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-rw-r--r--src/vnet/tcp/tcp_input.c3215
1 files changed, 3215 insertions, 0 deletions
diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c
new file mode 100644
index 00000000..63d6fd87
--- /dev/null
+++ b/src/vnet/tcp/tcp_input.c
@@ -0,0 +1,3215 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vppinfra/sparse_vec.h>
+#include <vnet/tcp/tcp_packet.h>
+#include <vnet/tcp/tcp.h>
+#include <vnet/session/session.h>
+#include <math.h>
+
+static char *tcp_error_strings[] = {
+#define tcp_error(n,s) s,
+#include <vnet/tcp/tcp_error.def>
+#undef tcp_error
+};
+
+/* All TCP nodes have the same outgoing arcs */
+#define foreach_tcp_state_next \
+ _ (DROP, "error-drop") \
+ _ (TCP4_OUTPUT, "tcp4-output") \
+ _ (TCP6_OUTPUT, "tcp6-output")
+
+typedef enum _tcp_established_next
+{
+#define _(s,n) TCP_ESTABLISHED_NEXT_##s,
+ foreach_tcp_state_next
+#undef _
+ TCP_ESTABLISHED_N_NEXT,
+} tcp_established_next_t;
+
+typedef enum _tcp_rcv_process_next
+{
+#define _(s,n) TCP_RCV_PROCESS_NEXT_##s,
+ foreach_tcp_state_next
+#undef _
+ TCP_RCV_PROCESS_N_NEXT,
+} tcp_rcv_process_next_t;
+
+typedef enum _tcp_syn_sent_next
+{
+#define _(s,n) TCP_SYN_SENT_NEXT_##s,
+ foreach_tcp_state_next
+#undef _
+ TCP_SYN_SENT_N_NEXT,
+} tcp_syn_sent_next_t;
+
+typedef enum _tcp_listen_next
+{
+#define _(s,n) TCP_LISTEN_NEXT_##s,
+ foreach_tcp_state_next
+#undef _
+ TCP_LISTEN_N_NEXT,
+} tcp_listen_next_t;
+
+/* Generic, state independent indices */
+typedef enum _tcp_state_next
+{
+#define _(s,n) TCP_NEXT_##s,
+ foreach_tcp_state_next
+#undef _
+ TCP_STATE_N_NEXT,
+} tcp_state_next_t;
+
+#define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \
+ : TCP_NEXT_TCP6_OUTPUT)
+
+vlib_node_registration_t tcp4_established_node;
+vlib_node_registration_t tcp6_established_node;
+
+/**
+ * Validate segment sequence number. As per RFC793:
+ *
+ * Segment Receive Test
+ * Length Window
+ * ------- ------- -------------------------------------------
+ * 0 0 SEG.SEQ = RCV.NXT
+ * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
+ * >0 0 not acceptable
+ * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND
+ * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND
+ *
+ * This ultimately consists in checking if segment falls within the window.
+ * The one important difference compared to RFC793 is that we use rcv_las,
+ * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
+ * peer's reference when computing our receive window.
+ *
+ * This:
+ * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
+ * however, is too strict when we have retransmits. Instead we just check that
+ * the seq is not beyond the right edge and that the end of the segment is not
+ * less than the left edge.
+ *
+ * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
+ * use rcv_nxt in the right edge window test instead of rcv_las.
+ *
+ */
+always_inline u8
+tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
+{
+ return (seq_geq (end_seq, tc->rcv_las)
+ && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
+}
+
+/**
+ * Parse TCP header options.
+ *
+ * @param th TCP header
+ * @param to TCP options data structure to be populated
+ * @return -1 if parsing failed
+ */
+int
+tcp_options_parse (tcp_header_t * th, tcp_options_t * to)
+{
+ const u8 *data;
+ u8 opt_len, opts_len, kind;
+ int j;
+ sack_block_t b;
+
+ opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t);
+ data = (const u8 *) (th + 1);
+
+ /* Zero out all flags but those set in SYN */
+ to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE);
+
+ for (; opts_len > 0; opts_len -= opt_len, data += opt_len)
+ {
+ kind = data[0];
+
+ /* Get options length */
+ if (kind == TCP_OPTION_EOL)
+ break;
+ else if (kind == TCP_OPTION_NOOP)
+ {
+ opt_len = 1;
+ continue;
+ }
+ else
+ {
+ /* broken options */
+ if (opts_len < 2)
+ return -1;
+ opt_len = data[1];
+
+ /* weird option length */
+ if (opt_len < 2 || opt_len > opts_len)
+ return -1;
+ }
+
+ /* Parse options */
+ switch (kind)
+ {
+ case TCP_OPTION_MSS:
+ if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th))
+ {
+ to->flags |= TCP_OPTS_FLAG_MSS;
+ to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2));
+ }
+ break;
+ case TCP_OPTION_WINDOW_SCALE:
+ if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th))
+ {
+ to->flags |= TCP_OPTS_FLAG_WSCALE;
+ to->wscale = data[2];
+ if (to->wscale > TCP_MAX_WND_SCALE)
+ {
+ clib_warning ("Illegal window scaling value: %d",
+ to->wscale);
+ to->wscale = TCP_MAX_WND_SCALE;
+ }
+ }
+ break;
+ case TCP_OPTION_TIMESTAMP:
+ if (opt_len == TCP_OPTION_LEN_TIMESTAMP)
+ {
+ to->flags |= TCP_OPTS_FLAG_TSTAMP;
+ to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2));
+ to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6));
+ }
+ break;
+ case TCP_OPTION_SACK_PERMITTED:
+ if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th))
+ to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
+ break;
+ case TCP_OPTION_SACK_BLOCK:
+ /* If SACK permitted was not advertised or a SYN, break */
+ if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th))
+ break;
+
+ /* If too short or not correctly formatted, break */
+ if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK))
+ break;
+
+ to->flags |= TCP_OPTS_FLAG_SACK;
+ to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK;
+ vec_reset_length (to->sacks);
+ for (j = 0; j < to->n_sack_blocks; j++)
+ {
+ b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 8 * j));
+ b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 8 * j));
+ vec_add1 (to->sacks, b);
+ }
+ break;
+ default:
+ /* Nothing to see here */
+ continue;
+ }
+ }
+ return 0;
+}
+
+/**
+ * RFC1323: Check against wrapped sequence numbers (PAWS). If we have
+ * timestamp to echo and it's less than tsval_recent, drop segment
+ * but still send an ACK in order to retain TCP's mechanism for detecting
+ * and recovering from half-open connections
+ *
+ * Or at least that's what the theory says. It seems that this might not work
+ * very well with packet reordering and fast retransmit. XXX
+ */
+always_inline int
+tcp_segment_check_paws (tcp_connection_t * tc)
+{
+ return tcp_opts_tstamp (&tc->rcv_opts) && tc->tsval_recent
+ && timestamp_lt (tc->rcv_opts.tsval, tc->tsval_recent);
+}
+
+/**
+ * Update tsval recent
+ */
+always_inline void
+tcp_update_timestamp (tcp_connection_t * tc, u32 seq, u32 seq_end)
+{
+ /*
+ * RFC1323: If Last.ACK.sent falls within the range of sequence numbers
+ * of an incoming segment:
+ * SEG.SEQ <= Last.ACK.sent < SEG.SEQ + SEG.LEN
+ * then the TSval from the segment is copied to TS.Recent;
+ * otherwise, the TSval is ignored.
+ */
+ if (tcp_opts_tstamp (&tc->rcv_opts) && seq_leq (seq, tc->rcv_las)
+ && seq_leq (tc->rcv_las, seq_end))
+ {
+ ASSERT (timestamp_leq (tc->tsval_recent, tc->rcv_opts.tsval));
+ tc->tsval_recent = tc->rcv_opts.tsval;
+ tc->tsval_recent_age = tcp_time_now ();
+ }
+}
+
+/**
+ * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19
+ *
+ * It first verifies if segment has a wrapped sequence number (PAWS) and then
+ * does the processing associated to the first four steps (ignoring security
+ * and precedence): sequence number, rst bit and syn bit checks.
+ *
+ * @return 0 if segments passes validation.
+ */
+static int
+tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0,
+ vlib_buffer_t * b0, tcp_header_t * th0, u32 * next0)
+{
+ if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0)))
+ return -1;
+
+ if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts)))
+ {
+ clib_warning ("options parse error");
+ return -1;
+ }
+
+ if (tcp_segment_check_paws (tc0))
+ {
+ if (CLIB_DEBUG > 2)
+ {
+ clib_warning ("paws failed\n%U", format_tcp_connection, tc0, 2);
+ clib_warning ("seq %u seq_end %u ack %u",
+ vnet_buffer (b0)->tcp.seq_number - tc0->irs,
+ vnet_buffer (b0)->tcp.seq_end - tc0->irs,
+ vnet_buffer (b0)->tcp.ack_number - tc0->iss);
+ }
+ TCP_EVT_DBG (TCP_EVT_PAWS_FAIL, tc0, vnet_buffer (b0)->tcp.seq_number,
+ vnet_buffer (b0)->tcp.seq_end);
+
+ /* If it just so happens that a segment updates tsval_recent for a
+ * segment over 24 days old, invalidate tsval_recent. */
+ if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE,
+ tcp_time_now ()))
+ {
+ /* Age isn't reset until we get a valid tsval (bsd inspired) */
+ tc0->tsval_recent = 0;
+ clib_warning ("paws failed - really old segment. REALLY?");
+ }
+ else
+ {
+ /* Drop after ack if not rst */
+ if (!tcp_rst (th0))
+ {
+ tcp_make_ack (tc0, b0);
+ *next0 = tcp_next_output (tc0->c_is_ip4);
+ TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
+ return -1;
+ }
+ }
+ }
+
+ /* 1st: check sequence number */
+ if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
+ vnet_buffer (b0)->tcp.seq_end))
+ {
+ /* If our window is 0 and the packet is in sequence, let it pass
+ * through for ack processing. It should be dropped later.*/
+ if (tc0->rcv_wnd == 0
+ && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
+ {
+ /* TODO Should segment be tagged? */
+ }
+ else
+ {
+ /* If not RST, send dup ack */
+ if (!tcp_rst (th0))
+ {
+ tcp_make_ack (tc0, b0);
+ *next0 = tcp_next_output (tc0->c_is_ip4);
+ TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
+ }
+ return -1;
+ }
+ }
+
+ /* 2nd: check the RST bit */
+ if (tcp_rst (th0))
+ {
+ tcp_connection_reset (tc0);
+ return -1;
+ }
+
+ /* 3rd: check security and precedence (skip) */
+
+ /* 4th: check the SYN bit */
+ if (tcp_syn (th0))
+ {
+ /* TODO implement RFC 5961 */
+ if (tc0->state == TCP_STATE_SYN_RCVD)
+ {
+ tcp_make_synack (tc0, b0);
+ TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0);
+ }
+ else
+ {
+ tcp_make_ack (tc0, b0);
+ TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, tc0);
+ }
+ *next0 = tcp_next_output (tc0->c_is_ip4);
+ return -1;
+ }
+
+ /* If segment in window, save timestamp */
+ tcp_update_timestamp (tc0, vnet_buffer (b0)->tcp.seq_number,
+ vnet_buffer (b0)->tcp.seq_end);
+ return 0;
+}
+
+always_inline int
+tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
+{
+ /* SND.UNA =< SEG.ACK =< SND.NXT */
+ return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
+ && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
+}
+
+/**
+ * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298
+ *
+ * Note that although the original article, srtt and rttvar are scaled
+ * to minimize round-off errors, here we don't. Instead, we rely on
+ * better precision time measurements.
+ *
+ * TODO support us rtt resolution
+ */
+static void
+tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt)
+{
+ int err, diff;
+
+ if (tc->srtt != 0)
+ {
+ err = mrtt - tc->srtt;
+
+ /* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
+ * The increase should be bound */
+ tc->srtt = clib_max ((int) tc->srtt + (err >> 3), 1);
+ diff = (clib_abs (err) - (int) tc->rttvar) >> 2;
+ tc->rttvar = clib_max ((int) tc->rttvar + diff, 1);
+ }
+ else
+ {
+ /* First measurement. */
+ tc->srtt = mrtt;
+ tc->rttvar = mrtt >> 1;
+ }
+}
+
+void
+tcp_update_rto (tcp_connection_t * tc)
+{
+ tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
+ tc->rto = clib_max (tc->rto, TCP_RTO_MIN);
+}
+
+/**
+ * Update RTT estimate and RTO timer
+ *
+ * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK
+ * timing. Middle boxes are known to fiddle with TCP options so we
+ * should give higher priority to ACK timing.
+ *
+ * This should be called only if previously sent bytes have been acked.
+ *
+ * return 1 if valid rtt 0 otherwise
+ */
+static int
+tcp_update_rtt (tcp_connection_t * tc, u32 ack)
+{
+ u32 mrtt = 0;
+
+ /* Karn's rule, part 1. Don't use retransmitted segments to estimate
+ * RTT because they're ambiguous. */
+ if (tcp_in_cong_recovery (tc) || tc->sack_sb.sacked_bytes)
+ goto done;
+
+ if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq))
+ {
+ mrtt = tcp_time_now () - tc->rtt_ts;
+ }
+ /* As per RFC7323 TSecr can be used for RTTM only if the segment advances
+ * snd_una, i.e., the left side of the send window:
+ * seq_lt (tc->snd_una, ack). This is a condition for calling update_rtt */
+ else if (tcp_opts_tstamp (&tc->rcv_opts) && tc->rcv_opts.tsecr)
+ {
+ mrtt = tcp_time_now () - tc->rcv_opts.tsecr;
+ }
+
+ /* Ignore dubious measurements */
+ if (mrtt == 0 || mrtt > TCP_RTT_MAX)
+ goto done;
+
+ tcp_estimate_rtt (tc, mrtt);
+
+done:
+
+ /* Allow measuring of a new RTT */
+ tc->rtt_ts = 0;
+
+ /* If we got here something must've been ACKed so make sure boff is 0,
+ * even if mrrt is not valid since we update the rto lower */
+ tc->rto_boff = 0;
+ tcp_update_rto (tc);
+
+ return 0;
+}
+
+/**
+ * Dequeue bytes that have been acked and while at it update RTT estimates.
+ */
+static void
+tcp_dequeue_acked (tcp_connection_t * tc, u32 ack)
+{
+ /* Dequeue the newly ACKed add SACKed bytes */
+ stream_session_dequeue_drop (&tc->connection,
+ tc->bytes_acked + tc->sack_sb.snd_una_adv);
+
+ tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
+
+ /* Update rtt and rto */
+ tcp_update_rtt (tc, ack);
+
+ /* If everything has been acked, stop retransmit timer
+ * otherwise update. */
+ tcp_retransmit_timer_update (tc);
+}
+
+/**
+ * Check if duplicate ack as per RFC5681 Sec. 2
+ */
+static u8
+tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
+ u32 prev_snd_una)
+{
+ return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
+ && seq_gt (tc->snd_una_max, tc->snd_una)
+ && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
+ && (prev_snd_wnd == tc->snd_wnd));
+}
+
+/**
+ * Checks if ack is a congestion control event.
+ */
+static u8
+tcp_ack_is_cc_event (tcp_connection_t * tc, vlib_buffer_t * b,
+ u32 prev_snd_wnd, u32 prev_snd_una, u8 * is_dack)
+{
+ /* Check if ack is duplicate. Per RFC 6675, ACKs that SACK new data are
+ * defined to be 'duplicate' */
+ *is_dack = tc->sack_sb.last_sacked_bytes
+ || tcp_ack_is_dupack (tc, b, prev_snd_wnd, prev_snd_una);
+
+ return ((*is_dack || tcp_in_cong_recovery (tc)) && !tcp_is_lost_fin (tc));
+}
+
+void
+scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole)
+{
+ sack_scoreboard_hole_t *next, *prev;
+
+ if (hole->next != TCP_INVALID_SACK_HOLE_INDEX)
+ {
+ next = pool_elt_at_index (sb->holes, hole->next);
+ next->prev = hole->prev;
+ }
+ else
+ {
+ sb->tail = hole->prev;
+ }
+
+ if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX)
+ {
+ prev = pool_elt_at_index (sb->holes, hole->prev);
+ prev->next = hole->next;
+ }
+ else
+ {
+ sb->head = hole->next;
+ }
+
+ if (scoreboard_hole_index (sb, hole) == sb->cur_rxt_hole)
+ sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
+
+ /* Poison the entry */
+ if (CLIB_DEBUG > 0)
+ memset (hole, 0xfe, sizeof (*hole));
+
+ pool_put (sb->holes, hole);
+}
+
+sack_scoreboard_hole_t *
+scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
+ u32 start, u32 end)
+{
+ sack_scoreboard_hole_t *hole, *next, *prev;
+ u32 hole_index;
+
+ pool_get (sb->holes, hole);
+ memset (hole, 0, sizeof (*hole));
+
+ hole->start = start;
+ hole->end = end;
+ hole_index = scoreboard_hole_index (sb, hole);
+
+ prev = scoreboard_get_hole (sb, prev_index);
+ if (prev)
+ {
+ hole->prev = prev_index;
+ hole->next = prev->next;
+
+ if ((next = scoreboard_next_hole (sb, hole)))
+ next->prev = hole_index;
+ else
+ sb->tail = hole_index;
+
+ prev->next = hole_index;
+ }
+ else
+ {
+ sb->head = hole_index;
+ hole->prev = TCP_INVALID_SACK_HOLE_INDEX;
+ hole->next = TCP_INVALID_SACK_HOLE_INDEX;
+ }
+
+ return hole;
+}
+
+void
+scoreboard_update_bytes (tcp_connection_t * tc, sack_scoreboard_t * sb)
+{
+ sack_scoreboard_hole_t *hole, *prev;
+ u32 bytes = 0, blks = 0;
+
+ sb->lost_bytes = 0;
+ sb->sacked_bytes = 0;
+ hole = scoreboard_last_hole (sb);
+ if (!hole)
+ return;
+
+ if (seq_gt (sb->high_sacked, hole->end))
+ {
+ bytes = sb->high_sacked - hole->end;
+ blks = 1;
+ }
+
+ while ((prev = scoreboard_prev_hole (sb, hole))
+ && (bytes < (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss
+ && blks < TCP_DUPACK_THRESHOLD))
+ {
+ bytes += hole->start - prev->end;
+ blks++;
+ hole = prev;
+ }
+
+ while (hole)
+ {
+ sb->lost_bytes += scoreboard_hole_bytes (hole);
+ hole->is_lost = 1;
+ prev = hole;
+ hole = scoreboard_prev_hole (sb, hole);
+ if (hole)
+ bytes += prev->start - hole->end;
+ }
+ sb->sacked_bytes = bytes;
+}
+
+/**
+ * Figure out the next hole to retransmit
+ *
+ * Follows logic proposed in RFC6675 Sec. 4, NextSeg()
+ */
+sack_scoreboard_hole_t *
+scoreboard_next_rxt_hole (sack_scoreboard_t * sb,
+ sack_scoreboard_hole_t * start,
+ u8 have_sent_1_smss,
+ u8 * can_rescue, u8 * snd_limited)
+{
+ sack_scoreboard_hole_t *hole = 0;
+
+ hole = start ? start : scoreboard_first_hole (sb);
+ while (hole && seq_leq (hole->end, sb->high_rxt) && hole->is_lost)
+ hole = scoreboard_next_hole (sb, hole);
+
+ /* Nothing, return */
+ if (!hole)
+ {
+ sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
+ return 0;
+ }
+
+ /* Rule (1): if higher than rxt, less than high_sacked and lost */
+ if (hole->is_lost && seq_lt (hole->start, sb->high_sacked))
+ {
+ sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
+ }
+ else
+ {
+ /* Rule (2): output takes care of transmitting new data */
+ if (!have_sent_1_smss)
+ {
+ hole = 0;
+ sb->cur_rxt_hole = TCP_INVALID_SACK_HOLE_INDEX;
+ }
+ /* Rule (3): if hole not lost */
+ else if (seq_lt (hole->start, sb->high_sacked))
+ {
+ *snd_limited = 1;
+ sb->cur_rxt_hole = scoreboard_hole_index (sb, hole);
+ }
+ /* Rule (4): if hole beyond high_sacked */
+ else
+ {
+ ASSERT (seq_geq (hole->start, sb->high_sacked));
+ *snd_limited = 1;
+ *can_rescue = 1;
+ /* HighRxt MUST NOT be updated */
+ return 0;
+ }
+ }
+
+ if (hole && seq_lt (sb->high_rxt, hole->start))
+ sb->high_rxt = hole->start;
+
+ return hole;
+}
+
+void
+scoreboard_init_high_rxt (sack_scoreboard_t * sb, u32 seq)
+{
+ sack_scoreboard_hole_t *hole;
+ hole = scoreboard_first_hole (sb);
+ if (hole)
+ {
+ seq = seq_gt (seq, hole->start) ? seq : hole->start;
+ sb->cur_rxt_hole = sb->head;
+ }
+ sb->high_rxt = seq;
+}
+
+/**
+ * Test that scoreboard is sane after recovery
+ *
+ * Returns 1 if scoreboard is empty or if first hole beyond
+ * snd_una.
+ */
+u8
+tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
+{
+ sack_scoreboard_hole_t *hole;
+ hole = scoreboard_first_hole (&tc->sack_sb);
+ return (!hole || seq_geq (hole->start, tc->snd_una));
+}
+
+void
+tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
+{
+ sack_scoreboard_t *sb = &tc->sack_sb;
+ sack_block_t *blk, tmp;
+ sack_scoreboard_hole_t *hole, *next_hole, *last_hole;
+ u32 blk_index = 0, old_sacked_bytes, hole_index;
+ int i, j;
+
+ sb->last_sacked_bytes = 0;
+ sb->snd_una_adv = 0;
+ old_sacked_bytes = sb->sacked_bytes;
+ sb->last_bytes_delivered = 0;
+
+ if (!tcp_opts_sack (&tc->rcv_opts)
+ && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
+ return;
+
+ /* Remove invalid blocks */
+ blk = tc->rcv_opts.sacks;
+ while (blk < vec_end (tc->rcv_opts.sacks))
+ {
+ if (seq_lt (blk->start, blk->end)
+ && seq_gt (blk->start, tc->snd_una)
+ && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_una_max))
+ {
+ blk++;
+ continue;
+ }
+ vec_del1 (tc->rcv_opts.sacks, blk - tc->rcv_opts.sacks);
+ }
+
+ /* Add block for cumulative ack */
+ if (seq_gt (ack, tc->snd_una))
+ {
+ tmp.start = tc->snd_una;
+ tmp.end = ack;
+ vec_add1 (tc->rcv_opts.sacks, tmp);
+ }
+
+ if (vec_len (tc->rcv_opts.sacks) == 0)
+ return;
+
+ tcp_scoreboard_trace_add (tc, ack);
+
+ /* Make sure blocks are ordered */
+ for (i = 0; i < vec_len (tc->rcv_opts.sacks); i++)
+ for (j = i + 1; j < vec_len (tc->rcv_opts.sacks); j++)
+ if (seq_lt (tc->rcv_opts.sacks[j].start, tc->rcv_opts.sacks[i].start))
+ {
+ tmp = tc->rcv_opts.sacks[i];
+ tc->rcv_opts.sacks[i] = tc->rcv_opts.sacks[j];
+ tc->rcv_opts.sacks[j] = tmp;
+ }
+
+ if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
+ {
+ /* If no holes, insert the first that covers all outstanding bytes */
+ last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
+ tc->snd_una, tc->snd_una_max);
+ sb->tail = scoreboard_hole_index (sb, last_hole);
+ tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
+ sb->high_sacked = tmp.end;
+ }
+ else
+ {
+ /* If we have holes but snd_una_max is beyond the last hole, update
+ * last hole end */
+ tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
+ last_hole = scoreboard_last_hole (sb);
+ if (seq_gt (tc->snd_una_max, last_hole->end))
+ {
+ if (seq_geq (last_hole->start, sb->high_sacked))
+ {
+ last_hole->end = tc->snd_una_max;
+ }
+ /* New hole after high sacked block */
+ else if (seq_lt (sb->high_sacked, tc->snd_una_max))
+ {
+ scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
+ tc->snd_una_max);
+ }
+ }
+ /* Keep track of max byte sacked for when the last hole
+ * is acked */
+ if (seq_gt (tmp.end, sb->high_sacked))
+ sb->high_sacked = tmp.end;
+ }
+
+ /* Walk the holes with the SACK blocks */
+ hole = pool_elt_at_index (sb->holes, sb->head);
+ while (hole && blk_index < vec_len (tc->rcv_opts.sacks))
+ {
+ blk = &tc->rcv_opts.sacks[blk_index];
+ if (seq_leq (blk->start, hole->start))
+ {
+ /* Block covers hole. Remove hole */
+ if (seq_geq (blk->end, hole->end))
+ {
+ next_hole = scoreboard_next_hole (sb, hole);
+
+ /* Byte accounting: snd_una needs to be advanced */
+ if (blk->end == ack)
+ {
+ if (next_hole)
+ {
+ if (seq_lt (ack, next_hole->start))
+ sb->snd_una_adv = next_hole->start - ack;
+ sb->last_bytes_delivered +=
+ next_hole->start - hole->end;
+ }
+ else
+ {
+ ASSERT (seq_geq (sb->high_sacked, ack));
+ sb->snd_una_adv = sb->high_sacked - ack;
+ sb->last_bytes_delivered += sb->high_sacked - hole->end;
+ }
+ }
+
+ scoreboard_remove_hole (sb, hole);
+ hole = next_hole;
+ }
+ /* Partial 'head' overlap */
+ else
+ {
+ if (seq_gt (blk->end, hole->start))
+ {
+ hole->start = blk->end;
+ }
+ blk_index++;
+ }
+ }
+ else
+ {
+ /* Hole must be split */
+ if (seq_lt (blk->end, hole->end))
+ {
+ hole_index = scoreboard_hole_index (sb, hole);
+ next_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
+ hole->end);
+
+ /* Pool might've moved */
+ hole = scoreboard_get_hole (sb, hole_index);
+ hole->end = blk->start;
+ blk_index++;
+ ASSERT (hole->next == scoreboard_hole_index (sb, next_hole));
+ }
+ else if (seq_lt (blk->start, hole->end))
+ {
+ hole->end = blk->start;
+ }
+ hole = scoreboard_next_hole (sb, hole);
+ }
+ }
+
+ scoreboard_update_bytes (tc, sb);
+ sb->last_sacked_bytes = sb->sacked_bytes
+ - (old_sacked_bytes - sb->last_bytes_delivered);
+ ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes);
+ ASSERT (sb->sacked_bytes == 0
+ || sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
+ ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
+ - seq_max (tc->snd_una, ack));
+ ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
+ || sb->holes[sb->head].start == ack + sb->snd_una_adv);
+}
+
+/**
+ * Try to update snd_wnd based on feedback received from peer.
+ *
+ * If successful, and new window is 'effectively' 0, activate persist
+ * timer.
+ */
+static void
+tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
+{
+ /* If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set
+ * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */
+ if (seq_lt (tc->snd_wl1, seq)
+ || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
+ {
+ tc->snd_wnd = snd_wnd;
+ tc->snd_wl1 = seq;
+ tc->snd_wl2 = ack;
+ TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
+
+ if (tc->snd_wnd < tc->snd_mss)
+ {
+ /* Set persist timer if not set and we just got 0 wnd */
+ if (!tcp_timer_is_active (tc, TCP_TIMER_PERSIST)
+ && !tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))
+ tcp_persist_timer_set (tc);
+ }
+ else
+ {
+ tcp_persist_timer_reset (tc);
+ if (!tcp_in_recovery (tc) && tc->rto_boff > 0)
+ {
+ tc->rto_boff = 0;
+ tcp_update_rto (tc);
+ }
+ }
+ }
+}
+
+void
+tcp_cc_init_congestion (tcp_connection_t * tc)
+{
+ tcp_fastrecovery_on (tc);
+ tc->snd_congestion = tc->snd_una_max;
+ tc->cc_algo->congestion (tc);
+ TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
+}
+
+static void
+tcp_cc_recovery_exit (tcp_connection_t * tc)
+{
+ /* Deflate rto */
+ tc->rto_boff = 0;
+ tcp_update_rto (tc);
+ tc->snd_rxt_ts = 0;
+ tc->snd_nxt = tc->snd_una_max;
+ tcp_recovery_off (tc);
+ TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
+}
+
+void
+tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
+{
+ tc->cc_algo->recovered (tc);
+ tc->snd_rxt_bytes = 0;
+ tc->rcv_dupacks = 0;
+ tc->snd_nxt = tc->snd_una_max;
+ tcp_fastrecovery_off (tc);
+ tcp_fastrecovery_1_smss_off (tc);
+ TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
+}
+
+static void
+tcp_cc_congestion_undo (tcp_connection_t * tc)
+{
+ tc->cwnd = tc->prev_cwnd;
+ tc->ssthresh = tc->prev_ssthresh;
+ tc->snd_nxt = tc->snd_una_max;
+ tc->rcv_dupacks = 0;
+ if (tcp_in_recovery (tc))
+ tcp_cc_recovery_exit (tc);
+ ASSERT (tc->rto_boff == 0);
+ TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
+ /* TODO extend for fastrecovery */
+}
+
+static u8
+tcp_cc_is_spurious_retransmit (tcp_connection_t * tc)
+{
+ return (tcp_in_recovery (tc) && tc->rto_boff == 1
+ && tc->snd_rxt_ts
+ && tcp_opts_tstamp (&tc->rcv_opts)
+ && timestamp_lt (tc->rcv_opts.tsecr, tc->snd_rxt_ts));
+}
+
+int
+tcp_cc_recover (tcp_connection_t * tc)
+{
+ ASSERT (tcp_in_cong_recovery (tc));
+ if (tcp_cc_is_spurious_retransmit (tc))
+ {
+ tcp_cc_congestion_undo (tc);
+ return 1;
+ }
+
+ if (tcp_in_recovery (tc))
+ tcp_cc_recovery_exit (tc);
+ else if (tcp_in_fastrecovery (tc))
+ tcp_cc_fastrecovery_exit (tc);
+
+ ASSERT (tc->rto_boff == 0);
+ ASSERT (!tcp_in_cong_recovery (tc));
+ ASSERT (tcp_scoreboard_is_sane_post_recovery (tc));
+ return 0;
+}
+
+static void
+tcp_cc_update (tcp_connection_t * tc, vlib_buffer_t * b)
+{
+ ASSERT (!tcp_in_cong_recovery (tc) || tcp_is_lost_fin (tc));
+
+ /* Congestion avoidance */
+ tc->cc_algo->rcv_ack (tc);
+ tc->tsecr_last_ack = tc->rcv_opts.tsecr;
+
+ /* If a cumulative ack, make sure dupacks is 0 */
+ tc->rcv_dupacks = 0;
+
+ /* When dupacks hits the threshold we only enter fast retransmit if
+ * cumulative ack covers more than snd_congestion. Should snd_una
+ * wrap this test may fail under otherwise valid circumstances.
+ * Therefore, proactively update snd_congestion when wrap detected. */
+ if (PREDICT_FALSE
+ (seq_leq (tc->snd_congestion, tc->snd_una - tc->bytes_acked)
+ && seq_gt (tc->snd_congestion, tc->snd_una)))
+ tc->snd_congestion = tc->snd_una - 1;
+}
+
+static u8
+tcp_should_fastrecover_sack (tcp_connection_t * tc)
+{
+ return (TCP_DUPACK_THRESHOLD - 1) * tc->snd_mss < tc->sack_sb.sacked_bytes;
+}
+
+static u8
+tcp_should_fastrecover (tcp_connection_t * tc)
+{
+ return (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD
+ || tcp_should_fastrecover_sack (tc));
+}
+
+/**
+ * One function to rule them all ... and in the darkness bind them
+ */
+static void
+tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
+{
+ u32 rxt_delivered;
+
+ /*
+ * Duplicate ACK. Check if we should enter fast recovery, or if already in
+ * it account for the bytes that left the network.
+ */
+ if (is_dack)
+ {
+ ASSERT (tc->snd_una != tc->snd_una_max
+ || tc->sack_sb.last_sacked_bytes);
+
+ tc->rcv_dupacks++;
+
+ if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD && !tc->bytes_acked)
+ {
+ ASSERT (tcp_in_fastrecovery (tc));
+ /* Pure duplicate ack. If some data got acked, it's handled lower */
+ tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
+ return;
+ }
+ else if (tcp_should_fastrecover (tc))
+ {
+ /* Things are already bad */
+ if (tcp_in_cong_recovery (tc))
+ {
+ tc->rcv_dupacks = 0;
+ goto partial_ack_test;
+ }
+
+ /* If of of the two conditions lower hold, reset dupacks because
+ * we're probably after timeout (RFC6582 heuristics).
+ * If Cumulative ack does not cover more than congestion threshold,
+ * and:
+ * 1) The following doesn't hold: The congestion window is greater
+ * than SMSS bytes and the difference between highest_ack
+ * and prev_highest_ack is at most 4*SMSS bytes
+ * 2) Echoed timestamp in the last non-dup ack does not equal the
+ * stored timestamp
+ */
+ if (seq_leq (tc->snd_una, tc->snd_congestion)
+ && ((!(tc->cwnd > tc->snd_mss
+ && tc->bytes_acked <= 4 * tc->snd_mss))
+ || (tc->rcv_opts.tsecr != tc->tsecr_last_ack)))
+ {
+ tc->rcv_dupacks = 0;
+ return;
+ }
+
+ tcp_cc_init_congestion (tc);
+ tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
+
+ /* The first segment MUST be retransmitted */
+ tcp_retransmit_first_unacked (tc);
+
+ /* Post retransmit update cwnd to ssthresh and account for the
+ * three segments that have left the network and should've been
+ * buffered at the receiver XXX */
+ tc->cwnd = tc->ssthresh + tc->rcv_dupacks * tc->snd_mss;
+ ASSERT (tc->cwnd >= tc->snd_mss);
+
+ /* If cwnd allows, send more data */
+ if (tcp_opts_sack_permitted (&tc->rcv_opts))
+ {
+ scoreboard_init_high_rxt (&tc->sack_sb,
+ tc->snd_una + tc->snd_mss);
+ tcp_fast_retransmit_sack (tc);
+ }
+ else
+ {
+ tcp_fast_retransmit_no_sack (tc);
+ }
+
+ return;
+ }
+ else if (!tc->bytes_acked
+ || (tc->bytes_acked && !tcp_in_cong_recovery (tc)))
+ {
+ tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK);
+ return;
+ }
+ else
+ goto partial_ack;
+ }
+
+partial_ack_test:
+
+ if (!tc->bytes_acked)
+ return;
+
+partial_ack:
+ /*
+ * Legitimate ACK. 1) See if we can exit recovery
+ */
+ /* XXX limit this only to first partial ack? */
+ tcp_retransmit_timer_update (tc);
+
+ if (seq_geq (tc->snd_una, tc->snd_congestion))
+ {
+ /* If spurious return, we've already updated everything */
+ if (tcp_cc_recover (tc))
+ {
+ tc->tsecr_last_ack = tc->rcv_opts.tsecr;
+ return;
+ }
+
+ tc->snd_nxt = tc->snd_una_max;
+
+ /* Treat as congestion avoidance ack */
+ tc->cc_algo->rcv_ack (tc);
+ tc->tsecr_last_ack = tc->rcv_opts.tsecr;
+ return;
+ }
+
+ /*
+ * Legitimate ACK. 2) If PARTIAL ACK try to retransmit
+ */
+ TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
+
+ /* RFC6675: If the incoming ACK is a cumulative acknowledgment,
+ * reset dupacks to 0 */
+ tc->rcv_dupacks = 0;
+
+ tcp_retransmit_first_unacked (tc);
+
+ /* Post RTO timeout don't try anything fancy */
+ if (tcp_in_recovery (tc))
+ return;
+
+ /* Remove retransmitted bytes that have been delivered */
+ ASSERT (tc->bytes_acked + tc->sack_sb.snd_una_adv
+ >= tc->sack_sb.last_bytes_delivered
+ || (tc->flags & TCP_CONN_FINSNT));
+
+ if (seq_lt (tc->snd_una, tc->sack_sb.high_rxt))
+ {
+ /* If we have sacks and we haven't gotten an ack beyond high_rxt,
+ * remove sacked bytes delivered */
+ rxt_delivered = tc->bytes_acked + tc->sack_sb.snd_una_adv
+ - tc->sack_sb.last_bytes_delivered;
+ ASSERT (tc->snd_rxt_bytes >= rxt_delivered);
+ tc->snd_rxt_bytes -= rxt_delivered;
+ }
+ else
+ {
+ /* Either all retransmitted holes have been acked, or we're
+ * "in the blind" and retransmitting segment by segment */
+ tc->snd_rxt_bytes = 0;
+ }
+
+ tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
+
+ /*
+ * Since this was a partial ack, try to retransmit some more data
+ */
+ tcp_fast_retransmit (tc);
+}
+
+void
+tcp_cc_init (tcp_connection_t * tc)
+{
+ tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO);
+ tc->cc_algo->init (tc);
+}
+
+/**
+ * Process incoming ACK
+ */
+static int
+tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b,
+ tcp_header_t * th, u32 * next, u32 * error)
+{
+ u32 prev_snd_wnd, prev_snd_una;
+ u8 is_dack;
+
+ TCP_EVT_DBG (TCP_EVT_CC_STAT, tc);
+
+ /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
+ if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
+ {
+ /* If we have outstanding data and this is within the window, accept it,
+ * probably retransmit has timed out. Otherwise ACK segment and then
+ * drop it */
+ if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
+ {
+ tcp_make_ack (tc, b);
+ *next = tcp_next_output (tc->c_is_ip4);
+ *error = TCP_ERROR_ACK_INVALID;
+ TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
+ vnet_buffer (b)->tcp.ack_number);
+ return -1;
+ }
+
+ TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
+ vnet_buffer (b)->tcp.ack_number);
+
+ tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
+ *error = TCP_ERROR_ACK_FUTURE;
+ }
+
+ /* If old ACK, probably it's an old dupack */
+ if (PREDICT_FALSE (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)))
+ {
+ *error = TCP_ERROR_ACK_OLD;
+ TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
+ vnet_buffer (b)->tcp.ack_number);
+ if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
+ {
+ TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
+ tcp_cc_handle_event (tc, 1);
+ }
+ /* Don't drop yet */
+ return 0;
+ }
+
+ /*
+ * Looks okay, process feedback
+ */
+
+ if (tcp_opts_sack_permitted (&tc->rcv_opts))
+ tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
+
+ prev_snd_wnd = tc->snd_wnd;
+ prev_snd_una = tc->snd_una;
+ tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
+ vnet_buffer (b)->tcp.ack_number,
+ clib_net_to_host_u16 (th->window) << tc->snd_wscale);
+ tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
+ tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
+ tcp_validate_txf_size (tc, tc->bytes_acked);
+
+ if (tc->bytes_acked)
+ tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
+
+ TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
+
+ /*
+ * Check if we have congestion event
+ */
+
+ if (tcp_ack_is_cc_event (tc, b, prev_snd_wnd, prev_snd_una, &is_dack))
+ {
+ tcp_cc_handle_event (tc, is_dack);
+ if (!tcp_in_cong_recovery (tc))
+ return 0;
+ *error = TCP_ERROR_ACK_DUP;
+ TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
+ return vnet_buffer (b)->tcp.data_len ? 0 : -1;
+ }
+
+ /*
+ * Update congestion control (slow start/congestion avoidance)
+ */
+ tcp_cc_update (tc, b);
+
+ return 0;
+}
+
+static u8
+tcp_sack_vector_is_sane (sack_block_t * sacks)
+{
+ int i;
+ for (i = 1; i < vec_len (sacks); i++)
+ {
+ if (sacks[i - 1].end == sacks[i].start)
+ return 0;
+ }
+ return 1;
+}
+
+/**
+ * Build SACK list as per RFC2018.
+ *
+ * Makes sure the first block contains the segment that generated the current
+ * ACK and the following ones are the ones most recently reported in SACK
+ * blocks.
+ *
+ * @param tc TCP connection for which the SACK list is updated
+ * @param start Start sequence number of the newest SACK block
+ * @param end End sequence of the newest SACK block
+ */
+void
+tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
+{
+ sack_block_t *new_list = 0, *block = 0;
+ int i;
+
+ /* If the first segment is ooo add it to the list. Last write might've moved
+ * rcv_nxt over the first segment. */
+ if (seq_lt (tc->rcv_nxt, start))
+ {
+ vec_add2 (new_list, block, 1);
+ block->start = start;
+ block->end = end;
+ }
+
+ /* Find the blocks still worth keeping. */
+ for (i = 0; i < vec_len (tc->snd_sacks); i++)
+ {
+ /* Discard if rcv_nxt advanced beyond current block */
+ if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt))
+ continue;
+
+ /* Merge or drop if segment overlapped by the new segment */
+ if (block && (seq_geq (tc->snd_sacks[i].end, new_list[0].start)
+ && seq_leq (tc->snd_sacks[i].start, new_list[0].end)))
+ {
+ if (seq_lt (tc->snd_sacks[i].start, new_list[0].start))
+ new_list[0].start = tc->snd_sacks[i].start;
+ if (seq_lt (new_list[0].end, tc->snd_sacks[i].end))
+ new_list[0].end = tc->snd_sacks[i].end;
+ continue;
+ }
+
+ /* Save to new SACK list if we have space. */
+ if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
+ {
+ vec_add1 (new_list, tc->snd_sacks[i]);
+ }
+ else
+ {
+ clib_warning ("sack discarded");
+ }
+ }
+
+ ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
+
+ /* Replace old vector with new one */
+ vec_free (tc->snd_sacks);
+ tc->snd_sacks = new_list;
+
+ /* Segments should not 'touch' */
+ ASSERT (tcp_sack_vector_is_sane (tc->snd_sacks));
+}
+
+/** Enqueue data for delivery to application */
+always_inline int
+tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
+ u16 data_len)
+{
+ int written, error = TCP_ERROR_ENQUEUED;
+
+ ASSERT (seq_geq (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
+
+ /* Pure ACK. Update rcv_nxt and be done. */
+ if (PREDICT_FALSE (data_len == 0))
+ {
+ return TCP_ERROR_PURE_ACK;
+ }
+
+ written = stream_session_enqueue_data (&tc->connection, b, 0,
+ 1 /* queue event */ , 1);
+
+ TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
+
+ /* Update rcv_nxt */
+ if (PREDICT_TRUE (written == data_len))
+ {
+ tc->rcv_nxt += written;
+ }
+ /* If more data written than expected, account for out-of-order bytes. */
+ else if (written > data_len)
+ {
+ tc->rcv_nxt += written;
+
+ /* Send ACK confirming the update */
+ tc->flags |= TCP_CONN_SNDACK;
+ }
+ else if (written > 0)
+ {
+ /* We've written something but FIFO is probably full now */
+ tc->rcv_nxt += written;
+
+ /* Depending on how fast the app is, all remaining buffers in burst will
+ * not be enqueued. Inform peer */
+ tc->flags |= TCP_CONN_SNDACK;
+
+ error = TCP_ERROR_PARTIALLY_ENQUEUED;
+ }
+ else
+ {
+ tc->flags |= TCP_CONN_SNDACK;
+ return TCP_ERROR_FIFO_FULL;
+ }
+
+ /* Update SACK list if need be */
+ if (tcp_opts_sack_permitted (&tc->rcv_opts))
+ {
+ /* Remove SACK blocks that have been delivered */
+ tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
+ }
+
+ return error;
+}
+
+/** Enqueue out-of-order data */
+always_inline int
+tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
+ u16 data_len)
+{
+ stream_session_t *s0;
+ int rv, offset;
+
+ ASSERT (seq_gt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt));
+
+ /* Pure ACK. Do nothing */
+ if (PREDICT_FALSE (data_len == 0))
+ {
+ return TCP_ERROR_PURE_ACK;
+ }
+
+ /* Enqueue out-of-order data with relative offset */
+ rv = stream_session_enqueue_data (&tc->connection, b,
+ vnet_buffer (b)->tcp.seq_number -
+ tc->rcv_nxt, 0 /* queue event */ , 0);
+
+ /* Nothing written */
+ if (rv)
+ {
+ TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
+ return TCP_ERROR_FIFO_FULL;
+ }
+
+ TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
+
+ /* Update SACK list if in use */
+ if (tcp_opts_sack_permitted (&tc->rcv_opts))
+ {
+ ooo_segment_t *newest;
+ u32 start, end;
+
+ s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
+
+ /* Get the newest segment from the fifo */
+ newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
+ if (newest)
+ {
+ offset = ooo_segment_offset (s0->server_rx_fifo, newest);
+ ASSERT (offset <= vnet_buffer (b)->tcp.seq_number - tc->rcv_nxt);
+ start = tc->rcv_nxt + offset;
+ end = start + ooo_segment_length (s0->server_rx_fifo, newest);
+ tcp_update_sack_list (tc, start, end);
+ svm_fifo_newest_ooo_segment_reset (s0->server_rx_fifo);
+ }
+ }
+
+ return TCP_ERROR_ENQUEUED;
+}
+
+/**
+ * Check if ACK could be delayed. If ack can be delayed, it should return
+ * true for a full frame. If we're always acking return 0.
+ */
+always_inline int
+tcp_can_delack (tcp_connection_t * tc)
+{
+ /* Send ack if ... */
+ if (TCP_ALWAYS_ACK
+ /* just sent a rcv wnd 0 */
+ || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
+ /* constrained to send ack */
+ || (tc->flags & TCP_CONN_SNDACK) != 0
+ /* we're almost out of tx wnd */
+ || tcp_available_snd_space (tc) < 4 * tc->snd_mss)
+ return 0;
+
+ return 1;
+}
+
+static int
+tcp_buffer_discard_bytes (vlib_buffer_t * b, u32 n_bytes_to_drop)
+{
+ u32 discard, first = b->current_length;
+ vlib_main_t *vm = vlib_get_main ();
+
+ /* Handle multi-buffer segments */
+ if (n_bytes_to_drop > b->current_length)
+ {
+ if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
+ return -1;
+ do
+ {
+ discard = clib_min (n_bytes_to_drop, b->current_length);
+ vlib_buffer_advance (b, discard);
+ b = vlib_get_buffer (vm, b->next_buffer);
+ n_bytes_to_drop -= discard;
+ }
+ while (n_bytes_to_drop);
+ if (n_bytes_to_drop > first)
+ b->total_length_not_including_first_buffer -= n_bytes_to_drop - first;
+ }
+ else
+ vlib_buffer_advance (b, n_bytes_to_drop);
+ vnet_buffer (b)->tcp.data_len -= n_bytes_to_drop;
+ return 0;
+}
+
+static int
+tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b,
+ u32 * next0)
+{
+ u32 error = 0, n_bytes_to_drop, n_data_bytes;
+
+ vlib_buffer_advance (b, vnet_buffer (b)->tcp.data_offset);
+ n_data_bytes = vnet_buffer (b)->tcp.data_len;
+ ASSERT (n_data_bytes);
+
+ /* Handle out-of-order data */
+ if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
+ {
+ /* Old sequence numbers allowed through because they overlapped
+ * the rx window */
+ if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
+ {
+ error = TCP_ERROR_SEGMENT_OLD;
+ *next0 = TCP_NEXT_DROP;
+
+ /* Completely in the past (possible retransmit) */
+ if (seq_leq (vnet_buffer (b)->tcp.seq_end, tc->rcv_nxt))
+ {
+ /* Ack retransmissions since we may not have any data to send */
+ tcp_make_ack (tc, b);
+ *next0 = tcp_next_output (tc->c_is_ip4);
+ goto done;
+ }
+
+ /* Chop off the bytes in the past */
+ n_bytes_to_drop = tc->rcv_nxt - vnet_buffer (b)->tcp.seq_number;
+ n_data_bytes -= n_bytes_to_drop;
+ vnet_buffer (b)->tcp.seq_number = tc->rcv_nxt;
+ if (tcp_buffer_discard_bytes (b, n_bytes_to_drop))
+ goto done;
+
+ goto in_order;
+ }
+
+ error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
+
+ /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open
+ * cwnd on remote peer when congested 2) acks leaving should have the
+ * latest rcv_wnd since the burst may eaten up all of it, so only the
+ * old ones could be filtered.
+ */
+
+ /* RFC2581: Send DUPACK for fast retransmit */
+ tcp_make_ack (tc, b);
+ *next0 = tcp_next_output (tc->c_is_ip4);
+
+ /* Mark as DUPACK. We may filter these in output if
+ * the burst fills the holes. */
+ if (n_data_bytes)
+ vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
+
+ TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
+ goto done;
+ }
+
+in_order:
+
+ /* In order data, enqueue. Fifo figures out by itself if any out-of-order
+ * segments can be enqueued after fifo tail offset changes. */
+ error = tcp_session_enqueue_data (tc, b, n_data_bytes);
+
+ /* Check if ACK can be delayed */
+ if (tcp_can_delack (tc))
+ {
+ if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
+ tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
+ goto done;
+ }
+
+ *next0 = tcp_next_output (tc->c_is_ip4);
+ tcp_make_ack (tc, b);
+
+done:
+ return error;
+}
+
+typedef struct
+{
+ tcp_header_t tcp_header;
+ tcp_connection_t tcp_connection;
+} tcp_rx_trace_t;
+
+u8 *
+format_tcp_rx_trace (u8 * s, va_list * args)
+{
+ CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+ CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+ tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
+ uword indent = format_get_indent (s);
+
+ s = format (s, "%U\n%U%U",
+ format_tcp_header, &t->tcp_header, 128,
+ format_white_space, indent,
+ format_tcp_connection, &t->tcp_connection, 1);
+
+ return s;
+}
+
+u8 *
+format_tcp_rx_trace_short (u8 * s, va_list * args)
+{
+ CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+ CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+ tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *);
+
+ s = format (s, "%d -> %d (%U)",
+ clib_net_to_host_u16 (t->tcp_header.src_port),
+ clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state,
+ t->tcp_connection.state);
+
+ return s;
+}
+
+void
+tcp_set_rx_trace_data (tcp_rx_trace_t * t0, tcp_connection_t * tc0,
+ tcp_header_t * th0, vlib_buffer_t * b0, u8 is_ip4)
+{
+ if (tc0)
+ {
+ clib_memcpy (&t0->tcp_connection, tc0, sizeof (t0->tcp_connection));
+ }
+ else
+ {
+ th0 = tcp_buffer_hdr (b0);
+ }
+ clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
+}
+
+always_inline void
+tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
+{
+ if (PREDICT_TRUE (!val))
+ return;
+
+ if (is_ip4)
+ vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
+ else
+ vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
+}
+
+always_inline uword
+tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame, int is_ip4)
+{
+ u32 n_left_from, next_index, *from, *to_next;
+ u32 my_thread_index = vm->thread_index, errors = 0;
+ tcp_main_t *tm = vnet_get_tcp_main ();
+ u8 is_fin = 0;
+
+ from = vlib_frame_vector_args (from_frame);
+ n_left_from = from_frame->n_vectors;
+
+ next_index = node->cached_next_index;
+
+ while (n_left_from > 0)
+ {
+ u32 n_left_to_next;
+
+ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+ while (n_left_from > 0 && n_left_to_next > 0)
+ {
+ u32 bi0;
+ vlib_buffer_t *b0;
+ tcp_header_t *th0 = 0;
+ tcp_connection_t *tc0;
+ u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
+
+ bi0 = from[0];
+ to_next[0] = bi0;
+ from += 1;
+ to_next += 1;
+ n_left_from -= 1;
+ n_left_to_next -= 1;
+
+ b0 = vlib_get_buffer (vm, bi0);
+ tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
+ my_thread_index);
+
+ if (PREDICT_FALSE (tc0 == 0))
+ {
+ error0 = TCP_ERROR_INVALID_CONNECTION;
+ goto done;
+ }
+
+ th0 = tcp_buffer_hdr (b0);
+ /* N.B. buffer is rewritten if segment is ooo. Thus, th0 becomes a
+ * dangling reference. */
+ is_fin = tcp_is_fin (th0);
+
+ /* SYNs, FINs and data consume sequence numbers */
+ vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
+ + tcp_is_syn (th0) + is_fin + vnet_buffer (b0)->tcp.data_len;
+
+ /* TODO header prediction fast path */
+
+ /* 1-4: check SEQ, RST, SYN */
+ if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
+ {
+ error0 = TCP_ERROR_SEGMENT_INVALID;
+ TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
+ vnet_buffer (b0)->tcp.seq_number,
+ vnet_buffer (b0)->tcp.seq_end);
+ goto done;
+ }
+
+ /* 5: check the ACK field */
+ if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
+ goto done;
+
+ /* 6: check the URG bit TODO */
+
+ /* 7: process the segment text */
+ if (vnet_buffer (b0)->tcp.data_len)
+ error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
+
+ /* 8: check the FIN bit */
+ if (PREDICT_FALSE (is_fin))
+ {
+ /* Enter CLOSE-WAIT and notify session. To avoid lingering
+ * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
+ /* Account for the FIN if nothing else was received */
+ if (vnet_buffer (b0)->tcp.data_len == 0)
+ tc0->rcv_nxt += 1;
+ tcp_make_ack (tc0, b0);
+ next0 = tcp_next_output (tc0->c_is_ip4);
+ tc0->state = TCP_STATE_CLOSE_WAIT;
+ stream_session_disconnect_notify (&tc0->connection);
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
+ TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
+ }
+
+ done:
+ b0->error = node->errors[error0];
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ tcp_rx_trace_t *t0 =
+ vlib_add_trace (vm, node, b0, sizeof (*t0));
+ tcp_set_rx_trace_data (t0, tc0, th0, b0, is_ip4);
+ }
+
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+ n_left_to_next, bi0, next0);
+ }
+
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ }
+
+ errors = session_manager_flush_enqueue_events (my_thread_index);
+ tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
+ tcp_flush_frame_to_output (vm, my_thread_index, is_ip4);
+
+ return from_frame->n_vectors;
+}
+
+static uword
+tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ );
+}
+
+static uword
+tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp4_established_node) =
+{
+ .function = tcp4_established,
+ .name = "tcp4-established",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
+ foreach_tcp_state_next
+#undef _
+ },
+ .format_trace = format_tcp_rx_trace_short,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established);
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp6_established_node) =
+{
+ .function = tcp6_established,
+ .name = "tcp6-established",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_ESTABLISHED_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n,
+ foreach_tcp_state_next
+#undef _
+ },
+ .format_trace = format_tcp_rx_trace_short,
+};
+/* *INDENT-ON* */
+
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established);
+
+vlib_node_registration_t tcp4_syn_sent_node;
+vlib_node_registration_t tcp6_syn_sent_node;
+
+static u8
+tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr)
+{
+ transport_connection_t *tmp;
+ if (!tc)
+ return 1;
+
+ u8 is_valid = (tc->c_lcl_port == hdr->dst_port
+ && (tc->state == TCP_STATE_LISTEN
+ || tc->c_rmt_port == hdr->src_port));
+
+ if (!is_valid)
+ {
+ if ((tmp =
+ stream_session_half_open_lookup (&tc->c_lcl_ip, &tc->c_rmt_ip,
+ tc->c_lcl_port, tc->c_rmt_port,
+ tc->c_transport_proto)))
+ {
+ if (tmp->lcl_port == hdr->dst_port
+ && tmp->rmt_port == hdr->src_port)
+ {
+ clib_warning ("half-open is valid!");
+ }
+ }
+ }
+ return is_valid;
+}
+
+/**
+ * Lookup transport connection
+ */
+static tcp_connection_t *
+tcp_lookup_connection (vlib_buffer_t * b, u8 thread_index, u8 is_ip4)
+{
+ tcp_header_t *tcp;
+ transport_connection_t *tconn;
+ tcp_connection_t *tc;
+ if (is_ip4)
+ {
+ ip4_header_t *ip4;
+ ip4 = vlib_buffer_get_current (b);
+ tcp = ip4_next_header (ip4);
+ tconn = stream_session_lookup_transport_wt4 (&ip4->dst_address,
+ &ip4->src_address,
+ tcp->dst_port,
+ tcp->src_port,
+ SESSION_TYPE_IP4_TCP,
+ thread_index);
+ tc = tcp_get_connection_from_transport (tconn);
+ ASSERT (tcp_lookup_is_valid (tc, tcp));
+ }
+ else
+ {
+ ip6_header_t *ip6;
+ ip6 = vlib_buffer_get_current (b);
+ tcp = ip6_next_header (ip6);
+ tconn = stream_session_lookup_transport_wt6 (&ip6->dst_address,
+ &ip6->src_address,
+ tcp->dst_port,
+ tcp->src_port,
+ SESSION_TYPE_IP6_TCP,
+ thread_index);
+ tc = tcp_get_connection_from_transport (tconn);
+ ASSERT (tcp_lookup_is_valid (tc, tcp));
+ }
+ return tc;
+}
+
+always_inline uword
+tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame, int is_ip4)
+{
+ tcp_main_t *tm = vnet_get_tcp_main ();
+ u32 n_left_from, next_index, *from, *to_next;
+ u32 my_thread_index = vm->thread_index, errors = 0;
+
+ from = vlib_frame_vector_args (from_frame);
+ n_left_from = from_frame->n_vectors;
+
+ next_index = node->cached_next_index;
+
+ while (n_left_from > 0)
+ {
+ u32 n_left_to_next;
+
+ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+ while (n_left_from > 0 && n_left_to_next > 0)
+ {
+ u32 bi0, ack0, seq0;
+ vlib_buffer_t *b0;
+ tcp_rx_trace_t *t0;
+ tcp_header_t *tcp0 = 0;
+ tcp_connection_t *tc0;
+ tcp_connection_t *new_tc0;
+ u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
+
+ bi0 = from[0];
+ to_next[0] = bi0;
+ from += 1;
+ to_next += 1;
+ n_left_from -= 1;
+ n_left_to_next -= 1;
+
+ b0 = vlib_get_buffer (vm, bi0);
+ tc0 =
+ tcp_half_open_connection_get (vnet_buffer (b0)->
+ tcp.connection_index);
+ if (PREDICT_FALSE (tc0 == 0))
+ {
+ error0 = TCP_ERROR_INVALID_CONNECTION;
+ goto drop;
+ }
+
+ /* Half-open completed recently but the connection was't removed
+ * yet by the owning thread */
+ if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE))
+ {
+ /* Make sure the connection actually exists */
+ ASSERT (tcp_lookup_connection (b0, my_thread_index, is_ip4));
+ goto drop;
+ }
+
+ ack0 = vnet_buffer (b0)->tcp.ack_number;
+ seq0 = vnet_buffer (b0)->tcp.seq_number;
+ tcp0 = tcp_buffer_hdr (b0);
+
+ /* Crude check to see if the connection handle does not match
+ * the packet. Probably connection just switched to established */
+ if (PREDICT_FALSE (tcp0->dst_port != tc0->c_lcl_port
+ || tcp0->src_port != tc0->c_rmt_port))
+ goto drop;
+
+ if (PREDICT_FALSE
+ (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0)))
+ goto drop;
+
+ /* SYNs, FINs and data consume sequence numbers */
+ vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0)
+ + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len;
+
+ /*
+ * 1. check the ACK bit
+ */
+
+ /*
+ * If the ACK bit is set
+ * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless
+ * the RST bit is set, if so drop the segment and return)
+ * <SEQ=SEG.ACK><CTL=RST>
+ * and discard the segment. Return.
+ * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable.
+ */
+ if (tcp_ack (tcp0))
+ {
+ if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt))
+ {
+ clib_warning ("ack not in rcv wnd");
+ if (!tcp_rst (tcp0))
+ tcp_send_reset_w_pkt (tc0, b0, is_ip4);
+ goto drop;
+ }
+
+ /* Make sure ACK is valid */
+ if (seq_gt (tc0->snd_una, ack0))
+ {
+ clib_warning ("ack invalid");
+ goto drop;
+ }
+ }
+
+ /*
+ * 2. check the RST bit
+ */
+
+ if (tcp_rst (tcp0))
+ {
+ /* If ACK is acceptable, signal client that peer is not
+ * willing to accept connection and drop connection*/
+ if (tcp_ack (tcp0))
+ tcp_connection_reset (tc0);
+ goto drop;
+ }
+
+ /*
+ * 3. check the security and precedence (skipped)
+ */
+
+ /*
+ * 4. check the SYN bit
+ */
+
+ /* No SYN flag. Drop. */
+ if (!tcp_syn (tcp0))
+ {
+ clib_warning ("not synack");
+ goto drop;
+ }
+
+ /* Parse options */
+ if (tcp_options_parse (tcp0, &tc0->rcv_opts))
+ {
+ clib_warning ("options parse fail");
+ goto drop;
+ }
+
+ /* Valid SYN or SYN-ACK. Move connection from half-open pool to
+ * current thread pool. */
+ pool_get (tm->connections[my_thread_index], new_tc0);
+ clib_memcpy (new_tc0, tc0, sizeof (*new_tc0));
+ new_tc0->c_c_index = new_tc0 - tm->connections[my_thread_index];
+ new_tc0->c_thread_index = my_thread_index;
+ new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end;
+ new_tc0->irs = seq0;
+ new_tc0->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
+ new_tc0->timers[TCP_TIMER_RETRANSMIT_SYN] =
+ TCP_TIMER_HANDLE_INVALID;
+
+ /* If this is not the owning thread, wait for syn retransmit to
+ * expire and cleanup then */
+ if (tcp_half_open_connection_cleanup (tc0))
+ tc0->flags |= TCP_CONN_HALF_OPEN_DONE;
+
+ if (tcp_opts_tstamp (&new_tc0->rcv_opts))
+ {
+ new_tc0->tsval_recent = new_tc0->rcv_opts.tsval;
+ new_tc0->tsval_recent_age = tcp_time_now ();
+ }
+
+ if (tcp_opts_wscale (&new_tc0->rcv_opts))
+ new_tc0->snd_wscale = new_tc0->rcv_opts.wscale;
+
+ /* RFC1323: SYN and SYN-ACK wnd not scaled */
+ new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
+ new_tc0->snd_wl1 = seq0;
+ new_tc0->snd_wl2 = ack0;
+
+ tcp_connection_init_vars (new_tc0);
+
+ /* SYN-ACK: See if we can switch to ESTABLISHED state */
+ if (PREDICT_TRUE (tcp_ack (tcp0)))
+ {
+ /* Our SYN is ACKed: we have iss < ack = snd_una */
+
+ /* TODO Dequeue acknowledged segments if we support Fast Open */
+ new_tc0->snd_una = ack0;
+ new_tc0->state = TCP_STATE_ESTABLISHED;
+
+ /* Make sure las is initialized for the wnd computation */
+ new_tc0->rcv_las = new_tc0->rcv_nxt;
+
+ /* Notify app that we have connection. If session layer can't
+ * allocate session send reset */
+ if (stream_session_connect_notify (&new_tc0->connection, 0))
+ {
+ clib_warning ("connect notify fail");
+ tcp_send_reset_w_pkt (new_tc0, b0, is_ip4);
+ tcp_connection_cleanup (new_tc0);
+ goto drop;
+ }
+
+ /* Make sure after data segment processing ACK is sent */
+ new_tc0->flags |= TCP_CONN_SNDACK;
+
+ /* Update rtt with the syn-ack sample */
+ tcp_update_rtt (new_tc0, vnet_buffer (b0)->tcp.ack_number);
+ TCP_EVT_DBG (TCP_EVT_SYNACK_RCVD, new_tc0);
+ }
+ /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */
+ else
+ {
+ new_tc0->state = TCP_STATE_SYN_RCVD;
+
+ /* Notify app that we have connection */
+ if (stream_session_connect_notify (&new_tc0->connection, 0))
+ {
+ tcp_connection_cleanup (new_tc0);
+ tcp_send_reset_w_pkt (tc0, b0, is_ip4);
+ TCP_EVT_DBG (TCP_EVT_RST_SENT, tc0);
+ goto drop;
+ }
+
+ tc0->rtt_ts = 0;
+ tcp_init_snd_vars (tc0);
+ tcp_make_synack (new_tc0, b0);
+ next0 = tcp_next_output (is_ip4);
+
+ goto drop;
+ }
+
+ /* Read data, if any */
+ if (PREDICT_FALSE (vnet_buffer (b0)->tcp.data_len))
+ {
+ ASSERT (0);
+ error0 = tcp_segment_rcv (tm, new_tc0, b0, &next0);
+ if (error0 == TCP_ERROR_PURE_ACK)
+ error0 = TCP_ERROR_SYN_ACKS_RCVD;
+ }
+ else
+ {
+ tcp_make_ack (new_tc0, b0);
+ next0 = tcp_next_output (new_tc0->c_is_ip4);
+ }
+
+ drop:
+
+ b0->error = error0 ? node->errors[error0] : 0;
+ if (PREDICT_FALSE
+ ((b0->flags & VLIB_BUFFER_IS_TRACED) && tcp0 != 0))
+ {
+ t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
+ clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header));
+ clib_memcpy (&t0->tcp_connection, tc0,
+ sizeof (t0->tcp_connection));
+ }
+
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+ n_left_to_next, bi0, next0);
+ }
+
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ }
+
+ errors = session_manager_flush_enqueue_events (my_thread_index);
+ if (errors)
+ {
+ if (is_ip4)
+ vlib_node_increment_counter (vm, tcp4_established_node.index,
+ TCP_ERROR_EVENT_FIFO_FULL, errors);
+ else
+ vlib_node_increment_counter (vm, tcp6_established_node.index,
+ TCP_ERROR_EVENT_FIFO_FULL, errors);
+ }
+
+ return from_frame->n_vectors;
+}
+
+static uword
+tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ );
+}
+
+static uword
+tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp4_syn_sent_node) =
+{
+ .function = tcp4_syn_sent,
+ .name = "tcp4-syn-sent",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_SYN_SENT_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
+ foreach_tcp_state_next
+#undef _
+ },
+ .format_trace = format_tcp_rx_trace_short,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent);
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp6_syn_sent_node) =
+{
+ .function = tcp6_syn_sent_rcv,
+ .name = "tcp6-syn-sent",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_SYN_SENT_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n,
+ foreach_tcp_state_next
+#undef _
+ },
+ .format_trace = format_tcp_rx_trace_short,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
+
+/**
+ * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
+ * as per RFC793 p. 64
+ */
+always_inline uword
+tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame, int is_ip4)
+{
+ tcp_main_t *tm = vnet_get_tcp_main ();
+ u32 n_left_from, next_index, *from, *to_next;
+ u32 my_thread_index = vm->thread_index, errors = 0;
+
+ from = vlib_frame_vector_args (from_frame);
+ n_left_from = from_frame->n_vectors;
+
+ next_index = node->cached_next_index;
+
+ while (n_left_from > 0)
+ {
+ u32 n_left_to_next;
+
+ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+ while (n_left_from > 0 && n_left_to_next > 0)
+ {
+ u32 bi0;
+ vlib_buffer_t *b0;
+ tcp_header_t *tcp0 = 0;
+ tcp_connection_t *tc0;
+ u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED;
+ u8 is_fin0;
+
+ bi0 = from[0];
+ to_next[0] = bi0;
+ from += 1;
+ to_next += 1;
+ n_left_from -= 1;
+ n_left_to_next -= 1;
+
+ b0 = vlib_get_buffer (vm, bi0);
+ tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
+ my_thread_index);
+ if (PREDICT_FALSE (tc0 == 0))
+ {
+ error0 = TCP_ERROR_INVALID_CONNECTION;
+ goto drop;
+ }
+
+ tcp0 = tcp_buffer_hdr (b0);
+ is_fin0 = tcp_is_fin (tcp0);
+
+ /* SYNs, FINs and data consume sequence numbers */
+ vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number
+ + tcp_is_syn (tcp0) + is_fin0 + vnet_buffer (b0)->tcp.data_len;
+
+ if (CLIB_DEBUG)
+ {
+ tcp_connection_t *tmp;
+ tmp = tcp_lookup_connection (b0, my_thread_index, is_ip4);
+ if (tmp->state != tc0->state)
+ {
+ clib_warning ("state changed");
+ ASSERT (0);
+ goto drop;
+ }
+ }
+
+ /*
+ * Special treatment for CLOSED
+ */
+ switch (tc0->state)
+ {
+ case TCP_STATE_CLOSED:
+ goto drop;
+ break;
+ }
+
+ /*
+ * For all other states (except LISTEN)
+ */
+
+ /* 1-4: check SEQ, RST, SYN */
+ if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0,
+ &next0)))
+ {
+ error0 = TCP_ERROR_SEGMENT_INVALID;
+ goto drop;
+ }
+
+ /* 5: check the ACK field */
+ switch (tc0->state)
+ {
+ case TCP_STATE_SYN_RCVD:
+ /*
+ * If the segment acknowledgment is not acceptable, form a
+ * reset segment,
+ * <SEQ=SEG.ACK><CTL=RST>
+ * and send it.
+ */
+ if (!tcp_rcv_ack_is_acceptable (tc0, b0))
+ {
+ clib_warning ("connection not accepted");
+ tcp_send_reset_w_pkt (tc0, b0, is_ip4);
+ goto drop;
+ }
+
+ /* Update rtt and rto */
+ tcp_update_rtt (tc0, vnet_buffer (b0)->tcp.ack_number);
+
+ /* Switch state to ESTABLISHED */
+ tc0->state = TCP_STATE_ESTABLISHED;
+
+ /* Initialize session variables */
+ tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
+ tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
+ << tc0->rcv_opts.wscale;
+ tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
+ tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
+ stream_session_accept_notify (&tc0->connection);
+
+ /* Reset SYN-ACK retransmit and SYN_RCV establish timers */
+ tcp_retransmit_timer_reset (tc0);
+ tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH);
+ TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
+ break;
+ case TCP_STATE_ESTABLISHED:
+ /* We can get packets in established state here because they
+ * were enqueued before state change */
+ if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
+ goto drop;
+
+ break;
+ case TCP_STATE_FIN_WAIT_1:
+ /* In addition to the processing for the ESTABLISHED state, if
+ * our FIN is now acknowledged then enter FIN-WAIT-2 and
+ * continue processing in that state. */
+ if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
+ goto drop;
+
+ /* Still have to send the FIN */
+ if (tc0->flags & TCP_CONN_FINPNDG)
+ {
+ /* TX fifo finally drained */
+ if (!stream_session_tx_fifo_max_dequeue (&tc0->connection))
+ tcp_send_fin (tc0);
+ }
+ /* If FIN is ACKed */
+ else if (tc0->snd_una == tc0->snd_una_max)
+ {
+ tc0->state = TCP_STATE_FIN_WAIT_2;
+ TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
+
+ /* Stop all retransmit timers because we have nothing more
+ * to send. Enable waitclose though because we're willing to
+ * wait for peer's FIN but not indefinitely. */
+ tcp_connection_timers_reset (tc0);
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
+ }
+ break;
+ case TCP_STATE_FIN_WAIT_2:
+ /* In addition to the processing for the ESTABLISHED state, if
+ * the retransmission queue is empty, the user's CLOSE can be
+ * acknowledged ("ok") but do not delete the TCB. */
+ if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
+ goto drop;
+ break;
+ case TCP_STATE_CLOSE_WAIT:
+ /* Do the same processing as for the ESTABLISHED state. */
+ if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
+ goto drop;
+ break;
+ case TCP_STATE_CLOSING:
+ /* In addition to the processing for the ESTABLISHED state, if
+ * the ACK acknowledges our FIN then enter the TIME-WAIT state,
+ * otherwise ignore the segment. */
+ if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
+ goto drop;
+
+ tc0->state = TCP_STATE_TIME_WAIT;
+ TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
+ goto drop;
+
+ break;
+ case TCP_STATE_LAST_ACK:
+ /* The only thing that [should] arrive in this state is an
+ * acknowledgment of our FIN. If our FIN is now acknowledged,
+ * delete the TCB, enter the CLOSED state, and return. */
+
+ if (!tcp_rcv_ack_is_acceptable (tc0, b0))
+ goto drop;
+
+ tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
+ /* Apparently our FIN was lost */
+ if (is_fin0)
+ {
+ tcp_send_fin (tc0);
+ goto drop;
+ }
+
+ tc0->state = TCP_STATE_CLOSED;
+ TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
+
+ /* Don't delete the connection/session yet. Instead, wait a
+ * reasonable amount of time until the pipes are cleared. In
+ * particular, this makes sure that we won't have dead sessions
+ * when processing events on the tx path */
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
+ tcp_retransmit_timer_reset (tc0);
+
+ goto drop;
+
+ break;
+ case TCP_STATE_TIME_WAIT:
+ /* The only thing that can arrive in this state is a
+ * retransmission of the remote FIN. Acknowledge it, and restart
+ * the 2 MSL timeout. */
+
+ if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
+ goto drop;
+
+ tcp_make_ack (tc0, b0);
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
+
+ goto drop;
+
+ break;
+ default:
+ ASSERT (0);
+ }
+
+ /* 6: check the URG bit TODO */
+
+ /* 7: process the segment text */
+ switch (tc0->state)
+ {
+ case TCP_STATE_ESTABLISHED:
+ case TCP_STATE_FIN_WAIT_1:
+ case TCP_STATE_FIN_WAIT_2:
+ if (vnet_buffer (b0)->tcp.data_len)
+ error0 = tcp_segment_rcv (tm, tc0, b0, &next0);
+ else if (is_fin0)
+ tc0->rcv_nxt += 1;
+ break;
+ case TCP_STATE_CLOSE_WAIT:
+ case TCP_STATE_CLOSING:
+ case TCP_STATE_LAST_ACK:
+ case TCP_STATE_TIME_WAIT:
+ /* This should not occur, since a FIN has been received from the
+ * remote side. Ignore the segment text. */
+ break;
+ }
+
+ /* 8: check the FIN bit */
+ if (!is_fin0)
+ goto drop;
+
+ switch (tc0->state)
+ {
+ case TCP_STATE_ESTABLISHED:
+ case TCP_STATE_SYN_RCVD:
+ /* Send FIN-ACK notify app and enter CLOSE-WAIT */
+ tcp_connection_timers_reset (tc0);
+ tcp_make_fin (tc0, b0);
+ tc0->snd_nxt += 1;
+ next0 = tcp_next_output (tc0->c_is_ip4);
+ stream_session_disconnect_notify (&tc0->connection);
+ tc0->state = TCP_STATE_CLOSE_WAIT;
+ TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
+ break;
+ case TCP_STATE_CLOSE_WAIT:
+ case TCP_STATE_CLOSING:
+ case TCP_STATE_LAST_ACK:
+ /* move along .. */
+ break;
+ case TCP_STATE_FIN_WAIT_1:
+ tc0->state = TCP_STATE_CLOSING;
+ tcp_make_ack (tc0, b0);
+ next0 = tcp_next_output (is_ip4);
+ TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
+ /* Wait for ACK but not forever */
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
+ break;
+ case TCP_STATE_FIN_WAIT_2:
+ /* Got FIN, send ACK! Be more aggressive with resource cleanup */
+ tc0->state = TCP_STATE_TIME_WAIT;
+ tcp_connection_timers_reset (tc0);
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
+ tcp_make_ack (tc0, b0);
+ next0 = tcp_next_output (is_ip4);
+ TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0);
+ break;
+ case TCP_STATE_TIME_WAIT:
+ /* Remain in the TIME-WAIT state. Restart the time-wait
+ * timeout.
+ */
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_TIMEWAIT_TIME);
+ break;
+ }
+ TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
+
+ drop:
+ b0->error = error0 ? node->errors[error0] : 0;
+
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ tcp_rx_trace_t *t0 =
+ vlib_add_trace (vm, node, b0, sizeof (*t0));
+ tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
+ }
+
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+ n_left_to_next, bi0, next0);
+ }
+
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ }
+
+ errors = session_manager_flush_enqueue_events (my_thread_index);
+ if (errors)
+ {
+ if (is_ip4)
+ vlib_node_increment_counter (vm, tcp4_established_node.index,
+ TCP_ERROR_EVENT_FIFO_FULL, errors);
+ else
+ vlib_node_increment_counter (vm, tcp6_established_node.index,
+ TCP_ERROR_EVENT_FIFO_FULL, errors);
+ }
+
+ return from_frame->n_vectors;
+}
+
+static uword
+tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ );
+}
+
+static uword
+tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp4_rcv_process_node) =
+{
+ .function = tcp4_rcv_process,
+ .name = "tcp4-rcv-process",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
+ foreach_tcp_state_next
+#undef _
+ },
+ .format_trace = format_tcp_rx_trace_short,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process);
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp6_rcv_process_node) =
+{
+ .function = tcp6_rcv_process,
+ .name = "tcp6-rcv-process",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_RCV_PROCESS_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n,
+ foreach_tcp_state_next
+#undef _
+ },
+ .format_trace = format_tcp_rx_trace_short,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process);
+
+vlib_node_registration_t tcp4_listen_node;
+vlib_node_registration_t tcp6_listen_node;
+
+/**
+ * LISTEN state processing as per RFC 793 p. 65
+ */
+always_inline uword
+tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame, int is_ip4)
+{
+ u32 n_left_from, next_index, *from, *to_next;
+ u32 my_thread_index = vm->thread_index;
+ u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
+
+ from = vlib_frame_vector_args (from_frame);
+ n_left_from = from_frame->n_vectors;
+
+ next_index = node->cached_next_index;
+
+ while (n_left_from > 0)
+ {
+ u32 n_left_to_next;
+
+ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+ while (n_left_from > 0 && n_left_to_next > 0)
+ {
+ u32 bi0;
+ vlib_buffer_t *b0;
+ tcp_rx_trace_t *t0;
+ tcp_header_t *th0 = 0;
+ tcp_connection_t *lc0;
+ ip4_header_t *ip40;
+ ip6_header_t *ip60;
+ tcp_connection_t *child0;
+ u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP;
+
+ bi0 = from[0];
+ to_next[0] = bi0;
+ from += 1;
+ to_next += 1;
+ n_left_from -= 1;
+ n_left_to_next -= 1;
+
+ b0 = vlib_get_buffer (vm, bi0);
+ lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index);
+
+ if (is_ip4)
+ {
+ ip40 = vlib_buffer_get_current (b0);
+ th0 = ip4_next_header (ip40);
+ }
+ else
+ {
+ ip60 = vlib_buffer_get_current (b0);
+ th0 = ip6_next_header (ip60);
+ }
+
+ /* Create child session. For syn-flood protection use filter */
+
+ /* 1. first check for an RST: handled in dispatch */
+ /* if (tcp_rst (th0))
+ goto drop; */
+
+ /* 2. second check for an ACK: handled in dispatch */
+ /* if (tcp_ack (th0))
+ {
+ tcp_send_reset (b0, is_ip4);
+ goto drop;
+ } */
+
+ /* 3. check for a SYN (did that already) */
+
+ /* Make sure connection wasn't just created */
+ child0 = tcp_lookup_connection (b0, my_thread_index, is_ip4);
+ if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN))
+ {
+ error0 = TCP_ERROR_CREATE_EXISTS;
+ goto drop;
+ }
+
+ /* Create child session and send SYN-ACK */
+ child0 = tcp_connection_new (my_thread_index);
+ child0->c_lcl_port = lc0->c_lcl_port;
+ child0->c_rmt_port = th0->src_port;
+ child0->c_is_ip4 = is_ip4;
+ child0->state = TCP_STATE_SYN_RCVD;
+
+ if (is_ip4)
+ {
+ child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32;
+ child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32;
+ }
+ else
+ {
+ clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address,
+ sizeof (ip6_address_t));
+ clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address,
+ sizeof (ip6_address_t));
+ }
+
+ if (stream_session_accept (&child0->connection, lc0->c_s_index, sst,
+ 0 /* notify */ ))
+ {
+ clib_warning ("session accept fail");
+ tcp_connection_cleanup (child0);
+ error0 = TCP_ERROR_CREATE_SESSION_FAIL;
+ goto drop;
+ }
+
+ if (tcp_options_parse (th0, &child0->rcv_opts))
+ {
+ clib_warning ("options parse fail");
+ goto drop;
+ }
+
+ child0->irs = vnet_buffer (b0)->tcp.seq_number;
+ child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
+ child0->rcv_las = child0->rcv_nxt;
+
+ /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
+ * segments are used to initialize PAWS. */
+ if (tcp_opts_tstamp (&child0->rcv_opts))
+ {
+ child0->tsval_recent = child0->rcv_opts.tsval;
+ child0->tsval_recent_age = tcp_time_now ();
+ }
+
+ if (tcp_opts_wscale (&child0->rcv_opts))
+ child0->snd_wscale = child0->rcv_opts.wscale;
+
+ child0->snd_wnd = clib_net_to_host_u16 (th0->window)
+ << child0->snd_wscale;
+ child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
+ child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
+
+ tcp_connection_init_vars (child0);
+ TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1);
+
+ /* Reuse buffer to make syn-ack and send */
+ tcp_make_synack (child0, b0);
+ next0 = tcp_next_output (is_ip4);
+ tcp_timer_set (child0, TCP_TIMER_ESTABLISH, TCP_SYN_RCVD_TIME);
+
+ drop:
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
+ clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header));
+ clib_memcpy (&t0->tcp_connection, lc0,
+ sizeof (t0->tcp_connection));
+ }
+
+ b0->error = node->errors[error0];
+
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+ n_left_to_next, bi0, next0);
+ }
+
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ }
+ return from_frame->n_vectors;
+}
+
+static uword
+tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ );
+}
+
+static uword
+tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp4_listen_node) =
+{
+ .function = tcp4_listen,
+ .name = "tcp4-listen",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_LISTEN_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
+ foreach_tcp_state_next
+#undef _
+ },
+ .format_trace = format_tcp_rx_trace_short,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen);
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp6_listen_node) =
+{
+ .function = tcp6_listen,
+ .name = "tcp6-listen",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_LISTEN_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_LISTEN_NEXT_##s] = n,
+ foreach_tcp_state_next
+#undef _
+ },
+ .format_trace = format_tcp_rx_trace_short,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen);
+
+vlib_node_registration_t tcp4_input_node;
+vlib_node_registration_t tcp6_input_node;
+
+typedef enum _tcp_input_next
+{
+ TCP_INPUT_NEXT_DROP,
+ TCP_INPUT_NEXT_LISTEN,
+ TCP_INPUT_NEXT_RCV_PROCESS,
+ TCP_INPUT_NEXT_SYN_SENT,
+ TCP_INPUT_NEXT_ESTABLISHED,
+ TCP_INPUT_NEXT_RESET,
+ TCP_INPUT_NEXT_PUNT,
+ TCP_INPUT_N_NEXT
+} tcp_input_next_t;
+
+#define foreach_tcp4_input_next \
+ _ (DROP, "error-drop") \
+ _ (LISTEN, "tcp4-listen") \
+ _ (RCV_PROCESS, "tcp4-rcv-process") \
+ _ (SYN_SENT, "tcp4-syn-sent") \
+ _ (ESTABLISHED, "tcp4-established") \
+ _ (RESET, "tcp4-reset") \
+ _ (PUNT, "error-punt")
+
+#define foreach_tcp6_input_next \
+ _ (DROP, "error-drop") \
+ _ (LISTEN, "tcp6-listen") \
+ _ (RCV_PROCESS, "tcp6-rcv-process") \
+ _ (SYN_SENT, "tcp6-syn-sent") \
+ _ (ESTABLISHED, "tcp6-established") \
+ _ (RESET, "tcp6-reset") \
+ _ (PUNT, "error-punt")
+
+#define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN)
+
+always_inline uword
+tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame, int is_ip4)
+{
+ u32 n_left_from, next_index, *from, *to_next;
+ u32 my_thread_index = vm->thread_index;
+ tcp_main_t *tm = vnet_get_tcp_main ();
+
+ from = vlib_frame_vector_args (from_frame);
+ n_left_from = from_frame->n_vectors;
+ next_index = node->cached_next_index;
+ tcp_set_time_now (my_thread_index);
+
+ while (n_left_from > 0)
+ {
+ u32 n_left_to_next;
+
+ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+ while (n_left_from > 0 && n_left_to_next > 0)
+ {
+ int n_advance_bytes0, n_data_bytes0;
+ u32 bi0;
+ vlib_buffer_t *b0;
+ tcp_header_t *tcp0 = 0;
+ tcp_connection_t *tc0;
+ transport_connection_t *tconn;
+ ip4_header_t *ip40;
+ ip6_header_t *ip60;
+ u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP;
+ u8 flags0;
+
+ bi0 = from[0];
+ to_next[0] = bi0;
+ from += 1;
+ to_next += 1;
+ n_left_from -= 1;
+ n_left_to_next -= 1;
+
+ b0 = vlib_get_buffer (vm, bi0);
+ vnet_buffer (b0)->tcp.flags = 0;
+
+ /* Checksum computed by ipx_local no need to compute again */
+
+ if (is_ip4)
+ {
+ ip40 = vlib_buffer_get_current (b0);
+ tcp0 = ip4_next_header (ip40);
+ n_advance_bytes0 = (ip4_header_bytes (ip40)
+ + tcp_header_bytes (tcp0));
+ n_data_bytes0 = clib_net_to_host_u16 (ip40->length)
+ - n_advance_bytes0;
+ tconn = stream_session_lookup_transport_wt4 (&ip40->dst_address,
+ &ip40->src_address,
+ tcp0->dst_port,
+ tcp0->src_port,
+ SESSION_TYPE_IP4_TCP,
+ my_thread_index);
+ tc0 = tcp_get_connection_from_transport (tconn);
+ ASSERT (tcp_lookup_is_valid (tc0, tcp0));
+ }
+ else
+ {
+ ip60 = vlib_buffer_get_current (b0);
+ tcp0 = ip6_next_header (ip60);
+ n_advance_bytes0 = tcp_header_bytes (tcp0);
+ n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length)
+ - n_advance_bytes0;
+ n_advance_bytes0 += sizeof (ip60[0]);
+ tconn = stream_session_lookup_transport_wt6 (&ip60->dst_address,
+ &ip60->src_address,
+ tcp0->dst_port,
+ tcp0->src_port,
+ SESSION_TYPE_IP6_TCP,
+ my_thread_index);
+ tc0 = tcp_get_connection_from_transport (tconn);
+ ASSERT (tcp_lookup_is_valid (tc0, tcp0));
+ }
+
+ /* Length check */
+ if (PREDICT_FALSE (n_advance_bytes0 < 0))
+ {
+ error0 = TCP_ERROR_LENGTH;
+ goto done;
+ }
+
+ /* Session exists */
+ if (PREDICT_TRUE (0 != tc0))
+ {
+ /* Save connection index */
+ vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index;
+ vnet_buffer (b0)->tcp.seq_number =
+ clib_net_to_host_u32 (tcp0->seq_number);
+ vnet_buffer (b0)->tcp.ack_number =
+ clib_net_to_host_u32 (tcp0->ack_number);
+
+ vnet_buffer (b0)->tcp.hdr_offset = (u8 *) tcp0
+ - (u8 *) vlib_buffer_get_current (b0);
+ vnet_buffer (b0)->tcp.data_offset = n_advance_bytes0;
+ vnet_buffer (b0)->tcp.data_len = n_data_bytes0;
+
+ flags0 = tcp0->flags & filter_flags;
+ next0 = tm->dispatch_table[tc0->state][flags0].next;
+ error0 = tm->dispatch_table[tc0->state][flags0].error;
+
+ if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH
+ || next0 == TCP_INPUT_NEXT_RESET))
+ {
+ /* Overload tcp flags to store state */
+ tcp_state_t state0 = tc0->state;
+ vnet_buffer (b0)->tcp.flags = tc0->state;
+
+ if (error0 == TCP_ERROR_DISPATCH)
+ clib_warning ("disp error state %U flags %U",
+ format_tcp_state, state0, format_tcp_flags,
+ (int) flags0);
+ }
+ }
+ else
+ {
+ if ((is_ip4 && tm->punt_unknown4) ||
+ (!is_ip4 && tm->punt_unknown6))
+ {
+ next0 = TCP_INPUT_NEXT_PUNT;
+ error0 = TCP_ERROR_PUNT;
+ }
+ else
+ {
+ /* Send reset */
+ next0 = TCP_INPUT_NEXT_RESET;
+ error0 = TCP_ERROR_NO_LISTENER;
+ }
+ }
+
+ done:
+ b0->error = error0 ? node->errors[error0] : 0;
+
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ tcp_rx_trace_t *t0 =
+ vlib_add_trace (vm, node, b0, sizeof (*t0));
+ tcp_set_rx_trace_data (t0, tc0, tcp0, b0, is_ip4);
+ }
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+ n_left_to_next, bi0, next0);
+ }
+
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ }
+
+ return from_frame->n_vectors;
+}
+
+static uword
+tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ );
+}
+
+static uword
+tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node,
+ vlib_frame_t * from_frame)
+{
+ return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp4_input_node) =
+{
+ .function = tcp4_input,
+ .name = "tcp4-input",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_INPUT_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_INPUT_NEXT_##s] = n,
+ foreach_tcp4_input_next
+#undef _
+ },
+ .format_buffer = format_tcp_header,
+ .format_trace = format_tcp_rx_trace,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input);
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (tcp6_input_node) =
+{
+ .function = tcp6_input,
+ .name = "tcp6-input",
+ /* Takes a vector of packets. */
+ .vector_size = sizeof (u32),
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
+ .n_next_nodes = TCP_INPUT_N_NEXT,
+ .next_nodes =
+ {
+#define _(s,n) [TCP_INPUT_NEXT_##s] = n,
+ foreach_tcp6_input_next
+#undef _
+ },
+ .format_buffer = format_tcp_header,
+ .format_trace = format_tcp_rx_trace,
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input);
+
+static void
+tcp_dispatch_table_init (tcp_main_t * tm)
+{
+ int i, j;
+ for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++)
+ for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++)
+ {
+ tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP;
+ tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH;
+ }
+
+#define _(t,f,n,e) \
+do { \
+ tm->dispatch_table[TCP_STATE_##t][f].next = (n); \
+ tm->dispatch_table[TCP_STATE_##t][f].error = (e); \
+} while (0)
+
+ /* SYNs for new connections -> tcp-listen. */
+ _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE);
+ _(LISTEN, TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET, TCP_ERROR_NONE);
+ _(LISTEN, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_NONE);
+ _(LISTEN, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RESET,
+ TCP_ERROR_NONE);
+ /* ACK for for a SYN-ACK -> tcp-rcv-process. */
+ _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(SYN_RCVD, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(SYN_RCVD, TCP_FLAG_SYN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ /* SYN-ACK for a SYN */
+ _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
+ TCP_ERROR_NONE);
+ _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
+ _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE);
+ _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT,
+ TCP_ERROR_NONE);
+ /* ACK for for established connection -> tcp-established. */
+ _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
+ /* FIN for for established connection -> tcp-established. */
+ _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
+ _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
+ TCP_ERROR_NONE);
+ _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
+ _(ESTABLISHED, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
+ TCP_ERROR_NONE);
+ _(ESTABLISHED, TCP_FLAG_SYN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
+ _(ESTABLISHED, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
+ TCP_ERROR_NONE);
+ /* ACK or FIN-ACK to our FIN */
+ _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
+ TCP_ERROR_NONE);
+ /* FIN in reply to our FIN from the other side */
+ _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(FIN_WAIT_1, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ /* FIN confirming that the peer (app) has closed */
+ _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
+ TCP_ERROR_NONE);
+ _(CLOSE_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(CLOSE_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
+ TCP_ERROR_NONE);
+ _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(LAST_ACK, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(LAST_ACK, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
+ TCP_ERROR_NONE);
+ _(LAST_ACK, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(TIME_WAIT, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(TIME_WAIT, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
+ TCP_ERROR_NONE);
+ _(TIME_WAIT, TCP_FLAG_RST, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(TIME_WAIT, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(CLOSED, TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
+ _(CLOSED, TCP_FLAG_RST, TCP_INPUT_NEXT_DROP, TCP_ERROR_CONNECTION_CLOSED);
+ _(CLOSED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_DROP,
+ TCP_ERROR_CONNECTION_CLOSED);
+#undef _
+}
+
+clib_error_t *
+tcp_input_init (vlib_main_t * vm)
+{
+ clib_error_t *error = 0;
+ tcp_main_t *tm = vnet_get_tcp_main ();
+
+ if ((error = vlib_call_init_function (vm, tcp_init)))
+ return error;
+
+ /* Initialize dispatch table. */
+ tcp_dispatch_table_init (tm);
+
+ return error;
+}
+
+VLIB_INIT_FUNCTION (tcp_input_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */