snd_nxt, tc->snd_una_max))
967 tc->snd_una_max = tc->snd_nxt;
968 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
971 TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
975 tcp_send_ack (tcp_connection_t * tc)
977 tcp_main_t *tm = vnet_get_tcp_main ();
978 vlib_main_t *vm = vlib_get_main ();
984 tcp_get_free_buffer_index (tm, &bi);
985 b = vlib_get_buffer (vm, bi);
987 /* Fill in the ACK */
988 tcp_make_ack (tc, b);
989 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
992 /* Send delayed ACK when timer expires */
994 tcp_timer_delack_handler (u32 index)
996 u32 thread_index = vlib_get_thread_index ();
997 tcp_connection_t *tc;
999 tc = tcp_connection_get (index, thread_index);
1000 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
1004 /** Build a retransmit segment
1006 * @return the number of bytes in the segment or 0 if there's nothing to
1010 tcp_prepare_retransmit_segment (tcp_connection_t * tc, vlib_buffer_t * b,
1011 u32 offset, u32 max_bytes)
1013 vlib_main_t *vm = vlib_get_main ();
1017 tcp_reuse_buffer (vm, b);
1019 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1020 ASSERT (max_bytes != 0);
1022 max_bytes = clib_min (tc->snd_mss, max_bytes);
1023 start = tc->snd_una + offset;
1025 /* Start is beyond snd_congestion */
1026 if (seq_geq (start, tc->snd_congestion))
1029 /* Don't overshoot snd_congestion */
1030 if (seq_gt (start + max_bytes, tc->snd_congestion))
1032 max_bytes = tc->snd_congestion - start;
1037 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1039 ASSERT (max_bytes <= tc->snd_mss);
1041 n_bytes = stream_session_peek_bytes (&tc->connection,
1042 vlib_buffer_get_current (b), offset,
1044 ASSERT (n_bytes > 0);
1045 b->current_length = n_bytes;
1046 tcp_push_hdr_i (tc, b, tc->state, 0);
1048 if (tcp_in_fastrecovery (tc))
1049 tc->snd_rxt_bytes += n_bytes;
1052 TCP_EVT_DBG (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1057 * Reset congestion control, switch cwnd to loss window and try again.
1060 tcp_rtx_timeout_cc (tcp_connection_t * tc)
1062 tc->prev_ssthresh = tc->ssthresh;
1063 tc->prev_cwnd = tc->cwnd;
1065 /* Cleanly recover cc (also clears up fast retransmit) */
1066 if (tcp_in_fastrecovery (tc))
1067 tcp_cc_fastrecovery_exit (tc);
1069 /* Start again from the beginning */
1070 tc->ssthresh = clib_max (tcp_flight_size (tc) / 2, 2 * tc->snd_mss);
1071 tc->cwnd = tcp_loss_wnd (tc);
1072 tc->snd_congestion = tc->snd_una_max;
1074 tcp_recovery_on (tc);
1078 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
1080 tcp_main_t *tm = vnet_get_tcp_main ();
1081 vlib_main_t *vm = vlib_get_main ();
1082 u32 thread_index = vlib_get_thread_index ();
1083 tcp_connection_t *tc;
1089 tc = tcp_half_open_connection_get (index);
1090 tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
1094 tc = tcp_connection_get (index, thread_index);
1095 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
1098 if (!tcp_in_recovery (tc) && tc->rto_boff > 0
1099 && tc->state >= TCP_STATE_ESTABLISHED)
1102 tcp_update_rto (tc);
1105 /* Increment RTO backoff (also equal to number of retries) */
1108 /* Go back to first un-acked byte */
1109 tc->snd_nxt = tc->snd_una;
1111 tcp_get_free_buffer_index (tm, &bi);
1112 b = vlib_get_buffer (vm, bi);
1114 if (tc->state >= TCP_STATE_ESTABLISHED)
1116 /* Lost FIN, retransmit and return */
1117 if (tc->flags & TCP_CONN_FINSNT)
1123 /* First retransmit timeout */
1124 if (tc->rto_boff == 1)
1125 tcp_rtx_timeout_cc (tc);
1127 /* Exponential backoff */
1128 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1130 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1);
1132 /* Send one segment */
1133 n_bytes = tcp_prepare_retransmit_segment (tc, b, 0, tc->snd_mss);
1134 /* TODO be less aggressive about this */
1135 scoreboard_clear (&tc->sack_sb);
1139 clib_warning ("could not retransmit anything");
1140 clib_warning ("%U", format_tcp_connection, tc, 2);
1142 /* Try again eventually */
1143 tcp_retransmit_timer_set (tc);
1144 ASSERT (0 || (tc->rto_boff > 1
1145 && tc->snd_una == tc->snd_congestion));
1149 /* For first retransmit, record timestamp (Eifel detection RFC3522) */
1150 if (tc->rto_boff == 1)
1151 tc->snd_rxt_ts = tcp_time_now ();
1153 /* Retransmit for SYN/SYNACK */
1154 else if (tc->state == TCP_STATE_SYN_RCVD || tc->state == TCP_STATE_SYN_SENT)
1156 /* Half-open connection actually moved to established but we were
1157 * waiting for syn retransmit to pop to call cleanup from the right
1159 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1161 ASSERT (tc->state == TCP_STATE_SYN_SENT);
1162 if (tcp_half_open_connection_cleanup (tc))
1164 clib_warning ("could not remove half-open connection");
1170 /* Try without increasing RTO a number of times. If this fails,
1171 * start growing RTO exponentially */
1172 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1173 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1175 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
1176 tcp_push_hdr_i (tc, b, tc->state, 1);
1178 /* Account for the SYN */
1181 TCP_EVT_DBG (TCP_EVT_SYN_RXT, tc,
1182 (tc->state == TCP_STATE_SYN_SENT ? 0 : 1));
1186 ASSERT (tc->state == TCP_STATE_CLOSED);
1187 clib_warning ("connection closed ...");
1193 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1195 /* Re-enable retransmit timer */
1196 tcp_retransmit_timer_set (tc);
1200 ASSERT (tc->state == TCP_STATE_SYN_SENT);
1202 /* This goes straight to ipx_lookup */
1203 tcp_push_ip_hdr (tm, tc, b);
1204 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
1206 /* Re-enable retransmit timer */
1207 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN,
1208 tc->rto * TCP_TO_TIMER_TICK);
1213 tcp_timer_retransmit_handler (u32 index)
1215 tcp_timer_retransmit_handler_i (index, 0);
1219 tcp_timer_retransmit_syn_handler (u32 index)
1221 tcp_timer_retransmit_handler_i (index, 1);
1225 * Got 0 snd_wnd from peer, try to do something about it.
1229 tcp_timer_persist_handler (u32 index)
1231 tcp_main_t *tm = vnet_get_tcp_main ();
1232 vlib_main_t *vm = vlib_get_main ();
1233 u32 thread_index = vlib_get_thread_index ();
1234 tcp_connection_t *tc;
1236 u32 bi, old_snd_nxt;
1239 tc = tcp_connection_get_if_valid (index, thread_index);
1244 /* Make sure timer handle is set to invalid */
1245 tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
1247 /* Problem already solved or worse */
1248 if (tc->state == TCP_STATE_CLOSED || tc->state > TCP_STATE_ESTABLISHED
1249 || tc->snd_wnd > tc->snd_mss || tcp_in_recovery (tc))
1252 /* Increment RTO backoff */
1254 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1256 /* Try to force the first unsent segment */
1257 tcp_get_free_buffer_index (tm, &bi);
1258 b = vlib_get_buffer (vm, bi);
1260 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1261 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1262 n_bytes = stream_session_peek_bytes (&tc->connection,
1263 vlib_buffer_get_current (b),
1264 tc->snd_una_max - tc->snd_una,
1266 /* Nothing to send */
1269 // clib_warning ("persist found nothing to send");
1270 tcp_return_buffer (tm);
1274 b->current_length = n_bytes;
1275 ASSERT (tc->snd_nxt == tc->snd_una_max || tc->rto_boff > 1
1276 || tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1278 /* Allow updating of snd_una_max but don't update snd_nxt */
1279 old_snd_nxt = tc->snd_nxt;
1280 tcp_push_hdr_i (tc, b, tc->state, 0);
1281 tc->snd_nxt = old_snd_nxt;
1282 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1284 /* Re-enable persist timer */
1285 tcp_persist_timer_set (tc);
1289 * Retransmit first unacked segment
1292 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1294 tcp_main_t *tm = vnet_get_tcp_main ();
1295 vlib_main_t *vm = vlib_get_main ();
1297 u32 bi, n_bytes, old_snd_nxt;
1299 old_snd_nxt = tc->snd_nxt;
1300 tc->snd_nxt = tc->snd_una;
1303 tcp_get_free_buffer_index (tm, &bi);
1304 b = vlib_get_buffer (vm, bi);
1306 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2);
1308 n_bytes = tcp_prepare_retransmit_segment (tc, b, 0, tc->snd_mss);
1311 tcp_return_buffer (tm);
1315 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1318 tc->snd_nxt = old_snd_nxt;
1322 * Do fast retransmit with SACKs
1325 tcp_fast_retransmit_sack (tcp_connection_t * tc)
1327 tcp_main_t *tm = vnet_get_tcp_main ();
1328 vlib_main_t *vm = vlib_get_main ();
1329 u32 n_written = 0, offset = 0, max_bytes;
1331 sack_scoreboard_hole_t *hole;
1332 sack_scoreboard_t *sb;
1333 u32 bi, old_snd_nxt;
1335 u8 snd_limited = 0, can_rescue = 0;
1337 ASSERT (tcp_in_fastrecovery (tc));
1338 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1340 old_snd_nxt = tc->snd_nxt;
1342 snd_space = tcp_available_snd_space (tc);
1344 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1345 while (hole && snd_space > 0)
1347 tcp_get_free_buffer_index (tm, &bi);
1348 b = vlib_get_buffer (vm, bi);
1350 hole = scoreboard_next_rxt_hole (sb, hole,
1351 tcp_fastrecovery_sent_1_smss (tc),
1352 &can_rescue, &snd_limited);
1355 if (!can_rescue || !(seq_lt (sb->rescue_rxt, tc->snd_una)
1356 || seq_gt (sb->rescue_rxt,
1357 tc->snd_congestion)))
1360 /* If rescue rxt undefined or less than snd_una then one segment of
1361 * up to SMSS octets that MUST include the highest outstanding
1362 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1363 * RecoveryPoint. HighRxt MUST NOT be updated.
1365 max_bytes = clib_min (tc->snd_mss, snd_space);
1366 offset = tc->snd_congestion - tc->snd_una - max_bytes;
1367 sb->rescue_rxt = tc->snd_congestion;
1368 tc->snd_nxt = tc->snd_una + offset;
1369 tcp_prepare_retransmit_segment (tc, b, offset, max_bytes);
1370 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1374 max_bytes = snd_limited ? tc->snd_mss : hole->end - sb->high_rxt;
1375 offset = sb->high_rxt - tc->snd_una;
1376 tc->snd_nxt = tc->snd_una + offset;
1377 n_written = tcp_prepare_retransmit_segment (tc, b, offset, max_bytes);
1379 /* Nothing left to retransmit */
1382 tcp_return_buffer (tm);
1386 sb->high_rxt += n_written;
1387 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1388 snd_space -= n_written;
1391 /* If window allows, send 1 SMSS of new data */
1392 tc->snd_nxt = old_snd_nxt;
1396 * Fast retransmit without SACK info
1399 tcp_fast_retransmit_no_sack (tcp_connection_t * tc)
1401 tcp_main_t *tm = vnet_get_tcp_main ();
1402 vlib_main_t *vm = vlib_get_main ();
1403 u32 n_written = 0, offset = 0, bi, old_snd_nxt;
1407 ASSERT (tcp_in_fastrecovery (tc));
1408 TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
1410 /* Start resending from first un-acked segment */
1411 old_snd_nxt = tc->snd_nxt;
1412 tc->snd_nxt = tc->snd_una;
1413 snd_space = tcp_available_snd_space (tc);
1415 while (snd_space > 0)
1417 tcp_get_free_buffer_index (tm, &bi);
1418 b = vlib_get_buffer (vm, bi);
1420 offset += n_written;
1421 n_written = tcp_prepare_retransmit_segment (tc, b, offset, snd_space);
1423 /* Nothing left to retransmit */
1426 tcp_return_buffer (tm);
1430 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1431 snd_space -= n_written;
1434 /* Restore snd_nxt. If window allows, send 1 SMSS of new data */
1435 tc->snd_nxt = old_snd_nxt;
1439 * Do fast retransmit
1442 tcp_fast_retransmit (tcp_connection_t * tc)
1444 if (tcp_opts_sack_permitted (&tc->rcv_opts)
1445 && scoreboard_first_hole (&tc->sack_sb))
1446 tcp_fast_retransmit_sack (tc);
1448 tcp_fast_retransmit_no_sack (tc);
1452 tcp_session_has_ooo_data (tcp_connection_t * tc)
1454 stream_session_t *s =
1455 stream_session_get (tc->c_s_index, tc->c_thread_index);
1456 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1460 tcp46_output_inline (vlib_main_t * vm,
1461 vlib_node_runtime_t * node,
1462 vlib_frame_t * from_frame, int is_ip4)
1464 u32 n_left_from, next_index, *from, *to_next;
1465 u32 my_thread_index = vm->thread_index;
1467 from = vlib_frame_vector_args (from_frame);
1468 n_left_from = from_frame->n_vectors;
1470 next_index = node->cached_next_index;
1472 while (n_left_from > 0)
1476 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1478 while (n_left_from > 0 && n_left_to_next > 0)
1482 tcp_connection_t *tc0;
1484 tcp_header_t *th0 = 0;
1485 u32 error0 = TCP_ERROR_PKTS_SENT, next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
1492 n_left_to_next -= 1;
1494 b0 = vlib_get_buffer (vm, bi0);
1495 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1497 if (PREDICT_FALSE (tc0 == 0 || tc0->state == TCP_STATE_CLOSED))
1499 error0 = TCP_ERROR_INVALID_CONNECTION;
1500 next0 = TCP_OUTPUT_NEXT_DROP;
1504 th0 = vlib_buffer_get_current (b0);
1505 TCP_EVT_DBG (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
1510 ih0 = vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4,
1511 &tc0->c_rmt_ip4, IP_PROTOCOL_TCP,
1514 VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_OFFLOAD_IP_CKSUM |
1515 VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1516 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ih0 - b0->data;
1517 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1525 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6,
1526 &tc0->c_rmt_ip6, IP_PROTOCOL_TCP);
1528 b0->flags |= VNET_BUFFER_F_IS_IP6 |
1529 VNET_BUFFER_F_OFFLOAD_IP_CKSUM |
1530 VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
1531 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ih0 - b0->data;
1532 vnet_buffer (b0)->l4_hdr_offset = (u8 *) th0 - b0->data;
1537 /* Filter out DUPACKs if there are no OOO segments left */
1539 (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1541 if (!tcp_session_has_ooo_data (tc0))
1543 error0 = TCP_ERROR_FILTERED_DUPACKS;
1544 next0 = TCP_OUTPUT_NEXT_DROP;
1549 /* Stop DELACK timer and fix flags */
1550 tc0->flags &= ~(TCP_CONN_SNDACK);
1551 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1553 /* If not retransmitting
1554 * 1) update snd_una_max (SYN, SYNACK, FIN)
1555 * 2) If we're not tracking an ACK, start tracking */
1556 if (seq_lt (tc0->snd_una_max, tc0->snd_nxt))
1558 tc0->snd_una_max = tc0->snd_nxt;
1559 if (tc0->rtt_ts == 0)
1561 tc0->rtt_ts = tcp_time_now ();
1562 tc0->rtt_seq = tc0->snd_nxt;
1566 /* Set the retransmit timer if not set already and not
1567 * doing a pure ACK */
1568 if (!tcp_timer_is_active (tc0, TCP_TIMER_RETRANSMIT)
1569 && tc0->snd_nxt != tc0->snd_una)
1571 tcp_retransmit_timer_set (tc0);
1576 /* Make sure we haven't lost route to our peer */
1577 if (PREDICT_FALSE (tc0->last_fib_check
1578 < tc0->snd_opts.tsval + TCP_FIB_RECHECK_PERIOD))
1581 (tc0->c_rmt_fei == tcp_lookup_rmt_in_fib (tc0)))
1583 tc0->last_fib_check = tc0->snd_opts.tsval;
1587 clib_warning ("lost connection to peer");
1588 tcp_connection_reset (tc0);
1593 /* Use pre-computed dpo to set next node */
1594 next0 = tc0->c_rmt_dpo.dpoi_next_node;
1595 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = tc0->c_rmt_dpo.dpoi_index;
1598 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
1599 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
1601 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
1603 b0->error = node->errors[error0];
1604 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1606 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1609 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1613 memset (&t0->tcp_header, 0, sizeof (t0->tcp_header));
1615 clib_memcpy (&t0->tcp_connection, tc0,
1616 sizeof (t0->tcp_connection));
1619 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1620 n_left_to_next, bi0, next0);
1623 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1626 return from_frame->n_vectors;
1630 tcp4_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1631 vlib_frame_t * from_frame)
1633 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1637 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1638 vlib_frame_t * from_frame)
1640 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1644 VLIB_REGISTER_NODE (tcp4_output_node) =
1646 .function = tcp4_output,.name = "tcp4-output",
1647 /* Takes a vector of packets. */
1648 .vector_size = sizeof (u32),
1649 .n_errors = TCP_N_ERROR,
1650 .error_strings = tcp_error_strings,
1651 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1653 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1654 foreach_tcp4_output_next
1657 .format_buffer = format_tcp_header,
1658 .format_trace = format_tcp_tx_trace,
1662 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output);
1665 VLIB_REGISTER_NODE (tcp6_output_node) =
1667 .function = tcp6_output,
1668 .name = "tcp6-output",
1669 /* Takes a vector of packets. */
1670 .vector_size = sizeof (u32),
1671 .n_errors = TCP_N_ERROR,
1672 .error_strings = tcp_error_strings,
1673 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1675 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1676 foreach_tcp6_output_next
1679 .format_buffer = format_tcp_header,
1680 .format_trace = format_tcp_tx_trace,
1684 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output);
1687 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
1689 tcp_connection_t *tc;
1691 tc = (tcp_connection_t *) tconn;
1692 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, 0);
1694 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
1696 tc->rtt_ts = tcp_time_now ();
1697 tc->rtt_seq = tc->snd_nxt;
1702 typedef enum _tcp_reset_next
1704 TCP_RESET_NEXT_DROP,
1705 TCP_RESET_NEXT_IP_LOOKUP,
1709 #define foreach_tcp4_reset_next \
1710 _(DROP, "error-drop") \
1711 _(IP_LOOKUP, "ip4-lookup")
1713 #define foreach_tcp6_reset_next \
1714 _(DROP, "error-drop") \
1715 _(IP_LOOKUP, "ip6-lookup")
1718 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1719 vlib_frame_t * from_frame, u8 is_ip4)
1721 u32 n_left_from, next_index, *from, *to_next;
1722 u32 my_thread_index = vm->thread_index;
1724 from = vlib_frame_vector_args (from_frame);
1725 n_left_from = from_frame->n_vectors;
1727 next_index = node->cached_next_index;
1729 while (n_left_from > 0)
1733 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1735 while (n_left_from > 0 && n_left_to_next > 0)
1741 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
1748 n_left_to_next -= 1;
1750 b0 = vlib_get_buffer (vm, bi0);
1752 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
1753 my_thread_index, is_ip4))
1755 error0 = TCP_ERROR_LOOKUP_DROPS;
1756 next0 = TCP_RESET_NEXT_DROP;
1760 /* Prepare to send to IP lookup */
1761 vnet_buffer (b0)->sw_if_index[VLIB_TX] = 0;
1762 next0 = TCP_RESET_NEXT_IP_LOOKUP;
1765 b0->error = node->errors[error0];
1766 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
1767 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1769 th0 = vlib_buffer_get_current (b0);
1771 th0 = ip4_next_header ((ip4_header_t *) th0);
1773 th0 = ip6_next_header ((ip6_header_t *) th0);
1774 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
1775 clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
1778 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1779 n_left_to_next, bi0, next0);
1781 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1783 return from_frame->n_vectors;
1787 tcp4_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1788 vlib_frame_t * from_frame)
1790 return tcp46_send_reset_inline (vm, node, from_frame, 1);
1794 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1795 vlib_frame_t * from_frame)
1797 return tcp46_send_reset_inline (vm, node, from_frame, 0);
1801 VLIB_REGISTER_NODE (tcp4_reset_node) = {
1802 .function = tcp4_send_reset,
1803 .name = "tcp4-reset",
1804 .vector_size = sizeof (u32),
1805 .n_errors = TCP_N_ERROR,
1806 .error_strings = tcp_error_strings,
1807 .n_next_nodes = TCP_RESET_N_NEXT,
1809 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
1810 foreach_tcp4_reset_next
1813 .format_trace = format_tcp_tx_trace,
1817 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset);
1820 VLIB_REGISTER_NODE (tcp6_reset_node) = {
1821 .function = tcp6_send_reset,
1822 .name = "tcp6-reset",
1823 .vector_size = sizeof (u32),
1824 .n_errors = TCP_N_ERROR,
1825 .error_strings = tcp_error_strings,
1826 .n_next_nodes = TCP_RESET_N_NEXT,
1828 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
1829 foreach_tcp6_reset_next
1832 .format_trace = format_tcp_tx_trace,
1836 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset);
1839 * fd.io coding-style-patch-verification: ON
1842 * eval: (c-set-style "gnu")