#!/usr/bin/env python3

import binascii
import socket
from socket import AF_INET, AF_INET6
import unittest
import sys

from framework import VppTestCase

from scapy.packet import Raw
from scapy.layers.l2 import Ether
from scapy.layers.inet import IP, UDP, TCP
from scapy.layers.inet6 import IPv6
from util import ppp


class TestClassifier(VppTestCase):

    @staticmethod
    def _resolve_mask_match(mask_match):
        mask_match = binascii.unhexlify(mask_match)
        mask_match_len = ((len(mask_match) - 1) // 16 + 1) * 16
        mask_match = mask_match + b'\0' * \
            (mask_match_len - len(mask_match))
        return mask_match, mask_match_len

    @classmethod
    def setUpClass(cls):
        """
        Perform standard class setup (defined by class method setUpClass in
        class VppTestCase) before running the test case, set test case related
        variables and configure VPP.
        """
        super(TestClassifier, cls).setUpClass()
        cls.acl_active_table = ''
        cls.af = AF_INET

    def setUp(self):
        """
        Perform test setup before test case.

        **Config:**
            - create 4 pg interfaces
                - untagged pg0/pg1/pg2 interface
                    pg0 -------> pg1 (IP ACL)
                           \
                            ---> pg2 (MAC ACL))
                             \
                              -> pg3 (PBR)
            - setup interfaces:
                - put it into UP state
                - set IPv4/6 addresses
                - resolve neighbor address using ARP

        :ivar list interfaces: pg interfaces.
        :ivar list pg_if_packet_sizes: packet sizes in test.
        :ivar dict acl_tbl_idx: ACL table index.
        :ivar int pbr_vrfid: VRF id for PBR test.
        """
        self.reset_packet_infos()
        super(TestClassifier, self).setUp()
        if self.af is None:  # l2_acl test case
            return

        # create 4 pg interfaces
        self.create_pg_interfaces(range(4))

        # packet sizes to test
        self.pg_if_packet_sizes = [64, 9018]

        self.interfaces = list(self.pg_interfaces)

        # ACL & PBR vars
        self.acl_tbl_idx = {}
        self.pbr_vrfid = 200

        # setup all interfaces
        for intf in self.interfaces:
            intf.admin_up()
            if self.af == AF_INET:
                intf.config_ip4()
                intf.resolve_arp()
            elif self.af == AF_INET6:
                intf.config_ip6()
                intf.resolve_ndp()

    def tearDown(self):
        """Run standard test teardown and acl related log."""
        if self.af is not None and not self.vpp_dead
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/*
 * Copyright (c) 2017 SUSE LLC.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <vnet/sctp/sctp.h>
#include <vnet/sctp/sctp_debug.h>

sctp_main_t sctp_main;

static u32
sctp_connection_bind (u32 session_index, transport_endpoint_t * tep)
{
  sctp_main_t *tm = &sctp_main;
  sctp_connection_t *listener;
  void *iface_ip;

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

  listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].subconn_idx =
    MAIN_SCTP_SUB_CONN_IDX;
  listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_c_index =
    listener - tm->listener_pool;
  listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection.lcl_port = tep->port;

  /* If we are provided a sw_if_index, bind using one of its IPs */
  if (ip_is_zero (&tep->ip, 1) && tep->sw_if_index != ENDPOINT_INVALID_INDEX)
    {
      if ((iface_ip = ip_interface_get_first_ip (tep->sw_if_index,
						 tep->is_ip4)))
	ip_set (&tep->ip, iface_ip, tep->is_ip4);
    }
  ip_copy (&listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection.lcl_ip,
	   &tep->ip, tep->is_ip4);

  listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].PMTU =
    vnet_sw_interface_get_mtu (vnet_get_main (), tep->sw_if_index, VLIB_TX);
  listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection.is_ip4 = tep->is_ip4;
  listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection.proto =
    TRANSPORT_PROTO_SCTP;
  listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_s_index = session_index;
  listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection.fib_index =
    tep->fib_index;
  listener->state = SCTP_STATE_CLOSED;

  sctp_connection_timers_init (listener);

  return listener->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_c_index;
}

u32
sctp_session_bind (u32 session_index, transport_endpoint_t * tep)
{
  return sctp_connection_bind (session_index, tep);
}

static void
sctp_connection_unbind (u32 listener_index)
{
  sctp_main_t *tm = vnet_get_sctp_main ();
  sctp_connection_t *sctp_conn;

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

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

  pool_put_index (tm->listener_pool, listener_index);
}

u32
sctp_session_unbind (u32 listener_index)
{
  sctp_connection_unbind (listener_index);
  return 0;
}

void
sctp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add)
{
  sctp_main_t *tm = &sctp_main;
  if (is_ip4)
    tm->punt_unknown4 = is_add;
  else
    tm->punt_unknown6 = is_add;
}

static int
sctp_alloc_custom_local_endpoint (sctp_main_t * tm, ip46_address_t * lcl_addr,
				  u16 * lcl_port, u8 is_ip4)
{
  int index, port;
  if (is_ip4)
    {
      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
    {
      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_address_t));
    }
  port = transport_alloc_local_port (TRANSPORT_PROTO_SCTP, lcl_addr);
  if (port < 1)
    {
      clib_warning ("Failed to allocate src port");
      return -1;
    }
  *lcl_port = port;
  return 0;
}

/**
 * Initialize all connection timers as invalid
 */
void
sctp_connection_timers_init (sctp_connection_t * sctp_conn)
{
  int i, j;

  /* Set all to invalid */
  for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
    {
      sctp_conn->sub_conn[i].RTO = SCTP_RTO_INIT;

      for (j = 0; j < SCTP_N_TIMERS; j++)
	{
	  sctp_conn->sub_conn[i].timers[j] = SCTP_TIMER_HANDLE_INVALID;
	}
    }
}

/**
 * Stop all connection timers
 */
void
sctp_connection_timers_reset (sctp_connection_t * sctp_conn)
{
  int i, j;
  for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
    {
      for (j = 0; j < SCTP_N_TIMERS; j++)
	sctp_timer_reset (sctp_conn, i, j);
    }
}

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

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

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

u8 *
format_sctp_connection_id (u8 * s, va_list * args)
{
  sctp_connection_t *sctp_conn = va_arg (*args, sctp_connection_t *);
  if (!sctp_conn)
    return s;

  u8 i;
  for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
    {
      if (sctp_conn->sub_conn[i].connection.is_ip4)
	{
	  s = format (s, "%U[#%d][%s] %U:%d->%U:%d",
		      s,
		      sctp_conn->sub_conn[i].connection.thread_index,
		      "T",
		      format_ip4_address,
		      &sctp_conn->sub_conn[i].connection.lcl_ip.ip4,
		      clib_net_to_host_u16 (sctp_conn->sub_conn[i].
					    connection.lcl_port),
		      format_ip4_address,
		      &sctp_conn->sub_conn[i].connection.rmt_ip.ip4,
		      clib_net_to_host_u16 (sctp_conn->sub_conn[i].
					    connection.rmt_port));
	}
      else
	{
	  s = format (s, "%U[#%d][%s] %U:%d->%U:%d",
		      s,
		      sctp_conn->sub_conn[i].connection.thread_index,
		      "T",
		      format_ip6_address,
		      &sctp_conn->sub_conn[i].connection.lcl_ip.ip6,
		      clib_net_to_host_u16 (sctp_conn->sub_conn[i].
					    connection.lcl_port),
		      format_ip6_address,
		      &sctp_conn->sub_conn[i].connection.rmt_ip.ip6,
		      clib_net_to_host_u16 (sctp_conn->sub_conn[i].
					    connection.rmt_port));
	}
    }
  return s;
}

u8 *
format_sctp_connection (u8 * s, va_list * args)
{
  sctp_connection_t *sctp_conn = va_arg (*args, sctp_connection_t *);
  u32 verbose = va_arg (*args, u32);

  if (!sctp_conn)
    return s;
  s = format (s, "%-50U", format_sctp_connection_id, sctp_conn);
  if (verbose)
    {
      s = format (s, "%-15U", format_sctp_state, sctp_conn->state);
    }

  return s;
}

/**
 * Initialize connection send variables.
 */
void
sctp_init_snd_vars (sctp_connection_t * sctp_conn)
{
  u32 time_now;
  /*
   * We use the time to randomize iss and for setting up the initial
   * timestamp. Make sure it's updated otherwise syn and ack in the
   * handshake may make it look as if time has flown in the opposite
   * direction for us.
   */

  sctp_set_time_now (vlib_get_thread_index ());
  time_now = sctp_time_now ();

  sctp_conn->local_initial_tsn = random_u32 (&time_now);
  sctp_conn->last_unacked_tsn = sctp_conn->local_initial_tsn;
  sctp_conn->next_tsn = sctp_conn->local_initial_tsn + 1;

  sctp_conn->remote_initial_tsn = 0x0;
  sctp_conn->last_rcvd_tsn = sctp_conn->remote_initial_tsn;
}

always_inline sctp_connection_t *
sctp_sub_connection_add (u8 thread_index)
{
  sctp_main_t *tm = vnet_get_sctp_main ();
  sctp_connection_t *sctp_conn = tm->connections[thread_index];

  u8 subconn_idx = sctp_next_avail_subconn (sctp_conn);

  ASSERT (subconn_idx < MAX_SCTP_CONNECTIONS);

  sctp_conn->sub_conn[subconn_idx].connection.c_index =
    sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection.c_index;
  sctp_conn->sub_conn[subconn_idx].connection.thread_index = thread_index;
  sctp_conn->sub_conn[subconn_idx].subconn_idx = subconn_idx;

  return sctp_conn;
}

u8
sctp_sub_connection_add_ip4 (vlib_main_t * vm,
			     ip4_address_t * lcl_addr,
			     ip4_address_t * rmt_addr)
{
  sctp_connection_t *sctp_conn = sctp_sub_connection_add (vm->thread_index);

  u8 subconn_idx = sctp_next_avail_subconn (sctp_conn);

  if (subconn_idx == MAX_SCTP_CONNECTIONS)
    return SCTP_ERROR_MAX_CONNECTIONS;

  clib_memcpy (&sctp_conn->sub_conn[subconn_idx].connection.lcl_ip,
	       &lcl_addr, sizeof (lcl_addr));

  clib_memcpy (&sctp_conn->sub_conn[subconn_idx].connection.rmt_ip,
	       &rmt_addr, sizeof (rmt_addr));

  sctp_conn->forming_association_changed = 1;

  return SCTP_ERROR_NONE;
}

u8
sctp_sub_connection_del_ip4 (ip4_address_t * lcl_addr,
			     ip4_address_t * rmt_addr)
{
  sctp_main_t *sctp_main = vnet_get_sctp_main ();

  u32 thread_idx = vlib_get_thread_index ();
  u8 i;

  ASSERT (thread_idx == 0);

  for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
    {
      sctp_connection_t *sctp_conn = sctp_main->connections[thread_idx];
      sctp_sub_connection_t *sub_conn =
	&sctp_main->connections[thread_idx]->sub_conn[i];
      ip46_address_t *lcl_ip =
	&sctp_main->connections[thread_idx]->sub_conn[i].connection.lcl_ip;
      ip46_address_t *rmt_ip =
	&sctp_main->connections[thread_idx]->sub_conn[i].connection.rmt_ip;

      if (!sub_conn->connection.is_ip4)
	continue;
      if (lcl_ip->ip4.as_u32 == lcl_addr->as_u32 &&
	  rmt_ip->ip4.as_u32 == rmt_addr->as_u32)
	{
	  sub_conn->state = SCTP_SUBCONN_STATE_DOWN;
	  sctp_conn->forming_association_changed = 1;
	  break;
	}
    }
  return SCTP_ERROR_NONE;
}

u8
sctp_sub_connection_add_ip6 (vlib_main_t * vm,
			     ip6_address_t * lcl_addr,
			     ip6_address_t * rmt_addr)
{
  sctp_connection_t *sctp_conn = sctp_sub_connection_add (vm->thread_index);

  u8 subconn_idx = sctp_next_avail_subconn (sctp_conn);

  if (subconn_idx == MAX_SCTP_CONNECTIONS)
    return SCTP_ERROR_MAX_CONNECTIONS;

  clib_memcpy (&sctp_conn->sub_conn[subconn_idx].connection.lcl_ip,
	       &lcl_addr, sizeof (lcl_addr));

  clib_memcpy (&sctp_conn->sub_conn[subconn_idx].connection.rmt_ip,
	       &rmt_addr, sizeof (rmt_addr));

  sctp_conn->forming_association_changed = 1;

  return SCTP_ERROR_NONE;
}

u8
sctp_sub_connection_del_ip6 (ip6_address_t * lcl_addr,
			     ip6_address_t * rmt_addr)
{
  sctp_main_t *sctp_main = vnet_get_sctp_main ();

  u32 thread_idx = vlib_get_thread_index ();
  u8 i;

  ASSERT (thread_idx == 0);

  for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
    {
      sctp_connection_t *sctp_conn = sctp_main->connections[thread_idx];
      sctp_sub_connection_t *sub_conn =
	&sctp_main->connections[thread_idx]->sub_conn[i];
      ip46_address_t *lcl_ip =
	&sctp_main->connections[thread_idx]->sub_conn[i].connection.lcl_ip;
      ip46_address_t *rmt_ip =
	&sctp_main->connections[thread_idx]->sub_conn[i].connection.rmt_ip;

      if (!sub_conn->connection.is_ip4)
	continue;
      if ((lcl_ip->ip6.as_u64[0] == lcl_addr->as_u64[0]
	   && lcl_ip->ip6.as_u64[1] == lcl_addr->as_u64[1])
	  && (rmt_ip->ip6.as_u64[0] == rmt_addr->as_u64[0]
	      && rmt_ip->ip6.as_u64[1] == rmt_addr->as_u64[1]))
	{
	  sub_conn->state = SCTP_SUBCONN_STATE_DOWN;
	  sctp_conn->forming_association_changed = 1;
	  break;
	}
    }
  return SCTP_ERROR_NONE;
}

sctp_connection_t *
sctp_connection_new (u8 thread_index)
{
  sctp_main_t *sctp_main = vnet_get_sctp_main ();
  sctp_connection_t *sctp_conn;

  pool_get (sctp_main->connections[thread_index], sctp_conn);
  memset (sctp_conn, 0, sizeof (*sctp_conn));
  sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].subconn_idx =
    MAIN_SCTP_SUB_CONN_IDX;
  sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_c_index =
    sctp_conn - sctp_main->connections[thread_index];
  sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_thread_index = thread_index;
  sctp_conn->local_tag = 0;

  return sctp_conn;
}

sctp_connection_t *
sctp_half_open_connection_new (u8 thread_index)
{
  sctp_main_t *tm = vnet_get_sctp_main ();
  sctp_connection_t *sctp_conn = 0;
  ASSERT (vlib_get_thread_index () == 0);
  pool_get (tm->half_open_connections, sctp_conn);
  memset (sctp_conn, 0, sizeof (*sctp_conn));
  sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_c_index =
    sctp_conn - tm->half_open_connections;
  sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].subconn_idx =
    MAIN_SCTP_SUB_CONN_IDX;
  return sctp_conn;
}

static inline int
sctp_connection_open (transport_endpoint_t * rmt)
{
  sctp_main_t *tm = vnet_get_sctp_main ();
  sctp_connection_t *sctp_conn;
  ip46_address_t lcl_addr;
  u16 lcl_port;
  uword thread_id;
  int rv;

  u8 idx = MAIN_SCTP_SUB_CONN_IDX;

  /*
   * Allocate local endpoint
   */
  if ((rmt->is_ip4 && vec_len (tm->ip4_src_addresses))
      || (!rmt->is_ip4 && vec_len (tm->ip6_src_addresses)))
    rv = sctp_alloc_custom_local_endpoint (tm, &lcl_addr, &lcl_port,
					   rmt->is_ip4);
  else
    rv = transport_alloc_local_endpoint (TRANSPORT_PROTO_SCTP,
					 rmt, &lcl_addr, &lcl_port);

  if (rv)
    return -1;

  /*
   * Create connection and send INIT CHUNK
   */
  thread_id = vlib_get_thread_index ();
  ASSERT (thread_id == 0);

  clib_spinlock_lock_if_init (&tm->half_open_lock);
  sctp_conn = sctp_half_open_connection_new (thread_id);
  sctp_conn->sub_conn[idx].PMTU =
    vnet_sw_interface_get_mtu (vnet_get_main (), rmt->sw_if_index, VLIB_TX);

  transport_connection_t *trans_conn = &sctp_conn->sub_conn[idx].connection;
  ip_copy (&trans_conn->rmt_ip, &rmt->ip, rmt->is_ip4);
  ip_copy (&trans_conn->lcl_ip, &lcl_addr, rmt->is_ip4);
  sctp_conn->sub_conn[idx].subconn_idx = idx;
  trans_conn->rmt_port = rmt->port;
  trans_conn->lcl_port = clib_host_to_net_u16 (lcl_port);
  trans_conn->is_ip4 = rmt->is_ip4;
  trans_conn->proto = TRANSPORT_PROTO_SCTP;
  trans_conn->fib_index = rmt->fib_index;

  sctp_connection_timers_init (sctp_conn);
  /* The other connection vars will be initialized after INIT_ACK chunk received */
  sctp_init_snd_vars (sctp_conn);

  sctp_send_init (sctp_conn);

  clib_spinlock_unlock_if_init (&tm->half_open_lock);

  return sctp_conn->sub_conn[idx].connection.c_index;
}

/**
 * Cleans up connection state.
 *
 * No notifications.
 */
void
sctp_connection_cleanup (sctp_connection_t * sctp_conn)
{
  sctp_main_t *tm = &sctp_main;
  u8 i;

  /* Cleanup local endpoint if this was an active connect */
  for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
    transport_endpoint_cleanup (TRANSPORT_PROTO_SCTP,
				&sctp_conn->sub_conn[i].connection.lcl_ip,
				sctp_conn->sub_conn[i].connection.lcl_port);

  int thread_index =
    sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection.thread_index;

  /* Make sure all timers are cleared */
  sctp_connection_timers_reset (sctp_conn);

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

int
sctp_session_open (transport_endpoint_t * tep)
{
  return sctp_connection_open (tep);
}

u16
sctp_check_outstanding_data_chunks (sctp_connection_t * sctp_conn)
{
  u8 i;
  for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
    {
      if (sctp_conn->sub_conn[i].state == SCTP_SUBCONN_STATE_DOWN)
	continue;

      if (sctp_conn->sub_conn[i].is_retransmitting == 1 ||
	  sctp_conn->sub_conn[i].enqueue_state != SCTP_ERROR_ENQUEUED)
	{
	  SCTP_DBG_OUTPUT
	    ("Connection %u has still DATA to be enqueued inboud / outboud",
	     sctp_conn->sub_conn[i].connection.c_index);
	  return 1;
	}

    }
  return 0;			/* Indicates no more data to be read/sent */
}

void
sctp_connection_close (sctp_connection_t * sctp_conn)
{
  SCTP_DBG ("Closing connection %u...",
	    sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection.c_index);

  sctp_conn->state = SCTP_STATE_SHUTDOWN_PENDING;

  sctp_send_shutdown (sctp_conn);
}

void
sctp_session_close (u32 conn_index, u32 thread_index)
{
  ASSERT (thread_index == 0);

  sctp_connection_t *sctp_conn =
    sctp_connection_get (conn_index, thread_index);
  if (sctp_conn != NULL)
    sctp_connection_close (sctp_conn);
}

void
sctp_session_cleanup (u32 conn_index, u32 thread_index)
{
  sctp_connection_t *sctp_conn =
    sctp_connection_get (conn_index, thread_index);

  if (sctp_conn != NULL)
    {
      sctp_connection_timers_reset (sctp_conn);
      /* Wait for the session tx events to clear */
      sctp_conn->state = SCTP_STATE_CLOSED;
    }
}

/**
 * Compute maximum segment size for session layer.
 */
u16
sctp_session_send_mss (transport_connection_t * trans_conn)
{
  sctp_connection_t *sctp_conn =
    sctp_get_connection_from_transport (trans_conn);

  if (sctp_conn == NULL)
    {
      SCTP_DBG ("sctp_conn == NULL");
      return 0;
    }

  update_cwnd (sctp_conn);
  update_smallest_pmtu_idx (sctp_conn);

  return sctp_conn->sub_conn[sctp_conn->smallest_PMTU_idx].cwnd;
}

u16
sctp_snd_space (sctp_connection_t * sctp_conn)
{
  /* Finally, let's subtract the DATA chunk headers overhead */
  return sctp_conn->sub_conn[sctp_conn->smallest_PMTU_idx].cwnd -
    sizeof (sctp_payload_data_chunk_t) - sizeof (sctp_full_hdr_t);
}

/**
 * Compute TX window session is allowed to fill.
 */
u32
sctp_session_send_space (transport_connection_t * trans_conn)
{
  sctp_connection_t *sctp_conn =
    sctp_get_connection_from_transport (trans_conn);

  return sctp_snd_space (sctp_conn);
}

transport_connection_t *
sctp_session_get_transport (u32 conn_index, u32 thread_index)
{
  sctp_connection_t *sctp_conn =
    sctp_connection_get (conn_index, thread_index);

  if (PREDICT_TRUE (sctp_conn != NULL))
    return &sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection;

  return NULL;
}

transport_connection_t *
sctp_session_get_listener (u32 listener_index)
{
  sctp_main_t *tm = vnet_get_sctp_main ();
  sctp_connection_t *sctp_conn;
  sctp_conn = pool_elt_at_index (tm->listener_pool, listener_index);
  return &sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection;
}

u8 *
format_sctp_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);
  sctp_connection_t *tc;

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

u8 *
format_sctp_listener_session (u8 * s, va_list * args)
{
  u32 tci = va_arg (*args, u32);
  sctp_connection_t *tc = sctp_listener_get (tci);
  return format (s, "%U", format_sctp_connection_id, tc);
}

void
sctp_expired_timers_cb (u32 conn_index, u32 timer_id)
{
  sctp_connection_t *sctp_conn;

  sctp_conn = sctp_connection_get (conn_index, vlib_get_thread_index ());
  /* note: the connection may have already disappeared */
  if (PREDICT_FALSE (sctp_conn == 0))
    return;

  SCTP_DBG ("%s expired", sctp_timer_to_string (timer_id));

  if (sctp_conn->sub_conn[conn_index].unacknowledged_hb >
      SCTP_PATH_MAX_RETRANS)
    {
      // The remote-peer is considered to be unreachable hence shutting down
      u8 i, total_subs_down = 1;
      for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
	{
	  if (sctp_conn->sub_conn[i].state == SCTP_SUBCONN_STATE_DOWN)
	    continue;

	  u32 now = sctp_time_now ();
	  if (now > (sctp_conn->sub_conn[i].last_seen + SCTP_HB_INTERVAL))
	    {
	      total_subs_down += 1;
	      sctp_conn->sub_conn[i].state = SCTP_SUBCONN_STATE_DOWN;
	    }
	}

      if (total_subs_down == MAX_SCTP_CONNECTIONS)
	{
	  /* Start cleanup. App wasn't notified yet so use delete notify as
	   * opposed to delete to cleanup session layer state. */
	  stream_session_delete_notify (&sctp_conn->sub_conn
					[MAIN_SCTP_SUB_CONN_IDX].connection);

	  sctp_connection_timers_reset (sctp_conn);

	  sctp_connection_cleanup (sctp_conn);
	}
      return;
    }

  switch (timer_id)
    {
    case SCTP_TIMER_T1_INIT:
      sctp_send_init (sctp_conn);
      break;
    case SCTP_TIMER_T1_COOKIE:
      sctp_send_cookie_echo (sctp_conn);
      break;
    case SCTP_TIMER_T2_SHUTDOWN:
      sctp_send_shutdown (sctp_conn);
      break;
    case SCTP_TIMER_T3_RXTX:
      sctp_timer_reset (sctp_conn, conn_index, timer_id);
      sctp_data_retransmit (sctp_conn);
      break;
    case SCTP_TIMER_T4_HEARTBEAT:
      sctp_timer_reset (sctp_conn, conn_index, timer_id);
      goto heartbeat;
    }
  return;

heartbeat:
  sctp_send_heartbeat (sctp_conn);
}

static void
sctp_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;

      SCTP_DBG ("Expired timer ID: %u", timer_id);

      /* Handle expiration */
      sctp_expired_timers_cb (connection_index, timer_id);
    }
}

void
sctp_initialize_timer_wheels (sctp_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, sctp_expired_timers_dispatch,
				      100e-3 /* timer period 100ms */ , ~0);
    tw->last_run_time = vlib_time_now (this_vlib_main);
  }));
  /* *INDENT-ON* */
}

clib_error_t *
sctp_main_enable (vlib_main_t * vm)
{
  sctp_main_t *tm = vnet_get_sctp_main ();
  vlib_thread_main_t *vtm = vlib_get_thread_main ();
  clib_error_t *error = 0;
  u32 num_threads;
  int thread;
  sctp_connection_t *sctp_conn __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
   */

  ip4_register_protocol (IP_PROTOCOL_SCTP, sctp4_input_node.index);
  ip6_register_protocol (IP_PROTOCOL_SCTP, sctp6_input_node.index);

  /*
   * 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);
    }

  /* 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);
  sctp_initialize_timer_wheels (tm);

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

  if (num_threads > 1)
    {
      clib_spinlock_init (&tm->half_open_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 *
sctp_enable_disable (vlib_main_t * vm, u8 is_en)
{
  if (is_en)
    {
      if (sctp_main.is_enabled)
	return 0;

      return sctp_main_enable (vm);
    }
  else
    {
      sctp_main.is_enabled = 0;
    }

  return 0;
}

transport_connection_t *
sctp_half_open_session_get_transport (u32 conn_index)
{
  sctp_connection_t *sctp_conn = sctp_half_open_connection_get (conn_index);
  return &sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].connection;
}

u8 *
format_sctp_half_open (u8 * s, va_list * args)
{
  u32 tci = va_arg (*args, u32);
  sctp_connection_t *sctp_conn = sctp_half_open_connection_get (tci);
  return format (s, "%U", format_sctp_connection_id, sctp_conn);
}

void
sctp_update_time (f64 now, u8 thread_index)
{
  sctp_set_time_now (thread_index);
  tw_timer_expire_timers_16t_2w_512sl (&sctp_main.timer_wheels[thread_index],
				       now);
  sctp_flush_frames_to_output (thread_index);
}

/* *INDENT OFF* */
const static transport_proto_vft_t sctp_proto = {
  .enable = sctp_enable_disable,
  .bind = sctp_session_bind,
  .unbind = sctp_session_unbind,
  .open = sctp_session_open,
  .close = sctp_session_close,
  .cleanup = sctp_session_cleanup,
  .push_header = sctp_push_header,
  .send_mss = sctp_session_send_mss,
  .send_space = sctp_session_send_space,
  .update_time = sctp_update_time,
  .get_connection = sctp_session_get_transport,
  .get_listener = sctp_session_get_listener,
  .get_half_open = sctp_half_open_session_get_transport,
  .format_connection = format_sctp_session,
  .format_listener = format_sctp_listener_session,
  .format_half_open = format_sctp_half_open,
  .tx_type = TRANSPORT_TX_DEQUEUE,
  .service_type = TRANSPORT_SERVICE_VC,
};

/* *INDENT ON* */

clib_error_t *
sctp_init (vlib_main_t * vm)
{
  sctp_main_t *tm = vnet_get_sctp_main ();
  ip_main_t *im = &ip_main;
  ip_protocol_info_t *pi;
  /* Session layer, and by implication SCTP, are disabled by default */
  tm->is_enabled = 0;

  /* Register with IP for header parsing */
  pi = ip_get_protocol_info (im, IP_PROTOCOL_SCTP);
  if (pi == 0)
    return clib_error_return (0, "SCTP protocol info AWOL");
  pi->format_header = format_sctp_header;
  pi->unformat_pg_edit = unformat_pg_sctp_header;

  /* Register as transport with session layer */
  transport_register_protocol (TRANSPORT_PROTO_SCTP, &sctp_proto,
			       FIB_PROTOCOL_IP4, sctp4_output_node.index);
  transport_register_protocol (TRANSPORT_PROTO_SCTP, &sctp_proto,
			       FIB_PROTOCOL_IP6, sctp6_output_node.index);

  sctp_api_reference ();

  return 0;
}

VLIB_INIT_FUNCTION (sctp_init);

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