2 * Copyright (c) 2016-2019 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>
19 typedef enum _tcp_output_next
22 TCP_OUTPUT_NEXT_IP_LOOKUP,
23 TCP_OUTPUT_NEXT_IP_REWRITE,
24 TCP_OUTPUT_NEXT_IP_ARP,
28 #define foreach_tcp4_output_next \
29 _ (DROP, "error-drop") \
30 _ (IP_LOOKUP, "ip4-lookup") \
31 _ (IP_REWRITE, "ip4-rewrite") \
34 #define foreach_tcp6_output_next \
35 _ (DROP, "error-drop") \
36 _ (IP_LOOKUP, "ip6-lookup") \
37 _ (IP_REWRITE, "ip6-rewrite") \
38 _ (IP_ARP, "ip6-discover-neighbor")
40 static char *tcp_error_strings[] = {
41 #define tcp_error(n,s) s,
42 #include <vnet/tcp/tcp_error.def>
48 tcp_header_t tcp_header;
49 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 u32 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);
68 #ifndef CLIB_MARCH_VARIANT
70 tcp_window_compute_scale (u32 window)
73 while (wnd_scale < TCP_MAX_WND_SCALE && (window >> wnd_scale) > TCP_WND_MAX)
79 * TCP's initial window
82 tcp_initial_wnd_unscaled (tcp_connection_t * tc)
84 /* RFC 6928 recommends the value lower. However at the time our connections
85 * are initialized, fifos may not be allocated. Therefore, advertise the
86 * smallest possible unscaled window size and update once fifos are
87 * assigned to the session.
90 tcp_update_rcv_mss (tc);
91 TCP_IW_N_SEGMENTS * tc->mss;
93 return tcp_cfg.min_rx_fifo;
97 * Compute initial window and scale factor. As per RFC1323, window field in
98 * SYN and SYN-ACK segments is never scaled.
101 tcp_initial_window_to_advertise (tcp_connection_t * tc)
103 /* Compute rcv wscale only if peer advertised support for it */
104 if (tc->state != TCP_STATE_SYN_RCVD || tcp_opts_wscale (&tc->rcv_opts))
105 tc->rcv_wscale = tcp_window_compute_scale (tcp_cfg.max_rx_fifo);
107 tc->rcv_wnd = tcp_initial_wnd_unscaled (tc);
109 return clib_min (tc->rcv_wnd, TCP_WND_MAX);
113 tcp_update_rcv_wnd (tcp_connection_t * tc)
115 u32 available_space, wnd;
118 ASSERT (tc->rcv_opts.mss < transport_rx_fifo_size (&tc->connection));
121 * Figure out how much space we have available
123 available_space = transport_max_rx_enqueue (&tc->connection);
124 if (PREDICT_FALSE (available_space < tc->rcv_opts.mss))
131 * Use the above and what we know about what we've previously advertised
132 * to compute the new window
134 observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
136 /* Bad. Thou shalt not shrink */
137 if (PREDICT_FALSE ((i32) available_space < observed_wnd))
139 wnd = clib_max (observed_wnd, 0);
140 TCP_EVT (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space);
144 wnd = available_space;
147 /* Make sure we have a multiple of rcv_wscale */
148 if (wnd && tc->rcv_wscale)
150 wnd &= ~((1 << tc->rcv_wscale) - 1);
152 wnd = 1 << tc->rcv_wscale;
155 tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale);
159 * Compute and return window to advertise, scaled as per RFC1323
162 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
164 if (state < TCP_STATE_ESTABLISHED)
165 return tcp_initial_window_to_advertise (tc);
167 tcp_update_rcv_wnd (tc);
168 return tc->rcv_wnd >> tc->rcv_wscale;
172 * Write TCP options to segment.
175 tcp_options_write (u8 * data, tcp_options_t * opts)
178 u32 buf, seq_len = 4;
180 if (tcp_opts_mss (opts))
182 *data++ = TCP_OPTION_MSS;
183 *data++ = TCP_OPTION_LEN_MSS;
184 buf = clib_host_to_net_u16 (opts->mss);
185 clib_memcpy_fast (data, &buf, sizeof (opts->mss));
186 data += sizeof (opts->mss);
187 opts_len += TCP_OPTION_LEN_MSS;
190 if (tcp_opts_wscale (opts))
192 *data++ = TCP_OPTION_WINDOW_SCALE;
193 *data++ = TCP_OPTION_LEN_WINDOW_SCALE;
194 *data++ = opts->wscale;
195 opts_len += TCP_OPTION_LEN_WINDOW_SCALE;
198 if (tcp_opts_sack_permitted (opts))
200 *data++ = TCP_OPTION_SACK_PERMITTED;
201 *data++ = TCP_OPTION_LEN_SACK_PERMITTED;
202 opts_len += TCP_OPTION_LEN_SACK_PERMITTED;
205 if (tcp_opts_tstamp (opts))
207 *data++ = TCP_OPTION_TIMESTAMP;
208 *data++ = TCP_OPTION_LEN_TIMESTAMP;
209 buf = clib_host_to_net_u32 (opts->tsval);
210 clib_memcpy_fast (data, &buf, sizeof (opts->tsval));
211 data += sizeof (opts->tsval);
212 buf = clib_host_to_net_u32 (opts->tsecr);
213 clib_memcpy_fast (data, &buf, sizeof (opts->tsecr));
214 data += sizeof (opts->tsecr);
215 opts_len += TCP_OPTION_LEN_TIMESTAMP;
218 if (tcp_opts_sack (opts))
222 if (opts->n_sack_blocks != 0)
224 *data++ = TCP_OPTION_SACK_BLOCK;
225 *data++ = 2 + opts->n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
226 for (i = 0; i < opts->n_sack_blocks; i++)
228 buf = clib_host_to_net_u32 (opts->sacks[i].start);
229 clib_memcpy_fast (data, &buf, seq_len);
231 buf = clib_host_to_net_u32 (opts->sacks[i].end);
232 clib_memcpy_fast (data, &buf, seq_len);
235 opts_len += 2 + opts->n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
239 /* Terminate TCP options */
242 *data++ = TCP_OPTION_EOL;
243 opts_len += TCP_OPTION_LEN_EOL;
246 /* Pad with zeroes to a u32 boundary */
249 *data++ = TCP_OPTION_NOOP;
250 opts_len += TCP_OPTION_LEN_NOOP;
256 tcp_make_syn_options (tcp_connection_t * tc, tcp_options_t * opts)
260 opts->flags |= TCP_OPTS_FLAG_MSS;
262 len += TCP_OPTION_LEN_MSS;
264 opts->flags |= TCP_OPTS_FLAG_WSCALE;
265 opts->wscale = tc->rcv_wscale;
266 len += TCP_OPTION_LEN_WINDOW_SCALE;
268 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
269 opts->tsval = tcp_time_now ();
271 len += TCP_OPTION_LEN_TIMESTAMP;
275 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
276 len += TCP_OPTION_LEN_SACK_PERMITTED;
279 /* Align to needed boundary */
280 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
285 tcp_make_synack_options (tcp_connection_t * tc, tcp_options_t * opts)
289 opts->flags |= TCP_OPTS_FLAG_MSS;
291 len += TCP_OPTION_LEN_MSS;
293 if (tcp_opts_wscale (&tc->rcv_opts))
295 opts->flags |= TCP_OPTS_FLAG_WSCALE;
296 opts->wscale = tc->rcv_wscale;
297 len += TCP_OPTION_LEN_WINDOW_SCALE;
300 if (tcp_opts_tstamp (&tc->rcv_opts))
302 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
303 opts->tsval = tcp_time_now ();
304 opts->tsecr = tc->tsval_recent;
305 len += TCP_OPTION_LEN_TIMESTAMP;
308 if (tcp_opts_sack_permitted (&tc->rcv_opts))
310 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
311 len += TCP_OPTION_LEN_SACK_PERMITTED;
314 /* Align to needed boundary */
315 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
320 tcp_make_established_options (tcp_connection_t * tc, tcp_options_t * opts)
326 if (tcp_opts_tstamp (&tc->rcv_opts))
328 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
329 opts->tsval = tcp_tstamp (tc);
330 opts->tsecr = tc->tsval_recent;
331 len += TCP_OPTION_LEN_TIMESTAMP;
333 if (tcp_opts_sack_permitted (&tc->rcv_opts))
335 if (vec_len (tc->snd_sacks))
337 opts->flags |= TCP_OPTS_FLAG_SACK;
338 if (tc->snd_sack_pos >= vec_len (tc->snd_sacks))
339 tc->snd_sack_pos = 0;
340 opts->sacks = &tc->snd_sacks[tc->snd_sack_pos];
341 opts->n_sack_blocks = vec_len (tc->snd_sacks) - tc->snd_sack_pos;
342 opts->n_sack_blocks = clib_min (opts->n_sack_blocks,
343 TCP_OPTS_MAX_SACK_BLOCKS);
344 tc->snd_sack_pos += opts->n_sack_blocks;
345 len += 2 + TCP_OPTION_LEN_SACK_BLOCK * opts->n_sack_blocks;
349 /* Align to needed boundary */
350 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
355 tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts,
360 case TCP_STATE_ESTABLISHED:
361 case TCP_STATE_CLOSE_WAIT:
362 case TCP_STATE_FIN_WAIT_1:
363 case TCP_STATE_LAST_ACK:
364 case TCP_STATE_CLOSING:
365 case TCP_STATE_FIN_WAIT_2:
366 case TCP_STATE_TIME_WAIT:
367 case TCP_STATE_CLOSED:
368 return tcp_make_established_options (tc, opts);
369 case TCP_STATE_SYN_RCVD:
370 return tcp_make_synack_options (tc, opts);
371 case TCP_STATE_SYN_SENT:
372 return tcp_make_syn_options (tc, opts);
374 clib_warning ("State not handled! %d", state);
380 * Update burst send vars
382 * - Updates snd_mss to reflect the effective segment size that we can send
383 * by taking into account all TCP options, including SACKs.
384 * - Cache 'on the wire' options for reuse
385 * - Updates receive window which can be reused for a burst.
387 * This should *only* be called when doing bursts
390 tcp_update_burst_snd_vars (tcp_connection_t * tc)
392 tcp_main_t *tm = &tcp_main;
394 /* Compute options to be used for connection. These may be reused when
395 * sending data or to compute the effective mss (snd_mss) */
396 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts,
397 TCP_STATE_ESTABLISHED);
399 /* XXX check if MTU has been updated */
400 tc->snd_mss = clib_min (tc->mss, tc->rcv_opts.mss) - tc->snd_opts_len;
401 ASSERT (tc->snd_mss > 0);
403 tcp_options_write (tm->wrk_ctx[tc->c_thread_index].cached_opts,
406 tcp_update_rcv_wnd (tc);
408 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
409 tcp_bt_check_app_limited (tc);
411 if (tc->snd_una == tc->snd_nxt)
413 tcp_cc_event (tc, TCP_CC_EVT_START_TX);
414 tcp_connection_tx_pacer_reset (tc, tc->cwnd, TRANSPORT_PACER_MIN_BURST);
418 #endif /* CLIB_MARCH_VARIANT */
421 tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b)
423 if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
424 vlib_buffer_free_one (vm, b->next_buffer);
425 /* Zero all flags but free list index and trace flag */
426 b->flags &= VLIB_BUFFER_NEXT_PRESENT - 1;
428 b->current_length = 0;
429 b->total_length_not_including_first_buffer = 0;
430 vnet_buffer (b)->tcp.flags = 0;
432 /* Leave enough space for headers */
433 return vlib_buffer_make_headroom (b, TRANSPORT_MAX_HDRS_LEN);
436 #ifndef CLIB_MARCH_VARIANT
438 tcp_init_buffer (vlib_main_t * vm, vlib_buffer_t * b)
440 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0);
441 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
442 b->total_length_not_including_first_buffer = 0;
444 vnet_buffer (b)->tcp.flags = 0;
445 VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b);
446 /* Leave enough space for headers */
447 return vlib_buffer_make_headroom (b, TRANSPORT_MAX_HDRS_LEN);
451 /* Compute TCP checksum in software when offloading is disabled for a connection */
453 ip6_tcp_compute_checksum_custom (vlib_main_t * vm, vlib_buffer_t * p0,
454 ip46_address_t * src, ip46_address_t * dst)
457 u16 payload_length_host_byte_order;
460 /* Initialize checksum with ip header. */
461 sum0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, p0)) +
462 clib_host_to_net_u16 (IP_PROTOCOL_TCP);
463 payload_length_host_byte_order = vlib_buffer_length_in_chain (vm, p0);
465 for (i = 0; i < ARRAY_LEN (src->ip6.as_uword); i++)
467 sum0 = ip_csum_with_carry
468 (sum0, clib_mem_unaligned (&src->ip6.as_uword[i], uword));
469 sum0 = ip_csum_with_carry
470 (sum0, clib_mem_unaligned (&dst->ip6.as_uword[i], uword));
473 return ip_calculate_l4_checksum (vm, p0, sum0,
474 payload_length_host_byte_order, NULL, 0,
479 ip4_tcp_compute_checksum_custom (vlib_main_t * vm, vlib_buffer_t * p0,
480 ip46_address_t * src, ip46_address_t * dst)
483 u32 payload_length_host_byte_order;
485 payload_length_host_byte_order = vlib_buffer_length_in_chain (vm, p0);
487 clib_host_to_net_u32 (payload_length_host_byte_order +
488 (IP_PROTOCOL_TCP << 16));
490 sum0 = ip_csum_with_carry (sum0, clib_mem_unaligned (&src->ip4, u32));
491 sum0 = ip_csum_with_carry (sum0, clib_mem_unaligned (&dst->ip4, u32));
493 return ip_calculate_l4_checksum (vm, p0, sum0,
494 payload_length_host_byte_order, NULL, 0,
499 tcp_compute_checksum (tcp_connection_t * tc, vlib_buffer_t * b)
502 if (PREDICT_FALSE (tc->cfg_flags & TCP_CFG_F_NO_CSUM_OFFLOAD))
504 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
505 vlib_main_t *vm = wrk->vm;
508 checksum = ip4_tcp_compute_checksum_custom
509 (vm, b, &tc->c_lcl_ip, &tc->c_rmt_ip);
511 checksum = ip6_tcp_compute_checksum_custom
512 (vm, b, &tc->c_lcl_ip, &tc->c_rmt_ip);
516 b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
525 tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
528 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
529 u8 tcp_opts_len, tcp_hdr_opts_len;
533 wnd = tcp_window_to_advertise (tc, state);
535 /* Make and write options */
536 tcp_opts_len = tcp_make_established_options (tc, snd_opts);
537 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
539 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
540 tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd);
542 tcp_options_write ((u8 *) (th + 1), snd_opts);
544 th->checksum = tcp_compute_checksum (tc, b);
546 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
549 tcp_zero_rwnd_sent_on (tc);
551 tcp_zero_rwnd_sent_off (tc);
555 * Convert buffer to ACK
558 tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
560 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
561 TCP_EVT (TCP_EVT_ACK_SENT, tc);
562 tc->rcv_las = tc->rcv_nxt;
566 * Convert buffer to FIN-ACK
569 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
571 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK);
575 * Convert buffer to SYN
578 tcp_make_syn (tcp_connection_t * tc, vlib_buffer_t * b)
580 u8 tcp_hdr_opts_len, tcp_opts_len;
583 tcp_options_t snd_opts;
585 initial_wnd = tcp_initial_window_to_advertise (tc);
587 /* Make and write options */
588 clib_memset (&snd_opts, 0, sizeof (snd_opts));
589 tcp_opts_len = tcp_make_syn_options (tc, &snd_opts);
590 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
592 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
593 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
595 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
596 tcp_options_write ((u8 *) (th + 1), &snd_opts);
597 th->checksum = tcp_compute_checksum (tc, b);
601 * Convert buffer to SYN-ACK
604 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
606 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
607 u8 tcp_opts_len, tcp_hdr_opts_len;
611 clib_memset (snd_opts, 0, sizeof (*snd_opts));
612 initial_wnd = tcp_initial_window_to_advertise (tc);
613 tcp_opts_len = tcp_make_synack_options (tc, snd_opts);
614 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
616 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
617 tc->rcv_nxt, tcp_hdr_opts_len,
618 TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd);
619 tcp_options_write ((u8 *) (th + 1), snd_opts);
621 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
622 th->checksum = tcp_compute_checksum (tc, b);
626 tcp_enqueue_to_ip_lookup_i (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
627 u8 is_ip4, u32 fib_index, u8 flush)
629 vlib_main_t *vm = wrk->vm;
630 u32 *to_next, next_index;
633 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
636 vnet_buffer (b)->sw_if_index[VLIB_TX] = fib_index;
637 vnet_buffer (b)->sw_if_index[VLIB_RX] = 0;
639 /* Send to IP lookup */
640 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
641 tcp_trajectory_add_start (b, 1);
643 f = wrk->ip_lookup_tx_frames[!is_ip4];
646 f = vlib_get_frame_to_node (vm, next_index);
648 wrk->ip_lookup_tx_frames[!is_ip4] = f;
651 to_next = vlib_frame_vector_args (f);
652 to_next[f->n_vectors] = bi;
654 if (flush || f->n_vectors == VLIB_FRAME_SIZE)
656 vlib_put_frame_to_node (vm, next_index, f);
657 wrk->ip_lookup_tx_frames[!is_ip4] = 0;
662 tcp_enqueue_to_ip_lookup_now (tcp_worker_ctx_t * wrk, vlib_buffer_t * b,
663 u32 bi, u8 is_ip4, u32 fib_index)
665 tcp_enqueue_to_ip_lookup_i (wrk, b, bi, is_ip4, fib_index, 1);
669 tcp_enqueue_to_ip_lookup (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
670 u8 is_ip4, u32 fib_index)
672 tcp_enqueue_to_ip_lookup_i (wrk, b, bi, is_ip4, fib_index, 0);
673 if (wrk->vm->thread_index == 0 && vlib_num_workers ())
674 session_flush_frames_main_thread (wrk->vm);
678 tcp_enqueue_to_output (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
683 b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
686 st = session_type_from_proto_and_ip (TRANSPORT_PROTO_TCP, is_ip4);
687 session_add_pending_tx_buffer (st, wrk->vm->thread_index, bi);
690 #endif /* CLIB_MARCH_VARIANT */
693 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
694 tcp_state_t state, u8 thread_index, u8 is_ip4)
699 ip4_address_t src_ip40, dst_ip40;
700 ip6_address_t src_ip60, dst_ip60;
701 u16 src_port, dst_port;
706 /* Find IP and TCP headers */
707 th0 = tcp_buffer_hdr (b0);
709 /* Save src and dst ip */
712 ih4 = vlib_buffer_get_current (b0);
713 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
714 src_ip40.as_u32 = ih4->src_address.as_u32;
715 dst_ip40.as_u32 = ih4->dst_address.as_u32;
719 ih6 = vlib_buffer_get_current (b0);
720 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
721 clib_memcpy_fast (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
722 clib_memcpy_fast (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t));
725 src_port = th0->src_port;
726 dst_port = th0->dst_port;
728 /* Try to determine what/why we're actually resetting */
729 if (state == TCP_STATE_CLOSED)
734 tmp = clib_net_to_host_u32 (th0->seq_number);
736 /* Got a SYN for no listener. */
737 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
738 ack = clib_host_to_net_u32 (tmp + 1);
743 flags = TCP_FLAG_RST;
744 seq = th0->ack_number;
748 tcp_reuse_buffer (vm, b0);
749 tcp_trajectory_add_start (b0, 4);
750 th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack,
751 sizeof (tcp_header_t), flags, 0);
755 ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40,
757 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
762 ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60,
764 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
771 #ifndef CLIB_MARCH_VARIANT
773 * Send reset without reusing existing buffer
775 * It extracts connection info out of original packet
778 tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt,
779 u32 thread_index, u8 is_ip4)
781 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
782 vlib_main_t *vm = wrk->vm;
784 u32 bi, sw_if_index, fib_index;
785 u8 tcp_hdr_len, flags = 0;
786 tcp_header_t *th, *pkt_th;
788 ip4_header_t *ih4, *pkt_ih4;
789 ip6_header_t *ih6, *pkt_ih6;
790 fib_protocol_t fib_proto;
792 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
795 b = vlib_get_buffer (vm, bi);
796 sw_if_index = vnet_buffer (pkt)->sw_if_index[VLIB_RX];
797 fib_proto = is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
798 fib_index = fib_table_get_index_for_sw_if_index (fib_proto, sw_if_index);
799 tcp_init_buffer (vm, b);
801 /* Make and write options */
802 tcp_hdr_len = sizeof (tcp_header_t);
806 pkt_ih4 = vlib_buffer_get_current (pkt);
807 pkt_th = ip4_next_header (pkt_ih4);
811 pkt_ih6 = vlib_buffer_get_current (pkt);
812 pkt_th = ip6_next_header (pkt_ih6);
815 if (tcp_ack (pkt_th))
817 flags = TCP_FLAG_RST;
818 seq = pkt_th->ack_number;
819 ack = (tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
823 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
825 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
828 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
829 seq, ack, tcp_hdr_len, flags, 0);
831 /* Swap src and dst ip */
834 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
835 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
836 &pkt_ih4->src_address, IP_PROTOCOL_TCP,
837 tcp_csum_offload (tc));
838 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
843 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
845 ih6 = vlib_buffer_push_ip6_custom (vm, b, &pkt_ih6->dst_address,
846 &pkt_ih6->src_address,
848 tc->ipv6_flow_label);
849 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
853 tcp_enqueue_to_ip_lookup_now (wrk, b, bi, is_ip4, fib_index);
854 TCP_EVT (TCP_EVT_RST_SENT, tc);
855 vlib_node_increment_counter (vm, tcp_node_index (output, tc->c_is_ip4),
856 TCP_ERROR_RST_SENT, 1);
860 * Build and set reset packet for connection
863 tcp_send_reset (tcp_connection_t * tc)
865 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
866 vlib_main_t *vm = wrk->vm;
870 u16 tcp_hdr_opts_len, advertise_wnd, opts_write_len;
873 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
875 b = vlib_get_buffer (vm, bi);
876 tcp_init_buffer (vm, b);
878 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
879 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
880 advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED);
881 flags = TCP_FLAG_RST;
882 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
883 tc->rcv_nxt, tcp_hdr_opts_len, flags,
885 opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
886 th->checksum = tcp_compute_checksum (tc, b);
887 ASSERT (opts_write_len == tc->snd_opts_len);
888 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
889 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
890 TCP_EVT (TCP_EVT_RST_SENT, tc);
891 vlib_node_increment_counter (vm, tcp_node_index (output, tc->c_is_ip4),
892 TCP_ERROR_RST_SENT, 1);
896 tcp_push_ip_hdr (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
901 vlib_buffer_push_ip4 (wrk->vm, b, &tc->c_lcl_ip4, &tc->c_rmt_ip4,
902 IP_PROTOCOL_TCP, tcp_csum_offload (tc));
906 vlib_buffer_push_ip6_custom (wrk->vm, b, &tc->c_lcl_ip6, &tc->c_rmt_ip6,
907 IP_PROTOCOL_TCP, tc->ipv6_flow_label);
914 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
915 * The packet is not forwarded through tcpx_output to avoid doing lookups
916 * in the half_open pool.
919 tcp_send_syn (tcp_connection_t * tc)
921 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
922 vlib_main_t *vm = wrk->vm;
927 * Setup retransmit and establish timers before requesting buffer
928 * such that we can return if we've ran out.
930 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
931 tc->rto * TCP_TO_TIMER_TICK);
933 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
935 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1);
939 b = vlib_get_buffer (vm, bi);
940 tcp_init_buffer (vm, b);
941 tcp_make_syn (tc, b);
943 /* Measure RTT with this */
944 tc->rtt_ts = tcp_time_now_us (vlib_num_workers ()? 1 : 0);
945 tc->rtt_seq = tc->snd_nxt;
948 tcp_push_ip_hdr (wrk, tc, b);
949 tcp_enqueue_to_ip_lookup (wrk, b, bi, tc->c_is_ip4, tc->c_fib_index);
950 TCP_EVT (TCP_EVT_SYN_SENT, tc);
954 tcp_send_synack (tcp_connection_t * tc)
956 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
957 vlib_main_t *vm = wrk->vm;
961 tcp_retransmit_timer_force_update (tc);
963 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
965 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
969 tc->rtt_ts = tcp_time_now_us (tc->c_thread_index);
970 b = vlib_get_buffer (vm, bi);
971 tcp_init_buffer (vm, b);
972 tcp_make_synack (tc, b);
973 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
974 TCP_EVT (TCP_EVT_SYNACK_SENT, tc);
978 * Flush ip lookup tx frames populated by timer pops
981 tcp_flush_frame_to_ip_lookup (tcp_worker_ctx_t * wrk, u8 is_ip4)
983 if (wrk->ip_lookup_tx_frames[!is_ip4])
986 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
987 vlib_put_frame_to_node (wrk->vm, next_index,
988 wrk->ip_lookup_tx_frames[!is_ip4]);
989 wrk->ip_lookup_tx_frames[!is_ip4] = 0;
994 * Flush v4 and v6 tcp and ip-lookup tx frames for thread index
997 tcp_flush_frames_to_output (tcp_worker_ctx_t * wrk)
999 tcp_flush_frame_to_ip_lookup (wrk, 1);
1000 tcp_flush_frame_to_ip_lookup (wrk, 0);
1007 tcp_send_fin (tcp_connection_t * tc)
1009 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
1010 vlib_main_t *vm = wrk->vm;
1015 fin_snt = tc->flags & TCP_CONN_FINSNT;
1019 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1021 /* Out of buffers so program fin retransmit ASAP */
1022 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
1026 /* Make sure retransmit retries a fin not data */
1027 tc->flags |= TCP_CONN_FINSNT;
1031 /* If we have non-dupacks programmed, no need to send them */
1032 if ((tc->flags & TCP_CONN_SNDACK) && !tc->pending_dupacks)
1033 tc->flags &= ~TCP_CONN_SNDACK;
1035 tcp_retransmit_timer_force_update (tc);
1036 b = vlib_get_buffer (vm, bi);
1037 tcp_init_buffer (vm, b);
1038 tcp_make_fin (tc, b);
1039 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1040 TCP_EVT (TCP_EVT_FIN_SENT, tc);
1041 /* Account for the FIN */
1045 tc->flags |= TCP_CONN_FINSNT;
1046 tc->flags &= ~TCP_CONN_FINPNDG;
1047 tc->snd_una_max = seq_max (tc->snd_una_max, tc->snd_nxt);
1052 * Push TCP header and update connection variables. Should only be called
1053 * for segments with data, not for 'control' packets.
1056 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b, u32 snd_nxt,
1057 u8 compute_opts, u8 maybe_burst, u8 update_snd_nxt)
1059 u8 tcp_hdr_opts_len, flags = TCP_FLAG_ACK;
1060 u32 advertise_wnd, data_len;
1061 tcp_main_t *tm = &tcp_main;
1064 data_len = b->current_length;
1065 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
1066 data_len += b->total_length_not_including_first_buffer;
1068 vnet_buffer (b)->tcp.flags = 0;
1069 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
1072 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1074 tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
1077 advertise_wnd = tc->rcv_wnd >> tc->rcv_wscale;
1079 advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED);
1081 if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
1083 if (seq_geq (tc->psh_seq, snd_nxt)
1084 && seq_lt (tc->psh_seq, snd_nxt + data_len))
1085 flags |= TCP_FLAG_PSH;
1087 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, snd_nxt,
1088 tc->rcv_nxt, tcp_hdr_opts_len, flags,
1093 clib_memcpy_fast ((u8 *) (th + 1),
1094 tm->wrk_ctx[tc->c_thread_index].cached_opts,
1099 u8 len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts);
1100 ASSERT (len == tc->snd_opts_len);
1104 * Update connection variables
1108 tc->snd_nxt += data_len;
1109 tc->rcv_las = tc->rcv_nxt;
1111 tc->bytes_out += data_len;
1112 tc->data_segs_out += 1;
1114 th->checksum = tcp_compute_checksum (tc, b);
1116 TCP_EVT (TCP_EVT_PKTIZE, tc);
1120 tcp_buffer_len (vlib_buffer_t * b)
1122 u32 data_len = b->current_length;
1123 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
1124 data_len += b->total_length_not_including_first_buffer;
1129 tcp_session_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
1131 tcp_connection_t *tc = (tcp_connection_t *) tconn;
1133 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1134 tcp_bt_track_tx (tc, tcp_buffer_len (b));
1136 tcp_push_hdr_i (tc, b, tc->snd_nxt, /* compute opts */ 0, /* burst */ 1,
1137 /* update_snd_nxt */ 1);
1139 tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max);
1140 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1141 /* If not tracking an ACK, start tracking */
1142 if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
1144 tc->rtt_ts = tcp_time_now_us (tc->c_thread_index);
1145 tc->rtt_seq = tc->snd_nxt;
1147 if (PREDICT_FALSE (!tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)))
1149 tcp_retransmit_timer_set (tc);
1152 tcp_trajectory_add_start (b, 3);
1157 tcp_send_ack (tcp_connection_t * tc)
1159 tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
1160 vlib_main_t *vm = wrk->vm;
1164 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1166 tcp_update_rcv_wnd (tc);
1169 b = vlib_get_buffer (vm, bi);
1170 tcp_init_buffer (vm, b);
1171 tcp_make_ack (tc, b);
1172 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1176 tcp_program_ack (tcp_connection_t * tc)
1178 if (!(tc->flags & TCP_CONN_SNDACK))
1180 session_add_self_custom_tx_evt (&tc->connection, 1);
1181 tc->flags |= TCP_CONN_SNDACK;
1186 tcp_program_dupack (tcp_connection_t * tc)
1188 if (!(tc->flags & TCP_CONN_SNDACK))
1190 session_add_self_custom_tx_evt (&tc->connection, 1);
1191 tc->flags |= TCP_CONN_SNDACK;
1193 if (tc->pending_dupacks < 255)
1194 tc->pending_dupacks += 1;
1198 tcp_program_retransmit (tcp_connection_t * tc)
1200 if (!(tc->flags & TCP_CONN_RXT_PENDING))
1202 session_add_self_custom_tx_evt (&tc->connection, 0);
1203 tc->flags |= TCP_CONN_RXT_PENDING;
1208 * Delayed ack timer handler
1210 * Sends delayed ACK when timer expires
1213 tcp_timer_delack_handler (u32 index, u32 thread_index)
1215 tcp_connection_t *tc;
1217 tc = tcp_connection_get (index, thread_index);
1222 * Send window update ack
1224 * Ensures that it will be sent only once, after a zero rwnd has been
1225 * advertised in a previous ack, and only if rwnd has grown beyond a
1226 * configurable value.
1229 tcp_send_window_update_ack (tcp_connection_t * tc)
1231 if (tcp_zero_rwnd_sent (tc))
1233 tcp_update_rcv_wnd (tc);
1234 if (tc->rcv_wnd >= tcp_cfg.rwnd_min_update_ack * tc->snd_mss)
1236 tcp_zero_rwnd_sent_off (tc);
1237 tcp_program_ack (tc);
1243 * Allocate a new buffer and build a new tcp segment
1245 * @param wrk tcp worker
1246 * @param tc connection for which the segment will be allocated
1247 * @param offset offset of the first byte in the tx fifo
1248 * @param max_deq_byte segment size
1249 * @param[out] b pointer to buffer allocated
1251 * @return the number of bytes in the segment or 0 if buffer cannot be
1252 * allocated or no data available
1255 tcp_prepare_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1256 u32 offset, u32 max_deq_bytes, vlib_buffer_t ** b)
1258 u32 bytes_per_buffer = vnet_get_tcp_main ()->bytes_per_buffer;
1259 vlib_main_t *vm = wrk->vm;
1264 seg_size = max_deq_bytes + TRANSPORT_MAX_HDRS_LEN;
1269 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1272 * Allocate and fill in buffer(s)
1275 /* Easy case, buffer size greater than mss */
1276 if (PREDICT_TRUE (seg_size <= bytes_per_buffer))
1278 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1280 *b = vlib_get_buffer (vm, bi);
1281 data = tcp_init_buffer (vm, *b);
1282 n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset,
1284 ASSERT (n_bytes == max_deq_bytes);
1285 b[0]->current_length = n_bytes;
1286 tcp_push_hdr_i (tc, *b, tc->snd_una + offset, /* compute opts */ 0,
1287 /* burst */ 0, /* update_snd_nxt */ 0);
1289 /* Split mss into multiple buffers */
1292 u32 chain_bi = ~0, n_bufs_per_seg, n_bufs;
1293 u16 n_peeked, len_to_deq;
1294 vlib_buffer_t *chain_b, *prev_b;
1297 /* Make sure we have enough buffers */
1298 n_bufs_per_seg = ceil ((double) seg_size / bytes_per_buffer);
1299 vec_validate_aligned (wrk->tx_buffers, n_bufs_per_seg - 1,
1300 CLIB_CACHE_LINE_BYTES);
1301 n_bufs = vlib_buffer_alloc (vm, wrk->tx_buffers, n_bufs_per_seg);
1302 if (PREDICT_FALSE (n_bufs != n_bufs_per_seg))
1305 vlib_buffer_free (vm, wrk->tx_buffers, n_bufs);
1309 *b = vlib_get_buffer (vm, wrk->tx_buffers[--n_bufs]);
1310 data = tcp_init_buffer (vm, *b);
1311 n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset,
1313 TRANSPORT_MAX_HDRS_LEN);
1314 b[0]->current_length = n_bytes;
1315 b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
1316 b[0]->total_length_not_including_first_buffer = 0;
1317 max_deq_bytes -= n_bytes;
1320 for (i = 1; i < n_bufs_per_seg; i++)
1323 len_to_deq = clib_min (max_deq_bytes, bytes_per_buffer);
1324 chain_bi = wrk->tx_buffers[--n_bufs];
1325 chain_b = vlib_get_buffer (vm, chain_bi);
1326 chain_b->current_data = 0;
1327 data = vlib_buffer_get_current (chain_b);
1328 n_peeked = session_tx_fifo_peek_bytes (&tc->connection, data,
1331 ASSERT (n_peeked == len_to_deq);
1332 n_bytes += n_peeked;
1333 chain_b->current_length = n_peeked;
1334 chain_b->next_buffer = 0;
1336 /* update previous buffer */
1337 prev_b->next_buffer = chain_bi;
1338 prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
1340 max_deq_bytes -= n_peeked;
1341 b[0]->total_length_not_including_first_buffer += n_peeked;
1344 tcp_push_hdr_i (tc, *b, tc->snd_una + offset, /* compute opts */ 0,
1345 /* burst */ 0, /* update_snd_nxt */ 0);
1347 if (PREDICT_FALSE (n_bufs))
1349 clib_warning ("not all buffers consumed");
1350 vlib_buffer_free (vm, wrk->tx_buffers, n_bufs);
1354 ASSERT (n_bytes > 0);
1355 ASSERT (((*b)->current_data + (*b)->current_length) <= bytes_per_buffer);
1361 * Build a retransmit segment
1363 * @return the number of bytes in the segment or 0 if there's nothing to
1367 tcp_prepare_retransmit_segment (tcp_worker_ctx_t * wrk,
1368 tcp_connection_t * tc, u32 offset,
1369 u32 max_deq_bytes, vlib_buffer_t ** b)
1371 u32 start, available_bytes;
1374 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
1375 ASSERT (max_deq_bytes != 0);
1378 * Make sure we can retransmit something
1380 available_bytes = transport_max_tx_dequeue (&tc->connection);
1381 ASSERT (available_bytes >= offset);
1382 available_bytes -= offset;
1383 if (!available_bytes)
1386 max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
1387 max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
1389 start = tc->snd_una + offset;
1390 ASSERT (seq_leq (start + max_deq_bytes, tc->snd_nxt));
1392 n_bytes = tcp_prepare_segment (wrk, tc, offset, max_deq_bytes, b);
1396 tc->snd_rxt_bytes += n_bytes;
1398 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1399 tcp_bt_track_rxt (tc, start, start + n_bytes);
1401 tc->bytes_retrans += n_bytes;
1402 tc->segs_retrans += 1;
1403 TCP_EVT (TCP_EVT_CC_RTX, tc, offset, n_bytes);
1409 tcp_check_sack_reneging (tcp_connection_t * tc)
1411 sack_scoreboard_t *sb = &tc->sack_sb;
1412 sack_scoreboard_hole_t *hole;
1414 hole = scoreboard_first_hole (sb);
1415 if (!sb->is_reneging && (!hole || hole->start == tc->snd_una))
1418 scoreboard_clear_reneging (sb, tc->snd_una, tc->snd_nxt);
1422 * Reset congestion control, switch cwnd to loss window and try again.
1425 tcp_cc_init_rxt_timeout (tcp_connection_t * tc)
1427 TCP_EVT (TCP_EVT_CC_EVT, tc, 6);
1429 tc->prev_ssthresh = tc->ssthresh;
1430 tc->prev_cwnd = tc->cwnd;
1432 /* If we entrered loss without fast recovery, notify cc algo of the
1433 * congestion event such that it can update ssthresh and its state */
1434 if (!tcp_in_fastrecovery (tc))
1435 tcp_cc_congestion (tc);
1437 /* Let cc algo decide loss cwnd and ssthresh post unrecovered loss */
1441 tc->cwnd_acc_bytes = 0;
1442 tc->tr_occurences += 1;
1443 tcp_recovery_on (tc);
1447 tcp_timer_retransmit_handler (u32 tc_index, u32 thread_index)
1449 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
1450 vlib_main_t *vm = wrk->vm;
1451 tcp_connection_t *tc;
1452 vlib_buffer_t *b = 0;
1455 tc = tcp_connection_get (tc_index, thread_index);
1457 /* Note: the connection may have been closed and pool_put */
1458 if (PREDICT_FALSE (tc == 0 || tc->state == TCP_STATE_SYN_SENT))
1461 /* Wait-close and retransmit could pop at the same time */
1462 if (tc->state == TCP_STATE_CLOSED)
1465 if (tc->state >= TCP_STATE_ESTABLISHED)
1467 TCP_EVT (TCP_EVT_CC_EVT, tc, 2);
1469 /* Lost FIN, retransmit and return */
1470 if (tc->flags & TCP_CONN_FINSNT)
1474 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1478 /* Shouldn't be here. This condition is tricky because it has to take
1479 * into account boff > 0 due to persist timeout. */
1480 if ((tc->rto_boff == 0 && tc->snd_una == tc->snd_nxt)
1481 || (tc->rto_boff > 0 && seq_geq (tc->snd_una, tc->snd_congestion)
1482 && !tcp_flight_size (tc)))
1484 ASSERT (!tcp_in_recovery (tc));
1489 /* We're not in recovery so make sure rto_boff is 0. Can be non 0 due
1490 * to persist timer timeout */
1491 if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
1494 tcp_update_rto (tc);
1497 /* Peer is dead or network connectivity is lost. Close connection.
1498 * RFC 1122 section 4.2.3.5 recommends a value of at least 100s. For
1499 * a min rto of 0.2s we need to retry about 8 times. */
1500 if (tc->rto_boff >= TCP_RTO_BOFF_MAX)
1502 tcp_send_reset (tc);
1503 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1504 session_transport_closing_notify (&tc->connection);
1505 session_transport_closed_notify (&tc->connection);
1506 tcp_connection_timers_reset (tc);
1507 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
1511 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1512 tcp_check_sack_reneging (tc);
1514 /* Update send congestion to make sure that rxt has data to send */
1515 tc->snd_congestion = tc->snd_nxt;
1517 /* Send the first unacked segment. If we're short on buffers, return
1518 * as soon as possible */
1519 n_bytes = clib_min (tc->snd_mss, tc->snd_nxt - tc->snd_una);
1520 n_bytes = tcp_prepare_retransmit_segment (wrk, tc, 0, n_bytes, &b);
1523 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
1527 bi = vlib_get_buffer_index (vm, b);
1528 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1530 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1531 tcp_retransmit_timer_force_update (tc);
1534 if (tc->rto_boff == 1)
1536 tcp_cc_init_rxt_timeout (tc);
1537 /* Record timestamp. Eifel detection algorithm RFC3522 */
1538 tc->snd_rxt_ts = tcp_tstamp (tc);
1541 if (tcp_opts_sack_permitted (&tc->rcv_opts))
1542 scoreboard_init_rxt (&tc->sack_sb, tc->snd_una + n_bytes);
1544 tcp_program_retransmit (tc);
1546 /* Retransmit SYN-ACK */
1547 else if (tc->state == TCP_STATE_SYN_RCVD)
1549 TCP_EVT (TCP_EVT_CC_EVT, tc, 2);
1553 /* Passive open establish timeout */
1554 if (tc->rto > TCP_ESTABLISH_TIME >> 1)
1556 tcp_connection_set_state (tc, TCP_STATE_CLOSED);
1557 tcp_connection_timers_reset (tc);
1558 tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
1562 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1564 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
1569 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1570 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1572 tcp_retransmit_timer_force_update (tc);
1574 b = vlib_get_buffer (vm, bi);
1575 tcp_init_buffer (vm, b);
1576 tcp_make_synack (tc, b);
1577 TCP_EVT (TCP_EVT_SYN_RXT, tc, 1);
1579 /* Retransmit timer already updated, just enqueue to output */
1580 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1584 ASSERT (tc->state == TCP_STATE_CLOSED);
1590 * SYN retransmit timer handler. Active open only.
1593 tcp_timer_retransmit_syn_handler (u32 tc_index, u32 thread_index)
1595 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
1596 vlib_main_t *vm = wrk->vm;
1597 tcp_connection_t *tc;
1598 vlib_buffer_t *b = 0;
1601 tc = tcp_half_open_connection_get (tc_index);
1603 /* Note: the connection may have transitioned to ESTABLISHED... */
1604 if (PREDICT_FALSE (tc == 0 || tc->state != TCP_STATE_SYN_SENT))
1607 /* Half-open connection actually moved to established but we were
1608 * waiting for syn retransmit to pop to call cleanup from the right
1610 if (tc->flags & TCP_CONN_HALF_OPEN_DONE)
1612 if (tcp_half_open_connection_cleanup (tc))
1613 TCP_DBG ("could not remove half-open connection");
1617 TCP_EVT (TCP_EVT_CC_EVT, tc, 2);
1620 /* Active open establish timeout */
1621 if (tc->rto >= TCP_ESTABLISH_TIME >> 1)
1623 session_stream_connect_notify (&tc->connection, 1 /* fail */ );
1624 tcp_connection_cleanup (tc);
1628 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1630 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1);
1634 /* Try without increasing RTO a number of times. If this fails,
1635 * start growing RTO exponentially */
1637 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1638 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1640 b = vlib_get_buffer (vm, bi);
1641 tcp_init_buffer (vm, b);
1642 tcp_make_syn (tc, b);
1644 TCP_EVT (TCP_EVT_SYN_RXT, tc, 0);
1646 /* This goes straight to ipx_lookup */
1647 tcp_push_ip_hdr (wrk, tc, b);
1648 tcp_enqueue_to_ip_lookup (wrk, b, bi, tc->c_is_ip4, tc->c_fib_index);
1650 tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
1651 tc->rto * TCP_TO_TIMER_TICK);
1655 * Got 0 snd_wnd from peer, try to do something about it.
1659 tcp_timer_persist_handler (u32 index, u32 thread_index)
1661 tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
1662 u32 bi, max_snd_bytes, available_bytes, offset;
1663 tcp_main_t *tm = vnet_get_tcp_main ();
1664 vlib_main_t *vm = wrk->vm;
1665 tcp_connection_t *tc;
1670 tc = tcp_connection_get_if_valid (index, thread_index);
1674 /* Problem already solved or worse */
1675 if (tc->state == TCP_STATE_CLOSED || tc->snd_wnd > tc->snd_mss
1676 || (tc->flags & TCP_CONN_FINSNT))
1679 available_bytes = transport_max_tx_dequeue (&tc->connection);
1680 offset = tc->snd_nxt - tc->snd_una;
1682 /* Reprogram persist if no new bytes available to send. We may have data
1684 if (!available_bytes)
1686 tcp_persist_timer_set (tc);
1690 if (available_bytes <= offset)
1692 ASSERT (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
1696 /* Increment RTO backoff */
1698 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1701 * Try to force the first unsent segment (or buffer)
1703 if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
1705 tcp_persist_timer_set (tc);
1708 b = vlib_get_buffer (vm, bi);
1709 data = tcp_init_buffer (vm, b);
1711 tcp_validate_txf_size (tc, offset);
1712 tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
1713 max_snd_bytes = clib_min (tc->snd_mss,
1714 tm->bytes_per_buffer - TRANSPORT_MAX_HDRS_LEN);
1715 n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset,
1717 b->current_length = n_bytes;
1718 ASSERT (n_bytes != 0 && (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)
1719 || tc->snd_nxt == tc->snd_una_max
1720 || tc->rto_boff > 1));
1722 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1724 tcp_bt_check_app_limited (tc);
1725 tcp_bt_track_tx (tc, n_bytes);
1728 tcp_push_hdr_i (tc, b, tc->snd_nxt, /* compute opts */ 0,
1729 /* burst */ 0, /* update_snd_nxt */ 1);
1730 tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max);
1731 tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
1732 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1734 /* Just sent new data, enable retransmit */
1735 tcp_retransmit_timer_update (tc);
1739 * Retransmit first unacked segment
1742 tcp_retransmit_first_unacked (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
1744 vlib_main_t *vm = wrk->vm;
1748 TCP_EVT (TCP_EVT_CC_EVT, tc, 1);
1750 n_bytes = tcp_prepare_retransmit_segment (wrk, tc, 0, tc->snd_mss, &b);
1754 bi = vlib_get_buffer_index (vm, b);
1755 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1761 tcp_transmit_unsent (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1764 u32 offset, n_segs = 0, n_written, bi, available_wnd;
1765 vlib_main_t *vm = wrk->vm;
1766 vlib_buffer_t *b = 0;
1768 offset = tc->snd_nxt - tc->snd_una;
1769 available_wnd = tc->snd_wnd - offset;
1770 burst_size = clib_min (burst_size, available_wnd / tc->snd_mss);
1772 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1773 tcp_bt_check_app_limited (tc);
1775 while (n_segs < burst_size)
1777 n_written = tcp_prepare_segment (wrk, tc, offset, tc->snd_mss, &b);
1781 bi = vlib_get_buffer_index (vm, b);
1782 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1783 offset += n_written;
1786 if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
1787 tcp_bt_track_tx (tc, n_written);
1789 tc->snd_nxt += n_written;
1790 tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max);
1798 * Estimate send space using proportional rate reduction (RFC6937)
1801 tcp_fastrecovery_prr_snd_space (tcp_connection_t * tc)
1806 pipe = tcp_flight_size (tc);
1807 prr_out = tc->snd_rxt_bytes + (tc->snd_nxt - tc->snd_congestion);
1809 if (pipe > tc->ssthresh)
1811 space = ((int) tc->prr_delivered * ((f64) tc->ssthresh / tc->prev_cwnd))
1817 limit = clib_max ((int) (tc->prr_delivered - prr_out), 0) + tc->snd_mss;
1818 space = clib_min (tc->ssthresh - pipe, limit);
1820 space = clib_max (space, prr_out ? 0 : tc->snd_mss);
1825 tcp_retransmit_should_retry_head (tcp_connection_t * tc,
1826 sack_scoreboard_t * sb)
1828 u32 tx_adv_sack = sb->high_sacked - tc->snd_congestion;
1829 f64 rr = (f64) tc->ssthresh / tc->prev_cwnd;
1831 if (tcp_fastrecovery_first (tc))
1834 return (tx_adv_sack > (tc->snd_una - tc->prr_start) * rr);
1838 tcp_max_tx_deq (tcp_connection_t * tc)
1840 return (transport_max_tx_dequeue (&tc->connection)
1841 - (tc->snd_nxt - tc->snd_una));
1844 #define scoreboard_rescue_rxt_valid(_sb, _tc) \
1845 (seq_geq (_sb->rescue_rxt, _tc->snd_una) \
1846 && seq_leq (_sb->rescue_rxt, _tc->snd_congestion))
1849 * Do retransmit with SACKs
1852 tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
1855 u32 n_written = 0, offset, max_bytes, n_segs = 0;
1856 u8 snd_limited = 0, can_rescue = 0;
1857 u32 bi, max_deq, burst_bytes;
1858 sack_scoreboard_hole_t *hole;
1859 vlib_main_t *vm = wrk->vm;
1860 vlib_buffer_t *b = 0;
1861 sack_scoreboard_t *sb;
1864 ASSERT (tcp_in_cong_recovery (tc));
1866 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection);
1867 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
1870 tcp_program_retransmit (tc);
1874 if (tcp_in_recovery (tc))
1875 snd_space = tcp_available_cc_snd_space (tc);
1877 snd_space = tcp_fastrecovery_prr_snd_space (tc);
1879 if (snd_space < tc->snd_mss)
1884 /* Check if snd_una is a lost retransmit */
1885 if (pool_elts (sb->holes)
1886 && seq_gt (sb->high_sacked, tc->snd_congestion)
1887 && tc->rxt_head != tc->snd_una
1888 && tcp_retransmit_should_retry_head (tc, sb))
1890 max_bytes = clib_min (tc->snd_mss, tc->snd_congestion - tc->snd_una);
1891 n_written = tcp_prepare_retransmit_segment (wrk, tc, 0, max_bytes, &b);
1894 tcp_program_retransmit (tc);
1897 bi = vlib_get_buffer_index (vm, b);
1898 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1901 tc->rxt_head = tc->snd_una;
1902 tc->rxt_delivered += n_written;
1903 tc->prr_delivered += n_written;
1904 ASSERT (tc->rxt_delivered <= tc->snd_rxt_bytes);
1907 tcp_fastrecovery_first_off (tc);
1909 TCP_EVT (TCP_EVT_CC_EVT, tc, 0);
1910 hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
1912 max_deq = transport_max_tx_dequeue (&tc->connection);
1913 max_deq -= tc->snd_nxt - tc->snd_una;
1915 while (snd_space > 0 && n_segs < burst_size)
1917 hole = scoreboard_next_rxt_hole (sb, hole, max_deq != 0, &can_rescue,
1921 /* We are out of lost holes to retransmit so send some new data. */
1922 if (max_deq > tc->snd_mss)
1927 /* Make sure we don't exceed available window and leave space
1928 * for one more packet, to avoid zero window acks */
1929 av_wnd = (int) tc->snd_wnd - (tc->snd_nxt - tc->snd_una);
1930 av_wnd = clib_max (av_wnd - tc->snd_mss, 0);
1931 snd_space = clib_min (snd_space, av_wnd);
1932 snd_space = clib_min (max_deq, snd_space);
1933 burst_size = clib_min (burst_size - n_segs,
1934 snd_space / tc->snd_mss);
1935 burst_size = clib_min (burst_size, TCP_RXT_MAX_BURST);
1936 n_segs_new = tcp_transmit_unsent (wrk, tc, burst_size);
1937 if (max_deq > n_segs_new * tc->snd_mss)
1938 tcp_program_retransmit (tc);
1940 n_segs += n_segs_new;
1944 if (tcp_in_recovery (tc) || !can_rescue
1945 || scoreboard_rescue_rxt_valid (sb, tc))
1948 /* If rescue rxt undefined or less than snd_una then one segment of
1949 * up to SMSS octets that MUST include the highest outstanding
1950 * unSACKed sequence number SHOULD be returned, and RescueRxt set to
1951 * RecoveryPoint. HighRxt MUST NOT be updated.
1953 hole = scoreboard_last_hole (sb);
1954 max_bytes = clib_min (tc->snd_mss, hole->end - hole->start);
1955 max_bytes = clib_min (max_bytes, snd_space);
1956 offset = hole->end - tc->snd_una - max_bytes;
1957 n_written = tcp_prepare_retransmit_segment (wrk, tc, offset,
1962 sb->rescue_rxt = tc->snd_congestion;
1963 bi = vlib_get_buffer_index (vm, b);
1964 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1969 max_bytes = clib_min (hole->end - sb->high_rxt, snd_space);
1970 max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes;
1974 offset = sb->high_rxt - tc->snd_una;
1975 n_written = tcp_prepare_retransmit_segment (wrk, tc, offset, max_bytes,
1977 ASSERT (n_written <= snd_space);
1979 /* Nothing left to retransmit */
1983 bi = vlib_get_buffer_index (vm, b);
1984 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
1986 sb->high_rxt += n_written;
1987 ASSERT (seq_leq (sb->high_rxt, tc->snd_nxt));
1989 snd_space -= n_written;
1994 tcp_program_retransmit (tc);
1998 transport_connection_tx_pacer_reset_bucket (&tc->connection, 0);
2003 * Fast retransmit without SACK info
2006 tcp_retransmit_no_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
2009 u32 n_written = 0, offset = 0, bi, max_deq, n_segs_now, max_bytes;
2010 u32 burst_bytes, sent_bytes;
2011 vlib_main_t *vm = wrk->vm;
2012 int snd_space, n_segs = 0;
2016 ASSERT (tcp_in_cong_recovery (tc));
2017 TCP_EVT (TCP_EVT_CC_EVT, tc, 0);
2019 burst_bytes = transport_connection_tx_pacer_burst (&tc->connection);
2020 burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss);
2023 tcp_program_retransmit (tc);
2027 snd_space = tcp_available_cc_snd_space (tc);
2028 cc_limited = snd_space < burst_bytes;
2030 if (!tcp_fastrecovery_first (tc))
2033 /* RFC 6582: [If a partial ack], retransmit the first unacknowledged
2035 while (snd_space > 0 && n_segs < burst_size)
2037 max_bytes = clib_min (tc->snd_mss,
2038 tc->snd_congestion - tc->snd_una - offset);
2041 n_written = tcp_prepare_retransmit_segment (wrk, tc, offset, max_bytes,
2044 /* Nothing left to retransmit */
2048 bi = vlib_get_buffer_index (vm, b);
2049 tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
2050 snd_space -= n_written;
2051 offset += n_written;
2055 if (n_segs == burst_size)
2060 /* RFC 6582: Send a new segment if permitted by the new value of cwnd. */
2061 if (snd_space < tc->snd_mss || tc->snd_mss == 0)
2064 max_deq = transport_max_tx_dequeue (&tc->connection);
2065 max_deq -= tc->snd_nxt - tc->snd_una;
2068 snd_space = clib_min (max_deq, snd_space);
2069 burst_size = clib_min (burst_size - n_segs, snd_space / tc->snd_mss);
2070 n_segs_now = tcp_transmit_unsent (wrk, tc, burst_size);
2071 if (n_segs_now && max_deq > n_segs_now * tc->snd_mss)
2072 tcp_program_retransmit (tc);
2073 n_segs += n_segs_now;
2077 tcp_fastrecovery_first_off (tc);
2079 sent_bytes = clib_min (n_segs * tc->snd_mss, burst_bytes);
2080 sent_bytes = cc_limited ? burst_bytes : sent_bytes;
2081 transport_connection_tx_pacer_update_bytes (&tc->connection, sent_bytes);
2087 tcp_send_acks (tcp_connection_t * tc, u32 max_burst_size)
2091 if (!tc->pending_dupacks)
2093 if (tcp_in_cong_recovery (tc) || !tcp_max_tx_deq (tc)
2094 || tc->state != TCP_STATE_ESTABLISHED)
2102 /* If we're supposed to send dupacks but have no ooo data
2103 * send only one ack */
2104 if (!vec_len (tc->snd_sacks))
2107 tc->pending_dupacks = 0;
2111 /* Start with first sack block */
2112 tc->snd_sack_pos = 0;
2114 /* Generate enough dupacks to cover all sack blocks. Do not generate
2115 * more sacks than the number of packets received. But do generate at
2116 * least 3, i.e., the number needed to signal congestion, if needed. */
2117 n_acks = vec_len (tc->snd_sacks) / TCP_OPTS_MAX_SACK_BLOCKS;
2118 n_acks = clib_min (n_acks, tc->pending_dupacks);
2119 n_acks = clib_max (n_acks, clib_min (tc->pending_dupacks, 3));
2120 for (j = 0; j < clib_min (n_acks, max_burst_size); j++)
2123 if (n_acks < max_burst_size)
2125 tc->pending_dupacks = 0;
2126 tc->snd_sack_pos = 0;
2127 tc->dupacks_out += n_acks;
2132 TCP_DBG ("constrained by burst size");
2133 tc->pending_dupacks = n_acks - max_burst_size;
2134 tc->dupacks_out += max_burst_size;
2135 tcp_program_dupack (tc);
2136 return max_burst_size;
2141 tcp_do_retransmit (tcp_connection_t * tc, u32 max_burst_size)
2143 tcp_worker_ctx_t *wrk;
2146 if (PREDICT_FALSE (tc->state == TCP_STATE_CLOSED))
2149 wrk = tcp_get_worker (tc->c_thread_index);
2151 if (tcp_opts_sack_permitted (&tc->rcv_opts))
2152 n_segs = tcp_retransmit_sack (wrk, tc, max_burst_size);
2154 n_segs = tcp_retransmit_no_sack (wrk, tc, max_burst_size);
2160 tcp_session_custom_tx (void *conn, u32 max_burst_size)
2162 tcp_connection_t *tc = (tcp_connection_t *) conn;
2165 if (tcp_in_cong_recovery (tc) && (tc->flags & TCP_CONN_RXT_PENDING))
2167 tc->flags &= ~TCP_CONN_RXT_PENDING;
2168 n_segs = tcp_do_retransmit (tc, max_burst_size);
2169 max_burst_size -= n_segs;
2172 if (!(tc->flags & TCP_CONN_SNDACK))
2175 tc->flags &= ~TCP_CONN_SNDACK;
2177 /* We have retransmitted packets and no dupack */
2178 if (n_segs && !tc->pending_dupacks)
2181 if (!max_burst_size)
2183 tcp_program_ack (tc);
2184 return max_burst_size;
2187 n_segs += tcp_send_acks (tc, max_burst_size);
2191 #endif /* CLIB_MARCH_VARIANT */
2194 tcp_output_handle_link_local (tcp_connection_t * tc0, vlib_buffer_t * b0,
2195 u16 * next0, u32 * error0)
2197 ip_adjacency_t *adj;
2200 /* Not thread safe but as long as the connection exists the adj should
2202 ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &tc0->c_rmt_ip,
2204 if (ai == ADJ_INDEX_INVALID)
2206 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
2207 *next0 = TCP_OUTPUT_NEXT_DROP;
2208 *error0 = TCP_ERROR_LINK_LOCAL_RW;
2213 if (PREDICT_TRUE (adj->lookup_next_index == IP_LOOKUP_NEXT_REWRITE))
2214 *next0 = TCP_OUTPUT_NEXT_IP_REWRITE;
2215 else if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP)
2216 *next0 = TCP_OUTPUT_NEXT_IP_ARP;
2219 *next0 = TCP_OUTPUT_NEXT_DROP;
2220 *error0 = TCP_ERROR_LINK_LOCAL_RW;
2222 vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ai;
2226 tcp46_output_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
2227 u32 * to_next, u32 n_bufs)
2229 u32 n_trace = vlib_get_trace_count (vm, node);
2230 tcp_connection_t *tc;
2236 for (i = 0; i < clib_min (n_trace, n_bufs); i++)
2238 b = vlib_get_buffer (vm, to_next[i]);
2239 th = vlib_buffer_get_current (b);
2240 tc = tcp_connection_get (vnet_buffer (b)->tcp.connection_index,
2242 t = vlib_add_trace (vm, node, b, sizeof (*t));
2243 clib_memcpy_fast (&t->tcp_header, th, sizeof (t->tcp_header));
2244 clib_memcpy_fast (&t->tcp_connection, tc, sizeof (t->tcp_connection));
2249 tcp_output_push_ip (vlib_main_t * vm, vlib_buffer_t * b0,
2250 tcp_connection_t * tc0, u8 is_ip4)
2252 TCP_EVT (TCP_EVT_OUTPUT, tc0,
2253 ((tcp_header_t *) vlib_buffer_get_current (b0))->flags,
2254 b0->current_length);
2257 vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
2258 IP_PROTOCOL_TCP, tcp_csum_offload (tc0));
2260 vlib_buffer_push_ip6_custom (vm, b0, &tc0->c_lcl_ip6, &tc0->c_rmt_ip6,
2261 IP_PROTOCOL_TCP, tc0->ipv6_flow_label);
2265 tcp_check_if_gso (tcp_connection_t * tc, vlib_buffer_t * b)
2267 if (PREDICT_TRUE (!(tc->cfg_flags & TCP_CFG_F_TSO)))
2270 u16 data_len = b->current_length - sizeof (tcp_header_t) - tc->snd_opts_len;
2272 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID))
2273 data_len += b->total_length_not_including_first_buffer;
2275 if (PREDICT_TRUE (data_len <= tc->snd_mss))
2279 ASSERT ((b->flags & VNET_BUFFER_F_L3_HDR_OFFSET_VALID) != 0);
2280 ASSERT ((b->flags & VNET_BUFFER_F_L4_HDR_OFFSET_VALID) != 0);
2281 b->flags |= VNET_BUFFER_F_GSO;
2282 vnet_buffer2 (b)->gso_l4_hdr_sz =
2283 sizeof (tcp_header_t) + tc->snd_opts_len;
2284 vnet_buffer2 (b)->gso_size = tc->snd_mss;
2289 tcp_output_handle_packet (tcp_connection_t * tc0, vlib_buffer_t * b0,
2290 vlib_node_runtime_t * error_node, u16 * next0,
2293 /* If next_index is not drop use it */
2294 if (tc0->next_node_index)
2296 *next0 = tc0->next_node_index;
2297 vnet_buffer (b0)->tcp.next_node_opaque = tc0->next_node_opaque;
2301 *next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
2304 vnet_buffer (b0)->sw_if_index[VLIB_TX] = tc0->c_fib_index;
2305 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
2311 if (PREDICT_FALSE (ip6_address_is_link_local_unicast (&tc0->c_rmt_ip6)))
2312 tcp_output_handle_link_local (tc0, b0, next0, &error0);
2314 if (PREDICT_FALSE (error0))
2316 b0->error = error_node->errors[error0];
2321 if (!TCP_ALWAYS_ACK)
2322 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
2328 tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2329 vlib_frame_t * frame, int is_ip4)
2331 u32 n_left_from, *from, thread_index = vm->thread_index;
2332 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
2333 u16 nexts[VLIB_FRAME_SIZE], *next;
2334 vlib_node_runtime_t *error_node;
2336 error_node = vlib_node_get_runtime (vm, tcp_node_index (output, is_ip4));
2338 from = vlib_frame_vector_args (frame);
2339 n_left_from = frame->n_vectors;
2340 tcp_set_time_now (tcp_get_worker (thread_index));
2342 if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
2343 tcp46_output_trace_frame (vm, node, from, n_left_from);
2345 vlib_get_buffers (vm, from, bufs, n_left_from);
2349 while (n_left_from >= 4)
2351 tcp_connection_t *tc0, *tc1;
2354 vlib_prefetch_buffer_header (b[2], STORE);
2355 CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
2357 vlib_prefetch_buffer_header (b[3], STORE);
2358 CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
2361 tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index,
2363 tc1 = tcp_connection_get (vnet_buffer (b[1])->tcp.connection_index,
2366 if (PREDICT_TRUE (!tc0 + !tc1 == 0))
2368 tcp_output_push_ip (vm, b[0], tc0, is_ip4);
2369 tcp_output_push_ip (vm, b[1], tc1, is_ip4);
2371 tcp_check_if_gso (tc0, b[0]);
2372 tcp_check_if_gso (tc1, b[1]);
2374 tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
2375 tcp_output_handle_packet (tc1, b[1], error_node, &next[1], is_ip4);
2381 tcp_output_push_ip (vm, b[0], tc0, is_ip4);
2382 tcp_check_if_gso (tc0, b[0]);
2383 tcp_output_handle_packet (tc0, b[0], error_node, &next[0],
2388 b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
2389 next[0] = TCP_OUTPUT_NEXT_DROP;
2393 tcp_output_push_ip (vm, b[1], tc1, is_ip4);
2394 tcp_check_if_gso (tc1, b[1]);
2395 tcp_output_handle_packet (tc1, b[1], error_node, &next[1],
2400 b[1]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
2401 next[1] = TCP_OUTPUT_NEXT_DROP;
2409 while (n_left_from > 0)
2411 tcp_connection_t *tc0;
2413 if (n_left_from > 1)
2415 vlib_prefetch_buffer_header (b[1], STORE);
2416 CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
2419 tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index,
2422 if (PREDICT_TRUE (tc0 != 0))
2424 tcp_output_push_ip (vm, b[0], tc0, is_ip4);
2425 tcp_check_if_gso (tc0, b[0]);
2426 tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
2430 b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
2431 next[0] = TCP_OUTPUT_NEXT_DROP;
2439 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
2440 vlib_node_increment_counter (vm, tcp_node_index (output, is_ip4),
2441 TCP_ERROR_PKTS_SENT, frame->n_vectors);
2442 return frame->n_vectors;
2445 VLIB_NODE_FN (tcp4_output_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
2446 vlib_frame_t * from_frame)
2448 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
2451 VLIB_NODE_FN (tcp6_output_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
2452 vlib_frame_t * from_frame)
2454 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
2458 VLIB_REGISTER_NODE (tcp4_output_node) =
2460 .name = "tcp4-output",
2461 /* Takes a vector of packets. */
2462 .vector_size = sizeof (u32),
2463 .n_errors = TCP_N_ERROR,
2464 .protocol_hint = VLIB_NODE_PROTO_HINT_TCP,
2465 .error_strings = tcp_error_strings,
2466 .n_next_nodes = TCP_OUTPUT_N_NEXT,
2468 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
2469 foreach_tcp4_output_next
2472 .format_buffer = format_tcp_header,
2473 .format_trace = format_tcp_tx_trace,
2478 VLIB_REGISTER_NODE (tcp6_output_node) =
2480 .name = "tcp6-output",
2481 /* Takes a vector of packets. */
2482 .vector_size = sizeof (u32),
2483 .n_errors = TCP_N_ERROR,
2484 .protocol_hint = VLIB_NODE_PROTO_HINT_TCP,
2485 .error_strings = tcp_error_strings,
2486 .n_next_nodes = TCP_OUTPUT_N_NEXT,
2488 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
2489 foreach_tcp6_output_next
2492 .format_buffer = format_tcp_header,
2493 .format_trace = format_tcp_tx_trace,
2497 typedef enum _tcp_reset_next
2499 TCP_RESET_NEXT_DROP,
2500 TCP_RESET_NEXT_IP_LOOKUP,
2504 #define foreach_tcp4_reset_next \
2505 _(DROP, "error-drop") \
2506 _(IP_LOOKUP, "ip4-lookup")
2508 #define foreach_tcp6_reset_next \
2509 _(DROP, "error-drop") \
2510 _(IP_LOOKUP, "ip6-lookup")
2513 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
2514 vlib_frame_t * from_frame, u8 is_ip4)
2516 u32 n_left_from, next_index, *from, *to_next;
2517 u32 my_thread_index = vm->thread_index;
2519 from = vlib_frame_vector_args (from_frame);
2520 n_left_from = from_frame->n_vectors;
2522 next_index = node->cached_next_index;
2524 while (n_left_from > 0)
2528 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2530 while (n_left_from > 0 && n_left_to_next > 0)
2536 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
2543 n_left_to_next -= 1;
2545 b0 = vlib_get_buffer (vm, bi0);
2547 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
2548 my_thread_index, is_ip4))
2550 error0 = TCP_ERROR_LOOKUP_DROPS;
2551 next0 = TCP_RESET_NEXT_DROP;
2555 /* Prepare to send to IP lookup */
2556 vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
2557 next0 = TCP_RESET_NEXT_IP_LOOKUP;
2560 b0->error = node->errors[error0];
2561 b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
2562 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
2564 th0 = vlib_buffer_get_current (b0);
2566 th0 = ip4_next_header ((ip4_header_t *) th0);
2568 th0 = ip6_next_header ((ip6_header_t *) th0);
2569 t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
2570 clib_memcpy_fast (&t0->tcp_header, th0,
2571 sizeof (t0->tcp_header));
2574 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
2575 n_left_to_next, bi0, next0);
2577 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2579 return from_frame->n_vectors;
2582 VLIB_NODE_FN (tcp4_reset_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
2583 vlib_frame_t * from_frame)
2585 return tcp46_send_reset_inline (vm, node, from_frame, 1);
2588 VLIB_NODE_FN (tcp6_reset_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
2589 vlib_frame_t * from_frame)
2591 return tcp46_send_reset_inline (vm, node, from_frame, 0);
2595 VLIB_REGISTER_NODE (tcp4_reset_node) = {
2596 .name = "tcp4-reset",
2597 .vector_size = sizeof (u32),
2598 .n_errors = TCP_N_ERROR,
2599 .error_strings = tcp_error_strings,
2600 .n_next_nodes = TCP_RESET_N_NEXT,
2602 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2603 foreach_tcp4_reset_next
2606 .format_trace = format_tcp_tx_trace,
2611 VLIB_REGISTER_NODE (tcp6_reset_node) = {
2612 .name = "tcp6-reset",
2613 .vector_size = sizeof (u32),
2614 .n_errors = TCP_N_ERROR,
2615 .error_strings = tcp_error_strings,
2616 .n_next_nodes = TCP_RESET_N_NEXT,
2618 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
2619 foreach_tcp6_reset_next
2622 .format_trace = format_tcp_tx_trace,
2627 * fd.io coding-style-patch-verification: ON
2630 * eval: (c-set-style "gnu")