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_nect
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>
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 *);
58 s = format (s, "TBD\n");
64 tcp_set_snd_mss (tcp_connection_t * tc)
68 /* TODO find our iface MTU */
71 /* TODO cache mss and consider PMTU discovery */
72 snd_mss = tc->opt.mss < snd_mss ? tc->opt.mss : snd_mss;
74 tc->snd_mss = snd_mss;
78 clib_warning ("snd mss is 0");
79 tc->snd_mss = dummy_mtu;
84 tcp_window_compute_scale (u32 available_space)
87 while (wnd_scale < TCP_MAX_WND_SCALE
88 && (available_space >> wnd_scale) > TCP_WND_MAX)
94 * TCP's IW as recommended by RFC6928
97 tcp_initial_wnd_unscaled (tcp_connection_t * tc)
99 return TCP_IW_N_SEGMENTS * dummy_mtu;
103 * Compute initial window and scale factor. As per RFC1323, window field in
104 * SYN and SYN-ACK segments is never scaled.
107 tcp_initial_window_to_advertise (tcp_connection_t * tc)
111 /* Initial wnd for SYN. Fifos are not allocated yet.
112 * Use some predefined value. For SYN-ACK we still want the
113 * scale to be computed in the same way */
114 max_fifo = TCP_MAX_RX_FIFO_SIZE;
116 tc->rcv_wscale = tcp_window_compute_scale (max_fifo);
117 tc->rcv_wnd = tcp_initial_wnd_unscaled (tc);
119 return clib_min (tc->rcv_wnd, TCP_WND_MAX);
123 * Compute and return window to advertise, scaled as per RFC1323
126 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
128 u32 available_space, max_fifo, observed_wnd;
130 if (state < TCP_STATE_ESTABLISHED)
131 return tcp_initial_window_to_advertise (tc);
134 * Figure out how much space we have available
136 available_space = stream_session_max_enqueue (&tc->connection);
137 max_fifo = stream_session_fifo_size (&tc->connection);
139 ASSERT (tc->opt.mss < max_fifo);
141 if (available_space < tc->opt.mss && available_space < max_fifo / 8)
145 * Use the above and what we know about what we've previously advertised
146 * to compute the new window
148 observed_wnd = tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
150 /* Bad. Thou shalt not shrink */
151 if (available_space < observed_wnd)
153 if (available_space == 0)
154 clib_warning ("Didn't shrink rcv window despite not having space");
157 tc->rcv_wnd = clib_min (available_space, TCP_WND_MAX << tc->rcv_wscale);
159 if (tc->rcv_wnd == 0)
161 tc->flags |= TCP_CONN_SENT_RCV_WND0;
164 return tc->rcv_wnd >> tc->rcv_wscale;
168 * Write TCP options to segment.
171 tcp_options_write (u8 * data, tcp_options_t * opts)
174 u32 buf, seq_len = 4;
176 if (tcp_opts_mss (opts))
178 *data++ = TCP_OPTION_MSS;
179 *data++ = TCP_OPTION_LEN_MSS;
180 buf = clib_host_to_net_u16 (opts->mss);
181 clib_memcpy (data, &buf, sizeof (opts->mss));
182 data += sizeof (opts->mss);
183 opts_len += TCP_OPTION_LEN_MSS;
186 if (tcp_opts_wscale (opts))
188 *data++ = TCP_OPTION_WINDOW_SCALE;
189 *data++ = TCP_OPTION_LEN_WINDOW_SCALE;
190 *data++ = opts->wscale;
191 opts_len += TCP_OPTION_LEN_WINDOW_SCALE;
194 if (tcp_opts_sack_permitted (opts))
196 *data++ = TCP_OPTION_SACK_PERMITTED;
197 *data++ = TCP_OPTION_LEN_SACK_PERMITTED;
198 opts_len += TCP_OPTION_LEN_SACK_PERMITTED;
201 if (tcp_opts_tstamp (opts))
203 *data++ = TCP_OPTION_TIMESTAMP;
204 *data++ = TCP_OPTION_LEN_TIMESTAMP;
205 buf = clib_host_to_net_u32 (opts->tsval);
206 clib_memcpy (data, &buf, sizeof (opts->tsval));
207 data += sizeof (opts->tsval);
208 buf = clib_host_to_net_u32 (opts->tsecr);
209 clib_memcpy (data, &buf, sizeof (opts->tsecr));
210 data += sizeof (opts->tsecr);
211 opts_len += TCP_OPTION_LEN_TIMESTAMP;
214 if (tcp_opts_sack (opts))
217 u32 n_sack_blocks = clib_min (vec_len (opts->sacks),
218 TCP_OPTS_MAX_SACK_BLOCKS);
220 if (n_sack_blocks != 0)
222 *data++ = TCP_OPTION_SACK_BLOCK;
223 *data++ = 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
224 for (i = 0; i < n_sack_blocks; i++)
226 buf = clib_host_to_net_u32 (opts->sacks[i].start);
227 clib_memcpy (data, &buf, seq_len);
229 buf = clib_host_to_net_u32 (opts->sacks[i].end);
230 clib_memcpy (data, &buf, seq_len);
233 opts_len += 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
237 /* Terminate TCP options */
240 *data++ = TCP_OPTION_EOL;
241 opts_len += TCP_OPTION_LEN_EOL;
244 /* Pad with zeroes to a u32 boundary */
247 *data++ = TCP_OPTION_NOOP;
248 opts_len += TCP_OPTION_LEN_NOOP;
254 tcp_make_syn_options (tcp_options_t * opts, u8 wnd_scale)
258 opts->flags |= TCP_OPTS_FLAG_MSS;
259 opts->mss = dummy_mtu; /*XXX discover that */
260 len += TCP_OPTION_LEN_MSS;
262 opts->flags |= TCP_OPTS_FLAG_WSCALE;
263 opts->wscale = wnd_scale;
264 len += TCP_OPTION_LEN_WINDOW_SCALE;
266 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
267 opts->tsval = tcp_time_now ();
269 len += TCP_OPTION_LEN_TIMESTAMP;
271 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
272 len += TCP_OPTION_LEN_SACK_PERMITTED;
274 /* Align to needed boundary */
275 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
280 tcp_make_synack_options (tcp_connection_t * tc, tcp_options_t * opts)
284 opts->flags |= TCP_OPTS_FLAG_MSS;
285 opts->mss = dummy_mtu; /*XXX discover that */
286 len += TCP_OPTION_LEN_MSS;
288 if (tcp_opts_wscale (&tc->opt))
290 opts->flags |= TCP_OPTS_FLAG_WSCALE;
291 opts->wscale = tc->rcv_wscale;
292 len += TCP_OPTION_LEN_WINDOW_SCALE;
295 if (tcp_opts_tstamp (&tc->opt))
297 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
298 opts->tsval = tcp_time_now ();
299 opts->tsecr = tc->tsval_recent;
300 len += TCP_OPTION_LEN_TIMESTAMP;
303 if (tcp_opts_sack_permitted (&tc->opt))
305 opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
306 len += TCP_OPTION_LEN_SACK_PERMITTED;
309 /* Align to needed boundary */
310 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
315 tcp_make_established_options (tcp_connection_t * tc, tcp_options_t * opts)
321 if (tcp_opts_tstamp (&tc->opt))
323 opts->flags |= TCP_OPTS_FLAG_TSTAMP;
324 opts->tsval = tcp_time_now ();
325 opts->tsecr = tc->tsval_recent;
326 len += TCP_OPTION_LEN_TIMESTAMP;
328 if (tcp_opts_sack_permitted (&tc->opt))
330 if (vec_len (tc->snd_sacks))
332 opts->flags |= TCP_OPTS_FLAG_SACK;
333 opts->sacks = tc->snd_sacks;
334 opts->n_sack_blocks = vec_len (tc->snd_sacks);
335 len += 2 + TCP_OPTION_LEN_SACK_BLOCK * opts->n_sack_blocks;
339 /* Align to needed boundary */
340 len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
345 tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts,
350 case TCP_STATE_ESTABLISHED:
351 case TCP_STATE_FIN_WAIT_1:
352 return tcp_make_established_options (tc, opts);
353 case TCP_STATE_SYN_RCVD:
354 return tcp_make_synack_options (tc, opts);
355 case TCP_STATE_SYN_SENT:
356 return tcp_make_syn_options (opts, tc->rcv_wscale);
358 clib_warning ("Not handled!");
363 #define tcp_get_free_buffer_index(tm, bidx) \
365 u32 *my_tx_buffers, n_free_buffers; \
366 u32 cpu_index = tm->vlib_main->cpu_index; \
367 my_tx_buffers = tm->tx_buffers[cpu_index]; \
368 if (PREDICT_FALSE(vec_len (my_tx_buffers) == 0)) \
370 n_free_buffers = 32; /* TODO config or macro */ \
371 vec_validate (my_tx_buffers, n_free_buffers - 1); \
372 _vec_len(my_tx_buffers) = vlib_buffer_alloc_from_free_list ( \
373 tm->vlib_main, my_tx_buffers, n_free_buffers, \
374 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX); \
375 tm->tx_buffers[cpu_index] = my_tx_buffers; \
377 /* buffer shortage */ \
378 if (PREDICT_FALSE (vec_len (my_tx_buffers) == 0)) \
380 *bidx = my_tx_buffers[_vec_len (my_tx_buffers)-1]; \
381 _vec_len (my_tx_buffers) -= 1; \
385 tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b)
387 vlib_buffer_t *it = b;
390 it->current_data = 0;
391 it->current_length = 0;
392 it->total_length_not_including_first_buffer = 0;
394 while ((it->flags & VLIB_BUFFER_NEXT_PRESENT)
395 && (it = vlib_get_buffer (vm, it->next_buffer)));
397 /* Leave enough space for headers */
398 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
399 vnet_buffer (b)->tcp.flags = 0;
406 tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state,
409 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
410 u8 tcp_opts_len, tcp_hdr_opts_len;
414 wnd = tcp_window_to_advertise (tc, state);
416 /* Make and write options */
417 tcp_opts_len = tcp_make_established_options (tc, snd_opts);
418 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
420 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
421 tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd);
423 tcp_options_write ((u8 *) (th + 1), snd_opts);
426 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
430 * Convert buffer to ACK
433 tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
435 tcp_main_t *tm = vnet_get_tcp_main ();
436 vlib_main_t *vm = tm->vlib_main;
438 tcp_reuse_buffer (vm, b);
439 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
440 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
444 * Convert buffer to FIN-ACK
447 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
449 tcp_main_t *tm = vnet_get_tcp_main ();
450 vlib_main_t *vm = tm->vlib_main;
453 tcp_reuse_buffer (vm, b);
455 flags = TCP_FLAG_FIN | TCP_FLAG_ACK;
456 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, flags);
458 /* Reset flags, make sure ack is sent */
459 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
465 * Convert buffer to SYN-ACK
468 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
470 tcp_main_t *tm = vnet_get_tcp_main ();
471 vlib_main_t *vm = tm->vlib_main;
472 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
473 u8 tcp_opts_len, tcp_hdr_opts_len;
478 memset (snd_opts, 0, sizeof (*snd_opts));
480 tcp_reuse_buffer (vm, b);
482 /* Set random initial sequence */
483 time_now = tcp_time_now ();
485 tc->iss = random_u32 (&time_now);
486 tc->snd_una = tc->iss;
487 tc->snd_nxt = tc->iss + 1;
488 tc->snd_una_max = tc->snd_nxt;
490 initial_wnd = tcp_initial_window_to_advertise (tc);
492 /* Make and write options */
493 tcp_opts_len = tcp_make_synack_options (tc, snd_opts);
494 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
496 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
497 tc->rcv_nxt, tcp_hdr_opts_len,
498 TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd);
500 tcp_options_write ((u8 *) (th + 1), snd_opts);
502 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
503 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
505 /* Init retransmit timer */
506 tcp_retransmit_timer_set (tc);
510 tcp_enqueue_to_ip_lookup (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
513 u32 *to_next, next_index;
516 b->flags |= VNET_BUFFER_LOCALLY_ORIGINATED;
519 /* Default FIB for now */
520 vnet_buffer (b)->sw_if_index[VLIB_TX] = 0;
522 /* Send to IP lookup */
523 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
524 f = vlib_get_frame_to_node (vm, next_index);
526 /* Enqueue the packet */
527 to_next = vlib_frame_vector_args (f);
530 vlib_put_frame_to_node (vm, next_index, f);
534 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
535 tcp_state_t state, u32 my_thread_index, u8 is_ip4)
537 u8 tcp_hdr_len = sizeof (tcp_header_t);
541 ip4_address_t src_ip40;
542 ip6_address_t src_ip60;
546 /* Find IP and TCP headers */
549 ih4 = vlib_buffer_get_current (b0);
550 th0 = ip4_next_header (ih4);
554 ih6 = vlib_buffer_get_current (b0);
555 th0 = ip6_next_header (ih6);
558 /* Swap src and dst ip */
561 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
562 src_ip40.as_u32 = ih4->src_address.as_u32;
563 ih4->src_address.as_u32 = ih4->dst_address.as_u32;
564 ih4->dst_address.as_u32 = src_ip40.as_u32;
566 /* Chop the end of the pkt */
567 b0->current_length += ip4_header_bytes (ih4) + tcp_hdr_len;
571 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
572 clib_memcpy (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
573 clib_memcpy (&ih6->src_address, &ih6->dst_address,
574 sizeof (ip6_address_t));
575 clib_memcpy (&ih6->dst_address, &src_ip60, sizeof (ip6_address_t));
577 /* Chop the end of the pkt */
578 b0->current_length += sizeof (ip6_header_t) + tcp_hdr_len;
581 /* Try to determine what/why we're actually resetting and swap
582 * src and dst ports */
583 if (state == TCP_STATE_CLOSED)
588 tmp = clib_net_to_host_u32 (th0->seq_number);
590 /* Got a SYN for no listener. */
591 th0->flags = TCP_FLAG_RST | TCP_FLAG_ACK;
592 th0->ack_number = clib_host_to_net_u32 (tmp + 1);
596 else if (state >= TCP_STATE_SYN_SENT)
598 th0->flags = TCP_FLAG_RST | TCP_FLAG_ACK;
599 th0->seq_number = th0->ack_number;
603 src_port0 = th0->src_port;
604 th0->src_port = th0->dst_port;
605 th0->dst_port = src_port0;
607 th0->data_offset_and_reserved = (tcp_hdr_len >> 2) << 4;
608 th0->urgent_pointer = 0;
610 /* Compute checksum */
613 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
618 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
626 * Send reset without reusing existing buffer
629 tcp_send_reset (vlib_buffer_t * pkt, u8 is_ip4)
633 tcp_main_t *tm = vnet_get_tcp_main ();
634 vlib_main_t *vm = tm->vlib_main;
635 u8 tcp_hdr_len, flags = 0;
636 tcp_header_t *th, *pkt_th;
638 ip4_header_t *ih4, *pkt_ih4;
639 ip6_header_t *ih6, *pkt_ih6;
641 tcp_get_free_buffer_index (tm, &bi);
642 b = vlib_get_buffer (vm, bi);
644 /* Leave enough space for headers */
645 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
647 /* Make and write options */
648 tcp_hdr_len = sizeof (tcp_header_t);
652 pkt_ih4 = vlib_buffer_get_current (pkt);
653 pkt_th = ip4_next_header (pkt_ih4);
657 pkt_ih6 = vlib_buffer_get_current (pkt);
658 pkt_th = ip6_next_header (pkt_ih6);
661 if (tcp_ack (pkt_th))
663 flags = TCP_FLAG_RST;
664 seq = pkt_th->ack_number;
669 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
671 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
674 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
675 seq, ack, tcp_hdr_len, flags, 0);
677 /* Swap src and dst ip */
680 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
681 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
682 &pkt_ih4->src_address, IP_PROTOCOL_TCP);
683 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
688 pkt_ih6 = (ip6_header_t *) (pkt_th - 1);
689 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
692 vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address,
693 &pkt_ih6->src_address, IP_PROTOCOL_TCP);
694 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
698 tcp_enqueue_to_ip_lookup (vm, b, bi, is_ip4);
702 tcp_push_ip_hdr (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b)
704 tcp_header_t *th = vlib_buffer_get_current (b);
709 ih = vlib_buffer_push_ip4 (tm->vlib_main, b, &tc->c_lcl_ip4,
710 &tc->c_rmt_ip4, IP_PROTOCOL_TCP);
711 th->checksum = ip4_tcp_udp_compute_checksum (tm->vlib_main, b, ih);
718 ih = vlib_buffer_push_ip6 (tm->vlib_main, b, &tc->c_lcl_ip6,
719 &tc->c_rmt_ip6, IP_PROTOCOL_TCP);
720 th->checksum = ip6_tcp_udp_icmp_compute_checksum (tm->vlib_main, b, ih,
729 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
730 * The packet is not forwarded through tcpx_output to avoid doing lookups
731 * in the half_open pool.
734 tcp_send_syn (tcp_connection_t * tc)
738 tcp_main_t *tm = vnet_get_tcp_main ();
739 vlib_main_t *vm = tm->vlib_main;
740 u8 tcp_hdr_opts_len, tcp_opts_len;
744 tcp_options_t snd_opts;
746 tcp_get_free_buffer_index (tm, &bi);
747 b = vlib_get_buffer (vm, bi);
749 /* Leave enough space for headers */
750 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
752 /* Set random initial sequence */
753 time_now = tcp_time_now ();
755 tc->iss = random_u32 (&time_now);
756 tc->snd_una = tc->iss;
757 tc->snd_una_max = tc->snd_nxt = tc->iss + 1;
759 initial_wnd = tcp_initial_window_to_advertise (tc);
761 /* Make and write options */
762 memset (&snd_opts, 0, sizeof (snd_opts));
763 tcp_opts_len = tcp_make_syn_options (&snd_opts, tc->rcv_wscale);
764 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
766 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
767 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
770 tcp_options_write ((u8 *) (th + 1), &snd_opts);
772 /* Measure RTT with this */
773 tc->rtt_ts = tcp_time_now ();
774 tc->rtt_seq = tc->snd_nxt;
776 /* Start retransmit trimer */
777 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN, tc->rto * TCP_TO_TIMER_TICK);
780 /* Set the connection establishment timer */
781 tcp_timer_set (tc, TCP_TIMER_ESTABLISH, TCP_ESTABLISH_TIME);
783 tcp_push_ip_hdr (tm, tc, b);
784 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
788 tcp_enqueue_to_output (vlib_main_t * vm, vlib_buffer_t * b, u32 bi, u8 is_ip4)
790 u32 *to_next, next_index;
793 b->flags |= VNET_BUFFER_LOCALLY_ORIGINATED;
796 /* Decide where to send the packet */
797 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
798 f = vlib_get_frame_to_node (vm, next_index);
800 /* Enqueue the packet */
801 to_next = vlib_frame_vector_args (f);
804 vlib_put_frame_to_node (vm, next_index, f);
811 tcp_send_fin (tcp_connection_t * tc)
815 tcp_main_t *tm = vnet_get_tcp_main ();
816 vlib_main_t *vm = tm->vlib_main;
818 tcp_get_free_buffer_index (tm, &bi);
819 b = vlib_get_buffer (vm, bi);
821 /* Leave enough space for headers */
822 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
824 tcp_make_fin (tc, b);
825 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
826 tc->flags |= TCP_CONN_FINSNT;
827 TCP_EVT_DBG (TCP_EVT_FIN_SENT, tc);
831 tcp_make_state_flags (tcp_state_t next_state)
835 case TCP_STATE_ESTABLISHED:
837 case TCP_STATE_SYN_RCVD:
838 return TCP_FLAG_SYN | TCP_FLAG_ACK;
839 case TCP_STATE_SYN_SENT:
841 case TCP_STATE_LAST_ACK:
842 case TCP_STATE_FIN_WAIT_1:
845 clib_warning ("Shouldn't be here!");
851 * Push TCP header and update connection variables
854 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
855 tcp_state_t next_state)
857 u32 advertise_wnd, data_len;
858 u8 tcp_opts_len, tcp_hdr_opts_len, opts_write_len, flags;
859 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
862 data_len = b->current_length;
863 vnet_buffer (b)->tcp.flags = 0;
865 /* Make and write options */
866 memset (snd_opts, 0, sizeof (*snd_opts));
867 tcp_opts_len = tcp_make_options (tc, snd_opts, next_state);
868 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
870 /* Get rcv window to advertise */
871 advertise_wnd = tcp_window_to_advertise (tc, next_state);
872 flags = tcp_make_state_flags (next_state);
874 /* Push header and options */
875 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
876 tc->rcv_nxt, tcp_hdr_opts_len, flags,
879 opts_write_len = tcp_options_write ((u8 *) (th + 1), snd_opts);
881 ASSERT (opts_write_len == tcp_opts_len);
883 /* Tag the buffer with the connection index */
884 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
886 tc->snd_nxt += data_len;
887 TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
890 /* Send delayed ACK when timer expires */
892 tcp_timer_delack_handler (u32 index)
894 tcp_main_t *tm = vnet_get_tcp_main ();
895 vlib_main_t *vm = tm->vlib_main;
896 u32 thread_index = os_get_cpu_number ();
897 tcp_connection_t *tc;
901 tc = tcp_connection_get (index, thread_index);
904 tcp_get_free_buffer_index (tm, &bi);
905 b = vlib_get_buffer (vm, bi);
907 /* Fill in the ACK */
908 tcp_make_ack (tc, b);
910 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
911 tc->flags &= ~TCP_CONN_DELACK;
913 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
916 /** Build a retransmit segment
918 * @return the number of bytes in the segment or 0 if there's nothing to
922 tcp_prepare_retransmit_segment (tcp_connection_t * tc, vlib_buffer_t * b,
925 tcp_main_t *tm = vnet_get_tcp_main ();
926 vlib_main_t *vm = tm->vlib_main;
927 u32 n_bytes, offset = 0;
928 sack_scoreboard_hole_t *hole;
931 tcp_reuse_buffer (vm, b);
933 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
934 ASSERT (max_bytes != 0);
936 if (tcp_opts_sack_permitted (&tc->opt))
938 /* XXX get first hole not retransmitted yet */
939 hole = scoreboard_first_hole (&tc->sack_sb);
943 offset = hole->start - tc->snd_una;
944 hole_size = hole->end - hole->start;
948 if (hole_size < max_bytes)
949 max_bytes = hole_size;
953 if (seq_geq (tc->snd_nxt, tc->snd_una_max))
957 n_bytes = stream_session_peek_bytes (&tc->connection,
958 vlib_buffer_get_current (b), offset,
960 ASSERT (n_bytes != 0);
962 tcp_push_hdr_i (tc, b, tc->state);
968 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
970 tcp_main_t *tm = vnet_get_tcp_main ();
971 vlib_main_t *vm = tm->vlib_main;
972 u32 thread_index = os_get_cpu_number ();
973 tcp_connection_t *tc;
975 u32 bi, max_bytes, snd_space;
979 tc = tcp_half_open_connection_get (index);
983 tc = tcp_connection_get (index, thread_index);
986 /* Make sure timer handle is set to invalid */
987 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
989 /* Increment RTO backoff (also equal to number of retries) */
992 /* Go back to first un-acked byte */
993 tc->snd_nxt = tc->snd_una;
996 tcp_get_free_buffer_index (tm, &bi);
997 b = vlib_get_buffer (vm, bi);
999 if (tc->state >= TCP_STATE_ESTABLISHED)
1001 tcp_fastrecovery_off (tc);
1003 /* Exponential backoff */
1004 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1006 /* Figure out what and how many bytes we can send */
1007 snd_space = tcp_available_snd_space (tc);
1008 max_bytes = clib_min (tc->snd_mss, snd_space);
1012 clib_warning ("no wnd to retransmit");
1015 tcp_prepare_retransmit_segment (tc, b, max_bytes);
1017 tc->rtx_bytes += max_bytes;
1019 /* No fancy recovery for now! */
1020 scoreboard_clear (&tc->sack_sb);
1024 /* Retransmit for SYN/SYNACK */
1025 ASSERT (tc->state == TCP_STATE_SYN_RCVD
1026 || tc->state == TCP_STATE_SYN_SENT);
1028 /* Try without increasing RTO a number of times. If this fails,
1029 * start growing RTO exponentially */
1030 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1031 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1033 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
1035 tcp_push_hdr_i (tc, b, tc->state);
1037 /* Account for the SYN */
1043 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1045 /* Re-enable retransmit timer */
1046 tcp_retransmit_timer_set (tc);
1050 ASSERT (tc->state == TCP_STATE_SYN_SENT);
1052 /* This goes straight to ipx_lookup */
1053 tcp_push_ip_hdr (tm, tc, b);
1054 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
1056 /* Re-enable retransmit timer */
1057 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN,
1058 tc->rto * TCP_TO_TIMER_TICK);
1063 tcp_timer_retransmit_handler (u32 index)
1065 tcp_timer_retransmit_handler_i (index, 0);
1069 tcp_timer_retransmit_syn_handler (u32 index)
1071 tcp_timer_retransmit_handler_i (index, 1);
1075 * Retansmit first unacked segment */
1077 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1079 tcp_main_t *tm = vnet_get_tcp_main ();
1080 u32 snd_nxt = tc->snd_nxt;
1084 tc->snd_nxt = tc->snd_una;
1087 tcp_get_free_buffer_index (tm, &bi);
1088 b = vlib_get_buffer (tm->vlib_main, bi);
1090 tcp_prepare_retransmit_segment (tc, b, tc->snd_mss);
1091 tcp_enqueue_to_output (tm->vlib_main, b, bi, tc->c_is_ip4);
1093 tc->snd_nxt = snd_nxt;
1094 tc->rtx_bytes += tc->snd_mss;
1098 tcp_fast_retransmit (tcp_connection_t * tc)
1100 tcp_main_t *tm = vnet_get_tcp_main ();
1101 u32 snd_space, max_bytes, n_bytes, bi;
1104 ASSERT (tcp_in_fastrecovery (tc));
1106 clib_warning ("fast retransmit!");
1108 /* Start resending from first un-acked segment */
1109 tc->snd_nxt = tc->snd_una;
1111 snd_space = tcp_available_snd_space (tc);
1115 tcp_get_free_buffer_index (tm, &bi);
1116 b = vlib_get_buffer (tm->vlib_main, bi);
1118 max_bytes = clib_min (tc->snd_mss, snd_space);
1119 n_bytes = tcp_prepare_retransmit_segment (tc, b, max_bytes);
1121 /* Nothing left to retransmit */
1125 tcp_enqueue_to_output (tm->vlib_main, b, bi, tc->c_is_ip4);
1127 snd_space -= n_bytes;
1130 /* If window allows, send new data */
1131 tc->snd_nxt = tc->snd_una_max;
1135 tcp_session_has_ooo_data (tcp_connection_t * tc)
1137 stream_session_t *s =
1138 stream_session_get (tc->c_s_index, tc->c_thread_index);
1139 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1143 tcp46_output_inline (vlib_main_t * vm,
1144 vlib_node_runtime_t * node,
1145 vlib_frame_t * from_frame, int is_ip4)
1147 u32 n_left_from, next_index, *from, *to_next;
1148 u32 my_thread_index = vm->cpu_index;
1150 from = vlib_frame_vector_args (from_frame);
1151 n_left_from = from_frame->n_vectors;
1153 next_index = node->cached_next_index;
1155 while (n_left_from > 0)
1159 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1161 while (n_left_from > 0 && n_left_to_next > 0)
1165 tcp_connection_t *tc0;
1167 u32 error0 = TCP_ERROR_PKTS_SENT, next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
1174 n_left_to_next -= 1;
1176 b0 = vlib_get_buffer (vm, bi0);
1177 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1179 if (PREDICT_FALSE (tc0 == 0 || tc0->state == TCP_STATE_CLOSED))
1181 error0 = TCP_ERROR_INVALID_CONNECTION;
1182 next0 = TCP_OUTPUT_NEXT_DROP;
1186 th0 = vlib_buffer_get_current (b0);
1187 TCP_EVT_DBG (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
1192 ih0 = vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4,
1193 &tc0->c_rmt_ip4, IP_PROTOCOL_TCP);
1194 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih0);
1201 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6,
1202 &tc0->c_rmt_ip6, IP_PROTOCOL_TCP);
1203 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih0,
1208 /* Filter out DUPACKs if there are no OOO segments left */
1210 (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1212 ASSERT (tc0->snt_dupacks > 0);
1214 if (!tcp_session_has_ooo_data (tc0))
1216 error0 = TCP_ERROR_FILTERED_DUPACKS;
1217 next0 = TCP_OUTPUT_NEXT_DROP;
1222 /* Retransmitted SYNs do reach this but it should be harmless */
1223 tc0->rcv_las = tc0->rcv_nxt;
1225 /* Stop DELACK timer and fix flags */
1227 ~(TCP_CONN_SNDACK | TCP_CONN_DELACK | TCP_CONN_BURSTACK);
1228 if (tcp_timer_is_active (tc0, TCP_TIMER_DELACK))
1230 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1233 /* If not retransmitting
1234 * 1) update snd_una_max (SYN, SYNACK, new data, FIN)
1235 * 2) If we're not tracking an ACK, start tracking */
1236 if (seq_lt (tc0->snd_una_max, tc0->snd_nxt))
1238 tc0->snd_una_max = tc0->snd_nxt;
1239 if (tc0->rtt_ts == 0)
1241 tc0->rtt_ts = tcp_time_now ();
1242 tc0->rtt_seq = tc0->snd_nxt;
1246 /* Set the retransmit timer if not set already and not
1247 * doing a pure ACK */
1248 if (!tcp_timer_is_active (tc0, TCP_TIMER_RETRANSMIT)
1249 && tc0->snd_nxt != tc0->snd_una)
1251 tcp_retransmit_timer_set (tc0);
1255 /* set fib index to default and lookup node */
1256 /* XXX network virtualization (vrf/vni) */
1257 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
1258 vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1260 b0->flags |= VNET_BUFFER_LOCALLY_ORIGINATED;
1262 b0->error = node->errors[error0];
1263 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1268 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1269 n_left_to_next, bi0, next0);
1272 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1275 return from_frame->n_vectors;
1279 tcp4_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1280 vlib_frame_t * from_frame)
1282 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1286 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1287 vlib_frame_t * from_frame)
1289 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1293 VLIB_REGISTER_NODE (tcp4_output_node) =
1295 .function = tcp4_output,.name = "tcp4-output",
1296 /* Takes a vector of packets. */
1297 .vector_size = sizeof (u32),
1298 .n_errors = TCP_N_ERROR,
1299 .error_strings = tcp_error_strings,
1300 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1302 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1303 foreach_tcp4_output_next
1306 .format_buffer = format_tcp_header,
1307 .format_trace = format_tcp_tx_trace,
1311 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output);
1314 VLIB_REGISTER_NODE (tcp6_output_node) =
1316 .function = tcp6_output,
1317 .name = "tcp6-output",
1318 /* Takes a vector of packets. */
1319 .vector_size = sizeof (u32),
1320 .n_errors = TCP_N_ERROR,
1321 .error_strings = tcp_error_strings,
1322 .n_next_nodes = TCP_OUTPUT_N_NEXT,
1324 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1325 foreach_tcp6_output_next
1328 .format_buffer = format_tcp_header,
1329 .format_trace = format_tcp_tx_trace,
1333 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output);
1336 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
1338 tcp_connection_t *tc;
1340 tc = (tcp_connection_t *) tconn;
1341 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED);
1345 typedef enum _tcp_reset_next
1347 TCP_RESET_NEXT_DROP,
1348 TCP_RESET_NEXT_IP_LOOKUP,
1352 #define foreach_tcp4_reset_next \
1353 _(DROP, "error-drop") \
1354 _(IP_LOOKUP, "ip4-lookup")
1356 #define foreach_tcp6_reset_next \
1357 _(DROP, "error-drop") \
1358 _(IP_LOOKUP, "ip6-lookup")
1361 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1362 vlib_frame_t * from_frame, u8 is_ip4)
1364 u32 n_left_from, next_index, *from, *to_next;
1365 u32 my_thread_index = vm->cpu_index;
1367 from = vlib_frame_vector_args (from_frame);
1368 n_left_from = from_frame->n_vectors;
1370 next_index = node->cached_next_index;
1372 while (n_left_from > 0)
1376 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1378 while (n_left_from > 0 && n_left_to_next > 0)
1382 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
1389 n_left_to_next -= 1;
1391 b0 = vlib_get_buffer (vm, bi0);
1393 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
1394 my_thread_index, is_ip4))
1396 error0 = TCP_ERROR_LOOKUP_DROPS;
1397 next0 = TCP_RESET_NEXT_DROP;
1401 /* Prepare to send to IP lookup */
1402 vnet_buffer (b0)->sw_if_index[VLIB_TX] = 0;
1403 next0 = TCP_RESET_NEXT_IP_LOOKUP;
1406 b0->error = node->errors[error0];
1407 b0->flags |= VNET_BUFFER_LOCALLY_ORIGINATED;
1408 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1413 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1414 n_left_to_next, bi0, next0);
1416 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1418 return from_frame->n_vectors;
1422 tcp4_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1423 vlib_frame_t * from_frame)
1425 return tcp46_send_reset_inline (vm, node, from_frame, 1);
1429 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1430 vlib_frame_t * from_frame)
1432 return tcp46_send_reset_inline (vm, node, from_frame, 0);
1436 VLIB_REGISTER_NODE (tcp4_reset_node) = {
1437 .function = tcp4_send_reset,
1438 .name = "tcp4-reset",
1439 .vector_size = sizeof (u32),
1440 .n_errors = TCP_N_ERROR,
1441 .error_strings = tcp_error_strings,
1442 .n_next_nodes = TCP_RESET_N_NEXT,
1444 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
1445 foreach_tcp4_reset_next
1451 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset);
1454 VLIB_REGISTER_NODE (tcp6_reset_node) = {
1455 .function = tcp6_send_reset,
1456 .name = "tcp6-reset",
1457 .vector_size = sizeof (u32),
1458 .n_errors = TCP_N_ERROR,
1459 .error_strings = tcp_error_strings,
1460 .n_next_nodes = TCP_RESET_N_NEXT,
1462 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
1463 foreach_tcp6_reset_next
1469 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset);
1472 * fd.io coding-style-patch-verification: ON
1475 * eval: (c-set-style "gnu")