#!/usr/bin/env python

from __future__ import print_function
import gc
import sys
import os
import select
import unittest
import tempfile
import time
import resource
from collections import deque
from threading import Thread, Event
from inspect import getdoc
from traceback import format_exception
from logging import FileHandler, DEBUG, Formatter
from scapy.packet import Raw
from hook import StepHook, PollHook
from vpp_pg_interface import VppPGInterface
from vpp_sub_interface import VppSubInterface
from vpp_lo_interface import VppLoInterface
from vpp_papi_provider import VppPapiProvider
from log import *
from vpp_object import VppObjectRegistry
if os.name == 'posix' and sys.version_info[0] < 3:
    # using subprocess32 is recommended by python official documentation
    # @ https://docs.python.org/2/library/subprocess.html
    import subprocess32 as subprocess
else:
    import subprocess

"""
  Test framework module.

  The module provides a set of tools for constructing and running tests and
  representing the results.
"""


class _PacketInfo(object):
    """Private class to create packet info object.

    Help process information about the next packet.
    Set variables to default values.
    """
    #: Store the index of the packet.
    index = -1
    #: Store the index of the source packet generator interface of the packet.
    src = -1
    #: Store the index of the destination packet generator interface
    #: of the packet.
    dst = -1
    #: Store the copy of the former packet.
    data = None

    def __eq__(self, other):
        index = self.index == other.index
        src = self.src == other.src
        dst = self.dst == other.dst
        data = self.data == other.data
        return index and src and dst and data


def pump_output(testclass):
    """ pump output from vpp stdout/stderr to proper queues """
    while not testclass.pump_thread_stop_flag.wait(0):
        readable = select.select([testclass.vpp.stdout.fileno(),
                                  testclass.vpp.stderr.fileno(),
                                  testclass.pump_thread_wakeup_pipe[0]],
                                 [], [])[0]
        if testclass.vpp.stdout.fileno() in readable:
            read = os.read(testclass.vpp.stdout.fileno(), 1024)
            testclass.vpp_stdout_deque.append(read)
        if testclass.vpp.stderr.fileno() in readable:
            read = os.read(testclass.vpp.stderr.fileno(), 1024)
            testclass.vpp_stderr_deque.append(read)
        # ignoring the dummy pipe here intentionally - the flag will take care
        # of properly terminating the loop


class VppTestCase(unittest.TestCase):
    """This subclass is a base class for VPP test cases that are implemented as
    classes. It provides methods to create and run test case.
    """

    @property
    def packet_infos(self):
        """List of packet infos"""
        return self._packet_infos

    @classmethod
    def get_packet_count_for_if_idx(cls, dst_if_index):
        """Get the number of packet info for specified destination if index"""
        if dst_if_index in cls._packet_count_for_dst_if_idx:
            return cls._packet_count_for_dst_if_idx[dst_if_index]
        else:
            return 0

    @classmethod
    def instance(cls):
        """Return the instance of this testcase"""
        return cls.test_instance

    @classmethod
    def set_debug_flags(cls, d):
        cls.debug_core = False
        cls.debug_gdb = False
        cls.debug_gdbserver = False
        if d is None:
            return
        dl = d.lower()
        if dl == "core":
            if resource.getrlimit(resource.RLIMIT_CORE)[0] <= 0:
                # give a heads up if this is actually useless
                print(colorize("WARNING: core size limit is set 0, core files "
                               "will NOT be created", RED))
            cls.debug_core = True
        elif dl == "gdb":
            cls.debug_gdb = True
        elif dl == "gdbserver":
            cls.debug_gdbserver = True
        else:
            raise Exception("Unrecognized DEBUG option: '%s'" % d)

    @classmethod
    def setUpConstants(cls):
        """ Set-up the test case class based on environment variables """
        try:
            s = os.getenv("STEP")
            cls.step = True if s.lower() in ("y", "yes", "1") else False
        except:
            cls.step = False
        try:
            d = os.getenv("DEBUG")
        except:
            d = None
        cls.set_debug_flags(d)
        cls.vpp_bin = os.getenv('VPP_TEST_BIN', "vpp")
        cls.plugin_path = os.getenv('VPP_TEST_PLUGIN_PATH')
        debug_cli = ""
        if cls.step or cls.debug_gdb or cls.debug_gdbserver:
            debug_cli = "cli-listen localhost:5002"
        cls.vpp_cmdline = [cls.vpp_bin,
                           "unix", "{", "nodaemon", debug_cli, "}",
                           "api-trace", "{", "on", "}",
                           "api-segment", "{", "prefix", cls.shm_prefix, "}"]
        if cls.plugin_path is not None:
            cls.vpp_cmdline.extend(["plugin_path", cls.plugin_path])
        cls.logger.info("vpp_cmdline: %s" % cls.vpp_cmdline)

    @classmethod
    def wait_for_enter(cls):
        if cls.debug_gdbserver:
            print(double_line_delim)
            print("Spawned GDB server with PID: %d" % cls.vpp.pid)
        elif cls.debug_gdb:
            print(double_line_delim)
            print("Spawned VPP with PID: %d" % cls.vpp.pid)
        else:
            cls.logger.debug("Spawned VPP with PID: %d" % cls.vpp.pid)
            return
        print(single_line_delim)
        print("You can debug the VPP using e.g.:")
        if cls.debug_gdbserver:
            print("gdb " + cls.vpp_bin + " -ex 'target remote localhost:7777'")
            print("Now is the time to attach a gdb by running the above "
                  "command, set up breakpoints etc. and then resume VPP from "
                  "within gdb by issuing the 'continue' command")
        elif cls.debug_gdb:
            print("gdb " + cls.vpp_bin + " -ex 'attach %s'" % cls.vpp.pid)
            print("Now is the time to attach a gdb by running the above "
                  "command and set up breakpoints etc.")
        print(single_line_delim)
        raw_input("Press ENTER to continue running the testcase...")

    @classmethod
    def run_vpp(cls):
        cmdline = cls.vpp_cmdline

        if cls.debug_gdbserver:
            gdbserver = '/usr/bin/gdbserver'
            if not os.path.isfile(gdbserver) or \
                    not os.access(gdbserver, os.X_OK):
                raise Exception("gdbserver binary '%s' does not exist or is "
                                "not executable" % gdbserver)

            cmdline = [gdbserver, 'localhost:7777'] + cls.vpp_cmdline
            cls.logger.info("Gdbserver cmdline is %s", " ".join(cmdline))

        try:
            cls.vpp = subprocess.Popen(cmdline,
                                       stdout=subprocess.PIPE,
                                       stderr=subprocess.PIPE,
                                       bufsize=1)
        except Exception as e:
            cls.logger.critical("Couldn't start vpp: %s" % e)
            raise

        cls.wait_for_enter()

    @classmethod
    def setUpClass(cls):
        """
        Perform class setup before running the testcase
        Remove shared memory files, start vpp and connect the vpp-api
        """
        gc.collect()  # run garbage collection first
        cls.logger = getLogger(cls.__name__)
        cls.tempdir = tempfile.mkdtemp(
            prefix='vpp-unittest-' + cls.__name__ + '-')
        file_handler = FileHandler("%s/log.txt" % cls.tempdir)
        file_handler.
/*
 * 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.
 */

/**
 * @file
 * @brief TCP host stack utilities
 */

#include <vnet/tcp/tcp.h>
#include <vnet/session/session.h>
#include <vnet/fib/fib.h>
#include <vnet/dpo/load_balance.h>
#include <vnet/dpo/receive_dpo.h>
#include <vnet/ip/ip6_neighbor.h>
#include <math.h>

tcp_main_t tcp_main;

static u32
tcp_connection_bind (u32 session_index, transport_endpoint_t * lcl)
{
  tcp_main_t *tm = &tcp_main;
  tcp_connection_t *listener;

  pool_get (tm->listener_pool, listener);
  memset (listener, 0, sizeof (*listener));

  listener->c_c_index = listener - tm->listener_pool;
  listener->c_lcl_port = lcl->port;

  if (lcl->is_ip4)
    {
      listener->c_lcl_ip4.as_u32 = lcl->ip.ip4.as_u32;
      listener->c_is_ip4 = 1;
    }
  else
    {
      clib_memcpy (&listener->c_lcl_ip6, &lcl->ip.ip6,
		   sizeof (ip6_address_t));

    }
  listener->c_transport_proto = TRANSPORT_PROTO_TCP;
  listener->c_s_index = session_index;
  listener->state = TCP_STATE_LISTEN;

  tcp_connection_timers_init (listener);

  TCP_EVT_DBG (TCP_EVT_BIND, listener);

  return listener->c_c_index;
}

u32
tcp_session_bind (u32 session_index, transport_endpoint_t * tep)
{
  return tcp_connection_bind (session_index, tep);
}

static void
tcp_connection_unbind (u32 listener_index)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  tcp_connection_t *tc;

  tc = pool_elt_at_index (tm->listener_pool, listener_index);

  TCP_EVT_DBG (TCP_EVT_UNBIND, tc);

  /* Poison the entry */
  if (CLIB_DEBUG > 0)
    memset (tc, 0xFA, sizeof (*tc));

  pool_put_index (tm->listener_pool, listener_index);
}

u32
tcp_session_unbind (u32 listener_index)
{
  tcp_connection_unbind (listener_index);
  return 0;
}

transport_connection_t *
tcp_session_get_listener (u32 listener_index)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  tcp_connection_t *tc;
  tc = pool_elt_at_index (tm->listener_pool, listener_index);
  return &tc->connection;
}

always_inline void
transport_endpoint_del (u32 tepi)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  clib_spinlock_lock_if_init (&tm->local_endpoints_lock);
  pool_put_index (tm->local_endpoints, tepi);
  clib_spinlock_unlock_if_init (&tm->local_endpoints_lock);
}

always_inline transport_endpoint_t *
transport_endpoint_new (void)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  transport_endpoint_t *tep;
  pool_get (tm->local_endpoints, tep);
  return tep;
}

/**
 * Cleanup half-open connection
 *
 */
void
tcp_half_open_connection_del (tcp_connection_t * tc)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  clib_spinlock_lock_if_init (&tm->half_open_lock);
  pool_put_index (tm->half_open_connections, tc->c_c_index);
  if (CLIB_DEBUG)
    memset (tc, 0xFA, sizeof (*tc));
  clib_spinlock_unlock_if_init (&tm->half_open_lock);
}

/**
 * Try to cleanup half-open connection
 *
 * If called from a thread that doesn't own tc, the call won't have any
 * effect.
 *
 * @param tc - connection to be cleaned up
 * @return non-zero if cleanup failed.
 */
int
tcp_half_open_connection_cleanup (tcp_connection_t * tc)
{
  /* Make sure this is the owning thread */
  if (tc->c_thread_index != vlib_get_thread_index ())
    return 1;
  tcp_timer_reset (tc, TCP_TIMER_ESTABLISH);
  tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT_SYN);
  tcp_half_open_connection_del (tc);
  return 0;
}

tcp_connection_t *
tcp_half_open_connection_new (void)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  tcp_connection_t *tc = 0;
  ASSERT (vlib_get_thread_index () == 0);
  pool_get (tm->half_open_connections, tc);
  memset (tc, 0, sizeof (*tc));
  tc->c_c_index = tc - tm->half_open_connections;
  return tc;
}

/**
 * Cleans up connection state.
 *
 * No notifications.
 */
void
tcp_connection_cleanup (tcp_connection_t * tc)
{
  tcp_main_t *tm = &tcp_main;
  u32 tepi;
  transport_endpoint_t *tep;

  /* Cleanup local endpoint if this was an active connect */
  tepi = transport_endpoint_lookup (&tm->local_endpoints_table, &tc->c_lcl_ip,
				    clib_net_to_host_u16 (tc->c_lcl_port));
  if (tepi != TRANSPORT_ENDPOINT_INVALID_INDEX)
    {
      tep = pool_elt_at_index (tm->local_endpoints, tepi);
      transport_endpoint_table_del (&tm->local_endpoints_table, tep);
      transport_endpoint_del (tepi);
    }

  /* Check if connection is not yet fully established */
  if (tc->state == TCP_STATE_SYN_SENT)
    {
      /* Try to remove the half-open connection. If this is not the owning
       * thread, tc won't be removed. Retransmit or establish timers will
       * eventually expire and call again cleanup on the right thread. */
      tcp_half_open_connection_cleanup (tc);
    }
  else
    {
      int thread_index = tc->c_thread_index;

      /* Make sure all timers are cleared */
      tcp_connection_timers_reset (tc);

      /* Poison the entry */
      if (CLIB_DEBUG > 0)
	memset (tc, 0xFA, sizeof (*tc));
      pool_put (tm->connections[thread_index], tc);
    }
}

/**
 * Connection removal.
 *
 * This should be called only once connection enters CLOSED state. Note
 * that it notifies the session of the removal event, so if the goal is to
 * just remove the connection, call tcp_connection_cleanup instead.
 */
void
tcp_connection_del (tcp_connection_t * tc)
{
  TCP_EVT_DBG (TCP_EVT_DELETE, tc);
  stream_session_delete_notify (&tc->connection);
  tcp_connection_cleanup (tc);
}

tcp_connection_t *
tcp_connection_new (u8 thread_index)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  tcp_connection_t *tc;

  pool_get (tm->connections[thread_index], tc);
  memset (tc, 0, sizeof (*tc));
  tc->c_c_index = tc - tm->connections[thread_index];
  tc->c_thread_index = thread_index;
  return tc;
}

/** Notify session that connection has been reset.
 *
 * Switch state to closed and wait for session to call cleanup.
 */
void
tcp_connection_reset (tcp_connection_t * tc)
{
  TCP_EVT_DBG (TCP_EVT_RST_RCVD, tc);
  switch (tc->state)
    {
    case TCP_STATE_SYN_RCVD:
      /* Cleanup everything. App wasn't notified yet */
      stream_session_delete_notify (&tc->connection);
      tcp_connection_cleanup (tc);
      break;
    case TCP_STATE_SYN_SENT:
      stream_session_connect_notify (&tc->connection, 1 /* fail */ );
      tcp_connection_cleanup (tc);
      break;
    case TCP_STATE_ESTABLISHED:
    case TCP_STATE_CLOSE_WAIT:
    case TCP_STATE_FIN_WAIT_1:
    case TCP_STATE_FIN_WAIT_2:
    case TCP_STATE_CLOSING:
      tc->state = TCP_STATE_CLOSED;
      TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc);

      /* Make sure all timers are cleared */
      tcp_connection_timers_reset (tc);
      stream_session_reset_notify (&tc->connection);

      /* Wait for cleanup from session layer but not forever */
      tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
      break;
    case TCP_STATE_CLOSED:
      return;
    }
}

/**
 * Begin connection closing procedure.
 *
 * If at the end the connection is not in CLOSED state, it is not removed.
 * Instead, we rely on on TCP to advance through state machine to either
 * 1) LAST_ACK (passive close) whereby when the last ACK is received
 * tcp_connection_del is called. This notifies session of the delete and
 * calls cleanup.
 * 2) TIME_WAIT (active close) whereby after 2MSL the 2MSL timer triggers
 * and cleanup is called.
 *
 * N.B. Half-close connections are not supported
 */
void
tcp_connection_close (tcp_connection_t * tc)
{
  TCP_EVT_DBG (TCP_EVT_CLOSE, tc);

  /* Send/Program FIN if needed and switch state */
  switch (tc->state)
    {
    case TCP_STATE_SYN_SENT:
      tc->state = TCP_STATE_CLOSED;
      break;
    case TCP_STATE_SYN_RCVD:
      tcp_send_fin (tc);
      tc->state = TCP_STATE_FIN_WAIT_1;
      break;
    case TCP_STATE_ESTABLISHED:
      if (!stream_session_tx_fifo_max_dequeue (&tc->connection))
	tcp_send_fin (tc);
      else
	tc->flags |= TCP_CONN_FINPNDG;
      tc->state = TCP_STATE_FIN_WAIT_1;
      break;
    case TCP_STATE_CLOSE_WAIT:
      tcp_connection_timers_reset (tc);
      tcp_send_fin (tc);
      tc->state = TCP_STATE_LAST_ACK;
      tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
      break;
    case TCP_STATE_FIN_WAIT_1:
      tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
      break;
    default:
      TCP_DBG ("state: %u", tc->state);
    }

  TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc);

  /* If in CLOSED and WAITCLOSE timer is not set, delete connection now */
  if (!tcp_timer_is_active (tc, TCP_TIMER_WAITCLOSE)
      && tc->state == TCP_STATE_CLOSED)
    tcp_connection_del (tc);
}

void
tcp_session_close (u32 conn_index, u32 thread_index)
{
  tcp_connection_t *tc;
  tc = tcp_connection_get (conn_index, thread_index);
  tcp_connection_close (tc);
}

void
tcp_session_cleanup (u32 conn_index, u32 thread_index)
{
  tcp_connection_t *tc;
  tc = tcp_connection_get (conn_index, thread_index);
  tcp_connection_timers_reset (tc);

  /* Wait for the session tx events to clear */
  tc->state = TCP_STATE_CLOSED;
  TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc);
  tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
}

void *
ip_interface_get_first_ip (u32 sw_if_index, u8 is_ip4)
{
  ip_lookup_main_t *lm4 = &ip4_main.lookup_main;
  ip_lookup_main_t *lm6 = &ip6_main.lookup_main;
  ip_interface_address_t *ia = 0;

  if (is_ip4)
    {
      /* *INDENT-OFF* */
      foreach_ip_interface_address (lm4, ia, sw_if_index, 1 /* unnumbered */ ,
      ({
        return ip_interface_address_get_address (lm4, ia);
      }));
      /* *INDENT-ON* */
    }
  else
    {
      /* *INDENT-OFF* */
      foreach_ip_interface_address (lm6, ia, sw_if_index, 1 /* unnumbered */ ,
      ({
        ip6_address_t *rv;
        rv = ip_interface_address_get_address (lm6, ia);
        /* Trying to use a link-local ip6 src address is a fool's errand */
        if (!ip6_address_is_link_local_unicast (rv))
          return rv;
      }));
      /* *INDENT-ON* */
    }

  return 0;
}

#define PORT_MASK ((1 << 16)- 1)
/**
 * Allocate local port and add if successful add entry to local endpoint
 * table to mark the pair as used.
 */
int
tcp_allocate_local_port (ip46_address_t * ip)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  transport_endpoint_t *tep;
  u32 tei;
  u16 min = 1024, max = 65535;	/* XXX configurable ? */
  int tries, limit;

  limit = max - min;

  /* Only support active opens from thread 0 */
  ASSERT (vlib_get_thread_index () == 0);

  /* Search for first free slot */
  for (tries = 0; tries < limit; tries++)
    {
      u16 port = 0;

      /* Find a port in the specified range */
      while (1)
	{
	  port = random_u32 (&tm->port_allocator_seed) & PORT_MASK;
	  if (PREDICT_TRUE (port >= min && port < max))
	    break;
	}

      /* Look it up */
      tei = transport_endpoint_lookup (&tm->local_endpoints_table, ip, port);
      /* If not found, we're done */
      if (tei == TRANSPORT_ENDPOINT_INVALID_INDEX)
	{
	  clib_spinlock_lock_if_init (&tm->local_endpoints_lock);
	  tep = transport_endpoint_new ();
	  clib_memcpy (&tep->ip, ip, sizeof (*ip));
	  tep->port = port;
	  transport_endpoint_table_add (&tm->local_endpoints_table, tep,
					tep - tm->local_endpoints);
	  clib_spinlock_unlock_if_init (&tm->local_endpoints_lock);

	  return tep->port;
	}
    }
  return -1;
}

/**
 * Initialize all connection timers as invalid
 */
void
tcp_connection_timers_init (tcp_connection_t * tc)
{
  int i;

  /* Set all to invalid */
  for (i = 0; i < TCP_N_TIMERS; i++)
    {
      tc->timers[i] = TCP_TIMER_HANDLE_INVALID;
    }

  tc->rto = TCP_RTO_INIT;
}

/**
 * Stop all connection timers
 */
void
tcp_connection_timers_reset (tcp_connection_t * tc)
{
  int i;
  for (i = 0; i < TCP_N_TIMERS; i++)
    {
      tcp_timer_reset (tc, i);
    }
}

#if 0
typedef struct ip4_tcp_hdr
{
  ip4_header_t ip;
  tcp_header_t tcp;
} ip4_tcp_hdr_t;

typedef struct ip6_tcp_hdr
{
  ip6_header_t ip;
  tcp_header_t tcp;
} ip6_tcp_hdr_t;

static void
tcp_connection_select_lb_bucket (tcp_connection_t * tc, const dpo_id_t * dpo,
				 dpo_id_t * result)
{
  const dpo_id_t *choice;
  load_balance_t *lb;
  int hash;

  lb = load_balance_get (dpo->dpoi_index);
  if (tc->c_is_ip4)
    {
      ip4_tcp_hdr_t hdr;
      memset (&hdr, 0, sizeof (hdr));
      hdr.ip.protocol = IP_PROTOCOL_TCP;
      hdr.ip.address_pair.src.as_u32 = tc->c_lcl_ip.ip4.as_u32;
      hdr.ip.address_pair.dst.as_u32 = tc->c_rmt_ip.ip4.as_u32;
      hdr.tcp.src_port = tc->c_lcl_port;
      hdr.tcp.dst_port = tc->c_rmt_port;
      hash = ip4_compute_flow_hash (&hdr.ip, lb->lb_hash_config);
    }
  else
    {
      ip6_tcp_hdr_t hdr;
      memset (&hdr, 0, sizeof (hdr));
      hdr.ip.protocol = IP_PROTOCOL_TCP;
      clib_memcpy (&hdr.ip.src_address, &tc->c_lcl_ip.ip6,
		   sizeof (ip6_address_t));
      clib_memcpy (&hdr.ip.dst_address, &tc->c_rmt_ip.ip6,
		   sizeof (ip6_address_t));
      hdr.tcp.src_port = tc->c_lcl_port;
      hdr.tcp.dst_port = tc->c_rmt_port;
      hash = ip6_compute_flow_hash (&hdr.ip, lb->lb_hash_config);
    }
  choice = load_balance_get_bucket_i (lb, hash & lb->lb_n_buckets_minus_1);
  dpo_copy (result, choice);
}

fib_node_index_t
tcp_lookup_rmt_in_fib (tcp_connection_t * tc)
{
  fib_prefix_t prefix;
  u32 fib_index;

  clib_memcpy (&prefix.fp_addr, &tc->c_rmt_ip, sizeof (prefix.fp_addr));
  prefix.fp_proto = tc->c_is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
  prefix.fp_len = tc->c_is_ip4 ? 32 : 128;
  fib_index = fib_table_find (prefix.fp_proto, tc->c_vrf);
  return fib_table_lookup (fib_index, &prefix);
}

static int
tcp_connection_stack_on_fib_entry (tcp_connection_t * tc)
{
  dpo_id_t choice = DPO_INVALID;
  u32 output_node_index;
  fib_entry_t *fe;

  fe = fib_entry_get (tc->c_rmt_fei);
  if (fe->fe_lb.dpoi_type != DPO_LOAD_BALANCE)
    return -1;

  tcp_connection_select_lb_bucket (tc, &fe->fe_lb, &choice);

  output_node_index =
    tc->c_is_ip4 ? tcp4_output_node.index : tcp6_output_node.index;
  dpo_stack_from_node (output_node_index, &tc->c_rmt_dpo, &choice);
  return 0;
}

/** Stack tcp connection on peer's fib entry.
 *
 * This ultimately populates the dpo the connection will use to send packets.
 */
static void
tcp_connection_fib_attach (tcp_connection_t * tc)
{
  tc->c_rmt_fei = tcp_lookup_rmt_in_fib (tc);

  ASSERT (tc->c_rmt_fei != FIB_NODE_INDEX_INVALID);

  tcp_connection_stack_on_fib_entry (tc);
}
#endif /* 0 */

/**
 * Initialize connection send variables.
 */
void
tcp_init_snd_vars (tcp_connection_t * tc)
{
  u32 time_now;

  /* Set random initial sequence */
  time_now = tcp_time_now ();
  tc->iss = random_u32 (&time_now);
  tc->snd_una = tc->iss;
  tc->snd_nxt = tc->iss + 1;
  tc->snd_una_max = tc->snd_nxt;
}

/** Initialize tcp connection variables
 *
 * Should be called after having received a msg from the peer, i.e., a SYN or
 * a SYNACK, such that connection options have already been exchanged. */
void
tcp_connection_init_vars (tcp_connection_t * tc)
{
  tcp_connection_timers_init (tc);
  tcp_init_mss (tc);
  scoreboard_init (&tc->sack_sb);
  tcp_cc_init (tc);
  if (tc->state == TCP_STATE_SYN_RCVD)
    tcp_init_snd_vars (tc);

  //  tcp_connection_fib_attach (tc);
}

int
tcp_connection_open (transport_endpoint_t * rmt)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  tcp_connection_t *tc;
  fib_prefix_t prefix;
  fib_node_index_t fei;
  u32 sw_if_index, fib_index;
  ip46_address_t lcl_addr;
  int lcl_port;

  /*
   * Find the local address and allocate port
   */
  memset (&lcl_addr, 0, sizeof (lcl_addr));

  /* Find a FIB path to the destination */
  clib_memcpy (&prefix.fp_addr, &rmt->ip, sizeof (rmt->ip));
  prefix.fp_proto = rmt->is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
  prefix.fp_len = rmt->is_ip4 ? 32 : 128;

  fib_index = fib_table_find (prefix.fp_proto, rmt->vrf);
  if (fib_index == (u32) ~ 0)
    {
      clib_warning ("no fib table");
      return -1;
    }

  fei = fib_table_lookup (fib_index, &prefix);

  /* Couldn't find route to destination. Bail out. */
  if (fei == FIB_NODE_INDEX_INVALID)
    {
      clib_warning ("no route to destination");
      return -1;
    }

  sw_if_index = fib_entry_get_resolving_interface (fei);

  if (sw_if_index == (u32) ~ 0)
    {
      clib_warning ("no resolving interface for %U", format_ip46_address,
		    &rmt->ip, IP46_TYPE_IP4);
      return -1;
    }

  if (rmt->is_ip4)
    {
      ip4_address_t *ip4;
      int index;
      if (vec_len (tm->ip4_src_addresses))
	{
	  index = tm->last_v4_address_rotor++;
	  if (tm->last_v4_address_rotor >= vec_len (tm->ip4_src_addresses))
	    tm->last_v4_address_rotor = 0;
	  lcl_addr.ip4.as_u32 = tm->ip4_src_addresses[index].as_u32;
	}
      else
	{
	  ip4 = ip_interface_get_first_ip (sw_if_index, 1);
	  lcl_addr.ip4.as_u32 = ip4->as_u32;
	}
    }
  else
    {
      ip6_address_t *ip6;
      int index;

      if (vec_len (tm->ip6_src_addresses))
	{
	  index = tm->last_v6_address_rotor++;
	  if (tm->last_v6_address_rotor >= vec_len (tm->ip6_src_addresses))
	    tm->last_v6_address_rotor = 0;
	  clib_memcpy (&lcl_addr.ip6, &tm->ip6_src_addresses[index],
		       sizeof (*ip6));
	}
      else
	{
	  ip6 = ip_interface_get_first_ip (sw_if_index, 0);
	  if (ip6 == 0)
	    {
	      clib_warning ("no routable ip6 addresses on %U",
			    format_vnet_sw_if_index_name, vnet_get_main (),
			    sw_if_index);
	      return -1;
	    }

	  clib_memcpy (&lcl_addr.ip6, ip6, sizeof (*ip6));
	}
    }

  /* Allocate source port */
  lcl_port = tcp_allocate_local_port (&lcl_addr);
  if (lcl_port < 1)
    {
      clib_warning ("Failed to allocate src port");
      return -1;
    }

  /*
   * Create connection and send SYN
   */
  clib_spinlock_lock_if_init (&tm->half_open_lock);
  tc = tcp_half_open_connection_new ();
  clib_memcpy (&tc->c_rmt_ip, &rmt->ip, sizeof (ip46_address_t));
  clib_memcpy (&tc->c_lcl_ip, &lcl_addr, sizeof (ip46_address_t));
  tc->c_rmt_port = rmt->port;
  tc->c_lcl_port = clib_host_to_net_u16 (lcl_port);
  tc->c_is_ip4 = rmt->is_ip4;
  tc->c_transport_proto = TRANSPORT_PROTO_TCP;
  tc->c_vrf = rmt->vrf;
  /* The other connection vars will be initialized after SYN ACK */
  tcp_connection_timers_init (tc);

  TCP_EVT_DBG (TCP_EVT_OPEN, tc);
  tc->state = TCP_STATE_SYN_SENT;
  tcp_init_snd_vars (tc);
  tcp_send_syn (tc);
  clib_spinlock_unlock_if_init (&tm->half_open_lock);

  return tc->c_c_index;
}

int
tcp_session_open (transport_endpoint_t * tep)
{
  return tcp_connection_open (tep);
}

const char *tcp_dbg_evt_str[] = {
#define _(sym, str) str,
  foreach_tcp_dbg_evt
#undef _
};

const char *tcp_fsm_states[] = {
#define _(sym, str) str,
  foreach_tcp_fsm_state
#undef _
};

u8 *
format_tcp_state (u8 * s, va_list * args)
{
  u32 state = va_arg (*args, u32);

  if (state < TCP_N_STATES)
    s = format (s, "%s", tcp_fsm_states[state]);
  else
    s = format (s, "UNKNOWN (%d (0x%x))", state, state);
  return s;
}

const char *tcp_connection_flags_str[] = {
#define _(sym, str) str,
  foreach_tcp_connection_flag
#undef _
};

u8 *
format_tcp_connection_flags (u8 * s, va_list * args)
{
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  int i, last = -1;

  for (i = 0; i < TCP_CONN_N_FLAG_BITS; i++)
    if (tc->flags & (1 << i))
      last = i;
  for (i = 0; i < last; i++)
    {
      if (tc->flags & (1 << i))
	s = format (s, "%s, ", tcp_connection_flags_str[i]);
    }
  if (last >= 0)
    s = format (s, "%s", tcp_connection_flags_str[last]);
  return s;
}

const char *tcp_conn_timers[] = {
#define _(sym, str) str,
  foreach_tcp_timer
#undef _
};

u8 *
format_tcp_timers (u8 * s, va_list * args)
{
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  int i, last = -1;

  for (i = 0; i < TCP_N_TIMERS; i++)
    if (tc->timers[i] != TCP_TIMER_HANDLE_INVALID)
      last = i;

  s = format (s, "[");
  for (i = 0; i < last; i++)
    {
      if (tc->timers[i] != TCP_TIMER_HANDLE_INVALID)
	s = format (s, "%s,", tcp_conn_timers[i]);
    }

  if (last >= 0)
    s = format (s, "%s]", tcp_conn_timers[i]);
  else
    s = format (s, "]");

  return s;
}

u8 *
format_tcp_congestion_status (u8 * s, va_list * args)
{
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  if (tcp_in_recovery (tc))
    s = format (s, "recovery");
  else if (tcp_in_fastrecovery (tc))
    s = format (s, "fastrecovery");
  else
    s = format (s, "none");
  return s;
}

u8 *
format_tcp_vars (u8 * s, va_list * args)
{
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  s = format (s, " flags: %U timers: %U\n", format_tcp_connection_flags, tc,
	      format_tcp_timers, tc);
  s = format (s, " snd_una %u snd_nxt %u snd_una_max %u",
	      tc->snd_una - tc->iss, tc->snd_nxt - tc->iss,
	      tc->snd_una_max - tc->iss);
  s = format (s, " rcv_nxt %u rcv_las %u\n",
	      tc->rcv_nxt - tc->irs, tc->rcv_las - tc->irs);
  s = format (s, " snd_wnd %u rcv_wnd %u snd_wl1 %u snd_wl2 %u\n",
	      tc->snd_wnd, tc->rcv_wnd, tc->snd_wl1 - tc->irs,
	      tc->snd_wl2 - tc->iss);
  s = format (s, " flight size %u send space %u rcv_wnd_av %d\n",
	      tcp_flight_size (tc), tcp_available_output_snd_space (tc),
	      tcp_rcv_wnd_available (tc));
  s = format (s, " cong %U ", format_tcp_congestion_status, tc);
  s = format (s, "cwnd %u ssthresh %u rtx_bytes %u bytes_acked %u\n",
	      tc->cwnd, tc->ssthresh, tc->snd_rxt_bytes, tc->bytes_acked);
  s = format (s, " prev_ssthresh %u snd_congestion %u dupack %u",
	      tc->prev_ssthresh, tc->snd_congestion - tc->iss,
	      tc->rcv_dupacks);
  s = format (s, " limited_transmit %u\n", tc->limited_transmit - tc->iss);
  s = format (s, " tsecr %u tsecr_last_ack %u\n", tc->rcv_opts.tsecr,
	      tc->tsecr_last_ack);
  s = format (s, " rto %u rto_boff %u srtt %u rttvar %u rtt_ts %u ", tc->rto,
	      tc->rto_boff, tc->srtt, tc->rttvar, tc->rtt_ts);
  s = format (s, "rtt_seq %u\n", tc->rtt_seq);
  s = format (s, " tsval_recent %u tsval_recent_age %u\n", tc->tsval_recent,
	      tcp_time_now () - tc->tsval_recent_age);
  s = format (s, " scoreboard: %U\n", format_tcp_scoreboard, &tc->sack_sb,
	      tc);
  if (vec_len (tc->snd_sacks))
    s = format (s, " sacks tx: %U\n", format_tcp_sacks, tc);

  return s;
}

u8 *
format_tcp_connection_id (u8 * s, va_list * args)
{
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  if (!tc)
    return s;
  if (tc->c_is_ip4)
    {
      s = format (s, "[#%d][%s] %U:%d->%U:%d", tc->c_thread_index, "T",
		  format_ip4_address, &tc->c_lcl_ip4,
		  clib_net_to_host_u16 (tc->c_lcl_port), format_ip4_address,
		  &tc->c_rmt_ip4, clib_net_to_host_u16 (tc->c_rmt_port));
    }
  else
    {
      s = format (s, "[#%d][%s] %U:%d->%U:%d", tc->c_thread_index, "T",
		  format_ip6_address, &tc->c_lcl_ip6,
		  clib_net_to_host_u16 (tc->c_lcl_port), format_ip6_address,
		  &tc->c_rmt_ip6, clib_net_to_host_u16 (tc->c_rmt_port));
    }

  return s;
}

u8 *
format_tcp_connection (u8 * s, va_list * args)
{
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  u32 verbose = va_arg (*args, u32);

  if (!tc)
    return s;
  s = format (s, "%-50U", format_tcp_connection_id, tc);
  if (verbose)
    {
      s = format (s, "%-15U", format_tcp_state, tc->state);
      if (verbose > 1)
	s = format (s, "\n%U", format_tcp_vars, tc);
    }

  return s;
}

u8 *
format_tcp_session (u8 * s, va_list * args)
{
  u32 tci = va_arg (*args, u32);
  u32 thread_index = va_arg (*args, u32);
  u32 verbose = va_arg (*args, u32);
  tcp_connection_t *tc;

  tc = tcp_connection_get (tci, thread_index);
  if (tc)
    s = format (s, "%U", format_tcp_connection, tc, verbose);
  else
    s = format (s, "empty\n");
  return s;
}

u8 *
format_tcp_listener_session (u8 * s, va_list * args)
{
  u32 tci = va_arg (*args, u32);
  tcp_connection_t *tc = tcp_listener_get (tci);
  return format (s, "%U", format_tcp_connection_id, tc);
}

u8 *
format_tcp_half_open_session (u8 * s, va_list * args)
{
  u32 tci = va_arg (*args, u32);
  tcp_connection_t *tc = tcp_half_open_connection_get (tci);
  return format (s, "%U", format_tcp_connection_id, tc);
}

u8 *
format_tcp_sacks (u8 * s, va_list * args)
{
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  sack_block_t *sacks = tc->snd_sacks;
  sack_block_t *block;
  int i, len = 0;

  len = vec_len (sacks);
  for (i = 0; i < len - 1; i++)
    {
      block = &sacks[i];
      s = format (s, " start %u end %u\n", block->start - tc->irs,
		  block->end - tc->irs);
    }
  if (len)
    {
      block = &sacks[len - 1];
      s = format (s, " start %u end %u", block->start - tc->irs,
		  block->end - tc->irs);
    }
  return s;
}

u8 *
format_tcp_rcv_sacks (u8 * s, va_list * args)
{
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  sack_block_t *sacks = tc->rcv_opts.sacks;
  sack_block_t *block;
  int i, len = 0;

  len = vec_len (sacks);
  for (i = 0; i < len - 1; i++)
    {
      block = &sacks[i];
      s = format (s, " start %u end %u\n", block->start - tc->iss,
		  block->end - tc->iss);
    }
  if (len)
    {
      block = &sacks[len - 1];
      s = format (s, " start %u end %u", block->start - tc->iss,
		  block->end - tc->iss);
    }
  return s;
}

u8 *
format_tcp_sack_hole (u8 * s, va_list * args)
{
  sack_scoreboard_hole_t *hole = va_arg (*args, sack_scoreboard_hole_t *);
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  if (tc)
    s = format (s, "  [%u, %u]", hole->start - tc->iss, hole->end - tc->iss);
  else
    s = format (s, "  [%u, %u]", hole->start, hole->end);
  return s;
}

u8 *
format_tcp_scoreboard (u8 * s, va_list * args)
{
  sack_scoreboard_t *sb = va_arg (*args, sack_scoreboard_t *);
  tcp_connection_t *tc = va_arg (*args, tcp_connection_t *);
  sack_scoreboard_hole_t *hole;
  s = format (s, "sacked_bytes %u last_sacked_bytes %u lost_bytes %u\n",
	      sb->sacked_bytes, sb->last_sacked_bytes, sb->lost_bytes);
  s = format (s, " last_bytes_delivered %u high_sacked %u snd_una_adv %u\n",
	      sb->last_bytes_delivered, sb->high_sacked, sb->snd_una_adv);
  s = format (s, " cur_rxt_hole %u high_rxt %u rescue_rxt %u",
	      sb->cur_rxt_hole, sb->high_rxt, sb->rescue_rxt);

  hole = scoreboard_first_hole (sb);
  if (hole)
    s = format (s, "\n head %u tail %u holes:\n", sb->head, sb->tail);

  while (hole)
    {
      s = format (s, "%U", format_tcp_sack_hole, hole, tc);
      hole = scoreboard_next_hole (sb, hole);
    }

  return s;
}

transport_connection_t *
tcp_session_get_transport (u32 conn_index, u32 thread_index)
{
  tcp_connection_t *tc = tcp_connection_get (conn_index, thread_index);
  return &tc->connection;
}

transport_connection_t *
tcp_half_open_session_get_transport (u32 conn_index)
{
  tcp_connection_t *tc = tcp_half_open_connection_get (conn_index);
  return &tc->connection;
}

/**
 * Compute maximum segment size for session layer.
 *
 * Since the result needs to be the actual data length, it first computes
 * the tcp options to be used in the next burst and subtracts their
 * length from the connection's snd_mss.
 */
u16
tcp_session_send_mss (transport_connection_t * trans_conn)
{
  tcp_connection_t *tc = (tcp_connection_t *) trans_conn;

  /* Ensure snd_mss does accurately reflect the amount of data we can push
   * in a segment. This also makes sure that options are updated according to
   * the current state of the connection. */
  tcp_update_snd_mss (tc);

  return tc->snd_mss;
}

always_inline u32
tcp_round_snd_space (tcp_connection_t * tc, u32 snd_space)
{
  if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss))
    {
      return tc->snd_wnd <= snd_space ? tc->snd_wnd : 0;
    }

  /* If not snd_wnd constrained and we can't write at least a segment,
   * don't try at all */
  if (PREDICT_FALSE (snd_space < tc->snd_mss))
    return snd_space < tc->cwnd ? 0 : snd_space;

  /* round down to mss multiple */
  return snd_space - (snd_space % tc->snd_mss);
}

/**
 * Compute tx window session is allowed to fill.
 *
 * Takes into account available send space, snd_mss and the congestion
 * state of the connection. If possible, the value returned is a multiple
 * of snd_mss.
 *
 * @param tc tcp connection
 * @return number of bytes session is allowed to write
 */
u32
tcp_snd_space (tcp_connection_t * tc)
{
  int snd_space, snt_limited;

  if (PREDICT_TRUE (tcp_in_cong_recovery (tc) == 0))
    {
      snd_space = tcp_available_output_snd_space (tc);

      /* If we haven't gotten dupacks or if we did and have gotten sacked
       * bytes then we can still send as per Limited Transmit (RFC3042) */
      if (PREDICT_FALSE (tc->rcv_dupacks != 0
			 && (tcp_opts_sack_permitted (tc)
			     && tc->sack_sb.last_sacked_bytes == 0)))
	{
	  if (tc->rcv_dupacks == 1 && tc->limited_transmit != tc->snd_nxt)
	    tc->limited_transmit = tc->snd_nxt;
	  ASSERT (seq_leq (tc->limited_transmit, tc->snd_nxt));

	  snt_limited = tc->snd_nxt - tc->limited_transmit;
	  snd_space = clib_max (2 * tc->snd_mss - snt_limited, 0);
	}
      return tcp_round_snd_space (tc, snd_space);
    }

  if (tcp_in_recovery (tc))
    {
      tc->snd_nxt = tc->snd_una_max;
      snd_space = tcp_available_snd_wnd (tc) - tc->snd_rxt_bytes
	- (tc->snd_una_max - tc->snd_congestion);
      if (snd_space <= 0 || (tc->snd_una_max - tc->snd_una) >= tc->snd_wnd)
	return 0;
      return tcp_round_snd_space (tc, snd_space);
    }

  /* RFC 5681: When previously unsent data is available and the new value of
   * cwnd and the receiver's advertised window allow, a TCP SHOULD send 1*SMSS
   * bytes of previously unsent data. */
  if (tcp_in_fastrecovery (tc) && !tcp_fastrecovery_sent_1_smss (tc))
    {
      if (tcp_available_output_snd_space (tc) < tc->snd_mss)
	return 0;
      tcp_fastrecovery_1_smss_on (tc);
      return tc->snd_mss;
    }

  return 0;
}

u32
tcp_session_send_space (transport_connection_t * trans_conn)
{
  tcp_connection_t *tc = (tcp_connection_t *) trans_conn;
  return clib_min (tcp_snd_space (tc),
		   tc->snd_wnd - (tc->snd_nxt - tc->snd_una));
}

i32
tcp_rcv_wnd_available (tcp_connection_t * tc)
{
  return (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
}

u32
tcp_session_tx_fifo_offset (transport_connection_t * trans_conn)
{
  tcp_connection_t *tc = (tcp_connection_t *) trans_conn;

  ASSERT (seq_geq (tc->snd_nxt, tc->snd_una));

  /* This still works if fast retransmit is on */
  return (tc->snd_nxt - tc->snd_una);
}

/* *INDENT-OFF* */
const static transport_proto_vft_t tcp_proto = {
  .bind = tcp_session_bind,
  .unbind = tcp_session_unbind,
  .push_header = tcp_push_header,
  .get_connection = tcp_session_get_transport,
  .get_listener = tcp_session_get_listener,
  .get_half_open = tcp_half_open_session_get_transport,
  .open = tcp_session_open,
  .close = tcp_session_close,
  .cleanup = tcp_session_cleanup,
  .send_mss = tcp_session_send_mss,
  .send_space = tcp_session_send_space,
  .tx_fifo_offset = tcp_session_tx_fifo_offset,
  .format_connection = format_tcp_session,
  .format_listener = format_tcp_listener_session,
  .format_half_open = format_tcp_half_open_session,
};
/* *INDENT-ON* */

void
tcp_timer_keep_handler (u32 conn_index)
{
  u32 thread_index = vlib_get_thread_index ();
  tcp_connection_t *tc;

  tc = tcp_connection_get (conn_index, thread_index);
  tc->timers[TCP_TIMER_KEEP] = TCP_TIMER_HANDLE_INVALID;

  tcp_connection_close (tc);
}

void
tcp_timer_establish_handler (u32 conn_index)
{
  tcp_connection_t *tc;

  tc = tcp_half_open_connection_get (conn_index);
  if (tc)
    {
      ASSERT (tc->state == TCP_STATE_SYN_SENT);
      stream_session_connect_notify (&tc->connection, 1 /* fail */ );
      TCP_DBG ("establish pop: %U", format_tcp_connection, tc, 2);
    }
  else
    {
      tc = tcp_connection_get (conn_index, vlib_get_thread_index ());
      /* note: the connection may have already disappeared */
      if (PREDICT_FALSE (tc == 0))
	return;
      TCP_DBG ("establish pop: %U", format_tcp_connection, tc, 2);
      ASSERT (tc->state == TCP_STATE_SYN_RCVD);
      /* Start cleanup. App wasn't notified yet so use delete notify as
       * opposed to delete to cleanup session layer state. */
      stream_session_delete_notify (&tc->connection);
    }
  tc->timers[TCP_TIMER_ESTABLISH] = TCP_TIMER_HANDLE_INVALID;
  tcp_connection_cleanup (tc);
}

void
tcp_timer_waitclose_handler (u32 conn_index)
{
  u32 thread_index = vlib_get_thread_index ();
  tcp_connection_t *tc;

  tc = tcp_connection_get (conn_index, thread_index);
  if (!tc)
    return;
  tc->timers[TCP_TIMER_WAITCLOSE] = TCP_TIMER_HANDLE_INVALID;

  /* Session didn't come back with a close(). Send FIN either way
   * and switch to LAST_ACK. */
  if (tc->state == TCP_STATE_CLOSE_WAIT)
    {
      if (tc->flags & TCP_CONN_FINSNT)
	{
	  clib_warning ("FIN was sent and still in CLOSE WAIT. Weird!");
	}

      tcp_send_fin (tc);
      tc->state = TCP_STATE_LAST_ACK;

      /* Make sure we don't wait in LAST ACK forever */
      tcp_timer_set (tc, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);

      /* Don't delete the connection yet */
      return;
    }

  tcp_connection_del (tc);
}

/* *INDENT-OFF* */
static timer_expiration_handler *timer_expiration_handlers[TCP_N_TIMERS] =
{
    tcp_timer_retransmit_handler,
    tcp_timer_delack_handler,
    tcp_timer_persist_handler,
    tcp_timer_keep_handler,
    tcp_timer_waitclose_handler,
    tcp_timer_retransmit_syn_handler,
    tcp_timer_establish_handler
};
/* *INDENT-ON* */

static void
tcp_expired_timers_dispatch (u32 * expired_timers)
{
  int i;
  u32 connection_index, timer_id;

  for (i = 0; i < vec_len (expired_timers); i++)
    {
      /* Get session index and timer id */
      connection_index = expired_timers[i] & 0x0FFFFFFF;
      timer_id = expired_timers[i] >> 28;

      TCP_EVT_DBG (TCP_EVT_TIMER_POP, connection_index, timer_id);

      /* Handle expiration */
      (*timer_expiration_handlers[timer_id]) (connection_index);
    }
}

void
tcp_initialize_timer_wheels (tcp_main_t * tm)
{
  tw_timer_wheel_16t_2w_512sl_t *tw;
  /* *INDENT-OFF* */
  foreach_vlib_main (({
    tw = &tm->timer_wheels[ii];
    tw_timer_wheel_init_16t_2w_512sl (tw, tcp_expired_timers_dispatch,
				      100e-3 /* timer period 100ms */ , ~0);
    tw->last_run_time = vlib_time_now (this_vlib_main);
  }));
  /* *INDENT-ON* */
}

clib_error_t *
tcp_main_enable (vlib_main_t * vm)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  ip_protocol_info_t *pi;
  ip_main_t *im = &ip_main;
  vlib_thread_main_t *vtm = vlib_get_thread_main ();
  clib_error_t *error = 0;
  u32 num_threads;
  int thread;
  tcp_connection_t *tc __attribute__ ((unused));
  u32 preallocated_connections_per_thread;

  if ((error = vlib_call_init_function (vm, ip_main_init)))
    return error;
  if ((error = vlib_call_init_function (vm, ip4_lookup_init)))
    return error;
  if ((error = vlib_call_init_function (vm, ip6_lookup_init)))
    return error;

  /*
   * Registrations
   */

  /* Register with IP */
  pi = ip_get_protocol_info (im, IP_PROTOCOL_TCP);
  if (pi == 0)
    return clib_error_return (0, "TCP protocol info AWOL");
  pi->format_header = format_tcp_header;
  pi->unformat_pg_edit = unformat_pg_tcp_header;

  ip4_register_protocol (IP_PROTOCOL_TCP, tcp4_input_node.index);
  ip6_register_protocol (IP_PROTOCOL_TCP, tcp6_input_node.index);

  /* Register as transport with session layer */
  session_register_transport (TRANSPORT_PROTO_TCP, 1, &tcp_proto);
  session_register_transport (TRANSPORT_PROTO_TCP, 0, &tcp_proto);

  /*
   * Initialize data structures
   */

  num_threads = 1 /* main thread */  + vtm->n_threads;
  vec_validate (tm->connections, num_threads - 1);

  /*
   * Preallocate connections. Assume that thread 0 won't
   * use preallocated threads when running multi-core
   */
  if (num_threads == 1)
    {
      thread = 0;
      preallocated_connections_per_thread = tm->preallocated_connections;
    }
  else
    {
      thread = 1;
      preallocated_connections_per_thread =
	tm->preallocated_connections / (num_threads - 1);
    }
  for (; thread < num_threads; thread++)
    {
      if (preallocated_connections_per_thread)
	pool_init_fixed (tm->connections[thread],
			 preallocated_connections_per_thread);
    }

  /*
   * Use a preallocated half-open connection pool?
   */
  if (tm->preallocated_half_open_connections)
    pool_init_fixed (tm->half_open_connections,
		     tm->preallocated_half_open_connections);

  /* Initialize per worker thread tx buffers (used for control messages) */
  vec_validate (tm->tx_buffers, num_threads - 1);

  /* Initialize timer wheels */
  vec_validate (tm->timer_wheels, num_threads - 1);
  tcp_initialize_timer_wheels (tm);

  /* Initialize clocks per tick for TCP timestamp. Used to compute
   * monotonically increasing timestamps. */
  tm->tstamp_ticks_per_clock = vm->clib_time.seconds_per_clock
    / TCP_TSTAMP_RESOLUTION;

  if (tm->local_endpoints_table_buckets == 0)
    tm->local_endpoints_table_buckets = 250000;
  if (tm->local_endpoints_table_memory == 0)
    tm->local_endpoints_table_memory = 512 << 20;

  clib_bihash_init_24_8 (&tm->local_endpoints_table, "local endpoint table",
			 tm->local_endpoints_table_buckets,
			 tm->local_endpoints_table_memory);

  /* Initialize [port-allocator] random number seed */
  tm->port_allocator_seed = (u32) clib_cpu_time_now ();

  if (num_threads > 1)
    {
      clib_spinlock_init (&tm->half_open_lock);
      clib_spinlock_init (&tm->local_endpoints_lock);
    }

  vec_validate (tm->tx_frames[0], num_threads - 1);
  vec_validate (tm->tx_frames[1], num_threads - 1);
  vec_validate (tm->ip_lookup_tx_frames[0], num_threads - 1);
  vec_validate (tm->ip_lookup_tx_frames[1], num_threads - 1);

  tm->bytes_per_buffer = vlib_buffer_free_list_buffer_size
    (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);

  vec_validate (tm->time_now, num_threads - 1);
  return error;
}

clib_error_t *
vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en)
{
  if (is_en)
    {
      if (tcp_main.is_enabled)
	return 0;

      return tcp_main_enable (vm);
    }
  else
    {
      tcp_main.is_enabled = 0;
    }

  return 0;
}

void
tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add)
{
  tcp_main_t *tm = &tcp_main;
  if (is_ip4)
    tm->punt_unknown4 = is_add;
  else
    tm->punt_unknown6 = is_add;
}

clib_error_t *
tcp_init (vlib_main_t * vm)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  tm->is_enabled = 0;
  tcp_api_reference ();
  return 0;
}

VLIB_INIT_FUNCTION (tcp_init);

static clib_error_t *
tcp_config_fn (vlib_main_t * vm, unformat_input_t * input)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  u64 tmp;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat
	  (input, "preallocated-connections %d",
	   &tm->preallocated_connections))
	;
      else if (unformat (input, "preallocated-half-open-connections %d",
			 &tm->preallocated_half_open_connections))
	;
      else if (unformat (input, "local-endpoints-table-memory %U",
			 unformat_memory_size, &tmp))
	{
	  if (tmp >= 0x100000000)
	    return clib_error_return (0, "memory size %llx (%lld) too large",
				      tmp, tmp);
	  tm->local_endpoints_table_memory = tmp;
	}
      else if (unformat (input, "local-endpoints-table-buckets %d",
			 &tm->local_endpoints_table_buckets))
	;


      else
	return clib_error_return (0, "unknown input `%U'",
				  format_unformat_error, input);
    }
  return 0;
}

VLIB_CONFIG_FUNCTION (tcp_config_fn, "tcp");


/**
 * \brief Configure an ipv4 source address range
 * @param vm vlib_main_t pointer
 * @param start first ipv4 address in the source address range
 * @param end last ipv4 address in the source address range
 * @param table_id VRF / table ID, 0 for the default FIB
 * @return 0 if all OK, else an error indication from api_errno.h
 */

int
tcp_configure_v4_source_address_range (vlib_main_t * vm,
				       ip4_address_t * start,
				       ip4_address_t * end, u32 table_id)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  vnet_main_t *vnm = vnet_get_main ();
  u32 start_host_byte_order, end_host_byte_order;
  fib_prefix_t prefix;
  vnet_sw_interface_t *si;
  fib_node_index_t fei;
  u32 fib_index = 0;
  u32 sw_if_index;
  int rv;
  int vnet_proxy_arp_add_del (ip4_address_t * lo_addr,
			      ip4_address_t * hi_addr, u32 fib_index,
			      int is_del);

  memset (&prefix, 0, sizeof (prefix));

  fib_index = fib_table_find (FIB_PROTOCOL_IP4, table_id);

  if (fib_index == ~0)
    return VNET_API_ERROR_NO_SUCH_FIB;

  start_host_byte_order = clib_net_to_host_u32 (start->as_u32);
  end_host_byte_order = clib_net_to_host_u32 (end->as_u32);

  /* sanity check for reversed args or some such */
  if ((end_host_byte_order - start_host_byte_order) > (10 << 10))
    return VNET_API_ERROR_INVALID_ARGUMENT;

  /* Lookup the last address, to identify the interface involved */
  prefix.fp_len = 32;
  prefix.fp_proto = FIB_PROTOCOL_IP4;
  memcpy (&prefix.fp_addr.ip4, end, sizeof (ip4_address_t));

  fei = fib_table_lookup (fib_index, &prefix);

  /* Couldn't find route to destination. Bail out. */
  if (fei == FIB_NODE_INDEX_INVALID)
    return VNET_API_ERROR_NEXT_HOP_NOT_IN_FIB;

  sw_if_index = fib_entry_get_resolving_interface (fei);

  /* Enable proxy arp on the interface */
  si = vnet_get_sw_interface (vnm, sw_if_index);
  si->flags |= VNET_SW_INTERFACE_FLAG_PROXY_ARP;

  /* Configure proxy arp across the range */
  rv = vnet_proxy_arp_add_del (start, end, fib_index, 0 /* is_del */ );

  if (rv)
    return rv;

  do
    {
      dpo_id_t dpo = DPO_INVALID;

      vec_add1 (tm->ip4_src_addresses, start[0]);

      /* Add local adjacencies for the range */

      receive_dpo_add_or_lock (DPO_PROTO_IP4, ~0 /* sw_if_index */ ,
			       NULL, &dpo);
      prefix.fp_len = 32;
      prefix.fp_proto = FIB_PROTOCOL_IP4;
      prefix.fp_addr.ip4.as_u32 = start->as_u32;

      fib_table_entry_special_dpo_update (fib_index,
					  &prefix,
					  FIB_SOURCE_API,
					  FIB_ENTRY_FLAG_EXCLUSIVE, &dpo);
      dpo_reset (&dpo);

      start_host_byte_order++;
      start->as_u32 = clib_host_to_net_u32 (start_host_byte_order);
    }
  while (start_host_byte_order <= end_host_byte_order);

  return 0;
}

/**
 * \brief Configure an ipv6 source address range
 * @param vm vlib_main_t pointer
 * @param start first ipv6 address in the source address range
 * @param end last ipv6 address in the source address range
 * @param table_id VRF / table ID, 0 for the default FIB
 * @return 0 if all OK, else an error indication from api_errno.h
 */

int
tcp_configure_v6_source_address_range (vlib_main_t * vm,
				       ip6_address_t * start,
				       ip6_address_t * end, u32 table_id)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  fib_prefix_t prefix;
  u32 fib_index = 0;
  fib_node_index_t fei;
  u32 sw_if_index;

  memset (&prefix, 0, sizeof (prefix));

  fib_index = fib_table_find (FIB_PROTOCOL_IP6, table_id);

  if (fib_index == ~0)
    return VNET_API_ERROR_NO_SUCH_FIB;

  while (1)
    {
      int i;
      ip6_address_t tmp;
      dpo_id_t dpo = DPO_INVALID;

      /* Remember this address */
      vec_add1 (tm->ip6_src_addresses, start[0]);

      /* Lookup the prefix, to identify the interface involved */
      prefix.fp_len = 128;
      prefix.fp_proto = FIB_PROTOCOL_IP6;
      memcpy (&prefix.fp_addr.ip6, start, sizeof (ip6_address_t));

      fei = fib_table_lookup (fib_index, &prefix);

      /* Couldn't find route to destination. Bail out. */
      if (fei == FIB_NODE_INDEX_INVALID)
	return VNET_API_ERROR_NEXT_HOP_NOT_IN_FIB;

      sw_if_index = fib_entry_get_resolving_interface (fei);

      if (sw_if_index == (u32) ~ 0)
	return VNET_API_ERROR_NO_MATCHING_INTERFACE;

      /* Add a proxy neighbor discovery entry for this address */
      ip6_neighbor_proxy_add_del (sw_if_index, start, 0 /* is_del */ );

      /* Add a receive adjacency for this address */
      receive_dpo_add_or_lock (DPO_PROTO_IP6, ~0 /* sw_if_index */ ,
			       NULL, &dpo);

      fib_table_entry_special_dpo_update (fib_index,
					  &prefix,
					  FIB_SOURCE_API,
					  FIB_ENTRY_FLAG_EXCLUSIVE, &dpo);
      dpo_reset (&dpo);

      /* Done with the entire range? */
      if (!memcmp (start, end, sizeof (start[0])))
	break;

      /* Increment the address. DGMS. */
      tmp = start[0];
      for (i = 15; i >= 0; i--)
	{
	  tmp.as_u8[i] += 1;
	  if (tmp.as_u8[i] != 0)
	    break;
	}
      start[0] = tmp;
    }
  return 0;
}

static clib_error_t *
tcp_src_address (vlib_main_t * vm,
		 unformat_input_t * input, vlib_cli_command_t * cmd_arg)
{
  ip4_address_t v4start, v4end;
  ip6_address_t v6start, v6end;
  u32 table_id = 0;
  int v4set = 0;
  int v6set = 0;
  int rv;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "%U - %U", unformat_ip4_address, &v4start,
		    unformat_ip4_address, &v4end))
	v4set = 1;
      else if (unformat (input, "%U", unformat_ip4_address, &v4start))
	{
	  memcpy (&v4end, &v4start, sizeof (v4start));
	  v4set = 1;
	}
      else if (unformat (input, "%U - %U", unformat_ip6_address, &v6start,
			 unformat_ip6_address, &v6end))
	v6set = 1;
      else if (unformat (input, "%U", unformat_ip6_address, &v6start))
	{
	  memcpy (&v6end, &v6start, sizeof (v6start));
	  v6set = 1;
	}
      else if (unformat (input, "fib-table %d", &table_id))
	;
      else
	break;
    }

  if (!v4set && !v6set)
    return clib_error_return (0, "at least one v4 or v6 address required");

  if (v4set)
    {
      rv = tcp_configure_v4_source_address_range (vm, &v4start, &v4end,
						  table_id);
      switch (rv)
	{
	case 0:
	  break;

	case VNET_API_ERROR_NO_SUCH_FIB:
	  return clib_error_return (0, "Invalid table-id %d", table_id);

	case VNET_API_ERROR_INVALID_ARGUMENT:
	  return clib_error_return (0, "Invalid address range %U - %U",
				    format_ip4_address, &v4start,
				    format_ip4_address, &v4end);
	default:
	  return clib_error_return (0, "error %d", rv);
	  break;
	}
    }
  if (v6set)
    {
      rv = tcp_configure_v6_source_address_range (vm, &v6start, &v6end,
						  table_id);
      switch (rv)
	{
	case 0:
	  break;

	case VNET_API_ERROR_NO_SUCH_FIB:
	  return clib_error_return (0, "Invalid table-id %d", table_id);

	default:
	  return clib_error_return (0, "error %d", rv);
	  break;
	}
    }
  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (tcp_src_address_command, static) =
{
  .path = "tcp src-address",
  .short_help = "tcp src-address <ip-addr> [- <ip-addr>] add src address range",
  .function = tcp_src_address,
};
/* *INDENT-ON* */

static u8 *
tcp_scoreboard_dump_trace (u8 * s, sack_scoreboard_t * sb)
{
#if TCP_SCOREBOARD_TRACE

  scoreboard_trace_elt_t *block;
  int i = 0;

  if (!sb->trace)
    return s;

  s = format (s, "scoreboard trace:");
  vec_foreach (block, sb->trace)
  {
    s = format (s, "{%u, %u, %u, %u, %u}, ", block->start, block->end,
		block->ack, block->snd_una_max, block->group);
    if ((++i % 3) == 0)
      s = format (s, "\n");
  }
  return s;
#else
  return 0;
#endif
}

static clib_error_t *
tcp_show_scoreboard_trace_fn (vlib_main_t * vm, unformat_input_t * input,
			      vlib_cli_command_t * cmd_arg)
{
  transport_connection_t *tconn = 0;
  tcp_connection_t *tc;
  u8 *s = 0;
  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "%U", unformat_transport_connection, &tconn,
		    TRANSPORT_PROTO_TCP))
	;
      else
	return clib_error_return (0, "unknown input `%U'",
				  format_unformat_error, input);
    }

  if (!TCP_SCOREBOARD_TRACE)
    {
      vlib_cli_output (vm, "scoreboard tracing not enabled");
      return 0;
    }

  tc = tcp_get_connection_from_transport (tconn);
  s = tcp_scoreboard_dump_trace (s, &tc->sack_sb);
  vlib_cli_output (vm, "%v", s);
  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (tcp_show_scoreboard_trace_command, static) =
{
  .path = "show tcp scoreboard trace",
  .short_help = "show tcp scoreboard trace <connection>",
  .function = tcp_show_scoreboard_trace_fn,
};
/* *INDENT-ON* */

u8 *
tcp_scoreboard_replay (u8 * s, tcp_connection_t * tc, u8 verbose)
{
  int i, trace_len;
  scoreboard_trace_elt_t *trace;
  u32 next_ack, left, group, has_new_ack = 0;
  tcp_connection_t _dummy_tc, *dummy_tc = &_dummy_tc;
  sack_block_t *block;

  if (!tc)
    return s;

  memset (dummy_tc, 0, sizeof (*dummy_tc));
  tcp_connection_timers_init (dummy_tc);
  scoreboard_init (&dummy_tc->sack_sb);
  dummy_tc->rcv_opts.flags |= TCP_OPTS_FLAG_SACK;

#if TCP_SCOREBOARD_TRACE
  trace = tc->sack_sb.trace;
  trace_len = vec_len (tc->sack_sb.trace);
#else
  trace = 0;
  trace_len = 0;
#endif

  for (i = 0; i < trace_len; i++)
    {
      if (trace[i].ack != 0)
	{
	  dummy_tc->snd_una = trace[i].ack - 1448;
	  dummy_tc->snd_una_max = trace[i].ack;
	}
    }

  left = 0;
  while (left < trace_len)
    {
      group = trace[left].group;
      vec_reset_length (dummy_tc->rcv_opts.sacks);
      has_new_ack = 0;
      while (trace[left].group == group)
	{
	  if (trace[left].ack != 0)
	    {
	      if (verbose)
		s = format (s, "Adding ack %u, snd_una_max %u, segs: ",
			    trace[left].ack, trace[left].snd_una_max);
	      dummy_tc->snd_una_max = trace[left].snd_una_max;
	      next_ack = trace[left].ack;
	      has_new_ack = 1;
	    }
	  else
	    {
	      if (verbose)
		s = format (s, "[%u, %u], ", trace[left].start,
			    trace[left].end);
	      vec_add2 (dummy_tc->rcv_opts.sacks, block, 1);
	      block->start = trace[left].start;
	      block->end = trace[left].end;
	    }
	  left++;
	}

      /* Push segments */
      tcp_rcv_sacks (dummy_tc, next_ack);
      if (has_new_ack)
	dummy_tc->snd_una = next_ack + dummy_tc->sack_sb.snd_una_adv;

      if (verbose)
	s = format (s, "result: %U", format_tcp_scoreboard,
		    &dummy_tc->sack_sb);

    }
  s = format (s, "result: %U", format_tcp_scoreboard, &dummy_tc->sack_sb);

  return s;
}

static clib_error_t *
tcp_scoreboard_trace_fn (vlib_main_t * vm, unformat_input_t * input,
			 vlib_cli_command_t * cmd_arg)
{
  transport_connection_t *tconn = 0;
  tcp_connection_t *tc = 0;
  u8 *str = 0;
  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "%U", unformat_transport_connection, &tconn,
		    TRANSPORT_PROTO_TCP))
	;
      else
	return clib_error_return (0, "unknown input `%U'",
				  format_unformat_error, input);
    }

  if (!TCP_SCOREBOARD_TRACE)
    {
      vlib_cli_output (vm, "scoreboard tracing not enabled");
      return 0;
    }

  tc = tcp_get_connection_from_transport (tconn);
  if (!tc)
    {
      vlib_cli_output (vm, "connection not found");
      return 0;
    }
  str = tcp_scoreboard_replay (str, tc, 1);
  vlib_cli_output (vm, "%v", str);
  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (tcp_replay_scoreboard_command, static) =
{
  .path = "tcp replay scoreboard",
  .short_help = "tcp replay scoreboard <connection>",
  .function = tcp_scoreboard_trace_fn,
};
/* *INDENT-ON* */

static clib_error_t *
show_tcp_punt_fn (vlib_main_t * vm, unformat_input_t * input,
		  vlib_cli_command_t * cmd_arg)
{
  tcp_main_t *tm = vnet_get_tcp_main ();
  if (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    return clib_error_return (0, "unknown input `%U'", format_unformat_error,
			      input);
  vlib_cli_output (vm, "IPv4 TCP punt: %s",
		   tm->punt_unknown4 ? "enabled" : "disabled");
  vlib_cli_output (vm, "IPv6 TCP punt: %s",
		   tm->punt_unknown6 ? "enabled" : "disabled");
  return 0;
}
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (show_tcp_punt_command, static) =
{
  .path = "show tcp punt",
  .short_help = "show tcp punt",
  .function = show_tcp_punt_fn,
};
/* *INDENT-ON* */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */