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 if (tc->rcv_las == tc->rcv_nxt)
456 flags = TCP_FLAG_FIN;
458 flags = TCP_FLAG_FIN | TCP_FLAG_ACK;
460 tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, flags);
462 /* Reset flags, make sure ack is sent */
463 vnet_buffer (b)->tcp.flags &= ~TCP_BUF_FLAG_DUPACK;
469 * Convert buffer to SYN-ACK
472 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
474 tcp_main_t *tm = vnet_get_tcp_main ();
475 vlib_main_t *vm = tm->vlib_main;
476 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
477 u8 tcp_opts_len, tcp_hdr_opts_len;
482 memset (snd_opts, 0, sizeof (*snd_opts));
484 tcp_reuse_buffer (vm, b);
486 /* Set random initial sequence */
487 time_now = tcp_time_now ();
489 tc->iss = random_u32 (&time_now);
490 tc->snd_una = tc->iss;
491 tc->snd_nxt = tc->iss + 1;
492 tc->snd_una_max = tc->snd_nxt;
494 initial_wnd = tcp_initial_window_to_advertise (tc);
496 /* Make and write options */
497 tcp_opts_len = tcp_make_synack_options (tc, snd_opts);
498 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
500 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
501 tc->rcv_nxt, tcp_hdr_opts_len,
502 TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd);
504 tcp_options_write ((u8 *) (th + 1), snd_opts);
506 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
507 vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
509 /* Init retransmit timer */
510 tcp_retransmit_timer_set (tc);
514 tcp_enqueue_to_ip_lookup (vlib_main_t * vm, vlib_buffer_t * b, u32 bi,
517 u32 *to_next, next_index;
520 b->flags |= VNET_BUFFER_LOCALLY_ORIGINATED;
523 /* Default FIB for now */
524 vnet_buffer (b)->sw_if_index[VLIB_TX] = 0;
526 /* Send to IP lookup */
527 next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
528 f = vlib_get_frame_to_node (vm, next_index);
530 /* Enqueue the packet */
531 to_next = vlib_frame_vector_args (f);
534 vlib_put_frame_to_node (vm, next_index, f);
538 tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
539 tcp_state_t state, u32 my_thread_index, u8 is_ip4)
541 u8 tcp_hdr_len = sizeof (tcp_header_t);
545 ip4_address_t src_ip40;
546 ip6_address_t src_ip60;
550 /* Find IP and TCP headers */
553 ih4 = vlib_buffer_get_current (b0);
554 th0 = ip4_next_header (ih4);
558 ih6 = vlib_buffer_get_current (b0);
559 th0 = ip6_next_header (ih6);
562 /* Swap src and dst ip */
565 ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
566 src_ip40.as_u32 = ih4->src_address.as_u32;
567 ih4->src_address.as_u32 = ih4->dst_address.as_u32;
568 ih4->dst_address.as_u32 = src_ip40.as_u32;
570 /* Chop the end of the pkt */
571 b0->current_length += ip4_header_bytes (ih4) + tcp_hdr_len;
575 ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
576 clib_memcpy (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
577 clib_memcpy (&ih6->src_address, &ih6->dst_address,
578 sizeof (ip6_address_t));
579 clib_memcpy (&ih6->dst_address, &src_ip60, sizeof (ip6_address_t));
581 /* Chop the end of the pkt */
582 b0->current_length += sizeof (ip6_header_t) + tcp_hdr_len;
585 /* Try to determine what/why we're actually resetting and swap
586 * src and dst ports */
587 if (state == TCP_STATE_CLOSED)
592 tmp = clib_net_to_host_u32 (th0->seq_number);
594 /* Got a SYN for no listener. */
595 th0->flags = TCP_FLAG_RST | TCP_FLAG_ACK;
596 th0->ack_number = clib_host_to_net_u32 (tmp + 1);
600 else if (state >= TCP_STATE_SYN_SENT)
602 th0->flags = TCP_FLAG_RST | TCP_FLAG_ACK;
603 th0->seq_number = th0->ack_number;
607 src_port0 = th0->src_port;
608 th0->src_port = th0->dst_port;
609 th0->dst_port = src_port0;
611 th0->data_offset_and_reserved = (tcp_hdr_len >> 2) << 4;
612 th0->urgent_pointer = 0;
614 /* Compute checksum */
617 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
622 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
630 * Send reset without reusing existing buffer
633 tcp_send_reset (vlib_buffer_t * pkt, u8 is_ip4)
637 tcp_main_t *tm = vnet_get_tcp_main ();
638 vlib_main_t *vm = tm->vlib_main;
639 u8 tcp_hdr_len, flags = 0;
640 tcp_header_t *th, *pkt_th;
642 ip4_header_t *ih4, *pkt_ih4;
643 ip6_header_t *ih6, *pkt_ih6;
645 tcp_get_free_buffer_index (tm, &bi);
646 b = vlib_get_buffer (vm, bi);
648 /* Leave enough space for headers */
649 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
651 /* Make and write options */
652 tcp_hdr_len = sizeof (tcp_header_t);
656 pkt_ih4 = vlib_buffer_get_current (pkt);
657 pkt_th = ip4_next_header (pkt_ih4);
661 pkt_ih6 = vlib_buffer_get_current (pkt);
662 pkt_th = ip6_next_header (pkt_ih6);
665 if (tcp_ack (pkt_th))
667 flags = TCP_FLAG_RST;
668 seq = pkt_th->ack_number;
673 flags = TCP_FLAG_RST | TCP_FLAG_ACK;
675 ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end);
678 th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port,
679 seq, ack, tcp_hdr_len, flags, 0);
681 /* Swap src and dst ip */
684 ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40);
685 ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address,
686 &pkt_ih4->src_address, IP_PROTOCOL_TCP);
687 th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
692 pkt_ih6 = (ip6_header_t *) (pkt_th - 1);
693 ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) ==
696 vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address,
697 &pkt_ih6->src_address, IP_PROTOCOL_TCP);
698 th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
702 tcp_enqueue_to_ip_lookup (vm, b, bi, is_ip4);
706 tcp_push_ip_hdr (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b)
708 tcp_header_t *th = vlib_buffer_get_current (b);
713 ih = vlib_buffer_push_ip4 (tm->vlib_main, b, &tc->c_lcl_ip4,
714 &tc->c_rmt_ip4, IP_PROTOCOL_TCP);
715 th->checksum = ip4_tcp_udp_compute_checksum (tm->vlib_main, b, ih);
722 ih = vlib_buffer_push_ip6 (tm->vlib_main, b, &tc->c_lcl_ip6,
723 &tc->c_rmt_ip6, IP_PROTOCOL_TCP);
724 th->checksum = ip6_tcp_udp_icmp_compute_checksum (tm->vlib_main, b, ih,
733 * Builds a SYN packet for a half-open connection and sends it to ipx_lookup.
734 * The packet is not forwarded through tcpx_output to avoid doing lookups
735 * in the half_open pool.
738 tcp_send_syn (tcp_connection_t * tc)
742 tcp_main_t *tm = vnet_get_tcp_main ();
743 vlib_main_t *vm = tm->vlib_main;
744 u8 tcp_hdr_opts_len, tcp_opts_len;
748 tcp_options_t snd_opts;
750 tcp_get_free_buffer_index (tm, &bi);
751 b = vlib_get_buffer (vm, bi);
753 /* Leave enough space for headers */
754 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
756 /* Set random initial sequence */
757 time_now = tcp_time_now ();
759 tc->iss = random_u32 (&time_now);
760 tc->snd_una = tc->iss;
761 tc->snd_una_max = tc->snd_nxt = tc->iss + 1;
763 initial_wnd = tcp_initial_window_to_advertise (tc);
765 /* Make and write options */
766 memset (&snd_opts, 0, sizeof (snd_opts));
767 tcp_opts_len = tcp_make_syn_options (&snd_opts, tc->rcv_wscale);
768 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
770 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss,
771 tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN,
774 tcp_options_write ((u8 *) (th + 1), &snd_opts);
776 /* Measure RTT with this */
777 tc->rtt_ts = tcp_time_now ();
778 tc->rtt_seq = tc->snd_nxt;
780 /* Start retransmit trimer */
781 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN, tc->rto * TCP_TO_TIMER_TICK);
784 /* Set the connection establishment timer */
785 tcp_timer_set (tc, TCP_TIMER_ESTABLISH, TCP_ESTABLISH_TIME);
787 tcp_push_ip_hdr (tm, tc, b);
788 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
792 tcp_enqueue_to_output (vlib_main_t * vm, vlib_buffer_t * b, u32 bi, u8 is_ip4)
794 u32 *to_next, next_index;
797 b->flags |= VNET_BUFFER_LOCALLY_ORIGINATED;
800 /* Decide where to send the packet */
801 next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
802 f = vlib_get_frame_to_node (vm, next_index);
804 /* Enqueue the packet */
805 to_next = vlib_frame_vector_args (f);
808 vlib_put_frame_to_node (vm, next_index, f);
815 tcp_send_fin (tcp_connection_t * tc)
819 tcp_main_t *tm = vnet_get_tcp_main ();
820 vlib_main_t *vm = tm->vlib_main;
822 tcp_get_free_buffer_index (tm, &bi);
823 b = vlib_get_buffer (vm, bi);
825 /* Leave enough space for headers */
826 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
828 tcp_make_fin (tc, b);
829 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
830 tc->flags |= TCP_CONN_FINSNT;
834 tcp_make_state_flags (tcp_state_t next_state)
838 case TCP_STATE_ESTABLISHED:
840 case TCP_STATE_SYN_RCVD:
841 return TCP_FLAG_SYN | TCP_FLAG_ACK;
842 case TCP_STATE_SYN_SENT:
844 case TCP_STATE_LAST_ACK:
845 case TCP_STATE_FIN_WAIT_1:
848 clib_warning ("Shouldn't be here!");
854 * Push TCP header and update connection variables
857 tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
858 tcp_state_t next_state)
860 u32 advertise_wnd, data_len;
861 u8 tcp_opts_len, tcp_hdr_opts_len, opts_write_len, flags;
862 tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
865 data_len = b->current_length;
866 vnet_buffer (b)->tcp.flags = 0;
868 /* Make and write options */
869 memset (snd_opts, 0, sizeof (*snd_opts));
870 tcp_opts_len = tcp_make_options (tc, snd_opts, next_state);
871 tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t);
873 /* Get rcv window to advertise */
874 advertise_wnd = tcp_window_to_advertise (tc, next_state);
875 flags = tcp_make_state_flags (next_state);
877 /* Push header and options */
878 th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
879 tc->rcv_nxt, tcp_hdr_opts_len, flags,
882 opts_write_len = tcp_options_write ((u8 *) (th + 1), snd_opts);
884 ASSERT (opts_write_len == tcp_opts_len);
886 /* Tag the buffer with the connection index */
887 vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
889 tc->snd_nxt += data_len;
892 /* Send delayed ACK when timer expires */
894 tcp_timer_delack_handler (u32 index)
896 tcp_main_t *tm = vnet_get_tcp_main ();
897 vlib_main_t *vm = tm->vlib_main;
898 u32 thread_index = os_get_cpu_number ();
899 tcp_connection_t *tc;
903 tc = tcp_connection_get (index, thread_index);
906 tcp_get_free_buffer_index (tm, &bi);
907 b = vlib_get_buffer (vm, bi);
909 /* Fill in the ACK */
910 tcp_make_ack (tc, b);
912 tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
913 tc->flags &= ~TCP_CONN_DELACK;
915 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
918 /** Build a retransmit segment
920 * @return the number of bytes in the segment or 0 if there's nothing to
924 tcp_prepare_retransmit_segment (tcp_connection_t * tc, vlib_buffer_t * b,
927 tcp_main_t *tm = vnet_get_tcp_main ();
928 vlib_main_t *vm = tm->vlib_main;
929 u32 n_bytes, offset = 0;
930 sack_scoreboard_hole_t *hole;
933 tcp_reuse_buffer (vm, b);
935 ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
936 ASSERT (max_bytes != 0);
938 if (tcp_opts_sack_permitted (&tc->opt))
940 /* XXX get first hole not retransmitted yet */
941 hole = scoreboard_first_hole (&tc->sack_sb);
945 offset = hole->start - tc->snd_una;
946 hole_size = hole->end - hole->start;
950 if (hole_size < max_bytes)
951 max_bytes = hole_size;
955 if (seq_geq (tc->snd_nxt, tc->snd_una_max))
959 n_bytes = stream_session_peek_bytes (&tc->connection,
960 vlib_buffer_get_current (b), offset,
962 ASSERT (n_bytes != 0);
964 tcp_push_hdr_i (tc, b, tc->state);
970 tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
972 tcp_main_t *tm = vnet_get_tcp_main ();
973 vlib_main_t *vm = tm->vlib_main;
974 u32 thread_index = os_get_cpu_number ();
975 tcp_connection_t *tc;
977 u32 bi, max_bytes, snd_space;
981 tc = tcp_half_open_connection_get (index);
985 tc = tcp_connection_get (index, thread_index);
988 /* Make sure timer handle is set to invalid */
989 tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
991 /* Increment RTO backoff (also equal to number of retries) */
994 /* Go back to first un-acked byte */
995 tc->snd_nxt = tc->snd_una;
998 tcp_get_free_buffer_index (tm, &bi);
999 b = vlib_get_buffer (vm, bi);
1001 if (tc->state >= TCP_STATE_ESTABLISHED)
1003 tcp_fastrecovery_off (tc);
1005 /* Exponential backoff */
1006 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1008 /* Figure out what and how many bytes we can send */
1009 snd_space = tcp_available_snd_space (tc);
1010 max_bytes = clib_min (tc->snd_mss, snd_space);
1014 clib_warning ("no wnd to retransmit");
1017 tcp_prepare_retransmit_segment (tc, b, max_bytes);
1019 tc->rtx_bytes += max_bytes;
1021 /* No fancy recovery for now! */
1022 scoreboard_clear (&tc->sack_sb);
1026 /* Retransmit for SYN/SYNACK */
1027 ASSERT (tc->state == TCP_STATE_SYN_RCVD
1028 || tc->state == TCP_STATE_SYN_SENT);
1030 /* Try without increasing RTO a number of times. If this fails,
1031 * start growing RTO exponentially */
1032 if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
1033 tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
1035 vlib_buffer_make_headroom (b, MAX_HDRS_LEN);
1037 tcp_push_hdr_i (tc, b, tc->state);
1039 /* Account for the SYN */
1045 tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4);
1047 /* Re-enable retransmit timer */
1048 tcp_retransmit_timer_set (tc);
1052 ASSERT (tc->state == TCP_STATE_SYN_SENT);
1054 /* This goes straight to ipx_lookup */
1055 tcp_push_ip_hdr (tm, tc, b);
1056 tcp_enqueue_to_ip_lookup (vm, b, bi, tc->c_is_ip4);
1058 /* Re-enable retransmit timer */
1059 tcp_timer_set (tc, TCP_TIMER_RETRANSMIT_SYN,
1060 tc->rto * TCP_TO_TIMER_TICK);
1065 tcp_timer_retransmit_handler (u32 index)
1067 tcp_timer_retransmit_handler_i (index, 0);
1071 tcp_timer_retransmit_syn_handler (u32 index)
1073 tcp_timer_retransmit_handler_i (index, 1);
1077 * Retansmit first unacked segment */
1079 tcp_retransmit_first_unacked (tcp_connection_t * tc)
1081 tcp_main_t *tm = vnet_get_tcp_main ();
1082 u32 snd_nxt = tc->snd_nxt;
1086 tc->snd_nxt = tc->snd_una;
1089 tcp_get_free_buffer_index (tm, &bi);
1090 b = vlib_get_buffer (tm->vlib_main, bi);
1092 tcp_prepare_retransmit_segment (tc, b, tc->snd_mss);
1093 tcp_enqueue_to_output (tm->vlib_main, b, bi, tc->c_is_ip4);
1095 tc->snd_nxt = snd_nxt;
1096 tc->rtx_bytes += tc->snd_mss;
1100 tcp_fast_retransmit (tcp_connection_t * tc)
1102 tcp_main_t *tm = vnet_get_tcp_main ();
1103 u32 snd_space, max_bytes, n_bytes, bi;
1106 ASSERT (tcp_in_fastrecovery (tc));
1108 clib_warning ("fast retransmit!");
1110 /* Start resending from first un-acked segment */
1111 tc->snd_nxt = tc->snd_una;
1113 snd_space = tcp_available_snd_space (tc);
1117 tcp_get_free_buffer_index (tm, &bi);
1118 b = vlib_get_buffer (tm->vlib_main, bi);
1120 max_bytes = clib_min (tc->snd_mss, snd_space);
1121 n_bytes = tcp_prepare_retransmit_segment (tc, b, max_bytes);
1123 /* Nothing left to retransmit */
1127 tcp_enqueue_to_output (tm->vlib_main, b, bi, tc->c_is_ip4);
1129 snd_space -= n_bytes;
1132 /* If window allows, send new data */
1133 tc->snd_nxt = tc->snd_una_max;
1137 tcp_session_has_ooo_data (tcp_connection_t * tc)
1139 stream_session_t *s =
1140 stream_session_get (tc->c_s_index, tc->c_thread_index);
1141 return svm_fifo_has_ooo_data (s->server_rx_fifo);
1145 tcp46_output_inline (vlib_main_t * vm,
1146 vlib_node_runtime_t * node,
1147 vlib_frame_t * from_frame, int is_ip4)
1149 u32 n_left_from, next_index, *from, *to_next;
1150 u32 my_thread_index = vm->cpu_index;
1152 from = vlib_frame_vector_args (from_frame);
1153 n_left_from = from_frame->n_vectors;
1155 next_index = node->cached_next_index;
1157 while (n_left_from > 0)
1161 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1163 while (n_left_from > 0 && n_left_to_next > 0)
1167 tcp_connection_t *tc0;
1169 u32 error0 = TCP_ERROR_PKTS_SENT, next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
1176 n_left_to_next -= 1;
1178 b0 = vlib_get_buffer (vm, bi0);
1179 tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
1181 if (PREDICT_FALSE (tc0 == 0 || tc0->state == TCP_STATE_CLOSED))
1183 error0 = TCP_ERROR_INVALID_CONNECTION;
1184 next0 = TCP_OUTPUT_NEXT_DROP;
1188 th0 = vlib_buffer_get_current (b0);
1193 ih0 = vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4,
1194 &tc0->c_rmt_ip4, IP_PROTOCOL_TCP);
1195 th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih0);
1202 ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6,
1203 &tc0->c_rmt_ip6, IP_PROTOCOL_TCP);
1204 th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih0,
1209 /* Filter out DUPACKs if there are no OOO segments left */
1211 (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
1213 ASSERT (tc0->snt_dupacks > 0);
1215 if (!tcp_session_has_ooo_data (tc0))
1217 error0 = TCP_ERROR_FILTERED_DUPACKS;
1218 next0 = TCP_OUTPUT_NEXT_DROP;
1223 /* Retransmitted SYNs do reach this but it should be harmless */
1224 tc0->rcv_las = tc0->rcv_nxt;
1226 /* Stop DELACK timer and fix flags */
1228 ~(TCP_CONN_SNDACK | TCP_CONN_DELACK | TCP_CONN_BURSTACK);
1229 if (tcp_timer_is_active (tc0, TCP_TIMER_DELACK))
1231 tcp_timer_reset (tc0, TCP_TIMER_DELACK);
1234 /* If not retransmitting
1235 * 1) update snd_una_max (SYN, SYNACK, new data, FIN)
1236 * 2) If we're not tracking an ACK, start tracking */
1237 if (seq_lt (tc0->snd_una_max, tc0->snd_nxt))
1239 tc0->snd_una_max = tc0->snd_nxt;
1240 if (tc0->rtt_ts == 0)
1242 tc0->rtt_ts = tcp_time_now ();
1243 tc0->rtt_seq = tc0->snd_nxt;
1248 ELOG_TYPE_DECLARE (e) =
1251 "output: snd_una %u snd_una_max %u",.format_args =
1257 ed = ELOG_DATA (&vm->elog_main, e);
1258 ed->data[0] = tc0->snd_una - tc0->iss;
1259 ed->data[1] = tc0->snd_una_max - tc0->iss;
1263 /* Set the retransmit timer if not set already and not
1264 * doing a pure ACK */
1265 if (!tcp_timer_is_active (tc0, TCP_TIMER_RETRANSMIT)
1266 && tc0->snd_nxt != tc0->snd_una)
1268 tcp_retransmit_timer_set (tc0);
1272 /* set fib index to default and lookup node */
1273 /* XXX network virtualization (vrf/vni) */
1274 vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
1275 vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
1277 b0->flags |= VNET_BUFFER_LOCALLY_ORIGINATED;
1280 b0->error = error0 != 0 ? node->errors[error0] : 0;
1281 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1286 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1287 n_left_to_next, bi0, next0);
1290 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1293 return from_frame->n_vectors;
1297 tcp4_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1298 vlib_frame_t * from_frame)
1300 return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ );
1304 tcp6_output (vlib_main_t * vm, vlib_node_runtime_t * node,
1305 vlib_frame_t * from_frame)
1307 return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
1310 VLIB_REGISTER_NODE (tcp4_output_node) =
1312 .function = tcp4_output,.name = "tcp4-output",
1313 /* Takes a vector of packets. */
1314 .vector_size = sizeof (u32),.n_errors = TCP_N_ERROR,.error_strings =
1315 tcp_error_strings,.n_next_nodes = TCP_OUTPUT_N_NEXT,.next_nodes =
1317 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1318 foreach_tcp4_output_next
1321 ,.format_buffer = format_tcp_header,.format_trace = format_tcp_tx_trace,};
1323 VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output)
1324 VLIB_REGISTER_NODE (tcp6_output_node) =
1326 .function = tcp6_output,.name = "tcp6-output",
1327 /* Takes a vector of packets. */
1328 .vector_size = sizeof (u32),.n_errors = TCP_N_ERROR,.error_strings =
1329 tcp_error_strings,.n_next_nodes = TCP_OUTPUT_N_NEXT,.next_nodes =
1331 #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n,
1332 foreach_tcp6_output_next
1335 ,.format_buffer = format_tcp_header,.format_trace = format_tcp_tx_trace,};
1337 VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output) u32
1338 tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
1340 tcp_connection_t *tc;
1342 tc = (tcp_connection_t *) tconn;
1343 tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED);
1347 typedef enum _tcp_reset_next
1349 TCP_RESET_NEXT_DROP,
1350 TCP_RESET_NEXT_IP_LOOKUP,
1354 #define foreach_tcp4_reset_next \
1355 _(DROP, "error-drop") \
1356 _(IP_LOOKUP, "ip4-lookup")
1358 #define foreach_tcp6_reset_next \
1359 _(DROP, "error-drop") \
1360 _(IP_LOOKUP, "ip6-lookup")
1363 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
1364 vlib_frame_t * from_frame, u8 is_ip4)
1366 u32 n_left_from, next_index, *from, *to_next;
1367 u32 my_thread_index = vm->cpu_index;
1369 from = vlib_frame_vector_args (from_frame);
1370 n_left_from = from_frame->n_vectors;
1372 next_index = node->cached_next_index;
1374 while (n_left_from > 0)
1378 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
1380 while (n_left_from > 0 && n_left_to_next > 0)
1384 u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
1391 n_left_to_next -= 1;
1393 b0 = vlib_get_buffer (vm, bi0);
1395 if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
1396 my_thread_index, is_ip4))
1398 error0 = TCP_ERROR_LOOKUP_DROPS;
1399 next0 = TCP_RESET_NEXT_DROP;
1403 /* Prepare to send to IP lookup */
1404 vnet_buffer (b0)->sw_if_index[VLIB_TX] = 0;
1405 next0 = TCP_RESET_NEXT_IP_LOOKUP;
1408 b0->error = error0 != 0 ? node->errors[error0] : 0;
1409 b0->flags |= VNET_BUFFER_LOCALLY_ORIGINATED;
1410 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
1415 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1416 n_left_to_next, bi0, next0);
1418 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1420 return from_frame->n_vectors;
1424 tcp4_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1425 vlib_frame_t * from_frame)
1427 return tcp46_send_reset_inline (vm, node, from_frame, 1);
1431 tcp6_send_reset (vlib_main_t * vm, vlib_node_runtime_t * node,
1432 vlib_frame_t * from_frame)
1434 return tcp46_send_reset_inline (vm, node, from_frame, 0);
1438 VLIB_REGISTER_NODE (tcp4_reset_node) = {
1439 .function = tcp4_send_reset,
1440 .name = "tcp4-reset",
1441 .vector_size = sizeof (u32),
1442 .n_errors = TCP_N_ERROR,
1443 .error_strings = tcp_error_strings,
1444 .n_next_nodes = TCP_RESET_N_NEXT,
1446 #define _(s,n) [TCP_RESET_NEXT_##s] = n,
1447 foreach_tcp4_reset_next
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
1470 * fd.io coding-style-patch-verification: ON
1473 * eval: (c-set-style "gnu")