X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fvnet%2Ftcp%2Ftcp_output.c;h=a21c012b5b7163c02db769e4a02a6a3d066ccba5;hb=573f44c2f5c883753bc9880eead1bd662586521d;hp=7be3de8e26bb3b7eb42ee109810845a3b80fb178;hpb=b3dce89a768aaffa2a830ba6579cd3d9c8cd967a;p=vpp.git

diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index 7be3de8e26b..a21c012b5b7 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -14,6 +14,7 @@
  */
 
 #include <vnet/tcp/tcp.h>
+#include <vnet/tcp/tcp_inlines.h>
 #include <math.h>
 
 typedef enum _tcp_output_next
@@ -55,12 +56,12 @@ format_tcp_tx_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_tx_trace_t *t = va_arg (*args, tcp_tx_trace_t *);
+  tcp_connection_t *tc = &t->tcp_connection;
   u32 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);
+  s = format (s, "%U state %U\n%U%U", format_tcp_connection_id, tc,
+	      format_tcp_state, tc->state, format_white_space, indent,
+	      format_tcp_header, &t->tcp_header, 128);
 
   return s;
 }
@@ -115,8 +116,6 @@ tcp_update_rcv_wnd (tcp_connection_t * tc)
   u32 available_space, wnd;
   i32 observed_wnd;
 
-  ASSERT (tc->rcv_opts.mss < transport_rx_fifo_size (&tc->connection));
-
   /*
    * Figure out how much space we have available
    */
@@ -168,90 +167,6 @@ tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
   return tc->rcv_wnd >> tc->rcv_wscale;
 }
 
-/**
- * Write TCP options to segment.
- */
-static u32
-tcp_options_write (u8 * data, tcp_options_t * opts)
-{
-  u32 opts_len = 0;
-  u32 buf, seq_len = 4;
-
-  if (tcp_opts_mss (opts))
-    {
-      *data++ = TCP_OPTION_MSS;
-      *data++ = TCP_OPTION_LEN_MSS;
-      buf = clib_host_to_net_u16 (opts->mss);
-      clib_memcpy_fast (data, &buf, sizeof (opts->mss));
-      data += sizeof (opts->mss);
-      opts_len += TCP_OPTION_LEN_MSS;
-    }
-
-  if (tcp_opts_wscale (opts))
-    {
-      *data++ = TCP_OPTION_WINDOW_SCALE;
-      *data++ = TCP_OPTION_LEN_WINDOW_SCALE;
-      *data++ = opts->wscale;
-      opts_len += TCP_OPTION_LEN_WINDOW_SCALE;
-    }
-
-  if (tcp_opts_sack_permitted (opts))
-    {
-      *data++ = TCP_OPTION_SACK_PERMITTED;
-      *data++ = TCP_OPTION_LEN_SACK_PERMITTED;
-      opts_len += TCP_OPTION_LEN_SACK_PERMITTED;
-    }
-
-  if (tcp_opts_tstamp (opts))
-    {
-      *data++ = TCP_OPTION_TIMESTAMP;
-      *data++ = TCP_OPTION_LEN_TIMESTAMP;
-      buf = clib_host_to_net_u32 (opts->tsval);
-      clib_memcpy_fast (data, &buf, sizeof (opts->tsval));
-      data += sizeof (opts->tsval);
-      buf = clib_host_to_net_u32 (opts->tsecr);
-      clib_memcpy_fast (data, &buf, sizeof (opts->tsecr));
-      data += sizeof (opts->tsecr);
-      opts_len += TCP_OPTION_LEN_TIMESTAMP;
-    }
-
-  if (tcp_opts_sack (opts))
-    {
-      int i;
-
-      if (opts->n_sack_blocks != 0)
-	{
-	  *data++ = TCP_OPTION_SACK_BLOCK;
-	  *data++ = 2 + opts->n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
-	  for (i = 0; i < opts->n_sack_blocks; i++)
-	    {
-	      buf = clib_host_to_net_u32 (opts->sacks[i].start);
-	      clib_memcpy_fast (data, &buf, seq_len);
-	      data += seq_len;
-	      buf = clib_host_to_net_u32 (opts->sacks[i].end);
-	      clib_memcpy_fast (data, &buf, seq_len);
-	      data += seq_len;
-	    }
-	  opts_len += 2 + opts->n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
-	}
-    }
-
-  /* Terminate TCP options */
-  if (opts_len % 4)
-    {
-      *data++ = TCP_OPTION_EOL;
-      opts_len += TCP_OPTION_LEN_EOL;
-    }
-
-  /* Pad with zeroes to a u32 boundary */
-  while (opts_len % 4)
-    {
-      *data++ = TCP_OPTION_NOOP;
-      opts_len += TCP_OPTION_LEN_NOOP;
-    }
-  return opts_len;
-}
-
 static int
 tcp_make_syn_options (tcp_connection_t * tc, tcp_options_t * opts)
 {
@@ -411,7 +326,7 @@ tcp_update_burst_snd_vars (tcp_connection_t * tc)
   if (tc->snd_una == tc->snd_nxt)
     {
       tcp_cc_event (tc, TCP_CC_EVT_START_TX);
-      tcp_connection_tx_pacer_reset (tc, tc->cwnd, TRANSPORT_PACER_MIN_MSS);
+      tcp_connection_tx_pacer_reset (tc, tc->cwnd, TRANSPORT_PACER_MIN_BURST);
     }
 }
 
@@ -565,7 +480,7 @@ tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b)
 /**
  * Convert buffer to FIN-ACK
  */
-void
+static void
 tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b)
 {
   tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK);
@@ -600,7 +515,7 @@ tcp_make_syn (tcp_connection_t * tc, vlib_buffer_t * b)
 /**
  * Convert buffer to SYN-ACK
  */
-void
+static void
 tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
 {
   tcp_options_t _snd_opts, *snd_opts = &_snd_opts;
@@ -622,13 +537,12 @@ tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b)
   th->checksum = tcp_compute_checksum (tc, b);
 }
 
-always_inline void
-tcp_enqueue_to_ip_lookup_i (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
-			    u8 is_ip4, u32 fib_index, u8 flush)
+static void
+tcp_enqueue_to_ip_lookup (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
+			  u8 is_ip4, u32 fib_index)
 {
+  tcp_main_t *tm = &tcp_main;
   vlib_main_t *vm = wrk->vm;
-  u32 *to_next, next_index;
-  vlib_frame_t *f;
 
   b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
   b->error = 0;
@@ -636,132 +550,99 @@ tcp_enqueue_to_ip_lookup_i (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
   vnet_buffer (b)->sw_if_index[VLIB_TX] = fib_index;
   vnet_buffer (b)->sw_if_index[VLIB_RX] = 0;
 
-  /* Send to IP lookup */
-  next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
   tcp_trajectory_add_start (b, 1);
 
-  f = wrk->ip_lookup_tx_frames[!is_ip4];
-  if (!f)
-    {
-      f = vlib_get_frame_to_node (vm, next_index);
-      ASSERT (f);
-      wrk->ip_lookup_tx_frames[!is_ip4] = f;
-    }
-
-  to_next = vlib_frame_vector_args (f);
-  to_next[f->n_vectors] = bi;
-  f->n_vectors += 1;
-  if (flush || f->n_vectors == VLIB_FRAME_SIZE)
-    {
-      vlib_put_frame_to_node (vm, next_index, f);
-      wrk->ip_lookup_tx_frames[!is_ip4] = 0;
-    }
-}
+  session_add_pending_tx_buffer (vm->thread_index, bi,
+				 tm->ipl_next_node[!is_ip4]);
 
-static void
-tcp_enqueue_to_ip_lookup_now (tcp_worker_ctx_t * wrk, vlib_buffer_t * b,
-			      u32 bi, u8 is_ip4, u32 fib_index)
-{
-  tcp_enqueue_to_ip_lookup_i (wrk, b, bi, is_ip4, fib_index, 1);
-}
-
-static void
-tcp_enqueue_to_ip_lookup (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
-			  u8 is_ip4, u32 fib_index)
-{
-  tcp_enqueue_to_ip_lookup_i (wrk, b, bi, is_ip4, fib_index, 0);
-  if (wrk->vm->thread_index == 0 && vlib_num_workers ())
-    session_flush_frames_main_thread (wrk->vm);
+  if (vm->thread_index == 0 && vlib_num_workers ())
+    session_queue_run_on_main_thread (wrk->vm);
 }
 
 static void
 tcp_enqueue_to_output (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi,
 		       u8 is_ip4)
 {
-  session_type_t st;
-
   b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
   b->error = 0;
 
-  st = session_type_from_proto_and_ip (TRANSPORT_PROTO_TCP, is_ip4);
-  session_add_pending_tx_buffer (st, wrk->vm->thread_index, bi);
+  session_add_pending_tx_buffer (wrk->vm->thread_index, bi,
+				 wrk->tco_next_node[!is_ip4]);
 }
 
 #endif /* CLIB_MARCH_VARIANT */
 
 static int
-tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0,
-			 tcp_state_t state, u8 thread_index, u8 is_ip4)
+tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b, u8 is_ip4)
 {
   ip4_header_t *ih4;
   ip6_header_t *ih6;
-  tcp_header_t *th0;
-  ip4_address_t src_ip40, dst_ip40;
-  ip6_address_t src_ip60, dst_ip60;
+  tcp_header_t *th;
+  ip4_address_t src_ip4, dst_ip4;
+  ip6_address_t src_ip6, dst_ip6;
   u16 src_port, dst_port;
-  u32 tmp;
-  u32 seq, ack;
+  u32 tmp, len, seq, ack;
   u8 flags;
 
   /* Find IP and TCP headers */
-  th0 = tcp_buffer_hdr (b0);
+  th = tcp_buffer_hdr (b);
 
   /* Save src and dst ip */
   if (is_ip4)
     {
-      ih4 = vlib_buffer_get_current (b0);
+      ih4 = vlib_buffer_get_current (b);
       ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40);
-      src_ip40.as_u32 = ih4->src_address.as_u32;
-      dst_ip40.as_u32 = ih4->dst_address.as_u32;
+      src_ip4.as_u32 = ih4->src_address.as_u32;
+      dst_ip4.as_u32 = ih4->dst_address.as_u32;
     }
   else
     {
-      ih6 = vlib_buffer_get_current (b0);
+      ih6 = vlib_buffer_get_current (b);
       ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60);
-      clib_memcpy_fast (&src_ip60, &ih6->src_address, sizeof (ip6_address_t));
-      clib_memcpy_fast (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t));
+      clib_memcpy_fast (&src_ip6, &ih6->src_address, sizeof (ip6_address_t));
+      clib_memcpy_fast (&dst_ip6, &ih6->dst_address, sizeof (ip6_address_t));
     }
 
-  src_port = th0->src_port;
-  dst_port = th0->dst_port;
+  src_port = th->src_port;
+  dst_port = th->dst_port;
+  flags = TCP_FLAG_RST;
 
-  /* Try to determine what/why we're actually resetting */
-  if (state == TCP_STATE_CLOSED)
+  /*
+   * RFC 793. If the ACK bit is off, sequence number zero is used,
+   *   <SEQ=0><ACK=SEG.SEQ+SEG.LEN><CTL=RST,ACK>
+   * If the ACK bit is on,
+   *   <SEQ=SEG.ACK><CTL=RST>
+   */
+  if (tcp_ack (th))
     {
-      if (!tcp_syn (th0))
-	return -1;
-
-      tmp = clib_net_to_host_u32 (th0->seq_number);
-
-      /* Got a SYN for no listener. */
-      flags = TCP_FLAG_RST | TCP_FLAG_ACK;
-      ack = clib_host_to_net_u32 (tmp + 1);
-      seq = 0;
+      seq = th->ack_number;
+      ack = 0;
     }
   else
     {
-      flags = TCP_FLAG_RST;
-      seq = th0->ack_number;
-      ack = 0;
+      flags |= TCP_FLAG_ACK;
+      tmp = clib_net_to_host_u32 (th->seq_number);
+      len = vnet_buffer (b)->tcp.data_len + tcp_is_syn (th) + tcp_is_fin (th);
+      ack = clib_host_to_net_u32 (tmp + len);
+      seq = 0;
     }
 
-  tcp_reuse_buffer (vm, b0);
-  tcp_trajectory_add_start (b0, 4);
-  th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack,
-					sizeof (tcp_header_t), flags, 0);
+  tcp_reuse_buffer (vm, b);
+  tcp_trajectory_add_start (b, 4);
+  th = vlib_buffer_push_tcp_net_order (b, dst_port, src_port, seq, ack,
+				       sizeof (tcp_header_t), flags, 0);
 
   if (is_ip4)
     {
-      ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40,
+      ih4 = vlib_buffer_push_ip4 (vm, b, &dst_ip4, &src_ip4,
 				  IP_PROTOCOL_TCP, 1);
-      th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4);
+      th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4);
     }
   else
     {
       int bogus = ~0;
-      ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60,
-				  IP_PROTOCOL_TCP);
-      th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus);
+      ih6 = vlib_buffer_push_ip6 (vm, b, &dst_ip6, &src_ip6, IP_PROTOCOL_TCP);
+      th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus);
       ASSERT (!bogus);
     }
 
@@ -850,7 +731,7 @@ tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt,
       ASSERT (!bogus);
     }
 
-  tcp_enqueue_to_ip_lookup_now (wrk, b, bi, is_ip4, fib_index);
+  tcp_enqueue_to_ip_lookup (wrk, b, bi, is_ip4, fib_index);
   TCP_EVT (TCP_EVT_RST_SENT, tc);
   vlib_node_increment_counter (vm, tcp_node_index (output, tc->c_is_ip4),
 			       TCP_ERROR_RST_SENT, 1);
@@ -877,7 +758,7 @@ tcp_send_reset (tcp_connection_t * tc)
 
   tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state);
   tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t);
-  advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED);
+  advertise_wnd = tc->rcv_wnd >> tc->rcv_wscale;
   flags = TCP_FLAG_RST;
   th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
 			     tc->rcv_nxt, tcp_hdr_opts_len, flags,
@@ -896,26 +777,15 @@ static void
 tcp_push_ip_hdr (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
 		 vlib_buffer_t * b)
 {
-  tcp_header_t *th = vlib_buffer_get_current (b);
-  vlib_main_t *vm = wrk->vm;
   if (tc->c_is_ip4)
     {
-      ip4_header_t *ih;
-      ih = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip4,
-				 &tc->c_rmt_ip4, IP_PROTOCOL_TCP,
-				 tcp_csum_offload (tc));
-      th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih);
+      vlib_buffer_push_ip4 (wrk->vm, b, &tc->c_lcl_ip4, &tc->c_rmt_ip4,
+			    IP_PROTOCOL_TCP, tcp_csum_offload (tc));
     }
   else
     {
-      ip6_header_t *ih;
-      int bogus = ~0;
-
-      ih = vlib_buffer_push_ip6_custom (vm, b, &tc->c_lcl_ip6,
-					&tc->c_rmt_ip6, IP_PROTOCOL_TCP,
-					tc->ipv6_flow_label);
-      th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih, &bogus);
-      ASSERT (!bogus);
+      vlib_buffer_push_ip6_custom (wrk->vm, b, &tc->c_lcl_ip6, &tc->c_rmt_ip6,
+				   IP_PROTOCOL_TCP, tc->ipv6_flow_label);
     }
 }
 
@@ -938,12 +808,12 @@ tcp_send_syn (tcp_connection_t * tc)
    * Setup retransmit and establish timers before requesting buffer
    * such that we can return if we've ran out.
    */
-  tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
+  tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN,
 		    tc->rto * TCP_TO_TIMER_TICK);
 
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
-      tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1);
+      tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN, 1);
       return;
     }
 
@@ -969,11 +839,11 @@ tcp_send_synack (tcp_connection_t * tc)
   vlib_buffer_t *b;
   u32 bi;
 
-  tcp_retransmit_timer_force_update (tc);
+  tcp_retransmit_timer_force_update (&wrk->timer_wheel, tc);
 
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
-      tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
+      tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT, 1);
       return;
     }
 
@@ -985,32 +855,6 @@ tcp_send_synack (tcp_connection_t * tc)
   TCP_EVT (TCP_EVT_SYNACK_SENT, tc);
 }
 
-/**
- * Flush ip lookup tx frames populated by timer pops
- */
-static void
-tcp_flush_frame_to_ip_lookup (tcp_worker_ctx_t * wrk, u8 is_ip4)
-{
-  if (wrk->ip_lookup_tx_frames[!is_ip4])
-    {
-      u32 next_index;
-      next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index;
-      vlib_put_frame_to_node (wrk->vm, next_index,
-			      wrk->ip_lookup_tx_frames[!is_ip4]);
-      wrk->ip_lookup_tx_frames[!is_ip4] = 0;
-    }
-}
-
-/**
- * Flush v4 and v6 tcp and ip-lookup tx frames for thread index
- */
-void
-tcp_flush_frames_to_output (tcp_worker_ctx_t * wrk)
-{
-  tcp_flush_frame_to_ip_lookup (wrk, 1);
-  tcp_flush_frame_to_ip_lookup (wrk, 0);
-}
-
 /**
  *  Send FIN
  */
@@ -1030,7 +874,7 @@ tcp_send_fin (tcp_connection_t * tc)
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
       /* Out of buffers so program fin retransmit ASAP */
-      tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
+      tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT, 1);
       if (fin_snt)
 	tc->snd_nxt += 1;
       else
@@ -1043,7 +887,7 @@ tcp_send_fin (tcp_connection_t * tc)
   if ((tc->flags & TCP_CONN_SNDACK) && !tc->pending_dupacks)
     tc->flags &= ~TCP_CONN_SNDACK;
 
-  tcp_retransmit_timer_force_update (tc);
+  tcp_retransmit_timer_force_update (&wrk->timer_wheel, tc);
   b = vlib_get_buffer (vm, bi);
   tcp_init_buffer (vm, b);
   tcp_make_fin (tc, b);
@@ -1157,7 +1001,8 @@ tcp_session_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
     }
   if (PREDICT_FALSE (!tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT)))
     {
-      tcp_retransmit_timer_set (tc);
+      tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
+      tcp_retransmit_timer_set (&wrk->timer_wheel, tc);
       tc->rto_boff = 0;
     }
   tcp_trajectory_add_start (b, 3);
@@ -1221,13 +1066,8 @@ tcp_program_retransmit (tcp_connection_t * tc)
  * Sends delayed ACK when timer expires
  */
 void
-tcp_timer_delack_handler (u32 index)
+tcp_timer_delack_handler (tcp_connection_t * tc)
 {
-  u32 thread_index = vlib_get_thread_index ();
-  tcp_connection_t *tc;
-
-  tc = tcp_connection_get (index, thread_index);
-  tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID;
   tcp_send_ack (tc);
 }
 
@@ -1413,6 +1253,7 @@ tcp_prepare_retransmit_segment (tcp_worker_ctx_t * wrk,
 
   tc->bytes_retrans += n_bytes;
   tc->segs_retrans += 1;
+  tcp_worker_stats_inc (wrk, rxt_segs, 1);
   TCP_EVT (TCP_EVT_CC_RTX, tc, offset, n_bytes);
 
   return n_bytes;
@@ -1457,23 +1298,19 @@ tcp_cc_init_rxt_timeout (tcp_connection_t * tc)
 }
 
 void
-tcp_timer_retransmit_handler (u32 tc_index)
+tcp_timer_retransmit_handler (tcp_connection_t * tc)
 {
-  u32 thread_index = vlib_get_thread_index ();
-  tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
+  tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
   vlib_main_t *vm = wrk->vm;
-  tcp_connection_t *tc;
   vlib_buffer_t *b = 0;
   u32 bi, n_bytes;
 
-  tc = tcp_connection_get (tc_index, thread_index);
+  tcp_worker_stats_inc (wrk, tr_events, 1);
 
-  /* Note: the connection may have been closed and pool_put */
-  if (PREDICT_FALSE (tc == 0 || tc->state == TCP_STATE_SYN_SENT))
+  /* Should be handled by a different handler */
+  if (PREDICT_FALSE (tc->state == TCP_STATE_SYN_SENT))
     return;
 
-  tc->timers[TCP_TIMER_RETRANSMIT] = TCP_TIMER_HANDLE_INVALID;
-
   /* Wait-close and retransmit could pop at the same time */
   if (tc->state == TCP_STATE_CLOSED)
     return;
@@ -1518,8 +1355,10 @@ tcp_timer_retransmit_handler (u32 tc_index)
 	  tcp_send_reset (tc);
 	  tcp_connection_set_state (tc, TCP_STATE_CLOSED);
 	  session_transport_closing_notify (&tc->connection);
+	  session_transport_closed_notify (&tc->connection);
 	  tcp_connection_timers_reset (tc);
-	  tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time);
+	  tcp_program_cleanup (wrk, tc);
+	  tcp_worker_stats_inc (wrk, tr_abort, 1);
 	  return;
 	}
 
@@ -1535,7 +1374,7 @@ tcp_timer_retransmit_handler (u32 tc_index)
       n_bytes = tcp_prepare_retransmit_segment (wrk, tc, 0, n_bytes, &b);
       if (!n_bytes)
 	{
-	  tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
+	  tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT, 1);
 	  return;
 	}
 
@@ -1543,7 +1382,7 @@ tcp_timer_retransmit_handler (u32 tc_index)
       tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
 
       tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
-      tcp_retransmit_timer_force_update (tc);
+      tcp_retransmit_timer_force_update (&wrk->timer_wheel, tc);
 
       tc->rto_boff += 1;
       if (tc->rto_boff == 1)
@@ -1570,13 +1409,14 @@ tcp_timer_retransmit_handler (u32 tc_index)
 	{
 	  tcp_connection_set_state (tc, TCP_STATE_CLOSED);
 	  tcp_connection_timers_reset (tc);
-	  tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time);
+	  tcp_program_cleanup (wrk, tc);
+	  tcp_worker_stats_inc (wrk, tr_abort, 1);
 	  return;
 	}
 
       if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
 	{
-	  tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
+	  tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT, 1);
 	  return;
 	}
 
@@ -1584,7 +1424,7 @@ tcp_timer_retransmit_handler (u32 tc_index)
       if (tc->rto_boff > TCP_RTO_SYN_RETRIES)
 	tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
 
-      tcp_retransmit_timer_force_update (tc);
+      tcp_retransmit_timer_force_update (&wrk->timer_wheel, tc);
 
       b = vlib_get_buffer (vm, bi);
       tcp_init_buffer (vm, b);
@@ -1605,23 +1445,17 @@ tcp_timer_retransmit_handler (u32 tc_index)
  * SYN retransmit timer handler. Active open only.
  */
 void
-tcp_timer_retransmit_syn_handler (u32 tc_index)
+tcp_timer_retransmit_syn_handler (tcp_connection_t * tc)
 {
-  u32 thread_index = vlib_get_thread_index ();
-  tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
+  tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
   vlib_main_t *vm = wrk->vm;
-  tcp_connection_t *tc;
   vlib_buffer_t *b = 0;
   u32 bi;
 
-  tc = tcp_half_open_connection_get (tc_index);
-
   /* Note: the connection may have transitioned to ESTABLISHED... */
-  if (PREDICT_FALSE (tc == 0 || tc->state != TCP_STATE_SYN_SENT))
+  if (PREDICT_FALSE (tc->state != TCP_STATE_SYN_SENT))
     return;
 
-  tc->timers[TCP_TIMER_RETRANSMIT_SYN] = TCP_TIMER_HANDLE_INVALID;
-
   /* Half-open connection actually moved to established but we were
    * waiting for syn retransmit to pop to call cleanup from the right
    * thread. */
@@ -1638,14 +1472,14 @@ tcp_timer_retransmit_syn_handler (u32 tc_index)
   /* Active open establish timeout */
   if (tc->rto >= TCP_ESTABLISH_TIME >> 1)
     {
-      session_stream_connect_notify (&tc->connection, 1 /* fail */ );
+      session_stream_connect_notify (&tc->connection, SESSION_E_TIMEDOUT);
       tcp_connection_cleanup (tc);
       return;
     }
 
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
-      tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1);
+      tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN, 1);
       return;
     }
 
@@ -1665,7 +1499,7 @@ tcp_timer_retransmit_syn_handler (u32 tc_index)
   tcp_push_ip_hdr (wrk, tc, b);
   tcp_enqueue_to_ip_lookup (wrk, b, bi, tc->c_is_ip4, tc->c_fib_index);
 
-  tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN,
+  tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN,
 		    tc->rto * TCP_TO_TIMER_TICK);
 }
 
@@ -1674,29 +1508,20 @@ tcp_timer_retransmit_syn_handler (u32 tc_index)
  *
  */
 void
-tcp_timer_persist_handler (u32 index)
+tcp_timer_persist_handler (tcp_connection_t * tc)
 {
-  u32 thread_index = vlib_get_thread_index ();
-  tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index);
+  tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
   u32 bi, max_snd_bytes, available_bytes, offset;
   tcp_main_t *tm = vnet_get_tcp_main ();
   vlib_main_t *vm = wrk->vm;
-  tcp_connection_t *tc;
   vlib_buffer_t *b;
   int n_bytes = 0;
   u8 *data;
 
-  tc = tcp_connection_get_if_valid (index, thread_index);
-  if (!tc)
-    return;
-
-  /* Make sure timer handle is set to invalid */
-  tc->timers[TCP_TIMER_PERSIST] = TCP_TIMER_HANDLE_INVALID;
-
   /* Problem already solved or worse */
   if (tc->state == TCP_STATE_CLOSED || tc->snd_wnd > tc->snd_mss
       || (tc->flags & TCP_CONN_FINSNT))
-    return;
+    goto update_scheduler;
 
   available_bytes = transport_max_tx_dequeue (&tc->connection);
   offset = tc->snd_nxt - tc->snd_una;
@@ -1705,15 +1530,12 @@ tcp_timer_persist_handler (u32 index)
    * next time */
   if (!available_bytes)
     {
-      tcp_persist_timer_set (tc);
+      tcp_persist_timer_set (&wrk->timer_wheel, tc);
       return;
     }
 
   if (available_bytes <= offset)
-    {
-      ASSERT (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT));
-      return;
-    }
+    goto update_scheduler;
 
   /* Increment RTO backoff */
   tc->rto_boff += 1;
@@ -1724,9 +1546,10 @@ tcp_timer_persist_handler (u32 index)
    */
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
-      tcp_persist_timer_set (tc);
+      tcp_persist_timer_set (&wrk->timer_wheel, tc);
       return;
     }
+
   b = vlib_get_buffer (vm, bi);
   data = tcp_init_buffer (vm, b);
 
@@ -1754,7 +1577,14 @@ tcp_timer_persist_handler (u32 index)
   tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
 
   /* Just sent new data, enable retransmit */
-  tcp_retransmit_timer_update (tc);
+  tcp_retransmit_timer_update (&wrk->timer_wheel, tc);
+
+  return;
+
+update_scheduler:
+
+  if (tcp_is_descheduled (tc))
+    transport_connection_reschedule (&tc->connection);
 }
 
 /**
@@ -1874,9 +1704,9 @@ static int
 tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
 		     u32 burst_size)
 {
-  u8 snd_limited = 0, can_rescue = 0, reset_pacer = 0;
   u32 n_written = 0, offset, max_bytes, n_segs = 0;
-  u32 bi, max_deq, burst_bytes, sent_bytes;
+  u8 snd_limited = 0, can_rescue = 0;
+  u32 bi, max_deq, burst_bytes;
   sack_scoreboard_hole_t *hole;
   vlib_main_t *vm = wrk->vm;
   vlib_buffer_t *b = 0;
@@ -1899,12 +1729,7 @@ tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
     snd_space = tcp_fastrecovery_prr_snd_space (tc);
 
   if (snd_space < tc->snd_mss)
-    {
-      reset_pacer = burst_bytes > tc->snd_mss;
-      goto done;
-    }
-
-  reset_pacer = snd_space < burst_bytes;
+    goto done;
 
   sb = &tc->sack_sb;
 
@@ -1951,8 +1776,10 @@ tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
 	      u32 n_segs_new;
 	      int av_wnd;
 
+	      /* Make sure we don't exceed available window and leave space
+	       * for one more packet, to avoid zero window acks */
 	      av_wnd = (int) tc->snd_wnd - (tc->snd_nxt - tc->snd_una);
-	      av_wnd = clib_max (av_wnd, 0);
+	      av_wnd = clib_max (av_wnd - tc->snd_mss, 0);
 	      snd_space = clib_min (snd_space, av_wnd);
 	      snd_space = clib_min (max_deq, snd_space);
 	      burst_size = clib_min (burst_size - n_segs,
@@ -1975,16 +1802,16 @@ tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
 	   * unSACKed sequence number SHOULD be returned, and RescueRxt set to
 	   * RecoveryPoint. HighRxt MUST NOT be updated.
 	   */
-	  max_bytes = clib_min (tc->snd_mss,
-				tc->snd_congestion - tc->snd_una);
+	  hole = scoreboard_last_hole (sb);
+	  max_bytes = clib_min (tc->snd_mss, hole->end - hole->start);
 	  max_bytes = clib_min (max_bytes, snd_space);
-	  offset = tc->snd_congestion - tc->snd_una - max_bytes;
-	  sb->rescue_rxt = tc->snd_congestion;
+	  offset = hole->end - tc->snd_una - max_bytes;
 	  n_written = tcp_prepare_retransmit_segment (wrk, tc, offset,
 						      max_bytes, &b);
 	  if (!n_written)
 	    goto done;
 
+	  sb->rescue_rxt = tc->snd_congestion;
 	  bi = vlib_get_buffer_index (vm, b);
 	  tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
 	  n_segs += 1;
@@ -2020,17 +1847,7 @@ tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
 
 done:
 
-  if (reset_pacer)
-    {
-      transport_connection_tx_pacer_reset_bucket (&tc->connection);
-    }
-  else
-    {
-      sent_bytes = clib_min (n_segs * tc->snd_mss, burst_bytes);
-      transport_connection_tx_pacer_update_bytes (&tc->connection,
-						  sent_bytes);
-    }
-
+  transport_connection_tx_pacer_reset_bucket (&tc->connection, 0);
   return n_segs;
 }
 
@@ -2139,6 +1956,7 @@ tcp_send_acks (tcp_connection_t * tc, u32 max_burst_size)
   if (!vec_len (tc->snd_sacks))
     {
       tcp_send_ack (tc);
+      tc->dupacks_out += 1;
       tc->pending_dupacks = 0;
       return 1;
     }
@@ -2192,7 +2010,7 @@ tcp_do_retransmit (tcp_connection_t * tc, u32 max_burst_size)
 }
 
 int
-tcp_session_custom_tx (void *conn, u32 max_burst_size)
+tcp_session_custom_tx (void *conn, transport_send_params_t * sp)
 {
   tcp_connection_t *tc = (tcp_connection_t *) conn;
   u32 n_segs = 0;
@@ -2200,8 +2018,7 @@ tcp_session_custom_tx (void *conn, u32 max_burst_size)
   if (tcp_in_cong_recovery (tc) && (tc->flags & TCP_CONN_RXT_PENDING))
     {
       tc->flags &= ~TCP_CONN_RXT_PENDING;
-      n_segs = tcp_do_retransmit (tc, max_burst_size);
-      max_burst_size -= n_segs;
+      n_segs = tcp_do_retransmit (tc, sp->max_burst_size);
     }
 
   if (!(tc->flags & TCP_CONN_SNDACK))
@@ -2213,13 +2030,13 @@ tcp_session_custom_tx (void *conn, u32 max_burst_size)
   if (n_segs && !tc->pending_dupacks)
     return n_segs;
 
-  if (!max_burst_size)
+  if (sp->max_burst_size <= n_segs)
     {
       tcp_program_ack (tc);
-      return max_burst_size;
+      return n_segs;
     }
 
-  n_segs += tcp_send_acks (tc, max_burst_size);
+  n_segs += tcp_send_acks (tc, sp->max_burst_size - n_segs);
 
   return n_segs;
 }
@@ -2261,16 +2078,17 @@ static void
 tcp46_output_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
 			  u32 * to_next, u32 n_bufs)
 {
-  u32 n_trace = vlib_get_trace_count (vm, node);
   tcp_connection_t *tc;
   tcp_tx_trace_t *t;
   vlib_buffer_t *b;
   tcp_header_t *th;
   int i;
 
-  for (i = 0; i < clib_min (n_trace, n_bufs); i++)
+  for (i = 0; i < n_bufs; i++)
     {
       b = vlib_get_buffer (vm, to_next[i]);
+      if (!(b->flags & VLIB_BUFFER_IS_TRACED))
+	continue;
       th = vlib_buffer_get_current (b);
       tc = tcp_connection_get (vnet_buffer (b)->tcp.connection_index,
 			       vm->thread_index);
@@ -2284,19 +2102,16 @@ always_inline void
 tcp_output_push_ip (vlib_main_t * vm, vlib_buffer_t * b0,
 		    tcp_connection_t * tc0, u8 is_ip4)
 {
-  u8 __clib_unused *ih0;
-  tcp_header_t __clib_unused *th0 = vlib_buffer_get_current (b0);
-
-  TCP_EVT (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length);
+  TCP_EVT (TCP_EVT_OUTPUT, tc0,
+	   ((tcp_header_t *) vlib_buffer_get_current (b0))->flags,
+	   b0->current_length);
 
   if (is_ip4)
-    ih0 = vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
-				IP_PROTOCOL_TCP, tcp_csum_offload (tc0));
+    vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4,
+			  IP_PROTOCOL_TCP, tcp_csum_offload (tc0));
   else
-    ih0 =
-      vlib_buffer_push_ip6_custom (vm, b0, &tc0->c_lcl_ip6, &tc0->c_rmt_ip6,
-				   IP_PROTOCOL_TCP, tc0->ipv6_flow_label);
-
+    vlib_buffer_push_ip6_custom (vm, b0, &tc0->c_lcl_ip6, &tc0->c_rmt_ip6,
+				 IP_PROTOCOL_TCP, tc0->ipv6_flow_label);
 }
 
 always_inline void
@@ -2356,9 +2171,6 @@ tcp_output_handle_packet (tcp_connection_t * tc0, vlib_buffer_t * b0,
 	}
     }
 
-  if (!TCP_ALWAYS_ACK)
-    tcp_timer_reset (tc0, TCP_TIMER_DELACK);
-
   tc0->segs_out += 1;
 }
 
@@ -2369,9 +2181,6 @@ tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
   u32 n_left_from, *from, thread_index = vm->thread_index;
   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
   u16 nexts[VLIB_FRAME_SIZE], *next;
-  vlib_node_runtime_t *error_node;
-
-  error_node = vlib_node_get_runtime (vm, tcp_node_index (output, is_ip4));
 
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
@@ -2409,8 +2218,8 @@ tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	  tcp_check_if_gso (tc0, b[0]);
 	  tcp_check_if_gso (tc1, b[1]);
 
-	  tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
-	  tcp_output_handle_packet (tc1, b[1], error_node, &next[1], is_ip4);
+	  tcp_output_handle_packet (tc0, b[0], node, &next[0], is_ip4);
+	  tcp_output_handle_packet (tc1, b[1], node, &next[1], is_ip4);
 	}
       else
 	{
@@ -2418,24 +2227,22 @@ tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	    {
 	      tcp_output_push_ip (vm, b[0], tc0, is_ip4);
 	      tcp_check_if_gso (tc0, b[0]);
-	      tcp_output_handle_packet (tc0, b[0], error_node, &next[0],
-					is_ip4);
+	      tcp_output_handle_packet (tc0, b[0], node, &next[0], is_ip4);
 	    }
 	  else
 	    {
-	      b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
+	      b[0]->error = node->errors[TCP_ERROR_INVALID_CONNECTION];
 	      next[0] = TCP_OUTPUT_NEXT_DROP;
 	    }
 	  if (tc1 != 0)
 	    {
 	      tcp_output_push_ip (vm, b[1], tc1, is_ip4);
 	      tcp_check_if_gso (tc1, b[1]);
-	      tcp_output_handle_packet (tc1, b[1], error_node, &next[1],
-					is_ip4);
+	      tcp_output_handle_packet (tc1, b[1], node, &next[1], is_ip4);
 	    }
 	  else
 	    {
-	      b[1]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
+	      b[1]->error = node->errors[TCP_ERROR_INVALID_CONNECTION];
 	      next[1] = TCP_OUTPUT_NEXT_DROP;
 	    }
 	}
@@ -2461,11 +2268,11 @@ tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	{
 	  tcp_output_push_ip (vm, b[0], tc0, is_ip4);
 	  tcp_check_if_gso (tc0, b[0]);
-	  tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
+	  tcp_output_handle_packet (tc0, b[0], node, &next[0], is_ip4);
 	}
       else
 	{
-	  b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
+	  b[0]->error = node->errors[TCP_ERROR_INVALID_CONNECTION];
 	  next[0] = TCP_OUTPUT_NEXT_DROP;
 	}
 
@@ -2551,8 +2358,8 @@ static uword
 tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 			 vlib_frame_t * from_frame, u8 is_ip4)
 {
+  u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
   u32 n_left_from, next_index, *from, *to_next;
-  u32 my_thread_index = vm->thread_index;
 
   from = vlib_frame_vector_args (from_frame);
   n_left_from = from_frame->n_vectors;
@@ -2567,11 +2374,10 @@ tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 
       while (n_left_from > 0 && n_left_to_next > 0)
 	{
-	  u32 bi0;
 	  vlib_buffer_t *b0;
 	  tcp_tx_trace_t *t0;
 	  tcp_header_t *th0;
-	  u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP;
+	  u32 bi0;
 
 	  bi0 = from[0];
 	  to_next[0] = bi0;
@@ -2581,20 +2387,11 @@ tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	  n_left_to_next -= 1;
 
 	  b0 = vlib_get_buffer (vm, bi0);
-
-	  if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags,
-				       my_thread_index, is_ip4))
-	    {
-	      error0 = TCP_ERROR_LOOKUP_DROPS;
-	      next0 = TCP_RESET_NEXT_DROP;
-	      goto done;
-	    }
+	  tcp_make_reset_in_place (vm, b0, is_ip4);
 
 	  /* Prepare to send to IP lookup */
 	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
-	  next0 = TCP_RESET_NEXT_IP_LOOKUP;
 
-	done:
 	  b0->error = node->errors[error0];
 	  b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
 	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))